Kyocera says it has developed one the world’s smallest optical blood-flow sensors for use in wearable devices and mobile health (mHealth) applications. Kyocera’s sensor is 1mm high, 1.6mm long and 3.2mm wide and can be used in cellphones and wearable devices.

Any devices that are equipped with Kyocera’s blood-flow sensor will measure blood-flow volume just under the skin by having the device placed on an ear, finger or forehead.

Kyocera will start sampling the sensors by April 2017 and plans to commercialize it by March 2018.

Researchers have studied physiological effects using the frequency shifts from the change of light reflected off of a blood cell. The sensor harnesses the frequency shift and the strength of the light reflected from the blood cells and uses that information to measure blood-flow volume. Fluctuation of frequencies with 1.0, 0.3, 0.1 and 0.04 Hz illustrate heartbeat, respiration, vasomotion and neurogenic activity.

Kyocera is studying the potential to use the sensor in mHealth applications, including monitoring stress, hydration, heatstroke and altitude sickness.

Those who are wearing earbuds with blood-flow sensors built in will be able to measure their stress levels or hypotension while listening to music. The sensor can also notify hikers about risky altitudes and altitude sickness while reminding them to stay hydrated.

The sensor can be built into a cellphone or wearable device for mHealth applications because of its high signal-to-noise ratio and low power consumption. The sensor includes a laser diode and photodiode sensor within a ceramic casing.

The market for noninvasive wearable sensors that monitor and maintain the users’ health is steadily growing. Shipments of healthcare wearables are expected to rise to 97.6 million units by 2021, which is almost 40 times the 2.5 million wearables shipped in 2016, according to Tractica.

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