JP2021145784A - Ultrasonic therapeutic device - Google Patents

Abstract

To provide an ultrasonic therapeutic device which can easily and accurately measure the electromagnetic wave generated from an affected part.SOLUTION: The ultrasonic therapeutic device comprises an ultrasonic wave irradiating part 2 for irradiating an affected part 1 of a patient P with ultrasonic wave, and a measurement part 3 for measuring temperature of the affected part 1 based on the electromagnetic wave induced by the ultrasonic wave. The measurement part 3 is positioned away from the ultrasonic wave irradiating part 2 and the affected part 1 such that the first electromagnetic wave generated by the affected part 1 by the ultrasonic wave and the second electromagnetic wave generated by the measurement part 3 itself by the ultrasonic wave do not interfere with each other, and is configured such that the affected part 1 is positioned between the ultrasonic wave irradiating part 2 and the measurement part 3 on an axial line L between the ultrasonic wave irradiating part 2 and a convergent point m at which the ultrasonic wave converges.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an ultrasonic therapy device for treating an affected area by irradiating an ultrasonic wave from outside the body to the inside of the body.

High-Intensity Focused Ultrasound (HIFU) is a device that irradiates affected areas such as bone cancer and painful areas of bone with focused ultrasonic waves from outside the body to the inside of the body to non-invasively cauterize the affected areas. The device is known. The prior art is described in, for example, Patent Documents 1 and 2. Further, in the prior art of Patent Document 3, when the bone is continuously irradiated with ultrasonic waves, the ultrasonic waves are intermittently irradiated, and the temperature of the bone is measured from the change in the electromagnetic wave intensity generated from the bone.

Special Fair 7-38858 Gazette Japanese Patent No. 5492822 International Publication No. 2018/097245

In such a device, it is required to improve the measurement accuracy of the bone temperature.

The ultrasonic therapy apparatus of the present disclosure includes an ultrasonic irradiation unit that irradiates an affected area with ultrasonic waves, and an ultrasonic irradiation unit.
It has an antenna and is equipped with a measuring unit that measures the temperature of the affected area based on electromagnetic waves induced by ultrasonic waves.
The output of the measuring unit due to the first electromagnetic wave generated from the affected area by the ultrasonic wave and the output of the measuring unit due to the second electromagnetic wave generated from the antenna itself by the ultrasonic wave can be distinguished on the time axis. The antenna is located away from the affected area and the ultrasonic wave irradiation area.

According to the present disclosure, the accuracy of measuring bone temperature can be improved.

It is a figure which shows the schematic structure of the ultrasonic therapy apparatus of one Embodiment of this disclosure. It is a flowchart for demonstrating operation of an ultrasonic therapy apparatus. It is a graph which showed the intensity of the induced electromagnetic wave when the relative position of a bone sample and a measuring part 3 was changed by voltage. It is a graph which showed the intensity of the induced electromagnetic wave when the relative position of a bone sample and a measuring part 3 was changed by voltage.

Hereinafter, embodiments of the ultrasonic therapy apparatus of the present disclosure will be described with reference to the accompanying drawings.

FIG. 1 is a diagram showing a schematic configuration of an ultrasonic therapy apparatus according to an embodiment of the present disclosure. The ultrasonic therapy apparatus of the present embodiment includes an ultrasonic irradiation unit 2 that irradiates the affected area 1 of the patient P with ultrasonic waves, and a measurement unit 3 that measures the temperature of the affected area 1 based on the electromagnetic waves induced by the ultrasonic waves. , Equipped with.

The measuring unit 3 has an antenna capable of receiving electromagnetic waves. The antenna is a conductor capable of acquiring an electromagnetic wave signal. As the antenna, for example, a loop antenna or a dipole antenna may be used. In this embodiment, a loop antenna is adopted. That is, the measuring unit 3 has a loop-shaped coil made of a conductor, and the measuring unit 3 can measure the temperature of the affected area 1 by receiving the electromagnetic wave generated from the affected area 1. As a result, when ultrasonic waves are irradiated from the ultrasonic irradiation unit 2 to the affected area 1, the bone, which is a piezoelectric body, mechanically vibrates to generate electromagnetic waves. Since the intensity of this electromagnetic wave changes depending on the temperature of the bone, the temperature of the affected area 1 can be measured by receiving the electromagnetic wave by the coil and measuring the induced electromotive force (voltage) caused by the electromagnetic wave.

