Method for the diagnosis of long-latency evoked potential brain and device for its implementation

 

The invention relates to medicine and can be used to diagnose disorders of the nervous system and higher mental functions. How is that affecting the subject of short duration signal, filtered in a narrow band signal caused by the activity of the brain with automatic change of the center frequency of the filter is subtracted from the signal caused by the electrical activity of the brain resulting from filtering of the signal. For analysis of the signal set two time interval of the search components of long-latency evoked potential, determining the minimum value of the signal in the first interval and the maximum on the second. The modulus of the difference between the maximum and the minimum value is compared with the value of the coefficient To set experimentally, and judge the presence or absence of long-latency evoked potential brain of the subject. The above embodiment of the device, allowing the registration of long-latency evoked potential brain. The invention provides for reducing the time of registration of evoked potential and improves the accuracy of diagnosis. 2 N. p. F.-ly, 4 Il.

A known method for the diagnosis of long-latency evoked potentials, namely, that affect the subject of short-duration signals a certain value, among which are the subject of in accordance with the received instruction must recognize different in any significant sign, responding to their account or by pressing the button, record the evoked electrical activity of the brain in the form of an electrical signal voltage average method synchronous accumulation, and then analyze the long-latency evoked potentials of the brain (see centuries Gnezdo to diagnose average long-latency evoked potential brain containing means for supplying to the subject of the short duration of the external signal a certain value, and means for recording electrical activity of the brain of the subject in the form of electrical voltage signal connected to the unit of analysis of long-latency evoked potentials of the brain (see Century. Century. Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 26-28, Fig. 8).

A disadvantage of the known method and device is a great time of registration of evoked potentials, because the potential is determined as a result of averaging 20 - 25 implementations of the series 150 200 supplied to the subject of incentives, and low diagnostic accuracy evoked potential brain due to significant differences in the amplitude and the shape of the curves in some implementations.

A known method for the diagnosis of averaged evoked potential brain and device for its implementation (patent RF №2109482 from 27.04.1998, application No. 95100822, MPK7 AND 61 IN 5/0484). How is that affecting the subject of a short duration signal of a certain value, the maximum value is less than the signal magnitude corresponding to a pain syndrome, and record the induced electric is a competent evoked potentials of the brain, and evoked electrical activity of the brain recorded for 500 MS, starting from the moment of the signal, in the form of an analog signal, set the search scope components N2, P3 long-latency evoked potential in the interval from the moment the alarm to 340 MS, allocate your search area two time interval from T1 to T2 and from T2 to 340 MS for N2 and P3 respectively, where T1 and T2 - the bounds of time intervals, depending on the type of receptor structure, determine the minimum value of the signal in the interval from T1 to T2 MS and the maximum value of the signal in the interval from T2 to 340 MS, calculate the modulus of the difference between certain maximum and minimum values of the signal, compare the value of the modulus of the difference with the value K, where K is established experimentally the coefficient, and the resulting comparison positive number is judged on the presence of long-latency evoked potential brain, and the resulting comparison of a negative number is judged about the lack of long-latency evoked potential brain.

The known device comprises a means for supplying the subject of the short duration of the external signal of a certain magnitude, the registration of the electrical activity of the brain of the subject in the form of electrical voltage signal, connected to the input of block averaging of evoked potentials, the output of which is connected to the input of the unit of analysis of long-latency evoked potentials of the brain, while the unit of analysis of long-latency evoked potentials of the brain contains the set of time intervals, the input of which is the input unit of analysis the unit of determining the minimum value of the signal at the first selected time interval and the unit determine the maximum value of the signal at the second selected interval, the inputs of which are connected to the outputs of the shaping unit time intervals, the unit for computing the modulus of the difference, to the inputs of which are connected the outputs of the blocks determine the maximum and minimum values of the signal on the selected interval, the block comparison the connected input to output of the unit for computing the modulus of the difference, the identification block long-latency evoked potential with a display, an input connected to the output of the Comparer, and the output of which serves as an output unit of analysis that is connected to the control unit means for supplying to the subject signal exposure, the output of which is connected to the means for supplying the subject of the short duration of the external signal specified value.

