KR20190036777A - Control method of muscle stimulation apparatus - Google Patents

Abstract

The present invention relates to a controlling method for a muscular stimulation device, which comprises: a step (a) of setting the dynamic system of a muscular stimulation device into a second ordinary differential equation having a plurality of parameters; a step (b) of inputting random input current into the muscular stimulation device; a step (c) of calculating a second moment response based on the output of the muscular stimulation device to the random input current; a step (d) of calculating values of the parameters of the second ordinary differential equation by using the second moment response; and a step (e) of modeling the muscular stimulation device by applying the calculated values of the parameters to the second ordinary differential equation. Therefore, the controlling method for a muscular stimulation device can provide precise control not only in low frequencies but also in high frequencies by precisely modeling a muscular stimulation device, composed of a dynamic system having mechanical output, in order to be strong to noises.

Description

[0001] CONTROL METHOD OF MUSCLE STIMULATION APPARATUS [0002]

More particularly, the present invention relates to a control method of a muscle stimulation apparatus capable of more precisely modeling a dynamic system of a muscle stimulation apparatus exposed to a noise to enable precise control not only at a low frequency but also at a high frequency The purpose is to provide.

Subcutaneous fat is composed of fat granules surrounded by cellulite. However, the fat surrounding the cellulite is not easily broken down by exercise. This is because the cellulite layer does not transfer lipase.

On the other hand, sound pressure, ultrasound, medium, low frequency, far infrared rays have been proved to be effective in removing subcutaneous fat and preventing skin aging through long time research. Among them, low frequency refers to electromagnetic waves with low frequency, stimulates human body skin with electric current, and produces an intended skin cosmetic effect. In other words, by flowing a weak current with a constant rhythm to the skin, it helps to relieve fatigue and relieve fatigue, relieve muscle pain, and improve blood circulation. More specifically, low frequency It has been reported that elasticity of collagen and elastin, which is caused by blood circulation promotion and massage effect, is increased due to repetition of contraction of muscles, thereby creating a resilient skin. Collagen and elastin are fibers that act like a rubber band that regulates the elasticity of the skin. The skin, which is connected to each other like a net, can be regarded as a skin without wrinkles and no sagging of the flesh. . In other words, it is known that low-frequency stimulation eliminates the wrinkles of the human skin and has the effect of refreshing the body line with elasticity.

On the other hand, mechanical vibration massage therapy is generally used to help the muscles rehabilitate. Vibration massage therapy is applied for the purpose of treating mechanical vibration. It is designed to transmit vibration to the body to make a vertical wave flow, improve blood flow, relax the contracted muscle tissue, Help.

Other effects of muscle stimulation using vibration include pain relief, fat dissolving and cosmetic effects, increased blood circulation and decreased blood pressure, and muscle relaxation.

In the past, the vibration massage device as described above was available in hospitals or rehabilitation centers. However, in recent years, various types of muscle vibration massage devices have been commercialized, which are miniaturized enough to be portable in home as well as improved in performance. As an example, Korean Registered Utility Model No. 20-0311328 discloses "muscle stimulation diastole ".

As described above, a system which is used for treatment of muscle pain through electrical stimulation, vibration, and pressure to the muscle requires a high-output specification, but a more accurate output is required depending on the intended use. In the case of a muscle stimulation device The control method becomes an important factor.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a muscle stimulation apparatus, which is composed of a dynamic system having mechanical output among muscular stimulation apparatus, by modeling robustly and more precisely, The present invention provides a control method of a muscle stimulation apparatus capable of performing a muscle stimulation.

According to the present invention, said object is achieved by a method for controlling a muscle stimulation apparatus comprising the steps of: (a) setting a dynamic system of said muscle stimulation apparatus into a second order differential equation having a plurality of parameters; (b) inputting a random input current to the muscle stimulation device; (c) calculating a second moment response based on the output of the muscle stimulation device for the random input current; (d) calculating a value of the parameter of the second order differential equation using the second moment response; (e) the value of the parameter calculated in the step (d) is applied to the second ordinary differential equation to model the muscle stimulation apparatus. .

Here, the quadratic ordinary differential equation is expressed by Equation

는 상기 근육 자극 장치의 출력 변위이고,

는 상기 근육 자극 장치의 입력 전류이고,

은 고유 주파수(Natural frequency)이고,

는 감쇄비(Damping ratio)이다)로 모델링될 수 있다.(

Is the output displacement of the muscle stimulation device,

Is the input current of the muscle stimulation device,

Is a natural frequency,

Is a damping ratio).

And, the second moment response may include a mean square distance response and a mean square velocity response.

The random input current may have an irregular waveform in the form of white noise.

The PID control technique is applied to the muscle stimulation device; The gain value of the PID control technique can be calculated by applying the Ziegler Nichols Second Method.

According to the present invention, a muscle stimulating apparatus composed of a dynamic system having a mechanical output among the muscle stimulating apparatuses can be modeled more robustly to noise to accurately control not only low frequencies but also high frequencies, A control method is provided.

