IEEE International Ultrasonics Symposium<BR>
Seattle, WA<BR>
November 7-10, 1995<BR>
<BR>
<B>Three-Dimensional Ultrasound Imaging Using Multiple 
Magnetic Tracking Systems and Miniature Magnetic Sensors </B>
<BR>
<BR>
Daniel F. Leotta, Paul R. Detmer, Odd Helge Gilja, Jing-Ming Jong, 
Roy W. Martin, Jean F. Primozich, Kirk W. Beach, and D. Eugene Strandness
<BR>
<BR>
Bioengineering, Surgery, Anesthesiology
University of Washington, Seattle, WA 98195
<BR>
<BR>
<B>Abstract</B> - We have used several configurations of a commercial 6D
magnetic position and orientation measurement system to 
track an ultrasound scanhead and reconstruct 2D ultrasound images in 3D space.  We have measured precision and accuracy 
with two magnetic sensors working in parallel, and with a miniaturized magnetic sensor. The use of two standard size sensors 
has shown limited improvement in precision (1.5 mm RMS uncertainty compared with 1.8 mm for a single sensor).  The 
miniature sensor has an average precision of 2.1 mm over its operating range.  The miniature sensor has been calibrated with 
an imaging system and has been used in 3D reconstructions of the stomach and the carotid artery.