JPS5839943A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To easily make scanning line intervals dense, by making an acoustic wave beam emitted from a vibrator array pass through a propagation medium, and after that, making it pass through an acoustic lens which is capable of sector linear conversion. CONSTITUTION:A probe consists of a vibrator array 1 formed by arraying plural striplike vibrators in a plane state, a packing material 2, a housing 3 for storing a propagation medium 4, and an acoustic lens 5. As for the housing 3, the vibrator array 1 is installed to its upper end, and it is formed so as to be spread out in a fan-shape toward its lower end. The lower end part of the housing 3 is made to tightly adhere onto a curved surfce 51 of the acoustic lens 5. The depth direction of the housing 3 and the acoustic lens 5 is formed almost uniformly and flatly. To each vibrator of the vibrator array 1, a delaying circuit to which a receiving circuit has been connected is connected. According to such a constitution, when sector scanning has been executed by phase-driving the vibrator array, an acoustic wave beam emitted from the tip of the probe becomes linear scanning, and by suitable controlling a delay time, a scanning line interval can be controlled optionally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an ultrasonic imaging device for use in an ultrasonic imaging device that projects ultrasonic waves onto a subject, receives the reflected waves, and obtains a tomographic image of the subject based on the signal. It concerns a sonic probe.

Conventionally, so-called linear scanning is performed in which a plurality of strip-shaped transducers are arranged in a straight line to form a transducer array, and the n transducers in the array are sequentially scanned while shifting one transducer one by one. There is an ultrasonic probe that scans a sound beam. In a probe with such a near scanning amount, the scanning line spacing is equal to the center spacing of adjacent transducers, so if scanning lines are to be made denser, the transducers must be made thinner.

However, if the vibrator is made thinner, the beam will spread, so in order to have sharp directivity, it is necessary to have a certain width of 11 degrees. Therefore, there is a drawback that the scanning line spacing cannot be made denser than a certain limit.

On the other hand, so-called sector scanning, in which n transducers are driven in phase and the beam is swung in a fan shape by sequentially changing the phase, is used to make the scanning line spacing, which is related to the center spacing of the transducers, denser. However, the scanning lines of such sector scanning are not parallel as in the case of linear scanning, but spread out in a fan shape, so there is a problem that the spacing between the scanning lines increases as the depth increases. Attempts have also been made to increase the spacing between scanning lines by combining sector scanning with a small deflection angle and near scanning. The purpose of the present invention is to eliminate such drawbacks and to develop an ultra-high-density ultrasonic technology that can generate parallel scanning lines extremely densely with a simple configuration, regardless of the center spacing of the vibrator. Our objective is to provide a sonic probe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below using examples and drawings. FIG. 1 is a block diagram showing an embodiment of an ultrasonic probe according to the present invention. In Fig.
3 is a packing material adhered to the back surface of the transducer play, 3 is a housing that houses a propagation medium 4 for propagating ultrasonic waves, and 5 is an acoustic lens made of a material such as acrylic. The casing S has the transducer array 1 attached to its upper end, and is formed into a fan-shaped shape (fan-shaped K) that gradually becomes wider toward the lower end. The lower end of this housing 3 has an acoustic lens 50 and a curved surface 51.
For example, the propagation medium 4
If the water is water, the lower end may be made of a thin film of rubber or the like. The depth (thickness) direction of the casing 3 and the acoustic lens S are almost uniformly flat as shown in FIG. In the figure, each vibrator 1□, 12. , , ,in are connected to delay circuits 311, 312°, , , 31n, respectively, as shown in the figure. These delay circuits have a transmitter circuit 3 in common.
2 and receiving circuit. 33 is connected to transmit and receive a vibrator excitation signal and an echo signal from the vibrator. These slow WLIil paths delay the signal by a predetermined time, and the delay time can be appropriately determined by a controller (not shown). By setting an appropriate delay time, it is possible to thin the acoustic beam over a wide area before the focal point (so-called electron focusing) and to perform so-called sector scanning, in which the beam direction is deflected little by little. In this case, the focal line acoustic lens 50-plane 51 of the beam, which is positioned on or near the acoustic lens 50-plane 51, is
The axis is formed into an inertial curve 11 that satisfies the following formula.

