Digital signal processing method for light-frequency conversion type pulse oximeter

Abstract

The invention relates to a digital signal processing method for a light-frequency conversion type pulse oximeter, comprising the following steps: continuously sampling digital pulse signals, and storing the sampled digital pulse signals into a sampled data first-in first-out queue; driving each light-emitting tube by adopting a light-emitting tube timer according to the pre-set timing sequence, and storing the on-off time value of each light-emitting tube into corresponding on-off time recording first-in first-out queues; processing the sampled data first-in first-out queue and the on-off time recording first-in first-out queues, and selecting a pulse period in the on-off time period of each light-emitting tube to calculate frequency; and setting the processed first-in first-out queues to track and maintain the head parts thereof. Because the controlling process and the sampling process are divided into two independent processes, the high time precision on the non-real-time operating system is realized, and the high precision of oximetry is realized. In addition, the operating performance and the time precision of the microprocessor system with low computing resource can be improved.

Description

technical field [0001] The invention relates to blood oxygen saturation measurement, in particular to a sampling and digital signal processing method of an optical-frequency conversion pulse oximeter. Background technique [0002] The key link in the existing blood oxygen saturation measurement is to measure the light intensity transmitted through or reflected from the finger, which can be realized by light-frequency conversion sensors. The light-frequency conversion sensor converts the light intensity into a digital pulse signal, and then obtains frequency information by counting the digital pulse signal, and calculates the light intensity. The working principle of the optical frequency converter, the key component of the blood oxygen measurement method, is that the optical frequency converter can convert light intensity information into electrical pulses of different frequencies, so that the light intensity information can be calculated by counting electrical pulses within...

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Problems solved by technology

For non-real-time operating systems similar to Linux, (for example, embedded systems based on ARM architecture usually use non-real-time Linux or WinCE to obtain good user interaction, communication and multitasking functions), because the system may have to process at the same time For example, timers, serial ports, USB and other terminals interact with users, which may cause conf

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