JPH1085218A - Ultrasonic diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic device conformable to low frequency type and high frequency type ultrasonic probes with a necessary minimum structure by arranging a first delay line having the same function as in the case when a delay line fitted to low frequency type ultrasonic probe is divided into a plurality of pieces, a change-over switch and a second delay line. SOLUTION: The change-over switch 7 of the phase matching adding circuit 1 of an ultrasonic diagnostic device is interposed between firsts delay lines 4, 5 on former stage side and latter stage side to switch the flowing direction of the output signal outputted form the former stage-side first delay line 4, and a second delay line 9 between the change-over switch 7 and an adder 8 delays the output signal from the former stage-side first delay line 4 with a preset minimum delay time. The change-over switch 7 is connected to a contact (a) to be connected to the latter stage-side first delay line 4 when low frequency type ultrasonic probe is used, and connected to a contact (b) to be connected to the second delay line when a high frequency type ultrasonic probe is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus configured to share a high-frequency ultrasonic probe and a low-frequency ultrasonic probe, and more particularly to a phasing and adding circuit.

[0002]

2. Description of the Related Art In an ultrasonic diagnostic apparatus, an ultrasonic probe such as a low-frequency sector scanning type or a convex scanning type, which is hardly attenuated when diagnosing a deep organ of a human body such as a heart or a gastrointestinal tract, is used. On the other hand, when diagnosing the thyroid gland or mammary gland in the shallow part of the human body, it is necessary to use a high-frequency linear scanning ultrasonic probe that can obtain a diagnostic image with good image quality. Generally, this type of ultrasonic diagnostic apparatus is provided with a phasing addition circuit 11 as shown in simplified form in FIG.

That is, the phasing and adding circuit 11 includes a delay line 13 for delaying a received signal in accordance with a delay time set by each delay tap 12, and a delay line 13 through each delay tap 12. Connected,
And a cross point switch 14 for selecting a delay tap 12 to which a received signal is input based on an instruction from a microcomputer (not shown) as a control means. After passing through the delay tap 12 selected by the cross point switch 14 and input to the delay line 13, the signal is delayed by the delay line 13, subjected to phasing addition, and then subjected to phasing addition from the delay line 13. It is to be output as a signal.

[0004]

By the way, the delay tap 1 in the delay-and-sum circuit 11 provided in the ultrasonic diagnostic apparatus is provided.
It is said that the delay time of the received signal set in each of the two needs to be different from each other by a required unit time that is equal to or less than ８ of the cycle of the center frequency in the ultrasonic wave to be used. Therefore, in an ultrasonic diagnostic apparatus using a low-frequency ultrasonic probe of 2.5 to 3.5 MHz,
Since the aperture ratio of the ultrasonic probe is large and the delay time is large, it is sufficient that a different delay time is set for each delay tap 12 constituting the phasing addition circuit 11 by a unit time of, for example, about 25 ns. On the other hand, 7.5MHz
In the phasing addition circuit 11 provided in the ultrasonic diagnostic apparatus when using the high-frequency ultrasonic probe of the above, since the aperture ratio of the ultrasonic probe is small and the frequency is high despite the small delay time, This means that each delay tap 12 needs to be set as a different delay time by, for example, a unit time of about 12.5 ns.

However, in an ultrasonic diagnostic apparatus configured to share a high-frequency ultrasonic probe and a low-frequency ultrasonic probe, a phasing addition circuit 11 required for the high-frequency ultrasonic probe is provided. If it is used as it is, it is inevitable that the cost of the phasing and adding circuit 11 including the delay line 13 and the cross point switch 14 is increased as a result of an increase in the circuit scale. In addition, when using the low-frequency ultrasonic probe of the ultrasonic diagnostic apparatus having the common configuration, the delay tap 12 having a different delay time set in a unit time more fine than necessary.
And has an excessive function.

