Preferred transducers in the substantial shapes of a three-dimensional bodies, normally spheres or cylinders, emit ultrasound omni-directionally. The transducers are secured to the wall of the cervix uteri of human female, preferably by a barb or corkscrew coil, so that a straight line ultrasonic acoustic...http://www.google.es/patents/US5438996?utm_source=gb-gplus-sharePatente US5438996 - Ambulatory, ultrasonic transit time, real-time, cervical effacement and dilatation monitor with disposable probes
Ambulatory, ultrasonic transit time, real-time, cervical effacement and ...