Further, the coil of the measuring unit 3 is arranged in the ultrasonic irradiation unit 2 and the affected area 1 so that the first electromagnetic wave generated from the affected area 1 by ultrasonic waves and the second electromagnetic wave generated from the measuring unit 3 itself by ultrasonic waves do not interfere with each other. It is located away from. That is, the output of the measurement unit 3 by the first electromagnetic wave generated from the affected area by the ultrasonic wave of the ultrasonic wave irradiation unit 2 and the output of the measurement unit 3 by the second electromagnetic wave generated from the coil itself by the ultrasonic wave of the ultrasonic wave irradiation unit 2. The coil is located away from the affected area 1 and the ultrasonic wave irradiation area 2 so that can be distinguished on the time axis.

Here, in the conventional HIFU device, in order to measure the temperature of the bone, the coil receives the electromagnetic wave generated from the bone. On the other hand, the ultrasonic waves radiated toward the bone may hit the coil. When ultrasonic waves hit the coil, the coil itself may generate electromagnetic waves. It is considered that this is a result of the induced electromotive force generated in the coil due to the electromagnetic induction action or the like. Therefore, the output caused by the electromagnetic wave generated from the bone and the output caused by the electromagnetic wave generated from the coil itself may be superimposed on the measuring unit 3, and the measurement accuracy of the bone temperature may be lowered.

On the other hand, in the ultrasonic therapy apparatus according to the present disclosure, the measurement unit 3 is arranged as described above, so that the first output of the measurement unit 3 caused by the first electromagnetic wave and the second electromagnetic wave are caused. The second output of the measuring unit 3 to be measured can be distinguished on the time axis, and the temperature of the affected part (bone) can be measured based on the first output. Therefore, in the ultrasonic therapy apparatus according to the present invention, the accuracy of measuring the bone temperature can be improved.

The ultrasonic wave irradiation unit 2 and the measurement unit 3 are housed in a box-shaped structure 20 that defines an electromagnetic wave shielding room (that is, a shield room or an electromagnetic wave shielding space) in order to block electromagnetic waves.

The affected area 1 is located between the ultrasonic wave irradiation unit 2 and the measurement unit 3. As a result, the measuring unit 3 can receive the electromagnetic wave generated from the affected part 1 in a time earlier than the electromagnetic wave generated by the ultrasonic wave hitting the coil. Therefore, each electromagnetic wave can be classified without being superimposed, and the electromagnetic wave of the affected portion 1 can be received with high accuracy.

The factor that can be divided in time is that the speed of electromagnetic waves propagates at the speed of light (30,000 km / s). On the other hand, the velocity of ultrasonic waves propagates at 1500 m / s in water, for example. Therefore, if the distances between the bone and the coil are different, ultrasonic waves are applied at different times according to the distances. However, since electromagnetic waves are generated at the moment when ultrasonic waves hit the bone and the coil, the electromagnetic waves of the bone and the coil can be separated in time.

The measuring unit 3 is located, for example, on the axis L connecting the ultrasonic wave irradiation unit 2 and the convergence point m where the ultrasonic waves are focused. As a result, the measuring unit 3 can receive a strong electromagnetic wave generated from the bone.

Further, the ultrasonic therapy apparatus may include a first waveguide 4 in which a fluid having a dielectric constant higher than that of air is sealed. The first waveguide 4 is connected to the ultrasonic irradiation unit 2 and the affected area 1. As a result, the affected part can be efficiently irradiated with ultrasonic waves, and when the measuring unit 3 is installed in the first waveguide 4, the electromagnetic wave generated from the bone can be efficiently received. The first waveguide 4 is also called a balloon. The first waveguide 4 is made of a liquid-tight structure having mechanical strength so that a liquid can be sealed.

Further, the ultrasonic therapy apparatus may include a second waveguide 5 in which a fluid having a dielectric constant higher than that of air is sealed. The measuring unit 3 is arranged in the second waveguide 5. Then, the second waveguide 5 is connected to the affected portion 1. As a result, the electromagnetic waves generated from the bone can be efficiently received. The second waveguide 5 is made of a liquid-tight structure having mechanical strength so that a liquid can be sealed.

For example, pure water may be sealed in the first waveguide 4 or the second waveguide 5 as a fluid having a dielectric constant higher than that of air. As a result, the electromagnetic waves generated from the bone can be efficiently received.

