Detecting laser induced thermal activity in tissue - a Doppler ultrasound approach

Hao Ying, Aamer Azeemi, Craig J. Hartley, Massoud Motamedi, Sohi Rastegar, Louis C. Sheppard

Research output: Contribution to journalConference articlepeer-review


There is a growing need for a real-time noninvasive technique to determine the extent and geometry of treated tissue during thermal therapy. We have developed an analog-digital hybrid system which measures the phase and amplitude of the ultrasonic echoes returned from a heated tissue at multiple depths. Two distinct types of echo modulations were observed in our in-vitro studies using beef muscle irradiated with an 810 nm diode laser. Type 1 modulation showed small and slow variations in amplitude and phase, whereas type 2 modulation demonstrated much larger and faster variations in both amplitude and phase. Our study suggests that type 1 modulation is consistent with tissue coagulation, whereas type 2 modulation is associated with tissue evaporation and explosive events.

Original languageEnglish (US)
Pages (from-to)1589-1592
Number of pages4
JournalProceedings of the IEEE Ultrasonics Symposium
StatePublished - 1995
EventProceedings of the 1995 IEEE Ultrasonics Symposium. Part 1 (of 2) - Seattle, WA, USA
Duration: Nov 7 1995Nov 10 1995

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


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