Flexible Electrode Contacting Device Strain Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical connections between flexible electrode lines and electrodes in implantable devices face challenges with mechanical and dynamic loads, leading to fatigue and insecurity, especially with smaller cross-sections, and thermal processes like welding cause mechanical weakening.
Innovation Solution
A contacting device with a conduction coil, an inner fixing sleeve featuring an axial feed-through slot and a peripheral winding groove, where the coiled wire sub-bundle is wrapped around the fixing sleeve at a minimum angle for secure attachment, reducing mechanical demands and enhancing strain relief.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional welding or crimping methods are used to connect the conductor coil to the electrode, then electrical connection is achieved, but the connection suffers from mechanical weakening and fatigue under dynamic loads
Solution Approach 1:
The connection system is divided into distinct functional segments: the conductor coil, the fixing sleeve with winding groove, and the electrode. The fixing sleeve acts as an intermediary that separates the electrical connection function from the mechanical strain relief function, allowing each component to be optimized independently for its specific purpose
Solution Approach 2:
The fixing sleeve serves as a mediator component between the conductor coil and the electrode. It provides a dedicated winding groove that receives and secures the conductor coil through wrapping, while its rigid structure absorbs mechanical stresses. This intermediary structure eliminates the need for direct welding or crimping between the coil and electrode, thereby preventing thermal or mechanical weakening at the connection point
2Strength
If the conductor coil is directly connected to the electrode without strain relief, then device complexity is reduced, but the connection cannot withstand dynamic movements and tensile stresses
Solution Approach 1:
The fixing sleeve combines multiple functions into a single component: it provides structural support, creates the winding groove for strain relief, and serves as the mounting base for the electrode. This merging of functions into one integrated component achieves strain relief capability without significantly increasing overall device complexity
Solution Approach 2:
The winding groove in the fixing sleeve is designed with a curved or circumferential path that allows the conductor coil to wrap around it. This curved geometry naturally distributes mechanical stresses along the wrap path and provides effective strain relief through the wrapping configuration, while maintaining a simple groove structure
3Volume of moving object
If smaller cross-section components are used to reduce implant size, then patient comfort and device miniaturization are improved, but the fatigue strength and safety for power transmission are compromised
Solution Approach 1:
The fixing sleeve with its winding groove provides beforehand cushioning for the conductor coil. The groove structure and wrapping configuration are designed to absorb and distribute mechanical stresses before they can reach the connection points or weaken the small-diameter wires. This pre-cushioning effect protects the miniaturized components from fatigue and failure under dynamic loads
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 solution provides reliable mechanical and electrical connections, reducing the need for high fatigue strength and allowing single-wire connections, ensuring secure contact and transmission of tensile forces without complex crimping methods, while minimizing mechanical stress and process fluctuations.
Implementation Method 1
the fixing sleeve is pressed onto the conductor coil with plastic deformation for additional secure fixing between the fixing sleeve and the sub-bundle
Implementation Method 2
The fixation takes place through friction-related self-locking of the wires
Data Source
AI summary
A contacting device for electrical connections on flexible electrode leads, particularly implantable ones, that can be inserted into a patient's body, comprises: - a coil (1) with several coradially bundled coiled wires (2.1 - 2.4), - an inner fixing sleeve (4, 4') for a partial bundle (3, 3') of the coiled wires (2.1, 2.2), wherein the fixing sleeve (4, 4') has an axially extending, continuous through-slot (5, 5') for the partial bundle (3, 3') of the coiled wires (2.1 - 2.4) and a circumferential winding groove (9, 9') for the exposed partial bundle (3, 3'), - an outer electrode sleeve, seated on the inner fixing sleeve (4, 4') and electrically contacted with the partial bundle (3, 3'). (10, 10').and - a tensile-resistant fixation between the fixing sleeve (4, 4') and the partial bundle (3, 3') guided through the feedthrough slot (5, 5') by applying pressure to the partial bundle (3, 3') by pressing the fixing sleeve (4, 4') onto the wire helix (1) under plastic deformation and by wrapping the extended partial bundle (3, 3') around the fixing sleeve (4, 4') in the winding groove (9, 9') by a minimum wrap angle (U).