End tip rotation drive mechanism for an endoscope and endoscope

Abstract

The application provides an end rotating driving mechanism for an endoscope and the endoscope, which comprises a sleeve, first and second flexible outer gear rings fixed to the outer wall of the sleeve, each outer gear ring being provided with inclined elastic sheets at intervals in the circumferential direction, a first rigid inner gear ring rotatably sleeved outside the first flexible outer gear ring, and a second rigid inner gear ring fixedly sleeved outside the second flexible outer gear ring, the inner circumferences of the two rigid inner gear rings being provided with driving teeth engaged with the elastic sheets, first and second actuators connected between the two rigid inner gear rings, the first rigid inner gear ring being alternately driven to rotate back and forth, when rotating forward, the driving teeth push against the elastic sheets to drive the sleeve to rotate, when rotating reversely, the driving teeth slide over the elastic sheets to deform the elastic sheets to make room, and at the same time, the driving teeth of the second rigid inner gear ring limit the second elastic sheets from rotating reversely, preventing the sleeve from rotating reversely; the mechanism is integrated at the end of the endoscope, only the head of the end is rotated, the tissue damage and torque hysteresis caused by the rotation of the whole endoscope are avoided, one-way step rotation is realized, each step is self-locked, the structure is compact, and the mechanism is suitable for narrow spaces.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an end-effector rotation drive mechanism and an endoscope. Background Technology

[0002] In minimally invasive diagnosis and treatment, after the endoscope is inserted into the body, the front lens needs to be able to move flexibly and circumferentially within the cavity to allow for multi-angle, comprehensive observation of the target area. Currently, there are two main approaches to achieving this capability, but each has encountered problems that are difficult to address simultaneously.

[0003] The first type, currently the most widely used solution, involves a curved section at the distal end of the insertion tube, controlled by multiple traction ropes. A motor or handwheel at the handle pulls this curved section via a long rope running through the entire lens, causing it to sway in various directions. This mechanism itself only handles bending. If the circumferential viewing direction of the lens needs to be adjusted, a rotational motion around an axis must be superimposed on the already bent section. The problem lies here—bending and rotation are strongly coupled in this parallel structure of rope traction. When the curved section is already at a significant angle, the tension distribution of the multiple ropes becomes mutually restrictive. If a rotation command is then input, the rope response becomes non-linear or even exhibits dead spots, preventing the operator from obtaining the desired lens pointing. Furthermore, the repeated sliding of the ropes within the insertion tube sheath, several hundred millimeters long, causes frictional signal lag, and wear and creep elongation over long-term use further degrade control accuracy. These are inherent flaws of this type of solution that are difficult to eliminate in principle.

[0004] The second approach, developed to circumvent these problems, involves directly using an electric motor to drive the entire endoscope to rotate around its own axis, with the insertion tube, its internal curved section, and the front lens rotating together. This decouples the rotational motion from the bending mechanism, but at the cost of the entire insertion tube becoming the mass of the rotation. Once the insertion tube is in a curved path within the body, a large area of ​​contact friction occurs between its outer wall and the mucosa of the cavity, drastically increasing rotational resistance and thus increasing the demands on motor power and transmission rigidity. Simultaneously, the entire tube twists in a curved state, subjecting the mucosal tissue to repeated twisting and friction stimulation, which is unsafe for the patient. Furthermore, the slender, flexible tube naturally exhibits a torsional lag when transmitting distal torque; the proximal end rotating does not necessarily mean the distal end follows, making it difficult to eliminate the sense of control lag.

