Cannula for ercp and endoscopic system

Abstract

[Problem] To provide: a cannula that can be easily inserted into a common bile duct or a pancreatic duct via a major duodenal papilla; and an endoscopic system provided with such a cannula. [Solution] A second camera 30 of a cannula 12 captures an image of the entrance of a common bile duct or a pancreatic duct in a state where the second camera 30 is inserted from the opening of a major duodenal papilla. A transparent shield 124 provides a cavity around the second camera 30 and ensures a field of view Vf of the second camera 30 in a state where the transparent shield 124 is inserted from the opening. The shield 124 has a convex surface 124c around the central axis CA of the field of view Vf of the second camera 30. The portion having the convex surface 124c has a uniform thickness. A guide wire 15 is configured to advance within the field of view Vf of the second camera 30.

Description

ERCP cannulas and endoscopic systems

[0001] The present invention relates to a cannula for inserting a guidewire via the major duodenal papilla, and an endoscope equipped with the cannula.

[0002] Endoscopic retrograde cholangiopancreatography (ERCP), used for the diagnosis and treatment of common bile duct stones and biliary tract cancer, is an examination method in which a contrast tube is inserted into the bile duct through the major papilla in the descending portion of the duodenum, and a contrast agent is injected from the tip of the tube to take X-ray images of the bile duct. This method allows the bile duct to be visualized on X-ray, enabling the diagnosis of gallstones, biliary tract cancer, and other conditions. In ERCP examinations, therapeutic ERCP may be performed following such diagnostic ERCP. In therapeutic ERCP, procedures such as surgical removal of gallstones from the common bile duct through the major papilla or placement of a stent in narrowed areas of the bile duct may be performed.

[0003] For example, in the overview of ERCP described in Patent Document 1 (Japanese Patent Publication No. 2023-75036), the endoscope is first inserted from the oral cavity through the esophagus and stomach to the descending portion of the duodenum. Next, the position of the tip of the endoscope is adjusted so that the major papilla is within the imaging range of the endoscope's (side-viewing endoscope) camera. Subsequently, after observing the shape of the opening of the major papilla using the endoscope, a cannula is extended from the tip of the endoscope, and the tip of the cannula is inserted from the opening of the major papilla towards the 11 o'clock position (patient's head side) at the top of the screen. The bile duct and pancreatic duct merge within the major papilla, but when diagnosing and treating biliary tract diseases, it is necessary to selectively adjust the angle of the cannula towards the bile duct opening at the confluence of the bile duct and pancreatic duct within the major papilla. The term "cannula" as used here refers to a pipe-shaped medical device that is inserted into a body cavity or blood vessel and used, for example, as a passage for injecting contrast agents or medicinal solutions, a passage for draining body fluids, an air passage during a tracheostomy, or a passage for a guidewire.

[0004] Next, after inserting the cannula into the main papilla, it is necessary to inject a contrast agent from the tip of the cannula to locate the bile duct opening. Currently, based on the experience and sense of the endoscopist, the contrast agent flows into the biliary tract only when the angle, insertion distance, etc. are adjusted so that the tip of the cannula faces the bile duct opening within the main papilla. The approximate position of the bile duct opening and the course of the common bile duct can be determined by X-ray imaging. When the approximate position of the bile duct opening is determined on the X-ray image, a guide wire is projected from the tip of the cannula, and the guide wire is inserted and removed while finely adjusting the angle and position of the endoscope so that the guide wire can be inserted into the bile duct opening. When the tip of the guide wire matches the position of the bile duct opening through this process, the guide wire can be inserted and retained in the common bile duct. As a result, the cannula can be advanced into the bile duct along the guide wire, enabling subsequent diagnosis and treatment of biliary tract diseases. However, the procedure of selectively inserting the cannula into the bile duct opening, as described above, requires the endoscopist and assistant to search for the bile duct opening within the duodenal main papilla that cannot be directly visualized from the endoscopic image based on their experience and sense. Therefore, the procedure may succeed or fail in performing cholangiography. Also, in the process of attempting to advance the contrast agent or guide wire selectively into the bile duct opening, the contrast agent or guide wire may accidentally enter the pancreatic duct, resulting in a complication called post-ERCP pancreatitis, which is also a problem.

[0005] Thus, ERCP, which can be said to be almost essential in the diagnosis and treatment of biliary tract diseases, currently depends on the experience and sense of the endoscopist and assistant for its success or failure and the occurrence of complications. The development of a safer and more reliable selective bile duct intubation method is eagerly awaited.

[0006] Japanese Patent Application Laid-Open No. 2023-75036

[0007] For deep intubation into the common bile duct, after inserting the cannula extended from the endoscope into the duodenal main papilla, it is necessary to search for the extremely small bile duct opening within the main papilla and then ensure reliable intubation into the common bile duct.

[0008] However, the procedure of selectively intubating the bile duct relies on the senses and contrast imaging of the examining physician (operator) and assistant, making it a difficult procedure even for experts, let alone beginners. Difficulties in inserting the bile duct can lead to a risk of complications such as pancreatitis after ERCP.

[0009] Furthermore, when inserting a bile duct, if a small amount of contrast agent is injected into the major papilla and X-ray imaging is performed to confirm the insertion position, there is a risk of radiation exposure for both the patient and the examining physician, as well as a risk of pancreatitis if the contrast agent flows into the pancreatic duct. Moreover, if contrast imaging of the common bile duct from the bile duct opening is not performed promptly, both the patient and the examining physician are forced to continue attempts at deep intubation while being exposed to X-ray radiation.

[0010] Up to this point, we have described the case of inserting a cannula into the common bile duct via the major duodenal papilla, but the same endoscope can also be used when inserting a cannula into the pancreatic duct via the major duodenal papilla.

[0011] The object of the present invention is to provide an ERCP cannula that can be easily inserted into the common bile duct or pancreatic duct via the major duodenal papilla, and an endoscopic system equipped with such a cannula.

[0012] Several embodiments of the solution to the problem are described below. These embodiments can be combined as needed.

[0013] The ERCP cannula according to the first invention of the present invention is an ERCP cannula that is inserted retrogradely into the common bile duct or pancreatic duct via the opening of the major duodenal papilla through the channel of an endoscope having a first camera for imaging the inside of the digestive tract. This ERCP cannula comprises a cannula body, a second camera, and a hollow transparent or translucent shield. The cannula body has a guidewire lumen through which a guidewire inserted into the common bile duct or pancreatic duct passes. Liquids such as contrast agents can also pass through the guidewire lumen. The second camera images the entrance to the common bile duct or pancreatic duct when in contact with the opening of the major papilla or when inserted into the major papilla. The hollow transparent or translucent shield is positioned at the tip of the cannula body and houses the second camera inside. The shield has a convex surface through which the central axis of the field of view of the second camera passes. The cannula body is designed so that the guidewire, which is fed out from the guidewire lumen, travels outside the shield within the field of view of the second camera.

[0014] In the ERCP cannula of the first invention, the guidewire moves within the field of view of the second camera, allowing the examining physician to visually confirm whether the guidewire is entering the common bile duct or the pancreatic duct using the second camera. More specifically, the examining physician can directly visualize the major papilla and its interior using the second camera of the ERCP cannula, and accurately select whether to insert the cannula body or the guidewire retrogradely into the common bile duct or the pancreatic duct. Therefore, with the ERCP cannula of the first invention, the examining physician can easily insert the cannula into the common bile duct or pancreatic duct via the major duodenal papilla.

