Artificial Pancreas on the Horizon
An artificial pancreas could revolutionize the treatment of diabetes, and it may only be a few years away.
Measuring Blood Sugar Levels
About two dozen companies and academic labs are developing
glucose sensors, Joseph says. Some are blood glucose sensors, others are tissue
fluid glucose sensors; some are placed under the skin by the patient, others
are implanted long-term in the body.
While glucose sensors have improved significantly over the past
few years, they are still the limiting factor in making the artificial
pancreas, he says.
Steve Lane, PhD, acting program leader of the Medical
Technologies Program at the Department of Energy's Lawrence Livermore National
"Almost certainly the goal of production of an artificial
pancreas will be achieved," says Lane, whose department worked on a
prototype of the artificial pancreas in partnership with MiniMed. "But
there are obstacles to be overcome, the major one being glucose sensing. To
date, no one has developed a foolproof way of sensing glucose."
Animas Corp. is developing an implantable optical glucose
sensor. In animal and preliminary human studies, the device accurately measured
blood sugar levels in the blood using infrared optics.
"A miniature sensor head is placed around a blood vessel,
and a light source is focused through the blood to a detector," says
Joseph. "The absorption of light at specific infrared wavelengths
determines the concentration of sugar in the blood."
Further along in development are Medtronic MiniMed's short-term
and long-term implantable glucose sensors, designed to continually measure the
level of sugar in the tissue fluid or blood.
First Artificial Pancreas Tested
In France, Renard is leading the first clinical trial of an
artificial pancreas -- a fully automated system that combines Medtronic
MiniMed's long-term glucose sensor and its implantable insulin pump.
In a minor surgical procedure, the implantable sensor is
inserted into a neck vein leading to the heart. The sensor is connected, via an
electrical-type wire under the skin, to the implantable insulin pump: As blood
sugar levels fluctuate, a signal tells the pump how much insulin to
"The patient doesn't have to do anything," Renard says.
"It's all automatic. Even if you're eating a high-carb meal, the sensor
will give the appropriate signal to deliver more insulin."