Snare with adjustable ferrule

Abstract

The invention discloses a snare with an adjustable ferrule, and belongs to the technical field of medical instruments. Comprising a ferrule, an outer pipe, an inner pipe, an inhaul cable, a sliding ring and a handle, the ferrule is made of shape memory alloy, the two ends of the root of the ferrule are connected with electrified wires respectively, and the two electrified wires are spirally wound on the inhaul cable in the length direction of the inhaul cable; an MEMS pressure sensor used for tension monitoring is arranged between the root of the ferrule and the inhaul cable, and a signal wire of the MEMS pressure sensor is spirally wound on the inhaul cable in the length direction of the inhaul cable. A connector is arranged on the slip ring, the electrified wire and the signal wire are electrically connected with the connector, and the connector is used for being connected with an external circuit; the shape and the open width of the ferrule can be adjusted according to different sizes and forms of polyps, meanwhile, the tension when the ferrule is tightened is monitored in real time through the MEMS pressure sensor, tissue tearing or bleeding caused by excessive tightening of the ferrule is prevented, and the safety in the operation process is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a loop adjustable snare. Background Art

[0002] A snare is a medical surgical instrument that ligates blood vessels, excises polyps or other diseased tissues, and captures and removes foreign bodies in the body by mechanically tightening a metal loop. The traditional snare has the following limitations in use: (1) The shape and opening of the loop are fixed, making it difficult to match polyps with complex shapes; (2) During the operation, the tension when the loop is tightened cannot be monitored in real time. The operator tightens the loop based on experience, and it is easy to cause tissue tearing or bleeding due to over-tightening; (3) The tube and the loop lack imaging markers, and intraoperative positioning depends on the endoscope vision. When encountering complex parts, operation blind spots are likely to occur. Summary of the Invention

[0003] In view of the limitations of the traditional snare in use, the present invention provides a loop adjustable snare.

[0004] The technical solution of the present invention is as follows: A loop adjustable snare includes a loop, an outer tube, an inner tube, a cable, a sliding ring and a handle. The outer tube is connected to the handle to provide support and guidance. The inner tube is arranged in the outer tube and connected to the sliding ring to accommodate the cable. The cable is located in the inner tube. One end of the cable is connected to the loop, and the other end is connected to the sliding ring. The sliding ring is slidably arranged on the handle; The loop is made of shape memory alloy. Both ends of the root of the loop made of shape memory alloy are respectively connected to energized wires. The two energized wires are spirally wound around the cable along the length direction of the cable; A MEMS pressure sensor for tension monitoring is arranged between the root of the loop and the cable. The signal wire of the MEMS pressure sensor is spirally wound around the cable along the length direction of the cable; A connector is arranged on the sliding ring. The energized wires and the signal wires are respectively electrically connected to the connector. The connector is used to connect to an external circuit.

[0005] In order to adjust the shape and opening of the loop to adapt to the complex polyp shape, the loop made of shape memory alloy in the present invention includes a temporary shape and a preset shape, and the opening of the preset shape is larger than that of the temporary shape. An energizing device is arranged in the external circuit. The energizing device is used to energize the loop made of shape memory alloy. When the loop made of shape memory alloy is heated to the Af temperature by the energizing device, it changes from the temporary shape to the preset shape.

[0006] As a preferred embodiment of the present invention, a tension controller is provided in the external circuit, the tension controller is electrically connected to the MEMS pressure sensor, and the tension controller is provided with a display, and the display is used to display the tension value monitored by the MEMS pressure sensor; the MEMS pressure sensor can monitor the tension when the loop is tightened in real time, and the monitored tension can be displayed in digital and graphical form using the display, so that the operator can know the tension when the loop is tightened, thereby preventing tissue tearing or bleeding due to excessive tightening of the loop.

[0007] In order to remind the operator that the tension is too high when the ring is tightened, the tension controller is electrically connected to an alarm device. The tension controller can set a tension threshold. When the tension value monitored by the MEMS pressure sensor is greater than the tension threshold set by the tension controller, the tension controller controls the alarm device to alarm.

