JP7301426B1 - HIFU irradiation equipment - Google Patents

Abstract

Kind Code: A1 An object of the present invention is to suppress the influence of an ultrasonic imaging probe on the propagation state of therapeutic ultrasonic waves in a HIFU irradiation apparatus. A plurality of ultrasonic transducers (2) arranged on a concave surface recessed upward, an ultrasonic imaging probe (10), and a probe driver (8) are provided. The ultrasound imaging probe 10 extends through the concave surface along the central axis of the concave surface and has a probe tip 32 at its lower end. The probe driving section 8 moves the ultrasonic imaging probe 10 along the central axis. The probe tip portion 32 has a pair of side surfaces along a pair of normal lines extending from the focal point of the plurality of ultrasonic transducers 2 toward the concave surface symmetrically with respect to the central axis. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a HIFU irradiation device with an ultrasonic imaging probe, and more particularly to improvements in the ultrasonic imaging probe.

Treatment devices using High Intensity Focused Ultrasound are widely used. This treatment apparatus is called a HIFU irradiation apparatus or HIFU irradiation system, and irradiates a treatment site with focused ultrasonic waves to necrotize living tissue.

Generally, a HIFU irradiation device has a plurality of ultrasonic transducers arranged on a concave surface. The plurality of ultrasonic transducers are arranged so that the ultrasonic waves emitted from each are irradiated to one point to form a focal point. At the time of treatment, ultrasonic waves are emitted with the focus position adjusted to the treatment site under the guidance of an ultrasonic diagnostic apparatus. As one method for confirming the irradiation position, there is a method using an ultrasonic diagnostic apparatus that represents a focal point on an ultrasonic image.

Patent Literature 1 below describes an ultrasonic therapeutic apparatus that observes the position of a focal point using an ultrasonic diagnostic apparatus that displays a B-mode image (tomographic image). In this device, ultrasonic waves of a weak level that do not affect tissues are emitted from a therapeutic ultrasonic transducer, and a tomographic image is displayed by transmission and reception of ultrasonic waves by an ultrasonic imaging probe. Since the acoustic properties of the tissue of the subject change according to the temperature change of the tissue, the tomographic image shows the position of the focal point by the strength of the luminance. Further, Patent Documents 2 and 3 describe the structure of an ultrasonic imaging probe as a technology related to the present invention.

JP-A-8-71069 JP 2012-135427 A Japanese Unexamined Patent Application Publication No. 2008-581

In general, in treatment using strong focused ultrasound under the guidance of an ultrasound diagnostic device, B-mode images are acquired by transmitting and receiving ultrasound waves with an ultrasound imaging probe, enabling observation of the patient's biological tissue and positioning of the treatment target. done. During treatment and preparation, ultrasonic waves are emitted from a therapeutic ultrasonic transducer and transmitted and received by an ultrasonic imaging probe. However, depending on the positional relationship between the therapeutic ultrasound transducer and the ultrasound imaging probe, and the shape and structure of the ultrasound imaging probe, the ultrasound imaging probe may interfere with the propagation of the therapeutic ultrasound or cause reflection and scattering. Problems such as irradiating therapeutic ultrasound to areas that should not be treated may occur.

An object of the present invention is to suppress the influence of an ultrasonic imaging probe on the propagation state of therapeutic ultrasonic waves in a HIFU irradiation apparatus.

The present invention provides a plurality of ultrasonic transducers arranged on a concave surface recessed upward, and an ultrasonic imaging probe penetrating the concave surface and extending along the central axis of the concave surface, wherein the ultrasonic waves are an ultrasound imaging probe having a probe tip directed to a focal point for a transducer; and a probe driver for moving the ultrasound imaging probe along the central axis, the probe tips having a plurality of has a pair of long-axis direction side surfaces that spread flatly in a direction along a pair of predetermined normal lines toward the concave surface symmetrically with respect to the central axis from the focal point of the ultrasonic transducer of the pair of When the ultrasonic imaging probe is located at the lowest position in the drivable range, the pair of longitudinal side surfaces are tangent to the pair of normals .

Desirably, at least part of the probe tip is made of a material that absorbs ultrasonic waves.

