WO2017126037A1 - Ultrasonic medical device - Google Patents

Abstract

An ultrasonic medical device (100) of the present invention is provided with: a drive unit (7) that drives an ultrasonic element (5) so as to sequentially output from the ultrasonic element (5) first ultrasonic waves (W1) for generating bubbles, and second ultrasonic waves (W2) that are weaker than the first ultrasonic waves (W1); a cavitation detection unit (11) that detects cavitation generated due to irradiation of the second ultrasonic waves (W2); and a control unit (9) that controls the drive unit (7) so as to adjust the output of the second ultrasonic waves (W2) on the basis of the results of the cavitation detection.

Description

Ultrasound medical device

The present invention relates to ultrasound medical devices.

Conventionally, an extracorporeal ultrasonic medical device capable of outputting two ultrasonic waves each exhibiting a thermal effect and a cavitation effect is known (see, for example, Patent Document 1). The thermal effect utilizes thermal energy generated by living tissue absorbing ultrasonic waves. The cavitation effect is that the minute gas bubbles generated by the pressure drop due to the ultrasonic vibration expand due to a further drop in the ambient pressure and locally release high energy through the collapse of the bubble when the critical diameter is reached. It uses physical energy to destroy tissue. The ultrasonic medical device of Patent Document 1 measures the temperature and the acoustic field pressure in the skin by a sensor, and controls the output of the ultrasonic wave based on the measured temperature and the acoustic field pressure.

Japanese Patent Publication No. 7-505793

However, in order to generate the cavitation effect, strong ultrasonic waves obtained by irradiating a beam that is strongly focused at the focal point or increasing the voltage applied to the element are required. Since the ultrasonic element mounted on the internal ultrasonic medical device is limited to a small size, using a large-aperture element for strong focusing or generating a strong ultrasonic wave using a large applied voltage It is difficult to do it. Furthermore, in the method of controlling the output of the ultrasonic wave based on the temperature and the acoustic field pressure in the skin as in Patent Document 1, it is not possible to accurately detect whether or not cavitation is occurring, and cavitation is surely performed. There is a problem that it is difficult to properly control the output of ultrasonic waves so as to occur.

The present invention has been made in view of the above-described circumstances, and cavitation can be reliably generated even using a small ultrasonic element, and can be effectively treated using cavitation. The purpose is to provide an acoustic wave medical device.

According to the present invention, a therapeutic ultrasonic wave is generated so that a first ultrasonic wave for generating a bubble in a living tissue and a second ultrasonic wave weaker than the first ultrasonic wave are sequentially output from the therapeutic ultrasonic element. A drive unit for driving the element, a cavitation detection unit for detecting cavitation generated in the living tissue by the irradiation of the second ultrasonic wave, and the second one based on the detection result of the cavitation by the cavitation detection unit And a control unit configured to control the drive unit to adjust an output of the ultrasonic wave.

According to the present invention, cavitation can be reliably generated even if a small ultrasonic element is used, and it is possible to effectively treat using cavitation.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the ultrasound medical device which concerns on the 1st Embodiment of this invention. It is a figure which shows the intensity | strength and output timing of the bubble formation ultrasound which the ultrasonic medical device of FIG. 1 outputs, and a treatment ultrasound. It is a flowchart which shows operation | movement of the ultrasound medical device of FIG. It is a whole block diagram of the ultrasound medical device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the intensity | strength and output timing of the bubble formation ultrasound which the ultrasonic medical device of FIG. 4 outputs, and a therapeutic ultrasound, and the output timing of a diagnostic ultrasound. It is a flowchart which shows operation | movement of the ultrasound medical device of FIG. It is a whole block diagram of the ultrasound medical device which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the ultrasound medical device of FIG. (A), (b) It is a figure explaining the movement of the focus in a 1st period, and the movement of the focus in a (c), (d) 2nd period. It is a figure which shows the timing of the output of the therapeutic ultrasound in a 2nd period. It is a flowchart which shows the modification of operation | movement of the ultrasound medical device of FIG. It is a figure which shows the intensity | strength and output timing of the bubble formation ultrasound which the ultrasonic medical device which concerns on the 4th Embodiment of this invention outputs, a therapeutic ultrasound, and a preheating ultrasound. It is a flowchart which shows operation | movement of the ultrasound medical device which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the modification of operation | movement of the ultrasound medical device which concerns on the 4th Embodiment of this invention.

First Embodiment
Hereinafter, an ultrasonic medical apparatus 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, the ultrasonic medical device 100 according to the present embodiment includes an elongated probe 1 insertable into the body, a housing 2 connected to the proximal end of the probe 1, and the housing 2. The operation unit 3 and the display unit 4 are connected.

