Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/3605—Implantable neurostimulators for stimulating central or peripheral nerve system
  • A61N1/3606—Implantable neurostimulators for stimulating central or peripheral nerve system adapted for a particular treatment
  • A61N1/36067—Movement disorders, e.g. tremor or Parkinson disease
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/3605—Implantable neurostimulators for stimulating central or peripheral nerve system
  • A61N1/3606—Implantable neurostimulators for stimulating central or peripheral nerve system adapted for a particular treatment
  • A61N1/36082—Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Definitions

• the invention relates to a device for treating patients by means of brain stimulation according to the preamble of claim 1, an electronic component and the use of the device and the electronic component in medicine and a medical treatment method.
• nerve cell associations in defined areas of the brain e.g. of thalamus and basal ganglia, pathologically active, for example exaggerated synchronously.
• a large number of neurons form action potentials synchronously, ie the neurons involved fire excessively synchronously.
• the neurons fire differently in these brain areas, for example in an uncorrelated manner.
• the pathologically synchronous activity changes the neuronal activity in areas of the cerebral cortex, such as, for example, in the primary motor cortex, for example by forcing their rhythm on them, so that the muscles controlled by these areas ultimately pathological activity, z.
• a depth electrode is implanted.
• a cable leads from the head to the so-called generator, which comprises a control unit with a battery and is implanted under the skin, for example in the region of the clavicle.
• the aim of this method is to suppress the firing of the neurons in the target areas.
• This standard deep stimulation acts like a reversible lesion - that is, like a reversible switch-off of the tissue.
• the mechanisms of action ie how exactly the standard irritation works, has not yet been sufficiently clarified.
• the high-frequency continuous stimulation as an unphysiological, ie unnatural input in the area of the brain, for example the thalamus or the basal ganglia
• the high-frequency continuous stimulation can lead to the adaptation of the affected nerve cell associations within a few years.
• stimulation with a higher stimulus amplitude must then take place as a result of this adaptation.
• German patent application 102 11 766.7 discloses a device for the treatment of patients by means of brain stimulation, in which, for the desynchronization of the neuronal activity when a pathological feature is recognized by a control, either a) a high-frequency pulse train followed by a single pulse or b) a low-frequency pulse train - followed by a single pulse or c) a high-frequency pulse train can be applied.
• the activity of the affected nerve cell associations should not simply be suppressed, but should be brought closer to the healthy functional state.
• the side effects such as the dysarthria, dysaesthesia, cerebellar ataxia, depression or schizophrenia-like symptoms, etc., which result from the methods according to the prior art, should be eliminated or at least reduced.
• a method and a device are to be created which manage with lower stimulus amplitudes especially to reduce or eliminate side effects for the patient.
• the device according to the invention it is now possible to treat patients without adaptation to the non-physiological permanent stimulus taking place, the above-mentioned side effects being reduced or prevented.
• the battery or power consumption can additionally be drastically reduced, which is why the batteries need to be replaced or charged less frequently.
• the device according to the invention can work with a lower stimulus amplitude and leads to an improved therapeutic effect compared to the device from DE 102 11 766.7.
• FIG. 1 A block diagram of the device Fig. 2 Exemplary pulse sequences according to the invention
• the device according to the invention shown in FIG. 1 comprises an isolating amplifier (1), to which at least one electrode (2) and sensors (3) for detecting physical test signals are connected.
• the isolation amplifier is also connected to a unit (4) for signal processing and control, which is connected to an optical transmitter for stimulation (5).
• the optical transmitter (5) is connected to an optical one via optical fibers (6)
• Receiver (7) connected, which is connected to a stimulator unit (8) for signal generation.
• the stimulator unit (8) for signal generation is connected to the electrode (2).
• the unit (4) is connected via a line (10) to a telemetry transmitter (11) which is connected to a telemetry receiver (12) which is located outside the device to be implanted and to which a means for visualization, processing and storage of the data (13) is connected.
• Figure 2 shows an example of the stimulus pattern according to the invention.
• the ordinate corresponds to the current intensity and the abscissa to time, both of which are shown in arbitrary units.
• a single single pulse is shown schematically in all figures as a rectangular block.
• FIG. 2a A single high-frequency pulse train consisting of 6 individual pulses is shown in FIG. 2a.
• FIG. 2b shows a resetting high-frequency pulse train, which is followed by a desynchronizing high-frequency pulse train.
• FIG. 2c shows a low-frequency resetting sequence of high-frequency pulse trains, which is followed by a desynchronizing high-frequency pulse train.
