Wire EDM Fixture Rotation for Multi-Plane Jointed Device Cutting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robotic surgical instruments face challenges in miniaturization due to friction, mechanical weakness, and complex fabrication processes, which compromise precision and reliability, limiting their effectiveness in microsurgical procedures.
Innovation Solution
A method using a wire electro-discharge machining fixture that allows for precise cutting of jointed devices on multiple planes without disassembly, enabling the fabrication of miniaturized, reliable, and durable surgical instruments through a simplified manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If guiding channels and sheaths are used to slide cables inside the jointed device, then the device can achieve multi-degree-of-freedom motion, but friction between the channels and cables limits positioning precision and prevents further miniaturization
Solution Approach 1:
The patent removes the guiding channels and sheaths from the jointed device structure. Instead of having cables slide inside channels, the cables are routed externally along the device members, eliminating the friction-causing interfaces while preserving the cable-driven actuation mechanism for achieving pitch and yaw motions.
Solution Approach 2:
The patent replaces the mechanical sliding system (cables inside guiding channels) with a cable routing system where cables are tensioned against the external surfaces of device members. This substitution eliminates friction-based mechanical interfaces while maintaining the ability to transmit actuation forces for precise positioning.
2Length of moving object
If the physical dimensions of medical instruments are reduced for miniaturization, then the instruments can access smaller surgical sites, but superficial forces like friction become dominant and reduce positioning precision
Solution Approach 1:
By removing the internal guiding channels from the miniaturized device, the patent eliminates the primary source of friction that would be disproportionately impactful at small scales. The cables now interact only with external surfaces, minimizing superficial forces that dominate in miniaturized systems.
3Ease of manufacture
If traditional fabrication methods like injection molding and machining are used for the tendon guiding system, then the device structure can be manufactured, but the device becomes difficult to miniaturize and has multiple locations of mechanical weakness
Solution Approach 1:
The patent removes the complex tendon guiding system with its channels and surfaces, eliminating the need for precision miniaturized fabrication. The simplified structure without internal guiding features can be manufactured using conventional methods without compromising structural integrity or enabling further miniaturization.
4Shape
If multiple cuts on different planes are performed sequentially with disassembly, then complex jointed device geometries can be manufactured, but manufacturing time increases and positioning accuracy decreases
Solution Approach 1:
The patent combines multiple cutting operations on different planes into a single fixtures setup. The fixture holds the workpiece in a position where a wire EDM can perform sequential cuts through multiple planes without requiring disassembly or repositioning of the workpiece, reducing manufacturing time and maintaining positioning accuracy.
Solution Approach 2:
The fixture is designed in advance to accommodate multi-plane cutting operations. The workpiece is positioned and secured in the fixture before all cutting operations begin, allowing continuous machining without interruption. This preliminary positioning enables efficient sequential cutting through different planes.
5Adaptability or versatility
If the tendon guiding system comprises channels surrounding the instrument shaft, then cable routing is achieved, but the device becomes very difficult to miniaturize and has mechanical weakness locations
Solution Approach 1:
The patent removes the tendon guiding channels from the device structure. Instead of routing cables through internal channels that surround the instrument shaft, the cables are routed externally along the device members, eliminating the space-consuming guiding structure and enabling miniaturization.
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 method enhances precision and efficiency in producing miniaturized surgical instruments with improved positioning accuracy and reduced manufacturing time, ensuring reliability and sterility for various medical therapies.
Implementation Method 1
A method using a wire electro-discharge machining fixture that allows for precise cutting of jointed devices on multiple planes
Data Source
Figure 1A~1B
Figure 1C~2A
Figure 2B~3
AI summary
A method of manufacturing a jointed device (70, 170, 270) of a robotic or mechatronic structure of precision mechanics and/or watchmaking and/or jewelery and/or fashion jewelery and/or for the assembly of electromechanical product comprising the following steps: (A) providing a machining fixture (112) on a wire electrical discharge machine having an electrical discharge wire (115), said machining fixture (112) comprising a plurality of member holes (116) each adapted to accommodate at least one workpiece (117), said workpiece (117) being adapted to form at least one portion of said jointed device (70, 170, 270); (B) providing at least two workpieces (117), comprising a first workpiece and a second workpiece, accommodated within at least two member holes (116) of said plurality of member holes (116); (C) associating said machining fixture (112) to the wire electrical discharge machine so that said electrical discharge wire (115) can cut at most one of said at least two workpieces (117) at time; (D) cutting said at least two workpieces (117) by said electrical discharge wire (115); (E)rotating the machining fixture (112) around a fixture rotation axis (R-R) of a predetermined fixture rotation angle, said predetermined fixture rotation angle being chosen to provide that said electrical discharge wire (115) can cut at most one of said at least two workpieces (117) at time; (F) cutting said workpieces (117) by said electrical discharge wire.