Wide-dynamic range pulse blood oxygen measurement system

Abstract

The invention relates to a wide-dynamic range pulse blood oxygen measurement system, which is mainly technically characterized by comprising a double-beam light-emitting unit, a pre-detection amplification circuit, a direct current elimination circuit, a buffer amplification unit, a central processor module and an output module, wherein the central processor module is connected with the double-beam light-emitting unit, the pre-detection amplification circuit, the direct current elimination circuit, the buffer amplification unit and the output module respectively; the pre-detection amplification circuit, the direct current elimination circuit and the buffer amplification unit are sequentially connected. The system is reasonable in design; two paths of light transmitted through the tail ends of tissues are added to the digital feedback direct current elimination circuit after being sampled, measured and pre-amplified, so that the intensity of photoelectric signals is improved, direct current components in the signals are reduced in a digital feedback way to realize the synchronous amplification of double-beam signals in a wider range and increase the signal to noise ratio, and the dynamic range of signal detection is widened.

Description

technical field [0001] The invention belongs to the technical field of physiological index detection, in particular to a pulse oximetry system with a wide dynamic range. Background technique [0002] The detection of pulse oximetry is a routine clinical detection index, which is widely used in ICU, CCU and other intensive care units, general wards and monitoring of surgical procedures, and can also be widely used in animal experiments to detect blood oxygen saturation. Pulse oximetry reflects the proportion of oxygenated hemoglobin in the body's blood, which can objectively reflect the body's blood oxygen status. The detection of pulse oximetry usually uses spectrophotometry, which includes transmitted light and reflected light methods, which is based on the Lambert-Beer law, using the light absorption coefficient of reduced hemoglobin and oxyhemoglobin difference to proceed. The Lambert-Beer law is: [0003] I=I 0 e - εCd (1) [0004] Among them, I is the transmitted ...

AI Technical Summary

Problems solved by technology

[0016] The disadvantage of the above technical solution is: since the DC component in the signal is much larger than the AC component, in order to avoid saturation distortion, it is usually necessary to limit the amplification factor of the pre-signal amplifier circuit, so it is impossible to do enough for the AC component. enlarge

However, due to amplifier saturation and cut-off limitations, expectations cannot be achieved, which directly affects the effective measurement of blood oxygen saturation, and cannot guarantee the accuracy of blood oxygen saturation values.

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