KR101365872B1 - Drive device for hifu and drive method thereof - Google Patents

Abstract

The present invention relates to a high-intensity focused ultrasound driving apparatus, and more particularly, to a high-intensity focused ultrasound driving apparatus for driving a high-intensity focused ultrasound transducer, comprising: a first frequency generator configured to generate an ultrasonic driving frequency; A variable voltage generator for generating a variable voltage; A first amplifier receiving the variable voltage generated by the variable voltage generator and first amplifying the frequency generated by the first frequency generator; A first impedance matching unit for amplifying the variable voltage received from the first amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus; A second frequency generator configured to generate an ultrasonic driving frequency; A second amplifier receiving the variable voltage generated by the variable voltage generator and performing secondary amplification of the frequency generated by the second frequency generator; A second impedance matching unit for amplifying the variable voltage received from the second amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus; A pulse selector for selectively selecting a high frequency generated by the first impedance matching unit and the second impedance matching unit; A high intensity focused ultrasound output unit configured to output a pulse selected by the pulse selector; And controlling pulses input to the first frequency generator and the second frequency generator, controlling a voltage input to the variable voltage generator, and controlling whether to select a pulse from the pulse selector. Control unit; It relates to a high-intensity focused ultrasonic drive device comprising a.

Description

High intensity focused ultrasonic drive device and driving method {DRIVE DEVICE FOR HIFU AND DRIVE METHOD THEREOF}

The present invention relates to a high-intensity focused ultrasound driving device and a driving method, and more particularly, to a high-voltage pulse generating circuit used in medical high-intensity focused ultrasound therapy apparatus.

The present invention also relates to a high-intensity focused ultrasound driving device and a driving method having stable ultrasonic output by impedance matching.

High Intensity Focused Ultrasound (HIFU) is an ultrasonic wave that focuses high-intensity ultrasound at one point by focusing a focused lens or ultrasonic transducer structure.

High-intensity focused ultrasound has been applied to various medical fields because the focusing method or frequency varies the non-invasive focusing point in the skin. The application field is applied to various fields such as cancer treatment, such as prostate cancer treatment, obesity treatment such as fat removal, skin beauty such as wrinkle removal, brain treatment, and non-invasive drug delivery.

As described above, in order to focus the high intensity focused ultrasound on the lower layer of the skin, it has to have a high ultrasound output frequency characteristic of 3 to 10 MHz, and a high output energy of 0.5 to 5 J in order to deteriorate the tissue to be treated. . In general, the diagnostic ultrasound has a characteristic of outputting a high frequency in a wide range of 1 to 10 MHz, but the output voltage is not as high as about -80 V (volts) to +80 V or 0 V to 200 V.

However, in order to drive the high intensity focused ultrasound as described above, a high voltage of 300 V or higher must be applied to the high intensity focused ultrasound transducer.

Therefore, the conventional techniques generate a high frequency by amplifying the voltage using a transformer. However, when using a transformer, the system's induction voltage and induced current are affected. Also, due to the large volume of the transformer, the volume of the system also increases.

In addition, when driving a high-intensity focused ultrasound by generating a high frequency using a transformer, it is difficult to match the impedance of the high-intensity focused ultrasound driving apparatus and the transducer.

1 is a view showing an embodiment of a conventional high intensity focused ultrasound generation method. As shown in FIG. 1, the conventional high intensity focused ultrasound generation cannot generate a variable voltage, and thus output energy is equally output. This can not control the output energy other than the method of fixing the output energy in the initial design of the high-intensity focused ultrasound driving device, there was a disadvantage that it is difficult to apply the high-intensity focused ultrasound frequency for medical purposes such as wrinkle treatment of the skin.

An object of the present invention is to provide a high-intensity focused ultrasound driving apparatus that occupies a large volume in system design and uses a transformer that does not affect a system with an induced voltage and an induced current in order to compensate for the above-mentioned disadvantages.

In addition, an object of the present invention is to provide a high-intensity focused ultrasound driving apparatus capable of selectively using a high-intensity focused ultrasound pulse by performing amplification and impedance matching for each high-intensity focused ultrasound transducer.

