NEURONAL SIGNAL SYSTEM FOR BEHAVIOR MODIFICATION

Abstract

The present invention relates to a system for stimulating the sensory cortex of an individual, comprising: means for obtaining a neuronal stimulation signal adapted to provide a movement cue for the individual and means for transmitting the neuronal stimulation signal to an electric contact of a neuronal stimulation electrode that is already implanted into the brain of the individual for a purpose different from providing the movement cue.

The present invention further relates to a system for communicating proprioceptive information to an individual, comprising means for obtaining information about the body posture of the individual; means for determining, based on the obtained information, a neuronal stimulation signal to be applied to at least one afferent axon targeting at least one sensory neuron in the cortex of the individual, wherein the determined neuronal stimulation signal corresponds to the proprioceptive information to be communicated and means for transmitting the determined neuronal stimulation signal to a neuronal stimulation means of the individual adapted to apply the determined neuronal stimulation signal to the at least one afferent axon.

The present invention further relates to a system for communicating movement information to an individual, comprising means for providing a first neuronal stimulation signal to be applied to the cortex of an individual adapted to provide a movement cue for the individual and means for providing a second neuronal stimulation signal to be applied to the cortex of the individual adapted to provide proprioceptive information to the individual, wherein the first and the second neuronal stimulation signal are adapted to be applied together to the cortex of the individual.

Claims

1. A system for stimulating the sensory cortex of an individual, comprising: a. a processor coupled to a non-transitory memory, wherein the non-transitory memory stores one or more neuronal stimulation signals adapted to provide a movement cue for the individual; b. transmitter circuitry coupled to the processor and configured to transmit a first neuronal stimulation signal of the one or more neuronal stimulation signals to an electric contact of a neuronal stimulation electrode implanted into the brain of the individual.

2. The system of claim 1, wherein the neuronal stimulation electrode is already implanted into the brain of the individual for a purpose different from providing the movement cue.

3. The system of claim 2, wherein the neuronal stimulation electrode is implanted for the purpose of at least one of: a. deep brain stimulation; b. neuronal sensing; c. an open-loop or closed-loop combination of deep brain stimulation and neuronal sensing; d. treatment of one or more of Parkinson's disease, epilepsy, dystonia or tremor; e. neuronal communication.

4. The system of claim 2, wherein the electric contact is not being used for the purpose different from providing the movement cue.

5. The system of claim 2, wherein the system further comprises circuitry for operating the neuronal stimulation electrode according to the purpose that is different from providing the movement cue.

6. The system of claim 1, wherein the first neuronal stimulation signal comprises a signal or a pulse train signal designed to be perceived by the individual as periodic.

7. The system of claim 1, wherein the transmitter circuitry is further configured to control one or more of a frequency, a pulse width, a pulse shape or an amplitude of the first neuronal stimulation signal.

8. The system of claim 7, wherein the transmitter circuitry is further configured to control one or more of the movement speed, pace regularity or balance of the individual via one or more of the frequency, the pulse width, the pulse shape or the amplitude of the first neuronal stimulation signal.

9. The system of claim 1, wherein the processor is further configured to select the first neuronal stimulation signals to be transmitted to the electric contact neuronal stimulation electrode.

10. The system of claim 9, wherein the processor is further configured to select a second neuronal stimulation signal of the one more neuronal stimulation signals having a different frequency than the first neuronal stimulation signal for transmission to the electric contact neuronal stimulation electrode.

11. The system of claim 10, wherein the first neuronal stimulation signal is adapted to control one or more of the movement speed, the pace regularity or the balance of the individual and the second neuronal stimulation signal is adapted to counteract a temporary movement impairment of the individual.

12. The system of claim 1, wherein the transmitter circuitry is further configured to transmit at least two different neuronal stimulation signals to two different contacts of the neuronal stimulation electrode at substantially the same time.

13. The system of claim 1, wherein the first neuronal stimulation signal is adapted to elicit a conscious sensory percept in the cortex of the individual.

14. The system of claim 13, wherein the sensory percept is elicited in at least one of: a. a somatosensory cortex area; b. a visual cortex area; c. an auditory cortex area.

