WO2001091810A1

WO2001091810A1 - Pulsed polychromatic light passthrough sterilization device

Info

Publication number: WO2001091810A1
Application number: PCT/US2001/016256
Authority: WO
Inventors: James Randall Cooper; Andrew H. Bushnell; Richard E. May; William Fries
Original assignee: PurePulse Technologies Inc
Current assignee: PurePulse Technologies Inc
Priority date: 2000-05-26
Filing date: 2001-05-21
Publication date: 2001-12-06
Anticipated expiration: 2002-11-26
Also published as: CA2409993A1; EP1284755A1; JP2003534100A; AU2001264709A1

Abstract

A pulsed polychromatic light passthrough sterilization device (100) comprising a housing (102) having a first opening (105) accessible from a non-sterile environment (248) and a second opening (107) accessible from a substantially sterile environment (250). The housing includes a volume within the housing extending from the first opening (105) to the second opening (107). A transmissive barrier (114) is positioned within the housing, wherein the transmissive barrier defines a sterilization chamber (228) as a portion of the volume that is within the transmissive barrier. One or more flashlamps (210) are positioned within a lamp chamber (230) of the housing, wherein the lamp chamber is defined as another portion of the volume that is between an inner surface of the housing and the transmissive barrier. The one or more flashlamps (210) produce short duration, high intensity pulses of polychromatic light. Cooling means (222) are coupled to the lamp chamber for cooling the one or more flashlamps. A first door (104) is adapted to fit the first opening, wherein the first door has an open position and a closed position, wherein the closed position seals the sterilization chamber from the non-sterile environment. And, a second door (106) is adapted to fit the second opening, wherein the second door has an open position and a closed position, wherein the closed position of the second door seals the sterilization chamber from the substantially sterile environment.

Description

PULSED POLYCHROMATIC LIGHT PASSTHROUGH STERILIZATION DEVICE

BACKGROUND OF THE INVENTION

The present invention relates to the sterilization of objects, and more particularly to passthrough devices for such sterilization. Even more particularly, the present invention relates to passthrough sterilization devices that use high intensity pulses of polychromatic light, such as broad- spectrum light or broadband light, to quickly and effectively sterilize objects to be passed from a contaminated or non-sterile environment into a sterile environment.

A passthrough device is generally known in the art as a treatment device or treatment chamber into which items or objects are placed from a "contaminated" or non-sterile environment, treated within the chamber, and then retrieved out of the chamber into a "clean" or sterile environment. Passthrough devices are commonly used in medical and pharmaceutical applications where objects, such as operating instruments or pharmaceutical devices, are placed within the treatment chamber, treated, and then retrieved for use into the sterile environment. Thus, it is desired that most contaminants from the non-sterile environment on the object are deactivated prior to entry into the sterile environment. Typically, only one side, or door, of the passthrough device, is open at a time, to prevent the free flow of air-borne contaminants into the sterile environment.

Many techniques are used to deactivate organisms on the surface of the object prior to being inserted into a sterile environment. One example is through the use of continuous wave ultraviolet light (also referred to as UV light) directed at an object to be transferred into the sterile environment. The continuous wave UV light is typically provided by low-pressure Mercury vapor lamps, which emit UV light at about 253 nm. An example of such an ultraviolet passthrough device is shown in U.S. Patent No. 5,446,289, entitled ULTRAVIOLET PASSTHROUGH STERILIZATION DEVICE, issued to Shodeen et al. (hereinafter referred to as the '289 patent). The object is placed into the treatment chamber of the UV passthrough device from a non-sterile environment through a first door, while a second door exposed to the sterile environment is closed. The first door is closed; thus, sealing the treatment chamber from both the non-sterile environment and the sterile environment, then the treatment chamber is irradiated with the UV light, generated by Mercury lamps, for about 30 seconds to 3 minutes at about 2000-6000 microwatts per square centimeter. For most applications, this is sufficient to deactivate most microorganisms on the object. However, sterilization of the object and the treatment chamber is not achieved in such devices, with microbial deactivation of bacterial spores being only on the order of 2 to 4 logs reduction (whereas greater than 6 logs reduction is generally recognized as sufficient to constitute sterilization). The object is then removed from the treatment chamber by opening the second door and removing the object into the sterile environment.

An important feature of the '289 patent is that the Mercury lamps that produce the UV light must be "sealed" from the treatment chamber (i.e. where the object is placed to be sterilized) in addition to being sealed from both the non-sterile environment and the sterile environment. Since Mercury lamps tend to break easily, sealing the Mercury lamps from the treatment chamber, non-sterile environment, and sterile environment prevents Mercury vapor exiting broken lamps from contaminating the sterile environment, the non-sterile environment and/or the object to be sterilized. Mercury contamination can be especially troublesome in the pharmaceutical and medical industries because maximum permissible Mercury levels in clean areas are frequently very low. It is difficult and very time consuming to completely remove a Mercury contamination, so a broken Mercury vapor lamp can be a rather expensive problem. Thus, the device of the '289 patent seals the Mercury lamps within a volume of the passthrough device defined as a "lamp cell". Another feature of the passthrough device of the '289 patent is that the treatment chamber, also referred to as the "treatment cell", must be sealed from the both the non-sterile environment and the sterile environment when objects are being treated with e.g. ultraviolet light. Furthermore, at least one end, or opening, of the treatment chamber must always be sealed to prevent the free flow of microorganisms between the non-sterile and sterile environments. One problem associated with UV passthrough devices, such as shown in the '289 patent, is the time required for the UV light to deactivate organisms. Disadvantageously, an object must be exposed to the continuous UV light from about 30 seconds to 3 minutes. Thus, there is a "waiting period" on the clean or sterile environment side that must be endured in order to ensure adequate deactivation of organisms on the object (i.e. at least adequate deactivation to the extent possible using UV light). In some applications, particularly medical applications, objects such as operating instruments may need to be "passed through" quickly in accordance with a prescribed treatment. In such instances, this waiting period is undesirable.

Another disadvantage to treatment with UV light using a Mercury lamp passthrough device, such as in the '289 patent, is that continuous exposure to UV light for periods of time does not ensure sterilization of the object. As stated above, it is commonly understood that exposure to UV light typically results in a microbial deactivation of about 2 to 4 logs reduction, whereas greater than 6 logs reduction is generally recognized as the level of microbial deactivation needed to constitute sterilization. Additionally, exposure to UV light is insufficient to deactivate or kill some known types of organisms. For example, oocyst forming protozoa, such as Cryptosporidium parvum and pigmented bacteria such as Aspergillus niger, are particularly difficult to "kill". Continuous wave UV light has proven ineffective in the deactivation of such oocyst forming protozoa and such pigmented bacteria.

Furthermore, treatment with UV light may not effectively deactivate air-borne microorganisms that are contained within air entering the passthrough device from the non-sterile environment, which will, in turn, enter and contaminate the sterile environment from the treatment chamber. Thus, the object itself may be treated with UV light, but other contaminants maybe allowed to enter the sterile environment through the air as the object is removed from the passthrough device into the sterile environment. What is needed is a passthrough sterilization chamber that can quickly and effectively deactivate microorganisms to a level of sterilization on objects to be passed from a non- sterile environment into a sterile environment and that can quickly and effectively deactivate air-borne microorganisms to a level of sterilization within the passthrough chamber. The present invention advantageously addresses the above and other needs.

SUMMARY OF THE INVENTION

The present invention advantageously addresses the needs above as well as other needs by providing a passthrough sterilization device using pulsed polychromatic light, such as broad- spectrum pulsed light (BSPL) in the form of high-intensity, short-duration pulses of incoherent, polychromatic light in a broad-spectrum, to quickly and effectively deactivate microorganisms on objects to be passed from a non-sterile environment into a sterile environment, as well as air-borne microorganisms within the passthrough sterilization device.

In one embodiment, the invention can be characterized as a pulsed polychromatic light passthrough sterilization device comprising a housing having a first opening accessible from a non-sterile environment and a second opening accessible from a substantially sterile environment. The housing includes a volume within the housing extending from the first opening to the second opening. A transmissive barrier is positioned within the housing, wherein the transmissive barrier defines a sterilization chamber as a portion of the volume that is within the transmissive barrier. One or more flashlamps are positioned within a lamp chamber of the housing, wherein the lamp chamber is defined as another portion of the volume that is between an inner surface of the housing and the transmissive barrier. The one or more flashlamps produce short duration, high intensity pulses of polychromatic light. Cooling means are coupled to the lamp chamber for cooling the one or more flashlamps. A first door is adapted to fit the first opening, wherein the first door has an open position and a closed position, wherein the closed position seals the sterilization chamber from the non-sterile environment. And, a second door is adapted to fit the second opening, wherein the second door has an open position and a closed position, wherein the closed position of the second door seals the sterilization chamber from the substantially sterile environment.

In another embodiment, the invention can be characterized as a pulsed polychromatic light passthrough sterilization device comprising a housing having a first opening accessible from a non-sterile environment and a second opening accessible from a substantially sterile environment, wherein the housing includes a sterilization chamber within the housing extending from the first opening to the second opening. One or more flashlamps are positioned within the housing, wherein the one or more flashlamps produce short duration, high intensity pulses of polychromatic light. A first door is adapted to fit the first opening, wherein the first door has an open position and a closed position, wherein the closed position seals the sterilization chamber from the non-sterile environment. And, a second door is adapted to fit the second opening, wherein the second door has an open position and a closed position, wherein the closed position of the second door seals the sterilization chamber from the substantially sterile environment.

In yet another embodiment, the invention can be characterized as a method of sterilizing an object from a non-sterile environment and passmg the object into a substantially sterile environment comprising the steps of: placing, from the non-sterile environment, the object into a sterilization chamber within a pulsed polychromatic light passthrough device, wherein the sterilization chamber is sealed from the substantially sterile environment; sealing the object within the sterilization chamber, wherein the sterilization chamber is sealed from both the non-sterile environment and the substantially sterile environment; illuminating the object with at least one high-intensity, short duration pulse of incoherent polychromatic light, thereby deactivating microorganisms present on the object; unsealing the sterilization chamber from the substantially sterile environment; and removing the object from the sterilization chamber into the substantially sterile environment.

In a further embodiment, the invention can be characterized as a method of treating an object from a non-sterile environment and passing the object into a substantially sterile environment comprising the steps of: mating a housing containing a treatment chamber to an interface of an isolation chamber, wherein the isolation chamber contains a substantially sterile environment sealed by the interface from the non-sterile environment, and wherein the treatment chamber is sealed from the substantially sterile environment; placing, from the non-sterile environment, the object into the treatment chamber; sealing the object within the treatment chamber, wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment; iUuminating the object with light, thereby deactivating microorganisms present on the object; unsealing the treatment chamber from the substantially sterile environment; and removing the object from the treatment chamber into the substantially sterile environment.

In an additional embodiment, the invention can be characterized as a method of removing an object from a substantially sterile environment and passing the object into a non-sterile environment comprising the steps of: mating a housing containing a treatment chamber to an interface of an isolation chamber, wherein the isolation chamber contains a substantially sterile environment sealed by the interface from the non-sterile environment, and wherein the treatment chamber is sealed from the substantially sterile environment; sealing the treatment chamber from the non-sterile environment, wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment; iUuminating the treatment chamber with light, thereby deactivating microorganisms within the treatment chamber; unsealing the treatment chamber from the substantially sterile environment; placing, from the substantially sterile environment, the object into the treatment chamber; sealing the object within the treatment chamber, wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment; unsealing the treatment chamber from the non-sterile environment; and removing the object from the treatment chamber into the non-sterile environment. In an added embodiment, the invention can be characterized as an improved beta assembly for mating to an alpha assembly of a transfer system comprising an inner door frame having a first end and a second end, wherein the inner door frame comprises a first opening foπned at the first end; a second opening formed at the second end; and a tubular neck extending from the first opening to the second opening, a first volume formed within the tubular neck from the first opening to the second opening. A treatment chamber of a treatment device is attached to the second end of the inner door frame, the treatment chamber having a second volume accessible from an outside environment via the second opening. An inner door body is adapted to fit within the tubular neck of the inner door frame between the first end and the second end. The inner door body sealingly engages the first opening at the first end and sealingly engages the second opening at the second end of the inner door frame, whereby the treatment chamber is sealed from the outside environment at the second opening.

In another embodiment, the invention can be characterized as an inner door body of a beta assembly for mating to an alpha assembly of a transfer system comprising a closed inner end; an outer end; a body extending from the closed inner end to the outer end, the body having an exterior surface; a first plurality of door body flanges at the exterior surface extending radially outward from the exterior surface and extending annularly around the exterior surface; and an annular seal at the closed inner end, wherein the annular seal is adapted to sealingly engage an opening to a treatment chamber.

In another embodiment, the invention can be characterized as a photodetector arrangement for detecting the intensity of light in a light treatment device comprising a light treatment chamber having a sealed volume and one or more reflective inner surfaces; a location within the light treatment chamber where an object to be treated by the light within the light treatment chamber is placed; and one or more photodetectors positioned to view reflected light from within the light treatment chamber and not directly reflected light from the object to be placed at the location. The one or more photodetectors are positioned off-center with respect to the location, wherein a central viewing axis of each of the one or more photodetectors does not pass through the location.

In yet another embodiment, the invention can be characterized as a method of accurate detection and measurement of an intensity of light within a light treatment chamber comprising the steps of: illuminating the light treatment chamber with the light; viewing the light reflected within the light treatment chamber, and not viewing the light directly reflected from an object being treated with the light; detecting the intensity of the light having been viewed; and measuring the intensity of the light having been detected, wherein the measured intensity is less affected by the natural reflectivity of the object. BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: FIG. 1 is a perspective view of a passthrough sterilization device that uses pulsed polychromatic light, such as broad-spectrum pulsed light in the form of high-intensity, short duration pulses of incoherent, polychromatic light in a broad-spectrum in one embodiment of the present invention;

FIG. 2 is a lengthwise cross sectional view of one embodiment of a housing of the passthrough sterilization device of FIG. 1 as "mated" to an isolation chamber with a specially designed mating interface, illustrating the interior of the housing;

FIG. 3 is a cross sectional view looking through the housing of FIG. 2 at plane 3-3 (FIG. 2), illustrating one embodiment of a sterilization chamber as defined by the volume within a transmissive barrier, and a lamp chamber as defined by the volume between an inner surface of the housing and an outer surface of the transmissive barrier;

FIGS. 4A-4C are lengthwise cross-sectional views of a second door assembly of one embodiment of FIG. 2 comprising a specially designed beta assembly and an alpha assembly, illustrating the application of "mating" the specially designed beta assembly of the housing to the alpha assembly of an isolation chamber such that the sterilization chamber may be sealingly attached to a sterile environment of the isolation chamber without breaking the confinement of the sterile environment;

FIG. 4D illustrates simplified end views of the components of the alpha assembly and the beta assembly of FIGS. 4A-4C, illustrating the orientation of respective interlocking flanges used in the "mating" of FIGS. 4A-4C; FIGS. 5A and 5B are an end view and a perspective view, respectively, of a support bracket of a housing support that allows rotation of a housing of the passthrough sterilization device of FIGS. 1 and 2;

FIGS. 5C and 5D are end views of two embodiments of the passthrough sterilization device of FIGS. 1-5B which allow vertical orientation of the housing to be adjusted to an appropriate height such that the specially designed beta assembly of the housing may be positionally aligned and mated to the alpha assembly of the isolation chamber;

FIG. 6 is a side cross-sectional view of the first door assembly of FIG. 2 that seals the sterilization chamber from the non-sterile environment, illustrating a specific design of a sealed door that minimizes exposure of a first seal to sterilizing light and minimizes "shading"; FIG. 7 is a close up, side cross-sectional view of the specially designed beta assembly that seals the sterilization chamber of FIG. 2 and FIGS. 4A-4C from an outside environment, illustrating that an o-ring seal is minimally exposed to sterilizing light and that the effects of "shading" are minimized and further illustrating a mechanism for detecting sealed closure of an inner door body within an inner door frame;

FIGS. 8A-8C are visual representations of steps performed in passing an object from a non-sterile environment (or outside environment) into the sterile environment of an isolation chamber utilizing the passthrough sterilization chamber of FIGS. 1-7; and

FIGS. 9A-9C are visual representations of the steps performed in passing an object from the sterile environment of the isolation chamber back into the non-sterile environment utilizing the passthrough sterilization chamber of FIGS. 1-7.

Corresponding reference characters indicate corresponding components throughout the several views of the drawings.

DETAD ED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.

The present invention provides an apparatus and related methods for quick, reliable and efficient deactivation (to the level commonly accepted as sterilization) of microorganisms on objects or items to be passed from a non-sterile environment into a sterile environment. Referring first to FIG. 1, a perspective view is shown of a passthrough sterilization device that uses pulsed polychromatic light, such as broad-spectrum pulsed light, in the form of high- intensity, short duration pulses of incoherent, polychromatic light in a broad-spectrum in one embodiment of the present invention. Shown is the passthrough sterilization device 100 including a housing 102 that includes a first door 104 (also referred to as a first door assembly) adapted to fit within a first opening 105, a door handle 106, an interior volume 108 (also referred to as the volume 108), housing handles 110, fan covers 112, a transmissive barrier 114 and a transmissive shelf 116. The housing 102 also includes a second door (not shown), also referred to as the second door assembly or beta assembly, adapted to be fit within a second opening 107. The passthrough sterilization device 100 also includes a base support 118 with wheels 120, a control panel 122, and a housing support 124 shown as including support stands 126 (viewable since a side panel of the housing support 124 has been removed). Also illustrated are positions of the transmissive shelf, e.g. side position 130, end position 132, center position 134 and corner position 136. These various positions are described in test results described near the end of the specification in EXAMPLE 1.

