CN104587605A - Electromyographic signal controlled peripheral magnetic stimulation system and method - Google Patents

Abstract

The invention provides an electromyographic signal controlled peripheral magnetic stimulation system and method. The peripheral magnetic stimulation system comprises an electromyographic signal acquiring module, an ARM processor, an LCD touch screen, a power amplifier and a stimulation coil; the ARM processor comprises an electromyographic signal analyzing module and a stimulation signal generation module. The working method of the system comprises the steps of acquiring electromyographic signals from a target area 30s after the activity is started and 30s before the activity is finished through the electromyographic signal acquiring module; calculating the root mean square of the electromyographic signals in the activity and the descent range of average power frequency through the electromyographic signal analyzing module; determining whether to recommend stimulation; if so, generating a group of stimulation parameters; then starting or stopping magnetic stimulation; generating a stimulation signal by the stimulation signal generating module according to the set stimulation parameters; converting by a D/ A conversion manner; then outputting; finally driving the stimulation coil through the power amplifier to magnetically stimulate the target muscles and peripheral nerves, so as to achieve the purpose of relieving peripheral fatigue.

Description

The peripheral magnetic stimulation system and method that a kind of electromyographic signal controls

Technical field

The invention belongs to rehabilitation medical instrument field, relate to the peripheral magnetic stimulation system that a kind of electromyographic signal controls.

Background technology

Fatigue is the common phenomenon in people's daily life, main manifestations is the drained of too early appearance after muscle power and mental activity, be difficult to start or maintain active exercise, fatigue person may need to spend larger strength to carry out unlabored activity before fatigue, have a strong impact on daily life, be even detrimental to health.In addition, in sports medical science, actively allaying tiredness effectively, regaining one's strength also is the key condition improving sports performance.

Neural stem cell technology is due to its noinvasive, painless and stimulating the advantage on the degree of depth and focusing to be widely used in multiple field.Neural stem cell utilizes changing currents with time to flow into coil to produce time-varying magnetic field, thus produce induction field and induced current in biological tissues, tissue produced excited.High-intensity magnetic field is very high for the requirement of instrument and equipment, needs professional person to operate, generally uses within the hospital, and for security consideration, stimulation time is generally unsuitable long.The magnetic field intensity of ultra low yield point steel is generally a few mT to tens mT, clinical diagnosis and treatment in can use for a long time, general stimulation time be dozens of minutes by one hour, treatment the course for the treatment of be one week or two weeks.Low frequency low-intensity magnetic field makes Neural stem cell can facilitate, securely and effectively be used.

Stimulating coil is the pith in magnetic stimulation system, existing peripheral magnetic stimulation system mostly adopts the figure-eight coil that circular coil or traditional transcranial magnetic stimulation instrument are conventional, well can not adapt to human body target muscle group and peripheroneural distribution is large, out-of-shape and the feature such as position is darker.The stimulating coil of peripheral magnetic stimulation system needs to design targetedly according to target muscles group and peripheral nervous.

Mostly existing stimulating system is to select related stimulus parameter according to doctors experience, as stimulus waveform, stimulus intensity, stimulus frequency, stimulation time etc., to effect of stimulation quantification, and can not carry out dynamic adjustments according to quantized result.Experimental optimum configurations and traditional stimulus modelity are difficult to satisfying personalized Treatment need, easily cause excessive stimulation or stimulate not enough, can not reach effective or optimum therapeuticing effect.The Therapeutic mode of individuation has the urgent market demand and important research meaning.

Summary of the invention

In order to solve the problem, the invention provides the peripheral magnetic stimulation system and method that a kind of electromyographic signal controls, the electromyographic signal of user self is utilized to carry out the stimulus parameter of setting individual, can be used for alleviating the feeling of fatigue of user, and low frequency, low-intensity make Neural stem cell can facilitate, securely and effectively be used.