However, t is the pointless distance related to this 1llIII, v1, and the speed of sound in the propagation medium, v2, is the speed of sound in the acoustic lens. From the lower end surface of the -IIIWc lens 5 such as OζO, which provides a substantially sufficient effect, a beam is projected in a direction substantially perpendicular to that surface. With this configuration, when the transducer array 1 is phase driven and sector scanned, the sound beam projected from the tip of the probe will be vertically scanned. Note that the reflected waves will also follow the same wave path as the projected waves. The interval between the respective acoustic beams thus projected into the object, that is, the interval between the scanning lines, depends on the deflection angle θ of the beam in the propagation medium 4, and this The deflection angle θ is determined by the delay time of the delay g circuit 311@312eHatake*31n. -gl'-), by appropriately controlling the delay time, the interval between scanning lines scanned on the nib can be arbitrarily controlled, and the interval can be easily made close.

No. 45A is another embodiment of the present invention, and No. 1r! The difference from A is that a convex acoustic lens 51 is used instead of the concave 1 m-shaped acoustic lens 5tC.

The acoustic lens 5I in this case is formed of a material such that the sonic velocity V in the lens is greater than the sonic velocity V in the propagation medium, and its convex curved surface 51° is as shown in FIG. - It is formed into a hyperbola that satisfies the following equation with respect to the y-axis.

In this case as well, instead of the hyperbola, it may be formed into a curved surface approximated by a circular arc curve with a radius of curvature R expressed by the following equation.

Such an acoustic lens can also achieve the same purpose as the probe of FIG.

Note that with electron focusing, it is possible to narrow down the beam width in the scanning direction, but it is not possible to narrow down the beam width in the thickness direction. An acoustic lens may be formed on the surface. That is, FIG. 6 0 (eO is a curved surface 51 made concave in the thickness direction, FIG. 6 B is a concave lower end surface of the lens 5, and FIG. 6 A is a curved surface. W511 is made convex, and the lower end surface of lens 5' is made convex in Fig. The beam may be narrowed down.Also, the transducer array section and the housing 3 may be configured to be detachable so that they can be easily attached to a probe dedicated to sector scanning.

As explained above, according to the present invention, the acoustic beam emitted from the transducer play is transmitted to the rear sector via the propagation medium.
Since it is configured to pass through an acoustic lens capable of linear conversion, by controlling the phase difference of the phase-driven transducer play, the scanning line spacing can be easily made dense without changing the arrangement spacing of the transducers. A sonic probe can be realized.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the ultrasonic probe according to the present invention, FIG. 2 is a diagram for explaining the curved surface of the acoustic lens 5, and FIG. Part configuration diagram, 4th
The figures show another embodiment of the present invention, FIG. S is a diagram for explaining the bending and straightness of the acoustic lens 5', and FIG. 6 shows another embodiment of the acoustic lens. 1... Vibrator play, 3... Housing, 4... Propagation medium, 5.51... Acoustic lens, 51.511...
Curved surface, 6...Object O tower! (If'!14

Claims (1)

[Scope of Claims] (1) A transducer array in which a plurality of transducers are arranged in a linear manner and a propagation medium for propagating ultrasonic waves are housed, and one end is bonded to the surface of the transducer play. It is equipped with a housing that is formed to widen toward the other end, and an acoustic lens that is glued to the other end of the housing and can convert the sound wave beam into sectors and linearly. An ultrasonic probe characterized in that it is capable of transmitting and receiving a linearly scanning acoustic beam by appropriately driving the phase. Ultrasonic probe 0(3) according to claim 1, characterized in that the acoustic lens has a concave shape or a convex shape. An ultrasonic probe according to claim 2 characterized by: (4) Claim 2, characterized in that the curved surface of the convex acoustic lens is a hyperbola or a circular arc.
Ultrasonic probe as described in section.