Spherical Linkage Catheter Coupler for Accurate Tissue Contact Sensing
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Solution Overview
Problem
Current catheter systems face challenges in ensuring consistent mechanical contact between the electrode and tissue, particularly in dynamic environments like a beating heart, leading to potential false positive outcomes due to the sensitivity of existing force sensors to radiofrequency, electromagnetic interference, and thermal effects.
Innovation Solution
A coupler assembly with a spherical linkage that connects the catheter shaft and distal tip, featuring link arms with compliant or revolute joints, allowing the distal end to move relative to the catheter and sense external forces, including axial and transverse forces, while minimizing interference from RF and thermal effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If remotely placed sensors are used to detect contact between the electrode and tissue, then the complexity of the catheter system is reduced, but false positive outcomes occur when the distal portion of the catheter contacts tissue instead of the electrode
Solution Approach 1:
A coupler assembly acts as an intermediary mechanical linkage between the electrode and the catheter shaft. This coupler includes link arms with joints that mechanically connect the electrode assembly to the catheter body, allowing force transmission while enabling independent movement of the distal catheter portion. The coupler mediates the interaction between the electrode and tissue, ensuring that force sensors can accurately detect electrode-tissue contact forces while the distal catheter can move independently to maintain electrode positioning.
2Measurement precision
If force sensors are made highly sensitive to detect electrode-tissue contact, then measurement precision is improved, but the sensors become susceptible to interference from radiofrequency, electromagnetic fields, and thermal effects
Solution Approach 1:
The patent replaces electrical force sensing mechanisms with a mechanical coupler assembly that transmits forces through physical linkages. The coupler includes link arms with joints (revolute or compliant) that mechanically connect the electrode to the catheter shaft, allowing force transmission through mechanical means rather than direct electrical sensing. This mechanical substitution isolates the force detection from RF and electromagnetic interference while maintaining measurement capability through the mechanical linkage's response to applied forces.
3Adaptability or versatility
If the distal portion of the catheter is made flexible to navigate the beating heart, then adaptability is improved, but consistent mechanical contact between the electrode and tissue becomes difficult to maintain
Solution Approach 1:
The catheter system is segmented into distinct functional components: the distal catheter portion, the coupler assembly, and the electrode assembly. The distal catheter portion can be flexible to navigate the beating heart and adapt to anatomical structures, while the electrode assembly is mechanically coupled through the coupler to maintain stable positioning. The coupler acts as an independent segment that transmits forces while allowing relative movement, enabling the flexible distal portion to navigate dynamically while maintaining consistent electrode-tissue contact.
4Strength
If a rigid coupler is used to connect the electrode and catheter shaft, then structural stability is improved, but the ability to sense external forces and allow relative movement is reduced
Solution Approach 1:
The coupler assembly employs dynamic joints that allow controlled movement and rotation. The link arms include joints (revolute or compliant) that enable the coupler to adapt its configuration in response to external forces. This dynamic design allows the coupler to maintain structural stability for force transmission while simultaneously allowing relative movement between the electrode and catheter shaft, enabling force sensing and adaptation to the beating heart environment.
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 coupler assembly provides accurate and robust force sensing, reducing false positives and maintaining consistent contact with the tissue, even in dynamic conditions, by correlating external forces with displacement and enabling precise control during procedures.
Implementation Method 1
The two link arms connect a portion of the structure to the distal end of the catheter and enable the structure to move relative to the distal end of the catheter in response to an external force exerted on the structure
Data Source
AI summary
Coupler assemblies and methods are disclosed as the coupler assemblies may be used with a catheter. An exemplary coupler assembly includes a spherical linkage coupler for a catheter. The coupler comprises a first cylinder portion for connecting to a structure, and a second cylinder portion for connecting to a distal end of a body of the catheter. The coupler also comprises a spherical linkage including at least two link arms. Each of the two link arms are connected on one end to the first cylinder portion and on the other end to the second cylinder portion. The two link arms connect a portion of the structure to the distal end of the catheter and enable the structure to move relative to the distal end of the catheter in response to an external force exerted on the structure.