A novel approach to wearable sensors
Researchers from the NCSEM-EM, along with colleagues from Loughborough University’s School of Electronic, Electrical and Systems Engineering, have developed a wearable sensor that uses a novel optical approach to provide reliable, continuous monitoring of vital signs.
The more people move, the more difficult it is to accurately monitor physiological parameters such as heart rate, oxygen levels, respiration and blood pressure.
Most progress has been made in the area of portable heart rate monitors which can be used under a wide spectrum of different types of movement, but they can be uncomfortable and sometimes impractical to use on a routine basis.
More user-friendly approaches have emerged based on the use of photoplethysmography (PPG), an optical approach that can measure multiple and critical parameters in addition to heart rate and lends itself to miniaturisation, as seen in the emergence of smart watches with inbuilt heart rate measurement.
The drawback with conventional PPG is that the sensor may be confused by body motion resulting in innacurate readings.
Carelight’s novel optical layout overcomes the limitations of PPG sensors to continuously deliver a clear signal, even in high intensity physical activity. The ultra-lightweight wearable PPG sensor can be placed on various parts of the body to provide reliable, continuous monitoring of vital signs including heart rate, respiration rate, heart rate variability, blood pressure, temperature and oxygenation levels.
The Carelight sensor relies on a novel combination of characteristics:
Incorporates multiple copies of illumination sources and several different wavelengths to allow for different skin types, colours, ages
Selects optimum illumination source / wavelength combination for the best quality signal at each illumination interval
Design incorporates additional sensor devices, for example an accelerometer and temperature sensor