The disadvantage Izov, because the subject is affected by a series of stimuli of which share significant incentives is only 10-20% of the total number, as well as low diagnostic accuracy averaged long-latency evoked potential due to the fact that the averaging involved in the realization of the signal, during which the subject made a mistake in the definition of a meaningful stimulus, resulting waveform evoked potential differs significantly from the case of proper definition of the nature of the stimulus and averaged (total) induced potential is distorted. As is well known (see Century. Century. Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 107, Fig. 33), with insignificant incentives, and, accordingly, if a significant incentive mistaken for a significant, long-latency evoked potential is absent, and participating in the averaging, this implementation will reduce the total induced potential. In addition, obtaining the curve of the long-latency evoked potential as a result of averaging multiple implementations is not possible to investigate the response of a subject to individual incentives, which may differ significantly from implementation to implementation.

The basis of the invention is the task of the joint venture is increased diagnostic accuracy and creates the opportunity to explore the responses of the subject on a separate incentives due to the narrow-band filtering of the signal caused by brain activity of the subject with automatic change of the center frequency of the filter, subtraction of the signal caused by the electrical activity of the brain of the subject obtained by filtering the signal and analysis of the presence of long-latency evoked potential obtained by subtracting the signal.

The basis of the present invention also given the task of creating a device for the diagnosis of long-latency evoked potential brain in which the presence of six adders, two phase detectors, four delay lines, integrator, four amplifiers with adjustable gain and their relationships with means for recording electrical activity of the brain of the subject in the form of electrical voltage signal and the block analysis of the long-latency evoked potentials allows to reduce time of registration, to improve the accuracy of diagnosis of long-latency evoked potential brain and creates the opportunity to explore the responses of the subject to individual incentives.

The problem is solved in that in the method for the diagnosis of long-latency evoked potential of the brain, namely, that affect the subject of a short duration signal, the maximum value is less than the signal magnitude corresponding to the painful Shin is 20 MS to 260 MS and 260 MS to 500 MS, determine the minimum value of the signal in the interval from 120 MS to 260 MS and the maximum value of the signal in the range from 260 MS to 500 MS, calculate the modulus of the difference between the determined maximum and minimum value of the signal, compare the value of the modulus of the difference value To set experimentally, and the resulting comparison positive number is judged on the presence of long-latency evoked potential brain, and the resulting comparison of a negative number is judged about the lack of long-latency evoked potential brain, according to the invention an electrical signal caused by brain activity of the subject is filtered in a narrow frequency band of constant width, the Central frequency of the band filter is changed at a speed proportional to the magnitude of the time intervals between the moments of passing through zero, the maximum and minimum values of the signals caused by the activity of the brain and the resulting filtered signal so that the passage of zero, the maximum and minimum values of the signal caused by the electrical activity of the brain previously obtained by filtering the signal Central frequency Anna electrical activity of the brain later obtained by filtering the signal Central frequency band of the filter increases, subtract from the signal caused by the electrical activity of the brain obtained by filtering the signal recording obtained by subtracting the signal within 500 MS from the moment the signal, and the received signal is judged on the presence of long-latency evoked potential.

The problem is solved also by the fact that the device for the diagnosis of long-latency evoked potential brain that contains one United block analysis of long-latency evoked potentials, the control unit means for supplying to the subject signal exposure and means for supplying to the subject of the short duration of the external signal a certain value, the maximum value is less than the signal magnitude corresponding to a pain syndrome, and means for recording electrical activity of the brain of the subject in the form of electrical voltage signal, according to the invention are connected to the output means of recording electrical activity of a brain of the subject of the first adder and consistently connected first and second delay lines, the first amplifier with an adjustable gain and a second adder, the output of which is connected to the second input pervoy detector, the fourth adder and the integrator, the output of which is connected to the control input of the first amplifier with an adjustable gain, the output of the second adder connected serially connected third and fourth delay lines and a second amplifier with an adjustable gain, the output of which is connected to the second input of the second adder, the output of the third delay line is connected to the second input of the third adder and to the input of the third amplifier with adjustable gain, the output of which is connected to the third input of the second adder, the output means of recording electrical activity of a brain of the subject connected in series United fifth adder and the second phase detector, the output of which is connected to the second input of the fourth adder, the output means of recording electrical activity of a brain of the subject is connected to the input of the fourth amplifier with adjustable gain, the output of which is connected to the fourth input of the second adder, the output of which is connected to the second input of the second phase detector and the first input of the sixth adder, the output of the sixth adder connected to the second input of the first phase detector, the control of photograther, the second and third inputs of the fifth adder connected respectively to the output of the first delay line and the output of the third adder, the second input of the sixth adder connected to the output means of recording electrical activity of a brain of the subject, and the output of the first adder connected to the input of the unit of analysis of long-latency evoked potentials.

