WO2025090925A1 - Ambulatory drainage system - Google Patents

Abstract

A system for controlled drainage or delivery of a fluid from or to a patient includes a metering device configured to control a flow of fluid from or to the patient. The metering device includes a housing having a first port connectable to provide communication with a catheter for delivery of fluid to or from the patient and a second port connectable to provide communication with a reservoir for said fluid. A patch is adapted to be affixed to a patient and has a first side configured to face the patient while in-use and a second side opposite the first side. The housing of the metering device may be configured to be attached to the second side of the patch.

Description

AMBULATORY DRAINAGE SYSTEM

Cross-Reference to Related Applications

[0001] This application claims the benefit of US provisional patent application No. 63/545,566 filed October 25, 2023, which is incorporated herein by reference.

Field of the Invention

[0002] This application relates generally to system for controlled drainage or delivery of a fluid from or to a patient. More specifically, it relates to an ambulatory system that can be used, e g., for controlled drainage of cerebrospinal fluid from a patient.

Background of the Invention

[0003] Normal Pressure Hydrocephalus (NPH) is a neurological disorder that afflicts an estimated 750,000 Americans. In NPH, the ventricles in the brain expand with cerebrospinal fluid (CSF) that is not cleared away, compressing surrounding brain tissue, causing debilitating symptoms such as impaired gait, urinary urgency and later incontinence, and cognitive decline. These symptoms are frequently mistaken for Parkinson’s disease or other degenerative, irreversible neurological disorders and therefore are not treated appropriately. The standard treatment for NPH is a surgical intervention called a shunt: a catheter that is inserted through the skull and into the ventricles and then routed under the skin to another site within the body, typically the abdominal cavity or venous system. The resulting continuous drainage of excess CSF from the ventricles to the other part of the body leads to abatement of symptoms.

[0004] To determine if a patient should receive a shunt, multiple tests can be performed. For example, patients can be trialed by draining CSF from the lumbar spine to simulate the shunt. This can be done either as a discrete, one-time spinal tap trial (outpatient) or as an inpatient multi-day test with a temporary catheter. Outpatient lumbar tap tests comprise only a very short simulation of drainage under controlled conditions. Usually only 25-50ml of CSF is removed. Inpatient tests require the patient to be immobilized, and a nurse attends to the patient during drainage, consuming valuable healthcare resources. During inpatient drainage trials, several hundred milliliters of fluid are removed. Even with the prevalence of NPH and the existing treatment methods, there are fewer than 25,000 shunt placements each year, and approximately half of those are replacements. As such, fewer than 2% of potential patients are being treated.

Brief Summary

[0005] In accordance with one aspect, a device for controlled drainage or delivery of a fluid from or to a patient may include a first line connected to a first chamber, a second connected to a second chamber, a third line connected to the first chamber, and a fourth line connected to the second chamber. The device may further comprise a motor actuatable between a first and second position. In the first position, a first hammer connected to the motor compresses the first line, and a second hammer connected to the motor compresses the fourth line. The compression of the first line and the fourth line may hinder flow through the first and fourth lines respectively. Fluid may be permitted to flow permitted through each of the second and third lines. In the second position, the first hammer compresses the third line, and the second hammer compresses the second line. The compression of the second and the third lines may hinder the flow of fluid through each of the second and third lines respectively. Fluid may be permitted to flow through each of the first and fourth lines.

[0006] In accordance with another aspect, a system for controlled drainage or delivery of a fluid from or to a patient may include a metering device configured to control a flow of fluid from or to the patient. The metering device may include a housing, said housing having a first port connectable to provide communication with a catheter for delivery of fluid to or from the patient. The housing may further have a second port connectable to provide communication with a reservoir for said fluid. The system further includes a patch adapted to be affixed to a patient having a first side configured to face the patient while in-use and a second side opposite the first side. The housing of the metering device may be configured to be attached to the second side of the patch.

[0007] In accordance with a further aspect, a method for draining fluid from an ambulatory patient may include affixing a patch to a patient and connecting a metering device to the patch. The metering device may have a first port configured to engage a catheter from the patient, a pumping assembly configured to control flow of fluid from the catheter, and a second port in fluid communication with a reservoir configured to store drained fluid. The method may further include detecting a fluid pressure of fluid being metered by the metering device and correlating the detected fluid pressure to a pressure of fluid within a body cavity of the patient from which the fluid is being drained. The method may further include adjusting a fluid drainage rate based on the correlated fluid pressure in said body cavity.

Brief Description of the Drawings

[0008] FIG. 1 is an illustration of an ambulatory drainage system placed on the back of a patient as herein disclosed;

[0009] FIG. 2A is a front view a housing of the ambulatory drainage system with a reservoir installed;

[0010] FIG. 2B is a left-side view the housing of the ambulatory drainage system with a reservoir installed;

[0011] FIG. 3A is a perspective view of an exemplary reservoir;

[0012] FIG. 3B is perspective view of another exemplary reservoir;

[0013] FIG. 4 illustrates the housing with its cover separated therefrom to show the internal cavity of the housing and an arrangement of subsystems within the housing;

[0014] FIG. 5 is a bottom perspective view of the housing shown in FIG. 4, with the cover removed;

[0015] FIG. 6 is a front view the housing shown in FIG. 4 with the cover removed, further illustrating the various subsystems within the housing;

[0016] FIG. 7 is a top perspective view of the reservoir shown in FIG. 3A;

[0017] FIG. 8 shows the back of the housing;

[0018] FIG. 9 is a perspective view of a placement patch of the ambulatory drainage system;

[0019] FIG. 10 is a perspective view of a catheter connection assembly of the patient patch shown in FIG. 9, where the catheter connection assembly is shown in an open position; [0020] FIG. 11 A right-side view of the catheter connection assembly shown in FIG. 10, where the catheter connection assembly is shown in a closed position;

[0021] FIG. 1 IB is a cross-section view of the catheter connection assembly shown in FIG. 10, shown in the open position;

[0022] FIG. 11C is a cross-section as in FIG. 1 IB, but where the catheter connection assembly is shown in a closed position;

[0023] FIG. 12A is a front view of the housing as described above applied over a patient patch as also described, prior to completing installation thereon;

[0024] FIG. 12B is rear perspective view showing the positioning of the catheter connection assembly on the patient patch relative thereto upon application of the assembly to the patch but prior to completing installation (i.e. in an uninstalled position as shown in FIG. 12A);

