DocumentCode :
3230030
Title :
The effect of acoustic parameters on the Non-Invasive Embolus Trap (NET) using a histotripsy-generated bubble cloud
Author :
Park, Simone ; Maxwell, Adam D. ; Owens, Gabe ; Gurm, Hitinder S. ; Cain, Charles A. ; Xu, Zhen
Author_Institution :
Dept. of Biomed. Eng., Univ. of Michigan, Ann Arbor, MI, USA
fYear :
2011
fDate :
18-21 Oct. 2011
Firstpage :
1878
Lastpage :
1881
Abstract :
Previous observations during histotripsy-mediated thrombolysis revealed that free-flowing clot fragments are attracted, trapped, and eroded simultaneously near the bubble cloud even with background flow. This feature may be used to develop a Noninvasive Embolus Trap (NET) that eliminates clot fragments during cardiovascular therapies. This study investigated the effect of histotripsy acoustic parameters on the trapping ability of NET in-vitro. A flow system was developed to circulate particles under a fixed mean background flow velocity. A 1-MHz, elliptical transducer (f# = 0.6) was used to generate a cavitation bubble cloud. Peak negative pressures ranging from 5 MPa to 20 MPa, PRFs from 30 Hz to 1000 Hz, and pulse durations from 5 to 50 cycles were used. The maximum trapping velocity was the performance metric used to assess the trapping ability of a particle for a given acoustic parameter set. The maximum trapping velocity increased linearly with increasing pressure after a bubble cloud was initiated, and nonlinearly with increasing PRF and pulse duration. At 20 MPa P-, 10 cycles, and 1000 Hz PRF, the maximum trapping velocity was 9.8cm/s. The size distribution of debris from blood clots exposed by NET showed that 93% of the sampled debris was less than 50 μm. These findings promote the idea that the NET could be a useful clinical tool to noninvasively eliminate emboli in many vascular applications, including ultrasound-mediated thrombolysis.
Keywords :
biomedical transducers; biomedical ultrasonics; blood; cardiovascular system; diseases; patient treatment; ultrasonic transducers; acoustic parameter set; acoustic parameters effect; blood clots; cavitation bubble cloud; clot cardiovascular therapies; elliptical transducer; fixed mean background flow velocity; flow system; free-flowing clot fragments; frequency 30 Hz to 1000 Hz; histotripsy acoustic parameters; histotripsy-generated bubble cloud; maximum trapping velocity; noninvasive embolus trap; peak negative pressures; performance metric; pressure 5 MPa to 20 MPa; pulse duration; sampled debris; trapping ability; ultrasound-mediated thrombolysis; Acoustics; Charge carrier processes; Fluids; Medical treatment; Phantoms; Transducers; Ultrasonic imaging; acoustic trapping; embolus trap; histotripsy; non-invasive; thrombolysis;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium (IUS), 2011 IEEE International
Conference_Location :
Orlando, FL
ISSN :
1948-5719
Print_ISBN :
978-1-4577-1253-1
Type :
conf
DOI :
10.1109/ULTSYM.2011.6293416
Filename :
6293416
Link To Document :
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