HIFU irradiation device and focus adjustment method

Abstract

The purpose of the present invention is to facilitate, in an HIFU irradiation device, an operation for aligning the position of the focal point of therapeutic ultrasound with a treatment site. A vibrator control unit (18) controls a plurality of ultrasonic vibrators (32) disposed along a concave surface (30). A probe drive unit (14) causes an ultrasonic probe (12), which is disposed on the central axis (40) of the concave surface (30), to rotate around the central axis (40). A data acquisition unit (16) acquires B-mode image data by means of the ultrasonic probe (12). A controller (22) controls the vibrator control unit (18), the probe drive unit (14), and the data acquisition unit (16). When the plurality of ultrasonic vibrators (32) are being caused to transmit ultrasound, the controller 22 executes a process for searching for the focal point F of the ultrasound being emitted from the plurality of ultrasonic vibrators (32) on the B-mode image represented by the B-mode image data while changing the rotation angle position of the ultrasonic probe (12) around the central axis (40).

Description

HIFU irradiation device and focus adjustment method

[0001] The present invention relates to a HIFU irradiation device and a method for adjusting the focus thereof, and more particularly to adjusting the position of the focus using a B-mode image.

[0002] A treatment device using high intensity focused ultrasound (HIFU) is widely used. This treatment device is called a HIFU irradiation device or a HIFU irradiation system, and irradiates a treatment site with focused ultrasound to cause necrosis of biological tissue.

[0003] Generally, a HIFU irradiation device includes a plurality of ultrasonic transducers for treatment arranged along a concave surface. The plurality of ultrasonic transducers are arranged so that ultrasonic waves emitted from each of the transducers are irradiated at a single point to form a focal point. During treatment, the focal point is aligned with the treatment area and ultrasonic waves are irradiated. To confirm the irradiation position, an ultrasonic diagnostic device that displays the focal point on an ultrasound image is used.

[0004] The following Patent Document 1 describes an ultrasound treatment device that observes the position of a focal point using an ultrasound diagnostic device that displays B-mode images (tomographic images). In this device, a therapeutic ultrasound transducer emits ultrasound waves at a low level that do not affect tissue, and an ultrasound imaging probe transmits and receives ultrasound waves to display a tomographic image. Because the acoustic properties of the patient's tissue change depending on changes in tissue temperature, the tomographic image shows the position of the focal point by varying brightness. Furthermore, as shown in Non-Patent Document 1, because the irradiation of the patient's tissue with ultrasound causes displacement, the tomographic image shows the position of the focal point by varying brightness.

[0005] Japanese Patent Application Publication No. 8-71069

[0006] Tissue hardness measurement using ARFI via the Internet<https: / / www.innervision.co.jp / sp / ad / suite / siemens / technical_notes / 140368>

[0007] In treatment using high-intensity focused ultrasound, if there is an area in the patient's tissue with acoustic characteristics different from the surrounding area, the refraction of the ultrasound emitted from the therapeutic ultrasound transducer may cause the focal position to shift compared to when the acoustic characteristics are uniform. This may cause the ultrasound focus to not appear on the B-mode image, making it difficult to align the focal position of the therapeutic ultrasound to the treatment area.

[0008] An object of the present invention is to facilitate the operation of aligning the focal position of therapeutic ultrasound waves to a treatment site in a HIFU irradiation device.

[0009] The HIFU irradiation device according to the present invention comprises a transducer control unit that controls a plurality of ultrasound transducers arranged along a concave surface, a probe driving unit that rotates an ultrasound probe arranged on the central axis of the concave surface around the central axis, a data acquisition unit that acquires B-mode image data by the ultrasound probe, and a controller that controls the transducer control unit, the probe driving unit, and the data acquisition unit, wherein the controller executes the following processes while causing the plurality of ultrasound transducers to transmit ultrasound: a process of searching for foci of ultrasound emitted from the plurality of ultrasound transducers, the foci appearing as varying brightness in a B-mode image indicated by the B-mode image data, based on the B-mode image data, while changing the rotational angle position of the ultrasound probe around the central axis; and a process of stopping the ultrasound probe at the rotational angle position when the foci are detected.

[0010] Preferably, the controller adjusts the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers while keeping the ultrasonic probe stationary at the rotation angle position when the focal point is detected, to bring the focal point closer to the central axis or position the focal point on the central axis.

[0011] Furthermore, the HIFU irradiation device according to the present invention comprises a transducer control unit that controls a plurality of ultrasonic transducers arranged along a concave surface, an ultrasound transducer drive unit that rotates the plurality of ultrasonic transducers around the central axis of the concave surface, a data acquisition unit that acquires B-mode image data using an ultrasound probe arranged on the central axis of the concave surface, and a controller that controls the transducer control unit, the ultrasound transducer drive unit, and the data acquisition unit, wherein the controller, while causing the plurality of ultrasonic transducers to transmit ultrasound, executes a process of searching for foci of ultrasound emitted from the plurality of ultrasonic transducers, which foci appear as intensity differences in a B-mode image indicated by the B-mode image data, based on the B-mode image data, while changing the rotation angle positions of the plurality of ultrasonic transducers around the central axis, and a process of stopping the plurality of ultrasonic transducers at the rotation angle positions when the foci are detected.

