Intracranial sensing & monitoring device with macro and micro electrodes

Abstract

A cortical sensing device for contact with the surface of the brain is provided that includes a support member, at least one macroelectrode sensing element secured with respect to the support member and at least one microelectrode sensing element secured with respect to the macroelectrode. The support member is substantially thin and made from flexibly-conformable material to accurately and safely place the sensing device upon the brain surface. The microelectrode sensing element is surrounded by the macroelectrode brain-contact surface of the macroelectrode sensing element. The first surface of the support member, the macroelectrode brain-contact surface and the microelectrode brain-contact surface are substantially co-planar to abut the surface of the brain for sensoring and monitoring.

1 . A sensing device for contact with brain tissue comprising:
 a flexible support sleeve having an outer surface and inner surface defining a cavity;   at least one macroelectrode sensing element secured with respect to the outer surface and having an arcuate macroelectrode brain-contact surface;   a lead wire secured to each macroelectrode sensing element and extending into and along the cavity;   at least one microelectrode sensing element secured with respect to the macroelectrode sensing element and having a microelectrode brain-contact surface contiguous with and insulated from the macroelectrode brain-contact surface; and   a micro-wire secured to each microelectrode sensing element and extending into and along the cavity, the micro-wire being insulated with a bio-compatible material to prevent electrical interaction between the microelectrode sensing element and the macroelectrode sensing element, the macroelectrode brain-contact surface and the microelectrode brain-contact surface being in substantially the same surface to abut brain tissue for sensing and monitoring, wherein the microelectrode sensing element is adapted to monitor cellular neuron activity signals within the brain while the macroelectrode sensing element is adapted to monitor EEG brain activity signals from the brain.   
     
     
         2 . The sensing device of  claim 1  wherein the macroelectrode element is arcuate and around the macroelectrode brain-contact surface 
     
     
         3 . The sensing device of  claim 1  further including a plurality of the microelectrode sensing elements spaced from one another on and surrounded by the macroelectrode sensing element. 
     
     
         4 . The sensing device of  claim 1  wherein the macroelectrode sensing element is comprised of a single layer of material having a thickness of about 0.0005-0.004 inches and a diameter of about 0.3-5.0 millimeters. 
     
     
         5 . The sensing device of  claim 4  wherein the macroelectrode sensing element is stainless steel or a noble alloy selected from the group consisting of platinum, gold, palladium, iridium and ruthenium alloys and combinations thereof. 
     
     
         6 . The sensing device of  claim 1  wherein the microelectrode brain-contact surface has a diameter of about 10-250 microns. 
     
     
         7 . The sensing device of  claim 6  wherein the microelectrode sensing element is comprised of a noble alloy selected from the group consisting of platinum, gold, palladium, iridium and ruthenium alloys and combinations thereof. 
     
     
         8 . The sensing device of  claim 1  wherein the macroelectrode brain contact surface is defined by a closed loop and the microelectrode brain contact surface is within such loop. 
     
     
         9 . A cortical sensing device for contact with the surface of the brain comprising:
 a support member of a flexibly-conformable;   at least one macroelectrode sensing element secured with respect to the support member and having a macroelectrode brain-contact surface;   at least one microelectrode sensing element secured with respect to the macroelectrode and having a microelectrode brain-contact surface contiguous with and insulated from the macroelectrode brain-contact surface, wherein the macroelectrode brain-contact surface and the microelectrode brain-contact surface are substantially co-planar to abut the surface of the brain for sensing and monitoring, the microelectrode sensing element is adapted to monitor cellular neuron activity signals within the brain while the macroelectrode sensing element is adapted to monitor EEG brain activity signals from the brain.   
     
     
         10 . The sensing device of  claim 9  wherein the microelectrode sensing element is a micro-wire insulated therealong to the microelectrode brain-contact surface with a bio-compatible material to prevent electrical interaction between the microelectrode sensing element and macroelectrode sensing element. 
     
     
         11 . The sensing device of  claim 9  wherein the support member has a first surface and the first surface is substantially co-planar with the macroelectrode brain contact surface and the microelectrode brain contact surface. 
     
     
         12 . The sensing device of  claim 9  wherein the macroelectrode sensing element is comprised of a single layer of material having a thickness of about 0.0005-0.004 inches and a diameter of about 0.3-5.0 millimeters. 
     
     
         13 . The sensing device of  claim 12  wherein the macroelectrode sensing element is stainless steel or a noble alloy selected from the group consisting of platinum, gold, palladium, iridium and ruthenium alloys and combinations thereof. 
     
     
         14 . The sensing device of  claim 9  wherein the microelectrode brain-contact surface has a diameter of about 10-250 microns. 
     
     
         15 . The sensing device of  claim 14  wherein the microelectrode sensing element is comprised of a noble alloy selected from the group consisting of platinum, gold, palladium, iridium and ruthenium alloys and combinations thereof. 
     
     
         16 . The sensing device of  claim 9  wherein the macroelectrode brain contact surface is defined by a closed loop and the microelectrode brain contact surface is within such loop. 
     
     
         17 . The sensing device of  claim 9  wherein the microelectrode sensing element is a micro-wire. 
     
     
         18 . The sensing device of  claim 17  further including a lead wire extending from the macroelectrode sensing element, the lead wire and the micro-wire being imbedded in and extending along the support member to exit therefrom for remote electrical connection. 
     
     
         19 . The sensing device of  claim 9  wherein the macroelectrode sensing element is a flat member and has peripheral portions engaged by the support member. 
     
     
         20 . The sensing device of  claim 9  further including a plurality of the microelectrode sensing elements surrounded by the macroelectrode sensing element. 
     
     
         21 . The sensing device of  claim 9  wherein the support member comprises:
 a center portion which includes the macroelectrode sensing element and its related microelectrode sensing element(s) and has a peripheral portion; and 
 a plurality of flexible pads thereabout, each pad located along the peripheral portion and having its own center, the plurality of pads being positioned such that the centers are not collinear, 
 
       whereby the flexible pads facilitate engagement of the sensing device with brain surface.