[0005] In reality, both approaches share a common root cause: they both attempt to handle rotational degrees of freedom using whole-scope or cross-scale transmission methods. However, clinically, what truly needs rotation is only the tiny head at the end, which carries the lens. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an end-tip rotation drive mechanism for an endoscope and an endoscope in order to solve one or more problems existing in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a distal rotation drive mechanism for an endoscope, comprising: a sleeve, the distal end of which is configured to connect to a bending module; a first flexible external gear ring, fixedly sleeved on the outer wall of the sleeve, comprising a plurality of first elastic plates spaced circumferentially, the first elastic plates extending obliquely in the same direction; a second flexible external gear ring, fixedly sleeved on the outer wall of the sleeve and axially spaced from the first flexible external gear ring, comprising a plurality of second elastic plates spaced circumferentially, the second elastic plates extending obliquely in the same direction; a first rigid internal gear ring, rotatably sleeved on the outside of the first flexible external gear ring, the inner circumference of which is provided with first actuating teeth that mesh with the first elastic plates; and a second rigid internal gear ring, fixedly... The sleeve is mounted on the outside of the second flexible outer gear ring. Its inner circumference is provided with a second actuating tooth that meshes with the second elastic plate. A first actuator and a second actuator are connected between the first rigid inner gear ring and the second rigid inner gear ring and are configured to alternately drive the first rigid inner gear ring to reciprocate along a first direction and the opposite second direction. When the first rigid inner gear ring rotates along the first direction, the first actuating tooth pushes against the first elastic plate to drive the sleeve to rotate. When the first rigid inner gear ring rotates along the second direction, the first actuating tooth slides over the first elastic plate and causes it to elastically deform and make way. The second actuating tooth of the second rigid inner gear ring restricts the second elastic plate from rotating along the second direction to prevent the sleeve from reversing.

[0008] Furthermore, the first actuator and the second actuator are shape memory alloy springs, which are configured to contract when energized and be passively stretched and reset when the other actuator is energized.

[0009] Furthermore, the first flexible external gear ring includes a first annular base, the first elastic sheet extends integrally from the outer peripheral surface of the first annular base, and the circumferential spacing between adjacent first elastic sheets constitutes a relief space for the elastic deformation of the first elastic sheet; the second flexible external gear ring includes a second annular base, the second elastic sheet extends integrally from the outer peripheral surface of the second annular base, and the circumferential spacing between adjacent second elastic sheets constitutes a relief space for the elastic deformation of the second elastic sheet.

[0010] Furthermore, the first elastic sheet and the second elastic sheet are each cantilever structures, having a root fixed to the corresponding base and a free end extending in the inclined direction.

[0011] Furthermore, the first and second actuating teeth are rigid teeth.

[0012] Furthermore, the second rigid internal gear ring is fixedly connected to the external bracket, which is used to fix the distal end of the endoscope's insertion tube.

[0013] Furthermore, it also includes a bending module, which is fixedly connected to the distal end of the sleeve. The bending module includes a plurality of tandemly hinged joints and an actuating element for driving the joints to bend.

[0014] A medical endoscope includes an insertion tube and a bending module disposed at the distal end of the insertion tube, characterized in that a distal rotation drive mechanism is disposed at the proximal end of the bending module, and the bending module is fixedly connected to the distal end of the sleeve.

[0015] Furthermore, it also includes a slip ring assembly disposed on the proximal side of the sleeve, wherein the rotor end of the slip ring assembly is connected to a cable segment that rotates with the sleeve, and the stator end is connected to a stationary cable segment inserted into the tube.

[0016] A control method for an end-effector rotary drive mechanism includes: The first actuator and the second actuator are driven alternately to make the first rigid internal gear ring reciprocate, thereby driving the sleeve to rotate in one direction. The magnitude and duration of the energizing current of the first actuator and the second actuator are controlled to adjust the step angle of the sleeve.

