KR20190031941A - Functional electrical stimulation system and controlling method thereof - Google Patents

Abstract

The present invention relates to an electric stimulation system which assists a rehabilitation exercise for a patient who cannot move muscles freely, such as a patient suffering from cerebral palsy. Specifically, the present invention relates to an electrical stimulation system comprising: an electrode unit for applying an electric stimulus to a motor point of the patient′s muscles; a brainwave sensor for sensing brainwaves of the patient; and a microprocessor for controlling the applied electrical stimulus based on the sensed brainwave.

Description

TECHNICAL FIELD [0001] The present invention relates to a functional electrical stimulation system and a control method thereof,

The present invention relates to a system for assisting rehabilitation of a muscle paralysis patient through stimulation of the peripheral nervous system and a control method thereof.

Functional electrical stimulation (FES) refers to a therapeutic action that causes a paralyzed muscle to perform a given function by sequentially applying an appropriate electrical stimulus to the paralyzed muscle. In other words, it not only helps the muscles to function by giving an electric stimulus to move the muscles, but also prevents or slows down the function of the muscles by preventing or delaying the muscle atrophy which occurs after the muscles are disconnected from the upper motor nervous system, This has the effect of retraining to maintain the original motor function. The former case is called functional electrical stimulation in the narrow sense, the latter case is called neuromuscular electrical stimulation, and the broad functional electrical stimulation includes both.

Control of muscle contraction is controlled by different electrical stimulation frequency according to upper extremity and lower extremity. Generally, low-frequency stimulation is used because it minimizes muscle fatigue and enables continuous functioning. In addition to the frequency of stimulation, it is controlled by the amplitude of the stimulus and the duration of the wave. The electric charge is increased by the continuous electrical stimulation and the electric field is widened, and the muscle contraction force can be enhanced by using a larger number of exercise units.

The present invention is directed to solving the above-mentioned problems and other problems. Another aim is to provide a rehabilitation training system that can effectively perform muscle rehabilitation training.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided an electrode unit for applying an electric stimulus to a motor point of a patient's muscles. An EEG sensor for sensing the EEG of the patient; And a microprocessor for controlling the applied electric stimulation based on the sensed EEG.

Effects of the electric stimulation system and its control method according to the present invention will be described as follows.

According to at least one of the embodiments of the present invention, there is an advantage that rehabilitation training can be performed effectively so that the muscles can be moved according to the will of the user.

Also, according to at least one of the embodiments of the present invention, it is advantageous to provide a system in which the rehabilitation trainee can give feedback on the training and can concentrate on the training effectively.

Further scope of applicability of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and specific examples, such as the preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

1 is a block diagram showing an electric stimulation system 1 according to an embodiment of the present invention.
2 is a view showing a state in which the electric stimulation system 1 is applied to the body of a patient according to an embodiment of the present invention.
3 is a flowchart showing the control method of the electric stimulation system 1 according to the embodiment of the present invention.
4 is a view for explaining an electrode attaching position of an EEG measuring device (i.e., an EEG sensor) according to an embodiment of the present invention.
5 is a view illustrating a rehabilitation region associated with the spinal cord according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

1 is a block diagram showing an electric stimulation system 1 according to an embodiment of the present invention.

2 is a view showing a state in which the electric stimulation system 1 is applied to the body of a patient according to an embodiment of the present invention.

The electric stimulation system 1 shown in Figs. 1 and 2 includes electrode portions 10-1 and 10-2 that can be placed on the skin of an animal such as a human being. In Fig. 2, the electrode portions 10-1 and 10-2 are positioned (contacted) with a part of the skin of the user's arm. However, the electrode portions 10-1, 10-2 may be located in other parts of the body and may have a shape adapted to the shape of the particular body part.

The electrode units 10-1 and 10-2 may be provided with at least one set 10-1 and 10-2 as shown in FIG. The electrodes of each set 10-1, 10-2 include a counter electrode acting as a ground as in the example of Fig. For example, when stimulating through any one of the set electrodes 10-1 and 10-2, the other electrode B can act as an opposing electrode or ground.

The electrode portions 10-1 and 10-2 can be placed on the skin in electrical contact with the skin, that is, the body tissue in contact with the muscle tissue under the skin. The contact between the electrode parts 10-1 and 10-2 and the muscle tissue will be electrical, and in particular, an electrical signal can be received by the muscle area under the skin area to which the electrode parts 10-1 and 10-2 are attached, or . In particular, the electrode portions 10-1 and 10-2 will be able to inject current into the muscle tissue through the skin in the form of a muscle stimulation signal to stimulate the muscle tissue.

