PERFORMANCE OF A MINIATURE MAGNETIC POSITION SENSOR FOR 3-DIMENSIONALULTRASOUND IMAGING

A miniature magnetic position sensor used for three-dimensional ultras ound imaging was tested for precision and accuracy in vitro. The senso r alone was able to locate points with root-mean-square (rms) uncertai nty of 1.7 mm and accuracy of 0.05 +/- 0.62 mm over its specified oper ating range of 50 cm, With an ultrasound imaging system, a point was l ocated from arbitrary viewing windows with 2.4-mm rms uncertainty and 0.06 +/- 0.68 mm accuracy, If viewing windows were Limited to those re presentative of a typical ultrasound examination, the system could ach ieve rms uncertainty in point location of < I mm, Performance was not affected by operation of the imaging system when the sensor was mounte d on an ultrasound scanhead. Sensitivity to metals in the operating en vironment was also measured, (C) 1997 World Federation for Ultrasound in Medicine & Biology.