1 is a view for explaining a general electro-magnetic-mechanical mechanism, and FIG.
2 is a view for explaining a control method of a muscle stimulation apparatus according to the present invention,
Figure 3a is a graph showing the mean square velocity response according to the present invention,
Figure 3b is a plot of the mean square distance response according to the present invention,
FIG. 4A is a natural frequency calculated by the control method of the muscle stimulation apparatus according to the present invention,
FIG. 4B is a view showing the attenuation ratio calculated by the control method of the muscle stimulation apparatus according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

가 입력으로 인가되고, 변위

가 출력인 가상의 시스템으로 모델링될 수 있다. 본 발명에 따른 근육 자극 장치는 기계적인 출력(Mechanical output)을 가지는 바, 도 1에 도시된 메커니즘이 적용 가능하다.Generally, an electro-magnetic-mechanical mechanism can be briefly modeled, as shown in FIG. That is,

Is applied as an input,

Lt; / RTI > is an output. Since the muscle stimulation apparatus according to the present invention has a mechanical output, the mechanism shown in FIG. 1 is applicable.

2 is a view for explaining a control method of a muscle stimulation apparatus according to the present invention.

와, 출력인 변위

를 이용하여, 근육 자극 장치의 동적 시스템을 [수학식 1]과 같은 2차 상미분 방정식으로 간략하게 설정한다(S10).First, the dynamic system of the muscle stimulation apparatus according to the present invention is modeled by a second order ordinary differential equation. The dynamic system of the muscle stimulation device has an electro-magnetic-mechanical mechanism as described above. Thus, the input of the muscle stimulation device is a current

And an output displacement

, The dynamic system of the muscle stimulation apparatus is briefly set as a second order ordinary differential equation (Equation 1) (S10).

[Equation 1]

은 고유 주파수(Natural frequency)이고,

는 감쇄비(Damping ratio)이다.The parameters of Equation (1)

Is a natural frequency,

Is the damping ratio.

The modeling of the dynamic system of the muscle stimulation apparatus is completed by calculating the natural frequency and the attenuation ratio, which are parameters in the second order ordinary differential equation modeled as described above. In the present invention, the dynamic system of the muscle stimulation apparatus . That is, the parameter of Equation (1) is calculated according to the probabilistic approach.

More specifically, referring to FIG. 2, an arbitrary random input current is input to the muscle stimulation apparatus (S11). In the present invention, it is assumed that a current having an irregular waveform of white noise type is input with a random input current.

Then, the second-order moment response is calculated on the basis of the output of the muscle stimulation device for the random input current, that is, the displacement (S12). In the present invention, it is assumed that the mean square distance response and the mean square velocity response are calculated in the second moment response. FIG. 3A is a graph showing a mean square velocity response, and FIG. 3B is a graph showing a mean square distance response.

Then, the parameters of the second order differential equation, i.e., the natural frequency and the attenuation ratio are calculated using the second moment response (S13). Here, the formula for calculating the natural frequency and the attenuation ratio can be expressed by Equation (2).

&Quot; (2) "

는 비정상 확률 밀도 함수(Non-stationary probability density function)이고,

는 변위 출력이고,

는 속도 출력이다.In Equation (2)

Is a non-stationary probability density function,

Is the displacement output,

Is the speed output.

According to the equation (2), the natural frequency and the attenuation ratio, which are the parameters of the second-order ordinary differential equation, can be calculated as shown in [Equation 3] and [Equation 4].

&Quot; (3) "

&Quot; (4) "

4A is a natural frequency calculated by Equation (3), and FIG. 4B is a diagram illustrating an attenuation ratio calculated by Equation (4).

When the natural frequency and the attenuation ratio (for example, average value) calculated through the above method are substituted into the second ordinary differential equation, the dynamic system of the muscle stimulation apparatus is modeled (S14).

Meanwhile, the control method of the muscle stimulation apparatus according to the present invention can be applied to the dynamic system modeled as described above, that is, the PID control scheme in the second order ordinary differential equation. In the present invention, the gain value of the PID control technique is calculated using the Ziegler Nichols Second Method.

That is, the PID controller reduces the proportional band so that the control loop becomes the limit oscillation, and then determines the integration and differential operation by calculating the period as a result. Then, the proportional operation is substituted into the arithmetic table of Ziegler-Nichols in the proportional band when the limit vibration is generated. Thereby, it is not necessary to disconnect the control loop, and even if the characteristics of the processor are not known, the gain value can be obtained only by adjusting the gain value of the PID controller.

Although several embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various modifications may be made without departing from the principles and spirit of the invention . The scope of the invention will be determined by the appended claims and their equivalents.

Claims (5)

A method for controlling a muscle stimulation apparatus,
(a) setting the dynamic system of the muscle stimulation apparatus to a second order ordinary differential equation having a plurality of parameters;
(b) inputting a random input current to the muscle stimulation device;
(c) calculating a second moment response based on the output of the muscle stimulation device for the random input current;
(d) calculating a value of the parameter of the second order differential equation using the second moment response;
and (e) the value of the parameter calculated in the step (d) is applied to the second ordinary differential equation to model the muscle stimulation apparatus. The method according to claim 1,
The second order ordinary differential equation is expressed by Equation

(

Is the output displacement of the muscle stimulation device,

Is the input current of the muscle stimulation device,

Is a natural frequency,

Is a damping ratio). ≪ / RTI > The method according to claim 1,
Wherein the second moment response comprises a mean square distance response and a mean square velocity response. 3. The method of claim 2,
Wherein the random input current has an irregular waveform of a white noise type. The method according to claim 1,
A PID control technique is applied to the muscle stimulation device;
Wherein the gain value of the PID control scheme is calculated by applying a Ziegler Nichols Second Method.

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