CN-121987212-A - Portable miniaturized magnetic core electric signal detection probe system

CN121987212ACN 121987212 ACN121987212 ACN 121987212ACN-121987212-A

Abstract

A portable miniaturized magnetic core electric signal detection probe system relates to the technical field of biomedical engineering and weak magnetic signal detection. The micro magnetic environment control system comprises a cylindrical micro shielding cavity, a triaxial biplane coil assembly and a measurement probe formed by a main measurement TMR sensor, and a reference probe formed by the cylindrical micro shielding cavity, the triaxial biplane coil assembly and the reference TMR sensor, wherein the weak signal acquisition subsystem is used for acquiring measurement data of the main measurement TMR sensor and background reference data of the reference TMR sensor, and the real-time data processing subsystem is used for carrying out data processing on the acquired measurement data and background reference data to obtain a magnetocardiogram signal. The invention constructs a local low magnetic noise measuring space in the probe, reduces the dependence on a large-scale building-level magnetic shielding room, and improves the availability at the bedside and in a moving scene.

Inventors

JIN LICHUAN
ZHANG QING
Xu Yeqian
ZHONG ZHIYONG

Assignees

电子科技大学

Dates

Publication Date: 20260508
Application Date: 20260327

Claims (10)

1. The portable miniaturized magnetic core electric signal detection probe system is characterized by comprising a miniature magnetic environment control subsystem, a weak signal acquisition subsystem and a real-time data processing subsystem; The miniature magnetic environment control subsystem comprises a measuring probe and a reference probe, wherein the measuring probe comprises a cylindrical miniature shielding cavity, a triaxial biplane coil assembly and a main measuring TMR sensor positioned at the center of the triaxial biplane coil assembly; The cylindrical micro shielding cavity is of a cylindrical hollow structure which is formed by winding soft magnetic thin strips; The three-axis double-plane coil assembly is positioned in the cylindrical miniature shielding cavity and comprises a first multilayer PCB positioned right above the TMR sensor and a second multilayer PCB positioned right below the TMR sensor, wherein the first multilayer PCB comprises an X-axis coil, a Y-axis coil and a Z-axis coil which are sequentially arranged from bottom to top, the second multilayer PCB comprises an X-axis coil, a Y-axis coil and a Z-axis coil which are sequentially arranged from top to bottom, and the X-axis coil, the Y-axis coil and the Z-axis coil are isolated through insulating dielectric layers; The weak signal acquisition subsystem comprises a measurement data acquisition subsystem and a reference data acquisition subsystem, wherein the measurement data acquisition subsystem is connected with the main measurement TMR sensor and used for acquiring measurement data of the main measurement TMR sensor, and the reference data acquisition subsystem is connected with the reference TMR sensor and used for acquiring background reference data of the reference TMR sensor; The real-time data processing subsystem is connected with the weak signal acquisition subsystem and is used for carrying out data processing on the acquired measurement data and background reference data to obtain a magnetocardiogram signal.
2. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein the cylindrical miniature shielded cavity and the tri-axial bi-planar coil assembly are identical in the measurement probe and the reference probe and the sensor is positioned in the same location.
3. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein the soft magnetic ribbon is a Co-based amorphous alloy ribbon, a Fe-based amorphous alloy ribbon, or a NiFe alloy ribbon.
4. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein a distance between the first multi-layer PCB and the second multi-layer PCB is 1-2 cm.
5. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein the measurement probe is positioned near the heart for detecting magnetic field signals of the heart and the reference probe is positioned at an extremity for detecting noise signals.
6. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein the X-axis coil is a left-right saddle-shaped planar coil, the Y-axis coil is an upper-lower saddle-shaped planar coil, and the Z-axis coil is a spiral coil.
7. The portable miniaturized magnetic core electrical signal detection probe system of claim 1, wherein the measurement data acquisition subsystem and the reference data acquisition subsystem comprise an ultra-low noise instrumentation amplifier, an anti-aliasing filter, and a high precision analog-to-digital converter connected in cascade.
8. The portable miniaturized magnetic core electrical signal detection probe system of claim 7, wherein the input reference noise of the ultra-low noise instrumentation amplifier is less than 1 nV/v Hz, the sampling rate of the analog-to-digital converter is not less than 1 kHz, and the resolution is not less than 24 bits.
9. The portable miniaturized magnetic core electric signal detection probe system according to claim 1 is characterized in that the real-time data processing subsystem comprises a signal extraction module, an adaptive noise cancellation module, a wavelet denoising and characteristic compression module and a communication module, wherein the signal extraction module is used for extracting collected measurement data and background reference data, the adaptive noise cancellation module adopts an adaptive filter, the background reference data is used as a noise source, the weight of the filter is updated in a real-time iteration mode, the noise source is stripped from the measurement data, the wavelet denoising and characteristic compression module carries out multi-scale decomposition on a signal denoised by the adaptive noise cancellation module, high-frequency random noise is removed through a soft threshold function, meanwhile data compression is achieved, and the communication module is used for sending the signal processed by the wavelet denoising and characteristic compression module to an upper computer for display, and a magnetocardiogram signal is obtained.
10. The portable miniaturized core electrical signal detection probe system of claim 9, wherein the adaptive filter employs an LMS algorithm or an RLS algorithm, and the wavelet denoising and feature compression module employs Daubechies 4, 5/3 lifting wavelet basis.

