RU2498769C2 - Apparatus for epileptiform activity detection and prevention - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment. An apparatus for epileptiform activity detection and prevention comprises a microelectrode system (1), a preamplifier (3), a filter (4) integrated into an information stimulation unit (2), and a power supply (9). When in use the microelectrode system (1) is implanted into an epileptiform activity site and serves as a diagnostic recorder or an electric neurostimulator. The apparatus comprises an electric neurostimulator (6), a receiver-transmitter (8), a micro antenna connected to a telemetry channel with a doctor's block (10) which are structurally combined within an evaluation and control unit (19). When in use the evaluation and control unit (19) is implanted into an infraclavicular region. The information stimulation unit (2) comprises a microsystem switch (7). The evaluation and control unit (19) comprises an electroencephalographic signal processing and analysis unit (5).

EFFECT: invention enables more reliable short-term eliteptiform activity prediction, as well as more effective neurostimulation for the purpose of epileptic discharge extension.

2 cl, 2 dwg

Description

The invention relates to medical equipment, in particular to medical information management systems used to predict and prevent epileptiform activity in patients with epilepsy.

A device is known that is used in clinical practice, including an electroencephalograph connected by a system of wires with electrodes and providing for the removal and processing of brain biopotentials, the results of which can only be used to study and evaluate the development of epileptiform activity and determine the moment of its onset, i.e. to obtain information after the fact and do not allow solving the problem of detecting and preventing epileptiform activity in real time and outside of clinical conditions. [Zenkov L.R. Clinical epileptology with elements of neurophysiology. // M. - Medical information agency, 2002. - S.281-283].

In addition, this device due to the presence of connecting wires connecting the electrode system located on the patient’s head with the processing equipment, restricts the patient’s movement, and can also be a source of interference, distorting the shape and spectrum of informative signals.

The last disadvantage of the above device is almost eliminated in the device for electroencephalographic studies [av. St. No. 1734687, IPC A6V 5/04 publ. 05/23/1992], providing the possibility of conducting a study of the patient without restricting the freedom of his movements.

This device consists of two parts, one of which contains a helmet that is worn on the patient’s head, with electrodes placed in it for removing the brain’s biopotentials, biopotential amplifiers, an information conversion unit, an electromagnetic signal transmitter equipped with a transmitting antenna, and a power supply, and the second part located in the zone of stable reception of electromagnetic waves, contains an electromagnetic signal receiver equipped with a receiving antenna, and an information processing and recording unit connected to the output receiver

However, this device in connection with the use of cutaneous electrodes does not allow predicting, with a sufficient time lead, the instant of occurrence of epileptiform activity in real time, since this process is detected only after the occurrence of an epileptic seizure. Among the many reasons that cause this delay, the greatest contribution is the time of conversion and transmission of an array of primary EEG signals via a telecommunication channel, as well as the reactive properties of an overhead electrode system. The devices discussed above are functionally designed only for recording EEG and solving diagnostic problems to determine the characteristics of epileptiform activity and do not allow the treatment process to be carried out in real time.

Known electroneurostimulator [US Pat. USA No. 6505077 B1 IPC A61N 1/36 publ. January 7, 2003], which contains the non-implantable part in the form of a pulse transmitter unit and the implantable part in the form of a receiver unit. The implantable part contains a processor, a memory unit, a power source, a loop antenna for recharging the power source from the outside, and other elements for receiving stimulation signals of the desired type. During the recharge of the power source, it is possible to reprogram the electrical neurostimulator using an external programmer and monitor the relative position of the antennas. In this case, the antenna for recharging can act as an antenna for telemetry, and the device as a whole allows you to act on the central nervous system by remote long-term stimulation with alternating current using implantable electrodes to suppress epileptiform activity.

However, this electroneurostimulator has limited functional capabilities (it does not at the same time and in combination solve diagnostic and therapeutic problems), and also does not provide separate modes of managing the treatment process for both the doctor and the patient.

Known multi-channel programmable electrical neurostimulator [US Pat. RF №2286182, IPC A61N 1/36 publ. October 27, 2006], which provides separate management for the doctor and patient, as well as complete mutual independence of the stimulation channels.