[0012] Preferably, the controller adjusts the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers while keeping the plurality of ultrasonic transducers stationary at the rotational angle position when the focal point is detected, thereby bringing the focal point closer to the central axis or positioning the focal point on the central axis.

[0013] Furthermore, a HIFU irradiation device according to the present invention is a focus adjustment method for a HIFU irradiation device comprising a plurality of ultrasonic transducers arranged along a concave surface, an ultrasonic probe arranged on the central axis of the concave surface so as to be rotatable around the central axis, and a data acquisition unit that acquires B-mode image data by the ultrasonic probe, wherein the HIFU irradiation device further comprises a transducer control unit that controls the plurality of ultrasonic transducers, and a probe drive unit that rotates the ultrasonic probe around the central axis, and is characterized in that, when a controller that controls the transducer control unit, the probe drive unit, and the data acquisition unit causes the plurality of ultrasonic transducers to transmit ultrasonic waves, the controller executes the steps of: searching for foci of ultrasonic waves emitted from the plurality of ultrasonic transducers, the foci appearing as varying brightness in a B-mode image shown by the B-mode image data, while changing the rotational angle position of the ultrasonic probe around the central axis, based on the B-mode image data; and keeping the ultrasonic probe stationary at the rotational angle position when the foci are detected.

[0014] Preferably, the method includes a step of adjusting the delay time of each ultrasonic wave emitted from the plurality of ultrasonic transducers while keeping the ultrasonic probe stationary at the rotation angle position when the focus is detected, to bring the focus closer to the central axis or position the focus on the central axis.

[0015] The present invention also provides a focus adjustment method for a HIFU irradiator comprising: a plurality of ultrasonic transducers arranged along a concave surface, the plurality of ultrasonic transducers being rotatably arranged around a central axis of the concave surface; an ultrasonic probe arranged on the central axis of the concave surface; and a data acquisition unit that acquires B-mode image data by the ultrasonic probe, wherein the HIFU irradiator further comprises: a transducer control unit that controls the plurality of ultrasonic transducers; a probe drive unit that rotates the ultrasonic probe around the central axis; and a controller that controls the transducer control unit, the probe drive unit, and the data acquisition unit, while causing the plurality of ultrasonic transducers to transmit ultrasonic waves, executes the following steps: searching for foci of ultrasonic waves emitted from the plurality of ultrasonic transducers, the foci appearing as intensity variations in a B-mode image shown by the B-mode image data, while changing the rotational angle positions of the plurality of ultrasonic transducers around the central axis; and a step of stopping the plurality of ultrasonic transducers at the rotational angle positions when the foci are detected.

[0016] Preferably, the method includes a step of adjusting the delay time of each ultrasonic wave emitted from the plurality of ultrasonic transducers while keeping the plurality of ultrasonic transducers stationary at the rotation angle position when the focus is detected, to bring the focus closer to the central axis or to position the focus on the central axis.

[0017] Furthermore, the HIFU irradiation device according to the present invention includes a transducer control unit that controls a plurality of ultrasound transducers arranged along a concave surface, a data acquisition unit that acquires B-mode image data using an ultrasound probe arranged on the central axis of the concave surface, and a controller that controls the transducer control unit and the data acquisition unit, wherein the controller, when causing the plurality of ultrasound transducers to transmit ultrasound, executes a process of searching for foci of ultrasound emitted from the plurality of ultrasound transducers, which foci appearing in a B-mode image represented by the B-mode image data, based on the B-mode image data, while adjusting a delay time of the ultrasound emitted from each of the plurality of ultrasound transducers. The controller may, when causing the plurality of ultrasound transducers to transmit ultrasound, execute a process of searching for foci of ultrasound emitted from the plurality of ultrasound transducers on the B-mode image represented by the B-mode image data, while adjusting a delay time of the ultrasound emitted from each of the plurality of ultrasound transducers.

[0018] Preferably, ultrasonic waves are generated from each of the plurality of ultrasonic transducers at the delay time when the focus is detected, and then the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers is adjusted to bring the focus closer to the central axis or position the focus on the central axis.

[0019] The present invention also provides a focus adjustment method for a HIFU irradiator including a plurality of ultrasound transducers arranged along a concave surface and a data acquisition unit that acquires B-mode image data using an ultrasound probe arranged on a central axis of the concave surface, wherein the HIFU irradiator further includes a transducer control unit that controls the plurality of ultrasound transducers, and includes the step of, when a controller that controls the transducer control unit and the data acquisition unit is causing the plurality of ultrasound transducers to transmit ultrasound, searching for foci of ultrasound emitted from the plurality of ultrasound transducers on a B-mode image represented by the B-mode image data based on the B-mode image data, while adjusting a delay time of ultrasound emitted from each of the plurality of ultrasound transducers, the foci appearing as intensity variations in the B-mode image represented by the B-mode image data. The focus adjustment method may include, when the plurality of ultrasound transducers are causing the plurality of ultrasound transducers to transmit ultrasound, searching for foci of ultrasound emitted from the plurality of ultrasound transducers on a B-mode image represented by the B-mode image data, while adjusting a delay time of ultrasound emitted from each of the plurality of ultrasound transducers.

