One characteristic of hemoglobin in blood is that it absorbs green light. Based on this fact, Fujitsu Laboratories has developed a technology that detects a person's pulse by measuring changes in the brightness of the person's face as blood flows through it. The technology starts to work by shooting video of a subject and calculating average values for the color components (red/green/blue) in a certain area of the face for each frame. Next it removes irrelevant signal data that is present in all three color components and extracts the brightness waveform from the green component. The pulse rate is then computed based on the peaks in that brightness waveform. This technique can measure pulse in as little as five seconds.
The acquired pulse data that is adversely affected by movements of the face or body is automatically removed. For example, moments when a person's head turns sideways while talking on the phone or standing up from a chair are automatically detected and removed. This makes it possible to continually monitor pulse during the course of a day while minimizing the impact of irrelevant data.
The technology has a wide range of potential uses, including health monitoring and maintenance as well as security applications.
Fujitsu Laboratories seeks to put this technology into practical use in fiscal 2013 for a variety of application scenarios such as a security or health monitoring and maintenance solution, building it into smartphones, tablets, and PCs.