Here’s what you need to know about the heart rate monitoring tech
Heart rate monitors on wearables are no longer a rare thing. Smartwatcheslike the Apple Watch or the Samsung Galaxy Watch have them. Most fitness trackers pack them, too, from high end ones like the Fitbit Charge 3 down to budget options like the Xiaomi Mi Band 3. They’re even starting to turn up on fashionable wearables like Fossil’s clan of Wear watches.
Generally, all of these heart rate monitors are based on the same technology. We’re talking light-based optical tech (PPG) that uses flashing LEDs that penetrate the skin to detect blood flow. The light reflected off that blood flow is captured by those sensors and with algorithm smarts produce the heart rate data. It’s a non-invasive way to measure heart rate and that’s why a lot of companies use it in their wearables.
But it’s not the gold standard – that’s achieved by ECG monitoring. And below, we’re going to break down how ECG works, why it’s considered more reliable, and how companies like Apple might seek to use the technology. Plus, we’ll tell you about the wearables that already offer ECG tech on the wrist and other parts of the body.
The current heart rate technology
Optical heart rate sensors are good for producing information like on-the-spot readings or resting heart rate data, which can be a good indication of you current state of health. They’re also pretty useful for adding HR data when you’re working out, too.
But optical heart rate sensors have an accuracy problem, and we’ve known that for a while. They’re getting better, but they still have issues at high intensity and keeping up with the likes of interval training. A variety of things can impact on readings including skin tone, as well, such as skin temperature or simply making sure the heart rate monitoring wearable is worn securely enough to produce reliable data.
It’s the reason why you might often see us write (particularly for fitness wearables), that if you need a wearable that monitors heart rate reliably and accurately, go for a heart rate monitoring chest strap. Why? Because it uses something called ECG to take heart rate measurements. This is the same method used in the medical industry. So when there’s talk of Apple potentially introducing ECG to its new Apple Watch, that’s a big deal. Not just from an accuracy point of view, but also for the fact that upgrading to a more reliable method of taking those readings could unlock the ability to use that information for greater insights into health and fitness.
Those three letters above stand for electrocardiogram and, as mentioned, it’s a term you’d more commonly hear in the medical industry. You might also hear it referred to as EKG as well, which means exactly the same thing. It refers to a medical test carried out with a electrocardiograph that’s used to detect any cardiac abnormalities.
How does it do that? An electrocardiograph usually requires placing multiple electrodes on the skin situated close to the heart that measures electrical activity produced by the heart as is contracts. This electrical activity is then sent to a receiver that records the information and is where the heart’s rhythm can be analysed and irregularities can be detected.
The benefits of ECG wearables
The obvious one is that it’s a more accurate method to measure that electrical activity from the heart. You don’t have to be plastered with all of those electrodes on your body to do it, either. Take a chest strap that uses ECG tech, for instance. While many people aren’t fans of wearing them, they do concentrate placement of those electrodes close to the heart to record and transmit the data. Those electrodes will require moisture or sweat to provide a reliable connection and it’s why you are prompted to wet the electrodes a little before sticking that chest strap on.
Another benefit is that ECG wearables work with smartphones and other wearables (like watches), replacing the need for one of those old school receivers to collate and log the data through companion apps or third-party apps. That means you can analyse the data in the comfort of your home or wherever you need to take a reading.
ECG heart rate monitors have already been embraced by wearables, but largely for fitness. In the case of chest straps for instance, it’s going to give you more reliable data particularly for high intensity training when the heart activity fluctuates. Optical sensors tend to take longer to adjust to those fluctuations.
ECG and the accuracy that comes with it also opens the door for companies to start exploring more serious health issues, specifically focused around the heart. We already know that both Fitbit and Apple intend to explore the possibility of its devices being used to manage heart health and detecting conditions like atrial fibrillation. The ability for your wearable to detect when there’s a serious problem with how your heart is functioning is obviously a huge thing to be able to do without potentially needing to visit a doctor or medical professional to find this out.
Challenges of making ECG wearables
When you start talking about selling wearable devices that enables anyone to diagnose a serious medical condition, you have to be certain that the technology can be relied on. There’s no doubts that companies who start exploring serious heart health monitoring realms will perform their own comprehensive testing before saying that their wearables can actually do this. They’ll also have to seek approval from the appropriate regulatory bodies. So in the US, that means getting the thumbs up from the FDA.
ECG wearables available right now
AliveCor is a startup that’s all about monitoring heart health, and has launched its KardiaBand that works with the Apple Watch. It uses electrocardiogram (ECG) technology, which detects the electrical activity produced by a heartbeat offering real-time detection of AFib. It remains the first and only medical accessory device for the Apple Watch cleared by the FDA.
$199.99, alivecor.com | Amazon
Qardio’s wearable takes the form of a chest strap and uses medical-grade ECG tech that can send live data on your heart rate, heart rate variability, respiratory rate, temperature and activity to your phone. Like AliveCor’s Apple Watch strap, the QardioCore is designed as a preventative, everyday (or week) health monitoring device to be used at home in between checkups. It’s currently only available to buy in Canada, Europe and Australia, as Qardio seeks approval from the FDA to ship in the US.
Hexoskin’s new gen connected garments are equipped with ECG tech that the startup says has been clinically validated to continuously track heartbeats. The iOS and Android compatible clothing can additionally take heart rate variability measurements to offer insights into stress, training effort, training load and fatigue.