Table 1. Characteristics of included studies.
| Author and year | Origin | Study design | Population and sample size | Target group | Sensor application options | Smart control methods | Action mechanisms | Sleep improvement indicators |
|---|---|---|---|---|---|---|---|---|
| Zhang et al, 201573 | Singapore | Single-arm, pre–post study | Adults (N=28): male (n=16); female (n=12) | Healthy people | Single-channel EEG. (Sleeping mask) |
The appropriate audio stimulation. (Stereo earphones) |
Based on the online EEG computing algorithm, the user’s sleep state is detected and appropriate audio stimulation is provided to shorten the time to sleep onset. | Sleep onset latency |
| Zhao et al, 202074 | China | Pilot study | Adults (N=2) | Healthy people | Light intensity sensor; Temperature and humidity sensor; Facial expression recognition sensor. |
The device automatically plays corresponding music. | Regulating heart rate and breathing, improving the user’s mood and promoting sleep quality. | Proportion of deep sleep; Subjective sleep quality |
| Wei et al, 202375 |
China | Single-arm, pre–post study | Adults (N=20): male (n=10); female (n=10) | Healthy people | Air pressure sensor; EEG |
Adjusting the pressure in three body zones in real time using the auto-air mattress. | Keeping the spine in normal physiological curvature through comfortable pressure support, which in turn improves sleep quality. | Total sleep time; Sleep efficiency; Proportion of deep sleep; Subjective sleep quality |
| Verhaert et al, 201376 | Belgium | Single-arm, pre–post study | Adults (N=30): male (n=16); female (n=14) | Healthy people | Linear displacement sensor/linear potentiometers. (Mattress indentation measurements) |
New bed configuration. (Active mechanical adjustment of mattress firmness in eight comfort zones) |
Spinal alignment is significantly improved, thus positively affecting sleep. | Sleep efficiency; Subjective sleep quality |
| Van der Loos et al, 200364 | USA | Pilot study | Not mentioned | People who snore or suffer from OSA | Force sensitive resistors; Resistive temperature devices; Microphone/acoustic sensor; Potentiometers/displacement sensor. |
Automatic adjustment of the bed frame. | Diagnosis and alleviation of mild sleep disorders. | Duration and frequency of snoring |
| Tang et al, 202372 | Japan | Single-arm, pre–post study | Older people (N=18): male (n=11); female (n=7) | Older people | A telehealth monitoring system centred around an electronic water metre; A sleep monitoring device: heart rate, respiratory rate, body movement, the status measured when the user is lying on the bed. | The telehealth system. | Improving people’s health, predicting health status and the risks of lifestyle-related diseases, and addressing the shortage of doctors, nurses and home caregivers. | Total sleep time; Sleep onset latency; Proportion of deep sleep |
| Liao et al, 202465 |
China | Development study | Not mentioned | People who snore | An IoT snore tracker contains a detection microphone/acoustic sensor. | The acoustic-controlled pillow with IoT features provides soothing sounds. | Reducing the effects of intrusive ambient noise, which leads to relaxation and sleep induction. | Sleep onset latency |
| Kim et al, 201966 |
Korea | Development study | Not mentioned | Older people or healthcare users | The smart mat system contains gyro sensors; the human body sensing pressure sensor. | The telehealth system intelligently sets the temperature at the optimal level for sleeping. | Improving people’s health and addressing the shortage of doctors, nurses and home caregivers. | Temperature control |
| Hu et al, 202167 |
Italy | Single-arm, pre–post study | Older people (N=19) | Older people | An environmental sensor package: passive infrared motion sensors; contact-based door sensors; pressure-based bed and chair sensors; and proximity-based toilet sensors. | A remote healthcare service system. | Improving elderly patients’ quality of life and alleviating pressure on the healthcare system. | Sleep continuity; Nap variables |
| He et al, 202268 |
China | Pilot study | Adults (N=1) | People who snore | A novel low-cost flexible patch with MEMS microphone and accelerometer. | Snoring suppression using a small vibration motor. | Snore suppression. | Duration of snoring |
| Ferrer-Lluis et al, 202169 | Spain | Single-arm, pre–post study | Adults (N=9) | People who snore or suffer from OSA | An Android smartphone containing an accelerometry sensor; Oximetry. |
The vibration. | Positional therapy using smartphones helps reduce supine position, improves ODI severity and is effective for pOSA patients. | Percentage of time spent in supine position |
| Donati et al, 202170 | Italy | Randomised controlled trial | Newborns (N=45) | Newborns with CHD | Biomedical sensor: ECG; heart rate; oxygen saturation; body temperature; body weight. | Telemedicine is born. | Improving quality of life for the whole family and reducing hospital admissions. | Subjective sleep quality |
| Bogan et al, 201771 | USA | Crossover randomised controlled trial | Adults (N=65) | People who suffer from OSA | CPAP device/air pressure sensor. | The adjustable SensAwake Pressure. | Reducing sleep-disordered breathing events, effectively controlling OSA and improving sleep quality and insomnia. | Subjective sleep quality |
CHD, congenital heart disease; CPAP, continuous positive airway pressure; ECG, electrocardiogram; EEG, electroencephalogram; IoT, Internet of things; MEMS, microelectromechanical system; ODI, oxygen desaturation index; OSA, obstructive sleep apnoea.