JPH0796016B2 - Ultrasonic diagnostic equipment - Google Patents

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, and more particularly, to delay control a delay line having a plurality of delay amounts by delay data to delay a received signal from a probe composed of a plurality of piezoelectric elements. The present invention relates to an electronic focusing ultrasonic diagnostic apparatus.

[0002]

2. Description of the Related Art In an electronic focus type ultrasonic diagnostic apparatus, a beam is focused at an arbitrary position and controlled so that the ultrasonic beam is focused at a designated depth position. Then, an ultrasonic pulse is transmitted from the oscillator, and a reflection echo due to the acoustic impedance difference of the biological tissue boundary surface,
Received signal processing of scattered echoes from internal uniform tissue,
Brightness modulation according to the signal strength is performed and an ultrasonic image (B mode image) is displayed.

When this electronic focusing method is used, a receiving dynamic focusing method for obtaining a clear image having a high resolution over the entire region from a shallow portion to a deep portion of a living body is possible. In the received dynamic focus method, the delay amount is controlled by switching and selecting a delay line through which a signal for driving each transducer or a signal received from the transducer passes. Delay data for controlling the delay amount is different for each scanning line of the ultrasonic beam and each focus point for each channel (each signal line). These delay data are transferred from an external storage device such as a hard disk to an internal RAM or are stored in advance in an internal storage device such as a ROM or RAM.

[0004]

Since this delay data is different for each channel for all scanning lines and focus points, if all of these data are stored in the internal storage device, the capacity will be several megabytes to several tens of megabytes. Requires a byte capacity. Therefore, a large number of storage elements are required, which causes an increase in the price of the device. When transferring delay data from an external storage device such as a hard disk to an internal storage device such as RAM, it is necessary to load the delay data from the external storage device to the internal storage device each time the probe is switched. Delay data of several megabytes to several tens of megabytes must be transferred. Therefore, it takes several tens of seconds to transfer the data, which may hinder the flow of diagnosis.

An object of the present invention is to reduce the storage capacity of data related to delayed data.

An ultrasonic diagnostic apparatus according to a first aspect of the present invention selectively controls a delay line having a plurality of delay amounts according to delay data to delay a received signal from a probe including a plurality of piezoelectric elements. , Storage means, delay data calculation means, and delay control means. The storage unit stores difference data obtained by performing n-th order difference on the delay data and control data including an initial value of each floor. The delay data calculation means calculates the original delay data from the difference data and the control data stored in the storage means. The delay control means performs delay line selection control based on the delay data calculated by the delay data calculation means.

An ultrasonic diagnostic apparatus according to a second aspect of the present invention selectively controls a delay line having a plurality of delay amounts according to delay data which changes with three parameters of a scanning line, a focus point and a signal channel, and a plurality of piezoelectric elements. Which delays the received signal from the probe, and comprises a storage means, a delay data calculation means, and a delay control means. The storage means stores difference data obtained by performing an nth-order difference with one of the three parameters as a difference direction, and control data including an initial value of each floor, a difference direction, and a bit length of the difference data. The delay data calculation means calculates the original delay data from the difference data and the control data according to the difference direction stored in the storage means. The delay control means controls the selection of the delay line based on the delay data calculated by the delay data calculation means.

[0008]

In the ultrasonic diagnostic apparatus according to the first aspect of the present invention, not the delay data but the difference data obtained by subtracting the delay data by the nth level and the control data including the initial value of each level are stored in the storage means. . Normally, when the delay data smoothly changes between the delay data and the difference data, a considerable number of bit lengths can be reduced. For example, if the delay data has a 16-bit length, the difference data obtained by the n-th order difference can have a length of about 2 bits. For this reason, only the difference data having a small bit length and the control data need be stored in the storage means, and the data capacity becomes smaller than the case where the delay data is stored as it is, and the capacity of the storage means can be reduced.

In the ultrasonic diagnostic apparatus according to the second aspect of the present invention, the control data includes data indicating the difference direction. The delay data changes with three parameters of the scanning line, the focus point, and the signal channel, but the difference direction can be selected in the direction in which the data reduction rate is high. Therefore, when the differential data is restored to the delayed data, if the calculation is performed according to the differential direction, the delayed data can be easily obtained, and the capacity of the storage unit can be further reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an ultrasonic diagnostic apparatus adopting an embodiment of the present invention. In the figure, the probe 1 is composed of a plurality of minute piezoelectric elements and is connected to the multiplexer 2. The multiplexer 2 is for selecting a piezoelectric element for performing electronic scanning, variable aperture, and the like. A transmission / reception circuit 3 is connected to the multiplexer 2. The transmission / reception circuit 3 includes a delay line for converging the transmission beam, a circuit for setting the delay amount of the delay line, and the like. Also, a preamplifier that amplifies the reflected echo signal,
It includes a delay line having a plurality of taps for controlling the delay amount of the amplified reflected echo signal, and an analog multiplexer for switching and selecting a plurality of taps of each delay line. Further, the transmitting / receiving circuit 2 is
It includes a phase synthesizing circuit for phasing and adding the received signals selected by the analog multiplexer, and a logarithmic amplification detection circuit for performing logarithmic amplification and detection processing to obtain tomographic data. An A / D converter 4 is connected to the transmission / reception circuit 3. The A / D converter 4 converts the image data of the reflected echo signal output from the wave transmitting / receiving circuit 3 into a digital signal.