[0025] FIG. 13 A is a front view of the housing shown in an installed and locked position on the patient patch;

[0026] FIG. 13B is rear perspective view of the housing engaged with catheter connection assembly on the patient patch (with the patch itself removed to visualize the foregoing elements) in the installed and locked position shown in FIG. 13 A;

[0027] FIG. 14A is front view of the housing and a reservoir in an uninstalled position;

[0028] FIG. 14B is front view of the housing and a reservoir in an installed position;

[0029] FIG. 15A is a perspective view of a first side of a pump assembly of the system;

[0030] FIG. 15B is a perspective view of a second side of the pump assembly;

[0031] FIG. 16 is an exploded view of the pump assembly;

[0032] FIG. 17 is an exploded view of a pinch switching unit of the pump assembly;

[0033] FIG. 18 is a perspective view of a pinching drive shaft of the pinch switching unit; [0034] FIG. 19 is an exploded perspective view of a diaphragm chamber subassembly of the pump assembly;

[0035] FIG. 20A is a schematic diagram illustrating the function of the pump assembly in a first operating state where hammers of the pinching drive shaft are in a first position;

[0036] FIG. 20B is a schematic diagram as in FIG. 20A but in a second operating state where the hammers are in a second position;

[0037] FIG. 21 is a perspective view of an exemplary drip chamber;

[0038] FIG. 22 is a cross-section front view of the exemplary drip chamber in FIG. 21;

[0039] FIG. 23A is a first schematic drawing of the ambulatory drainage system operating in a drainage mode and FIG 23B is a schematic drawing thereof operating in an infusion mode; and

[0040] FIG. 24A is a second schematic drawing of the ambulatory drainage system operating in a drainage mode and FIG 24B is a schematic drawing thereof operating in an infusion mode.

Description of Example Embodiments

[0041] An ambulatory drainage system is disclosed that allows for testing patient-response to a shunt through an extended CSF drainage trial with ambulatory freedom for the patient. The ambulatory drainage system helps to minimize the required healthcare resources, and ultimately enables longer trials that can be conducted in an outpatient setting. These trials will more accurately assess patient response to drainage with a shunt over time, rather than merely at a snapshot in time under controlled conditions. These improvements may also increase the clinical and patient acceptance of longer-duration drainage trials and increase the number of patients who can be directed to the appropriate treatment.

[0042] Prior to undertaking an expensive and invasive therapy such as cerebral shunting, the ambulatory drainage system provides patients the opportunity to receive a temporary, external device that will simulate the therapy by draining a controlled amount of CSF over a predetermined time period. The portable drainage system provides the clinician and patient both experience and data on the efficacy of the ultimate treatment (i.e. a shunt) before opting for the expensive and more invasive treatment.

[0043] In the embodiment illustrated in FIGS. 1-3B, the ambulatory drainage system includes a housing 10 attached to a catheter line 30 that was previously implanted and emerges through the skin of a patient, configured to draw CSF from the spinal column (e.g. via a conventional spinal tap). A reservoir 50 may be coupled to the housing 10 in fluid communication with a pump subsystem therein to receive CSF from the patient. A patient patch 60 can be selectively placed on the patient, for instance on the back of the patient near or over the location where the catheter line 30 emerges from the patient. As will be described in further detail below, the housing 10 can be attached to the patient patch 60 to secure the ambulatory drainage system to the patient.

[0044] Referring now to FIGS. 4-6, the housing 10 has an inner cavity 18 that houses a pump assembly 100. In the illustrated embodiment, it also houses a battery 200 and a controller 300. The battery 200 supplies power to the pump assembly 100 and the controller 300. The controller 300 is configured to control the operation of the pump assembly 100. The controller 300 may be programmed to communicate wirelessly to transmit data to an external device, e.g., a cell phone, computer, or other personal electronic device. The transmitted data may include, but is not limited to, the amount of fluid drained or infused, battery status, measured system pressure, a status of the system (e.g. ON/OFF/STANDBY), the presence of a blockage in the system, or other system parameters. The transmitted data may also include information related to the patient for patient monitoring, e.g. vital signs, activity level (like steps taken over time), or the position and orientation of the patient (e.g. based on one or more sensors that also may be disposed within the housing, or which otherwise communicate with the controller). The transmitted data sent to the external device can be later transferred to the cloud for review by a caregiver or medical professional. It is contemplated that the system can transmit the data in real time to provide live statistics related to the patient’s treatment allowing for real-time monitoring of the patient. In one embodiment, the communication with the external device is intended to be one-way only from the controller 300 to the external device. In an alternative embodiment, the communication can be two-way allowing the external device to control the system, for example to adjust pumping rates and/or timed intervals during which the pump assembly is to be operated. [0045] As best seen in FIG. 8 depicting the rear of the housing (which is configured to face the patient in-use), the housing 10 includes an inlet port 12 at its rear. The inlet port 12 is connectable to the catheter line 30 from the patient. The housing 10 further includes an outlet port 14, which can be at the bottom of the housing 10 as shown in FIG. 5, to communicate fluid into a reservoir 50 that can be removably connectable to the housing 10. The housing 10 may include mounting features on the rear of the housing 10 configured to mount the housing 10 to the patient patch 60. As shown in Fig. 8, the housing 10 includes mounting slots 16 on the rear of the housing 10 for connecting the housing 10 to a patient patch 60, as described in detail below. Alternatively, the mounting features could be keyhole slots or holes configured to engage complementary features on the patient patch 60.

[0046] Referring to FIGS. 3 A, 3B, and 7, the ambulatory drainage system is configured to drain fluid, like CSF, from the patient into a reservoir 50. The reservoir 50 includes an inlet port 52 that is connectable to the outlet port 14 of the housing 10. The inlet port 52 allows fluid, like CSF, to flow into the reservoir 50. Alternatively, in embodiments where the system is configured to pump fluid from the reservoir, it can be supplied (or filled) with the appropriate fluid and connected to the housing 10 to facilitate delivery to the patient. Either way, the reservoir 50 may be removably connected to the housing 10. In the embodiment illustrated, locking tabs 54 extend upward from (adjacent to edges of) the upper surface of the reservoir to reversibly connect the reservoir 50 to the housing 10 in a manner that establishes fluid communication between the inlet port 52 of the housing and the outlet port 14 of the housing 10. The locking tabs 54 can extend through holes 20 (shown in FIG. 5) in the bottom of the housing 10, and a portion of each locking tab 54 can engage a catch, such as a catch hole 22 in a side wall of the housing 10, to provide a snap-fit attachment between the housing 10 and the reservoir 50. Alternatively, the reservoir 50 can be attached to the housing via a friction fit, one or more mechanical fastener (e.g. screws, bolts, pins, latches), or some other suitable attachment mechanism. In another embodiment, the reservoir 50 may be integrally formed with the housing 10.