For achieving the above object, the peripheral magnetic stimulation system that a kind of electromyographic signal provided by the invention controls, it is characterized in that, comprise electromyographic signal collection module, arm processor, power amplifier and stimulating coil successively, LCD touch screen is connected to arm processor; Described electromyographic signal collection module comprises myoelectric amplification module and A/D converter; Described arm processor comprises electromyographic signal analysis module and stimulus signal generation module; Described LCD touch screen comprises display module and key-press module; Described stimulating coil is double square coil or quatrefoil coil;

Described arm processor comprises electromyographic signal analysis module and stimulus signal generation module, described electromyographic signal analysis module is for calculating the fall of electromyographic signal root-mean-square in motion and frequency of average power, and then determine whether recommend to carry out Neural stem cell, carry out Neural stem cell if recommend, provide one group of stimulus parameter; Described stimulus signal generation module is used for producing stimulus signal according to the parameter such as stimulus frequency, intensity, stimulus duration of setting, carrying out D/A conversion and export.

Further, stimulus signal adopts monophasic pulses if, repeats Neural stem cell mode, and the persistent period of stimulus frequency, stimulus intensity and stimulation is adjustable: the minimum gear of stimulus frequency is 50Hz, maximum gear 100Hz, and adjustment step-length is 10Hz, and gear number is 6; The minimum gear of stimulus intensity is 10mT, and maximum gear is 30mT, and adjustment step-length is 5mT, and gear number is 5; The minimum gear of stimulation time is 10min, and maximum gear is 30min, and adjustment step-length is 5min, and gear number is 5.

Further, described power amplifier comprises preamplifier, low pass filter, photoelectric coupling, post amplifier and 50Hz wave trap, and the cut-off frequency of low pass filter is 500Hz.

The method of work of described electromyographic signal analysis module, comprising:

Step 1, calculate the root-mean-square (RMS) of electromyographic signal and the downward trend of frequency of average power (MPF) in motion, namely calculate motion and terminate percentage ratio PERr and PERm that RMS and MPF of the electromyographic signal of front 30s and motion start RMS and MPF of the electromyographic signal of 30s, and get per=min [PERr, PERm];

Step 2, judges whether fatigue according to per, and regulation per is less than 90% for tired, if the fatigue of being judged as, recommends to carry out Neural stem cell, otherwise does not recommend to carry out Neural stem cell;

Step 3, when recommending to carry out Neural stem cell, calculate the recommendation of stimulus frequency, stimulus intensity and stimulus duration according to per, if the step-length of certain regulating parameter is ss, adjusting shift figure place is d, and regulatory factor is n, so the recommendation of this regulating parameter

$S\left(n\right)=\left\{\begin{array}{cc}{S}_{\min }+(d-n)\&times;\mathrm{ss}& 1<n\&le;d\\ S_{\max }& n=1\end{array}\right.---\left(1\right)$

Wherein, S _minrefer to the minimum gear of this kind of regulating parameter setting, S _maxrefer to the maximum gear of this kind of regulating parameter setting, regulatory factor n is the function about per, and computational methods are as follows

$n\left(\mathrm{per}\right)=\left\{\begin{array}{cc}\mathrm{CEILING}(\frac{(\mathrm{per}-50\%)}{(90\%-50\%)}\&times;d)& 50\%<\mathrm{per}<9C\\ 1& 0<\mathrm{per}\&le;50\%\end{array}\right.---\left(2\right)$

CEILING () in above formula is the function that rounds up.

Described LCD touch screen comprises display module and key-press module, and described display module is for showing recommendation information, stimulus parameter and information; Described key-press module is used for the parameter of manual adjustments recommendation and selects to start or stop Neural stem cell.

The signal that described power amplifier is used for stimulus signal generation module exports carries out power amplification.