As shown in FIG. 1, the system 1 further includes an operation unit 50 connected to the electrode units 10-1 and 10-2 through a connection unit 18. The operation unit 50 is connected to the electrode units 10-1 and 10-2. In the example of Figure 1, the connection 18 is a wire connection. However, the connection 18 may be a wireless connection. For example, the electrode units 10-1 and 10-2 are battery powered and may include a wireless transmit / receive unit.

The operation unit 50 receives signals generated by the electrode unit 50 and can control the operation of the electrode units 10-1 and 10-2 as will be described in more detail below.

The electrode portions 10-1 and 10-2 may be provided on the surface of a flexible, preferably elastic, carrier. This allows the electrode part to adapt to the shape of the body part where the electrode parts 10-1, 10-2 are located. The carrier may have electrical components that connect the electrode portions 10-1 and 10-2 to the operation unit 50 through the connecting portion 18. [

For example, the operation unit 50 includes a housing. A control unit 53 connected to the optional user interface 56 and connected to the electrode portions 10-1 and 10-2 via the connection portion 18 is provided inside the housing. The user interface 56 includes control buttons forming a display and an input interface, for example, forming an output interface for outputting information to a user of the system 1. For example, the user may provide input, such as intended settings for operation performed by the device, to the control unit 53, via the user interface 56. [

In this example, the output interface allows visual output of data, but data may alternatively or additionally be output in audio or other suitable manner.

The control unit 53 includes an electrode selector 530 that can distribute different stimuli to each set 10-1 and 10-2, as shown in Fig. For example, the electrode selector 530 may apply a first electric stimulus to the first set electrode 10-1 and a second electric stimulus to the second set electrode 10-2.

The signal generator 531 is connected to the electrode selector 530. In operation, the signal generator 531 provides an electrical muscle stimulation signal to the selected set of electrodes by the electrode selector 530 in accordance with the activation pattern. An electric stimulation signal is transmitted to the surface on which the electrode portions 10-1 and 10-2 are located, that is, the skin. Corresponding to what the muscle tissue can then contract, the electrode signal penetrates through the skin into muscle tissue. In doing so, the motor point of the muscle tissue (motor point) is stimulated.

The values of the parameters of the stimulus, such as the amount of current and duration of the stimulation period, can be determined by the signal generator 531 based on the data stored in the memory of the signal generator 531. [ The signal generator 531 is coupled to a programmable microprocessor 536 that is adapted to set parameters for stimulation. The values of the parameters of the stimulus may be determined by the user via the user interface 56.

The microprocessor 536 is coupled to the electrode selector 530 and may control the electrode selector 530 to select the stimulation electrodes according to the activation pattern.

The microprocessor 536 may be implemented, for example, by a microprocessor 536 such that the sequence of steps of the method for providing an electrical muscle stimulation signal to the body tissue through the electrode portions 10-1, 10-2, And a timer for controlling the operating sequence of the processor 536. [

In addition, the microprocessor 536 is coupled to and / or includes a memory 533 for storing data or stimulus parameters associated with response signals, for example, to be described below.

In the example of FIG. 1, the electrode units 10-1 and 10-2 include independent sensors in the form of two sensor electrodes 30. In this example, the sensor electrodes 30 may be positioned parallel to each other on the opposite sides of the electrode portions 10-1 and 10-2. For example, the sensor electrodes are electrode pads forming, for example, rectangular strips. In the example of Figure 1, the sensor is a bipolar electric field (EMG) sensor.

The sensor can sense the characteristics of the muscle tissue, which characterizes the activity of the muscle tissue. The sensor has a sensor output, which is connected to the input of the signal processing unit 537 in the control unit 53. Through the sensor output, the sensor can provide the sensor signal to the signal processing unit 537. The signal processing unit 537 may determine a reference value for activity from the sensor signal, that is, measure the signal sensed by the sensor and output the value to the microprocessor 536 via the processor output.

For example, the microprocessor 536 may determine the parameters of the muscle tissue based on the value determined by the signal processing unit 537 and may output this value in a user-perceptible shape at the user interface 56 .

It is apparent that another example of the sensor 30 may be provided in the form of a single sensor electrode.

In one embodiment of the present invention, the sensor 30 may further include an EEG (Electroencephalogram) sensor.

Electroencephalogram (EEG) was recorded through an electrode attached to the scalp. Electroencephalogram (EEG) was recorded through an electrode attached to the scalp. The EEG had a frequency of 1 to 50 Hz and an amplitude of about 10 to 200 μV. The physiologist Hansberger Hans Berger). This electrical activity was later referred to as EEG and showed that the EEG changes with the mental state of the experimenter.

