| 摘要 |
PROBLEM TO BE SOLVED: To prevent an ultrasonograph using harmonic component from lowering of sensitivity at deep part of a subject. SOLUTION: Harmonic wave component and fundamental wave component are extracted from the signal outputted from a phase adder circuit 32 using a harmonic wave component filter circuit 34 and a fundamental wave component filter circuit 36. The signals obtained from those components are converted logarithmically at LOG conversion parts 42, 52, and inputted to DC adder part 44, 54. The gain of those components, corresponding to the depth at the test specimen, is read from gain tables 46, 56, and added to the logarithmic signal of each components at the DC adder part 44, 54, and each components is weighted. They are added and synthesized at a synthetic adder part 60. By the above, an ultrasonogram of which, attenuation of harmonic wave component at the deep part is compensated by fundamental wave component, is obtained. |