And, in the application in the medical field, high-intensity focused ultrasound driving device for driving high-intensity focused ultrasound that can be applied to beauty, such as wrinkle removal, acne treatment, hair removal by focusing high intensity focused ultrasound on the lower layer of the skin. It is about.

The high-intensity focused ultrasound driving device of the present invention for solving the above problems and achieving the above object,

A high intensity focused ultrasound driving apparatus for driving a high intensity focused ultrasound transducer, comprising: a first frequency generator configured to generate an ultrasonic driving frequency; A variable voltage generator for generating a variable voltage; A first amplifier receiving the variable voltage generated by the variable voltage generator and first amplifying the frequency generated by the first frequency generator; A first impedance matching unit for amplifying the variable voltage received from the first amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus; A second frequency generator configured to generate an ultrasonic driving frequency; A second amplifier receiving the variable voltage generated by the variable voltage generator and performing secondary amplification of the frequency generated by the second frequency generator; A second impedance matching unit for amplifying the variable voltage received from the second amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus; A pulse selector for selectively selecting a high frequency generated by the first impedance matching unit and the second impedance matching unit; A high intensity focused ultrasound output unit configured to output a pulse selected by the pulse selector; And controlling pulses input to the first frequency generator and the second frequency generator, controlling a voltage input to the variable voltage generator, and controlling whether to select a pulse from the pulse selector. Control unit; Characterized in that comprises a.

In the present invention, the first frequency generator and the second frequency generator comprises a programmable oscillator, wherein the first amplifier and the second amplifier, using an E-class amplifier for frequency amplification It is characterized by.

The energy of the pulse output from the high intensity focused ultrasound output unit may be changed by controlling the output voltage generated by the variable voltage generation unit according to a change in time, and the output from the high intensity focused ultrasound output unit is performed. The pulse is characterized in that at least one, characterized in that the pulse selection unit is configured by the FET element.

The driving method of the high intensity focused ultrasound driving apparatus of the present invention includes: a frequency generating step of generating ultrasonic driving frequencies from the first frequency generator and the second frequency generator, respectively; A variable voltage generation step of generating a variable voltage in the variable voltage generation unit; Receiving a variable voltage generated in the variable voltage generation step from the first amplifier and the second amplifier receives a variable voltage for transmitting a variable voltage to the first amplifier matching unit, the second amplifier is a second impedance matching unit, respectively And a delivery step; A first amplifying unit amplifying a frequency generated from the first frequency generator, and a second amplifying unit amplifying a frequency generated from the second frequency generator; A variable voltage amplifying step of amplifying a variable voltage received from the first amplifier, and a second impedance matching unit amplifying the variable voltage received from the second amplifier; An impedance matching step of performing impedance matching between the first impedance matching unit and the second impedance matching unit and the high intensity focused ultrasound driving apparatus; A pulse selecting step of selecting one of a high frequency generated by the first impedance matching unit and the second impedance matching unit by the pulse selecting unit; And a pulse output step of outputting the pulse selected by the pulse selector from the high intensity focused ultrasound output unit.

Here, when the frequency is generated from the first frequency generator and the second frequency generator in the frequency generating step, an input pulse control step of controlling a pulse input to the first frequency generator and the second frequency generator in the control unit; Characterized in that further comprises.

And, when generating the variable voltage in the variable voltage generation step, the input voltage control step of controlling the voltage input to the variable voltage generation unit in the control unit; characterized in that it further comprises.

The control unit may further include a pulse selection control step of controlling the selection of the pulse selection unit by the control unit when selecting one of the high frequencies generated by the first impedance matching unit or the second impedance matching unit in the pulse selection step. It is done.

According to the characteristics of the present invention, the high-intensity focused ultrasound driving apparatus of the present invention has an effect of increasing stability and performance by performing amplification and impedance matching using a capacitor and an inductor.

In addition, since the high-intensity focused ultrasound driving apparatus of the present invention does not include a transformer, the size of the system can be reduced and designed.