[0020] Preferably, the method includes a step of generating ultrasonic waves from each of the plurality of ultrasonic transducers at the delay time when the focus is detected, and then adjusting the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers to bring the focus closer to the central axis or position the focus on the central axis.

[0021] According to the present invention, the operation of adjusting the focal position of therapeutic ultrasound to the treatment site can be facilitated.

[0022] It is a diagram showing the configuration of the HIFU irradiation device according to the first embodiment. It is a diagram explaining the focus adjustment process. It is a diagram explaining the focus adjustment process. It is a diagram explaining the focus adjustment process. It is a diagram showing the configuration of the HIFU irradiation device according to the second embodiment.

[0023] An embodiment of the present invention will be described with reference to the drawings. The same components shown in multiple drawings are designated by the same reference numerals to simplify the description. Fig. 1 shows the configuration of a HIFU irradiation device 100 according to a first embodiment of the present invention. The HIFU irradiation device 100 includes a HIFU transducer unit 10, an ultrasonic probe 12, a coupling bag 24, a probe driver 14, a data acquisition unit 16, a transducer controller 18, a display unit 20, and a controller 22.

[0024] 1 shows a cross section of a HIFU transducer unit 10. The HIFU transducer unit 10 includes a transducer housing 26 having a concave surface 30 with an opening facing downward, and a plurality of ultrasound transducers 32 arranged along the concave surface 30 of the transducer housing 26 and fixed to the transducer housing 26. The HIFU transducer unit 10 does not necessarily have to have an actual concave surface 30. In this case, the plurality of ultrasound transducers 32 may be fixed to the transducer housing 26 so as to be arranged along a virtual concave surface.

[0025] The concave surface 30 of the transducer housing 26 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 straight lines extending from a point in space to a bottom surface. The concave surface 30 of the transducer housing 26 may also have a dome-like shape bulging upward. Each ultrasonic transducer 32 is fixed to the transducer housing 26 so that when each ultrasonic transducer 32 emits ultrasound, the intensity of the ultrasound is increased at a treatment reference point P below the transducer housing 26.

[0026] The controller 22 may be a personal computer, a tablet computer, or the like. The controller 22 may realize each function by executing a program. An operating device (not shown) for a user to operate the HIFU irradiation device 100 is connected to the controller 22. The operating device may include a mouse, a touch panel integrated with the display unit 20, a switch, a keyboard, or the like.

[0027] The transducer control unit 18 may be configured by a processor that executes a program to control each ultrasonic transducer 32. The transducer control unit 18 causes each ultrasonic transducer 32 to generate ultrasonic waves in accordance with the control of the controller 22. Furthermore, the transducer control unit 18 adjusts at least one of the intensity and delay time of the ultrasonic waves generated by each ultrasonic transducer 32 in accordance with the control of the controller 22.

[0028] The ultrasonic probe 12, which extends in the vertical direction, is attached to the transducer housing 26 so that ultrasonic waves are transmitted and received at a position below the transducer housing 26 and above the treatment reference point P. In this embodiment, the ultrasonic probe 12 passes through the apex of the concave surface 30 of the transducer housing 26 in the vertical direction, and the transmitting and receiving unit 28 that transmits and receives ultrasonic waves faces downward.

[0029] A coupling bag 24 is provided below the HIFU transducer unit 10 to match acoustic impedance between each ultrasonic transducer 32 and the patient, and between the ultrasonic probe 12 and the patient. The coupling bag 24 may be a bag filled with a liquid such as water. The ultrasonic probe 12 passes through the coupling bag 24 from above to inside, and a transmitting / receiving unit 28 is located inside the coupling bag 24.

[0030] An ultrasound diagnostic device may be used as the data acquisition unit 16. The data acquisition unit 16 performs the following processing in accordance with the control of the controller 22. That is, the data acquisition unit 16 causes the ultrasound probe 12 to transmit ultrasound waves and causes scanning with a beam of the transmitted ultrasound waves (ultrasonic beam).

[0031] The transmitting / receiving unit 28 of the ultrasonic probe 12 has defined long and short axis directions, and an ultrasonic beam is scanned across an observation surface 44 that extends in the long axis direction and in a direction away from the transmitting / receiving unit 28. The ultrasonic probe 12 is attached to the HIFU transducer unit 10 so that the observation surface 44 includes a central axis 40 that passes vertically through the apex of the concave surface 30 of the transducer housing 26.

[0032] The data acquisition unit 16 causes the ultrasonic probe 12 to receive reflected ultrasonic waves arriving from the direction in which the ultrasonic beam is directed, and acquires reception signals based on the reflected ultrasonic waves received from each direction in which the ultrasonic beam is directed. The data acquisition unit 16 generates ultrasound data based on the reception signals obtained at the observation plane 44, and outputs the ultrasound data to the controller 22. The ultrasound data may be, for example, data representing a B-mode image (tomographic image) acquired for the observation plane 44.

