Atrial stiffness is the next big health feature in Fitbit's crosshairs, according to a newly released patent spotted by Wareable
Google-owned Fitbit is working on detecting arterial stiffness – a noted precursor for life-threatening heart conditions like atrial fibrillation (AFib), hypertension, and coronary artery disease.
In a recently updated patent filing, Fitbit explains how a pulse wave analysis conducted during exercise using a photoplethysmogram (PPG) sensor can measure for the condition that can predict or identify serious cardiac issues.
The technology could feature within a future Fitbit health-tracking wearable or Pixel Watch smartwatch with health and fitness features powered by Fitbit.
We’ve already seen arterial stiffness feature on Huawei wearables, notably the Huawei Watch 4.
In the filing with the United States Patent and Trademark Office, Fitbit explains that “arteries harden as a result of vascular aging and other physiological factors such as pathologies and diets. Arterial stiffness indicates cardiovascular dysfunction and is an established independent predictor of cardiovascular risk.”
The non-invasive system devised to detect this hardening, Fitbit says, identifies “morphological features” of pulse waveforms (blood volume change caused by pulsed blood flow) known to correlate with arterial stiffness.
The aggregated indicator includes the augmentation index, reflection index, and pulse transit time, which a wrist-born wearable device can detect via the PPG sensor. In a wearable form, Fitbit argues, it could save users a visit to the doctors for time consuming tests in a clinical setting.
The filing, originally posted in September 2023, also explains the measurements would take place during physical activity, to provide better quality data.
The patent reads: “In some implementations, the one or more processors are further configured to determine the user’s heart rate [and respiration rate] using the PPG sensor data and trigger obtaining the PPG sensor data for a number of pulse waveforms, wherein the number of pulse waveforms depends at least partly on the user’s heart rate. In some implementations, the number of pulse waveforms increases as the user’s heart rate increases.”
The breakthrough could provide yet another tool in the growing arsenal for health-conscious users – mostly focused on heart data. Measurements like blood oxygen, heart rate variability, resting heart rate, and respiratory rate all offer deep insights into the wearers overall wellbeing.
Plenty of smart watches also have a build in electrocardiogram (ECG) to detect symptoms of AFib – typified by an irregular heartbeat – that can lead to blood clots and increases the risk of stroke and heart-failure.
Those suffering from the condition don’t always manifest irregular heart rhythms, meaning AFib can go undetected. However, there are other indicators, including the atrial stiffness Fitbit speaks of in the patent.
