WO2008016195A1

WO2008016195A1 - An endoscope and a method for operating it

Info

Publication number: WO2008016195A1
Application number: PCT/KR2006/003040
Authority: WO
Inventors: Han Bo Shim; Won Woo Cho; Jung Jin Hwang; Kwang Seop Kim; Young Dae Seo
Original assignee: Intromedic Co Ltd
Current assignee: Intromedic Co Ltd
Priority date: 2006-08-02
Filing date: 2006-08-02
Publication date: 2008-02-07
Anticipated expiration: 2009-02-02

Abstract

An endoscope (100) is disclosed. The endoscope includes a ring-shaped light source (20) mounted in an endoscope body (10) for projecting light having uniform spatial distribution to a subject. According to the present invention, light emitted from the light source (20) is uniformly projected to the subject for a long period of time. Consequently, the present invention provides the effect of acquiring high-quality information.

Description

[DESCRIPTION]

AN ENDOSCOPE AND A METHOD FOR OPERATING IT

Technical Field The present invention relates to an endoscope, and more particularly, to a capsule-type endoscope. Background Art

An endoscope is an instrument that can be inserted into internal organs, lesion of which cannot be observed without a surgical operation or a postmortem examination, to observe the internal organs. The endoscope may be classified as a direct delivery endoscope having a single tube to directly observe internal organs with the naked eye, an endoscope using a lens system, an endoscope having a camera that can be directly inserted into the internal organs (a stomach camera) , or a fiber scope using glass fiber. An endoscope for digestive organs, especially a stomach, has been developed to a high degree. For this reason, the endoscope generally refers to the stomach camera or the stomach fiber scope. However, patients suffer pain and feel uncomfortable when the patients are examined using the above-specified endoscopes, and therefore, most of the patients wish to undergo medical treatment by medicine instead of the endoscope examination. For this reason, a capsule-type endoscope has been developed to remedy the above-mentioned problems and to use for diagnosis of disease in the small intestine, which is the longest among the digestive organs.

The capsule-type endoscope is a subminiature endoscope which can be swallowed by a patient. When the patient swallows the capsule-type endoscope like a medicinal pill, the capsule- type endoscope moves along the digestive organs, such as the stomach or the small intestine such that a doctor can directly observe the internal parts of the digestive organs through a video screen or a computer monitor. However, the conventional capsule-type endoscope has the following problems.

The capsule-type endoscope must acquire image information in the human body. Consequently, the capsule-type endoscope needs a light source. At the present time, an LED is used as the light source. The LED has high light efficiency, and therefore, it is suitable for a product having relatively small power consumption, such as the endoscope. Furthermore, the LED has high directionality, and therefore, a larger amount of emitted light can be transmitted to the subject, and a large amount of light can be emitted with low voltage. However, the light is not uniformly projected to the subject, i.e., the light is concentrated on only a portion of the subject, due to the directionality of the LED. As a result, image information acquired by the camera may be distorted. In addition, use of a plurality of LEDs as the light source may be considered. However, the capsule-type endoscope is operated in a wireless fashion, and therefore, the plurality of LEDs cannot be used for a long period of time due to limited power. Disclosure of Invention An object of the present invention devised to solve the problem lies on an endoscope that is capable of uniformly projecting light to a subject, thereby acquiring high-quality image information.

Another object of the present invention devised to solve the problem lies on an endoscope having a light source that is capable of uniformly projecting light to a subject for a long period of time with limited power.

The object of the present invention can be achieved by providing an endoscope comprising: a ring-shaped light source mounted in an endoscope body for projecting light having uniform spatial distribution to a subject.

Preferably, the endoscope further comprises: a reflecting plate disposed between the ring-shaped light source and the endoscope body for reflecting light emitted from the ring- shaped light source to the front of the endoscope body.