[0047] The housing 10 can be configured to confirm that the reservoir 50 is firmly attached to the housing 10. The reservoir 50 can include a circuit board 56 having electrical landing pads 58 configured to align with and engage electrical pins 24 located on the housing 10 when the reservoir 50 and the housing 10 are attached. The controller 300 can communicate via with one or more such landing pads 58 via pins 24 to confirm that the reservoir 50 has been properly attached and seated to the housing 10, via electrical contact between the pins 24 on the housing 10 and the respective landing pads 58 on the reservoir 50 when the two are joined. As shown in FIG. 7, the circuit board 56 with its landing pads 58 can disposed at the top of the reservoir 50, e.g. flush or integrated with its top wall), and the electrical pins 24 may protrude from the bottom wall of the housing 10. In one embodiment, the circuit board 56 can be included on a lid that is removably positionable on the top of the reservoir 50. Alternatively, the circuit board can be integrally formed with the reservoir 50.

[0048] The reservoir 50 may include one or more sensors or control inputs that communicate with the controller 300 within the housing 10 via electrical signals transmitted through contact between the respective pins 24 and landing pads when seated. Such sensors may transmit details such as reservoir-fluid level, fluid temperature, fluid conductivity (as an indicator of electrolyte concentration), the detection of infection or other biological markers that may be useful for diagnosis or patient monitoring, and other parameters. The housing 10 and/or the reservoir 50 also can include another sensor to confirm the attachment to the reservoir 50. For instance, the housing and/or reservoir can include a physical button that is depressed when seated together. One or both also may include a proximity sensor, RFID sensor, electromagnetic sensor, or other suitable sensor to adapted to detect that the reservoir 50 and the housing 10 have been attached and properly seated. It is contemplated that the reservoir-resident circuit board 56 (or another integrated circuit elsewhere on the reservoir 50 that communicates with the circuit board 56 (or its landing pads 58)) may be programmed with operational data associated with the particular reservoir 50 or its contents. For example, different reservoirs may have different volumes, or they may be suitable for different therapies. Hence the reservoir-resident circuit board(s) can be programmed with data such as the maximum volume of the reservoir 50 and/or other pertinent information, e.g., motor duty cycle, minimum and maximum infusion or drainage rates, minimum and maximum infusion or drainage volumes, algorithms that ensure drainage or infusion only when the patient is in a particular spatial orientation, etc., suitable for operating the system to provide particular therapy.

[0049] The reservoir 50 may include a drain port (not shown) to allow for draining of fluid collected in the reservoir 50, e.g., for collecting a sample of the fluid. The reservoir 50 may vary in size depending on the volume of fluid to be drained from the patient over a trial; or in the case of infusion therapy, the volume of fluid to be supplied. For instance, FIGs. 3 A and 3B respectively illustrate different reservoirs 50 having maximum fluid capacities of 60cc and 120cc. It will be appreciated that other volumes of fluid may be drained from (or infused into) a patient for other tests or procedures, and the reservoir 50 can be designed to hold an appropriate volume of fluid accordingly. While the ambulatory drainage system has been described in relation to a system and method for metered drainage of CSF from a patient, it also may be operated to drain other fluids from other body cavities, as well as to infuse fluid via catheterized drug infusion for targeted drug therapies.

[0050] In the embodiment illustrated and described above, the battery 200 is secured to an inner wall of the cover of the housing 10. But this is not required; the battery may be disposed in any suitable manner within the housing. The battery can be a rechargeable battery or a disposable battery, for instance at least one AA battery. It will be appreciated that the kind and size of battery can be chosen through sound engineering judgement based on the needs of the system. If the battery is disposable it can be configured to be replaced periodically as needed via removal of the cover from the reservoir to access the battery 200 for replacement. Alternatively, the housing 10 and its contents can be configured as a disposable unit, designed to be disposed of once the battery within is discharged. In a further alternative (not illustrated), the battery 200 may be located in or otherwise be supplied as part of the reservoir 50, wherein a power signal from the battery can be communicated to the operative elements within the housing 10 via the electrical landing pads 58 on the reservoir 50 in communication with the electrical pins 24 on the housing 10 as described above. In this manner embodiment, the battery and the reservoir may be treated together as a disposable unit that is changed relative to a durable, non-disposable housing 10 as successive infusion/drainage operations may demand.

[0051] Referring to FIGS. 8 and 9, the system includes a patient patch 60 that is attachable to a skin surface of the patient. When used to facilitate CSF drainage, for example, the patch will be affixed to the patient’s back adjacent to or over the location where a spinal catheter emerges from the skin. The patient patch 60 may have a front surface 62 and a rear surface 64. The rear surface 64 of the patient patch 60 may have an adhesive that allows the patch 60 to be adhered to the patient by placing the rear surface 64 of the patient patch 60 directly on the skin of the patient. Alternatively, there may be anchors on the patch 60 usable to sew the patch 60 to the skin of the patient. The front surface 62 of the patch 60 can include mounting features configured to engage complementary mounting features on the back of the housing 10. As illustrated, connection tabs 66 are dimensioned and positioned on the patch 60 so as to be slidably received within the mounting slots 16 on the back of the housing 10 (shown in FIG. 8) when attaching the housing 10 to the patch 60, as described in detail below. The front surface 62 of the patch 60 also includes a catheter-connection assembly 70 positioned on the patch 60 for connecting and establishing closed fluid communication between the catheter line 30 and the inlet port 12 of the housing 10.