The base support 118 is shown as a cart having wheels 120 such that the cart is moveable. The base support 118 includes a control panel 122 such that an operator may operate the passthrough sterilization device 100 and/or configure the operating parameters of the passthrough sterilization device 100. The housing support 124 is mounted on the base support 118 and includes support stands 126 that assist in supporting the housing 102 within the housing support 124. Furthermore, as will be described with reference to FIG. 5, the support stands 126 allow the housing 102 to rotate within the curvature of the housing support 124. The operator rotates the housing by gripping the housing handles 110 and physically turning the housing 102 within the housing support 124. As will be further described below, this rotation allows for locking the sterilization chamber to a bayonet-style mount on an isolation chamber.

The housing 102 is the component of the passthrough sterilization device where the sterilization of objects takes place. As illustrated, a first door 104 has an open position and a closed position such that while in the open position, the interior volume 108 of the housing 102 is accessible from the outside environment via the first opening 105. This interior volume 108 may also be referred to as the treatment chamber or the sterilization chamber. While in the closed position, the interior volume 108 of the housing 102 is sealed from the outside environment. In operation, an object or item to be sterilized is placed within the interior volume 108 of the housing and the first door 104 is closed against the first opening 105. The object is typically placed on a shelf (e.g., transmissive shelf 116) positioned within the interior volume 108. The passthrough sterilization device also includes a second door (not shown) that is located at the back side (the far side of FIG. 1) of the housing 102. While the object is placed within the interior volume 108 via the first opening 105, the second door is in a corresponding closed position against the second opening 107, such that the second door seals the interior volume 108 from the outside environment exposed to the second door i.e., typically the sterile environment. Then, the first door 104 is sealed to the first opening 105 of the housing by re-closing the first door 104.

In practice, according to one embodiment, once the object is sealed within the housing 102, i.e. the first door 104 and the second door are closed, then the object is sterilized by illuminating the object with high-intensity, short duration pulses of incoherent polychromatic light in a broad spectrum, also referred to as broad-spectrum pulsed light (i.e. BSPL) or broadband pulsed light. For example, the object is illuminated by at least one, preferably two and most preferably between three and sixty consecutive short duration (e.g., less than about 100 ms, preferably about 0.3 ms) pulses of high-intensity (e.g., 0.001 J/cm² to 50 J/cm², e.g., 1.0 J/cm² to 2.0 J/cm², measured at the surface of the item) incoherent polychromatic light in a broad spectrum (e.g., 170 nm to 2600 nm; i.e., 1.8 xlO¹⁵ Hz to 1.2 x 10¹⁴ Hz). The specific parameters may be set by an operator using the control panel 122. For example, in one embodiment, there is one pulse (or flash of the flashlamps) every five seconds. In another embodiment there is one pulse (or flash of the flashlamps) every two seconds, up to a maximum often consecutive flashes.

As a result of such illumination, microorganisms on the surface of the object and contained within the air within the interior volume 108 are effectively deactivated to a level of 6 to 7 or more logs reduction of microbial spores, which is generally accepted as sterilization of the object, within a matter of seconds. Furthermore, if the object to be decontaminated or sterilized itself is transmissive to the broad spectrum pulsed light, e.g. a transparent container holding a fluid, microorganisms contained within the object may be deactivated, at least to the extent that the material within the transmissive container is transmissive to such light.

This broad-spectrum pulsed light illumination is accomplished through the use of Xenon gas flashlamps, as opposed to Mercury lamps of the prior art passthrough devices, such as the passthrough device of U.S. Patent No. 5,446,289, entitled ULTRAVIOLET PASSTHROUGH

STERILIZATION DEVICE, issued to Shodeen et al. (hereinafter referred to as the '289 patent). The Xenon flashlamps (not shown) are typically positioned or mounted within the interior volume 108 of the housing about the inner surface of the housing 102 such that they project light toward a central portion of the interior volume 108 of the housing i.e., the sterilization chamber. Broad-spectrum pulsed light (BSPL) described through this specification may also be referred to generically as "pulsed polychromatic light". Pulsed polychromatic light represents pulsed light radiation over multiple wavelengths. For example, the pulsed polychromatic light may comprise light having wavelengths between 170 nm and 2600 nm inclusive, such as between 180 nm and 1500 nm, between 180 ran and 300 nm, between 200 and 300 nm, between 240 and 280 nm, or between any specific wavelength range within the range of 170-2600 nm, inclusive. For example, the Xenon flashlamps referred to above produce pulsed polychromatic light having wavelengths at least from the far ultraviolet (200-300 nm), through the near ultraviolet (300-380 nm) and visible (380 nm-780 nm), to the infrared (780-1100 nm). According to one embodiment, the pulsed polychromatic light produced by these Xenon flashlamps is such that approximately 25% of the energy distribution is ultraviolet, 45% of the energy distribution is visible, and 30% of the energy distribution is infrared and beyond. Furthermore, in preferred embodiments, at least 1% (preferably at least 5% or at least 10% and more preferably at least 50%) of an energy density of the pulsed polychromatic light is concentrated at wavelengths within a range of 200 nm to 320 nm. The duration of the pulses of the pulsed polychromatic light should be approximately from about 0.001 ms to about 100 ms, for example, about 0.3 ms. The intensity of the pulsed polychromatic light should from 0.001 J/cm² to 50 J/cm², e.g., 1.0 J/cm² to 2.0 J/cm², measured at the surface of the item. As such, in one example using pulsed polychromatic light, objects are illuminated by at least one, preferably two and most preferably three short duration (e.g., less than about 100 ms, preferably about 0.3 ms) pulses of high-intensity (e.g., 0.001 J/cm² to 50 J/cm², e.g., 0.01 J/cm² to 1.0 J/cm², e.g., 0.05 J/cm² to 1.0 J/cm², measured at the surface of the object) incoherent polychromatic light having a range of wavelengths (e.g., 170 nm to 2600 nm; i.e., 1.8 xl0¹⁵ Hz to 1.2 x 10" Hz). However, such polychromatic light may be within any subset of the range of 170 nm to 2600 nm, e.g., the energy density of the pulsed light may be concentrated within wavelengths between 170 nm and 1000 nm, between 200 nm and 500 nm, or between 200 nm and 300 run, for example. As a result of such illumination, microorganisms on the surface of the object, on the inner surfaces of the treatment chamber, and contained within the air within the treatment chamber are effectively deactivated to a level of 6 to 7 logs reduction (i.e., a microbial reduction level that is commonly accepted as sterilization). Furthermore, in some embodiments, a transmissive barrier 114 maybe positioned within the interior volume 108 such that the flashlamps are positioned between the outer edge of the transmissive barrier and the inner surface of the housing 102. The flashlamps then project sterilizing light through the transmissive barrier 114, which is at least partially transmissive to light having wavelengths between at least 170 nm to 2600 nm. In a preferred embodiment, the transmissive barrier 114 takes the form of a cylinder, such that the housing 102 and the transmissive barrier 114 comprise concentric cylinders. In this case, the volume within the transmissive barrier 114 is specifically referred to as the sterilization chamber. Further details of the configuration of the interior volume 108 within the housing 102 including the transmissive barrier 114, are described with reference to FIGS. 2- 7.

Additionally, a transmissive shelf 116 may be positioned within the interior volume 108 which is primarily used to hold the object to be sterilized within the central portion of the interior volume 108 or the sterilization chamber; thus, maximizing the illumination or irradiation of the object. The transmissive shelf 116 is also transmissive to light produced by the flashlamps, such that all surfaces of the object are adequately illuminated. In the embodiment shown in FIG. 1, the transmissive shelf 116 is positioned within the transmissive barrier 114.

Furthermore, fan covers 112 are shown which typically cover vents (not shown) located within the housing 102 which are designed to allow fans (not shown) to pull cooling air into the housing 102 to cool the flashlamps, which generate significant heat during operation. In the embodiment shown that includes the fan covers 112 on the non-sterile environment side of the passthrough sterilization device, a transmissive barrier 114 is necessary to separate the volume within the housing 102 that constitutes the sterilization chamber from the volume within the housing that includes the flashlamps (which is referred to as the lamp chamber). Thus, the transmissive barrier 114 prevents the non-sterile air that cools the flashlamps from entering the sterilization chamber and contaminating the sterile environment. Further description of these details are presented with reference to FIG. 2.

Additionally, it is noted that although the embodiment pictured in FIG. 1 illustrates a cylindrical shaped housing 102 and a generally cylindrical interior volume 108, other geometries may be used for the housing 102 and or the respective interior volume 108. Thus, the housing 102 may be shaped as a cuboid or a rectangular parallelepiped. Likewise, the geometry of the first and second doors and respective first and second openings 105 and 107 may have other than circular external dimensions.

Advantageously, it has been found by the inventors herein that the use of short duration, high intensity polychromatic pulsed light, such as broad-spectrum pulsed light (i.e., BSPL), effectively reduces the waiting time of treatment of the object significantly (e.g., about 2 to 20 seconds compared to about 30 seconds to 3 minutes), increases the deactivation rate of microorganisms on objects to a level commonly accepted as sterilization (about greater than 6 logs reduction compared to 2-4 logs reduction), as well as deactivates air-borne microorganisms, in comparison to known continuous wave UV passthrough devices, such as shown in the '289 patent. Furthermore, the use of broad-spectrum pulsed light using Xenon flashlamps completely eliminates the problem of Mercury contamination due to broken Mercury lamps that is frequently encountered in known continuous wave UV passthrough devices, since Xenon is an inert gas which is harmless if exposed due to leakage or breaking of the Xenon flashlamp.

Several apparatus designed to provide high-intensity, short duration pulsed incoherent polychromatic light in a broad-spectrum are described, for example, in U.S. Patent Nos. 4,871,559 of Dunn, et al., entitled METHODS FOR PRESERVATION OF FOODSTUFFS, issued 10/03/89; 4,910,942 of Dunn, et al., entitled METHODS FOR ASEPTIC PACKAGING OF MEDICAL DEVICES, issued 03/27/90; 5,034,235 of Dunn, et al, entitled METHODS FOR PRESERVATION OF FOODSTUFFS, issued 07/23/91; 5,489,442 of Dunn, et al., entitled PROLONGATION OF SHELF LIFE IN PERISHABLE FOOD PRODUCTS, issued 02/06/96; 5,768,853 of Bushnell, et al., entitled DEACTIVATION OF MICROORGANISMS, issued 06/23/98; 5,786,598 of Clark, et al, entitled STERILIZATION OF PACKAGES AND THEIR CONTENTS USING HIGH-DENSITY, SHORT-DURATION PULSES OF INCOHERENT POLYCHROMATIC LIGHT IN A BROAD SPECTRUM, issued 07/28/98; and 5,900,211 of Dunn, et al, entitled DEACTIVATION OF ORGANISMS USING HIGH-INTENSITY PULSED POLYCHROMATIC LIGHT, issued 05/04/99, all of which are assigned to PurePulse Technologies of San Diego, California. Common to the apparatus used to provide broad-spectrum pulsed light treatment are that the treatment chamber is light-tight; flashlamp(s) are positioned within the apparatus, such that the light emitting therefrom is optimally directed at the object; reflective material is, preferably, employed to further maximize the pulsed light that is directed toward the object; and transmissive materials {i.e., quartz, sapphire or similar material) are employed where material is required between the flashlamp(s) and object (such as supporting structures for the object within the treatment chamber), so that interference with the broad-spectrum pulsed light is minimized.

The passthrough sterilization device 100 of the present invention is a particular application of such pulsed polychromatic light (e.g., BSPL) sterilization apparatus referred to above that incorporates a specially configured sterilization chamber that addresses the unique issues of the sealing of the sterilization chamber (e.g. sealing the interior volume 108 of the housing 102) from both the non-sterile environment and the sterile environment, the interfacing with the sterile environment without contamination thereof, and other unique issues relative to the application of such technology to passthrough devices.

The passthrough sterilization device 100 embodied in FIG. 1 may be configured several different ways. As shown, the passthrough sterilization device 100 may be mounted on a base support 118, such as a cart as shown. Advantageously, the entire passthrough sterilization device 100 is moveable from one location to another.

In a preferred embodiment, the moveable passthrough sterilization device 100 is positioned against an interface to an isolation chamber that contains the sterile environment, or other interface into a sterile environment. In operation, the second door of the passthrough sterilization device 100 "mates" to the interface to the sterile environment and allows access to and from the sterile environment via the second door of the housing 102. In one embodiment, the entire housing 102 rotates (as allowed by the housing support 124 and the support stands 126 as briefly described above) such that opposing flanges of the second door and the interface to the isolation chamber interlock. The complete details of this "mating" process and the structure that accomplishes the process are described further with reference to FIGS. 2 and 4A-4C. In such an application, the object to be sterilized is placed into the interior volume 108 via the first opening 105 while the second door is kept closed, i.e. the interior volume 108 is sealed from the sterile environment, but not sealed from the non-sterile environment. Then the first door 104 is then closed which seals the interior volume 108, e.g. the sterilization chamber, of the housing 102 from both the non-sterile environment and the sterile environment of the isolation chamber. Then, the object is sterilized with broad-spectrum pulsed light within the interior volume 108. Upon sterilization, the second door is unsealed from the sterile environment while the first door 104 remains sealed and the object is retrieved into the sterile environment of the isolation chamber via the second opening 107. The second door is then resealed, i.e. the second door is closed, and the passthrough sterilization device is ready for the next object to be sterilized (after reopening the first door 104).

In an alternative embodiment, the entire housing 102 can be built or incorporated into a wall or dividing structure that separates a non-sterile environment from a sterile environment. Thus, an entire room may constitute a sterile environment and objects are passed into the sterile environment through the housing 102 which is built into the wall. Similarly, the housing 102 can be permanently attached into the structure of an isolation chamber such that no interfacing or "mating" is required between the housing 102 and the isolation chamber containing the sterile environment.

In another embodiment, the housing 102 may only have one opening, e.g. the first opening 105, and only one door, e.g. the first door 104, and not a second opening with a second door. In such an application, the sterilization device is used to sterilize objects within the interior volume 108 or sterilization chamber of the housing 102 to be retrieved back into the outside environment. Such an application can be particularly useful in deactivating microorganisms within a sealed light transmissive package or container. For example, a clear or light transmissive package containing a light transmissive fluid, for example, can be placed within the interior volume 108 via the first opening 105 and illuminated with BSPL. Depending on the specific transmissiveness of the sealed package and the light transmissive fluid within the sealed package, the light treatment can be used to deactivate microorganisms within the sealed container (e.g., within the light transmissive fluid) and on the inside surfaces of the sealed container. When the sealed container is retrieved back into the outside environment through the first opening 105, the light transmissive fluid and inner surfaces of the sealed package remain sterilized, whereas the outside surface of the container may be re-contaminated.

The descriptions below primarily illustrate the embodiment where the passthrough sterilization device 100 is mobile and mates to an interface of an isolation chamber, although slight variations which would achieve the other described embodiments are well within the ability of a person of ordinary skill in the art to practice without experimentation.

Note that the passthrough sterilization device 100 is an example of a "light treatment device" that uses pulsed polychromatic light, such as BSPL. A light treatment device is generally a device in which light is used to treat or deactivate microorganisms on objects placed within the light treatment device. The passthrough sterilization device 100 actually treats the objects to the level commonly considered to be sterilization, i.e. greater than a 6 log microbial reduction of bacterial spores. Although a light treatment chamber may use one of several treating lights, such as continuous wave UV, the passthrough sterilization device 100 uses pulsed polychromatic light (e.g., BSPL) as the sterilizmg light. Generally, as described throughout this specification, when a device is referred to as light treatment device employing a treating light, unless other wise stated, a device is described which uses any type of light for deactivation of microorganisms, e.g. continuous wave UV or pulsed polychromatic light, such as BSPL. However, when reference is made to a sterilization device using a sterilizing light, a device is described that is capable of deactivation at a level accepted as sterilization, i.e. greater than a 6 log microbial reduction of bacterial spores.

