US-12622722-B2 - Surgical instrument shears

US12622722B2US 12622722 B2US12622722 B2US 12622722B2US-12622722-B2

Abstract

A medical device includes a blade support, a blade supported by the blade support, and a pin. The blade support includes a bore with an inner portion oriented toward the blade and an outer portion oriented away from the blade. A discontinuity is located at a boundary between the inner and outer portions of the bore. The pin includes a longitudinal axis and a yaw plane is defined perpendicular to the longitudinal axis. A rotational yaw degree of freedom is defined about the longitudinal axis of the pin. The blade support is operable to rotate about the pin in the yaw degree of freedom, contact the pin at the discontinuity of the bore, and tilts away from the yaw plane at the discontinuity of the bore in response to a force applied in a lateral direction.

Inventors

Paul FLOYD
Erik Nelson
Matthew Wixey

Assignees

Intuitive Surgical Operations, Inc.

Dates

Publication Date: 20260512
Application Date: 20220816

Claims (20)

1 . A medical device comprising: a blade support, a blade supported by the blade support, and a pin; wherein the blade support comprises a bore; wherein the bore comprises an inner portion oriented toward the blade, an outer portion oriented away from the blade, and a discontinuity at a boundary between the inner portion and the outer portion of the bore; wherein the pin extends through the bore of the blade support; wherein the pin includes a first end and a second end opposite the first end; wherein a longitudinal axis of the pin is defined between the first and second ends of the pin, a yaw plane is defined perpendicular to the longitudinal axis of the pin, a lateral direction is defined as a direction away from the yaw plane, and a rotational yaw degree of freedom is defined about the longitudinal axis of the pin; and wherein the blade support rotates about the pin in the rotational yaw degree of freedom, contacts the pin at the discontinuity of the bore, and tilts away from the yaw plane at the discontinuity of the bore in response to a force applied in the lateral direction.
2 . The medical device of claim 1 , wherein: the blade is a first blade; in an unflexed state of the first blade in the lateral direction, the first blade has a first lateral curvature; in a first flexed state of the first blade in the lateral direction, the first blade has a second lateral curvature straighter than the first lateral curvature; in a second flexed state of the first blade in the lateral direction, the first blade has a third lateral curvature straighter than the second lateral curvature; at a first cut point position on the first blade in relation to a second blade, the first blade is in the first flexed state or the second flexed state; at a second cut point position on the first blade in relation to the second blade, the first blade is in a third flexed state; and the blade support tilts away from the yaw plane at the discontinuity of the bore as the first blade rotates from the first cut point position to the second cut point position.
3 . The medical device of claim 1 , wherein: the blade support comprises an inner support portion oriented toward the blade and an outer support portion oriented away from the blade; the inner support portion of the blade support supports the blade; the outer support portion of the blade support comprises an actuating cable groove; and the actuating cable groove is positioned with reference to the discontinuity in the bore such that a tension in an actuating cable extending from the actuating cable groove away from the outer support portion of the blade support does not cause the blade support to tilt away from the yaw plane at the discontinuity of the bore.
4 . The medical device of claim 1 , wherein: the medical device further comprises a cable; the blade support comprises an inner support portion oriented toward the blade and an outer support portion oriented away from the blade; the inner support portion of the blade support supports the blade; the outer support portion of the blade support comprises a cable groove; the cable is positioned in and extends away from the cable groove; a tension on the cable away from the blade support urges the blade support to rotate about the pin in the rotational yaw degree of freedom; and the cable groove is positioned such that the tension on the cable does not cause the blade support to tilt away from the yaw plane at the discontinuity of the bore.
5 . The medical device of claim 1 , wherein: contact between the outer portion of the bore and the pin limits tilting of the blade support at the discontinuity of the bore.
6 . The medical device of claim 1 , wherein: the blade is a first blade and comprises a distal end portion; the medical device further comprises a second blade; the second blade rotates about the pin and comprises a distal end portion; and at a first yaw orientation in the rotational yaw degree of freedom of the first blade with reference to the second blade, the first blade contacts the second blade at a first cut point proximal of the distal end portion of the first blade, and the distal end portion of the first blade overlaps the distal end portion of the second blade in the yaw plane.