[0033] The ultrasonic probe 12 is rotatable around a central axis 40 by a probe driver 14. The probe driver 14 rotates the ultrasonic probe 12 around the central axis 40 relative to the HIFU transducer unit 10. That is, the probe driver 14 rotates the ultrasonic probe 12 around the central axis 40 and rotates an observation surface 44 of the ultrasonic probe 12 around the central axis 40 in accordance with the control of the controller 22.

[0034] During treatment, the coupling bag 24, the ultrasonic probe 12, and the HIFU transducer unit 10 are positioned so that the lower part of the coupling bag 24 is in close contact with the patient. Before the therapeutic ultrasonic waves are irradiated from the HIFU transducer unit 10 to the patient, the following positioning process is performed.

[0035] The transducer control unit 18 causes each ultrasound transducer 32 included in the HIFU transducer unit 10 to transmit ultrasound waves with an intensity lower than that used during treatment. The probe driver 14 sets the rotation angle position (position represented by a rotation angle) of the ultrasound probe 12 so that the ultrasound beam scans an observation plane 44 extending in a predetermined direction.

[0036] The data acquisition unit 16 causes the ultrasound probe 12 to scan an ultrasound beam on an observation plane 44 defined by the rotational angle position of the ultrasound probe 12, acquires ultrasound data, and outputs the data to the controller 22. The controller 22 causes the display unit 20 to display a B-mode image represented by the ultrasound data superimposed on an image representing the treatment reference point P. The user as a practitioner refers to the image displayed on the display unit 20 to confirm the difference between the position (focal point F) where the ultrasound transmitted from the HIFU transducer unit 10 is intensified and the position of the treatment reference point P.

[0037] If the difference between the position of the focal point F and the position of the treatment reference point P is not within an acceptable range, the user changes the position or posture of the coupling bag 24, the ultrasound probe 12, and the HIFU transducer unit 10. Alternatively, the user changes the contact state between the coupling bag 24 and the patient 34. After confirming that the position of the focal point F and the position of the treatment reference point P coincide with each other or that the difference between the positions of the focal point F and the treatment reference point P is within an acceptable range, the user operates the controller 22 for treatment. The controller 22 controls the transducer control unit 18 in response to the user's operation. The transducer control unit 18 transmits therapeutic ultrasound having an intensity required for treatment to each ultrasound transducer 32 in response to control by the controller 22. This cauterizes the living tissue at the focal point F, thereby performing treatment.

[0038] In treatment using high-intensity focused ultrasound, if there is an area in the patient's tissue with acoustic characteristics different from the surrounding area, the position of the focal point F may be shifted compared to when the acoustic characteristics are uniform due to refraction of the ultrasound emitted from the ultrasound transducer 32. This may cause the ultrasound focal point F to not appear on the B-mode image, making positioning difficult.

[0039] Therefore, in the HIFU irradiation device 100 according to this embodiment, a focus adjustment process described below may be performed before the positioning process is performed. By the focus adjustment process, the focus F moves onto the observation plane 44 of the ultrasound probe 12. Furthermore, the focus F may be moved closer to the central axis 40 or set on the central axis 40.

[0040] The controller 22 controls the data acquisition unit 16 to cause the data acquisition unit 16 to acquire B-mode image data as ultrasound data. The data acquisition unit 16 causes the ultrasound probe 12 to transmit ultrasound waves and scan the observation plane 44 with the ultrasound beam. The data acquisition unit 16 causes the ultrasound probe 12 to receive reflected ultrasound waves arriving from the direction in which the ultrasound beam is directed, and acquires received signals based on the reflected ultrasound waves received from each direction in which the ultrasound beam is directed. The data acquisition unit 16 generates ultrasound data based on the received signals obtained at the observation plane 44 and outputs the data to the controller 22.

[0041] Furthermore, the controller 22 controls the transducer control section 18 to cause each of the ultrasound transducers 32 included in the HIFU transducer unit 10 to transmit ultrasound waves with an intensity lower than that used during treatment.

[0042] 2 to 4 are diagrams illustrating the focus adjustment process. The left side of Fig. 2 shows a state in which the minor axis direction of the transceiver 28 is oriented left and right. The right side of Fig. 2 shows a state in which the major axis direction of the transceiver 28 is oriented left and right. Fig. 3 shows a state in which the major axis direction of the transceiver 28 is oriented left and right, and Fig. 4 shows a state in which the minor axis direction of the transceiver 28 is oriented left and right.

[0043] The left side of FIG. 2 shows a state in which the focal point F is located at a position away from the observation plane 44. However, for clarity, the coupling bag 24 is omitted from this figure. The coupling bag 24 is also omitted from FIGS. 3 and 4 , which will be described later. The controller 22 controls the probe driver 14 to rotate the ultrasonic probe 12 about the central axis 40 while searching for the focal point F on the B-mode image represented by the ultrasound data output from the data acquisition unit 16. The probe driver 14 rotates the ultrasonic probe 12 around the central axis 40 within a range of at least 90°. The controller 22 controls the probe driver 14 to stop the ultrasonic probe 12 at the rotation angle position when the focal point F is detected on the B-mode image. The right side of FIG. 2 and the left side of FIG. 3 schematically show an ultrasonic beam scanning area 42 and the focal point F when the focal point F is detected on the B-mode image. Here, the ultrasonic beam scanning area 42 is the area scanned with the ultrasonic beam, and B-mode image data is generated for this area.

