Ultrasound therapy device

Abstract

To facilitate confirmation that an affected part is irradiated with a therapeutic ultrasonic wave in the therapy using an ultrasonic therapeutic device.SOLUTION: In therapeutic ultrasonic wave transmission processing, an ultrasonic vibrator 28 is caused to transmit a therapeutic ultrasonic wave 38. In irradiation region image generation processing, a plurality of imaging pulses 46 are transmitted to an ultrasonic probe 16 at different timings and by different phases as a plurality of ultrasonic waves after the therapeutic ultrasonic wave 38 is transmitted, and reflected by a biological tissue, and a plurality of reception signals based on a plurality of the reflected ultrasonic waves received by the ultrasonic probe 16 are added and totalled so that irradiation region data based on a non-linear component of each reception signal is generated. In assistance ultrasonic wave transmission processing, the ultrasonic vibrator 28 is caused to transmit an interleave pulse 50 at a timing between two timings at which two imaging pulses adjacent to each other on a temporal axis of the plurality of imaging pulses 46 are transmitted.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic therapy device, and more particularly to a device including an ultrasonic transducer for therapy and an ultrasonic probe for generating images. [Background technology]

[0002] Treatment devices using high intensity focused ultrasound (HIFU) therapy are widely used. These ultrasound treatment devices are called HIFU irradiation devices or HIFU irradiation systems, and irradiate the treatment area with ultrasound to cause tissue necrosis.

[0003] In general, a HIFU irradiation device is equipped with a plurality of ultrasonic transducers arranged on a bowl-shaped surface. The plurality of ultrasonic transducers are arranged so that ultrasonic waves emitted from each of them are irradiated to one point to form a focus. During treatment, the position of the focus is adjusted to the treatment area and ultrasonic waves are irradiated. To confirm the irradiation position, an ultrasonic imaging device that displays the focus on an ultrasonic image is used.

[0004] The following Patent Document 1 describes an ultrasonic treatment device that observes the position of a focal point using an ultrasonic imaging device that displays B-mode images (tomographic images). In this device, a therapeutic ultrasonic transducer emits ultrasonic waves at a low level that do not affect tissue, and an ultrasonic imaging probe transmits and receives ultrasonic waves to display a tomographic image. Since the acoustic properties of the subject's tissue change in response to changes in the tissue's temperature, the position of the focal point is indicated in the tomographic image by varying brightness.

[0005] Patent Document 2 describes, as a technology related to the present invention, a technology for visualizing echo components scattered by a microbubble contrast agent by clearly distinguishing them from components caused by nonlinear propagation of a transmission pulse. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-71069 [Patent Document 2] International Publication No. 2005 / 087109 [Patent Document 3] Japanese Patent Application Publication No. 2023-79320 Summary of the Invention [Problem to be solved by the invention]

[0007] Generally, when a powerful therapeutic ultrasound wave is irradiated to an affected area of ​​biological tissue, bubbles (cavities) are generated at the irradiated area due to cavitation. In a conventional treatment using a HIFU irradiation device, methods for confirming that the therapeutic ultrasound wave has been irradiated to the affected area include observing the positions of bubbles generated by cavitation and observing the patient's biological tissue. As described in Patent Document 3, for example, the observation of the positions of bubbles is performed by harmonic imaging, in which ultrasound waves are transmitted from an ultrasound probe toward the affected area and harmonics generated around the bubbles are received by the ultrasound probe. Furthermore, the observation of the patient's biological tissue is performed by acquiring B-mode images by transmitting and receiving ultrasound waves by the ultrasound probe.

[0008] In treatment using a HIFU irradiation device, for example, when the affected area is small, the therapeutic ultrasound is irradiated in a small area, and therefore, due to the small amount of bubbles generated, it may be difficult to confirm that the therapeutic ultrasound has been irradiated to the affected area.

[0009] An object of the present invention is to make it easier to confirm that therapeutic ultrasound has been irradiated onto an affected area during treatment using an ultrasonic treatment device. [Means for solving the problem]

[0010] The present invention comprises a therapeutic ultrasound transducer, an ultrasound probe, and a control unit that controls the ultrasound transducer and the ultrasound probe, wherein the control unit executes a therapeutic ultrasound transmission process that causes the ultrasound transducer to transmit therapeutic ultrasound, an auxiliary ultrasound transmission process that causes the ultrasound transducer to transmit auxiliary ultrasound, and an irradiation area image generation process that, after the therapeutic ultrasound has been transmitted, causes the ultrasound probe to transmit a plurality of ultrasound waves at different timings and different phases, and synthesizes a plurality of received signals based on a plurality of reflected ultrasound waves that are reflected by biological tissue and received by the ultrasound probe, thereby generating irradiation area data that indicates an irradiation area irradiated with the therapeutic ultrasound. The auxiliary ultrasound transmission process is characterized in that it includes a process of causing the ultrasound transducer to transmit the auxiliary ultrasound at a timing between two timings at which two adjacent ultrasound waves on the time axis are transmitted out of a plurality of ultrasound waves to be synthesized, which are the ultrasound waves that are the source of the plurality of received signals synthesized in the irradiation area image generation process, thereby increasing the contrast ratio of the irradiation area image indicated by the irradiation area data. Preferably, the auxiliary ultrasonic wave is composed of a plurality of ultrasonic pulses successively arranged on a time axis, and the contrast ratio is determined according to the number of the ultrasonic pulses constituting the auxiliary ultrasonic wave. Preferably, the auxiliary ultrasonic wave is composed of ultrasonic pulses, and the contrast ratio is determined according to the amplitude of the ultrasonic pulses.

