Researchers have shown that the brain waves characterizing deep sleep, so-called slow waves, can be improved by playing precisely timed sounds through earphones while sleeping. While this works well in the sleep laboratory under controlled conditions, there has thus far been no at home solution.
To address this problem, researchers at ETH Zurich have developed a device named SleepLoop that can be used at home and aims to promote deep sleep through auditory brain stimulation.
The SleepLoop system consists of a headband that is put on at bedtime and worn throughout the night. This headband contains electrodes and a microchip that constantly measure the brain activity of the person sleeping. Data from this is analyzed in real-time on the microchip using custom software. As soon as the sleeping person shows slow waves in the brain activity characterizing deep sleep, the system triggers a short auditory signal (clicking). This helps to synchronize the neuronal cells and enhance the slow waves. What makes the solution unique is that the person sleeping is not consciously aware of this sound during deep sleep.
Researchers from ETH Zurich and University Hospital Zurich have conducted a clinical study with this device for the first time. The results have been published in the latest issue of the journal Communications Medicine.
The study involved equipping participants, between 60 -- 80 years old, with the SleepLoop system, which they were required to operate themselves in their own home. The system is designed to function independently even by users with little technical experience.
The results of the study show that it was indeed possible to enhance the slow waves through auditory signals during deep sleep in most participants. However, the individual differences were extensive with some of the subjects responding very well to the stimuli, while others responded minimally or not at all.
In a report posted April 10 on the ETH Zurich’s website, the researchers said they are currently using these individual differences to better predict how a given individual will respond to the auditory stimulus. This in turn helps them to optimize and improve the performance of SleepLoop, which will be produced and marketed by Tosoo AG, a company affiliated with the institute.