Moving Research into Action
Ed Damiano: A Personal Research Agenda
One recipient of a Coulter grant is biomedical engineer Ed Damiano. For many years he did what he calls “basic science stuff,” investigating the biomechanics of the circulation system. But six years ago he was drawn to an entirely new field of research. His son, then not yet a year old, was diagnosed with type 1 diabetes, historically referred to as insulin-dependent or juvenile diabetes. The disease requires constant vigilance, including frequent monitoring of blood glucose levels, close attention to diet and exercise, and either multiple daily insulin injections or continuous insulin infusion with an insulin pump.
Spurred by the experience of living with a child with type 1 diabetes, Damiano began to work on an automated system that would continually measure glucose levels and provide insulin as needed—a system that would mimic the natural function of the insulin-producing cells of the pancreas. He recruited his wife, pediatrician Toby Milgrome, in this effort.
Almost two million Americans have type 1 diabetes, an autoimmune disease in which the body attacks the insulin-producing beta cells in the pancreas. The trigger for the attack is unknown. Without insulin, most of the body’s cells are unable to absorb and use the glucose that fuels cell processes. The glucose remains in the bloodstream where high glucose levels can lead to a range of problems including kidney disease, blindness, nerve damage, high blood pressure, heart attack, and stroke. “There is no cure for type 1 diabetes, but if people can maintain their blood glucose within the normal range, they can reduce and possibly eliminate the deleterious consequences of type 1 diabetes,” says Damiano. “But,” he continues, “because glucose levels fluctuate constantly (especially after meals), even intensive therapy fails to adjust insulin levels to their every rise and fall.”
Insulin pumps, devices the size of a cell phone that administer insulin through a small catheter implanted in the skin, are an increasingly common treatment alternative. These devices provide a baseline dosage of insulin throughout the day and the patient administers a bolus (or additional dose) when glucose levels increase (most commonly after meals). But to know how much additional insulin is needed, glucose levels must be checked several times a day using a small meter that tests a tiny drop of blood. Damiano and his wife check their son twelve times a day, more than most.
Damiano, his research team, and Milgrome are designing a more automated system that combines an insulin pump with a device to automatically measure glucose levels every few minutes via an electrochemical wire embedded in the skin. A small computer chip will use this data to instruct the device to deliver more insulin if needed.
Although the system uses technology already approved by the FDA, some technical hurdles remain. The meter they are using tests interstitial fluids, not blood. Glucose levels in these fluids lag behind and are less concentrated relative to blood glucose. Since it is the blood glucose levels that must be treated, this poses a problem. One of Damiano’s former graduate students, Firas El-Khatib (now a post-doc in his lab), is working on extending his original glucose-control algorithm by developing a scheme that translates the glucose measurements from the interstitial fluid into estimates of blood glucose.
Also, the individual pieces of technology must communicate with each other. Damiano and El-Khatib have already tested the system on pigs, by combining wirelessly actuated insulin pumps, a glucose meter, and their control algorithm running on a laptop computer. They had to sedate the pigs to keep them from running around and upsetting the system. They plan to use the Coulter grant to build a system that can be mounted on a pig’s back and tested while the pigs are awake and active.
Damiano is also looking ahead to introducing their system to people with diabetes. He hopes to begin his first trials on patients in a closely monitored clinical setting, using a non-portable system, within a year—and thinks a fully portable system could be ready to test in two to three years. “I have a deadline,” says Damiano. “I have to have this ready before my son goes to college.”
For more information, see www.bu.edu/dbin/bme/faculty/?prof=edamiano.
— by Trina Arpin