JPH031846A - Instrument for ultrasonic diagnosis - Google Patents

Abstract

PURPOSE:To enable a control for avoiding saturation of received echo in a short distance receive sound field independently of a control for improving the receive sound field by installing signal generators for applying reference voltages, which are properly varied in accordance with depths in live body distance directions, to D/A converters. CONSTITUTION:Every D/A converter 5 receives a weighted data from ROM 8 through each latch circuit 10 while receiving a PRE-STC signal from a PRE- STC generation circuit 6 as a reference voltage, and sends out a D/A converted output to an interpolation-relocation circuit 11. Therefore, every D/A converter is driven on a receive dynamic focus system, and a combination of address generater 1, ROM 8, shift register 9 and each latch circuit 10 function as a control device for changing variously a setting of weighted data, which is used by every D/A converter, in accordance with a depth in a direction of live body distance at every receive dynamic focus step.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention provides ultrasonic scanning by pressing a probe consisting of a plurality of ultrasonic transducers against a subject and scanning the subject while moving. The present invention relates to an ultrasonic diagnostic device that reconstructs a sound wave image, and in particular to an improvement in an ultrasonic diagnostic device that uses a D/A converter to perform arbitrary weighting on received echoes from each ultrasonic transducer of a probe. tJ-ru.

(Prior Art) Conventionally, in this type of ultrasonic diagnostic equipment, when a received echo from each ultrasonic transducer of a probe is amplified by each corresponding preamplifier, a gain control signal for each preamplifier is obtained. D/
Using an A converter, arbitrary weighting is applied to the received echoes by sufficient quantization of, for example, 8 pits (256 gradations) by the D/A converter, thereby avoiding saturation of the received echoes in a near-field receiving sound field; The receiving sound field was improved by reducing side lobes and improving the beam width of the main beam.

(Problem to be Solved by the Invention) However, in the conventional case, weighting control is performed by the D/A converter in a non-separable relationship between avoiding the saturation of the received echo and improving the received sound field.
In order to perform desired weighting control, it is unavoidable to increase the storage capacity of a storage means such as a ROM for storing weighting data, and there is also the problem that the control system becomes complicated and large-scale.

The present invention has been made with attention to such circumstances, and its purpose is to perform control to avoid saturation of reception echoes in a short-range reception sound field independently of control to improve the reception sound field. The purpose of the present invention is to provide an ultrasonic diagnostic device.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention amplifies received echoes obtained by transmitting and receiving with a probe consisting of a plurality of ultrasonic transducers. In an ultrasonic diagnostic apparatus that applies a D/A converter output as a gain control signal to each amplifier and reconstructs an ultrasonic image based on the received echoes that have been arbitrarily weighted thereby, the D/A converter In contrast, the present invention is characterized in that it includes a signal generation source that applies a reference voltage while changing it appropriately depending on the depth in the biological distance direction.

(Function) With the configuration of the ultrasonic diagnostic apparatus according to the present invention, it is possible to apply a reference voltage that is appropriately changed according to the depth of the received sound field from the signal generation source to the D/A converter. If the D/A converter output, which is changed by the reference voltage, is used as a gain control signal for each amplifier for amplifying received echoes, it is possible to avoid saturation of received echoes in the short-range receiving sound field.

Therefore, if weighting data is used with the variable reference voltage applied to the D/A converter, this weighting data will be used as a weighting data dedicated to improving the receiving sound field, such as reducing side lobes and improving the main beam. data, and the amount of data is small.

Therefore, the desired weighting control can be achieved without increasing the storage capacity of the storage means such as ROM that stores the weighting data, and since the amount of data is smaller than before, the configuration of the control system can be simplified. can be converted into

Furthermore, even when obtaining an ultrasound image using the reception dynamic focus method, by adopting a control means that can change various settings of the weighting data in correspondence with the depth in the biological distance direction for each reception dynamic focus stage, the above-mentioned To easily and reliably make adjustments to improve a receiving sound field.

