Blood glycemic level, also known as blood sugar level or blood glucose level,
especially that reaching high values (hyperglycemia) 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 thesis 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 kW, making it suitable for
skin impedance measurements.
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