15. A system for communicating proprioceptive information to an individual, comprising: one or more sensors configured to obtain information about the body posture of the individual; a processor coupled to a non-transitory memory, wherein the processor is configured to determine, based on the obtained information, a neuronal stimulation signal to be applied to at least one afferent axon targeting at least one sensory neuron in the cortex of the individual, wherein the determined neuronal stimulation signal corresponds to the proprioceptive information to be communicated; and transmitter circuitry configured to transmit the determined neuronal stimulation signal to a neuronal stimulation electrode of the individual adapted to apply the determined neuronal stimulation signal to the at least one afferent axon.

16. The system of claim 15, wherein the information about the body posture of the individual comprises at least one of: a. information about an articulation state of a joint of the individual; b. information about a flexing angle of a joint of the individual; c. information about the balance of the body of the individual; d. information about a tone of a muscle of the body of the individual; e. information about a position of a part of the body of the individual with respect to a reference position; f. information about a surface contact of a part of the body of the individual.

17. The system of claim 15, wherein the one or more sensors for obtaining information about the body posture of the individual comprise one or more of: a. a pressure sensor; b. a tension sensor; c. a balance sensor; d. an acceleration sensor; e. a temperature sensor; f. an image sensor; g. a force sensor; h. a distance sensor; i. an angle sensor; and j. a speed sensor.

18. The system of claim 15, wherein the processor is further configured to access relations stored on the non-transitory memory, wherein the relations are specific for the individual, wherein the relations comprise relations between a plurality of proprioceptive information and a plurality of corresponding neuronal stimulation signals.

19. The system of claim 18, wherein the relations are based at least in part on proprioceptive learning data for the individual, wherein the learning data associates the plurality of proprioceptive information with the plurality of corresponding neuronal stimulation signals.

20. The system of claim 15, wherein the neuronal stimulation signal is configured to elicit a conscious or a subconscious sensory percept in the cortex of the individual.

21. A system for communicating movement information to an individual, comprising: first transmitter circuitry configured to: provide a first neuronal stimulation signal to be applied to the cortex of an individual and adapted to provide movement information for the individual; and provide a second neuronal stimulation signal to be applied to the cortex of the individual and adapted to provide proprioceptive information to the individual, wherein the first and the second neuronal stimulation signals are adapted to be applied together to the cortex of the individual.

22. The system of claim 21, wherein one or more of the first and second neuronal stimulation signals are applied via at least one portion of a neuronal stimulation electrode already implanted for a purpose different from the communicating of the movement information.

23. The system of claim 21, wherein the proprioceptive information is related to a body part of the individual involved in a movement of the individual associated with the movement information.

24. The system of claim 21, wherein the second neuronal stimulation signal is adapted to provide one or more of the following information: a. information about an articulation state of a joint of the individual; b. information about a flexing angle of a joint of the individual; c. information about the balance of the body of the individual; d. information about a tone of a muscle of the body of the individual; e. information about a position of a part of the body of the individual with respect to a reference position; and f. information about a surface contact of a part of the body of the individual.

25. The system of claim 21, wherein the transmitter circuitry is adapted to control one or more of a frequency, a pulse width, a pulse shape and or an amplitude of one or both of the first and second neuronal stimulation signals and/or a relative timing between the first and the second neuronal stimulation signals.

26. The system of claim 25, wherein the second neuronal stimulation signal is adapted to be provided at a rate that is more than 20 times larger than a frequency of the first neuronal stimulation signal.

27. The system of claim 26, wherein the second neuronal stimulation signal is adapted to be provided quasi-continuously with respect to the first neuronal stimulation signal.

28. The system of claim 21, the system further comprising one or more sensors configured to obtain information about the body posture of the individual, wherein the one or more sensors comprise one or more of: a. a pressure sensor; b. a tension sensor; c. a balance sensor; d. an acceleration sensor; e. a temperature sensor; f. an image sensor; g. a force sensor; h. a distance sensor; i. an angle sensor; and j. a speed sensor.

29. The system of claim 28, wherein the one or more sensors are integrated into one or more of: a. a piece of apparel, b. a piece of footwear, c. a prothesis, d. an orthosis, e. an exoskeleton, f. an autonomous robotic companion, g. a wearable electronic device, and h. an implanted device.

