Catheter Sensor Sleeve Isolating Position Sensor from Shape Wire Stress
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Solution Overview
Problem
Existing electrophysiology (EP) catheters face challenges in incorporating electromagnetic position sensors while maintaining shape wire functionality, as sensors are prone to damage due to mechanical stress from shape wire bending and deformation.
Innovation Solution
The design incorporates an electromagnetic position sensor within an outer sleeve that separates it from the catheter shaft, allowing movement relative to the shape wire, reducing mechanical stress and enabling reliable navigation during medical procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electromagnetic position sensor is incorporated into the catheter shaft, then navigation functionality is enabled, but the sensor is prone to damage due to mechanical stress from shape wire bending and deformation
Solution Approach 1:
The catheter structure is segmented into distinct functional zones: a sensor protection zone where the electromagnetic position sensor is housed in a dedicated sensor assembly with its own structural support, separated from the shape wire deformation zone. This segmentation isolates the sensor from mechanical stress while maintaining overall catheter functionality.
Solution Approach 2:
A sensor assembly acts as an intermediary structure between the shape wire and the electromagnetic position sensor. This assembly includes a sensor housing and mounting mechanism that decouples the sensor from direct mechanical coupling with the shape wire, allowing the shape wire to deform without transmitting stress to the sensor.
2Shape
If a shape wire is used to provide preformed shape, then catheter shape control is achieved, but mechanical stress is transmitted to embedded sensors causing potential damage
Solution Approach 1:
The catheter is divided into a shape-defining section containing the shape wire and a sensor-protected section with the electromagnetic position sensor housed in a separate assembly. The sensor assembly is positioned and structured to remain outside the high-stress deformation zone of the shape wire.
Solution Approach 2:
The sensor assembly serves as a mechanical intermediary that breaks the direct stress transmission path between the shape wire and the sensor. The assembly includes flexible connections or mounting mechanisms that allow shape wire deformation without transmitting damaging forces to the sensor.
3Stability of the object's composition
If the sensor is rigidly fixed in the wall, then positioning stability is improved, but the sensor is vulnerable to damage during catheter deformation
Solution Approach 1:
The sensor mounting transitions from a rigid fixed configuration to a dynamic flexible mounting system. The sensor is attached via flexible printed circuit boards, compliant mounts, or telescoping mechanisms that allow relative movement between the sensor and catheter wall during deformation, maintaining electrical connection while accommodating shape changes.
Solution Approach 2:
Flexible printed circuit boards or thin flexible mounting films are used to attach the sensor to the catheter structure. These flexible interconnects maintain electrical and mechanical coupling while allowing the sensor to move independently during catheter deformation, preventing stress concentration on the sensor.
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
This configuration minimizes sensor damage and maintains navigation accuracy, allowing the EP catheter to maintain its preformed shape and functionality, enhancing its applicability in various medical procedures.
Implementation Method 1
The assembly includes one of an electromagnetic position sensor, an impedance-sensing electrode, and an acoustically-responsive element
Data Source
AI summary
A distal tip assembly for an elongate medical device having an axis comprises a shaft having a proximal end portion, a distal end portion, a wall, and a central lumen extending axially between said proximal end portion and said distal end portion. The distal tip assembly further comprises a position sensor disposed in an outer sleeve such that the sensor can shift relative to the sleeve. The sleeve is disposed at least in part in the wall and is substantially fixed thereto.