Research Team: Dr Pantelis Georgiou, Dr Pau Herrero Vinas, Dr Nick Oliver, Dr Monika Reddy, Dr Mohamed El Sharkawy, Dr Christina Morris, Dr Peter Pesl, Professor Des Johnston, and Prof Chris Toumazou
It is estimated that 5% of today’s UK population has diabetes and it is predicted that the incidence of diabetes will continue to rise. 10% of the whole diabetes population have type 1 diabetes mellitus (T1DM), which is caused by T-cell mediated autoimmune destruction of the pancreatic beta-cells. This results in an inability of the pancreas to produce insulin in response to a glucose stimulus. If left untreated, the condition is fatal. The majority of patients with T1DM are managed in specialist diabetes clinics and are either on daily multiple subcutaneous insulin injections or continuous subcutaneous infusion of insulin via a pump.
However, there are still multiple reasons why these patients do not achieve optimal glycaemic control, including insulin resistance, non-compliance with multiple insulin injections, needle-phobia and significant hypoglycaemic (low blood glucose) episodes needing correction with carbohydrates. Poor control of diabetes is associated with long-term microvascular complications including blindness, kidney failure and nerve damage as well as macrovascular complications such as heart disease and strokes. It is well established that intensive treatment of T1DM reduces the risk of developing complications. Achieving optimal glycaemic control can be very challenging for patients with T1DM due to the increased risk of hypoglycaemia with intensive treatment. The closed-loop insulin delivery system, also known as the artificial pancreas, has the potential to prevent hypoglycaemia and avoid large fluctuations in blood glucose levels by adjusting the insulin delivery dose frequently i.e. every 5 minutes according to the glucose concentration.
We are developing the world’s first bio-inspired artificial pancreas (BiAP) for treatment of diabetes. This differs from conventional closed-loop systems in that our algorithm is based on the glucose responses of biological alpha and beta cells of the pancreas providing physiological control, in addition to being fully implemented on a miniature CMOS microchip.
Physiological regulation is important because insulin has both metabolic and mitogenic effects. Delivery algorithms designed to minimise glucose excursions without consideration of delivered insulin may risk excessive weight gain, hypertension or arteriosclerosis. Implementing the artificial pancreas in CMOS technology adds advantages of miniaturisation, and therefore adaptation of the microchip to any sensor or pump, low-power consumption, allowing prolonged battery life and cheap cost of manufacture due to the economies of scale of silicon. Furthermore, the technology can interface to any type of electrical glucose sensor, electrochemical, optical, magnetic, making it future proof.
Our complete system comprises a miniature CMOS microchip that reproduces physiological insulin and glucagon release, a commercial continuous glucose sensor and continuous subcutaneous infusion pumps to provide bi-hormonal glucose control.
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1. Herrero P, Georgiou P, Oliver N, et al, A Bio-Inspired Glucose Controller Based on the Pancreatic beta-Cell Physiology, Journal of Diabetes Science and Technology, 2012, Vol:6
2. Oliver N, Georgiou P, Johnston D, et al, A benchtop closed-loop system controlled by a bio-inspired silicon implementation of the pancreatic beta cell., J Diabetes Sci Technol, 2009, Vol:3, Pages:1419-1424
3. 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
4. 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