OSRAM Opto Semiconductors presents its first integrated optical sensor
SFH 7050 is the first integrated optical sensor from OSRAM Opto Semiconductors for automatic fitness tracking. The sensor is used in mobile devices, such as smart watches and fitness armbands, and simplifies personal heart rate or pulse rate measurements during jogging for example. The sensor contains three light emitting diodes with different wavelengths, based on highly efficient chip technology. This helps save power and also offers high signal quality for particularly reliable measurements. A built-in photodetector receives the reflected optical signals and is separated from the emitters by an opaque barrier.
The three emitters built into the sensor have wavelengths of 530 nm (green), 660 nm (red) and 940 nm (infrared). These enable the pulse at the wrist or fingertip and the oxygen content of the blood at the fingertip to be measured. The emitters can be controlled individually so the sensor can be used for different applications. Green light has become established as the best option for measuring the pulse at the wrist. Red or infrared emitters are generally used for measuring the pulse at the finger as they can then also measure the oxygen content of the blood (pulse oximetry).