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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1006
DTSTART:20080128T220000Z
DURATION:PT1H0M0S
DTSTAMP:20260409T030705Z
LAST-MODIFIED:19700101T060000Z
LOCATION:1345 Health Science Learning Center (refreshments will be ser
 ved)
SUMMARY:Evaluation of a Pressure Sensing Array for use with Ultrasound
  Strain Imaging\, Medical Physics Seminar\, Lee Kiessel Research Assis
 tant\, Department of Medical Physics\, UW-School of Medicine and Publi
 c Health
DESCRIPTION:Mechanical in vitro tests and in vivo elasticity imaging h
 ave shown differences between breast tissue types in their nonlinear s
 tress/strain behavior. This information could be utilized to different
 iate between benign and malignant lesions potentially reducing the ben
 ign biopsy rate. Stress and strain measurements are required for absol
 ute measures of this non-linear behavior in vivo. A variety of tests w
 ere performed with a prototype pressure sensor array to gauge its stab
 ility\, sensitivity and calibration in reference to its application in
  ultrasound elastography. In addition\, data was collected from patien
 ts undergoing ultrasound elasticity imaging at the University of Wisco
 nsin Breast Center. Initial tests show that the pressure sensor array 
 is stable in an ultrasound imaging environment. A reliable calibration
  technique was developed\, which demonstrates reproducibility to withi
 n 5% for most elements. Tests also show a wide disparity in sensitivit
 y among elements. The most sensitive elements are capable of detecting
  pressure as low as about 100 Pa. Unfortunately\, the average minimum 
 detectable pressure was about 800 Pa. The most sensitive elements make
  the array capable of detecting initial contact and measuring the cont
 act force during a deformation of the breast - a critical task for qua
 ntifying stress/strain nonlinearities. The preliminary clinical trial 
 confirmed this prediction. However\, surface pressure distribution mea
 surements on phantoms have shown only modest agreement with FEA simula
 tions. Geometric uncertainties on the surface of the sensor as well as
  the variability of the absolute calibration make the array ill suited
  to measure accurate maps of the surface pressure distribution which m
 ight limit its utility for stress distribution measurements and elasti
 c modulus reconstructions 
URL:https://www.physics.wisc.edu/events/?id=1006
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