| 摘要 |
PROBLEM TO BE SOLVED: To improve accuracy of temperature information obtained using nonlinear characteristics of ultrasonic waves.SOLUTION: A reception BF 14 forms a reception beam corresponding to a transmission beam scanned inside a measurement area D on the basis of signals obtained from a vibrator 10D for measurement, and outputs a reception signal obtained along the reception beam. An HPF processing part extracts secondary higher harmonic components included in the reception signal, and an LPF processing part extracts fundamental wave components included in the reception signal. A normalization processing part divides the amplitude of the secondary higher harmonic components by the amplitude of the fundamental wave components and calculates a normalized nonlinear coefficient. Then, temperature information inside a subject is obtained on the basis of the normalized nonlinear coefficient. Thus, influence of reflectance is reduced, the influence of the reflectance is eliminated desirably, and the accuracy of the temperature information is improved. |
