The growing rate of public health problem for increasing number of people afflicted with poor sleep quality suggests the importance of developing portable sleep electroencephalogram (EEG) monitoring systems. The system could record the overnight EEG signal, classify sleep stages automatically, and grade the sleep quality. We in our laboratory collected the signals in an easy way using a single channel with three electrodes which were placed in frontal position in case of the electrode drop-off during sleep. For a test, either silver disc electrodes or disposable medical electrocardiographic electrodes were used. Sleep EEG recorded by the two types of electrodes was compared to each other so as to find out which type was more suitable. Two algorithms were used for sleep EEG processing, i. e. amplitude-integrated EEG (aEEG) algorithm and sample entropy algorithm. Results showed that both algorithms could perform sleep stage classification and quality evaluation automatically. The present designed system could be used to monitor overnight sleep and provide quantitative evaluation.
Algorithms ; Electrodes ; Electroencephalography ; instrumentation ; Equipment Design ; Humans ; Polysomnography ; Sleep

Through the study of the pathology of sleep apnea-hypopnea syndrome, evaluation indexes, diagnosis requirements and so on, a portable sleep monitoring system was designed, which had the characteristics of convenience, wireless transmission and no disturbance. The system can be assessed by respiration monitoring and pulse oximetry, which is based on the pressure variation in miniature air-bag and spectral absorption method. It provides the value of the apnea-hypopnea index (AHI), which is used to evaluate OSAHS severity. The experiment of the system's stability and accuracy is done, which exhibits good performance, it can diagnose OSAHS effectively and provide convenience for home monitoring.
Humans ; Oximetry ; Polysomnography ; instrumentation ; Sleep Apnea, Obstructive ; diagnosis

OBJECTIVE: To explore an electrode suitable for wireless portable sleep monitoring equipment and analyze the result of the signals of electrooculogram (EOG) and electroencephalography (EEG) collected by this kind of flexible electrodes. METHODS: The flexible electrodes were prepared by microelectromechanical systems (MEMS) technology. This kind of electrodes consisted parylene, chromium, and gold. Parylene, the flexible substrate of this kind of flexible electrodes, was of biocompatibility. Between parylene and gold there was an adhesion layer of chromium, which connected parylene and gold tightly. Then the flexible electrodes were stuck to medical adhesive tape. The electrodes were designed and made into a grid to make sure that the medical adhesive tape could tape on the skin tightly, so that the contact impedance between the electrodes and the skin would be reduced. Then the alternating current impedance of the electrode were tested by the CHI660E electrochemical workstation after the electrode was achieved. To make sure that this kind of electrodes could be used in EOG monitoring, the electrodes were connected to a wireless signal acquisition suite containing special biological signal acquisition and digital processing chip to gather different sites around the eyes and the electrical signals of different directions of the eye movements, then analyzed the signal-to-noise ratio of the EOG. At the end, the Philips A6 polysomnography was used to compare the noise amplitude of the EEG signals collected by the flexible electrode and the gold cup electrode. RESULTS: The electrodes stuck to the skin tightly, and these electrodes could collect signals that we wanted while the experiment was performed. The alternating current impedance of the flexible electrode was between 4 kΩ and 13 kΩ while with the frequency of alternating current under 100 Hz, most EEG signal frequencies were at this range. The EOG signals collected by the flexible electrodes were in line with the clinical requirements. The noise amplitude of EEG signals collected by the flexible electrodes was lower than that of the electrical signals collected by the gold cup electrodes. CONCLUSION The flexible electrode could be taken into consideration as an alternative electrode for monitoring EOG and EEG signals, and the wireless portable sleep monitoring devices are to be further developed in the future.
Electric Impedance ; Electrodes ; Electroencephalography ; Humans ; Polysomnography/instrumentation* ; Skin ; Sleep/physiology*

Recording the sleep-multigraph is an important method for sleep monitoring and research. In this study, after the all-night sleep in six nights being monitored, the process of sleep is shown by EEG complexity and spectrum feature. It can provide a new path for estimating the sleep quality by sleep staging. Especially, the EEG complexity in different sleep stages is studied. The results indicate that the deeper the sleep, the smaller the EEG complexity of whole cortex. This is of significance to the study on sleep biopsychology.
Electroencephalography ; instrumentation ; Humans ; Polysomnography ; instrumentation ; Signal Processing, Computer-Assisted ; Sleep ; physiology ; Sleep Stages ; physiology