[0017] The present invention describes a terminal rotation drive mechanism and endoscope for use in endoscopes. Its advantages are as follows: the rotation drive mechanism is fully integrated into the endoscope terminal, driving only the terminal head to rotate while the insertion tube remains stationary throughout the entire process. This fundamentally avoids the risk of tissue friction damage caused by the rotation of the entire endoscope and the response lag problem of long-distance torque transmission. At the same time, through the alternating drive of two sets of actuators and the unidirectional transmission structure of the flexible external gear ring elastic plate and the rigid internal gear ring actuating teeth, the reciprocating oscillation of the actuator is converted into the unidirectional stepping rotation of the sleeve. Each step is mechanically locked by the second rigid internal gear ring, maintaining the rotation angle without continuous power supply. The positioning is stable and reliable, the structure is compact, and it is suitable for integration into the narrow space of the endoscope terminal. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the combined state of the rotating module and the bending module of the present invention; Figure 2 This is an exploded view of the rotating module and bending module of the present invention; Figure 3 This is a schematic diagram of the bending module of the present invention in a bent state; Figure 4 This is an exploded view of the rotating module of the present invention; Figure 5This is a schematic diagram of an endoscope equipped with the end-rotation drive mechanism of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 10, sleeve; 20, bending module; 21, joint; 22, bending memory alloy spring; 23, straightening memory alloy spring; 31, first flexible external gear ring; 32, second flexible external gear ring; 41, first rigid internal gear ring; 42, second rigid internal gear ring; 51, first spring assembly; 52, second spring assembly. Detailed Implementation

[0020] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0021] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] To further illustrate the principles and structure of the present invention, preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] This embodiment provides a medical endoscope with a rotating and bending end. Its core structure consists of a rotating drive mechanism and a bending module arranged in series axially. For ease of description, the end closer to the operator's handle is referred to as the proximal end, and the free end entering the body cavity is referred to as the distal end. The entire end-drive mechanism comprises two parts: a rotating module and a bending module 20. The bending module 20 is located at the distal end, with the rotating module immediately following it.

[0024] Structure of the bending module The bending module 20 adopts a structure in which serrated joints 21 are connected in series and hinged. Multiple joints 21 are hinged end to end to form a flexible segment that can be bent in two orthogonal planes. Each joint 21 has a cavity inside for passing through cables and probes, and an axially through guide groove is opened on the outer peripheral sidewall.

[0025] The elements driving the bending of the joint 21 are two sets of shape memory alloy springs: one set is a bending shape memory alloy spring 22, and the other is a straightening shape memory alloy spring 23, both made of nickel-titanium based shape memory alloy wire with a diameter of 0.1 to 0.3 mm. These two sets of springs axially penetrate the entire bending module 20, passing through guide grooves in the sidewalls of the joint 21. Their ends are fixed to the head base and proximal base of the bending module 20, respectively, while the middle portion can slide freely relative to the guide grooves of each joint 21. The guide grooves constrain the radial position of the springs, preventing them from getting stuck or dislodging at the joint 21 gaps.

[0026] When bending is required, the control handle issues a command to energize the bending shape memory alloy spring 22 located on the side of the bending target. The spring undergoes a martensitic-to-austenitic phase transformation upon heating, shrinking in length and pulling each segment 21 towards that side. To restore straightness, the straightening shape memory alloy spring 23 is energized, causing it to contract and pull the segments 21 back to their original position. The alternating energization and contraction of the two sets of springs allows the bending module 20 to deflect at any angle in space.

[0027] Structure of the rotating module The assembly relationship of the rotating module is as follows: the innermost layer is a cylindrical hollow sleeve 10, and the power supply and signal cables of the probe and image sensor pass through the central hole of the sleeve 10. The far end of the sleeve 10 is fixedly connected to the proximal base of the bending module 20. When the sleeve 10 rotates circumferentially, the entire bending module 20, together with the front probe, rotates synchronously.

[0028] Two flexible external gear rings are fixed on the outer wall of the sleeve 10, arranged sequentially along the axial direction, and are respectively referred to as the first flexible external gear ring 31 and the second flexible external gear ring 32. Each flexible external gear ring consists of an annular base and multiple elastic plates spaced apart along the outer circumferential surface of the base. The elastic plates extend obliquely from the outer circumferential surface of the base in the same circumferential direction, forming a cantilever structure with a fixed root and a free tip. The circumferential gap between adjacent elastic plates constitutes the relief space when the elastic plates are compressed and bent.