Preferably, the ring-shaped light source is a light emitting diode (LED) light source. More preferably, the LED light source includes: at least one blue-light LED mounted at the front surface of the endoscope body; and a yellow fluorescent substance layer formed on the at least one blue- light LED .

Preferably, the LED light source includes: light sources for emitting red, green, and blue lights, lights emitted from the respective light sources being combined into a white light, which is projected to the subject.

Preferably, the ring-shaped light source is an organic electroluminescence (EL) light source. More preferably, white light is emitted from the organic EL light source.

In another aspect of the present invention, provided herein is a method for operating an endoscope, comprising: emitting blue light from at least one LED light source and projecting the emitted blue light to a yellow fluorescent substance layer; and exciting the yellow fluorescent substance layer using the blue light, such that white light is emitted from the yellow fluorescent substance layer, and projecting the emitted white light to a subject.

In another aspect of the present invention, provided herein is a method for operating an endoscope, comprising: selecting one or two LED light sources from LED light sources emitting red, green, and yellow lights; and emitting light from the selected LED light sources to project the emitted light to a subject.

In a further aspect of the present invention, provided herein is a method for operating an endoscope, comprising: projecting white light from a ring-shaped organic EL light source to a subject; and acquiring image information of the subject by means of an image information acquisition unit.

According to the present invention, light emitted from the light source, which is mounted in the endoscope, is uniformly projected to a subject for a long period of time, and light is uniformly illuminated on the subject. Consequently, it is possible to acquire high-quality image information. Also, only a specific color can be projected to the subject. Consequently, it is possible to intensively acquire image information of a specific region. Furthermore, it is possible to use an infrared LED light source, whereby the driving time for the capsule-type endoscope is increased. Brief Description of Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a sectional view illustrating an endoscope according to an embodiment of the present invention.

FIG. 2 is a view illustrating a first embodiment of the light source shown in FIG. 1.

FIG. 3 is a view illustrating a second embodiment of the light source shown in FIG. 1. FIG. 4 is a view illustrating a third embodiment of the light source shown in FIG. 1.

FIG. 5 is a perspective view illustrating a fourth embodiment of the light source shown in FIG. 1.

FIG. 6 is a sectional view taken along line I-I' of FIG. 5.

FIG. 7 is a view illustrating a method for operating an endoscope according to an embodiment of the present invention. Best Mode for Carrying Out the Invention

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. For convenience of easy description, the same components of the present invention as those of the conventional art are denoted by the same terms and the same reference numerals, and a detailed description thereof will be omitted.

The endoscope according to the present invention includes a light source for uniformly projecting light to a subject.

Preferably, the light source is formed in a ring shape.

Specifically, the ring-shaped light source is mounted at the front surface of an endoscope body, and an aperture is formed in the center of the ring-shaped light source. In the conventional art, a spot-type light source including a light emitting diode (LED) is used. As a result, the distribution of light projected to a subject is not uniform. In order to solve this problem, the number of the spot-type light source may be increased; however, the power consumption is excessively increased, which is not preferable.

According to the present invention, on the other hand, the light source is formed in a ring shape. In this case, light emitted from the ring-shaped light source is dispersed in every direction while the light propagates to a subject. As a result, the light is uniformly distributed, and therefore, the light is uniformly projected to the subject. After the subject absorbs the light, the subject emits a predetermined amount of the light. Consequently, the emitted light is introduced into a camera mounted in the endoscope body through the above-described aperture and stored in the camera as image information.

FIG. 1 is a sectional view illustrating an endoscope according to an embodiment of the present invention. Hereinafter, the endoscope according to the present invention will be described in detail with reference to FIG. 1.

Preferably, the endoscope 100 according to the present invention is a wireless capsule-type endoscope. Specifically, the endoscope 100 includes an endoscope body 10, a ring-shaped light source 20, a camera 30, a lens 40, an aperture 50, and an image processing unit 60. The endoscope body 10 serves to receive the camera 30 in an integrated fashion. The endoscope body 10 may be constructed in other types different from the capsule type so long as internal components of the endoscope can be mounted in the endoscope body 10. The endoscope body 10 may have a circular or polygonal section. However, it is preferable that the endoscope body 10 be constructed in a capsule structure having a circular section in consideration of ease of used or removal of pain during the introduction of the endoscope body 10 into the human body.

