5A-3 Spatial and Temporal Controlled Tissue Heating on a Modified Clinical Ultrasound Scanner for Generating Mild Hyperthermia in Tumors

摘要: We present a new system for generating controlled tissue heating with clinical ultrasound scanner and initial in vitro vivo results that demonstrate both transient sustained the mild- hyperthermia range of 37-42degC. The consists Siemens Antarestrade scanner, custom dual-frequency 3-row transducer array, an external temperature feedback control system. has 2 outer rows operate at 1.5 MHz center row operates 5 B-mode imaging. Temperature measurement is accomplished using thermocouple encased within 29 gauge stainless steel needle. measurements are fed into modified proportional-differential-integral (PID) loop programmed LabVIEWtrade running on PC. Modifications to PID include limited bandwidth differential section integrator anti-windup. controls duty cycle by varying PRF SIEMENS Antares resulting update rate approximately 3 Hz. beam directed pulsed-Doppler cursor reference image. updates also occur In show chicken breast 8degC focus. able maintain 0.1degC desired vivo. tests were performed mouse bearing Met-1 tumors, which model aggressive, metastatic highly vascular cancer. superficially implanted we temperatures 39-42degC range, ideal releasing drugs from thermally-sensitive liposomes.