Described stimulating coil is for being fixed on the top of target muscles group, under the driving of the stimulus signal through power amplification, alternating current is converted to alternating electromagnetic field, Space Coupling target approach region, stimulation target muscle group and peripheral nervous, thus fatigue alleviating.Described stimulating coil is double square coil or quatrefoil coil, and sphere of action is 10-20cm ², the stimulation degree of depth is 1.5-3cm, and all adopt the enamel covered wire coiling of copper core diameter 0.35mm, described double square coil, interior minister is 10cm, and wide is 5cm, high 2cm, the thick 7.5mm in limit; Four described leaf coils, the inside radius of its four circles is 20mm, outer radius 26mm, high 15mm.

The method of work of the peripheral magnetic stimulation system that electromyographic signal provided by the invention controls, comprising:

Step 1, electromyographic signal collection module, gathers the electromyographic signal of target area 30s before Moving Rigid starts 30s and motion terminates;

Step 2, whether electromyographic signal analysis module, calculates the fall of this motor signal of telecommunication root-mean-square and frequency of average power, then determine to recommend to stimulate on display module, stimulates if recommend, and display module provides one group of stimulus parameter recommended;

Step 3, carries out manual adjustments at key-press module to the stimulus parameter recommended, starts Neural stem cell afterwards.Stimulus signal generation module generates stimulus signal according to the stimulus parameter of setting, exports through D/A conversion, then through power amplifier, drives the stimulating coil be placed in above target muscles group, carry out Neural stem cell to target muscles group and peripheral nervous.

Compared with prior art, the peripheral magnetic stimulation system that electromyographic signal provided by the invention controls, by gathering the electromyographic signal of user self, according to the situation of change of electromyographic signal root-mean-square and frequency of average power, then personalized Neural stem cell parameter is formulated, for fatigue alleviating; The mode such as low frequency, low-intensity is adopted to make Neural stem cell can facilitate, securely and effectively be used; Stimulating coil of the present invention is double square coil or quatrefoil coil, and field stimulation is rectangle or rhombus, the shape of field stimulation, size and stimulate the degree of depth to meet designing requirement; The stimulus waveform adopted is monophasic pulses if, simple, and after stimulating, myocyte's irritability persistent period is long.The present invention not only may be used for alleviating the fatigue in training, in the functional rehabilitation that also can promote the use of other and sports medical science, and is adapted at using in family and community.

Accompanying drawing explanation

Fig. 1 is magnetic stimulation system block diagram of the present invention

Fig. 2 is stimulating coil schematic diagram of the present invention

Fig. 3 is Distribution of Magnetic Field figure of the present invention

Fig. 4 is stimulation flow chart of the present invention

Fig. 5 is stimulus modelity figure of the present invention

Fig. 6 is effect of stimulation figure of the present invention

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is further described.

The composition frame chart of peripheral magnetic stimulation system of the present invention as shown in Figure 1, is made up of electromyographic signal collection module, arm processor, LCD touch screen, power amplifier and stimulating coil.Magnetic stimulation system is under electromyographic signal controls, the monophasic pulses if signal of varying strength and frequency is produced by arm processor, amplify through power amplifier, alternating magnetic field is produced in coil, by Space Coupling, act on target muscles group and peripheral nervous and, in body, produce faradic current, stimulate respective organization cell, cause the changing features of electromyographic signal.

Myoelectric amplification module comprises preamplifier, low pass filter, photoelectric coupling, post amplifier and 50Hz wave trap.Enlarge leadingly adopts instrument amplifier AD620, and gain is 1000 ~ 1500; The cut-off frequency of low pass filter is 500Hz; Photoelectrical coupler adopts LTP521; 50Hz wave trap adopts double-T shaped structure.

ARM adopts STM32F103ZET6 microprocessor, comprise ADC and DAC of 11 intervalometers and built-in 12, for generation and the adjustment of the control of stimulation time, the collection of electromyographic signal and stimulation pulse signal, the SRAM of Flash and 64KB of built-in 512KB, the SD card of more than 32Gb can also be extended out as mass-memory unit, for the storage of myoelectricity Treatment Analysis program and data by SPI.