Desirably, at least part of the probe tip has at least two layers, an ultrasonic wave absorbing layer and a heat conducting layer.

Desirably, the short axis direction side surface of the probe tip has a protruding region protruding in the long axis direction.

According to the present invention, the HIFU irradiation apparatus can suppress the influence of the ultrasonic imaging probe on the propagation state of therapeutic ultrasonic waves.

It is a figure which shows the structure of a HIFU irradiation system. FIG. 2 is a view of a cross section of the HIFU transducer unit parallel to the xy plane and an ultrasound probe viewed in the negative z-axis direction; FIG. 2 is a view of a cross section of the HIFU transducer unit parallel to the xy plane and an ultrasound probe viewed in the positive and negative z-axis directions; FIG. 2 is a view of a cross section of the HIFU transducer unit parallel to the yz plane and an ultrasound probe viewed in the positive direction of the x axis;

An embodiment of the present invention will be described with reference to each drawing. The same reference numerals are attached to the same components shown in a plurality of drawings, and the description thereof is omitted. Terms such as up, down, left, and right in this specification indicate directions in the drawings. These directional terms are for convenience of explanation, and do not limit the posture when arranging each component.

FIG. 1 shows the configuration of a HIFU irradiation system 1 according to an embodiment of the invention. The HIFU irradiation system 1 includes a probe driving unit 8, an ultrasonic imaging probe 10 (hereinafter referred to as the ultrasonic probe 10), a HIFU transducer unit 12, a coupling bag 14, a robot arm 18, a controller 22 and a display device 24. there is In FIG. 1, a plane (observation target plane) on which an ultrasonic image such as a B-mode image is to be observed in the patient 30 is a plane parallel to the yz coordinate plane, and a coordinate axis perpendicular to the yz coordinate plane is the x axis. there is

The HIFU transducer unit 12 includes a transducer housing 16 and a plurality of ultrasonic transducers 2 fixed to the transducer housing 16 . The transducer housing 16 has a plurality of ultrasonic transducers 2 arranged on a concave surface that is recessed upward. Here, the concave surface may be a virtual surface on which the plurality of ultrasonic transducers 2 are arranged. That is, the transducer housing 16 does not necessarily have a concave surface, and may have a structure in which the plurality of ultrasonic transducers 2 are arranged on the concave surface.

The concave surface may be in the shape of a side surface of a cone. Also, the concave surface may have a shape in which the apex side of the pyramid is cut off by a cutting line that surrounds the circumference of the pyramid. In this case, the concave surface may have a frame-like or ring-like shape with the perforation line as the inner periphery. Then, only the ultrasonic transducers arranged on the concave surface outside the cut line may be selectively driven to generate and focus ultrasonic waves. Here, a cone refers to a three-dimensional shape formed by a collection of straight lines extending from one point in space to the bottom surface. Each ultrasonic transducer 2 is arranged in a transducer housing such that when each ultrasonic transducer 2 emits an ultrasonic wave, the intensity of the ultrasonic wave is increased at the treatment reference point P below the transducer housing 16. 16 is fixed. That is, each ultrasonic transducer 2 is fixed to the transducer housing 16 so as to form a focal point on the treatment reference point P. As shown in FIG.

The ultrasonic probe 10 is attached to the transducer housing 16 so that ultrasonic waves are transmitted and received at a position below the transducer housing 16 and above the treatment reference point P. FIG. In this embodiment, the ultrasonic probe 10 vertically penetrates through the center portion of the transducer housing 16, and the probe distal end portion 32 for transmitting and receiving ultrasonic waves faces downward. The ultrasonic probe 10 has directionality, and ultrasonic waves are transmitted and received on an observation surface facing a direction according to the structure of the ultrasonic probe 10 . In this embodiment, the probe tip 32 has its long axis directed in the z-axis direction and its short axis directed in the x-axis direction, so that the observation surface extends in the long axis direction. As will be described later, the support portion 34 of the ultrasonic probe 10 is driven by the probe driving portion 8 to move vertically. Also, the ultrasound probe 10 may be rotatable about its longitudinal axis.