The ultrasonic therapy device of the present embodiment is for relieving bone pain caused by metastatic bone cancer, arthralgia, etc., that is, pain generated in a shallow part of the body having a depth of about 1 mm to 30 mm from the body surface. It may be used for. The ultrasonic irradiation unit 2 includes a high-intensity focused ultrasound (HIFU) transducer 6 including a plurality of transducers made of a piezoelectric material, a housing 7 in which the HIFU transducer 6 is housed, and a HIFU transducer 6 It also has a drive device 8 that holds the housing 7 in a displaceable manner.

A therapeutic support 9 on which the patient can lie on his / her back or lying down is provided below the ultrasonic irradiation unit 2, and a second waveguide 5 is provided below the therapeutic support 9. The measurement unit 3 and the support device 10 that supports the measurement unit 3 in a displaceable manner are housed in the second waveguide 5. A hole may be formed in the central portion of the treatment support base 9 so that the second waveguide 5 is in contact with the affected portion 1.

The drive device 8, the treatment support 9 and the support device 10 of the HIFU transducer 6 are X orthogonal to each other on a horizontal virtual plane so that ultrasonic waves can be applied to any part of the patient on the treatment support 9. Move relatively freely along the axes and Y-axis, and the Z-axis, which is the height direction perpendicular to the X-axis and Y-axis, to position the ultrasonic irradiation target site at an appropriate position directly under the HIFU transducer 6. It is configured for positioning.

In the ultrasonic therapy apparatus shown in FIG. 1, the ultrasonic irradiation unit 2 holds a curved disk-shaped HIFU transducer 6 that spreads over the affected area 1 and cooling water for cooling the ultrasonic irradiation target portion of patient P. The first waveguide 4, which is a balloon made of a resin film for the purpose of the ultrasonic wave, and a housing 7 which is suspended on the body of the patient P and which is supported by the driving device 8 and can be moved are mainly configured. Has been done. The connection between each member such as piping and wiring in FIG. 1 is not shown.

The HIFU transducer 6 is located above the affected area 1 as a whole and has a concave parabolic shape downward downward. The plurality of vibrators described above are arranged and arranged on the concave inner surface. Since the inner surface of the HIFU transducer 6 is formed on a curved surface having a radius of curvature that focuses toward the convergence point m, when each oscillator oscillates ultrasonic waves at the same time, the oscillated ultrasonic waves are at one point ( Focuses on the focus) and becomes HIFU.

The HIFU transducer 6 (ultrasonic wave irradiation unit) has a disk-like shape that extends above the affected area 1 as described above, so that as many oscillators as possible can be placed on a wide surface facing the affected area 1. This is to ensure the ultrasonic transmission intensity by arranging them side by side. Therefore, the shape of the HIFU transducer 6 is not limited to the above-mentioned disk shape or disc shape, and the overall shape of the irradiated portion is particularly limited as long as a wide surface facing the affected portion 1 can be secured. It's not a thing. For example, the outer shape may be circular or quadrangular, or may be a flat plate.

Further, if the transducer is a phased array type HIFU transducer that can change the focal point of ultrasonic waves and the depth of field, the radius of curvature of the parabolic shape in the HIFU transducer 6 can be changed, or a flat flat plate can be used. It is also possible to adopt a shaped irradiation unit.

The first waveguide 4 is configured by using a transparent or translucent film made of resin, and degassed cold water (in this case, a water temperature of about 18 ° C.) produced in a cooling water generating portion (not shown) cools the first waveguide 4. By circulating with the water generating portion, the water temperature in the first waveguide 4 is maintained at a constant temperature, and the body surface in contact with the lower part (bottom) of the first waveguide 4 can be cooled. ..

The reason why the body surface of the patient P (the skin surface of the ultrasonic irradiation target site) is cooled by the first waveguide 4 is to reduce burns on the body surface and the surface layer due to the ultrasonic irradiation. The chilled water to be circulated is circulated in a degassed state in order to suppress the generation of bubbles due to ultrasonic irradiation. Further, "transparent or translucent" of the first waveguide 4 in the present embodiment means that the light transmittance of the resin film used in the visible light wavelength band and the ultraviolet light wavelength band is 80% or more. Say something.

Further, the ultrasonic treatment device includes a drive circuit 6a and a power amplifier 6b of the HIFU transducer 6 that irradiates ultrasonic waves, a control device 13 of the drive device 8, an ultrasonic diagnostic device 14 for diagnosing the affected area 1, and ultrasonic waves to the affected area 1. Control that is a control mechanism of a device 15 that supplies pure water to the first waveguide 4 and the second waveguide 5 that serve as an irradiation path, and a support device 10 of the measurement unit 3 that includes a coil that detects electromagnetic waves and the like. It is configured to include the device 16. These are controlled by the system controller 17, control values are input from the input device 18, and each control value, measurement data, and the like are displayed as images by the image display device 19. The system controller 17 may be realized by, for example, a personal computer. The input device 18 may be realized by, for example, a keyboard, a touch panel, or the like. The image display device 19 may be realized by, for example, a liquid crystal display device, an EL display device, an LED display device, or the like.