The probe 1 has a therapeutic ultrasonic element 5 which alternatively outputs a bubbling ultrasonic wave (first ultrasonic wave) W1 and a therapeutic ultrasonic wave (second ultrasonic wave) W2, and a sound wave reflected in a living tissue And a receiving element 6 for receiving. In FIG. 1, although the positions of the treatment ultrasonic element 5 and the receiving element 6 are separated, harmonics and subharmonics generated in the vicinity of the focal point F and the focal point F by the therapeutic ultrasonic wave W2 output from the therapeutic ultrasonic element 5 Of the treatment ultrasonic element 5 and the reception element 6 so that the treatment ultrasonic element 5 and the reception element 6 can both be inserted into the body with the treatment ultrasonic element 5 facing the affected area. Are arranged close to each other.

The housing 2 generates a drive signal for generating the bubbling ultrasonic wave W1 or the therapeutic ultrasonic wave W2 and applies the drive signal to the therapeutic ultrasonic element 5; The switching control unit 8 that switches the ultrasonic waves W1 and W2 generated in the ultrasonic element 5, the output control unit 9 that controls the output of the bubbling ultrasonic wave W1 and the therapeutic ultrasonic wave W2, and the sound wave received by the receiving element 6 A signal processing unit 10 for extracting a cavitation signal S from the inside, a cavitation detection unit 11 for detecting cavitation based on the strength of the cavitation signal S extracted by the signal processing unit 10, and a detection result by the cavitation detection unit 11 A central control unit (control unit) 12 that controls the output control unit 9 based on the above, and a storage unit 13 are provided.

The therapeutic ultrasonic element 5 outputs focused ultrasonic waves (HIFU) focused to the same focal point F as a bubbling ultrasonic wave W1 and a therapeutic ultrasonic wave W2. The bubbling ultrasonic wave W1 is for bubbling nanodroplets to generate microbubbles. Nanodroplets are liquid-filled, nanometer-sized capsules made of lipid membranes, membranes of proteins or polymers. The membrane holds a ligand that specifically binds to a specific component (eg, cancer cell) present in the affected area in the living body. Thus, nanodroplets administered to a living body are to be accumulated in the affected area. The survival and disappearance of the microbubbles depend on the relationship between the boiling point of the droplet and the ambient temperature. When the boiling point of the droplet is lower than the ambient temperature at the time of bubbling, the microbubbles remain, and when the boiling point of the droplet is higher than the ambient temperature at the time of bubbling, the microbubble disappears. The droplets have a boiling point equal to or less than the body temperature (37 ° C.) so as to easily cause air bubbles in the living body.

The nanodroplet is bubbled by being irradiated with an ultrasonic wave having an amplitude of a predetermined value or more. Therefore, the bubbled ultrasonic wave W1 has an amplitude equal to or greater than a predetermined value. When the nanodroplet is irradiated with the bubbling ultrasonic wave W1, the capsule of the nanodroplet is broken, the drop enclosed in the capsule is dispersed in the living tissue, and the drop is bubbled. , Micro bubbles which are air bubbles of micrometer size are generated. Since the boiling point of the liquid is below the body temperature, once generated microbubbles remain stably for a long time. The bubbled ultrasonic wave W1 is a short pulse and does not directly affect the living body.

The therapeutic ultrasonic wave W2 is for generating cavitation and has an amplitude smaller than that of the bubbled ultrasonic wave W1. Cavitation means that the pressure of the liquid is locally reduced by ultrasonic vibration to generate a bubble, and furthermore, the high energy resulting from the adiabatic compression accompanying the crush phenomenon that occurs when the bubble reaches a critical diameter is locally released Phenomenon. When cavitation occurs in the living tissue due to the irradiation of the therapeutic ultrasonic wave W2, harmonics and subharmonics of the focal point F of the therapeutic ultrasonic wave W2 and the therapeutic ultrasonic wave W2 generated near the focal point F are enhanced. These harmonics and subharmonics are received by the receiving element 6 as a cavitation signal S.

The switching control unit 8 switches between the bubbling ultrasonic wave W1 and the therapeutic ultrasonic wave W2 having an amplitude smaller than that of the bubbling ultrasonic wave W1 by switching the amplitude of the drive signal generated by the driving signal generation unit 7. Here, as shown in FIG. 2, the switching control unit 8 causes the therapeutic ultrasonic element 5 to generate the bubbled ultrasonic wave W1 in the first period, and the treatment is over performed in the second period following the first period. The drive signal generation unit 7 is controlled to cause the therapeutic ultrasonic element 5 to generate the acoustic wave W2.

The output control unit 9 controls the start and end of the output of the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2 by controlling the timing at which the driving signal generation unit 7 generates a driving signal. The bubbling ultrasonic wave W1 is a pulse for bubbling, and if the pulse length is excessively long, cavitation may proceed during irradiation of the bubbling ultrasonic wave W1, so a pulse of an appropriate length is generated. Need to adjust to the length.