[0015] The ERCP cannula according to the second invention is an ERCP cannula according to the first invention, further comprising an illumination means for illuminating at least a portion of the field of view of the second camera.

[0016] In the ERCP cannula of the second invention, the guide wire is illuminated by the illumination means, making it easier to see the guide wire with the second camera.

[0017] The ERCP cannula according to the third invention is an ERCP cannula according to the first or second invention, wherein the shield is positioned such that, in the longitudinal direction of the cannula body, the front end of the shield is located in front of the front end of the guidewire lumen outlet. Furthermore, the guidewire lumen is positioned such that, in the longitudinal direction of the cannula body, the front end of the outlet is located in front of the front surface of the lens of the second camera.

[0018] In the third invention of the ERCP cannula, the second camera can photograph the destination of the guidewire through a convex surface. This allows for clear imaging of the guidewire's path, making it easier to accurately perform selective intubation into the common bile duct and the pancreatic duct.

[0019] The ERCP cannula according to the fourth invention is an ERCP cannula according to the third invention, wherein the guidewire lumen has its exit positioned within the field of view of the second camera.

[0020] In the ERCP cannula of the fourth invention, the guidewire is reliably within the field of view of the second camera immediately after exiting the guidewire lumen, making it easier to accurately perform selective intubation of the common bile duct and pancreatic duct.

[0021] The ERCP cannula according to the fifth invention is an ERCP cannula according to the third invention, wherein the cannula body has a housing hole for housing a second camera formed next to the guide wire lumen. The second camera is positioned such that, in the longitudinal direction of the cannula body, the front end of the lens is located in front of or next to the opening of the housing hole.

[0022] In the ERCP cannula of the fifth invention, the end of the cannula body that forms the opening of the housing hole is prevented from entering the field of view of the second camera, making it easier to secure a wide field of view for the second camera.

[0023] The ERCP cannula according to the sixth invention is an ERCP cannula of the first or second invention, wherein the cannula body includes a curved portion from the tip to a predetermined length, which is shaped to form a curve that bends in one direction. The guidewire lumen is located on the inside of the curved portion.

[0024] In the ERCP cannula of the sixth invention, when inserting the ERCP cannula into the opening of the main papilla in the usual direction toward the patient's head (towards the common bile duct) within the duodenum, it becomes easier to position the guidewire closer to the common bile duct and the second camera closer to the pancreatic duct. By positioning the guidewire closer to the common bile duct, the pancreatic duct can be blocked, for example, with a shield, making it easier to insert the guidewire into the common bile duct.

[0025] The ERCP cannula according to the seventh invention includes, in the ERCP cannula of the second invention, a light housed inside the shield together with the second camera as an illumination means. The light is positioned so that reflected light from the shield does not enter the second camera.

[0026] In the ERCP cannula of the seventh invention, the reflection of light from the inner surface of the shield is suppressed from appearing in the image captured by the second camera, making it easier to accurately perform selective intubation into the common bile duct and the pancreatic duct.

[0027] The ERCP cannula according to the eighth invention is the ERCP cannula of the second invention, wherein the illumination means includes a light located outside the shield.

[0028] In the ERCP cannula of the eighth invention, the reflection of light from the inner surface of the shield is suppressed from appearing in the image captured by the second camera, making it easier for the examining physician to accurately perform selective intubation into the common bile duct and the pancreatic duct.

[0029] The ERCP cannula according to the ninth invention is an ERCP cannula according to the first or second invention, wherein the second camera is positioned at an angle to the longitudinal direction of the cannula body so as to face the guide wire fed out from the guide wire lumen.

[0030] In the ERCP cannula according to the ninth invention, when the cannula body is advanced longitudinally and the shield blocks the pancreatic duct, the guidewire can be inserted into the common bile duct while the bile duct opening is visible through the second camera, making it easier to insert the guidewire into the common bile duct.

[0031] The ERCP cannula according to the tenth invention is an ERCP cannula according to the first or second invention, wherein the convex surface of the shield has a uniform thickness region in the area included in the field of view of the second camera.

[0032] In the ERCP cannula of the tenth invention, the convex surface of the shield has a uniform thickness region, which suppresses distortion of light passing through the convex surface and reaching the second camera, making it easier to confirm the guide wire in the image captured by the second camera.

[0033] The ERCP cannula according to the eleventh invention is an ERCP cannula according to the first invention, wherein the cannula body has a projection that protrudes from the wall surface on the second camera side near the exit, which is part of the wall surface forming the guidewire lumen.

[0034] In the ERCP cannula of the eleventh invention, the guidewire being fed out from the exit rides up on the projection. As a result, the guidewire is fed out of the guidewire lumen while being guided away from the central axis of the second camera's field of view.

[0035] The ERCP cannula according to the twelfth invention is an ERCP cannula according to the first invention, wherein the cannula body has a tubular main portion and a convex ridge that protrudes from the outer circumferential surface of the main portion and extends in the longitudinal direction of the main portion.

[0036] In the ERCP cannula of the 12th invention, the examining physician can control the orientation of the cannula body with a hand gesture.

[0037] The endoscopic system according to the 13th invention comprises an endoscope having a first camera for photographing the inside of the digestive tract, and an ERCP cannula provided on the endoscope and configured to be inserted retrogradely into the common bile duct or pancreatic duct from the endoscope located in the duodenum, via the opening of the major duodenal papilla. The ERCP cannula has a cannula body, a second camera, and a hollow transparent or translucent shield. The cannula body has a guidewire lumen through which a guidewire inserted into the common bile duct or pancreatic duct passes. The second camera photographs the entrance to the common bile duct or pancreatic duct when in contact with the opening of the major papilla or when inserted into the major papilla. The hollow transparent or translucent shield is located at the tip of the cannula body and houses the second camera inside. The shield has a convex surface through which the central axis of the second camera's field of view passes. The cannula body is configured so that the guidewire, which is fed out from the guidewire lumen, travels through the field of view of the second camera outside the shield.

[0038] In the endoscopic system of the 13th invention, since the guidewire moves within the field of view of the second camera of the ERCP cannula, the examining physician can confirm with the second camera whether the guidewire is entering the common bile duct or the pancreatic duct. More specifically, the examining physician can directly visualize the major papilla and its interior with the second camera of the ERCP cannula, and accurately intubate by selecting whether to insert the cannula body or the guidewire retrogradely into the common bile duct or the pancreatic duct. Therefore, according to the endoscopic system of the 13th invention, the examining physician can easily intubate into the common bile duct or the pancreatic duct via the major duodenal papilla.

[0039] According to the ERCP cannula or endoscope of the present invention, the examining physician can easily intubate the common bile duct or pancreatic duct via the major duodenal papilla.

