Pulse delay control program, ultrasonic diagnostic device, and pulse delay control method

Abstract

There has conventionally been the problem that it is necessary to transmit and receive ultrasonic signals the number of times equal to the number of focal depths. A pulse control program according to the present invention executes a pulse output process for outputting, on the basis of a delay setting value for each of vibrators, a driving pulse that has a delay amount corresponding to the delay setting value to each of the vibrators. The delay setting value is calculated on the basis of a delay curve in which the delay amount increases toward the center in the scanning direction of a plurality of vibrators, and the delay amount decreases toward the start point and the end point in the scanning direction. The delay curve is different for each focal depth. The delay setting value includes, for each vibrator group in which the plurality of vibrators are grouped in accordance with the number of target focal depths, a value that is calculated on the basis of the delay curve corresponding to the corresponding focal depth. In the pulse output process, a plurality of driving pulses that each have the delay amount which has been calculated on the basis of the different delay curve are output in one scanning period.

Description

Pulse delay control program, ultrasonic diagnostic device, and pulse delay control method

[0001] The present invention relates to a pulse delay control program, an ultrasonic diagnostic apparatus, and a pulse delay control method, and more particularly to a pulse delay control program, an ultrasonic diagnostic apparatus, and a pulse delay control method for transmitting and receiving ultrasonic signals using a large number of transducers arranged in an array.

[0002] Ultrasound diagnostic devices obtain images of an object to be examined by transmitting and receiving ultrasonic waves using transducers. One of the ultrasound transmission and reception methods used in these ultrasound diagnostic devices is a focus technique, which transmits ultrasonic waves with a spherical wavefront to increase the signal strength at a single focal position. Another focus technique is a multi-focus technique, which sets focal positions at different depths in the object to be examined. Examples of this multi-focus technique are disclosed in Patent Document 1 and Non-Patent Document 1.

[0003] Patent Literature 1 discloses a technique for outputting signals for each focal depth a number of times according to the number of focal points, thereby adjusting the focus to different focal positions in the depth direction. Non-Patent Literature 1 discloses a technique for transmitting scanning signals a number of times according to the number of focal positions (focal depths).

[0004] Japanese Patent Application Laid-Open No. 2004-321647

[0005] Simultaneous Axial Multifocal Imaging using a Single Acoustical Transmission: a Practical Implementation, IEEE Trans Ultrason Ferroelectr Freq Control. 2019 Feb; 66(2): 273-284.

[0006] However, in the techniques disclosed in Patent Document 1 and Non-Patent Document 1, when setting focal positions at different positions in the depth direction, ultrasonic signals must be transmitted and received the same number of times as the number of focal depths, which poses a problem of limiting the frame rate.

[0007] A pulse delay control program according to the present invention is a pulse delay control program executed by the pulse generation circuit in an ultrasonic vibration device having a plurality of transducers arranged in an array and a pulse generation circuit that transmits a drive pulse to each of the plurality of transducers, the program performing a pulse output process that outputs a drive pulse having a delay amount corresponding to a delay set value to each of the transducers based on a delay set value for each of the transducers held in a delay set value holding unit, the delay set value being a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the plurality of transducers and becomes smaller toward the start point and end point of the operation direction, the delay curve having a different curve for each focal depth, and the delay set value includes a value calculated based on the delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, and the pulse output process outputs a plurality of the drive pulses having delay amounts calculated based on the different delay curves in one scanning period.

[0008] An ultrasonic diagnostic apparatus according to the present invention has a plurality of transducers arranged in an array, and a delay setting value holding unit, and a pulse generation circuit that outputs to each of the transducers a drive pulse having a delay amount corresponding to the delay setting value based on the delay setting value for each of the transducers held in the delay setting value holding unit, the delay setting value being a value calculated based on a delay curve in which the delay amount is larger toward the center of the plurality of transducers in a scanning direction and becomes smaller toward the start point and the end point of the scanning direction, the delay curve having a different curve for each focal depth, and the delay setting value includes a value calculated based on the delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, and the pulse generation circuit outputs the plurality of drive pulses having delay amounts calculated based on the different delay curves in one scanning period.