[0052] Referring to FIGS. 10-11C, the catheter-connection assembly 70 is a guillotine-type device that is configured to simultaneously cut and align the catheter line 30. The catheterconnection assembly 70 includes a base that is affixed to the front surface 62 of the patch 60, and a deflectable cutting arm 74 cantilevered from the base. A catheter-support body 72 having an opening 76 that extends longitudinally therethrough (and through which a catheter may be inserted) is disposed between the base of the catheter-connection assembly 70 and its cutting arm 74. Preferably, the catheter support body 72 is a block or other solid mass of viscoelastic material, such as silicone, that may be self-healing following a penetration, similar to a septum. This results in the catheter line 30 radially expanding the perimeter wall of the longitudinal opening 76 through the support body 72 to accommodate the catheter line 30 as it is inserted from the rear of the assembly 70 (adjacent to where the cutting arm 74 is cantilevered to its base), until a distal end 32 of the catheter line 30 emerges from the longitudinal opening 76 and extends beyond the cutting arm 74, as shown in FIG. 10 and discussed further below. It also results in the perimeter wall of the longitudinal opening 76 elastically and uniformly compressing radially inward against the circumference of the catheter line 30 extending through that opening 76.

[0053] In the illustrated embodiment, the catheter-connection assembly 70 is attached to the patch 60. Alternatively, it is contemplated that the catheter-connection assembly 70 may be provided separate from the patch 60. When supplied separately, the catheter-connection assembly 70 first is attached to the catheter line 30, and then both the catheter-connection assembly 70 and the catheter line 30 (as a combined assembly) are attached to the patch 60. The catheter-connection assembly 70 may be attached to the patch 60 by sliding the catheter-connection assembly 70 into engagement with tabs (not shown) on the patch 60 so that the catheter-connection assembly 70 is secured to the patch 60. Alternatively, the catheter-connection assembly 70 may be attached to the patch 60 via a snap fit connection, mechanical fasteners, press and/or friction fit, sutures, an adhesive, or some other suitable fastener.

[0054] In the illustrated embodiment, the cutting arm 74 is integrally hinged to the base of the catheter-connection assembly 70, and is movable from a first, as-supplied open position (shown in FIGS. 10 and 11B) to a second, engaged position (shown in FIGS. 11A and 11C) wherein the cutting arm 74 has been depressed toward that base. With the arm 74 in the open position, the catheter line 30 may be inserted through the longitudinal opening 76 in the body 72 until a distal end 32 of the catheter line 30 protrudes out of the body 72, forward of the cutting arm 74 as illustrated in FIGS. 10 and 1 IB. The cutting arm 74 is then moved to its engaged position wherein a blade 78 affixed to the arm 74 severs the terminal portion of the catheter line 30 including its distal end 32, forward ofthe catheter body 72. As shown in FIGS. 9 and 10, the base of the catheterconnection assembly 70 is positioned such that the cutting arm 74 moves toward the patch 60, or toward the patient, to move to the engaged position. In this configuration, the force from moving the cutting arm 74 to the engaged position may be transferred from the cutting arm 74 to the patient through the patch 60. In an alternative embodiment, the base of the catheter-connection assembly 70 may be positioned on a side of the catheter-connection assembly 70 such that the cutting arm 74 moves parallel to the front surface 62 of the patch 60. In this configuration, to move the cutting arm 74 to the engaged position, the cutting arm 74 can be pinched closed and the forces experienced by the patient may be minimized.

[0055] As shown in FIG. 11C, the resulting newly exposed distal end of the catheter line 30 remains snugly housed and fixed in position inside a forward end of the longitudinal opening 76 of the catheter body 72. When in the engaged position, the cutting arm 74 may compress the catheter-support body 72 (which preferably is elastically compressible) between the cutting arm 74 and the base of the catheter-connection assembly 70. The cutting arm 74 can be held in the engaged position by a snap-fit connection. Tabs 80 on the arm 74 are dimensioned and positioned to engage locating tabs 82 on the base of the catheter-connection assembly 70 to retain the cutting arm 74 in the engaged position once it has been depressed. The tabs 80 and locating tabs 82 may include ramps that cause either the tabs 80 or locating tabs 82 to deflect when the cutting arm 74 is moved to the engaged position. The cutting blade 78 itself can have an opening through which the forward end of the longitudinal opening in the catheter-support body 72 will be accessible to allow for connection to the inlet port 12 of the housing 10 as described below.

[0056] Referring now to FIGS. 12A to 14B, the process of attaching the housing 10 to the patient patch 60 is described. The housing 10 can be attached to the patch 60 by aligning and engaging the mounting features on the housing and the patch. As illustrated, the housing 10 can be attached to the patch 60 by sliding the housing 10 along the patch 60 in the direction indicated by the arrow in FIG. 12A so that the connection tabs 66 are received into the mounting slots 16 of the housing 10. As the housing 10 is slid on the connection tabs 66, the inlet port 12 of the housing 10, which is dimensioned and positioned to align with the longitudinal opening 76 through the catheter-support body 72, aligns with the with the catheter connection assembly 70 as shown in FIG. 12B. As shown in FIG. 13B, when the housing 10 is attached to the patch 60, the longitudinal opening 76 through the catheter-support body 72 sealingly engages the inlet port 12 of the housing 10 within and fluidly connects to the forward end of that longitudinal opening 76. The engagement of the opening 76 and the inlet port 12 establishes fluid communication between the freshly cut distal end of the catheter line 30 affixed therein, and the inlet port 12. In this manner, the combined snug affixation of the catheter line 30 within the catheter-support body 72, combined with the guillotine action of the cutting arm 74 and its blade 78, ensure reliable placement and affixation of the catheter line 30 to the inlet port 12 of the device when affixed to the patch 60. The connection tabs 66 on that patch 60 may include detents for locking the housing 10 to the patch 60 once the housing 10 is fully engaged to the newly cut end of the catheter line 30. Once connected, the drainage system is fluidly connected to the catheter line 30 so that fluid from the patient may be transferred to the reservoir 50.

