The new bed sensor technology is based on the Ballistocardiographic (BCG) principle. When the heart pumps blood there is a recoil effect to the opposite direction. This means that when e.g. lying on a bed, the entire bed will be subject to micro movements due to the blood flow. We use an ultra-sensitive Murata accelerometer to capture this signal. A microcontroller with a specially made algorithms are able to extract heart rate and many other vital signs from the signal.
The BCG module/node outputs vital signs and bed occupancy information such as:
- Heart rate
- Respiration rate
- Heart rate variability (correlates to stress level)
- Relative stroke volume (how much blood the heart pumps)
- Bed status indicator (is the bed empty, is patient in bed, is patient moving in bed)
- Other information such as a data log of timestamp, signal strength etc.