[0011] Preferably, the auxiliary ultrasonic transmission process includes: The synthetic target The method includes a process of causing the ultrasonic transducer to transmit the auxiliary ultrasonic wave at a timing earlier than the intermediate timing between two timings at which two of the plurality of ultrasonic waves adjacent on the time axis are transmitted.

[0012] Preferably, the auxiliary ultrasound transmission process includes, after the therapeutic ultrasound is transmitted, The synthetic target The method includes a process of causing the ultrasonic transducer to transmit the auxiliary ultrasonic wave at an earlier timing than the plurality of ultrasonic waves.

[0013] Preferably, the plurality of received signals are sequentially transmitted from the ultrasonic probe with a phase difference of 360° / M. The synthetic target M Street Super The signals are based on a plurality of reflected ultrasonic waves received by the ultrasonic probe based on the acoustic waves.

[0014] Preferably, the control unit executes a B-mode image generation process for generating B-mode image data of the biological tissue using any one of the plurality of received signals.

[0015] Preferably, the control unit causes a display device to display an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data.

[0016] Preferably, the control unit causes the display device to display an irradiation region image based on the irradiation region data and a B-mode image based on the B-mode image data in a superimposed manner. Preferably, the therapeutic ultrasound transmission process is a process of repeatedly transmitting the therapeutic ultrasound from the ultrasound transducer, and the irradiation area image generation process includes a process of transmitting the multiple ultrasound waves to be synthesized to the ultrasound probe at different timings and different phases during irradiation pause periods between the repeated transmission of the therapeutic ultrasound. [Effects of the Invention]

[0017] According to the present invention, it is possible to easily confirm that the therapeutic ultrasound has been applied to the affected area. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing the configuration of a HIFU irradiation device. [Figure 2] FIG. 1 is a diagram conceptually showing the transmission timing of therapeutic ultrasound and HIFU / imaging hybrid waves. [Figure 3] FIG. 10 is a diagram illustrating the configuration of an interleaved pulse. [Figure 4] 10A and 10B are diagrams showing a B-mode image and an irradiation area image as experimental results. [Figure 5] FIG. 10 is a diagram showing experimental results of the contrast ratio of an illumination area image. [Figure 6] FIG. 10 is a diagram showing experimental results of the contrast ratio of an illumination area image. [Figure 7] FIG. 1 is a diagram conceptually showing the transmission timing of a therapeutic ultrasound pulse not including a heating burst and a HIFU / imaging hybrid wave. [Figure 8] FIG. 10 shows experimental results of contrast ratio when therapeutic ultrasound pulses without heating bursts are used. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to the drawings. The same components shown in multiple drawings are assigned the same reference numerals to simplify the description. Fig. 1 shows the configuration of a HIFU irradiation device 100 (ultrasonic treatment device) according to an embodiment of the present invention. The HIFU irradiation device 100 includes a HIFU transducer unit 10, a HIFU drive circuit 14, an ultrasonic probe 16, a transmission / reception circuit 18, an imaging calculation unit 20, a controller 22, a display device 24, and a drive device 26.

[0020] The controller 22 may be a personal computer, a tablet computer, etc. An operation device (not shown) for a user to operate the HIFU irradiation device 100 is connected to the controller 22. The operation device may include a mouse, a touch panel integrated with the display device 24, a switch, a keyboard, etc.

[0021] The HIFU transducer unit 10 includes a transducer housing 12 having a concave surface 4 with an opening facing downward, and a plurality of ultrasonic transducers 28 arranged along the concave surface 4 of the transducer housing 12 and fixed to the transducer housing 12. The HIFU transducer unit 10 does not necessarily have to have an actual concave surface 4. In this case, the plurality of ultrasonic transducers 28 may be fixed to the transducer housing 12 so as to be arranged along a virtual concave surface 4.

[0022] The concave surface 4 of the transducer housing 12 may have a shape similar to the side surface of a pyramid. Here, a pyramid refers to a three-dimensional shape formed by a collection of lines extending from a point in space to a bottom surface. The concave surface 4 of the transducer housing 12 may also have a dome-like bulge on the upper side. Each ultrasonic transducer 28 is fixed to the transducer housing 12 so that when each ultrasonic transducer 28 emits ultrasound, the intensity of the ultrasound is intensified at a focal point F below the transducer housing 12.