A DSC 5 is connected to the A / D converter 4. The DSC 5 converts the input image data into a standard television signal. C for DSC5
RT6 is connected. On the other hand, the transmission / reception circuit 3 is connected to the delay control section 7. The delay control section 7 is for controlling the delay line of the wave transmission / reception circuit 3 and the analog multiplexer, and outputs a control signal for tap switching to them. A differential direction switching control unit 8 and an adder 9 are connected to the delay control unit 7. The differential direction switching control unit 8 is for switching the differential direction (scan line, focus point, signal channel) of the delay data. A register group 10 for temporarily storing data for calculating delay data and a bit extracting unit 11 are connected to the adder 9. The adder 9 adds the bit data extracted by the bit extraction unit 11 and the data in the register group 10, stores the result in the register group 10 again, and when the delay data is calculated, stores it. It is output to the delay control unit 7. The register group 10 has registers for storing delay data and difference data of each floor except the last floor.

A RAM 12 is connected to the bit extraction unit 11. The bit extraction unit 11 is for extracting data of a predetermined bit length from the RAM 12. RAM
12 stores the initial value of the delay data, the initial value of each floor of the differential data obtained by performing the n-level difference of the delay data, and the differential data of the final floor. Further, the RAM 12 stores the bit length data of the difference data on the last floor and the data indicating the difference direction. These data may be stored for each probe, or for a plurality of probes. The RAM 12 is also connected to the register group 10, and when initializing the register group 10, transfers the initial value of data among them to the register group 10.

Next, the delay amount control operation of the ultrasonic diagnostic apparatus configured as described above will be described with reference to the flow charts shown in FIGS. Here, the delay amount control operation will be described by taking the case where the number of scanning lines of the ultrasonic beam is 256, the number of focus points is 8 and the number of channels is 64. First, in step S1 of FIG.
The data in the difference direction stored in 2 is read. The data in the difference direction is data indicating in which direction the difference was taken when the delay data was stored in the RAM 12 as the nth difference. For example, if the data reduction rate of delayed data in the channel direction is high, take the difference in that direction,
This is stored in the RAM 12 as data indicating the difference direction. When the data reduction rate in the focus direction is high, the difference data in the focus direction is stored, and when the data reduction rate in the scan line direction is high, the difference data in the scan line direction is stored. These difference directions are stored as difference direction data.

In step S2, the difference direction is determined from the read difference direction data. When it is determined that the difference direction is the channel direction, steps S2 to S3
Move to. In step S3, delay control processing in the channel direction is performed. Similarly, if it is determined to be the focus direction, the process proceeds to step S4, and if it is determined to be the line direction, the process proceeds to step S5. Then, in step S4 or step S5, similarly, delay control processing in the focus direction or the line direction is performed.

In the delay processing in the channel direction at step S3, as shown in FIG. 3, first, the scan line number (LN) is set to 0 at step S11. Step S1
At 2, the focus point number (FN) is set to 0.
In step S13, the channel number (CN) is set to 0. In step S14, first, the initial value of the delay data and the initial value of the difference data of the first to (n-1) th order differences are transferred from the RAM 12 to the register group 10. As described above, the register group 10 stores x registers for storing delay data and d1 to d1 for storing n−1 pieces of difference data.
and a dn-1 register.

In step S15, the delay data is calculated by the processing described in detail later. In step S16, the channel number is incremented. Step S
At 17, it is determined whether the channel number has reached 64. When the channel number has not reached 64, the process returns to step S15, and the delay data for the next channel number is calculated. If it is determined that the channel number has reached 64, the process proceeds to step S18. Step S1
At 8, the focus point number is incremented. In step S19, it is determined whether or not the focus number has reached 8. If the focus number has not reached 8, the process proceeds to step S13. Then, the subsequent processing is repeated to calculate the delay data of each channel number at the next focus point. If it is determined that the focus point number has reached 8, then the flow shifts to step S20. In step S20, the line number is incremented. In step S21, it is determined whether the line number reaches 256. When it is determined that the line number has not reached 256, the process returns to step S12. In step S12, the subsequent processing is repeated to calculate the delay data of the next line. When it is determined that the line number has reached 256, the processing ends.