[0009] A pulse delay control method according to the present invention is a pulse delay control method for an ultrasonic vibration device having a plurality of transducers arranged in an array and a pulse generation circuit that transmits drive pulses to the plurality of transducers, the method storing a delay setting value in a delay setting value holding unit implemented in the pulse generation circuit, and outputting a drive pulse having a delay amount corresponding to the delay setting value to each of the transducers, the delay setting value being a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the plurality of transducers and becomes smaller toward the start point and end point of the scanning direction, the delay curve having a different curve for each focal depth, the delay setting value including a value calculated based on the delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, and outputting a plurality of the drive pulses having delay amounts calculated based on the different delay curves in one scanning period.

[0010] According to the pulse delay control program, ultrasonic diagnostic apparatus, and pulse delay control method of the present invention, images with different focal positions in the depth direction can be obtained by transmitting and receiving an ultrasonic signal once.

[0011] Fig. 1 is a block diagram of an ultrasonic diagnostic apparatus according to a first embodiment. Fig. 2 is a diagram explaining an example of delay setting values ​​of drive pulses in the ultrasonic diagnostic apparatus according to the first embodiment. Fig. 3 is a diagram explaining a focus range in the ultrasonic diagnostic apparatus according to the first embodiment. Fig. 4 is a diagram explaining another example of delay setting values ​​of drive pulses in the ultrasonic diagnostic apparatus according to the first embodiment. Fig. 5 is a block diagram of an ultrasonic diagnostic apparatus according to a second embodiment. Fig. 6 is a block diagram of an ultrasonic diagnostic apparatus according to a third embodiment.

[0012] First Embodiment For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. Furthermore, each element shown in the drawings as a functional block performing various processes can be configured in hardware by a CPU (Central Processing Unit), memory, and other circuits, and in software by a program loaded into memory, etc. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware alone, software alone, or a combination thereof, and are not limited to any of these. In addition, identical elements are designated by the same reference numerals in each drawing, and redundant explanations are omitted as necessary.

[0013] Furthermore, the above-described program includes a set of instructions (or software code) that, when loaded into a computer, causes the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0014] Figure 1 shows a block diagram of an ultrasound diagnostic device 1 according to embodiment 1. Of the functional blocks constituting the ultrasound diagnostic device 1, the block diagram shown in Figure 1 shows only the blocks related to the adjustment process of the delay amount of the drive pulses that drive the transducers 210 to 214, but the ultrasound diagnostic device 1 also includes many functional blocks (not shown) related to the transmission and reception of ultrasound signals.

[0015] The example shown in FIG. 1 illustrates a pulse generator 10 and multiple transducers in the ultrasound diagnostic device 1. While FIG. 1 illustrates transducers 210-214, the number of transducers implemented in the ultrasound diagnostic device 1 may vary depending on the product specifications, e.g., 32, 64, 128, or 192. Furthermore, in the ultrasound diagnostic device 1, the multiple transducers are arranged in an array. In the following description, by adjusting the delay amount of the drive pulses applied to multiple transducers arranged in the array in the scanning line direction (the direction in which transducers that simultaneously output ultrasound waves in one scanning process are arranged), ultrasound signals having a spherical wavefront are transmitted, thereby concentrating the energy of the ultrasound signal at a single focal point. In this case, by adjusting the delay amount of the drive pulses set between the transducers, the ultrasound diagnostic device 1 can adjust the focal point to different positions in the depth direction.

[0016] In the ultrasound diagnostic device 1 according to the first embodiment, multiple transducers driven at one scan timing are grouped into multiple transducer groups, and drive pulses having delay amounts corresponding to different focal depths are applied to each transducer group, thereby obtaining images from focal positions at multiple depths in one scan process. To perform such driving, the ultrasound diagnostic device 1 includes a pulse generator 10.