[0008] As a preferred embodiment of the present invention, the alarm device includes an audible and visual alarm and a micro-vibrator. The audible and visual alarm is arranged on the tension controller to provide audible and visual alarms. The audible and visual alarm can adopt a buzzer and a red LED light. The micro-vibrator is arranged on the slip ring to provide vibration feedback. Under the effect of the vibration feedback, the operator can be better reminded that the tension of the ring exceeds the set tension threshold. The micro-vibrator is built into the slip ring, and the vibration generated by the micro-vibrator is transmitted to the slip ring. The operator's fingers feel the vibration more directly. When the operator's fingers feel the vibration on the slip ring, the operator's fingers can quickly adjust the strength to reduce the tension of the ring.

[0009] As a preferred embodiment of the present invention, a circular ring is provided at the root of the ferrule, the MEMS pressure sensor is fixed on the inner side of the circular ring, a connecting ring is provided at the front end of the cable, and the connecting ring is interlocked with the circular ring; when the ferrule is tightened, the cable is pulled backward, and the pulling force (tension) is accurately measured; at the same time, when the ferrule is released, the cable is pushed forward, and the thrust is efficiently transmitted, thereby achieving both functionality and reliability at the connection between the ferrule, MEMS pressure sensor, and cable.

[0010] Furthermore, the surface of the MEMS pressure sensor is covered with medical-grade flexible epoxy resin glue, and a window not covered by the medical-grade flexible epoxy resin glue is reserved in the sensitive area of the MEMS pressure sensor; the use of medical-grade flexible epoxy resin glue to wrap the MEMS pressure sensor can not only protect electronic components but also improve the waterproof level. Its hardness is close to that of biological tissue, avoiding stress dispersion due to excessive material rigidity.

[0011] Furthermore, there is a movable gap between the connecting ring and the circular ring, and the movable gap is 0.1 mm; this enables relative movement between the connecting ring and the circular ring, but the movement range is limited to avoid affecting the operation when the cable pulls the ferrule; micro bumps corresponding to and cooperating with the sensitive area of the MEMS pressure sensor are formed on the connecting ring; this ensures that the force directly acts on the sensitive area of the MEMS pressure sensor.

[0012] As a preference of the present invention, strip-shaped developing marks extending along the length direction of the inner tube are embedded in the tube wall of the inner tube, and circular developing marks are arranged at equal intervals; the strip-shaped developing marks and the circular developing marks cooperate with each other to improve the developing effect and facilitate precise positioning under X-ray or endoscope imaging; at the same time, since the inner tube and the outer tube are usually made of transparent materials to facilitate checking the cable in the inner tube before use, the strip-shaped developing marks and the circular developing marks do not affect the operator's inspection of the cable in the inner tube before use. Compared with the way of setting a full-coverage developing layer in the tube body of traditional medical devices, the present invention achieves the developing effect and ensures the transparency of the inner tube.

[0013] As a preference of the present invention, at least four developing alloy points are welded on the ferrule; the developing alloy points are made of platinum-iridium alloy. Multiple developing alloy points can improve the developing effect of the ferrule under X-ray, making the contour of the ferrule clearly visible under X-ray, and facilitating the operator to determine the shape of the ferrule and precisely position it during the operation of the ferrule.

[0014] The beneficial effects of the present invention are as follows: (1) The ferrule is made of shape memory alloy and has two forms, enabling the shape and opening width of the ferrule to be adjusted according to the different sizes and shapes of polyps. (2) The MEMS pressure sensor is used to monitor the tension when the ferrule is tightened in real time. When the tension value monitored by the MEMS pressure sensor is greater than the tension threshold set by the tension controller, the tension controller controls the alarm device to alarm, thereby preventing tissue tearing or bleeding caused by excessive tightening of the ferrule and improving the safety during the operation. (3) The present invention innovatively designs a structure of interlocking rings at the connection of the ferrule, the MEMS pressure sensor, and the cable, achieving both functionality and reliability at the connection of the ferrule, the MEMS pressure sensor, and the cable. (4) The present invention embeds strip-shaped developing marks and circular developing marks in the tube wall of the inner tube. Compared with the way of setting a full-coverage developing layer in the tube body of traditional medical devices, the present invention achieves the developing effect and ensures the transparency of the inner tube. (5) The present invention welds multiple developing alloy points on the ferrule. Multiple developing alloy points can improve the developing effect of the ferrule under X-ray, making the contour of the ferrule clearly visible under X-ray, and facilitating the operator to determine the shape of the ferrule and precisely position it during the operation of the ferrule. Brief Description of the Drawings