[0044] The controller 22 controls the transducer control unit 18 to adjust the delay time of the ultrasonic waves generated by each of the multiple ultrasonic transducers 32 and move the focal point F within the observation plane 44. That is, the transducer control unit 18 adjusts the delay time of the ultrasonic waves generated by each of the multiple ultrasonic transducers 32 in accordance with the control of the controller 22, moves the focal point F within the observation plane 44, and moves the focal point F closer to the central axis 40 or positions the focal point F on the central axis 40. The right side of Figure 3 schematically shows the ultrasonic beam scanning area 42 and the focal point F when the focal point F is positioned on the central axis 40.

[0045] In the HIFU irradiation device 100, as shown on the left side of FIG. 3, even if the focal point F is not located on the central axis 40, the positioning process may be performed with the focal point F on the B-mode image, or as shown on the right side of FIG. 3, the positioning process may be performed with the focal point F located on the central axis 40.

[0046] The focus adjustment process may be performed by adjusting the delay time of the ultrasonic waves emitted from each of the multiple ultrasonic transducers 32 without rotating the ultrasonic probe 12. The left side of Fig. 4 shows a state in which the focal point F is located away from the observation plane 44. The controller 22 controls the transducer control unit 18 to adjust the delay time of the ultrasonic waves generated by each of the multiple ultrasonic transducers 32 and move the focal point F within a plane intersecting the observation plane 44, for example, within a plane perpendicular to the observation plane 44. That is, the transducer control unit 18 adjusts the delay time of the ultrasonic waves generated by each of the multiple ultrasonic transducers 32 in accordance with the control of the controller 22, and moves the focal point F within the plane intersecting the observation plane 44, thereby positioning the focal point F on the observation plane 44. The right side of Fig. 4 schematically shows the ultrasonic beam scanning region 42 and the focal point F when the focal point F is positioned on the observation plane 44.

[0047] The state shown on the right side of Fig. 4 is the same as the state shown on the left side of Fig. 3. The controller 22 controls the transducer control unit 18 to adjust the delay time of the ultrasound waves generated by each of the multiple ultrasound transducers 32 and move the focal point F within the observation plane 44. That is, the transducer control unit 18 adjusts the delay time of the ultrasound waves generated by each of the multiple ultrasound transducers 32 in accordance with the control of the controller 22, moves the focal point F within the observation plane 44, and moves the focal point F closer to the central axis 40 or positions the focal point F on the central axis 40. The right side of Fig. 3 schematically shows the ultrasound beam scanning area 42 and the focal point F when the focal point F is positioned on the central axis 40.

[0048] Even when the ultrasonic probe 12 is not rotated, the HIFU irradiation device 100 may perform the positioning process with the focus F on the B-mode image even if the focus F is not located on the central axis 40, as shown on the left side of Fig. 3. Alternatively, the positioning process may be performed with the focus F located on the central axis 40, as shown on the right side of Fig. 3.

[0049] In this way, in the HIFU irradiation device 100, the focus adjustment process is performed by a focus adjustment method including the following steps (i) to (iii): (i) a step of searching for a focus F of ultrasound waves emitted from the plurality of ultrasound transducers 32 on a B-mode image shown by the B-mode image data while changing the rotational angle position of the ultrasound probe 12 around the central axis 40 while causing the plurality of ultrasound transducers 32 to transmit ultrasound waves, (ii) a step of stopping the ultrasound probe 12 at the rotational angle position when the focus F is detected, and (iii) a step of adjusting the delay time of each ultrasound wave emitted from the plurality of ultrasound transducers 32 while the ultrasound probe 12 is stopped at the rotational angle position when the focus F is detected, to bring the focus closer to the central axis 40 or to position the focus F on the central axis 40.

[0050] In the focus adjustment method, the above step (iii) does not necessarily have to be performed. The focus adjustment method may be one in which the above steps (i) and (ii) are performed.

[0051] Furthermore, in the HIFU irradiation device 100, the focus adjustment process may be performed by a focus adjustment method including the following steps (a) and (b): (a) a step of searching for a focus F of ultrasound emitted from the plurality of ultrasound transducers 32 on a B-mode image shown by the B-mode image data while adjusting a delay time of the ultrasound emitted from each of the plurality of ultrasound transducers 32 while causing the plurality of ultrasound transducers 32 to transmit ultrasound waves, and (b) a step of adjusting a delay time of the ultrasound emitted from each of the plurality of ultrasound transducers 32 after generating ultrasound waves from each of the plurality of ultrasound transducers 32 with the delay time when the focus F is detected, to bring the focus closer to the central axis 40 or position the focus F on the central axis 40.

[0052] In the focus adjustment method, the step (b) above does not necessarily have to be performed. The focus adjustment method may be one in which the step (a) above is performed.

