Abstract: Apparatus is provided to serve as a phantom for evaluation of prosthetic valves and cardiac ultrasound procedures, wherein a controlled pulsatile flow of a blood-mimicking fluid is passed through a multi-chambered region into which are mounted mitral and aortic valves and adjustably positionable ultrasound transducers. A low friction, drive which involves very low levels of extraneous vibrational inputs, is provided with adjustment of both the volume flow rate of blood-mimicking fluid moved in each operational pulse with further control provided by relatively easily adjusted screws to selectively regulate the systolic and diastolic times of the pulsatile flow generated by a bellows arrangement. Windows made of silicone elastomer material presenting both tissue-equivalent impedance for ultrasound transmission and tissue-equivalent attenuation of the ultrasound are provided in controlled thickness to permit detailed observation of valvular flow parameters of interest, e.g.

Abstract: A system and technique for determining the total radiated ultrasonic power output from a diagnostic ultrasound device having an output transducer includes a water chamber having a parabolic reflector. The transducer is mounted on the chamber at a location so that acoustic power from the transducer is focussed by the parabolic reflector to a first thermistor chip mounted in the chamber on a sound-absorbing rubber plate. The rise in temperature of the thermistor chip due to sound absorption changes its resistance. The thermistor chip is connected in one leg of a Wheatstone bridge. A reference thermistor chip is mounted on the rubber plate away from the ultrasonic beam and is connected in an opposite leg of the bridge. Starting from a null setting of the bridge, the output of the bridge after a suitable "response time" is in accordance with the acoustic energy delivered by the transducer.