Prof Sir Bruce Keogh, NHS England's medical director, believe wearable technology, like Apple's Watch, could revolutionise the NHS and future healthcare. Photograph: Getty

Devices worn on the wrist like the ones that record your heart rate, calorie intake or distance run have a vital part to play in securing the NHS’s future, the service’s medical director says.

Prof Sir Bruce Keogh believes that gadgets similar to fitness trackers, which are growing in popularity, and others resembling games consoles will revolutionise the monitoring of patients’ health, especially those with a serious condition.

“Fitness trackers are becoming increasingly sophisticated. But there are devices coming along which not only measure how much exercise you do but can also measure your heart rate, your respiratory rate, and whether or not you’ve got excess fluid in your body – quite complex changes in your physiology.

“Technology is emerging which enables those to be brought together and transmitted through mobile phones or other methods where health professionals can analyse them and act upon any warning signs,” Keogh says.

Wearable technology could easily prove useful for people with heart failure – one of the most common causes of admission to hospital – and thus relieve the strain on overcrowded hospitals.

“I see a time where someone who’s got heart failure because they’ve had a previous heart attack is sitting at home and wearing some unobtrusive sensors, and his phone goes, and it’s a health professional saying: ‘Mr Smith, we’ve been monitoring you and we think you’re starting to go back into heart failure. Someone’s going to be with you in half an hour to give you some diuretics’,” says Keogh.

Technology “enables you to predict things, to act early and to prevent unnecessary admissions, thereby not only taking a load off the NHS but, more importantly, actually keeping somebody safe and feeling good”.

Sitting in his office on the “corridor of power” occupied by the bosses at NHS England’s south London headquarters, Keogh is almost evangelical about how technology can improve health and cut NHS costs at the same time.

With a fitness tracker just visible under the left cuff of his white shirt, Keogh says in the future “people will use more wearable technology. People with conditions such as diabetes, heart failure, liver disease or asthma will wear devices, skin sensors or clothes capable of detecting deterioration and bringing this to the attention of the patient or anyone else they choose, through mobile phones.

“This monitoring will help keep people safe in their own homes rather than just waiting for serious deterioration necessitating an ambulance or GP call, followed by admission to hospital for several days.”

A polo shirt that can track the wearer’s gait, breathing and heart rate, created for tennis players, shows how quickly technology is developing that makes such monitoring simple, he says.

“The other day, on a visit to the Kent, Surrey and Sussex Academic Health Science Network, I saw a device that looks a bit like a games console. It’s much easier for elderly people to use. They hold it with both hands and a little screen asks you questions such as ‘are you breathless?’, and they just press a button that says yes or no. While they are holding the device, it is measuring their heart rate and transmitting their ECG, among other things. It can also monitor changes in bodily fluid, which is an early sign of heart failure.”

In case this all comes over as wildly futuristic, Keogh cites the results of an eight-month trial in 2013-14 of “low intensity telehealth” among 92 residents of nursing and care homes in Sussex. They had typical ailments of old age: congestive heart failure, diabetes, serious breathing problems and urinary tract infections. The local NHS community care trust gave the homes involved Android tablet computers fitted with an app devised by Docobo, a digital health company. That enabled staff to ask the patients questions regularly about how they were feeling, with the information then analysed remotely by four “admission avoidance matrons”. Anything untoward about a patient’s readings triggered an alert.

During the trial, the matrons received 252 alerts as a result of heart failure, 181 for breathing problems, 36 for a UTI and 20 for diabetes. Previously most patients whose health deteriorated ended up in hospital. But the early warning system, which cost just 90p a day per patient, led to a 75% drop in those who had to be admitted. Staff were able to intervene earlier and, for example, change their drug regime to stabilise their health.

Over the next few years the NHS will push forward with “a huge rollout” of such devices as part of “a revolution in self-care”, Keogh says.