Sheet assembly for an endoscope and method for sheathing an endoscope

Abstract

This invention discloses an elongated folding cannula that unfolds into a cannula after the endoscope extends into the body. This cannula is folded into a telescope-like or accordion-like fold and has an end-cap at the distal end and an end-guard at the proximal end. After the endoscope extends into the end-guard, the folding cannula engages with the end-cap, and is opened by pushing the folding cannula from within the end-cap. Alternatively, the end-cap is fixed to at least one external instrument channel extending through the cannula and exiting the end-guard, allowing the folding cannula to be opened within both the endoscope and the external instrument channel. Therefore, the cannula can be a mating cannula that restricts movement of the endoscope and external instrument channel while allowing easy opening within both channels.

Description

Endoscope cannula assembly The present invention relates to the field of endoscopy for providing surgical instruments into the gastrointestinal tract for performing minimally invasive surgery. Some types of endoscopes contain a flexible tube that allows a physician to insert it through the patient's mouth or anus into the gastrointestinal (GI) tract. The physician pushes the endoscope through the portion of the endoscope that remains outside the patient's body until the tip of the endoscope is near the target GI tract. These endoscopes typically contain two instrument channels, each with an opening at the endoscope tip and another opening at the inner end of the endoscope. Surgical instruments are inserted through openings in the endoscope's handle and passed through the instrument channels to operate at the target location at the endoscope tip. Some physicians prefer endoscopes with more than two instrument channels. However, some endoscopes lack instrument channels altogether, and upgrading these endoscopes rather than replacing them would be more economical. Therefore, there is a need to expand the functionality of existing endoscopes. One approach has been to place a plastic tube along the length of the endoscope to serve as an external instrument channel. Adhesive tape is then used to wrap around the plastic tube and endoscope, securing them together. However, this approach would eliminate flexibility along the entire length of the endoscope, making it extremely difficult to insert the rigid endoscope into the body. Furthermore, manual modification is not only time-consuming, but also results in unstable quality of the modified object itself. Some have proposed using discontinuous joints to attach the external instrument channel to the endoscope tube to reduce endoscope stiffness. If two external instrument channels are connected in this manner, the surrounding portions of the unconnected external instrument channels can easily become entangled with each other due to the twisting / torque of the endoscope caused by the physician attempting to insert the endoscope into the body. If entanglement occurs in the portion of the endoscope that has already entered the body, it becomes extremely difficult to separate the entangled portions, and the endoscope and instruments located within the external instrument channels may not respond appropriately to manipulations. Some have proposed using a plastic sleeve to cover the combined endoscope and external instrument channel. However, pulling the plastic sleeve to cover the assembly is not easy because the operator must repeatedly push different parts of the sleeve to cover the entire assembly, which is not only time-consuming but also increases the risk of infection due to repetitive movements. Therefore, there is a need in the art for a method and / or apparatus for adding one or more external instrument channels to an endoscope without sacrificing its flexibility. In addition, it is also necessary to provide a cannula that can quickly cover the endoscope. A first aspect of the present invention relates to a cannula assembly for an endoscope, comprising: a hollow cannula having a proximal end connected to an end cap, and a distal end connected to an annular member within the end cap, suitable for allowing an endoscope to extend through the annular member and the hollow cannula to be mated with the end cap; the cannula is folded into a plurality of folds, each fold being a circumferential portion of the cannula, which is folded toward its adjacent circumferential portion along the length of the cannula; wherein the folds can be opened as the endoscope pushes the end cap away from the end cap. Thus, the present invention provides a foldable sleeve capable of accommodating endoscopes of increasing lengths inserted therein. Unfolding the distal end of the sleeve to cover the portion of the endoscope immediately after it passes through the end cap eliminates the need to pull the sleeve to cover the endoscope and, therefore, eliminates the associated shear stress. This also facilitates covering the endoscope within the mating sleeve. Typically, the end cap is sized to allow entry into the gastrointestinal tract, but the end cap is too large to enter the mouth or anus. Therefore, to advance the endoscope within the cannula into the body, the end cap must be pushed further into the body, away from the end cap that cannot enter the body. Alternatively, the endoscope can be folded into a series of telescopic folds. Typically, the telescopic folds comprise a length of the cannula that is folded along its circumference so that it extends along the length of the cannula until the next telescopic fold. An end cap is attached to the distal end of the cannula and is pulled out and opened before the proximal fold. Preferably, each telescopic fold extends beyond the edge of the next telescopic fold. Preferably, the cannula assembly includes a plurality of eyelets, each eyelet being connected to an over-extending edge; the eyelets being arranged along the length of the cannula. A tubing (e.g., an external instrument channel) can be inserted into the cannula through the arranged eyelets to prevent the tubing from moving. In certain specific embodiments, the edge of a farther telescopic fold extends over the edge of a next closer telescopic fold. In other embodiments, the edge of a closer telescopic fold extends over the edge of a next farther telescopic fold. Alternatively, the sleeve may be folded into accordion-style pleats. Generally speaking, the sleeve is easier to fold into a telescopic style because there are fewer parts to fold. Also, when the sleeve is pulled by moving the end caps, it is certain that the pleats farther apart will open first. However, when the sleeve is opened, there is significant slippage between the pleats. Accordion pleats are less pliable, but they are easier to open than telescopic pleats because there is no slippage between the pleats. Furthermore, accordion pleats are smaller when the sleeve is folded into an accordion style. Preferably, the sleeve assembly includes a plurality of holes, each hole being connected to the accordion pleats, and the holes are arranged along the length of the sleeve. More preferably, the sleeve assembly includes a second plurality of holes arranged along the length of the sleeve, wherein the first plurality of holes and the