Somnomat: a novel actuated bed to investigate the effect of vestibular stimulation

Abstract

Rocking movements are known to affect human sleep. Previous studies have demonstrated that the transition from wake to sleep can be facilitated by rocking movements, which might be related to relaxation. However, it is not yet known which movements would have the greatest effect. Thus, a 6-degree-of-freedom tendon-based robotic bed was developed, for systematic evaluation of vestibular stimuli. The applicability of the device was evaluated with 25 subjects. Six movement axes were tested and analyzed for differences in promoting relaxation. Relaxation was assessed by electroencephalogram, electrocardiogram, respiration and a questionnaire. The developed device fulfilled all needed requirements proving the applicability of this technology. Movements had no significant effects on the electroencephalogram and electrocardiogram. Respiration frequency was significantly lower for baseline measurements without movement (median 0.183-0.233 Hz) compared to movement conditions (median 0.283-0.300 Hz). Questionnaire ratings showed a trend (p = 0.057) toward higher relaxation for movements along the vertical axis (z-axis) (median 4.67; confidence interval 4.33-5.67) compared to the roll-axis (median 4.33; confidence interval 3.67-5.00). Movements along the vertical axis (z-axis), therefore, appear most promising in promoting relaxation, though no effects were found in electroencephalogram and electrocardiogram variables. This lack of effect might be attributed to the short exposure to the movements and the large inter-individual variability and individual preferences among subjects.

Rocking Promotes Sleep in Mice through Rhythmic Stimulation of the Vestibular System

“…More recently, healthy adult subjects rocked laterally during a single afternoon nap showed reduced sleep-onset latency, increased N2 duration, and enhanced electroencephalographic (EEG) markers of sleep quality [5]. Conversely, Omlin and colleagues, testing various planes of motion and rocking rates with a rhythmically moving bed, did not observe any influence of rocking on adult sleep [6,7]. Of note, rocking conditions, such as the duration, rate, and displacement, differed among the three studies.…”

A Novel Approach to Assess Sleep-Related Rhythmic Movement Disorder in Children Using Automatic 3D Analysis

“…A number of authors have suggested treatment approaches that include, for example, aversion or stimulus substitution approaches (5, 27, 28), which rely on a response to initiation of movement. For example, the Somnomat rocking bed, which formed part of this feasibility study (19), could be activated in response to the patient’s RMs.…”

“…Data were collected as part of a feasibility study () of sensory stimulation therapy in children with RMD (18, 19). Assessments were made in the University of Zurich, sleep laboratory, Switzerland.…”

“…The participants slept one night in a standard bed (adaptation night) and another one in a bed that can rock gently (Somnomat) (18, 19) but was stationary for the measurement (baseline night). In both nights, Sheets were of average thickness.…”

Effect of vestibular stimulation using a rotatory chair in human rest/activity rhythm

“…In humans, vestibular stimulation through swinging has demonstrated an accelerated effect in the wake/sleep transition and have highlighted sleep consolidation during napping Bayer et al 2011). Otolith stimulation induced by accelerated linear bed movements seems to have a potential effect on drowsiness (Woodward et al 1990;Crivelli et al 2016). Positive effects of vestibular stimulation on the wake/sleep transition were recently confirmed in mice (Kompotis et al 2019).…”