Pressure measuring system with ultrasonic wave

Claim 2

A pressure measuring system by ultrasonic wave, characterized in that two or more kinds of ultrasonic wave with high and low center frequencies are used, fine bubbles are generated within a medium by applying a low frequency ultrasonic wave to a measuring medium (2), generation of said bubbles is detected by transmission, scattering or reflection of the high or low harmonic ultrasonic wave generated by the bubbles or a high frequency ultrasonic wave applied to the measuring area (4), and a pressure (Pa +P ) of said measuring medium in said measuring area or the bubble generation critical pressure (P ) is measured from the relation previously taken between low frequency ultrasonic wave pressure (Q o sin 2 π ft ); measuring medium pressure (Pa + P ) and bubble generation critical pressure (P ).

Claim 3

A pressure measuring system by ultrasonic wave as claimed in claim 1, characterized in that fine bubbles are generated in the medium by applying a low frequency ultrasonic wave to the medium in an area different from said measuring area (4); generation of such bubbles is detected by the transmission, scattering or reflection of a high or low harmonic frequency ultrasonic wave generated by the bubbles or a high frequency ultrasonic wave applied to the measuring area, a pressure of the medium in said different measuring area is measured by another method and the relation between said low frequency ultrasonic wave pressure, medium pressure and bubble generation critical pressure is thereby calibrated.

Claim 4

A pressure measuring system by ultrasonic wave as claimed in claim 1 or 2, characterized in that generation of bubbles is detected by the Doppler frequency shift included in the reflected wave of a high frequency ultrasonic wave on the occasion of detecting bubbles generated by said high frequency ultrasonic wave.

Claim 5

A pressure measuring system by ultrasonic wave as claimed in claim 2, characterized in that the range of time generating bubbles in the medium is determined by the said detecting means operated in a plurality of mutually different timings (t , t t 31 ...) in the time regions of negative pressure of said low frequency ultrasonic wave , a low frequency ultrasonic wave pressure required for generation of bubbles is obtained from said time range, and thereby a pressure of measuring medium at the measuring area can be obtained from the above relation.

Claim 6

A pressure measuring system by ultrasonic wave as claimed in any of claims 1 to 4, characterized in that the pulse wave, burst wave or continuous wave having a center frequency under 1000 kHz is used as said low frequency ultrasonic wave, while the pulse wave, burst wave or continuous wave having a center frequency of 100 kHz or higher is used as said high frequency ultrasonic wave.

Claim 7

A pressure measuring system by ultrasonic wave as claimed in any of claims I to 5, characterized in that said measuring medium is the blood of a human body.

Claim 8

A pressure measuring system by ultrasonic wave as claimed in any of-claims 1 to 6, characterized in that a substance which is easily soluble thereto, and easily generates bubbles, is dissolved previously into said measuring medium.

Claim 9

A pressure measuring system by ultrasonic wave characterized in that it comprises : . a means(1, 5, 20 - 36) where two or more kinds of ultrasonic waves in the high and low center frequencies are used, fine bubbles are generated within the measuring medium by applying thereto a low frequency ultrasonic wave, generation of said bubbles is detected by the transmission, scattering or reflection of a high or low harmonics frequency ultrasonic wave generated by said bubbles or a high frequency ultrasonic wave applied to the measuring region, a pressure of measuring medium or bubble generation, critical pressure of said measuring area is measured from the relation previously obtained between the low frequency ultrasonic wave pressure, measuring medium pressure and the bubble generation critical pressure, . a means (81 - 83) for sequentially moving and setting said measuring area along the bidimensional plane, . a means (88) for storing the measured values at the measuring areas sequentially set to the position corresponding to the coordinates of said bidimensional plane, and . a means (87) for displaying the measured values being stored in said memory by the brightness or color tone in accordance with such values as the bidimensional plane image; and also characterized in that it comprises display means for displaying pressure distribution of the measuring medium or distribution of characteristic parameter relating to the critical pressure.

Claim 10

A pressure measuring system by ultrasonic wave characterized in that it comprises : . a means(1, 5, 20 - 36) where two or more kinds of ultrasonic waves in the high and low center frequencies are used, fine bubbles are generated within the measuring medium by applying thereto a low frequency ultrasonic wave, generation of said bubbles is detected by the transmission, scattering or reflection of a high or low harmonics frequency ultrasonic wave generated by said bubbles or a high frequency ultrasonic wave applied to the measuring region, a pressure of measuring medium or bubble generation, critical pressure of said measuring area is measured from the relation previously obtained between the low frequency ultrasonic wave pressure, measuring medium pressure and the bubble generation critical pressure, . a means (81 - 83) for sequentially moving and setting said measuring area along the bidimensional plane, . a means (88) for storing the measured values at the measuring areas sequentially set to the position corresponding to the coordinates of said bidimensional plane, and . a means (87) for displaying the measured values being stored in said memory by the brightness or color tone in accordance with such values as the bidimensional plane image; and also characterized in that it comprises display means for displaying pressure distribution of the measuring medium or distribution of characteristic parameter relating to the critical pressure.

Claim 11

A pressure measuring system by ultrasonic wave as claimed in claim 8, characterized in that said measuring means includes a means (86) for temporarily storing the results of measurement and a calculating means (89), whereby the bubble generation critical pressure of blood is measured at the blood vessel in a living body and the results are stored in said temporary holding means, the bubble generation critical pressure is measured along the bidimensional plane for the tissues at the desired areas in said living body, a difference or ratio between the result.and the data in the said temporary holding means is calculated by said calculation means and such difference or ratio values are stored in said memory means (88) and then displayed.