second plurality of holes are respectively located on opposite sides of the circumference of the sleeve. Preferably, the cannula assembly further comprises an inflatable balloon surrounding the end cap. Preferably, the cannula assembly further comprises an external instrument channel extending from the end cap through the cannula and out through the annular member on the end shield. More preferably, the cannula assembly further comprises two external instrument channels extending from the end cap through the cannula and passing through the annular member on the end shield; the distal ends of the external instrument channels are arranged on the end cap in a manner converging with each other. Because the outer pleats of the sleeve cover the portion of the endoscope that passes through the end cap, there is no need to pull the sleeve over the endoscope; the opened portion of the sleeve simply covers the portion of the endoscope that passes through. This allows the sleeve to mate with the endoscope and two (or any number of) external instrument channels, preventing the endoscope and the two external instrument channels from stacking and tangling with each other, while allowing the endoscope and the two external instrument channels to slide relative to each other, minimizing endoscope stiffness. Typically, the cannula assembly includes two apertures connected to the inner surface of the cannula and located on either side of the circumference of the cannula; each of the two external instrument channels can extend through a different one of the two apertures. The apertures are connected to the inner surface of the cannula and are separated from the end cap by a distance; wherein the distance (when the cannula is opened) is less than or equal to half the length of the curved portion of the endoscope or the distance is less than or equal to 10 cm. The purpose of providing these apertures is not to separate the external instrument channels, but to ensure that the distal end of the external instrument channel does not rotate around the end cap. Most curved portions are about 18-20 cm long, and the distance of about 10 cm between the end cap and the aperture may fall in the middle of the length of most curved portions. In a further aspect, the present invention provides a method for sheathing an endoscope, comprising: providing a hollow sleeve folded into a plurality of pleats, each pleat being a circumferential portion of the sleeve that is folded along the length of the sleeve and over an adjacent circumferential portion of the sleeve; inserting the endoscope through the proximal end of the sleeve; pushing the endoscope into the sleeve and pushing the distal end of the sleeve away from the proximal end of the sleeve to open the sleeve; wherein the pleats of the sleeve, after being opened, cover the portion of the endoscope opened by the pleats of the sleeve. Although most embodiments describe an end cap at the distal end of the cannula, other connecting objects may be provided between the distal end of the cannula and the tip of the endoscope, and this step of the method of the present invention is not limited to providing an end cap to the distal end of the cannula. Typically, the step of advancing the distal end of the cannula away comprises advancing the distal end of the cannula into the gastrointestinal tract of the human body. Preferably, the method further comprises: providing at least one tube connected to the distal end of the sleeve; wherein the pleats of the sleeve are opened to cover a portion of the endoscope, and the at least one tube passes through the opened pleats of the sleeve. This arrangement of having a section or open pleat of the cannula covering the portion through which the endoscope passes eliminates the need to pull the cannula over the endoscope (and any such tubing connected to the distal end of the cannula) and also allows the cannula to be more adaptable to the endoscope than prior art methods that required pulling the cannula over the endoscope. FIG1 illustrates a robotic endoscopic surgery system comprising a medical device and a robotic apparatus. The medical device is used to support a rigid endoscope 201 for use in the human urethra, as shown in FIG1 , or a flexible endoscope 201 for use in the human gastrointestinal tract, not shown in FIG1 . Typically, endoscopic surgery is performed using a robotic instrument system with an endoscope tip effector. Figure 1 primarily shows a workbench 101, a positioning cart 103, a control console 105, and a display screen located atop a shelf 107. The positioning cart 103 and workbench 101 are aligned. In the distance, between the cart 103 and workbench 101, is a shelf 107 with a display screen. Nearby is the control console 105, where the physician operates the robotic instruments. It also allows the physician to view the endoscope's images in real time on the display screen while simultaneously monitoring the patient. FIG2 is a photograph of an endoscope 201 suitable for oral or anal insertion into the human gastrointestinal (GI) tract. At the proximal end of endoscope 201 is an axially aligned handle 203 with a dial 207 for rotating a curved portion 205 at the distal end of endoscope 201. A rod 209 extends from handle 203 and is connected to an image processor in housing 107, as well as a pump and container for supplying air and water to the subject through the endoscope. It can also be used to collect fluid aspirated from the GI tract. Endoscopic surgery begins with the physician manually inserting an endoscope 201 into a patient lying on a workbench 101. A light source 403 and a camera 405 are located at the tip of endoscope 201, which transmit the endoscope's progress through the GI to a display screen. When the tip of endoscope 201 approaches the intended surgical site in the GI, the endoscope's handle 203 is mounted on a fixed arm 109 extending from a positioning cart 103, keeping endoscope 201 as stable as possible. On the handle 203 of the endoscope are two proximal openings 211 for instrument channels, and a distal opening is located at the endoscope tip. Each instrument channel can be inserted into a surgical instrument. If no surgical instrument is inserted, the endoscope 201 has no surgical use. Figure 3 is a photograph of a surgical instrument. A typical surgical instrument 300 includes a delivery tube 301, approximately 0.5 to 1.8 meters long, as its main body. A small, approximately 3-centimeter-long robotic arm, called a "manipulator arm 303," is located at the distal end of the delivery tube 301. The tip of the manipulator arm 303 has an end effector 401, which is used to perform surgical procedures (e.g., cutting, grasping, and suturing) within the human body. A wire connecting the manipulator arm 303 to the end effector 401 at one end is coiled through the delivery tube 301 and connected to a spool in a coupler 305, which is connected to the positioning vehicle 103 at the other end. Figure 4 shows two maneuverable arms 303 extending through the instrument channel of the endoscope tip, located below a light source 403 and camera 405, which are also located on the endoscope tip. Each maneuverable arm 303 has an end effector 401. Figure 5 illustrates how the endoscope 201 is mounted on the fixed arm 109. The actuating platform 501 on the top of the positioning vehicle 103 has receptacles that can be mated with the coupler of the surgical instrument 300. Console 105 is a modified dental stool, also known as a "surgical chair." This type of dental stool is commonly found in general clinics and is designed for dentists or physicians who need to sit and work in an ergonomic manner. An electromagnetic field (EMF) generator in console 105 creates an EMF that is used to monitor the coordinated movement of two controllers that respond to the EMF. This EMF generator is about the size of a brick and is mounted only on the front edge of the surgical chair seat. Therefore, the EMF is always in front of the physician at console 105. The actuation platform 501 manipulates the wire on the spool in coupler 305 to continuously reposition the manipulable arm 303 and end effector 401 based on the coordinated movement of the controller in the EMF (held and moved by the physician in the GI or urinary surgical position at console 105). 