• FIG. 2d shows a resetting single pulse, which is followed by a desynchronizing high-frequency pulse train.
• Epicortical electrodes, deep electrodes, brain electrodes or peripheral electrodes can be used as sensors (3), for example.
• the electrode (2) is at least two wires, at the ends of which a potential difference is applied for the purpose of stimulation.
• the electrode (2) is a means of applying the stimulus. In a broader sense, it can also be a means of measuring physiological signals. It can be macro or microelectrodes.
• a potential difference can be measured via the electrode (2) in order to determine a pathological activity.
• the electrode (2) can also consist of only a single wire. In this case, for the purpose of stimulation, a potential difference is created between the end of this wire on the one hand and a metallic counterpart on the other.
• the metallic counterpart can be, for example, a housing of the device or a part thereof, or any other electrode or other metallic object which is connected to the stimulator unit (8) in a manner analogous to the wire of the electrode (2).
• the electrode (2) can also consist of more than two individual wires, which can be used both for determining a measurement signal in the brain and for stimulation.
• four wires can be accommodated in one conductor cable, a potential difference being able to be applied or measured between different ends. This allows the size of the derived or stimulated target area to be varied.
• the number of wires from which the electrode is built is limited according to the upper values only by the thickness of the cable to be inserted into the brain, so that as little brain material as possible is to be damaged.
• Commercially available electrodes comprise four wires, but five, six or more wires can also be used, but only three wires be included.
• the suitable electrodes are known to the person skilled in the art and are not restricted to the electrodes listed by way of example.
• the electrode (2) comprises more than two wires
• at least two of these wires can also act as sensors (3), so that in this special case there is an embodiment in which the electrode (2) and the sensor ( 3) are combined in a single component.
• the wires of the electrode (2) can have different lengths, so that they can penetrate into different brain depths. If the electrode (2) consists of n wires, stimulation can take place via at least one pair of wires, any pairing of wires being possible when pairing.
• sensors (3) that are not structurally combined with the electrode (2) can also be present.
• the unit for signal processing and control 4 comprises means for univariate and / or bivariate data processing, as described, for example, in "Detection of n: m Phase Locking fro noisysy Data: Application to Magnetoencephalography" by P. Tass, et.al. in Physical Review Letters, 81,3291 (1998).
• the device is equipped with means which recognize the signals of the electrode (2) and or of the sensors (3) as pathological and, in the presence of a pathological pattern, emit stimuli via the electrode (2) which cause the pathological neuronal activity either suppressed briefly or modified so that it comes closer to natural, physiological activity.
• the pathological activity differs from the healthy activity by a characteristic change in its pattern and / or its amplitude, which are known to the person skilled in the art and which can be detected using known methods.
• the means for recognizing the pathological pattern are a computer which processes the measured signals of the electrode (2) and / or the sensor (3) and compares them with data stored in the computer.
• the computer has a data carrier that stores data that was determined as part of a calibration procedure. By way of example, these data can be determined by systematically varying the stimulation parameters in a series of test stimuli and the success of the stimulation via the electrode (2) and / or
• Sensor (3) is determined by means of the control unit (4).
• the determination can be carried out by uni- and / or bi- and / or multivariate data analysis to identify the frequency properties and the interaction (e.g. coherence, phase synchronization, directionality and stimulus-response relationship), as described for example in P.A. Tass: “Phase resetting in Medicine and Biology. Stochastic Modeling and Data Analysis. "Springer Verlag, Berlin 1999.
• the device therefore comprises a computer which contains a data carrier which carries the data of the clinical picture, compares it with the measured data and, in the event of pathological activity, emits an irritation signal to the electrode (2), so that the brain tissue is stimulated.
• the data of the clinical picture stored in the data carrier can either be person-specific, optimal stimulation parameters determined by calibration, or a data pattern that has been determined from a patient collective and typically represents optimal stimulation parameters that occur.
• the computer recognizes the pathological pattern and / or the pathological amplitude.
• the control unit (4) can comprise, for example, a chip or another electronic device with comparable computing power.
• the control unit (4) preferably controls the electrode (2) in the following manner.
• the control data are forwarded by the control unit (4) to an optical transmitter for stimulation (5), which controls the optical receiver (7) via the light guide (6).
• Electrode (2) is prevented.
• a photoelectric cell can be used as the optical receiver (7), for example.
• the optical receiver (7) forwards the signals input via the optical transmitter for the stimulation (5) to the stimulator unit (8).
• Targeted stimuli are then passed on via the electrodes (2) to the target region in the brain via the stimulator unit (8).
