A Glucose Concentration Detector With Wide-Range Converter Used on Livestock

In this study, a glucose concentration detector was used to detect the glucose concentration in the drinking solution of livestock for the first time. The detector comprised a glucose sensor and a proposed wide-range glucose concentration converter. The proposed wide-range glucose concentration converter can linearly convert the concentration of glucose into a duty cycle. To allow them to be used in various glucose sensors, scaling circuits were added to the glucose concentration detector to enable adaptation to the currents generated by glucose sensors. All functions of the glucose sensor and proposed wide-range glucose concentration converter were proved by conducting measurements. The measured input current range of the proposed converter was 30 nA to 3 mA. This ensured that a wide dynamic range of input currents of 100 dB was guaranteed. A glucose concentration in the range of 5%-30% could be detected, and the corresponding duty cycle of the proposed detector was in the range of 4.67%-89.5%. The maximum linear error was -0.75%. The sensitivity of the proposed detector was 3.39%/%, and the chip size was 1.13 $\times$ 1.13 mm
²
. Finally, an experiment to detect the glucose concentration in the drinking solution of livestock was conducted. The results revealed that the proposed converter was suitable for glucose concentration detection.