Closed Loop Control of Blood Glucose Diabetes is a disease that is now regarded an epidemic in the world and a sign icant eort is directed towards nding better ways to manage diabetes. Keeping bloodglucoselevelsasclosetonormalaspossible leadstoasubstantialdecrease in long term complications of diabetes and can bring signicant cost reductions associated with the disease. Traditionally managing diabetes has been through intermittent monitoring of blood glucose and then administering an appropriate dose of insulin into the blood stream. This method of intermittent monitoring and administration of insulin cannot ensure blood glucose remains at near n mal levels at all times and therefore there is considerable interest in managing diabetes on a continuous basis. The development of articial organs apparatus that regulate human’s blood glucose level has been in progress since 1960. The aim was to measure blood glucose level ex vivo and then injecting an appropriate amount of insulin to the hyperglycaemic patient thereby correcting the high glucose level. This aim of closing the “loop” is still being challenged by technological barriers even today and progress are being made constantly both in overcoming the challenges and understanding more about the workings of glucose regulatory system. The purpose of this book is to introduce the eld of closed loop blood g cose control in a simple manner to the reader. This includes the hardware and software components that make up the control system (see Chapter 2). The hardware components involved the dierent types of glucose sensor ( vasive minimally invasive and non invasive) and the dierent types of insulin. Glucose Control: Input and Output Glucose Control: Patient Dynamics Mathematics of Glucose Control Closed Loop Control Apparatus Example Conclusions.