JP3824115B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus used when a tomographic image of a subject is obtained by scanning an ultrasonic beam.
[0002]
[Prior art]
A conventional ultrasonic diagnostic apparatus of this type, for example, a linear scanning type, has a configuration shown in FIG.
[0003]
In FIG. 3, 1 _{1 to} 1p are p transducers for transmitting and receiving ultrasonic waves, and 2 is a transducer (here, a channel) that is a driving target for ultrasonic emission from among these transducers 1 _{1 to} 1p. This is a multiplexer for selecting n as a number. In the case of the linear scanning type, the number of channels n is usually smaller than the total number p of the transducers _{11 to} 1p, and is set to n = 64 for p = 128, for example.
[0004]
Further, 3 _{1 to} 3 n are drive pulse generators for generating drive pulses for driving the vibrators for n channels selected by the multiplexer 2, and 4 _{1 to} 4 n are predetermined with respect to trigger pulses for generating drive pulses. This is a delay circuit for giving a delay amount. The delay amounts of the delay circuits 4 _{1 to} 4 n are set in advance so as to follow the delay curve for setting the focus position.
[0005]
Reference numerals 5 _{1 to} 5 n denote echo signal receivers that perform processing such as amplification detection on echo signals obtained by receiving ultrasonic echoes from a subject outside the figure by the transducers 11 to ₁ p, and 6 denotes each echo signal. This is an adder circuit for phasing and adding echo signals output from the receiving units 5 _{1 to} 5n.
[0006]
Reference numeral 7 denotes a control circuit for generating a trigger pulse for generating a drive pulse and controlling the multiplexer 2.
[0007]
In the conventional device, the drive pulse generators 3 _{1 to} 3n, the delay circuits 4 _{1 to} 4n, and the echo signal receivers 5 _{1 to} 5n are all provided by the number corresponding to the number of channels n of the vibrator. ing.
[0008]
Next, the operation of the ultrasonic diagnostic apparatus having the above configuration will be described.
[0009]
The trigger pulse generated from the control circuit 7 is given to each delay circuit 4 ₁ to 4 n.
[0010]
The trigger pulses that pass through the delay circuits 4 ₁ to 4 n and are given predetermined delay amounts along the delay curves are applied to the drive pulse generators 3 ₁ to 3 n.
[0011]
Each of the drive pulse generators 3 _{1 to} 3n generates a drive pulse having a predetermined delay amount in response to the trigger pulse, and this drive pulse is applied to an n-channel transducer selected in advance via the multiplexer 2. Applied. Thereby, ultrasonic waves generated by the transducers for n channels are emitted toward the subject.
[0012]
In this case, since the emission timing of the ultrasonic wave is shifted by the delay amount, the ultrasonic wave is focused at a predetermined focus position in the subject without being diverged.
[0013]
On the other hand, ultrasonic echoes from the subject are received again by the transducers for n channels, and echo signals obtained thereby are input to the echo signal receiving units 5 ₁ to 5 n via the multiplexer 2 and amplified here. Processing such as detection is performed.
[0014]
Subsequently, the echo signals output from the respective echo signal receivers 5 ₁ to 5 n are phased and added in the same phase in the adder circuit 6 and output.
[0015]
Thus, in the conventional device, the drive pulse generators 3 _{1 to} 3n, the delay circuits 4 _{1 to} 4n, and the echo signal receivers 5 _{1 to} 5n are all the same number as the number of channels n of the transducer. Provided, drive pulses having respective delay amounts are individually generated from the drive pulse generators 3 _{1 to} 3n.
[0016]
[Problems to be solved by the invention]
Incidentally, the conventional ultrasonic diagnostic apparatus shown in FIG. 3 has the following problems.
[0017]
When trying to obtain a precise image by increasing the scanning line density of ultrasonic waves, it is preferable that the number of channels n is large. However, when the number of channels n is increased in this way, the drive pulse is correspondingly increased. The number of generating parts 3 _{1 to} 3n also increases. In particular, the drive pulse generators 3 _{1 to} 3 n are large in circuit components in order to generate high-voltage pulses, which increases the overall size of the apparatus and makes it difficult to handle, as well as an extra cost. Become.