1 is a view showing an embodiment of a conventional high intensity focused ultrasound generation method,
Figure 2 is a block diagram showing the configuration according to the high-intensity focused ultrasonic drive device of the present invention,
3 is a view showing an embodiment of a high-intensity focused ultrasound generation method according to the high-intensity focused ultrasound driving apparatus of the present invention,
Figure 4 is a flow chart of a driving method of the high intensity focused ultrasonic drive device of the present invention.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the high-intensity focused ultrasonic drive window for driving the high-intensity focused ultrasound transducer of the present invention will be described in detail.

2 is a block diagram showing the configuration according to the high-intensity focused ultrasound driving apparatus of the present invention. As shown in FIG. 2, the high-intensity focused ultrasound driving apparatus of the present invention includes a first pulse generator 100, a second pulse generator 200, a controller 500, a variable voltage generator 300, and a pulse. It is composed of a selection unit 400 and a high intensity focused ultrasound output unit 600.

The first pulse generator 100 includes a first frequency generator 110, a first amplifier 120, and a first impedance matching unit 130, and the second pulse generator 200 has a second frequency. The generator 210, the second amplifier 220, and the second impedance matching unit 230 are included.

The first frequency generator 110 generates an ultrasonic driving frequency. The first amplifier 120 receives the variable voltage generated by the variable voltage generator 300 and first amplifies the frequency generated by the first frequency generator 110.

The variable voltage generator 300 generates a variable voltage and transmits the generated variable voltage to the first amplifier 120 and the second amplifier 220. The variable voltage generator 300 is transferred to the first amplifier 120 and the second amplifier 220. The variable voltage is amplified by the first impedance matching unit 130 and the second impedance matching unit 230.

In addition, the first impedance matching unit 130 matches the impedance of the transducer and the high intensity focused ultrasound driving apparatus. At this time, by amplifying the variable voltage received from the first amplifier 120 using the capacitor and the inductor in the first impedance matching unit 130 and performing impedance matching, there is an effect that the performance is stable and high.

The configuration of the first pulse generator 100 is as described above. Similarly, operations of the components of the second pulse generator 200 are as follows. The second frequency generator 210 generates an ultrasonic driving frequency having a frequency different from that of the first frequency generator 110.

The second amplifier 220 receives the variable voltage generated by the variable voltage generator 300 and secondly amplifies the frequency generated by the second frequency generator 210. Like the first impedance matching unit 130, the second impedance matching unit 230 matches the impedances of the transducer and the high intensity focused ultrasound driving apparatus.

The pulse selector 400 selects any one of the high frequencies generated by the first impedance matching unit 130 and the second impedance matching unit 230. Here, the high frequency selection of the pulse selector 400 is selected under the control of the controller 500. At this time, the controller 500 controls the input pulse input to the first frequency generator 110 or the second frequency generator 210 and also controls the voltage input to the variable voltage generator 300.

Finally, the high frequency signal selected from the pulse selector 400 is output as a pulse from the high intensity focused ultrasound output unit 600. In this case, one or more pulses output from the high intensity focused ultrasound output unit 600 may be selectively output.

In a preferred embodiment of the present invention, the first frequency generator 110 and the second frequency generator 210 are configured as a programmable oscillator. The first amplifier 120 and the second amplifier 220 use a class E amplifier for frequency amplification. In addition, the pulse selector 400 uses an FET device.

In the high intensity focused ultrasonic drive device of the present invention having the above-described configuration, the first frequency generator 110, the second frequency generator 210, the variable voltage generator 300, the pulse selector 400, the controller The organic interaction of the pulses output from the 500 and the high intensity focused ultrasound output unit 600 will be described in detail with reference to FIG. 3.

3 is a view showing an embodiment of a high-intensity focused ultrasound generation method according to the high-intensity focused ultrasound driving apparatus of the present invention. As shown in FIG. 3, an output waveform 110a of the first frequency generator 110 and an output waveform 210a of the second frequency generator 210 are generated.

In addition, the pulse of the variable voltage 300a output from the variable voltage generator 300 is controlled by the control signal 500a generated by the controller 500. For the purpose of describing the preferred embodiment of the present invention, it is assumed that the selection signal 400a of the pulse selecting unit 400 has an output level of +1, 0, -1.