The present invention has been made in view of these disadvantages, and has a phasing and adding circuit which is capable of supporting both low-frequency and high-frequency ultrasonic probes with a minimum necessary configuration. The purpose of the present invention is to provide an ultrasonic diagnostic apparatus comprising:

[0007]

SUMMARY OF THE INVENTION An ultrasonic diagnostic apparatus according to the present invention comprises a plurality of first delay lines for delaying a received signal corresponding to a delay time set by each delay tap, and each delay tap. And a cross point switch connected to the first delay line via the first delay line, and an output signal output from the first delay line on the front side after being interposed between the first and second delay lines on the front and rear sides. A changeover switch for changing the flow direction, an adder disposed on the output side of the first delay line on the subsequent stage, and an output from the first delay line on the previous stage interposed between the changeover switch and the adder And a second delay line for delaying the signal by a preset minimum delay time.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a simplified block diagram showing the configuration of a phasing addition circuit provided in the ultrasonic diagnostic apparatus according to the present embodiment.
Is shown.

The ultrasonic diagnostic apparatus according to the present embodiment uses a low frequency sector scanning type or convex scanning type ultrasonic probe to diagnose a deep part of a human body, while using a high frequency linear scanning type. It is possible to diagnose a shallow part of a human body by using an ultrasonic probe, and this ultrasonic diagnostic apparatus includes a phasing addition circuit 1 configured as shown in FIG. . And this phasing addition circuit 1
A pair of first delay lines 4 and 5 for delaying a received signal in accordance with the delay time set by each of the delay taps 2 and 3, and a first delay line 4 via each of the delay taps 2 and 3 , 5 connected to each other, and each of the delay taps 2, 3 connecting each of the first delay lines 4, 5 and the cross point switch 6 to each other has a different delay time by a unit time. On the other hand, the cross point switch 6 selects the delay taps 2 and 3 to which the received signal of each channel is input in accordance with an instruction from a microcomputer (not shown) which is a control means. ing.

That is, the first delay lines 4 and 5 here are delay lines 1 constituting a phasing addition circuit 11 adapted to a low-frequency ultrasonic probe in a conventional form.
In this case, the delay taps 2 and 3 connecting each of the first delay lines 4 and 5 and the crosspoint switch 6 are suitable for a low-frequency ultrasonic probe. Have different delay times for each unit time
For example, the delay time is set from 0 ns to 600 ns in steps of 25 ns.

The phasing addition circuit 1 is provided between the first and second delay lines 4 and 5 and outputs the output signal from the first delay line 4 at the previous stage. A changeover switch 7 for switching the flow direction, an adder 8 disposed on the output side of the first delay line 5 on the subsequent stage, and a first switch on the front stage after being interposed between the changeover switch 7 and the adder 8. A second delay line 9 for delaying an output signal from the delay line 4 by a preset minimum delay time, wherein the second delay line 9 is, for example, 1/2 of 25 ns. There is 12.
5 ns is set as the minimum delay time. The minimum delay time of the second delay line 9 is not limited to 12.5 ns.
Of course, it is also possible to set the value to 1/3 of the unit time between them.

In this case, the changeover switch 7
Output from the first delay line 4 in the preceding stage according to the instruction of the microcomputer based on which of the low frequency type and the high frequency type ultrasonic probe is used, or the depth of the part to be diagnosed. The basic operation is to connect the a-contact connected to the first delay line 5 on the subsequent stage when using the low-frequency ultrasonic probe. On the other hand, when a high-frequency ultrasonic probe is used, the connection to the contact b connected to the second delay line 9 is made. The basic operation of the change-over switch 7 is as described above. However, the change-over switch 7 is used for diagnosing an organ in a shallow part or a deeper part of a human body while using a low-frequency ultrasonic probe. The switch 7 follows the instruction of the microcomputer based on the set depth and the like, and connects the first delay line 4 on the preceding stage to the contact b connected to the second delay line 9. Further, the adder 8 here is configured to output a phase-adjusted signal output from the first delay line 4 on the previous stage through the second delay line 9 and a phase-adjusted signal output from the first delay line 5 on the subsequent stage. And outputs a phasing addition signal.

