Spatial and Functional Selectivity of Peripheral Nerve Signal Recording With the Transversal Intrafascicular Multichannel Electrode (TIME)

Thow

Adv Healthcare Materials

et al. 2017

Artificial sensors on the skin are proposed as a way to capture information that can be used in intracortical microstimulation or peripheral intraneural stimulation to restore sensory feedback to persons with tetraplegia. However, the ability of these artificial sensors to replicate the density and complexity of the natural mechanoreceptors is limited. One relatively unexplored approach is to make use of the signals from surviving tactile and proprioceptive receptors in existing limbs by recording from their transmitting axons within the primary sensory nerves. Here, a novel spiked ultraflexible neural (SUN) interface that is implanted into the peripheral nervous system to capture sensory information from these mechanoreceptors in acute rat experiments is described. The novel 3D design, which integrates spiked structures for intrafascicular nerve recording with an ultraflexible substrate, enables a unique conformal interface to the target nerve. With the high-quality recording (average signal-to-noise-ratio of 1.4) provided by the electrode, tactile from proprioceptive stimuli can be differentiated in terms of the firing rate. In toe pinching experiments, high spatial resolution classification can be achieved with support vector machine classifier. Further work remains to be done to assess the chronic recording capability of the SUN interface.

supporting

confidence: 89%

mentioning

confidence: 99%

A Highly Selective 3D Spiked Ultraflexible Neural (SUN) Interface for Decoding Peripheral Nerve Sensory Information

Thow

Adv Healthcare Materials

et al. 2017

Biomed. Phys. Eng. Express

“…While capable of single-unit recordings, most action potentials recorded by the Utah slanted array are from myelinated A-type axons; unmyelinated C-type axons are underrepresented in recordings using intra-fascicular arrays (unpublished communications). Although efficient at recruiting individual muscle via focal stimulation [17], longitudinal and transverse intrafascicular multichannel electrode arrays generally do not record single-units from axons [8, 18, 19]. The needle electrodes used in microneurography allow reliable recordings from unmyelinated C-fibers in humans.…”

Section: Introductionmentioning

confidence: 99%

In vitro multichannel single-unit recordings of action potentials from the mouse sciatic nerve

Chen

Ilham

Guo

et al. 2017

Electrode arrays interfacing with peripheral nerves are essential for neuromodulation devices targeting peripheral organs to relieve symptoms. To modulate (i.e., single-unit recording and stimulating) individual peripheral nerve axons remains a technical challenge. Here, we report an in vitro setup to allow simultaneous single-unit recordings from multiple mouse sciatic nerve axons. The sciatic nerve (~30 mm) was harvested and transferred to a tissue chamber, the ~5mm distal end pulled into an adjacent recording chamber filled with paraffin oil. A custom-built multi-wire electrode array was used to interface with split fine nerve filaments. Single-unit action potentials were evoked by electrical stimulation and recorded from 186 axons, of which 49.5% were classed A-type with conduction velocities (CV) greater than 1 m/s and 50.5% were C-type (CV < 1 m/s). The single-unit recordings had no apparent bias towards A- or C-type axons, were robust and repeatable for over 60 minutes, and thus an ideal opportunity to assess different neuromodulation strategies targeting peripheral nerves. For instance, ultrasonic modulation of action potential transmission was assessed using the setup, indicating increased nerve conduction velocity following ultrasound stimulus. This setup can also be used to objectively assess the design of next-generation electrode arrays interfacing with peripheral nerves.

“…The development of neural interfaces for recording peripheral nerve activity, including signal processing algorithms to analyze this activity, is a rapidly growing area of research [1][2][3][4][5][6][7]. Peripheral neural signals have the potential to provide the necessary motor, sensory, or autonomic information for robust control in many neuroprosthetic [8][9][10][11][12] and neuromodulation applications [13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Classification of naturally evoked compound action potentials in peripheral nerve spatiotemporal recordings

Koh

Nachman

Zariffa

2018

Preprint

Peripheral neural signals have the potential to provide the necessary motor, sensory or autonomic information for robust control in many neuroprosthetic and neuromodulation applications. However, developing methods to recover information encoded in these signals is a significant challenge. We introduce the idea of using spatiotemporal signatures extracted from multi-contact nerve cuff electrode recordings to classify naturally evoked compound action potentials (CAP). 9 Long-Evan rats were implanted with a 56-channel nerve cuff on the sciatic nerve. Afferent activity was selectively evoked in the different fascicles of the sciatic nerve (tibial, peroneal, sural) using mechano-sensory stimuli. Spatiotemporal signatures of recorded CAPs were used to train three different classifiers. Performance was measured based on the classification accuracy, F 1 -score, and the ability to reconstruct original firing rates of neural pathways. The mean classification accuracies, for a 3-class problem, for the best performing classifier was 0.686 ± 0.126 and corresponding mean F 1 -score was 0.605 ± 0.212. The mean Pearson correlation coefficients between the original firing rates and estimated firing rates found for the best classifier was 0.728 ± 0.276. The proposed method demonstrates the possibility of classifying individual naturally evoked CAPs in peripheral neural signals recorded from extraneural electrodes, allowing for more precise control signals in neuroprosthetic applications.