30. The system of claim 21, further comprising a computing device configured to receive a neuronal measurement signal corresponding to a neuronal excitation pattern recorded via a neuronal excitation measurement device.

31. The system of claim 30, wherein the neuronal excitation pattern corresponds to one or more of a movement intention and motor-sensory information of the individual.

32. The system of claim 30, wherein the neuronal measurement signal is received from at least one of the following: a. an electroencephalography, EEG, device; b. a neuro-electrode; c. a deep brain stimulation electrode; d. a sub-dural electrode; e. a sub-dural electrode array; f. a connected wearable device; and g. a transcranial excitation measurement device.

33. An electronic information processing device, comprising: a processor coupled to a non-transitory memory, wherein the non-transitory memory stores one or more neuronal stimulation signals adapted to provide a movement cue for the individual; transmitter circuitry coupled to the processor and configured to transmit a first neuronal stimulation signal of the one or more neuronal stimulation signals to an electric contact of a neuronal stimulation electrode implanted into the brain of the individual.

34. A distributed electronic information processing system, comprising: one or more sensors configured to obtain information about the body posture of an individual; a processor coupled to a non-transitory memory, wherein the processor is configured to determine, based on the obtained information, a neuronal stimulation signal to be applied to at least one afferent axon targeting at least one sensory neuron in the cortex of the individual, wherein the determined neuronal stimulation signal corresponds to the proprioceptive information to be communicated; and transmitter circuitry configured to transmit the determined neuronal stimulation signal to a neuronal stimulation electrode of the individual adapted to apply the determined neuronal stimulation signal to the at least one afferent axon.

35. A computer program, comprising program instructions which, when executed by an electronic information processing device or a distributed electronic information processing system, cause transmitter circuitry to: provide a first neuronal stimulation signal to be applied to the cortex of an individual and adapted to provide movement information for the individual; and provide a second neuronal stimulation signal to be applied to the cortex of the individual and adapted to provide proprioceptive information to the individual, wherein the first and the second neuronal stimulation signals are adapted to be applied together to the cortex of the individual.

36. A computer program, comprising program instructions which, when executed by an electronic information processing device or a distributed electronic information processing system, cause a processor to: obtain information about the body posture of an individual from one or more sensors; determine, based on the obtained information, a neuronal stimulation signal to be applied to at least one afferent axon targeting at least one sensory neuron in the cortex of the individual, wherein the determined neuronal stimulation signal corresponds to proprioceptive information to be communicated; and cause transmitter circuitry to: transmit the determined neuronal stimulation signal to a neuronal stimulation electrode of the individual adapted to apply the determined neuronal m stimulation signal to the at least one afferent axon.

37. A computer program, comprising program instructions which, when executed by an electronic information processing device or a distributed electronic information processing system, cause a processor to: obtain a first neuronal stimulation signal from one or more neuronal stimulation signals stored on non-transitory memory, wherein the one or more neuronal stimulation signals are adapted to provide a movement cue for an individual; and cause transmitter circuitry to: transmit the first neuronal stimulation signal to an electric contact of a neuronal stimulation electrode implanted into the brain of the individual.

Description

4. SHORT DESCRIPTION OF THE FIGURES

[0120] Aspects of the present invention are described in more detail in the following by reference to the accompanying figures. These figures show:

[0121] FIG. 1 a diagram illustrating an individual operating a neuronal stimulation system according to an embodiment of the present invention;

[0122] FIG. 2 a diagram illustrating a neuronal stimulation electrode for stimulating afferent axons targeting the sensory cortex of an individual. The neuronal stimulation electrode can be interfaced with a neuronal stimulation system according to an embodiment of the present invention;

[0123] FIG. 3 a diagram illustrating a therapeutic multi-contact neuromodulation electrode adapted for modulation of brain nuclei associated with a movement impairment. Unused contacts of the electrode can be used for stimulating afferent axons targeting the sensory cortex of an individual via a neuronal stimulation system according to an embodiment of the present invention.

