JPS6361161A - Converging type ultrasonic probe - Google Patents

Abstract

PURPOSE:To obtain a characteristic excellent in resolving power in a longitudinal direction, by making it possible to converge ultrasonic waves emitted from a vibrator to the arbitrary point of a sound axis while the refractive power of an acoustic lens is changed. CONSTITUTION:An ultrasonic vibrator 1 is mounted in the case 10 of a probe and an acoustic matching layer 12 is provided to the front part of said vibrator 11 and, further, an ultrasonic wave permeable membrane substance 14 packing an ultrasonic wave conductive liquid or gell like substance 13 in a convex form is mounted to said matching layer 12 through a ring member 15. A packing material 16, a driving force transmitting member 17 and an actuator 18 are further arranged behind the vibrator 11. The driving force generated by the actuator 18 can move through the vibrator 11 in the direction of a sound axis P through the member 17. At this time, the pressure of the substance 13 increases or decreases and the radius of curvature of the membrane substance 14 changes and the refractive power of the acoustic lens consisting of the membrane substance 14 and the substance 13 filling the same changes and a converging point 0 moves on the sound axis P.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a focused ultrasound probe that can be usefully used in ultrasound diagnostic equipment and the like.

[Prior Art] Conventionally, in order to improve the resolution of an ultrasonic diagnostic apparatus, it has been common practice to focus ultrasonic waves emitted from an ultrasonic transducer onto one point inside a subject. As a method of focusing this ultrasonic wave, as shown in Fig. 3, the ultrasonic transducer 1 is processed into a concave shape, or as shown in Fig. 4, the planar ultrasonic transducer 1 is processed into a concave shape. An acoustic lens 2 attached thereto, or a ring-shaped ultrasonic transducer 1 arranged concentrically on a substrate 2 as shown in FIGS. 5(a) and (b), and each transducer 1 generates There are some types of ultrasonic waves that are focused by mutual interference.

All of these methods focus ultrasonic waves on one point on the sound axis and attempt to obtain high resolution at this point. However, these methods have the disadvantage that the ultrasonic beam spreads rapidly before and after the focal point, and the resolution in the longitudinal direction of the acoustic axis is reduced.

[Object of the Invention] An object of the present invention is to eliminate the drawbacks of the conventional example described above, and to achieve focusing with excellent longitudinal resolution by focusing the ultrasonic waves emitted from the transducer at any point on the sound axis. The purpose of the present invention is to provide a type ultrasonic probe.

[Summary of the Invention] The gist of the present invention to achieve the above-mentioned object is to provide an ultrasonic probe that transmits and receives ultrasonic waves, which includes an acoustic lens whose refractive power can be adjusted on the transmitting and receiving surface side of the ultrasonic transducer. This is a focused ultrasonic probe characterized by comprising:

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

1 and 2 show an embodiment of the present invention, in which an ultrasonic transducer 11 is built in a probe case 10, an acoustic matching layer 12 is provided in the front part of the probe, and an ultrasonic transducer 11 is provided in the front part of the transducer. A thin film material 14 that surrounds a conductive liquid or gel material 13 in a convex shape and is transparent to ultrasonic waves is attached via a ring member 15 . Further, behind the vibrator 11, a backing material 16, a driving force transmission member 17. An actuator 18 is arranged.

In this configuration, the driving force generated by the actuator 18 transfers the vibrator 11 via the transmission member 17 to the sound axis P.
can move in the direction. At this time, as the pressure of the substance 13 increases as shown in FIG. 2(a) or decreases as shown in FIG. 2(b), the radius of curvature of the thin film 2 is deformed,
The thickness of the acoustic lens made of the thin film 2 and the substance 13 filled therein changes. As a result, the refractive power of the acoustic lens changes, and the focal point 0 moves on the acoustic axis P, as shown in FIGS. 2(a) and 2(b).

Note that instead of using the actuator 18 to move the ultrasonic transducer 11, air pressure is used to move the ultrasonic transducer 11.
By moving the actuator 18, there is no need to include the actuator 18 in the ultrasonic probe, and the ultrasonic probe can be configured compactly.

Further, the shape of the thin film 2 can be not only spherical but also aspherical.

[Effects of the Invention] As explained above, the ultrasonic probe according to the present invention is capable of focusing the ultrasonic waves emitted from the transducer to any point on the acoustic axis by changing the refractive power of the acoustic lens. By doing so, characteristics with excellent longitudinal resolution can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of an ultrasonic probe according to the present invention;
Figures 2 (a) and (b) are explanatory diagrams of its operation, Figure 3 is a vertical cross-sectional view of a conventional concave vibrator, Figure 4 is a cross-sectional view of a conventional vibrator equipped with an acoustic lens, and Figure 5 is a cross-sectional view of a conventional concave vibrator. Figure (a) is a front view of a conventional ring-shaped vibrator, and figure (b) is a cross-sectional view thereof. 10 is a case, 11 is an ultrasonic transducer, 12 is an acoustic matching layer, 13 is a thin film material, 14 is a liquid material, 16 is a backing material, 17 is an actuator driving force transmission member, 1
8 is an actuator. Patent applicant: Canon Co., Ltd. Figure 3 Figure 4 Figure 5 (a) (b)

Claims (1)

[Claims] 1. A focused ultrasonic probe that transmits and receives ultrasonic waves, characterized in that an acoustic lens whose refractive power can be adjusted is provided on the transmitting and receiving surface side of the ultrasonic transducer. Sonic probe. 2. The focusing ultrasonic probe according to claim 1, wherein the acoustic lens is composed of an elastic thin film and a liquid or gel-like elastic material filled inside the acoustic lens. 3. The focused ultrasound probe according to claim 1, wherein the surface of the acoustic lens is spherical or aspherical. 4. The focusing ultrasonic probe according to claim 1, wherein the refractive power of the acoustic lens is adjusted by applying pressure from behind.