Here, in the treatment, the irradiation sequence of the cycle shown in FIG. 2 is repeated, and it is 1 mm from the end of the irradiation of the therapeutic ultrasonic wave W2 to the start of the irradiation of the next bubbling ultrasonic wave W1. A pause of about seconds to 10 milliseconds is provided. After generation of cavitation due to the therapeutic ultrasonic wave W2, minute air bubbles (residue air bubbles) may be generated. When the residual bubbles are irradiated with the bubbling ultrasonic wave W1, the residual bubbles become cavitation nuclei and cavitation occurs even in the first period, and the effect of the nanodroplet is accurately detected from the cavitation signal S. Can not By providing a rest period and waiting for the disappearance of residual bubbles, the next bubbled ultrasonic wave W1 is irradiated, so that only stable microbubbles generated by the bubbling of nanodroplets can be used as cavitation nuclei.

The signal processing unit 10 extracts the cavitation signal S from the sound waves received by the receiving unit. That is, the signal processing unit 10 generates a component having a frequency n (n = 2, 3,...) And 1 / m (m = 2, 3,...) Times the frequency (drive frequency) of the drive signal. Extract at least one of them. In particular, the occurrence of cavitation significantly enhances the second, third and fourth harmonics. Therefore, it is preferable that the signal processing unit 10 extract one of the components having a frequency twice, three times, or four times the drive frequency, which corresponds to a second, third, or fourth harmonic. .

The cavitation detection unit 11 compares the strength of the cavitation signal S extracted by the signal processing unit 10 with a predetermined threshold. When the strength of the cavitation signal S is equal to or more than a predetermined threshold, the cavitation detection unit 11 determines that cavitation is occurring. On the other hand, when the strength of the cavitation signal S is less than the threshold value, the cavitation detection unit 11 determines that cavitation has not occurred. The cavitation detection unit 11 transmits the cavitation detection result to the central control unit 12.

The central control unit 12 causes the cavitation detection unit 11 to detect cavitation in the second period, receives the detection result, and controls the output control unit 9 based on the received detection result. Specifically, when cavitation is detected, the central control unit 12 repeats the irradiation sequence of FIG. 2 and continues the irradiation of the ultrasonic waves W1 and W2. When cavitation is not detected, the central control unit 12 repeats the irradiation sequence of FIG. Control the output control unit 9 so as to complete the process.

The operation unit 3 allows a user to input treatment conditions. The treatment conditions are, for example, the output conditions (amplitude, output time, frequency) of the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2, the boiling point of the liquid of the nanodroplet, and the like. The treatment conditions input to the operation unit 3 are stored in the storage unit 13. The central control unit 12 controls the switching control unit 8 and the output control unit 9 in accordance with the treatment conditions stored in the storage unit 13.

Next, the operation of the ultrasonic medical apparatus 100 configured as described above will be described with reference to FIG.
First, a user administers a drug containing nanodroplets to a living body. Nanodroplets administered in vivo accumulate in the affected area. Next, the user inputs treatment conditions using the operation unit 3 (step S1). Next, the user aligns the probe 1 with the affected area so that the focal point F of the bubbling ultrasonic wave W1 and the therapeutic ultrasonic wave W2 is located at the affected area, and operates the operation unit 3 to operate the ultrasonic wave to the affected area. Irradiation of W1 and W2 is started.

First, the switching control unit 8 causes the therapeutic ultrasonic element 5 to output the bubbled ultrasonic wave W1 in the first period (step S2). As a result, microbubbles are generated in the affected area. Next, the switching control unit 8 causes the therapeutic ultrasonic element 5 to output a therapeutic ultrasonic wave W2 weaker than the bubbling ultrasonic wave W1 in the second period (step S3). When the therapeutic ultrasound W2 is irradiated to the affected area, cavitation occurs due to the microbubbles present in the affected area, and the cavitation signal S is received by the receiving element 6 (step S4), and the cavitation signal S is extracted by the signal processing unit 10 Ru. The cavitation detection unit 11 detects whether cavitation is occurring based on the strength of the cavitation signal S while the treatment ultrasonic wave W2 is being output (step S5).

The cavitation signal S has a strength equal to or higher than the threshold value because cavitation is strongly generated by the irradiation of the treatment ultrasonic wave W2 while the microbubbles are present in the affected area. When the irradiation of bubbling ultrasonic wave W1 and therapeutic ultrasonic wave W2 is repeated, the number of nanodroplets decreases and the amount of microbubbles generated decreases gradually, so that the cavitation weakens and the strength of the cavitation signal S falls below the threshold. become.