[0023] The HIFU driver circuit 14 generates ultrasonic waves from each ultrasonic transducer 28 included in the HIFU transducer unit 10 in accordance with the control of the controller 22. Furthermore, the HIFU driver circuit 14 adjusts the intensity of the ultrasonic waves generated by each ultrasonic transducer 28 in accordance with the control of the controller 22.

[0024] The ultrasonic probe 16 is fixed to the transducer housing 12 so that ultrasonic waves are transmitted and received at a position below the transducer housing 12 and above the focal point F. In this embodiment, the ultrasonic probe 16 passes through the top of the transducer housing 12 in the vertical direction, and the transmitter / receiver unit 2 that transmits and receives ultrasonic waves faces downward.

[0025] A general ultrasonic imaging device may be used for the transmission / reception circuit 18 and the imaging calculation unit 20. The imaging calculation unit 20 may be configured by a processor that executes a program to control the transmission / reception circuit 18. The transmission / reception circuit 18 performs the following processing under the control of the imaging calculation unit 20. That is, the transmission / reception circuit 18 causes the ultrasonic probe 16 to transmit ultrasonic waves and scan with a beam of the transmitted ultrasonic waves (ultrasound beam). The ultrasonic beam scans an observation plane including a central axis 3 extending vertically from the vertex of the transducer housing 12. The transmission / reception circuit 18 causes the ultrasonic probe 16 to receive reflected ultrasonic waves arriving from the direction in which the ultrasonic beam is directed, and acquires, from the ultrasonic probe 16, received signals based on the reflected ultrasonic waves received from each direction in which the ultrasonic beam is directed. The transmission / reception circuit 18 outputs each received signal to the imaging calculation unit 20.

[0026] The imaging calculation unit 20 generates ultrasound data based on each reception signal output from the transmission / reception circuit 18. The ultrasound data may be irradiation area data indicating an area in which a nonlinear component occurs in the patient's biological tissue, or B-mode image data indicating a B-mode image (tomographic image) acquired from the patient's biological tissue.

[0027] The driving device 26 moves the HIFU transducer unit 10 and the ultrasonic probe 16 and adjusts their positions in accordance with the control of the controller 22. The driving device 26 may also rotate the ultrasonic probe 16 around the central axis 3 in accordance with the control of the controller 22, and rotate the observation surface of the ultrasonic probe 16 around the central axis 3.

[0028] Before therapeutic ultrasound is irradiated onto a patient from the HIFU transducer unit 10, the following positioning process is executed. The HIFU driver circuit 14 causes each ultrasonic transducer 28 to transmit ultrasound waves with lower intensity than that used during treatment. The driver 26 sets the rotation angle position of the ultrasonic probe 16 so that the ultrasonic probe 16 scans the ultrasonic beam on the observation plane at a predetermined rotation angle position.

[0029] The imaging calculation unit 20 causes the ultrasonic probe 16 to scan the ultrasonic beam on the observation surface, acquires B-mode image data as ultrasonic data, and outputs it to the controller 22. The controller 22 displays the B-mode image on the display device 24. The user as a practitioner refers to the B-mode image displayed on the display device 24 and confirms the difference between the position (focus) where the ultrasonic waves transmitted from the HIFU transducer unit 10 are intensified and the position of the affected area.

[0030] If the difference between the position of the focal point F and the position of the affected area is not within an allowable range, the user changes the position or posture of the ultrasonic probe 16 and the HIFU transducer unit 10. After the user confirms that the position of the focal point F matches the position of the affected area or that the difference between the position of the focal point F and the position of the affected area is within an allowable range, the user operates the controller 22 for treatment. The controller 22 controls the HIFU driver circuit 14 in accordance with the user's operation. The HIFU driver circuit 14 transmits therapeutic ultrasonic waves having an intensity required for treatment to each ultrasonic transducer 28 in accordance with the control of the controller 22. As a result, the living tissue is cauterized at the focal point F, and treatment is performed.

[0031] The HIFU irradiation device 100 performs irradiation area display processing to display an image (irradiation area image) showing the irradiation area irradiated with the therapeutic ultrasound on the display device 24 while irradiating the patient with therapeutic ultrasound. The irradiation area image is an image indicated by irradiation area data. The irradiation area image may be displayed alongside the B-mode image, or may be displayed superimposed on the B-mode image. Here, the processing to display two images superimposed may be processing to generate new image data by synthesizing image data so that one image can be seen through the other, and to display an image based on the new image data.

[0032] FIG. 2 conceptually shows the transmission timing of the therapeutic ultrasound 38 transmitted from the HIFU transducer unit 10 and the HIFU / imaging hybrid wave 36 transmitted from the HIFU transducer unit 10 and the ultrasound probe 16 when the irradiation region display process is executed.