It is also known as Sensorimotor Rhythms (SMR) or Motor Imagery, based on the fact that changes in brain waves appear when moving parts of the body are similar to those of imagining movements. Use the left hand, right hand, foot, or tongue movement imagery, which is relatively far from the area dominated by the brain cortex.

Hereinafter, a brain-computer interface (hereinafter referred to as BCI) capable of inducing active participation of a trainee in rehabilitation exercise will be described.

When a person thinks or acts on something, synapses in the brain use neurotransmitters to transmit information. At this time, a current is generated due to a potential difference between neurons. The current is measured through an electrode attached to the scalp, which is brainwaves or the above-mentioned EEG signal. BCI technology is a technology that can use human brain waves to transmit human thought or will directly to the system without going through other movements of language or body.

BCI technology has a great significance in that it can provide new means of communication for people who can not express or convey their opinions due to physical defects or obstacles. Using this technical advantage, It can be used in many applications ranging from devices to games with new interfaces using brain waves, electronics for home automation, and learning aids.

The present invention utilizes this BCI technique to provide an environment in which a trainer can determine whether an effort is made to move the actual muscle, and to actively participate based on such determination.

In visual rhythm, while imagining left-handed or right-handed movements, activity in the rhythm area of the subject is weakened or blocked, or suppressed, and this phenomenon is referred to as event-related desynchronization (ERD). Mainly occurs in β in the μ rhythm and β rhythm region. ERS is a phenomenon that is opposite to that of ERD and increases the amplitude of the EEG.

STFT (Short-Time Fourier Transform) is the simplest method for time-frequency analysis. It performs Fourier transform on a desired part in a short time domain and shows the frequency distribution based on the time axis. STFT can be used to express frequency domain analysis and time domain analysis.

In the present invention, in addition to sensing the brain waves in real time through the sensor 30 (the sensor 30 may further include an electroencephalogram sensor), and based on the detected brain waves, the trainee actively participates in the training (Hereinafter referred to as active participation) and to control the electric stimulation applied to the exercise point.

3 is a flowchart showing the control method of the electric stimulation system 1 according to the embodiment of the present invention.

Referring to FIG. 3, the method of analyzing a user active participation perception according to an exemplary embodiment may include an EEG acquisition step S301, a filtering application step S302, and an STFT application step S303. The method of analyzing the user active participation awareness according to one embodiment can be performed by the user active participation awareness analyzing apparatus which will be described below.

First, in the EEP acquisition step S301, the microprocessor 536 can acquire a measured raw EEG signal from an EEG sensor, specifically, an EEP measurement apparatus (for example, an EPO apparatus of Emotiv). Next, the microprocessor 536 can perform a preprocessing process on brain wave data by removing noise from the acquired brain wave data or amplifying weak brain wave data.

In this embodiment, 14-channel electrodes having a sampling rate of 128SPS (2048 Hz) can be attached to a user in accordance with the 10-20 electrode position method to acquire real brain wave data of a user. A sampling rate higher than necessary causes an increase in the data to be processed, resulting in a problem of lowering the processing speed and can be a limitation in real time driving. In this embodiment, 128SPS, which is the minimum necessary sampling number required for EEG analysis, is preferable. However, it is not limited to 128SPS, and it can be changed within a certain range (128 +?

4 is a view for explaining an electrode attaching position of an EEG measuring device (i.e., an EEG sensor) according to an embodiment of the present invention. As shown in FIG. 4, the positions of the electrodes for measuring EEG were measured according to the 10-20 electrode system of the International Standard Corporation, and 19 electrodes (Fp1 , Fp2, F7, F8, F3, F4, Fz, T3, T4, C3, C4, Cz, T5, T6, P3, P4, Pz, O1, O2) have.

Referring again to FIG. 3, in the filtering application step S302, the microprocessor 536 can classify the mu rhythm (mu) region of 8 to 30 Hz in the obtained EEG data. At this time, the microprocessor 536 can classify a necessary area using a DNF (digital notch filter) or a BPF (band pass filter) to analyze whether the user is active participation. This is because the characteristics of the kinesthetic sensation in EEG appear mainly in the frequency range of 8-30 Hz.

In the STFT applying step S303, the microprocessor 536 can perform the Fourier transform on the time domain in which the EEG data in the 8-30 Hz region is briefly cleaved.

That is, the microprocessor 536 can input pre-processed EEG data into a predetermined algorithm to analyze the active participation of the trainee, convert the EEG data into a frequency signal, and classify the desired EEG according to the converted frequency domain.

The microprocessor 536 according to an embodiment of the present invention can control the electric stimulation based on the brain waves in steps S301 to S303.

