Feasibility analysis of a house device for the prevention of heart failure

To date, the impressive incidence, hospitalization and mortality rates of heart failure, especially in elderly subjects, jointly with a lack of efficient screening tools in the clinical context, have a strong social, logistical and economical impact on the healthcare system. The objective of the present work is to analyze the feasibility of a home device for the prevention and early diagnosis of heart failure. The device is based on the noninvasive acquisition of electrocardiographic and phonocardiographic signals devolved to the computation of the time delay between the occurrence of the first heart sound and the peak of R-wave in ECG (R-T1); an increase in the latter was proved to correlate with heart failure onset and severity. The experimental setup is composed of two electrodes for the recording of one non-standard ECG lead, three microphone probes for the acquisition of three PCG signals, a 3D printed flexible structure to provide the positioning of electrodes and microphone probes on the patient's chest and the commercial acquisition system ReMotus by It-MeD, complete with its own software interface. The raw recorded signals' processing aimed at obtaining a reliable estimation of the mean R-T1 value throughout the cardiac cycles is implemented in Matlab. First, electrocardiogram is bandpass filtered and R-wave peaks are identified through a modified version of Pan-Tompkins algorithm. Digital filtering is also applied to each of the three phocardiographic signals, whose mutual time delay is then computed through GCC-PHAT methodology and used to perform beamforming and obtain a single PCG signal of better quality on which heart sounds are detected as the Shannon Energy's peaks. At last, the delay between the mitralic component of first heart sound and the R-wave peaks is computed and analyzed. The prototype was tested on 25 healthy subjects, heterogeneous in terms of age, gender and body size, with promising results, both in terms of validation of R-T1 as heart failure correlating parameter, in terms of stability over time and in terms of device feasibility.