LG Innotek, a mobile device component affiliate of LG Group, said on Feb. 16 that it has successfully developed the world’s best super-slim heartbeat sensor module. Heartbeat sensors in wearable devices and smartphones are widely used to measure body status information such as heart rate, stress index and oxygen saturation rate.
The company said the new heartbeat sensor module is thinner, consumes less energy and has improved accuracy. Accordingly, users can be now provided more accurate body information.
The key in wearable device technologies is to downsize devices while minimizing electricity consumption. Because users should wear the devices to use them, wearable devices cannot be popular no matter how excellent they are functionally if they are cumbersome and consume too much energy.
LG Innotek said its heartbeat sensor combines a photo diode (PD), light-emitting diodes (LED) and a semiconductor chip in a single module only 1 millimeter thick. When applied to wearable devices and smartphones, this module will allow for slimmer and freer designs.
The company said it has used printed circuit board (PCB) embedded technology to reduce the thickness. It is the technology that embeds a semiconductor chip in PCB. Previously, there was a limit to reduce the thickness of module since a semiconductor chip, which processes living body signals, should be mounted on PCB and other components, including PD, afterward.
The new heartbeat sensor module is much thinner but consumes less energy compared to existing modules. It measures the blood flow rate with LED lights and minimizes light loss inside. As the efficiency for light utilization increases, the living body signal reception capability has been improved by 30 percent compared to existing modules, and thus can detect accurate bio-signals with less energy. When using this module, it can operate with about 20 percent less energy consumption.
The company also said the module has higher measurement accuracy. It said the module can measure pulse within an error range of 5 beats per minute (bpm) during exercise and within an error range of 2 bpm at a steady state, which is comparable to that of medical devices.
When a user measures the heart rate with wearable devices during exercise, existing modules have an error range of 8 bpm. If the actual heart rate of the user is 120 bpm, existing modules of wearable devices will show the figure from 112 to 128 bpm. LG Innotek’s heartbeat sensor module improves the figure from 115 to 125 bpm.