Abstract: The present disclosure describes system and methods for determining cardiac events from a physiological data signal and optionally constructing a Pressure-Volume (PV) loop display from non-simultaneously acquired measurements of pressure and volume data. One such method comprises obtaining, by a computing device, a physiological data signal of a heart of an individual; identifying, by the computing device, features of the physiological data signal and applying the features as inputs to a prediction model; determining, by the computing device using the prediction model, the cardiac events for one or more valves of the heart, wherein the cardiac events include timing of opening and closing of the one or more valves of the heart; and outputting, by the computing device, the cardiac events determined using the prediction model. The physiological data signal can be combined with non-simultaneously acquired volume data to create a PV loop display.

Abstract: A portable resistance tester comprises a pair of regulator circuits used to drive a bridge circuit and a detector circuit when measuring the resistance values of "in-circuit" test nodes. The tester produces an audible signal when the resistance of a measured test node falls within, or without, a predetermined resistance range.