Development of an intraventricular impedance imaging (III) system: design of the signal acquisition module

The objective of the authors' research is to develop an Intraventricular Impedance Imaging system (III) which will be used for real time ventricular volume estimation, cardiac catheter position determination, and cavitary imaging. After analyzing the previous versions of the III system, a new system hardware realization was proposed. The approach is based on an intracavitary placed multi-electrode impedance catheter measurement method, using synchronous sampling at 60 Hz with 32 analog channels. Here, the authors discuss the realization of this method, using the newest generation of highly integrated electronic components-AD7850 for the signal acquisition module. It is used for differential amplification, analog filtering, gain control, and analog to digital conversion. It is easy to control and reduces the circuit size. This approach enables building each channel of the III system as a angle PC board.