[0017] The pulse generator 10 has a delay setting value holding unit 11 and pulse output units 120 to 124. Based on the delay setting value for each vibrator held in the delay setting value holding unit 11, the pulse generator 10 outputs a drive pulse having a delay amount corresponding to the delay setting value to each vibrator.

[0018] Here, the pulse generator 10 can be realized, for example, by a microcomputer having a calculation unit and capable of controlling pulse signals by a program executed by the calculation unit. In the ultrasound diagnostic apparatus 1, the pulse generator 10 realizes its functions by executing a pulse delay control program.

[0019] The pulse delay control program executes a delay setting value read process and a pulse output process. In the delay read process, the delay setting value for each transducer stored in the delay setting value storage unit 11 is read. In the pulse output process, the program instructs the pulse output units 120 to 124 provided corresponding to each transducer to output a drive pulse having a delay amount according to the delay setting value for each drive period (e.g., scanning timing).

[0020] Here, one of the features of the ultrasound diagnostic device 1 is the delay setting value stored in the delay setting value storage unit 11, so the delay setting value will be described in detail. The delay setting value is a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of multiple transducers and becomes smaller toward the start and end points of the scanning direction. Furthermore, the delay curve is a different curve for each focal depth. The delay setting value includes a value calculated based on a delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping multiple transducers according to the number of target focal depths.

[0021] Therefore, Fig. 2 is a diagram illustrating an example of delay setting values ​​of drive pulses in the ultrasound diagnostic apparatus according to the first embodiment. The example shown in Fig. 2 shows the setting values ​​of the delay amounts included in the delay setting values ​​when the focal position is set to three different depths: deep, medium, and shallow. In the example shown in Fig. 2, the horizontal axis represents the number of the transducers arranged in the scanning direction (e.g., channel number), and the vertical axis represents the magnitude of the delay amount given to each transducer.

[0022] As shown in Figure 2, when setting the focal point in the depth direction, the delay amount to be set for each transducer is calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the multiple transducers and smaller toward the start and end points of the scanning direction. Furthermore, the deeper the focal point, the more gently convex the delay curve becomes. In the example shown in Figure 2, the delay curve corresponding to the deepest focal position is shown as the first delay curve, the delay curve corresponding to the shallowest focal position is shown as the third delay curve, and the delay curve corresponding to a focal position at a depth intermediate between the two aforementioned focal positions is shown as the second delay curve.

[0023] When scanning three focal depths in the ultrasound diagnostic device 1, the 64-channel transducers are grouped into three transducer groups. In the example shown in Fig. 2, 21 channels, 0 to 10 and 54 to 63, are grouped into a first focal group corresponding to the deepest focal position, 21 channels, 11 to 20 and 43 to 53, are grouped into a second focal group corresponding to an intermediate focal position, and 22 channels, 21 to 42, are grouped into a third focal group corresponding to the shallowest focal position.

[0024] In the ultrasound diagnostic device 1, the delay setting value for the transducers belonging to the first focus group includes a delay amount calculated based on the first focus curve, the delay setting value for the transducers belonging to the second focus group includes a delay amount calculated based on the second focus curve, and the delay setting value for the transducers belonging to the third focus group includes a delay amount calculated based on the third focus curve.

[0025] Next, we will explain the focus range of the ultrasound diagnostic device 1 when drive pulses are generated based on delay setting values ​​generated according to the above-mentioned rules. FIG. 3 is a diagram illustrating the focus range of the ultrasound diagnostic device 1 according to the first embodiment. The example shown in FIG. 3 shows, by using shading, the energy intensity of ultrasound waves in an object under examination when a single scan is performed by the ultrasound diagnostic device 1. In the example shown in FIG. 3, the lighter the color, the higher the energy intensity of the ultrasound signal. As shown in FIG. 3, the ultrasound diagnostic device 1 according to the first embodiment sets focal points at three different depths, and it can be seen that the energy of the ultrasound signal increases in the depth direction along the line where these three focal points are aligned. In other words, the ultrasound diagnostic device 1 according to the first embodiment can obtain images from different focal positions in the depth direction with a single scan.

