Research Of Snoring Detection System Based On Bone-conduction Sensor

Obstructive sleep apnea-hypopnea syndrome is a sleep disorder that seriously endangers human health.Patients with the sleep disorders are usually the obesity and elderly,moreover,it has a tendency to rapidly become common among young people.Because of its close relationship with the complications of other various diseases,it has attracted more and more attention from the general public.Snore,as a prominent feature of OSAS,is often used as one of the main symptoms for the preliminary screening of OSAS.Based on the bone-conduction sensor fabricated by piezoelectric film and the development principles and technologies of embedded system,a low-cost,portable and easy-to-operate bone conduction snoring detection system was developed in this paper.And,the operating power consumption,size,data storage,using-environment and other factors were also comprehensively considered in design.Experiments for simultaneous testing between the device and the medical portable PSG had also been completed.After analyzing and discussing the process of snore formation,based on the short-term energy and short-term average zero-crossing rate of short-term analysis technology,the snore endpoint detection method with adaptive threshold values was used to divide the snore signal,so as to obtain its snore segments and silence segments.Furthermore,two methods for the preliminary screening of OSAS based on snore silence segments were proposed—Snoring Silence Index Diagnostic Method(SSI-Diagnosis)and Silence Time Ratio Diagnostic Method(?-Diagnosis).28 sets of experimental data were involved in this article,and the OSAS groups were divided into 4 blocking levels according to the “gold standard” diagnosis results.Results showed that,in the Bland-Altman diagram,all cases were distributed in the 95% CI ranges,indicating that the SSI value obtained by the SSI-diagnostic method and the PSG-AHI values obtained by the PSG diagnosis had strong agreement and relationship between them.In addition,the SSI-diagnostic method can distinguish between mild/moderate OSAS and moderate/severe OSAS more than simple snoring/mild OSAS patients.Moreover,the internal relationship between the SSI values and the patients' ages and BMIs had also been discussed and illustrated.The above results corroborate the feasibility of bone-conduction snoring signals and SSI values for OSAS preliminary screening.The ?-diagnostic method was also a simple and easy-to-understand preliminary OSAS screening method based on obtaining the Silence segments of snoring,which characterized the proportion of the duration of apnea events during the total sleep process.The ?-ROC curve chart was used to obtain the current diagnostic thresholds for the ?-diagnosis,which were 0.02632,0.09349,and 0.26257 for with/without disease,mild/moderate OSAS,and moderate/severe OSAS,respectively.Results showed that the ?-diagnostic method had the ability to distinguish OSAS more accurately,truthfully,and balanced than the SSI-diagnostic method in the preliminary screening of OSAS.Both diagnostic methods are suitable as detection indicators for the preliminary screening of potential OSAS and the self-examination of rehabilitation training among OSAS patients,especially at home,and the ?-diagnostic method had a better performance in the current data samples.In summary,the bone-conduction snore signals could be used for the preliminary screening of OSAS,and the proposed screening method had also achieved good diagnostic authenticity and preliminary screening effect in current samples.The bone-conduction way of snore with the characteristic of reducing the intensity of environmental noise interference,it will definitely provide new solutions with research value and significance for the development of portable,low-cost,easy-to-use level III and level IV of the sleep apnea detection equipment.