The electroneurostimulator contains a non-implantable part in the form of a pulse transmitter block with pulse-width modulation and an implantable part in the form of a receiver block. The blocks are made with the possibility of magnetic induction coupling. The pulse transmitter contains a tunable high-frequency generator, a telemetry channel receiver, a programmable transmitter microcontroller, a control and programming keyboard, an LCD alphanumeric display, and a power supply. The transmitter is connected to a remote antenna for transmitting high-frequency energy and receiving telemetric information. The receiver unit contains an antenna for receiving high-frequency energy and transmitting telemetric information, a programmable microcontroller for the receiver unit, a digital-to-analog converter, amplifier, multi-channel switch, electrodes and connectors for connecting electrodes to a single-channel switch. The multichannel switch is connected by its signal inputs and outputs, forming the contacts of the receiver unit, with the electrodes through the connectors, forming stimulation channels that are switched on individually or by any groups, or all at the same time.

However, this device has limited functionality, because It does not allow to register primary EEG signals and, therefore, to solve the diagnostic tasks necessary for the simultaneous and full implementation of the treatment and diagnostic process in patients with epilepsy. This virtually eliminates the possibility of using this device for the integrated solution of problems in the detection and prevention of epileptiform activity.

As a prototype adopted radio-controlled neuromodulating system [US Pat. USA No. 20070282389 A1, IPC A61N 1/18, publ. December 6, 2007], which includes microelectrodes implanted in the zone of the focus of epileptiform activity, each of which has its own amplifier, filter, and threshold sensor, which excludes the transmission of a distorted signal when a specified level is exceeded. The output of the threshold sensor is connected to a wireless transceiver connected to a communication device (for example, USB), which is connected to the input of a personal computer that processes and analyzes incoming signals in order to assess the inevitability of an attack and generate commands for activating an electrical neurostimulator or for delivering an antiepileptic drug. In addition, the system is equipped with micro-antenna and autonomous power, implanted in a place remote from the location of the microelectrodes.

The system allows you to carry out the diagnostic and treatment process in a volume that includes the functions of registration and therapy by electroneurostimulation.

However, the formation of a prognosis for the approximation of epileptiform activity is based on a single symptomatic symptom that allows one to construct a single-channel system characterized by insufficient reliability of noise immunity, and reliability of information about the fact of approaching an epileptic seizure and the validity of the nature and parameters of neuro-stimulating effects to prevent it.

The proposed technical solution is aimed at eliminating this drawback. The technical result to which the claimed invention is directed is to increase the reliability of the prognosis of the appearance of epileptiform activity in the short term, as well as the effectiveness of neurostimulation to stop the spread of an epileptic discharge.

The technical result is achieved by the fact that in the inventive device containing an information-stimulating unit, consisting of a system of microelectrodes, when using implantable in the location area of the focus of epileptiform activity, a preamplifier and a filter, as well as an evaluation and control unit, when used, implantable in the subclavian region, a power supply unit, an electrical neurostimulator, a transceiver and a micro-antenna for telemetric communication with a doctor’s unit, the new one is that the information-stimulating unit contains It holds a microsystem switch, which provides the alternate counter direction of movement of the flow of informative signals and the flow of neuro-stimulating effects, and the evaluation and control unit contains a module for processing and analysis of electroencephalographic signals and the formation of neuro-stimulating effects.

The invention is illustrated in figure 1 and figure 2, where figure 1 is a structural diagram of a device for detecting and preventing epileptiform activity, figure 2 is a module for processing and analysis of electroencephalographic signals.

Here:

1 - a system of microelectrodes; 2 - information-stimulating block; 3 - amplifier; 4 - filter; 5 - module processing and analysis of electroencephalographic signals; 6 - electrical neurostimulator; 7 - microsystem switch; 8 - transceiver; 9 - power supply; 10 - doctor’s block; 11 - analog-to-digital Converter, 12 - digital filter; 13 - block segmentation of the EEG signals; 14 - block allocation biorhythm; 15 - block assessment of symptomatic signs; 16 - block job constants; 17 - block comparison; 18 - quorum element; 19 is an assessment and management unit.

A device for detecting and preventing epileptiform activity comprises an information-stimulating unit 2 and an evaluation and control unit 19.

The information-stimulating block 2 consists of a system of microelectrodes 1, using epileptiform activity that are implanted into the zone of the focus of the focus, performing a recording function in the diagnostic mode, and in the stimulating mode, they provide electrical neurostimulation, connected through the first hour to the second information inputs of the microsystem switch 7 with the preamplifier 3 connected in series and a filter 4, the output of which is the output of the information-stimulating unit 2. The microsystem switch 7 is equipped with the transmitting input, which is the first input of the information-stimulating unit 2 and determining the diagnostic or stimulating mode of operation of the device, connected to the 2 output of the processing and analysis module of electroencephalographic signals 5 of the evaluation and control unit 19, as well as the stimulating input connected to the electroneurostimulator 6 of the evaluation and control unit 19.