[0040] This is a block diagram showing an example of the configuration of an endoscope system according to an embodiment. This is a schematic diagram for explaining the state of the endoscope in the duodenum. This is a cross-sectional view showing an example of a junction when there is a common tube between the common bile duct and the pancreatic duct. This is a front view showing the main papilla with its opening open to explain the junction in the case of Figure 3A. This is a cross-sectional view showing an example of a junction when the common bile duct and the pancreatic duct merge at the main papilla. This is a front view showing the main papilla with its opening open to explain the junction in the case of Figure 4A. This is a cross-sectional view showing an example of a junction when the common bile duct and the pancreatic duct separate at the main papilla. This is a front view showing the main papilla with its opening open to explain the junction in the case of Figure 5A. This is a cross-sectional view showing another example of a junction when the common bile duct and the pancreatic duct separate at the main papilla. This is a front view showing the main papilla with its opening open to explain the junction in the case of Figure 6A. This is an enlarged perspective view showing an example of the configuration of the tip of the endoscope. This is an enlarged perspective view of the tip of the cannula according to an embodiment. This is an enlarged side view of the tip of the cannula in Figure 8. This is an enlarged cross-sectional view of the tip of the cannula in Figure 8. This is an enlarged front view showing an example of the configuration of the tip of the cannula in Figure 8. This is a perspective view showing an example of an endoscope. This is a pictorial view showing an image of a cannula inserted into the major duodenal papilla. This is an enlarged cross-sectional view of the major papilla into which the cannula is inserted. This is an enlarged cross-sectional view of the tip of the cannula body according to a modified example. This is an enlarged front view showing a part of the tip of the cannula body according to a modified example. This is an enlarged side view showing an example of the configuration of the tip of the cannula according to a modified example. This is an enlarged cross-sectional view of an example of a shield according to a modified example. This is an enlarged cross-sectional view of another example of a shield according to a modified example. This is an enlarged cross-sectional view of the major papilla into which the cannula of a modified example is inserted. This is an enlarged cross-sectional view of the tip of the cannula according to a modified example. This is a schematic diagram for explaining the curved part of the cannula body according to a modified example. This is a schematic diagram showing an example of the relationship between the cannula body and the forceps channel according to a modified example. This is a schematic diagram showing another example of the relationship between the cannula body and the forceps channel according to a modified example. This is a schematic diagram showing another example of the relationship between the cannula body and the forceps channel according to a modified example. This is a diagram illustrating the operation of the forceps device of an endoscope.

[0041] (1) Overview of the Endoscope Operation System The Endoscope Operation System 1 comprises the Endoscope System 10 shown in Figure 1 and the Operation Device 200. The Endoscope System 10 comprises an endoscope 11 and a cannula 12 (ERCP cannula), which is a treatment instrument.

[0042] The endoscope system 10 is a medical device used by inserting it into the body of patient 500 to observe the inside of the patient's body. The operating device 200 is used to operate the endoscope system 10. The endoscope operating system 1 may include peripheral equipment other than the operating device 200. Peripheral equipment other than the operating device 200 includes, for example, treatment instruments such as forceps, hemostatic clips, trocars, and electrosurgical units. The endoscope 11 has a channel for inserting treatment instruments and is used to deliver treatment instruments into the human body. The illustrations of forceps, hemostatic clips, trocars, and electrosurgical units are omitted here.

[0043] In endoscopic retrograde cholangiopancreatography (ERCP), used for the diagnosis and treatment of common bile duct stones and biliary tract cancer, the endoscope 11 of the endoscopic system 10 is inserted through the mouth of the patient 500 (see Figure 1) and reaches the duodenum 510, as shown in Figure 2. The endoscopic system 10 can extend and protrude a cannula 12 from the tip of the endoscope 11 through the forceps channel 7d to access the common bile duct 521 or pancreatic duct 531 retrogradely from the duodenum 510 (see Figure 7). After reaching the duodenum 510, the endoscopic system 10 is held at an angle that brings the major papilla 550, the exit of the common bile duct 521, into view. Subsequently, the cannula 12 for bile duct intubation is inserted through the channel 9 provided in the endoscope 11 from the inlet 9i of the channel 9 (see Figure 12). The cannula 12 inserted into channel 9 is bent at a right angle at the forceps channel 7e located at the tip of the endoscope 11 and inserted into the main papilla 550. The common bile duct 521 is the downstream part of the bile duct and is a thin tube (with a diameter of approximately 6 mm to 10 mm) that carries bile from the common hepatic duct 541 and the gallbladder 520 to the duodenum 510. The pancreatic duct 531 is a tube that leads to the duodenum 510 after several small tubes merge within the pancreas 530 and is a thin tube (with a diameter of approximately 2 mm to 5 mm) that carries pancreatic juice, which aids digestion, through exocrine pancreatic secretion.

[0044] Around the opening 551 of the main papilla 550, there is the sphincter of Oddi 552, and the sphincter of Oddi 552 surrounds the confluence of the common bile duct 521 and the pancreatic duct 531. The sphincter of Oddi 552 regulates the excretion of bile and pancreatic juice through relaxation and contraction. When the sphincter of Oddi 552 relaxes, the excretion of bile and pancreatic juice increases. The opening 551 of the main papilla 550 is usually closed by the sphincter of Oddi 552, and in ERCP, the sphincter of Oddi 552 acts in a direction that hinders the insertion of the cannula 12. In the insertion of the cannula 12, it is necessary to forcibly expand the opening 551 of the main papilla 550. Although there are other methods different from the method described in this embodiment of expanding the opening 551 of the main papilla 550 by incision to facilitate the insertion of the cannula 12, here, an insertion method without such an incision is described.

[0045] (1-1) Shape of the confluence of the common bile duct and the pancreatic duct It is known that there are individual differences in the morphology of the confluence of the common bile duct 521 and the pancreatic duct 531 in the main papilla 550. From FIG. 3A to FIG. 6B, the shapes of the confluences of the common bile duct 521 and the pancreatic duct 531 are shown. In FIGS. 3A, FIG. 4A, FIG. 5A and FIG. 6A, cross-sections around the main papilla 550 are shown, and in FIGS. 3B, FIG. 4B, FIG. 5B and FIG. 6B, the state of the opened opening 551 of the main papilla 550 as seen from inside the duodenum 510 is shown. As described above, usually, since the opening 551 of the main papilla 550 is closed by the sphincter of Oddi 552, when the main papilla 550 is viewed from the duodenum 51, it does not look like that shown in FIGS. 3B to 6B.

[0046] In the shape of the confluence shown in FIGS. 3A and 3B, after the common bile duct 521 and the pancreatic duct 531 merge, a common duct 559 is formed and the common duct extends to the opening 551 of the main papilla 550. At the part where the common duct 559 branches into the common bile duct 521 and the pancreatic duct 531, there are the inlets of the common bile duct 521 and the pancreatic duct 531. In the shape of the confluence shown in FIGS. 4A and 4B, the common bile duct 521 and the pancreatic duct 531 merge near the opening 551 of the main papilla 550. In the shapes of the confluences shown in FIGS. 5A, 5B, 6A and 6B, the common bile duct 521 and the pancreatic duct 531 are separated at the opening 551 of the main papilla 550.

[0047] Most of the shapes of the confluence parts are the shapes shown in FIGS. 3A to 4B. Although the shapes of the confluence parts shown in FIGS. 5A, 5B, 6A and 6B are few, in this shape, the common bile duct 521 and the pancreatic duct 531 are separated, so it is easy to selectively insert the cannula 12 into the common bile duct 521.

[0048] In the case of the shape of the confluence part shown in FIGS. 3A to 4B, by using the cannula 12 of the present embodiment, deep insertion into the common bile duct 521 or the pancreatic duct 531 becomes particularly easier than in the past.

[0049] (2) Details of the endoscope operation system The endoscope 11 includes a first camera 20 having an objective lens 21 for photographing the main papilla 550 (see FIG. 7). The imaging element (not shown) of the first camera 20 is arranged inside the endoscope 11. Further, the cannula 12 includes a second camera 30 at the tip of the cannula 12 (see FIGS. 10 and 11). In order to process the image data photographed by the first camera 20 and the second camera 30 and display the photographed image to the examining doctor, the operation device 200 shown in FIG. 1 includes a data processing device 210 and a display device 220. The display device 220 has, for example, an LCD monitor screen (not shown).

