Replicating the functions of the pancreas has long been the dream of medical professionals working with patients who suffer from Type 1 diabetes. For some researchers in the life sciences sector, the emphasis has always been on finding a cure for this condition, but for others it has been more about assisting people with Type 1 diabetes to hit their recommended targets for glucose control over the long term. Without being able to regulate their body’s glucose levels, patients are left at an increased risk of developing the sometime severe complications associated with diabetes. As the pancreas plays a crucial role in this regulation in healthy people, the idea of an artificial one – which could help many more diabetes sufferers achieve their glucose targets – should not only lessen risk of longer term complications but mean that fewer cases of hypoglycaemia develop.
The concept of an artificial organ of any description is simple enough to understand, but not so easy to put into practice. In the case of an artificial pancreas, this would be a piece of technology that could carry out all of the functions of a healthy pancreas. Crucially for Type 1 diabetes sufferers, an artificial pancreas would administer precisely the right amount of insulin to the bloodstream, at just the right time. In order to achieve this, the technology needs to have three elements working together – an insulin pump, a glucose sensor under the skin and a computer program held in an external monitor that works out how much insulin to deliver and when.
The first of these three components, the insulin pump, is simply a delivery system designed to administer insulin to the patient’s body. Most insulin pumps currently deliver insulin via a catheter which is inserted under the skin. The insulin can be stored in the monitor and the two connect together through a thin section of flexible tubing. Secondly, the artificial pancreas needs a glucose sensor. Held within the body, this keeps a constant check on the level of blood sugar and relays the information wirelessly to the monitor.
At the heart of the systems currently in development, the monitor does all of the clever work. Firstly, the monitor receives data from the sensor and records it into its program. Held outside of the body, these are worn by patients near to their waist and can even be clipped onto their clothing, rather like a pager. With the information sent to it by the sensor, the monitor then decides whether or not to send insulin to the pump which, in turn, administers it to the body. Since the sensor continues to offer feedback about the level of glucose that remains in the body, the monitor can decide to either continue with more insulin delivery or to stop, just as a real pancreas would.
At the moment, many Type 1 diabetes sufferers will be well aware that they must monitor their glucose levels on a regular basis. Based on the results of such monitoring they will then often need to administer insulin – usually by injecting themselves. The principle behind the artificial pancreas is that it will fully automate this monitoring and delivery system. For some patients, this may simply mean that they have an improved quality of life, due to the greater peace of mind they get knowing that they are not, for instance, making mistakes. However, this is not the only advantage of an artificial pancreas. Researchers believe that, because glucose levels will be monitored constantly and not just a few times a day, the accuracy of insulin delivery – when it is needed – will be improved. Furthermore, patients can expect overnight monitoring to continue, thus reducing the risk of hypos during sleep. Overall, the better glucose control afforded by an artificial pancreas should reduce the longer term risk of the sort of complications common among Type 1 diabetes sufferers.
In the UK, there are two major research projects which are currently ongoing that are focussing on the development of an artificial pancreas which could be used in the field. Both are run by researchers at the University of Cambridge. Dr Roman Hovorka is working on a project to generate a first generation prototype. His artificial pancreas is being assessed in a five and a half year programme to see whether it will improve blood glucose control in domestic settings and be able to lessen the risk of overnight hypos in adults. In 2014, his research team announced results from a study of 24 adults with Type 1 diabetes. Each of the people in the programme used their device overnight in their homes for a period of four weeks and did so with no medical supervision. It was found that diabetes sufferers using Hovorka’s system spent more time with their glucose at ideal levels. This translated to a 13.5 per cent improvement when compared to people using other highly-regarded insulin therapies.
Dr Hovorka said that a larger scale clinical trial of the prototype will be the next step in developing these promising findings. “We want to make an end product that will help to transform the management of Type 1 diabetes,” he said. “By reducing the risk of blood glucose levels falling dangerously low at night time… such a product should be viable with existing technology.”
Since 2011, Dr Helen Murphy has been working on a similar system which is specifically aimed at pregnant women with Type 1 diabetes. Like Hovorka’s device, her artificial pancreas system can automatically calculate the right amount of insulin required to maintain normal glucose levels in the bloodstream to help prevent nocturnal hypoglycaemia. Murphy’s work is focussed on both the early and late stages of pregnancy. Her team has already shown the safety and effectiveness of an artificial pancreas for pregnant women over a 24-hour period. Her system was found to have protected against extremely low blood glucose levels, even after periods of modest exercise. On average, women using the system in her trials found that their glucose levels remained within the recommended range for in excess of 19 hours a day.