JPS58188432A - Ultrasonic diagnostic apparatus - 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] [Technical Field of the Invention] The present invention relates to an ultrasonic diagnostic apparatus, and particularly relates to an IJ near electronic scanning type ultrasonic diagnostic apparatus that scans an ultrasonic beam by switching a plurality of transducers. be.

[Technical background of the invention and its problems]

Linear electronic scanning ultrasound diagnostic equipment uses a scanning method (hereinafter also referred to as linear electronic scanning) in which a large number of transducers are arranged and the center position of the ultrasound beam is electronically moved by switching the transducers one by one. This is what was adopted. In such linear electronic scanning, various driving methods have been proposed in which beam scanning is performed at intervals narrower than the pitch interval of the transducers in order to improve the resolution of the ultrasonic image.

For example, the one shown in FIG.
587), first, the five transducers T, -T are simultaneously driven by the pulsers P1 to R to generate an ultrasonic beam having the center at position B, and then the six transducers T ,−
By simultaneously driving T, by pulsers P1 to P, an ultrasonic beam having a center at position B is generated,
Next is T! ~T,,T,~T,,i',~1゛嘗,...
The purpose is achieved by sequentially driving a combination of the following to perform beam scanning with an interval of 1/2 of the transducer pitch. With K in this manner, the number of vibrators and circuits connected thereto can be reduced, and an image with high scanning line density can be obtained. However, since the number of transducers to be driven simultaneously increases and decreases alternately, the output of the emitted ultrasonic waves differs alternately, resulting in a difference in the intensity of the reflected waves and the problem that a striped pattern appears in the image. In this case, a method of adjusting the gain of the amplifier by alternately increasing and decreasing it has been adopted, but the circuit configuration becomes complicated, and since s and qv do not change depending on the gain, stripes still occur for weak signals with weak reflections. This will result in a pattern.

In addition, a method has been proposed in which the number of driving transducers during transmission and the number of driving transducers during reception are different, thereby scanning the ultrasound beam at an interval of 1/4 of the transducer pitch (%
However, since the number of transducers used during transmission and reception differs, the energy of each ultrasonic wave changes, resulting in a striped pattern similar to the above.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and moves the center of the ultrasonic beam at intervals finer than the transducer pitch.
Another object of the present invention is to provide a linear electronic scanning ultrasonic diagnostic device that can equalize the ultrasonic energy transmitted and received each time.

[Summary of the invention]

In order to achieve the above object, the present invention performs ultrasonic scanning by sequentially shifting the position of each transducer group including n transducers smaller than the total number of transducers in a plurality of transducers arranged and driving them simultaneously. The device is characterized by a combination of simultaneous driving of n adjacent transducers and simultaneous driving of n+α transducers except for the six sensors located in the center. That is.

[Embodiments of the invention]

The present invention will be specifically explained below with reference to the drawings.

FIG. 2 is a diagram explaining the principle of the present invention. As shown in the figure, first, when six transducers T1 to TI are driven simultaneously, the center position of the ultrasound beam is B! (the same figure (α1
), then when six transducers excluding T4 and ranging from <TI to 1mm are simultaneously driven, the center position of the ultrasonic beam becomes position B8 (1h+ in the same figure), and similarly K and 1mm to T1. Until 0
When six transducers are driven simultaneously, the center and position of the ultrasonic beam becomes B4 (IC+ in the same figure), and then 8 <1゛! When the six transducers up to T are driven simultaneously, the center position of the ultrasonic beam will be at position B.

In this way, beam scanning can be performed at intervals of 1/2 of the transducer pitch, and since the number of simultaneously driven transducers is always the same, the ultrasonic energy emitted each time can be made uniform.

The above explanation has been about the driving method when transmitting ultrasonic waves, but it goes without saying that the same applies to the case of receiving ultrasonic waves.

FIG. 3 shows the configuration of an embodiment of the present invention in which a phase control function for electronic focusing is added and transmission/reception is performed, in which eight consecutive ultrasonic transducers T, ~1"64 Eight groups 31, 32...

The transducers are divided into 68 groups, and the transducers are located at the same position between each group 61 to 58, that is, the transducers located at the first position from the end in each group are T, , T, , ..., i", , ,
Second position T, ,T,, ・,T,, ,
- Eight variable delay lines D1 to D8 are provided that commonly correspond to the eighth positions T, , T@, respectively. And each of these variable delay lines D1-D.

, the drive timing of each pulser that supplies pulses to the corresponding transducer (timing of the clock pulse supplied to each pulser) and the analog electrical signal of the ultrasonic pulse received by the corresponding transducer are delayed. 1, AI” A is an amplifier that amplifies the received ultrasonic pulse extracted by the switching circuit, Ft + #
ta, FOr~V10- is a switch that switches the output side of the variable delay lines D1~D, in order to share them during transmission and reception. Also, 81 to S.6 are switching circuits, G, -G@, are NAND gate circuits, L+
~Le4 is an IJ mitter, and P1 to P61 are pulsars. Further, 11 is a clock pulse generator, and 15 is a high frequency amplifier.