In Fig.1 shows a block diagram of a device for the diagnosis of long-latency evoked potential brain in Fig.2 is a block diagram of a narrowband filter with a variable center frequency, in Fig.3 is a diagram of signals of the device of Fig.4 - curves caused by the electrical activity of a brain of the subject and signal long-latency evoked potential recorded on it components N2, P3.

Device for the diagnosis of long-latency evoked potential brain contains the unit 1 control vehicle alarm impact (Fig.1) tool 2 filing entity 3 short duration of the external signal of a certain magnitude. The maximum value of the signal delivered to the subject 3, is less than the signal magnitude corresponding to pain syndrome. Evoked electrical brain activity of the subject 3 is removed from the scalp in the form of electrical activity of a brain of the subject in the form of electrical voltage signal. Output means 5 is connected to the input of the notch filter 6 with variable center frequency. To the first input 7 and the second input 8 of the first adder 9 is connected respectively to the outputs of the narrow band filter 6 with variable center frequency and means 5 records the electrical activity of a brain of the subject in the form of electrical voltage signal. The output of the first adder 9 is connected to the input unit 10 analysis of long-latency evoked potentials connected to the unit 1 control means for supplying to the subject signal effects. In narrow-band filter 6 with variable center frequency to the first input 11, the second input 12, a third input 13 and the fourth input 14 of the second adder 15 are connected respectively to the outputs of the first amplifier 16 with an adjustable gain of the second amplifier 17 with an adjustable gain of the third amplifier 18 with adjustable gain and fourth amplifier 19 with adjustable gain. Output means 5 records the electrical activity of a brain of the subject in the form of electrical voltage signal is connected to the signal input 20 of the first amplifier 16 with adjustable gain through the first line of badergline. The output of the second adder 15, which is the output of the narrowband filter 6 with variable center frequency, is connected to the signal input 24 of the third amplifier 18 with adjustable gain through a third delay line 25. The output of the third delay line 25 is connected to the signal input 26 of the second amplifier 17 with adjustable gain through the fourth delay line 27. To the first input 28 and the second input 29 of the third adder 30 is connected respectively to the outputs of the second adder 15 and the third delay line 25. The output of the third adder 30 is connected to the first input 31 of the first phase detector 32, the output of which is connected to the first input 33 of the fourth adder 34, the output of which is connected to the input of the integrator 35. With the first input 36 and a second input 37 of the fifth adder 38 are connected respectively to the input and output of the first delay line 21. To the first input 39 and the second input 40 of the second phase detector 41 are connected respectively to the outputs of the fifth adder 38 and the second adder 15, the output of the second phase detector 41 is connected to the second input 42 of the fourth adder 34. To the first input 43 and the second input 44 of the sixth adder 45 are connected respectively to the outputs of the second adder 15 and a means 5 of the register is RA 45 is connected to the second input 46 of the first phase detector 32. To the third input 47 of the fifth adder 38 is connected to the output of the third adder 30. The output of integrator 35 is connected to the control input 48 of the first amplifier 16 with adjustable gain control input 49 of the second amplifier 17 with adjustable gain control input 50 of the third amplifier 18 with adjustable gain and control input 51 of the fourth amplifier 19 with adjustable gain.

The way to diagnose average long-latency evoked potential brain is carried out as follows. Influence of subject 3 (Fig.1) the short duration of the external signal of a certain value, the maximum value is less than the signal magnitude corresponding to pain syndrome. An electrical signal caused by brain activity of the subject is filtered in a narrow frequency band of constant width, the Central frequency of the band filter is changed at a speed proportional to the magnitude of the time intervals between the moments of passing through zero, the maximum and minimum values of the signals caused by the activity of the brain and the resulting filtered signal so that the passage of zero, maximum, and is Tracii signal Central frequency band of the filter is reduced, and when passing through zero, the maximum and minimum values signom caused by electrical activity of the brain later obtained by filtering the signal Central frequency band of the filter increases. Subtract from the signal caused by the electrical activity of the brain obtained by filtering the signal. Record obtained by subtracting the signal in the form of an analog electrical signal within 500 MS from the moment the alarm. For the analysis obtained by subtracting the signal set two time interval of the search components of long-latency evoked potential - first from 120 MS to 260 MS and the second from 260 MS to 500 MS. In the first interval to determine the minimum value of the signal in the second interval determines the maximum value of the signal. The boundaries of time intervals 120, 260 and 500 MS are established on the basis of the statistical characteristics (mathematical expectation and standard deviation “Sigma”) of the latencies of the peaks of N2 and P3 long-latency evoked potential, certain centuries Gnosticism and a number of other researchers on large groups of subjects of different ages (see Century. Century. Gazdecki. Evoked potentials MH is agnosti between the previously defined maximum and minimum value of the signal compare the value of the modulus of the difference value To set experimentally. For the comparison, a positive number is judged on the presence of long-latency evoked potential brain, and the resulting comparison of a negative number is judged about the lack of long-latency evoked potential brain. The experimentally determined K-factor represents a combination of micropolitan the peak amplitude of RH, as measured relative to the peak N2, for long-latency evoked potential brain is 5.1 mV, at a confidence level of 95% (see Century. Century. Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 111, PL. 11.4).