[0050] The image data of the images photographed by the first camera 20 and the second camera 30 are output from the first camera 20 and the second camera 30 to the data processing device 210. The data processing device 210 processes the image data, converts it into a signal for display on the display device 220, and outputs it to the display device 220. Generally, the data processing device 210 includes a storage device (not shown) for storing image data. The display device 220 displays the images photographed by the first camera 20 and the second camera 30 based on the signal transmitted from the data processing device 210. The endoscope system 10 and the operation device 200 are connected by a universal code 3, and the image data output by the first camera 20 and the second camera 30 is transmitted to the operation device 200 through the universal code 3. Note that the outputs of the first camera 20 and the second camera 30 may be output to different data processing devices respectively.

[0051] In the endoscopic operation system 1, it is preferable that the areas to be photographed inside the body are illuminated in order to improve the quality of images taken inside the patient 500. For this purpose, the operating device 200 of the endoscopic operation system 1 is equipped with a light source device 230 for supplying light to the tip 7 of the endoscope 11 (see Figure 1). The light supplied from the light source device 230 is sent from the universal cord 3 through, for example, an optical fiber (not shown) placed inside the endoscope 11, and is irradiated from the light guide lens 13 at the tip 7 of the endoscope 11 (see Figure 7). The light irradiated from the light guide lens 13 illuminates the lumen of the duodenum 510, centering on the main papilla, the area to be photographed by the first camera 20. However, the method of illumination is not limited to supplying light through an optical fiber. For example, it is also possible to configure the system to place a light (not shown) inside the endoscope 11 and supply electricity from the light source device 230 to light up the light inside the endoscope 11.

[0052] The second camera 30 of the cannula 12 has a lens 31 and a light 40 (see Figure 11). An image sensor (not shown) is located behind the lens 31. Power is supplied to the light 40 from a light source device 230, for example, by a wire passing through the cannula 12, endoscope 11, and universal cord 3. The light 40 lights up with the power supplied from the light source device 230. Here, the case in which power is supplied from the light source device 230 has been described, but it is also possible to configure the device so that light is supplied to the light 40 from the light source device 230 by an optical fiber, similar to how light is supplied to the light guide lens 13 by an optical fiber.

[0053] The operating device 200 may include a water supply device 240 for supplying water to clean the endoscope 11 and maintain its field of view, and an air supply device 250 for supplying gas to expand the digestive tract and ensure a clear field of view. Water and air flow between the water supply device 240 and the air supply device 250 and the endoscope 11 through a universal cord 3. The air supply device 250 may also have a suction function that allows gas to flow from the endoscope 11 to the air supply device 250.

[0054] (3) As shown in the detailed diagram of the endoscope 12, the endoscope 11 is equipped with an operating section 4 for operation and an insertion section 5 that is inserted into the body of the patient 500 (see Figure 1). The tip of the insertion section 5 has a bending section 6 and a tip section 7, and the operating section 4 and the bending section 6 are connected by a flexible section 8. The operating section 4 is equipped with buttons 4a such as a suction button, an air / water supply button and an image capture button. By operating the buttons 4a, the endoscope 11 can perform actions such as supplying air, supplying water, or suctioning through the insertion section 5. In addition, by operating the imaging-related buttons 4a such as the image capture button, the first camera 20, the second camera 30, and the illumination can be operated.

[0055] The angle knob 4b of the operating section 4 is connected to the tip section 7 by, for example, a guide wire (not shown). By operating the angle knob 4b, the endoscope 11 can bend the bending section 6 in various directions (for example, up, down, left, and right), and the tip section 7 can be directed in various directions. Because the bending section 6 of the endoscope 11 can be bent, it facilitates the insertion of the insertion section 5 into the body of the patient 500 and can be used for observation of the inside of the body cavity.

[0056] Near the operating section 4 is the entrance 9i of the channel 9. The entrance 9i is used to insert and remove treatment instruments into the channel 9. For example, forceps inserted through the entrance 9i of the channel 9 are advanced to the tip 7. Treatment instruments are not only transported into the patient 500 through the inside of the insertion section 5, but also into the patient 500 using, for example, a guide tube (not shown) provided on the surface of the insertion section 5.

[0057] As shown in Figure 7, the tip portion 7 is provided with, for example, an objective lens 21 and a light guide lens 13. Inside the objective lens 21, an image sensor, such as a CMOS or CCD image sensor (not shown), is positioned. Images captured by the CMOS or CCD image sensor are sent to the operating device 200 via the universal code 3 and displayed on the display device 220. A CMOS or CCD image sensor is also used as the image sensor for the second camera 30.

[0058] (4) Details of the Cannula Next, the details of the cannula 12 will be explained with reference to the diagram. The directions of "front" and "back" used in the following explanation correspond to the directions indicated by the arrows in Figures 9 and 10. More specifically, "front" is the direction in which the cannula 12 is pushed out from the tip 7 when using the endoscope 11, and "back" is the opposite direction. Also, "tip" refers to the tip at the front.

[0059] The cannula 12 is a tubular instrument inserted into the channel 9 (see Figure 12) of the endoscope 11. The cannula 12 protrudes from the forceps channel 7d provided at the tip 7 of the endoscope 11 and is inserted into the opening 551 of the main papilla 550. The tip of the cannula 12 is guided by the examiner to reach the common bile duct 521. The cannula 12 is made of a flexible tube, which allows it to move along complex shapes.

[0060] The cannula 12 comprises a cannula body 121, a shield 124, and a second camera 30. As shown in Figures 8, 10, and 11, the shield 124 is attached to the tip 121t of the cannula body 121, and an exit 125e for the guidewire lumen 125 is provided. The second camera 30 is housed inside the shield 124. As shown in Figure 9, when the cannula 12 is viewed from the side, the shield 124 protrudes forward from the tip 121t of the cannula body 121. The cannula body 121 also has a guidewire lumen 125 through which the guidewire 15 passes. The diameter of the cannula body 121 is, for example, 2 mm to 3 mm.

[0061] As shown in Figure 10, the shield 124 has a cylindrical portion 124y and a convex surface 124c that protrudes forward at the tip of the cylindrical portion 124y. The end of the cylindrical portion 124y opposite to the convex surface 124c is open and has a cylindrical fitting portion 124d that fits into the opening of a housing hole 121h (described later) provided in the cannula body 121. The shield 124 is made of a transparent or translucent material. Specifically, the shield 124 is made of a transparent or translucent resin. This transparent resin is, for example, polycarbonate resin. The shield 124 is hollow.

[0062] The second camera 30 is attached to the tip of the cannula body 121 such that its lens 31 faces forward and the central axis CA of the field of view Vf (in other words, the optical axis of the lens 31) is parallel to the central axis 125c of the guide wire lumen 125 (see Figure 10). At least a portion of the second camera 30 is housed in a housing hole 121h formed in the cannula body 121 alongside the guide wire lumen 125.

[0063] The size of the second camera 30 as viewed from the front is, for example, 500 μm x 500 μm. The diameter of the cylindrical part of the shield 124 is, for example, 1 mm to 1.5 mm.

