Modular Force Sensor for Telerobotic Surgery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current telerobotic surgical systems face challenges in providing accurate feedback of forces and torques to surgeons, particularly due to the need to route wires through flexible wrist joints, which complicates the mechanical actuation of end effectors and limits the precision of force sensing at the instrument tip.
Innovation Solution
A modular force sensor system with axially oriented strain gauges positioned proximal to the wrist joint, allowing for accurate sensing of forces and torques at the instrument tip without errors from wrist configuration changes or temperature variations, and eliminating the need for delicate wire routing through flexible joints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force sensors are placed distal to the wrist joints, then force sensing at the instrument tip is achieved, but wires must be routed through the flexing wrist joint which complicates the mechanical actuation
Solution Approach 1:
The force sensor is divided into modular components: a proximal portion that couples to the instrument shaft and a distal portion that couples to the wrist joint assembly. This segmentation allows the sensor to be positioned at the optimal location for force sensing while avoiding the complexity of routing wires through the flexing wrist joint, as each module can be independently configured and connected.
Solution Approach 2:
The modular force sensor assembly acts as an intermediary component between the instrument shaft and the wrist joint. By positioning the sensor in this intermediate location, the system achieves accurate force sensing without requiring direct wire routing through the flexing wrist joint, thus resolving the contradiction between measurement precision and device complexity.
2Reliability
If wires are routed through the flexing wrist joint, then force sensing is enabled, but the mechanical actuation of end effectors is complicated
Solution Approach 1:
The force sensor is divided into modular components: a proximal portion that couples to the instrument shaft and a distal portion that couples to the wrist joint assembly. This segmentation allows the sensor to be positioned at the optimal location for force sensing while avoiding the complexity of routing wires through the flexing wrist joint, as each module can be independently configured and connected.
Solution Approach 2:
The force sensing capability is extracted from the wrist joint assembly and implemented as a separate modular sensor unit. This extraction eliminates the need to route wires through the flexing wrist joint, thereby simplifying the mechanical actuation of end effectors while preserving force sensing reliability.
3Measurement precision
If strain gauges are positioned on the instrument shaft, then force and torque sensing is achieved, but errors occur due to wrist configuration changes and temperature variations
Solution Approach 1:
The modular force sensor assembly acts as an intermediary component between the instrument shaft and the wrist joint. By positioning the sensor in this intermediate location, the system achieves accurate force sensing without requiring direct wire routing through the flexing wrist joint, thus resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent employs temperature compensation techniques and positioning strategies that change the operational parameters of the strain gauges to minimize the effects of temperature variations and wrist configuration changes, thereby improving measurement accuracy.
4Ease of manufacture
If a single integrated sensor design is used, then manufacturing is simplified, but the sensor and instrument shaft must be made from the same material which may compromise sensor performance
Solution Approach 1:
The force sensor is divided into modular components: a proximal tube portion for operably coupling to a shaft of a surgical instrument and a distal tube portion for proximally coupling to a wrist joint. This segmentation allows each module to be manufactured from optimal materials independently, with the proximal portion using materials suitable for sensor performance and the distal portion using materials compatible with the instrument shaft.
Solution Approach 2:
The modular force sensor design provides universality by allowing different material compositions for different modules while maintaining compatibility through standardized coupling interfaces. This enables the sensor to achieve optimal performance without being constrained by the material requirements of the instrument shaft.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances force and torque feedback to surgeons, improving user control and awareness during robotic surgery by integrating a modular force sensor that can be manufactured and calibrated separately, with the option to use different materials for the sensor and instrument shaft, thus reducing mechanical interference and enhancing precision.
Implementation Method 1
a tube portion including a plurality of strain gauges
Data Source
AI summary
A modular force sensor apparatus, method, and system are provided to improve force and torque sensing and feedback to the surgeon performing a telerobotic surgery. In one embodiment, a modular force sensor includes a tube portion including a plurality of strain gauges, a proximal tube portion for operably coupling to a shaft of a surgical instrument that may be operably coupled to a manipulator arm of a robotic surgical system, and a distal tube portion for proximally coupling to a wrist joint coupled to an end portion.