7 . The medical device of claim 6 , wherein: at the first yaw orientation of the first blade with reference to the second blade, the first blade and the second blade are separated in the lateral direction by a gap; and the gap is located proximal of the first cut point.
8 . The medical device of claim 6 , wherein: at a second yaw orientation in the rotational yaw degree of freedom of the first blade with reference to the second blade, the first blade contacts the second blade at a second cut point distal of the first cut point; and the distal end portion of the first blade does not overlap the distal end portion of the second blade in the lateral direction.
9 . The medical device of claim 6 , wherein: the first blade comprises a proximal portion located proximal of the pin; the second blade comprises a proximal portion located proximal of the pin; and at the first yaw orientation of the first blade with reference to the second blade, the proximal portion of the first blade contacts the proximal portion of the second blade, the first and second blades are separated by a gap in the lateral direction, and the gap is located between the proximal portions of the first and second blades and the first cut point.
10 . The medical device of claim 1 , wherein: the medical device further comprises a clevis and a spring; the clevis comprises a clevis ear; the pin extends from the blade support through the spring to the clevis ear; and the spring urges the blade support in the lateral direction toward the blade.
11 . The medical device of claim 1 , wherein: the blade is a stamped metal blade.
12 . The medical device of claim 1 , wherein: the outer portion of the bore is tapered outward in the lateral direction away from the blade.
13 . A medical device comprising: a blade support, a blade supported by the blade support, and a pin; wherein the blade support comprises a bore; wherein the bore comprises an inner portion oriented toward the blade, an outer portion oriented away from the blade, and a discontinuity at a boundary between the inner portion and the outer portion of the bore; wherein the pin extends through the bore of the blade support; wherein the blade support rotates about the pin in a yaw degree of freedom; and wherein a force on the blade in a lateral direction parallel to a longitudinal axis of the pin tilts the blade support in the lateral direction at the discontinuity of the bore.
14 . The medical device of claim 13 , wherein: the blade is a first blade; the first blade is flexible in the lateral direction; in an unflexed state, the first blade has a first lateral curvature; in a first flexed state, the first blade has a second lateral curvature straighter than the first lateral curvature; in a second flexed state, the first blade has a third lateral curvature straighter than the second lateral curvature; at a first cut point position on the first blade in relation to a second blade, the first blade is in the first flexed state or the second flexed state; at a second cut point position on the first blade in relation to the second blade, the first blade is in a third flexed state; and the blade support tilts at the discontinuity of the bore as the first blade rotates to cut from the first cut point position to the second cut point position.
15 . The medical device of claim 13 , wherein: the blade support comprises an inner support portion oriented toward the blade and an outer support portion oriented away from the blade; the inner support portion of the blade support supports the blade; the outer support portion of the blade support comprises an actuating cable groove; and a solid plane defined by the actuating cable groove intersects the inner portion of the bore such that tension on an actuating cable in the actuating cable groove does not cause the blade support to tilt at the discontinuity of the bore.
16 . The medical device of claim 13 , wherein: the medical device further comprises a cable; the blade support comprises an inner support portion oriented toward the blade and an outer support portion oriented away from the blade; the inner support portion of the blade support supports the blade; the outer support portion of the blade support comprises a cable groove; the cable is positioned in the cable groove; a tension on the cable urges the blade support to rotate in the yaw degree of freedom; and the cable groove is positioned such that the tension on the cable does not cause the blade support to tilt at the discontinuity of the bore.
17 . The medical device of claim 13 , wherein: contact between the outer portion of the bore and the pin limits tilting of the blade support at the discontinuity of the bore.
18 . The medical device of claim 13 , wherein: the blade is a first blade and comprises a distal end portion; the medical device further comprises a second blade, the second blade rotates about the pin, and the second blade comprises a distal end portion; and at a first yaw orientation of the first blade with reference to the second blade, the first blade contacts the second blade at a first cut point proximal of the distal end portion of the first blade, and the distal end portion of the first blade does not extend beyond the distal end portion of the second blade in the lateral direction.
19 . The medical device of claim 18 , wherein: at the first yaw orientation of the first blade with reference to the second blade, the first blade and the second blade are separated by a gap in the lateral direction; and the gap is located proximal of the first cut point.