[0053] 5 shows the configuration of a HIFU irradiation device 102 according to a second embodiment of the present invention. The HIFU irradiation device 102 is configured by adding a transducer unit driver 90 to the HIFU irradiation device 100. The transducer unit driver 90 rotates the HIFU transducer unit 10 around the central axis 40 with respect to a reference coordinate system fixed to a bed or the like on which a patient 34 lies, under the control of the controller 22. That is, the transducer unit driver 90 functions as an ultrasound transducer driver that rotates the multiple ultrasound transducers 32 arranged along the concave surface 30 around the central axis 40.

[0054] In this embodiment, the probe driver 14 maintains the ultrasonic probe 12 in a stationary state. Here, the stationary state of the ultrasonic probe 12 refers to a state in which the ultrasonic probe 12 is stationary in the reference coordinate system. The transducer unit driver 90 rotates the HIFU transducer unit 10 in a rotation direction opposite to the rotation direction of the ultrasonic probe 12 in the focus adjustment process described with reference to FIGS. 2 to 4 for the first embodiment.

[0055] The probe driver 14 rotates the ultrasonic probe 12 around the central axis 40 relative to the HIFU transducer unit 10. Therefore, by setting the rotation angle of the ultrasonic probe 12 relative to the HIFU transducer unit 10 to the same angle in the opposite direction as the rotation angle in the reference coordinate system of the HIFU transducer unit 10, the ultrasonic probe 12 becomes stationary in the reference coordinate system. This allows the position of the focal point F on the B-mode image to be adjusted without changing the B-mode image displayed on the display unit 20.

[0056] In the HIFU irradiation device 102, focus adjustment processing is performed by a focus adjustment method including the following steps (α) to (γ): (α) a step of searching for a focus F of ultrasound emitted from the plurality of ultrasound transducers 32 on a B-mode image shown by B-mode image data while changing the rotation angle position of the HIFU transducer unit 10 around the central axis 40, i.e., the rotation angle positions of the plurality of ultrasound transducers 32, while causing the plurality of ultrasound transducers 32 to transmit ultrasound waves; (β) a step of stopping the HIFU transducer unit 10 at the rotation angle position when the focus F is detected; and (γ) a step of adjusting the delay time of each ultrasound wave emitted from the plurality of ultrasound transducers 32 while the HIFU transducer unit 10 is stopped at the rotation angle position when the focus F is detected, to bring the focus closer to the central axis 40 or to position the focus F on the central axis 40.

[0057] In the focus adjustment method, the above step (γ) does not necessarily have to be performed, but the focus adjustment method may be one in which the above steps (α) and (β) are performed.

[0058] According to the focus adjustment process described above, the focus F can be positioned on the observation plane 44. Therefore, even if the focus F does not appear in the B-mode image due to refraction, the positioning process can be performed by positioning the focus F on the observation plane 44. Furthermore, in the focus adjustment process, the focus F may be moved closer to the central axis 40, or the focus F may be set on the central axis 40. In this case, the focus F is positioned below the ultrasound probe 12, and the image of the focus F is positioned at a position where it is easy to see in the B-mode image. This makes the positioning process easier.