Below the HIFU transducer unit 12, there are couplings for holding liquid such as degassed water, which is a good propagation medium for ultrasound waves, between each of the ultrasound transducers 2 and the ultrasound probe 10 and the patient 30. A bag 14 is provided. The coupling bag 14 may be a bag filled with liquid such as degassed water. The coupling bag 14 may be made of a material that transmits light, and may be transparent or translucent. That is, the ultrasonic probe 10 may be seen through from the outside of the coupling bag 14 .

The ultrasonic probe 10, HIFU transducer unit 12, and coupling bag 14 are attached to the tip of a robot arm 18 as a transport mechanism. The robot arm 18 is composed of a plurality of arms 18a connected by joints 18b, and is attached to the housing of the controller 22 via the joints 18b. By swinging each arm 18a around the joint 18b as a rotation axis, the robot arm 18 moves the movable body 20 including the probe driving section 8, the ultrasonic probe 10, the HIFU transducer unit 12 and the coupling bag 14 along the x-axis. , y-axis and z-axis.

The controller 22 has a HIFU control section 26 and a robot control section 28 . The HIFU control section 26 includes a computer, an electric circuit for controlling the probe driving section 8 , an electric circuit for controlling the ultrasonic probe 10 , and an electric circuit for controlling the HIFU transducer unit 12 . The computer included in the HIFU control unit 26 may be a computer for business use, a personal computer, a tablet computer, or the like. By executing the program, the computer executes processing for generating each image and processing for displaying each image. The HIFU control unit 26 is connected with an operation device (not shown) for the user to operate the HIFU irradiation system 1 . The operating device may include a mouse, a touch panel integrated with the display device 24, a switch, a keyboard, and the like.

The HIFU control section 26 executes processing for operating the probe driving section 8, the ultrasonic probe 10 and the HIFU transducer unit 12. FIG. For example, the HIFU controller 26 controls the probe driver 8 . The probe drive unit 8 drives the ultrasonic probe 10 vertically under the control of the HIFU control unit 26 . In addition, the HIFU control unit 26 causes the ultrasonic probe 10 to transmit and receive ultrasonic waves, generates B-mode image data based on the received signal based on the ultrasonic waves received by the ultrasonic probe 10, and displays the B-mode image data on the display device 24. Display the mode image. The HIFU control unit 26 further causes each ultrasonic transducer 2 included in the HIFU transducer unit 12 to transmit therapeutic ultrasonic waves.

The robot control section 28 may control the robot arm 18 according to the control of the HIFU control section 26 to cause the robot arm 18 to transport the movable body 20 . Also, the robot control section 28 may be provided with an operating device. In this case, the robot control section 28 may control the robot arm 18 according to the user's operation of the operating device.

Before therapeutic ultrasound is emitted from the HIFU transducer unit 12 to the patient 30, the following positioning process may be performed. The HIFU control unit 26 causes each ultrasonic transducer 2 to transmit ultrasonic waves with a lower intensity than during treatment. The position and orientation of the ultrasonic probe 10 are set such that the observation plane of the ultrasonic probe 10 matches the observation target plane of the patient 30 . The HIFU control unit 26 causes the ultrasonic probe 10 to scan the observation target plane of the patient 30 with an ultrasonic beam to obtain B-mode image data. The HIFU control unit 26 causes the display device 24 to display the B-mode image. A user as a practitioner refers to the B-mode image displayed on the display device 24 to confirm the difference between the focus of the ultrasonic waves transmitted from the HIFU transducer unit 12 and the position of the affected area.

The user operates the robot arm 18 and the probe driving section 8 to change the positions or postures of the ultrasonic probe 10 and the HIFU transducer unit 12 when the difference between the focus position and the affected part position is not within the allowable range. . After confirming that the position of the focus and the position of the affected area match, the user operates the HIFU control unit 26 for treatment. The HIFU control unit 26 causes each ultrasonic transducer 2 to transmit therapeutic ultrasonic waves having an intensity necessary for treatment according to user's operation. This causes the living tissue to be cauterized and treated at the focal point.

FIG. 2 shows a cross section of the HIFU transducer unit 12 parallel to the xy plane and a diagram of the ultrasonic probe 10 viewed in the negative z-axis direction. This figure shows the ultrasonic probe 10 in the lowest position. Also, the short-axis direction side surface of the probe tip portion 32 is exposed.

