"Blood glucose monitoring is important in the care of diabetes mellitus and is presently accomplished via a “finger-stick” in which a lancet is used to prick the finger and withdraw a small amount of blood for testing. The problem with the existing “finger-stick”-devices is that blood sampling is painful, it increases the risk for infections and the test is discontinuous. A method for measuring the status of a diabetes patient continuously is preferred, especially at night when the risk of undetected hypoglycaemia is present. Systems for continuous (non-invasive) blood glucose monitoring show promising results for measuring high blood glucose values (hyperglycaemia). However, these systems are not reliable when it comes to measuring low blood glucose values (hypoglycaemia). This is due to the fact that a small variation in the blood glucose concentration in the “hypo-region” has a great impact on the status of the patient. In this project volatile components emanated from the skin are used to determine the state of diabetes patient; one of these components is acetone. An apparatus to clinically test the relation between the amount of acetone and the state of hypoglycaemia (and the concentration of blood glucose) has to be developed. Clinical tests (clamp tests) will be performed in an (academic)hospital. Furthermore, research has to be performed into the combination of several techniques (e.g. impedance spectroscopy) with skin gas measurements to obtain an overall picture of the status of a diabetes patient. Measurements of acetone permeation through the skin and the use of membranes to protect the sensor and/or to enhance the signal are needed. Sensors need to be developed to miniaturise the system. The ultimate goal is to develop a sensing system capable of measuring the condition of a diabetes patient satisfactory and in addition is able to steer the function of, among others an insulin pump."