A potentially life-saving device is being offered to vulnerable Covid sufferers in Devon.

It enables them to measure their blood oxygen levels at home, providing an early warning system of what could be a dangerous deterioration in their condition.

One of the dangers of coronavirus is that it can cause levels of oxygen in the blood to drop dramatically without any obvious symptoms.

The patient can go on to become very unwell, but may be admitted to hospital too late to be treated effectively.

The pulse oximeter is being offered to patients over 65 or in a clinically extremely vulnerable group, to use during the first 14 days of coronavirus symptoms.

By monitoring their blood oxygen levels three times a day, they can detect whether their condition is getting worse, and alert the NHS.

Margaret Butler, 76, from Dawlish, was given the device by her GP practice earlier this month.

She said: "I would 100% encourage people to use it – it gives reassurance and peace of mind that you will know if something is going wrong and you need help.

"It's not complicated and I entered the readings via an app on the iPad which was simple to download."

The oximeter is put on the tip of the finger and measures the oxygen level in the blood by transmitting light. It's more accurate than the measuring devices on smart watches or phones, which work by reflecting light off the skin.

Patients record their results using a smartphone app, web portal or paper diary. Normal oxygen levels are between 95 and 100 per cent. Individuals whose levels drop are given clear clinical advice from the NHS on what to do, which may include contacting their GP, calling 111 or 999, or attending A&E.

If, after 14 days of the onset of symptoms, patients show no signs of deterioration with coronavirus, they will be appropriately discharged from the service and given advice on returning the oximeter safely, and how to continue supporting themselves at home.

NHS Volunteer Responders are on hand to support the service by delivering oximeters to people's homes where needed.

The Oximetry At Home service is a new initiative, and if patients aren't offered a device they're advised to contact their GP to ask for one.

More information is available here

For more general information on Covid, visit the NHS website.