Preloaded Surgical Instrument Coupler for Backlash-Free Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surgical instrument systems face challenges with backlash in the mechanical interface, which affects the transmission of controlled torque and position, leading to unpredictable instrument motion during installation procedures.
Innovation Solution
A surgical system with a low backlash mechanical interface is developed, featuring a surgical instrument manipulator assembly with a drive unit and a drive output assembly that includes a low backlash coupler. This assembly applies a preload force to ensure zero backlash for torque levels used in surgical procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical interface with gears or disks is used to couple the drive system to the surgical instrument, then the instrument can be mounted and driven, but backlash occurs in the mechanical interface which affects torque and position transmission
Solution Approach 1:
The patent replaces the traditional mechanical interface with gears or disks with a belt-driven pulley system. The belt connects a drive pulley to a driven pulley, eliminating the need for meshing gears and thereby reducing backlash while maintaining the mechanical coupling function between the drive system and surgical instrument.
Solution Approach 2:
The patent changes the mechanical parameters of the interface by using a belt drive system with specific pulley ratios and tensions. By adjusting belt tension and pulley dimensions, the system achieves reliable torque transmission without the backlash inherent in gear-based systems.
2Ease of operation
If drive cables or tendons are used to transmit motion from the backend mechanism to the functional tip, then the instrument can be actuated, but unpredictable instrument motion occurs during installation due to backlash
Solution Approach 1:
The patent replaces the backend mechanism with drive cables or tendons with a direct belt-driven pulley system. The belt connection provides more predictable motion transmission during installation, eliminating the unpredictable instrument motion caused by backlash in cable-driven systems.
3Reliability
If a sterile barrier with a sterile adaptor is interposed between the docking port and instrument backend, then sterilization can be maintained, but the mechanical interface complexity increases
Solution Approach 1:
The patent designs the belt-driven pulley system to be universally compatible with both sterile and non-sterile configurations. The same mechanical interface can accommodate a sterile adaptor when needed, or operate directly without one, reducing overall system complexity while maintaining sterilization capability when required.
Data Source
AI summary
A surgical system includes a surgical instrument that is sensitive to backlash that would adversely affect the transmission of controlled torque and position to the surgical instrument. The surgical instrument is coupled to motors in a surgical instrument manipulator assembly via a mechanical interface. The combination of the mechanical interface and surgical instrument manipulator assembly have low backlash, e.g., less than 0.7 degrees. The backlash is controlled in the surgical instrument manipulator assembly. From the drive output disk in the surgical instrument manipulator assembly to the driven disk of the surgical instrument, the mechanical interface has zero backlash for torque levels used in surgical procedures.