Santa Barbara researchers to test artificial pancreas
Santa Barbara will soon host trials of a first-ever artificial pancreas being developed by researchers at UC Santa Barbara and Sansum Diabetes Research Institute to help treat type 1 diabetes.
Under development for the past several years in Santa Barbara, the artificial pancreas is now in clinical trials around the globe. Much of the funding has come from the Juvenile Diabetes Research Foundation.
The system that will be tested in Santa Barbara this fall — made up of off-the-shelf equipment linked by a crucial control algorithm developed by chemical engineers at UCSB — is likely to resemble what may eventually reach consumers, though researchers say a commercially available artificial pancreases could still be years away.
Type 1 diabetes, sometimes known as juvenile diabetes, can’t be controlled with diet and exercise alone. It’s an autoimmune disorder in which the patient’s body attacks cells that produce insulin, the hormone that helps the body turn food into energy.
There’s no cure, and the only treatment is relentless blood sugar monitoring coupled with careful diet control and insulin injections.
Over the long term, high blood sugar puts type 1 diabetics at risk of kidney disease, heart disease and blindness. But pumping in too much insulin can bring blood sugar down to dangerously low levels in the short term.
“It can cause seizures, and it can kill people,” said Aaron Kowalski, research director of the artificial pancreas project for the New York-based Juvenile Diabetes Research Foundation. “It’s a balancing act.”
Today, there are devices that constantly monitor blood sugar, also know as glucose. There are also devices that pump insulin into the blood. But the connection between the two — how much insulin it takes to get blood sugar in a safe range — has mostly been a matter of keeping paper logs and simple calculation.
Even with careful monitoring, many patients spend a lot of time outside the normal blood sugar range.
“Even though we see bad outcomes because of bad glucose control throughout the population, it’s not that people aren’t trying,” Kowalski said. “We believe that with computers and the amazing technology that’s evolved over the years, we can do much better.”
That’s where UCSB’s engineers came in.
“We started to think about closing the loop,” said Eyal Dassau, lead scientist for UCSB’s artificial pancreas system team. “The missing link is the brain — the control algorithm that will take measurements, calculate the optimal dose for that specific time and send a command to the pump.”
The engineers have been working closely with Sansum, and the institutions consider themselves a singular unit when it comes to the artificial pancreas project.
“We teach them about medicine, and they teach us about engineering,” said Howard Zisser, director of clinical research and diabetes technology at Sansum. “It’s hard for one person with one hat to figure out the intricacies of the system.”
And those intricacies are many. First, the algorithm has to deal with only being able to move blood sugar in one direction — insulin generally lowers blood glucose levels. That makes controlling blood sugar with insulin “like driving a car with just your accelerator pedal,” Zisser said.
Another problem is the limitations of the equipment. The blood sugar sensor has both a lag and a margin of error. On top of that, the insulin used doesn’t hit peak effectiveness until 45 minutes after its pumped under the skin. It’s like driving without seeing a curve until you’ve passed it, and the tires not responding until well after you’ve turned the wheel.
“The algorithm has to do a really good job at predicting the future,” Kowalski said.
On top of that, researchers are working on ways to detect meals and adjust for meals and exercise, both of which have an effect on blood sugar. “We believe our best approach right now is to have a personalized model for each patient,” Dassau said. “We take data from the patient and develop a model that is fit to the patient.”
As studies unfold in France, Israel and the United States, Kowalski — who has type 1 diabetes himself — said the research wouldn’t have been possible without the contributions from Santa Barbara.
“It’s not an understatement to say they’re some of the best people in the world and are key to driving this science forward,” Kowalski said. “I’ve been holding out to participate in this trial so I could come to Santa Barbara to do it.”