Robotic Surgical Control Arm With Cable Drive and Haptic Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robotic surgical systems face challenges in maintaining degrees of freedom of movement for control arms while preventing interference with other arms and offsetting gravitational, frictional, and inertial forces, while also providing haptic feedback to clinicians.
Innovation Solution
A drive mechanism comprising first, second, and third motors associated with axes of rotation, along with a system of pulleys and cables, is used to manipulate the control arm, allowing independent rotation and pivoting of its components to maintain movement freedom and provide haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a control arm is designed to maintain degrees of freedom of movement, then the gimbal can move freely in multiple directions, but the control arm may interfere with other control arms in the robotic surgical system
Solution Approach 1:
The control arm employs dynamic positioning through active drive mechanisms that continuously adjust the arm's position and orientation. The system uses motors and cable-driven mechanisms to dynamically reposition the control arm, ensuring it maintains its degrees of freedom while avoiding interference zones with other arms during surgical procedures.
2Reliability
If the control arm structure is made complex to provide haptic feedback and offset gravitational forces, then haptic feedback and force offsetting are improved, but the device complexity increases
Solution Approach 1:
The drive mechanism incorporates counterbalancing elements that offset gravitational forces acting on the control arm and gimbal assembly. By integrating counterweights or spring-loaded mechanisms within the drive system, the patent reduces the net force required to move the arm, thereby providing haptic feedback while managing the complexity through force equilibrium.
Solution Approach 2:
The system implements haptic feedback through sensors and actuators in the drive mechanism that detect the position and movement of the control arm, then provide resistive or assistive forces to the clinician's manual input. This feedback loop enhances reliability by providing tactile information about arm position and surgical tool status without requiring overly complex external systems.
3Measurement precision
If multiple drive motors are added to independently control each axis of rotation, then precise control of the control arm is improved, but the device complexity and number of components increase
Solution Approach 1:
The control arm system is segmented into distinct rotational axes, each controlled by its own drive mechanism. This segmentation allows independent control of each degree of freedom, improving precision while organizing complexity into manageable modular units. Each axis can be controlled separately, enabling precise positioning without requiring a monolithic complex system.
Solution Approach 2:
The drive mechanism uses universal components such as cable-driven systems and pulley assemblies that can serve multiple functions across different axes. A single cable system can control both positioning and orientation, reducing the total number of independent motors and components needed while maintaining precise control capability.
Data Source
AI summary
A control arm for a robotic surgical system includes a base, a swivel member, a vertical member, a horizontal member, and a drive mechanism. The swivel member is rotatably supported on the base about a first axis of rotation. The vertical member is pivotally supported on the swivel member about a second axis of rotation. The horizontal member is pivotally supported by the vertical member about a third axis of rotation. The drive mechanism is disposed on the base and is configured to independently rotate the swivel member about the first axis of rotation, to pivot the vertical member about the second axis of rotation, and to pivot the horizontal member about the third axis of rotation.