Catheter Sensor with Exposed Windings for Position and ECG
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Solution Overview
Problem
Existing catheter systems that rely on Active Current Location (ACL) components for position tracking are less accurate compared to magnetic position sensors, and they require driving current which interferes with physiologic signals.
Innovation Solution
A multi-functional sensor unit integrated on a catheter with an inner and outer coil configuration, where the inner coil is insulated and the outer coil has exposed windings, allowing it to sense physiologic signals, environmental impedance, and magnetic fields without driving current, thereby providing accurate position and tissue proximity information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Active Current Location (ACL) components are used for position tracking, then position tracking capability is provided, but measurement accuracy deteriorates and interference with physiologic signals occurs
Solution Approach 1:
The patent replaces the ACL electrical current-based position tracking system with a magnetic field-based position sensor. The magnetic field penetrates tissue without significant attenuation and does not require injection of electrical current into the body, thereby eliminating interference with physiologic signals while maintaining position tracking capability. This substitution of the underlying physical mechanism resolves the contradiction between providing position tracking and avoiding signal interference.
Solution Approach 2:
The patent integrates multiple functions into a single catheter system: magnetic position sensing, physiologic signal sensing (ECG electrodes), and impedance sensing. By making the system multi-functional and eliminating the need for separate ACL components, the invention achieves accurate position tracking without the harmful effects of ACL current injection, while simultaneously providing physiologic signal measurement capabilities.
2Measurement precision
If dedicated coils are used for magnetic position sensing, then position sensing accuracy is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple sensing functions into integrated sensor units on the catheter: magnetic position sensors (coils), physiologic signal electrodes, and impedance sensing elements are merged into a unified catheter structure. This consolidation maintains the accuracy benefits of dedicated magnetic position sensors while reducing overall system complexity by eliminating separate ACL components and integrating functions into a single multi-functional device.
Solution Approach 2:
The catheter is designed as a multi-functional device that performs magnetic position sensing, physiologic signal recording, and impedance measurement simultaneously. This universal design approach allows the catheter to provide multiple functions without requiring separate dedicated devices for each function, thereby maintaining sensing accuracy while managing device complexity through functional integration.
3Adaptability or versatility
If electrical current is injected for ACL positioning, then position tracking is enabled, but interference with physiologic signals occurs
Solution Approach 1:
The patent substitutes electrical current injection with magnetic field-based position sensing. The magnetic field used for position tracking does not require electrical current injection into the patient's body and does not interfere with physiologic electrical signals such as ECG. This fundamental substitution of the physical mechanism eliminates the harmful interference while preserving position tracking functionality.
Solution Approach 2:
The patent uses magnetic fields as an intermediary for position tracking instead of direct electrical current injection. The magnetic field acts as a mediator that can penetrate tissue and provide position information without directly interacting with or interfering with the body's own electrical signals, thereby enabling position tracking without harmful interference.
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 integrated sensor unit enhances accuracy by simultaneously measuring physiologic signals and determining tissue proximity and position, reducing system complexity and interference, while maintaining precise location tracking.
Implementation Method 1
The coil has an inductive impedance that is determined by the coil geometry and a secondary impedance determined by the environment to which the exposed windings are exposed. The overall impedance of the coil therefore changes with the environment, and the change in impedance can be detected based on electrical signals (e.g. current and/or voltage signals) output from the coil which are induced by a known magnetic flux from a generated magnetic field acting on the coil.
Implementation Method 2
The coil has an inductive impedance that is determined by the coil geometry and a secondary impedance determined by the environment to which the exposed windings are exposed. The secondary impedance may include a resistive component, a capacitive component, an inductive component, or any combination thereof. The change in coil impedance can provide an indication of proximity to tissue because tissue has a different impedance than blood
Implementation Method 3
The exposed windings allow the multi-functional sensor unit to sense environmental impedance and physiologic, sent as electrical impulses (signals) from the heart (e.g., heart wall) during contraction. The exposed windings can measure physiologic signals (e.g. ECG signals) when in contact with biological tissue.
Data Source
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AI summary
A sensor for a medical probe having one or more coils with at least two exposed winding portions. The one or more coils can be configured to output 1) electrocardiogram (ECG) signals received at the at least two exposed windings, and 2) signals indicative of environmental impedance/conductance in the vicinity of the at least two exposed windings. The one or more coils can further be configured to determine a position of the sensor based on magnetic field, determine a curvature of the sensor, directionally measure environmental impedance/conductance, and/or measure temperature. Insulated portions of the one or more coils can be interleaved with the at least two exposed winding portions. The sensor can be integral to a catheter or guide wire.