[0064] The shield 124 is fixed to the cannula body 121 to prevent liquid from entering the internal space from the outside. Specifically, the shield 124 is fixed to the cannula body 121 by fitting the fitting portion 124d into the opening of the housing hole 121h. In this way, the shield 124 houses the second camera 30 and protects the second camera 30 from liquids such as mucus and mucus present in the main papilla. The second camera 30 is protected from by the shield 124 from, for example, body tissues such as the bile duct wall, pancreatic duct wall, and tumors, as well as gallstones and pancreatic stones, blood, bile, pancreatic juice, and pus. Since the second camera 30, protected by the shield 124, does not come into direct contact with internal tissues present in the external space, the second camera 30 can be used repeatedly. One method for repeatedly using the second camera 30 is to replace the shield 124 and the cannula body 121 after each surgery, and then attach the second camera 30 used in the previous surgery to the replaced shield 124 and cannula body 121. This method eliminates the need to clean the shield 124 and cannula body 121 after each surgery, and allows the same second camera 30 to be used in multiple surgeries.

[0065] The shield 124 is fixed to the cannula body 121 such that the central axis CA of the field of view Vf of the second camera 30 passes through the convex surface 124c. In other words, the portion of the shield 124 through which the central axis CA of the field of view Vf of the second camera 30 passes is convex surface 124c.

[0066] The shield 124 has a uniform thickness on its convex surface 124c. Specifically, the shield 124 has a uniform thickness region on its convex surface 124c that is included in the field of view Vf. This suppresses distortion of light that passes through the convex surface 124c and reaches the second camera 30, thereby suppressing distortion in the image captured by the second camera 30 through the shield 124. Here, the concept of a uniform thickness includes not only cases where the thickness is constant, but also cases where the thickness varies to the extent of manufacturing tolerances.

[0067] The boundary between the convex surface 124c and the cylindrical portion 124y is formed smoothly. Specifically, for example, as shown in Figure 10, when the convex surface 124c is formed in a hemispherical shape, the opening side (rear) end of the convex surface 124c and the (front) end of the cylindrical portion 124y are smoothly joined. Furthermore, the thickness of the convex surface 124c and the thickness of the cylindrical portion 124y are formed to be the same. In addition, to reduce image distortion, the convex surface 124c is composed of a smooth curved surface. It is preferable that the convex surface 124c has a shape that is rotationally symmetric with respect to the central axis CA. For example, the cross-section of the convex surface 124c when cut by a hemisphere or a plane containing the central axis CA is formed in an arch shape. This suppresses damage to the main papilla 550 at the tip portion 121t when the cannula 12 is inserted into the opening 551 of the main papilla 550. Some of the arch shape includes a shape in which a part of the spherical shell has been cut off. If the convex surface 124c of the shield 124 is shaped like a part of a spherical shell, it is easier to manufacture a mold for manufacturing the shield 124, thus simplifying the manufacture of the shield 124. The arch shape includes not only circular arcs, but also three-dimensional shapes whose cross-section is an outwardly convex curve such as an elliptical arc, part of an egg shape, a parabola, and a hyperbola. To prevent light reflection, an anti-reflective coating may be provided on at least one of the outer and inner surfaces of the shield 124. By applying such an anti-reflective treatment, the reflection of light from the light 40 (illumination means) of the second camera 30 off the inner surface of the shield 124 is suppressed.

[0068] Furthermore, an anti-fouling material may be applied to the outer surface of the shield 124. By providing an anti-fouling material to the outer surface of the shield 124, it is possible to prevent dirt from adhering to the outer surface of the shield 124 and impairing the camera's field of view.

[0069] The guidewire lumen 125 is an elongated cylindrical hole. At the tip 121t of the cannula 12, the central axis 125c of the guidewire lumen 125 is parallel to the central axis CA of the field of view Vf of the second camera 30. The guidewire lumen 125 is a passage for guiding the guidewire 15. The tip of the guidewire 15 that has passed through the guidewire lumen 125 is fed out from the outlet 125e. The diameter of the guidewire 15 is, for example, 0.25 inches to 0.035 inches. The shield 124 and the guidewire lumen 125 are arranged side by side adjacent to each other. This adjacent arrangement of the shield 124 and the guidewire lumen 125 makes it easier for the portion of the guidewire 15 that has emerged from the outlet 125e of the guidewire lumen 125 to enter the field of view Vf of the second camera 30.

[0070] As shown in Figures 8 and 9, the tip portion 121t of the cannula body 121 has a perpendicular surface 121c that is perpendicular to the longitudinal direction of the cannula body 121 and an inclined surface 121d that intersects obliquely with the longitudinal direction of the cannula body 121 (the front-to-back direction in Figures 8 and 9).

[0071] As shown in Figures 8, 9, and 10, the shield 124 is attached to the cannula body 121 so as to protrude forward from the inclined surface 121d. The outlet 125e is formed spanning the orthogonal surface 121c and the inclined surface 121d. The opening of the housing hole 121h is formed in the inclined surface 121d. As can be seen from Figure 8, a portion of the outer surface of the shield 124 faces the outlet 125e of the guidewire lumen 125. As shown in Figure 10, the second camera 30 is positioned so that the outlet 125e of the guidewire lumen 125 is within the field of view Vf.

[0072] (4-1) Position of each part of the cannula 12 Next, the positional relationship of the predetermined positions of the cannula 12, P1 to P5 (see Figure 10), will be explained. P1 to P5 are defined as follows.

[0073] P1 is the tip of the shield 124. P2 is the position of the connection between the convex surface 124c and the cylindrical portion 124y. P3 is the intersection of the front surface 31f of the lens 31 of the second camera 30 and the central axis CA. P4 is the foremost edge of the cannula 12 that forms the opening of the outlet 125e. P5 is the edge of the cannula body 121 that forms the opening of the housing hole 121h and is the point closest to the outlet 125e.

[0074] In this embodiment, P1 is the intersection of the front surface of the convex surface 124c and the central axis CA of the field of view Vf of the second camera 30, however, P1 does not necessarily have to be located on the central axis CA of the field of view Vf.

[0075] In this embodiment, P3 is a point on the central axis CV of the field of view Vf of the second camera 30. If the center point of the lens 31 does not coincide with a point on the central axis CV of the field of view Vf of the second camera 30, then P3 is defined as the center point of the lens 31.

[0076] The cannula 12 is preferably formed such that P1 is located in front of P4. This positioning of P1 in front of P4 makes it easier for the shield 124 to be inserted into the main papilla 550 before the cannula body 121. As a result, the convex surface 124c of the shield 124 can widen the opening 551 of the main papilla 550, thus facilitating the insertion of the cannula 12 into the main papilla 550.

[0077] The cannula 12 is preferably formed such that P4 is positioned in front of P3. By positioning P4 in front of P3 in this way, the exit 125e of the guidewire lumen 125 and / or the guidewire 15 coming out of the exit 125e can easily enter the field of view Vf of the second camera 30. Therefore, if the field of view Vf of the second camera 30 is set appropriately, the exit 125e can be photographed by the second camera 30.

[0078] The cannula 12 is preferably formed such that P3 is located in front of P5, or that P3 is aligned with P5 in the front-to-back direction. By positioning P3 in front of or aligned with P5 in this way, the obstruction of the field of view Vf of the second camera 30 by the edge of the cannula body 121 that forms the opening of the housing hole 121h is suppressed.

