Irreversible long-term damage in patients suffering from cardiac disease could often be prevented with a timely intervention, provided that a decline in health status is noticed early. Measurement of left-ventricular (LV) volume is one possibility for monitoring the health status and could be done continuously if integrated in an implantable device i.e., pacemakers or blood pumps. Acoustic resonance is proposed as a measurement method for LV volume that is expected to be independent of the positioning of the sensor. We explore the potential of a resonant acoustic method with a pressure acoustic simulation. Two sets of simulations of extreme cases were carried out: the heart was 1) surrounded by air and 2) embedded in the thorax. The idealized heart was modeled as a blood-filled sphere surrounded by myocardium, pericardial fluid and embedded in an entirely muscular, cylindrical thorax. A pressure source excited the heart at LV volumes of 195 ±25% and ±50%. The independence of positioning was confirmed. The resonance frequency turns out to be sensitive to LV volume if surrounded by air (31 Hz/mL), but not as pronounced if embedded in the thorax (0.055 Hz/mL). Given the low sensitivity of the resonant acoustic method, future experiments focused on technical feasibility should be aimed at assessing the influence of lung parenchyma and noise.