The proposed device operates as follows. In unit 1, control means for supplying a signal of the impact parameters of the signal influence on subject - amplitude and pulse width so that the maximum value of the signal means 2 of the supply of short-term duration of the external signal was less than the signal magnitude corresponding to pain syndrome. Evoked electrical brain activity of the subject 3 is removed from the scalp in the form of electrical Signa of the subject in the form of electrical voltage signal. The output signal U5 (Fig.3) the means 5 records the electrical activity of the brain represents the sum of the spontaneous or background activity of the brain, independent of external stimuli, and responses to external stimuli (see Methods research in psychophysiology / Doroshenko C. A., Kanunnikov I. E., Smirnov, A., and others; Ed. by Batueva A. S.-Petersburg, Izd-vo S.-Petersburg Univ. 1994, S. 46). In the background activity at 75 - 80% of subjects (from age 7-9 years) dominant alpha rhythm amplitude 50-150 mV and a frequency of 8-13 Hz (see Biopotentials of mosea person. The mathematical analysis. / Ed. by B. C. Rusinova. -M.: Medicine. 1987, S. 34, S. 42, PL. 1; research Methods in psychophysiology / Doroshenko C. A., Kanunnikov I. E., Smirnov, A., and others; Ed. by Batueva A. S. - Petersburg, Izd-vo S.-Petersburg Univ. 1994, S. 6; centuries of Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 11, Fig. 1). The amplitude of the long-latency evoked potential measured for the components N2 and P3, is from 5 to 18 µv (see Century. Century. Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 111, PL. 11.4), and the frequency is determined by the interval from the minimum (N2) to maximum (P3) - 5 Hz and below. During one period of the alpha rhythm Donnelley brain highs minimum and zero values relative to spontaneous alpha rhythm. In the diagram of Fig.3 signal U5shown schematically as a sum of sinusoids of the alpha rhythm and slowly changing signal long-latency evoked potential (in the diagram, Fig.3 labeled “DVP”). The signal U5arrives at the inputs of the fourth amplifier 19 with adjustable gain, the first delay line 21, the first input 36 of the fifth adder 38 and the second input 44 of the sixth adder 45. The second adder 15 with delay lines 21, 22, 25, 27, amplifiers 16, 17, 18, 19 with adjustable gain forms a narrow-band filter. Delay lines 21, 22, 25 and 27 are identical and provide a net delay of its output signals with respect to the input (U21regarding U5and U25regarding U15, Fig.3) by the value of t is chosen in the range of 1-3 MS). The gains of the amplifiers 16, 17, 18, 19 are determined by the formula

wherePthe half band filter is selected in the range of 2-4 Hz;

P- Central (resonant) frequency band filter changes during Raita, described below.

Since the frequency of the signal DVP lies outside the band filter 2Pat the output of the narrowband filter 6 (the output of the second adder 15) contains only alpha-rhythm signal U15, Fig.3.

The resonant frequency of the narrowband filter 6 in General does not coincide with the frequency of the alpha rhythm, so the signal U15or “behind” from the signal U5or “ahead” in passing zero, the maximum and minimum values in accordance with vasovasostomy characteristic of the notch filter (see C. A. Buscarse, E. P. Popov. Theory of automatic control systems. - M.: Nauka, 1975, S. 76-77, Fig. 4.18, S. 93-100). The third adder 30, the input of which receives the output signal of the second adder 15 and he after a third delay line 25, the signal processing

U30=U15-U25,

which crosses zero at those points in time when the signal U15reaches its maximum and minimum values (Fig.3). The sixth adder 45 generates a signal relay form.

U45=A sign(U5)-Asign(U15),

where A=1,

sign (x) is a function of the sign of the number X.

The width of the pulse signal U45equal intervals between kamentatorov equal time intervals between the moments of passing the maximum and minimum values of the signals U5and U15forms the fifth adder 38 by the formula

U38=A sign (U5-U21)-A sign (U30).