The camera 30 serves to photograph images of a subject, such as digestive organs of the human body. Preferably, an image sensor, such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) , is used as the camera 30, although other different optical devices may be used as the camera 30. The lens 40 is a device for projecting light emitted from the subject and incident through the aperture 40 to the camera 30. As shown in FIG. 1, the lens 40 is a convex lens. However, any other lens may be used so long as the focus of the image of the subject can be adjusted by the lens .

The aperture 50 is a space defined in the ring-shaped light source 20. In this embodiment, the aperture 50 is formed in the shape of a circle, although the aperture 50 may be formed in other different shapes, such as a polygon. Furthermore, it is preferable to construct the aperture 50 by forming a transparent substrate in the inner space of the ring-shaped light source in order to prevent foreign matter from being introduced into the endoscope body. The image processing unit 60 serves to transmit image information obtained by the camera 30 or to process the image information according to the command of a user. Specifically, the image process unit 50 may transmit the image of the subject to a server of the user without modification, or may process, for example, compress the image of the subject and transmit the compressed image of the subject. It is preferable that the image processing unit 60 have only the transmitting function in consideration of the fact that the capsule-type endoscope is small-sized and lightweight. In addition to the above-described components, it is preferable that the endoscope according to the present invention further include a driving unit for driving the camera 30, which is apparent to those skilled in the art to which the present invention pertains, and therefore, a further detailed description thereof will not be given.

Although not shown in the drawing, it is preferable that the endoscope further include a reflecting plate. Preferably, the reflecting plate is disposed between the ring-shaped light source 20 and the endoscope body 10 for reflecting light, emitted from the ring-shaped light source 20 and propagating to the endoscope body 10, to the front. The "front" means the direction in which most of light emitted from the ring-shaped light source 20 propagates. In other words, the "front" means the direction opposite to the direction in which the light emitted from the ring-shaped light source 20 propagates to the endoscope body 10. Preferably, the reflection plate is made of epoxy containing a material for easily reflecting light, such as glass. It should be noted, however, that the reflecting plate is not a requisite component of the endoscope in this embodiment. The reflecting plate serves to uniformly distribute the light when the light emitted from the ring-shaped light source 20 is excessively dispersed. Specifically, the reflecting plate, which is made of epoxy, is disposed in the front part of the endoscope body 10, which is made of polychlorinated biphenyl (PCB) , such that a small amount of light propagating from the ring-shaped light source 20 to the endoscope body 10 is reflected by the reflecting plate to control the intensity of illumination and the dispersion of the light. Preferably, the angle of the reflecting plate is adjusted to control the dispersion of the light.

Hereinafter, various different embodiments of the ring- shaped light source will be described. The ring-shaped light source is used to illuminate internal digestive organs of the human body and to photograph images of the internal digestive organs. Accordingly, it is preferable that the ring-shaped light source emit white light. When specific regions are illuminated and photographed, as will be described hereinafter, however, the ring-shaped light source may be constructed to emit visible rays of a specific wavelength range. The ring-shaped light source 20 is used to illuminate the subject. Consequently, it is preferable that the ring-shaped light source 20 be mounted at the front surface of an endoscope body 10. Of course, light emitted from the endoscope may be reflected and projected to a subject, or light incident from the subject may be reflected and projected to the camera. For a simplified structure, it is preferable to dispose the ring-shaped light source 20 in the same direction as the aperture, through which the image of the subject is introduced.

The space defined in the ring-shaped light source 20 constitutes the aperture 50, which is a channel for guiding the image of the subject- into the endoscope body. Also preferably, the ring-shaped light source 20 is an LED. As described above, the LED has high light efficiency, high directionality, and low power consumption. Consequently, the LED is preferable to use as the light source.

