A six-minute walk test is more work than it sounds. It measures a patient’s health by getting them to walk up a measured length of corridor, turn around and walk back, wearing a finger sensor that records blood oxygen level and pulse, with two healthcare professionals counting the turns and monitoring the sensor data.
“The corridor is used by lots of different people,” says Dr Elizabeth Orchard, a consultant cardiologist at Oxford University Hospitals NHS foundation trust. “Anybody who walks along there, any beds that come along there, any trolleys, it’s very difficult to continue walking.” At Oxford’s John Radcliffe hospital, the nearest suitable corridor is about 200 metres from the cardiology outpatient department, which means that a simple six minute test takes much longer, particularly if the patient has to be taken to the corridor in a wheelchair.
Not only that, but doctors can sometimes get the numbers wrong, forgetting to count a turn because they’re talking to the patient. Echocardiograms and the patient’s own reports are taken into account, but, says Orchard: “We are deciding on expensive therapies depending on the results of this.”
Patients can stay at home
The trust is testing wearable technology to let patients carry out walk tests at home. Since summer 2015, Dario Salvi, an engineering science research assistant at the University of Oxford, has worked with Orchard to build a smartphone app that uses the phone’s motion sensors to count turns (if the test is carried out outside, it uses GPS location tracking). Blood oxygen level and pulse are taken at the fingertip by a medically-tested wearable device that sends the data to the smartphone using Bluetooth wireless technology.
They are currently testing the system with about 10 patients, and although not yet used for treatment decisions, its data has already provided insights. Salvi shows an online graph for one patient’s recent outdoor six-minute walk with the pulse staying at a low 50 beats per minute; Orchard says this was because the patient’s pacemaker failed to respond to increased physical activity, and will be adjusted.
Results from the app will be compared against the standard in-hospital tests and it could be available for clinical purposes in 2018. Orchard says using it would save patients from unnecessary hospital trips but also allow clinicians to make quicker decisions on changing types or levels of drugs.
Wearables are improving patient care
Oxford isn’t the only trust to look at wearables. NHS England has chosen seven sites, known as test beds, to pilot the use of wearable devices to monitor conditions such as diabetes and respiratory disease. The hope is both to save the NHS money, enable patients to stay in their own home for longer and help doctors identify, and react to, problems more quickly.
Other parts of the NHS are independently testing the technology. Dorset Epilepsy Service is issuing up to 200 Microsoft Band 2 fitness wristbands to its patients, which use 11 sensors to record data that includes sleep and activity patterns. Dr Rupert Page, the service’s clinical lead, says that the wristband data can reliably detect around 85% of the most serious generalised tonic-clonic seizures. But absence seizures - a loss of awareness that may last just 30 seconds - cannot be detected by the wristband so patients use a smartphone app to record them.
The aim is to use both types of data to work out when patients are more likely to experience seizures. “All of these things allow us to develop new insights for patients from that data,” says Page.
The trial is using a commercially-available fitness wristband rather than a medical one. “There’s a lot of stigma attached to epilepsy,” he says. Smartwatches were considered, but they needed recharging too often – running all the sensors constantly drains their batteries.
Apps motivate people to change their lifestyles
King’s Health Partners, an academic health science centre, is using healthcare-focused wristbands from Buddi to examine how to help patients avoid developing type 2 diabetes. It plans to involve around 200 patients in Southwark and Lambeth, chosen by applying algorithms to GP-held data to find people who have high blood sugar levels that indicate a risk of diabetes.
Some participants will also get an app that coaches people to improve their health, using physical activity data gathered by the wristband and a standard workbook of advice. “The idea is to continually motivate people in a positive way, suggesting solutions to potential barriers,” says Dr David Hopkins, the centre’s joint clinical academic group lead. Other participants will just see activity data such as number of steps taken, without the associated advice.
The trial will test the theory that people need coaching as well as data to change their lifestyles. Hopkins describes some of the studies of wearable technology, where users just see data, as a “bit disappointing”. To make long-term changes, people typically require opportunities, motivation and continuous reinforcement from healthcare professionals: “We believe by providing it in an automated way we can achieve the same.”
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- This article was amended on 31 March 2017. An earlier version quoted a Dr Rupert Poole. He is Dr Rupert Page.
