Fujitsu technology measures a person’s real time pulse using facial imaging
Fujitsu has developed a technology that detects a person’s pulse by measuring variations in the brightness of the person’s face thought to be caused by the flow of blood. It is based on the characteristic of hemoglobin in blood, which absorbs green light. It requires no special hardware and can measure pulse rate simply by pointing a camera at a person’s face for as little as five seconds. It also automatically chooses moments when the person’s body and face are relatively still to minimize the effects of irrelevant data on measurements. This technology has a wide range of potential uses, including health monitoring and maintenance as well as security applications.
One characteristic of hemoglobin in blood is that it absorbs green light. Based on this fact, Fujitsu 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.