FIG. 2 is a view illustrating a first embodiment of the light source shown in FIG. 1. Hereinafter, the first embodiment of the ring-shaped light source will be described with reference to FIG. 2.

In this embodiment, it is preferable that the ring-shaped light source 22 be a single light source emitting white light. More preferably, the ring-shaped light source 22 is an LED. Specifically, white light is emitted from the ring-shaped light source 22, and is then uniformly projected to a subject. Preferably, the ring-shaped light source 22 comprises a single LED. However, it is also possible that a plurality of LED elements are disposed on a PCB substrate, and fluorescent substance is applied to the LED elements, whereby the light has uniform spatial distribution as in the single light source. FIG. 3 is a view illustrating a second embodiment of the light source shown in FIG. 1. Hereinafter, the second embodiment of the ring-shaped light source will be described with reference to FIG. 3.

In this embodiment, it is preferable that the ring-shaped light source comprise one or more LEDs 24 emitting blue light, and the respective blue-light LEDs 24 are constructed in a ring shape. The ring-shaped light source must be attached to the front surface of the endoscope body. Consequently, when the section of the endoscope body is a polygon or a circle, the blue-light LEDs are arranged in the shape corresponding to the polygon or the circle. Preferably, the blue-light LEDs 24 are arranged in a ring shape. This embodiment is also characterized by a yellow fluorescent substance layer 26 formed on the blue-light LEDs 24.

When voltage is applied to the blue-light LEDs 24, blue light is emitted from the blue-light LEDs 24. When the blue light is incident upon the yellow fluorescent substance layer 26, the yellow fluorescent substance layer 26 is excited, and therefore, white light is emitted from the yellow fluorescent substance layer 26. This embodiment has the same effect as the previous embodiment in which the white light is emitted from the single ring-shaped light source.

FIG. 4 is a view illustrating a third embodiment of the light source shown in FIG. 1. Hereinafter, the third embodiment of the ring-shaped light source will be described with reference to FIG. 4. In this embodiment, the ring-shaped light source comprises one or more white light sources 27. Preferably, each white light source 27 includes a red light source 27a, a green light source 27b, and a blue light source 27c. More preferably, the respective light sources are LEDs. Specifically, each white light source 27 includes R, G, and B light sources. When voltage is applied to the respective light sources, R, G, and B lights are emitted from the respective light sources. The emitted R, G, and B lights are combined into white light, which is projected to the subject. Lights emitted from the respective white light sources are combined, and the combined lights are uniformly projected to the subject while the combined lights have uniform spatial distribution.

Preferably, the red, green, and blue light sources are independently driven. When the respective light sources are independently driven, the respective light sources can perform the following operations.

When the respective light sources are independently- driven, it is possible to project only one of the red, green, and blue lights to the subject. For example, when only the red light is emitted, it is possible to increase efficiency for selecting intestinal hemorrhage and atrophy and to easily distinguish blood vessels. When only the green light is projected to the subject, it is possible to easily diagnose a normal mucous membrane in the stomach. When only the blue light is projected to the subject, it is possible to easily distinguish digestive fluids in the digestive organs.

When the red light, the green light, and the blue lights are independently emitted as described above, it is possible to project only one desired light to the subject, thereby more accurately acquiring image information of a lesion to be observed. In addition, it is also possible to simultaneously drive two or more of the light sources such that combined lights can be projected to the subject. Alternatively, only a blue light source and a yellow light source may be included in order to emit only the white light.