• a relay (9) is also triggered, starting from the optical transmitter for the stimulation (5), via the optical receiver (7), which prevents the interference from interference signals.
• the relay (9) or the transistor ensures that the neural activity can be measured again immediately after each stimulus without the isolating amplifier overdriving.
• the galvanic decoupling does not necessarily have to be done by optically coupling the control signals; rather, other alternative controls can also be used. These can be acoustic couplings, for example in the ultrasound range. Trouble-free control can also be implemented, for example, with the help of suitable analog or digital filters.
• the device according to the invention is preferably provided with means for visualizing and processing the signals and for data backup (13) via the telemetry receiver
• the unit (13) can use the above-mentioned methods for uni- and / or bi- and / or multivariate data analysis.
• the device according to the invention can be connected to an additional reference database via the telemetry receiver (13) in order to accelerate the calibration process, for example.
• Two types of stimulation are typically used in neurosurgery: 1. Continuous high-frequency stimulation (to suppress neuronal activity) and 2. Low-frequency stimulation (to amplify or stimulate neuronal activity).
• the frequency of the continuous high-frequency stimulation is typically greater than 100 Hz, e.g. 130 Hz.
• the frequency of the low-frequency continuous stimulation is around 2 Hz to 30 Hz.
• novel stimulus forms are used in the device according to the invention, which particularly efficiently influence the phase dynamics and the extent of the synchronization of neuronal rhythmic activity.
• novel stimulus forms composed of short high-frequency pulse trains, bring the pathologically synchronous activity close to the natural, non-pathological activity in a particularly effective manner or completely match it.
• the pathological neuronal activity via an electrode (2) such as a) brain electrode, for. B. a depth electrode, a b) epicortocal electrode or via c) a muscle electrode and is used as a feedback signal, ie a control signal, for demand-controlled stimulation.
• the feedback signal from the sensor (3) is transmitted to the isolation amplifier (1) via a line.
• the feedback signal can also be - without Use of an isolation amplifier - be transmitted tele etrically.
• sensor (3) is connected to an amplifier via a cable.
• the amplifier is connected to a telemetry transmitter via a cable.
• sensor (3) and amplifier and telemetry transmitter are implanted, for example, in the area of an affected extremity, while the telemetry receiver is connected to the control unit (4) via a cable.
• the activity is measured and the measurement signal is used as a trigger for demand-driven stimulation.
• the pathological neuronal activity can also occur in different neuron populations. For this reason, several signals measured via the electrode (2) and / or sensors (3) can also be used to control the stimulation. Whenever a pathological characteristic of the activity is detected in at least one of the neuron polulations, an irritation is triggered.
• the electrode (2) can also act as a sensor (3). This makes it possible to derive the activity of the neuron population at the treatment point of the electrode (2).
• the measurement signal or the measurement signals serve or serve as feedback signals. This means that stimulation takes place depending on the activity detected via the measurement signal. Whenever a pathological characteristic of neuronal activity (that is, pathologically increased amplitude or pathologically increased pronounced activity pattern) occurs and / or increases, stimulation takes place.
• irritation then occurs when pathologically synchronized nerve cell activity in the target area (derived via electrode (2)) (eg in Parkinson's disease in areas of the thalamus) or in another area or muscle relevant to the disease (derived via sensors (3)) is present.
• This is determined, for example, by the bandpass filtering of the signals measured via electrode (2) and / or sensors (3) in the frequency range which is characteristic of the pathological activity.
• the next control pulse is forwarded to the optical transmitter (5) via the control unit (4), which generates the electrode (2) via the optical waveguide (6) and the optical receiver (7) Stimulates.
• the aim here is not to simply suppress the firing of the neurons as with standard continuous stimulation.
• a synchronized neuron population can be desynchronized by applying an electrical stimulus of the correct intensity and duration, provided that the stimulus is administered in a vulnerable phase of the pathological rhythmic activity.
• These optimal stimulation parameters are determined during the calibration procedure, for example by systematically varying these parameters and comparing them with the stimulation success (e.g. damping
• the calibration can be accelerated by using so-called phase resetting curves.
• the stimulation with a single high-frequency pulse train is only efficient if the stimulus is i which is applied or close enough to the vulnerable phase of the activity to be stimulated.
• complex forms of stimulation can also be used.
• a resetting stimulus is, for example, a short high-frequency pulse train.
• control unit (4) In the case of the use of a single short high-frequency pulse train, the control unit (4) must predict the occurrence of the vulnerable phase in advance if the threshold value determined by the calibration is exceeded by means of standard prediction algorithms implemented by the electronics (control unit (4)) in order to hit it precisely enough. When the complex stimuli according to the invention are applied, the control unit (4) only has to produce a new complex stimulus of the same type when the threshold value determined by the calibration is exceeded.