(Embodiment) FIG. 1 is a block diagram showing a circuit configuration of a main part of an ultrasonic diagnostic apparatus according to an embodiment to which the present invention is applied.

The ultrasonic diagnostic apparatus of this embodiment drives and controls a probe 1 consisting of 96 ultrasonic transducers CHI to CH96 by a selection drive unit 2, and transmits and receives data between the probe 1 and the subject. I do. Each ultrasonic transducer CHI to CH of this probe 1
The received echo received by 96 is preamplified PREAI~PR.
A weighting control section 4 is provided to control the gain of the preamplifier group 3 when amplifying with the preamplifier group 3 made up of EA96.

The weighting control unit 4 includes 48 D/A converters (DA
CI~DAC48)5, PRE-8TC generation circuit 6, address generator 7, ROM8, shift register 9.48 latch circuits (LATCH1~LATC-) (48)1
0, and an interpolation/reordering circuit 11.

Each D/A converter 5 connects the PRE-8TC to the REF terminal.
It receives the PRE-8TC signal from the generation circuit 6 as a reference voltage, receives weighted data from the ROM 8 via each latch circuit 10, and sends the D/A conversion output to the interpolation/rearrangement circuit 11. There is.

The PRE-8TC generation circuit 6 receives an ultrasonic rate signal from a system controller (not shown), and can set the slope and initial offset voltage of the PRE-3TC signal in a graph for each repetition scan rate. Further, the ROM 8 stores weighting curve function data for reducing side lobes and weighting curve function data for improving the beam width of the main beam in different memory areas, and the address generator 7 Waiting curve function data is read out from each latch circuit 10 according to the read address from the latch circuit 10.

The address generation circuit 7 includes a weighting code for selecting each weighting curve function data stored in the ROM 2, a reception dynamic focus switching clock,
The data latch clock is received from the system controller, and the top three weighting codes are sent to ROM8.
The bit selects the type of weighting curve function, and the lower 5 bits address the data of 48 channels.

At the same time, the shift register 9 receives a reception dynamic focus switching clock and a data latch clock from the system controller, and sends each latch circuit 10
The CKI and GK2 terminals are enabled alternately while sequentially shifting the CKI and GK2 terminals.

Therefore, each D/A converter 7 is driven by the reception dynamic focus method using two reception systems, and the address generators 7, 110M8. Shift register9. The combination of each latch circuit 10 functions as a control means that can change various settings of the weighting data used in each D/A converter 7 in correspondence with the depth in the biological distance direction for each receiving dynamic focus stage.

FIG. 2 is a timing chart schematically shown to explain the operation status of each part in FIG. 1. As shown in the diagram, clock 1. Clock 3. Clock 5. . . . in odd-numbered stages such as the clock 47, enable signals LE1-1 . LE2-1. LE3-1. ...
LE48-1 is output. Also, the clock 2. which is indicated by the rising pulse. Clock 4. Clock 6°...
At even stages such as the clock 48, an enable signal is sent from the shift register 9, and El-2, 1E-2° 1E3-2, .
...LE48-2 is output.

Therefore, the CKI terminal of each latch circuit 10 is enabled in odd-numbered stages of dynamic GK, and its GK2 terminal is enabled in even-numbered stages of dynamic CK. As a result, the weighting curve function data selected from the ROM 8 is latched in each of the odd and even stages of the dynamic GK in each latch circuit 10 and output to each D/A converter 5. In FIG. 2, LEl-1 to LE48-1 indicate signals shifted by 1 CK in odd-numbered stages, and LEl-2 to LE48-
2 indicates a signal shifted by ICK in even-numbered stages.

Therefore, PRE-8'T of PRE-8TC generation circuit 6
In each D/A converter 5 to which the C signal is applied as a reference voltage, the weighting curve function data selected from the ROM 8 is sequentially D/A converted by the reception dynamic focus method and is applied to the interpolation/rearrangement circuit 11. . And this interpolation/reordering circuit 11
When the D/A conversion output of each D/A converter 5 is linear, the gain control signal PRE-8TCI of the preamplifier group 3
- Interpolated and rearranged according to the address of the ultrasonic raster so that it can be used as PRE-3TC96.

