ULTRASOUND DIAGNOSTIC APPARATUS

• US 20090036779A1
• Filed: 01/23/2007
• Published: 02/05/2009
• Est. Priority Date: 01/24/2006
• Status: Active Grant

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Tsubai, Masayoshi, Fukuda, Osamu, Ueno, Naohiro, Akiyama, Morito
• Granted Patent: US 8,075,489 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 8/14 Echo-tomography
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: B06B 1/0629 Square array
• CPC Class Codes: G01S 15/899 Combination of imaging systems with ancillary equipment

Abstract

Pressure distribution on a surface of an ultrasonic probe can be measured directly. Piezoelectric sensors, in which a piezoelectric thin film is formed on a film-like substrate, are arranged in the form of an array on the surface of an ultrasonic probe, and a sensor output signal processing unit outputs pressure measured for each piezoelectric sensor S1, S2 to S9 based on output signals from each of the piezoelectric sensors to an image processing unit. The image processing unit generates a histogram of the measured pressures for piezoelectric sensors S1, S2 to S9, and displays the histogram, while plotting the piezoelectric sensors on the x axis and the measured pressures on the Y axis, along with the resulting ultrasound tomographic image, on a monitor.

Claims

1. An ultrasound diagnostic apparatus which is provided with an ultrasonic probe that contacts a specimen, and which generates an ultrasound tomographic image by transmitting and receiving ultrasonic waves through the ultrasonic probe, wherein

a plurality of piezoelectric sensors, configured by using a film having a thickness of 145 μ

m or less as a substrate, are arranged on or in the vicinity of a surface of the ultrasonic probe and in a region directly provided for transmission and reception of the ultrasonic waves,

measuring means is provided for measuring pressure distribution on or in the vicinity of the surface based on the arrangement of each of the plurality of piezoelectric sensors on or in the vicinity of the surface and output signals from the piezoelectric sensors, and

display means is provided for displaying the pressure distribution in a visible form.

2. The ultrasound diagnostic apparatus according to claim 1, wherein the piezoelectric sensors have a piezoelectric aluminum nitride thin film formed on the substrate.

3. The ultrasound diagnostic apparatus according to claim 1, wherein the piezoelectric sensors are arranged in the form of an array or a matrix on or in the vicinity of the surface.

4. The ultrasound diagnostic apparatus according to any one of claims 1 to 3, wherein the display means displays so as to enable comparison between the pressure distribution and the ultrasound tomographic image.

5. The ultrasound diagnostic apparatus according to claim 4, wherein the display means displays an image composed in the form of an aggregate of image regions corresponding to the arrangement of each piezoelectric sensor, an output signal from each piezoelectric sensor being reflected in an image value of the image region corresponding to that sensor.

14. The ultrasound diagnostic apparatus according to claim 1, comprising deformation amount measuring means for measuring the amount of deformation of each tissue layer constituting the specimen, based on ultrasonic wave information obtained by the transmission and reception of ultrasonic waves, and

estimation means for estimating the value of elasticity, viscosity or inertia of each of the tissue layers from a signal output of the piezoelectric sensors and the measured deformation amount of the specimen based on the elasticity, viscosity and inertia of the specimen along with an equation of motion of a physical model describing the relationship between force applied to the specimen and the amount of deformation of each layer constituting the specimen.

6. An ultrasound diagnostic apparatus which is provided with an ultrasonic probe that contacts a specimen, and which generates an ultrasound tomographic image by transmitting and receiving ultrasonic waves through the ultrasonic probe, wherein

a plurality of sheet-like piezoelectric sensors are arranged on or in the vicinity of a surface of the ultrasonic probe, measuring means is provided for measuring pressure distribution on or in the vicinity of the surface based on the arranged positions of each of the plurality of piezoelectric sensors on or in the vicinity of the surface thereof and output signals from the piezoelectric sensors, and display means is provided for displaying the pressure distribution in a visible form;

and

the measuring means accumulates an output signal at each time for each piezoelectric sensor for a prescribed amount of time, and measures the fluctuation status in the specimen or specifies the location of a fluctuation site based on time-based changes in the accumulated output signals and the arrangement of the piezoelectric sensors on or in the vicinity of the surface.

7. The ultrasound diagnostic apparatus according to claim 6, wherein the display means displays to enable comparison between the accumulated output signals and the ultrasound tomographic image, and displays an output signal of each piezoelectric sensor while arranging in parallel image regions corresponding to the arrangement of the piezoelectric sensors in the ultrasound tomographic image.

8. The ultrasound diagnostic apparatus according to claim 6, wherein the measuring means measures the velocity of prescribed signals between a plurality of piezoelectric sensors based on the arrangement interval of the piezoelectric sensors and the output time difference of the prescribed signals.

9. The ultrasound diagnostic apparatus according to claim 6, wherein the measuring means measures the period of a prescribed signal of a specific piezoelectric sensor based on the output interval of the prescribed signal in the specified piezoelectric sensor.

10. The ultrasound diagnostic apparatus according to claim 6, wherein the measuring means specifies the piezoelectric sensor that initially outputs a prescribed signal, and the display means displays the arrangement of that piezoelectric sensor.

11. The ultrasound diagnostic apparatus according to claim 6, wherein the measuring means specifies the piezoelectric sensor that outputs a signal for which the peak-to-peak amplitude reaches a maximum, and the display means displays the arrangement of that piezoelectric sensor.

12. The ultrasound diagnostic apparatus according to claim 10 or claim 11, wherein the display means displays the ultrasound tomographic image in a form that allows specification of an image region corresponding to the arrangement of the specified piezoelectric sensor.

13. The ultrasound diagnostic apparatus according to claim 12, wherein the display means displays an enlarged view of the corresponding image region.