When cavitation is detected by the cavitation detection unit 11 (YES in step S5), the central control unit 12 controls the output control unit 9 to continuously output the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2 repeatedly ( Steps S2 and S3). On the other hand, when the cavitation detection unit 11 detects no cavitation (NO in step S5), the central control unit 12 causes the output control unit to stop the repetitive output of the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2. 9 is controlled (step S6). Thus, while the cavitation can be generated by the microdroplets derived from the nanodroplets, the bubbling ultrasonic wave W1 and the therapeutic ultrasound W2 are irradiated to the affected area, and the nanodroplets disappear in the affected area, and the microbubbles are generated. When the cavitation ceases to occur, the irradiation of the bubbling ultrasonic waves W1 and the treatment ultrasonic waves W2 is automatically stopped.

As described above, according to the present embodiment, whether or not cavitation occurs in the affected area can be accurately detected based on the cavitation signal S. Then, while the cavitation effect is obtained, the irradiation of the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2 is repeated and continued, and the irradiation of the bubbling ultrasonic wave W1 and the treatment ultrasonic wave W2 is ended when the cavitation effect is not obtained. This has the advantage that cavitation can be used to treat the affected area efficiently.

Furthermore, the microbubbles promote the generation of cavitation by vibrating the microbubbles by irradiation of the therapeutic ultrasonic wave W2. By combining the therapeutic ultrasound W2 with such microbubbles, cavitation can be generated in the affected area even with the low energy therapeutic ultrasound W2. Therefore, there is an advantage that a small therapeutic ultrasonic element 5 can be used, and treatment using the cavitation effect by the internal ultrasonic medical device 100 can be enabled.

Furthermore, the area where cavitation occurs due to the low energy therapeutic ultrasonic wave W2 is limited to the area where the microbubbles exist. Therefore, even if the region other than the affected area of the living tissue is irradiated with the therapeutic ultrasonic wave W2, the generation of cavitation in the region other than the affected area can be prevented.

More specifically, cavitation occurs when there are bubbles serving as cavitation nuclei, and micro bubbles are generated after cavitation. Although the microbubbles disappear quickly, if the microbubbles are irradiated with ultrasonic waves before the disappearance, the microbubbles may become cavitation nuclei and cavitation may occur. Therefore, by providing an ultrasonic stop time (rest period) of 1 ms to 10 ms after the irradiation with the therapeutic ultrasonic wave W2, the microbubbles (residue bubbles) generated by cavitation are eliminated, and the remaining microdroplets derived from nanodroplets are eliminated. There is an advantage that cavitation can be prevented from occurring in the area other than the affected area where the bubble is present.
Furthermore, it is prevented that the controllability of the cavitation generation area is lowered by causing the sound pressure reflected place by the ultrasonic wave reflected by the air bubble accompanying the cavitation and the place different from the desired ultrasonic sound pressure distribution. You can also.

In the present embodiment, in the second period, the central control unit 12 stops the output of the therapeutic ultrasonic wave W2 based on the cavitation signal (that is, adjusts the amplitude of the therapeutic ultrasonic wave W2 to zero). Alternatively, or in addition to this, the drive signal generator 7 may be controlled to adjust the amplitude of the therapeutic ultrasonic wave W2 according to the strength of the cavitation signal.

For example, the central control unit 12 may control the drive signal generation unit 7 so as to reduce the intensity of the therapeutic ultrasonic wave W2 in accordance with the decrease in the intensity of the cavitation signal. By doing this, it is possible to prevent the treatment ultrasound W2 from being excessively irradiated to the affected area.
According to the above-described method, selective cavitation on the part where the drug is present can be selectively treated by using the accumulation of antibodies on the drug surface.

Second Embodiment
Next, an ultrasonic medical apparatus 101 according to a second embodiment of the present invention will be described with reference to FIGS. 4 to 6.
The ultrasound medical device 101 according to the present embodiment is the first embodiment in that the time variation of the luminance value of the ultrasound image is used as a cavitation signal instead of the harmonics and subharmonics of the therapeutic ultrasound W2. It is mainly different from the ultrasonic medical device 100 concerned. Hereinafter, the configuration different from the first embodiment will be mainly described, and the configuration common to the first embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

In the ultrasonic medical device 101 according to the present embodiment, as shown in FIG. 4, an observation ultrasonic element that outputs an observation ultrasonic wave (third ultrasonic wave) W3 to the probe 1 instead of the receiving element 6 14 is provided. The housing 2 is further provided with a drive signal generation unit 15 for driving the observation ultrasonic element 14 and an image acquisition unit 16 which generates an ultrasonic image based on a reflection echo of the observation ultrasonic wave W3. .