[0124] FIG. 4A a block diagram of a neuronal stimulation signal generator for driving a neuronal stimulation electrode which can be interfaced with a neuronal stimulation system according to an embodiment of the present invention;

[0125] FIG. 4B a block diagram of a neuronal stimulation system according to an embodiment of the present invention;

[0126] FIG. 5 a diagram illustrating how a movement cueing channel can be implemented using a neuronal stimulation system according to an embodiment of the present invention;

[0127] FIG. 6 a diagram illustrating exemplary neuronal stimulation signals adapted to provide a movement cue and a FOG break-out signal;

[0128] FIG. 7 a diagram illustrating an individual operating a neuronal stimulation system according to a further embodiment of the present invention;

[0129] FIG. 8 a diagram illustrating how a proprioceptive information channel can be implemented using a neuronal stimulation system according to an embodiment of the present invention;

[0130] FIG. 9 a diagram illustrating how the proprioceptive information channel of FIG. 8 can be used to communicate information on the articulation state of a knee joint of an individual;

[0131] FIG. 10 a diagram illustrating the relative timing of the movement cue channel of FIG. 6 and the joint articulation state channel of FIGS. 8 and 9 while the individual depicted in FIG. 7 performs a walking task.

5. DETAILED DESCRIPTION OF SOME EXEMPLARY EMBODIMENTS

[0132] In the following, some exemplary embodiments of the present invention are described in more detail, with reference to neuronal stimulation and/or communication systems that can be interfaced with neuronal stimulation electrodes such as deep brain stimulation (DBS) electrodes. However, the systems provided by the present invention can also be used with different neuronal stimulation means (e.g. opto-neuronal) that are capable to stimulate the sensory cortex of an individual e.g. via stimulating afferent axons targeting the sensory cortex. While specific feature combinations are described in the following with respect to the exemplary embodiments of the present invention, it is to be understood that the disclosure is not limited to such embodiments. In other words, not all features have to be present for realizing the invention, and the embodiments may be modified by combining certain features of one embodiment with one or more features of another embodiment. Specifically, the skilled person will understand that features, components and/or functional elements of one embodiment can be combined with technically compatible features, components and/or functional elements of any other embodiment of the present invention.

[0133] FIG. 1 depicts an individual too, e.g. a PD patient, that has been implanted with a neuronal stimulation electrode 120 such as a DBS electrode that may have multiple independently controllable electric contacts, as illustrated in FIG. 3 below. For instance, the neuronal stimulation electrode 120 may be already implanted into the brain of the individual too for the purpose of providing a neuromodulation therapy for certain PD symptoms such as tremor, dystonia and/or rigidity. However, the neuronal stimulation electrode 120 may also be implanted for other purposes such as for the purpose of neuronal communication and/or treatment of other movement impairments and neurological diseases such as epilepsy. Alternatively, the electrode 120 may also be implanted dedicated as an interface for the systems provided by the present invention.

[0134] The individual 100 may be further equipped with a neuronal stimulation signal generator device 110 that may be arranged on the head of the individual 100 or somewhere else on or in the vicinity of the body of the individual 100. The neuronal signal generator 110 may be in wireless communication (e.g. via a Bluetooth or similar wireless interface) with a control device 130, that may be implemented by a smartphone or a similar electronic information processing device. Depending on implementation details the systems provided by the present invention may be implemented by the control device 130, the neuronal signal generator 110, an additional system (such as the system 400 of FIG. 4B) or a combination thereof. For instance, the control device 130, the signal neuronal signal generator device 110 or both may be provided with application specific hardware and/or software modules comprising circuitry and/or software instructions to implement a system according to the present invention.

[0135] The control device 130 may provide the individual with a user interface to adjust the neuronal stimulation signals and/or the neuromodulation therapy applied via the signal generator 110 and the neuronal stimulation electrode 120. For instance, the individual 100 may adjust signal parameters such as a signal frequency, a pulse width, a pulse shape and/or a signal amplitude. For example, the individual may use the control device 130 to select a perceived periodicity of a movement cue provided by a neuronal stimulation signal to the cortex of the individual 100. For example, if the movement cue is used to provide guidance to the individual 100 during a movement such as walking, the control device 130 may be used to select and set a movement pace associated with the perceived periodicity of the movement cue.