If the output level of the selection signal 400a output from the pulse selector 400 is +1, the output high frequency of the first impedance matching unit 130 is selected. When the selection signal 400a is -1, the output high frequency of the second impedance matching unit 230 is selected. In addition, when the selection signal 400a is 0, no high frequency is output.

For example, when the selection signal 400a of the pulse selector 400 is +1, when the control signal 500a of the controller 500 is high, the variable voltage generation unit 300 output voltage 300a is output. The high intensity focused ultrasound output waveform 600a is output according to the output waveform 110a of the first frequency generator 110.

When the selection signal 400a of the pulse selector 400 is -1, when the control signal 500a of the controller 500 is high, the output voltage 300a of the variable voltage generator 300 is removed. The high intensity focused ultrasound output waveform 600a is output according to the output waveform 210a of the two frequency generator 210.

Here, when the control signal 500a of the controller 500 is low or the selection signal 400a of the pulse selector 400 is 0, it is obvious that the high intensity focused ultrasound output waveform 600a is not output.

This can be confirmed through the t1 section and the t2 section shown in FIG. 3. When the selection signal 400a of the pulse selector 400 is +1 and the control signal 500a of the controller 500 is high in the period t1, the high intensity focusing is performed according to the output voltage 300a of the variable voltage generator 300. The type ultrasonic output waveform 600a is output.

In addition, when the selection signal 400a of the pulse selector 400 is -1 and the control signal 500a of the controller 500 is high in the period t2, the variable voltage generator 300 outputs 300a according to the output voltage 300a. The high intensity focused ultrasound output waveform 600a is output.

Here, as can be seen from the change in the output waveform 600a in the t1 section and the t2 section, the high-intensity focused ultrasound driving device of the present invention can change the output waveform 600a according to time, and at least one frequency 110a, The output waveform 600a may be variously modified by the signal 210a and the variable voltage 300.

4 is a flow chart of a driving method of the high intensity focused ultrasound driving apparatus of the present invention. As shown in Figure 4, the driving method of the high-intensity focused ultrasound driving device is a frequency generating step (S10), a variable voltage generating step (S20), a variable voltage receiving and transmitting step (S30), a frequency amplifying step (S40), It consists of a variable voltage amplification step (S50), impedance matching step (S60), pulse selection step (S70) and pulse output step (S80).

Hereinafter, a driving method of the high intensity focused ultrasonic drive device will be described in detail with reference to the high intensity focused ultrasound drive device of the present invention.

The frequency generating step S10 is a step of generating ultrasonic driving frequencies from the first frequency generating part and the second frequency generating part, respectively, and the variable voltage generating step S20 is a step of generating a variable voltage in the variable voltage generating part.

In the variable voltage receiving and transmitting step (S30), the variable voltage generated in the variable voltage generating step (S20) is received by the first amplifier and the second amplifier, the first amplifier is the first impedance matching unit, the second amplifier is A variable voltage is transferred to each of the second impedance matching units.

The frequency amplifying step S40 is a step of amplifying a frequency generated from the first frequency generator in the first amplifier and amplifying a frequency generated from the second frequency generator in the second amplifier.

In the variable voltage amplification step S50, the first impedance matching unit amplifies the variable voltage received from the first amplifier, and the second impedance matching unit amplifies the variable voltage received from the second amplifier.

In the impedance matching step S60, the first impedance matching part and the second impedance matching part perform impedance matching between the transducer and the high intensity focused ultrasound driving apparatus. In the pulse selecting step S70, the first impedance matching part is performed by the pulse selecting part. And a high frequency generated by the second impedance matching unit.

Finally, in the pulse output step S80, the pulse selected by the pulse selector is output by the high intensity focused ultrasound output unit.

Here, the steps may be performed further including an input pulse control step S11, an input voltage control step S21, and a pulse selection control step S71. In the input pulse control step S11, when a frequency is generated from the first frequency generator and the second frequency generator in the frequency generating step S10, a pulse input to the first frequency generator and the second frequency generator by the control unit. To control.

In the input voltage control step S21, when the variable voltage is generated in the variable voltage generation step S20, the control unit controls the voltage input to the variable voltage generation unit.