Referring next to FIG. 2, a lengthwise cross sectional view is shown of one embodiment of the housing of the sterilization passthrough device of FIG. 1 as "mated" to an isolation chamber with a specially designed mating interface, illustrating the interior of the housing. Shown is the passthrough sterilization device 100 (i.e. a specific embodiment of a light treatment device) including the housing 102 having a length and two ends that generally defines the passthrough sterilization device 100. An inner surface 202 of the housing 102 generally defines a volume or chamber that contains components of the passthrough sterilization device 100 (i.e, interior volume 108 of FIG. 1). Also shown are a first door 104 (also referred to as the first door assembly 104) closed against the first opening 105, second door 206 (also referred to as the second door assembly 206) closed against the second opening 107 (and the second door 206' in an open position), a transmissive barrier 114, Xenon flashlamps 210, a lamp tube 212, reflective portions 214, off-centered photodetectors 216, door hinges 218, door handles 106, door arms 220, a transmissive shelf 116, fans 222, fan covers 112, vents (not shown), a first reflective end wall 224, a second reflective end wall 225, and reflective inner door surfaces 226. Also shown are a volume of the housing defining the sterilization chamber 228 which, in this embodiment, is a volume defined within the transmissive barrier 114, and a volume within the housing that houses the flashlamps 210, which shall be referred to as a lamp chamber 230, which, in this embodiment, is a volume between the inner surface 202 of the housing 102 and the outer surface 203 of the transmissive barrier 114. Note that the sterilization chamber 228 is a specific embodiment of a light treatment chamber. Additional structural features shown are collars 232, lamp support bushings 234, insulating rings 236, retaining walls 238, a back housing cover 240, a front housing cover 242, door latches 244, and high voltage insulators 246. Also illustrated are the contaminated or non-sterile environment 248 and the sterile environment 250. Other features shown include a magnetic sensor 252 and a magnetic material 254. The first door assembly includes a first door frame 266, first door body 268 and a first seal 270. The second door assembly 206 shown includes an alpha assembly comprising an outer door frame 256 and an outer door body 258; and further includes a beta assembly comprising an inner door frame 260 and an inner door body 262. The housing 102 is shown as being "mated" to an isolation chamber including the isolation chamber wall 264 and the alpha assembly. The specific design of the second door assembly 206 including the alpha assembly and the beta assembly is an improvement of the well-known La Calhene DPTE transfer system, which has been the industry standard for the introduction and removal of materials into and out of barrier isolators or isolation chambers for many years. The housing 102 of the passthrough sterilization device 100 is generally a cylindrical shell that defines an interior volume within that includes the sterilization chamber 228 which is where the sterilization of objects is to occur. It is the configuration of the volume within the housing, e.g. the design of the sterilization chamber 228, and the sealing of the housing 102, e.g. the design of the first door assembly 104 within the first opening 105 and the second door assembly 206 within the second opening 107, that are important to the level of sterilization to be achieved within the housing 102. It will be appreciated that depending on the specific embodiment, the housing 102 maybe other shapes than cylindrical, such as a cuboid or rectangular parallelepiped, for example; thus, the present embodiment is not limited to cylindrical shaped passthrough sterilization devices 100.

In this embodiment, the volume within the housing 102 includes a lamp chamber 230 and a sterilization chamber 228. The lamp chamber 230 is defined as the volume formed between the inner surface 202 of the housing 102 and the outer surface of the transmissive barrier 114. The lamp chamber 230 includes at least one Xenon flashlamp 210, each contained within a lamp tube 212, and mounted within retaining walls 238 such that each flashlamp 210 is spaced equiangularly around the perimeter of the transmissive barrier 114 and designed to emit light into the sterilization chamber 228 through the transmissive barrier 114. Furthermore, the flashlamps 210 are held approximately equidistantly from the center of the sterilization chamber 228. The flashlamps 210 are held in place within the retaining walls 238 by lamp support bushings 234, collars 232 and insulating rings 236. Thus, advantageously, the flashlamps 210 are positioned to surround the sterilization chamber 228 (this is best illustrated in FIG. 3), such that the object to be sterilized may be illuminated from all angles. As described above, the flashlamps 210 each project broad-spectrum pulsed light (BSPL) within the housing 102.

Illumination of the entire surface of the object is preferred and is achieved within the sterilization chamber 228 by spacing the flashlamps 210 so as to surround the sterilization chamber 228 and by providing reflective portions 214, located within the lamp chamber 230 in this embodiment, for each individual flashlamp 210. Each of the reflective portions 214 reflects the light emitted from the flashlamps 210 at various angles back at the object to be sterilized and to other areas within the sterilization chamber 228. Preferably, the reflective portions 214 are in the shape of a parabolic sheet (or parabolic cylinder, defined by Z=ax² having a major axis parallel to a central axis of the housing 102 or sterilization chamber 228. The reflective portions 214 are used to maximize the amount of intense, short-duration light pulses that is directed into the sterilization chamber 228 containing the object to be sterilized. The reflective portions 214 are also mounted within the retaining walls 238 and are best illustrated in FIG. 2. While the illustrated embodiment uses straight flashlamps 210 and reflective portions

214 that are in the shape of parabolic sheets (or parabolic cylinders), other arrangements may be utilized. For example, flashlamps 210 may be constructed in virtually any shape in much the same way that neon lighting signs can also be made to virtually any shape. Similarly, the reflector portions 214 may be made of many different materials in many different geometries to accommodate imaging the light from the flashlamp 210 upon the object to be treated with a desired energy density distribution. "The Optical Design of Reflectors", Second Edition, William B. Elmer, Published by John Wiley and Sons, Inc., New York, is an appropriate resource as an introduction to the fundamentals of reflector design

Furthermore, to enhance the effectiveness of the sterilizing light reflected into the sterilization chamber 228 by the flashlamps 210 and the reflector portions 214 (e.g. parabolic reflectors), the interior of the housing 102 is made as reflective as possible. Thus, advantageously, the first and second door assemblies 104 and 206 each have reflective inner door surfaces 226 and the inner surfaces of the end walls are reflective, i.e. first and second reflective end walls 224 and 225. Also, the inner surfaces of the retaining walls 238 within the lamp chamber 230 are reflective. Furthermore, off-centered photodetectors 216 are incorporated into the sterilization passthrough device which detect the intensity of the light emitted within the housing 102. These off- centered photodetectors 216 are described in more detail with reference to FIG. 3.

It is also important to note that the housing 102 is "light-tight". To ensure that the housing 102 is "light-tight", i.e. that the sterilizing light produced by the flashlamps 210 does not exit the housing 102, the first door assembly 104 seals the first opening 105 of the housing 102 and the second door assembly 206 seals the second opening 107 of the housing 102.

Furthermore, the front housing cover 242 is positioned at the front end of the housing 102 (e.g. the end exposed to the non-sterile environment 248) and the back housing cover 240 is positioned at the back end of the housing 102 (e.g. the end including the second opening 107, exposed to the sterile environment 250). The front housing cover 242 includes a vent (or opening) adapted for a fan 222 that provides cooling air to circulate over the flashlamps 210, since the flashlamps 210 generate significant heat during use.

Fan covers 112 that fit over the fans 222 and vents of the front housing cover 242 prevent any BSPL from within the lamp chamber 230 of the housing from escaping into the non-sterile environment 248. The inner surfaces of the fan covers 112 are advantageously painted black or otherwise made non-reflective to minimize light escaping into the non-sterile environment 248.

Additionally, the interior surfaces of the back housing cover 240, the housing 102, and the front housing cover 242 may be painted black or made non-reflective to reduce the amount of light that projects through the cracks between the reflective portions 214, retaining walls 238, etc. from reflecting toward the fans 222 and the fan covers 112.

As shown, the interior volume within the housing 102 includes the sterilization chamber 228 which, in this embodiment, is the volume formed within the transmissive barrier 114. Additionally, the transmissive shelf 116 is positioned within the transmissive barrier 114 and is used as a shelf to place objects on within the sterilization chamber 228. The transmissive barrier 114 is typically cylindrical in shape and preferably takes on the same shape as the housing 102, such that the housing 102 and the transmissive barrier 114 generally form concentric cylinders, although other shapes may be easily implemented by one skilled in the art. Advantageously, the transmissive shelf 116 is able to position the obj ect to be sterilized optimally within a central portion of the housing 102, i.e. the portion of the sterilization chamber 228 that is optimally designed to receive the most illumination from the flashlamps 210.

Both the transmissive barrier 114 and the transmissive shelf 116 are advantageously comprised of a material that is transmissive to light emitted from the flashlamps, such as quartz or sapphire or another suitable material. Thus, the material of the transmissive barrier 114 and the transmissive shelf 116 is at least 10%, more preferably at least 50%, and most preferably at least 70- 95% transmissive to broad-spectrum pulsed light. Thus, in a preferred embodiment, the transmissive barrier 114 is a quartz cylinder and the transmissive shelf 116 is a quartz shelf that extends the length of the quartz cylinder. The transmissive shelf 116 is generally planar and rectangular and is fixed within the transmissive barrier 114.

It is important to note that the transmissive barrier 114 is not required in some embodiments. The transmissive barrier 114 merely separates the volume defined as the lamp chamber 230 from the volume defined as the sterilization chamber 228 within the housing 102. The transmissive barrier 114 serves the several purposes. First, the transmissive barrier 114 protects the flashlamps 210 from being accidentally broken or damaged while placing objects and removing objects from the passthrough sterilization device 100. It also limits the hiding places for air-borne contaminants entering the interior volume of the housing 102 from the non-sterile environment 248 to the volume within the transmissive barrier 114. Furthermore, as in the embodiment shown, the transmissive barrier 114 may seal the lamp chamber 230 from the sterilization chamber 238, which is advantageous where cooling air from the non-sterile environment 248 is used to cool the flashlamps 210. In this case, if the sterilization chamber 228 was not sealed from the lamp chamber 230 by the transmissive barrier 114, air-borne contaminants would re-contaminate the object and the air within the housing 102 that was sterilized. Thus, a transmissive barrier 114 as shown in FIG. 2 is not required. In the embodiments where the transmissive barrier 114 as illustrated (cylindrical barrier separating the sterilization chamber 228 from the lamp chamber 230) is not required, the flashlamps 210 may actually be located within the sterilization chamber 228, as opposed to within a separate lamp chamber 230. As such, the lamp tubes 212 function as a transmissive protector for the flashlamps 210. Note that the fan 222 and the vent (not shown) in the housing describe one type of cooling device or cooling means for cooling the flashlamps 210 during operation. Other types of cooling devices or cooling means may be used, such a pump that pumps a cooling liquid, e.g. water, through the lamp tube 212 (or through a transmissive sheath surrounding the lamp tube 212), in which case, cooling air provided by the fans 222 from the non-sterile environment would be unnecessary. Additionally, this pump may be used to pump a cooling gas, e.g. air, through the lamp tube 212 (or through a transmissive sheath surrounding the lamp tube 212). In any case a cooling medium, e.g. a gas (air) or a liquid (water) is circulated about the flashlamps 210 for the purpose of cooling the flashlamps 210 during operation. The first opening 105 exposed to the non-sterile environment 248 and the second opening 107 exposed to the sterile environment 250 are sealed from the respective environments by the first door assembly 104 and the second door assembly 206. The first door assembly 104 and the second door assembly 206 incorporate features of and constitute an improvement over a sealed door system designed by La Cahlene of Bezons, France and also of Rush City, Minnesota. This sealed door system improves upon the La Cahlene DPTE ("Double Porte de Transfert Etanche") transfer system, which is well known in the art and has been the industry standard for the introduction and removal of materials into and out-of the aseptic processing environment of barrier isolators for many years. Thus, the La Cahlene DPTE transfer system has traditionally been used to mate and sealingly lock and connect two volumes without breaking their respective confinements to an outside environment. Specifically, the DPTE transfer system connects an isolation chamber to a sealed drum, canister or cylinder that contains a sterilized object to be passed into the isolation chamber.

The passthrough sterilization device 100 of this embodiment operates in a manner similar to the La Cahlene DPTE transfer system, but allows, unlike the La Cahlene DPTE transfer system, objects sterilized within the passthrough sterilization device 100 to be transferred into and out- of isolation chambers that are mated to an opening of the passthrough sterilization device (i.e. the second opening 107 of the housing 102 via the second door assembly). The improved sealed door system uses a complex mechanical combination of interlocking flanged doors mechanically held together and including precisely molded annular seals or gaskets. U.S. Patent No. 4,494,586, issued 1/22/85 to Picard, entitled SAFETY DEVICE FOR A LOCKING AND OPENING SYSTEM, illustrates some features found in the La Cahlene DPTE transfer system.

In this embodiment of the passthrough sterilization device 100, the first door assembly 104 consists of the first door frame 266 and the first door body 268 having a first seal 270 or gasket extending annularly about the inner perimeter of the first door body 268. The first door frame 266 forms the first reflective end wall 224 and sealingly engages the retaining wall 238, and the transmissive barrier 114. The first door frame 266 includes a door hinge 218 and a door arm 220. The door arm 220 is attached to an outer portion of the first door body 268. The first door frame 266 also includes a latch 244 which locks the first door body 268 into position against the first opening 105; thus, sealing the sterilization chamber 228 at the first opening 105. The details of the latch 244 are described with reference to FIG. 6. The first seal 270 sealingly contacts a sealing surface of the first door frame 266, such that the first seal 270 itself has minimal exposure to the sterilizing light within the housing 102. Furthermore, the first door body 268 is adapted to fit against the first opening 105 such that "shading" is minimized. The inner surface of the first door body is also advantageously reflective, i.e. reflective inner door surface 226. Further details regarding the structure and operation of the first door assembly 104, and other features, such as the minimization of shading and the exposure of the first seal 270 to the sterilizing light are described with reference to FIG. 6.

The design of the second door assembly 206 is critical to the step of "mating" the sterilization chamber 228 of the passthrough sterilization device 100 to the sterile environment 250 of an isolation chamber without breaking the confinement of the sterile environment 250. The second door assembly 206 includes an alpha assembly and a beta assembly. The beta assembly is typically attached to the housing 102 of the passthrough sterilization device, while the alpha assembly is typically fixed within an opening or a mating interface of the isolation chamber.

The beta assembly includes an inner door frame 260 and an inner door body 262. The inner door frame 260 is permanently attached to the housing 102 of the passthrough sterilization device such that the inner door frame 260 forms the second reflective end wall 225 and sealingly engages the transmissive barrier 114, and the retaining wall 238. The second opening 107, which is circular in shape, is formed within the inner door frame 260. The inner door body 262 of the beta assembly is adapted to fit within the volume formed by the opening of the inner door frame 260 and locks thereto with annular flanges that extend and interlock with corresponding annular flanges of the inner door body 262. The inner door frame 260 is sealed to the inner door body 262. Additionally, the inner door body 262 seals the second opening 107 of the sterilization chamber 228. The details of these interlocking flanges and the seals created are more fully described with reference to FIGS. 4A- 4C. The alpha assembly of the isolation chamber, which is incorporated into an opening in the isolation chamber wall 264, includes the outer door frame 256 and the outer door body 258. The outer door frame 256 includes a door hinge 218 attached to a door arm 220. The door arm 220 is attached to the outer door body 258 which is sealingly held in place within the outer door frame 256 by a latch 244 (similar to the latch 244 of the first door assembly 104). Thus, the outer door frame 256 is sealed to the inner door frame 260, and together, the outer door frame 256 and the outer door body 258 seal the sterile environment 250 of the isolation chamber from the non-sterile environment 248. Further details of the alpha assembly are described with reference to FIGS. 4A-4C.

Next, the beta assembly of the housing 102 is "mated" to the alpha assembly of the isolation chamber. The mating process, which is fully described with reference to FIGS. 4A-4C, results in the inner door frame 260 being attached and sealed to the outer door frame 256 in addition to the inner door body 262 being attached and sealed to the outer door body 258. Thus, the combination of the inner door body 262 and the outer door body 258 (shown as the second door assembly 206') may be opened to the sterile environment 250 to retrieve and place objects from and into the sterilization chamber 228 of the housing.

A typical operation includes "mating" the beta assembly of the second door assembly 206 to the alpha assembly of the isolation chamber. Next, the first door assembly 104 is opened (with the second door assembly 206 closed) and placing the object to be sterilized within the sterilization chamber 228 of the housing, e.g. on the transmissive shelf 116. Next, the first door assembly 104 is closed sealing the sterilization chamber 228 from both the non-sterile and sterile environments, the object is then illuminated with broad-spectrum pulsed light as described herein. Then, the second door assembly 206' is opened (while the first door assembly 104 remains closed) and the object is retrieved into the sterile environment 250.

In alternative embodiments, instead of having first and second openings 105 and 107, the housing 102 of the passthrough sterilization device may only contain one opening, having one door assembly that seals the volume of the housing from the outside environment. In such case, the object is not necessarily passed from a non-sterile environment into a sterile environment, but it is sterilized and then returned to the environment that the object was placed into from.

Furthermore, in such a single opening housing design, the single opening could be configured similar to the second opening 107 that includes the second door assembly 206, i.e. the beta assembly that mates to an alpha assembly. In such embodiment, the inner door body 262 of the beta assembly may be removed from the inner door frame 260, an object to be sterilized is placed within the opening, the inner door body 262 is then placed back into the inner door frame 260; thus, sealing the sterilization chamber 228 from the outside environment. Then, the object is sterilized using broad- spectrum pulsed light. Finally, the beta assembly of the second door assembly 206 is mated to an alpha assembly of an isolation chamber such that the object may be removed into the sterile environment 250. Thus, advantageously, the object may be passed from a non-sterile environment into a sterile environment using a sterilization device that has only one sealed door assembly.

Furthermore, the single opening design may be embodied as having one door assembly that resembles the first door assembly 104. As such, it would not be possible to mate the housing 102 to an isolation chamber incorporating the La Cahlene DPTE transfer system, since the first door assembly 104 is not suited to mate with the alpha assembly of the isolation chamber wall 264. However, advantageously, such an embodiment may be useful in situations wherein the object to be sterilized is a light transmissive container such that material within the container is to be sterilized.