Also, the endoscope according to the above-described embodiment provides more excellent effects when an automatic diagnosis software is used instead of diagnosis of an expert, for example, a doctor. Specifically, when a specific color is emitted from the subject, such as the digestive organs, and therefore, the diagnosis region is prominent, voltage is applied to the specific-color light source so as to intensively project visible rays having a wavelength suitable to photograph the image of the diagnosis region. FIG. 5 is a perspective view illustrating a fourth embodiment of the light source shown in FIG. 1, and FIG. 6 is a sectional view taken along line I-I' of FIG. 5. Hereinafter, the fourth embodiment of the ring-shaped light source will be described with reference to FIGs. 5 and 6. This embodiment is characterized that organic electroluminescence (EL) is used as the ring-shaped light source. The organic EL is a device in which, when electric charge is injected to a light emitting layer formed between an electron injection electrode (a cathode) and a hole injection electrode (an anode) , electrons and holes are recombined in pairs, thereby emitting light. The organic EL is a display device that can be driven at low voltage and with low power consumption.

As shown in FIG. 5, the display surface of the organic EL 20 is formed in a ring shape, and light is emitted from the ring-shaped display surface of the organic EL 20. As shown in FIG. 6, an aperture 210 is formed in the center of the ring- shaped organic EL. In this embodiment, the organic EL is constructed in an upper light emitting structure. The organic EL includes a transparent substrate 220, an anode 230, a hole injection layer 240, a hole transport layer 250, a light emitting layer 260, an electron transport layer 270, an electron injection layer 280, and a cathode 290. The respective components of the organic EL are identical to the conventional components. As holes emitted from the anode 230 and electrons emitted from the cathode 290 are recombined, white light is emitted from the light emitting layer 260.

Hereinafter, the operation of the endoscope having the ring-shaped light source according to the fourth embodiment of the present invention will be described in detail.

White light emitted from the ring-shaped organic El light source is uniformly projected to a subject while the white light has uniform spatial distribution, thereby improving image information of the subject. The organic EL has rapid response time, high contrast ratio, wide field angle, and low power consumption. Consequently, the organic EL can be driven with low power consumption within short time to uniformly project light to an internal subject, such as digestive organs.

In another embodiment of the endoscope according to the present invention, an infrared LED may be used as the ring- shaped light source of the endoscope.

The capsule-type endoscope has a limited power source. As a result, output voltage inputted to the light source is decreased as time passes. Consequently, visible ray emitting LED stops operating because the LED requires high operating voltage, and therefore, it is not possible to photograph the subject. On the other hand, the infrared LED has low operating voltage, and therefore, the service life of the capsule-type endoscope can be increased. FIG. 7 is a view illustrating a method for operating an endoscope according to an embodiment of the present invention. Hereinafter, the method for operating the endoscope according to the present invention will be described with reference to FIG. 7. The illuminating operation of the endoscope according to the present invention is performed to project white light to a subject. Specifically, blue light is emitted from a blue light source (S710) , and the emitted blue light is projected to a yellow fluorescent substance (S720) . The yellow fluorescent substance is excited by the blue light. As a result, white light is emitted from the yellow fluorescent substance (S730) , and the emitted white light is projected to the subject. Preferably, the blue light source is an LED emitting blue light. The blue-light LED is an LED emitting visible rays having a wavelength of 400 to 450 nm. When the wavelength is shorter, it is more difficult to develop a compound semiconductor emitting light. For this reason, the blue-light LED has been developed recently. It is possible to realize true color by using the blue-light. A method for operating an endoscope according to another embodiment of the present invention includes selecting one or two light sources from light sources emitting red, green, and yellow lights, and emitting light from the selected light sources to project the emitted light to a subject. Preferably, each light source is an LED. In this embodiment, only one or two light sources are selected, and light emitted from the selected light sources is illuminated to the subject such that only lights having a specific wavelength can be projected to the subject. Consequently, as described above, it is possible to more accurately acquire image information of a specific lesion.

The endoscope operating method according to the present invention includes projecting white light from the ring-shaped organic EL light source to a subject and acquiring image information of the subject by means of an image information acquisition unit. The image information acquisition unit includes a camera and a lens. When light emitted from the subject is introduced through the aperture formed in the center of the ring-shaped organic EL light source, the focal distance is adjusted through the lens, and then, image information of the subject is stored in the camera, such as CCD or CMOS.