The evaluation and control unit 19, when used, is implantable in the subclavian region, contains a module for processing and analysis of electroencephalographic signals 5, the input of which is the input of the evaluation and control unit 19 and connected to the output of the information-stimulating unit 2, its first output is connected to the input of the neurostimulator 6, the second output, which is the second output of the evaluation and control unit 19, is to the first input of the information-stimulating unit 2, the second input of which is connected to the first output of the evaluation and control unit 19. Bl appraisal and control 19 also includes a transceiver 8, a microantenna included in the telemetry channel with the doctor’s unit 10, and a power supply 9.

The module for processing and analysis of electroencephalographic signals 5 contains a series-connected analog-to-digital converter 11, a digital filter 12, an EEG signal segmentation unit 13, a biorhythm allocation unit 14 and a symptom evaluation unit 15, a constant setting unit 16, a comparison unit 17, the inputs of which are the outputs of the block for evaluating symptomatic signs 15 and the block for setting constants 16, and the quorum element 18, the input of which is connected to the output of the comparison unit 17, while the first and second outputs of the quorum element 18 are the second and second outputs of the module for processing and analysis of electroencephalographic signals 5 and are connected respectively to the input of the electroneurostimulator 6 and to the first input of the information-stimulating unit 2, and the input of the module for processing and analysis of electroencephalographic signals 5, which is the input of the analog-to-digital converter 11, is connected to the output of the information -stimulating unit 2, and the output of the electroneurostimulator 6 which is the first output of the evaluation and control unit 19, is connected to the second input of the information-stimulating unit eye 2, which is the stimulating input of the microsystem switch 7.

The main units of the device are implemented as follows:

1. Implemented in accordance with those used in US Pat. USA No. 200660276866 IPC A61N 1/18, publ. 12/07/2006 "Microelectrode array for chronic deep - brain microstimulation for recording" ("Array of microelectrodes for deep brain microstimulation and recording"). Douglas B. McCreery.

2. Ageev O.A., Mamikonov V.M., Petrov V.V., Kotov V.N., Negodenko O.N. Microelectronic converters of non-electrical quantities: a Training manual. Taganrog: Publishing house of TRTU, 2000 .-- 153 p.

3.140UD24, ICL7650; Integrated Circuits: Operational Amplifiers. Volume 1. - M .: Fizmatlit, 1993.240 s., P. 65.

4. pat. RF №2286182, IPC A61N 1/36 publ. 10.27.2006. Multichannel programmable electrical neurostimulator. Gutorko V.A., Barmotin S.V., Petrov I.A., Lovkov S.A.

5.140UD25, OR-27; Integrated Circuits: Operational Amplifiers. Volume 1. - M .: Fizmatlit, 1993.240 s., P. 81.

6. It is implemented on the basis of the PIC16F877 microcontroller.

7. Chesnokov G.I., Yakubovich A.M. Analog majority device with averaging of most signals. - Zh.: “Automation and Telemechanics”, No. 8, 1968. - p.137.

8. Implemented in accordance with used in US Pat. USA No. 20070282389 A1, IPC A61N 1/18, publ. December 6, 2007. Wireless controlled neuromodulation system (radio-controlled neuromodulating system) / Inventors: Karen Moxon (Collingswood, NJ); Andrew Khair; (Monroeville, NJ); Michael Darling (Trenton, NJ); Ebraheem Sultan (Shuwaikh, KW).

The operation of the device is as follows:

Brain biopotentials from the microelectrode system 1 [1], implanted according to the results of preliminary studies on the epileptiform activity center, arrive at the microsystem switch 7 [2], which in the diagnostic mode of the device transmits the flow of diagnostic information by connecting the microelectrode system 1 to the preamplifier 3 [ 3] information-stimulating block 2, and in the stimulating mode transmits a stream of stimulating pulses by connecting microelectrodes 1 to the electroneurostimulator 6 [4] of the block o Enki and control 19. In the diagnostic mode, the amplified signal is supplied to the input of the filter 4 [5], which suppresses high-frequency interference caused by radiotelephones and myographic interference.

