Eddy Current Catheter Force Sensor Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical devices lack effective mechanisms to accurately measure mechanical forces applied to catheters during procedures, such as ablation, which hinders precise contact detection and pressure assessment on tissues.
Innovation Solution
A catheter equipped with a flexible distal portion and a conducting element that generates eddy currents in response to mechanical forces, utilizing transmitting and receiving coils to detect variations in the magnetic fields, allowing a processor to ascertain the magnitude and direction of applied forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional force sensors are used in catheters, then contact detection capability is limited, but device complexity and measurement precision requirements increase
Solution Approach 1:
The patent replaces traditional mechanical force sensors with an electromagnetic sensing system. A conducting element (such as a conducting fluid or gel) is used in conjunction with transmitting and receiving coils to detect mechanical forces through electromagnetic induction. When mechanical force is applied to the catheter tip, it displaces the conducting element, which modulates the electromagnetic coupling between coils, enabling force detection without mechanical contact sensors.
Solution Approach 2:
The conducting element serves as an intermediary between the mechanical force applied to the catheter and the electromagnetic detection system. The conducting fluid or gel transduces mechanical displacement into electromagnetic signal changes by modulating the magnetic coupling between transmitting and receiving coils, enabling indirect but precise force measurement.
2Reliability
If mechanical force sensors are integrated into the catheter, then contact detection improves, but the flexibility and navigability of the catheter may be compromised
Solution Approach 1:
By replacing rigid mechanical force sensors with a flexible conducting element (fluid or gel) and electromagnetic coils, the system maintains catheter flexibility while enabling reliable force detection. The conducting fluid or gel can conform to the catheter's flexible structure, and the electromagnetic sensing occurs through magnetic coupling that does not require rigid mechanical connections.
Solution Approach 2:
The patent utilizes a conducting fluid or gel (hydraulic/pneumatic medium) as the sensing element. This conducting fluid can be contained within flexible chambers or pathways in the catheter, allowing the catheter to maintain its flexibility and navigability while the fluid transduces mechanical forces into electromagnetic signals through its displacement and compression.
3Measurement precision
If the conducting element is positioned distally in the flexible portion, then force measurement precision improves, but the structural integrity and positioning stability may be reduced
Solution Approach 1:
The conducting element acts as a compliant intermediary that can be positioned distally in the flexible portion of the catheter. Its fluid or gel nature allows it to remain stable within the flexible structure while translating distal displacements and forces into electromagnetic signal changes, maintaining both positioning stability and measurement precision.
Solution Approach 2:
The conducting fluid or gel is contained within flexible chambers or pathways in the catheter's distal portion. This flexible containment structure maintains the conducting element's positioning stability while allowing the overall assembly to remain flexible and responsive to distal forces, enabling precise force measurement at the catheter tip.
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 measurement of mechanical forces applied to the catheter tip, facilitating accurate contact detection and pressure assessment, enhancing procedural precision and safety.
Implementation Method 1
at least one transmitting coil, disposed within the catheter proximally to the conducting element, configured to generate an alternating magnetic field that induces, in the conducting element, eddy currents that vary with the position of the conducting element
Implementation Method 2
eddy currents that vary with the position of the conducting element... a secondary magnetic field generated by the eddy currents
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Described embodiments include an apparatus, which includes a catheter configured for insertion into a body of a subject, the catheter comprising a flexible distal portion configured to flex in response to a mechanical force applied to the catheter, a conducting element, held by the flexible distal portion of the catheter such that a position of the conducting element changes as the flexible distal portion flexes, at least one transmitting coil, disposed within the catheter proximally to the conducting element, configured to generate an alternating magnetic field that induces, in the conducting element, eddy currents that vary with the position of the conducting element, and one or more receiving coils, disposed within the catheter proximally to the conducting element, configured to output respective signals responsively to a superposition of (i) the magnetic field generated by the transmitting coil, and (ii) a secondary magnetic field generated by the eddy currents.