Patent ID: 7205701
Filing Date: 2007-04-17
Classification: G01N,G01S

Abstract:
1. A method for sensing a concentration of a chemical and/or biochemical constituent in a body fluid, the method comprising the steps of: providing a surface acoustic wave device having an absorbing layer, wherein the absorbing layer absorbs the chemical and/or biochemical constituent and affects an output signal of the surface acoustic wave device dependent on the concentration of the chemical and/or biochemical constituent; exposing the absorbing layer to the body fluid, thereby exposing the absorbing layer to the chemical and/or biochemical constituent; wirelessly providing power to the surface acoustic wave device via a power signal; wirelessly receiving the output signal from the surface acoustic wave device; wherein an altered output signal correlates to the concentration of the chemical and/or biochemical constituent in the body fluid; and wirelessly providing a desorb signal to the surface acoustic wave device, wherein the desorb signal causes the surface acoustic wave device to produce an acoustic wave that vibrates and causes heat in the absorbing layer, thereby causing the absorbing layer to desorb at least some of the absorbed chemical and/or biochemical constituent; wherein the desorb signal has a different frequency than the power signal.