• At least one component from the group of stimulus patterns a) to d) of simple stimuli and / or complex stimuli can be used: a) stimulation with a short high-frequency pulse train. b) stimulation with a resetting, short high-frequency pulse train, followed by a desynchronizing short high-frequency pulse train, c) stimulation with a resetting low-frequency sequence of short high-frequency pulse trains, followed by a desynchronizing high-frequency pulse train. d) stimulation with a resetting, single pulse followed by a desynchronizing short radio frequency pulse train.
• the stimulus pattern a) is a simple stimulus and the stimulus patterns c) -d) are complex stimuli
• a short high-frequency pulse train in the sense of the invention is understood to mean a short high-frequency sequence of individual electrical stimuli.
• All high-frequency pulse trains preferably have the same number of individual stimuli. However, at least two high-frequency pulse trains can also consist of a different number of individual stimuli.
• the number of individual stimuli that make up a resetting high-frequency pulse train is in the range of two, preferably 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18 , 19, 20, 50 or up to 100 individual stimuli.
• the number of individual stimuli from which a resetting high-frequency pulse train consists is preferably in the range from 4 to 20 individual stimuli.
• the number of individual stimuli that make up a desynchronizing high-frequency pulse train is in the range of two, preferably 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 , 19, 20, 50 or up to 100 individual stimuli.
• the number of individual stimuli from which a desynchronizing high-frequency pulse train consists is preferably in the range from 3 to 15 individual stimuli.
• high frequency means that the frequency is preferably between 50 to 250 Hz, preferably between 80 and 150 Hz, particularly preferably between 100 and 140. All high-frequency pulse trains preferably have the same frequency. However, at least two high-frequency pulse trains can also consist of individual stimuli of different frequencies.
• the time duration of a short high-frequency pulse train finds a natural limit in that the short high-frequency pulse train should preferably not exceed the period length of the pathological neuronal oscillation in order to be effective.
• the stated values are not restrictive.
• An electrical individual stimulus is understood to mean an essentially charge-neutral electrical stimulus known to the person skilled in the art.
• Charge-neutral in the sense of the invention means that the time integral of the charge entry is essentially zero.
• the time course of the charge entry can be symmetrical or asymmetrical. This means that with these biphasic single pulses the cathodic and anodic part of the single pulse can be symmetrical or asymmetrical. In the symmetrical case, the cathodic and the anodic part of the single pulse are identical except for the sign of the current flow.
• the amplitude of the high-frequency pulse trains can be in the order of 0 to 16 V.
• the amplitude of the high-frequency pulse trains is preferably between 2 and 7 V.
• the usual resistance of the electrode and brain tissue is, for example, in the range from 800 to 1200 ⁇ .
• the amplitude is preferably the same for all high-frequency pulse trains, but it can also be different for at least two high-frequency pulse trains.
• the resetting high-frequency pulse trains are preferably stronger in comparison to the desynchronizing high-frequency pulse trains. This means that the amplitude and / or the number of individual pulses is larger in the resetting high-frequency pulse trains. is greater than with a desynchronizing high-frequency pulse train.
• the amplitude of the individual stimuli that make up a resetting high-frequency pulse train is in the range from 0 to 16 V, preferably between 3 and 7 V.
• the amplitude of the individual stimuli that make up a desynchronizing high-frequency pulse train is in the range from 0 to 15 V, preferably between 2 and 6 V.
• a high-frequency pulse train can consist of individual stimuli, which preferably have the same amplitude and / or the same duration. However, at least two individual stimuli can also have the same amplitude and / or the same duration.
• a high-frequency pulse train can also consist of individual stimuli, of which at least two individual stimuli have different amplitudes and / or different durations.
• the duration and / or the amplitude of the individual stimuli can be given by deterministic and / or stochastic laws and / or combinations of both.
• a combination of stochastic and deterministic regularities is a functional connection in which deterministic and stochastic terms are functionally related, e.g. B. are connected by addition or multiplication.
• the amplitude of the jth individual pulse can be given by f (j), where f is a deterministic function and / or a stochastic process and / or a combination of both.
• a combination of deterministic and stochastic regularities is understood below to mean a functional connection in which deterministic and stochastic terms are functionally, e.g. are connected to one another by addition and / or multiplication.
• a low-frequency sequence of short high-frequency pulse trains preferably comprises 2-30, particularly preferably 2-20 or 2-10 high-frequency pulse trains.
