Diabetes can Be Cured – The Bionic Pancreas for Type I Diabetics
By Live Dr - Thu Jan 06, 3:52 pm
Principal Investigator: Professor Chris Toumazou,
Co-Investigators: Dr Pantelis Georgiou, Dr Nick Oliver, Professor Des Johnston
Research Team: Dr Pau Herrero Vinas, Mohamed El Sharkawy, Christina Morris, Peter Pesl
Type 1 diabetes is caused by antibodies attacking insulin-producing β-cells in the pancreas. Treatment is usually by regular insulin injections, informed by glucose measurements from fingerprick blood samples. However, these do not mimic the normal behaviour of the β-cell and this leads to suboptimal blood glucose control and complications including kidney failure, blindness, nerve damage and heart disease. Aggressive treatment can help but may lead to potentially-dangerous low blood glucose levels (hypoglycaemia).
The DCCT trial demonstrated that intensive management of type 1 diabetes reduced complications by 50-76% compared with conventional therapy. This was achieved at the expense of increased hypoglycaemia, especially when HbA1c levels <7.5% were achieved. A closed loop system provides the potential to improve HbA1c levels while avoiding hypoglycaemia.
In non-diabetic subjects, the pancreatic β-cell membrane depolarises in response to elevated glucose. At glucose levels <7mM, the cell is electrically silent, but bursting activity occurs as glucose rises >7mM. A novel silicon chip simulation of the β cell’s bursting behaviour has been developed at Imperial and is being refined. This provides the opportunity to develop a closed-loop insulin delivery device based on bio-inspired, physiological control. The “silicon β cell” replicates first phase insulin response and, being electrically silent at low glucose concentrations, avoids hypoglycaemia. The input will be from a novel, amperometric microprobe array sensor and insulin delivery will be via a near-continuous flow pump
The project combines the expertise of physiologists, biomedical engineers and clinical investigators to develop a novel closed-loop insulin delivery system for type 1 diabetes centred around a silicon β cell incorporating a novel glucose biosensor, a physiological control algorithm and insulin infusion pump.
Project video: Bio-inspired Artificial Pancreas
1. Oliver NS, Toumazou C, Cass T, Johnston DG. Glucose Biosensors. Submitted 2008
2. Radomska A, Singhal S, Ye H, Lim M, Mantalaris A, Yue X, Drakakis EM, Toumazou C, Cass T. Biocompatible ion selective electrode for monitoring metabolic activity during the growth and cultivation of human cells. Submitted 2007
3. Ho M, Georgiou P, Singhal S, Oliver N, Toumzou C. A bio-inspired closed-loop insulin delivery based on the silicon pancreatic beta cell, 2008 IEEE International Symposium on Circuits and Systems. ISCAS 2008, Proceedings (accepted for publication 2007)
4. Georgiou P, Oliver NS, Touazmou C. A silicon beta cell: towards an intelligent closed loop insulin delivery system EASD 2007
5. Georgiou P, Toumazou C. A Silicon Pancreatic Beta Cell for Diabetes, IEEE Transactions on Biomedical Circuits and Systems, vol.1, no.1, pp.39-49, March 2007
6. Georgiou P, Toumazou C. Towards an ultra low power chemically inspired electronic beta cell for diabetes, 2006 IEEE International Symposium on Circuits and Systems. ISCAS 2006, Proceedings, pp. 4, 21-24 May 2006