Figure 7.

(a) Maximum temperature rise at the geometric focus in one ex vivo porcine tissue sample when the ultrasound beam was unsteered using 50 acoustic watts for 30 s. Five separate measurements were taken. The error bars represent one standard deviation. (b)–(d) Mean temperature rise at the hottest voxel in five different porcine muscle samples when the beam was focused at the geometric focus and steered ±15 mm in each coordinate direction using 70 acoustic watts. The steered distance is represented as (Δy,Δx,Δz). The error bars in all plots represent the standard deviation. Mean temperature with beam steered at (b) geometric focus, (0,0,15) and (0,0,−15); (c) geometric focus (with error bars removed), (0,15,0), (0,−15,0); (d) geometric focus, (15,0,0), (−15,0,0).