In the present embodiment, an example is described in which the second waveguide 5, the measuring unit 3, and the support device 10 are arranged inside the therapeutic support 9. In other embodiments, the second waveguide 5, the measuring unit 3, and the support device 10 may be outside the therapeutic support 9. Further, the second waveguide 5, the measuring unit 3 and the support device 10 may be located at positions apart from the HIFU transducer 6 and in contact with the body surface.

The support device 10 may be realized by a serial link, a parallel link mechanism, or the like as a typical drive mechanism for position control from the HIFU transducer 6. Such a mechanism may be used to control all three-dimensional positions and rotations of the X-axis, Y-axis, and Z-axis, but even a mechanism that controls only the position or rotation of at least one axis. good. Further, the position of the measuring unit 3 may be fixed as long as the coil is not exposed to ultrasonic waves and emits unnecessary electromagnetic waves.

FIG. 2 is a flowchart for explaining the operation of the ultrasonic therapy apparatus. First, in step S1, the cauterizing position and the temperature measurement position of the affected area 1 are set, and in step S2, ultrasonic waves are irradiated to each irradiation position of the affected area 1 and the distance is measured from the reflected wave. The position information also uses the position control information of the HIFU transducer 6.

In step S3, the measuring unit 3 is brought closer to the affected area 1 under the positional conditions set. If the irradiation position and the temperature measurement position match, the burst wave for temperature measurement is irradiated as it is. However, the temperature measurement position can be arbitrarily set based on the irradiation position. If the electromagnetic wave intensity of the bone sample when the burst wave is generated in step S4 is sufficiently high, the process proceeds to the next step S5.

If the electromagnetic wave intensity of the bone sample when the burst wave is generated in step S4 is low, the irradiation intensity of the burst wave is increased in step S8, and vice versa if it is too high. Further, the sensitivity of the coil of the measuring unit 3 may be adjusted.

If the electromagnetic wave intensity of the bone sample is still low, the process proceeds to step S9, the HIFU transducer 6 is moved by the drive device 8, and the temperature measurement position is adjusted. The moving distance depends on the focal length of the HIFU transducer 6 and the like, but when the focal length is 100 mm, it moves about 1 mm. There are the following two methods for moving.

(1) When the HIFU transducer 6 is a multi-piezoelectric element type HIFU transducer, the HIFU focal position is moved by controlling the phase of the input signal to each piezoelectric element.
(2) The HIFU transducer 6 itself is moved by mechanical control by the drive device 8.

After obtaining sufficient electromagnetic wave intensity of the bone sample, the position of the measuring unit 3 is moved by the support device 10 in step S3. The moving distance depends on the focal length of the HIFU transducer 6 and the like, but when the focal length is 100 mm, it is moved by about 1 mm to 2 mm at a time within a range of about ± 20 mm. At the same time, the angle of the measuring unit 3 may be changed by about 5 ° at a time.

Next, the process proceeds to step S5, a burst wave is similarly generated at the moved position, and in step S6, the coil of the measuring unit 3 and the electromagnetic wave generation time of the bone sample are confirmed by an image of the image display device 19 or the like. As a result of the confirmation, it is confirmed that the coil of the measuring unit 3 and the electromagnetic wave generation start time of the bone sample are different, and the net electromagnetic wave of the bone sample can be detected independently. The process proceeds to step S7.

In step S7, the bone sample is irradiated with continuous ultrasonic waves to monitor the temperature of the bone sample. After the bone sample reaches the set temperature, the ultrasound irradiation is stopped. After that, the cauterization position and the temperature measurement position of the affected part 1 are set, and the cauterization by the continuous wave of the HIFU, the temperature measurement by the burst wave, and the temperature monitoring of the temperature measurement position are repeated a predetermined number of times.

<Example>
3 and 4 are graphs showing the intensity of the induced electromagnetic wave when the relative positions of the bone sample and the measuring unit 3 are changed in terms of voltage. The inventor confirmed the effect of the coil position of the measuring unit 3 on the net electromagnetic wave of the bone sample.

