Multi-sensor non-invasive blood glucose monitoring instrument based on impedance spectroscopy-optical method

A multi-sensor non-invasive blood glucose monitoring instrument based on impedance spectroscopy optics, the monitoring instrument comprising:

• a detection probe;
• a microprocessor;
• a display unit;
• and
• a storage unit,
• wherein the detection probe comprises a pair of high-frequency electrodes, a pair of low-frequency electrodes, a temperature and humidity sensor, an LED array, a photoelectric sensor, and a contact plate,
• wherein the microprocessor controls an excitation signal generation circuit to generate high frequency and low frequency excitation signals,
• wherein feedback signals from the high-frequency electrodes and the low-frequency electrodes are inputted to the microprocessor via an amplitude and phase detection circuit, and then high-frequency impedance and low-frequency impedance are obtained through calculation,
• wherein temperature signals and humidity signals of a tested part are measured with the temperature and humidity sensor, and then are conditioned and inputted to the microprocessor,
• wherein the LED array is controlled by a transmitter control circuit,
• wherein light intensity signals measured by the photoelectric sensor are amplified and filtered, and then inputted to the microprocessor to obtain optical characteristics of tissue of the tested part,
• wherein the microprocessor is configured to use a model to calculate a blood glucose concentration of the test part based on the optical characteristics, the high-frequency impedance and low-frequency impedance, and the conditioned temperature signals and humidity signals,
• wherein the microprocessor outputs the calculated blood glucose concentration to the display unit for display, and the optical characteristics, the high-frequency impedance and low-frequency impedance, and the conditioned temperature signals and humidity signals are saved in the storage unit at the same time,
• wherein the high-frequency electrodes comprise a pair of parallel electrodes, and a matching inductor L is directly soldered to one of the electrodes,
• wherein a distance between a positive electrode and a negative electrode of the low-frequency electrodes is 1 cm-2 m,
• wherein a vertical distance from a bottom of the temperature and humidity sensor to a bottom of the contact plate is 0.1 mm-20 mm, and
• wherein the temperature and humidity sensor and the tested part form an enclosed space, and slits or pores are arranged in a wall of the enclosed space to form a balanced heat and moisture storage structure.