A method and system for extracting fetal heart rate based on automatic weighted average algorithm in window

Abstract

The invention belongs to the technical field of sound signal preprocessing, and discloses a fetal heart rate extraction method and system based on an automatic weighted average algorithm in a window. A sensor is used to collect an original fetal heart sound signal; Average operation; normalize the fetal heart sound signal after de-averaging; perform noise reduction processing on the preprocessed fetal heart sound signal; downsample the fetal heart sound data; The fetal heart rate was extracted by the automatic weighted average algorithm from the audio signal; the fetal heart rate data extracted by the automatic weighted average algorithm in the window was further modified by the exponential weighted average algorithm outside the window. The invention uses the windowing method, adopts the idea of ​​averaging to weaken the influence of noise, and proposes an exponentially weighted averaging algorithm within the window, which overcomes the deficiency of interference to the fetal heart rate data when the fetal heart sound data has peak misdetection and missed detection. This makes the fetal heart rate data calculated by the algorithm within the window more accurate.

Description

technical field [0001] The invention belongs to the technical field of sound signal preprocessing, and in particular relates to a fetal heart rate extraction method and system based on an automatic weighted average algorithm within a window. Background technique [0002] The essence of fetal heart sounds is the sound signal produced by the beating heart of the fetus. The fetal heart rate is extracted from the fetal heart sound signal, which is one of the important indicators reflecting the health status of the human body. Fetal heart rate refers to the number of times the heart beats in one minute under normal circumstances, ranging from 120 to 160. In theory, a complete fetal heart sound consists of four parts, sorted from one to four, that is, the first fetal heart sound (S1), the second fetal heart sound (S2), the third fetal heart sound (S3), the fourth Fetal heart sounds (S4). Generally speaking, the third and fourth fetal heart sounds are so weak that they cannot be...

AI Technical Summary

Problems solved by technology

The disadvantages are: during the peak detection, there will be missed detection and wrong picking of the peak, and the position of the peak will shift left and right due to noise, which will affect the accuracy and stability of the heart rate.

Does not meet the requirements of real-time output

[0005] In summary, the existing problems in the prior art are: due to individual differences and external interference and other factors, the collected fetal heart sound signal is unstable; When the peak is missed or picked up wrongly, the extracted fetal heart rate data fluctuates greatly.

In addition, the idea of ​​adding a window is conducive to weakening the interference of noise, but at the same time affects the smallest unit of fetal heart rate change

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