6-8 are schematic diagrams showing different orientations and configurations of the cannula assembly 700. The cannula assembly 700 provides an effective and quick way to sheath the endoscope 201. Cannula assembly 700 includes a cannula 711 made of a thin, foldable hollow plastic tube. The proximal end of the cannula is sealed to the outer surface of a ring, which serves as an end cap 701. End cap 701 has an inner hole with a diameter approximately the same as that of endoscope 201. A narrow annular lip 703 extends from the inner surface of end cap 701 and is flush with the distal end of end cap 701. Therefore, the endoscope tip can be inserted into the end cap from the proximal end to secure it to the end cap. The lip extending from the distal end of end cap 701 protects the endoscope. Although narrow, annular lip 703 does not obstruct the operation of the camera 405, light source 403, and instrument channel on the endoscope tip. Instead, the circumference of the proximal opening of the cannula is connected to the end cap 715 and extends over an annular member in the center of the end cap. The size of the end cap 701 is such that the end cap can pass through the mouth or anus and into the GI, but the size and shape of the end shield must prevent the end shield from moving into the mouth or anus. Two channels 705 are integrated into one outer surface of end cap 701, parallel to the axis of end cap 701. Figure 6 includes an illustration, outlined by dashed lines, showing a side view of these two channels 705 in end cap 701. Each channel 705 is secured to the distal end of a hollow tube without deforming the inner surface of the tube. This hollow tube serves as an external instrument channel 707, and thus its length exceeds the length of the portion of endoscope 201 typically intended for insertion into the body. A simple guideline is that the length of external instrument channel 707 is similar to or greater than the average instrument channel length or the length of most commonly used endoscopes 201. Furthermore, the inner diameter of external instrument channel 707 should be similar to the inner diameter of the instrument channels of most endoscopes 201. This makes external instrument channel 707 almost instantly compatible with the length of current surgical instruments 300, with minimal dimensional discrepancies. Another variation of this embodiment is to have end cap 701 with only a single channel 705, located immediately adjacent to external instrument channel 707 (not shown). The hollow tube serving as the external instrument channel 707 preferably has the following characteristics: (1) low bending resistance, at least less than the bending resistance of the endoscope 201; (2) good structural resistance to radial deformation, which prevents bending when the tube is bent and keeps the instrument channel open; and (3) a smooth inner surface so that the surgical instrument 300 can pass through repeatedly and smoothly during surgery. An example of a hollow tube that retains the above characteristics is a thermoplastic polyurethane tube embedded with a stainless steel spring (spring-embedded tube). Basically, a spring-embedded tube consists of a plastic-coated "helical spring" with smooth inner and outer surfaces. The edges of the coils on one side of the coil spring can be separated, allowing the coil spring to bend toward the other side. Because a unit length of tube contains a large number of coils, only a slight movement of a certain number of coils on the convex side is required to bend the coil spring toward the concave side. This small movement results in little or no bending resistance. Consequently, the bending resistance of this coil spring tube is extremely low, and the tube can be described as floppy. That is, the spring-embedded tube can bend in any direction with essentially no structural bias or strength to hold it upright. Therefore, the external instrument channel 707 made of this spring-embedded tube can bend arbitrarily within the GI folds as the endoscope 201 is moved. Furthermore, the coil of the spring itself is very thin at the edges but quite wide in the radial direction, making the coil resistant to radial deformation. Therefore, the external instrument channel 707 provided by the tube containing the spring will not buckle or suddenly fold in the GI, thus ensuring that the external instrument channel 707 remains unobstructed under normal circumstances. When the channel on the end cap is used as the external instrument channel 707, the distal end of the sleeve 711 must be sealed (preferably sealed in an airtight manner) to the outer surface of the end cap 701 and the channel 705. The edge of the sleeve 711 can be folded to enable it to mate with the end cap 701 and the channel 705 to ensure an effective seal. Another preferred feature of this embodiment is that the end cap 701 is placed inside a donut-shaped balloon 709. Donut-shaped balloon 709 is made of elastic or inelastic plastic. In Figures 6 and 7, the balloon is flattened and folded inside the end cap 701. In Figure 8, the balloon is inflated. A torus refers to a 3D shape that's circular in plan view but has an open, upright core in the center. Essentially, it's a donut shape, but the balloon's height-to-diameter ratio is preferably larger than a typical donut's. The outer surface of the core of the balloon 709 is tightly adhered or sealed to each side of the end cap 701. The passage 705, any exposed portion of the inflation tube 710 on the outer surface of the end cap, and the edge of the sleeve 711 are sealed to the end cap 701. Air is introduced into balloon 709 via an inflation tube 710. Tube 710 is typically made of highly flexible silicone or another polymer. The distal end of tube 710 is inserted through the annular core and into balloon 709. The remainder of tube 710 extends between sealed tubing 711 and end cap 701 (and passageway 705), through the hollow portion of cannula 711, and through the annular member in end cap 715. Tube 710 is at least as long as external instrument channel 707. Outside the end cap 715, the proximal end of the inflation tube 710 is connected to the needle port of the system 1501 that uses a syringe piston to pump air into the balloon 709. The same syringe is used to pump air out of the balloon to deflate it, especially when the balloon is made of