CN-122028863-A - Miniature capstan actuator for surgical instrument

Abstract

The medical device includes one or more winches distally spaced from the force transmitting member and coupled to the one or more elongate rotatable drive elements. The medical device further includes one or more tension elements each coupled to one of the one or more winches and the distal end of the medical device. The length of each of the one or more tension elements is configured to wind around a capstan to which it is coupled, thereby exerting an axial force on the distal end of the medical device.

Inventors

• B.M. Sherner

Assignees

• 直观外科手术操作公司

Dates

Publication Date

20260512

Application Date

20241015

Priority Date

20231016

Claims (20)

1. 1. A medical device, comprising: a proximal force transmission member comprising one or more rotatable inputs configured to receive a force or torque from an external device; An elongate shaft having a proximal end coupled to the proximal force transmission member, the elongate shaft housing one or more elongate rotatable drive elements each coupled to one of the one or more rotatable inputs of the proximal force transmission member; One or more capstans coupled to the distal end of the elongate shaft, each of the one or more capstans including a first end coupled to one of the one or more elongate rotatable drive elements, each of the one or more capstans being distally spaced from the proximal force transmitting member via the elongate shaft, and One or more tension elements, each of the one or more tension elements coupled to one of the one or more winches and a distal end of the medical device, respectively.
2. 2. The medical device of claim 1, wherein the one or more elongate rotatable drive elements are a plurality of elongate rotatable drive elements, the one or more capstans are a plurality of capstans, and the one or more tension elements are a plurality of tension elements.
3. 3. The medical device of claim 1, wherein each of the one or more capstans comprises a shaft, and wherein each of the one or more tension elements is configured to slide axially down the shaft of one of the one or more capstans when wrapped therearound.
4. 4. The medical device of claim 1, wherein each of the one or more tension elements comprises a braided polymer.
5. 5. The medical device of claim 1, wherein each of the one or more tension elements is lubricated.
6. 6. The medical device of claim 1, wherein the elongate shaft is flexible.
7. 7. The medical device of claim 1, wherein the elongate shaft is rigid.
8. 8. The medical device of any one of claims 1-7, wherein each of the one or more tension elements pre-winds one of the one or more capstans to have a substantially constant effective gear ratio for subsequent winding.
9. 9. The medical device of any one of claims 1-7, wherein at least one of the one or more capstans has a shaft with a cross-section that varies along a longitudinal axis such that an effective gear ratio varies when one of the one or more tension elements is wound on the shaft of at least one of the one or more capstans.
10. 10. The medical device of claim 9, wherein the medical device is an endoscope and the change in cross-section corresponds to a change in bending angle of the endoscope.
11. 11. The medical device of claim 10, wherein the change in the cross-section adjusts an effective gear ratio to compensate for an increase in friction caused by a change in the bending angle of the endoscope.
12. 12. The medical device of any one of claims 1-7, wherein the distal end of the medical device is manually actuatable when the medical device is uncoupled from the external device.
13. 13. The medical device of any one of claims 1-7, wherein the one or more capstans are arranged in an antagonistic pair.
14. 14. The medical device of any one of claims 1-7, wherein the elongate shaft has a length greater than or equal to one meter.
15. 15. The medical device of any one of claims 1-7, further comprising a distal bulkhead coupled to the one or more capstans, the distal bulkhead including one or more capstans recesses for receiving respective capstans of the one or more capstans and a redirecting aperture adjacent each capstans recess for each of the one or more tension elements.
16. 16. The medical device of claim 15, wherein the redirecting aperture adjacent to each capstan recess is configured to redirect one of the one or more tension elements from a wrap angle relative to a longitudinal axis of the capstan to an axial angle substantially parallel to the longitudinal axis of the capstan.
17. 17. The medical device of claim 16, wherein the redirecting aperture adjacent to each capstan recess comprises a shoulder having a smooth surface.
18. 18. The medical device of any one of claims 1-7, each of the one or more capstans having a second end comprising a conical section having a spherical dome tip.
19. 19. The medical device of any one of claims 1-7, further comprising a proximal bulkhead coupled to the one or more capstans, the proximal bulkhead including a rotational bearing for each of the one or more capstans.
20. 20. The medical device of claim 19, wherein the first end of each of the one or more capstans is positioned within a respective rotational bearing of the proximal bulkhead.