The ultrasonic probe 10 includes a support portion 34 whose longitudinal direction is the y-axis direction, and a probe distal end portion 32 provided at the lower end of the support portion 34 . The support portion 34 is attached to the probe driving portion 8 . The probe distal end portion 32 has a pair of longitudinal side surfaces 44 whose facing distance increases upward from the lower end of the probe distal end portion 32 . A pair of longitudinal side surfaces 44 are a pair of side surfaces whose surfaces extend along a pair of normal lines 42 extending from the treatment reference point P (focus) toward the concave surface 40 . With the ultrasound probe 10 in its lowest position, each longitudinal side 44 may meet along each normal 42 . Here, the pair of normal lines 42 extend from the treatment reference point P toward the concave surface 40 within a plane parallel to the xy plane and symmetrical with respect to the central axis 48 of the concave surface 40 .

The width of the tip surface 36 (lower end surface) of the probe tip portion 32 in the x-axis direction is, for example, 14 mm. Moreover, the distance along the y-axis direction from the distal end surface 36 to the treatment reference point P is, for example, 30 mm.

The pair of long-axis direction side surfaces 44 may extend inside the pair of normal lines 42 along the pair of normal lines 42 when the ultrasonic probe 10 is at the lowest position. .

According to the structure of the ultrasonic probe 10 as described above, an outer ultrasonic wave emitted from the ultrasonic transducer 2 located outside the reference circle 46 passing through the intersection of the normal 42 and the concave surface 40 and perpendicular to the central axis 48 is detected. Acoustic waves contribute to treatment at the treatment reference point P. The propagation state of the outer ultrasonic wave is not easily disturbed by the ultrasonic probe 10 . By making the structure of the probe distal end portion 32 a structure in which a pair of longitudinal side surfaces 44 are widened along a pair of normal lines 42, the reference circle 46 becomes smaller, and the ultrasonic probe 10 is in a propagation state of therapeutic ultrasonic waves. impact on

In addition, the thickness of the support portion 34 of the ultrasonic probe 10 in the x-axis direction becomes larger than the thickness of the probe distal end portion 32 in the x-axis direction, and the mechanical strength of the ultrasonic probe 10 increases. Furthermore, it becomes easier to arrange various components within the ultrasound probe 10 .

FIG. 3 shows a cross section of the HIFU transducer unit 12 parallel to the xy plane and a view of the ultrasonic probe 10 in the positive and negative directions of the z axis. This figure shows a state in which the ultrasonic probe 10 is above the lowest position. In the state shown in FIG. 3 , the pair of longitudinal side surfaces 44 are inside the pair of normal lines 42 . Therefore, the number of ultrasonic transducers 2 contributing to treatment at the treatment reference point P is greater than the state shown in FIG. Therefore, when the ultrasonic probe 10 is above the lowest position, the ultrasonic probe 10 exerts less influence on the propagation state of therapeutic ultrasonic waves than when it is at the lowest position.

FIG. 4 shows a cross section of the HIFU transducer unit 12 parallel to the yz plane and a diagram of the ultrasonic probe 10 viewed in the positive x-axis direction. This view shows the longitudinal side of the probe tip 32 . As shown in FIG. 4, the short axis direction side surface 50 on the right side of the probe tip portion 32 is formed with a projecting region 52 projecting in the positive z-axis direction, and the short axis direction side surface 50 on the left side is formed with a z A projecting region 52 projecting in the negative axial direction is formed. Here, the radius of curvature Rp of the convex surface of the projecting region 52 may satisfy Rp≦Rf−Lg. However, Rf is the radius of curvature of the concave surface, and Lg is the distance between the projecting region 52 and the concave surface when the ultrasonic probe 10 is at the lowest position. Further, the probe tip portion 32 may have a shape in which a plurality of projecting portions that satisfy the condition of the curvature radius with respect to the convex surface of the projecting region 52 are arranged. In this way, some of the therapeutic ultrasound waves emitted from the plurality of ultrasound transducers 2 are scattered in all directions by the projecting region 52 . As a result, the ultrasonic waves reflected by the probe distal end portion 32 are prevented from being locally focused and irradiated within the body of the patient 30 . Therefore, the influence of the ultrasonic probe 10 on the state of treatment is suppressed.