Phase detectors 32 and 41 form respectively relay the signals U32and U41according to the formula

U32=U45·Asign(U15);

U41=U38·Asign (U30).

The fourth adder 34 performs the algebraic summation of the signals U32and U41by the formula

U34=U41-U32.

In the diagram of Fig.3 the output signal of the fourth adder 34 U34shown together with the output signal U35integrator 35, where it is seen as a signal U35increases during the passage of the pulses of the signal U34following with four times the frequency of the dominant alpha rhythm, and remains constant during the absence of pulses U34. In proportion to the signal U35changes the resonant frequency of the notch filter according to the formula

p=pH+Cand·U35,

wherepH- the initial value of the resonance frequency (selectable in the range of 8-13 Hz);

Kand=1 1/p-gain of the integrator 35. In accordance with the current>8and K19amplifiers 16, 17, 18, 19. Thus the bandwidth of the filter 2Premains constant, which ensures a constant slope vasovasostomy characteristics regardless of the resonance frequency, the stability of the regulatory process (see C. A. Buscarse, E. P. Popov. Theory of automatic control systems. - M.: Nauka, 1975, S. 76-77, Fig. 4.18, S. 93-100, pages 133-139) and minimal distortion when filtering the alpha rhythm. When approaching the resonance frequency of the filter with the frequency of the alpha rhythm output signal U15will be less different from the signal of the alpha rhythm in the moments of passing through zero, the maximum and minimum values, the width of the pulses in the signal U34will tend to zero, the gain K16, K17, K18and K19amplifiers 16, 17, 18, 19 will become permanent. The output signal of the first adder U9(Fig.3) will only signal long-latency evoked potential, which will allow long-latency evoked potential in one implementation from a single exposure of the stimulus.

An example implementation of the method. The patient Century. 9 years. Almost healthy. Used equipment - photostimulator, shestnadcatiletniy stress Hz. Recording electrodes (checkoway, silver-charterer) were placed on the scalp according to the “10-20” in leads O1O2P3P4With3With4T5T6. Alpha-rhythm frequency of 8.8 Hz dominated leads O1O2. (amplitude 83 UV) and R3P4(amplitude 32 µv). The patient sat in a chair, relaxed, with your eyes closed. After recording the background EEG, the patient was instructed to be careful and count the flashes of light produced by photostimulation. Was one outbreak that caused a partial reduction of the alpha rhythm in a patient - a decrease in the amplitude of 50 mV. Analyzed the signal from the lead About2. Due to the small age of the test (expected low frequency of the alpha rhythm) the initial value of the resonant frequencypHis chosen equal to 8 Hz. In Fig.4 shows that the output signal of the first adder U9fluctuations of the alpha rhythm disappear within 0.15 after the filing of the stimulus (time t=0 in the diagram), which corresponds to theoretical calculations. The received signal was analyzed at time intervals from 120 to 260 from 260 MS and 500 MS. In the first interval of the detected minimum value Usnasti amounted to D=Umax-Umin=37,33 µv. Because D>To, is diagnosed with long-latency evoked potential. The latency of the peak P3 corresponds to the average age of the patient (see Century. Century. Gazdecki. Evoked potentials of the brain in clinical practice. Taganrog, publisher TSURE, 1997, S. 114, Fig. 37).

The proposed method ensures the ultimate goal of reducing the time of registration, povysheniya precision diagnostics long-latency evoked potential brain and provide opportunities to explore the responses of the subject on a separate incentives by filtering an electrical signal caused by the activity of a brain of the subject within a narrow frequency band of constant width, the change in the Central frequency band filtering at a speed proportional to the magnitude of the time intervals between the moments of passing through zero, the maximum and minimum values of the signals caused by the activity of the brain and the resulting filtered signal so that when passing through zero, the maximum and minimum values of the signal caused by the electrical activity of the brain previously obtained by filtering the signal Central frequency band of the filter is reduced, and the passage of Mulago by filtering the signal Central frequency band of the filter increases, subtraction of the signal caused by the electrical activity of the brain resulting from filtering of the signal.

Check-in time is reduced compared with the known method in 150-200 times, since the proposed method is used to diagnose every impulse, and not a series of 150=200. The diagnostic accuracy increased as long-latency evoked potential latency time of about 300 MS need occurs when a conscious choice, a decision.

Thus, the set of features of the proposed method and device provides the goal and benefits exceeds the sum of positive effects from the introduction of the proposed operations and elements of the device.