an inelastic material (and therefore cannot be deflated by force). Preferably, a valve is provided at the proximal end of the inflation tube 710. The valve can be opened to allow air to pass into the balloon 709. Alternatively, the valve can be closed to prevent air from escaping from the balloon 709 and allow the syringe 1501 to be removed from the inflation tube 710. Preferably, a pressure relief valve is provided downstream between the valve and the end cap 715 to allow excess air in the balloon 709 to be released to prevent the balloon 709 from bursting or injuring the subject. For the sake of simplicity, the two external instrument channels 707 and the inflation tube 710 are collectively referred to as “tubular members” in the following paragraphs. Therefore, before use, the cannula is folded to shorten its length, and it can be seen that most of the tubular elements extend from the folded cannula beyond the annular member of the end cap. However, after the endoscope has passed through the annular member and the folded cannula, the tubular elements can be pulled into the annular member, inserted into the body, and installed on the endoscope tip together with the end cap. By opening the fold at the far end and covering and surrounding the endoscope and the tubular element just passed, there is no need to pull and adjust the cannula over the endoscope and the tubular element. Therefore, the end cap assembly can easily and tightly cover the endoscope and the tubular component. FIG9 is a series of diagrams illustrating how endoscope 201 is inserted into a human body and simultaneously enclosed. The top diagram shows the pre-insertion preparation process, in which the cannula assembly is about to be installed on endoscope 201. The second diagram shows the endoscope being inserted into the ring member and the hollow folded cannula being inserted into the end cap 701 (not shown). With the end cap of the cannula assembly mounted on the endoscope tip, the endoscope and cannula assembly are ready to be inserted into the human body. The cannula assembly is then placed in the subject's mouth, where they wear a mouthguard to keep their mouth open. The endoscope is pushed through the ring and into the end cap. The end cap on the endoscope tip is slowly passed through the throat, esophagus, and stomach, pulling the end cap along the unfolded cannula. Because the end cap is designed to be too large to enter the oral cavity, it provides resistance, allowing the end cap to pull the cannula open, typically systematically starting with the distal fold. This pulls the external instrument channel and inflation tube into the annular member and cannula. Thus, an endoscope, external instrument channel, and inflation tube can be introduced into the subject's GI system through the end cap and dynamically captured as the cannula opens. When inserting an endoscope through the anus, the cannula assembly is used in the same manner. The end cap, attached to the endoscope tip, is pushed into the anal cavity. Because the end cap is designed to prevent entry into the anus, as the end cap moves further into the body and away from the end cap, it pulls the folding cannula open, covering the endoscope and cannula assembly as it enters the end cap. The function of sleeve 711 is to make tubular element as close as possible to endoscope, and at the same time make tubular element and endoscope 201 can slide over each other.This sliding makes endoscope 201 have complete controllable movement ability in GI. Once endoscope 201 has been pushed to the desired location within the body, the physician can place the handle 203 of endoscope 201 on a fixed arm 109 extending from positioning cart 103 to keep endoscope 201 stationary. Next, a large syringe 1501 is used to pump air into inflation tube 710 and then into balloon 709, inflating the balloon and thereby stabilizing the endoscope tip within the body. The inflated balloon 709 gently presses against a large surface area within the GI tract, stabilizing the endoscope tip within the body and providing the traction needed to insert or retrieve surgical instrument 300. The inflated balloon also acts as a seal within the esophagus or rectum, preventing air from escaping. The physician can then insert the desired number of end-effectors into the external instrument channels. Using the image provided by the camera, the physician can see whether the manipulator arms of the surgical instruments are extended through the external instrument channels and are ready to be used to perform the surgery. The physician can then connect the couplers of the surgical instruments to the actuator platform on the positioning vehicle. The physician, seated at the console 105, can then perform the surgical maneuvers by holding the controller, guided by the real-time image of the GI situation. The coordinated movements of the controller in the EMF generated by the console 105 are transmitted back to the actuator and converted into real-time movements of the manipulator arms and end-effectors. FIG8 shows the cannula assembly 700 in operation, wherein the tip of the endoscope 201, extending through the annular member 713 of the end cap 715 and into the cannula 711, is inserted into the end cap 701. FIG8 also shows the balloon 709 in an inflated state surrounding the end cap. The inset in FIG8 shows the annular inflated balloon 709. FIG11 depicts an inflated balloon 709 surrounding the tip of endoscope 201. A cannula 711 is connected to the proximal end of end cap 701 and encloses an external instrument channel 707 immediately adjacent to channel 705 of end cap 701. FIG11 also shows an inflation tube 710 extending from one end into balloon 709 and into the hollow portion of cannula 711 between the cannula 711 and the surface of end cap 701. FIG11 shows a surgical instrument 300 inserted into each external instrument channel. Each surgical instrument 300 has a manipulator arm 303 extending from its respective external instrument channel 707, wielding an end effector 401. Figure 12 is a front view of a preferred feature of the balloon 709 on the end cap 701, showing the balloon 709 inflated around the end cap 701. The core of the donut-shaped balloon 709 is eccentric to the circumference of the balloon 709. This allows the end cap 701 to be elevated above the axis of the GI, with the balloon 709 positioned more below the end cap 701 than above it, representing y>x, where x is the distance from the center of the hole to the top of the balloon 709 and y is the distance from the center of the hole to the bottom of the balloon 709. This configuration provides greater stability by reducing the chance of axial twisting of the endoscope 201. It is important to note that the technique for inserting the endoscope 201 into the body involves axially twisting the endoscope 201 without the balloon 709 getting in the way, as the balloon 709 is not inflated until the endoscope 201 reaches the target site. Furthermore, this configuration elevates the endoscope tip, allowing more space for the maneuverable arm 303 to approach the target site. Figure 13 is a photograph of endoscope 201 mounted within prototype cannula assembly 701. Figure 14 is an enlarged view of the block of Figure 13, transferred to a negative. Figure 15 is a photograph of the same assembly shown in Figure 