Description  Claims  Drawing  Cited references 

US5321333A   [0011] 
WO2012172136A   [0012]  [0021] 

Ultrasound in Obstetrics \&Gynecology   [0013] 
Submitted to J. Mechanical Behavior of Biomedical Materials   [0013] 
American journal of obstetrics and gynecology   [0013]  [0013]