Multi-arm catheter pressure sensing via arm deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical probes face challenges in accurately measuring and maintaining contact pressure between their distal tips and intra-body tissues, which is crucial for diagnostic and therapeutic procedures, as excessive pressure can cause tissue damage and inadequate pressure may hinder procedure effectiveness.
Innovation Solution
A multi-arm catheter with position transducers on each arm and an additional transducer on the central shaft, which measures arm positions and calculates pressure exerted on the tissue by bending, allowing for real-time pressure estimation and verification of physical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single distal tip catheter is used, then the device structure is simple, but the measurement precision of contact pressure is insufficient
Solution Approach 1:
The catheter is divided into multiple segments: a central shaft and multiple resilient arms extending from it. Each arm is equipped with its own position sensor, allowing independent measurement of contact pressure at multiple locations. This segmentation enables precise pressure measurement while maintaining a relatively simple overall structure by reusing the same basic arm-sensor module across multiple arms.
2Measurement precision
If multiple resilient arms with position sensors are used, then the measurement precision of contact pressure is improved, but the device complexity increases
Solution Approach 1:
The multiple resilient arms serve multiple functions: they provide structural support for the distal tip, enable contact with tissue at multiple points, and each acts as a pressure sensing element through its position sensor. This multi-functionality reduces the need for separate pressure sensing mechanisms, thereby limiting the increase in device complexity while improving measurement precision.
Solution Approach 2:
Traditional mechanical pressure sensors are replaced with position sensors that measure the deflection of resilient arms. The contact pressure is calculated indirectly from the position changes of the arms using magnetic field sensing, substituting a complex mechanical pressure measurement system with a more compact and precise magnetic positioning system.
3Reliability
If contact pressure is increased to ensure effective tissue engagement, then the reliability of tissue contact is improved, but harmful factors increase due to potential tissue damage
Solution Approach 1:
The position sensors continuously monitor the deflection of each resilient arm, providing real-time feedback on the contact pressure being applied to the tissue. This feedback is used to adjust the positioning and force applied by the catheter arms, ensuring that contact pressure remains within the optimal range for reliable tissue engagement without exceeding thresholds that could cause damage.
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 precise control of contact pressure, ensuring effective tissue engagement without causing damage, thereby improving the accuracy and safety of medical procedures like intracardiac mapping and cardiac ablation.
Implementation Method 1
Magnetic field generators are typically placed at known positions external to the patient. One or more magnetic field sensors within the distal end of a probe generate electrical signals in response to these magnetic fields
Implementation Method 2
The distal tip of the catheter is coupled to the distal end of the catheter insertion tube by a resilient member, such as a spring, which deforms in response to force exerted on the distal tip when it presses against endocardial tissue
Data Source
AI summary
A method for operating a medical probe includes pressing a distal end of the medical probe, which includes one or more arms that extend diagonally outward from a central shaft and have respective position transducers coupled thereto, against an intra-body surface, so as to cause the arms to exert pressure on the surface and bend with respect to the central shaft in response to the pressure. Positions of the respective position transducers coupled to the arms are measured, and the pressure exerted by the arms is estimated responsively to the measured positions.