From counting steps and heart rate, to measuring biomarkers and delivering drugs, wearable tech is offering help for a range of conditions.
Dr Karl Gruber (PhD) reports
Wearable devices that monitor health might have been around for more than a decade after the first Fitbit watch was released in 2009, but they have evolved significantly, allowing for the detection and monitoring of multiple biomarkers of health.
The devices are composed of two key components: a receptor and a transducer. The receptor recognises a target signal, such as heartbeat, and responds accordingly. The transducer then converts the receptor’s response into a useful signal, which can then be interpreted by a patient or doctor.
A skin patch was recently designed by researchers from the University of California San Diego and is able to monitor blood flow through major arteries and veins. The computer-controlled patch uses ultrasound to accurately monitor blood blow deep in the body.
The device may one day help clinicians detect people who are at risk of a stroke or heart attack, long before symptoms appear.
Australian researchers are also working in this space, developing new wearable technologies that are poised to revolutionise health care.
Local conditions
With the heart in mind, Australia-based company WearOptimo is designing sticker-like devices containing sensors that provide real-time monitoring of different health markers, which are forwarded to a doctor. The aim is to provide doctors with early warning for patients who may be at risk of developing life-threatening conditions such as heart attack and heat stroke.
According to WearOptimo founder and CEO, Professor Mark Kendall, their wearable devices may one day save the life of seriously ill patients.
“For example, we are developing micro-wearable sensors to detect and alert dehydration while people are on the job, or dehydration in the elderly,” he said.
“Another micro-wearable sensor is being developed to help the early detection of heart attacks and cardiovascular disease, which is responsible for 20 million deaths per year.”
In Victoria, a team from Royal Melbourne Institute of Technology has designed a UV-active ink that changes colour when exposed to different UV wavelengths. The ink is part of a sensor that can be worn as a wristband or sticker to warn people when they have received too much sunlight. According to Professor Vipul Bansal, who led this research, the device could help reduce the risk of sun damage to the skin.
“Monitoring your personal exposure is important because people have different solar UV exposure needs. Those with lighter skin are more sensitive to sun damage, while those with darker skin need more sun exposure to produce vitamin D,” he said.
More recently, University of Sydney researchers, led by Professor Emmanuel Stamatakis, are evaluating the potential of wearable devices such as Fitbit to help predict if a person has COVID-19.
The concept is to use a wearable device to monitor a person’s heart rate, physical activity or sleep patterns, and detect when something is amiss, which could be indicative of an influenza-like illness such as COVID-19.
“Wearable devices objectively track so many elements of our daily lives – from our step count and heart rate to our sleep. What we aim to find out here is if these measures could be used for early detection of illnesses such as the flu or COVID-19, potentially even before people are diagnosed,” Prof Stamatakis said.
Generally, wearable health devices can be classified in two broad categories: general wellness devices (e.g., Fitbit and Apple Watch) or regulated medical grade devices, which need TGA approval.
Money push
The Australian Government has committed about $7 million as part of a Primary Health Care Research Initiative grant to support the testing and implementing new applications for existing wearable electronics as well as point-of-care testing in rural areas.
According to Health Minister Greg Hunt, this would lead to patients managing their own health, reducing the number of doctor’s visits.
Real-time monitoring of biomarkers has the potential to track the health of patients, particularly those suffering from chronic illnesses such as cardiovascular disease, diabetes or neurological disorders.
Even healthy people could benefit from wearable technology, as knowing how your heart behaves while you exercise, for example, may reveal important information about your health. Likewise, knowing other details about your body can help guide changes to improve and maintain health.
“The possibilities this presents for us to understand the impact of people’s daily habits on their health and to encourage change are only just beginning to be realised,” Prof Stamatakis said.
In Australia, only a handful of wearable health devices have been approved by the TGA and are available on the market, of those, they target three key areas: cardiovascular health, diabetes and motion disorders.
What’s out there?
One of these cardiovascular wearable devices, the TelePatch cardiac monitor, can detect symptoms commonly associated with cardiac arrhythmia, such as shortness of breath and palpations.
Other devices such as Bioflux can capture events such as bradycardia, tachycardia, pause and atrial fibrillation. Data is delivered to a server wirelessly, where a doctor can analyse and interpret the collected data.
Another such device, the VitalPatch VitalConnect platform, works over a 96 to 120-hour period and can detect heart rate, electrocardiography, heart rate variability, R-R interval, respiratory rate, skin temperature, activity (including step count), and posture (body position relative to gravity).
Other systems are more like a Fitbit and resemble a smart watch.
The Kardia Band System can record, store and transfer single-channel ECG rhythms. This device can detect the presence of atrial fibrillation and normal sinus rhythms.
The HealthSTAT blood pressure monitoring device measures systolic and diastolic blood pressure and pulse rate. It employs the radial pulse waveform to derive the central aortic systolic pressure. This device is intended for patients with palpable radial pulse, who have uncommon arrhythmias such as atrial or ventricular premature beats or atrial fibrillation.
For patients with diabetes, some devices measure and store glucose data, which can then be interpreted by a doctor.
Other devices, such as the Animas vibe system, not only read levels of glucose in the body, but also includes an insulin pump which can deliver a single dose of insulin when needed.
These devices generally have a small wire or tip that is inserted under the skin to detect glucose. In the case of the Animas device, a wire is inserted under the skin of the abdomen to measure glucose levels.
With movement disorders, wearable devices are used to measure movement and muscle activity.
The ViMove uses wireless sensor technology to measure activity of the lower back. Another device, the neuromuscular motion disorder long-term ambulatory recorder-analyser, is targeted at patients with Parkinson’s disease. It can monitor physical motion and activity, and use the data to determine if there are instances of kinematics of movement disorder symptoms, such as tremors.
But some wearable health devices remain more about general information and are not intended to replace a formal diagnosis or monitoring. Even those with medical value, their benefit depends on proper use by the patient and professional medical interpretation.