The Freewavz earphones can track your heart rate and share your exercise data via a synthesized voice just like the LG Heart Rate Earphones I reviewed earlier this month. But unlike LG’s product, this new Kickstarter project does away with messy wires and uses a pulse oximeter sensor to divine heart rate and blood oxygen saturation data.
The Freewavz inventor—an ear, nose and throat doctor named Eric Hensen—says this sensor offers improved accuracy relative to a more rudimentary spectroscopic approach employed by LG.
Specifically, Hensen says, LG’s sensor is just a single-piece affair. It shines a beam of light at blood vessels and measures what’s been reflected to determine heart rate. But the Freewavz oximeter depends on two pieces, just like equipment used in hospitals. It shines light through the thin tissue of your earlobe, and measures that light after it hits a photodetector on the other side. … (Read more)