[0033] The therapeutic ultrasound 38 is composed of a therapeutic ultrasound pulse 44 including a trigger pulse 40 and a heating burst 42 following the trigger pulse 40. The therapeutic ultrasound pulse 44 is repeatedly transmitted from the HIFU transducer unit 10 over time. An irradiation pause 48 is provided between adjacent therapeutic ultrasound pulses 44 on the time axis, and during the irradiation pause 48, transmission of the therapeutic ultrasound 38 is stopped. The amplitude of the heating burst 42 may be smaller than the amplitude of the trigger pulse 40. The time length T1 of the trigger pulse 40 may be shorter than the time length T3 of the heating burst 42.

[0034] When the therapeutic ultrasonic pulse 44 is transmitted from the HIFU transducer unit 10, the biological tissue is cauterized at the focal point F. As the trigger pulse 40 is irradiated onto the biological tissue, bubbles are generated from the biological tissue, and the state in which the bubbles are generated by the irradiation of the heating burst 42 is maintained.

[0035] During the irradiation pause period 48, the HIFU / imaging hybrid wave 36 is transmitted from the HIFU transducer unit 10 and the ultrasonic probe 16. The HIFU / imaging hybrid wave 36 includes a first imaging pulse 46-1, a second imaging pulse 46-2, and a third imaging pulse 46-3 transmitted from the ultrasonic probe 16 at a time interval of time τ0. The second imaging pulse 46-2 is delayed in phase with respect to the first imaging pulse 46-1 by 120°. The third imaging pulse 46-3 is delayed in phase with respect to the second imaging pulse 46-2 by 120°. In the following description, any one of the first imaging pulse 46-1 to the third imaging pulse 46-3 that is not specified may be referred to as an imaging pulse 46.

[0036] The HIFU / imaging hybrid wave 36 further includes a first interleaved pulse 50-1 and a second interleaved pulse 50-2 transmitted from the HIFU transducer unit 10. In the following description, the first interleaved pulse 50-1 and the second interleaved pulse 50-2 that are not specified may be referred to as an interleaved pulse 50.

[0037] The first interleaved pulse 50-1 is transmitted at a timing between the two timings at which the first imaging pulse 46-1 and the second imaging pulse 46-2 are transmitted, and the second interleaved pulse 50-2 is transmitted at a timing between the two timings at which the second imaging pulse 46-2 and the third imaging pulse 46-3 are transmitted.

[0038] Specifically, the first interleaved pulse 50-1 is transmitted when a time τ1 has elapsed since the first imaging pulse 46-1 was transmitted, and the second interleaved pulse 50-1 is transmitted when a time τ2 has elapsed since the first interleaved pulse 50-1 was transmitted. Imaging Pulse 46In addition, the second interleaved pulse 50-2 is transmitted when a time τ1 has elapsed since the second imaging pulse 46-2 was transmitted, and the third interleaved pulse 50-2 is transmitted when a time τ2 has elapsed since the second interleaved pulse 50-2 was transmitted. Imaging Pulse 46 -3 is sent.

[0039] Time τ1 is shorter than time τ2. That is, the first interleaved pulse 50-1 is transmitted at a timing earlier than the intermediate timing between the timing at which the first imaging pulse 46-1 is transmitted and the timing at which the second imaging pulse 46-2 is transmitted. Here, the intermediate timing refers to the timing corresponding to the midpoint between two points on the time axis. Also, the second interleaved pulse 50-2 is transmitted at a timing earlier than the intermediate timing between the timing at which the second imaging pulse 46-2 is transmitted and the timing at which the third imaging pulse 46-3 is transmitted.

[0040] The times τ1 and τ2 may be determined so that the HIFU / imaging hybrid wave 36 acts on the biological tissue as follows: The first interleaved pulse 50-1 reaches the affected area after the reflected ultrasonic waves generated based on the first imaging pulse 46-1 are received by the ultrasonic probe 16, and vibrates bubbles generated in the affected area. The second imaging pulse 46-2 reaches the affected area after the multiple reflected waves generated in the biological tissue by the first interleaved pulse 50-1 have sufficiently attenuated. The second interleaved pulse 50-2 reaches the affected area after the reflected ultrasonic waves generated based on the second imaging pulse 46-2 are received by the ultrasonic probe 16, and vibrates bubbles generated in the affected area. The third imaging pulse 46-3 reaches the affected area after the multiple reflected waves generated in the biological tissue by the second interleaved pulse 50-2 have sufficiently attenuated.

[0041] Each interleaved pulse 50 may be composed of one ultrasonic pulse, or may be composed of multiple ultrasonic pulses connected on the time axis. The lower right of Fig. 3 shows the timing of each ultrasonic pulse when the interleaved pulse 50 is composed of, from top to bottom, one ultrasonic pulse, three ultrasonic pulses, and ten ultrasonic pulses.

[0042] In the example shown in FIG. 2, the time between the transmission of the first imaging pulse 46-1 and the transmission of the first interleaved pulse 50-1 is equal to the time between the transmission of the second imaging pulse 46-2 and the transmission of the second interleaved pulse 50-2, but these times may be different.

