Smartwatches have long used PPG sensors (i.e. photodiodes) to measure vital signals. However WBD101 is a pioneer in using PPG for in-ear sensing (earbuds), given our first patents date back to 2008.

Both WBD101 and competitors use photoplethysmogram (PPG) sensors that measure reflected light from the skin, but while our light source is medical infrared, competitors use green LED. Green LED is absorbed by skin pigment (melanin), distorting the signal in darker skin tones, and the cold weather-induced low blood flow near the skin surface further decreases accuracy. Infrared also has energy-conserving and aesthetic benefits, as the light is invisible. Blood produces pulsatile signals which reflect light to our sensors’ algorithm to derive heart rate data.

Competitors rely on accelerometers to detect motion noise artifact—movement from the subject that can interfere with measurements. However, WBD101 uses multi-PPG to categorise targeted and untargeted signals without exclusion. Accelerometers often miss slow movements, can be affected by variations in skin contact, and only identifies targeted signals, filtering out untargeted signals that may contain useful information for uncovering more vitals.

WBD101’s patented multiple sensor array allows 360 degree monitoring of blood vessels. By comparing signals from multiple light paths, our algorithm can clearly separate true pulse signals from motion noise without accelerometers. Unlike accelerometers that can only distinguish signal frequencies that often overlap, our PPG sensors utilise the signals’ unique spatial patterns for more accurate differentiation.

WBD101 enhances accuracy with custom-designs optimised for different ear locations. Competitors use fixed-shape photosensors, but WBD101 offers multiple earbud shapes, maximising sensor contact and stability with the skin for consistent PPG data collection. This multi-angled sensing with tailored fit establishes WBD101 as a pioneer in delivering reliable health monitoring beyond accelerometer-based devices.