The drive signal generation unit 15 generates a drive signal for causing the observation ultrasonic element 14 to generate the observation ultrasonic wave W3 under the control of the central control unit 12, and applies the drive signal to the ultrasonic element.

The observation ultrasonic element 14 outputs an observation ultrasonic wave W3 which is a pulse ultrasonic wave by applying a drive signal from the drive signal generation unit 15, receives a reflection echo of the observation ultrasonic wave W3, and receives a reflection echo received. It converts into an electrical signal, and transmits the electrical signal to the signal processing unit 10. The observation ultrasonic element 14 is arranged to irradiate the observation ultrasonic wave W3 in a range including the focal point F of the treatment ultrasonic wave W2. The microbubbles reflect the observation ultrasonic wave W3 at a higher reflectance than the biological tissue. Therefore, the focal point F and the microbubbles generated in the vicinity of the focal point F are observed in the ultrasound image as a high brightness area.

In the present embodiment, as shown in FIG. 5, a third period is provided between the first period and the second period. The central control unit 12 controls the output control unit 9 and the drive signal generation unit 15 such that the observation ultrasonic wave element 14 generates the observation ultrasonic wave W3 in the third period and the second period. Therefore, ultrasound images are acquired in the third and second periods. Here, in order to avoid interference between the treatment ultrasound W2 and the observation ultrasound W3 in the second period, the treatment ultrasound W2 is intermittently output, and the observation ultrasound W3 is output at a timing different from that of the treatment ultrasound W2. Be done. Alternatively, the electrical signal of the reflection echo received by the observation ultrasonic element 14 is subjected to signal processing for removing noise derived from the therapeutic ultrasonic wave W2, and an ultrasonic image is generated from the processed electrical signal. The third period is set to be longer than the order of milliseconds, and is preferably several seconds to several minutes.

In the present embodiment, the signal processing unit 10 converts the electrical signal received from the observation ultrasonic element 14 into a luminance value, and transmits the luminance value to the cavitation detection unit 11 and the image acquisition unit 16.
The image acquisition unit 16 generates an ultrasound image using the luminance value received from the signal processing unit 10, outputs the ultrasound image to the display unit 4, and causes the display unit 4 to display the ultrasound image.

The cavitation detection unit 11 stores the luminance values received from the signal processing unit 10 in time series, and calculates a time change amount of the luminance value as a cavitation signal. The cavitation detection unit 11 compares the calculated cavitation signal with a predetermined threshold. When the cavitation signal is equal to or more than a predetermined threshold value, the cavitation detection unit 11 determines that cavitation is occurring. On the other hand, when the cavitation signal is less than the threshold value, the cavitation detection unit 11 determines that cavitation has not occurred. The cavitation detection unit 11 transmits the cavitation detection result to the central control unit 12.

Next, the operation of the ultrasonic medical apparatus 101 configured as described above will be described with reference to FIG.
In the same manner as in the first embodiment, a drug containing nanodroplets is administered to a living body, a treatment condition is input (step S1), and irradiation of ultrasonic waves W1, W2, and W3 to the affected area is started.

First, in the first period, the switching control unit 8 causes the therapeutic ultrasonic element 5 to output the bubbled ultrasonic wave W1 (step S2). As a result, microbubbles are generated in the affected area. Next, in the third period, the central control unit 12 causes the observation ultrasonic element 14 to output the observation ultrasonic wave W3 (step S7). As a result, an ultrasound image of a range including the focal point F is generated by the image acquisition unit 16, and the ultrasound image is displayed on the display unit 4. In the ultrasound image, the affected area where the microbubbles are present has a higher luminance value than the periphery. Therefore, the user can clearly observe the affected area in the ultrasound image.

Next, in the second period, the switching control unit 8 causes the therapeutic ultrasonic element 5 to output a therapeutic ultrasonic wave W2 weaker than the bubbling ultrasonic wave W1 (step S3). Furthermore, the central control unit 12 causes the observation ultrasonic wave element 14 to output the observation ultrasonic wave W3 so that the ultrasonic image is continuously acquired, and the time variation of the brightness value of the ultrasonic image becomes the cavitation detection unit 11 as a cavitation signal. Are acquired by the (step S4).

When the treatment area is irradiated with the therapeutic ultrasonic wave W2, cavitation occurs due to the microbubbles present in the affected area, the amount of time variation of the intensity of the reflection echo received by the observation ultrasonic element 14 increases, and the brightness of the ultrasonic image The amount of change in value increases. When the microbubbles disappear gradually by the irradiation of the treatment ultrasonic wave W2 and the amount of microbubbles decreases, the cavitation weakens and the change amount of the luminance value of the ultrasonic image decreases. As described above, while the microbubbles are present, the luminance value of the ultrasonic image largely fluctuates, so the cavitation signal becomes equal to or higher than the threshold.
Steps S5 and S6 are the same as in the first embodiment, and thus the description thereof is omitted.