Next, the operation of this device will be explained. First, when the first clock pulse is output from the clock pulse generator 11,
The clock pulse is passed through the solid line side of the switch 1Vi, ~Wts, the variable delay line DI~⇠, and the solid line side of the switch Fo+~FO@ through the pulser P-
P, and the pulsers P1 to P. are driven. At this time, each delay time of variable delay lines D1 to D8 is 1° to t,
tl -b , tl -t7 , tI-tl ,
If controlled to an appropriate value such as tl <tl <tl, the ultrasonic beam will converge at the desired position. At this time, only the switching circuits 81 to S@ are turned on, and the reflected ultrasonic pulse is transmitted to the transducer T1. Only the pulses received at ~7゛6 pass through limiters L, -L, switching circuits S, ~S, and then amplifier AI""' A@.

Switcher Fil ~ Fz @ dotted line side, variable delay line DI-,
Z)s (t+ to t· are set the same as during transmission), and as a result, the reflected ultrasonic pulse from the desired position is input to the high frequency amplifier 16 in an emphasized form. At this time, the center position of the ultrasonic beam transmission and reception is located between the transducers T and T4. Then, when the second clock pulse is output, the NAND gates are set to 6 excluding G4.
1~G7 only switching circuits are 51~S excluding S.
Only 1 turns on, and P1 to Pma, 1゛1 to T, , S, -5, except p, , T, and S4 operate.
At this time, the relationship between the delay times i and -t of the variable delay lines D1 to D is as follows: t, -b, bh, tl-it, t
Shift I<ts<et al. At this time, the center position of the ultrasonic beam becomes the center of the transducer T4 and has moved by 1/2 of the sensor pitch. Next, when the third clock pulse is output, the pulse passing through the delay lines -D and wo activates the pulsers p and -p to drive the oscillators T and -T. In the switching circuit, only S~S1 is on, and only the ultrasonic waves received at 1~T are sent to the delay circuit A.
.about.D1 and supplied to the high frequency amplifier 13. The delay times are b-tv, b-ta, t,
-ta, becomes snow, and becomes self, tl. At this time, the center position of the ultrasonic beam is located between transducers TI and 8, and has moved by one pitch compared to the case of the first clock pulse. In the fourth clock pulse, except G,,S,<
Activate the NAND gates and switching circuits of Gf~GI, Skan~Ss, and turn on the delay circuits, tl -t
a, ta -tv, t, -t・, 1. <1.
<11. At the 5th glue qtsuku pulse, HAG, ~G,
, S, ~Sa only, delay time is I! s-tm
, tl-b, tI-ta, et al. <-1
,, at the sixth clock pulse Gl, Ga wo l) J
((ym~G, and S, -S.

ON, and the delay time is tl-tl, tl-t
@, tl-1y.

1m<11<1. shall be. Thereafter, the same operations are repeated one after another to move the ultrasonic beam 1/2 pitch at a time in a converged state.

FIG. 4 is an explanatory diagram of another embodiment of the present invention.

First, T1-Ta is used for transmission, and T1 to T6 are used for reception (ψ), then T1 to Ts are used for transmission, and T4 is used for reception.
Excluding <T.

〜T1 is used in the same figure (bl), and the fifth one is in the same figure (C), in which TI is excluded for both transmission and reception.
The th is K T at the time of transmission, ~T number, T at the time of reception, except T,
- The same figure (d;) shows that T is used for both transmission and reception.
, -T (see figure (gl)), the center position of the ultrasonic beam can be moved at an interval of 1/4 of the transducer pitch.

According to the present invention described in detail above, the center position of the ultrasonic beam, that is, the scanning line position can be moved at intervals finer than the pitch of the transducer.

Since the energy (or power) when transmitting and receiving ultrasonic waves is the same each time, there is no need for amplifier gain correction as in the conventional method.
Striped patterns due to essential SI differences do not occur.

Furthermore, since the selection of transducers during transmission and reception is always performed symmetrically, there is also the advantage that it is convenient for electronic focusing.

(91

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a detailed explanatory diagram of the present invention, Fig. 6 is a configuration diagram of one embodiment of the device of the present invention, and Fig. 4 is an explanatory diagram of another embodiment of the present invention. It is. T, ~T, c・, oscillator, P, -P,, --... pulsar, AI~A6... amplifier, D1~D... delay line, 31~38... oscillator group, . Agent Patent attorney Noriyuki Chika (and 1 other person) (10) -166- (・)day±■

Claims (1)

[Claims] (11) Ultrasonic scanning is performed by sequentially shifting the position of each group of transducers including a number of transducers smaller than the total number of transducers in a plurality of transducers arranged and driving them simultaneously. The ultrasonic device is characterized in that it combines simultaneous driving of adjacent L transducers and simultaneous driving of trL+a transducers excluding α transducers located in the center part. Diagnostic device (where α and α are integers). (2) The ultrasonic diagnostic device according to claim 1, wherein the number of transducers in the transducer group is an even number.