[0018]
The present invention has been made to solve the above-described problems, and it is an object of the present invention to reduce the number of channels of the drive pulse generation unit as compared with the prior art and to reduce the size of the apparatus. To do.
[0019]
[Means for Solving the Problems]
The delay amount given to the drive pulse is set in advance so as to follow the delay curve of the focus position setting, but in this case, the delay amount of the drive pulse is greatly different to the extent that it does not affect the transmission of the ultrasonic wave. For example, these drive pulses do not necessarily have to be generated from the drive pulse generator provided individually corresponding to each channel as in the prior art, but are generated in multiple times from the same drive pulse generator. It should be.
[0020]
In this way, it is not necessary to provide as many drive pulse generators as the number corresponding to the number of channels of the vibrator, and the number can be reduced.
[0021]
In order to solve the above-described problems, the present invention generates a drive pulse to which a predetermined delay amount is given from the drive pulse generator, and applies the drive pulse to the transducer to generate ultrasonic waves. In the ultrasonic diagnostic apparatus that receives the ultrasonic echo from the subject with the vibrator and processes the amplified echo signal in the echo signal receiving unit, etc. The following configuration is adopted.
[0022]
That is, in the present invention, when n is the number of channels of the transducer to be selectively driven for ultrasonic emission, the number of the drive pulse generators is set to be smaller than the number of channels n of the transducer. In addition, the drive pulses are generated in a predetermined drive pulse generator multiple times in a time-sharing manner so that the total number of drive pulses generated in each drive pulse generator is the same as the number of channels n. In addition, there is provided pulse distribution means for individually selecting each drive pulse generation unit by the number of times of generation of the drive pulse and equally allocating the drive pulse to the transducers of each channel.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a configuration of a linear scanning ultrasonic diagnostic apparatus according to an embodiment of the present invention, and portions corresponding to the conventional example shown in FIG.
[0024]
In FIG. 1, 1 _{1 to} 1p are p oscillators, 2 is a multiplexer, and here n oscillators for n channels (where n <p) out of p oscillators 1 _{1 to} 1p. Is to be selected.
[0025]
Reference numerals 3 _{1 to} 3 m denote drive pulse generators, 4 _{1 to} 4 n denote delay circuits, 5 _{1 to} 5 n denote echo signal receivers, 6 denotes an adder circuit, and 7 denotes a control circuit.
[0026]
In this embodiment, the delay amounts of the delay circuits 4 _{1 to} 4 n are set in advance along the delay curve C of the focus position setting as shown in FIG.
[0027]
The delay circuits 4 _{1 to} 4 n and the echo signal receivers 5 _{1 to} 5 n are provided in the same number as the number of channels n of the vibrator, but the number m of the drive pulse generators 3 _{1 to} 3 m is the number of vibrators. The number of channels is less than n (m <n).
[0028]
However, the total number of drive pulses generated by each of the drive pulse generators 3 _{1 to} 3 m within a certain unit time is the same as the number n of channels of the transducer, and (n−m) specific numbers For the drive pulse generator, a plurality of delay circuits are connected in common.
[0029]
For example, in the figure, with respect to the driving pulse generating section of code 3 _1, 4 ₁ and 4i 2 one delay circuit is commonly connected, for driving the pulse generating unit of the code 3 _2, 42 and 4i Two delay circuits of ₊₁ are connected in common. As a result, drive pulses are generated a plurality of times in a time division manner from (n−m) specific drive pulse generation units.
[0030]
The control circuit 7 is configured to generate a trigger pulse for generating a drive pulse and to control the multiplexer 2 and a switch circuit 8 described later.