[0043] Each imaging pulse 46 is reflected within the biological tissue. When the imaging pulse 46 is reflected around the bubbles generated by the therapeutic ultrasonic pulse 44, nonlinear components such as harmonics are generated. Therefore, the reflected ultrasound waves from the biological tissue contain nonlinear components caused by the bubbles in addition to the fundamental wave. Generally, the greater the number of bubbles generated, the greater the intensity of the generated nonlinear components.

[0044] 1, a description will be given of the process in which the HIFU irradiation device 100 receives reflected ultrasonic waves corresponding to each imaging pulse 46. The ultrasonic probe 16 receives the first reflected ultrasonic waves to the third reflected ultrasonic waves corresponding to the first imaging pulse 46-1 to the third imaging pulse 46-3, and outputs the first received signal to the transmitting and receiving circuit 18, respectively. The transmitting and receiving circuit 18 amplifies the first received signal to the third received signal, and outputs the signals to the imaging calculation unit 20.

[0045] The imaging calculation unit 20 adds up the first to third received signals and generates a nonlinear signal by adding up the nonlinear components contained in each of the first to third received signals. Due to the phase relationship between the first imaging pulse 46-1 to the third imaging pulse 46-3, the fundamental wave component is suppressed in the signal by adding up the first to third received signals. The imaging calculation unit 20 generates nonlinear signals for the first to third reflected ultrasonic waves arriving from each direction toward which the ultrasonic beam is directed, and generates irradiation area data based on the nonlinear signals generated for each direction. The irradiation area data is image data showing an irradiation area image that indicates an area where bubbles have occurred within the area scanned by the ultrasonic beam.

[0046] Furthermore, the imaging calculation unit 20 generates a B-mode image based on one of the first to third reflected ultrasonic waves. For example, the imaging calculation unit 20 generates pixel data of a B-mode image in each direction based on the second reflected ultrasonic wave arriving from each direction toward which the ultrasonic beam is directed, and generates B-mode image data based on the pixel data acquired for each direction. Note that the reflected ultrasonic wave that is the source of the B-mode image data may be the first reflected ultrasonic wave or the third reflected ultrasonic wave.

[0047] The imaging calculation unit 20 outputs the irradiation area data and the B-mode image data to the controller 22. The controller 22 causes the display device 24 to display an image in which the irradiation area image is superimposed on the B-mode image (B-mode irradiation area image) based on the irradiation area data and the B-mode image data.

[0048] The imaging calculation unit 20 outputs the irradiation region data and B-mode image data at frame time intervals (the reciprocal of the frame rate) to the controller 22. The controller 22 causes the display device 24 to display the B-mode irradiation region images sequentially over time.

[0049] The controller 22 may display the irradiation area image and the B-mode image separately without superimposing them. For example, the controller 22 may display the irradiation area image and the B-mode image side by side on the display device 24 so that they can be compared.

[0050] FIG. 4 shows the experimental results. The upper left and lower left of FIG. 4 show a B-mode image and an irradiation area image, respectively, when conventional basic imaging ultrasound was used. The basic imaging ultrasound is obtained by removing the first interleaved pulse 50-1 and the second interleaved pulse 50-2 from the HIFU / imaging hybrid wave 36. In the transmission of the basic imaging ultrasound, the second imaging pulse 46-2 is transmitted when a time τ0 has elapsed since the first imaging pulse 46-1 was transmitted without the first interleaved pulse 50-1 being transmitted. Furthermore, the third imaging pulse 46-3 is transmitted when a time τ0 has elapsed since the second imaging pulse 46-2 was transmitted without the second interleaved pulse 50-2 being transmitted. In each drawing, the horizontal axis represents width [mm], and the vertical axis represents depth [mm]. An image of a bubble 60 appears in each image.

[0051] The upper right and lower right of Figure 4 show a B-mode image and an image of the irradiation area, respectively, for this embodiment in which the HIFU / imaging hybrid wave 36 was used. The interleaved pulse 50 used was composed of three ultrasound pulses connected on the time axis. In each figure, the horizontal axis represents width [mm], and the vertical axis represents depth [mm]. Images of bubbles 60 appear in each image. As is clear from the lower left and lower right figures, bubbles 60 generated in the irradiation area are more clearly visible when the HIFU / imaging hybrid wave 36 is used than when the basic imaging ultrasound is used.

[0052] FIG. 5 shows the bubble-to-tissue contrast ratio (hereinafter referred to as contrast ratio) of the irradiation area image. The contrast ratio when using the HIFU / imaging hybrid wave 36 is approximately 9 dB higher than the contrast ratio when using basic imaging ultrasound without the interleaved pulse 50. The experimental conditions are as follows: The period T0 from the transmission of the previous trigger pulse 40 to the transmission of the next trigger pulse 40 is 50 msec. The time length T1 of the trigger pulse 40 is 0.1 msec. The time T2 from the end of transmission of the trigger pulse 40 to the start of transmission of the heating burst 42 is 3 msec. The time length T3 of the heating burst 42 is 43.9 msec. ec The time T4 from the end of the transmission of the heating burst 42 to the start of the transmission of the HIFU / imaging hybrid wave 36 is 1 ms. ec The time τ1 in the HIFU / imaging hybrid wave 36 is 120 μsec, and the time τ2 is 280 μsec. The irradiation pause period T5 is 3 msec.

