The hardware circuit system of bioelectrical impedance imaging system based on can bus

Abstract

The invention provides a bioelectricity impedance imaging system hardware circuit system based on a CAN bus. The hardware circuit comprises a middle control plate and a plurality of data collecting plates. The middle control plate is connected to a computer through a serial port connecting cable and receives an instruction sent by the computer. The middle control plate is connected with the data collecting plates through the CAN bus and a shield cable, and a unified programmable clock signal output by the middle control plate is input to the data collecting plates. The DSP of the data collecting plates acquires data through external interruption to carry out digital phase-sensitive demodulation, and the demodulation result is sent to the middle control plate through the CAN bus and finally sent to the computer. The bioelectricity impedance imaging system hardware circuit system has the advantages that the sweep frequency range of system drive signals ranges from 10 KHz to 10 MHz, the bioelectricity impedance imaging system hardware circuit system can be used as a flexible signal generator through the field programmability of an FPGA and can also carry out real-time compensation for collected signals of various channels, the effect on effective signals is offset, and the real-time performance and reliability are ensured.

Description

technical field [0001] The invention relates to an electrical imaging technology, in particular to a frequency-sweeping hardware circuit system applied to bioelectrical impedance imaging. Background technique [0002] Electrical Impedance Tomography (EIT) is one of the hot research topics in biomedical engineering today. It is a new generation of non-invasive functional imaging technology that has emerged in the past 20 years after morphology and structure imaging. EIT is to apply a small alternating current or voltage signal to the measured object by means of the excitation electrode placed on the body surface, and at the same time detect the voltage or current signal on the tissue surface through the measuring electrode, and calculate the corresponding electrical impedance and its change from the measured signal , and then according to different application purposes, extract the electrical characteristic information of tissues or organs related to human physiological and ...

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Problems solved by technology

However, when the frequency band exceeds 1MHz, the existence of the shunt impedance will destroy the measured useful signal, so how to compensate the influence of the shunt impedance in the high frequency band is the key to the circuit design

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