[0057] The system may include elements to confirm the positioning and attachment of the housing 10 to the patch 60. For instance, as illustrated, the housing 10 may include visual indicators that align with visual indicators on the patch 60. The visual indicators may indicate where to start the engagement of the connection tabs 66 and the slots 16 and the location where the connection tabs 66 and the grooves are fully engaged and in locked position. Additionally, the patch 60 may include a magnet configured to interact with a sensor within the housing 10 to confirm the positioning of the housing 10 relative to the patch 60. [0058] The patch 60 may also protect the catheter line 30 from external tensile forces that otherwise might tug at the catheter tending to pull it from the skin-penetration wound. As described above, the housing 10 is secured to the patch 60 via the connection tabs 66. The connection tabs 66 and/or the adhesive on the patch 60 may be designed so that if the housing 10 is pulled on (e.g. accidentally snagged on an object), the housing 10 will pull away from the patch 60 with little pulling force applied to the catheter line 30. This will help reduce the likelihood that the catheter line 30 may pull out of the patient if the housing 10 is accidentally snagged or pulled from the patient. The patch 60 may also include perforation lines 68 (see Fig. 9) that extend the length of the patch 60. The perforation lines prevent forces that can pull off the device from pulling the catheter from the surgical site, by preventing the pulling force from being translated to the catheter connection assembly 70 that holds the catheter line 30. If the housing 10 experiences a strong enough pulling force, the patch can tear along the perforation lines 68 and the middle part of the patch 60 having the catheter connection assembly 70 can remain on the patient. The patch 60 can also include a portion to wrap around the catheter to prevent the catheter line 30 from being pulled away from the body.

[0059] To provide flexibility to the patient and allow for different lifestyles and activities, alternative attaching or suspending means may be used to secure the housing 10 to the patient. Therefore, it is contemplated that other mounting or suspending arrangements, e.g. adhesives, straps, carrying cases/bags, or some other suitable mounting or suspending solution may be used to secure the housing 10 to the patient. The housing 10 may be worn around the torso of the patient. For instance, a belt can be provided with a pocket configured to hold the housing 10 or a mount configured to engage the mounting slots 16 on the housing 10. The belt with a pocket configured to hold the housing 10. The housing 10 can include a clip configured to attach to the patient or an article of clothing worn by the patient. For instance, the clip on the housing can attach to a belt, a pocket, the waistband of an article of clothing, or some other suitable article of clothing worn by the patient. Alternatively, the patient can wear a lightweight vest with a pocket configured to hold the system or a mount configured to engage the mounting slots 16 on the housing 10. An adjustable shoulder strap can be used to suspend the housing 10 on the patient similar to a side bag. The housing 10 may include a mounting feature, like an eyelet, ring, or hole, to engage a lanyard or strap worn by the patient, for instance around the neck of the patient. The choice of mounting or suspending method can be determined on a patient-by-patient basis based on sound professional judgment made by the medical practitioner, specific requirements of the treatment regiment, patient preference, or patient comfort.

[0060] Referring to FIGS. 6 and 15A-19, the pump system 100 is shown. The pump system 100 includes a reciprocating motor 130, a pump switching unit (PSU) 140, and a diaphragm assembly 150. Referring to FIG. 17 and 18, the pump switching unit 140 includes a pinching drive shaft 144 within a switch housing 142. The pinching drive shaft 144 includes a first hammer 146 extending radially outward from the shaft 144 and a second hammer 148 extending radially outward from the drive shaft 144 opposite the first hammer 146. The pinching drive shaft 144 is driven by the reciprocating motor to rotate the pinching drive shaft 144 between a first rotational position and a second rotational position within the switch housing 142. Referring to 15A, 15B, and 19, the diaphragm assembly 150 includes a first chamber 152 on one side of a flexible membrane 151 and a second chamber 154 on an opposite side of the flexible membrane 151. The first chamber 152 and the second chamber 154 can be coupled together by snap fit, adhesive, or mechanical fasteners. A first port 152a and a second port 152b are connected to the first chamber 152 and a third port 154a and a fourth port 154b are connected to the second chamber 154. The pump system 100 may be a passive flow system. The flow of fluid can be generated by gravitational forces and/or from a pressure difference between internal fluid pressure from the patient and atmospheric pressure. For instance, the flow of CSF can be generated by the pressure difference between intracranial pressure and atmospheric pressure.

[0061] An inlet line 112 (partially obstructed in FIG. 6) extends from the inlet port 12 of the housing 10 and connects to an inlet tube 116 that is fluidly connected to both the first port 152a and the third port 154a via lines 156a and 158a respectively, as shown in FIGS. 15A and 15B. An outlet line 114 extends between the outlet port 14 of the housing and an outlet tube 118 that is fluidly connected to both the second port 152b and the fourth port 154b via lines 156b and 158b respectively, as shown in FIGS. 6, 15 A, and 15B. Thus, it will be appreciated that both the inlet line 112 and the outlet line 114 connect to and are in fluid communication with the first chamber 152 and the second chamber 154. The inlet line 112 connects to the first port 152a of the first chamber 152 via line 156a and to the third port 154a of the second chamber 154 via line 158a. The outlet line 114 connects to the second port 152b of the first chamber 152 via line 156b and to the fourth port 154b of the second chamber 154 via line 158b. [0062] As previously described, the reciprocating motor 130 is coupled to the pinching drive shaft 144 to rotate the drive shaft 144 within the switch housing 142 of the PSU 140. As illustrated, the drive shaft 144 can be separate from the reciprocating motor 130. The drive shaft 144 can include a spline to engage the output shaft of the motor 130. The drive shaft 144 can be press fit or mechanically fastened to the output shaft. Alternatively, the drive shaft 144 can be an output shaft integrated with the reciprocating motor 130. As illustrated in FIGS. 6, 15A, 15B, and 16, the lines 156a, 156b, 158a, and 158b extend through the switch housing 142 and can been engaged by the first hammer 146 or the second hammer 148. As shown in FIG. 15A, the line 156a and the line 156b extends through the switch housing 142 so that the first hammer 146 alternately compresses (i.e. pinches shut) the line 156a and the line 156b. When the first hammer 146 compresses the line 156a, the line 156a is pinched closed such that fluid communication from the inlet line 112 to the first chamber 152 is interrupted while fluid communication from the outlet line 114 to the first chamber 152 is allowed. Similarly, when the first hammer 146 compresses the line 158a, fluid communication from the inlet line 112 is allowed to the first chamber while fluid communication from the outlet line 114 to the first chamber 152 is interrupted.

[0063] As shown in FIG. 15B, the line 158a and the line 158b extends through the switch housing 142 so the second hammer 148 alternately compresses (i.e. pinches shut) the line 158a and the line 158b. When the second hammer 148 compresses the line 158a, fluid communication from the inlet line 1 12 to the second chamber 154 is interrupted while fluid communication from the outlet line 114 to the second chamber 154 is allowed. Similarly, when the second hammer 148 compresses the line 158b, fluid communication from the inlet line 112 is allowed to the second chamber 154 while fluid communication from the outlet line 114 to the second chamber 154 is interrupted.