[0053] FIG. 6 shows contrast ratios for different configurations of the HIFU / imaging hybrid wave 36. The first to third rows from the left show contrast ratios for cases where the interleaved pulse 50 is composed of ten high-intensity ultrasonic pulses, three high-intensity ultrasonic pulses, and one high-intensity pulse, respectively. The fourth to sixth rows from the left show contrast ratios for cases where the interleaved pulse 50 is composed of ten medium-intensity ultrasonic pulses, three medium-intensity ultrasonic pulses, and one medium-intensity pulse, respectively. Here, the high-intensity ultrasonic pulse refers to an ultrasonic pulse with the same amplitude as the trigger pulse 40, and the medium-intensity ultrasonic pulse refers to an ultrasonic pulse with the same amplitude as the heating burst 42. The rightmost row shows contrast ratios when using basic imaging ultrasound.

[0054] As shown in FIG. 6, the greater the amplitude of the interleaved pulse 50, the greater the contrast ratio tends to be, and the greater the number of ultrasonic pulses that make up the interleaved pulse 50, the greater the contrast ratio tends to be.

[0055] As described above, in the HIFU irradiation device 100 according to this embodiment, by transmitting the HIFU / imaging hybrid wave 36, the first interleaved pulse 50-1 is transmitted during the period from when the first imaging pulse 46-1 is transmitted until when the second imaging pulse 46-2 is transmitted. By transmitting the first interleaved pulse 50-1 to the affected area, bubbles generated in the affected area are vibrated by the therapeutic ultrasound 38, and the nonlinear component generated by the second imaging pulse 46-2 increases. Furthermore, the second interleaved pulse 50-2 is transmitted during the period from when the second imaging pulse 46-2 is transmitted until when the third imaging pulse 46-3 is transmitted. By transmitting the second interleaved pulse 50-2 to the affected area, bubbles generated in the affected area are vibrated by the therapeutic ultrasound 38, and the nonlinear component generated by the third imaging pulse 46-3 increases. This increases the magnitude of the nonlinear signal, emphasizing the bubbles shown in the irradiation area image, making it easier for the user to confirm that the therapeutic ultrasound 38 has been irradiated to the affected area.

[0056] In the above description, the interleaved pulse 50 is transmitted between the timings of two adjacent imaging pulses 46 on the time axis. The interleaved pulse 50 may be transmitted after the therapeutic ultrasound pulse 44 is transmitted and before the first imaging pulse 46 is transmitted.

[0057] In the above description, the imaging pulses 46 for generating ultrasound data are transmitted three times. The imaging pulses 46 may be transmitted two times or four or more times. When the imaging ultrasound waves are transmitted M times (M is an integer equal to or greater than 2), the phase difference between adjacent imaging pulses 46 on the time axis is set to 360° / M. Alternatively, the phase of each imaging ultrasound wave may be set so that a phase of θ+i·360° / M (θ is an arbitrary phase, and i is an integer between 0 and M−1) is assigned to M imaging pulses 46, regardless of the transmission order.

[0058] The imaging calculation unit 20 adds up the first through Mth received signals and generates a nonlinear signal by adding up the nonlinear components contained in each of the first through Mth received signals. The imaging calculation unit 20 also generates a B-mode image based on one of the first through Mth reflected ultrasonic waves.

[0059] In the above, an embodiment has been shown in which a pulse including a trigger pulse 40 and a heating burst 42 following the trigger pulse 40 is used as the therapeutic ultrasound pulse 44. A pulse including only the trigger pulse 40, without the heating burst 42, may also be used as the therapeutic ultrasound pulse 44.

[0060] 7 conceptually shows the timing of transmission of the therapeutic ultrasound pulse 44 not including the heating burst 42 and the HIFU / imaging hybrid wave 36. When an irradiation pause period T5 has elapsed since the end of transmission of the previous trigger pulse 40, the next trigger pulse 40 is transmitted. During the irradiation pause period T5, the HIFU / imaging hybrid wave 36 is transmitted when a time T4 has elapsed since the end of transmission of the trigger pulse 40.

[0061] 8 shows the contrast ratio when a therapeutic ultrasound pulse 44 that does not include a heating burst 42 is used. The left side shows the contrast ratio when a HIFU / imaging hybrid wave 36 in which an interleaved pulse 50 is composed of three high-intensity ultrasound pulses is used. The right side shows the contrast ratio when a basic imaging ultrasound is used. The contrast ratio when a HIFU / imaging hybrid wave 36 is used is approximately 6 dB higher than the contrast ratio when a basic imaging ultrasound is used. Even when the therapeutic ultrasound pulse 44 does not include a heating burst 42, the contrast ratio tends to be higher when a HIFU / imaging hybrid wave 36 is used compared to when a basic imaging ultrasound is used, just as when the therapeutic ultrasound pulse 44 includes a heating burst 42.

