“…In the noninvasive devices, no needles or direct contact with the body are needed [ 8 , 14 , 15 ]. Different techniques have been proposed for glucose level measurements such as electrical [ 8 ], optical [ 16 , 17 , 18 , 19 , 20 , 21 ], thermal [ 22 , 23 ] and radiofrequency [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] sensing methods.…”