Patent ID: 8752416

Claim:
A method of measuring properties of a medium that is a fluid or compliant solid, such as a gel, comprising: (a) providing a conductor electrically connected to a current source, so as to permit said current source to send a current through said conductor; (b) creating a magnetic field about said conductor; (c) introducing said conductor into said medium; (d) periodically sending a current waveform, having a frequency, through said conductor, so as to cause said conductor to move, due to force exerted on said conductor from interaction of said current and said magnetic field; (e) alternately sensing the conductor current and producing a sense signal at a sense signal node; (f) amplifying said sense signal to produce an amplified sense signal; (g) measuring the phase relationship between said current waveform and said amplified sense signal; (h) adjusting said current waveform frequency so as to create a phase lock loop; (i) measuring said frequency when said phase lock loop is in lock state and calculating fluid properties from said measured frequencies.