At least part of the surface of the probe distal end portion 32 may be made of a sound absorbing material. For the sound absorbing material, for example, when degassed water having a specific acoustic impedance of about 1.5×10 ⁶ kg/m ² /sec is used as the ultrasonic propagation medium, a material having acoustic properties close to that is used. you can Such materials include elastomers such as silicone rubber, natural rubber, polyurethane, or low density plastic materials or their porous or foamed materials. Also, the sound absorbing material may be a composite material in which metal particles, metal oxide particles, gas-encapsulated microballoons, or the like are mixed into a base material such as general rubber material or plastic material. Such composites facilitate tuning acoustic impedance and absorption coefficients. As a result, the ultrasonic waves emitted from the ultrasonic transducer 2 and incident on the portion of the probe distal end portion 32 formed of the sound absorbing material are absorbed by the sound absorbing material. Therefore, the influence of the ultrasonic probe 10 on the propagation state of therapeutic ultrasonic waves is suppressed.

Further, at least a portion of the probe tip 32 may have at least two layers, an ultrasound absorbing layer and a heat conducting layer. For example, at least part of the surface of the probe distal end portion 32 may be composed of two layers, the layer of the sound absorbing material and the heat conductive layer provided inside thereof. The heat-conducting layer is made of a material having good heat conductivity, and diffuses and dissipates heat generated by the absorption of ultrasonic waves locally in the sound-absorbing material. The heat-conducting layer may be formed of, for example, a metal plate such as copper or aluminum, or a foil, a metal oxide sintered body, or a composite material or grease containing metal particles or metal oxide particles. As a result, the acoustic characteristics of the sound absorbing layer are prevented from being changed or deteriorated due to the temperature rise accompanying the absorption of the ultrasonic waves, and the effect of suppressing the influence of the ultrasonic probe 10 on the propagation state of the therapeutic ultrasonic waves is stably achieved. can get.

1 HIFU irradiation system, 2 ultrasonic transducer, 8 probe drive unit, 10 ultrasonic imaging probe, 12 HIFU transducer unit, 14 coupling bag, 16 transducer housing, 18 robot arm, 18a arm, 18b joint, 20 Movable body 22 Controller 24 Display device 26 HIFU control section 28 Robot control section 30 Patient 32 Probe tip section 34 Support section 36 Tip surface (lower end surface) 40 Concave surface 42 Normal line 44 Long axis directional side, 46 reference circle, 48 central axis, 50 short axis direction side, 52 projecting area.

Claims (4)

a plurality of ultrasonic transducers arranged on the concave surface;
an ultrasound imaging probe extending through the concave surface and along a central axis of the concave surface, the ultrasound imaging probe having a probe tip directed to a focal point for the plurality of ultrasound transducers;
a probe driving unit that moves the ultrasonic imaging probe along the central axis;
The probe tip is
having a pair of long-axis direction side surfaces that extend flatly in a direction along a pair of predetermined normal lines toward the concave surface symmetrically with respect to the central axis from the focal point of the plurality of ultrasonic transducers;
The pair of longitudinal side surfaces are spaced apart from each other as they go upward from the lower end of the probe tip,
The HIFU irradiation apparatus, wherein the pair of longitudinal side surfaces are in contact with the pair of normal lines when the ultrasonic imaging probe is at the lowest position in a drivable range. In the HIFU irradiation device according to claim 1 ,
A HIFU irradiation apparatus, wherein at least part of the probe tip is made of a material that absorbs ultrasonic waves. In the HIFU irradiation device according to claim 1 or claim 2 ,
A HIFU irradiation apparatus, wherein at least part of the probe tip portion has at least two layers of an ultrasonic wave absorbing layer and a heat conductive layer. In the HIFU irradiation device according to claim 1 or claim 2 ,
The short-axis direction side surface of the probe tip is
A HIFU irradiation device characterized by having a projecting region projecting in a longitudinal direction.

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