[0031]
Reference numeral 8 denotes a switch circuit. The switch circuit 8 selects each of the drive pulse generators 3 ₁ to 3 m individually by the number of times of the drive pulse and is selected by the multiplexer 2 under the control of the control circuit 7. The drive pulses are equally allocated to the n transducers of each channel. Therefore, the switch circuit 8 and the control circuit 7 correspond to the pulse distribution means in the claims.
[0032]
Next, the operation of the ultrasonic diagnostic apparatus having the configuration shown in FIG. 1 will be described with reference to FIG.
[0033]
Finally, as shown in FIG. 2, drive pulses having a predetermined delay amount are individually applied to the n-channel transducers along the delay curve C for setting the focus position. However, since the number of drive pulse generators 3 _{1 to} 3m is m and is smaller than the number of channels n of the vibrator (m <n), the drive pulse generators 3 _{1 to} 3m The number will be deficient by (n−m).
[0034]
Therefore, in this embodiment, a drive pulse is generated a plurality of times from a specific drive pulse generation unit so as to compensate for the lacking (n−m) drive pulses. In that case, the control circuit 7 adjusts the connection relationship between the drive pulse generators 3 _{1 to} 3 m and the multiplexer 2 by the switch circuit 8, and individually controls the transducers for n channels selected by the multiplexer 2. Control is performed so that drive pulses having a predetermined delay amount are allocated.
[0035]
Specifically, for example, in FIG. 2, when the trigger pulse for the first time at time t ₀ in the control circuit 7 is generated, the trigger pulse is inputted to the delay circuits 4 ₁ to 4n.
[0036]
Then, the trigger pulse, the upper side of the delay circuit 4 _1, tau _1, the next stage of the delay circuit 4 ₂ In tau _2, the next delay circuit 4 ₃ In tau _3, the middle of the i th channel of the delay circuit 4i .tau.i further, the delay circuit 4n at _-1 tau ₂ of the lower side, so that the delay circuit 4n in tau ₁ lowermost further delay along the predetermined delay curve C is output given.
[0037]
Trigger pulses each delay amount in this way is given, since the input to each drive pulse generating section 3 ₁ to 3M, the drive pulse generator 3 ₁ to 3M is given in response to each trigger pulse A drive pulse given a delay amount is generated.
[0038]
Here, as described above, since (n−m) specific drive pulse generators have a plurality of delay circuits connected in common, (n−m) specific drive pulses are connected. From the generation unit, drive pulses are generated a plurality of times in a time division manner.
[0039]
For example, when focusing on the driving pulse generating section 3 ₁ uppermost, from the drive pulse generation unit 3 _1, firstly, the driving pulse by a trigger pulse from the delay circuit 4 _first uppermost (delay tau ₁₎ is generated Next, a drive pulse (delay amount τi) is generated again by the trigger pulse of the delay circuit 4 of the i-th channel. However, the difference in delay amount (τi−τ ₁ ) in this case is considered so as to have a magnitude that does not affect each other when transmitting ultrasonic waves.
[0040]
The control circuit 7 controls the switch circuit 8 as follows so that n drive pulses having a predetermined delay amount are individually applied to the transducers for n channels.
[0041]
In the above example, the drive pulse (delay amount τ ₁ ) generated from the upper drive pulse generator 3 ₁ is transferred to the first channel vibrator and the drive pulse generated from the next drive pulse generator 3 _2. The (delay amount τ ₂ ) is the second channel transducer, and the drive pulse (delay amount τ ₂ ) generated from the lower drive pulse generator 3 m _-1 is the (n−1) channel transducer. Furthermore, the drive pulse (delay amount τ ₁ ) generated from the lowermost drive pulse generator 3m is applied to the n-th transducer. Furthermore, the upper side of the driving pulse again the generated drive pulse from the generator 3 ₁ (delay amount .tau.i) The i-th channel of the oscillator, the next stage again the generated drive pulse from the drive pulse generator 3 ₂ (delay The quantity τ i ₊₁ ) is added to the vibrator of the i + 1 channel.
