JPS639428A - Ultrasonic probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is an ultrasonic probe that is composed of a plurality of transducer elements and that forms an ultrasonic beam by applying appropriate delay operations to each element. Concerning improvements to the configuration of.

(Prior art) Ultrasonic diagnostic equipment that uses pulsed ultrasound uses ultrasound pulses transmitted from an ultrasound probe and reflected pulses reflected from the subject's body and received by the ultrasound probe. This device diagnoses by knowing the distance from the ultrasonic probe to the reflection point based on the time difference between the reflection point and the amplitude, and the attenuation degree of the reflection point and the portion leading to the reflection point based on the amplitude. In the ultrasonic probe used in this ultrasonic diagnostic device, a large number of weekly elements are arranged at a constant pitch. For example, in a scanning method such as linear scan, a fixed number of elements are used among the many elements. The transmitter/receiver probe has a certain aperture, and the aperture is sequentially moved to scan a wide range. In this case, beam alignment is achieved by applying appropriate delay operations to each element within the opening to obtain the best condition at the counter-contamination target point.

Figure 5 is a diagram showing the arrangement of elements of an ultrasonic probe.
Figure (a) shows the arrangement of elements, and figure (b) is an enlarged view of one element. In the figure, 1
2 is an element that transmits and receives waves to the subject, and 2 is an opening among all elements that transmits and receives waves at the same time. This opening 2 forms one sound ray. (b) In the figure, 3 is a microelement obtained by sub-dicing element 1. Conventionally, when forming sound rays, the width of the opening 2 is changed depending on the depth from the body surface of the diagnostic site. That is, when the diagnostic site is shallow from the body surface, the width of the aperture 2 is narrowed to improve the resolution in the scanning direction, and when the diagnostic site is deep, the width of the aperture 2 is widened to increase the resolution in the depth direction. .

However, since the beam width of element 1 is proportional to the wavelength of the emitted ultrasound and inversely proportional to the width of the element, the beam width is determined by the width of the element, and therefore, if the width of the element does not change, the aperture depends on the position of the target point. The maximum width of is fixed. FIG. 6 is a diagram showing this state.

In the figure, 2 is an aperture of the ultrasonic probe, and 4 is a target point on which the ultrasonic beam is focused.

θ is the angle called the prospect angle, and the endmost element 1
is the angle determined by the spread angle of .

(Problem to be Solved by the Invention) When the diagnostic site becomes deeper, it is necessary to make the aperture 2 wider in order to increase the resolution in the depth direction. is determined, so in order to use it with a wide aperture 2, it is necessary to increase the viewing angle θ shown in FIG. As mentioned above, the beam width of element 1 is inversely proportional to the width of element 1, so if element 1 is made into a small element and excited individually, the beam width will be expanded and a large angle of view can be obtained, making it possible to enlarge the aperture. can. If the element 1 is divided into microelements for use with such a wide aperture, a large number of microelements 3 must be driven at the same time, which increases the number of transmitter/receiver circuits required.
It had become a large-scale device.

The present invention has been made in view of the above points, and its purpose is to reduce the scale of an ultrasonic diagnostic apparatus without increasing the number of transmitter/receiver circuits, while diagnosing deep areas with good resolution by widening the aperture. The aim is to realize an ultrasonic probe that can be

(Means for Solving the Problems) The present invention, which solves the above-mentioned problems, is an ultrasonic probe that is composed of a plurality of transducer elements and forms an ultrasonic beam by applying an appropriate delay operation to each element. The tactile element is characterized in that the element is divided into a plurality of microelements, each microelement is connected via a switching means, and the number of actuating elements is changed by turning on and off the switching means to change the directional characteristics. That is.

(Function) The number of excitation fine elements at the end of the aperture is reduced compared to the center, and even if the diagnosis site becomes deep, the aperture is widened and resolution is increased without increasing the required number of transmitting/receiving circuits.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of elements of an ultrasonic probe showing an embodiment of the present invention. In the figure, 21 is a unit element connected to one transmitting/receiving circuit (not shown),
An opening 22 is formed by 16 elements 21,
Each element 21 within the aperture 22 is a transmitting/receiving circuit T/R.
Connected to o~T/R・5. 23 is element 2
The micro-elements 23 are each divided into five parts, and each micro-element 23 is connected via a high-voltage switch 24. Details of element 21 are shown in FIG. In the figure, the same parts as in FIG. 1 are given the same reference numerals. The switch 24 is turned on and off in response to a control signal from an aperture control memory. The fixed terminal side of the switch 24 is connected to a transmitting/receiving circuit.

When all the switches 24 are on, there is only one transmitting/receiving circuit, so the beam width is the same as when the element 21 emits an ultrasonic beam, even though it is divided into fine elements. The element 21 is sub-diced to form a fine element 23.
When set to , the vibration mode is thickness vibration, so the oscillation frequency does not change.