In addition, the pulse selection control step (S71) is a step of controlling the selection of the pulse selection unit in the control unit when selecting any one of the high frequency generated in the first impedance matching unit or the second impedance matching unit in the pulse selection step (S70). .

The high intensity focused ultrasound driving apparatus of the present invention is configured to selectively use high intensity focused ultrasound pulses by performing amplification and impedance matching for each high intensity focused ultrasound transducer.

The characteristics of the high intensity focused ultrasound can be obtained through the following equations.

여기서, I는 초음파의 출력 에너지, F는 힘, x는 거리이다.

Where I is the output energy of the ultrasonic wave, F is the force, and x is the distance.

여기서, I는 초음파의 출력 에너지, I₀ 는 초음파의 초기 출력 에너지, α는 감쇠계수, x는 거리이다.

Where I is the output energy of the ultrasonic wave, I ₀ is the initial output energy of the ultrasonic wave, α is the attenuation coefficient, and x is the distance.

로 표현할 수 있고, F₀ 는 초기 힘, P₀ 는 초음파 초기 파워,

는 밀도, c는 음파 속도,

는 이득계수, a는 트랜스튜서 반경, R_C 는 곡률반경이다.here,

Where F ₀ is the initial force, P ₀ is the ultrasonic initial power,

Is density, c is sound velocity,

Is the gain factor, a is the radius of the transducer, and R _C is the radius of curvature.

는 주사 시간, f는 주파수이다. 상기 수식들로부터 초음파 출력 에너지, 필요 전기 에너지 등을 계산 할 수 있고, 고강도 집속형 초음파를 이용하여 비침습적으로 피부속을 치료하기 위해서는 주파수, 음압, 출력 강도, 주사 시간, 포커싱 지점의 면적 등을 고려해야 한다.Where E is electrical energy, I is the output energy of ultrasound,

Is the scan time and f is the frequency. Ultrasonic output energy, required electrical energy, etc. can be calculated from the above formulas, and in order to treat the skin non-invasively using high intensity focused ultrasound, frequency, sound pressure, output intensity, injection time, area of focusing point, etc. Should be considered

As described above, when the characteristics of the high intensity focused ultrasound are determined, the high intensity focused ultrasound driving apparatus of the present invention drives the high intensity focused ultrasound using the FET. In the present invention, the FET device serves as a switch, and the termination circuit constitutes a capacitor in parallel to the switch. In addition, when the switch is on, the voltage waveform of the inductor and the collector is determined by the switch, and when the switch is off, the voltage waveform of the inductor and the collector is determined by the transition response of the termination circuit. This configuration of the present invention can reduce the loss due to the switching interval of the voltage and current in the switching mode amplifier.

For the configuration of the present invention, the circuit parameters are determined and designed as in the following equations.

An RF choke inductor is configured to cut off the RF signal and supply only DC power, and the inductance value can be derived from the following equations under the assumption that the impedance is 50 ohm.

Where L is the inductance value of the RF choke inductor and fo is the center frequency. The FET is switched by the charging and discharging effects of the capacitor. Therefore, the sum of the inherent capacitor inside the FET and the outside capacitor can be expressed by the following equation.

Where VDC is the applied voltage, fo is the center frequency, Cp is the sum of the internal and external capacitors of the FET, and W is the output power.

A load impedance matched LC network consists of a series capacitor and a series inductor to eliminate harmonic signals. At this time, the inductance (L-series) of the inductor and the capacitance (C-series) of the capacitor are determined by the Q value, which is the attenuation characteristic according to the frequency of the resonance circuit, and is calculated by the following equation.

Here, VDC denotes an applied voltage, W denotes an output power, and fo denotes a center frequency.

The parallel capacitor serves to compensate the phase of the switching current such that the phase difference between the switching voltage and the current of the active element is 100%, and is calculated as in the following equation.

Where C is the capacitance value of the parallel capacitor, W is the output power, fo is the center frequency, and VDC is the applied voltage.

Equation 1 to Equation 9 can determine the characteristics of the output of the high-intensity focused ultrasound and can design a drive circuit capable of driving the determined high-intensity focused ultrasound.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of course, this is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the equivalents as well as the claims that follow.

