There has been considerable growth in wearable-health technology in recent years, particularly in the diagnosis, treatment, and monitoring of patients with cardiac arrhythmias and other heart-related disorders. This article will discuss how advancements in antenna and battery technology have enabled a new frontier of wearable heart-monitoring solutions for both home and in-patient use.
Moving beyond the treadmill
In their infancy, wearable electronics for health purposes were often limited to devices aimed at the fitness community. For individuals looking to track their heart rate for the purpose of measuring the intensity and effectiveness of exercise, wearable devices from companies like Fitbit, Garmin, and even Apple were great options. These devices made it possible for individuals to access data about their exercise and athletic performance right on their wrists, but the benefits of this data essentially stopped there. Today, however, advances in sensor and power technology have opened new doors to the impact of wearable devices in the health-care industry, particularly for the detection, monitoring, and prevention of heart-related health issues. This article looks at some of the ways in which wearable tech is deployed for heart health and the advances in technology that have made it possible.
In an interview with CNBC back in early 2019, Apple CEO Tim Cook said, “I believe if you zoom into the future and you look back, and you ask the question, ‘What was Apple’s greatest contribution to mankind?’ It will be about health.” A bold claim from one of the biggest names in computer and cellphone technology. But at this time, Cook saw the promise of the Apple Watch, a product in its relative infancy, and the ways that proactive health monitoring through the tracking of core vitals could change the face of medicine.
Building on the Holter monitor
The concept of a wearable device for heart-health monitoring is not necessarily new. The Holter monitor is a device that has been around for years, which is used to continuously monitor cardiac conditions like arrhythmias over longer periods of time than a traditional ECG. This device is useful for individuals who have periodic arrhythmias that come and go, which can make measurement in an office setting difficult. With a Holter monitor, the individual wears a box-shaped device, usually from a lanyard around their neck or on a clip on their waist that is connected to electrodes adhered to the chest. However, the device, while effective, is still obtrusive and cumbersome. In addition to the monitor itself, there are wires and electrode pads to deal with. The Holter monitor is certainly a device used for a purposeful study of the heart and not for continuous monitoring — that is where today’s wearable technology comes in.
Acceptance in the medical community
In the past, fitness watches were equipped with heart-rate sensors that could detect the beat of the heart but not much more. These sensors worked by using a flashing LED that penetrates the skin and can detect blood flow. A clever algorithm takes that information and uses it to measure heart rate — useful in general, but not particularly accurate in terms of medical measurement. Today, however, new sensor technology has brought ECG capabilities to many devices, including offerings from Apple, Fitbit, and Samsung. These devices are equipped with ECG sensors that are significantly more accurate. In fact, Fitbit claims that their ECG app software algorithm can correctly identify people with atrial fibrillation (AFib, an irregular and rapid-heart–rate condition) 98.7% of the time. But do the claims of Fitbit hold up in the medical community?
According to a study published in “Trends in Cardiovascular Medicine,” these claims hold up surprisingly well, with the Apple Watch algorithm producing results with 95.5% sensitivity. In fact, even the FDA is on board, giving the Apple Watch Class II FDA approval for over-the-counter ECG detection. So how do the Apple Watch and other wearable devices achieve these levels of accuracy?
When it comes to the Apple Watch, it is helpful to look back to the Holter monitor. This device uses several electrodes that are adhered to the user’s chest and connected to the monitor via wires. These leads can measure the electric pulses of the heart as it beats and can then record this information. The results, however, must be analyzed by a medical professional to look for potential issues. What the Apple Watch does is create a single-lead ECG via a circuit between the back of the watch and the digital crown. This information is then processed via a sophisticated algorithm that can detect irregularities and provide the user with notifications when abnormalities are found.
Continuous health monitoring to prevent disease
So why does this all matter? According to the same study from “Trends in Cardiovascular Medicine,” AFib is one of the most significant contributors to heart-related diseases. Approximately 3% of the adult population has AFib, and it is associated with not only increased morbidity and mortality but as much as a fivefold increase in stroke risk.
In a story published on the University of Alabama at Birmingham (UAB) Medicine website, Dr. Tom McElderry, an electrophysiologist with the UAB Cardiovascular Institute, had this to say about the promising tech:
“Wearable devices are particularly helpful for people who have infrequent episodes of arrhythmia. Historically, our options have been to have patients wear prescription devices that capture episodes over a time span of 24 hours, two weeks, or 30 days. The advantage of an Apple Watch or a KardiaMobile monitor is that the patient owns it, so they can monitor for any length of time to detect arrhythmia.”
Indeed, the promise of wearable tech for the future of cardiac care is immense. By putting medical-grade technology into the hands of the masses, there is a significant opportunity to not only detect medical issues before they occur but to also collect and analyze vast amounts of health-related data at a scale that has never been seen before. The promise of the IoT for health-related issues is strong. Armed with this data and equipped with modern artificial intelligence and big-data–processing capabilities, doctors can explore heart-function data in vast new ways. With connectivity solutions for medical needs raising to keep up with the demands of the MedTech industry, the future of connected health-care solutions looks brighter than ever.