LCD touch screen adopts the TFT LCD module of 2.8 cun, interface is 80 parallel ports of 16, resolution is 320 × 240, support the display of 65K color, for showing recommendation information, stimulus parameter and information, carry touch screen, as control inputs, can start for manual adjustments recommended parameter and selection or stop Neural stem cell.

Power amplifier adopts high performance LM3886 audio power amplifier, and the average output power under 8 Ω loads is 30W, and can pulse signals effectively amplify, the distortion factor is only 0.03%.

Peripheral magnetic stimulation adopts the repetition Neural stem cell mode of monophasic pulses if, and each stimulus parameter is adjustable, and the minimum gear of stimulus frequency is 50Hz, maximum gear 100Hz, and adjustment step-length is 10Hz, and gear number is 6; The minimum gear of stimulus intensity is 10mT, and maximum gear is 30mT, and adjustment step-length is 5mT, and gear number is 5; The minimum gear of stimulation time is 10min, and maximum gear is 30min, and adjustment step-length is 5min, and gear number is 5.

Adopt COMSOL Multiphysics finite element analysis software, the shape, winding etc. of magnetic stimulating coil are designed and simulation calculation is carried out to the magnetic field produced, wherein copper core footpath determines the maximum current allowing to pass through, winding and the number of plies can affect focusing and maximal stimulus intensity, and shape and size determine field stimulation, stimulate shape, stimulate a series of performances such as the degree of depth.The present invention devises two kinds of stimulating coils, and Fig. 2 (a) is double square coil, and Fig. 2 (b) is quatrefoil coil, and wire all adopts diameter to be the enamel-cover copper conductor of 0.35mm.Double square coil, the rectangle be affixed by two long limits is formed, and each rectangle inside is long is 10cm, and wide is 5cm, high 2cm, the thick 7.5mm in limit, adopts multilamellar winding, every layer of 17 circle, totally 50 layers.The inside radius of four leaf coils, four circles is 20mm, outer radius 26mm, high 15mm, adopts multilamellar winding, every layer of 14 circle, totally 42 layers.

Fig. 3 (a) (b) is respectively the Distribution of Magnetic Field figure below double square and four leaf coils on four different depths, the below of the central area of double square faying surface and quatrefoil coil all can form spike, peak value is exponentially form reduction along with the increase of the degree of depth, but still has good focusing when the degree of depth is greater than 2cm.The field stimulation of double square coil faying surface is narrow rectangle, and the sphere of action at degree of depth 2cm place is about 20cm ²; The field stimulation in quatrefoil hub of a spool region assumes diamond in shape, and the sphere of action at degree of depth 2cm place is about 12cm ².The degree of depth and field stimulation is stimulated to meet target muscles group and peripheroneural stimulation requirement.

Electromyographic signal adopts bipolar lead mode, according to the training mission determination target muscles performed.To the electromyographic signal segmentation gathered, be one section with 5 seconds and calculate root-mean-square according to formula (3), calculate frequency of average power according to formula (4), then ask the average of multistage.

$\mathrm{RMS}\left[s\left(t\right)\right]=\sqrt{\frac{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{x}_i^2}{m-1}}---\left(3\right)$

Wherein, s (t) presentation surface electromyographic signal, x _irepresent the amplitude sampled value of electromyographic signal, m represents sampling number.

$\mathrm{MPF}=\frac{\underset{0}{\overset{\&infin;}{\&Integral;}}\mathrm{f\; P}\left(f\right)\mathrm{df}}{\underset{0}{\overset{\&infin;}{\&Integral;}}P\left(f\right)\mathrm{df}}---\left(4\right)$

P (f) represents the power spectrum of electromyographic signal, and f represents signal frequency.

