Ultrasound heating in a tissue-bone phantom.
Temperature rise generated by focused ultrasound beams was tested on semipermanent tissue-bone phantoms. The phantoms were capped (sealed) plastic hollow cylindrical containers filled with tissue-mimicking material (TMM), in which were imbedded 25 microns diameter copper-constantan thermocouples (TC) and a piece of compact human or cow bone. The acoustic frequency specific attenuation coefficient of TMM was adjusted to be 0.3 dB cm-1 MHz-1 as specified by the FDA for a frequency range of 1-5 MHz. A high density 0.318 cm thick polyethylene sheet was chosen as the material to make caps of the phantoms. A formula developed to estimate the upper limit of temperature rises at tissue-bone interfaces generated by focused ultrasound has been proved to be appropriate experimentally using the semipermanent phantoms.
O'Neill
T P
TP
Department of Physics, University of Vermont, Burlington 05405.
Winkler
A J
AJ
Wu
J
J
D000818:Animals; D001842:Bone and Bones; D002417:Cattle; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008954:Models, Biological; D008961:Models, Structural; D011095:Polyethylenes; D014465:Ultrasonics / Q000009:adverse effects*; D014463:Ultrasonography / Q000009:adverse effects
D011095:Polyethylenes