• the low-frequency sequence of short high-frequency pulse trains preferably consists of a periodic sequence of short high-frequency pulse trains, the frequency of which essentially corresponds to the pathological frequency - for example, approximately 5 Hz in Parkinson's disease.
• a low-frequency sequence of short high-frequency pulse trains preferably consists of the same high-frequency pulse trains.
• the high-frequency pulse trains of such a low-frequency sequence can also differ in their pattern.
• the pattern of a high-frequency pulse train includes the following properties:
• the pattern from high-frequency pulse train to high-frequency pulse train can be varied deterministically and / or stochastically and / or combined deterministically / stochastically.
• the frequency in the individual high-frequency pulse train can be varied within a low-frequency sequence of short high-frequency pulse trains.
• the pattern of a high-frequency pulse train can be varied from application to application.
• the number of individual stimuli and / or their amplitudes and / or their durations and / or their pauses from application to application can be deterministic and / or stochastic and / or combined deterministic / stochastic can be varied.
• repeated application of a short desynchronizing high-frequency pulse train its pattern can thus be determined deterministically and / or stochastically and / or combined deterministically / stochastically from application to application.
• the frequency of the desynchronizing high-frequency pulse train can be varied from application to application.
• a short resetting high-frequency pulse train With repeated application of a short resetting high-frequency pulse train, its pattern can be varied deterministically and / or stochastically and / or combined deterministically / stochastically from application to application.
• the frequency of the desynchronizing high-frequency pulse train can be varied from application to application. If a short high-frequency pulse train is used for desynchronization - as described under a) to d) - its intensity, e.g. B. in the sense of the charge input per unit of time is preferably less or less than the intensity of a short high-frequency pulse train that is used for the reset.
• the device according to the invention can choose between the stimulus forms described under a) -d) according to stochastic and / or deterministic and / or combined stochastic-deterministic laws.
• the device is equipped with means for wireless transmission of data, such as the measurement signals and stimulation control signals, so that data can be transmitted from the patient to an external receiver, for example for the purpose of therapy monitoring and optimization. In this way it can be recognized at an early stage whether the stimulation parameters used are no longer optimal.
• a wireless transmission of data to a reference database and early reaction to typical changes in irritability in the target tissue is equipped with means for wireless transmission of data, such as the measurement signals and stimulation control signals, so that data can be transmitted from the patient to an external receiver, for example for the purpose of therapy monitoring and optimization.
• a wireless transmission of data to a reference database and early reaction to typical changes in irritability in the target tissue.
• an electronic component is made available which recognizes the occurrence and the disappearance of a pathological feature of the electrical signal, which is measured by the sensor (3, 2), and when the pathological feature occurs, at least one pulse sequence from the group according to the pattern a) to d) on the electrode (2) and switches off the stimulus pattern when the pathological feature disappears.
• it comprises univariate data processing and / or furthermore multivariate and / or bivariate data processing.
• the electronic component is preferably designed in such a way that at least one of the univariate, bivariate and multivariate data processing works with methods of statistical physics, the method of statistical physics being able to come from the area of the stochastic phase resetting.
• the device according to the invention and the electronic component according to the invention can be used in medicine, preferably in neurology and psychiatry.
• the following diseases can be treated:
• Parkinson's disease Parkinson's syndrome, epilepsy, dystonia, obsessive-compulsive illnesses Alzheimer's, depression, essential tumor, tremor in multiple sclerosis, tremor as a result of a stroke or other tumorous tissue damage.
• brain regions can be stimulated for this:
• Parkinson's disease Nucleus subthalamicus, thalamus, globus pallidum, nucleus ventralis intermedius thalami.
• Parkinson's syndrome subthalamic nucleus, thalamus, globus pallidum, nucleus ventralis intermedius thalami.
• Epilepsy focal foci, hippocampus, subthalamic nucleus, cerebellum, thalamic core areas, caudate nucleus.
• Dystonia Globus pallidum
• Compulsive diseases nucleus accumbens, capsula interna essential tremor: thalamus, nucleus ventralis intermedius thalami
• Tremor in multiple sclerosis Nucleus ventralis intermedius thalami.

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• 2004
  • 2004-05-24 DE DE102004025825A patent/DE102004025825A1/de not_active Withdrawn
• 2005
  • 2005-04-23 WO PCT/DE2005/000747 patent/WO2005113063A1/de not_active Ceased
  • 2005-04-23 JP JP2007513665A patent/JP4757868B2/ja not_active Expired - Fee Related
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• 2006
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