Acute human brain responses to intracortical microelectrode arrays: challenges and future prospects

Abstract

The emerging field of neuroprosthetics is focused on the development of new therapeutic interventions that will be able to restore some lost neural function by selective electrical stimulation or by harnessing activity recorded from populations of neurons. As more and more patients benefit from these approaches, the interest in neural interfaces has grown significantly and a new generation of penetrating microelectrode arrays are providing unprecedented access to the neurons of the central nervous system (CNS). These microelectrodes have active tip dimensions that are similar in size to neurons and because they penetrate the nervous system, they provide selective access to these cells (within a few microns). However, the very long-term viability of chronically implanted microelectrodes and the capability of recording the same spiking activity over long time periods still remain to be established and confirmed in human studies. Here we review the main responses to acute implantation of microelectrode arrays, and emphasize that it will become essential to control the neural tissue damage induced by these intracortical microelectrodes in order to achieve the high clinical potentials accompanying this technology.

Brain–machine interfaces for rehabilitation of poststroke hemiplegia

“…Once movements are sufficient to perform actions of daily life, constraint-induced movement therapy (CIMT) (Taub et al, 1999) becomes applied. of electrode positions, and the preservation of electric properties between the brain and the electrodes (eg, Fernández et al, 2014).…”

Mechanical Properties of Thin-Film Parylene–Metal–Parylene Devices

“…The average transverse impedance from a PMP devices (which peel testing showed good adhesion between the Parylene and metal (Figure 5) dropped slightly in magnitude at lower frequencies which are more sensitive to device failure (Fernández et al, 2014), but remained relatively constant at higher frequencies ( Figure 12A). The −90° phase of the PMP devices suggested that traces were fully insulated before bending, however, the insulation was in part compromised after the first set of bend Mechanical properties of thin-film Parylene-metal-Parylene devices Frontiers in Mechanical Engineering | www.frontiersin.org tests as indicated by the drop in phase at lower frequencies.…”

Development of a cortical visual neuroprosthesis for the blind: Replacing the role of the retina

“…For this reason we are using the Utah Electrode Array (UEA), which has 100 microelectrodes, each 1.5 mm long, arranged in a square grid contained in a package 4.2 mm by 4.2 mm. This array of penetrating electrodes has been designed to compromise as little cortical volume as possible, is able to selectively access individual or small groups of cortical neurons and is the only intracortical microelectrode array that has been FDA approved for long-term human studies [8]. Thus, each needle has been made as slender as possible yet retain sufficient strength to withstand the implantation procedure.…”