As mentioned above, the gain control signal PRE-3T of preamplifier group 3
By generating CI~PRE-8TC96 in the weighted number control unit 4, control to avoid saturation of reception echoes in the short-range reception sound field can be performed independently of control to improve the reception sound field. This situation is schematically shown in FIG.

In FIG. 3, VPRE-svc is PRE-8 of a PRE-8TC generation circuit that is applied to each D/A converter 5 in correspondence with the receiving dynamic focus stage.
8TC signal is shown. This VPRE-5TC
By lowering the gain V near the body surface where each of the ultrasonic transducers CHI to CH96 of the probe is in contact, saturation of received echoes in the short-distance receiving sound field can be avoided. In other words, since there is no attenuation of ultrasound near the body surface and the reflected echo from above the body is strong, the weighting determined by the weighting function data in ROM8 is
By multiplying by 5TC, the gain of the preamplifier group 3 is controlled, so that reception echoes in the short-range reception sound field can be collected.

In this way, when saturation of reception echoes in the short-distance reception sound field is avoided, the above-mentioned weighting data used in each D/A converter 5 is stored in the ROM 8, and the following steps are taken to reduce the sidelobes. The weighting curve function data and the weighting curve function data for improving the main beam width mean that saturation of received echoes does not need to be considered.

The use of each weighting curve function data is shown by VSTC in Figure 3, and when the depth in the biological distance direction is shallow, weighting is performed to reduce side lobes. In addition, weighting is performed to improve the beam width of the main beam when the distance in the biological distance direction is deep.

Note that when the output signal of the preamplifier group 3 is sent to the image reconstruction section 12, the ultrasound image is reconstructed in the image reconstruction section 12, and the reconstructed contents are displayed as an image on the display 13.

In the case of the configuration of the embodiment of the present invention, as described above, the control to avoid the saturation of reception echoes in the short-range reception sound field is performed independently of the control to improve the reception sound field. Since the desired weighting control can be performed in each D/A converter 5 without increasing the storage capacity of the ROM 8, the configuration of the control system is simplified. Regardless of the situation, the receiving sound field can be improved easily and reliably.

[Effects of the Invention] As explained above, the ultrasonic diagnostic apparatus of the present invention has D/
Since the A converter is equipped with a signal generation source that applies a reference voltage that is appropriately changed depending on the depth in the biological distance direction, the saturation of received echoes in the near-field receiving sound field is independent of the weighting of the received echoes. It is something that can be controlled.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the circuit configuration of the main parts of an ultrasonic diagnostic apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining the operating status of each part in FIG. 1. FIG. 3 is a waveform diagram schematically showing the control state in one embodiment of the present invention. 1... Probe 2... Selection drive section 3...
・Preamplifier group 4...Weighting control section 5...
D/A converter 6...PiE-8TC generation circuit 7...Shift register 8...ROM9...Shift register 10...Latch circuit 11...Interpolation
Sorting circuit 12...image reconstruction unit 13...display

Claims (3)

[Claims] (1) Add the D/A converter output as a gain control signal to each amplifier that amplifies the received echo obtained by transmitting and receiving with a probe consisting of a plurality of ultrasonic transducers,
In an ultrasound diagnostic apparatus that reconstructs an ultrasound image based on the received echoes that have been arbitrarily weighted, the D/A converter is changed as appropriate depending on the depth in the biological distance direction. An ultrasonic diagnostic apparatus comprising a signal generation source that applies a reference voltage. (2) The ultrasonic diagnostic apparatus according to claim 1, wherein the D/A converter is driven by a reception dynamic focus method using two reception systems. (3) In the ultrasonic diagnostic apparatus according to claim 2, the D
1. An ultrasonic diagnostic apparatus comprising: a control means capable of changing various settings of weighting data used in the /A converter in correspondence with the depth in the biological distance direction for each receiving dynamic focus stage.