In another alternative, the housing 102 of the passthrough sterilization device may be incorporated in a wall structure or barrier between a non-sterile environment 248 and a sterile environment 250. In such case, the passthrough sterilization device 100 is not moveable, but is fixed within the dividing structure between the non-sterile and sterile environments. Furthermore, in this embodiment, a complex sealed door, such as the second door assembly 206 comprising the beta assembly that mates with an alpha assembly, is not required. Thus, simply two sealed doors similar to the first door assembly 104 would be needed, one for the respective openings of the housing 102 to the sterile and non-sterile environments.

Regardless of which specific sealed door design is chosen, a system that seals the volume of the housing 102, specifically the volume defined as the sterilization chamber 228, from both the non-sterile environment 248 and the sterile environment 250 is required, such that deactivation of objects to the level of sterilization can be achieved.

As described above, a major distinction between the pulsed polychromatic light passthrough sterilization device 100 of this embodiment and known UV passthrough devices is that instead of using a continuous UV light source to treat objects within the passthrough device, this embodiment of the present invention advantageously employs Xenon flashlamps 210 that emit broad- spectrum pulsed light (also referred to as BSPL) to sterilize an object. The broad-spectrum pulsed light is in the form of high-intensity, short-duration pulses of incoherent, polychromatic light in a broad-spectrum for the deactivation of microorganisms (i.e. sterilization).

Pulsed polychromatic light, such as BSPL, is different from non-pulsed or continuous wave UV light in a number of ways. The spectrum of BSPL contains UV light, but also includes a broader light spectrum, in particular between about 170 nm and about 2600 nm. The spectrum of BSPL is similar to that of sunlight at sea level, although it is 90,000 times more intense, and includes UV wavelengths between 200 and 300 nm which are normally filtered by the earth's atmosphere. BSPL is applied in short duration pulses of relatively high power, compared to the longer exposure times and lower power of non-pulsed UV light. See for example, the '559 patent, the '942 patent, the '235 patent, the '442 patent, the '853 patent, the '598 patent. Thus, advantageously, a microbial reduction of 6-7 logs, i.e. sterilization, is achieved on the object and the inner surfaces of the sterilization chamber as well as the air within the passthrough device, as opposed to only 4-5 logs reduction common using continuous wave UV light for such treatment. Pulsed polychromatic light, such as BSPL, has been used to decontaminate and/or sterilize various objects, such as food products, packages, water and other fluid, semifluid and solid objects. Primarily, such is accomplished by exposing the object to an appropriate number of flashes of BSPL at an appropriate energy level and for an appropriate duration. See, for example, the '235 patent, the '442 patent, the '853 patent, the '598 patent, and the '211 patent. Additionally, BSPL provides biological effects which are different from non-pulsed or continuous wave UV light. For example, pigmented bacteria, such as Aspergillus niger, are known to be more resistant to UV radiation than are bacillus spores. In studies using BSPL, however, Aspergillus niger was more sensitive, on dry surfaces, to BSPL than were three different bacillus spores: Bacillus stearothermophilus, Bacillus subtilis and Bacillus pumilus. (Unpublished results of internal testing at PurePulse Technologies, San Diego, California.) Further, conventional UV treatment injures DNA by mechanisms that may be reversed under certain experimental conditions classified as either "dark enzymatic repair" or "light enzymatic repair" (Block, S, Disinfection. Sterilization and Preservation, 4^th ed, Williams and Wilkins, U.S.A. (1991)). This photo reactivation by either dark or light enzymes does not occur when BSPL is used to treat the same microorganism (such as, Bacillus subtilis, Bacillus pumilus, Aspergillus niger, Clostridium sporogenes, Candida albicans, Staphylococcus aureus, Escherichia coli, Salmonella choleraesuis and Pseudomonas aeruginosa). (Furukawa, et al, "Brand New Pulsed Light Sterilization Technology Can Sterilize Both Injectable Solution and its 2 mL Polyethylene Container", presented at the PDA International Congress, Japan (Feb., 1999)).

Furthermore, BSPL has proven very effective in the deactivation of oocyst forming bacteria, such as Cryptosporidium parvum, against which traditional forms of deactivation, including continuous UV light treatments, heat treatments and chemical treatments, such as chlorine, have proved ineffective. For example, see U.S. Patent No. 5,900,211.

Furthermore, by using BSPL, air-borne organisms are effectively deactivated as shown in the '211 patent, in addition to the organisms at the surface of the object to be sterilized. Furthermore, organisms that are found on the inner surface of the transmissive barrier 114 (e.g. quartz cylinder) and the transmissive shelf 116 (e.g. quartz shelf) are also deactivated, whereas the UV light in a UV passthrough device primarily deactivates only organisms at the surface of the object, not within the air or at the inner surfaces of the device.

The presence of wavelengths in the visible range further differentiates BSPL from UV light as does the means for generating the two different lights. UV light is generated using Mercury lamps, which poses some safety hazards due to breakage and leakage of Mercury vapor; whereas BSPL is generated using Xenon flashlamps which contain an inert gas.

In practice, the intense, short duration pulses of broad spectrum polychromatic light of this embodiment are generated using flashlamps 210 that are part of a flashlamp system, such as PUREBRIGHT Model No. PBS-1 available from PurePulse Technologies of San Diego, California. The flashlamp system includes a pulsing device that includes a DC power supply that charges energy storage capacitors; a switch used to discharge the capacitors; a trigger circuit used to fire the switch at pre-programmed time intervals, in response to sensors that detect the position of the object to be treated, or in response to a button being depressed by an operator; and a set of high voltage coaxial cables carrying the discharge pulses from a capacitor-switch assembly to each flashlamp 210 within the housing 102, e.g. within the lamp chamber 230. The lamp chamber 230 includes from one to eight flashlamps 210 (although depending on the implementation, more or less flashlamps maybe used) mounted in the retaining walls 238 and with reflective portions 214, e.g. metal parabolic reflectors, that direct the BSPL emitted from the flashlamps 210 toward the center of the sterilization cell 228, where the object to be sterilized is located.

Inside the sterilization chamber 228 of the housing, the object is exposed to intense (i.e, 0.001 to 50 J/cm², e.g., 0.5 J/cm², energy density measured at the surface of the object), short duration (i.e, from 0.001 to 100 milliseconds, e.g., 0.3 milliseconds) pulses of polychromatic light in a broad spectrum (i.e, 170 to 2600 nm; 1.8xl0¹⁵ Hz to 1.2^χl0^I4 Hz). For example, the object may be exposed to at least one pulse, for example, four pulses (or flashes) of the polychromatic light from the flashlamps at 1.5 J/cm² per burst. Specially designed photodetectors are used to detect the intensity of BSPL that is emitted into the sterilization chamber 228 and are described more fully with reference to FIG. 3.

Another important advantage of the passthrough sterilization device 100 is that the time for sterilization to be completed is significantly less than the treatment time of a passthrough device that uses continuous UV light treatment. For example, the object is sterilized to a level of 6-7 logs microbial reduction typically within 1 to 2 seconds using the passthrough sterilization device, in contrast the object being treated to a level of 4-5 logs microbial reduction from 30 seconds to 2 minutes using a UV passthrough device, such as shown in the '289 patent. Thus, in comparison, the passthrough sterilization device 100 provides effectively little or no waiting time for the object to be sterilized and further provides significantly better deactivation than the UV passthrough device. This is particularly advantageous in medical or pharmaceutical applications in which an object may be needed urgently such that a corresponding "wait time" is unacceptable.

Yet another feature of the passthrough sterilization device 100 is that the problem of Mercury contamination associated with UV passthrough devices is eliminated, since Xenon flashlamps 210 are used instead of Mercury vapor lamps. Typically, in UV passthrough devices, the lamp cell containing the UV lamps must be sealed from the sterilization cell, the non-sterile environment, and the sterile environment to prevent Mercury contamination. In contrast, the lamp chamber 230 of the passthrough sterilization device 100 does not need to be sealed from all three of the sterilization chamber 228, the non-sterile environment 248, or the sterile environment 250, since Xenon is an inert gas. Thus, if a Xenon flashlamp 210 breaks in the passthrough sterilization device, there is no danger of contamination.

Note that in the embodiment shown in FIG. 2, the lamp chamber 230 is sealed from the sterilization chamber 228 and also the sterile environment 250. This is because of the cooling air that drawn from the non-sterile environment to cool the Xenon flashlamps 210, which generate significant heat while providing the high intensity flashes of light. Thus, in the embodiment of FIG. 2, it is necessary to seal the sterilization chamber 228 and the sterile environment 250 from the lamp chamber 230 in order to prevent air-borne organisms from the non-sterile environment 248 (entering the lamp chamber 230 from the fans 222) from contaminating the sterilization chamber 228 and subsequently the sterile environment 250 after the object has been treated with the broad-spectrum pulsed light.

Note that this sealing of the lamp chamber 230 from both the sterilization chamber 228 and sterile environment 250 is necessary only for the specific embodiment shown in FIG. 2, which uses non-sterile cooling air. In other embodiments, in which for example, cooling air or water is circulated over the flashlamps 210 through the lamp tubes 212 (or sheaths over the lamp tubes), the lamp chamber 230 may not be sealed from the sterilization chamber 228 as long as the lamp chamber 230 is sealed from both the non-sterile environment 248 and the sterile environment 250. In fact, in this alternative, the transmissive barrier 114 may not be required at all; thus, the lamp chamber 230 and the sterilization chamber 228 would comprise the same interior volume within the housing 102.

Regardless of how the exact sealing is accomplished, it is important that the Xenon flashlamps 210 within the lamp chamber 230 are not required to be sealed from all three of the non- sterile environment 248, the sterile environment 250, and the sterilization chamber 228, in contrast to the UV passthrough device of the '289 patent. As such, the lamp chamber 230 must be sealed to at least two of the non-sterile environment 248, the sterile environment 250 and the sterilization chamber 228, e.g. as shown in FIG. 2, the lamp chamber 230 is sealed from the sterile environment 250 and the sterilization chamber 228. Furthermore, it is important to note that only one of the first door assembly 104 and the second door assembly 206 may be opened to the respective environments at a time. Thus, the free flow of air borne microorganisms from the non-sterile environment 248 into the sterile environment 250 is prevented.

Referring next to FIG. 3, a cross sectional end view is shown looking through the housing of FIG. 2 at plane 3-3 of (FIG. 2), illustrating the sterilization chamber as defined by the volume within the transmissive barrier, and the lamp chamber as defined by the volume between an inner surface of the housing and an outer surface of the transmissive barrier. Shown is the housing 102 having an interior volume. The interior volume within the housing 102 includes the lamp chamber 230 including flashlamps 210, lamp tubes 212, off-centered photodetectors 216, axial photodetectors 302 and reflective portions 214. Also shown is the transmissive barrier 114, which forms the boundary between the lamp chamber 230 and the sterilization chamber 228. The sterilization chamber 228 includes the transmissive shelf 116 and an object 304 to be sterilized. Also shown are dashed lines 308 and 310 and a viewing angle 306 extending from an off-centered photodetector 216, and a location 312 (on portion 312) within the sterilization chamber 228 where the object 304 is located. Dashed line 310 is also referred to as the central viewing axis 310.

As shown, the object 304 within the sterilization chamber 228 is irradiated or illuminated with short-duration, high intensity pulses of broad-spectrum pulsed light (shown as arrows). The pulses of light generated by the flashlamps 210, e.g. Xenon flashlamps, are directed at a variety of angles within the sterilization chamber 228 so that all areas of the object 304 are illuminated. As shown, each flashlamp 210 emits light in all directions, such that the BSPL that is emitted away from the object 304 is advantageously reflected back towards the object using the reflective portions 214 (shown as parabolic reflectors); thus, maximizing the spread of BSPL upon the object 304 which increases the effectiveness of the deactivation of microorganisms on the object. Additionally, the reflective portions 214 could be other than a parabolic shape, or may be one cylindrical reflector that surrounds all of the flashlamps 210. Furthermore, FIG. 3 illustrates that the flashlamps 210 are positioned equidistantly about the transmissive barrier 114 with relation to one another as well as spaced equiangularly from each other with respect to the center of the sterilization chamber 228; thus, maximizing the BSPL directed within the sterilization chamber 228. An additional feature shown in FIG. 3 is that off-centered photodetectors are used to detect the intensity of BSPL present within the housing 102. The off-centered photodetectors 216 are each positioned behind a respective reflective portion 214 in the lamp chamber 228 so that the off- centered photodetector 216 does not interfere with the reflection of light within the lamp chamber 230 and the sterilization chamber 228. The off-centered photodetectors 216 "see" into the sterilization chamber 228 through a small pin hole (not shown) in the reflective portion 214. In the embodiment shown, there are four off-centered photodetectors 216, although the number of off-centered photodetectors 216 may vary depending on the exact configuration and size of the passthrough sterilization device and its housing 102. The off-centered photodetectors 216 are part ofa feedback system that enables the passthrough sterilization device to quantify the intensity of broad-spectrum pulsed light that enters the sterilization chamber 228. As such, it can be determined if the flashlamps 210 are correctly functioning and additionally determined, which flashlamps 210 may not be performing well or if a particular flashlamp 210 is not functioning at all. Rather than having the off-centered photodetectors 216 positioned to look directly at the object 304, i.e, rather than having them "centered", as indicated by a dashed line 308 that extends from the off-centered photodetector 216 to a location 312 within the sterilization chamber 228 where the object 304 is to be located, the off-centered photodetectors 216 are positioned or oriented along the curvature of the reflective portion 214, i.e, they are "off-centered", as indicated by another dashed line 310 that extends from the off-centered photodetectors 216 to a location within the sterilization chamber 228 where the object 304 is not to be located. It is noted that depending on the configuration, the location 312 within the sterilization chamber 228 that is designed to hold the object 304 may be variously located within the sterilization chamber 228 and represents a three-dimensional volume. Thus, each off-centered photodetector 216 looks off-center of the location 312 (i.e, object 304) or misaligned with the location 312 (i.e, object 304). This is indicated by dashed line 310 which extends from the off-centered photodetector 216 in a direction deliberately off center from the location 312 within the sterilization chamber 228 (i.e, the off-centered photodetector 216 does not look directly at the object 304 which would be indicated at line 308). Thus, the dashed line 310 is aligned with one of the reflective portions 214, and not aligned with the location 312. Dashed line 310 is also referred to as a central viewing axis of the off-centered photodetector 216. Advantageously, this more accurately measures the intensity of the light that is reflected throughout the sterilization chamber 228 and not the light which is directly reflected back from the object 304 at the off-center photodetector 216.

Disadvantageously, the measurements taken by a photodetector looking directly at an object 304 are effected by the reflectiveness and/or color of the object 304 to be sterilized. For example, a dark object, e.g. black in color, may actually reflect less of the pulsed light than a lightly colored object, e.g. white in color. As such, the dark object would appear to be receiving "less light" than a white object, when actually, both objects 304 are being subjected to the same amount and intensity of the light. Thus, advantageously, in this embodiment, the off-centered photodetectors 216 look off to the side of the object 304 at the other reflective portions 216; thus, yielding more accurate measurements of the intensity of the light emitted by the flashlamps 210 within the housing 102.

Furthermore, the off-centered photodetectors 216 are configured to see light from an input angle of about 30 degrees, for example, configured to see light up to 15 degrees to either side of the central viewing axis or dashed line 310, rather than just light entering along the central viewing axis or dashed line 310. This input angle is illustrated in FIG. 3 as the viewing angle 306. This allows a wide angle of light to be measured by each off-centered photodetector 216. The off-centered photodetectors 216 used are conventional off-the-shelf silicon photodiodes. The off-centered photodetectors 216 also include electronics, such as signal conditioning and amplification circuits. The off-centered photodetectors 216 of the present embodiment also have UV filters incorporated to view ultraviolet light centered around 260 nm. For example, in one embodiment, the UV filters allow the passage of light having wavelengths between 235 and 285. Although, the light within the sterilization chamber 228 is within the full spectrum of between 170 nm and 2600 nm, the spectrum of light below 300 nm is the portion of the flashlamp output that is the most sensitive to disturbance. Thus, light around 260 nm (e.g., between 235 nm and 285 nm) is a good indicator of the intensity of the light in the entire spectrum within the housing 102.

Additionally, axial photodetectors 302 are positioned behind the retaining wall which the flashlamps are mounted within and are able to look into the lamp chamber 230 through a small pin hole. Thus, the axial photodetectors 302 look axially from one end of the lamp chamber 230 to the other end of the lamp chamber 230. Again, the axial photodetectors 302 are configured such that they do not "look" directly at the object 304 to be sterilized, since the intensity measurements may be effected by the color of the object 304. The axial photodetectors 302 differ from the off-centered photodetectors 216 in that they are oriented to "look" axially through the lamp chamber 230, whereas the off-centered photodetectors 216 are oriented to "look" into the sterilization chamber 228 and/or the lamp chamber 230 in a direction off-center from the center of the sterilization chamber 228 and the object 304. These axial photodetectors 302 may be used in conjunction with the off-centered photodetectors 216. Alternatively, the housing 102 may incorporate one or the other of the off- centered photodetectors 216 or the axial photodetectors 302. Further details regarding photodetectors for detecting an intensity of sterilizing light are found in U.S. Patent No. 5,925,885, of Clark, et al, entitled PARAMETRIC CONTROL IN PULSED LIGHT STERILIZATION OF PACKAGES AND THEIR CONTENTS, issued 7/20/99.

