ABSTRACT
OBJECTIVE: To systematically evaluate the efficacy and safety of scalp acupuncture in the treatment of insomnia. METHODS: CNKI, Wanfang database, CQVIP database, CBM, Web of Science, Cochrane Library, and PubMed were searched for the literature on the treatment of insomnia by scalp acupuncture from the establishment of the database to July 23, 2020. Two researchers independently screened the literatures and extracted the data, then evaluated the quality of the literatures, and used RevMan 5.3 software for statistical analysis. RESULTS: A total of 21 studies including 1606 cases were included. 21 studies were included in the analysis of effective rate. The heterogeneity test showed that there was no significant heterogeneity. The fixed effect model was used, P < 0.00001. The effective rate of scalp acupuncture in the treatment of insomnia was significantly higher than that of the control group. The analysis of PSQI score was finally included in 19 studies. The heterogeneity test showed that there was obvious heterogeneity. The random effect model was used, and the subgroup analysis was conducted according to the different intervention measures of the control group. The P values of the drug group and the blank group were both less than 0.05, indicating that the improvement of PSQI score in the scalp acupuncture treatment of insomnia was significantly better than that in the drug group and the blank group; P = 0.05 in other acupuncture groups, suggesting in scalp acupuncture treatment, there was no difference between insomnia and other acupuncture in improving the PSQI score. Six studies were included in the analysis of adverse events. The heterogeneity test showed no significant heterogeneity. The fixed effect model was used, P = 0.04 < 0.05, indicating that the adverse events of scalp acupuncture in the treatment of insomnia were better than those of the control group. No publication bias analysis was conducted due to the small number of adverse events included. Publication bias was analyzed for effective rate and PSQI score. Egger's TSTs test (effective rate P = 0.001, PSQI score P = 0.001) and funnel plot showed publication bias. CONCLUSION: Scalp acupuncture is effective and safe in the treatment of insomnia, which is worthy of clinical application. However, due to the limited number of included literature, the methodology of some studies is slightly low and the quality of literature is slightly poor. In the future, we need to design rigorous, large sample, multiple center randomized controlled study to further verify the conclusion of this study.
ABSTRACT
A software phase-locked amplifier demodulation method is proposed in order to demodulate the second harmonic (2f) signal of quasi-continuous laser wavelength modulation spectroscopy (WMS) properly, based on the analysis of its signal characteristics. By judging the effectiveness of the measurement data, filter, phase-sensitive detection, digital filtering and other processing, the method can achieve the sensitive detection of quasi-continuous signal The method was verified by using carbon dioxide detection experiments. The WMS-2f signal obtained by the software phase-locked amplifier and the high-performance phase-locked amplifier (SR844) were compared simultaneously. The results show that the Allan variance of WMS-2f signal demodulated by the software phase-locked amplifier is one order of magnitude smaller than that demodulated by SR844, corresponding two order of magnitude lower of detection limit. And it is able to solve the unlocked problem caused by the small duty cycle of quasi-continuous modulation signal, with a small signal waveform distortion.
ABSTRACT
According to the modulation signal applied on laser diodes, wavelength modulation spectroscopy (WMS) can be divided into continuous wave (CW) WMS and quasi-continuous wave (QCW) WMS. In order to deeply compare CW-WMS and QCW-WMS, we used a specific software-realized lock-in amplifier for continuous and quasi-continuous modulation signal demodulation. The invalid signal in quasi-continuous modulation spectrum was filtered off, and then the effective detection signal was demodulated to obtain the second harmonic signal (WMS-2f). It was compared with the 2f signal demodulated continuous laser modulation spectrum with software. The results show that while the same system parameters are set, the signal-to-noise of the quasi-continuous modulation spectrum is 5% higher than the continuous modulation spectrum with software demodulation measurements, and the detection limit is 11.3% lower. And without the invalid signal in quasi-continuous modulation spectrum, the standard WMS-2f signal can be demodulated, which has potential to be used for the investigation of gas absorption profile. This work has provided accurate reference for selections of the laser modulation spectroscopy.