13, but stripped back to show all components. FIG13 does not show the folded sleeve 711. Instead, FIG13 shows the sleeve 711 fully unfolded and pulled over to cover the endoscope 201, the two external instrument channels 707, and the inflation balloon 709. It can be seen that the circumference of the sleeve 711 conforms to the circumference of the endoscope 201 and the tubular elements within the sleeve 711. Therefore, the sleeve 711 provides only limited radial space to allow the tubular elements to remain close together without causing them to slide axially relative to each other, nor does it render the assembly rigid. Figure 13 shows a white rectangle at the proximal opening of cannula 711, representing end cap 715. External instrument channels 707 extend outward from end cap 715 of cannula 711, toward the left of the figure. Each external instrument channel 707 can be inserted into a surgical instrument 300. As can be seen on the left side of Figure 13, each surgical instrument 300 has a coupler 305, and each coupler 305 has a delivery tube 301 extending from it into the external instrument channel 707. The maneuverable arm 303 at the other end of the delivery tube 301 extends through the external instrument channel 707. However, the external instrument channel 707 is not visible in the figure because it is obscured by cannula 711 and balloon 709. Furthermore, a syringe 1501 is connected to the proximal end of inflation tube 710, which extends into cannula 711 and end cap 715, ready to connect with balloon 709 on end cap 701. The figure shows that the balloon 709 is in a semi-inflated state, surrounding the distal end of the endoscope 201. In Figure 15 , cannula assembly 700 is disassembled into its components and placed next to endoscope 201. These components include: external instrument channel 707, adjacent to end cap channel 705; inflation tube 710, extending from balloon 709 to the needle hub of syringe 1501; and open cannula 711, removed from end cap 701. Figure 15 does not include surgical instrument 300 and end cap 715. Various variations of casing folds In Figures 6, 7, and 8, the cannula is folded into accordion folds. Specifically, the cannula is repeatedly folded inward and outward. The inward folding involves folding a small section of cannula 711 into an outer folded edge that surrounds its circumference. The inner edge tends to have more crease than the outer edge, allowing for more cannula material to be accommodated within a smaller circumference. Suitable cannula materials are thin, easily foldable plastics such as TPU or PE that are safe for use in the human body. FIG10 shows a variation of the sleeve assembly 700. The upper view of FIG10 is one of its unused states. It can be seen that the sleeve 711 is folded into a telescopic shape. The telescopic fold of the sleeve 711 is achieved by folding the sleeve using the circumference of the sleeve as a folding line. After folding several times, a plurality of nested tubes are formed, with each smaller tube being nested inside a larger tube. Preferably, the sleeve 711 is tapered from the proximal end to the distal end, so that each outward fold has a slightly larger diameter, making it easier to accommodate the next inward fold. The outermost fold is the proximal end of the sleeve 711 and is connected to the end cover 715, and the innermost fold is the distal end of the sleeve and is connected to the end cap 701. In the embodiment of FIG. 10 , a telescopically foldable cannula 711 is positioned proximally to an end cap 715, allowing the distal end of the end cap 715 to rest against the proximal edge of the end cap 701. End cap 701 has a balloon 709 folded onto its outer surface. Two external instrument channels 707 and an inflation tube 710 are connected to the end cap, extending from end cap 701 through the hollow, foldable cannula 711 and out the annular member 713 of end cap 715. The lower figure shows end cap 701 mounted on the tip of endoscope 201, which extends into the annular member and through the hollow, foldable cannula 711. As more of endoscope 201 is pushed forward, endoscope 201 pushes end cap 701 away from end cap 715. End cap 701, when removed from end cap 715, pulls on the attached sleeve 711, causing the innermost telescopic folds to open before the outer folds. The opened portion of sleeve 711 then encloses the tubular element and, together with endoscope 201, passes through annular member 713 on end cap 715. Balloon 709 is not yet inflated. Because only the innermost folds of the telescopic folds contact the endoscope, the user can easily install the end cap on the endoscope tip, as only one edge of the fold needs to be guided into the sleeve and end cap. In contrast, the edges of all accordion folds face inward, meaning that during installation, the endoscope tip must be carefully guided through each fold, which can be challenging without first clearing a path from the proximal end of the sleeve to the distal end. Preferably, the length of the sleeve 711 is longer than the length of the endoscope 201 generally expected to be inserted into the human body. Therefore, in some cases, not every fold needs to be opened. The figure below shows that several folds of the sleeve 711 have not been opened. The figure also shows that there is a gap between the end shield 715 and the end cover 701, which can be used to introduce lubrication into the fold of the sleeve 711. Because the folded sleeve 711 is located proximal to the end cap 715, rather than between the end cap 715 and the end cover 701 as shown in FIG6 , this configuration allows the end cap 701 to seal the annular member 713 on the end cap 715. A releasable seal is used around the annular member 713 and the proximal edge of the end cap 701. Alternatively, the connection between the end cap and the end cap can be a snap-on or twist-lock connection. The reader should understand that the manner in which the sleeve 711 is folded, whether telescopically, accordion-like, or in any other manner, is an independent feature and is not related to the embodiment in which the folded sleeve 711 is entirely positioned proximal to the end cap 715. Furthermore, there are many ways to fold the sleeve 711, depending on factors such as the material of the sleeve 711 selected, the thickness of the sleeve, the flexibility of the material, and the overall shape of the sleeve. FIG16 illustrates another variation of a cannula 711. The figure shows an open section of cannula 711 with three series of eyelets 1601 secured to the inner surface of the cannula 711 by stitching, lamination, or other means. For clarity, the endoscope 201 is not depicted in the figure. Each series of eyelets 1601 runs along the length of the cannula 711. Each of the two external instrument channels 707 and the inflation tube 710 passes through a different series of eyelets 1601 within the three series of eyelets 1601. The eyelets 1601 prevent any other two external instrument channels 707 and the inflation tube 710 from becoming entangled with each other and keep the instrument channels and the inflation tube separate. The inset of Figure 16 is a radial cross-section of cannula 711, showing three series of holes located at different positions around the circumference of cannula 711. Also visible are cross-sections of external instrument