In the world of wearable tech, where heart rate monitoring is commonplace, Google is making waves with a groundbreaking approach. While traditional devices rely on photoplethysmography (PPG) using light to measure heart rate, Google’s scientists have ventured into the realm of audioplethysmography (APG), harnessing ultrasound to track your heart rate. What’s truly remarkable is that they’ve achieved this feat using readily available active noise-canceling (ANC) earbuds and a simple software update, potentially transforming the health tech landscape.
Google’s innovative method involves sending low-intensity ultrasound signals into the ear canal and cleverly repurposing the built-in microphone responsible for ANC to detect minuscule skin surface changes caused by blood circulation. Their research blog reports the technique’s remarkable resilience, even when dealing with imperfect ear seals, varying ear canal sizes, and individuals with darker skin tones. The latter is especially noteworthy as wearables have long struggled to provide accurate heart rate readings for those with darker skin or tattoos.
What’s intriguing is that this ultrasonic approach works seamlessly, even when grooving to music. However, Google’s scientists are candid about challenges encountered in noisy environments and occasional signal interference due to body movements. Yet, they’ve cleverly surmounted these issues by experimenting with multiple frequencies, pinpointing the most precise signal amidst the noise.
To comprehensively evaluate their technique, the study included off-the-shelf earbuds and purpose-built prototypes designed to assess the influence of microphone placement. A field study involving 153 participants produced impressive results, with median error rates of 3.21 percent for heart rate and 2.70 percent for heart rate variability.
While heart rate monitoring headphones have been on the market for some time, they predominantly rely on PPG. They can be somewhat demanding, especially during intense physical activity or if they don’t fit correctly.
It’s crucial to remember that this research is exploratory and doesn’t imply an imminent release of Google headphones featuring this technology. Nevertheless, it offers a tantalizing glimpse into Google’s ambitions in the wearables arena, hinting at the potential for exciting innovations shortly.
For those eager to dive into the nitty-gritty of the study, Google has made it available for detailed perusal on their website.