Surgical Adapter Worm Gear Assembly for Rotary-to-Linear Actuation
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Solution Overview
Problem
Existing surgical end effectors driven by linear force are not compatible with surgical devices using rotary motion, requiring complex adapters with many parts and labor-intensive assembly, and there is a need for simpler, more economical adapter assemblies that improve pulley designs and cable tensioning.
Innovation Solution
An adapter assembly with a cable drive system featuring a worm gear, cable gear, and capstan that translates rotational motion into axial translation of cables to actuate end effectors, including pulleys to direct the cables and a firing assembly that operates independently of the cable drive, supported by an outer and inner housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If complex adapters with many parts are used to interface linear-driven end effectors with rotary-driven surgical devices, then compatibility is achieved, but assembly complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple adapter components into a single integrated adapter assembly that includes the outer tube, inner tube, cable drive assembly, and pulley system as one unified structure. This merging of parts maintains compatibility between linear-driven end effectors and rotary-driven surgical devices while significantly reducing assembly complexity and the number of discrete parts that must be manually assembled.
Solution Approach 2:
The adapter assembly is designed as a universal interface that can accommodate different end effector types while working with rotary-driven surgical devices. The standardized cable drive assembly and pulley system provide multi-functional capability, allowing the same adapter structure to interface with various end effectors through the distal opening, thereby achieving broad compatibility without requiring device-specific customization.
2Speed
If lead screw designs are used for cable drive assemblies, then linear motion is generated, but additional length is required to accommodate coordinated cable take-up and release
Solution Approach 1:
The patent replaces the lead screw mechanical system with a pulley-based cable drive system. The pulley assembly with groove-configured pulleys redirects cables to generate linear motion at the distal end without requiring the extended axial length that lead screws would necessitate. This substitution maintains the ability to generate coordinated linear motion for cable take-up and release while significantly reducing the overall length of the adapter assembly.
3Length of moving object
If pulley designs are used instead of lead screws, then compactness is improved, but assembly and tensioning considerations become more complex
Solution Approach 1:
The patent merges the pulley assembly with the inner tube structure, where the pulleys are directly mounted on or integrated with the inner tube. This integration eliminates separate assembly steps for mounting pulleys and simplifies cable tensioning, as the pulleys are pre-positioned in the correct locations. The combined design maintains compactness while significantly improving ease of manufacture and assembly compared to separate pulley components.
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 adapter assembly simplifies the interconnection of linear-driven end effectors with rotary-driven surgical devices, reducing assembly complexity and manufacturing costs while improving cable tensioning and actuation efficiency.
Implementation Method 1
a worm gear, a cable gear coupled to the worm gear and rotatable in response to rotation of the worm gear
Implementation Method 2
a capstan coupled to the cable gear and rotatable in response to rotation of the cable gear, and a cable coupled to the capstan. The cable may be axially translatable in response rotation of the capstan
Data Source
AI summary
A surgical system includes an end effector, a handle assembly that operates the end effector, and an adapter assembly that connects the end effector to the handle assembly. The adapter assembly includes an adapter housing, an outer tube, at least one gear assembly, and a worm gear assembly. The adapter housing has a proximal end portion connected to a distal end portion of the handle assembly. The outer tube extends distally from the adapter housing and supports the end effector on a distal end portion of the outer tube. The worm gear assembly is engaged with the at least one gear assembly and rotatable with the at least one gear assembly in the adapter housing to operate the end effector.