When cavitation is occurring, generation and disappearance of air bubbles are repeated, whereby the time variation of the luminance value of the ultrasonic image becomes large. Therefore, according to the present embodiment, whether or not cavitation has occurred in the affected area can be accurately detected based on the time change amount of the luminance value of the ultrasonic image. In addition, there is an advantage that the cavitation signal can be acquired by using the observation ultrasonic element 14 for acquiring an ultrasonic image generally provided in the probe of the ultrasonic medical device. In addition, by combining the boiling point-adjusted nanodroplet with such an irradiation sequence, a third period on the order of several seconds to several minutes is provided between the first period and the second period. This has the advantage of being able to confirm the appearance of the affected area where the microbubbles are accumulated.
The other effects of the present embodiment are the same as those of the first embodiment, so the description will be omitted.

In the present embodiment, the time change amount of the luminance value of the ultrasonic image is used as the cavitation signal, but instead, the time change amount of the amplitude of the electrical signal output from the observation ultrasonic element 14 is You may use as a cavitation signal.
Also in this case, the same effect as in the case of using the time change amount of the luminance value can be obtained.

Further, in the present embodiment, the observation ultrasonic element 14 is provided in the probe 1, but instead, the observation ultrasonic element 14 is provided separately from the probe 1, and the affected area from outside the body The observation ultrasonic wave W3 may be irradiated toward the
By doing this, the diameter of the probe 1 can be reduced.

Moreover, in the present embodiment, the observation ultrasonic element 14 transmits and receives the observation ultrasonic wave W3 in the second period, but instead, the output of the observation ultrasonic wave W3 is stopped in the second period. To receive the harmonics and subharmonics of the therapeutic ultrasonic wave W2 generated in the vicinity of the focal point F and the focal point F and enhanced by cavitation as a cavitation signal, as in the receiving element 6 in the first embodiment It may be configured.

Further, in the present embodiment, the reflection echo is received by the observation ultrasonic element 14 separate from the treatment ultrasonic element 5 to obtain the luminance value, but instead, the treatment ultrasonic element 5 is used. Using the output of the treatment ultrasound W2 and reception of the reflection echo, the time variation of the intensity of the reflection echo received by the treatment ultrasound element 5, or the harmonics and subharmonics of the treatment ultrasound W2 to be enhanced You may use as a cavitation signal. In this case, during the second period, the therapeutic ultrasonic element 5 may alternately perform the output of the therapeutic ultrasonic wave W2 and the transmission and reception of the therapeutic ultrasonic wave W2. By doing this, the observation ultrasonic element 14 becomes unnecessary, and the apparatus configuration can be further simplified.

Third Embodiment
Next, an ultrasonic medical apparatus 102 according to a third embodiment of the present invention will be described with reference to FIGS. 7 to 11.
As shown in FIG. 7, the ultrasonic medical apparatus 102 according to the present embodiment includes first and second focal position adjusting units 17 for adjusting the position of the focal point F of the therapeutic ultrasonic element 5. Mainly different from the ultrasonic medical devices 100 and 101 according to the embodiments of the present invention. Hereinafter, configurations different from the first and second embodiments will be mainly described, and configurations common to the first embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

Although FIG. 7 shows a configuration in which the focal position adjusting unit 17 is added to the ultrasonic medical device 101 of the second embodiment, the focal position adjustment of the ultrasonic medical device 100 of the first embodiment is shown. The unit 17 may be added.

As the focus position adjustment unit 17, any method of moving the focus F electrically or mechanically is used. For example, the therapeutic ultrasonic element 5 is formed of an array of a plurality of transducers, and the focal position adjusting unit 17 is configured to move the focal point F by controlling the phase of the drive signal applied to each transducer. May be Alternatively, the treatment ultrasonic element 5 may be a single transducer, and the focal position adjusting unit 17 may be configured to move or deform the treatment ultrasonic element 5 by an actuator (not shown). For example, the focal position adjusting unit 17 may be configured to move the focal point F by changing the curvature of the vibrator.

The central control unit 12 adjusts the focal position so as to move the focal point F of the bubbled ultrasonic wave W1 from the position separated from the therapeutic ultrasonic element 5 in the direction to approach the therapeutic ultrasonic element 5 in the first period. Control unit 17;

Next, the operation of the ultrasonic medical apparatus 102 configured as described above will be described with reference to FIGS. 8 to 10.
In the present embodiment, as shown in FIG. 8, in the first period, the central control unit 12 controls the focal position F from the position away from the therapeutic ultrasonic element 5 by the focal position adjusting section 17 and the therapeutic ultrasonic element The bubbling ultrasonic wave W1 is output while moving in the direction close to 5 (step S2 '). As a result, as shown in FIGS. 9A and 9B, the microbubbles B are sequentially generated from the deep position of the living tissue A toward the shallow position.

