Performance of a Miniature Magnetic Position Sensor
for Three-Dimensional Ultrasound Imaging
Daniel F. Leotta, Paul R. Detmer and Roy W. Martin
Abstract - A miniature magnetic position sensor used for
three-dimensional
ultrasound imaging was
tested for precision and accuracy in vitro. The sensor alone was able to
locate points with root-mean-square (rms) uncertainty of 1.7 mm and accuracy
of 0.05 ± 0.62 mm over its specified operating range of
50 cm. With an ultrasound imaging system, a point was located from arbitrary
viewing windows with
2.4 mm rms uncertainty and 0.06 ± 0.68 mm accuracy. If viewing windows
were limited to those
representative of a typical ultrasound exam, the system could achieve rms
uncertainty in point location of
less than 1 mm. Performance was not affected by operation of the imaging
system when the sensor was
mounted on an ultrasound scanhead. Sensitivity to metals in the operating
environment was also measured.