Claims

1. A method of registering long-latency evoked potential of the brain, namely, that affect the subject of a short duration signal, the maximum value is less than the signal magnitude corresponding to pain syndrome register evoked brain activity in the form of an electrical signal, set two time interval of the search components of long-latency evoked potential, the ale from 120 to 260 MS and the maximum value of the electrical signal caused by brain activity of the subject in the second interval from 260 MS, calculate the modulus of the difference between the determined maximum and minimum value of the signal, compare the value of the modulus of the difference with the value K, where K is a coefficient determined experimentally, and the resulting comparison positive number is judged on the presence of long-latency evoked potential brain, and the resulting comparison of a negative number is judged about the lack of long-latency evoked potential of the brain, characterized in that the boundary of the second interval is set to 500 MS, and the electric signal caused by brain activity of the subject is filtered in a narrow frequency band of constant width, the center frequency of which change with speed, proportional to the value of time intervals between the moments of passing through zero, the maximum and minimum values of the signals caused by the activity of the brain and the resulting filter the signal so that the passage of zero, the maximum and minimum values of the signal caused by the electrical activity of the brain before the signal obtained by filtering the band center frequency of the filter is reduced, and when passing through zero, maximalisatie filter, the band center frequency of the filter increases, the values of the modulus of the difference using the result of subtracting from the signal caused by the electrical activity of the brain signal resulting from filtering.

2. The device for recording the long-latency evoked potential brain that contains one United block analysis of long-latency evoked potentials, the control unit means for supplying to the subject signal exposure and means for supplying to the subject of the short duration of the external signal a certain value, the maximum value is less than the signal magnitude corresponding to a pain syndrome, as well as the sensor and means for recording electrical activity of the brain of the subject in the form of electrical voltage signal, wherein the output means of recording electrical activity of the brain of a subject connected to the first input of the first adder, the output of which is connected to the input of the unit of analysis of long-latency evoked potentials, to the output means of recording electrical activity of a brain of the subject connected serially connected first and second delay lines, the first amplifier with adjustable coefficientsfor connected serially connected third adder, the first phase detector, a fourth adder and the integrator, the output of which is connected to the control input of the first amplifier with an adjustable gain, the output of the second adder connected serially connected third and fourth delay lines and a second amplifier with an adjustable gain, the output of which is connected to the second input of the second adder, the output of the third delay line is connected to the second input of the third adder and to the input of the third amplifier with adjustable gain, the output of which is connected to the third input of the second adder, the output means of recording electrical activity of a brain of the subject connected in series United fifth adder and the second phase detector, the output of which is connected to the second input of the fourth adder, the output means of recording electrical activity of a brain of the subject is connected to the input of the fourth amplifier with adjustable gain, the output of which is connected to the fourth input of the second adder, the output of which is connected to the second input of the second phase detector and the first input of the sixth adder, the output of which is connected to the second input of the first phase detector, obtained to the output of the integrator, the second and third inputs of the fifth adder connected respectively to the output of the first delay line and the output of the third adder and the second input of the sixth adder connected to the output means of recording electrical activity of a brain of the subject.



 

Same patents:
The invention relates to medicine, namely, neurology

The invention relates to ophthalmology, and in particular to means for testing visual acuity that does not depend on perception or reaction of the patient
The invention relates to medicine, namely to ophthalmology

The invention relates to medicine and can be used to diagnose disorders of the nervous system and higher mental functions
The invention relates to medicine, in particular to clinical neurophysiology, and can be used for the diagnosis of organic and functional changes in the system of visual afferention in children and adolescents

The invention relates to medicine, namely, neurology, and can be used in the differential diagnosis of lesions of the first (I) branches of the trigeminal nerve (TN) (nervus ophthalmicus) and second (II) branch TN (nervus maxillaris)

The invention relates to medicine, in particular to Pediatrics, namely, to the diagnosis of cerebral disorders in the damage of the cervical spine in newborns

The invention relates to medicine, more specifically to neurosurgery, and may find application in surgical interventions on the brain

The invention relates to medicine, namely, neurology, and can be used in the diagnosis of lesions of the afferent systems of the spinal cord, for example, in patients with multiple sclerosis

The invention relates to medicine, namely, neurology, and can be used in the diagnosis of lesions, dynamic monitoring of treatment effectiveness, expert assessment of disability and prognosis

FIELD: medicine.

SUBSTANCE: method involves carrying out intraoperative neural motor evoked potential monitoring. Spinal nerve stimulation is carried out with rectangular pulses of 0.2 ms duration, frequency of 4.1 Hz, intensity of 10-25 mA and distance between electrodes equal to 4 mm. Neural motor evoked potentials are recorded in popliteal space in sciatic nerve projection area. Peak No 1 latent period being longer than 21 ms, pulse conduction dysfunction is diagnosed in spinal nerve motor fibers.

