Catheter Electrode Tip Force and Torque Sensing
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Solution Overview
Problem
Current methods for determining contact force and torque between medical device electrodes and tissue, such as cardiac tissue, are inadequate due to reliance on clinician experience, two-dimensional imaging, time-consuming procedures, and high false positive/negative rates, limiting the effectiveness and safety of ablation procedures.
Innovation Solution
A system with a contact sensing assembly that includes a catheter with force and torque sensors, pressure sensors, and a predetermined sensitivity, allowing for vector reconstruction of net tip contact force and torque measurement, providing real-time feedback to prevent excessive or insufficient force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If contact force is determined using clinician sense and tactile feedback, then the determination depends on clinician experience, but the reliability and precision of measurement deteriorate due to subjectivity and variability
Solution Approach 1:
The patent replaces the mechanical tactile feedback system with electronic force sensors that directly measure contact force. The force sensor assembly includes sensors that detect contact force between the electrode tip and tissue, converting mechanical interaction into electrical signals for precise digital measurement and display.
Solution Approach 2:
The patent introduces force sensors as an intermediary between the electrode and tissue to objectively measure contact force. These sensors act as mediators that translate physical contact into quantifiable data, eliminating the need for subjective clinician interpretation while providing real-time feedback.
2Loss of information
If fluoroscopic imaging is used to assess contact force, then visual assessment is provided, but measurement precision deteriorates due to two-dimensional projection limitations and similar x-ray attenuation of blood and myocardium
Solution Approach 1:
The patent replaces the optical fluoroscopic imaging system with direct mechanical force sensing. Instead of using x-rays to indirectly visualize contact, force sensors directly measure the contact force magnitude, providing accurate quantitative data without the limitations of two-dimensional projection and tissue attenuation.
3Loss of information
If intracardiac echo is used to assess contact force, then contact assessment is provided, but productivity deteriorates due to time-consuming procedures and difficulty in aligning the echo beam with the ablation catheter
Solution Approach 1:
The patent replaces the acoustic echo imaging system with direct force sensing mechanics. The force sensors provide immediate contact force measurements without requiring time-consuming beam alignment or image interpretation, enabling real-time feedback that maintains procedural efficiency.
4Reliability
If alation electrode is applied with excessive force to ensure proper contact, then contact effectiveness is improved, but harmful factors increase due to tissue perforation and damage
Solution Approach 1:
The patent implements a feedback system where force sensors continuously monitor contact force between the electrode tip and tissue. The measured force is displayed to the clinician in real-time, providing feedback that enables precise control of contact force to maintain reliable tissue contact while preventing excessive force that could cause tissue perforation or damage.
Solution Approach 2:
The patent applies preliminary anti-action by using force sensors to detect and prevent excessive contact force before tissue damage occurs. The system proactively monitors contact force and alerts the clinician to reduce force before harmful effects manifest, rather than waiting for damage to occur.
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 system enables precise measurement and feedback on contact force and torque, enhancing the safety and effectiveness of ablation procedures by minimizing tissue damage and ensuring proper lesion creation, while reducing false positives and negatives.
Implementation Method 1
one or more force and torque sensors may be disposed generally adjacent the base portion and may include one or more pressure sensors for measuring pressure applied to the electrode tip portion and providing a pressure signal related to the measured pressure
Data Source
AI summary
A contact sensing assembly including a catheter including an electrode having a base portion mounted adjacent a head portion of the catheter body. A sensor is disposed adjacent the base portion for measuring compression or tensile forces applied to an electrode tip portion, and includes a predetermined sensitivity. The base and head portions include predetermined rigidity so that forces applied to the electrode tip portion are determinable as a function of the sensitivity and a sensor output. A contact sensing assembly also includes an electrode pipe operatively connected to the catheter body for movement and bending with the catheter body, and an electrode wire disposed in the electrode pipe and including insulation. A change in capacitance resulting from movement of the electrode wire toward the electrode pipe or contact of the electrode wire with the electrode pipe during bending of the catheter correlates to a force applied to the catheter.