Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

Figure 9

(a) Thermal profiles along -direction on the acoustic propagation axis for the experiment and the models. Temperature of model A is produced by the ideal piston, and temperature of model B is produced when the measured acoustic field was used as the input excitation of the FE heating model. (b) Relative error between the measured data and both of the modeled temperatures of part (a). (c) Radial thermal profiles at 4 cm of depth for the experiment versus both of the models. (d) Relative error between the measured data and both of the modeled temperature increments of graph (c). Using the same radiation parameters, the piston (model A) produced less temperature increments than the experiment. Relative errors indicate large variations (from 10% to 20% in some regions) due to differences in the acoustic field patterns. The results are better when using the measured acoustic field as the input variable of FE simulations (model B).

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