Research Progress in Millimeter Wave Radar-Based non-contact Sleep Monitoring - A Review

Compared with traditional contact medical devices, non-contact sleep monitoring based on millimeter wave radar has the advantages of non-contact, simple operation, and long-term monitoring of human respiration rate (RR) and heart rate (HR), which has broad research value and market prospects. In this paper, we review the recent developments, current challenges and future directions in the field of non-contact sleep monitoring based on millimeter wave radar. We first summarize some representative research works published in recent years to discuss vital sign monitoring, sleep posture estimation, and obstructive sleep apnea (OSA) detection. It is illustrated that vital signs such as RR and HR can be used as indicators for diagnosing many diseases, helping to diagnose sleep disorders and providing information on the classification of different sleep stages. Sleep posture estimation can be used as a diagnostic indicator for many chronic diseases and may help in pharmacological treatment. OSA monitoring is one of the most valuable research and application prospects in sleep monitoring. Finally, the challenges now facing measurement accuracy and stability, multi-user monitoring, and processing device computational performance are discussed, and future research directions in the field of sleep monitoring are proposed.