Effect of Rocking Movements on Respiration

Nocturnal vestibular stimulation using a rocking bed improves a severe sleep disorder in a patient with mitochondrial disease

Mitochondrial diseases are rare genetic disorders often accompanied by severe sleep disorders. We present the case of a 12-year-old boy diagnosed with a severe primary mitochondrial disease, exhibiting ataxia, spasticity, progressive external ophthalmoplegia, cardiomyopathy and severely disrupted sleep, but no cognitive impairment. Interestingly, his parents reported improved sleep during night train rides. Based on this observation, we installed a rocking bed in the patient's bedroom and performed different interventions, including immersive multimodal vestibular, kinesthetic and auditory stimuli, reminiscent of the sensory experiences encountered during train rides. Over a 5-month period, we conducted four 2-week nocturnal interventions, separated by 1-week washout phases, to determine the subjectively best-perceived stimulation parameters, followed by a final 4-week intervention using the optimal parameters. We assessed sleep duration and quality using the Mini Sleep Questionnaire, monitored pulse rate changes and used videography to document nocturnal interactions between the patient and caregivers. Patient-reported outcome measures, clinical examinations and personal outcomes of specific interests were used to document daytime sleepiness, restlessness, anxiety, fatigue, cognitive performance and physical posture. In the final 4-week intervention, sleep duration increased by 25%, required caregiver interactions reduced by 75%, and caregiving time decreased by 40%. Subjective fatigue, assessed by the Checklist Individual Strength, decreased by 40%, falling below the threshold of severe fatigue. Our study suggests that rocking beds could provide a promising treatment regime for selected patients with persistent severe sleep disorders. Further research is required to validate these findings in larger patient populations with sleep disorders and other conditions.

Development of a Cushion-Shaped Device to Induce Respiratory Rhythm and Depth for Enhanced Relaxation and Improved Cognition

Workplace stress is a pertinent problem in today's world. Preventing and overcoming stress is critical for a healthy lifestyle because it is linked to various health problems and can lead to poor work performance. Controlling your breathing is one of the most effective ways to promote relaxation. However, regulating one's breathing necessitates some training and is not something that everyone can do easily. As a result, we concentrated on the relaxing effect of breathing and developed a cushion-shaped device that displays the desired respiratory motion. We used the effect of inducing one's respiratory movements by watching others' respiratory movements. When the user hugged the device, it changed the user's respiratory rhythm and depth. We conducted a user study with this device, which revealed that presenting respiratory motion can induce the user's respiratory rhythm and depth without any pre-training. Furthermore, subjective evaluation and ECG data suggested that using this device during task breaks can improve the relaxation effect and thus task performance after the break.

Electrical vestibular nerve stimulation as an adjunctive therapy in the management of type 2 diabetes

OBJECTIVES

Vestibular nerve stimulation using the portable battery-operated vestibular nerve stimulator is a sophisticated method noninvasive, safe, and easy to operate. It was hypothesized that vestibular nerve stimulation is effective in the management of type 2 diabetes. Hence, the present study was undertaken to determine the effectiveness of vestibular nerve stimulation using portable battery-operated vestibular nerve stimulator in the management of diabetes.

METHODS

The present study was a double-blind randomized controlled trial with 1:1 split between the control and experimental groups. A total of 30 participants with type 2 diabetes were part of the study after obtaining the written informed consent. After recording the baseline values, the vestibular nerve stimulation was administered to the participants in the intervention group for 90 days. Sham stimulation was administered to the control group for 90 days. Outcome measures were recorded after 30 days and after 90 days of the intervention in both the groups.

RESULTS

There was significant decrease in the total body weight, fasting, postprandial blood glucose, glycosylated hemoglobin levels, leptin, very low density lipoproteins levels followed by the intervention. There was significant improvement in both spatial and verbal memory scores. Depression and stress scores and systolic blood pressure decreased and remained in normal limits.