[0064] Turning to FIGS. 20A and 20B, the operation of the reciprocating motor 130 and PSU 140 is schematically illustrated. The reciprocating motor 130, the drive shaft 144, and its associated hammers 146, 148 are configured to reciprocally move between a first position schematically illustrated in FIG. 20A and a second position schematically illustrated in FIG. 20B. When the motor 130 is in the first position, the first hammer 146 compresses the line 156a and the second hammer 148 compresses the line 158b. In this position, fluid communication is established between the inlet line 112 and the second chamber 154, and fluid communication separately is established between the outlet line 1 14 and the first chamber 152. When the motor 130 is in the second position, the first hammer 146 compresses the line 156b and the second hammer 148 compresses the line 158a. In this position, fluid communication is established between the inlet line 112 and the first chamber 152, and fluid communication separately is established between the outlet line 114 and the second chamber 154.

[0065] When the reciprocating motor 130 and PSU 140 are in the first position in FIG. 20A, in a fluid-drainage mode of operation such as when it is desired to drain CSF, fluid pressure provided by the patient forces fluid into the second chamber 154 and causes the flexible membrane 151 to deflect toward the first chamber 152. Fluid in the first chamber 152 is forced out of the first chamber 152 through the outlet line 114 to the reservoir 50. When the reciprocating motor 130 and PSU 140 are in the second position in FIG. 20B, fluid pressure provided by the patient forces fluid into the first chamber 152 and causes the flexible membrane 151 to deflect toward the second chamber 154. Fluid in the second chamber 154 is forced out of the second chamber 154 through the outlet line 114 to the reservoir 50.

[0066] The controller 300 is programmed to control the operation of the reciprocating motor 130 to facilitate alternate filling and draining of the opposing chambers 152 and 154 according to a predetermined program in order to meter the rate of fluid drainage. For example, if each chamber 152, 154 has a maximum total volume of 0.5 cc and the controller 300 is programmed to reciprocate the motor every five minutes, then the maximum possible rate of CSF drainage from the patient will be 6 cc per hour (i.e. no more than 0.5 cc every five minutes). Moreover, the duration of permitted drainage also may be controlled; for example, the controller 300 may be programmed to successively actuate the motor 130 between the first position and the second position for a predetermined period of time after which it stops and further drainage is prevented. The controller 300 may also be programmed to actuate the motor 130 according to a predetermined duty cycle, i.e., a fixed number of such oscillations per hour or per day. These oscillations cause the first chamber 152 and the second chamber 154 to alternately fill with fluid from the patient and to alternately discharge the fluid to the reservoir 50. In particular, as the first chamber 152 fills with fluid from the patient, the second chamber 154 discharges fluid to the reservoir 50. Similarly, as the first chamber 152 discharges fluid to the reservoir 50 the second chamber 154 fills with fluid from the patient. By adjusting the speed at which the reciprocating motor 130 moves, the controller 300 may adjust the rate at which fluid is drained from the patient and supplied to the reservoir 50. Alternatively, in an infusion mode the rate of infusion can be similarly metered, albeit with flow occurring in the opposite direction.

[0067] Returning to FIGS. 6 and 15B, a port 162 of the diaphragm assembly 150 is connected via a line 164 to a pressure sensor 166. The pressure sensor 166 continuously monitors the pressure of the fluid in the second chamber 154. This monitored pressure may be used to infer the cerebrospinal fluid (CSF) pressure of the patient. For example, the pressure sensor 166 may continuously transmit information to an external device, e g. a smartphone, smart device, personal computer, or some other suitable electronic device. The pressure reading output may be given as an absolute value and an intracranial pressure may be indirectly calculated and calibrated based on the patient’s dimensions and orientation (the latter as discussed below).

[0068] The pump assembly 100 may be configured to prevent operation of the pump assembly 100 at a pressure below a lower threshold of acceptable physiologic CSF pressure. The pump may operate, although with diminishing flow rate, at a pressure lower than a desired lower threshold of acceptable physiologic CSF pressure because of the hydrostatic pressures inside the pump system 100 and due to capillary effects. In one embodiment, a drip chamber 170, shown in FIGS. 21 and 22, may be provided in the system between the diaphragm assembly 150 and the outlet 14 of the housing. The drip chamber 170 is designed to allow the ambient air pressure to exist inside the drip chamber 170. As an example, when a drip chamber 170 is in fluid communication with the pump assembly 100, fluid may be prevented from flowing through the pump assembly when the CSF pressure at the inlet is 6 cmH20 or lower. The drip chamber 170 includes an inlet 172 that is in fluid communication with an outlet pipe 118 so that the inlet 172 is in fluid communication with lines 156b and 158b. The drip chamber 170 further includes an outlet 174 that is in fluid communication with the outlet line 114 and outlet 14 of the housing. Accordingly, the drip chamber 170 can receive fluid from the diaphragm assembly 150 through lines 156b and 158b, and the fluid can continue to flow through the outlet 174 to the outlet 14 of the housing 10 through the outlet line 114. The drip chamber 170 includes an air vent 176 that is open to air to stop the extremely slow fluid drip due to pressure differential below the desired pressure threshold and due to capillary action. The drip chamber 170 may be placed at the highest point within the housing near to the outlet pipe 118 of the pump assembly 100. It is contemplated that the ambient air pressure in the drip chamber 170 can be also facilitated through use of a selectively permeable membrane, which allows air to permeate, but not liquid.

[0069] To provide an accurate estimate of a supine position CSF pressure when the patient is not supine, the controller 300 also includes an orientation sensor (not shown) configured to provide a signal to the controller that is indicative of the patient’s orientation. The orientation sensor may be an accelerometer. It is known that 5-15 cmFhO of CSF pressure is average when a patient is supine, i.e., lying flat face upward. Draining the patient below 5 cmFbO of pressure in that position typically is undesirable. When the patient stands up, the pressure sensor readings include an additional pressure head, e.g., 60 cmFhO of measured pressure would correlate to 10 cmFCO of pressure when supine (due to about 50 crnkhO hydrostatic pressure head in this example based on the height of the patient). The controller 300 is programmed to use the signals from the orientation sensor to determine the patient’s orientation and the signals from the pressure sensor 166 to adjust or even stop the draining of fluid from the patient upon reaching a bottom threshold of acceptable physiologic CSF pressure based on the then-effective orientation of the patient. It is contemplated that the controller 300 may provide signals indicative of the orientation of the patient to an external device, e.g. a smartphone, to allow for tracking of the patient’s movement. The orientation sensor can detect a variety of positions including but not limited to prone and supine positions, Fowler’s position, sitting up, and standing upright.