[0029] Two rigid internal gear rings are respectively fitted onto the outside of two flexible external gear rings. The one closer to the distal end is the first rigid internal gear ring 41, which has a ring of actuating teeth on its inner circumference. The teeth themselves are rigid and do not deform under force. The first rigid internal gear ring 41 is directly fitted onto the outer periphery of the sleeve 10, leaving a gap between them, allowing it to rotate freely circumferentially relative to the sleeve 10. The one closer to the proximal end is the second rigid internal gear ring 42, which also has a ring of rigid actuating teeth on its inner circumference. The second rigid internal gear ring 42 is fixedly connected to the distal wall of the endoscope insertion tube and cannot rotate.

[0030] The components driving the reciprocating rotation of the first rigid internal gear ring 41 are two sets of tension springs wound with shape memory alloy wire, referred to as the first spring group 51 and the second spring group 52, respectively. Both sets of springs are arranged tangentially along the circumference, with one end attached to the corresponding hole on the first rigid internal gear ring 41 and the other end attached to the corresponding hole on the second rigid internal gear ring 42. Using alloy wire with a single-pass shape memory effect, the wire contracts to generate driving force when heated by electricity, but does not return to its original length after cooling and is de-energized, requiring external force to stretch and reset it.

[0031] Working process of the rotating module In the initial state, both the first spring group 51 and the second spring group 52 are in the state of natural extension after power failure, and the sleeve 10 is stationary.

[0032] When rotation is required, the control system outputs a pulse current to the first spring assembly 51. The first spring assembly 51 contracts upon heating, pulling the first rigid internal gear ring 41 to rotate clockwise relative to the fixed second rigid internal gear ring 42. At this time, the rigid actuating teeth of the first rigid internal gear ring 41 push against the root of the elastic plate of the first flexible external gear ring 31. Because the direction of the force is opposite to the tilt direction of the elastic plate, the elastic plate cannot bend and reposition itself. The actuating teeth transmit torque through the elastic plate to the base and sleeve 10, causing the sleeve 10 and bending module 20 to rotate clockwise by a preset step angle. During this process, the second spring assembly 52 is stretched synchronously.

[0033] The control system then cuts off the current to the first spring assembly 51 and simultaneously energizes the second spring assembly 52. ​​The second spring assembly 52 contracts, pulling the first rigid internal gear ring 41 back to its original position in a counterclockwise direction. At this time, the actuating teeth of the first rigid internal gear ring 41 slide along the inclined direction of the elastic plate of the first flexible external gear ring 31, and the actuating teeth press against the free end of the elastic plate, causing it to bend elastically. The elastic plate moves aside, and the first rigid internal gear ring 41 rotates back to its original position without transmitting reverse torque to the sleeve 10. At the same time, after losing the positive driving force, the sleeve 10 tends to rotate counterclockwise, but the elastic plate of the second flexible external gear ring 32, which is fixed to the sleeve 10, is blocked head-on by the actuating teeth of the fixed second rigid internal gear ring 42. The inclined direction of the elastic plate determines that it cannot bend and move aside at this time. The second rigid internal gear ring 42 applies a circumferential blocking force to the sleeve 10, firmly locking the sleeve 10 at the current angle.

[0034] By repeatedly alternating between the two steps described above, the reciprocating oscillation of the first rigid internal gear ring 41 is transformed into a unidirectional continuous stepping rotation of the sleeve 10 and the bending module 20. The step angle of each step can be precisely controlled by adjusting the magnitude of the energizing current and the pulse duration.

[0035] Cable anti-torsion solution Because the sleeve 10 drives the bending module 20 and the probe to rotate continuously in one direction, and the power supply and signal cables of the probe and image sensor need to travel from the handle end through the inside of the insertion tube to the far end, if the cables directly pass through the center hole of the sleeve 10 and connect to the probe, the continuous rotation of the sleeve 10 will cause the cables to twist or even break. To solve this problem, this embodiment provides a miniature slip ring assembly on the proximal side of the sleeve 10. The rotor end of the slip ring assembly is connected to the cable segment that rotates with the sleeve 10, and the stator end is connected to the stationary cable segment inside the insertion tube. The power supply and signal of the probe and image sensor are continuously transmitted through the slip ring assembly at the rotating interface, and the rotation of the sleeve 10 will not be transmitted to the stationary cable segment inside the insertion tube, thereby completely avoiding the cable twisting problem.