[0079] Furthermore, to minimize shadows at the shooting location, the lights 40 are positioned so as to sandwich the lens 31 when viewed from the direction of the tip of the cannula 12. In this embodiment, three lights 41, 42, and 43 and three lights 44, 45, and 46 are arranged in a straight line on both sides of the lens 31. The diameter of each of the lights 41 to 46 is, for example, 20 μm to 100 μm. The multiple lights 40 are positioned so that the reflected light from the shield 124 does not enter the lens 31. For example, by experimenting with the multiple lights 40 turned on and taking a picture with the second camera 30, it is confirmed that the reflected light from the shield 124 of the multiple lights 40 does not appear in the second camera 30. This allows the multiple lights 40 to be positioned so that the reflected light from the shield 124 of the multiple lights 40 does not enter the lens 31. An anti-reflective coating to suppress light reflection may be installed on the inner surface of the housing hole 121h. Furthermore, visibility can be further improved by injecting liquid into the internal space covered by the shield 124.

[0080] (5) Using the first camera 20 of the deep intubation endoscope 11 with a cannula, the cannula 12 is inserted into the opening 551 of the main papilla 550, as shown in Figure 2, while photographing the main papilla 550 inside the duodenum 510. Figure 13 shows the state in which the cannula 12 has been inserted into the opening 551 of the main papilla 550. It is necessary to select the intubation site and perform deep intubation in order to avoid mistakenly inserting into the common bile duct 521 or the pancreatic duct 531.

[0081] To select the intubation site, for example, as shown in Figure 14, the cannula 12 is stopped with the shield 124 inserted into the common duct 559 between the common bile duct 521 and the pancreatic duct 531. The second camera 30 is used to photograph the entrances to the common bile duct 521 and the pancreatic duct 531 from inside the shield 124. Next, as shown in Figure 14, the guidewire 15 is advanced and inserted into the common bile duct 521. The guidewire 15 moves through the field of view Vf of the second camera 30. With the guidewire 15 in place in the common bile duct 521, the cannula 12 is retracted. The guidewire 15 remaining in the common bile duct 521 serves as a guide, for example, to access the common bile duct 521.

[0082] Alternatively, after inserting the guidewire 15 into the common bile duct 521, the cannula 12 may be intubated into the common bile duct 521 using the guidewire 15. Alternatively, the cannula 12 intubated into the common bile duct 521 may be examined using the second camera 30. After intubation of the cannula 12, a contrast agent may be injected through the guidewire lumen 125 for a detailed examination of the bile duct.

[0083] (6) Features (6-1) The cannula 12 is an ERCP cannula that is inserted retrogradely into the common bile duct 521 or pancreatic duct 531 via the opening 551 of the main papilla 550 of the duodenum 510 through the channel 9 of an endoscope 11 having a first camera 20 for imaging the inside of the digestive tract. The cannula 12 comprises a cannula body 121, a second camera 30, and a hollow transparent or translucent shield 124. The cannula body 121 has a guidewire lumen 125 through which a guidewire 15 inserted into the common bile duct 521 or pancreatic duct 531 passes. The second camera 30 images the entrance to the common bile duct 521 or pancreatic duct 531 when in contact with the opening 551 of the main papilla 550, or when inserted into the main papilla 550. A hollow, transparent or translucent shield 124 is positioned at the tip of the cannula body 121 and houses the second camera inside. The shield 124 has a convex surface through which the central axis CA of the field of view Vf of the second camera 30 passes. The cannula body 121 is formed so that the guidewire 15, which is fed out from the guidewire lumen 125, travels through the field of view Vf of the second camera 30 outside the shield 124.

[0084] With the cannula 12, the guidewire 15 moves within the field of view Vf of the second camera 30, allowing the examiner to visually confirm with the second camera 30 whether the guidewire 15 will enter the common bile duct 521 or the pancreatic duct 531. More specifically, the examiner can directly visualize the major papilla 550 and its interior with the second camera 30 of the cannula 12, and accurately intubate by selecting whether to insert the cannula body 121 or the guidewire 15 retrogradely into the common bile duct 521 or the pancreatic duct 531. Therefore, with the cannula 12, the examiner can easily intubate the common bile duct 521 or the pancreatic duct 531 via the major papilla 550 of the duodenum 510.

[0085] (6-2) As shown in Figure 11, the cannula 12 is equipped with a light 40 as an illumination means to illuminate at least a portion of the field of view Vf of the second camera 30. After the cannula 12 is inserted through the main papilla 550, the guidewire 15 is illuminated by the light 40, making it easy to see the guidewire 15 in the second camera 30.

[0086] Furthermore, the cannula 12 shown in Figure 11 has multiple lights 41-46 around the second camera 30. The multiple lights 41-46 are positioned so that reflected light from the shield 124 does not enter the second camera 30. This suppresses the inclusion of light reflected from the inner surface of the shield 124 into the image captured by the second camera 30, making it easier to accurately perform selective intubation into the common bile duct 521 and the pancreatic duct 531.

[0087] (6-3) As shown in Figure 10, the shield 124 is positioned such that, in the longitudinal direction of the cannula body 121, the tip of the shield 124 (P1) is located in front of the front end (P4) of the exit 125e of the guidewire lumen 125. The guidewire lumen 125 is also positioned such that, in the longitudinal direction of the cannula body 121, the front end (P4) of the exit 125e is located in front of the front surface (P3) of the lens 31 of the second camera 30. With the cannula 12 configured in this way, the second camera 30 can photograph the destination of the guidewire 15 as it extends through the convex surface 124c. As a result, the destination of the guidewire 15 is clearly photographed, making it easier to accurately perform selective intubation into the common bile duct 521 and the pancreatic duct 531.

[0088] (6-4) The exit 125e of the guidewire lumen 125 is positioned within the field of view Vf of the second camera 30. When the exit 125e of the guidewire lumen 125 is positioned within the field of view Vf of the second camera 30, the guidewire 15 immediately after exiting the exit 125e of the guidewire lumen 125 is reliably positioned within the field of view Vf of the second camera 30, making it easier to accurately perform selective intubation of the common bile duct 521 and the pancreatic duct 531.

[0089] (6-5) As shown in Figure 10, the cannula body 121 has a housing hole 121h for housing the second camera 30, which is formed next to the guide wire lumen 125. The second camera 30 is positioned such that, in the longitudinal direction of the cannula body 121, the front end of the lens 31 is located in front of or next to the opening of the housing hole 121h. This prevents the end of the cannula body 121 that forms the opening of the housing hole 121h from entering the field of view Vf of the second camera 30, making it easier to secure a wide field of view Vf of the second camera 30.

[0090] (6-6) In the cannula 12 of the above embodiment, the convex surface 124c of the shield 124 has a uniform thickness region that is uniform in the area included in the field of view Vf of the second camera 30. The uniform thickness region of the convex surface 124c suppresses distortion of light that passes through the convex surface 124c and reaches the second camera 30. As a result, it becomes easier for the examining physician to confirm the guidewire 15 from the image captured by the second camera 30, and it becomes easier to select and accurately intubate the guidewire 15 or cannula 12 retrogradely into the common bile duct 521 and pancreatic duct 531 via the main papilla 550.

[0091] (7) Modified Examples (7-1) The cannula 12 may have a structure that guides the tip of the guidewire 15 that is fed out from the outlet 125e in a direction away from the central axis CA of the field of view Vf of the second camera 30. Specifically, the cannula body 121 may have a projection 125p formed in the guidewire lumen 125 that guides the fed-out guidewire 15. As shown in Figures 15 and 16, the projection 125p is formed to protrude from the wall surface on the second camera 30 side near the outlet 125e of the wall surface forming the guidewire lumen 125.

