Portable Diabetic Ketoacidosis Detector via the Human Exhaled Breath Analysis

Ketoacidosis is a life-threatening condition among diabetic patients prevalent in the general population. The acetone level in human exhaled breath symbolizes the diabetic ketoacidosis, which normally requires a complex laboratory equipment to quantify. A portable device using the metal-oxide-semiconductor sensors, therefore, is developed to measure low-concentration of acetone in the human exhaled breath – allowing diabetic patients monitor and manage their ailments at home. Multiple techniques and analysis methods, such as sensor array, the Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were uniquely integrated into this automatic device. The work was further advanced by measuring acetone level in the presence of other volatile organic compounds (VOCs) such as ethanol. Experimental data indicated that the device was able to measure a sample gas of acetone concentrations at 0.32 ppm, 0.45 ppm and 0.65 ppm with mean responses of
$\boldsymbol{R}=\mathbf{1.03}$
(SD 0.03), 1.12 (SD 0.02) and 1.14 (SD 0.02), respectively, representing a useful resolution of 0.3 ppm. The PCA revealed that acetone-only, ethanol-only, and binaries of the two gases can be well distinguished in a lower-dimension subspace.