Design And Evaluation Of A Pc Card For Acoustic Radiation Force Based Mechanical Characterization

The development of a new system that consists of a custom printed circuit board housed in and controlled by a standard PC is described. All transmit and receive electronics, prior to digitization, are placed on one PCI bus compatible card. The transmit circuitry is bipolar and composed of a cascade of paired N- and P-type MOSFETs, with programmable on and off times operating at a maximum transmit voltage of +/- 121V and up to center frequencies of 25MHz. Various parameters such as the pulse repetition frequency (PRF), bandwidth, and center frequency of the transmit pulse are controlled using a Complex Programmable Logic Device (CPLD). The receive electronics consist of two stages, a protection and an amplification stage. The protection stage protects downstream electronics by shunting high voltages using multiple diode pairs. The amplification stage consists of two non-inverting operational amplifier (op amp) based amplifiers with a maximum total gain of 80dB. The PC card is fully assembled and has been tested for functionality and timing accuracy of transmit and receive signals.