Murata Manufacturing Co Ltd demonstrated a device that measures the fatigue degree of its user at Ceatec Japan 2010, a trade show that runs from Oct 5 to 9, 2010, in Japan.
The fatigue degree ranges from 0 to 100% (The higher the percentage, the more tired the user is). When I used the device, which the company calls "vital sign sensor," my fatigue degree was calculated to be 11%.
The vital sign sensor is made by integrating a photoplethysmographic sensor, which measures a pulse and a blood oxygen saturation level, and electrodes that measure electrocardiogram (ECG).
It consists of two sensing parts. One is composed of the photoplethysmographic sensor and an electrode for ECG (for a finger of the right hand), and the other is an electrode for ECG (for a finger of the left hand).
Based on the pulse, blood oxygen saturation level and electrocardiogram measured by the sensing parts, a fatigue degree is calculated.
"Pulse and electrocardiogram are highly correlated with fatigue degree, and they are always changing," Murata said. "So, they are indicators that are suited to be measured every day."
The company expects that the vital sign sensor will be equipped in mobile phones and portable game consoles. To use the device for them, the two sensing parts have to be exposed.
The vital sign sensor is equipped with a microcontroller (I2C interface). Murata plans to start shipping the device in volume in fiscal 2011.