Albasha, LutfiHusseini, GhalebGeorgeous, Joel Nabil2025-06-252025-06-252025-0535.232-2025.11https://hdl.handle.net/11073/26149A Master of Science thesis in Biomedical Engineering by Joel Nabil Georgeous entitled, “Acetone Sensor Readout Circuit for Noninvasive Diabetes Diagnosis and Monitoring”, submitted in May 2025. Thesis advisor is Dr. Lutfi Albasha and thesis co-advisor is Dr. Ghaleb Husseini. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This thesis explores the development of a breath acetone sensor readout method for the non-invasive monitoring and diagnosis of diabetes mellitus (DM). DM is a chronic metabolic disorder characterized by insufficient insulin production or its impaired use in the cells, leading to a high blood glucose level. This disease requires constant monitoring of blood glucose levels. Traditional blood glucose monitoring techniques are invasive and inconvenient, highlighting the need for non-invasive alternatives. Breath acetone, a byproduct of fat metabolism in diabetic patients, has been identified and used as a biomarker for diabetes as it is directly related to blood glucose levels. Its concentration is significantly higher in the breath of diabetic patients, making it an effective indicator of the disease’s progression. This research aims to develop a real-time, precise readout method for a highly selective and sensitive acetone sensor developed previously in the literature. The sensor utilizes a capacitive measurement technique where its dielectric constant varies with acetone concentrations. A capacitive readout circuit processes the sensor’s output, which converts capacitance to a DC output voltage. The capacitance is measured through a series of inverters that output a pure square wave. The phase shift in the square wave is correlated with a change in the sensor’s capacitance. A subtractor op-amp finds the difference between the original square wave and the one with a phase shift. A passive low-pass filter finds the average of the difference output signal, generating a DC signal with a value corresponding to the difference extent. Next, the signal is processed in a microprocessor that displays health information on a graphic user interface (GUI).en-USDiabetesDiabetic ketoacidosisAcetone detectionAcetone sensorCapacitive sensorCapacitive readout circuitThesis