100: first pulse generator 110: first frequency generator
120: first amplifier 130: first impedance matching unit
200: second pulse generator 210: second frequency generator
220: second amplifier 230: second impedance matching unit
300: variable voltage generator 400: pulse selector
500 control unit 600 high-intensity focused ultrasound output unit

Claims (10)

In the high intensity focused ultrasound drive device for driving a high intensity focused ultrasound transducer,
A first frequency generator configured to generate an ultrasonic driving frequency;
A variable voltage generator for generating a variable voltage;
A first amplifier receiving the variable voltage generated by the variable voltage generator and first amplifying the frequency generated by the first frequency generator;
A first impedance matching unit for amplifying the variable voltage received from the first amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus;
A second frequency generator configured to generate an ultrasonic driving frequency;
A second amplifier receiving the variable voltage generated by the variable voltage generator and performing secondary amplification of the frequency generated by the second frequency generator;
A second impedance matching unit for amplifying the variable voltage received from the second amplifier and matching impedances of the transducer and the high intensity focused ultrasound driving apparatus;
A pulse selector for selectively selecting a high frequency generated by the first impedance matching unit and the second impedance matching unit;
A high intensity focused ultrasound output unit configured to output a pulse selected by the pulse selector; And
A controller for controlling pulses input to the first frequency generator and the second frequency generator, controlling a voltage input to the variable voltage generator, and controlling which pulse to select from the pulse selector; High intensity focused ultrasonic drive device, characterized in that comprising a. The method of claim 1,
And the first frequency generator and the second frequency generator comprise a programmable oscillator. The method of claim 1,
The first amplifier and the second amplifier, high intensity lumped ultrasonic drive device characterized in that for using the E-class amplifier for frequency amplification. The method of claim 1,
The high intensity focused ultrasound driving apparatus of claim 1, wherein the energy of the pulse output from the high intensity focused ultrasound output unit is changed by controlling the output voltage generated by the variable voltage generator according to a change in time. The method of claim 1,
High intensity focused ultrasound driving apparatus, characterized in that for outputting at least one pulse output from the high intensity focused ultrasound output unit. The method of claim 1,
The pulse selection unit is a high-intensity focused ultrasound driving device, characterized in that composed of FET elements. In the driving method of a high intensity focused ultrasonic drive device,
A frequency generating step of generating ultrasonic driving frequencies from the first frequency generator and the second frequency generator, respectively;
A variable voltage generation step of generating a variable voltage in the variable voltage generation unit;
Receiving a variable voltage generated in the variable voltage generation step from the first amplifier and the second amplifier receives a variable voltage for transmitting a variable voltage to the first amplifier matching unit, the second amplifier is a second impedance matching unit, respectively And a delivery step;
A first amplifying unit amplifying a frequency generated from the first frequency generator, and a second amplifying unit amplifying a frequency generated from the second frequency generator;
A variable voltage amplifying step of amplifying a variable voltage received from the first amplifier, and a second impedance matching unit amplifying the variable voltage received from the second amplifier;
An impedance matching step of performing impedance matching between the first impedance matching unit and the second impedance matching unit and the high intensity focused ultrasound driving apparatus;
A pulse selecting step of selecting one of a high frequency generated by the first impedance matching unit and the second impedance matching unit by the pulse selecting unit;
And a pulse output step of outputting the pulse selected by the pulse selecting unit from the high intensity focused ultrasound output unit. 8. The method of claim 7,
An input pulse control step of controlling a pulse input to the first frequency generator and the second frequency generator by the control unit when a frequency is generated from the first frequency generator and the second frequency generator in the frequency generating step; A driving method of a high intensity focused ultrasonic drive device, characterized in that comprises. 8. The method of claim 7,
The input voltage control step of controlling the voltage input to the variable voltage generation unit in the control unit when generating a variable voltage in the variable voltage generation step; drive method of a high-intensity focused ultrasonic drive device characterized in that it further comprises. 8. The method of claim 7,
And a pulse selection control step of controlling the selection of the pulse selection unit by the control unit when selecting one of the high frequencies generated by the first impedance matching unit or the second impedance matching unit in the pulse selection step. Driving method of high intensity focused ultrasonic drive device.

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