[0136] FIG. 2 depicts a diagram illustrating a neuronal stimulation electrode 120 for stimulating afferent axons 230 targeting sensory neurons in the cortex of a human brain. The afferent axons 230 may target different areas 210, 220 of the cortex that may be related to different sensory modalities (e.g. touch, temperature sense, vision, hearing, etc.) and/or different body regions (e.g. cochlea, retina, hand, tongue, foot etc.) from which the respective sensory modality is perceived by the respective area of the cortex. For instance, the cortical area 210 may be a somatosensory area of the right foot and the cortical area 220 may be a somatosensory area of the left hand.

[0137] The afferent axons 230 are connected via synapses (not shown) with their respective target neurons in the respective sensory area 210, 220. For instance, the axons 230 may be thalamocortical axons relaying sensory information from the thalamus to the cerebral cortex. The neuronal stimulation electrode 120 may comprises a plurality of independently controllable electric contacts (see FIG. 3 below) that may be arranged in the vicinity of a bundle of afferent axons 230 targeting the sensory areas 220 and 210 of the cerebral cortex.

[0138] In the illustrated example, the neuronal stimulation electrode 120 is connected to a neuronal stimulation signal generator 110, which is adapted to apply neuronal stimulation signals to the afferent axons 230, e.g. via independently controllable electric contacts of the neuronal stimulation electrode 120. In addition, the neuronal stimulation electrode 120 may further comprise a wireless interface for interfacing the signal generator 110 with a neuronal stimulation system which may be adapted to obtain and/or determine the waveform and/or signal parameters (e.g. pulse width, pulse shape, frequency, amplitude, number of pulses etc.) of the neuronal stimulation signal that is generated and applied by the signal generator 110 to the afferent axons 230 via the stimulation electrode 120.

[0139] For instance, the neuronal stimulation system provided by the present invention may determine the waveform and/or signal parameters of the neuronal stimulation signal such that a desired sensory percept is elicited in a desired area of the sensory cortex of the individual. In some embodiments of the present invention, the cortex of the individual which is receiving the neuronal stimulation signal (i.e. via afferent action potentials of the stimulated afferent axons 230) may associate the corresponding sensory percept with a movement cue and/or other type of movement related information such as proprioceptive information relating to the body posture of the individual operating the neuronal stimulation system. For example, similar to learning how to understand Morse code, the individual may have previously participated in a learning procedure establishing an associative link between a given sensory percept elicited by a given stimulation signal and a corresponding movement cue (see FIGS. 5 and 6 below) or a piece of proprioceptive information (e.g. see FIGS. 8 and 9 below) that is to be communicated to the individual via the neuronal stimulation electrode 120.

[0140] In this approach no nuclei or neuron-rich grey matter are preferably targeted by the neuronal stimulation electrode 120 but preferably the axon-rich white matter of the brain, which contains the information transmitting pathways the brain uses for natural neural communication. In this manner, the present invention provides a white-matter computer-brain-interface (CBI), i.e. a system that generates and provides electrical signals the brain can interpret as meaningful input, e.g. as a rhythmic movement cue or any other type of movement related information such as a commence movement trigger (e.g. a FOG break-out signal) or information about the current body posture of the individual (e.g. proprioceptive information). As discussed in section 3 above, such information may be provided by different types of measurement devices or sensors (see also FIG. 7).

[0141] In other embodiments of the present invention, the neuronal stimulation electrode 120, the signal generator 110 and/or the wireless interface may also be part of an integrated neuronal stimulation and/or communication system, e.g. if said components are customized for the intended application. For instance, a neuronal communication system may comprise of specialized communication software running on a multi-purpose information processing device such as a smartphone and a customized assembly of signal generator 110 and stimulation electrode 120 which communicate with the multi-purpose communication device via a wireless interface using conventional wireless data transmission technology such as Wi-Fi, Bluetooth and/or NFC.

[0142] In other embodiments of the present invention the neuronal stimulation electrode 120 may be directly connected via wires to a neuronal stimulation system comprising a data processing system and a signal generator similar to the signal generator no. In this case a wireless interface is not needed.