Specifically, FIGS. 3 and 4 are graphs in which a bone sample (pork cortical bone) is irradiated with ultrasonic waves of burst waves, electromagnetic waves generated from the bones at that time are measured by a coil, and a voltage is displayed. At this time, a plate-shaped pig cortical bone having a thickness of 4.5 mm and a height of 20 mm was used as a sample. Further, the bone sample and the measuring unit 3 were installed in the first waveguide 4. The HIFU transducer used at this time is a concave transducer having a radius of curvature of 100 mm. The burst wave generated from the HIFU transducer was a 1 MHz sine wave, and the wave was repeatedly irradiated at a frequency of 100 Hz. The sound pressure of the ultrasonic waves at this time is 3 MPa.

As shown in FIGS. 3 and 4, the bone sample was fixed at the HIFU focal position (Z = 100 mm), and the measuring unit 3 was moved in the irradiation axis direction of the HIFU transducer 6 (Z = 130 mm). The illustrated bone sample and the electromagnetic wave signal of the measuring unit 3 show the values averaged to remove the extraneous random noise received by the measuring unit 3.

When the position of the measuring unit 3 is Z = 130 mm, the electromagnetic wave signals of the measuring unit 3 and the bone sample are independent (FIG. 4). However, when Z = 100 mm, it was confirmed that the electromagnetic wave signals of the measuring unit 3 and the bone sample were superimposed, and the net electromagnetic wave signal of the bone sample could not be obtained (FIG. 3).

In the present disclosure, the position of the measuring unit 3 can be set at an appropriate position by the mechanical system by the support device 10.

According to the ultrasonic treatment apparatus of the present disclosure, the measuring unit 3 is placed at an appropriate position with respect to the ultrasonic irradiation unit and the affected area, that is, the first electromagnetic wave generated from the affected area by ultrasonic waves and the measuring unit itself by ultrasonic waves. When the affected part 1 such as a bone, which is a weak piezoelectric body, is irradiated with ultrasonic waves, it can be moved and positioned by the support device 10 to a position away from the ultrasonic irradiation part and the affected part so as not to interfere with the second electromagnetic wave. It is possible to easily search for a portion having a high intensity of the induced ultrasonic wave generated in the affected portion 1, and it is possible to monitor a change in the intensity or a temperature change of the electromagnetic wave derived only from the affected portion 1.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various changes, improvements, etc. may be made without departing from the gist of the present disclosure. It is possible. Needless to say, all or a part of each of the above embodiments can be combined as appropriate and within a consistent range.

1 Affected part 2 Ultrasonic irradiation part 3 Measuring part 4 1st waveguide 5 2nd waveguide 6 HIFU transducer 7 Housing 8 Drive device 9 Treatment support 10 Support device 13 Control device 14 Ultrasonic diagnostic device 15 Pure water Supply device 16 Control device 17 System controller 18 Input device 19 Image display device 20 Box-shaped structure m Convergence point L-axis

Claims (6)

An ultrasonic irradiation part that irradiates the affected area with ultrasonic waves,
It has an antenna and is equipped with a measuring unit that measures the temperature of the affected area based on electromagnetic waves induced by ultrasonic waves.
The output of the measuring unit due to the first electromagnetic wave generated from the affected area by the ultrasonic wave and the output of the measuring unit due to the second electromagnetic wave generated from the antenna itself by the ultrasonic wave can be distinguished on the time axis. An ultrasonic therapy apparatus in which the antenna is located away from the affected area and the ultrasonic wave irradiation area. The ultrasonic therapy apparatus according to claim 1.
An ultrasonic therapy device in which the affected area is located between the ultrasonic wave irradiation unit and the measurement unit. The ultrasonic therapy apparatus according to claim 2.
The measuring unit is an ultrasonic therapy device located on an axis connecting the ultrasonic wave irradiation unit and a convergence point at which the ultrasonic waves are focused. The ultrasonic therapy apparatus according to any one of claims 1 to 3.
Further equipped with a first waveguide in which a fluid having a higher dielectric constant than air is enclosed,
The first waveguide is an ultrasonic therapy apparatus connected to the ultrasonic irradiation portion and the affected portion. The ultrasonic therapy apparatus according to any one of claims 1 to 4.
Further equipped with a second waveguide in which a fluid having a higher dielectric constant than air is enclosed,
The measuring unit is arranged in the second waveguide.
The second waveguide is an ultrasonic therapy device connected to the affected area. The ultrasonic therapy apparatus according to any one of claims 1 to 5.
An ultrasonic therapy apparatus in which pure water is sealed in the first waveguide or the second waveguide.

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