After step S2 ', the irradiation of the treatment ultrasound W2 to the living tissue A is started (step S3'), and the irradiation of the treatment ultrasound W2 continues until cavitation is not detected (YES in step S5). Therefore, as shown in FIGS. 9C and 9D, when the treatment ultrasound W2 is irradiated to the living tissue A while moving the focal point F in the second period, the microbubbles B generated in step S2 ' When it disappears (NO of step S5), the irradiation of the treatment ultrasonic wave W2 is stopped (step S6 ').

Since the microbubbles B hardly transmit the bubbled ultrasonic waves W1, the bubbled ultrasonic waves W1 are not irradiated at a position deeper than the microbubbles B. Therefore, by moving the focal point F of the bubbling ultrasonic wave W1 toward a position close to the therapeutic ultrasonic element 5 from a position far from the therapeutic ultrasonic element 5, the microbubbles B are generated uniformly in the depth direction of the living tissue A It has the advantage of being able to

At this time, as shown in FIG. 10, in the second period in which the therapeutic ultrasonic wave W2 is irradiated, the stopping time of 1 millisecond to 10 millisecond at which the output of the therapeutic ultrasonic wave W2 temporarily stops is periodically performed. Provided in This stop time is the time to wait for the disappearance of the microbubbles (residue bubbles) generated as a result of the cavitation since only the bubbles derived from the nanodroplet are used as cavitation nuclei. In this way, cavitation can be prevented from occurring in the region other than the affected area where the remaining microbubbles derived from nanodroplets are present. In addition, the fact that cavitation ceases to occur is equivalent to the fact that the nanodroplet ceases to act on the living body, so it can be confirmed that the treatment has been completed.
In the present embodiment, at each position of the affected area, a time interval occurs between the irradiation of the bubbling ultrasonic wave W1 and the irradiation of the therapeutic ultrasonic wave W2. This time interval will be longer than the millisecond order.

In the present embodiment, a step of selecting a treatment plan may further be included between step S1 and step S2 'or step S2' and step S7. The treatment plan is a plan that defines the movement of the focal point F of the aerated ultrasound W1. By selecting a treatment plan suitable for the shape and size of the affected area, microbubbles can be generated more reliably in the entire affected area.

In the present embodiment, the focal point F is moved in the first period during which the bubbling ultrasonic wave W1 is irradiated, but instead, as shown in FIG. 11, the bubbling ultrasonic wave W1 and the treatment are The focal point F may be moved after the irradiation of the ultrasonic waves W2 (steps S2 to S5) (step S9), and then the next irradiation of the bubbling ultrasonic waves W1 may be performed (step S2).
By doing this, a wider range can be treated.

Fourth Embodiment
Next, an ultrasonic medical apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS. 12 to 14.
The ultrasonic medical apparatus according to the present embodiment outputs a preheated ultrasonic wave (fourth ultrasonic wave) W4 for preheating the affected area before the first period, as shown in FIG. This is mainly different from the ultrasonic medical devices 100, 101, 102 according to the first to third embodiments. The device configuration of the ultrasonic medical device of the present embodiment is the same as the device configuration of any of the ultrasonic medical devices of the first to third embodiments. Hereinafter, configurations different from the first to third embodiments will be mainly described, and the configurations in common with the first to third embodiments will be assigned the same reference numerals and descriptions thereof will be omitted.

The nanodroplet liquid used in this embodiment has a boiling point higher than the body temperature (37 ° C.) and lower than the treatment temperature of the affected area (the heating temperature by the treatment ultrasonic wave W2 in the second period) .
The preheating ultrasonic wave W4 is output from the treatment ultrasonic element (preheating ultrasonic element) 5 or the observation ultrasonic element (preheating ultrasonic element) 14. The amplitude and output time of the preheating ultrasonic wave W4 so that the affected area is heated to a preheating temperature (for example, 40 ° C. to 43 ° C.) lower than the boiling point of the liquid and lower than the treatment temperature of the affected area by the irradiation of the preheating ultrasonic wave W4. Is adjusted.

Next, the operation of the ultrasonic medical apparatus configured as described above will be described with reference to FIG.
In the present embodiment, the central control unit 12 outputs the preheated ultrasonic wave W4 from the therapeutic ultrasonic element 5 or the observation ultrasonic element 14 prior to the output of the bubbled ultrasonic wave W1 (step S10). Thus, the affected area is preheated by the irradiation of the preheated ultrasonic wave W4. Next, the bubbling ultrasonic wave W1 is irradiated to the affected area (step S2). As shown in FIG. 12, the amplitude of the preheating ultrasonic wave W4 needs to be equal to or less than the amplitude of the bubbling ultrasonic wave W1.

