Patent ID: 7385392

Claim:
An apparatus for measuring electrical impedance for multiple elements of a sensor array comprising: a signal generator controlled by a master microcontroller that creates a sinusoidally time varying excitation signal with at least one prescribed frequency which is applied to a conducting drive of the sensor array; a plurality of data acquisition channels, each data acquisition channel measuring a signal from an individual sense element, and each data acquisition channel including a data acquisition microcontroller and an analog to digital converter, the measuring of the signal being triggered by the master microcontroller of the signal generator, with an in-phase response measured for each channel simultaneously at each prescribed frequency, and a quadrature phase response measured for each channel simultaneously at each prescribed frequency; a computer for processing and storing measured values; a plurality of data communication lines connecting the sensor array and the plurality of data acquisition channels; and separate communication lines between the computer and the signal generator master microcontroller and between the computer and each data acquisition microcontroller.