The invention relates to a measuring device for the non-invasive determination of a
blood sugar concentration in the body of a
mammal, comprising a housing (G), a measuring
electronics (IC) in the housing (G), wherein the measuring
electronics (IC) further comprises at least one
transmitter (Tx) for emitting high-frequency signals with a frequency of more than 0.1 THz and less than 10 THz, at least one
receiver (Rx) for receiving high-frequency signals with a frequency of more than 0.1 THz and less than 10 THz, wherein the at least one
transmitter (Tx) is designed such that during operation it emits the high-frequency
signal via an antenna (
ANT_Tx) integrated in the measuring device, wherein the at least one
receiver (Rx) is designed such that, during operation, it receives a high-frequency
signal via an antenna (
ANT_Rx) integrated in the measuring device, wherein the measuring device is configured to be attached relative to a
nail plate (NP) on a nail of a finger or
toe of the
mammal, wherein the high-frequency signals from at least one
transmitter (Tx) are coupled through the
nail plate (NP) into the nail
bed (NB) of the
mammal during operation, and wherein the high-frequency signals backscattered from the nail
bed (NB) of the mammal through the
nail plate (NP) during operation are received by at least one
receiver (Rx), wherein the measuring device further comprises an evaluation device (CPU) which is configured to evaluate the backscattered high-frequency signals received by at least one receiver (Rx) in order to determine the
blood sugar concentration in the body of a mammal.