[0026] As described above, the ultrasound diagnostic device 1 according to the first embodiment groups multiple transducers that transmit ultrasound signals at one scan timing into multiple transducer groups, and sets delay amounts corresponding to different focal depths for each transducer group. This makes it possible for the ultrasound diagnostic device 1 according to the first embodiment to obtain images from multiple focal positions in a single scan process. In other words, with the ultrasound diagnostic device 1 according to the first embodiment, even if the number of focal depths at which images are obtained is increased, there is no need to increase the number of scans required to obtain the images, and therefore it is possible to maintain the frame rate regardless of the number of focal depths at which images are obtained.

[0027] Furthermore, in the ultrasound diagnostic device 1 according to the first embodiment, the grouping of transducers in the delay setting value can be set by the value of the delay amount for each transducer included in the delay setting value. Therefore, if the ultrasound diagnostic device 1 has a function that allows the focal depth to be changed in the depth direction, no further hardware changes are required.

[0028] An example of setting the delay setting value of the drive pulse is shown in Fig. 2. The method of setting the delay setting value is not limited to the example shown in Fig. 2. Therefore, Fig. 4 is a diagram for explaining another example of the delay setting value of the drive pulse in the ultrasonic diagnostic apparatus according to the first embodiment.

[0029] In the example shown in Fig. 4, the delay amount to be given to each transducer is determined along the first to third delay curves, which are the same as the example shown in Fig. 2. In the example shown in Fig. 4, a group of transducers with channel number 3n (n is an integer, the same applies below) is assigned to the first focal group, a group of transducers with channel number 3n+1 is assigned to the second focal group, and a group of transducers with channel number 3n+2 is assigned to the third focal group. In this way, various forms of transducer grouping methods are possible.

[0030] In the second embodiment, an ultrasound diagnostic device 2 will be described, which is another embodiment of the ultrasound diagnostic device 1 according to the first embodiment. In the description of the second embodiment, the components described in the first embodiment will be assigned the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

[0031] FIG. 5 shows a block diagram of an ultrasonic diagnostic apparatus 2 according to a second embodiment. As shown in FIG. 2, the ultrasonic diagnostic apparatus 2 according to the second embodiment includes a pulse generator 10a instead of the pulse generator 10. The pulse generator 10a includes pulse output units 120-124, a delay adjustment unit 30, and a delay control circuit 40. The delay adjustment unit 30 includes delay circuits 310-314. The delay control circuit 40 includes a delay setting value holding unit 41. In the pulse generator 10a, the pulse output units 120-124 output multiple drive pulses with a relative delay amount set to zero. In the pulse generator 10a, the delay control circuit 40 sets the delay amount to be added to the drive pulse by the delay circuits 310-314 based on the delay setting value stored in the delay setting value holding unit 41. In other words, in the pulse generator 10a, the delay circuits 310-314 add a delay amount corresponding to the delay setting value to each of the multiple drive pulses output by the pulse output units 120-124. That is, in the pulse output process in the pulse generator 10a, the magnitude of the delay amount set in the delay circuits 310 to 314 is set for each drive pulse.

[0032] As explained above, the ultrasonic diagnostic apparatus 2 according to the second embodiment adds a delay amount to the drive pulse by the delay circuit. As described above, there are various methods for adding a delay amount to the drive pulse, but by setting a delay amount for each transducer based on a delay setting value, it becomes possible to set a delay amount according to the focal depth for each delay element group.

[0033] In the third embodiment, an ultrasonic diagnostic device 3 will be described, which is another embodiment of the ultrasonic diagnostic device 1 according to the first embodiment. In the description of the third embodiment, the components described in the first embodiment will be assigned the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

[0034] Fig. 6 shows a block diagram of an ultrasonic diagnostic apparatus 3 according to the third embodiment. As shown in Fig. 6, the ultrasonic diagnostic apparatus 3 according to the third embodiment is configured by adding a delay setting value generating unit 50 to the ultrasonic diagnostic apparatus 1. The delay setting value generating unit 50 is, for example, a computing device capable of executing a program such as a computer.