The element 21 connected in this way allows four modes if we take an example in which the microelement is divided into five parts. However, the center of the element 21 is related to the acoustic pitch, and it is convenient to keep the pitch constant in order to perform delay operations.
Each mode must be arranged symmetrically around the center. The four modes are shown in FIG. In the figure, the same reference numerals as in FIG. 2 are given. As mentioned above, it is necessary to arrange them symmetrically around the center, so the following modes are: all channels off, 1 channel on, 3 channels on,
There are four modes: all channels off.

Returning to FIG. 1, in the group of eight elements 27 in the center of the 25 ci opening 22, each element 21
is the mode where all channels are on. 26 is group 25
Each 2i[1! 41 consisting of 21 elements of l
In the group of element 21 of 11i1, element 2
1 is a 3-channel on mode.

27 is a group of four elements 21 each consisting of two elements 21 outside the group 26, and is in a one channel mode.

Groups 25a, 26a, and 27a indicated by broken lines correspond to the aforementioned groups 25, 26, and 27, respectively, and the elements 21 when the sound ray is moved and radiated from the aperture 22a after the ultrasonic wave is radiated from the aperture 22. In a group of
The element that newly belongs to group 25a is set to switch 2 by a control signal so that all channels are turned on.
Switch 4. In the case of groups 26a and 27a, the modes are similarly switched to groups 2G and 27.

Next, the operation of the above embodiment will be explained.

When diagnosis is started, a transmission signal is sent from the transmitting/receiving circuit so that an ultrasonic beam is emitted from the aperture 22, and the element 21 is excited. Since all channels of group 25 are on, element 21 operates like a single element and emits ultrasonic waves with a narrow beam width but high radiant energy. Since group 26 is 3-channel on, the radiation energy is slightly less (60%), but it emits ultrasonic waves with a wide beam width. Group 27 has one channel on, so it has a wide beam width, and by taking the desired viewing angle θ(q), it is possible to diagnose the area at the required depth.In the next step, the sound ray is moved to the right of element 21 by 1111i1. and therefore group 258.2 of element 21
The switches 24 are moved to positions 6a and 27a, and the switches 24 are turned on and off in response to signals from the control memory to form the aforementioned groups. If the depth of the diagnostic site is shallow, the opening 22 is configured as shown in FIG. 4, for example. In the figure, the same parts as in FIG. 1 are given the same reference numerals. If the diagnostic site is shallow, the element 21 with all channels on is 111.3 elements 21 with all channels on are configured as four as shown in the figure. In this case as well, the elements 21 for each mode are arranged symmetrically about the center of the aperture 22.

As described above, by dividing each element 21 into microelements 23, connecting them via the switch 24, and controlling the on/off of the switch 24, a wide aperture can be achieved without increasing the number of transmitter/receiver circuits. . It is particularly effective for applications where the viewing angle is more important than linear probes such as convex probes.

Note that the present invention is not limited to this embodiment. For example, when the connections within the element 21 are always symmetrical, by making the connections of the element 21 as shown in Fig. 7,
The number of switches required can be reduced.

(Effects of the Invention) As described in detail above, according to the present invention, by dividing the vibrator element into microelements, connecting each of them via a switch, and appropriately selecting on/off of the switch,
By increasing the number of transmitter/receiver circuits, the aperture can be made wider, and the scale of the ultrasonic diagnostic apparatus can therefore be reduced, allowing diagnosis of deep parts with good resolution.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an element of an ultrasonic probe according to an embodiment of the present invention, Fig. 2 is a diagram showing details of the element, Fig. 3 is a diagram showing the mode of connection of microelements, and Fig. 4 is a diagram showing the details of the element. is a diagram of another example of the element configuration of the aperture, Figure 5 (a) is a diagram showing the arrangement of the elements of the ultrasonic probe, <mouth> is an enlarged view of one element, and Figure 6 is the target. This is a diagram showing the relationship between the target point and the aperture, and FIG. 7 is a diagram of another embodiment in which the connections within the elements are changed. 1.21...Element 2.22.22a...Aperture 3.23...Small element 24...Switch 25.25a...Element group with all channels on 26.268...3 channels on Element group 27.27a...1 Channel-on element group Patent applicant Yokogawa Medical Systems Co., Ltd. Figure 6 F2I opening 41 vs. key point θI viewing angle 21i Element 23i @ Saiko 24i Switch

Claims (1)

[Claims] In an ultrasonic probe that consists of a plurality of transducer elements and forms an ultrasonic beam by applying an appropriate delay operation to each element, the element is divided into a plurality of microelements, and each microelement is connected to a switching means. 1. An ultrasonic probe characterized in that the directivity characteristics are changed by adjusting the number of operating microelements by turning on and off a switching means.