| 摘要 |
<p>Concentration of a target chemical, glucose, in the presence of another substance, NaCl, in a specimen (4) is determined by subjecting (2) the specimen (4) to radio frequencies (6, 16) up to about 5 GHz. The real and imaginary components of the reflected and/or transmitted signal are examined (18) to identify the presence and/or concentration of the chemical of interest. The examination includes analysis of the effective complex impedance presented by the specimen (4) and/or the effective phase shift between the transmitted and reflected signals. The effects of NaCl on glucose concentration measurements can be nulled-out by examining impedance magnitude at a cross-over frequency or measuring NaCl concentration in a first frequency range and subtracting from a combined glucose/NaCl concentration measurement in a second frequency range. This technique can be used by diabetics to measure blood flucose in-vivo or in-vitro.</p> |
