Smart pens could soon be helping hospitals take better care of patients.
Regular monitoring helps health care
When combined with digital paper, the pens make it much easier to track a patient's vital signs during their stay in hospital.
By constantly capturing data about patients during routine examinations, it should become possible to spot problems before they get serious.
Some hospitals in France are already considering a trial of the digital pen and paper combination.
The prototype healthcare system using digital paper and pen has been developed by the research labs of technology consultancy Accenture.
The health watching system adapts technology developed by Swedish firm Anoto.
The key to the technology is the complex pattern of dots printed on paper sheets.
"It is a pattern of dots that does not repeat over a vast area," said Ceri Carlill, head of Accenture's lab in Sophia Antipolis in France, "no part of it is identical."
This means that every point on every sheet of paper effectively has an address. A pen fitted with a tiny camera can read the dots on the paper and work out where it is and what is being written with it.
Accenture has used the pen and paper combination to make it easier to digitise the information regularly recorded on the health charts at the foot of every patient's bed.
These charts record fluctuations in vital signs such as blood pressure and temperature.
Key health signs can be logged easily
Mr Carlill said it was better to find a way to work with existing practices than adopt an expensive alternative.
"Putting a tablet PC at the end of every bed is not commercially viable," he said.
"The health chart is a pen intensive application that's not going to change," he added. "It's a system that's evolved over the years to provide a very effective form of care."
By printing the charts on the patterned paper it becomes possible to swiftly create a "digital double" of everything nurses record on the health chart.
The pattern on the paper makes it possible to ensure that information about temperature and other vital signs shows up in the right place on the computer copy.
Information is uploaded to a central computer system when the pen is replaced in a docking cradle at the nurses' station on a ward.
Every piece of information recorded on the chart is also time stamped to give a doctor a better idea of how a patient is progressing and to help highlight any worrying trends in their life signs.
This data can easily be seen by doctors around the hospital letting them keep an eye on the health of patients without having to make regular trips to the ward.
"Doctors spend less time walking around and more time treating patients," said Mr Carlill
Accenture has already had interest from some French hospitals keen to try the health watching system.