The wearable respiratory inductive plethysmograph(RIP) system is a non-intrusive respiratory monitoring system. Sleep monitoring was performed on 9 human subjects suspected of having sleep apnea hypersomnolence syndrome (SAHS) and 7 healthy volunteers using both the wearable RIP system and the conventional polysomnography(PSG), and the sensitivity and specificity of the wearable RIP system were analyzed by comparison with the PSG results. According to the characteristic of the wearable RIP system in detecting sleep apnea/hypopnea event, the diagnostic criteria of sleep apnea/hypopnea event were put forward. All subjects with SAHS diagnosed by the wearable RIP were confirmed by PSG,the sensitivity and specificity of the wearable RIP system for detecting sleep apnea/hypopnea events were 99.0% and 94.6% respectively. The wearable RIP system can be used reliably in detecting sleep apnea/hypopnea events. This system can be used at home for detecting the sleep apnea/hypopnea events non-intrusively.
Equipment Design ; Humans ; Plethysmography ; instrumentation ; methods ; Polysomnography ; instrumentation ; methods ; Sleep Apnea Syndromes ; diagnosis ; physiopathology

OBJECTIVETo evaluate the diagnostic value of portable monitor device (PMD) in potential obstructive sleep apnea hypopnea syndrome (OSAHS) patients.

METHODSAll patients met the inclusion criteria were asked to finish the questionniar and underwent anthropometric measurements, and then completed polysomnography (PSG) test and PMD test simultaneously. The correlation between AHI-PMD and AHI-PSG, between MinSaO2-PMD and MinSaO2-PSG were analyzed by Spearman analysis. T test was used to compare the correlation coefficient between the two groups; ROC analysis was used to evaluate the sensitivity and specificity of PMD in diagnosis of OSAHS, and got the Cut-off value between moderate and severe OSAHS and mild OSAHS.

RESULTSThrough PSG test, of all the 111 cases, including 4 simple snoring cases, accounting for 3.6%, OSAHS patients with 107 cases, accounting for 96.4% which including 11 patients (9.9%) with mild, 17 patients (15.3%) with moderate, 79 patients (71.2%) with severe. The correlation of AHI-PMD and AHI-PSG between moderate and severe OSAHS patients was stronger than simple snoring and mild OSAHS patients. The coefficient test between the two groups was statistically significant (P=0.026). The correlation of MinSaO2-PMD and MinSaO2-PSG was statistically significant (P<0.001), the correlation of MinSaO2-PMD and MinSaO2-PSG between moderate and severe OSAHS group and snoring and mild OSAHS group was not statistically significant (P=0.270). A statistically significant correlation between AHI-PMD and AHI-PSG was found (P<0.001). PMD had a sensitivity and specificity of 96.9% and 86.7%, respectively (AUC=0.990, 95%CI 0.970-1.000). The cut-off value between moderate and severe OSAHS and mild OSAHS was AHI-PMD≥12 times/h.

CONCLUSIONPMD had a satisfactory sensitivity and specificity for diagnosing and judging the severity of moderate and severe OSAHS.

To meet the need of cost-effective multi-biosignal monitoring devices nowadays, we designed a system based on super low power MCU. It can collect, record and transfer several signals including ECG, Oxygen saturation, thoracic and abdominal wall expansion, oronasal airflow signal. The data files can be stored on a flash chip and transferred to a computer by a USB module. In addition, the sensing data can be sent wirelessly in real time. Considering that long term work of wireless module consumes much energy, we present a low-power optimization method based on delay constraint. Lower energy consumption comes at the cost of little delay. Experimental results show that it can effectively decrease the energy consumption without changing wireless module and transfer protocol. Besides, our system is powered by two dry batteries and can work at least 8 hours throughout a whole night.
Computers ; Electric Power Supplies ; Humans ; Monitoring, Physiologic ; Polysomnography ; instrumentation ; Wireless Technology