[0036] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A distal end rotation drive mechanism for an endoscope, characterized in that, include: A sleeve, the distal end of which is configured to connect to a bending module; A first flexible external gear ring is fixedly sleeved on the outer wall of the sleeve, and includes a plurality of first elastic pieces arranged circumferentially spaced apart, the first elastic pieces extending inclinedly in the same direction; The second flexible external gear ring is fixedly sleeved on the outer wall of the sleeve and axially spaced from the first flexible external gear ring. It includes a plurality of second elastic pieces arranged circumferentially spaced, and the second elastic pieces extend inclinedly in the same direction. The first rigid internal gear ring is rotatably fitted around the outside of the first flexible external gear ring, and its inner circumference is provided with a first actuating tooth that meshes with the first elastic sheet. The second rigid inner gear ring is fixedly installed and fitted on the outside of the second flexible outer gear ring, and its inner circumference is provided with a second actuating tooth that meshes with the second elastic sheet; A first actuator and a second actuator are connected between the first rigid internal gear ring and the second rigid internal gear ring, and are configured to alternately drive the first rigid internal gear ring to reciprocate along a first direction and the opposite second direction. Specifically, when the first rigid internal gear ring rotates along the first direction, the first actuating tooth pushes against the first elastic plate to drive the sleeve to rotate; when the first rigid internal gear ring rotates along the second direction, the first actuating tooth slides over the first elastic plate and causes it to elastically deform and make way, and the second actuating tooth of the second rigid internal gear ring restricts the second elastic plate from rotating along the second direction to prevent the sleeve from reversing.

2. The end-rotation drive mechanism according to claim 1, characterized in that, The first actuator and the second actuator are shape memory alloy springs, which are configured to contract when energized and be passively stretched and reset when the other actuator is energized.

3. The end-rotation drive mechanism according to claim 1, characterized in that, The first flexible external gear ring includes a first annular base, the first elastic sheet extends integrally from the outer peripheral surface of the first annular base, and the circumferential spacing between adjacent first elastic sheets constitutes the yield space for the elastic deformation of the first elastic sheet; the second flexible external gear ring includes a second annular base, the second elastic sheet extends integrally from the outer peripheral surface of the second annular base, and the circumferential spacing between adjacent second elastic sheets constitutes the yield space for the elastic deformation of the second elastic sheet.

4. The end-rotation drive mechanism according to claim 3, characterized in that, The first elastic sheet and the second elastic sheet are each cantilever structures, having a root fixed to the corresponding base and a free end extending in the inclined direction.

5. The end-rotation drive mechanism according to claim 1, characterized in that, The first and second actuating teeth are rigid teeth.

6. The end-rotation drive mechanism according to claim 1, characterized in that, The second rigid internal gear ring is fixedly connected to the external bracket, which is used to fix the distal end of the endoscope insertion tube.

7. The end-rotation drive mechanism according to claim 1, characterized in that, It also includes a bending module, which is fixedly connected to the distal end of the sleeve. The bending module includes a plurality of tandemly hinged joints and an actuating element for driving the joints to bend.

8. A medical endoscope, comprising an insertion tube and a curved module disposed at the distal end of the insertion tube, characterized in that, An end-rotation drive mechanism according to any one of claims 1 to 7 is provided at the proximal end of the bending module, and the bending module is fixedly connected to the distal end of the sleeve.

9. The medical endoscope according to claim 8, characterized in that, It also includes a slip ring assembly disposed on the proximal side of the sleeve, wherein the rotor end of the slip ring assembly is connected to a cable segment that rotates with the sleeve, and the stator end is connected to a stationary cable segment inserted into the tube.

10. A control method based on the end-rotation drive mechanism of claim 1, characterized in that, include: The first actuator and the second actuator are driven alternately to make the first rigid internal gear ring reciprocate, thereby driving the sleeve to rotate in one direction. The magnitude and duration of the energizing current of the first actuator and the second actuator are controlled to adjust the step angle of the sleeve.

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