Referring next to FIGS. 4A-4C are lengthwise cross-sectional views of the second door assembly comprising the specially designed beta assembly and the alpha assembly of one embodiment of the passthrough sterilization device of FIG. 2, illustrating the application of "mating" the specially designed beta assembly of the housing to the alpha assembly of an isolation chamber such that the sterilization chamber maybe sealingly attached to the sterile environment of the isolation chamber without breaking the confinement of the sterile environment. Shown is the back housing cover 240 of the passthrough sterilization device, the transmissive barrier 114, the transmissive shelf 116, the sterilization chamber 228, the second opening 107, and the second door assembly 206 which consists in part of an alpha assembly 402 and a beta assembly 404 (both the alpha assembly 402 and the beta assembly 404 are indicated as respectively cross-hatched components). The beta assembly 404 includes the inner door frame 260 and the inner door body 262. The inner door frame 260 includes the second reflective end wall 225, first door frame flanges 408, second door frame flanges 410, an inner seal 412, a magnetic sensor 414, a tubular neck portion 450, an exterior surface 452, and an interior surface 454. The inner door body 262 includes the reflective inner door surface 226, an o- ring seal 416 (also referred to as an annular seal), first door body flanges 418, second door body flanges 420, a magnetic material 422, an exterior surface 456, and interior surface 458 a body portion 460, an inner end 462, and an outer end 464. Also shown is the isolation chamber wall 264 including the alpha assembly 402 of the second door assembly. The alpha assembly 402 (also referred to as an interface to an isolation chamber) includes the outer door frame 256 and the outer door body 258. The outer door frame 256 includes the door hinge 218, door arm 220, latch 244, latch support 424, and outer door frame flanges 440. The outer door body 258 includes door handle 106, outer door body flanges 426 and an outer seal 428. Also shown are the sterile environment 250, the non-sterile environment 248, dashed lines 430, 432 and 434, arrows A, B and B', mounting depth 442, volume 435 (which is best illustrated in FIG. 4C) formed within the interior surface 454 of the inner door frame 262, volume 436 formed between the inner door frame 260 and the inner door body 262, and volume 438 formed between the inner door body 262 and the outer door body 258 once sealed together (see FIGS. 4A and 4B).

In operation and as shown in FIGS. 4A through 4C, the beta assembly 404 (which is part of the housing) and the alpha assembly 402 (which is part of the isolation chamber wall 264) are mated together such that the volume of the sterilization chamber 228 and the sterile environment 250 may be coupled together without breaking the confinement of the isolation chamber's sterile environment 250. As described above, this mating system is an improvement of the conventional La Cahlene DPTE transfer system, which is well known in the art and is used for the aseptic transfer of objects into and out-of isolation chambers from sealed drums or cylinders. The improved mating system allows for the transfer of objects into and out-of the sterile environment of an isolation chamber from a passthrough sterilization device, such as that shown in FIGS. 1 through 3. The entire alpha assembly 402 of the second door assembly 206 is identical to the conventional La Cahlene alpha assembly. In contrast, the beta assembly 404 is the component of the conventional DPTE transfer system that has been improved for this particular application.

First, referring to FIG. 4A, both the beta assembly 404 of the housing and the alpha assembly 402 of the isolation chamber wall 264 are shown before being "mated" together. The beta assembly 404 includes the inner door frame 260 and the inner door body 262. The inner door frame 260 is permanently attached to the housing of the passthrough sterilization device such that an inner end of the inner door frame 260 forms the second reflective end wall 225 of the sterilization chamber 228 and sealingly engages the transmissive barrier 114 and the retaining wall 238. The circular second opening 107 is formed within the inner end of the inner door frame 260.

Furthermore, the inner door frame 260 includes a tubular neck portion 450 that extends outward from the sterilization chamber 228 (to the right of dashed line 434, resembling a cylinder). The tubular neck portion 450 extends to an outer end of the inner door frame, i.e, the end furthest away from the sterilization chamber 228. The tubular neck portion 450 forms another opening at the outer end which is typically similar to the circular second opening 107 and allows access into the sterilization chamber 228. The tubular neck portion 450 includes an exterior surface 452 and an interior surface 454. Volume 435 is defined within the interior surface 454 of the inner door frame 260 extending the length of the tubular neck portion 450 from the inner end to the outer end of the inner door frame 260. Furthermore, the inner door frame 260 includes annular flanges near its outer end. The first door frame flanges 408 are at the interior surface 454 and extend radially inward into the volume 435 and extend annularly about the interior surface 454. The second door frame flanges 410 are at the exterior surface 452 and extend radially outward from the exterior surface 452 and extend annularly around the exterior surface 452. Note that the first door frame flanges 408 are near the outer end of the inner door frame 260, while the second door frame flanges 410 are at the outer end. These flanges alternate annularly about the respective exterior and interior surfaces of the tubular neck portion 450. Note that a simplified end view is illustrated in FIG. 4D of the inner door frame 260 having the first door frame flanges 408 and the second door frame flanges 410. The inner door body 262 of the beta assembly 404 is adapted to fit within volume

435 formed within the inner door frame 260 and to attach to the inner door frame 260 so as to seal the sterilization chamber 228 from the outside environment. The inner door body 262 includes a body portion 460 having an inner end 462 and an outer end 464. The inner end 462 is closed and includes the reflective inner door surface 226. The outer end 464 is illustrated as open. The body portion 460 includes an interior surface 458 and an exterior surface 456. The inner door body 262 also includes annular flanges. The first door body flanges 418 are at the exterior surface 456 and extend radially outward from the exterior surface 456 and extend annularly around the exterior surface 456. The second door body flanges 420 are at the interior surface 458 and extend radially inward from the interior surface 458 and extend annularly about the interior surface 458. Likewise, the first and second door body flanges 418 and 420 alternate annularly about the respective interior and exterior surfaces of the body portion 460 of the inner door body 262. It is noted that generally when referring to an "inner" part of an "outer" part, the modifier "inner" refers to being closer to the sterilization chamber 228 (e.g., further left) and the modifier "outer" refers to being further from the sterilization chamber 228 (e.g., further right). Refer to FIG. 4D for a simplified end view of the inner door body 262 illustrating the first door body flanges 418 and the second door body flanges 420.

The first door body flanges 418 correspond to the first door frame flanges 408 of the inner door frame 260. As such, the inner door body is positioned within volume 435 formed within the inner door frame 260 such that the alternating first door body flanges 418 fit in between the alternating first door frame flanges 408. The inner door body 262 is then rotated (as shown by arrow "A") until the first door body flanges 418 are locked underneath the first door frame flanges 408. Thus, the inner door body 262 is mechanically attached to the inner door frame 260. These interlocking flanges are a well known feature of the La Cahlene DPTE transfer system. Furthermore, the inner door frame 260 also includes the inner seal 412 at the outer end of the inner door frame 260 (also referred to as an annular seal) that extends annularly at about the interior surface 454 of the inner door frame 260 at its outer end. The first sealing surface 412' of the inner seal 412 creates a seal between the inner door body 262 and the inner door frame 260. Located at the inner end 462 (i.e. the end facing the interior of the housing) of the inner door body 262 is the annular o-ring seal 416, which seals against the sealing surface at the inner end of the inner door frame such that the exposure of the o-ring seal 416 itself to the sterilizing light is minimized. This minimization of the o-ring seal 416 to the sterilizing light and the sealing surface are described in further detail with reference to FIG. 7. Thus, as shown in FIG. 4A, the inner door frame 260 and the inner door body 262 seal the volume within the housing, e.g. the sterilization chamber 228, from the non-sterile environment 248.

Furthermore, since the inner door body 262 has a reflective inner surface, i.e. reflective inner door surface 226, at its inner end 462 it is able to maximize the reflectivity of light within the sterilization chamber 228. Another feature of the improved beta assembly 404 is that the inner door frame 260 includes a magnetic sensor 414 and the inner door body 262 includes the corresponding magnetic material 422. When the inner door body 262 is fully inserted into the inner door frame 260 and fully rotated into a locked position, the magnetic material 422 aligns with the magnetic sensor 414. Thus, the magnetic sensor 414 senses the magnetic material 422 and sends a signal indicating that the inner door body 262 has been successfully locked into the inner door frame 260; thus, the inner door body 262 has been sealed to the inner door frame 260, which advantageously seals the sterilization chamber 228. Further details of the magnetic sensor 414 and magnetic material 422 are described with reference to FIG. 7.

Additionally, note that volume 436 (which is a smaller portion of volume 435) has been formed between the inner door frame 260 and the inner door body 262. This volume 436 is sealed from the sterilization chamber 228 of the housing by the o-ring seal 416 and sealed from the outside environment by the first sealing surface 412' of the inner seal 412. In operation, this volume 436 is pre-sterilized, for example, in an autoclave, prior to inserting the inner door body 262 into the inner door frame 260.

Still referring to FIG. 4A, the alpha assembly 402, also referred to as an "interface of an isolation chamber") of the isolation chamber wall 264 includes the outer door frame 256 and the outer door body 258. The outer door frame 256 of the alpha assembly 402 is constructed within an opening of the isolation chamber wall 264 or dividing structure that separates the sterile environment of the isolation chamber from the non-sterile environment. The door arm is attached to the outer door frame 256 via the door hinge 220. The door arm 220 attaches to the inside surface (i.e. the side within the isolation chamber) of the outer door body 258. As such, the outer door body 258 is designed to fit within an opening formed within the outer door frame 256 and is mechanically held in a closed position using the latch 244 which is coupled to the latch support 424 of the outer door frame 256. Once the latch 244 is closed, the outer door body 258 is sealingly closed within the outer door frame 256. The seal is effected by the first sealing surface 428' of the outer seal 428 (also referred to as an annular seal) which extends annularly around the outer door body 258. The first sealing surface 428' of the outer seal 428 contacts and sealingly engages the inside thickness of the outer door frame 256. Thus, advantageously, the outer door frame 256 and the outer door body 258 effectively seal the sterile environment 250 of the isolation chamber from the non-sterile environment 248. The alpha assembly 402 of the isolation chamber is identical to the alpha assembly of the La Cahlene DPTE system. Thus, the alpha assembly 402 is entirely conventional. The beta assembly 404 has been improved over the conventional La Cahlene beta assembly of the DPTE transfer system to allow for the sterile transfer of objects from the passthrough sterilization device into and out-of the sterile environment 250 of the isolation chamber. Dashed line 430 in FIG. 4A represents the dividing line between the conventional La Cahlene beta assembly and the improved beta assembly 404. Everything to the right of dashed line 430 is similar to the conventional La Cahlene beta assembly. In fact, if lines 430 and 432 were solid, this would indicate the end wall of the conventional beta assembly. The conventional La Cahlene DPTE transfer system is designed primarily to transfer objects contained within drums or enclosed cylinders into and out-of the isolation chamber. The drum would resemble the tubular neck portion 450 of the inner door frame 260 to the right of dashed line 434 and simply be a straight cylinder wall, such as between dashed lines 434 and 430 of FIG. 4A until the end of the drum or cylinder. The inner door body of the conventional beta assembly, indicated as being to the right of dashed line 430, and including a wall between dashed lines 430 and 432, is termed the "lid" or "stub connection" of the conventional beta assembly. In contrast, the inner door body 262 of the improved beta assembly 404 includes a body portion 460 which resembles an elongated "neck" (i.e. the portion of the inner door body 262 to the left of dashed line 430) that extends into volume 435 formed within the inner door frame 260 to a sealing surface at the inner end of the inner door frame 260 that is offset by a distance from the interlocking flanges, i.e. the first door frame flanges 408 and the first door body flanges 418. Thus, the volume of the sterilization chamber 228 to be coupled to the sterile environment 250 of the isolation chamber is separated by an intermediate volume, i.e. volume 436 (which is a subset of volume 435). This elongated neck and intermediate volume 436 are required due to the mounting depth 442 of the flashlamps that are mounted within the retaining walls (refer to FIG. 2). The ends of the flashlamps extend through the retaining wall 238 and are attached with collars, insulating rings and lamp support bushings. Furthermore, the electrical cables that provide the discharging current and power to the flashlamps require space behind the retaining wall 238; thus, requiring the mounting depth 442.

In this embodiment of the present invention, it is important that the inner door body 262 is flush or nearly flush with the second reflective end wall 225 of the inner door frame, i.e, reflective inner door surface 226 is as flush as possible with the second reflective end wall 225. If the inner door body comprised the conventional beta assembly without the elongated "neck" teπriinating at line 430; thus, the reflective inner door surface was at line 430, then the volume between the reflective inner door surface 226 and dashed line 430 would be subject to "shading" such that microorganisms could hide in the corners of this volume. Thus, disadvantageously, deactivation of microorganisms within the air and located on the inner surfaces of the sterilization chamber to the level of sterilization may not be possible since microorganisms within any potentially shaded portions would not likely be deactivated.

Further in contrast to the conventional beta assembly, there are two sealing surfaces of the improved beta assembly 404: the seal at the interface to the sterilization chamber (e.g. at the o- ring seal 416 at the inner ends of the inner door body 262 and the inner door frame 260) and the seal at the interface to the non-sterile environment (e.g. at the inner seal 412 at the outer ends of the inner door body 262 and the inner door frame 260). The conventional beta assembly only has one seal, i.e. at the inner seal 412, which seals the volume within a drum from a non-sterile environment. Note in the improved beta assembly 404, which will operate with a passthrough sterilization chamber of this embodiment of the present invention, that the intermediary volume 436 is sealed from both the sterilization chamber 250 and the non-sterile environment 248. Advantageously, this intermediary volume 436 is maintained sterile since the inner door frame 260 and inner door body 262 are pre- sterilized, e.g. by autoclaving. Next, referring to FIG.4B, the entire passthrough sterilization device is then moved or positioned such that the beta assembly 404 may be mated to the alpha assembly 402 of the isolation chamber. In operation, the alternating, annular second door frame flanges 410 are oriented such that they are inserted in between the corresponding alternating outer door frame flanges 440 of the outer door frame 256. The outer door frame flanges 440 extend radially inward at the perimeter edge of the outer door frame 256. Refer to FIG. 4D for a simplified end view of the outer door frame 256 illustrating the outer door frame flanges 440. Then, the entire housing is rotated as shown by arrow "B". This rotation of the entire housing is described further with reference to FIGS. 5A and 5B. The rotation effectively causes the second door frame flanges 410 of the inner door frame 260 to move underneath the outer door frame flanges 440 until they are stopped by a locking pin, edge, or other detent means commonly employed in the LaCahlene DPTE transfer system. Thus, the inner door frame 260 is locked and sealed to the outer door frame 256, i.e. the alpha assembly 402 is locked and sealed to the beta assembly 404. The second sealing surface 412" of the inner seal 412 seals the inner door frame 260 at its outer end to the outer door frame 256.

Additionally, when the beta assembly 404 is inserted into the alpha assembly 402, the alternating annular second door body flanges 420 are inserted in between the alternating outer door body flanges 426. Thus, the second door body flanges 420 insert in between the outer door body flanges 426 at the same time that the second door frame flanges 410 insert in between the outer door frame flanges 440. Refer to FIG. 4D for a simplified end view of outer door body 258 illustrating the outer door body flanges 426. Furthermore, the rotation of the entire housing shown by arrow "B", at the same time as causing the inner door frame 262 to lock underneath the outer door frame 256, causes the second door body flanges 420 to lock beneath the outer door body flanges 426; thus, the inner door body 262 is sealed and locked to the outer door body 258. Even further, once the inner door body 262 is locked to the outer door body 258, the inner door body 262 stops rotating while the remainder of the housing, i.e. the inner door frame 262, continues to rotate in the direction of arrow B. The stopping of the rotation of the inner door body is caused by locking pin, retaining edge or lip (or detent means as referred in the conventional DPTE transfer system) under the outer door body flanges 426. Once the second door body flanges 420 contact the locking pin, the inner door body 262 is prevented from further rotation underneath the outer door body flanges 426. The continued rotation of the inner door frame 260 relative to the non-rotation of the inner door body 262, now having been locked to the outer door body 258, causes the first door body flanges 418 to continue to slide from underneath the first door frame flanges 408 to a position in between the first door frame flanges 408. Thus, advantageously, the inner door body 262 is unlocked from the inner door frame 260. Note that the second sealing surface 428" of the outer seal 428 seals the inner door body 262 to the outer door body 258.

Thus, upon completion of the rotation of the housing, the alpha assembly 402 has been "mated" to the beta assembly 404. As such, the inner door frame 260 is locked and sealed to the outer door frame 256 while the inner door body 262 is locked and sealed to the outer door frame 258. Note that the inner door body 262 still seals the sterilization chamber 228 at the o-ring seal 416 and the sterile environment 250 of the isolation chamber remains sealed as well. At this point, objects are typically placed within the sterilization chamber 228 from the first door assembly while the second door assembly 206, i.e. the mated alpha and beat assemblies, remains sealed. The first door assembly is then closed and the object is sterilized by illuminating the object to broad-spectrum pulsed light. Once, the object is sterilized, the object is to be removed through the second door assembly 206' into the sterile environment 250 of the isolation chamber as shown in FIG. 4C.

