Patent ID: 8570186
Filing Date: 2013-10-29
Classification: A61B,G08C,H04Q

Abstract:
1. A wireless sensor reader comprising: a transmit circuit configured to generate an excitation pulse to cause a wireless sensor to emit a ring signal; an antenna configured to transmit said excitation pulse and receive said ring signal; a phase-locked loop circuit configured to receive said ring signal, said phase-locked loop circuit including a voltage-controlled oscillator configured to generate a count signal at a frequency related to said ring signal frequency; a circuit for identifying a set of possible frequency values of said ring signal for an individual reading; wherein said phase-locked loop circuit is capable of being placed in a sample mode to receive said ring signal and adjust the frequency of said count signal based on the frequency of said ring signal; wherein at least one of said transmit circuit, said phase-locked loop circuit, said antenna, and said voltage-controlled oscillator are tunable to the identified set of possible frequency values; and further wherein said phase-locked loop circuit is capable of being placed in a hold mode to hold the frequency of said count signal constant for a length of time sufficient to determine the frequency of said count signal.