CONCLUSIONS

The study results have proven multimodal action of vestibular stimulation. It not only acts on regulation of the glucose metabolism but also can regulate the autonomic activity and improve cognition and relieve stress. This is the interesting finding of our study, which needs detailed further research to support implementation of vestibular nerve stimulation as an adjunctive therapy in the management of diabetes.

Respiration Rate Estimation Based on Independent Component Analysis of Accelerometer Data: Pilot Single-Arm Intervention Study

Background

As the mobile environment has developed recently, there have been studies on continuous respiration monitoring. However, it is not easy for general users to access the sensors typically used to measure respiration. There is also random noise caused by various environmental variables when respiration is measured using noncontact methods in a mobile environment.

Objective

In this study, we aimed to estimate the respiration rate using an accelerometer sensor in a smartphone.

Methods

First, data were acquired from an accelerometer sensor by a smartphone, which can easily be accessed by the general public. Second, an independent component was extracted to calibrate the three-axis accelerometer. Lastly, the respiration rate was estimated using quefrency selection reflecting the harmonic component because respiration has regular patterns.

Results

From April 2018, we enrolled 30 male participants. When the independent component and quefrency selection were used to estimate the respiration rate, the correlation with respiration acquired from a chest belt was 0.7. The statistical results of the Wilcoxon signed-rank test were used to determine whether the differences in the respiration counts acquired from the chest belt and from the accelerometer sensor were significant. The P value of the difference in the respiration counts acquired from the two sensors was .27, which was not significant. This indicates that the number of respiration counts measured using the accelerometer sensor was not different from that measured using the chest belt. The Bland-Altman results indicated that the mean difference was 0.43, with less than one breath per minute, and that the respiration rate was at the 95% limits of agreement.

Conclusions

There was no relevant difference in the respiration rate measured using a chest belt and that measured using an accelerometer sensor. The accelerometer sensor approach could solve the problems related to the inconvenience of chest belt attachment and the settings. It could be used to detect sleep apnea through constant respiration rate estimation in an internet-of-things environment.

Sensory stimulation in the treatment of children with sleep-related rhythmic movement disorder: a feasibility and acceptability study

Background

Sleep-related rhythmic movement disorder is characterized by repetitive gross-motor movements at sleep onset or during sleep, which result in clinical consequences such as impact on daytime functioning and injury. No well-established therapies exist today. Substituting the patient’s movements with external sensory stimulation may offer a treatment modality. The aim of the current study was to test the feasibility and acceptability of vestibular stimulation using a rocking bed (Somnomat) in children with rhythmic movement disorder and to assess children’s movement preference.

Methods

Children with rhythmic movement disorder (n = 6, Age: 5–14 years) were studied over three nights in a sleep laboratory: adaptation night (normal bed) and randomised-order baseline (Somnomat) and intervention nights (Somnomat). Child’s preferred movement direction (head-to-toe or side-to-side) and frequency (between 0.25 and 2 Hz), determined during an afternoon protocol, were applied using the Somnomat for 1 h after lights out, and in response to subsequent episodes of rhythmic movement during intervention nights. Comfort assessed using a questionnaire, and objective sleep parameters assessed using videosomnography, were compared.

Results

The participants’ sometimes violent rhythmic movements did not disturb device performance. All children rated intervention nights equally or more comfortable than baseline nights. Self-reported sleep quality, as well as the number and duration of movement episodes did not significantly differ between baseline and intervention nights.

Conclusions

Providing rocking movements using the Somnomat is both technically feasible and acceptable to the target population. The therapeutic value of this novel stimulus substitution for rhythmic movement disorder should now be evaluated in a larger sample over a longer period in the home setting.

Trial registration

The trial was retrospectively registered at clinicaltrials.gov (NCT03528096) on May 17th 2018.

