An instrument for measuring the absolute output acoustic intensity,effective radiating area and beam non-uniformity ratio of medicalultrasound devices

摘要

A computer-controlled acoustic intensity measuring system (AIMS)for measuring the acoustic output of commercially manufactureddiagnostic and therapeutic ultrasound devices is described. The hardwareand software performance criteria and design tradeoffs resulting fromexperience with biomedical sound fields are also presented. The systemallows three-orthogonal-axis (X, Y, and Z)position translation of up to 10 in by 10 in by 20 in with a 6.5-μmminimum step size, and is capable of waveform acquisition with a 50-MHzanalog bandwidth and a maximum equivalent time sample rate of 5 GHz. Theinstrument can perform planar scans wherein the scan plane contains theacoustic beam axis, and two polar axes of position rotation can be addedto the main positioner assembly at a later date