Device for calibrating magnetic field-voltage coefficient of multi-channel magnetocardiogram detection system

Abstract

The invention discloses a device for calibrating a magnetic field-voltage coefficient of a multi-channel magnetocardiogram detection system. The device comprises a current excitation device which outputs a corresponding excitation current to a magnetic field generation mechanism based on a current control instruction, a magnetic field generating mechanism which generates a uniform magnetic field in a magnetometer area of the multi-through magnetograph, and a signal acquisition and analysis device which acquires voltage signals output by all the magnetometers, records voltage values of all the magnetometers under different magnetic field intensities, and fits voltage-magnetic field relation curves of all the magnetometers, wherein the fitting slope of the voltage-magnetic field relation curves is the voltage-magnetic field coefficient, and a magnetometer is excited by the uniform magnetic field to generate a voltage signal. The range of a uniform region of a magnetic field generated by the biplane coil and the uniformity of the magnetic field in the uniform region are larger than those of a common coil so that the accuracy of voltage-magnetic field coefficient calibration is improved; and an open space is formed between the double-plane coils so that the device is suitable for placing a magnetocardiography system with a complex structure and a relatively large volume, and the convenience of calibration operation is improved.

Description

technical field [0001] The invention belongs to the technical field of magnetic field-voltage coefficient calibration, and more specifically, the invention relates to a calibration device and method for magnetic field-voltage coefficient of a multi-channel magnetic field detection system. Background technique [0002] The human heart will be accompanied by the generation of extremely weak biomagnetic field (ie magnetism) during the electrophysiological activity process. The accurate detection of magnetism has great clinical application potential in diagnosing heart diseases and locating abnormal areas of the heart. A system that detects magnetic signals and performs extraction, imaging, and analysis of magnetic signals is a magnetocardiograph. The strength of a typical cardiomagnetic signal is tens of pT (10 -12 Tesla), and the typical strength of the earth's magnetic field is 30-50μT (10 -6 Tesla) in order to detect such a weak signal, the use of sensors with extremely hi...

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Problems solved by technology

[0005] The magnetic field generated by the circular coil can be obtained by the Biot-Safar law. When using a circular coil for calibration, it is necessary to accurately obtain the spatial position relationship between the magnetometer and the circular coil. However, due to the magnetometer (such as SQUID) is generally placed in a closed constant temperature container, we cannot accurately obtain this spatial position relationship, so the magnetic field-voltage coefficient obtained by calibration has a large error; at the same time, in order to obtain multi-point array magnetic signals for functional imaging, magnetocardiogram The number of magnetometers included in the magnetocardiograph system can reach more than dozens, and the arrangement of the magnetometers has the characteristics of a spatial layered layout. Use a calibration device based on a circular coil to calibrate the magnetometers in the magnetocardiograph one by one. low efficiency

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