Referring next to FIG. 4C, the latch 244 is opened and a unitary alpha/beta door body (also referred to as the second door assembly 206') is opened. The unitary door body is the sealed combination of the inner door body 262 and the outer door body 258. Thus, an operator from within the sterile environment 250 can now access the volume within the housing, specifically the sterilization chamber 228 to retrieve the sterilized object. Note that the inner door frame 260 and the outer door frame 256 remain sealed together with the second sealing surface 412" of the inner seal 412 and locked together with corresponding interlocking annular flanges, i.e. the second door frame flanges 410 and the outer door frame flanges 440. Furthermore, the inner door body 262 and the outer door body 258 remain sealed together with the second sealing surface 428" of the outer seal 428 and locked together with corresponding interlocking annular flanges, i.e. the second door body flanges 420 and the outer door body flanges 426. It is also important to note that volume 438 contained within the inner door body 262 and the outer door body 258 is non-sterile, but this volume 438 has been sealed between the inner door body 262 and the outer door body 258 such that the contaminants within the volume 438 can not escape. Furthermore, note that the volume 436 that was previously formed in between the inner door frame 260 and the inner door body 262 has now been exposed; however, such volume 436 was conveniently pre-sterilized. Note that volume 435 that is within the inner door frame 260 is illustrated here. It is important that the first door assembly remain closed at this time so that the free flow of microorganisms from the non-sterile environment into the sterile environment is not allowed.

Further details of the operation of the interlocking mechanical flanges and locking or detent means between them are not described herein. Such operation is well known in the art as the conventional La Cahlene DPTE transfer system; thus, no further explanation is required.

Once it is desired to remove an object from the sterile environment 250, the unitary door body 206' (e.g. the second door assembly 206') is closed such that the empty sterilization chamber 228 may be illuminated with broad-spectrum pulsed light (the first door assembly is also closed at this time). Then, the unitary door body 206' is opened (as in FIG. 4C) and the object is placed into the sterilization chamber. Then the unitary door body 206' is closed (as in FIG. 4B) and the object is removed by opening the first door assembly and removing the object.

To separate, or "un-mate", the alpha and beta assemblies 402 and 404, the reverse process of rotating the entire housing in the opposite direction about arrow B' is performed. As such, the inner door body 262 unseals and unlocks from the outer door body 258 and seals and locks to the inner door frame 260 at the o-ring seal 416 and the inner seal 412. Furthermore, the inner door frame 260 unlocks and unseals from the outer door frame 256 and reseals and locks to the inner door body 262. As such, the beta assembly 404 may be pulled out of the alpha assembly 402; thus, un-mating the alpha and beta assemblies. For further details regarding the steps performed in passing an object into a sterile environment, refer to FIGS. 8A-8C. For further details regarding the steps performed when removing an object from the sterile environment, refer to FIGS. 9A-9C.

Note that FIGS. 4A through 4C illustrate one embodiment of the present invention in which the passthrough sterilization device is adapted to be mated to an isolation chamber using an improved version of the La Cahlene DPTE transfer system. This improved beta assembly 404 specifically allows, unlike the conventional beta assembly, for items sterilized within the passthrough sterilization device to be transferred into and out-of isolation chambers. It is also noted that there are embodiments of the present invention which do not use the improved version of the beta assembly 404, but use a second door assembly similar to the first door assembly. Typically, in this case, the housing is built directly into the structure of a dividing wall or barrier between the sterile environment 250 and the non-sterile environment 248.

Referring next to FIG. 4D, simplified end views are shown of the inner door frame, the inner door body, the outer door frame and the outer door body illustrating the orientation of the respective interlocking flanges. The inner door frame 260 includes first door frame flanges 408 and second door frame flanges 410. The inner door body 262 mcludes first door body flanges 418 (which are designed to interlock with the first door frame flanges 408 of the inner door frame 260) and second door body flanges 420. The outer door body 258 includes outer door body flanges 426 which are designed to interlock with the second door body flanges 420 of the inner door body 262. The outer door frame 256 includes outer door frame flanges 440 which are designed to interlock with the second door frame flanges 410 of the inner door frame 260. The desired interlocking flanges are further illustrated with dashed lines extending therebetween. Note that the illustrations are simplified and intended to show one orientation of the respective flanges of the respective components of the alpha assembly and the beta assembly.

Referring next to FIGS. 5A and 5B, an end view and a perspective view, respectively, are shown of the support stand of the housing support that allows rotation of the housing of FIGS. 1 and 2. Shown is the housing 102, the first door assembly 104, the housing handles 110, electrical cables 514 and a support stand 126 (within the housing support 124 as shown in FIG. 1). The support stand 126 includes two support walls 502 and 504 each with curved edges 516, a travel groove 506, a travel stop bracket 508, housing connectors 518, rollers 510, wall connectors 512, and slot 520.

The apparatus shown in FIGS. 5 A and 5B allows the housing 102 to be rotated within the housing support 124, as shown in FIG. 1, which enables the "mating" of the housing 102 to an isolation chamber as described above. There are typically two support stands 126 that are located within the housing support, each of which supports the housing 102 within the curvature formed in the housing support and the support stands 126, e.g. at the curved edges 516, and also allows the housing 102 to rotate within the housing support as shown by arrows "C". The support stands 126 generally perform most of the supporting functions within the housing support, since the housing support simply consisting of end walls or cover plates. FIG. 1 shows a perspective view from the side of the housing support having one of the cover plates of the housing support removed such that two support stand 126 are exposed to view.

Each support stand 126 consists of two support walls 502 and 504 that are spaced apart, yet rigidly fixed together with the wall connectors 512. The support walls 502 and 504 are also connected together with rollers 510, which attach to the support walls 502 and 504 at their axis, but which also freely rotate to assist in the rotation of the housing 102 within the curvature of the support walls 502 and 504 at curved edges 516. A travel groove 506 is located within one of the two support walls, e.g. support wall 504, and runs radially adjacent to the curved edge 516 of the support stand 126. The travel groove 506 is simply a slot cut or formed within the support wall 504. The travel groove 506 is designed such that it is a certain length within the support wall 504. A travel stop bracket 508 is adapted to slide within the travel groove 506. For example, a bolt or a pin with a "head" is fed through the travel groove 506 and is rigidly coupled to the travel stop bracket 508. The travel stop bracket 508 also rigidly attaches to the underside of the housing 102 with housing connectors 518, e.g. with rivets or bolts. In operation, the housing 102 has an opening in which the electrical cables 514 that extend from the base support into the housing 102 itself. Such electrical cables 514 typically carry the pulsing current for the flashlamps as well as other control signals and power to operate the passthrough sterilization chamber. These electrical cables 514 provide the electrical interface into and out-of the housing 102 from the control panel and other electrical subsystems of the passthrough sterilization device. Thus, advantageously, the electrical cables 514 run between support walls 502 and 504 of the support stand 126 and into a slot 520 within the base support. Note that a light-tight seal is positioned within the housing 102 which allows the electrical cables 514 to pass therethrough into the housing 102. In operation, when it is desired to rotate the entire housing 102 in the directions shown by arrow "C", the operator grips the housing handles 110 and physically rotates the entire housing 102. Since the travel stop bracket 508 is attached to the housing 102, the travel stop bracket 508 moves along the curvature of the travel slot 506 as indicated by arrow "D" until the travel stop bracket 508 hits an end of the travel slot 506. The rotation of the housing 102 is designed such that the beta assembly of the housing 102 is rotated in order to mate with the alpha assembly of an isolation chamber (see FIGS. 4A-4C). This rotation allows for the sterilization chamber of the passthrough sterilization device to be coupled to the sterile environment of the isolation chamber without breaking the confinement of the sterile environment. During the rotation, the electrical cables 514 safely hang into the slot 520 of the base support while moving within the slot 520 shown by arrow "E". Thus, the electrical cables 514 do not kink or twist during the rotation.

Further advantageously, the housing 102 is designed such that when the beta assembly of the housing is locked to the alpha assembly of the isolation chamber, the transmissive shelf is oriented horizontally. Thus, once sealed to the alpha assembly, the first door of the housing 102 may be opened such that objects to be sterilized may be placed onto the horizontally aligned transmissive shelf.

Referring next to FIGS. 5C and 5D, two embodiments are shown of the passthrough sterilization device of FIGS. 1-5B which allows for the vertical orientation of the housing to be adjusted to an appropriate height to mate the improved beta assembly of the housing to a corresponding alpha assembly of an isolation chamber. Shown in FIG. 5C are the housing 102, housing support 124, base support 118, support plate 534 (or top of the base support 118), the improved beta assembly 404, threaded risers 530, and vertical displacement arrow 532.

In FIG. 5C, the entire housing support 124 including the support stands 126 is adjustable vertically by incorporating threaded risers 530 attached to the bottom of the housing support 124 and to the support plate 534. These threaded risers 530 are placed at different locations underneath the housing support 124 to provide proper support for the housing 102, especially when a rotating force is applied to rotate the housing 102 within the housing support 124, as described with reference to FIGS. 5A and 5B. As such, the threaded risers 530 are rotated when has the effect of raising or lowering the housing support 124 which supports the housing 102. Thus, the improved beta assembly 404 as described above, may be adjusted to properly match the height of the beta assembly 404 with the alpha assembly of a corresponding isolation chamber that the beta assembly is to be mated to. This vertical adjustment is shown as vertical displacement arrow 532.

Shown in FIG. 5D, are the housing 102, housing support 124, base support 118, support plate 534 (or top of the base support 118), the improved beta assembly 404 having been raised, threaded screw riser 536, adjustment bracket 538, adjustment hinge 540, and vertical displacement arrows 532.

In this embodiment, one side of the housing support 124 and the corresponding support brackets 126 are mechanically attached to the support plate 534 via the adjustment hinge 540. The adjustment hinge 540 rigidly attaches to both one side or panel of the housing support 124 and the support plate 534, while allowing rotational movement between the housing support 124 and the support plate 534. On the opposite side or panel of the housing support 124, an adjustment bracket 538 is rigidly attached to the housing support 124. The adjustment bracket 538 includes a threaded hole (not shown) into which a threaded screw riser 536 is fed through. The head of the threaded screw riser 536 is placed against the support plate 534 and rotated which causes the threaded screw riser 536 to thread through the threaded hole in the adjustment bracket 538. This, in turn causes the entire housing support 124 and the housing 102 to raise (or lower depending on the direction of the threading. The threaded screw riser 536 supports the weight of the housing support 124 and the housing 102 against the support plate 534 as the support housing 124 is raised. The effect is that the housing support 124 and the housing 102 including the beta assembly 404 are raised to allow the fine adjustment of vertical orientation of the beta assembly 404 to be mated to an alpha assembly of an isolation chamber. This vertical adjustment is shown as vertical displacement arrow 532. These two embodiments are simply two ways that the height of the housing including the beta assembly 404 may be vertically adjusted. Other methods, such as including risers on base support legs or wheels may also be used. In some embodiments, especially where the beta assembly 404 and the alpha assembly are not already aligned, it is important that the vertical orientation of the beta assembly 404 is included since the improved beta assembly as described above should be in alignment with the alpha assembly of the isolation chamber to allow proper alpha/beta mating. Furthermore, although only one threaded screw riser 536 is shown, there may be several threaded screw risers 536 positioned along the opposite side of the housing support 124 so that the weight of the housing support 124 and the housing 102 is supported by more than one threaded screw riser 536.

Referring next to FIG. 6, a side cross-sectional view is shown of the first door assembly of FIG. 2 that seals the sterilization chamber from the non-sterile environment, illustrating a specific design of a sealed door that minimizes exposure of the seal to the sterilizing light and minimizes "shading". Shown is the first door assembly 104 including the first door body 268, the first door frame 266, a door hinge 218, a door arm 220, a door handle 106, and reflective inner door surface 226. Also shown is the latch 244, latch support 610, latch tab 608, latch door piece 612 and groove 613. The first door body 268 includes a first seal 270 that is adapted to seal against a first door frame sealing surface 602 of a first retaining lip 603 of first door frame 266. Only the corner 604 of the first seal is exposed to the sterilizmg light. Also shown is the thickness 606 of the first retaining lip 603 of the first door frame 266. Also shown are the non-sterile environment 248, the sterilization chamber 228, the first opening 105, the first reflective end wall 224, the lamp chamber 230, the transmissive barrier 114, the transmissive shelf 116, retaining wall 238, seal 614 and surface 616.

The first door frame 266 is coupled to housing, i.e. the retaining walls 238. The latch support 610 is coupled to a portion of the first door frame 266. The door hinge 218 and door arm 220 are coupled to the first door frame 266 at an opposite portion of the first door frame 266 as the latch support 610. The first door body 268 is coupled to the door arm 220. Furthermore, the first door body 268 includes a latch door piece 612 that includes a groove 613 to receive the latch tab 608 of the latch support 610.

In operation, the first door assembly 104 seals the first opening 105 of the housing, which is formed by the space within the circular or annular first retaining lip 603 of the first door frame 266, and as described above with reference to FIG. 2. The first door body 268 is positioned within the first opening 105 such that the first seal 270 is positioned against the first door frame sealing surface 602. The latch 244 is then moved in the direction of arrow D which causes the latch tab 608 of the latch support 610 to move in the direction of arrow E into a groove 613 within the latch door piece 612. Thus, the first door body 268 is held or locked within the first opening 105. To unlock the first door body 268 from the first opening 105, the latch 244 is simply moved in the direction of arrow D', which causes the latch tab 608 to move out of the groove 613 in the direction of arrow E'.

Once locked into place, the first door body 268 is sealed to the first door frame sealing surface 602 of the first door frame 266 with the first seal 270; thus, the first door assembly 104 sealingly engages the first opening 105. The first seal 270 is an annular seal, typically made of molded PVC or silicon that extends around the outer perimeter of the first door body 268. The first door frame sealing surface 602 is an outer surface of the first retaining lip 603, i.e. the first door frame sealing surface 602 faces away from the sterilization chamber 228. Advantageously, the first seal 270 is designed to fit against the first door frame sealing surface 602 of the first retaining lip 603 such that the portion of the first seal 270 that is exposed to the sterilizing light within the sterilization chamber 228 is minimized. This is due to the fact that such seals physically degrade due to repeated exposure to sterilizing light, e.g. the broad- spectrum pulsed light emitted by the flashlamps. Thus, only the very corner 604 of the first seal 270 is exposed to the sterilizing light. This is contrasted with sealed door systems of UV passthrough devices, such as shown in the '289 patent, wherein the seals to the sealed doors are exposed to the sterilizing tight, i.e. UV light, without specific regard to minimizing the exposure of the seal to the light. And thus, in contrast to such devices as shown in the '289 patent, the degradation of the first seal 270 is minimized, reducing the frequency that the first seal 270 needs to be replaced.

Another feature of the seal created is that the effects of "shading" are minimized. "Shading" refers to that fact that there may be areas (e.g. cracks or obstructions) within the sterilization chamber 228 that are essentially "shaded" from the sterilizing light, i.e. BSPL, such that microorganisms hiding in the shaded areas may not be deactivated, which may lead to the contamination of the sterile environment, or at least lead to a worsening of the level of deactivation present in the sterile environment.

In order to minimize the effects of shading, the first seal 270 extends along the first door frame sealing surface 602 up to its end (e.g. to the end of the first retaining lip 603), such that only the corner 604 of the first seal 270 is exposed to the sterilization chamber 228. Thus, there are no cracks that microorganisms may hide within to avoid the sterilizing light. Note that the purpose of the reduction of shading conflicts with the purpose of avoiding exposing the first seal 270 to the sterilizing light. For example, the first seal 270 may be placed such that it is well away from the sterilizing light (e.g. sealed along surface 616), but then cracks are created in which microorganisms can hide. Thus, it is advantageous that the first seal 270 extends completely to the end of the interface between the first door body 268 and the first door frame 266 (at the first door frame sealing surface 602 of the first retaining lip 603) so that shaded area will not be created. However, this is at the cost of exposing a small portion of the first seal 270 to the sterilizing light; and thus, advantageously, only the corner 604 of the first seal 270 is exposed to the sterilization chamber 228. In contrast, such seals of known UV passthrough devices, such as shown in the '289 patent, create significant areas for shading at the interfaces of the doors within the respective openings.

Furthermore, in order to further reduce "shading", the thickness 606 of the first retaining lip 603 that includes first door frame sealing surface 602 is made as thin as structurally possible such that areas shaded from the sterilizing light are not created by the thickness 606 of the first retaining lip 603. These features are also absent from such UV passthrough devices as shown in the '289 patent. Such features are likely not required anyway in such UV passthrough devices, since such devices are only capable of microbial reduction of about 4-5 logs, not capable of deactivation to the level of sterilization (i.e. 6-7 logs reduction), as provided by the passthrough sterilization device of the present invention.