[0070] It is contemplated that the diaphragm may be structurally designed to have a minimal activation pressure below which the diaphragm will not be actuated. This minimal activation pressure may be used to prevent the passage of CSF fluid below 5 cmFhO of CSF pressure. For example, the elasticity of the diaphragm may be selected so that it will not be readily deflected by differential pressures below a particular threshold.

[0071] It is contemplated that the ambulatory drainage system may include one or more check valves. As illustrated, a valve 26, for instance a one-way valve, is provided between the inlet port 12 and the inlet line 112 for allowing fluid flow in one direction through the system and/or for preventing operation of the system below a predetermined pressure. It will be appreciated that additional valves may be used in the system, or the valve may be in fluid communication with the pump assembly 100 in another location, for instance between the outlet port 14 and the outlet line 114.

[0072] While the pump assembly 100 is operating, the fluid being drained may follow the following path. The fluid enters the housing from the catheter line 30 through the inlet port 12 and check valve at the inlet port 12 and flows into the inlet line 112. The inlet line 112 is in fluid communication with both lines 156a and 158a to allow the fluid to flow from the inlet line 112 into either the first chamber 152 or the second chamber 154 depending on the position of the reciprocating motor 130 and the pump switching unit 140. The fluid may then flow from either the first chamber 152 or the second chamber 154 through lines 156b or 158b to the outlet pipe 118. In embodiments having a drip chamber 170, the fluid can flow from the outlet pipe 118 to the inlet 172 of the drip chamber 170. The fluid may flow out of the drip chamber 170 through the outlet 174 of the drip chamber 170, through the outline line 114 to the outlet port 14 and ultimately into the reservoir 50. In embodiments without a drip chamber, the fluid can flow from the outlet pipe 118 through the outlet line 114 to the outlet port and ultimately into the reservoir.

[0073] While it is contemplated that the ambulatory drainage system will communicate with an external electronic device, the housing 10 may contain various user interface and user feedback elements to provide control of the system and provide user feedback regarding the status of the system in addition to or alternative to the external electronic device. For instance, the housing 10 may include feedback elements like a buzzer or speaker to provide audible feedback, a vibrating motor configured to vibrate the housing to provide haptic feedback, or at least one LED or a display, like an LCD/LED display, to provide visual feedback. These feedback elements can provide information like operating status of the pump, battery life, confirmation of proper attachment of the housing 10 to the patch 60, confirmation of proper attachment of the reservoir 50 to the housing 10, or any other status errors. The housing 10 can further include buttons, switches, a touchscreen interface, or other suitable control elements to control the function of the system. These feedback and control elements can communicate with and controlled by the controller 300 within the housing 10.

[0074] The controller 300 may run the system in several modes. The controller 300 may run the system in a standby mode when the housing is placed on the patient without a reservoir 50. When the controller 300 recognizes that a reservoir 50 has been attached, the controller 300 can run the system in a running mode in which fluid is drained from the patient. During either mode, the controller 300 monitors the connection of the housing 10 to the patch 60 and the connection of the reservoir 50 to the housing 10. The controller 300 can also monitor battery level and the reservoir capacity. If the battery level is low, the reservoir is filled to capacity, or the device is not properly installed, the controller 300 can provide alerts through the external electronic device or the feedback elements in the housing. Furthermore, the controller 300 can control the drainage rate depending on the size of the reservoir 50 attached to the housing 10 or the position of the patient. The controller 300 can validate the number of uses of a specific reservoir 50 and prevent drainage of fluid if a reservoir has been used more than a predetermined number of drainage cycles. For instance, the controller 300 may prevent drainage to a reservoir 50 if it has been filled in two previous drainage cycles. The controller 300 can adjust the operation of the motor 130 and the PSU 140 if pressure is too high/low or if patient is in a position that might be harmful.

[0075] As previously described, the controller 300 may transmit data to an external device. The controller may be configured to transmit telemetry communication of CSF pressure, telemetry communication of patient orientation relative to vertical, telemetry communication of device status (on/standby/disabled/blocked/canister full), and estimated intracranial pressure based on height of patient.

[0076] Turning to FIGS. 22 and 23, in an alternative mode of operation, the ambulatory drainage system as disclosed herein also can be used to facilitate metered infusion of medication or other therapeutic agents if operated in reverse compared to its function described above. Accordingly, the ambulatory system can be used as an infusion system. The system can be used to facilitate metered infusion of medication or other therapeutic agents if operated in reverse and while using an external source of pressurized fluid. For example, the reservoir 50 can be supplied charged with a therapeutic agent under pressure for infusion into a patient at a rate metered by reciprocation of the motor 130 discussed above. The external source of pressure could be a separate pump within the reservoir 50, or the reservoir itself could be pressurized similar to an aerosol pressure can. [0077] While using the system in a drug infusion mode, the reservoir 50 may be a replaceable cartridge and fdled with a drug to be infused. The replaceable cartridge may be attached to the system (similar to method previously described for the reservoir 50). It will be appreciated that various drugs and therapeutic agents could be provided in the cartridge depending on the treatment being administered. The replaceable cartridge may include a chip or other device that provides an indication to the system controller that the system is to be used to infuse a drug instead of drain fluid from a patient. Various indicators can be included on the reservoir to ensure the correct reservoir and, therefore the proper drug or therapeutic agent, is being administered. For instance, the reservoir may include a barcode, smart QR code (illustrated in FIG. 3 A), RFID chip, or similar device that can be scanned to confirm the contents of the reservoir and for tracking purposes. Additionally, the reservoir 50 itself may act as an indicator based on the color, shape, or size of the reservoir and any external markings on the reservoir 50.

[0078] When the system is used as a drug infusion system, the direction of fluid flow is reversed, as compared to the previously described drainage system, by adding a controlled source of pressure to the replaceable cartridge containing the drug to be infused. The supplied pressure would slightly exceed the pressure inside the patient’s spinal column and the check valve in the housing 10 would be deactivated. The pressure differential between the replaceable cartridge and the spinal column can also be controlled via a custom pressure regulator. The catheter to the patient may be primed with the drug to be infused. The length of the catheter would need to be known so that drug delivery is possible in a controlled volume. Additionally, it is contemplated that the direction of fluid flow through the catheter may be temporarily reversed, or the catheter may be aspirated to remove all of the drug from the catheter. This would allow the catheter to be cleared of the drug in cases where a different drug is to be infused or a rate of delivery is changed.

