Experimental Study about the Immunity Features of Field Programmable Analog Arrays (FPAA)-based Biomedical Application Devices to Radiated Disturbance

This research activity is based on the assessment of the immunity features of a field programmable analog array (FPAA) circuit to radiated disturbance. The methodology is focused on the evaluation of the effects of the radiated electromagnetic field onto the functional and operational characteristics of a front-end element to be used in ECG signal conditioning devices. More specifically, possible effects of electromagnetic disturbance on the parameters of the ECG signal, within a range of frequency from 250 MHz to 3 GHz, are investigated. The research is carried out with a methodology based on both time and frequency domain analysis, relying on a typical ECG signal. The obtained measurements revealed a complex effect of the EM radiation on the FPAA input and output channels, which consist not only of additive noise on the useful signal, but is also causing an important offset shift, a superposition of several harmonics of the amplitude-modulation carrier added to the useful signal on both channels, and a non linear behavior of the FPAA. Moreover, the electromagnetic disturbance has a considerable effect on the time duration of different parts of the ECG signal (P-wave duration, PR interval to name a few) which can lead to wrong diagnosis. The main objective of this work is to contribute and propose modifications to the immunity test standards for these kind of applications.