Additionally, it is noted that seal 614 creates the seal between the transmissive barrier 114, the first door frame 266 and the retaining wall 238. Thus, the first reflective end wall 224 of the first inner door frame 266 sealingly engages the transmissive barrier 114. Furthermore, the sterilization chamber 228 is sealed from the lamp chamber 230. This seal 614 is an annular seal. A similar seal is used at the opposite end of the sterilization chamber 228 to seal the other end of the transmissive barrier 114 to the second reflective end wall 225 of the inner door frame 260 and the retaining wall 238. Referring next to FIG. 7, a close up, side cross-sectional view is shown of the improved beta assembly that seals the sterilization chamber of FIG. 2 and FIGS. 4A-4C from the outside environment, illustrating that the o-ring seal that is minimally exposed to the sterilizing light and also mmimizes the effects of "shading". Additionally, FIG. 7 illustrates a mechanism for detecting the sealed closure of the inner door body within the inner door frame, i.e. indicating that the sterilization chamber is sealed. Shown is the inner door frame 260 including the second reflective end wall 225, an inner door frame side wall or interior surface 452, and a retaining lip 703 having a thickness 708 and including an inner door frame sealing surface 702. Also shown is the inner door body 262 including the body portion 460, an exterior surface 456, the o-ring seal 416 having an exposed portion 710, a channel 704, and the reflective inner door surface 226 at the inner end 462. Furthermore, shown are the sterilization chamber 228, volumes 436 and 438, magnetic material 422, magnetic sensor 414, location 712 and coating layers 706.

As shown, the o-ring seal 416 (also referred to as an annular seal) of the inner door body 262 is placed within an annular channel 704 that extends about the perimeter of the inner door body 262 at its inner end 462 and is adapted to sealingly engage the inner door frame sealing surface 702 of the second retaining lip 703 of the inner door frame 260. The second retaining lip 703 extends into the second opening of the sterilization chamber 228 and is designed with a minimum thickness 708, such that "shading" is not created by the thickness 708 of the second retaining lip 703. The o-ring seal 416 is also designed to be as close to the sterilization chamber 228 to mmfmize the areas of shading. Thus, as shown, the o-ring seal 416 is set into the channel 704 and is very near the second opening (i.e, second opening 107). Thus, the amount of space that microorganisms may hide and escape deactivation is minimized.

Furthermore, the exposed portion of the o-ring seal 416 is also minimized such that the o-ring seal 416 does not need to be replaced frequently due to degradation from repeated exposure to the sterilizing light within the sterilization chamber 228. Note that only the exposed portion of the o-ring seal 416 is exposed to the sterilizing light. This is in contrast to sealed door devices, such as those of the systems of the '289 patent, in which either the seal is entirely exposed to the light (requiring frequent replacement) or the seal located further back away from the sterilizing light (e.g. the seal could be at location 712). As a result of locating the seal back into the interface between the door and sealing surface, substantial shaded areas are created which allow microorganisms to hide and escape deactivation by the light. Thus, as shown, the o-ring seal 416 advantageously, is positioned as close to the interface between the inner door frame 260 and the inner door body 262 to minimize shading while minimizing the exposed portion of the o-ring seal 416 to minimize degradation of the o-

The o-ring seal 416 is adapted to seal against the inner door frame sealing surface

702 of the retaining lip 703. Additionally, as the inner door body 262 is rotated within the inner door frame 260, the o-ring seal 416 rotates against the inner door frame sealing surface 702 while ma taining its seal thereto; thus, the inner door frame sealing surface 702 acts as a slipping surface for the o-ring seal 416. Also note that the o-ring seal seals the sterilization chamber 228 in addition to sealing the volume 436 formed between the inner door frame 260 and the inner door body 262 as described above.

Furthermore, FIG. 7 illustrates the mechanism that detects the locking of the inner door body 262 within the inner door frame 260 and also detects the complete closure of the inner door body 262 within the inner door frame 260 once it is locked and sealed to the outer door body (as described with reference to FIGS. 4A-4C). Thus, this mechanism results in providing an indication that the second opening 107 of the sterilization chamber 228 is sealed at the second door assembly.

The magnetic material 422 is inserted into a hole that is typically bored into the door body side wall or exterior surface 456 of the body portion 460. A coating layer 706, such as silicon or another suitable material, is typically formed over the magnetic material 422 such that no cracks are formed for microorganisms to hide. Alternatively, the magnetic material 422 may simply be embedded into the body portion; thus, a coating layer 706 is not required. However, it is much simpler to construct the embodiment using the coating layer 706 rather than completely embedding the magnetic material 422 within the body portion 460.

A magnetic sensor 414 is located in the adjacent door frame side wall, e.g. within a hole bored into the interior surface 452 of the inner door frame 262, and may also include a protective coating layer 706, e.g. silicon, that covers the magnetic sensor 414 and is flush with the surface of the interior surface 452 to eliminate cracks that microorganisms may hide. In operation, the magnetic sensor 414 works in two ways. First, the magnetic sensor

414 operates to detect when the inner door body 262 is locked and sealed within the inner door frame 260. As such, the magnetic sensor 414 is position within the interior surface 452 such that when the inner door body 262 is inserted into the inner door frame 260 initially (as described with reference to FIG. 4A), the magnetic sensor 414 is not aligned with the magnetic material 422. However, upon rotating the inner door body 262 within the inner door frame 260 underneath the respective interlocking annular flanges, the magnetic material 422 is brought into alignment with the magnetic sensor 414. Then, the magnetic sensor 414 senses the magnetic material 422 and provides an output signal that indicates to the passthrough sterilization device that the inner door body 262 is sealed and locked to the inner door frame 260. Thus, the sterilization chamber 228 is sealed at the second opening.

Second, the magnetic sensor 414 serves to indicate when the unitary combination of the inner door body 262 and the outer door body 258 is fully within the second opening 107 of the sterilization chamber (see FIG. 4C). In this case, the inner door body 262 is free from the inner door frame 260 and instead is locked and sealed to the outer door body 258. When the unitary door body (shown as the second door assembly 206' in FIG. 4C) is closed and fully within the second opening such that the o-ring seal 416 sealingly engages the inner door frame sealing surface 702, the magnetic material 422 is fully aligned with the magnetic sensor 414. Thus, the signal output from the magnetic sensor 414 indicates that the second door assembly 206' is within the second opening and; therefore, that the sterilization chamber 228 is sealed at the second opening 105.

Referring next to FIGS. 8A-8C, simplified visual representations are shown of the steps performed in passing an object from a non-sterile environment into the sterile environment of an isolation chamber utilizing the passthrough sterilization chamber of FIGS. 2-7. Shown is one embodiment of the passthrough sterilization device 100 as described with reference to FIGS. 2-7 that will be used to sterilize the object 304 to be passed into the sterile environment 250. The passthrough sterilization device 100 includes the housing 102, base support 118, first door assembly 104, the second door assembly including the improved beta assembly 404. The improved beta assembly 404 includes the inner door frame 260 and the inner door body 262. Also shown within the housing 102 are the sterilization chamber 228, flashlamps 210 and the transmissive barrier 114. Additionally shown is an isolator or isolation chamber 802 that is adapted to be "mated" to the passthrough sterilization device 100. The alpha assembly 402 of the second door assembly is shown as being attached to an isolation chamber wall 264 of an isolation chamber 802. The alpha assembly 402 includes the outer door frame 256 and the outer door body 258. Furthermore, the sterile environment 250 is contained within the isolation chamber 802 and the non-sterile environment 248 is outside of the isolation chamber 802.

First, as shown in FIG. 8 A, the passthrough sterilization device 100 and the isolation chamber 802 are illustrated prior to being "mated". As shown, the isolation chamber includes the alpha assembly 402 while the housing 102 of the passthrough sterilization device 100 includes the improved beta assembly 404. The alpha assembly 402 seals the sterile environment 250 of the isolation chamber 802 from the non-sterile environment 248.

Next, as shown in FIG. 8B, the PSD 100 is "mated" to the isolation chamber 802. In operation, the passthrough sterilization device 100 is moved into position against the isolation chamber 802 such that the beta assembly 404 of the housing 102 fits within the alpha assembly 402 of the isolation chamber 802. Once the beta assembly 404 is positioned within the alpha assembly 402, the entire housing 102 is rotated, as described earlier, such that the inner door frame 260 of the beta assembly 402 is caused to be locked and sealed to the outer door frame 256 of the alpha assembly 402. Furthermore, this rotation also causes the inner door body 262 to lock and seal to the outer door body 258, while at the same time the inner door body 262 is unlocked from the inner door frame 260. This completes the "mating" of the housing 102 to the isolation chamber 802. It is important to note that the sterilization chamber 228 of the housing 102 remains sealed by the inner door body 262 within the inner door frame 260 and also that the outer door frame 256 remains sealed to the outer door body 258; thus, the sterilization chamber 228 is sealed from the sterile environment 250, in addition to being sealed from the non-sterile environment 248.

Next, the first door assembly 104 is opened (i.e. the sterilization chamber is unsealed from the non-sterile environment 248) and the object 304 to be sterilized is placed into the volume of the housing 102, e.g. into the sterilization chamber 228 defined as the volume within the transmissive barrier 114 (on a transmissive shelf, for example). Once the object 304 is within the sterilization chamber 228, the first door assembly 104 is sealingly closed. Thus, the sterilization chamber 228 is now sealed from both the sterile environment 250 (by the second door assembly, i.e. the alpha and beta assemblies 402 and 404) and the non-sterile environment 248 (by the first door assembly 104). Next, as shown in FIG. 8C, the object is illuminated with broad-spectrum pulsed light as described above. The effect of such illumination is to deactivate microorganisms on the object 304 to a level considered as sterilization, i.e. about 6 or higher logs microbial reduction. Furthermore, air-borne microorganisms are also deactivated to the level of sterilization. Additionally, the inner surfaces of the sterilization chamber 228, e.g. the inner surfaces of the first door assembly 104, inner door body 262, first and second end walls, transmissive shelf are also sterilized. Note that the object 304 may be a non-sterile object or may be a pre-sterilized object contained within a package. Thus, the illumination sterilizes the surface of the package. Additionally, the package may be light transmissive so that the illumination will sterilize the object 304 (which may also be a fluid) contained within the light transmissive package. Finally, while the first door assembly 104 remains sealed, the object 304 is removed into the sterile environment 250 of the isolation chamber 802 by unlocking the outer door body 258 from the outer door frame 256 (e.g. moving a latch) and the unitary door body, which is a sealed combination of the inner door body 262 and the outer door body 258 is opened such that the operator may reach into the sterilization chamber 228 and retrieve the object 304 having been sterilized. Thus, the sterilization chamber 228 is unsealed from the sterile environment 250 and the object 304 is removed. It is important to note that the space between the inner door body 262 and the outer door body 258 may be contaminated; however, advantageously, it is sealed within the inner door body 262 and the outer door body 258. Advantageously, the improved La Cahlene DPTE transfer system is employed to connect the volume within the passthrough sterilization device 100 to the sterile environment 250 of the isolation chamber 802 without compromising the integrity of the sterile environment 250. Further advantageously, this improved transfer system allows for such connection of isolation chambers 802 to passthrough sterilization devices 100 of this embodiment of the present invention, which present unique concerns (e.g. mounting depths of flashlamps, reducing "shading", and intermediary volumes as described above), compared to the conventional DPTE transfer systems which are designed only to be mated to sealed drums or cylinders containing pre-treated objects.

Finally, referring to FIGS. 9A-9C, simplified visual representations are shown of the steps performed in passing an object from the sterile environment of the isolation chamber of FIGS. 8A-8C back into the non-sterile environment utilizing the passthrough sterilization chamber of FIGS. 2-7. FIGS. 9A through 9C have the same components as shown in FIGS. 8A through 8C. First, as shown in FIG. 9A, the isolation chamber 802 and the passthrough sterilization device 100 are shown as "unmated" or separated and the isolation chamber 802 includes an object 304 to be removed out-of the sterile environment 250. Initially, the empty sterilization chamber 228 of the housing 102 must be sterilized to deactivate any microorganisms that are contained within the air of the sterilization chamber 228 or on any of its inner surfaces. Again, this sterilized is done by illuminating the empty sterilization chamber 228 with broad-spectrum pulsed light while the first door assembly 104 seals the first opening of the sterilization chamber 228 and the second door assembly (specifically, the inner door body 262) seals the second opening of the sterilization chamber 228.

Then, as shown in FIG. 9B, the passthrough sterilization device 100 is "mated" to the isolation chamber 802. As such, the improved beta assembly 404 of the housing 102 is mated to the alpha assembly 402 of the isolation chamber 802 as described above. Note that the housing 102 may have been previously mated to the isolation chamber 802, in which case, this step is not required. Once mated, the unitary door body, i.e. the locked and sealed inner door body 262 and outer door body 258 is opened (i.e. the sterilization chamber is unsealed from the sterile environment) and the object 304 is placed into the sterilization chamber 228. This step should make it apparent that the pre- sterilization step of the empty sterilization chamber 228 is so that the sterile environment 250 of the isolation chamber 802 will not be contaminated with non-sterile air or other microorganisms within the sterilization chamber 228. Next, the combination of the inner door body 262 and the outer door body 258 is re-closed; thus, the sterilization chamber 228 is resealed from the sterile environment 250.

Next, as shown in FIG. 9C, the first door assembly 104 is opened (i.e. the sterilization chamber 228 is unsealed from the non-sterile environment 248) and the object is retrieved out of the sterilization chamber into the non-sterile environment 248, while the second door assembly, e.g. the alpha and beta assemblies 402 and 404 seal the sterile environment 250. Optionally, the object 304 may be additionally sterilized (i.e. illuminating with broad-spectrum pulsed light) prior to removing the object in the non-sterile environment 248 as required.

EXAMPLE I The following represents the test results of an embodiment of the passthrough sterilization device 100 as illustrated in FIGS. 1-3 to test the level of microbial reduction using BSPL as the sterilizing light source. An aqueous suspension of Bacillus stearothermophilus spores was sprayed onto 52 polyethylene coupons (4x5 cm; one side only) and 52 stainless steel coupons (4x5 cm; one side only). The coupons were then allowed to dry. These coupons were placed inside the passthrough sterilization device 100 and facing up on the transmissive shelf 116 in different locations on the transmissive shelf 116 and tested using a different number of flashes or pulses of the broad spectrum pulsed light as described above. Referring to FIG. 1, for each respective level of 4, 8, 16 and 32 flashes, 1 polyethylene coupon was placed in each of the center position 134, the side position 130, the end position 132, and the corner position 136 on the transmissive shelf 116 and were treated. This was repeated two more times. A control batch with zero flashes included 1 polyethylene coupon placed at each of the positions of the transmissive shelf 116. Likewise, the same test was repeated for the stainless steel coupons, in that for each respective level of 4, 8, 16 and 32 flashes, a stainless steel coupon was placed in each of the center position 134, the side position 130, the end position 132, and the comer position 136 of the transmissive shelf 116 and were treated. This was also repeated two more times. Again, a control batch with zero flashes included 1 stainless steel coupon placed at each of the positions on the transmissive shelf 116.

With the respective coupons in place, the flashlamps 210 were flashed or pulsed with BSPL the desired number of times and then retrieved from the sterilization chamber 228. Note that the sterilization device tested employed eight flashlamps 210 and the flashes or pulses were simultaneous. The coupons were transferred to a laminar flow hood and the spores on each (control and treated) were recovered using a calcium alginate swab moistened with phosphate buffered saline (0.05M sodium phosphate, 0.9% saline), followed by a dry swab to collect the moisture film left on the coupons. The swab .tips were broken off into a 10 ml tube of phosphate buffered saline. The sample recovery tubes were vortexes for 1 minute to saturate the swabs and then placed in a 5 °C refrigerator overnight to allow the swabs to dissolve. For each treated sample aliquots of 5.0 ml, 1.0 ml, as well as the remaining volume were pour plated with trypticase soy agar (TSA). Control samples were serially diluted and 1.0 ml of each dilution pour plated with TSA. the plates were incubated at 56 °C and the colonies enumerated after 3 and 7 days.

The control recovery for the polyethylene coupons was 6.2 CFU's. Treated polyethylene coupons at all four positions (i.e. the center position 134, the side position 130, the end position 132 and the corner position 136) had no survivors at 32, 16, 8 and 4 flashes, for a log reduction of greater than 6.2 for all samples. These results are presented in Table 1. The control recovery for the stainless steel coupons was 6.1 log CFU's. All stainless steel coupons treated at 32, 16 and 8 flashes showed no survivors at all positions on the transmissive shelf 116, for a log reduction of greater than 6.1. There was a single survivor on one of three coupons treated with 4 flashes in the side position 130 for a log reduction of 6.1. The results of the stainless steel coupons are shown in Table 2. The results demonstrate the ability of the passthrough sterilization device 100 to deliver a level of deactivation of microorganisms at a level commonly accepted as sterilization, i.e. greater than a 6 log reduction of bacterial spores on the surfaces of light transmissive and non-light transmissive materials.

