Blood Sugar Level Monitoring

Blood glycemic level, also known as blood sugar level or blood glucose level, especially that reaching high values (hyper glycaemia) and persisting in time, is strongly linked to the development of type 2 diabetes and consequently serious medical conditions such as neuropathy, cardiovascular diseases, sensitivity to infections etc. Nowadays the only effective and reliable way of monitoring blood sugar level is to directly analyze the blood (capillary or venous), interstitial or other body fluids. The former method is the most used. Its main disadvantage is puncturing of patient skin (finger pricking for example) which frequently causes pain and the risk of viruses and bacteria entering the body. The development of an effective and accurate noninvasive method for blood glucose monitoring has been recognized as a crucial goal for future studies of blood sugar and implementations of such methods into wearable devices. In this paper, we propose monitoring of blood glucose level employing skin impedance measurement. A measurement system featuring an Application-Specific Integrated Circuit (ASIC) is presented and analyzed. The fabricated ASIC in 350 nm CMOS technology with dimensions 1223 μm x 1388 μm, typically consumes 450 μA at 3.3 V supply voltage and operates in frequency region from 5 kHz to 16 MHz. The system exhibits a good linear response for loads up to a few kΩ, making it suitable for skin impedance measurements.