[0092] The guide wire 15, fed out from the exit 125e, rides onto the projection 125p. As a result, the guide wire 15 is fed out of the guide wire lumen 125 while being guided away from the central axis CA of the field of view Vf of the second camera 30. The projection 125p can be formed, for example, by pressing or bending.

[0093] In a cannula 12 provided with a projection 125p, it is preferable that P2 is formed to be located in front of P4. By having P2 in front of P4 in this way, the edge of the cannula 12 that forms the opening of the exit 125e is prevented from obstructing the movement of the guide wire 15 being fed out from the guide wire lumen 125.

[0094] (7-2) In the above embodiment, the case in which the light 40 is provided in a part covered by the shield 124 has been described. However, the light 40 may be placed outside the shield 124. For example, as shown in Figure 17, the light 40 may be provided on both sides of the shield 124 on the front of the cannula body 121. This suppresses the light reflected from the inner surface of the shield 124 from appearing in the image captured by the second camera 30, making it easier for the examining physician to accurately perform selective intubation into the common bile duct and the pancreatic duct.

[0095] The light 40 may be embedded inside the cannula body 121, or a lumen (not shown) for the light 40 may be provided in the cannula body 121 and the optical fiber 231 which will be the light 40 may be passed through the lumen.

[0096] With the illumination means, the light 40, configured in this way, direct reflected light from the light 40 towards the second camera 30 does not occur on the inner surface of the shield 124. Therefore, the reflected light from the light 40 does not interfere with the image of the guide wire 15 captured by the second camera 30, making it easier to accurately perform selective intubation into the common bile duct 521 and the pancreatic duct 531.

[0097] (7-3) In the above embodiment, the case in which the light 40 is provided in a part covered by the shield 124 was described, and in Modification 7-2, the case in which the light 40 is provided outside the shield 124 was described. However, the light 40 may be connected to the shield 124 so that the light emitted from the light 40 is guided through the shield 124. For example, as shown in Figures 18 and 19, the light 40 is constructed by inserting an optical fiber 231 into a hole 126 made in the cannula body 121 and fixing it with an optically clear adhesive. Examples of optically clear adhesives include OCA (Optical Clear Adhesive) and OCR (Optical Clear Resin). The refractive index of these optically clear adhesives is preferably about the same as that of the material of the shield 124.

[0098] Figure 18 shows a surface irregularity 127 located within the optical path of the optical fiber 231, where numerous fine irregularities are formed on the surface of the shield 124. In Figure 18, parts of the cannula 12 other than the optical fiber and shield 124 are omitted from the illustration. In a cannula configured as shown in Figure 18, the light emitted from the optical fiber 231 and diffusely reflected by the surface irregularity 127 is directed forward in the direction of travel of the shield 124. The irregularities formed on the surface irregularity 127 may be, for example, extraction gratings.

[0099] Figure 19 shows an optical extraction structure 128 located within the optical path of the optical fiber 231 and formed on the surface of the shield 124. The optical extraction structure 128 shown in Figure 19 is designed so that light is emitted at an angle close to perpendicular. In the optical extraction structure 128, the angle between the outer surface of the shield 124 and the optical path of the optical fiber 231 is 90 degrees or close to it compared to the surrounding outer surface. Therefore, in the optical extraction structure 128, Fresnel reflection is kept low because the light emitted from the optical fiber 231 is emitted substantially perpendicularly from the outer surface of the shield 124. Here, "substantially perpendicular" means that it may be slightly different from perpendicular due to manufacturing tolerances, etc.

[0100] (7-4) In the above embodiment, the case in which the space enclosed by the shield 124 is filled with air has been described. However, the space enclosed by the shield 124 may be filled with a fluid such as a liquid. For example, it may be filled with a liquid having a refractive index close to that of the material of the shield 124. For example, the space enclosed by the shield 124 may be filled with an oil that has a refractive index close to that of the material of the shield 124 and is harmless to the human body.

[0101] (7-5) In the above embodiment, the second camera 30 is positioned parallel to the direction of travel of the guidewire 15, in other words, parallel to the longitudinal DRL (see Figure 20) of the insertion portion of the cannula body 121 into the main papilla 550. However, in order to reliably guide the guidewire 15 into the common bile duct 521, a method of blocking the pancreatic duct 531 with a shield 124 can be considered, in which case the image of the part of the shield 124 that is blocking the pancreatic duct 531 becomes less important. Therefore, in the cannula 12 shown in Figure 20, the second camera 30 is positioned at an angle with respect to the longitudinal DRL of the insertion portion of the cannula body 121 so that it faces the guidewire 15 that has been fed out from the guidewire lumen 125. Even when the pancreatic duct 531 is blocked by the shield 124 and the guidewire 15 is reliably inserted into the common bile duct 521, the second camera 30 is positioned at an angle to the longitudinal DRL, making it easier to capture the guidewire 15 entering the common bile duct 521 within the field of view of the second camera 30. In addition to the fact that the cannula body 121 is advanced along the longitudinal DRL and the shield 124 is blocked by the pancreatic duct 531 to prevent the guidewire 15 from being mistakenly inserted into the pancreatic duct 531, it is possible to insert the guidewire 15 while visualizing the bile duct opening with the guidewire 15 in the field of view Vf using the second camera 30, thus making the insertion of the guidewire 15 into the common bile duct 521 easier.

[0102] (7-6) In the above embodiment, the case was described in which the shield 124 covers the second camera 30 and does not cover the area around the exit 125e of the guidewire 15. However, as shown in Figure 21, the shield 124 may be formed so as to cover the area around the exit 125e of the cannula body 121 where the exit 124e of the guidewire 15 is formed. In this case as well, the shield 124 is provided with an inner wall 124w to protect the second camera 30 from solids and liquids inside the body. The inner wall 124w divides the space covered by the shield 124 into the space where the second camera 30 is located and the space through which the guidewire 15 passes. The field of view Vf of the second camera 30 contains two exits 124e and 125e. In other words, the second camera 30 may be formed to photograph two locations: the exit 125e where the guidewire 15 exits and the exit 124e where the guidewire 15 exits.

[0103] (7-7) In the above embodiment, the case described was that the cannula body 121 is configured to extend straight when no force is applied to the cannula body 121. However, the cannula body 121 may include a curved portion 121e, which is formed to form a curve that bends in one direction, between the tip portion 121t and a predetermined length, as shown in Figure 22. In other words, the cannula body 121 in Figure 22 is configured so that the curved portion 121e of the cannula body 121 bends when no force is applied to the cannula body 121. The cannula body 121 having the curved portion 121e is configured so that the guidewire lumen 125 is located on the inside. For example, if the part of the cannula body 121 that maintains its shape is mainly made of thermoplastic resin, the curved portion 121e can be formed by applying heat to the cannula body 121 to plastically deform it, and then cooling the cannula body 121 while maintaining that shape.

[0104] As a result, even if the orientation of the cannula body 121 is reversed somewhere in the endoscope 11, the guidewire 15 will be positioned closer to the common bile duct 521 than the second camera 30 when it exits the tip 7 of the endoscope 11, making it easier to guide the guidewire 15 into the common bile duct 521. Therefore, in the usual insertion into the opening of the major papilla, where the cannula 12 is advanced in the direction toward the patient's head (towards the common bile duct) within the duodenum, it becomes easier to position the guidewire 15 closer to the common bile duct 521 and the second camera 30 closer to the pancreatic duct 531. By positioning the guidewire 15 closer to the common bile duct 521, for example, the pancreatic duct 531 can be blocked with the shield 124 to prevent the guidewire 15 from entering, making it easier to insert the guidewire 15 into the common bile duct 521.