[0059] [Configurations of the Present Invention] Configuration 1: A HIFU irradiation device comprising: a transducer control unit that controls a plurality of ultrasound transducers arranged along a concave surface; a probe driving unit that rotates an ultrasound probe arranged on the central axis of the concave surface around the central axis; a data acquisition unit that acquires B-mode image data by the ultrasound probe; and a controller that controls the transducer control unit, the probe driving unit, and the data acquisition unit, wherein the controller executes the following processes: when causing the plurality of ultrasound transducers to transmit ultrasound waves, searching for focal points of ultrasound emitted from the plurality of ultrasound transducers on a B-mode image shown by the B-mode image data while changing the rotational angle position of the ultrasound probe around the central axis; and when the focal point is detected, keeping the ultrasound probe stationary at the rotational angle position. Configuration 2: The HIFU irradiation device according to claim 1, wherein the controller adjusts delay times of ultrasonic waves emitted from each of the plurality of ultrasonic transducers while keeping the ultrasonic probe stationary at the rotation angle position when the focus is detected, to bring the focus closer to the central axis or position the focus on the central axis. Configuration 3: A HIFU irradiation device comprising: a transducer control unit that controls a plurality of ultrasound transducers arranged along a concave surface; an ultrasound transducer drive unit that rotates the plurality of ultrasound transducers around the central axis of the concave surface; a data acquisition unit that acquires B-mode image data using an ultrasound probe arranged on the central axis of the concave surface; and a controller that controls the transducer control unit, the ultrasound transducer drive unit, and the data acquisition unit, wherein the controller executes the following processes: when causing the plurality of ultrasound transducers to transmit ultrasound, searching for focal points of ultrasound emitted from the plurality of ultrasound transducers on a B-mode image shown by the B-mode image data while changing the rotational angle positions of the plurality of ultrasound transducers around the central axis; and when the focal points are detected, stopping the plurality of ultrasound transducers at the rotational angle positions.4: The HIFU irradiation device according to claim 3, wherein the controller adjusts a delay time of ultrasound waves emitted from each of the plurality of ultrasound transducers while keeping the plurality of ultrasound transducers stationary at the rotation angle position when the focus is detected, to bring the focus closer to the central axis or position the focus on the central axis. 5: A HIFU irradiation device comprising: a transducer control unit that controls the plurality of ultrasound transducers arranged along the concave surface, a data acquisition unit that acquires B-mode image data using an ultrasound probe arranged on the central axis of the concave surface, and a controller that controls the transducer control unit and the data acquisition unit, wherein the controller executes a process of searching for a focus of ultrasound waves emitted from the plurality of ultrasound transducers on a B-mode image shown by the B-mode image data while adjusting a delay time of ultrasound waves emitted from each of the plurality of ultrasound transducers while causing the plurality of ultrasound transducers to transmit ultrasound. 4. The HIFU irradiation device according to claim 3, wherein, after generating ultrasound from each of the plurality of ultrasound transducers with the delay time when the focus is detected, the delay time of the ultrasound emitted from each of the plurality of ultrasound transducers is further adjusted to bring the focus closer to the central axis or to position the focus on the central axis. 5. The HIFU irradiation device according to claim 4, wherein, after generating ultrasound from each of the plurality of ultrasound transducers with the delay time when the focus is detected, the delay time of the ultrasound emitted from each of the plurality of ultrasound transducers is further adjusted to bring the focus closer to the central axis or to position the focus on the central axis. 6. The HIFU irradiation device according to claim 4, wherein,and a data acquisition unit that acquires B-mode image data by the ultrasonic probe, the data acquisition unit acquiring ... 10: The focus adjustment method according to claim 9, comprising the step of adjusting a delay time of each ultrasonic wave emitted from the plurality of ultrasonic transducers to bring the focus closer to the central axis or to position the focus on the central axis, while keeping the plurality of ultrasonic transducers stationary at the rotation angle position when the focus was detected. 11: A focus adjustment method for a HIFU irradiator comprising: a plurality of ultrasonic transducers arranged along a concave surface; and a data acquisition unit that acquires B-mode image data by an ultrasonic probe arranged on the central axis of the concave surface, comprising the step of searching for a focus of the ultrasonic waves emitted from the plurality of ultrasonic transducers on a B-mode image shown by the B-mode image data while adjusting a delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers, while causing the plurality of ultrasonic transducers to transmit ultrasound waves.Configuration 12: The focus adjustment method according to claim 11, further comprising the step of: generating ultrasonic waves from each of the plurality of ultrasonic transducers at the delay time when the focus is detected; and then adjusting the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers to bring the focus closer to the central axis or position the focus on the central axis.

[0060] 10 HIFU transducer unit, 12 ultrasonic probe, 14 probe driver, 16 data acquisition unit, 18 transducer control unit, 20 display unit, 22 controller, 24 coupling bag, 26 transducer housing, 28 transmitter / receiver unit, 30 concave surface, 32 ultrasonic transducer, 40 central axis, 42 ultrasonic beam scanning area, 44 observation surface, 90 transducer unit driver, 100, 102 HIFU irradiation device.

Claims

1. A HIFU irradiation device comprising: a transducer control unit that controls multiple ultrasound transducers arranged along a concave surface; a probe drive unit that rotates an ultrasound probe arranged on the central axis of the concave surface around the central axis; a data acquisition unit that acquires B-mode image data by the ultrasound probe; and a controller that controls the transducer control unit, the probe drive unit, and the data acquisition unit, wherein the controller executes the following processes: when causing the multiple ultrasound transducers to transmit ultrasound, searching for focal points of ultrasound emitted from the multiple ultrasound transducers based on the B-mode image data while changing the rotation angle position of the ultrasound probe around the central axis, the focal points appearing as varying brightness in a B-mode image shown by the B-mode image data; and when the focal points are detected, stopping the ultrasound probe at the rotation angle position.

2. A HIFU irradiation device as described in claim 1, wherein the controller adjusts the delay time of the ultrasound emitted from each of the multiple ultrasound transducers while keeping the ultrasound probe stationary at the rotation angle position when the focus is detected, to bring the focus closer to the central axis or to position the focus on the central axis.

3. A HIFU irradiation device comprising: a transducer control unit that controls multiple ultrasonic transducers arranged along a concave surface; an ultrasonic transducer drive unit that rotates the multiple ultrasonic transducers around the central axis of the concave surface; a data acquisition unit that acquires B-mode image data using an ultrasonic probe arranged on the central axis of the concave surface; and a controller that controls the transducer control unit, the ultrasonic transducer drive unit, and the data acquisition unit, wherein the controller executes the following processes: when causing the multiple ultrasonic transducers to transmit ultrasound, searching for focal points of ultrasound emitted from the multiple ultrasonic transducers based on the B-mode image data while changing the rotation angle positions of the multiple ultrasonic transducers around the central axis, the focal points appearing as strengths and weaknesses of brightness in a B-mode image shown by the B-mode image data; and stopping the multiple ultrasonic transducers at the rotation angle position when the focal points are detected.