Next, the operation of the ultrasonic diagnostic apparatus according to the present embodiment will be described.

First, when diagnosing an organ deep in the human body by using an ultrasonic diagnostic apparatus, a low-frequency ultrasonic probe is used. The change-over switch 7 interposed between the first and second delay lines 4 and 5 is connected to the contact a. The received signal of each channel is input to the first delay lines 4 and 5 through the delay taps 2 and 3 selected by the cross point switch 6 operating according to the instruction from the microcomputer. A received signal from a portion having a delay time that may be up to 600 ns passes through the delay tap 3 selected by the cross point switch 6 and is input to the first delay line 5 at the subsequent stage. The signal is delayed by 5 and is subjected to phasing addition to be a phasing addition signal, which is then passed through the adder 8 and output.

A signal received from a portion having a required maximum delay time of more than 600 ns to 1.2 μs is passed through the delay tap 2 and then the first delay line 4
After being delayed by the first delay line 4, the signal is passed through the changeover switch 7 and re-input to the first delay line 5 on the subsequent stage, whereby the delay is further delayed by 600 ns, and the phasing is performed. After being added, the signal is converted into a phasing addition signal, which is then passed through the adder 8 and output. As a result , in the phasing addition circuit 1 when the low-frequency ultrasonic probe is used, a maximum delay time of 1.2 μs is secured by the pair of first delay lines 4 and 5, At this time, the unit delay time of the received signal is 25 ns.

On the other hand, when a shallow part of a human body is diagnosed by using an ultrasonic diagnostic apparatus, a high-frequency ultrasonic probe is used, and the changeover switch 7 constituting the phasing addition circuit 1 is It is connected to the contact b in accordance with the instruction from the microcomputer. Therefore, at this time, the first delay line 4 on the preceding stage is connected to the second delay line 9 via the changeover switch 7, and the received signal of each channel is selected by the cross point switch 6. Then, the signals are input to the first delay lines 4 and 5 on either the front stage or the rear stage through the delay taps 2 and 3.

That is, the received signal of each channel is applied to the delay tap 3 selected by the cross point switch 6.
After passing through the first delay line 5 which is used in a normal stage after passing through the first delay line 5, the signal is output after being delayed by the first delay line 5, and after passing through the delay tap 2, After being input to the first delay line 4 on the side and delayed, the signal is output after being delayed by 12.5 ns from the changeover switch 7 through the second delay line 9.

More specifically, in this case, in this case, the received signal of the channel having the delay time of 0 ns passes through the delay tap 3 of the latter stage having the delay time of 0 ns and the first delay of the latter stage. The received signal output after being input to the line 5 and having a delay time of 12.5 ns is input to the first delay line 4 of the preceding stage through the delay tap 2 of the preceding stage having the delay time of 0 ns. Then, the signal is output through the changeover switch 7 and the second delay line 9. A received signal having a delay time of 25 ns is output after being input to the first delay line 5 on the subsequent stage through the delay tap 3 on the subsequent stage where the delay time is set to 25 ns, while being output. The received signal of 37.5 ns is input to the first delay line 4 of the previous stage through the delay tap 2 of the previous stage having a delay time of 25 ns, and is then switched to the changeover switch 7 and the second delay line 9.
Will be output.

The phasing signal output from the first delay line 5 on the subsequent stage and the second
The phasing signal output after being delayed by 2.5 ns is added by the adder 8, and then output from the adder 8 as a phasing addition signal. As a result, in the phasing addition circuit 1 when using the high-frequency ultrasonic probe, a phasing addition signal having a maximum delay time of 600 ns and a unit delay time of 12.5 ns can be obtained. become.