Description

Portable miniaturized magnetic core electric signal detection probe system Technical Field The invention relates to the technical field of biomedical engineering and weak magnetic signal detection, in particular to a miniaturized magnetic core electricity (Magnetocardiography, MCG) detection probe system which does not need a large-scale magnetic shielding room and can be used by hand or wearing and a signal processing method. Background The heart produces extremely weak magnetic fields (i.e., magnetocardiographic signals) when subjected to electrophysiological activity, typically on the order of 10 -12 Tesla (pT), which is only one fifth of the geomagnetic field (about 50 μt). Compared with the traditional Electrocardiogram (ECG), the electrocardiogram (MCG) has higher sensitivity and spatial resolution in the aspects of ischemic heart disease detection, fetal heart monitoring and the like, and belongs to completely noninvasive detection. However, the existing core electricity detection technology faces a huge technical bottleneck in clinical popularization, and is mainly embodied in the following aspects: reliance on large magnetic shielding chambers currently mainstream MCG equipment, such as SQUID superconducting quantum interferometers based systems, must operate in expensive, bulky and weighing up to several tons of magnetic shielding chambers (MSRs) to isolate environmental electromagnetic interference. This makes MCG unusable in Intensive Care Units (ICU), emergency vehicles or general outpatients, severely limiting its application scenario. Limitations of sensor technology: The SQUID sensor has extremely high sensitivity, but requires liquid helium cooling, has extremely high maintenance cost, and cannot be miniaturized. Atomic magnetometers (OPMs), although achieving room temperature detection, have a relatively narrow dynamic range and extremely high requirements for zero magnetic environments, and generally still need to be used with shielded rooms. Magneto-resistive sensors (TMR/GMR) are small in size, low in cost and fast in response, but have high 1/f noise level (usually in nT/. V Hz level), and are extremely susceptible to geomagnetic fluctuation as vector sensors, and are directly used for pT level magnetocardiogram detection with extremely high difficulty. Hysteresis of signal processing, the existing TMR detection scheme mostly adopts a mode of transmitting collected TMR to a PC end for software filtering. The method has high requirements on data transmission bandwidth, cannot realize microsecond real-time feedback control, and is difficult to cope with rapidly-changing electromagnetic environment interference. Therefore, there is a need for a portable magnetic core electrical detection system that is free of large-scale shielding room dependence, compact, low cost, and has real-time high-precision noise suppression capability. Disclosure of Invention The invention aims at solving the problems existing in the background technology and provides a portable miniaturized magnetic core electric signal detection probe system. According to the magnetic core electric signal detection probe system, the cooperation of the triaxial biplane coil, the acquisition circuit and the FPGA real-time processing link, which are used for loading preset current, is realized through local miniature shielding in the probe, the constant current source driving circuit, so that the real-time suppression of environmental noise is realized, and the detection sensitivity and the signal to noise ratio of the weak magnetocardiogram signal are improved. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A portable miniaturized magnetic core electric signal detection probe system comprises a miniature magnetic environment control subsystem, a weak signal acquisition subsystem and a real-time data processing subsystem; The miniature magnetic environment control subsystem comprises a measuring probe and a reference probe, wherein the measuring probe comprises a cylindrical miniature shielding cavity, a triaxial biplane coil assembly and a main measuring TMR sensor positioned at the center of the triaxial biplane coil assembly; The cylindrical micro shielding cavity is of a cylindrical hollow structure which is wound by soft magnetic thin strips and is used for passively attenuating an external low-frequency magnetic field; The three-axis double-plane coil assembly is positioned in the cylindrical miniature shielding cavity and comprises a first multilayer PCB positioned right above the TMR sensor and a second multilayer PCB positioned right below the TMR sensor, wherein the first multilayer PCB is used for obtaining uniform magnetic field distribution at the central position so as to be matched with the shielding cavity to construct a low magnetic noise measuring environment, the first multilayer PCB comprises an X-axis coil, a Y-axis coil and a Z-axis coil which are sequenti