[0015] Figure 1 is a schematic diagram of the structure of the invention after the ferrule is released, Figure 1 wherein the ferrule is in a temporary form; Figure 2 is a schematic diagram of the structure of the invention after the ferrule is released, Figure 2 wherein the ferrule is in a preset form; Figure 3 is a schematic diagram of the structure at the ferrule of the invention; Figure 4 is Figure 3 an enlarged view of part A in Figure 5 is Figure 3 an enlarged view of part A in Figure 6 is a schematic diagram of the ferrule structure of the invention; Figure 7 is a circuit connection framework diagram of the invention; Figure 8 is a schematic diagram of the developing mark on the inner tube of the invention.

[0016] Meanings of the reference numerals in the drawings: 1 - Ferrule, 2 - Outer tube, 3 - Inner tube, 4 - Cable, 5 - Slip ring, 6 - Handle, 7 - Limiting block; 8 - MEMS pressure sensor, 9 - Signal wire, 10 - Energized wire; 11 - Connector, 12 - Developing alloy point, 13 - Micro vibrator, 20 - Micro bump; 21 - Ring, 22 - Connecting ring, 30 - Annular developing mark, 31 - Strip-shaped developing mark. Detailed Description of the Invention

[0017] The present invention will be specifically introduced below in conjunction with the drawings and specific embodiments.

[0018] As Figure 1 and 2 shown, this embodiment is a ferrule adjustable snare, including a ferrule 1, an outer tube 2, an inner tube 3, a cable 4, a slip ring 5 and a handle 6. The outer tube 2 is connected to the handle 6 to provide support and guidance. The inner tube 3 is arranged in the outer tube 2 and connected to the slip ring 5 to accommodate the cable 4. The cable 4 is located in the inner tube 3. One end of the cable 4 is connected to the ferrule 1, and the other end is connected to the slip ring 5. The slip ring 5 is slidably arranged on the handle 6. By operating the cable 4 through the slip ring 5, the ferrule 1 is driven to extend out of the outer tube 2 to release or be retracted into the outer tube 2 to tighten; A limiting block 7 is usually also arranged on the handle 6 for limiting; The above is the prior art and will not be elaborated here.

[0019] As Figure 1-5As shown in the figure, in this embodiment, the ferrule 1 is made of shape memory alloy. Both ends of the root of the ferrule 1 made of shape memory alloy are respectively connected to the energized wires 10. The two energized wires 10 are spirally wound around the cable 4 along the length direction of the cable 4. A MEMS pressure sensor 8 for tension monitoring is arranged between the root of the ferrule 1 and the cable 4. The signal wire 9 of the MEMS pressure sensor 8 is spirally wound around the cable 4 along the length direction of the cable 4. A connector 11 is arranged on the slip ring 5. The energized wires 10 and the signal wire 9 are respectively electrically connected to the connector 11. The connector 11 is used to connect to an external circuit. The energized wires 10 and the signal wire 9 are made of silver-plated copper wires and are coated with a polytetrafluoroethylene insulating layer or a polyimide insulating layer.

