Gravity compensation of end effector arm for robotic surgical system
Inventors
Chappuis, Olivier • Kostrzewski, Szymon
Assignees
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Publication Number
US-12458454-B2
Publication Date
2025-11-04
Expiration Date
Abstract
An end effector arm for use with a surgical navigation system includes a base configured to attach to an end effector coupler of a surgical robot arm and a mechanical linkage. The mechanical linkage includes a first end rotatably coupled to the base and a second end opposite the first end, the second end configured to be removably coupled to a handheld surgical tool. The end effector arm further includes a spring mechanism configured to impart a variable rotational force on the mechanical linkage based on an angle of rotation of the mechanical linkage with respect to the base.
Core Innovation
The disclosed invention relates to an end effector arm for use with a robotic surgical system that provides gravity compensation using a spring mechanism imparting a variable rotational force on a mechanical linkage based on an angle of rotation of the mechanical linkage. The mechanical linkage includes a first end rotatably coupled to a base and a second end opposite the first end, with the second end removably coupled to a handheld surgical tool. The variable rotational force is configured to reduce unwanted behavior as the mechanical linkage rotates with respect to the base, including behavior when the resection plane is inclined or near-vertical.
In the gravity compensation spring mechanism, a spring, a cable, and a cam are arranged to maintain a defined relationship between the linkage rotation angle and the rotational force imparted to the mechanical linkage. The spring includes a first end and a second end, where the first end of the spring is coupled to one of the base and the first end of the mechanical linkage, and the cable includes a first end and a second end with the first end coupled to the first end of the spring. A cam is coupled to the other of the base and the first end of the mechanical linkage, and the second end of the cable is coupled to the cam, with the cam including a cam guide configured to receive and maintain the second end of the cable within the cam guide during rotation of the mechanical linkage with respect to the base.
The invention further supports a gravity-compensating functional relationship by configuring the variable rotational force to substantially equal gravitational force acting on the second end over a range of angles of rotation of the mechanical linkage relative to the base. The spring mechanism response is described in terms of deformation that changes non-linearly relative to rotation, and the system includes a selective locking mechanism to selectively lock the handheld surgical tool relative to the base.
Claims Coverage
The document contains three independent claims. Across these independent claims, the core coverage is a robotic surgical gravity-compensating end effector arm that imparts variable rotational force as a function of mechanical linkage rotation angle, using a spring/cable/cam arrangement with a cam guide that maintains the cable during rotation, and in a broader surgical system that includes tracking of poses for both the anatomical structure and the surgical tool.
Gravity compensation end effector arm with variable rotational force based on linkage rotation angle
An end effector arm for use with a robotic surgical system comprising a base configured to attach to an end effector coupler of a surgical robot arm; a mechanical linkage including a first end rotatably coupled to the base and a second end opposite the first end, the second end configured to be removably coupled to a handheld surgical tool; and a spring mechanism configured to impart a variable rotational force on the mechanical linkage based on an angle of rotation of the mechanical linkage.
Spring-cable-cam arrangement with cam guide maintaining cable during rotation
The spring mechanism comprising a spring including a first end and a second end, the first end of the spring coupled to one of the base and the first end of the mechanical linkage; a cable including a first end and a second end, the first end of the cable coupled to the first end of the spring; and a cam coupled to the other of the base and the first end of the mechanical linkage, the second end of the cable coupled to the cam, the cam including a cam guide configured to receive and maintain the second end of the cable within the cam guide during rotation of the mechanical linkage with respect to the base.
Surgical tool guidance system with robotic end effector arm and handheld surgical tool coupling
A surgical tool guidance system comprising a robot arm configured to be positioned by a surgical robot, the robot arm including an end effector coupler; an end effector arm including a base configured to attach to the end effector coupler of the robot arm, a mechanical linkage including a first end rotatably coupled to the base and a second end opposite the first end, and a spring mechanism configured to impart a variable rotational force on the mechanical linkage based on an angle of rotation of the mechanical linkage; and a handheld surgical tool configured to couple to the second end of the mechanical linkage.
Surgical system with tracking poses and spring-based variable rotational force end effector arm
A surgical system comprising a tracking system configured to determine a pose of an anatomical structure that is to be engaged by a handheld surgical tool and to determine a pose of the surgical tool; a surgical robot including a robot base, a robot arm connected to the robot base, the robot arm including an end effector coupler, and at least one motor operatively connected to move the robot arm relative to the robot base; an end effector arm including a base configured to attach to the end effector coupler of the robot arm, a mechanical linkage including a first end rotatably coupled to the base and a second end opposite the first end, and a spring mechanism configured to impart a variable rotational force on the mechanical linkage based on an angle of rotation of the mechanical linkage with respect to the base; and a handheld surgical tool coupled to the second end of the mechanical linkage.
Across independent claim coverage, the invention centers on a robotic surgical end effector arm that applies variable rotational force as a function of mechanical linkage rotation angle using a spring/cable/cam mechanism with a cam guide that maintains the cable during rotation, and that is integrated into a surgical system with robotic motion and pose tracking.
Stated Advantages
Reduces surgeon hand load and helps avoid unwanted acceleration/behavior when a resection plane is inclined or near-vertical.
Prevents unwanted acceleration/behavior by gravity-compensating variable rotational force as the mechanical linkage rotates relative to the base.
Documented Applications
Robotic surgical gravity compensation for osteotomy, including knee arthroplasty, using an end effector arm with a variable-compensation torque mechanism responsive to mechanical linkage angle of rotation.
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