OBJECTIVE: To investigate the relevance and clinical value of synchronous monitoring with Apnea Graph (AG) and micro movement sensitive mattress sleep monitoring system (MSMSMS) for the patient with obstructive sleep apnea-hypopnea syndrome before surgery. METHOD: One hundred and fifteen patients diagnosed as OSAHS by PSG were synchronous examined by two methods: MSMSMS and AG with continuous upper airway pressure recording at night in Peking Union Medical College Hospital. The apnoeic and oxygen desaturation events during sleep determined by the two methods were compared. The correlation between MSMSMS and AG were analyzed. RESULT: According to the OSAHS severity grading: the mild, moderate and severe were 6, 16, 93 for AG and 8, 26, 81 for MSMSMS respectively, and the hypoxemia severity grading:the mild, moderate, severe were 14, 70, 27 for AG and 6, 72, 37 for MSMSMS respectively. There were no statistically difference in the severity grading of OSAHS and hypoxemia during sleep determined by AG and MSMSMS. According to the parameters of the two methods, the AHI are (51.5 +/- 21.2) times/h (x +/- s, similarly hereinafter) and (48.1 +/- 24.2) times/h, r = 0.947; the LSaO2 are 0.736 +/- 0.110 and 0.710 +/- 0.108, r = 0.935; the correlation coefficient (r) of apnea index and obstructive apnea and hypopnea index were 0.856 and 0.841, P < 0.01 respectively, the data monitored by the two methods is positively correlated. CONCLUSION There is no significant difference in determining the severity of OS AHS between the AG and MSMSMS. The two methods had good correlation in respiratory disturbance index and oxygen decline index, and revealed well-prospects of preoperative assessment in patients with OSAHS.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Polysomnography ; instrumentation ; methods ; Sleep Apnea, Obstructive ; physiopathology ; Young Adult

Sleep posture recognition is the core index of diagnosis and treatment of positional sleep apnea syndrome. In order to detect body postures noninvasively, we developed a portable approach for sleep posture recognition using BCG signals with their morphological difference. A type of piezo-electric polymer film sensor was applied to the mattress to acquire BCG, the discrete wavelet transform with cubic B-spline was used to extract characteristic parameters and a naive Bayes learning phase was adapted to predict body postures. Eleven healthy subjects participated in the sleep simulation experiments. The results indicate that the mean error obtained from heart rates was 0.04±1.3 beats/min (±1.96 SD). The final recognition accuracy of four basic sleep postures exceeded 97%, and the average value was 97.9%. This measuring system is comfortable and accurate, which can be streamlined for daily sleep monitoring application.
Bayes Theorem ; Beds ; Humans ; Polysomnography ; instrumentation ; Posture ; Sleep ; Sleep Apnea Syndromes ; diagnosis

OBJECTIVE: To investigate the result of child-type micro-sensitive mattress sleep monitor on obstructive sleep apnea-hypopnea syndrome in children. METHOD: The PSG and child-type micro-sensitive mattress sleep monitor were synchronously performed on 58 cases of children with OSAHS. The breathing and sleep metrics were compared. RESULT: By PSG monitoring, 41 cases were diagnosed as mild OSAHS, 14 cases were moderate and 3 cases were severe. The results of mattress system monitoring showed mild OSAHS in 37 cases, 16 cases of moderate and severe OSAHS in 5 cases. Seven patients diagnosed as mild OSAHS monitored by PSG were classified as moderate by mattress system monitoring; three cases diagnosed as mild OSAHS by mattress system monitoring system were diagnosed as moderate by PSG. Among 14 cases of children diagnosed as moderate by PSG, three cases were diagnosed as mild by mattress system monitor and two cases as severe. Children diagnosed as severe by PSG got the same result by mattress system monitor. Two kinds of sleep monitoring methods were compared and there were no statistically significant difference in AHI (t = 2.316, P > 0.05), deep and shallow sleep constituent ratio (t = 2.280, t = 2.388, PF > 0.05). while there was significant difference in REM period Sleep constituent ratio (t = 3.135, P < 0.01). CONCLUSION Child-type micro-sensitive mattress is in good agreement with the PSG for diagnosing OSAHS in children, which can be used as a monitoring method in clinical work.
Child ; Child, Preschool ; Female ; Humans ; Male ; Polysomnography ; instrumentation ; methods ; Sleep Apnea, Obstructive ; diagnosis