[0105] (7-8) In the above embodiment, a case was described in which one cannula 12 is provided with one second camera 30 and one lens 31. However, the number of second cameras 30 and lenses 31 provided on one cannula 12 is not limited to one. There may be multiple second cameras 30. Similarly, there may be multiple lenses 31.

[0106] (7-9) In the above embodiment, the case in which one guide wire 15 is provided for one cannula 12 has been described. However, multiple guide wires may be provided for one cannula 12.

[0107] (7-10) In the above embodiment, the case was described in which the entire portion of the shield 124 that is within the field of view Vf is a uniform thickness region. However, the shield 124 does not have to have a uniform thickness throughout; for example, it may be configured so that only the thickness of the portion of the guide wire 15 that is visible is uniform.

[0108] (7-11) In the above embodiment, the case in which the cross-section of the cannula body 121 is circular has been described. However, the cross-sectional shape of the cannula body 121 may be made non-circular so that the direction in which the cannula body 121 is fed out from the tip 7 of the endoscope 11 can be controlled. Figures 23A, 23B, and 23C schematically show the forceps stage 7e provided at the tip 7 of the endoscope 11 and the cross-sectional shape of the cannula body 121 whose direction is controlled by the forceps stage 7e. The forceps stage 7e has a V-shaped guide 7eg. The cannula body 121 has a tubular main part 121m and a protrusion 121s that protrudes from the outer circumferential surface of the main part 121m and extends in the longitudinal direction of the main part 121m. The protrusion 121s is formed to fit into the V-shaped guide 7eg. On the side where the protrusion 121s is formed, for example, a housing hole 121h is provided. The cannula bodies 121 shown in Figures 23A, 23B, and 23C differ in the shape of the convex ridges 121s, but they share the common function of allowing their orientation to be controlled by the forceps stage 7e.

[0109] Figure 24 shows the movement of the forceps channel 7e. The examiner operating the endoscope 11 can repeatedly change the position of the forceps channel 7e between a state where the tip is facing forward and a state where the tip is facing upward as shown in Figure 24, by manipulating the device with their hand. Through repeated manipulation in this manner, even if the convex rib 121s is not initially properly positioned within the V-shaped guide 7eg, the cannula 12 will gradually rotate, allowing it to be properly positioned within the V-shaped guide 7eg. In other words, the examiner can control the orientation of the cannula body 121 with hand manipulation.

[0110] In a cannula body 121 with a convex rib 121s formed thereon, it is preferable that the guidewire lumen 125 is located away from the convex rib 121s, and the second camera 30 is located near the convex rib 121s. This allows the second camera 30 to be positioned close to the pancreatic duct 531 and the guidewire 15 to be advanced close to the common bile duct 521 when using the cannula 12, so that the examiner can easily insert the guidewire 15 into the common bile duct 521.

[0111] Furthermore, a mark may be provided at the entrance 9i of the channel 9 of the endoscope 11 to specify the direction of insertion of the cannula body 121. By specifying the direction of insertion of the cannula body 121, the cannula body 121 may be configured to reach the tip 7 of the endoscope 11 in the direction shown in Figures 23A to 23C.

[0112] Furthermore, a knob-like structure may be provided at the handle portion of the cannula body 121 to rotate the cannula body 121 and change its orientation. The orientation of the cannula body 121 may be controlled by operating the knob.

[0113] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. In particular, the embodiments and modifications described herein can be combined as needed.

[0114] 1 Endoscopy operating system 10 Endoscopy system 11 Endoscope 12 Cannula 15 Guidewire 20 First camera 30 Second camera 40, 41-46 Light 121 Cannula body 124 Shield 124c Convex surface 125e Guidewire lumen exit 510 Duodenum 521 Common bile duct 531 Pancreatic duct 550 Main papilla 551 Opening

Claims

1. An ERCP cannula inserted retrogradely into the common bile duct or pancreatic duct via the opening of the major papilla of the duodenum through a channel of an endoscope having a first camera for imaging the inside of the digestive tract, comprising: a cannula body formed with a guidewire lumen for passing a guidewire inserted into the common bile duct or the pancreatic duct; a second camera for imaging the entrance to the common bile duct or the pancreatic duct while in contact with the opening of the major papilla or while inserted into the major papilla; and a hollow transparent or translucent shield attached to the tip of the cannula body and housing the second camera inside, wherein the shield has a convex surface through which the central axis of the field of view of the second camera passes, and the cannula body is formed so that the guidewire, which is fed out from the guidewire lumen, travels through the field of view of the second camera outside the shield.

2. The ERCP cannula according to claim 1, further comprising illumination means for illuminating at least a portion of the field of view of the second camera.

3. The ERCP cannula according to claim 1 or claim 2, wherein the shield is positioned such that its front end is located forward of the front end of the exit of the guidewire lumen in the longitudinal direction of the cannula body, and the guidewire lumen is positioned such that its front end of the exit is located forward of the front surface of the lens of the second camera in the longitudinal direction of the cannula body.

4. The ERCP cannula according to claim 3, wherein the guide wire lumen has an outlet positioned within the field of view of the second camera.

5. The ERCP cannula according to claim 3, wherein the cannula body has a housing hole for housing the second camera formed alongside the guide wire lumen, and the second camera is positioned such that, in the longitudinal direction of the cannula body, the front end of the lens is located in front of or aligned with the opening of the housing hole.

6. The ERCP cannula according to claim 1 or claim 2, wherein the cannula body includes a curved portion from the tip to a predetermined length that is shaped to form a curve that bends in one direction, and the guidewire lumen is located on the inside of the curved portion.

7. The ERCP cannula according to claim 2, wherein the illumination means includes a light housed inside the shield together with the second camera, and the light is positioned so that reflected light from the shield does not enter the second camera.

8. The ERCP cannula according to claim 2, wherein the illumination means includes a light positioned outside the shield.

9. The ERCP cannula according to claim 1 or 2, wherein the second camera is positioned at an angle with respect to the longitudinal direction of the cannula body so as to face the guide wire that is fed out from the guide wire lumen.

10. The ERCP cannula according to claim 1 or claim 2, wherein the shield has a uniform thickness region on the convex surface that has a uniform thickness in the area included in the field of view of the second camera.

11. The ERCP cannula according to claim 1, wherein the cannula body has a projection formed to protrude from the wall surface on the second camera side near the exit of the wall surface forming the guide wire lumen.

12. The ERCP cannula according to claim 1, wherein the cannula body has a tubular main portion and a convex ridge protruding from the outer circumferential surface of the main portion and extending in the longitudinal direction of the main portion.

13. An endoscope system comprising: an endoscope having a first camera for photographing the inside of the digestive tract; an ERCP cannula provided on the endoscope and inserted retrogradely into the common bile duct or pancreatic duct from the endoscope located in the duodenum via the opening of the major papilla of the duodenum, wherein the ERCP cannula has a cannula body formed with a guidewire lumen through which a guidewire inserted into the common bile duct or pancreatic duct passes; a second camera for photographing the entrance to the common bile duct or pancreatic duct while in contact with the opening of the major papilla or inserted into the major papilla; and a hollow transparent or translucent shield attached to the tip of the cannula body for housing the second camera, wherein the shield has a convex surface through which the central axis of the field of view of the second camera passes, and the cannula body is formed so that the guidewire sent out from the guidewire lumen travels outside the shield within the field of view of the second camera.

Images