Instantaneous effect of meridian point stimulation for managing sleep apnoea

Abstract

Background The compliance and efficacy of current conservative management of sleep apnoea are questionable. Meridian point stimulation is reported to be effective in relieving symptoms of sleep apnoea but the instantaneous effect on sleep apnoea is yet to be determined. Aims To identify a critical physiological signal to promptly indicate the occurrence of obstructive sleep apnoea (OSA) and to evaluate the effectiveness of a new approach - instantaneous meridian point stimulation - in managing the symptoms of OSA. Methods This research was divided into two stages. Stage 1 involved selecting and evaluating a critical signal for immediate indication of OSA. Ten subjects with OSA underwent nocturnal sleep study and their physiological signals were recorded. Stage 1 involved 3 tests. Test 1 evaluated the promptness of using the pulse oximetry (SpO2) level to indicate OSA by measuring time difference between cessation of airflow and the selected threshold. Test 2 evaluated Receiver operating characteristic (ROC) value using phase relationship between thoracic and abdominal signals to indicate OSA. Phase relationship was evaluated by measuring the magnitude excursion of the peak of the two signals in a breathing cycle during OSA and normal breathing. Test 3 evaluated sensitivity and specificity using the mean absolute amplitude of thoracic and abdominal effort of the subjects to indicate OSA. OSA was indicated if a reduction in mean absolute amplitude was found at 10 seconds before and from the onset of OSA. Stage 2 evaluated the efficacy of instantaneous meridian point stimulation in managing OSA using a single-blinded research design. Twenty-seven subjects were randomly assigned to three groups, namely LU7 meridian point group, sham point group and no stimulation group. They received two nights of sleep study, with one baseline test and one intervention test. Frequency and duration of sleep apnoea, average SpO2 levels and average number of arousals were compared between the two nights. Results Stage 1: In Test 1 the mean time difference (MTD) between ONAC and the threshold was 22 seconds. In Test 2, ROC value using phase relation of thoracic and abdominal signals to indicate OSA was 0.427. In Test 3, sensitivity and specificity values using the mean absolute amplitude of thoracic and abdominal signals were over 0.8. Stage 2: Frequency and duration of sleep apnoea, and average oxygen desaturation were significantly improved only in the MPSG with a p-value <0.05. Discussion Findings in Stage 1 suggested that the mean absolute amplitude of thoracic and abdominal signals was likely to effectively and promptly indicate the occurrence of OSA. Findings in Stage 2 suggested that subjects who received meridian point stimulation exhibited better management of sleep apnoea than the other groups with significant differences in terms of frequency and duration of sleep apnoea, and the average SpO2 level between the baseline and intervention study, while the number of arousals did not increase dramatically. Conclusion In this research, the criteria and efficacy of meridian point stimulation were identified and tested. Study findings suggested very promising results for the application of this new method in managing symptoms of OSA and also showed that the method would be non-invasive, convenient and easy to use.