C-Shaped MR Sensor Assembly for 6DoF Medical Probe Tracking

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Solution Overview

Problem

Existing medical device tracking systems are limited in their ability to accurately track the location and orientation of probes within a patient, particularly in six degrees of freedom, due to the constraints of space and the reliance on single magnetic field sensors.

Innovation Solution

A magnetic field sensor with a novel C-shaped flexible circuit substrate and multiple magnetic field sensing elements, such as MR sensors, is integrated into the medical device shaft to provide six degrees of freedom tracking, optimizing space utilization and enhancing tracking accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single magnetic field sensor is used in the medical device, then the device complexity is reduced, but the measurement precision for six degrees of freedom tracking deteriorates

Engineering Contradiction:
Improvesensor structure complexityVSAvoidtracking accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor assembly is segmented into multiple independent magnetic field sensors (first magnetic field sensor and second magnetic field sensor) with different sensing directions. Each sensor measures a specific component of the magnetic field, and the combination of these measurements enables complete six degrees of freedom tracking, resolving the contradiction between simplicity and precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a second magnetic field sensor with a sensing direction orthogonal to the first sensor's primary sensing direction. This dimensional expansion from single-axis to multi-axis sensing enables the system to capture magnetic field components in multiple directions, achieving six degrees of freedom tracking capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple magnetic field sensors are integrated into the medical device shaft, then the measurement precision for six degrees of freedom tracking is improved, but the space requirements and device complexity increase

Engineering Contradiction:
Improvetracking accuracyVSAvoidspace requirements
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

Multiple magnetic field sensors, magnetic field transmitter assemblies, and processing circuitry are merged into a single integrated sensor assembly that can be incorporated into the medical device shaft. This consolidation reduces the overall space requirement compared to having separate components, while maintaining the functionality of multiple sensors for six degrees of freedom tracking.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor assembly is designed as a multi-functional unit that performs multiple tracking functions simultaneously using multiple magnetic field sensors with different sensing orientations. This universal design allows the single sensor assembly to handle six degrees of freedom tracking without requiring separate dedicated sensors for each degree of freedom.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Volume of moving object

If the magnetic field sensor uses a flexible circuit substrate with C-shaped configuration, then the space utilization is optimized, but the manufacturing complexity increases

Engineering Contradiction:
Improvespace utilizationVSAvoidmanufacturing simplicity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The flexible circuit substrate is configured in a C-shaped curved structure rather than a straight linear arrangement. This curvature allows the substrate to conform to the medical device shaft geometry and optimizes space utilization by positioning sensors in a compact arrangement, while the curved design can be manufactured using standard flexible circuit fabrication processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent employs a flexible circuit substrate that can be formed into a C-shaped configuration. This flexible substrate allows for compact sensor arrangement and optimal space utilization within the medical device shaft, while maintaining ease of manufacture through standard flexible circuit techniques that can accommodate curved geometries.

Inventive Principle:
Principle #30Flexible shells and thin films

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 magnetic field sensor enables precise tracking of medical devices in six degrees of freedom, minimizing space requirements while maintaining functional integrity, thereby improving the accuracy and efficiency of medical procedures.

Implementation Method 1

Tracking systems can use generated magnetic fields that are sensed by at least one tracking sensor in the tracked medical device

Methodology Applied
Scientific EffectMagnetic field sensing: Magnetic Field

Implementation Method 2

The position and orientation sensor package includes a first magneto-resistance sensor chip and a second magneto-resistance sensor chip

Methodology Applied
Scientific EffectMagneto-resistance effect: Magnetoresistance

Data Source

PatentEP4340715B1Magnetic field sensor for a medical device
Publication Date: 2025.11.19 BOSTON SCIENTIFIC SCIMED INC
  • EP4340715B1 patent drawingFigure 1
  • EP4340715B1 patent drawingFigure 2
  • EP4340715B1 patent drawingFigure 3

AI summary

A magnetic field sensor for a medical device, the magnetic sensor assembly comprising a substrate having a plurality of planar sections, wherein adjacent planar sections are joined by a transition section, and wherein the planar sections are arranged in a substantially C-shaped arrangement such that an inner surface of the magnetic field sensor is concave, and wherein the plurality of planar sections includes a first planar section oriented in a first plane and a second planar section oriented in a second plane orthogonal to the first plane. A first magneto-resistive (MR) sensor is mounted to the first planar section and defining a first axis of sensitivity, and a second MR sensor is mounted to the second planar section and defining a second axis of sensitivity that is orthogonal to the first axis of sensitivity.