Reliability of Neural Implants-Effective Method for Cleaning and Surface Preparation of Ceramics.

Neural implants provide effective treatment and diagnosis options for diseases where pharmaceutical therapies are missing or ineffective. These active implantable medical devices (AIMDs) are designed to remain implanted and functional over decades. A key factor for achieving reliability and longevity are cleaning procedures used during manufacturing to prevent failures associated with contaminations.

Stability of flexible thin-film metallization stimulation electrodes: analysis of explants after first-in-human study and improvement of in vivo performance.

Objective: Micro-fabricated neural interfaces based on polyimide (PI) are achieving increasing importance in translational research. The ability to produce well-defined micro-structures with properties that include chemical inertness, mechanical flexibility and low water uptake are key advantages for these devices.

Approach: This paper reports the development of the transverse intrafascicular multichannel electrode (TIME) used to deliver intraneural sensory feedback to an upper-limb amputee in combination with a sensorized hand prosthesis.

Delaying discharge after the stimulus significantly decreases muscle activation thresholds with small impact on the selectivity: an in vivo study using TIME.

The number of devices for electrical stimulation of nerve fibres implanted worldwide for medical applications is constantly increasing. Stimulation charge is one of the most important parameters of stimulation. High stimulation charge may cause tissue and electrode damage and also compromise the battery life of the electrical stimulators.

Subchronic stimulation performance of transverse intrafascicular multichannel electrodes in the median nerve of the Göttingen minipig.

This work evaluated the subchronic stimulation performance of an intraneural multichannel electrode (transverse intrafascicular multichannel electrode, TIME) in a large human-sized nerve. One or two TIMEs were implanted in the right median nerve above the elbow joint in four pigs for a period of 32 to 37 days (six TIMEs in total). The ability of the contact sites to recruit five muscles in the forelimb was assessed via their evoked electromyographic responses.

Restoring natural sensory feedback in real-time bidirectional hand prostheses.

Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prostheses should involve both a reliable decoding of the user's intentions and the delivery of nearly "natural" sensory feedback through remnant afferent pathways, simultaneously and in real time.

Stimulation selectivity of the “thin-film longitudinal intrafascicular electrode” (tfLIFE) and the “transverse intrafascicular multi-channel electrode” (TIME) in the large nerve animal model.

Neural prostheses are limited by the availability of peripheral neural electrodes to record the user's intention or provide sensory feedback through functional electrical stimulation. Our objective was to compare the ability of the novel “transverse intrafascicular multi-channel electrode” (TIME) and an earlier generation “thin-film longitudinal intrafascicular electrode” (tfLIFE) to selectively stimulate nerve fascicles and activate forelimb muscles in pigs. TIME was designed to access a larger subpopulation of fascicles than tfLIFE and should therefore be able to selectively activate a larger number of muscles.

Development of a neurotechnological system for relieving phantom limb pain using transverse intrafascicular electrodes (TIME).

Phantom limb pain (PLP) is a chronic condition that develops in the majority of amputees. The underlying mechanisms are not completely understood, and thus, no treatment is fully effective. Based on recent studies, we hypothesize that electrical stimulation of afferent nerves might alleviate PLP by giving sensory input to the patient if nerve fibers can be activated selectively.

High-porous platinum electrodes for functional electrical stimulation.

This paper reports on the preparation and characterization of highly porous platinum electrodes for functional electrical stimulation. Thin-film platinum electrodes were roughened by electrochemical deposition of platinum-copper alloys and subsequent removal of copper using cyclic voltammetry (CV). Prepared samples were characterized by electrochemical impedance spectroscopies (EIS), CVs and long-term pulse testing.

Biocompatibility of chronically implanted transverse intrafascicular multichannel electrode (TIME) in the rat sciatic nerve.

The transverse intrafascicular multichannel electrode (TIME) is intended to be transversally implanted in the peripheral nerve and to selectively interface subsets of axons in different fascicles within the same nerve. Two versions of TIME (TIME-2, TIME-3) were designed and tested for biocompatibility and safety in the sciatic nerve of the rat. TIME-2 was implanted in two groups: one group had only an acute implant and the second group had chronic implantation for 2 months; a third group was also chronically implanted with the TIME-3 version, designed to avoid the mechanical traction produced by muscles motion.

Comparative analysis of transverse intrafascicular multichannel, longitudinal intrafascicular and multipolar cuff electrodes for the selective stimulation of nerve fascicles.

The selection of a suitable nerve electrode for neuroprosthetic applications implies a trade-off between invasiveness and selectivity, wherein the ultimate goal is achieving the highest selectivity for a high number of nerve fascicles by the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME) is intended to be transversally inserted into the peripheral nerve and to be useful to selectively activate subsets of axons in different fascicles within the same nerve. We present a comparative study of TIME, LIFE and multipolar cuff electrodes for the selective stimulation of small nerves.

On the stability of poly-ethylenedioxythiopene as coating material for active neural implants.

This article deals with the stability of poly-ethylenedioxythiopene (PEDOT) coatings under high loads of current pulses. Test parameters were chosen to match many peripheral nervous system applications in regard of charge injection, pulse width, and repetition frequency. PEDOT coatings were characterized with electrochemical impedance spectroscopes and pulse tests.

A transverse intrafascicular multichannel electrode (TIME) to interface with the peripheral nerve.

Many different concepts of peripheral nerve interfaces have been developed over the past few decades and transferred into neuroscientific or clinical applications with varying degrees of success. In this study, we present a novel electrode design that transversally penetrates the peripheral nerve and is intended to selectively activate subsets of axons in different fascicles within the nerve. The "transverse intrafascicular multichannel electrode" (TIME) has been designed and fabricated using the micromachining and patterning of a polyimide substrate and insulation material and platinum electrode sites.