First record object muscle electromyographic signal of 30 seconds before Moving Rigid starts 30 seconds and motion terminates, initial value R0 and M0 of electromyographic signal calculating RMS and MPF of 30s is started according to motion, the percentage ratio of RMS and MPF and initial value that the electromyographic signal terminating front 30s according to moving again tries to achieve this motor task electromyographic signal is respectively PERr and PERm, get per=min [PERr, PERm].Then judge whether fatigue according to per, regulation per is less than 90% for tired, only just recommends when fatigue to carry out epicycle stimulation.The last stimulus parameter carrying out calculated recommendation according to formula (1) and (2).When per is less than or equal to 50%, stimulus intensity gets maximum gear; When per is greater than 50%, the increase according to per is successively decreased by stimulus intensity, to regulate step-length ss and gear number d for foundation.

To perform right-hand grip task, the method for work of the peripheral magnetic stimulation system that electromyographic signal provided by the invention controls is described:

Step 1, is placed on flexor carpi radialis or flexor carpi ulnaris m. surface, two electrode gap 5cm by electromyographic electrode, utilize electromyographic signal collection module record grasping movement to start 30s and terminate the electromyographic signal of front 30s;

Step 2, electromyographic signal grasping movement being started 30s is divided into 6 sections with 5s mono-section, calculates RMS and MPF of every section according to formula (1) and (2), then asks 6 sections average, obtains initial value R0 and M0 of electromyographic signal RMS and MPF; Electromyographic signal grasping movement being terminated front 30s is divided into 6 sections with 5s mono-section, RMS and MPF of every section is calculated according to formula (1) and (2), ask 6 sections average again, the percentage ratio of RMS and MPF and initial value R0 and M0 that try to achieve this motor task electromyographic signal is respectively PERr and PERm, get per=min [PERr, PERm].Suppose that PERr and PERm is respectively 85% and 80%, then per=80%, per are less than 90%, according to the rules, judge now as fatigue state, recommend to carry out Neural stem cell.For the setting of stimulus intensity, the minimum gear of known stimulus intensity is 10mT, and maximum gear is 30mT, and adjustment step-length is 5mT, and gear number is 5, first calculates the regulatory factor of stimulus intensity $n=\mathrm{CEILING}(\frac{(80\%-50\%)}{(90\%-50\%)}\&times;5)=\mathrm{CEINLING}\left(3.75\right)=4,$ Then calculate recommendation S=10+ (the 5-4) × 5=15mT of stimulus intensity, for the recommendation setting of stimulus frequency and stimulus duration and stimulus intensity similar, do not repeat them here;

Step 3, LCD touch screen shows and recommends Neural stem cell and one group of stimulus parameter recommended, and the stimulus parameter recommended by key-press module manual adjustments is also selected to start to carry out Neural stem cell.Stimulus signal generation module generates stimulus signal according to the stimulus parameter of setting, through D/A conversion and power amplification, drive and be fixed on the top stimulating coil of user right upper arm flexor carpi radialis or flexor carpi ulnaris m., Neural stem cell is carried out to the target muscles group of user right upper arm and peripheral nervous.Overall flow as shown in Figure 4.

Fig. 5 is the stimulus modelity that the present embodiment adopts.Adopt monophasic pulses if to repeat Neural stem cell mode, stimulus frequency is adjustable, and scope is 50-100Hz.The advantage of this stimulation mode is simple to operation, adjustable parameter enrich, stimulate after peripheral nervous and myocyte's irritability persistent period long, good effect of stimulation can be obtained.Noinvasive, without sensation of pricking, can life-time service.

Fig. 6 is the maximum autonomous grip figure of the right hand carrying out peripheral magnetic stimulation after the present embodiment motion terminates and do not carry out peripheral magnetic stimulation, and as can be seen from the figure: when muscle occurs tired, power output declines; After Neural stem cell, response speed and the maximum autonomous dynamics of muscle are all better than the state of not carrying out Neural stem cell; The peripheral magnetic stimulation system that electromyographic signal provided by the invention controls has excited myoneural tissue, alleviates the beneficial effect of peripheric movement fatigue.

