
Heart-rate sensor reduces power consumption by 80% for wearable electronics
As the heart-rate sensor consumes about 80 percent of the power in smartwatches and fitness wearables the technlogy is expected to gain design wins in that area. ActLight is a fabless chip company that licenses out its DPD Intellectual Property (IP) and provides design and technical support services to its customers.
The DPD technology is similar to the avalanche photodiode in performance but has no need for an amplifier and it works at an operation voltage of about 1V, compatible with standard CMOS. In addition, the DPD typically measures time to triggering instead of the amplitude of an output photocurrent which makes for an easier to obtain digital value.
Typically, wearables use photoplethysmography (PPG) to measure pulse and oxygen uptake in the blood by measuring the amount of light reflected back from blood flowing in an artery. But that bright light, needed to make adequate measurements is a major power drain. By using the DPD technology it should be possible to reduce the light power required by 80 percent, ActLight said.
The sensor has been developed with École polytechnique fédérale de Lausanne (EPFL) and an unnamed global semiconductor vendor with experience in the medical technology sector. Already tested and calibrated, ActLight’s heartrate sensor is ready to be produced in large series to equip next generation wearables.
Next: Video
“Increased interest in fitness and wellness – has necessitated more affordable, precise, wearable sensing options. Our technology offers unique competitive advantages to our partners when compared to existing Photo Diodes used in wearable heartrate solutions” stated Serguei Okhonin, CEO of ActLight, in a statement. “We are open for IP licensing of our patented DPD technology that we own 100 percent,” he added.
Other applications for the technology could include: photodiodes for laser barcode scanners, proximity and gesture control sensors, light data transfer such as Li-Fi and ultimately optical data transfer on-chip.