[0062] As described above, the HIFU irradiation device 100 is an ultrasonic treatment device comprising the HIFU transducer unit 10 including the therapeutic ultrasonic transducer 28, the ultrasonic probe 16, and the control unit 30 that controls the ultrasonic transducer 28 and the ultrasonic probe 16. The control unit 30 is made up of the HIFU drive circuit 14, the transmitting / receiving circuit 18, the imaging calculation unit 20, and the controller 22.

[0063] The control unit 30 executes a therapeutic ultrasound transmission process, an auxiliary ultrasound transmission process, and an irradiation area image generation process. The therapeutic ultrasound transmission process is a process that causes the ultrasound transducer 28 to transmit therapeutic ultrasound 38. The irradiation area image generation process is a process that is executed after the therapeutic ultrasound 38 is transmitted. The irradiation area image generation process is a process that causes the ultrasound probe 16 to transmit a plurality of imaging pulses 46 as a plurality of ultrasound waves at different timings, and adds up (combines) the first to Mth received signals (a plurality of received signals) based on the first reflected ultrasound waves to the Mth reflected ultrasound waves (a plurality of reflected ultrasound waves) that are reflected by biological tissue and received by the ultrasound probe 16, thereby generating irradiation area data based on the nonlinear components of each received signal.

[0064] The auxiliary ultrasound transmission process also includes a process of causing the ultrasound transducer 28 to transmit an interleaved pulse 50 as an auxiliary ultrasound wave at a timing between two timings at which two adjacent imaging pulses 46 on the time axis are transmitted.

[0065] In addition, the auxiliary ultrasound transmission process may include a process of causing the ultrasound transducer 28 to transmit an interleaved pulse 50 as an auxiliary ultrasound wave at an earlier timing than the multiple imaging pulses 46 after the therapeutic ultrasound wave 38 has been transmitted.

[0066] The control unit 30 executes a B-mode image generation process for generating B-mode image data of the living tissue using any one of the plurality of received signals.

[0067] The control unit 30 executes a display process to display an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data on the display device 24. The control unit 30 may cause the display device 24 to display the irradiation area image and the B-mode image in an overlapping manner.

[0068] With this configuration and processing, the therapeutic ultrasound 38 is irradiated onto the biological tissue, and the region irradiated with the therapeutic ultrasound 38 is displayed on the irradiation region image. This makes it easy for the user to confirm that the therapeutic ultrasound 38 has been irradiated onto the affected area. Furthermore, the transmission of the interleaved pulse 50 increases the nonlinear component generated by the imaging pulse 46. This increases the magnitude of the nonlinear signal, highlighting the bubbles displayed on the irradiation region image, making it easy for the user to confirm that the therapeutic ultrasound 38 has been irradiated onto the affected area.

[0069] [Configuration of the present invention] Configuration 1: a therapeutic ultrasound transducer; an ultrasound probe; a control unit that controls the ultrasonic transducer and the ultrasonic probe, The control unit a therapeutic ultrasound transmission process for transmitting therapeutic ultrasound from the ultrasound transducer; an auxiliary ultrasonic wave transmission process for causing the ultrasonic transducer to transmit auxiliary ultrasonic waves; After the therapeutic ultrasound is transmitted, a plurality of ultrasound waves are transmitted to the ultrasound probe at different timings and different phases, and the ultrasound waves are reflected by biological tissue. A plurality of reception signals based on the plurality of reflected ultrasound waves received by the ultrasound probe are synthesized to generate irradiation area image data based on nonlinear components of the reception signals. The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic wave from the ultrasonic transducer at a timing between two timings at which two adjacent ultrasonic waves on the time axis are transmitted among the plurality of ultrasonic waves. Configuration 2: The ultrasonic treatment device according to configuration 1, The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic wave from the ultrasonic transducer at a timing earlier than the intermediate timing between two timings at which two of the multiple ultrasonic waves adjacent on the time axis are transmitted. Configuration 3: The ultrasonic treatment device according to the first or second aspect of the present invention, The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic waves from the ultrasonic transducer at an earlier timing than the plurality of ultrasonic waves after the therapeutic ultrasonic waves have been transmitted. Configuration 4: The ultrasonic treatment device according to any one of the first to third aspects, An ultrasonic treatment device characterized in that the multiple received signals are signals based on the multiple reflected ultrasonic waves received by the ultrasonic probe based on M types of ultrasonic waves sequentially transmitted from the ultrasonic probe with a phase difference of 360° / M. Configuration 5: Structure An ultrasonic treatment device according to any one of the first to fourth configurations, The control unit An ultrasonic treatment device characterized by performing a B-mode image generation process for generating B-mode image data of the biological tissue using any of the plurality of received signals. Configuration 6: The ultrasonic treatment device according to configuration 5, The control unit An ultrasonic treatment device characterized in that an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data are displayed on a display device. Configuration 7: The ultrasonic treatment device according to configuration 5, The control unit An ultrasonic treatment device characterized in that an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data are displayed on a display device in an overlapping manner. [Explanation of symbols]