EFFECT: high accuracy of diagnosis.

5 dwg, 3 tbl

FIELD: medicine.

SUBSTANCE: method involves carrying out acoustic monoaural stimulation with frequency of 8-12 Hz and recording cerebral auditory evoked stem potentials. Changes are detected when comparing to reference value in norm. No significant changes in cerebral auditory evoked stem potentials being found, additional stimulation is carried out with frequency of 30-100 Hz. Auditory evoked stem potentials are recorded. Significant changes being found when compared to norm, functional brainstem disorders are diagnosed.

EFFECT: high accuracy of early stage diagnosis.

FIELD: medicine, neurosurgery, neurology.

SUBSTANCE: one should study wink reflex to detect the lesion of oral departments in tegmentum of brain stem bridge and caudal departments of brain stem being counterlateral against vestibular schwannoma, moreover, it is necessary to study stem induced potentials. By the data obtained one should determine diagnostic coefficient that characterizes the degree of ischemic lesion of brain stem by the following formula: I=4.47+2.08φ1-2.18φ2-2.43α1+2.26α3+0.53α5, where φ1, φ2- patient's values at lesions of caudal departments of brain stem and oral departments of tegmentum of brain stem bridge are accepted to be equal to 1, and in case of no lesion - to -1; α1, α3, α5 - the values of latent periods I, III, V in peaks of acoustic stem induced potentials are accepted to be equal to -1 in case of correspondence to standard; and at any deviation against the standard - equal to 1 and at obtaining I=5±0.5 one should diagnose high-degree ischemic lesion of brain stem, at values of I=1±0.2 - average-degree ischemic lesion of brain stem; at I=0.5±0.1 - light-degree brain stem ischemia, at negative I values ischemic lesion of brain stem is inconsiderable. The innovation enables to increase significance of diagnostics due to combined analysis of factors that characterize ischemic lesion of brain stem.

EFFECT: higher accuracy of diagnostics.

3 ex

FIELD: medicine.

SUBSTANCE: method involves carrying out electroencephalography and cognitive evoked potentials examination on showing binaural acoustic stimulation with 50 ms long pulses which intensity is of 80 dB with 2 s long pauses between stimuli, significant tone frequency equal to 2000 Hz, insignificant one equal to 1000 Hz when shown in pseudo random order. Three series of averaging are recorded with significant tone being repeated 26 times in each of them. The testee counts the significant tones in mind within the second and third series. N2, P3 peak latency and P3 peak amplitude are determined in the first (A1) and in the second (A2) averaging series. Habituation is calculated as A2/A1*100 and A coefficient as ratio of habituation P3 peak amplitude and P3 amplitude of the first averaging series. P3 peak latency being increased when compared to normal reference value in combination with dominated slow electroencephalography activity, severe uremic encephalopathy is to be diagnosed. Habituation P3 peak amplitude growing higher than 100%, P3 peak latency being normal and A coefficient not exceeding 12.31% mcV in combination with electroencephalogram beta-rhythm dominated by frequency below 25 Hz spread allover the whole convex with distinct rhythm mastering response to rhythmic photostimulation in broad frequency bandwidth taking place, mild uremic encephalopathy severity degree is to be diagnosed. Coefficient A value exceeding 12.31% mcV, P3 peak latency being normal in combination with high distant oscillation synchronization, low frequency alpha-rhythm being recorded, zonal amplitude differences being smoothed and theta-waves outbursts being available in frontal central leads, moderate uremic encephalopathy severity degree is to be diagnosed.

EFFECT: high diagnosis reliability.

2 cl, 8 tbl

FIELD: medicine, resuscitation.

SUBSTANCE: intensive therapy should be carried out, moreover, it is necessary to register somatosensor evoked potentials (SSEP), measure inter-peak interval N13-N18 at spinal lesions at C1-C2 level, N11-N13 at lesion at C1-C6 level and N22-C30 at lesions at C7-L3 level. Then one should calculate average arterial pressure (APav) and prescribe pressure-regulating medicinal preparations. Then comes control SSEP registration and at decreased values of inter-peak intervals one should change the preparation applied and its dosage, at constant level of inter-peak intervals - the dosage should be increased, and at increased values of intervals - one should intensify therapy due to increasing the dosage or substituting the preparation applied. SSEP values should be evaluated after changing the dosage of the preparation applied and in dynamics of investigation on the 3d, 5th and 9th d and, also, in case of deterioration of patient's health state. It has been provided due to applying a high-sensitive value that reflects the state of spinal cord.