4. A HIFU irradiation device as described in claim 3, wherein the controller adjusts the delay time of the ultrasound emitted from each of the plurality of ultrasonic transducers while keeping the plurality of ultrasonic transducers stationary at the rotation angle position when the focus is detected, thereby moving the focus closer to the central axis or positioning the focus on the central axis.

5. A focus adjustment method for a HIFU irradiation device comprising: a plurality of ultrasonic transducers arranged along a concave surface; an ultrasonic probe arranged on a central axis of the concave surface and rotatable around the central axis; and a data acquisition unit that acquires B-mode image data by the ultrasonic probe, wherein the HIFU irradiation device further comprises: a transducer control unit that controls the plurality of ultrasonic transducers; and a probe drive unit that rotates the ultrasonic probe around the central axis, wherein a controller that controls the transducer control unit, the probe drive unit and the data acquisition unit executes the following steps: while causing the plurality of ultrasonic transducers to transmit ultrasonic waves, searches for a focus of ultrasonic waves emitted from the plurality of ultrasonic transducers, the focus appearing as a difference in brightness in a B-mode image shown by the B-mode image data, based on the B-mode image data, while changing the rotation angle position of the ultrasonic probe around the central axis; and a step of stopping the ultrasonic probe at the rotation angle position when the focus is detected.

6. A focus adjustment method as described in claim 5, characterized in that the controller executes a step of adjusting the delay time of each ultrasonic wave emitted from the plurality of ultrasonic transducers while keeping the ultrasonic probe stationary at the rotational angle position when the focus is detected, to bring the focus closer to the central axis or to position the focus on the central axis.

7. A focus adjustment method for a HIFU irradiation device comprising: a plurality of ultrasonic transducers arranged along a concave surface, the plurality of ultrasonic transducers being arranged rotatably around a central axis of the concave surface; an ultrasonic probe arranged on the central axis of the concave surface; and a data acquisition unit that acquires B-mode image data by the ultrasonic probe, wherein the HIFU irradiation device further comprises: a transducer control unit that controls the plurality of ultrasonic transducers; a probe drive unit that rotates the ultrasonic probe around the central axis; and a controller that controls the transducer control unit, the probe drive unit and the data acquisition unit, while causing the plurality of ultrasonic transducers to transmit ultrasonic waves, searches for focal points of ultrasonic waves emitted from the plurality of ultrasonic transducers, the focal points appearing as strengths and weaknesses of brightness in a B-mode image shown by the B-mode image data, based on the B-mode image data, while changing the rotation angle positions of the plurality of ultrasonic transducers around the central axis; and a step of stopping the plurality of ultrasonic transducers at the rotation angle position when the focal points are detected.

8. A focus adjustment method as described in claim 7, characterized in that the controller executes a step of adjusting the delay time of each ultrasonic wave emitted from the multiple ultrasonic transducers while keeping the multiple ultrasonic transducers stationary at the rotational angle position when the focus is detected, to bring the focus closer to the central axis or to position the focus on the central axis.

9. A HIFU irradiation device comprising: a transducer control unit which controls a plurality of ultrasonic transducers arranged along a concave surface; a data acquisition unit which acquires B-mode image data by an ultrasonic probe arranged on the central axis of the concave surface; and a controller which controls the transducer control unit and the data acquisition unit, wherein the controller executes a process of searching for a focus of ultrasonic waves emitted from the plurality of ultrasonic transducers, the focus appearing in a B-mode image represented by the B-mode image data based on the B-mode image data, while adjusting a delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers when the plurality of ultrasonic transducers are being caused to transmit ultrasonic waves.

10. A HIFU irradiation device as described in claim 9, characterized in that, after generating ultrasound from each of the plurality of ultrasound transducers at the delay time when the focus is detected, the delay time of the ultrasound emitted from each of the plurality of ultrasound transducers is further adjusted to bring the focus closer to the central axis or to position the focus on the central axis.

11. A focus adjustment method for a HIFU irradiation device comprising: a plurality of ultrasonic transducers arranged along a concave surface; and a data acquisition unit that acquires B-mode image data by an ultrasonic probe arranged on the central axis of the concave surface, wherein the HIFU irradiation device further comprises a transducer control unit that controls the plurality of ultrasonic transducers, and a controller that controls the transducer control unit and the data acquisition unit executes a step of searching for a focus of ultrasonic waves emitted from the plurality of ultrasonic transducers, the focus appearing in a B-mode image represented by the B-mode image data based on the B-mode image data, while adjusting a delay time of ultrasonic waves emitted from each of the plurality of ultrasonic transducers, when the plurality of ultrasonic transducers are transmitting ultrasonic waves.

12. A focus adjustment method as described in claim 11, characterized in that the controller executes a step of: from a state in which ultrasonic waves are generated from each of the plurality of ultrasonic transducers at the delay time when the focus is detected, adjusting the delay time of the ultrasonic waves emitted from each of the plurality of ultrasonic transducers to bring the focus closer to the central axis or position the focus on the central axis.

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