In other words, when the trainer concentrates to move his arm, the corresponding EEG will be generated more strongly, and the electric stimulation will be applied more strongly to the generated EEG.

On the other hand, an EEG for use in controlling electric stimulation may be an EEG associated with a specific part of the classified EEG. For example, when it is applied to rehabilitation training to avoid the arms of a cerebral palsy being kept in a bent state, the electric stimulation can be controlled by using an EEG associated with the exercise point of the arm.

First, only a small intensity electrical stimulus can be applied before an EEG is detected. That is, the microprocessor controls the electrode units 10-1 and 10-2 to apply a first-level electric stimulus irrespective of whether the brain waves are sensed or not, and when the sensed EEG exceeds a predetermined reference level, It will be possible to further promote the rehabilitation training of rehabilitation trainees by adjusting the electric stimulation of the first century to the second century.

In other words, when the rehabilitation trainee concentrates on the muscles of the arm to move the arm, it becomes possible to concentrate on the rehabilitation training because the electric stimulation becomes more severe due to the generated EEG.

In particular, the present invention proposes that the second intensity is proportional to the intensity of the sensed EEG for more effective rehabilitation training. That is, the more strongly a trainer thinks, the more sen- sitive electrical stimuli can be applied.

When the trainer actually concentrates (imagines) to try to move his arm, the EEG activity becomes higher. At this time, the index of EEG activity may be obtained as an average of EEGs generated during a predetermined period, but may be obtained based on ERS (event-related synchronization) calculated by Equation 1 below.

는 fk　주파수에서의 r0에서 r0+m 시간의 평균 파워를 나타낸다.Where P represents power, j represents time, fk represents frequency,

Represents the average power at r0 to r0 + m time at fk frequency.

Furthermore, in the embodiment of the present invention, it is proposed to give different electric stimuli to the first set electrode 10-1 and the second set electrode 10-2.

In patients with cerebral palsy, muscles that normally bend the arm in the middle are acted with too much force (spastic agonist), and muscles (antagonist, antagonist) that breathe the arms out are rarely active. Therefore, the main muscle is always developed, but the antagonist is degenerated.

In the present invention, the first set electrode 10-1 is disposed on the main muscle to give a first stimulus for releasing the force (i.e., force can be released) to the muscles, and the second set electrode 10- 2) are placed to give a second stimulus to give strength to the muscles.

To this end, the electrode selector 530 may select and transmit an electric stimulus to each set electrode so as to give different stimuli to the first and second set electrodes 10-1 and 10-2.

Further, the present invention further proposes a specific specification of a first stimulus capable of depressing a muscle and a second stimulus for applying a force to the muscle.

The specifications of the first stimulus are shown in Table 1 below. The first and second magnetic poles may be applied as a square wave or a sinusoidal wave.

Carrier frequency 0.5 Hz Authorization method Continuous amplitude Gradually increase Application time 7 to 15 minutes

The specifications of the second stimulus are shown in Table 2 below.

Carrier frequency 2500 Hz Authorization method With 12 seconds
18 seconds break amplitude Gradually increase Application time 10 minutes

As described above, the microprocessor 536 can apply the first and second magnetic poles to the first and second electrodes differently through the electrode selector 530, induce muscle relaxation for the main muscle, , It can induce the muscles to give strength.

Furthermore, such an embodiment may be fused with the above-described EEG sensing embodiment. That is, the intensity of the first and / or second stimulus may be controlled to be changed based on the intensity of the sensed EEG. Particularly, in an embodiment of the present invention, it is proposed that the intensity of the first magnetic pole, which is the intensity of the main magnetic pole, is kept constant, but only the intensity of the second magnetic pole, which is the strength of the antagonistic muscle, is changed. This is because the first stimulus applied to the main muscle is a stimulus for releasing the muscles of the main muscle, not a stimulus for moving.

That is, in step S304, the microprocessor 536 can control only the strength of the second magnetic pole acting on the antagonistic muscle. The intensity of the first stimulus may be constantly applied irrespective of the brain waves.

In the above-described embodiment, only the electric stimulus applied to the motor point of the muscle is described by the stimulus applied to the rehabilitation trainee. Furthermore, in the present invention, it is proposed to stimulate the brain directly with stimulation (rTMS, repetitive transcranial magnetic stimulation) or stimulate the spinal cord, in addition to exercise point stimulation that stimulates the peripheral nerves directly by stimulating the brain directly. To this end, a brain stimulation unit (not shown) for stimulating the brain may be further provided, or a spinal cord stimulation unit (not shown) may be further provided.