Claims (4)

1. a peripheral magnetic stimulation system for electromyographic signal control, it is characterized in that, comprise electromyographic signal collection module, arm processor, power amplifier and stimulating coil successively, LCD touch screen is connected to arm processor; Described electromyographic signal collection module comprises myoelectric amplification module and A/D converter; Described arm processor comprises electromyographic signal analysis module and stimulus signal generation module; Described LCD touch screen comprises display module and key-press module; Described stimulating coil is double square coil or quatrefoil coil;

Described double square coil, adopt the enamel covered wire coiling of copper core diameter 0.35mm, interior minister is 10cm, and wide is 5cm, high 2cm, the thick 7.5mm in limit; Sphere of action is 10-20cm ², the stimulation degree of depth is 1.5-3cm;

Four described leaf coils, adopt the enamel covered wire coiling of copper core diameter 0.35mm, and the inside radius of four circles of composition quatrefoil coil is 20mm, outer radius 26mm, high 15mm; Sphere of action is 10-20cm ², the stimulation degree of depth is 1.5-3cm.

2. the peripheral magnetic stimulation system of electromyographic signal control as claimed in claim 1, it is characterized in that, stimulus signal adopts monophasic pulses if, repeat Neural stem cell mode, the persistent period of stimulus frequency, stimulus intensity and stimulation is adjustable: the minimum gear of stimulus frequency is 50Hz, maximum gear 100Hz, adjustment step-length is 10Hz, and gear number is 6; The minimum gear of stimulus intensity is 10mT, and maximum gear is 30mT, and adjustment step-length is 5mT, and gear number is 5; The minimum gear of stimulation time is 10min, and maximum gear is 30min, and adjustment step-length is 5min, and gear number is 5.

3. the peripheral magnetic stimulation system of electromyographic signal control as claimed in claim 1, it is characterized in that, described power amplifier comprises preamplifier, low pass filter, photoelectric coupling, post amplifier and 50Hz wave trap, and the cut-off frequency of low pass filter is 500Hz.

4. the method for application system as described in claim 1-3 any one, it is characterized in that, step is as follows:

Step 1, calculate the root-mean-square RMS of electromyographic signal and the downward trend of frequency of average power MPF in motion, namely calculate motion and terminate percentage ratio PERr and PERm that RMS and MPF of the electromyographic signal of front 30s and motion start RMS and MPF of the electromyographic signal of 30s, and get per=min [PERr, PERm];

Step 2, judges whether fatigue according to per, and regulation per is less than 90% for tired, if the fatigue of being judged as, recommends to carry out Neural stem cell, otherwise does not recommend to carry out Neural stem cell;

Step 3, when recommending to carry out Neural stem cell, calculate the recommendation of stimulus frequency, stimulus intensity and stimulus duration according to per, if the step-length of certain regulating parameter is ss, adjusting shift figure place is d, and regulatory factor is n, and the recommendation of so this regulating parameter is

$S\left(n\right)=\left\{\begin{array}{cc}{S}_{\min }+(d-n)\&times;\mathrm{ss}& 1<n\&le;d\\ S_{\max }& n=1\end{array}\right.$

Wherein, S _minrefer to the minimum gear of this kind of regulating parameter setting, S _maxrefer to the maximum gear of this kind of regulating parameter setting, regulatory factor n is the function about per, and computational methods are as follows

$n\left(\mathrm{per}\right)=\left\{\begin{array}{cc}\mathrm{CEILING}(\frac{(\mathrm{per}-50\%)}{(90\%-50\%)}\&times;d)& 50\%<\mathrm{per}<90\%\\ 1& 0<\mathrm{per}\&le;50\%\end{array}\right.$

CEILING () in above formula is the function that rounds up.