[0042]
In this way, the emission timing of the ultrasonic waves emitted from the transducers for n channels is given a delay amount along a predetermined delay curve for each of the n channels, as in the past. (See FIG. 2).
[0043]
Thus, the ultrasonic waves emitted from the n-channel transducers are focused at a predetermined focus position within the subject without being diverged.
[0044]
The ultrasonic echoes from the subject are received again by the transducers for n channels, and the echo signals obtained thereby are input to the echo signal receiving units 5 ₁ to 5 n via the multiplexer 2 and amplified here. Processing such as detection is performed, and subsequently, these echo signals are phased and added in phase in the adder circuit 6 and output.
[0045]
As described above, in this embodiment, the delay circuits 4 _{1 to} 4 n and the echo signal receiving units 5 _{1 to} 5 n are provided by the number corresponding to the number of channels n of the transducers. _{Since 1 to} 3 m may be a number m (<n) smaller than the number of channels n of the vibrator, the circuit scale can be reduced as compared with the conventional case.
[0046]
In the above embodiment, the delay amounts of the delay circuits 4 _{1 to} 4 n are set so as to follow a constant delay curve (thus, the focus position is constant). If the circuit 7 is configured so that the delay amounts of the delay circuits 4 _{1 to} 4 n can be controlled, the delay position can be arbitrarily set to adjust the focus position.
[0047]
However, in that case, it is necessary to consider the generation timing of the drive pulses generated from the same drive pulse generator in a plurality of times so as not to affect the transmission / reception of the ultrasonic waves.
[0048]
Furthermore, in this embodiment, the number of channels n of the transducers 1 _{1 to} 1p is constant, but the number of channels can be arbitrarily changed by controlling the multiplexer 2 by the control circuit 7 according to the setting of the focus position. It is also possible to make it possible.
[0049]
In this embodiment, the linear scanning type has been described. However, in the case of the sector scanning type in which the ultrasonic beam is scanned in a fan shape with the total number p of the transducers _{11 to} 1p equal to the number of channels n. The present invention can be applied.
[0050]
【The invention's effect】
The present invention has the following effects.
[0051]
(1) Since the number of channels of the drive pulse generation unit can be reduced as compared with the prior art, the apparatus can be miniaturized.
[0052]
(2) On the contrary, in order to increase the scanning line density of ultrasonic waves and obtain a precise image, even when the number of channels of the vibrator is set large, it is not necessary to provide drive pulse generators corresponding to the number of channels. Therefore, it is possible to suppress the apparatus from becoming large.
[Brief description of the drawings]
FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus showing an embodiment of the present invention.
FIG. 2 is a timing chart showing the relationship between the transducer of each channel and the generation timing of a drive pulse.
FIG. 3 is a block diagram of a conventional ultrasonic diagnostic apparatus.
[Explanation of symbols]
1 _{1 to} 1p: vibrator, 2 ... multiplexer, 3 _{1 to} 3m: drive pulse generator, 4 _{1 to} 4n: delay circuit, 5 _{1 to} 5n: echo signal receiver, 6: adder circuit, 7: control circuit, 8: Switch circuit.

Claims (1)

A drive pulse to which a predetermined delay amount is given from the drive pulse generator is generated, and this drive pulse is applied to the vibrator to emit an ultrasonic wave toward the subject, while an ultrasonic echo from the subject is In an ultrasound diagnostic apparatus that receives an echo signal and performs processing such as amplification detection on an echo signal obtained thereby,
When the number of channels of the transducer to be selected and driven for ultrasonic emission is n, the number of the drive pulse generators is set to be smaller than the number of channels n, and each drive pulse is generated. The drive pulse is generated in a predetermined drive pulse generation unit a plurality of times in a time-sharing manner so that the total number of drive pulses generated in the unit is the same as the channel number n, and each An ultrasonic diagnostic apparatus comprising: pulse distribution means for individually selecting a drive pulse generation unit as many times as the number of generation of the drive pulse, and equally allocating the drive pulse to the transducers of each channel.

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