[0143] FIG. 3 depicts of a multi-contact neuromodulation electrode 120 adapted for neuromodulation of the sub-thalamic nucleus 320 via electric contacts 330. The electrode 120 can also be used for stimulating afferent axons 342, 344 projecting from the thalamus 310 to the sensory cortex of an individual via a neuronal stimulation system according to the present invention. For example, neuronal stimulation signals may be provided by unused contacts 340, 350 of the neuromodulation electrode 120 that was implanted for a therapeutic purpose (e.g. neuromodulation of the subthalamic nucleus 320 via the therapeutic electric contacts 330) different from providing the neuronal stimulation signal to the afferent sensory axons 344, 342. For instance, the contacts that are not used for neuromodulation of the sub-thalamic nucleus 320 may be used to provide a sensory movement cue and/or proprioceptive information to the cortex of the individual. An example of such a sensory movement cue may be a rhythmic sensory percept elicited by a neuronal stimulation signal applied to the axons 344 targeting a cortex area related to a touch sensation for instance in the left foot.

[0144] In many cases, a DBS electrode 120 that is used as a neuromodulator, e.g. for treatment of PD symptoms, is not always active and/or may comprise independently controllable contacts that are not required for achieving the therapeutic purpose. Thus, the neuromodulation electrode can also be used for applying neuronal stimulation signals provided by a system according to the present invention. For DBS electrodes, specifically, some of the electrode contacts located outside of the stimulation area of interest are not used. However, if implantation in e.g. the subthalamic nucleus 320 is conducted for the tip contacts 330 to control, for example, the primary PD symptoms more distal contacts 340, 350 could be used in combination with the above disclosed invention to communicate a movement cue and/or a continuous movement biofeedback signal into the brain the patient can utilize to navigate better and/or break free from FOG.

[0145] FIG. 4A depicts is a block diagram of a neuronal stimulation signal generator 110 which can be used to apply neuronal stimulation signals to afferent axons 230 via a neuronal stimulation electrode such as the stimulation electrode 110 of FIGS. 1-3. The neuronal stimulation signal generator 110 may comprise a wireless interface 410 for communicating with a remote neuronal stimulation system (e.g. see FIG. 4B) which may be adapted to obtain, to determine, to select and/or to transmit a waveform and/or signal parameter of the neuronal stimulation signal to the signal generator 110 in order generate a neuronal stimulation signal adapted to elicit a desired sensory percept associated with a movement cue (see FIGS. 5 and 6) and/or proprioceptive information (see FIGS. 8 and 9).

[0146] For instance, the neuronal stimulation signal generator 110 may receive digital data packets specifying a desired neuronal stimulation signal via the wireless interface 410. Receiver (RX) circuitry may process (e.g. filter, amplify, mix, down-convert to baseband etc.) the received digital data packets and feed the processed digital data packets to a digital signal processor (DSP) with may comprise an integrated digital-to-analog converter (DAC). The DSP then processes the digital data packets to generate one or more neuronal stimulation signals which may then be amplified and applied to a neuronal stimulation electrode such as electrode 120 of FIG. 2 and FIG. 3 by an output amplifier (AMP). For instance, the output AMP may be configured to drive four (or any other number) independently controllable electric contacts 330, 340, 350 of a stimulation electrode such as electrode 120 via the output wires 420.

[0147] In other embodiments, the DSP may receive the digital data packets specifying the neuronal stimulation signal also via a wire-based interface or directly from a collocated processing circuit (e.g. a CPU) which may be adapted to determine the waveform and/or signal parameters of a desired neuronal stimulation signal corresponding to a desired sensory movement cue and/or proprioceptive information to be elicited in the cortex of the to the individual.

[0148] FIG. 4B depicts a block-type circuit diagram of an exemplary neuronal stimulation system 400 according to an embodiment of the present invention. The neuronal stimulation system 400 may for instance comprise a wireless interface 412 and transmitter (TX) circuitry for communicating (e.g. via Bluetooth or a similar interface) with a neuronal stimulation signal generator such as the generator circuit 110 described above with reference to FIG. 4A. The TX circuitry may be adapted to process (i.e. filter, modulate, mix, amplify, and/or upconvert) digital data packets to be communicated via the wireless interface 412. The neuronal stimulation system 400 may further comprise a digital signal processor (DSP) operably connected with the TX circuitry and adapted to provide digital data packets specifying the waveform and/or the signal parameters (e.g. frequency, phase, pulse width, pulse amplitude, pulse shape, channel count, etc.) of a desired neuronal stimulation signal to be applied via a neuronal stimulation electrode such as the electrode 120 of FIGS. 2 and 3 and via a neuronal stimulation signal generator such as signal generator 110 of FIG. 4A.

