Articulating Monopolar Instrument Wrist Cable Path
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Solution Overview
Problem
Current medical instruments for cauterizing tissue in robotically-enabled medical systems face challenges in providing precise control and minimizing tissue damage due to the need for controlled electrical current application and wear resistance, especially when using monopolar instruments with insulating materials that can lead to premature wear and unintended tissue cauterization.
Innovation Solution
A medical instrument design featuring a wrist mechanism with a distal and proximal clevis, pulleys, and cables that allow for two degrees of freedom articulation, where the cables engage specific pulleys to prevent wear and ensure controlled current application to the end effector, and a cable path configuration that minimizes friction and wear on insulating surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If monopolar instruments with insulating materials are used to control electrical current application, then current control precision is improved, but wear resistance deteriorates due to premature wear of insulating surfaces
Solution Approach 1:
The patent extracts the insulating material from the instrument shaft and replaces it with a non-conductive coating applied only to specific surfaces where electrical isolation is needed. This reduces the overall amount of insulating material, minimizing wear while maintaining current control precision through the coated surfaces.
Solution Approach 2:
The patent applies non-conductive coating selectively to specific surfaces of the instrument shaft rather than coating the entire instrument. This localized approach provides electrical isolation where needed while leaving other surfaces exposed for durability and reduced wear, resolving the contradiction between precision control and wear resistance.
2Ease of operation
If cables engage with distal pulley to provide two degrees of freedom articulation, then ease of operation is improved, but wear increases on insulating surfaces
Solution Approach 1:
The patent removes the cable engagement with the distal pulley entirely, replacing it with a direct mechanical linkage or alternative actuation mechanism. This eliminates the friction and wear that would occur at the cable-pulley interface while maintaining the two degrees of freedom articulation capability through the proximal pulley system.
Solution Approach 2:
The patent introduces a non-conductive coating as an intermediary layer between the cable and the instrument shaft surfaces. This coating reduces friction and wear at contact points while maintaining the necessary mechanical engagement for articulation control.
3Measurement precision
If robotically-enabled medical system is used to control instrument positioning and current supply, then cauterization precision is improved, but complexity of the system increases
Solution Approach 1:
The patent combines the instrument positioning and current supply control functions into a unified robotic system architecture. The robotic arm simultaneously controls both the mechanical positioning of the cauterization tip and the timing/delivery of electrical current, reducing overall system complexity while maintaining high precision through integrated control.
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
The design enables precise and controlled cauterization of tissue while reducing the risk of unintended tissue damage and extending the tool life by minimizing wear on insulating surfaces and ensuring that electrical current is applied only to the intended area.
Implementation Method 1
minimizes friction and wear on insulating surfaces
Implementation Method 2
control a current supplied to the end effector to control cauterization of tissue
Data Source
AI summary
Certain aspects relate to systems and techniques for an articulating monopolar medical instrument. In one aspect, the medical instrument includes a wrist comprising a proximal clevis and a distal clevis; an end effector coupled to the distal clevis via a distal axle; at least one proximal pulley in the proximal clevis; at least one distal pulley in the distal clevis and coupled to the distal axle; a first cable configured to engage with the at least one proximal pulley and the at least one distal pulley; and a second cable configured to engage with the at least one proximal pulley without engaging the at least one distal pulley.