While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. TABLE 1 POLYETHYLENE COUPON RESULTS

TABLE 2 STAINLESS STEEL COUPON RESULTS

^; One repetition showed a single survivor

Claims

CLAIMSWhat is claimed is:

1. A pulsed polychromatic light passthrough sterilization device (100) comprising: a housing (102) having a first opening (105) accessible from a non-sterile environment (248) and a second opening (107) accessible from a substantially sterile environment (250), wherein the housing includes a volume within the housing extending from the first opening to the second opening; a transmissive barrier (114) positioned within the housing, wherein the transmissive barrier defines a sterilization chamber (228) as a portion of the volume that is within the transmissive barrier; one or more flashlamps (210) positioned within a lamp chamber (230) of the housing, wherein the lamp chamber is defined as another portion of the volume that is between an inner surface of the housing and the transmissive barrier, wherein the one or more flashlamps produce short duration, high intensity pulses of polychromatic light; cooling means (222) coupled to the lamp chamber for cooling the one or more flashlamps; a first door (104) adapted to fit the first opening, wherein the first door has an open position and a closed position, wherein the closed position seals the sterilization chamber from the non-sterile environment; and a second door (206) adapted to fit the second opening, wherein the second door has an open position and a closed position, wherein the closed position of the second door seals the sterilization chamber from the substantially sterile environment.

2. The device of Claim 1 wherein each of said one or more flashlamps (210) produces less than 100 millisecond pulses of broad-spectrum light within a range of 170 nm to 2600 nm having an energy density greater than 0.001 Joules per square centimeter.

3. The device of Claim 1 wherein at least 1% of an energy density of the polychromatic light is concentrated at wavelengths within a range of 200 nm to 320 nm.

4. The device of Claim 1 wherein each of said one or more flashlamps (210) produces less than 100 millisecond pulses of the polychromatic light within a range of at least 200 nm to 320 nm.

5. The device of Claim 1 wherein each of said one or more flashlamps (210) produces less than 100 millisecond pulses of the polychromatic light within a range of at least 180 nm to 300 nm.

6. The device of Claim 1 wherein each of said one or more flashlamps ( 10) produces less than 100 millisecond pulses of the polychromatic light within a range of at least 240 nm to 280 nm.

7. The device of Claim 1 further comprising a reflective portion (214) positioned between an inner surface of said housing and a respective one of said one or more flashlamps (210), wherein the reflective portion directs light from the respective one of said one or more flashlamps into the sterilization chamber (228) through the transmissive barrier (114).

8. The device of Claim 1 further comprising one or more photodetectors (216, 302) positioned within the housing to measure an intensity of pulsed polychromatic light within said volume, wherein at least one of said one or more photodetectors views the pulsed polychromatic light that is reflected from within said volume and not pulsed polychromatic light reflected directly from an object to be placed at a location within the sterilization chamber (228), wherein the at least one of said one or more photodetectors is oriented away from the location, wherein a central viewing axis of each of the at least of said one or more photodetectors does not pass through the location.

9. The device of Claim 1 further comprising a transmissive shelf (116) positioned within the sterilization chamber.

10. The device of Claim 1 further comprising a cooling medium circulated about the one or more flashlamps (210) by the cooling means (222).

11. The device of Claim 1 wherein the cooling means comprises a fan (222) positioned against a respective vent of said housing, wherein the fan draws air to cool said one or more flashlamps during operation.

12. The device of Claim 11 further comprising a fan cover (112) positioned over the fan (222), wherein the fan cover prevents pulsed polychromatic light from escaping said housing.

13. The device of Claim 1 wherein said first door (104) includes a first seal (270) positioned at a periphery of the first door and adapted to sealingly engage a sealing surface (602) of the first opening such that a minimum surface of the first seal is exposed to light from said one or more flashlamps.

14. The device of Claim 13 further wherein an edge of said sealing surface (602) of said first opening is sufficiently thin to minimize the effect of shading.

15. The device of Claim 1 further comprising a housing support (124) having a portion generally conforming to a portion of an exterior surface of said housing (102), wherein the housing support supports said housing and allows rotation of the housing relative to the housing support.

16. The device of Claim 1 further comprising support means (124) for supporting the housing and allowing rotation of the housing relative to the support means.

17. The device of Claim 1 further comprising an inner door frame (260) forming said second opening (107), wherein the inner door frame includes a tubular neck (450) extending outward of the second opening away from said sterilization chamber (228), wherein another volume (436) is formed within the tubular neck.

18. The device of Claim 17 wherein said second door (206) comprises an inner door body (262) adapted to fit within said other volume (436) of said inner door frame, wherein the inner door body includes a seal (416) adapted to sealingly engage a surface (702) of said inner door frame (260) proximate to said second opening, whereby said sterilization chamber is sealed from the substantially sterile environment (250).

19. The device of Claim 18 wherein said inner door frame (260) and said inner door body (262) are adapted to be mated to an interface of an isolation chamber containing said substantially sterile environment.

20. The device of Claim 18 further comprising a first plurality of inner door frame flanges (408) at an interior surface of said tubular neck (450) and extending radially inward into said other volume and extending annularly around the interior surface.

21. The device of Claim 20 further comprising a first plurality of inner door body flanges (418) at an exterior surface of said inner door body (262) and extending radially outward from the exterior surface and extending annularly around said exterior surface, wherein respective ones of the first plurality of inner door body flanges (418) are adapted to fit between and rotate underneath respective ones of the first plurality of inner door frame flanges (408), whereby securing the inner door body (262) to the inner door frame (260).

22. The device of Claim 21 further comprising a second plurality of inner door frame flanges (410) at an exterior surface of said tubular neck (450) and extending radially outward from said exterior surface and extending annularly around said tubular neck, wherein respective ones of the second plurality of inner door frame flanges (410) are adapted to be interlocked with respective ones of a corresponding plurality of outer door frame flanges (440) of an outer door frame (256) of an alpha assembly (402) of an isolation chamber.

23. The device of Claim 22 further comprising a second plurality of inner door body flanges (420) at an interior surface of said inner door body (262) and extending radially inward from the interior surface and extending annularly around the interior surface, wherein respective ones of the second plurality of inner door body flanges (420) are adapted to interlock with respective ones of a corresponding plurality of outer door body flanges (426) of an outer door body (258) of said alpha assembly (402).

24. A pulsed polychromatic light passthrough sterilization device (100) comprising: a housing (102) having a first opening (105) accessible from a non-sterile environment (248) and a second opening (107) accessible from a substantially sterile environment (248), wherein the housing includes a sterilization chamber (228) within the housing extending from the first opening to the second opening; one or more flashlamps (210) positioned within the housing, wherein the one or more flashlamps produce short duration, high intensity pulses of polychromatic light; a first door (104) adapted to fit the first opening, wherein the first door has an open position and a closed position, wherein the closed position seals the sterilization chamber from the non-sterile environment (248); and a second door (206) adapted to fit the second opening, wherein the second door has an open position and a closed position, wherein the closed position of the second door seals the sterilization chamber from the substantially sterile environment (250).

25. The device of Claim 24 further comprising a transmissive barrier (114) positioned within the housing, wherein the transmissive barrier defines the sterilization chamber as a volume within the transmissive barrier.

26. The device of Claim 24 further cooling means (222) coupled to the one or more flashlamps for cooling the one or more flashlamps.

27. The device of Claim 24 further comprising a respective transmissive barrier surrounding each of the one or more flashlamps.

28. The device of Claim 27 further cooling means (222) coupled to the one or more flashlamps for cooling the one or more flashlamps, wherein the cooling means passes a cooling medium within each respective transmissive barrier.

29. A method of sterilizing an object (304) from a non-sterile environment (248) and passing the object into a substantially sterile environment (250) comprising: placing, from the non-sterile environment (248), the object (304) into a sterilization chamber (228) within a pulsed polychromatic light passthrough device (100), wherein the sterilization chamber is sealed from the substantially sterile environment (250); sealing the object (304) within the sterilization chamber (228), wherein the sterilization chamber is sealed from both the non-sterile environment and the substantially sterile environment; illuminating the object (304) with at least one high-intensity, short duration pulse of incoherent polychromatic light, thereby deactivating microorganisms present on the object; unsealing the sterilization chamber (228) from the substantially sterile environment (250); and removing the object (304) from the sterilization chamber (228) into the substantially sterile environment (250).

30. The method of Claim 29 wherein said illuminating comprises deactivating microorganisms to a level of at least 6 logs microbial reduction, whereby said object is sterilized.

31. The method of Claim 29 wherein said illuminating comprises deactivating microorganisms to a level of at least 7 logs microbial reduction, whereby said object is sterilized.

32. The method of Claim 29 wherein said illuminating comprises illuminating said object with said at least one high-intensity, short duration pulse of incoherent polychromatic light, wherein the pulse duration is less than 100 miUiseconds, the pulse intensity is greater than 0.001 Joules per square centimeter, and the light wavelengths are between 200 nm and 320 nm.

33. The method of Claim 29 wherein at least 1 % of an energy density of the incoherent polychromatic light is concentrated at wavelengths within a range of 200 nm to 320 nm.

34. The method of Claim 29 further comprising viewing portions of the at least one high-intensity, short duration pulse of incoherent polychromatic light that are reflected within the sterilization chamber (228), and not other portions of the at least one high-intensity, short duration pulse of incoherent polychromatic light that are directly reflected from said object (304), whereby detecting an intensity of the portions of the least one high-intensity, short duration pulse of incoherent polychromatic light.

35. A method of treating an object (304) from a non-sterile environment (248) and passing the object into a substantially sterile environment (250) comprising: mating a housing (102) containing a treatment chamber (228) to an interface (402) of an isolation chamber (802), wherein the isolation chamber contains a substantially sterile environment (250) sealed by the interface (402) from the non-sterile environment, and wherein the treatment chamber (228) is sealed from the substantially sterile environment; placing, from the non-sterile environment (248), the object (304) into the treatment chamber (228); sealing the object (304) within the treatment chamber (228), wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment; illuminating the object (304) with light, thereby deactivating microorganisms present on the object; unsealing the treatment chamber (228) from the substantially sterile environment (250); and removing the object (304) from the treatment chamber (228) into the substantially sterile environment (250).

36. The method of Claim 35 wherein said mating comprises mating a beta assembly (404) of the housing (102) that is coupled to the treatment chamber (228) with said interface, wherein said interface comprises an alpha assembly (402) of the isolation chamber (802) that is coupled to the substantially sterile environment.

37. The method of Claim 36 wherem said mating further comprises rotating the housing (102) such that the beta assembly (404) is caused to rotate within the alpha assembly (402), wherein an inner door frame (260) of the beta assembly (402) is sealed and locked to an outer door frame (256) of the alpha assembly (402), and wherein an inner door body (262) of the beta assembly (404) is sealed and locked to an outer door body (258) of the alpha assembly (402).

38. The method of Claim 37 wherein said unsealing comprises opening a unitary door body (206') from the inner door frame (260) and the outer door frame (256) having been sealed and locked together, wherein the unitary door body (206') comprises the inner door body (262) and the outer door body (258) having been sealed and locked together.

39. A method of removing an object (304) from a substantially sterile environment (250) and passing the object into a non-sterile environment (248) comprising: mating a housing (102) containing a treatment chamber (228) to an interface (402) of an isolation chamber (802), wherein the isolation chamber contains a substantially sterile environment (250) sealed by the interface (402) from the non-sterile environment (248), and wherein the treatment chamber (228) is sealed from the substantially sterile environment (250); sealing the treatment chamber (228) from the non-sterile environment (248), wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment (250); illuminating the treatment chamber (228) with light, thereby deactivating microorganisms within the treatment chamber; unsealing the treatment chamber (228) from the substantially sterile environment (250); placing, from the substantially sterile environment (250), die object (304) into the treatment chamber; sealing the object within the treatment chamber (228), wherein the treatment chamber is sealed from both the non-sterile environment and the substantially sterile environment; unsealing the treatment chamber (228) from the non-sterile environment; and removing the object (304) from the treatment chamber into the non-sterile environment.

40. An improved beta assembly (404) for mating to an alpha assembly (402) of a transfer system comprising: an inner door frame (260) having a first end and a second end, wherein the inner door frame comprises: a first opening formed at the first end; a second opening (107) formed at the second end; and a tubular neck (450) extending from the first opening to the second opening (107), a first volume (436) formed within the tubular neck from the first opening to the second opening (107); a treatment chamber (228) of a treatment device (100) attached to the second end of the inner door frame (260), the treatment chamber (228) having a second volume accessible from an outside environment via the second opening (107); an inner door body (262) adapted to fit within the tubular neck of the inner door frame (260) between the first end and the second end; and wherein the inner door body (262) sealingly engages the first opening at the first end and sealingly engages the second opening (107) at the second end of the inner door frame (260), whereby the treatment chamber (228) is sealed from the outside environment at the second opening (107).

41. The improved beta assembly of Claim 40 further comprising a first annular seal

(416) at an inner end (462) of said inner door body (262), wherein the first annular seal (416) sealingly engages a sealing surface (702) of said inner door frame (260) at said second opening (107).

42. The improved beta assembly of Claim 40 further comprising a second annular seal (412) at said first end of said tubular neck (450) of said inner door frame (260), wherein the second annular seal sealingly engages said inner door body (262) proximate to an outer end of said inner door body.

43. The improved beta assembly of Claim 40 further comprising a first plurality of flanges (408) at an interior surface (454) of said tubular neck (450) and extending radially inward into said first volume (436) and extending annularly around the interior surface.

44. The improved beta assembly of Claim 43 further comprising a second plurality of flanges (418) at an exterior surface (456) of said inner door body (262) and extending radially outward from the exterior surface and extending annularly around said exterior surface, wherein respective ones of the second plurality of flanges (418) are adapted to fit between and rotate underneath respective ones of the first plurality of flanges (408), whereby securing the inner door body (262) to the inner door frame (260).

45. The improved beta assembly of Claim 40 further comprising a first plurality of flanges (410) at an exterior surface (452) of said tubular neck (450) and extending radially outward from said exterior surface and extending annularly around said tubular neck, wherein respective ones of the first plurality of flanges (410) are adapted to be interlocked with respective ones of a second plurality of flanges (440) of an outer door frame (256) of said alpha assembly (402).

46. The improved beta assembly of Claim 40 further comprising a first plurality of flanges (420) at an interior surface (458) of said inner door body (262) and extending radially inward from the interior surface and extending annularly around the interior surface, wherein respective ones of the first plurality of flanges (420) are adapted to interlock with respective ones of a corresponding plurality of flanges (426) of an outer door body (258) of said alpha assembly (402).

47. The improved beta assembly of Claim 40 wherein said first volume (436) is sealed from said treatment chamber at said second opening (107) and is sealed from said outside environment at said first opening.

48. The improved beta assembly of Claim 40 further comprising a magnetic material (422) at or near a portion of an exterior surface of said inner door body (262).

49. The improved beta assembly of Claim 48 further comprising a magnetic sensor (414) at or near a portion of an interior surface of said tubular neck (450), wherein said magnetic material and the magnetic sensor are in alignment with respective to one another when said inner door body (262) seals said treatment chamber (228) from said outside environment at said second opening (107).

50. An inner door body (262) of a beta assembly (404) for mating to an alpha assembly (402) of a transfer system comprising: a closed inner end (462); an outer end (464); a body (460) extending from the closed inner end to the outer end, the body having an exterior surface (456); a first plurality of door body flanges (418) at the exterior surface (456) extending radially outward from the exterior surface and extending annularly around the exterior surface; and an annular seal (416) at the closed inner end (464), wherein the annular seal is adapted to sealingly engage an opening (107) to a treatment chamber (228).

51. The inner door body of Claim 50 further comprising a magnetic material (422) at or near a portion of said exterior surface (456).

52. The inner door body of Claim 50 further comprising an opening into said body (460) at said outer end (464), wherein the opening includes an interior surface (458), wherein the interior surface is concentric with a portion of said exterior surface (456).

53. The inner door body of Claim 52 further comprising a second plurality of door body flanges (420) at said interior surface (458) and extending radially inward and extending annularly around said interior surface.

54. The inner door body of Claim 50 wherein said closed inner end (462) further includes a reflective surface (226).

55. A photodetector arrangement for detecting the intensity of light in a light treatment device comprising: a light treatment chamber (228) having a sealed volume and one or more reflective inner surfaces (214); a location (312) within the light treatment chamber where an object (304) to be treated by the light within the light treatment chamber is placed; and one or more photodetectors (216, 302) positioned to view reflected light from within the light treatment chamber and not directly reflected light from the object to be placed at the location, wherein the one or more photodetectors are positioned off-center with respect to the location, wherein a central viewing axis (310) of each of the one or more photodetectors (216) does not pass through the location (312).

56. The photodetector arrangement of Claim 55 wherein said each of said one or more photodetectors (216) is adapted to view said reflected light within said light treatment chamber over a range of an input viewing angle (306), wherein the range is defined as an angular offset about said central viewing axis, wherein said angular offset is less than or equal to 15 degrees.

57. The photodetector arrangement of Claim 55 wherein one or more of said one or more photodetectors comprise a photodetector selected from a group consisting of: an off-center photodetector (216) and an axial photodetector (302) .

58. A method of accurate detection and measurement of an intensity of light within a light treatment chamber comprising: illuminating the light treatment chamber (228) with the light; viewing the light reflected within the light treatment chamber, and not viewing the light directly reflected from an object (304) being treated with the light; detecting (216, 302) the intensity of the light having been viewed; and measuring (216, 302) the intensity of the light having been detected, wherein the measured intensity is less affected by the natural reflectivity of the object (304).