TRANSVAGINAL SONOGRAPHIC ORIENTATION DETECTION SYSTEM USING CERAMIC GYROSCOPES

Use of three-dimensional ultrasonograms in daily clinical medicine req uires the development of data accumulation techniques and image recons truction techniques. We describe an image position and orientation det ection technique using small piezoelectric vibratory gyroscopes. Such gyroscopes, of the same type that is used in an automobile navigation system, produce angular velocity by Coriolis force. After attaching th ree gyroscopes to an ordinary transvaginal probe, we attempted to dete ct image orientation to assist transvaginal scanning and to reconstruc t three-dimensional projection images. Three-dimensional images were r econstructed by simple white and black inversion thresholding techniqu e. Using free hand transvaginal scanning, the direction of the transva ginal ultrasound beam was displayed with B-mode ultrasonography. Using a personal computer, three-dimensional images of follicles ai td fetu ses were successfully reconstructed within a few minutes. Our system p rovides easy understanding of transvaginal sonographic images and pote ntially might allow ordinary ultrasound machines to handle three-dimen sional images in a day-to-day clinical practice.