Sleep monitoring for individuals with spinal cord injury using contact-free bed sensors

Sleep disorders are common in individuals with spinal cord injury (SCI), and contact-free bed sensors can detect these problems. This study examined whether these sensors apply to these individuals, especially at the cervical level, with a high degree of paralysis and limited mobility. First, we investigated whether their motion characteristics affect heart rate (HR), sleep latency, and sleep stage. We compared three commercial contact-free sensors: Emfit QS (Emfit Ltd., Finland), EarlySense Live (EarlySense Ltd., Israel), and SCA11H (Murata Manufacturing Ltd., Japan) with polysomnography (PSG)-a standard for sleep assessment. Then, we monitored the sleep on hospital and home beds and observed the percentages of timestamps and average HR and respiration rate (RR) recorded on the three devices. Compared with PSG, Emfit QS and EarlySense Live recorded an earlier sleep onset. Furthermore, the mean HR recorded by Emfit QS, EarlySense Live, and SCA11H differed by 0 to 8 beats per minute (BMP). In hospital beds, the collection rate for all three sensors was higher than 98% and HR, and RR differed by only 1.1 BPM and 0.5 BPM, respectively. Contrastingly, the rates differed by 13.7 BPM and 9.9 BMP at home, respectively. While these sensors differed from PSG and their data coverage rate was low, they can help clarify sleep disorders. Continuous sleep monitoring is essential for individuals with SCI, and sleep-monitoring devices are expected to contribute to this and help improve their quality of life.