Wireless Recording and Stimulation of Brain Activity

• US 20100198297A1
• Filed: 01/14/2010
• Published: 08/05/2010
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: EIC Laboratories, Sigenics, Inc., University of Chicago
• Original Assignee: Sigenics, Inc.
• Inventors: Cogan, Stuart F., Ebersole, John S., Towle, Vernon L., Troyk, Philip R.
• Granted Patent: US 8,849,369 B2
• Time in Patent Office: Days
• US Class Current: 607/45
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/293 Invasive
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/025 Digital circuitry features of electrotherapy devices, e.g. memory, clocks, processors
• CPC Class Codes: A61N 1/0504 Subcutaneous electrodes
• CPC Class Codes: A61N 1/0529 Electrodes for brain stimulation
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/36064 Epilepsy
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36139 with automatic adjustment

Abstract

Subdural arrays transmit electrocorticogram recordings wirelessly, across the patient'"'"'s skull, allowing the craniotomy used for surgical placement of the arrays to be completely closed. In various embodiments, the arrays also respond to commands, applying signal patterns to the patient'"'"'s brain for diagnostic and treatment purposes.

Claims

1. An implantable medical device comprising:

an array of electrodes for communicating with a subject'"'"'s brain;

control circuitry in communication with the electrodes;

wireless transmission circuitry, responsive to the control circuitry, for transmitting digital data corresponding to brain signals sensed by the electrodes outside a site of device implantation; and

wireless receiver circuitry for receiving wireless commands from outside the site of device implantation, the control circuitry responsively providing an electrical stimulus to the subject'"'"'s brain via the electrodes in accordance with the commands.

2. The implantable medical device of claim 1 wherein the transmission circuitry includes means facilitating magnetic inductive coupling.

3. The implantable medical device of claim 2 wherein the receiver circuitry includes means facilitating magnetic inductive coupling.

4. The implantable medical device of claim 3 wherein means facilitating magnetic inductive coupling comprises a single metal coil.

5. The implantable medical device of claim 1 wherein the electrodes and the circuitry are mounted on a substrate comprising one or more layers of flexible polymer.

6. The implantable medical device of claim 1 wherein the electrodes are coated with iridium oxide.

7. The implantable medical device of claim 5 further comprising metal conductors disposed on the substrate and connecting the circuitry and the electrodes.

8. The implantable medical device of claim 5 wherein the substrate comprises a plurality of layers, and further comprising at least one film that itself comprises at least one of (a) amorphous silicon carbide or (b) amorphous silicon oxycarbide.

9. The implantable medical device of claim 8 wherein the film is disposed between a layer of the substrate and the conductors.

10. The implantable medical device of claim 8 wherein the film is disposed between two of the layers of the substrate.

11. The implantable medical device of claim 1 wherein at least some of the electrodes are physically removable without disrupting connections between the remaining electrodes and the control circuitry.

12. The implantable medical device of claim 1 further comprising a program memory modifiable in response to signals wirelessly received by the receiver circuitry, the control circuitry being responsive to the program memory.

13. The implantable medical device of claim 1 further comprising a pattern memory, operatively coupled to the control circuitry, for storing signal patterns to be applied to the array by the control circuitry.

14. The implantable medical device of claim 13 wherein the pattern memory is externally modifiable in response to signals wirelessly received by the receiver circuitry.

15. The implantable medical device of claim 5 wherein the substrate comprises slits facilitating flexure thereof.

16. A method of brain monitoring and treatment, the method comprising the steps of:

subdurally implanting a device comprising an array of electrodes for communicating with a patient'"'"'s brain;

causing wireless transmission of digital data corresponding to brain signals sensed by the electrodes; and

transmitting wireless commands to cause provision of an electrical stimulus to the patient'"'"'s brain via the electrodes in accordance with the commands.

17. The method of claim 16 wherein the wireless commands specify parameters comprising one or more selected electrodes of the array, a stimulus magnitude for each of the selected electrodes, a stimulus frequency for each of the selected electrodes, and a stimulus duration for each of the selected electrodes, the selected electrodes being energized in accordance with the parameters.

18. A method of monitoring brain signals, the method comprising the steps of:

implanting at least one wireless array subdurally in a patient;

maintaining the patient on a normal regimen of anti-seizure medication; and

wirelessly measuring, via the wireless array, brain signals for a period of time sufficient to record adequate habitual seizure activity to localize pharmacologically intractable epileptogenic foci.

19. The method of claim 18 further comprising conducting cortical mapping studies via wireless communication with the wireless array, the wireless array responsively causing electrical stimulation of the patient'"'"'s brain.

20. A method of determining optimum stimulation parameters for suppressing epileptogenic seizures comprising:

implanting at least one wireless array subdurally in a patient;

maintaining the patient on a normal regimen of anti-seizure medication; and

causing wireless transmission of digital data corresponding to brain signals sensed by the array;

identifying, based on the transmitted digital data, the onset of habitual seizures; and

wirelessly causing the array to apply electrical stimulation signals at one or more electrode sites thereon, the sites being selected and magnitudes of the stimulation signals being determined so as to treat the seizures.