[0020] In order to adjust the shape and opening of the ferrule 1 to adapt to the complex polyp morphology, in this embodiment, the ferrule 1 made of shape memory alloy includes a temporary shape and a preset shape, and the opening of the preset shape is larger than that of the temporary shape. An energizing device is arranged in the external circuit. The energizing device is used to energize the ferrule 1 made of shape memory alloy. When the ferrule 1 made of shape memory alloy is in the energized state, the current will cause the resistance heating effect in the material, making its temperature rise. When the ferrule 1 made of shape memory alloy is energized and heated to the Af temperature by the energizing device, it changes from the temporary shape to the preset shape. The Af temperature of the ferrule 1 made of shape memory alloy is designed to be 45±2°C, meeting the shape recovery requirements in the body temperature environment.

[0021] As Figure 1 and 2 shown in the figure, in this embodiment, the temporary shape of the ferrule 1 made of shape memory alloy is hexagonal, and the preset shape is elliptical. Of course, in actual application, the temporary shape can also be designed as a semi-circular shape, and the preset shape can be designed as a circular shape. When in use, first use the ferrule 1 in the temporary shape with a smaller opening to snare a smaller polyp. When the smaller polyp is processed, use the energizing device to energize the ferrule 1. When the ferrule 1 is energized and heated to the Af temperature by the energizing device, the ferrule 1 changes from the temporary shape with a smaller opening to the preset shape with a larger opening. Then use the preset shape with a larger opening to snare a larger polyp. Thus, it is realized that the shape and opening of the ferrule 1 can be adjusted according to the different sizes and morphologies of polyps.

[0022] As Figure 7As shown, in this embodiment, a tension controller is set in the external circuit, the tension controller is electrically connected to the MEMS pressure sensor 8, and the tension controller is provided with a display, which is used to display the tension value monitored by the MEMS pressure sensor 8; the MEMS pressure sensor 8 can monitor the tension of the ring 1 when it is tightened in real time, and the monitored tension can be displayed in digital and / or graphical form using the display, so that the operator can know the tension of the ring 1 when it is tightened, and prevent tissue tearing or bleeding due to excessive tightening of the ring 1; the display adopts a touch screen display, so that the tension controller can be operated and information input through the touch screen display; the tension controller adopts a microcontroller MCU-STM32 series.

[0023] In order to remind the operator that the tension of the ring 1 is too large when tightening, the tension controller in this embodiment is also electrically connected to an alarm device. The tension controller can set a tension threshold. When the tension value monitored by the MEMS pressure sensor 8 is greater than the tension threshold set by the tension controller, the tension controller controls the alarm device to sound an alarm; the alarm device includes an audible and visual alarm and a micro vibrator 13. The audible and visual alarm is arranged on the tension controller for providing audible and visual alarms. The audible and visual alarm adopts a buzzer and a red LED light; the micro vibrator 13 is arranged on the slip ring 5 for providing vibration feedback. The micro vibrator 13 is connected to the external circuit through the connector 11 on the slip ring 5. Under the action of vibration feedback, it can better remind the operator that the tension of the ring 1 exceeds the set tension threshold; the micro vibrator 13 is built into the slip ring 5, and the vibration generated by the micro vibrator 13 is transmitted to the slip ring 5. The operator's fingers feel the vibration more directly. When the operator's fingers feel the vibration on the slip ring 5, the operator's fingers can quickly adjust the force to reduce the tension of the ring 1.

[0024] like Figure 3-5 As shown, in this embodiment, a circular ring 21 is provided at the base of the ferrule 1. A current-carrying wire 10 connected to the ferrule 1 passes through the ring body of the circular ring 21. The MEMS pressure sensor 8 is fixed on the inner side of the circular ring 21. The signal wire 9 of the MEMS pressure sensor 8 passes through the ring body of the circular ring 21. A connecting ring 22 is provided at the front end of the cable 4, and the connecting ring 22 is interlocked with the circular ring 21. This achieves accurate measurement of the pulling force (tension) when the ferrule 1 is tightened, and ensures that the cable 4 pushes forward when the ferrule 1 is released, thereby ensuring efficient transmission of the thrust, thereby achieving both functionality and reliability at the connection between the ferrule 1, MEMS pressure sensor 8, and cable 4. The surface of the MEMS pressure sensor 8 is covered with medical-grade flexible epoxy resin glue (not shown in the figure), and a window is reserved in the sensitive area of the MEMS pressure sensor 8 that is not covered by the medical-grade flexible epoxy resin glue. The use of medical-grade flexible epoxy resin glue to wrap the MEMS pressure sensor 8 can not only protect the electronic components but also improve the waterproof level. Its hardness is close to that of biological tissue.

