Medical Implantable Lead Fixation Detection Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical implantable leads with rotatable and extendable helix fixation means lack a reliable method to verify proper embedding into tissue, leading to potential incomplete fixation and risk of disengagement, as existing verification methods are either inaccurate or risky.
Innovation Solution
Incorporating a second electric contact surface on the helix or shaft, initially insulated or separate from the first contact surface, to allow detection of tissue contact through electrical measurements during implantation, ensuring secure embedding without over-screwing and tissue perforation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a helix is used as both fixation means and electrode member, then the device structure is simplified and multi-functionality is achieved, but there is no reliable method to verify proper embedding into tissue
Solution Approach 1:
The helix is divided into two distinct contact surfaces: a first contact surface for electrical signal transmission and a second contact surface for fixation verification. This segmentation allows the same helical structure to serve multiple functions while enabling independent verification of embedding depth through the second contact surface.
Solution Approach 2:
The helix simultaneously functions as a fixation means by being screwed into tissue and as an electrode member for electrical signal transmission. The addition of a second contact surface extends this multi-functionality to include fixation verification, allowing a single component to perform multiple critical roles.
2Reliability
If current of injury measurements or mechanical pull tests are performed to verify fixation, then some indication of proper fixation is obtained, but these methods can appear to indicate proper fixation even when only a small part of the helix is secured to the tissue
Solution Approach 1:
The patent replaces mechanical verification methods (pull tests) and indirect electrical measurements (current of injury) with a direct electrical contact method. The second contact surface provides a reliable electrical connection that can be measured to confirm proper embedding depth, substituting unreliable mechanical and indirect electrical methods with a direct electrical measurement approach.
3Ease of operation
If the number of wire loops visible beyond the distal end of the header is counted to verify helix extension, then the extension depth can be estimated, but it is not possible to see whether these wire loops are embedded into tissue or not
Solution Approach 1:
The second contact surface acts as an intermediary element that bridges the gap between visible extension (easy to observe) and actual tissue embedding (difficult to verify). By providing an electrical contact point at a known position on the helix, it mediates between the observable extension depth and the unobservable embedding status, enabling verification through electrical measurement.
4Reliability
If the helix rotating control member is rotated more than the theoretically required number of turns to ensure sufficient screwing out, then proper fixation is more likely achieved, but the distal end of the whole lead may be twisted and may perforate e.g. a heart wall
Solution Approach 1:
The second contact surface provides real-time feedback during the screwing process by enabling electrical measurements that indicate when sufficient embedding has been achieved. This feedback mechanism allows the physician to stop rotation at the appropriate point, preventing over-rotation that could lead to lead twisting and tissue perforation while ensuring adequate fixation security.
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
Enables reliable verification of helix embedding into tissue, ensuring secure attachment and reducing the risk of disengagement by allowing for precise electrical confirmation of fixation depth without over-rotation, thereby improving long-term stability and safety.
Implementation Method 1
a second contact surface being positioned on or adjacent a proximal portion of the helix which is located beyond the distal end of the shaft and being connectible to a connector at the proximal end of the lead by means of an electric conductor
Data Source
AI summary
A lead comprises a mechanical switch at a proximal end of a rotatable shaft. The mechanical switch has a first position to electrically connect a first electric conductor to a second electric conductor for electrically activating a pin and has a second position to electrically connect the first electric conductor to the rotatable shaft for electrically activating a helix. Proper fixation of the helix to an organ is determined by inserting a stylet into the mechanical switch to render the pin electrically active and the helix electrically inactive. Upon determination of proper fixation of the helix to the organ, the stylet is removed from the mechanical switch to render the helix electrically active and the pin electrically inactive.