Methods and systems for non-invasive measurement of blood glucose concentration by transmission of millimeter waves through human skin

A method of in vivo transdermal blood glucose concentration measurement, the method comprising:

• providing a clip having a first pad and a second pad opposite the first pad, the first pad comprising a first directional antenna that comprises a flexible polymer substrate and a flexible metallic structure and the second pad comprising a second directional antenna that comprises a flexible polymer substrate and a flexible metallic structure;
• clipping the clip to opposing sides of a biological tissue containing blood vessels, the biological tissue being either a human ear lobe having a thickness of 1 mm or more or a human skin fold between fingers having a thickness of 1 mm or more;
• i) applying, by the first directional antenna, electromagnetic waves at a frequency in the range of 20 to 300 GHz to the biological tissue,
• ii) receiving, by the second directional antenna, the electromagnetic waves transmitted through the biological skin fold;
• iii) analyzing the received electromagnetic waves for changes in transmittance magnitude or phase;
• iv) estimating a chemical concentration or a change in the chemical concentration in the biological tissue, based on the analyzed electromagnetic waves averaged over a range of frequencies, wherein:
• the chemical concentration is of blood glucose, and is estimated based on an inverse proportionality between the chemical concentration of blood glucose and absorption of the electromagnetic waves or a direct proportionality between the chemical concentration of glucose and the transmittance of the electromagnetic waves, and
• the step of applying the electromagnetic waves is performed by an electromagnetic wave transmitter comprising an electromagnetic wave source and the first directional antenna;
• and
• v) diagnosing or monitoring metabolic disorders of carbohydrate metabolism characterized by hyperglycemia or hypoglycemia or monitoring changes in carbohydrate metabolism in response to a diet or activity pattern, based on the blood glucose concentration,
• wherein step v) is performed continuously over at least a 24-hour period by continuously performing, over the at least 24-hour period, steps i)-iv),
• wherein steps i)-iv) comprise tuning a frequency in the range of 27 to 40 GHz of the electromagnetic waves in order to enhance the signal-to-noise ratio for a particular subject or application without changing geometries of said first directional antenna and said directional second antenna and also without changing placements of said first directional antenna and said second directional antenna,
• and
• a distance between the first directional antenna and the second directional antenna is between one and two wavelengths of the electromagnetic wave.