Real-time measurement system for acquiring murine left ventricular pressure-volume relations

Myocardial functions can be characterized from ventricular pressure-volume relations. In small animals, the instantaneous ventricular volume is typically measured by using a miniaturized conductance catheter. In this work, a DSP-based conductance catheter measurement system is proposed, which adopts the admittance measurement method to estimate the myocardial contribution, and Wei´s nonlinear equation to convert the blood conductance to volume. In vivo rat experiments were performed with the proposed measurement system, and real-time left ventricular pressure-volume relations can be obtained.