channel 707 and inflation tube 710 inserted into corresponding holes 1601. The dotted circle within cannula 711 represents the center of cannula 711, which is also where endoscope 201 would be located (if inserted into cannula 711), but would be outside of holes 1601. Preferably, holes 1601 have a thin edge so that they can be stacked on top of each other when cannula 711 is folded. They can be made of thin wire, plastic rings, elastic plastic, fabric, or rope. FIG17 shows another variation of the cannula 711. The endoscope is not depicted, and an eyelet 1601 is connected to the proximal end of each fold of the cannula 711, which is folded into a telescopic shape. Each outward fold is closer to the proximal end than the adjacent inward fold. Each eyelet 1601 in the three series of eyelets, and each subsequent eyelet in each series, is connected to the proximal edge of an outwardly extending outer fold (adjacent to each inner fold). It should be noted that not every fold needs to have an eyelet 1601. Of course, eyelets 1601 can also be located between folds, but doing so would prevent the manufacturer from pre-inserting the external instrument channel 707 and the inflation tube 710 therein. Therefore, as shown in FIG17 , each series of eyelets 1601 already has an external instrument channel 707 and an inflation tube 710 pre-inserted therein, respectively. Figure 18 illustrates another variation of the telescopic flap. In this embodiment, the distal end of each outward-folding flap extends beyond the adjacent, inward-folding flap. Typically, the sleeve 711 tapers or narrows from distal to proximal. The distal-most flap is connected to the end cap 701 and is the first to open when the endoscope 201 is inserted. Eyelets 1601 are located on the outward-extending distal edge of each outward-folding flap. The left side of the top illustration in Figure 18 shows a side view of the folded sleeve 1701 and the eyelets 1601 without the end cap 701; the right side of the top illustration shows a schematic view of the left-hand illustration from the distal end, illustrating the arrangement of the three series of eyelets 1601. The bottom illustration shows how each external instrument channel 707 and inflation tube 710 are inserted into the corresponding eyelet 1601. In this embodiment, the folded sleeve 711 is located between the end cap 701 and the end shield 715. It should be noted that the sleeve 711 does not necessarily need to be tapered, but only to facilitate folding into a telescope-shaped fold. Other factors such as the foldability or elasticity of the sleeve material may also affect whether it can be folded into a telescope-shaped fold. FIG19 shows how the eyelet 1601 is connected to the accordion-shaped folds of the sleeve 711. As mentioned above, the accordion-shaped folds include a plurality of folds that alternately fold inward and outward. As with the folds that fold into a telescope shape, the sleeve 711 does not need to be tapered. Accordion-shaped folds are more compact than telescope-shaped folds, making them suitable for large-scale storage and shipping. The inner edge of the folds tends to have more folds to accommodate more sleeve material within a smaller circumference. Therefore, the sleeve 711 can be constructed of any thin, easily foldable plastic material, such as TPU or PE. The left-hand figure shows the distal end of the folded sleeve 711 sealed to the proximal edge of the end cap 701. Two external instrument channels 707 and an inflation tube 710 extend from the end cap 701, pass through a series of eyelets 1601 in the folded sleeve 711, and exit through the ring 713 of the end cap 715. The right-hand figure shows the sleeve 711 in its open state. Figure 20 illustrates another variation of the folding sleeve 711, in which the end cap is nested within the innermost telescopic fold. In this configuration, an eyelet 1601 is located on each of the outward folds (i.e., beyond the inner fold) toward the proximal end. Generally, the length of the folds depends on the thickness of the sleeve 711 wall, the material of the sleeve 711, the angle at which the sleeve 711 tapers, the location, diameter, and thickness of the eyelet 1601, and the length of the endoscope 201 to be enclosed by the sleeve 711. FIG. 21 shows another variation of a foldable sleeve 711, in which the inflation tube 710 does not pass through any of the eyelets 1601, and instead each instrument channel 707 passes through a different series of eyelets 1601. Because two series of eyelets 1601 provide sufficient space for each of the three tubular elements, the inflation tube 710 can share space with the endoscope 201. FIG. 22 shows another variation of a folded sleeve 711 in which three series of holes are provided, but the holes in each series are spaced a great distance apart. Specifically, the positions of the three series of holes 1601 along the sleeve 711 are staggered. This maximizes the effectiveness of the holes 1601 in preventing the tubular elements from becoming entangled with one another, while minimizing the number of holes 1601. FIG24 illustrates the simplest embodiment, in which a foldable sleeve 711 connected to an end cap 701 can be secured to the tip of an endoscope 201, with no inflation tube 710, balloon 709, or external instrument channel 707 connected to the end cap 701. The end cap 701 is simply a ring and is not connected to any channel 705. In FIG24 , the foldable sleeve 711 is entirely placed on the proximal side of the end shield 715. In this simple embodiment, where only the sleeve 711 is connected to the end caps 701 and 715 at both ends, other folding methods can also be used. This embodiment simply serves to wrap the sleeve 711 around the endoscope 201 and does not provide any other functionality. The advantage is that it can reduce the chance of contamination of the outer surface of the endoscope. FIG25 shows another simple embodiment having only an end cap 701 without an external instrument channel 707, an inflation tube 710, or a balloon 709. In this embodiment, the end cap 701 is sleeved within a telescopic folding sleeve 711. The folding sleeve 711 and the sleeved end cap 701 rest against the distal end of the end shield 715. In some variations of the sleeve 711, only one hole 1601 is provided in each instrument channel, rather than a series of holes 1601. Providing a single hole 1601 on the inner surface of the sleeve near the end cap 701 limits the chance of the outer instrument channel 707 being wrapped around the end cap 701. Changes to end caps and end shields FIG26 is a front view of an end cap 701 having a preferred feature, showing a hole that is the vertex of a triangle formed by two lower sleeve channels 705 and the sides of the hole. The other components of the sleeve assembly 700 are not shown. The channels 705 are spaced apart along the circumference of the hole. The axes of the channels 705 within the hole and the axis of the external instrument channel 707, as well as the axis of the surgical instrument 300 that can be inserted into the instrument channel, form equal angles. a o From the plan view of Figure 27, channel 705 is a b o The angles are placed on either side of the axis of the hole so that the steerable arms converge toward a point forward of the endoscope tip. a o and angles b o The angle of the