TMR Sensor Array for Room-Temperature Biomagnetism Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional biomagnetism measuring devices using SQUID sensors face challenges such as complex refrigerant management, large and heavy sensor units, inflexibility in accommodating varying body sizes and shapes, limited high-density sensor placement, and inability to measure magnetic fields in multiple axes, leading to inaccurate measurements.
Innovation Solution
The use of tunnel magneto-resistive (TMR) elements allows for a lightweight, flexible, and highly sensitive biomagnetism measurement system that can operate at normal temperatures, enabling accurate measurement of magnetic fields in three axes without the need for cooling mechanisms, and can be easily positioned on or worn by subjects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SQUID sensors are used to measure biomagnetism, then measurement sensitivity is improved, but the device requires complex refrigeration systems and becomes large and heavy
Solution Approach 1:
The patent changes the operating temperature parameter from cryogenic (SQUID) to room temperature (TMR elements), eliminating the need for complex refrigeration systems while maintaining measurement capability through a different physical mechanism (tunnel magneto-resistive effect)
Solution Approach 2:
The patent replaces the mechanical refrigeration system with electronic temperature compensation circuits and algorithms that can operate at room temperature, substituting mechanical cooling infrastructure with electronic control mechanisms
2Measurement precision
If SQUID sensors are used, then measurement sensitivity is improved, but the sensor unit becomes large and heavy requiring mechanical support structures
Solution Approach 1:
By changing from cryogenic SQUID sensors to room-temperature TMR elements, the patent dramatically reduces the weight of the sensor unit, eliminating heavy refrigeration equipment and associated mechanical support structures
3Measurement precision
If SQUID sensors are arranged in a fixed Dewar flask configuration, then measurement capability is achieved, but adaptability to varying body sizes and shapes is reduced
Solution Approach 1:
The patent transforms the static, fixed Dewar flask configuration into a dynamic, flexible sensor array that can be positioned and shaped according to the subject's anatomy, allowing adaptation to various body sizes and measurement targets
Solution Approach 2:
The patent divides the monolithic Dewar flask into discrete, independently positionable TMR sensor elements that can be arranged in custom configurations to match different body geometries and measurement requirements
4Measurement precision
If SQUID sensors are placed close to the living body, then measurement accuracy is improved, but the large sensor size limits high-density arrangement
Solution Approach 1:
The patent changes the sensor form factor from large SQUID sensors to miniaturized TMR elements, enabling high-density arrangements that can be placed in close proximity to the body surface for improved measurement accuracy
5Device complexity
If SQUID sensors measure magnetic field in one direction, then sensor design is simplified, but the ability to measure in-plane magnetic field components is lost
Solution Approach 1:
The patent makes the TMR sensor system multi-functional by enabling measurement of magnetic field components in multiple directions (including in-plane components), allowing a single sensor array to perform comprehensive biomagnetic field mapping
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 enables precise and flexible biomagnetism measurement with reduced noise levels, allowing for accurate detection of magnetic fields in multiple directions, improving diagnostic capabilities and reducing costs and power consumption compared to SQUID sensors.
Implementation Method 1
a first tunnel magneto-resistive element array which includes a plurality of first tunnel magneto-resistive elements for detecting a magnetic field in a first direction, and a second tunnel magneto-resistive element array which includes a plurality of second tunnel magneto-resistive elements for detecting a magnetic field in a second direction
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Provided are a biomagnetism measuring device, a biomagnetism measuring system, and a biomagnetism measuring method, which measure biomagnetism with high precision using magnetic sensors that can be used at room temperature. According to the embodiment, biomagnetism is measured based on output signals which correspond to changes in the resistance of tunneling magnetoresistance elements (TMR elements 67). A magnetic sensor which outputs a single unit output signal is configured of a TMR array (68), which comprises TMR elements arrayed in a lattice between input and output electrodes. Each magnetic sensor is positioned in either a single-axis direction or in mutually intersecting two-axis or three-axis directions, and is brought close to a portion of the surface of a subject (i.e., the head). A plurality of said magnetic sensors are distributed upon said portion of the surface of the subject, whereupon the output signals are obtained from the plurality of magnetic sensors, and the biomagnetism emitted from the portion of the surface of the subject is measured based on the output signals.