How the handheld ultrasound scanner works
By Fergus Walsh
Medical correspondent, BBC News
An ultrasound scanner the size of a large mobile phone has been launched in Europe and North America.
The Vscan can be used to image the heart and other organs.
Developer GE Healthcare says the portable device, priced at about £5,000 in the UK, is not designed to replace existing machines.
But it may offer rapid early diagnosis to triage patients in hospitals and the community who would then be referred for more specialist examination.
It looks like a cross between a flip-top phone and the medical scanner used by Dr McCoy in the TV series Star Trek.
The Vscan is not science fiction but a hand-held ultrasound machine with a scanning wand attached, which has been approved for use in Europe and North America.
The device is being used in the cardiac investigation unit at St George's Hospital in south London.
The moving colour images show blood flow around the heart and by switching to black and white you can see heart valves opening and closing.
George Sutherland, professor of cardiac imaging at St George's, believes hand-held scanners will one day be standard issue for doctors on ward rounds.
He said: "In terms of clinical practice it's a huge step forward.
"Here we are giving people essentially an electronic stethoscope in their pocket that images and looks at all parts of the body.
"With adequate training this should mean we can diagnose rapidly and treat accordingly. It should be an amazing development."
The portability of the device means it is likely to have use outside hospital - allowing scanning to be done wherever it is needed, in the home or perhaps for the military - on the battlefield.
Julie Walton, president of the British Medical Ultrasound Society, said it could eventually be used by paramedics on ambulances.
She said: "This type of system is designed for point-of-care ultrasound, where we take ultrasound to the patient rather then bringing the patient to ultrasound.
"It also has the possibility to be used in many clinical settings such as primary care, intensive care and casualty".