[0079] The invention has been described with reference to example embodiments. Modifications and alterations thereto will be evident to persons of skill in the art upon a reading and understanding this specification.

Claims

What is claimed is:

1. A device for controlled drainage or delivery of a fluid from or to a patient, the device comprising: a first line connected to a first chamber; a second connected to a second chamber; a third line connected to the first chamber; a fourth line connected to the second chamber; and a motor actuatable between: a first position wherein a first hammer connected to the motor compresses the first line and a second hammer connected to the motor compresses the fourth line thereby hindering flow through each of the first and fourth lines, but wherein flow is permitted through each of the second and third lines, and a second position wherein the first hammer compresses the third line and the second hammer compresses the second line thereby hindering flow through each of the second and third lines, but wherein flow is permitted through each of the first and fourth lines.

2. The device of claim 1, further comprising: a first port; a second port; and a diaphragm separating the first chamber from the second chamber, the diaphragm being deflectable toward a wall of the first chamber wherein the first chamber contracts and the second chamber expands, and oppositely toward a wall of the second chamber wherein the second chamber contracts and the first chamber expands; said first line connecting the first port to said first chamber; said second line connecting the first port to said second chamber; said third line connecting said second port to said first chamber; and said fourth line connecting said second port to said second chamber; wherein when said motor is in said first position, fluid communication is hindered between the first port and the first chamber, and separately is hindered between the second port and the second chamber; and wherein when said motor is in said second position, fluid communication is hindered between said second port and said first chamber, and separately is hindered between said first port and said second chamber.

3. The device of claim 2, further comprising a catheter-connection assembly for securing a catheter line to one of the first port or the second port.

4. The device of claim 2, wherein the first and second ports are formed in a housing that encloses the diaphragm chamber and the motor.

5. The device of claim 4, further comprising a reservoir adapted to be placed in reversible fluid communication with the first port, said second port being adapted to be placed in fluid communication with a catheter line configured to deliver fluid to or from a patient.

6. The device of claim 5, wherein the reservoir is removably attachable to the housing.

7. The device of claim 6, the reservoir further comprising locking tabs configured to engage with the housing to removably attach the reservoir to the housing.

8. The device of claim 1, further comprising a drip chamber in fluid communication with the first chamber and the second chamber, the drip chamber having a vent exposed to an ambient pressure.

9. The device of claim 4, further comprising a controller in said housing and configured to: actuate the motor between the first position and the second position, communicate data to an external electronic device.

10. The device of claim 9, further comprising a pressure sensor in said housing and configured to detect a fluid pressure within one or both of said first and second chambers, wherein the controller is further configured to actuate said motor based on the detected fluid pressure.

11. A system for controlled drainage or delivery of a fluid from or to a patient, the system comprising: a metering device configured to control a flow of fluid from or to the patient and comprising a housing, said housing having a first port connectable to provide communication with a catheter for delivery of fluid to or from the patient, and a second port connectable to provide communication with a reservoir for said fluid; and a patch adapted to be affixed to a patient and having a first side configured to face the patient in-use and a second side opposite the first side; wherein the housing of the metering device is configured to be attached to the second side of the patch.

12. The system of claim 11, the patch further comprising a connecting tab and the metering device further comprising a groove on said housing, wherein the connecting tab and the groove slidingly engage each other to secure the metering device to the patch in a locked position.

13. The system of claim 11, wherein the first side of the patch comprises adhesive configured to attach the patch to the patient.

14. The system of claim 11, the patch further comprising a catheter connection assembly comprising a viscoelastic body having a longitudinal opening therethrough adapted to receive said catheter, and a cutter adapted to cut an end of said catheter to yield a newly exposed distal end thereof disposed within said longitudinal opening.

15. The system of claim 14, the catheter connection assembly further comprising a deflectable arm movable from an open position in which the catheter can be passed through said longitudinal opening, and an engaged position in which said cutter is engaged to cut said end of the catheter to yield said newly exposed distal end thereof within the longitudinal opening.

16. The system of claim 15, the patch further comprising a connecting tab and the metering device further comprising a groove on said housing, wherein the connecting tab and the groove slidingly engage each other to secure the metering device to the patch in a locked position wherein the longitudinal opening of said viscoelastic body sealingly engages the first port of said housing thereby establishing fluid communication between said first port and the newly exposed distal end of the catheter within said viscoelastic body.

17. The system of claim 11, said metering device further comprising a diaphragm separating a first chamber from a second chamber, the diaphragm being deflectable toward a wall of the first chamber wherein the first chamber contracts and the second chamber expands, and oppositely toward a wall of the second chamber wherein the second chamber contracts and the first chamber expands.

18. The system of claim 17, further comprising: a first line connecting the first port to the first chamber; a second line connecting the first port to the second chamber; a third line connecting the second port to the first chamber; a fourth line connecting the second port to the second chamber; and a motor actuatable between: a first position wherein a first hammer connected to the motor compresses the first line and a second hammer connected to the motor compresses the fourth line thereby hindering fluid communication between the first port and the first chamber, and separately hindering fluid communication between the second port and the second chamber, and a second position wherein the first hammer compresses the third line and the second hammer compresses the second line thereby hindering fluid communication between the second port and the first chamber, and separately hindering fluid communication between the first port and the second chamber.

19. A method for draining fluid from an ambulatory patient, the method comprising: affixing a patch to a patient; connecting a metering device to the patch, the metering device having a first port configured to engage a catheter from the patient, a pumping assembly configured to control flow of fluid from the catheter, and a second port in fluid communication with a reservoir configured to store drained fluid; detecting a fluid pressure of fluid being metered by the metering device and correlating the detected fluid pressure to a pressure of fluid within a body cavity of the patient from which the fluid is being drained; and adjusting a fluid drainage rate based on the correlated fluid pressure in said body cavity.

20. The method of claim 19, further comprising detecting a position of the patient with a positioning sensor of the metering device; and further adjusting the fluid drainage rate based on data relating the detected position of the patient.