Proving the Business Case for the Internet of Things

Kyocera develops mhealth sensor to measure blood flow

Steve Rogerson
December 21, 2016

Japanese company Kyocera has developed one of the smallest known optical blood-flow sensors for measuring the volume of blood flow in subcutaneous tissue.
With the sensor, Kyocera is researching a variety of mobile health applications such as monitoring stress levels or preventing dehydration, heatstroke and altitude sickness by studying trends or changes in blood-flow volume, providing alerts for these conditions and developing algorithms for detection.
Leveraging the company’s expertise in miniaturisation, the sensor –1mm high, 1.6mm long and 3.2mm wide – is for use in small devices such as mobile phones and wearable devices. The company will offer sensor module samples starting April 2017, and aims to commercialise the technology as a device by March 2018.
Potential mhealth applications in research and development include blood-flow sensing earbuds, allowing the checking of stress levels or orthostatic hypotension while music plays by analysing blood flow.
It could also be used in wearable devices for heatstroke prevention, helping prevent dehydration or heatstroke by detecting changes in blood flow. And mountain climbers could benefit with a wearable that helps avoid dehydration or altitude sickness by monitoring blood flow and sending notifications to rehydrate when there are potential risks.
The wearable device market has expanded in recent years, focused primarily on health and fitness. New mhealth applications are being developed for a wide range of healthcare uses including chronic diseases, eldercare and wellness.
Kyocera, which provides a wide range of components for smartphones and wearables, has been developing slimmer, smaller products to support higher functionality in more compact devices. The company developed this sensor as an integrated module, incorporating the laser diode and photodiode into a single ceramic package, based on its expertise in miniaturisation technologies.
Devices equipped with this sensor will be able to measure blood-flow volume in subcutaneous tissue by placing the device in contact with an ear, finger or forehead. When light is reflected on blood within a blood vessel, the frequency of light varies – called a frequency or Doppler shift – according to the blood-flow velocity. This sensor uses the relative shift in frequency, which increases as blood flow accelerates, and the strength of the reflected light, which grows stronger when reflected off a greater volume of red blood cells, to measure blood-flow volume.
Featuring a high signal-to-noise ratio, small size and 0.5mW output, the sensor can be integrated into a smartphone or wearable device for mhealth applications.