TRANSLATIONAL RESEARCH IN HIGH-INTENSITY THERAPEUTIC ULTRASOUND: NOVEL TECHNIQUES FOR PRE-CLINICAL TESTING

摘要

The techniques presented here show considerable promise for noninvasively characterizing HITU systems. Both the streaming and IR thermography techniques provide intensities in an entire transverse plane at once, thus considerably reducing measurement time compared to hydrophone scanning. From the perspective of damage to the apparatus, there is no maximum intensity at which the techniques can be applied. However, at this point the techniques are not capable of separating individual harmonics generated by nonlinear propagation effects at higher intensities. Hence, using the output of the techniques for purposes such as temperature prediction is limited to moderate intensities (roughly 1000 W/cm~2 or less), where accounting for frequency dependence of the attenuation is not required. Resolving higher harmonics using the streaming and IR thermography techniques is an area of ongoing research. A second limitation of the streaming and IR techniques is the relative high cost, due to the requirement of the laser system (streaming) or IR camera (IR thermography). However, given the potential for high throughput that the techniques provide, the tradeoff may be worthwhile.