Description

Miniature capstan actuator for surgical instrument Cross Reference to Related Applications The present application claims the benefit of priority from U.S. provisional application No.63/590,748 filed 10/16 at 2024, the entire contents of which are incorporated herein by reference. Technical Field The present disclosure relates to miniature winch (capsule) actuators for surgical instruments. Background Minimally invasive medical techniques aim to reduce the amount of damaged tissue in a medical procedure, thereby reducing patient recovery time, discomfort, and deleterious side effects. Such minimally invasive techniques may be performed through natural orifices in the patient's anatomy or through one or more surgical incisions. Through these natural orifices or incisions, the operator may insert minimally invasive medical instruments to reach the target tissue site. Minimally invasive medical instruments include instruments such as therapeutic, diagnostic, biopsy, and surgical instruments. The medical instrument may be inserted into the anatomical passageway and directed toward a region of interest within the patient's anatomy. Some anatomical passageways, such as the gastrointestinal tract (GI), are long and tortuous. Surgical instruments for GI procedures such as endoscopic submucosal dissection (Endoscopic Submucosal Dissection, ESD) and endoscopic submucosal resection (Endoscopic Mucosal Resection, EMR) can be operated through long, flexible working channels of standard or custom endoscopes or otherwise along such endoscopes, which can be over 1.6 meters in length. Articulation of the instrument and/or endoscope may be by a tension element (e.g., a drive cable) wound on a rotating capstan. The capstan is operably coupled to an external device, such as a robotic manipulator, and receives force/torque from the manipulator to drive the instrument and/or endoscope. However, with longer lengths of instrument/endoscope and associated drive cables, capstan friction from moving the tensioning cable through a tortuous path may hinder actuation of the surgical instrument, as capstan friction increases exponentially based on the angle of bending. Even a small increase in the bending angle multiplies the force loss to the point that the surgical instrument is malfunctioning or completely out of operation and reaches the cumulative bending angle of the cecum, which may exceed 360 degrees, for example. In short, the design of flexible surgical instruments is limited by the actuation challenge posed by capstan friction. There is a need for an instrument that can operate without unduly increasing capstan friction to achieve a medical procedure. Disclosure of Invention Consistent with some examples, a medical device may include a proximal force transmitting member, an elongate shaft, one or more winches, and one or more tension elements. The proximal force transmitting member may include one or more rotatable inputs configured to receive a force or torque from an external device. The elongate shaft may have a proximal end coupled to a proximal force transmitting member. The elongate shaft may house one or more elongate rotatable drive elements that are each coupled to one of the one or more rotatable inputs of the proximal force transmission member. One or more winches may be coupled to the distal end of the elongate shaft. One or more winches may each include a first end coupled to one of the elongate rotatable drive elements. Each of one or more winches may be distally spaced from the force transmitting member via the elongate shaft. Each of one or more tension elements may be coupled to one of the one or more winches and to a distal end of the medical device. Consistent with some examples, a medical device may include a proximal force transmitting member, an elongate shaft, one or more winches, and one or more tension elements. The proximal force transmitting member may include one or more rotatable inputs configured to receive a force or torque from an external device. The elongate shaft may have a proximal end coupled to a proximal force transmitting member. The elongate shaft may house one or more elongate rotatable drive elements that are each coupled to one of the one or more rotatable inputs of the proximal force transmission member. One or more winches may be coupled to the distal end of the elongate shaft. One or more winches may each include a first end coupled to one of the elongate rotatable drive elements. Each of the one or more tension elements may have a first end coupled to one of the one or more capstans, a second end directly coupled to the distal end of the medical device, and a length configured to wrap around the one of the one or more capstans. The second end of each of the one or more tension elements may be configured to exert an axial force on the distal end of the medical device when the length of the tension element is wrapped around one of the one or more capstans. Consistent with some exam