[0149] The neuronal stimulation system 400 may further comprise general data processing circuitry such as a CPU operably connected to the DSP and at least one digital memory device operably connected to the CPU. The CPU 320 and the memory may interact to determine a desired neuronal stimulation signal corresponding to a desired sensory percept such as the desired movement cue and/or the desired proprioceptive information to be communicated to the cortex of the individual.

[0150] For instance, the memory may contain a personalized communication library for the individual, the library storing relations between a plurality of movement cues and/or perceptive information blocks and a plurality of corresponding neuronal stimulation signals.

[0151] Such a stimulation library can be calibrated for each individual through neuroimaging and/or individualized testing of the individual. Neuroimaging may first be used to identify theoretically possible ranges of activation for an individual stimulation electrode while individualized testing determines which points in the parameter space of stimulation signal parameters (for details see FIG. 5 and FIG. 8 below) can be perceived and decoded by the cortex of the individual. It should be emphasized that conscious individualized testing of an individual is merely one specific example how to generate the individualized relations stored in the memory. In other embodiments such relations may also be obtained from unconscious patients, e.g. through the non-invasive observation of corresponding functional MRI responses on the somatosensory cortex or EEG recordings.

[0152] Further, once or while the communication library (i.e. the plurality of relations stored in the memory) is established or is being established for an individual a specific training procedure can be executed (again not necessarily in a conscious individual). As long as the cortex of the individual responds to classical conditioning, pair learning can be executed. In the context of the present invention, such a pair consists of a given sensory percept corresponding to a given neuronal stimulation signal and a movement cue and/or a piece of proprioceptive information to be associated with said given sensory percept and the corresponding neuronal stimulation signal.

[0153] Importantly, the type of information to be conveyed via the neuronal stimulation system 400 whether it is a movement cue, a FOG breakout signal or a piece of proprioceptive information can be chosen freely. Any information or message which can be broken down into message blocks (i.e. pieces of conceptual information that can be decoded by the cortex of an individual) can be transmitted. This includes continuous signals such as signals needed for e.g. an artificial balance, orientation signals or other sensor measurement signals.

[0154] Learning paradigms for continuous signals deviate from classical conditioning, since they involve more interactive training scenarios where utilization of the signal is a relevant success factor (e.g. orientation in an artificial virtual environment using the input signal). Continuous signals (e.g. intensity) also deviate from signal configurations for messages containing sequentially delivered message blocks. In the case of continuous signals, intensity might be coded via either pulse width or frequency variations (or combinations of the two; see FIG. 8 below), while not varying the location and target areas in the sensory cortex targeted by the recruited axon fibers.

[0155] FIGS. 5 and 6 illustrates how embodiments of the present invention can be used to establish a sensory movement cueing channel to the to the cortex of an individual and to use said cueing channel to provide a periodic movement cue and a FOG break-out signal that may be used for behavior modification, e.g. to support the individual during a walking task.

[0156] For instance, three different walking paces (e.g. 1 step per second, 0.5 steps per second, 2 steps per second) may be encoded by providing a pulse train signal via a neuronal stimulation interface and system as discussed above. Such a pulse train (being characterized by signal parameters such as pulse width, pulse frequency, pulse shape and/or pulse amplitude) may elicit a periodic/rhythmic sensory percept in the targeted area of the sensory cortex of the individual. For instance, such a pulse train signal may be configured to elicit a periodically appearing tough sensation in the palm of the right hand or in a leg of the individual. Similar to an auditory movement cue provided to the individual via earphones such a neuronal movement cue may help the individual to walk at a constant pace and without experiencing a FOG period. Moreover, the same neuronal communication channel can also be used to communicate a FOG breakout signal to the individual. For instance, the FOG breakout signal may be encoded by choosing a different combination of pulse train parameters such as a combination of a larger pulse frequency and a larger pulse width as indicted in FIG. 5.