Then the signal is fed to the input of the processing and analysis module of electroencephalographic signals 5 [6], which is part of the evaluation and control unit 19, in which the analog-to-digital conversion of signals in block 11 takes place, digital filtering of the converted signal by adaptive segmentation in block 12, which allows suppress interference caused by uninformative biorhythms, as well as contractile activity of the patient’s cardiac system and respiratory system. To simplify the processing of the EEG signal, it is segmented in block 13, which makes it possible to divide the recording of brain biopotentials into quasistationary regions. The signal from the segmentation block of the EEG signals 13 enters the biorhythm extraction system 14, in which spectral analysis is performed, which allows one to select information that is valuable for preventing the epileptiform activity of the α, β, θ and δ rhythms. Then, the estimates of the symptomatic signs of the approach of epileptiform activity in block 15 are calculated, the threshold values of these signs are set in block 16, and the calculated values of the estimates of symptomatic signs are compared with the threshold values in block 17.

Analysis of epileptiform activity is carried out on the basis of an algorithm consisting in sequential and sequential determination and comparison of estimates of a set of symptomatic signs with their threshold values obtained from preliminary studies of a particular patient with epilepsy.

Symptomatic signs of an approach of epileptiform activity include:

1 - the number of excesses of the pulsation peaks of the waves of α-, β-, θ-, δ-rhythms of the threshold value set for each of them for a fixed time interval;

и

для соответствующих диапазонов частот с предельным значением этих отношений, определяемых на основе обработки данных клинических исследований здоровых людей;2 - assessment of the ratio of the peaks of power spectra

and

for the corresponding frequency ranges with the limit value of these relations, determined on the basis of processing data from clinical studies of healthy people;

3 - assessment of the presence of correlation relationships of θ and δ rhythms.

The quorum element 18 [7] is triggered provided that the threshold values are exceeded by at least 2 symptomatic signs from the 1st population and at least 1 symptom from the 2nd and 3rd population. In this case, a control pulse is formed to turn on the electrical neurostimulator 6, as well as a control pulse to the microsystem switch 7 to put the microelectrode system 1 in stimulation mode by connecting them to the output of the electrical neurostimulator 6.

The microantenna [8] implanted in the patient and located in the evaluation and control unit 19 provides a link through which information is transmitted to the doctor unit 10, which is necessary to confirm the neurostimulation mode being performed or to correct the parameters of neurostimulating impulses.

Thus, the claimed device, taking into account the proposed structure and algorithms for processing the flow of diagnostic information and its subsequent verification, has advanced functionality and direct placement of implantable electrodes for timely retarding the development of epileptiform activity in the brain region.

Claims (2)

1. A device for detecting and preventing epileptiform activity, containing a system of microelectrodes, using epileptiform activity implanted in the zone of the focus of the focus, performing a recording function in the diagnostic mode, and providing electroneurostimulation in the stimulating mode, connected in series with the preamplifier and filter, combined into an information-stimulating unit, the output of which is the output of the filter, as well as a power supply, an electrical neurostimulator, a transceiver, the input of which connected to the input of the electroneurostimulator, and the output is connected to the microantenna entering the telemetry communication channel with the doctor’s unit, which are structurally integrated into the evaluation and control unit, when used, it is implantable in the subclavian region, the first output of which is the output of the neurostimulator, characterized in the stimulating unit contains a microsystem switch, through the first and second information inputs of which the microelectrode system is connected to the preamplifier, and the control and stimulating the first inputs of the microsystem switch are the first and second inputs of the information-stimulating block, and the evaluation and control block contains a module for processing and analysis of electroencephalographic signals, the input of which is the input of the evaluation and control block and is connected to the output of the information-stimulating block, its first output is connected to the input electroneurostimulator, the second output, which is the second output of the evaluation and control unit, is to the first input of the information-stimulating unit, the second input of which is connected to the first the output of the evaluation and control unit. 2. The device for detecting and preventing epileptiform activity according to claim 1, characterized in that the module for processing and analyzing electroencephalographic signals contains a series-connected analog-to-digital converter, a digital filter, an EEG signal segmentation unit, a biorhythm allocation unit, and a symptom sign evaluation unit, a unit assigning constants, a comparison unit, the inputs of which are the outputs of the unit for evaluating symptomatic signs and the unit for setting constants, and a quorum element, the input of which is connected to the output comparison unit, while the first and second outputs of the quorum element are the first and second outputs of the module for processing and analysis of electroencephalographic signals and are connected respectively to the input of the electroneurostimulator and to the first input of the information-stimulating block, and the input of the module for processing and analysis of electroencephalographic signals, which is an analog input -digital converter, connected to the output of the information-stimulating unit.

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