The recent FDA approval of the Medtronic MiniMed 670G – the world’s first hybrid closed loop system – was cause for celebration in the type 1 diabetes (T1D) community. It marks a life-changing breakthrough in the history of T1D management. We sat down with Dr. Bruce Buckingham, Professor of Pediatric Endocrinology at The Lucille Salter Packard Children’s Hospital, Stanford University, and principal investigator of the Medtronic MiniMed 670G at Stanford University:
When did you begin your investigation of the “artificial pancreas” system?
I received my first JDRF grant in 2006, 10 years ago.
What were your most significant discoveries during early human clinical trials? Were patients happy with results?
Closed loop systems can do very well at achieving good overnight control, significantly decreasing the risk of nocturnal hypoglycemia and hyperglycemia, and can allow people with T1D to start the day with a good glucose level. The initial systems often had issues with communication between devices, and often required a utility belt to carry cell phones, sensor receivers, and pumps. Even with these hassles, people were happy to have some of the burden of diabetes decreased by a closed loop system. Most asked after a study “when can I get one of these?”
What comprises the Medtronic MiniMed 670G artificial pancreas system?
A new “Enlite3” sensor which provides a significant improvement in accuracy, and the 670G pump which has a new user interface, and the control algorithm resides on the pump. The sensor is calibrated with an Asencia (previously the Bayer) Contour Link meter (automatic glucose transmission to the pump).
Will patients still have to administer insulin when they eat?
Yes. This is a hybrid system, meaning that the person with T1D is still giving meal boluses. They will need to enter their carbohydrates, do a meter glucose reading, and use the pump bolus wizard calculator. Any correction dose will also require a finger stick reading.
How will the system ease the burden of overnight T1D management?
The controller should significantly decrease their risk of hypoglycemia or hyperglycemia overnight. It targets a glucose of 120 mg/dl, and generally comes within about 15% of this value in the morning. People with T1D will still need to do meter glucose readings in the day.
What other systems are you currently studying?
Bigfoot Biomedical, Insulet, Tandem Diabetes, Bionic Pancreas, Animas, and Type 0.
What developments do you foresee in the near future?
Many more systems with different nuances of managing T1D, progressive improvement in making systems user friendly, more automation, correction boluses based on sensor values, adapting to meals, and eventually different forms of full closed loop (user not directly entering carbohydrates for meals, perhaps no meal announcement, adding accelerometers or heart rate monitors for exercise and determination of sleep), and much more, hopefully all leading to decreased burden of T1D care while maintaining good glycemic control.
Read more about the historic FDA approval of the Medtronic MiniMed 670G and JDRF’s pivotal involvement here.