[0025] In this embodiment, there is a movable gap between the connecting ring 22 and the circular ring 21, and the movable gap is 0.1mm; so that the connecting ring 22 and the circular ring 21 can move relative to each other, but the range of movement is limited to avoid affecting the action of the cable 4 when pushing and pulling the ring 1; Figure 5 As shown, micro-bumps 20 corresponding to the sensitive areas of the MEMS pressure sensor 8 are formed on the connecting ring 22; when the ring 1 is tightened, the sensitive areas of the MEMS pressure sensor 8 are pressed by the micro-bumps 20, thereby ensuring that the force acts directly on the sensitive areas of the MEMS pressure sensor 8.

[0026] like Figure 6 As shown, in this embodiment, eight developing alloy points 12 are welded on the ferrule 1. The eight developing alloy points 12 are arranged at intervals. The developing alloy points 12 are made of platinum-iridium alloy. The eight developing alloy points 12 can improve the developing effect of the ferrule 1 under X-rays, so that the outline of the ferrule 1 under X-rays is clearly visible, which is convenient for the operator to determine the shape of the ferrule 1 and accurately position the ferrule 1 when operating it. In actual application, the number of developing alloy points 12 welded on the ferrule 1 can also be appropriately increased or decreased, but it should be at least four.

[0027] In another embodiment of the present invention, the wall of the inner tube 3 is embedded with a strip-shaped developing mark 31 extending along the length direction of the inner tube 3, and annular developing marks 30 are arranged at equal intervals, such as Figure 8 As shown; the strip developing mark 31 and the annular developing mark 30 use barium sulfate developing lines. The strip developing mark 31 and the annular developing mark 30 work together to improve the developing effect, which is convenient for accurate positioning under X-ray or endoscopic images; at the same time, since the inner tube 3 and the outer tube 2 are usually made of transparent materials, it is convenient to check the cable 4 before use. Therefore, the strip developing mark 31 and the annular developing mark 30 do not affect the operator's inspection of the cable 4 before use. Compared with other traditional medical devices that set a full-coverage developing layer in the tube body, this embodiment achieves the developing effect and ensures the transparency of the inner tube 3.

[0028] This embodiment is suitable for endoscopic polypectomy. When in use, the snare is inserted through the endoscopic forceps channel, and the polyp is positioned using the endoscope and the imaging mark. The slip ring 5 is pushed to release the snare 1 so that the snare 1 is wrapped around the base of the polyp. The snare 1 is slowly tightened, and attention is paid to the tension of the snare 1 to ensure that the tension of the snare 1 does not exceed the set tension threshold. If the operator sees the red LED light on, hears the buzzer sound, or feels vibration on the slip ring 5, the operator quickly adjusts the force of the finger to reduce the tension of the snare 1; after the tension stabilizes, the snare 1 is fully tightened to remove the polyp, and this operation is repeated until all polyps are removed, and finally the snare is withdrawn.

[0029] During the process of removing polyps, first use the loop 1 in a temporarily smaller opening state to snare the smaller polyp. After the smaller polyp is processed, then use the energizing device to energize the loop 1, so that the loop 1 changes from the temporarily smaller opening state to the preset state with a larger opening. Then use the preset state with a larger opening to snare the larger polyp.

[0030] Operation Example 1: Resection of sessile polyps After the loop 1 is released, it is in a temporarily hexagonal shape with an opening width d of 25 mm, as Figure 1 shown; the tension threshold is set to 18 N; After the loop 1 completely wraps the polyp, the tension stabilizes at 16 N during tightening, and the resection is successfully completed.

