Oximetry front-end direct-current filtering circuit applicable to smart band and adjustment method

Abstract

The invention discloses an oximetry front-end direct-current filtering circuit applicable to a smart band. The oximetry front-end direct-current filtering circuit applicable to the smart band comprises a signal primary input end, wherein the signal primary input end is sequentially connected with a TIA (Totally Integrated Automation) circuit, a controllable bias reduction circuit, a secondary amplifying circuit, an ADC sampling circuit and a processor; a draw-off current circuit is also connected between the signal primary input end and the TIA circuit, and is connected with the processor; the processor is used for controlling the draw-off current circuit to adjust the current signal strength of the signal initial input end. The invention also discloses an adjustment method of the oximetry front-end direct-current filtering circuit applicable to the smart band, and the exposure intensity of an oximetry signal can be further improved without worrying about the saturation of the TIA circuit through adding the draw-off current circuit, so that the dynamic range of the TIA circuit is enlarged in another way. Meanwhile, by the adjustable draw-off current capacity of the draw-off current circuit and a feedback mechanism of the processor, the prime draw-off current capability can be adjusted in real time, and the oximetry front-end direct-current filtering circuit can adapt to different environments.

Description

technical field [0001] The present invention relates to an internal circuit of a wearable multi-parameter health index collection medical device, in particular to an internal circuit worn on the wrist for collecting multi-parameter health index smart bracelets, and in particular to a photoelectric measurement Methods The blood oxygen measurement front-end circuit of the smart wristband for collecting blood oxygen parameters and its adjustment method belong to the technical field of photoelectric blood oxygen measurement in medical electronics. Background technique [0002] Most of the existing blood oxygen measurement circuits for smart bracelets that use photoelectric measurement methods to collect blood oxygen parameters use the signal as a whole to pass through the TIA amplifier (current to voltage), then subtract the bias voltage and then amplify the processing, such as figure 1 As shown, but this requires two prerequisites: 1) The front-stage current signal has a high s...

AI Technical Summary

Problems solved by technology

[0005] The present invention mainly solves the technical problems of insufficient front-stage TIA dynamic range, low signal-to-noise ratio, and poor measurement stability in the prior art. The first purpose of the present invention is to provide a blood oxygen sensor suitable for smart bracelets. Measuring the front-end DC filter circuit, the second purpose of the present invention is to provide an adjustment method for the blood oxygen measurement front-end DC filter circuit suitable for smart bracelets

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