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Early interfaced neural activity from chronic amputated nerves.

Garde K, Keefer E, Botterman B, Galvan P, Romero MI - Front Neuroeng (2009)

Bottom Line: Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees.Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user.Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic Surgery, University of Texas Southwestern Medical Center Dallas, TX, USA.

ABSTRACT
Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees. Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user. However, reactive gliosis, micro hemorrhages, axonopathy and excessive inflammation currently limit their long-term use. Here we demonstrate that enticement of peripheral nerve regeneration through a non-obstructive multi-electrode array, after either acute or chronic nerve amputation, offers a viable alternative to obtain early neural recordings and to enhance long-term interfacing of nerve activity. Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface. Our findings suggest that regenerative multi-electrode arrays of open design allow early and stable interfacing of neural activity from amputated peripheral nerves and might contribute towards conveying full neural control and sensory feedback to users of robotic prosthetic devices.

No MeSH data available.


Related in: MedlinePlus

Multi-electrode array nerve implants. (A) Illustration of the electrode array nerve guide and head cap connection. Schematic representation of the acute and chronic injury/implantation paradigm [(B) arrow indicates denervation induced atrophy of the normal target muscle]. (C) Top view of the 18 pin multi-electrode array mounted in a tubular nerve guide (top removed for clarity). The length of the electrodes varied from 0.5–0.9 mm, with the taller ones placed in the center of the array (insert). (D) Photograph of the regenerated nerve through the electrode-conduit assembly in an acute animal 3 weeks post-implantation. (E) Photograph showing the perforations left by the MEA in a chronic injured implanted animal (arrows in insert) and (F) through a collagen-filled tube. Scale bar = 2 mm (C), 5 mm (D) and 800 μm (E).
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Figure 1: Multi-electrode array nerve implants. (A) Illustration of the electrode array nerve guide and head cap connection. Schematic representation of the acute and chronic injury/implantation paradigm [(B) arrow indicates denervation induced atrophy of the normal target muscle]. (C) Top view of the 18 pin multi-electrode array mounted in a tubular nerve guide (top removed for clarity). The length of the electrodes varied from 0.5–0.9 mm, with the taller ones placed in the center of the array (insert). (D) Photograph of the regenerated nerve through the electrode-conduit assembly in an acute animal 3 weeks post-implantation. (E) Photograph showing the perforations left by the MEA in a chronic injured implanted animal (arrows in insert) and (F) through a collagen-filled tube. Scale bar = 2 mm (C), 5 mm (D) and 800 μm (E).

Mentions: Custom-made floating arrays with 18-pin Parylene-C insulated platinum/iridium electrodes were used (150–250 kohm impedance at 1 kHz, Microprobes Inc, MD, USA). Individual electrodes were approximately 50 μm in diameter at the shank, varied in height (0.5–0.9 mm with 2 μm active tips), and were placed 400 μm apart to maximize contact with the regenerating nerve fibers. The array cable was fabricated from Palylene-C insulated 25 μm gold wires wound in helix and coated with MDX4-4210 silicone elastomer and was 17 cm in length. Microarrays were placed in the lumen of polyurethane nerve guide tubes prior to implantation (Micro-Renathane®, Braintree Scientific, Inc; OD 3 mm, ID 1.75 mm, and 7 mm in length). The entire assembly was sterilized and the lumen filled with collagen I/III (0.3% Chemicon, Tamacula, CA, USA) prior to surgery (Figure 1A).


Early interfaced neural activity from chronic amputated nerves.

Garde K, Keefer E, Botterman B, Galvan P, Romero MI - Front Neuroeng (2009)

Multi-electrode array nerve implants. (A) Illustration of the electrode array nerve guide and head cap connection. Schematic representation of the acute and chronic injury/implantation paradigm [(B) arrow indicates denervation induced atrophy of the normal target muscle]. (C) Top view of the 18 pin multi-electrode array mounted in a tubular nerve guide (top removed for clarity). The length of the electrodes varied from 0.5–0.9 mm, with the taller ones placed in the center of the array (insert). (D) Photograph of the regenerated nerve through the electrode-conduit assembly in an acute animal 3 weeks post-implantation. (E) Photograph showing the perforations left by the MEA in a chronic injured implanted animal (arrows in insert) and (F) through a collagen-filled tube. Scale bar = 2 mm (C), 5 mm (D) and 800 μm (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2691654&req=5

Figure 1: Multi-electrode array nerve implants. (A) Illustration of the electrode array nerve guide and head cap connection. Schematic representation of the acute and chronic injury/implantation paradigm [(B) arrow indicates denervation induced atrophy of the normal target muscle]. (C) Top view of the 18 pin multi-electrode array mounted in a tubular nerve guide (top removed for clarity). The length of the electrodes varied from 0.5–0.9 mm, with the taller ones placed in the center of the array (insert). (D) Photograph of the regenerated nerve through the electrode-conduit assembly in an acute animal 3 weeks post-implantation. (E) Photograph showing the perforations left by the MEA in a chronic injured implanted animal (arrows in insert) and (F) through a collagen-filled tube. Scale bar = 2 mm (C), 5 mm (D) and 800 μm (E).
Mentions: Custom-made floating arrays with 18-pin Parylene-C insulated platinum/iridium electrodes were used (150–250 kohm impedance at 1 kHz, Microprobes Inc, MD, USA). Individual electrodes were approximately 50 μm in diameter at the shank, varied in height (0.5–0.9 mm with 2 μm active tips), and were placed 400 μm apart to maximize contact with the regenerating nerve fibers. The array cable was fabricated from Palylene-C insulated 25 μm gold wires wound in helix and coated with MDX4-4210 silicone elastomer and was 17 cm in length. Microarrays were placed in the lumen of polyurethane nerve guide tubes prior to implantation (Micro-Renathane®, Braintree Scientific, Inc; OD 3 mm, ID 1.75 mm, and 7 mm in length). The entire assembly was sterilized and the lumen filled with collagen I/III (0.3% Chemicon, Tamacula, CA, USA) prior to surgery (Figure 1A).

Bottom Line: Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees.Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user.Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic Surgery, University of Texas Southwestern Medical Center Dallas, TX, USA.

ABSTRACT
Direct interfacing of transected peripheral nerves with advanced robotic prosthetic devices has been proposed as a strategy for achieving natural motor control and sensory perception of such bionic substitutes, thus fully functionally replacing missing limbs in amputees. Multi-electrode arrays placed in the brain and peripheral nerves have been used successfully to convey neural control of prosthetic devices to the user. However, reactive gliosis, micro hemorrhages, axonopathy and excessive inflammation currently limit their long-term use. Here we demonstrate that enticement of peripheral nerve regeneration through a non-obstructive multi-electrode array, after either acute or chronic nerve amputation, offers a viable alternative to obtain early neural recordings and to enhance long-term interfacing of nerve activity. Non-restrictive electrode arrays placed in the path of regenerating nerve fibers allowed the recording of action potentials as early as 8 days post-implantation with high signal-to-noise ratio, as long as 3 months in some animals, and with minimal inflammation at the nerve tissue-metal electrode interface. Our findings suggest that regenerative multi-electrode arrays of open design allow early and stable interfacing of neural activity from amputated peripheral nerves and might contribute towards conveying full neural control and sensory feedback to users of robotic prosthetic devices.

No MeSH data available.


Related in: MedlinePlus