Multifrequency synchronous excitation current source used in bio-electrical impedance frequency spectrum measurement

Abstract

The invention discloses a multifrequency synchronous excitation current source used in bio-electrical impedance frequency spectrum measurement, which comprises a multifrequency synchronous signal generating module, a unipolar-bipolar conversion module, and a voltage control current source module in sequential connection, wherein the multifrequency synchronous signal generating module adopts an FPGA (Field Programmable Gate Array) as a carrier, performs hardware programming through utilizing a Verilog HDL (Hardware Description Language), generates unipolar MFS voltage signal V FPGA based on finite state machine principles, and inputs the signal V FPGA to the unipolar-bipolar conversion module; the unipolar-bipolar conversion module is used for converting unipolar MFS voltage signal V FPGA into symmetric bipolar MFS voltage signal V OUT, and inputting the signal V FPGA into the voltage control current source module; and the voltage control current source module is used for converting the bipolar MFS voltage signal V OUT output by the unipolar-bipolar conversion module into bipolar MFS current signal IOUT and directly exerting the bipolar MFS current signal IOUT onto a tested biomass target receiving BIS (Bispectral) measurement. The multifrequency synchronous excitation current source provided by the invention lays a foundation for the realization of BIS multifrequency synchronous measurement.

Description

technical field [0001] The invention belongs to the technical field of medical electronic instruments and test and measurement, and relates to a multi-frequency synchronous excitation current source for bioelectrical impedance spectrum measurement. Background technique [0002] As a non-invasive detection method, Bioimpedance Spectroscopy (BIS) technology has broad application prospects in the monitoring of human physiological and pathological parameters. BIS measurement usually applies a small alternating current (voltage signal) to the measured object by means of excitation electrodes placed on the body surface, and at the same time detects the voltage (current signal) on the tissue surface through the measurement electrodes, and calculates the corresponding resistance from the measured signal Antibody and its changes, to obtain relevant physiological and pathological information. The technology is cheap, safe, non-toxic and harmless, easy to operate, etc., and has broad ...

AI Technical Summary

Problems solved by technology

As far as the current technology is concerned, it is relatively easy to synchronize two signals on the same DDS chip, but it is difficult to achieve synchronization between more signals generated by different DDS chips. or low-cost implementation

The theoretical basis of BIS technology is the Cole-Cole impedance model, and the four parameters of the Cole-Cole impedance model (R 0 , R ∞ , α, τ) requires impedance data of at least 4 frequency points. It can be seen that the synchronous excitation signal containing only two frequency points cannot meet the requirements of subsequent data processing, and only the synchronous excitation signal containing more than 4 frequency points can have Actual measurement application value

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