When the difference direction is the focus point, as shown in FIG. 4, the channel number is set to 0 in step S31. In step S32, the line number is set to 0. In step S33, the focus number is set to 0. The subsequent operations in steps S34 to S41 are similar to the operations in steps S14 to S21 in FIG. When the difference direction is the line direction, as shown in FIG. 5, the channel number is set to 0 in step S51, the focus point number is set to 0 in step S52, and the line number is set to 0 in step S53. Set to. After that, the operations in steps S54 to S61 are performed by referring to
The description is omitted because it is similar to steps S14 to S21.

As described above, since the RAM 12 stores the difference data that has been reduced in the direction of high reduction rate,
The difference direction switching control unit 8 can select the optimum difference direction.
The selection of the difference direction is determined according to the characteristics of the probe and the like. Next, a specific delay data calculation procedure will be described. Here, as an example, as shown in FIG. 6, there is six pieces of data x (0) to x (5) as delay data. If these are subjected to the second-order difference, ddx (0)-
Four second-order difference data of ddx (3) are obtained. These four difference data, the initial value x (0) of the delay data and the initial value dx of the first-order difference data as the control data
(0) “2” indicating the bit length of the second-order difference data and data indicating the difference direction (for example, channel direction) are RA
It is stored in M12. That is, the data indicated by O in FIG. 6 is stored in the RAM 12.

In step S14 of FIG. 3, the initial value x (0) = 44006 of the delay data and the initial value dx (0) = 4000 of the first-order difference data are transferred to the register group 10. Then, in step S15, x (0) and dx (0)
And are added by the adder 9. As a result, the delay data x
(1) = 48006 is calculated. The calculated delay data x (1) is transmitted via the delay control unit 7 to the transmission / reception circuit 3
Given to. On the other hand, the calculated delay data x (1)
Is stored in the x register in the register group 10. Then, when the process returns to S15 through steps S16 and S17,
Initial value d of the first-order difference data stored in the register group 10
x (0) = 4000, and RA via the bit extraction unit 11
The initial value ddx (0) =-2 of the 2-bit second-order difference data stored in M12 is called and added by the adder 9. As a result, the first-order difference data dx (1) = 399
8 is calculated. The calculated data is stored in the dx register of the register group 10. Subsequently, the calculated first-order difference data dx (1) and the delay data x (1) stored in the x register are added to obtain the delay data x (2).
= 52004 is calculated.

By repeating this in order, the delay data x
(3) to x (5) are calculated in order. In this way, by taking the difference in the direction of high data reduction efficiency and storing the difference data in the RAM 12, the original delay data is 16 bits as shown in FIG.
The data of the floor difference is 2 bits. This makes RAM1
The capacity of 2 can be reduced. Further, since the difference direction is controlled by the difference direction switching control unit 8, the difference data in the optimum difference direction can be stored according to the probe.

[Other Embodiments] In the above embodiment, the delay data is changed by three parameters, but the delay data may be changed by only one of them.

[0022]

In the delay amount control device according to the present invention, since the delay data is not stored in the storage means as it is, but the nth-order difference data of the delay data is stored, the storage capacity can be reduced. Further, by further selecting the difference direction and storing the storage means, it is possible to increase the data reduction rate and further reduce the storage capacity.

[Brief description of drawings]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus adopting an embodiment of the present invention.

FIG. 2 is a flowchart of a delay amount control operation.

FIG. 3 is a flowchart when the channel direction is a difference direction.

FIG. 4 is a flowchart when the focus direction is a difference direction.

FIG. 5 is a flowchart when the line direction is the difference direction.

FIG. 6 is a diagram showing a delay data calculation procedure.

[Explanation of symbols]

 1 Probe 3 Transmission / Reception Circuit 7 Delay Control Section 8 Differential Direction Switching Control Section 9 Adder 10 Register Group 11 Bit Extraction Section 12 RAM

Claims (2)

[Claims] 1. An electronic focus type ultrasonic diagnostic apparatus for selectively controlling a delay line having a plurality of delay amounts according to delay data to delay a received signal from a probe composed of a plurality of piezoelectric elements. Storage means for storing difference data obtained by performing n-level difference of data and control data including an initial value of each floor; delay data for calculating original delay data from the difference data and the control data stored in the storage means. An ultrasonic diagnostic apparatus comprising: a calculation unit; and a delay control unit that controls the selection of the delay line based on the delay data calculated by the delay data calculation unit. 2. A delay line that has a plurality of delay amounts is selectively controlled by delay data that changes with three parameters of a scanning line, a focus point, and a signal channel, and a received signal from a probe composed of a plurality of piezoelectric elements is received. In the delayed electronic focus ultrasonic diagnostic apparatus, difference data obtained by performing n-level difference of the delay data with one of the three parameters as a difference direction, an initial value of each floor, a difference direction, and a bit of the difference data Storage means for storing control data including length, and delay data for calculating original delay data from the difference data stored in the storage means and the control data according to the difference direction stored in the storage means A selection means and a delay line selection control are performed based on the delay data calculated by the delay data calculation means. Ultrasonic diagnostic apparatus having an extending control means.