external instrument channel depends on the thickness and circumference of the endoscope 201, which in turn depends on the number of channels and other contents of the endoscope 201. However, for most endoscopes 201 suitable for rectal surgery, the angle of the external instrument channel is a o and angles b o It is usually 15 degrees. FIG28 shows a simplified diagram of an end cap 715 having another feature. The end cap 715 is made of plastic and includes a band that can be placed over the tip of the endoscope. However, this band is split into two ends that are opposite to each other in length, and a one-way locking mechanism can be used to close the two ends facing each other on both sides of the split, including a wavy strip on one side and a toothed structure that can engage with the wavy strip on the other side. The advantage of this structure is that the end cap 715 can be matched with various rings of slightly different thicknesses in the endoscope 201, and can be firmly fixed to the endoscope 201 to prevent the end cap from falling off or getting tangled, and no additional adhesive is required. The ring has a hood extending toward the distal end to prevent intestinal tissue from obscuring the camera 405. FIG29 illustrates a variation of an end cap 715 in which a plurality of rings 713 are provided. Each ring 713 is sized to match the size of the corresponding tubular element extending through the end cap 715, and the rings 713 are also arranged according to the arrangement of the tubular elements in the end cap 701. According to the arrangement shown in FIG29, the largest ring 713 (also the ring at the top) is used to insert the endoscope 201, which is then connected to the tip of the end cap 701 through the folded sleeve core. The ring 713 at the bottom is used to allow the inflation tube to extend through the sleeve. The two rings 713 at the same vertical position are each used to allow external instruments to pass through the sleeve. FIG30 is a prototype diagram of an end cap 715 having a wavy outer surface that facilitates gripping, with individual annular members 713 through which the endoscope 201, two external instrument channels 707, and an inflation tube 710 can pass. Therefore, the embodiment includes a cannula that is folded in the longitudinal direction and can be opened to enclose an endoscope within the cannula and then inserted into the human body. In other words, the embodiment includes a cannula assembly for an endoscope, comprising a hollow cannula having a proximal end connected to an end cap and a distal end connected to an annular member within the end cap, adapted to allow the endoscope to extend through the annular member and the hollow cannula to mate with the end cap; the cannula is folded into a plurality of folds, each fold being a circumferential portion of the cannula that is folded toward its adjacent circumferential portion along the longitudinal direction of the cannula; wherein the folds can be opened as the endoscope pushes the end cap away from the end cap. The use of the described embodiments includes a method of sheathing an endoscope, comprising: providing a hollow sleeve folded into a plurality of pleats, each pleat being a circumferential portion of the sleeve that is folded along the length of the sleeve and extends over an adjacent circumferential portion of the sleeve; inserting the endoscope through the proximal end of the sleeve; pushing the endoscope into the sleeve and pushing the distal end of the sleeve away from the proximal end of the sleeve to open the sleeve; wherein the pleats of the sleeve, after being opened, cover the portion of the endoscope that is opened by the pleats of the sleeve. The preferred embodiments of the present invention have been described in detail above. Those skilled in the art should understand that various changes or modifications may be made to the above designs, and that the present invention may be constructed and operated without departing from the scope of the present invention. For example, the circumference is used to describe the radial cross-section of the casing, which can be oval or rhombus-shaped. The same folding method can be used to fold such tubes with different radial cross-sections into accordion-shaped or telescope-shaped folding casings. 101: Workbench 103: Positioning cart 105: Console 107: Shelf 109: Fixed arm 201: Endoscope 203: Handle 205: Bending portion 207: Dial 209: Rod 211: Proximal opening 300: Surgical instrument 301: Delivery tube 303: Manipulable arm 305: Coupler 401: End effector 403: Light source 405: Camera 700: Cannula assembly 701: End cap 703: Annular lip 705: Channel 707: External instrument channel 709: Donut-shaped balloon 710: Inflation tube 711: Cannula 713: Ring 715: End cap 1501: Syringe 1601: Eyelet To make the above and other objects, features, advantages and embodiments of the present invention more clearly understood, the accompanying drawings are described as follows: FIG1 illustrates a robotic endoscopic surgery system; Figure 2 may be used as a photograph of an endoscope for the system in Figure 1; Figure 3 is a photograph of surgical instruments that can be inserted into the endoscope in Figure 2; FIG4 is a diagram of a steerable arm extending through the tip of the endoscope shown in FIG2; FIG5 illustrates how the endoscope of FIG2 is mounted on the positioning vehicle of the system of FIG1; FIG6 is a schematic diagram of a cannula assembly for expanding the functionality of the endoscope shown in FIG2; FIG7 illustrates another schematic diagram of the sleeve assembly shown in FIG6; FIG8 is another schematic diagram of the sleeve assembly shown in FIG6; FIG9 is a series of schematic diagrams illustrating the use of the bushing assembly; FIG10 illustrates another variation of the sleeve assembly shown in FIG6 ; FIG11 illustrates a cannula assembly with an inflatable balloon; FIG12 shows a front view of the balloon of FIG11; Figure 13 is a photograph of the endoscope coupled to a prototype sleeve assembly; Figure 14 is an image of the boxed portion of Figure 13; Figure 15 is a photograph of the assembly in Figure 13 after it has been broken down into its components; FIG16 is a schematic diagram of a variation of the sleeve assembly; FIG17 is a schematic diagram of a variation of the sleeve assembly; FIG18 is a schematic diagram of a variation of the sleeve assembly; FIG19 is a schematic diagram of a variation of the sleeve assembly; FIG20 is a schematic diagram of a variation of a sleeve assembly; FIG21 is a schematic diagram of a variation of the sleeve assembly; FIG22 is a schematic diagram of a variation of the sleeve assembly; FIG23 is a schematic diagram of a variation of the sleeve assembly; Figure 24 is a schematic diagram of one of the simplest variations of the bushing assembly; FIG25 shows another simplest variation of the bushing assembly; FIG26 is a preferred feature diagram of the end cap of the casing assembly; FIG27 illustrates preferred features of the end cap; FIG28 illustrates another preferred feature of the end cap; FIG29 shows a variation of the end shield; and Figure 30 shows a prototype of the end shield. 701: End cap 703: Annular lip 705: Channel 707: External instrument channel 709: Donut-shaped balloon or balloon 710: Inflatable tube 711: Casing 713: Ring 715: End shield

