Development of small aperture polymer transducers for high frequency imaging

Poor receiver sensitivity has hampered the development of small aperture (/spl les/2 mm diameter) polymer transducers for high frequency (30-80 MHz) medical imaging. The authors have developed a miniature spherically shaped polymer transducer incorporating an integrated circuit pre-amplifier. The pre-amplifier reduces the problem of poor receiver sensitivity by providing a high input impedance buffer. Using this approach, the amplitude of the pulse-echo response for a 1 mm diameter transducer is increased ten times compared with an identical transducer using an external 50 /spl Omega/ pre-amplifier.