Method and apparatus for exciting sensing coiles of multi-channel breathing sensitive volume discribing device

Abstract

A method for exciting the sensing coils of multi-channel respiration volume tracer is disclosed, which features that a HF signal exciting source is used to periodically apply the HF exciting pulses to the sensing coils of all channels in time-sharing mode. Its apparatus is composed of an exciting source, timing circuit, multi-channel pulse switch circuit controlled by timing signals and connected to the said sensing coils, and signal conditioning circuit connected to the outputs of sensing coils and the multi-channel switch circuit. Its advantages are low electric consumption, high exciting power and low interference.

Description

technical field [0001] The invention belongs to a breathing state detection method and device, in particular to an excitation method and a device for sensing coils of a multi-channel breathing induction plethysmograph for measuring and recording human breathing movement. Background technique [0002] Respiratory induction plethysmography (RIP) technology is a method that can non-invasively measure ventilation and perform quantitative analysis. The main structure of the measurement device is to wrap two insulated sensing coils on the chest of the subject through elastic bands. And the abdomen or other parts, breathing movement can lead to the contraction of the chest and abdomen, resulting in changes in the cross-sectional area of ​​the corresponding parts of the chest and abdomen. Driven by the elastic band, the cross-sectional area surrounded by the insulating sensing coil also changes , thus bringing about changes in the inductance of the coil, the respiratory induction pl...

AI Technical Summary

Problems solved by technology

[0005] Since the inductance of the RIP coil itself as a sensor is very small (about 2uH), the change in the cross-sectional area of ​​the chest or abdomen brings about a smaller change in inductance. In order to detect the change in inductance, obtain high-quality signals, and obtain high Signal-to-noise ratio, it is hoped that the excitation current will be large, and the large excitation current will inevitably increase the power consumption of the system, so there is a contradiction between excitation power and power consumption

[0006] 2. There is a problem of mutual interference between RIP sensing coils of various channels (such as chest and abdomen or more channels)

[0007] Respiratory induction plethysmograph records chest and abdomen respiratory movement by detecting changes in the self-inductance of the sensing coil. One sensing coil generates interference, that is, the two sensing signals crosstalk each other, resulting in the change of inductance in one coil having both self-inductance and mutual inductance components, which affects the accuracy of each sensing signal

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