A smart mattress for detecting and correcting the prone position: A feasibility study toward night-time SUDEP prevention.

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in otherwise healthy patients with epilepsy; about 70% occurs during sleep, and nearly 90% of patients are found prone (face-down). Following a nocturnal seizure, terminal apnea occurs between 2.5 and 10.8 min postictally (median ~ 5 min), defining a narrow but actionable window for intervention. Although body-position sensors are well established in sleep medicine and have been applied in epilepsy, no current product combines prone-position detection with autonomous repositioning into a recovery (sideways) position. METHODS: Korus is a smart mattress made of an array of inflatable cells. Korus consists of a sensor system to rapidly detect body change with high accuracy and a grid of expandable cells that reposition a patient from the prone to the recovery position. RESULTS: Ten normative control subjects were recruited, nine of whom were systematically tested. Each Korus cell generated a lift of 454 kg/cell at 5 cm/s. The sensor array detected body position changes within 5 s. Manually controlling the cells to reposition the subject from prone to recovery was successful in 100% of attempts in an average of 21.75 (±5.85) seconds. Body position detection was 96.8% accurate in detecting the prone position and 92.4% accurate overall in detecting the correct body position (supine, prone, left, right). False body position detection rate was 2.3 events/h. There were no incorrect position detections when subjects switched into the prone position. SIGNIFICANCE: This study demonstrates the feasibility of developing a smart mattress to detect the prone position and rapidly reposition subjects into a recovery position. Future development includes a control system to automate repositioning based on sensor data. The Korus device, when paired with a seizure detection device, may help lower the risk of night-time SUDEP, though the magnitude of any benefit remains to be established. PLAIN LANGUAGE SUMMARY: Sudden unexpected death in epilepsy (SUDEP) most frequently occurs at night, and the prone position is a major risk factor. A device to autonomously reposition a patient to the recovery position may markedly reduce the rates of SUDEP. Here we describe the Korus, a smart mattress with the ability to reposition patients out of the prone position in their sleep.