It is obvious that the above-described ring-shaped light source and the method for operating the same can be used in conventional endoscope in addition to the capsule-type endoscope. It is also obvious that the above-described ring- shaped light source and the method for operating the same can be applied to other technical fields in addition to the endoscope, i.e., a video camera that uniformly projects light to a subject and acquires image information of the subject. Furthermore, the endoscope according to the present invention can be used to photograph digestive organs of animals as well as to photograph the internal parts of the human body.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Industrial Applicability

According to the present invention, light is uniformly projected to a subject for a long period of time with limited power. Consequently, the present invention provides the effect of improving the performance of the capsule-type endoscope. Furthermore, an organic EL is used as the light source, and therefore, it is possible to uniformly project light to the subject. Consequently, the present invention provides the effect of acquiring high-quality information.

Claims

[CLAIMES]

1. An endoscope comprising: a ring-shaped light source mounted in an endoscope body for projecting light having uniform spatial distribution to a subject.

2. The endoscope according to claim 1, further comprising: an image information acquisition unit; and a data processing unit.

3. The endoscope according to claim 1, further comprising: a reflecting plate disposed between the ring-shaped light source and the endoscope body for reflecting light emitted from the ring-shaped light source to the front of the endoscope body.

4. The endoscope according to claim 2, wherein an image information acquisition unit includes: a camera; and a lens.

5. The endoscope according to claim 1, wherein the ring- shaped light source is a light emitting diode (LED) light source .

6. The endoscope according to claim 5, wherein the LED light source emits white light.

7. The endoscope according to claim 6, wherein the LED light source includes: at least one blue-light LED mounted at the front surface of the endoscope body; and a yellow fluorescent substance layer formed on the at least one blue-light LED.

8. The endoscope according to claim 6, wherein the LED light source includes: light sources for emitting red, green, and blue lights, lights emitted from the respective light sources being combined into a white light, which is projected to the subject.

9. The endoscope according to claim 8, wherein the light sources for emitting red, green, and blue lights are independently driven.

10. The endoscope according to claim 5, wherein the LED is an infrared LED.

11. The endoscope according to claim 1, wherein the ring- shaped light source is an organic electroluminescence (EL) light source.

12. The endoscope according to claim 11, wherein the organic EL light source includes a light emitting layer formed between a first electrode and a second electrode, and the organic EL light source is constructed such that electrons emitted from the first electrode and holes emitted from the second electrode are recombined in the light emitting layer, whereby white light is emitted from the light emitting layer.

13. The endoscope according to claim 12, wherein the light emitting layer emits the white light as the electrons and the holes are recombined.

14. The endoscope according to claim 12, wherein the organic EL light source further includes a hole injection layer and a hole transport layer for transmitting the electrons emitted from the first electrode to the light emitting layer.

15. The endoscope according to claim 12, wherein the organic EL light source further includes an electron injection layer and an electron transport layer for transmitting the holes emitted from the second electrode to the light emitting layer .

16. A method for operating an endoscope, comprising: emitting blue light from at least one LED light source and projecting the emitted blue light to a yellow fluorescent substance layer; and exciting the yellow fluorescent substance layer using the blue light, such that white light is emitted from the yellow fluorescent substance layer, and projecting the emitted white light to a subject.

17. A method for operating an endoscope, comprising: selecting one or two LED light sources from LED light sources emitting red, green, and yellow lights; and emitting light from the selected LED light sources to project the emitted light to a subject.

18. A method for operating an endoscope, comprising: projecting white light from a ring-shaped organic EL light source to a subject; and acquiring image information of the subject by means of an image information acquisition unit.

19. The method according to claim 18, wherein the acquiring image information includes projecting light emitted from the subject to a camera through a lens.