A man walking down the street checks a device attached to his wrist. The device is an Epson-made monitor that measures his pulse rate, but whose only contact point is his wrist. The face on the LCD screen tells him how much exercise is required to burn fat, and is designed to encourage him to do the correct amount of exercise.
Wristwatch-type pulse monitor
Below: Let’s pick up the pace!
Good: Burning fat efficiently
Above: Pulse rate too high. Drop the
On October 15, 2012, Epson launched sales of its wristwatch-type pulse monitor to company health unions in Japan. These statutory organizations are established in all companies over a certain size, and provide health-related support to employees including advice on exercise and diet.
* As of June 2012 this product was only on sale to Japanese company health unions.
This article discusses the development story behind the wristwatch-type pulse monitor that contains Epson’s sensing technology, and Epson’s plans to grow its healthcare business.
Conventional pulse monitors – including those previously manufactured on an OEM basis by Epson – involve a band wrapped around the finger, which contains a lot of blood vessels. However, finger bands are easily noticed and make it difficult for patients to perform manual work. Epson developed its new product to answer patients’ demands for a pulse monitor that did not require a finger band.
Conventional-type pulse monitor
To create this product, Epson drew on its 20 years of experience in pulse sensing technology with the aim of creating a wristwatch-type device. The product that emerged takes advantage of the light-absorbing property of hemoglobin. The monitor directs harmless LED light inside the skin, and then uses light-absorbing elements to measure the amount of light that is not absorbed by the hemoglobin and which is reflected back from inside the body. The amount of hemoglobin in the blood increases when the blood vessels expand – for example after exercise - meaning that the amount of light absorbed by the body also increases. On the other hand, when blood vessels contract the amount of hemoglobin decreases along with the amount of light absorbed. Epson’s product measures the pulse rate according to the amount of light entering the light-absorbing elements.
How the pulse sensor works
There are two main challenges associated with pulse rates from the wrist. The first of these is that there are far fewer blood vessels that can be used for measuring the pulse rate in the wrist compared to the finger. The amount of light that can be detected from the wrist by the light-absorbing elements is only one thirtieth of the amount that can be detected from the finger. To solve this issue, Epson increased the efficiency of the light-absorbing elements and developed a sensor that concentrates these elements on the wrist to ensure a stable pulse signal.
The pulse sensor obtains a stable signal from the user’s wrist.
The second challenge was the blood flow noise generated when moving the arm while walking is greater than that in the pulse spectrum. This can make it difficult to measure the pulse rate.
Pulse data sample
Epson therefore built into the pulse monitor an accelerometer capable of measuring the data generated when the arms moved. This data is automatically removed from the noise generated by the overall blood flow meaning that it is possible to measure the pulse rate accurately.
Epson has created a new type of pulse monitor by refining its sensing technology and by conducting a lengthy series of trial and error experiments. Thanks to these efforts it’s now possible for people to measure their pulse rate simply by attaching the monitor to their wrists. In addition to supporting people looking to lose weight, Epson hopes that the pulse monitor will become a useful tool in the exercise programs of people suffering from mild diabetes symptoms and recovering from heart ailments.
Going forward, Epson aims to contribute to people’s healthy lifestyles by leveraging its technologies to create new value-added products in healthcare, sports and medical care.
Business development plan for Epson’s wristwatch-type pulse monitor