MEASUREMENT OF VELOCITY AND FLOW IN THE UTERINE ARTERIES

THE LONG-TERM GOAL IS TO REFINE A VAGINAL TRANSDUCER FOR MEASURING BLOOD VELOCITY AND FLOW IN THE UTERINE ARTERIES OFPREGNANT AND NONPREGNANT SUBJECTS. THE PROTOTYPE USES A REMOTELY ROTATED ULTRASOUND CRYSTAL INSIDE A TRANSDUCER THAT IS HELD IN STABLE POSITION ON THE CERVIX WITH RIGID CERVICAL CUPS. INITIAL TRIALS IN NONPREGNANT SUBJECTS SHOWED CLEAN AND WELL-DEFINED ARTERY VELOCITY SPECTRA AND MEANS OF THE SPECTRA; LOSS OF THE SIGNALS WAS UNUSUAL EVEN WITH KEGEL AND OTHER MANEUVERS. RECORDINGS IN PREGNANCY SHOWED WELL-DEFINED TRACES OF THE UTERINE ARTERY AND THREE OF ITS BRANCHES. THERE WERE NO INJURIES TO SUBJECTS. THE GOALS OF PHASE I ARE TO MODIFY THE PROBE FOR TWO PLANES OF CRYSTAL ROTATION AND FOR MEASUREMENT OF INSONICATION ANGLES. PHASE II GOALS ARE TO ADD A SECTOR SCANNER FOR ARTERY DIAMETER MEASUREMENTS, TO EVALUATE THE ACCURACY OF THE PROBE FOR FLOW MEASUREMENTS, AND TO RECORD VELOCITY AND FLOW IN BOTH UTERINE ARTERIES SIMULTANEOUSLY. THE QUALITY AND STABILITY OF THE SIGNALS WITH BOTH PREGNANT AND NONPREGNANT SUBJECTS INDICATE THAT THE METHOD MAY HAVE SIGNIFICANT ADVANTAGES AND MULTIPLE APPLICATIONS FOR RESEARCH AND CLINICAL OBSTETRICS AND GYNECOLOGY.