Electrical stimulation of excitable tissue: design of efficacious and safe protocols.

Response of brain tissue to chronically implanted neural electrodes.

Microneedles for drug and vaccine delivery.

Recent technological and scientific advances have generated wide interest in the possibility of creating a brain-machine interface (BMI), particularly as a means to aid paralyzed humans in communication. Advances have been made in detecting neural signals and translating them into command signals that can control devices. We now have systems that use externally derived neural signals as a command source, and faster and potentially more flexible systems that directly use intracortical recording are being tested. Studies in behaving monkeys show that neural output from the motor cortex can be used to control computer cursors almost as effectively as a natural hand would carry out the task. Additional research findings explore the possibility of using computers to return behaviorally useful feedback information to the cortex. Although significant scientific and technological challenges remain, progress in creating useful human BMIs is accelerating.

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Connecting Cortex to Machines: Recent Advances in Brain Interfaces

This paper describes the development of a high-density electronic interface to the central nervous system. Silicon micromachined electrode arrays now permit the long-term monitoring of neural activity in vivo as well as the insertion of electronic signals into neural networks at the cellular level. Efforts to understand and engineer the biology of the implant/tissue interface are also underway. These electrode arrays are facilitating significant advances in our understanding of the nervous system, and merged with on-chip circuitry, signal processing, microfluidics, and wireless interfaces, they are forming the basis for a family of neural prostheses for the possible treatment of disorders such as blindness, deafness, paralysis, severe epilepsy, and Parkinson's disease.

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Wireless implantable microsystems: high-density electronic interfaces to the nervous system

The promise of advanced neuroprosthetic systems to significantly improve the quality of life for a segment of the deaf, blind, or paralyzed population hinges on the development of an efficacious, and safe, multichannel neural interface for the central nervous system. The candidate implantable device that is to provide such an interface must exceed a host of exacting design parameters. The authors present a thin-film, polyimide-based, multichannel intracortical Bio-MEMS interface manufactured with standard planar photo-lithographic CMOS-compatible techniques on 4-in silicon wafers. The use of polyimide provides a mechanically flexible substrate which can be manipulated into unique three-dimensional designs. Polyimide also provides an ideal surface for the selective attachment of various important bioactive species onto the device in order to encourage favorable long-term reactions at the tissue-electrode interface. Structures have an integrated polyimide cable providing efficient contact points for a high-density connector. This report details in vivo and in vitro device characterization of the biological, electrical and mechanical properties of these arrays. Results suggest that these arrays could be a candidate device for long-term neural implants.

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Flexible polyimide-based intracortical electrode arrays with bioactive capability

An implant device for creating a neural interface with the central nervous system having a polyimide-based electrode array is presented along with a method for making the device. The device may be configured as a three dimensional structure and is capable of sensing multi-unit neural activity from the cerebral cortex. Mechanical, electrical and biological characteristics of the device support its use as a reliable, long term implant.

Device for creating a neural interface and method for making same

Some embodiments of the invention comprise a customizable multichannel microelectrode array with a modular planar microfabricated electrode array attached to a carrier and a high density of recording and/or stimulation electrode sites disposed thereon. Novel methods of making and using same are also disclosed.

Modular multichannel microelectrode array and methods of making same

One embodiment of the invention includes an implantable electrode lead system that includes a series of shims stacked upon each other, a series of first components, and a series of second components connected to the series of first components through a series of connectors. One of the first components extends from one of the shims, and another of the first components extends from another one of the shims. The shims position the first components in a three dimensional arrangement.

Implantable Electrode Lead System with a Three Dimensional Arrangement and Method of Making the Same

Goal: Develop and characterize the functionality of a novel thin-film probe technology with a higher density of electrode contacts than are currently available with commercial deep brain stimulation (DBS) lead technology. Such technology has potential to enhance the spatial precision of DBS and enable a more robust approach to sensing local field potential activity in the context of adaptive DBS strategies. Methods: Thin-film planar arrays were microfabricated and then assembled on a cylindrical carrier to achieve a lead with 3-D conformation. Using an integrated and removable stylet, the arrays were chronically implanted in the subthalamic nucleus and globus pallidus in two parkinsonian nonhuman primates. Results: This study provides the first in vivo data from chronically implanted DBS arrays for translational nonhuman primate studies. Stimulation through the arrays induced a decrease in parkinsonian rigidity, and directing current around the lead showed an orientation dependence for eliciting motor capsule side effects. The array recordings also showed that oscillatory activity in the basal ganglia is heterogeneous at a smaller scale than detected by the current DBS lead technology. Conclusion: These 3-D DBS arrays provide an enabling tool for future studies that seek to monitor and modulate deep brain activity through chronically implanted leads. Significance: DBS lead technology with a higher density of electrode contacts has potential to enable sculpting DBS current flow and sensing biomarkers of disease and therapy.

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David S. Pellinen

Papers

Flexible polyimide-based intracortical electrode arrays with bioactive capability

Device for creating a neural interface and method for making same

Modular multichannel microelectrode array and methods of making same

Implantable Electrode Lead System with a Three Dimensional Arrangement and Method of Making the Same

A Novel Lead Design for Modulation and Sensing of Deep Brain Structures