[0035] The delay setting value generating unit 50 receives input of a plurality of depth setting values ​​indicating focal depths, and determines a plurality of transducer groups from a plurality of transducers according to the number of depth setting values. The delay setting value generating unit 50 then generates a delay setting value for each transducer group based on a delay curve according to the depth setting value associated with each transducer group. The delay setting value generating unit 50 then stores the generated delay setting values ​​in the delay setting value holding unit 11.

[0036] In this way, by providing the delay setting value generating unit 50, it becomes possible to flexibly change the number and depths to be diagnosed depending on the usage situation.

[0037] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention.

[0038] This application claims priority based on Japanese Patent Application No. 2024-86287, filed May 28, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0039] 1 to 3: Ultrasonic diagnostic device 10, 10a: Pulse generator 11, 41: Delay setting value holding unit 120 to 124: Pulse output unit 210 to 214: Transducer 30: Delay adjustment unit 310 to 314: Delay circuit 40: Delay control circuit

Claims

1. In an ultrasonic vibration device having a plurality of transducers arranged in an array and a pulse generation circuit that transmits a drive pulse to each of the plurality of transducers, a pulse delay control program executed by the pulse generation circuit, which performs a pulse output process that outputs a drive pulse having a delay amount corresponding to a delay setting value to each of the transducers based on a delay setting value for each of the transducers stored in a delay setting value storage unit, the delay setting value being a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the plurality of transducers and becomes smaller toward the start point and end point of the scanning direction, the delay curve having a different curve for each focal depth, the delay setting value including a value calculated based on the delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, and the pulse output process outputs a plurality of the drive pulses having delay amounts calculated based on the different delay curves in one scanning period.

2. The pulse generation circuit has a pulse output unit that outputs a plurality of drive pulses with a relative delay amount set to zero, and a delay circuit that adds a delay amount corresponding to the delay setting value to each of the plurality of drive pulses output by the pulse output unit, and the pulse output process sets the magnitude of the delay amount to be set in the delay circuit for each of the drive pulses.

3. A pulse delay control program as described in claim 1, which performs a delay setting value generation process in which a plurality of depth setting values ​​indicating the focal depth are input, a plurality of transducer groups are determined from the plurality of transducers according to the number of the depth setting values, the delay setting value is generated for each transducer group based on the delay curve according to the depth setting value associated with each of the transducer groups, and the delay setting value is stored in the delay setting value storage unit.

4. An ultrasonic diagnostic device comprising: a plurality of transducers arranged in an array; and a pulse generation circuit having a delay setting value storage unit and outputting to each of the transducers a drive pulse having a delay amount corresponding to the delay setting value based on the delay setting value for each of the transducers stored in the delay setting value storage unit, wherein the delay setting value is a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the plurality of transducers and becomes smaller toward the start point and end point of the scanning direction, and the delay curve has a different curve for each focal depth, and the delay setting value includes a value calculated based on the delay curve corresponding to the corresponding focal depth for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, and the pulse generation circuit outputs the plurality of drive pulses having delay amounts calculated based on the different delay curves in one scanning period.

5. A pulse delay control method for an ultrasonic vibration device having a plurality of transducers arranged in an array and a pulse generation circuit that transmits drive pulses to the plurality of transducers, the method comprising: storing a delay setting value in a delay setting value storage unit implemented in the pulse generation circuit; outputting a drive pulse having a delay amount corresponding to the delay setting value to each of the transducers; the delay setting value being a value calculated based on a delay curve in which the delay amount is larger toward the center of the scanning direction of the plurality of transducers and becomes smaller toward the start point and end point of the scanning direction, the delay curve having a different curve for each focal depth; the delay setting value including, for each transducer group obtained by grouping the plurality of transducers according to the number of target focal depths, a value calculated based on the delay curve corresponding to the corresponding focal depth; and outputting a plurality of the drive pulses having delay amounts calculated based on different delay curves in one scanning period.

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