Unconstrained Sleep Respiration Measurement Using Flexible Pressure Sensor Array

Sleep Apnea Syndrom(SAS)is a systemic chronic disease that can cause coronary heart disease,stroke,diabetes and insulin resistance and other diseases,seriously affecting the quality of life and life of patients.Sleep monitoring of patients is one of the effective ways to screen and discover SAS.Clinically,thoracic and abdominal breathing is often used to monitor sleep,but it is expensive,inconvenient and has a strong bondage to the monitored,while the more mature uncontrollable monitoring method can monitor the respiratory rate and Breathing movement,but can not distinguish between chest and abdominal movement,it can not determine the type of apnea.In this paper,a method of monitoring sleep breathing based on a flexible pressure sensor array is proposed.The chest and abdominal respiratory signals are obtained by monitoring the dynamic pressure of the chest and abdomen acting on the sensor array during sleep.This article aims to extract the chest and abdomen breathing signal,observe the respiratory signal characteristics,summed up the general rule;clear the mattress elasticity of the sensor array to extract the chest and abdomen breathing signal Impact;analyze the causes of the phase difference between chest and abdomen respiratory signals in different breathing modes in supine position.The following is the main contents of this paper:1.Determination of optimal extraction region for chest and abdomen and denoising of respiratory signal extracted by flexible pressure sensor array.Body parts recognition based on graph structure model to achieve dynamic capture of chest and abdomen position under different sleeping positions.In this paper,the original chest and abdomen respiration signal extracted by the self-designed acquisition board is denoised by using the wavelet function to obtain the complete and smooth respiration signal with the effective components.2.Reliability of Flexible Respiration Sensor Extraction of Respiratory SignalsThe simultaneous detection system of chest and abdomen breathing signal with flexible pressure sensor array and Embla N7000 PSG was established.The reliability of flexible pressure sensor array in detecting chest and abdomen respiratory signal and respiratory rate was verified,which laid the foundation for further research.3.Experiment of the extraction of respiratory signals by flexible pressure sensor array and effect of different mattress elasticities on respiration signal extraction.The maximum value of each respiratory cycle was extracted,the respiratory frequency was obtained by the interval between the most values,and the characteristics of chest and abdomen breathing signals were observed and summarized under different sex,differentbreathing patterns and different sleeping positions.Experiments show that different mattress elasticity has no obvious effect on the detection of chest and abdomen respiration signal of flexible pressure sensor array.4.Analysis of chest and abdomen respiratory mechanics modelThe two-dimensional model was established based on the phenomenon of the phase difference between the chest and abdomen respiratory signals of different genders measured by flexible pressure sensor array under different sleeping positions.In this paper,the causes of the phase difference between chest and abdomen respiratory signals in different breathing modes in supine position are analyzed from the point of view of mechanics.