Background About 70% of children and adolescents worldwide do not meet the recommended level of physical activity (PA), which is closely associated with physical, psychological, and cognitive well-being. Nowadays, the use of technologies to change PA is of interest due to the need for novel, more effective intervention approaches. The previous meta-analyses have examined smartphone-based interventions and their impact on PA in adults, but evidence in children and adolescents still needs further research. Objective This systematic review and meta-analysis aimed to determine the effectiveness of smartphone-based interventions for improving PA in children and adolescents. Methods Five electronic databases (PubMed, Web of Science, OVID, Scopus, and the China National Knowledge Infrastructure) were searched up to June 29, 2020. Randomized controlled trials with a control group that examine the effect of smartphone interventions on PA among children and adolescents were included. Bias risks were assessed using the Cochrane collaboration tool. Meta-analysis was performed to assess the pooled effect on PA using a random effects model. Subgroup analyses were conducted to examine the potential modifying effects of different factors (eg, types of intervention, intervention duration, age, measurement, study quality). Results A total of 9 studies were included in this review, including 4 mobile app interventions, 3 SMS text messaging interventions, and 2 app + SMS text messaging interventions. In general, the risk of bias of included studies was low. Compared with the control group, the use of smartphone intervention significantly improved PA (standardized mean difference [SMD] 0.44, 95% CI 0.11-0.77, P=.009), especially for total PA (TPA; weighted mean difference [WMD] 32.35, 95% CI 10.36-54.33, P=.004) and daily steps (WMD 1185, 95% CI 303-2068, P=.008), but not for moderate-to-vigorous PA (WMD 3.91, 95% CI –1.99 to 9.81, P=.19). High statistical heterogeneity was detected (I2=73.9%, P<.001) for PA. Meta-regression showed that duration (β=–.08, 95% CI –0.15 to –0.01, n=16) was a potential factor for high heterogeneity. The results of subgroup analyses indicated that app intervention (SMD 0.76, 95% CI 0.23-1.30, P=.005), children (SMD 0.64, 95% CI 0.10-1.18, P=.02), “≤8 weeks” (SMD 0.76, 95% CI 0.23-1.30, P=.005), objective measurement (SMD 0.50, 95% CI 0.09-0.91, P=.02), and low risk of bias (SMD 0.96, 95% CI 0.38-1.54, P=.001) can significantly improve PA. Conclusions The evidence of meta-analysis shows that smartphone-based intervention may be a promising strategy to increase TPA and steps in children and adolescents. Currently, app intervention may be a more effective strategy among smartphone intervention technologies. To extend the promise of smartphone intervention, the future needs to design comparative trials among different smartphone technologies. Trial Registration PROSPERO CRD42019148261; https://tinyurl.com/y5modsrd

For a given neural drive, oesophageal pressure during apnoeic episodes may differ from that during airflow, since inspiratory airflow and increased lung volume both reduce pressure generation. It was, therefore, hypothesised that diaphragm electromyography (EMG) may provide additional data to oesophageal pressure when used for the assessment of neural drive in patients with obstructive sleep apnoea, whose breathing is associated with variable airflow and changes in lung volume.Neural respiratory drive was assessed using diaphragm EMG recorded from multipair oesophageal electrodes in 12 patients with obstructive sleep apnoea. Oesophageal pressure was also recorded.The mean¡SD inspiratory oesophageal pressure swing was 11.0¡3.7 cmH 2 O during wakefulness, 38.2¡15.7 cmH 2 O at the end of the apnoea and reduced to 28.5¡10.4 cmH 2 O at the beginning of arousal. The mean peak inspiratory diaphragm EMG signal was 21.8¡6.5 mV during wakefulness, 38.6¡14.0 mV at the end of the apnoea and further increased to 59.6¡32.0 mV at the beginning of arousal.It was concluded that the pattern of neural drive assessed by oesophageal pressure differs from that measured by diaphragm electromyography during apnoeic events and, therefore, that diaphragm electromyography may be a useful adjunct to measurement of oesophageal pressure for the assessment of neural drive in patients with obstructive sleep apnoea.

Background: It is unknown whether neural drive is comparable in constant rate and incremental exercise tests. Few data have previously been available to address this question because of the lack of reliable methods to assess neural respiratory drive in patients with chronic obstructive pulmonary disease (COPD). Objectives: The aims of this study are to determine whether neural respiratory drive during constant rate exercise differs from that during incremental exercise and to determine whether neural respiratory drive was maximal at the end of exhaustive exercise tests. Methods: We studied sixteen patients with moderate-severe COPD (mean ± SD FEV₁ 29 ± 10%). Both diaphragmatic electro-myogram (EMG) and transdiaphragmatic pressure were recorded with a combined multipair electrode balloon catheter during incremental and constant (80% of maximal oxygen consumption derived from a prior incremental exercise test) treadmill exercise. Minute ventilation and oxygen uptake were also measured. Results: Root mean square (RMS) of the diaphragmatic EMG increased gradually without a plateau during incremental exercise, whereas the RMS increased initially and reached a plateau during constant work rate exercise. The RMS of the diaphragmatic EMG at the end of exercise was similar for both incremental and constant work rate exercise (176 ± 42 µV vs. 184 ± 39 µV); these values were 70 and 73% of maximal values recorded over the study. Conclusions: The pattern of increase in neural respiratory drive during incremental exercise is different to that observed during constant work rate exercise, but both exercise protocols are terminated when the patients achieve a similar but submaximal drive.

Infrared thermal imaging can be effectively used in DVT detection and adjunctive diagnostic screening because of its specific infrared PDCs and TDs values.