[0031] Operation Example 2: Resection of pedunculated large polyps Switch the shape of the loop 1 so that after the loop 1 is released, it is in a preset elliptical shape with an opening width d of 35 mm, as Figure 2 shown; the tension threshold is set to 20 N; After the loop 1 completely wraps the polyp, the tension stabilizes at 17 N during tightening, and the resection is successful.

[0032] This embodiment can significantly improve the surgical accuracy, safety and operation efficiency, and is applicable to various endoscopic lower digestive tract polyp resection scenarios.

[0033] In the description of the present invention, it should be understood that: the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation of the present invention.

[0034] In the description of the present invention, it should be noted that: unless otherwise clearly specified and limited, the terms "installation", "connection", "setting", "formation" should be understood in a broad sense; for example: it can be a fixed connection, setting, or a detachable connection, setting, or an integrated structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, and can also be the communication inside two elements; for those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form. Any technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A loop adjustable snare, comprising a loop, an outer tube, an inner tube, a cable, a slip ring and a handle. The outer tube is connected to the handle to provide support and guidance. The inner tube is arranged in the outer tube and connected to the slip ring to accommodate the cable. The cable is located in the inner tube. One end of the cable is connected to the loop, and the other end is connected to the slip ring. The slip ring is slidably arranged on the handle. It is characterized in that: The loop is made of shape memory alloy. Both ends of the root of the loop made of shape memory alloy are respectively connected with energized wires, and the two energized wires are spirally wound around the cable along the length direction of the cable; A MEMS pressure sensor for tension monitoring is arranged between the root of the loop and the cable. The signal wire of the MEMS pressure sensor is spirally wound around the cable along the length direction of the cable; A connector is arranged on the slip ring. The energized wires and the signal wires are respectively electrically connected to the connector, and the connector is used for connecting to an external circuit.

2. The adjustable snare according to claim 1, wherein The loop made of shape memory alloy includes a temporary shape and a preset shape, and the opening of the preset shape is larger than that of the temporary shape. An energizing device is arranged in the external circuit, and the energizing device is used for energizing the loop made of shape memory alloy. When the loop made of shape memory alloy is energized and heated to the Af temperature by the energizing device, it changes from the temporary shape to the preset shape.

3. The adjustable snare according to claim 1, characterized in that, A tension controller is arranged in the external circuit. The tension controller is electrically connected to the MEMS pressure sensor. The tension controller is provided with a display, and the display is used for displaying the tension value monitored by the MEMS pressure sensor.

4. The adjustable snare according to claim 3, wherein, The tension controller is electrically connected with an alarm device. The tension controller can set a tension threshold. When the tension value monitored by the MEMS pressure sensor is greater than the tension threshold set by the tension controller, the tension controller controls the alarm device to give an alarm.

5. The adjustable snare according to claim 4, wherein, The alarm device includes an audible and visual alarm and a micro vibrator. The audible and visual alarm is arranged on the tension controller to provide audible and visual alarm. The micro vibrator is arranged on the slip ring to provide vibration feedback.

6. The adjustable snare according to claim 1, wherein, A circular ring is arranged at the root of the loop. The MEMS pressure sensor is fixed inside the circular ring. A connecting ring is arranged at the front end of the cable, and the connecting ring is buckled with the circular ring.

7. The adjustable snare according to claim 6, wherein The surface of the MEMS pressure sensor is covered with a medical-grade flexible epoxy resin glue, and a window without the coverage of the medical-grade flexible epoxy resin glue is reserved in the sensitive area of the MEMS pressure sensor.

8. The adjustable snare according to claim 6, wherein, There is an active gap between the connecting ring and the circular ring, and the active gap is 0.1 mm; Micro bumps corresponding to the sensitive area of the MEMS pressure sensor are formed on the connecting ring.

9. A ferrule adjustable snare according to claim 1, characterized in that, Strip-shaped developing marks extending along the length direction of the inner tube are embedded in the tube wall of the inner tube, and circular developing marks are arranged at equal intervals.

10. A ferrule adjustable snare according to any one of claims 1-9, characterized in that, At least four developing alloy points are welded on the loop.

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