[0157] FIG. 6 illustrates a typical use scenario of a neuronal stimulation system provided by the present invention. When occurrence of a FOG event has been determined (either by the neuronal stimulation system itself, a human supervisor or a control device associated with the individual performing the walking task) the neuronal stimulation system may obtain the FOG breakout signal (e.g. from its memory or via a wireless communication interface) and transmits it to an electric contact of a neuronal stimulation electrode such as the DBS electrode illustrated in FIGS. 2 and 3 to suppress the FOG event.

[0158] After a FOG event has been suppressed the neuronal stimulation system can switch into a pacemaker operation mode and may apply a slow periodic movement cue to help the individual to resume normal walking. After the individual has resumed slow walking he could provide a user input to the neuronal stimulation system indicating the intention to switch from the slow movement cue to a faster one.

[0159] Such user input may for example be provided via a control device such as a smartphone or via a neuronal excitation measurement equipment recording a neuronal excitation pattern corresponding to a motor intent of the individual. For instance, such a neuronal excitation measurement equipment may involve recoding from the contacts of the same neuronal electrode that is also used for applying the neuronal stimulation signal (e.g. in the form of Local Field Potentials). In some embodiments the system may also comprise an EEG device, a sub-dural electrode array and/or a transcranial excitation measurement device.

[0160] Such neuronal excitation measurement equipment may be used to provide the individual with an essentially closed loop stimulation system, wherein measurements motor related neuronal excitation patterns directly affect how the neuronal stimulation system is operating.

[0161] FIG. 7 depicts an individual 100, e.g. a PD patient, having been implanted with a neuronal stimulation electrode 120 such as a DBS electrode that may have multiple independently controllable electric contacts, as illustrated in FIG. 3. In addition to the devices discussed above with reference to FIG. 1 the individual 100 may further be equipped with sensors 710 and 720 that are configured to obtain information on the body posture of the individual 100. For instance, sensor 710 may be configured to measure the balance of the body of the individual 100 while the sensors 720 may be configured to measure the articulation state/flexing angle of the knee joints of the individual 100.

[0162] The sensors 710, 720 may be in wireless communication with the neuronal signal generator 110, the control device 130 and/or a neuronal stimulation system similar to the one discussed above with reference to FIG. 4B.

[0163] The measurement signals (providing information about the body posture of the individual 100) may be transmitted by the sensors 710 and 720 to the processing means of a neuronal stimulation system. The system may then determine, based on the obtained information, a neuronal stimulation signal to be applied to at least one afferent axon targeting at least one sensory neuron in the cortex of the individual, wherein the determined neuronal stimulation signal corresponds to proprioceptive information that is communicated to the individual.

[0164] For instance, as illustrated in FIG. 8 and FIG. 9 neuronal stimulation system may use the measurements of the knee joint sensors 720 to determine a neuronal stimulation signal that is adapted to communicate the articulation state of the knee joint to the cortex of the individual. As shown in FIG. 8, the articulation state of the knee joint may be encoded by a combination of signal parameters such as pulse width and pulse frequency of a pulse train signal. In the example shown in FIG. 8 a low frequency pulse train having a short pulse width (A) corresponds to a knee joint that is essentially fully stretched out (A) whereas a high frequency pulse train having a long pulse width (D) corresponds to a knee joint that is almost fully bent (D).

[0165] FIG. 10 illustrates how the movement cueing channel of FIGS. 5 and 6 and the proprioceptive information channel of FIGS. 8 and 9 can be combined to improve the performance of a neuronal stimulation system intended for treatment of movement impairments. In the illustrated example a neuronal stimulation signal that is providing the joint articulation state information (e.g. the proprioceptive information channel) is applied quasi-continuously while the individual performs a movement (e.g. walking, dancing etc.) paced by the movement cue signal. If the individual walks synchronized with the movement cue signal every time a movement cue pulse is perceived by the individual the joint articulation signal communicates a fully stretched state (A) of the knee joint to the individual. Between two movement cue pulses the knee joint of the individual first bends (A-B-C-D) and then stretches out again (D-C-B-A).

[0166] Compared to systems that only provide movement cues a system providing both, a m movement cue and proprioceptive information together to the cortex of an individual substantially improves the movement performance of the individual because synchronizing the movement of the individual with an external movement cue is much easier if proprioceptive information is provided as feedback to the brain that indicates the phase of the movement relative to the timing of the movement cue.