Claims

1. An endoscope cannula assembly comprising: a hollow cannula having a distal end connected to an end cap, and a proximal end connected to an annular member within the end cap, adapted to allow the endoscope to extend through the annular member and the hollow cannula to mate with the end cap; the cannula being folded into a plurality of folds, each fold being a circumferential portion of the cannula formed by folding along the length of the cannula toward its adjacent circumferential portion; the folds being operable as the endoscope pushes the end cap away from the end cap, wherein... The end cap has a distal side facing the end cover and a proximal side facing away from the end cover; and the folded sleeve is placed on the proximal side of the end cap.

2. The endoscope cannula assembly as described in claim 1, wherein the end cap is sized to allow it to enter the gastrointestinal tract of a human body, but the end cap is too large to enter the mouth or anus of the human body.

3. An endoscope sleeve assembly as described in claim 1 or 2, wherein the sleeve is folded into a series of telescope-like folds.

4. The endoscope sleeve assembly as claimed in claim 3, wherein the telescope fold includes a length portion of the sleeve that is folded along the circumference of the sleeve so that it extends along the length of the sleeve to the next telescope fold of the sleeve.

5. The endoscope sleeve assembly as described in claim 4, wherein the edge of each telescope fold extends over the edge of the next telescope fold.

6. The endoscope sleeve assembly as described in claim 5 further comprises: a plurality of eyelets located within the sleeve, each eyelet being connected to an over-extending edge of the next telescope fold; wherein, The plurality of holes are arranged along the length of the sleeve.

7. The endoscope sleeve assembly as claimed in claim 6, further comprising: a second plurality of eyelets, each eyelet being connected to an overextended edge; the second plurality of eyelets being arranged along the length of the sleeve; wherein, The plurality of holes and the second plurality of holes are located at different positions on the circumference of the sleeve, spaced apart from each other.

8. An endoscope sleeve assembly as described in claim 1 or 2, wherein the sleeve is folded into an accordion shape.

9. The endoscope sleeve assembly as claimed in claim 8 further comprises: a plurality of eyelets, each connected to the accordion folds; and the plurality of eyelets arranged along the length of the sleeve.

10. The endoscope sleeve assembly as claimed in claim 9, further comprising: a second plurality of eyelets, each connected to the accordion-style folds; the second plurality of eyelets being arranged along the length of the sleeve; wherein, These plurality of holes and the second plurality of holes are located at different positions on the circumference of the sleeve, spaced apart from each other.

11. The endoscope sleeve assembly as described in claim 1 or 2 further comprises: an inflatable balloon disposed around the end cap.

12. The endoscope sleeve assembly as described in claim 11, wherein the end cap and the balloon are concentrically arranged.

13. The endoscope cannula assembly as claimed in claim 1 or 2, further comprising: at least one external instrument channel extending from the end cap through the cannula and exiting the annular element on the end cap.

14. The endoscope cannula assembly as claimed in claim 13 further includes two external instrument channels extending from the end cap through the cannula and exiting the annular element on the end cap.

15. The endoscope cannula assembly as claimed in claim 14, wherein the distal ends of the external instrument channel are arranged in a convergent manner on the end cap.

16. The endoscope cannula assembly as claimed in claim 15 further comprises: two orifices connected to the inner surface of the cannula and located at different positions on the circumference of the cannula; two external instrument channels, each extending through a different orifice in the two orifices; wherein, These holes are connected to the inner surface of the sleeve and are separated from the end cap by a distance.

17. The endoscope cannula assembly as claimed in claim 15 further comprises: two orifices connected to the inner surface of the cannula and located at different positions on the circumference of the cannula; two external instrument channels, each extending through a different orifice in the two orifices; the orifices being connected to the inner surface of the cannula and spaced from the end cap by a distance; wherein the distance is less than or equal to half the length of the curved portion of the endoscope or the distance is less than or equal to 10 cm.

18. The endoscope sleeve assembly as claimed in claim 1, wherein the end cap is provided with a plurality of annular elements.

19. A method of securing an endoscope, comprising: providing a hollow cannula as described in claim 1; inserting the endoscope through a proximal end of the cannula; pushing the endoscope into the cannula and pushing a distal end of the cannula away from the proximal end of the cannula to open the cannula; wherein, The folds of the sleeve are opened and cover part of the endoscope that is opened through the folds of the sleeve.

20. The method as described in claim 19, wherein the step of pushing the distal end of the cannula away comprises: pushing the distal end of the cannula into the gastrointestinal tract of the human body.

21. The method as described in claim 20, further comprising: providing at least one fitting connected to the distal end of the sleeve; wherein, The sleeve is partially covered by an open fold, and the at least one fitting passes through the open fold of the sleeve.

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