Bio-electrical impedance measuring method and apparatus

Abstract

The invention discloses a measuring method of biological electric impedance, which is characterized in that the method comprises constant-current outputting the sine wave pumping signal with preset frequency to the measuring electrode which is arranged in a region for measuring, inspiring the region for measuring, receiving and magnifying the analog signal which passes through the region for measuring, A / D converting the analog signal, extracting a plurality of digital signals in one cycle of A / D conversion, calculating a group of impedance values corresponding to a plurality of digital signals through the fast Fourier algorithm, calculating the impedance values of different frequency points in the range of preset frequency through repeating above steps to form an impedance frequency diagram, and calculating the characteristic parameter of the region for measuring at the time point through coincidence circularity method according to the impedance frequency diagram. The invention provides pure electrical signal through effectively shielding inference signal, thereby guaranteeing the measurement precision. The invention adopts the fast Fourier algorithm and coincidence circularity method, which improves the precision of impedance calculation and effectively reduces the cost of circuit.

Description

technical field [0001] The invention relates to the field of bioelectrical impedance detection, in particular to a method and device for measuring bioelectrical impedance. Background technique [0002] Bioelectrical impedance measurement is a detection technology that uses the electrical characteristics of biological tissues and organs and their changes to extract biomedical information related to physiological and pathological conditions. The bioelectrical impedance measurement method can be used to extract Corresponding electrical characteristics and their variation information. It can be used to measure and monitor various electrical parameters of organisms, such as electrocardiography, bioimpedance measurement, electroencephalography, etc., including placing electrodes on the organism, and then measuring during or after electrical stimulation electric signal. [0003] For organisms, due to the similarities and differences in cell types, arrangement density, intercellul...

AI Technical Summary

Problems solved by technology

Biological tissue multi-frequency impedance measurement instrument is not yet practical

In addition, the existing instruments in the development and experiment stage are relatively complex in design, simple in performance, simple in algorithm and realized in function, high in cost, and do not have the function of extraction and analysis of impedance model parameters, and cannot monitor biological impedance in vivo for a long time Model parameters, etc.

[0006] In addition, the hardware part used in the measurement will produce errors and interference during the measurement process, such as: the surface potential signal error caused by the contact resistance caused by the electrode paste, the interference signal generated by various instruments, etc., will cause the electrical impedance calculation. The purity of the electrical signal used is not enough, that is, it cannot accurately reflect the impedance distribution of the area to be measured, resulting in unsatisfactory imaging accuracy, and cannot accurately and truly reflect the changes in the body's condition

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