ELECTRICAL STIMULATOR SYSTEM WITH AUTOMATIC EEG
TOGGLE SWITCH
DESCRIPTION
Technical Field
The present invention relates to system for carrying out experimental stimulations by invasive and/or non-invasive electrodes installed on subjects or neuromodulation stimulations by non-invasive electrodes in humans and EEG (electroencephalography) measurements collectively, to control whether a stimulation provided is within security limits and to continue to perform EEG measurement with minimum delay upon stimulation is provided.
Background of the Invention
It is enabled to change brain functions, to trigger and then observe undesired neurological seizures and to suppress neurological activities by means of electromagnetic stimulation in subjects and humans. Stimulations which are applied to invasive and/or non-invasive electrodes installed on subjects, repeated and increased at certain time intervals cause arc-discharges to develop, spread electrophysiologically and interictal sharp discharges to occur, whereas they may also cause kindling epileptic seizures to develop and be observed behaviourally. It is required to fit stimulations -which are applied to non-invasive electrodes in humans, provide neuromodulation by regulating electrophysiological activity- for patients entirely by means of calibration in order to ensure electrophysiological stabilization of patients and supress the neurological problem aimed to be prevented. Stimulations should be applied as pulses with short-pulse width and high voltage in order that stimulations which are applied to invasive and/or non-invasive electrodes installed on subjects and stimulations which are applied by non- invasive electrodes to humans can produce desired electrophysiological effects. The fact that the pulse width of transmitted stimulations is longer than the requested time due to an unpredictable reason may lead to transient and/or permanent damage in the brain tissue of the subject or human who received the stimulation or in the body of the researcher who cause the stimulation to be damaged by contacting the connections that transmit the stimulation.
It is required to have EEG record with minimum loss of time in terms of being able to have real-time electrophysiological measurements and to carry out correct electrophysiological evaluations without loss of time upon electrical stimulations which trigger kindling epileptic seizures in subjects are provided to the subject or upon changes which are made during calibration of neuromodulation stimulations in humans; however researchers have to change cable between stimulator and EEG device manually in existing systems. In the event that this connection transition is performed manually, loss of time that will cause loss of important electrophysiological data occurs and damages take place in the resulting arc- discharge record.
Considering the deficiencies of electrophysiological stimulator systems in the current technique, it is seen that there is need for a system for carrying out experimental stimulations by invasive and/or non-invasive electrodes installed on subjects or neuromodulation stimulations by non-invasive electrodes in humans and EEG measurements collectively, to control whether a stimulation provided is within security limits and to continue to perform EEG measurement with minimum delay upon stimulation is provided in the state of the art. The United States patent document no. US10780268, an application in the state of the art, discloses a system for providing stimulation from transcranial electrodes so as to be used in electrophysiological testing and treatment processes, and performing measurement. The said system enables to connect transcranial electrodes to EEG device and stimulation device by a switching circuit, and to carry out stimulation and measurement transactions according to instructions in pre-programmed stimulation set.
Summary of the Invention
An objective of the present invention is to realize a system for carrying out experimental stimulations by invasive and/or non-invasive electrodes installed on subjects or neuromodulation stimulations by non-invasive electrodes in humans and EEG measurements collectively, to control whether a stimulation provided is within security limits and to continue to perform EEG measurement with minimum delay upon stimulation is provided.
Detailed Description of the Invention “An Electrical Stimulator System with Automatic EEG Toggle Switch” realized to fulfil the objective of the present invention is shown in the figure attached, in which:
Figure l is a schematic block diagram of the inventive device.
The components illustrated in the figure are individually numbered, where the numbers refer to the following:
1. System 2. Stimulator 3. Controlled energy source
4. Switching unit EC: EEG Device
The inventive system (1) for carrying out experimental stimulations by invasive and/or non-invasive electrodes installed on subjects or neuromodulation stimulations by non-invasive electrodes in humans and EEG measurements collectively, to control whether a stimulation provided is within security limits and to continue to perform EEG measurement with minimum delay upon stimulation is provided comprises:
- a stimulator (2) which is configured to record a stimulation scheme comprising the type of stimulation and the timing of measurement - namely, the total stimulation time, the pulse width of stimulation, the stimulation frequency, the stimulation current, monophasic or biphasic- transiently and/or permanently; to create stimulation pulses and transmit them to electrodes; and to create transition instructions between transmission and measurement;
- a controlled energy source (3) which is configured to control the pulse width and voltage of the transmitted stimulation and to provide the safe operating voltage; and
- a switching unit (4) which is configured to connect to the stimulator (2), the EEG device (EC) and electrodes; to connect the electrodes to the stimulator (2) or the EEG device (EC) automatically according to transition instructions between transmission and measurement in the stimulation scheme.