EFFECT: higher efficiency of prophylaxis.

3 ex

FIELD: medicine, anesthesiology, neurosurgery.

SUBSTANCE: at resecting a basal meningioma due to applying Nd-YAG-laser of 45-55 W power one should register acoustic stem evoked potentials at the stage of operation after premedication and at the stage of meningioma's resection. At altering amplitude-temporal parameters of their components at the stage of resection against the stage of premedication in combination with bradycardia being 48-52 strokes per min for 15 min with tendency to hypertension one should predict unfavourable result of operation. The method widens the number of ways for predicting the result of operation in case of removing cerebral basal tumors.

EFFECT: higher accuracy of prediction.

1 ex

FIELD: medicine, narcology.

SUBSTANCE: it is necessary to observe anamnesis, carry out neurological, psychiatric, psychological and electroencephalographic trials and register cognitive induced potentials. While gathering anamnesis one should detect the presence of heredity burden, birth traumas, early organic lesions of central nervous system (CNS); in the course of neurological trial - the presence of focal neurological symptomatics, epilepsy or neuroinfections or cranio-cerebral traumas; at psychiatric trial - the presence of psychopathies, psychic diseases, evaluation of social environment; at psychological trial - hyperthymic and epileptoid types of personalities; at EEG - the presence of dysfunction of median cerebral structures, epiactivity; while studying cognitive induced potentials it is necessary to detect affected processes of perception, identification and decreased volume of operative memory. The characteristics detected should be classified by the sign of their presence or absence as 1 or 0 points and the sum of points being above 7 one should conclude upon the tendency for addiction to psychoactive substances (PAS) or psychoactive actions (PAA), at the sum being 6 or 7 points - the boundary state, and at the sum being up to 6 points - the absence of the above-mentioned addictions. In case of no data on anamnesis the addiction to PAS and PAA should be determined at the sum of points being above 6, boundary state - at the sum of 5 or 6 points, and at the sum of 5 points - the absence of addiction. The innovation widens the number of preparations that help us to detect pathological addiction to PAS and PAA at early stages in 15-25-yr-aged persons.

EFFECT: higher accuracy and efficiency of detection.

FIELD: medicine, pediatrics.

SUBSTANCE: it is necessary to apply electrodes upon a palm, supply stimulating sound or visual stimuli to register an evoked skin autonomic potential (ESAP). According to the type obtained ESAP should be referred to either the first or the second type followed by detecting the values of amplitude, the duration of latent period and that of every ESAP-phase. Then comes the diagnostics for the presence or absence of deviations due to comparing the obtained ESAP values against corresponding values in a healthy child. Moreover, one should additionally isolate the third type of ESAP in which immediately after latent period one may observe at first ascending and then - descending parts of the second phase finished with the third phase in the form of a trace wave. While comparing ESAP values it is useful to apply quantitative ratios distributed according to age groups: children aged 3-6, 7-11 and 12-15. The innovation widens the number of diagnostic means for predicting the state of autonomic nervous system structures.

EFFECT: higher accuracy and efficiency of diagnostics.

1 dwg, 3 tbl

FIELD: medicine.

SUBSTANCE: it is necessary to carry out registration and studying somatosensory evoked potentials (SSEP); moreover, one should conduct stimulation of tibial nerve, register spinal potential above spinous process of the 1st lumbar vertebra and cortical potential above the projection of parietal lobe. It is important to determine the amplitude N22 (A(N22)) of spinal potential and that of P37 (A(P37)) of cortical potential to calculate the coefficient of standardized amplitude value (CSAV) by the following formula: At CSAV being < 2.2 one should diagnose the decreased functional activity of affected cerebral structures and at CSAV being > 4.5 - the cortical lesion. The innovation enables to fulfill additional estimation of cortical potential amplitude.

EFFECT: higher significance of evaluation.

3 dwg, 3 ex

FIELD: medicine, neurology, pediatrics.

SUBSTANCE: it is necessary to evaluate auditory potentials, moreover, on the 3d d a patient should be supplied with series of auditory significant and insignificant stimuli. One should determine latent period of endogenous wave R300 and at wave length ranged 314.1±1.42 msec it is possible to diagnose the concussion of brain, and at wave length ranged 317.9±1.63 - the light-degree bruise of brain should be diagnosed. The innovation helps to widen the quantity of measures for conducting differential diagnostics.

EFFECT: higher accuracy of diagnostics.

2 ex

Up!