Scientists say a glucose sensor could be linked to a portable insulin infusion pump to create the artificial pancreas.

The prospect is still some way off, but closer on the horizon are implanted glucose sensors which will give continuous measurements that can be read from remote hand-held devices.

The sensors would send small electric shocks through the skin, which would open up pores so that fluid could be extracted and glucose concentrations monitored.

In a series on 21st century medicine in this week's British Medical Journal, researchers say that the main reason for developing in vivo (in a living being) glucose sensors is for the detection of hypoglycaemia (low blood sugar) in diabetic patients.

Patients with insulin dependent (Type 1) diabetes have a problem with monitoring low blood sugar levels, especially during the night, when self-monitoring is not possible. Those who do not experience warning symptoms also need help.

The researchers, Drs John Pickup, Lydia McCartney, Olaf Rolinski and Professor David Birch of Guy's, King's College and St Thomas' School of Medicine in London, say that several new approaches will speed up the development of glucose sensors.

Total sensor implants

These include sensors implanted in the body which will have more robust artificial glucose receptors.

These could be checked from outside the body by measuring changes in infrared fluorescence intensity or the time certain materials in the sensor take to decay.

Sampling of tissue fluid and extraction techniques would enable glucose to be measured outside the body under more controlled conditions, but will need further development, say the researchers.

In the more distant future, it may be possible to link up a sensor to a portable insulin infusion pump via a computer to create a portable artificial pancreas, they say.

The ultimate goal would be an implantable artificial pancreas which would regulate the flow of insulin, but this idea is still far from becoming a reality.

"Safe delivery of insulin in this way will require glucose sensors that have proved totally reliable after many years of "open loop" testing. We are far from being at that stage," they say.