Chest Surface Vibration Mapping Method: An Innovative Approach To cardiac Evaluation

Background: Heart sounds full appreciation requires a time-expensive learning curve under expert supervision. An accurate cardiac examination could be enhanced by technological tools and, in fact, many works in literature dealt with finding phonocardiography (PCG) signatures of cardiac events. Purpose: In such a framework the current computer-based availabilities in signal processing enabled us to move from the standard PCG to unexplored characteristics of heart-related sounds: their spatial distribution on the chest surface and its evolution in time. Methods and Results: 50 normal subjects were examined. Data have been collected by microphones located on 34 different points of the chest surface, digitalized, ecg-synchronized and then processed by a specifically developed software (FIG1) . Based on our novel approach, acoustic fingerprints of the cardiac events can be defined : heart sounds possess time-evolving "shapes" which can be associated to different moments of systo-diastolic cycle as well as to different cardiac morpho-functional aspects (FIG2 shows the typical pattern appearing related to the QRS) . Conclusions: an innovative approach to cardiac evaluation based on the vibration surface mapping method can be proposed and considered to develop a low-cost cardiac evaluation tool.