Ultrasonic observation apparatus, operation method of the same, and computer readable recording medium

An operation method of an ultrasonic observation apparatus that transmits an ultrasonic wave to a specimen and receives the ultrasonic wave reflected from the specimen, the operation method comprising:

• analyzing, by a frequency analyzing unit, frequencies of the ultrasonic wave at a plurality of points which are respectively positioned on a plurality of acoustic rays of the received ultrasonic wave and different from each other to calculate a frequency spectrum of each of the points;
• approximating, by a feature amount extracting unit, a portion included in a frequency band between a first frequency and a second frequency larger than the first frequency, by a polynomial, in the calculated frequency spectrum of each of the points to extract at least first spectrum intensity which is a value of the polynomial in a third frequency included in a domain of the polynomial and second spectrum intensity which is a value of the polynomial in a fourth frequency different from the first to third frequencies, as a feature amount of the frequency spectrum of each of the points;
• and
• associating, by a feature amount image data generating unit, any one of (a) the first spectrum intensity, (b) the second spectrum intensity, and (c) a function of a difference or a ratio between the first spectrum intensity and the second spectrum intensity, with first visual information to generate a feature amount image which visually indicates a distribution of the feature amount.

A non-transitory computer readable recording medium with an executable program stored thereon, wherein the program instructs a processor to perform:

• analyzing, by a frequency analyzing unit, frequencies of an ultrasonic wave at a plurality of points which are respectively positioned on a plurality of acoustic rays of the ultrasonic wave and different from each other to calculate a frequency spectrum of each of the points;
• approximating, by a feature amount extracting unit, a portion included in a frequency band between a first frequency and a second frequency larger than the first frequency, by a polynomial, in the calculated frequency spectrum of each of the points to extract at least first spectrum intensity which is a value of the polynomial in a third frequency included in a domain of the polynomial and second spectrum intensity which is a value of the polynomial in a fourth frequency different from the first to third frequencies, as a feature amount of the frequency spectrum of each of the points;
• and
• associating, by a feature amount image data generating unit, any one of (a) the first spectrum intensity, (b) the second spectrum intensity, and (c) a function of a difference or a ratio between the first spectrum intensity and the second spectrum intensity, with first visual information to generate a feature amount image which visually indicates a distribution of the feature amount.