20 . The medical device of claim 18 , wherein: at a second yaw orientation of the first blade with reference to the second blade, the first blade contacts the second blade at a second cut point distal of the first cut point; and the distal end portion of the first blade does not extend beyond the distal end portion of the second blade in lateral direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. national stage filing under 35 U.S.C. § 371 of International Application No. PCT/US2022/040452, entitled “Surgical Instrument Shears,” filed Aug. 16, 2022, which claims benefit of priority to U.S. Provisional Application Ser. No. 63/234,662, entitled “Surgical Instrument Shears,” filed Aug. 18, 2021, each of which is incorporated herein by reference in its entirety. BACKGROUND The embodiments described herein relate to medical devices, and more specifically to endoscopic tools. More particularly, the embodiments described herein relate to devices that include instrument tools, such as shears, that rotate and tilt about a supporting pin to improve cutting. Known techniques for Minimally Invasive Surgery (MIS) employ instruments to manipulate tissue that can be either manually controlled or controlled via computer-assisted teleoperation. Many known MIS instruments include a therapeutic or diagnostic end effector (e.g., forceps, a cutting tool, or a cauterizing tool) mounted on a wrist mechanism at the distal end of a shaft. During an MIS procedure, the end effector, wrist mechanism, and the distal end of the shaft are inserted into a small incision or a natural orifice of a patient to position the end effector at a work site within the patient's body. The optional wrist mechanism can be used to change the end effector's orientation with reference to the shaft to perform the desired procedure at the work site. Known wrist mechanisms generally provide the desired mechanical degrees of freedom (DOFs) for movement of the end effector. For example, known wrist mechanisms are able to change the pitch and yaw orientation of the end effector with reference to the shaft's longitudinal axis. A wrist may optionally provide a roll DOF for the end effector with reference to the shaft, or an end effector roll DOF may be implemented by rolling the shaft, wrist, and end effector together as a unit. An end effector may optionally have additional mechanical DOFs, such as grip or knife blade motion. In some instances, wrist and end effector mechanical DOFs may be combined to provide various end effector control DOFs. For example, U.S. Pat. No. 5,792,135 (filed May 16, 1997) discloses a mechanism in which wrist and end effector grip mechanical DOFs are combined to provide an end effector yaw control DOF. To enable the desired movement of the distal wrist mechanism and end effector, known instruments include cables that extend through the shaft of the instrument and that connect the wrist mechanism to a mechanical structure configured to move the cables to operate the wrist mechanism and end effector. For teleoperated systems, the mechanical structure is typically motor driven and is operably coupled to a computer processing system to provide a user interface for a clinical user (e.g., a surgeon) to control the instrument as a whole, as well as the instrument's components and functions. Patients benefit from continual efforts to improve the effectiveness of MIS methods and devices. For example, reducing the size and/or the operating footprint of the shaft and wrist mechanism can allow for smaller entry incisions and reduced need for space at the surgical site, thereby reducing the negative effects of surgery, such as pain, scarring, and undesirable healing time. But producing small medical devices that implement the clinically desired functions for minimally invasive procedures can be challenging. Specifically, simply reducing the size of known wrist mechanisms by scaling down the components will not result in an effective solution because required component and material properties do not scale at relatively small physical dimensions. For example, efficient implementation of a wrist mechanism can be complicated because the cables must be carefully routed through the wrist mechanism to maintain cable tension throughout the range of motion of the wrist mechanism or end effector and to minimize the interactions (coupling effects) of motion about one rotation axis upon motion about another rotation axis. As another example, pulleys and/or contoured surfaces are generally needed to reduce cable friction, which extends instrument life and permits operation without excessive forces being applied to the cables or other structures in the wrist mechanism. But increased localized forces that may result from smaller structures and cable bend radii (including smaller diameter cables and other wrist and end effector components) can result in undesirable lengthening (e.g., stretch or creep) of the cables during storage and use, reduced cable life, and the like. Further, the wrist mechanism generally provides specific degrees of freedom for movement of the end effector. For example, for forceps or other grasping tools, the wrist may be able to change the end effector pitch, yaw, and grip orientations with reference to the instrument shaft. More degrees of freedom could be impleme