Influence of graviceptor stimulation initiated by off-vertical axis rotation on ventilation

NEW FINDINGS

What is the central question of this study? It is known that respiration is affected by graviceptors, but it remains unclear to what extent labyrinthine and non-labyrinthine graviceptors are involved in this process. What is the main finding and its importance? Our results suggest that the modulation of respiration is not a result of a simple reflex arc, but that it involves a higher integration of different types of receptors with variable contributions of either type of graviceptor among subjects.

ABSTRACT

It has been suggested that the otolith system is involved in the physiological response to changes in body orientation with respect to gravity. In studies on animals, an otolith-respiratory reflex has been observed, but data on humans are scarce and inconclusive, mainly because pure otolithic stimulation is difficult to produce in humans. To assess the otolithic-respiratory reflex in humans, we used an off-vertical axis rotation (OVAR) that produces periodic and pure stimulation of graviceptors. The inspiratory flow was measured during earth vertical axis rotation (EVAR, control conditions) and OVAR in 21 subjects. To distinguish the effects of the labyrinthine and non-labyrinthine graviceptors on ventilation, these measurements were repeated with two different static head positions: head turned leftward and rightward in yaw. The velocity of rotation was individually selected to match spontaneous breathing rate (mean 11.4 cycles min^-1 , 0.19 Hz). Average ventilatory flow was higher in OVAR than in EVAR, as was tidal volume. In OVAR, the transition between inspiration and expiration occurred mainly in the forward pitch position. The phase of this transition in most subjects was driven mostly by the body position rather than by the head position, suggesting that respiratory modifications during OVAR mainly involved non-labyrinthine receptors. However, the study demonstrated a high intersubject variability both in the ability of OVAR to synchronize breathing and in the influence of labyrinthine stimulation. We conclude that the respiratory response to changes in orientation of the body with respect to the vertical involves labyrinthine and non-labyrinthine stimulation, with the gain of each signal varying individually.

Neck movement but not neck position modulates skin sympathetic nerve activity supplying the lower limbs of humans

We previously showed that dynamic, but not static, neck displacement modulates muscle sympathetic nerve activity (MSNA) to lower limbs of humans. However, it is not known whether dynamic neck displacement modulates skin sympathetic nerve activity (SSNA). Tungsten microelectrodes inserted into the common peroneal nerve were used to record SSNA in 5 female and 4 male subjects lying supine on a table that fixed their head in space but allowed trapezoidal ramp (8.1 ± 1.2°/s) and hold (17.5° for 53 s) or sinusoidal (35° peak to peak at 0.33-0.46 Hz) horizontal displacement of the body about the head. SSNA recordings were made before, during, and after trapezoidal and sinusoidal displacements of the body. Spike frequency analysis of trapezoidal displacements and cross-correlation analysis during sinusoidal displacements revealed that SSNA was not changed by trapezoid body-only displacement but was cyclically modulated during sinusoidal angular displacements (median, 95% CI: 27.9%, 19.6-48.0%). The magnitude of this modulation was not statistically ( P > 0.05) different from that of cardiac and respiratory modulation at rest (47.1%, 18.7-56.3% and 48.6%, 28.4-59.3%, respectively) or during sinusoidal displacement (10.3%, 6.2-32.1% and 26.9%, 13.6-43.3%, respectively). Respiratory frequency was entrained above its resting rate (0.26 Hz, 0.2-0.29 Hz) during sinusoidal neck displacement; there was no significant difference ( P > 0.05) between respiratory frequency (0.38 Hz, 0.25-0.49 Hz) and sinusoidal displacement frequency (0.39 Hz, 0.35-0.42 Hz). This study provides evidence that SSNA is modulated during neck movement, raising the possibility that neck mechanoreceptors may contribute to the cutaneous vasoconstriction and sweat release associated with motion sickness. NEW & NOTEWORTHY This study demonstrates that dynamic, but not static, stretching of the neck modulates skin sympathetic nerve activity in the lower limbs.