By the way, in the ultrasonic diagnostic apparatus according to the present embodiment, it is assumed that a low-frequency ultrasonic probe is used and a deep organ of a human body is diagnosed, and a high-frequency ultrasonic probe is used. It is said that the shallow part of the human body is diagnosed by performing the above procedure.However, it may be necessary to diagnose the shallow part of the human body using a low-frequency ultrasonic probe. Although it is undeniable that the image quality is inferior to that of the type ultrasonic probe, it is desired to obtain a diagnostic image with good image quality even if it is a little. And according to the ultrasonic diagnostic apparatus concerning this Embodiment, it becomes possible to respond to such a request. That is, the changeover switch 7 in this case is connected to the contact b in accordance with the instruction of the microcomputer, and the first delay line 4 and the second delay line 9 on the preceding stage are connected through the changeover switch 7. Are connected to each other.

Therefore, similarly to the case of using the high-frequency ultrasonic probe, the received signal of each channel passes through the delay taps 2 and 3 selected by the cross point switch 6 and is provided on either the front stage or the rear stage. Are input to the first delay lines 4 and 5. That is, the received signal of each channel at this time passes through the delay tap 3 selected by the cross point switch 6 and is then input to the first delay line 5 at the subsequent stage used in normal operation. 5 and output after being delayed by
After passing through the first delay line 4 at the previous stage and being delayed, the signal is delayed from the changeover switch 7 through the second delay line 9 by 12.5 ns and output. Therefore, a diagnostic image with improved image quality can be obtained while using a low-frequency ultrasonic probe. Here, the case of diagnosing the shallow part of the human body while using a low-frequency ultrasonic probe is described,
The same applies to the case where the maximum delay time may be up to 600 ns as the depth of the part to be diagnosed becomes deeper.

Further, in the delay-and-sum circuit 1 according to the present embodiment, a pair of first delay lines 4 and 5 are provided, and a changeover switch 7 is provided between the first delay lines 4 and 5. However, the configuration is not limited to only such a configuration, and a configuration in which three or more first delay lines are provided and a changeover switch is provided between the first delay lines may be adopted. Of course. Further, in the present embodiment, the unit time of the delay between the delay taps 2 and 3 is 25 ns, but it is needless to say that the unit time is not limited to 25 ns.

[0024]

As described above, according to the delay-and-sum circuit of the ultrasonic diagnostic apparatus according to the present invention, the delay line suitable for the low-frequency ultrasonic probe in the conventional embodiment is divided into a plurality of delay lines. Not only a low-frequency ultrasonic probe but also a high-frequency ultrasonic probe with a minimum necessary configuration in which only a changeover switch and a second delay line are newly provided together with a first delay line having the same function as A probe can be used. Therefore, it is possible to prevent an increase in the circuit scale required for a high-frequency ultrasonic probe, and to eliminate excessive functions for a low-frequency ultrasonic probe, thereby significantly The effect that a significant cost reduction can be realized is obtained.

[Brief description of the drawings]

FIG. 1 is a simplified block diagram showing a configuration of a phasing addition circuit included in an ultrasonic diagnostic apparatus according to the present embodiment.

FIG. 2 is a simplified block diagram showing a configuration of a phasing addition circuit provided in an ultrasonic diagnostic apparatus according to a conventional embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 phasing addition circuit 2 delay tap 3 delay tap 4 first delay line 5 first delay line 6 crosspoint switch 7 changeover switch 8 adder 9 second delay line

Claims (1)

[Claims] 1. A plurality of first delay lines for delaying a received signal corresponding to a delay time set by each delay tap, and a cross connected to the first delay line via each delay tap. A point switch, a changeover switch that is interposed between the first and second delay lines and switches a flow direction of an output signal output from the first delay line on the front stage, and a first delay on the second stage An adder disposed on the output side of the line, and a delay switch interposed between the changeover switch and the adder, which delays the output signal from the first delay line on the preceding stage with a preset minimum delay time. An ultrasonic diagnostic apparatus comprising a phasing addition circuit having two delay lines.