[0070] 2 Transmitting and receiving unit, 3 Central axis, 4 Concave surface, 10 HIFU transducer unit, 14 HIFU driving circuit, 16 Ultrasonic probe, 18 Transmitting and receiving circuit, 20 Imaging calculation unit, 22 Controller, 24 Display device, 26 Driving device, 28 Ultrasonic transducer, 30 Control unit, 36 HIFU / imaging hybrid wave, 38 Therapeutic ultrasound, 40 Trigger pulse, 42 Heating burst, 44 Therapeutic ultrasound pulse, 46-1 First imaging pulse, 46-2 Second imaging pulse, 46-3 Third imaging pulse, 48 Irradiation pause period, 50-1 First interleaved pulse (auxiliary ultrasound), 50-2 Second interleaved pulse (auxiliary ultrasound), 60 Air bubble, 100 HIFU irradiation device (ultrasonic treatment device).

Claims

1. a therapeutic ultrasound transducer; an ultrasound probe; a control unit that controls the ultrasonic transducer and the ultrasonic probe, The control unit a therapeutic ultrasound transmission process for transmitting therapeutic ultrasound from the ultrasound transducer; an auxiliary ultrasonic wave transmission process for causing the ultrasonic transducer to transmit auxiliary ultrasonic waves; After the therapeutic ultrasound is transmitted, a plurality of ultrasound waves are transmitted to the ultrasound probe at different timings and different phases, and the ultrasound waves are reflected by biological tissue. The plurality of received signals are then combined to generate irradiation area data representing the irradiation area irradiated with the therapeutic ultrasound waves. The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic waves to the ultrasonic transducer at a timing between two timings at which two adjacent ultrasonic waves on the time axis are transmitted, which are the ultrasonic waves that are the source of the multiple received signals to be synthesized in the irradiation area image generation process, thereby increasing the contrast ratio of the irradiation area image indicated by the irradiation area data.

2. 2. The ultrasonic treatment device according to claim 1, the auxiliary ultrasonic waves are composed of a series of ultrasonic pulses on a time axis, An ultrasonic treatment device characterized in that the contrast ratio is determined depending on the number of ultrasonic pulses that constitute the auxiliary ultrasonic waves.

3. 2. The ultrasonic treatment device according to claim 1, The auxiliary ultrasound is constituted by an ultrasound pulse, An ultrasonic treatment device characterized in that the contrast ratio is determined according to the amplitude of the ultrasonic pulse.

4. The ultrasonic treatment device according to any one of claims 1 to 3, The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic wave to the ultrasonic transducer at a timing earlier than the intermediate timing between two timings at which two adjacent ultrasonic waves on the time axis are transmitted among the multiple ultrasonic waves to be synthesized.

5. The ultrasonic treatment device according to any one of claims 1 to 3, The auxiliary ultrasonic wave transmission process includes: An ultrasonic treatment device characterized by including a process of transmitting the auxiliary ultrasonic waves to the ultrasonic transducer at an earlier timing than the multiple ultrasonic waves to be synthesized after the therapeutic ultrasonic waves are transmitted.

6. The ultrasonic treatment device according to any one of claims 1 to 3, The multiple received signals are signals based on the multiple reflected ultrasound waves received by the ultrasound probe based on the M types of ultrasound waves to be synthesized that are sequentially transmitted from the ultrasound probe with a phase difference of 360° / M. An ultrasound treatment device characterized in that

7. The ultrasonic treatment device according to any one of claims 1 to 3, The control unit An ultrasonic treatment device characterized by performing a B-mode image generation process to generate B-mode image data of the biological tissue using any of the plurality of received signals.

8. The ultrasonic treatment device according to claim 7, The control unit An ultrasonic treatment device characterized in that an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data are displayed on a display device.

9. The ultrasonic treatment device according to claim 7, The control unit An ultrasonic treatment device characterized in that an irradiation area image based on the irradiation area data and a B-mode image based on the B-mode image data are displayed on a display device in an overlapping manner.

10. The ultrasonic treatment device according to any one of claims 1 to 3, The therapeutic ultrasound transmission process includes: a process of repeatedly transmitting the therapeutic ultrasound from the ultrasound transducer; The irradiation area image generation process includes: An ultrasonic treatment device characterized by including a process of transmitting the multiple ultrasonic waves to be synthesized to the ultrasonic probe at different timings and different phases during irradiation pause periods between repeated transmissions of the therapeutic ultrasonic waves.

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