When the bubbled ultrasonic wave W1 is irradiated to the region preheated to the temperature above the boiling point of the liquid, microbubbles are easily generated, and the microbubbles generated once continue to remain stably. On the other hand, microbubbles are difficult to be generated even if the area that has not been preheated is irradiated with the bubbling ultrasonic wave W1, and even if microbubbles are generated, they quickly disappear. Therefore, microbubbles can be stably generated selectively in the preheated area.

Therefore, according to the present embodiment, even if nanodroplets exist in the area other than the affected area, nanobubbles and cavitation can be generated only in the area preheated by the preheating ultrasonic wave W4. This has the advantage of preventing cavitation from occurring in unintended areas and protecting unintended areas from cavitation.

In addition, microbubbles generated once in the area preheated to the temperature above the boiling point of the liquid continue to remain stable even if the temperature of the affected area is subsequently lowered from the preheat temperature, so that treatment with therapeutic ultrasound W2 is possible A long time can be secured. That is, once the microbubbles are generated, there is no need to irradiate the preheating ultrasonic wave W4, and only the irradiation of the therapeutic ultrasonic wave W2 needs to be performed, so the work can be simplified.

In the present embodiment, the treatment ultrasonic element 5 or the observation ultrasonic element 14 is used as a preheating ultrasonic element, but instead of this, it is different from the treatment ultrasonic element 5 and the observation ultrasonic element 14 Another ultrasound element of the body may be provided on the probe 1 and the other ultrasound element may be used as a preheating ultrasound element.

In the present embodiment, as shown in FIG. 14, the output of the therapeutic ultrasonic wave W2 may be continued until no cavitation is detected in the second period, as in the third embodiment. Also in this case, in the second period, a stop time (see FIG. 10) at which the output of the treatment ultrasonic wave W2 is temporarily stopped is periodically provided.

DESCRIPTION OF SYMBOLS 1 probe 2 case 3 operation part 4 display part 5 therapeutic ultrasonic element 6 receiving element 7 drive signal generation part (drive part)
8 switching control unit 9 output control unit 10 signal processing unit 11 cavitation detection unit 12 central control unit (control unit)
13 storage unit 14 observation ultrasonic element 15 drive signal generation unit (preheating drive unit)
16 image acquisition unit 17 focus position adjustment unit W1 bubbling ultrasound (first ultrasound)
W2 treatment ultrasound (second ultrasound)
W3 observation ultrasound (3rd ultrasound)
W4 Preheating ultrasound (4th ultrasound)

Claims (5)

The therapeutic ultrasonic element is driven to cause the therapeutic ultrasonic element to sequentially output a first ultrasonic wave for generating a bubble in living tissue and a second ultrasonic wave weaker than the first ultrasonic wave. A drive unit,
A cavitation detection unit that detects cavitation generated in the living tissue by the irradiation of the second ultrasonic wave;
And a control unit configured to control the drive unit to adjust the output of the second ultrasonic wave based on the detection result of the cavitation by the cavitation detection unit. The cavitation detection unit is configured to set the cavitation detector when at least one of a harmonic and a subharmonic of the second ultrasonic wave generated in the living tissue by the irradiation of the second ultrasonic wave is equal to or greater than a predetermined threshold. The ultrasonic medical device according to claim 1, which detects cavitation. An image acquisition unit configured to acquire an ultrasonic image of the living tissue based on a reflection echo of a third ultrasonic wave output from the observation ultrasonic element;
The image acquisition unit acquires the ultrasound image during a period in which the second ultrasound is output from the treatment ultrasound element;
The ultrasonic medical device according to claim 1 or 2, wherein the cavitation detection unit detects the cavitation based on a temporal change amount of a luminance value of the ultrasonic image. A focal position adjusting unit for moving a focal point at which the first ultrasonic wave is focused in a direction toward and away from the treatment ultrasonic element;
A direction in which the focal position adjusting unit moves the focus away from the therapeutic ultrasonic element from the position away from the therapeutic ultrasonic element during a period in which the first ultrasonic wave is output from the therapeutic ultrasonic element; The ultrasonic medical device according to any one of claims 1 to 3, wherein the ultrasonic medical device is moved. And a preheating driver for driving the preheating ultrasonic element to output a fourth ultrasonic wave for preheating the living tissue from the preheating ultrasonic element.
The control unit controls the preheating driving unit to output the fourth ultrasonic wave from the preheating ultrasonic element before outputting the first ultrasonic wave from the treatment ultrasonic element. The ultrasonic medical device according to any one of claims 1 to 4.

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