LMD puts cuffless blood-pressure monitoring in smartphones

  • December 3, 2019
  • imc

Accurate blood pressure measurement can be cuffless, calibration-free and built in to every smartphone using technology from Swiss company Leman Micro Devices (LMD).
The first measurement of blood pressure was made in 1896 by squeezing the flesh around an artery. This method remains the only non-invasive way to measure blood pressure and, 123 years later, there is only one device in the world that claims it can do it without a cuff and to medical accuracy.
That device, the V-Sensor, is the technical implementation of proven medical science by LMD, a developer of regulated consumer healthcare products that is backed by major players within the mobile device industry.
There are many ways of tracking changes in blood pressure and a plethora of wearable and non-wearable devices now on the market that do it. These devices are not cuffless, they require the input of cuff-measured blood pressure and then monitor changes over the next few days. Then a new calibration is necessary using a cuff again.
That doesn’t help the one billion plus people in the world at risk of dying from hypertension because they do not know they have it; once they have used a cuff to calibrate a device, they will know that they’re ill and don’t need the device. Other wearable devices are not medically accurate, which can be even worse.
LMD’s patented technology uses the same principle as a cuff but acts on the fingertip. Its V-Sensor module instructs the user to press harder or softer to occlude the arteries of the tip of the index finger and detects it optically using a pulse oximeter. The V-Sensor is small enough and cheap enough to be built into every mobile phone and is engineered for production in smartphone quantities.
Its accuracy for both systolic and diastolic blood pressure measurement complies with international standard ISO 81060-2: mean error < 5mm Hg and standard deviation < 8mm Hg. With no personal calibration, V-Sensor has demonstrated accuracy for systolic blood pressure of mean error -0.4mm Hg, standard deviation 7.2mm Hg, and for diastolic blood pressure of mean error -0.2mm Hg, standard deviation 6.0mm Hg, both within the deviation allowed by the ISO standard.
Mark-Eric Jones, LMD CEO, said: “By creating our unique technical solution – the V-Sensor – in a device that can be built into every smartphone as well as wearables, we bring massive health benefits because we give users medically-accurate blood pressure measurement that is truly cuffless and calibration-free. V-Sensor with our e-Checkup software will save lives.”
LMD is based in Lausanne, Switzerland, in the heart of the Health Valley and close to EPFL University and major phone sensor companies. Founded in 2010 with funding by business angels, venture capital and two major players in the smartphone sector, LMD developed its e-Checkup system for integration into smartphones.