Wireless Recording and Stimulation of Brain Activity

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.

What is claimed is: 
     
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         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. 
     
     
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         21 . The method of  claim 18  wherein said at least one wireless array is housed on a flexible substrate having a dura-facing side and an opposing brain-facing side. 
     
     
         22 . The method of  claim 21  wherein the flexible substrate comprises an array of electrodes positioned on the brain-facing side for sensing signals generated by the patient's brain or applying an electrical stimulus to the patient's brain. 
     
     
         23 . The method of  claim 21  wherein the flexible substrate comprises a reference electrode positioned on the dura-facing side wherein said reference electrode is physically separated from the subject's brain by the flexible substrate and is adapted to provide a reference voltage. 
     
     
         24 . The method of  claim 23  further comprising recording sensed electrical signals based on said reference voltage and said sensed electrical signals. 
     
     
         25 . The method of  claim 24  further comprising wirelessly transmitting digital data derived from the brain signals sensed by electrodes within said array of electrodes. 
     
     
         26 . The method of  claim 25  further comprising transmitting wireless commands to cause a delivery of an electrical stimulus to the patient's brain via at least two electrodes within said array of electrodes. 
     
     
         27 . The method of  claim 26  wherein the wireless commands specify parameters comprising one or more selected electrodes of the array of electrodes, 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, wherein each of the selected electrodes are energized in accordance with the parameters. 
     
     
         28 . 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; 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, wherein said electrical stimulation signals are based on 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, wherein each of the selected electrodes are energized in accordance with the parameters so as to treat the seizures. 
     
     
         29 . The method of  claim 28  wherein said at least one wireless array is housed a flexible substrate having a dura-facing side and an opposing brain-facing side. 
     
     
         30 . The method of  claim 29  wherein the flexible substrate comprises an array of electrodes positioned on the brain-facing side for sensing signals generated by the patient's brain or applying an electrical stimulus to the patient's brain. 
     
     
         31 . The method of  claim 29  wherein the flexible substrate comprises a reference electrode positioned on the dura-facing side wherein said reference electrode is physically separated from the subject's brain by the flexible substrate and is adapted to provide a reference voltage. 
     
     
         32 . The method of  claim 31  further comprising recording sensed electrical signals based on said reference voltage and said sensed electrical signals. 
     
     
         33 . A method of monitoring brain signals for treatment, the method comprising the steps of: subdurally implanting a device comprising a flexible substrate having a dura-facing side and an opposing brain-facing side, wherein the flexible substrate comprises an array of electrodes positioned on the brain-facing side for sensing signals generated by the subject's brain or applying an electrical stimulus to the subject's brain and a reference electrode positioned on the dura-facing side wherein said reference electrode is physically separated from the subject's brain by the flexible substrate and is adapted to provide a reference voltage; recording sensed electrical signals based on said reference voltage and said sensed electrical signals; wirelessly transmitting digital data derived from the brain signals sensed by electrodes within said array of electrodes; and transmitting wireless commands to cause a delivery of an electrical stimulus to the patient's brain via at least two electrodes within said array of electrodes; 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. 
     
     
         34 . The method of  claim 33  wherein the wireless commands specify parameters comprising one or more selected electrodes of the array of electrodes, 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, wherein each of the selected electrodes are energized in accordance with the parameters.