Multilayer PCB Coil Array for Accurate MEG Sensor Localization

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Solution Overview

Problem

The challenge of accurately determining the position and orientation of magnetic field sensors in on-scalp magnetoencephalography (MEG) systems, particularly due to flexible sensor placement and misalignment issues with Optically Pumped Magnetometers (OPMs), complicates the co-registration process, leading to inaccurate sensor localization.

Innovation Solution

A multilayer Printed Circuit Board (PCB) based coil array with predefined electromagnetic coils is used, where each coil has a predetermined magnetic moment, minimizing stray fields from connecting wires and traces, and is mounted on a rigid platform to ensure precise localization without external calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flexible on-scalp sensor placement is used, then adaptability to individual head shapes is improved, but sensor localization accuracy deteriorates

Engineering Contradiction:

Improveadaptability to individual head shapesVSAvoidsensor localization accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent introduces electromagnetic coils as intermediary objects that mediate between the flexible sensor placement and the need for precise localization. The coils are positioned at known locations on the scalp and generate magnetic fields that serve as reference markers, allowing the sensor positions to be determined relative to these known coil locations through magnetic field measurements.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical localization methods (such as optical tracking or physical markers) with electromagnetic field-based localization. By using the magnetic fields generated by the coils, the system determines sensor positions through electromagnetic interaction rather than mechanical measurement, enabling accurate localization despite flexible sensor placement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If complex co-registration methods are used, then sensor localization accuracy is improved, but procedure time and complexity increase

Engineering Contradiction:

Improvesensor localization accuracyVSAvoidco-registration procedure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-positioning electromagnetic coils at known locations on the scalp before the actual MEG measurement. These coils serve as pre-established reference markers that simplify the subsequent localization process. By preparing the localization infrastructure in advance, the complex co-registration procedure is reduced to measuring magnetic fields from these pre-positioned coils.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If OPM sensors with poor internal calibration are used, then flexibility in sensor placement is improved, but localization parameter definition deteriorates

Engineering Contradiction:

Improveflexibility in sensor placementVSAvoidlocalization parameter definition

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent uses electromagnetic coils as intermediary reference objects that provide well-defined magnetic field characteristics. These coils serve as external calibration references that compensate for the poor internal calibration of the OPM sensors. By measuring the magnetic fields from the coils, the system can determine accurate localization parameters even when the sensor本身的 calibration is insufficient.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach allows for rapid, accurate, and cost-effective determination of sensor positions and orientations, simplifying the co-registration process and enhancing the reliability of sensor localization in MEG systems.

Implementation Method 1

an array of at least five electromagnetic coils comprised of an electrically conductive coil trace and at least five wires that connect to and power the electromagnetic coils

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

magnetic field sensors with respect to the brain

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentUS12543969B2Multilayer PCB-based coil array for sensor localization in magnetoencephalography

Publication Date: 2026.02.10 QUSPIN INC

AI summary

The present application is drawn to a system and method, as well as method for manufacture of a device and system for determining the position and orientation of at least one magnetic field sensor comprising: a rigid structure comprising an array of at least five electromagnetic coils; at least one wire that connects to and powers the electromagnetic coils; wherein the placement and orientation of the electromagnetic coils on the rigid structure are predetermined; wherein the electromagnetic coils, each having a predefined magnetic moment per unit current, are constructed with a printed circuit board (PCB) comprising at least one conductive layer; and wherein the system is configured such that a stray magnetic field emanating from the at least one, as measured at the location of the at least one magnetic field sensor, generates substantially lower magnetic field intensity than that produced by each of the at least five electromagnetic coils.