It is a procedure to give direct magnetic stimulation to the dorsum of the brain, but it is not necessarily limited to such stimulation, although it may be exemplified by a cranial magnetic stimulation (aka rTMS).

That is, in the embodiment, at the time of controlling the stimulation in step S304, the brain stimulation may be additionally performed as the kind of the controlled stimulus. Furthermore, the specific area where stimulation occurs when stimulating the brain may be a site associated with the rehabilitation.

Furthermore, stimulation may be applied to the spinal cord with or without the brain stimulation. The area where stimulation is applied to the spinal cord may also stimulate the area involved in rehabilitation training. These stimulating regions will be described in detail with reference to FIG. 5 and related explanations.

5 is a view illustrating a rehabilitation region associated with the spinal cord according to an embodiment of the present invention. (Or myotome) pattern of the corresponding lumbar nerve associated with muscle weakness. According to the level of the spinal cord, the place where the exercise is controlled is called the eradication.

For example, C5 spinal level damage indicates that biceps (bends elbows, elbow flexors) can be used. Accordingly, in an embodiment of the present invention, it is possible to excite the C6 level of Deltoids, Extensor Carpii (bends wrists back, wrist extensor) will be.

That is, in one embodiment of the present invention, stimulation is applied to the peripheral nerve (or the central nerve) of the spinal cord corresponding to the electrical stimulation of the exercise point during the above-described rehabilitation training, thereby proposing effective rehabilitation.

In this way, the microprocessor 536 can control the brain stimulation unit and / or the spinal cord stimulation unit based on the brain waves sensed in step S304 to directly stimulate specific parts of the brain or spinal cord to assist in rehabilitation training will be.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, The scope of the idea is not to be limited / limited by the description with reference to the drawings or the drawings. It will also be appreciated by those skilled in the art that the concepts and embodiments of the invention set forth herein may be used as a basis for modifying or designing other structures for carrying out the same purposes of the present invention It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. And various changes, substitutions, and alterations can be made without departing from the scope of the invention.

Claims (14)

An electrode unit for applying an electric stimulus to a motor point of the patient's muscle;
An EEG sensor for sensing the EEG of the patient; And
And a microprocessor for controlling the applied electric stimulation based on the sensed EEG.
Electrical stimulation system.
2. The microprocessor according to claim 1,
And controlling the intensity of the applied electric stimulation based on the sensed EEG,
Electrical stimulation system.
The method according to claim 1,
Wherein the EEG sensor senses an EEG wave associated with a motion point for applying the electric stimulus,
Electrical stimulation system.
The method of claim 3,
The microprocessor controls the electrode unit to apply a first-level electric stimulus irrespective of whether the EEG is sensed or not,
And adjusting the electric stimulus of the first intensity to a second intensity when the sensed EEG is above a predetermined reference,
Electrical stimulation system.
5. The method of claim 4,
Wherein the second intensity is proportional to the intensity of the sensed EEG.
Electrical stimulation system.
The method according to claim 1,
Wherein the electrode portion includes a plurality of electrode sets,
Wherein the electrode set is constituted by a magnetic pole electrode to which an electric magnetic pole is applied and an opposite electrode which faces the magnetic pole electrode.
Electrical stimulation system.
The method according to claim 6,
Further comprising an electrode selector for inputting different stimuli to the plurality of electrode sets,
Electrical stimulation system.
Applying an electrical stimulus to the motor point of the patient muscle through the electrode portion;
Sensing an EEG of the patient; And
And controlling the applied electric stimulation based on the sensed EEG.
Control method of electric stimulation system.
9. The method of claim 8,
And controlling the intensity of the applied electric stimulation based on the sensed EEG,
Control method of electric stimulation system.
9. The method of claim 8,
Wherein the sensing step senses an EEG wave associated with a motion point for applying the electric stimulus.
Control method of electric stimulation system.
11. The method of claim 10,
Wherein the controlling step controls the electrode unit to apply the electric stimulus of the first intensity regardless of whether the brain wave is sensed,
And adjusting the electric stimulus of the first intensity to a second intensity when the sensed EEG is above a predetermined reference,
Control method of electric stimulation system.
12. The method of claim 11,
Wherein the second intensity is proportional to the intensity of the sensed EEG.
Control method of electric stimulation system.
9. The method of claim 8,
Wherein the electrode portion includes a plurality of electrode sets,
Wherein the electrode set is constituted by a magnetic pole electrode to which an electric magnetic pole is applied and an opposite electrode which faces the magnetic pole electrode.
Control method of electric stimulation system.
14. The method of claim 13,
Further comprising an electrode selector for inputting different stimuli to the plurality of electrode sets,
Control method of electric stimulation system.

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