The stimulator (2) included in the inventive system (1) is configured to record a stimulation scheme comprising the type of stimulation and the timing of measurement -namely, the total stimulation time, the pulse width of stimulation, the stimulation frequency, the stimulation current, monophasic or biphasic- transiently and/or permanently; to create stimulation pulses and transmit them to electrodes; and to create transition instructions between transmission and measurement
The controlled energy source (3) included in the inventive system (1) is configured to control the pulse width and voltage of the transmitted stimulation and to provide the safe operating voltage. In one preferred embodiment of the invention, the controlled energy source (3) is configured to ensure the subject, human and researcher security by reducing the voltage supplied to the stimulator (2) when the amplitude of stimulation pulse transmitted exceeds a pre-determined amplitude limit. In one preferred embodiment of the invention, the controlled energy source (3) is configured to follow up the amount of transmitted energy by using the amplitude and the voltage of the stimulation pulse transmitted. In one preferred embodiment of the invention, the controlled energy source (3) is configured to reduce the voltage supplied to the stimulator (2) in order to maintain the amount of energy, that is transferred to the tissue in unit time independently of the stimulation amplitude and the stimulation frequency, below a pre-determined energy limit.
The switching unit (4) included in the inventive system (1) is configured to connect to the stimulator (2), the EEG device (EC) and electrodes; to connect the electrodes to the stimulator (2) or the EEG device (EC) automatically according to transition instructions between transmission and measurement in the stimulation scheme. In one preferred embodiment of the invention, the switching unit (4) is configured to connect the stimulator (2) to reference resistors and to ensure that trial stimulation is provided in order to calibrate the stimulator (2) before application of the stimulation scheme. In one preferred embodiment of the invention, the switching unit (4) is configured to connect the stimulator (2) to electrodes in order to send the stimulations determined in the stimulation scheme. In one preferred embodiment of the invention, the switching unit (4) is configured to connect the EEG device (EC) to electrodes according to the measurement time determined in the stimulation scheme.
Industrial Applicability of the Invention
In the inventive system (1), when the electrodes and the EEG device (EC) are connected and operated, the switching unit (4) connects the electrodes to the EEG device (EC) as the base connection scheme and thus ensures that preliminary electrophysiological reading is received from a subject or human. Following the preliminary electrophysiological reading, a stimulation scheme comprising the type of stimulation and the timing of measurement -namely, the total stimulation time, the pulse width of stimulation, the stimulation frequency, the stimulation current, monophasic or biphasic determined by the researcher- is created and saved to the stimulator (2) transiently and/or permanently. When the stimulation scheme is determined, the switching unit (4) ensures that the stimulator (2) is calibrated by trial stimulation by connecting the stimulator (2) to reference resistors and connects the stimulator (2) to electrodes in order that stimulation is initiated by separating the electrodes from the EEG device (EC). In a stimulation carried out in accordance with the stimulation scheme, the controlled energy source (3) controls the pulse width and voltage of the transmitted stimulation and reduces the voltage supplied to the stimulator (2) in order to keep the amount of energy, transferred to the tissue in unit time independently of the undesired stimulation amplitude and the stimulation frequency when an undesired stimulation amplitude and/or the voltage, below a pre-determined energy limit. According to the timing of measurement determined in the stimulation scheme, the switching unit (4) separates the electrodes from the stimulator (2) and then connects them to the EEG device (EC) and it is again ensured that electrophysiological reading can be received. The inventive system (1) enables to provide electrophysiological stimulations by maintaining the subject, human and researcher security at maximum level by means of the stimulator (2); to limit the maximum power that a subject, a human and a researcher may be subjected to in undesired stimulation errors by means of the controlled energy source (3); to connect the EEG device (EC) to electrodes automatically upon the stimulations provided to subjects or humans by means of the switching unit (4); and to receive electrophysiological measurements without loss of time. Within these basic concepts; it is possible to develop various embodiments of the inventive “Electrical Stimulator System with Automatic EEG Toggle Switch (1)”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.