scholarly journals An actuated neural probe architecture for reducing gliosis-induced recording degradation

2018 ◽  
Author(s):  
Travis L. Massey ◽  
Leane S. Kuo ◽  
Jiang Lan Fan ◽  
Michel M. Maharbiz
Keyword(s):  
Silicon On Insulator ◽  
Proof Of Concept ◽  
Signal Loss ◽  
Neural Probes ◽  
Neural Implant ◽  
Glial Scarring ◽  
Mechanical Proof ◽  
Minimize Tissue Damage ◽  
Target Depth ◽  
Brain Phantom

AbstractGlial encapsulation of chronically implanted neural probes inhibits recording and stimulation, and this signal loss is a significant factor limiting the clinical viability of most neural implant topologies for decades-long implantation. We demonstrate a mechanical proof of concept for silicon shank-style neural probes intended to minimize gliosis near the recording sites. Compliant whiskers on the edges of the probe fold inward to minimize tissue damage during insertion. Once implanted to the target depth and retracted slightly, these whiskers splay outward. The splayed tips, on which recording sites could be patterned, extend beyond the typical 50-100 micron radius of a glial scar. The whiskers are micron-scale to minimize or avoid glial scarring. Electrically inactive devices with whiskers of varying widths and curvature were designed and monolithically fabricated from a five-micron silicon-on-insulator (SOI) wafer, and their mechanical functionality was demonstrated in a 0.6% agar brain phantom. Deflection was plotted versus deflection speed, and those that were most compliant actuated successfully. This probe requires no preparation for use beyond what is typical for a shank-style silicon probe.

Navigating conjugated polymer actuated neural probes in a brain phantom

2012 ◽  
Author(s):  
Eugene D. Daneshvar ◽  
Daryl Kipke ◽  
Elisabeth Smela
Keyword(s):  
Conjugated Polymer ◽  
Neural Probes ◽  
Brain Phantom

scholarly journals The density difference between tissue and neural probes is a key factor for glial scarring

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Gustav Lind ◽  
Cecilia Eriksson Linsmeier ◽  
Jens Schouenborg
Keyword(s):  
Density Difference ◽  
Neural Probes ◽  
Key Factor ◽  
Glial Scarring

scholarly journals Engineering strategies towards overcoming bleeding and glial scar formation around neural probes

2022 ◽  
Author(s):  
Elisabeth Otte ◽  
Andreas Vlachos ◽  
Maria Asplund
Keyword(s):  
Surgical Techniques ◽  
Microelectrode Arrays ◽  
Biological Response ◽  
Neural Probes ◽  
Clinical Neuroscience ◽  
The Past ◽  
Brain Interface ◽  
Glial Scarring ◽  
The Brain

AbstractNeural probes are sophisticated electrophysiological tools used for intra-cortical recording and stimulation. These microelectrode arrays, designed to penetrate and interface the brain from within, contribute at the forefront of basic and clinical neuroscience. However, one of the challenges and currently most significant limitations is their ‘seamless’ long-term integration into the surrounding brain tissue. Following implantation, which is typically accompanied by bleeding, the tissue responds with a scarring process, resulting in a gliotic region closest to the probe. This glial scarring is often associated with neuroinflammation, neurodegeneration, and a leaky blood–brain interface (BBI). The engineering progress on minimizing this reaction in the form of improved materials, microfabrication, and surgical techniques is summarized in this review. As research over the past decade has progressed towards a more detailed understanding of the nature of this biological response, it is time to pose the question: Are penetrating probes completely free from glial scarring at all possible?

scholarly journals Study of the UTBB BESOI Tunnel-FET working as a Dual-Technology Transistor

2021 ◽  
Vol 16 (2) ◽  
pp. 1-6
Author(s):  
Carlos Augusto Bergfeld Mori ◽  
Paula Ghedini Der Agopian ◽  
João Antonio Martino
Keyword(s):  
Electric Field ◽  
Device Simulation ◽  
Silicon On Insulator ◽  
Gate Bias ◽  
Proof Of Concept ◽  
Back Gate ◽  
Tunnel Fet ◽  
Working Principle ◽  
P Type

In this work, we further investigate the operation of the BESOI (Back-Enhanced Silicon-On Insulator) Dual-Technology FET, analyzing not only its behavior as a p-type Tunnel-FET when a negative back bias is applied to the struc-ture, but also as an nMOS when a positive back bias is ap-plied. The working principle is based on the generation of a channel of either holes or electrons by the back gate electric field, which can then be depleted through the front gate bias. TCAD device simulation was used for the proof of concept.

scholarly journals All-polymeric transient neural probe for prolonged in-vivo electrophysiological recordings

2021 ◽  
Author(s):  
Laura Ferlauto ◽  
Paola Vagni ◽  
Elodie Geneviève Zollinger ◽  
Adele Fanelli ◽  
Katia Monsorno ◽  
...  
Keyword(s):  
Foreign Body ◽  
Medical Devices ◽  
Foreign Body Reaction ◽  
Brain Activity ◽  
Degradation Process ◽  
Proof Of Concept ◽  
Neural Probes ◽  
Electrophysiological Recordings ◽  
Transient Metals

AbstractTransient bioelectronics has grown fast, opening possibilities never thought before. In medicine, transient implantable devices are interesting because they could eliminate the risks related to surgical retrieval and reduce the chronic foreign body reaction. However, despite recent progress in this area, the short functional lifetime of devices due to short-lived transient metals, which is typically a few days or weeks, still limits the potential of transient medical devices. We report that a switch from transient metals to an entirely polymer-based approach allows for a slower degradation process and a longer lifetime of the transient probe, thus opening new possibilities for transient medical devices. As a proof-of-concept, we fabricated all-polymeric transient neural probes that can monitor brain activity in mice for a few months rather than a few days or weeks. Also, we extensively evaluated the foreign body reaction around the implant during the probe’s degradation. This kind of devices might pave the way for several applications in neuroprosthetics.

scholarly journals Computational and Histological Analyses for Investigating Mechanical Interaction of Thermally Drawn Fiber Implants with Brain Tissue

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 394
Author(s):  
Kanghyeon Kim ◽  
Changhoon Sung ◽  
Jungjoon Lee ◽  
Joonhee Won ◽  
Woojin Jeon ◽  
...  
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Cross Sections ◽  
Strain Distribution ◽  
Element Model ◽  
Signal Loss ◽  
Mechanical Interaction ◽  
Neural Probes ◽  
Element Analysis ◽  
Lower Strain

The development of a compliant neural probe is necessary to achieve chronic implantation with minimal signal loss. Although fiber-based neural probes fabricated by the thermal drawing process have been proposed as a solution, their long-term effect on the brain has not been thoroughly investigated. Here, we examined the mechanical interaction of thermally drawn fiber implants with neural tissue through computational and histological analyses. Specifically, finite element analysis and immunohistochemistry were conducted to evaluate the biocompatibility of various fiber implants made with different base materials (steel, silica, polycarbonate, and hydrogel). Moreover, the effects of the coefficient of friction and geometric factors including aspect ratio and the shape of the cross-section on the strain were investigated with the finite element model. As a result, we observed that the fiber implants fabricated with extremely softer material such as hydrogel exhibited significantly lower strain distribution and elicited a reduced immune response. In addition, the implants with higher coefficient of friction (COF) and/or circular cross-sections showed a lower strain distribution and smaller critical volume. This work suggests the materials and design factors that need to be carefully considered to develop future fiber-based neural probes to minimize mechanical invasiveness.

scholarly journals Invisible ECG for High Throughput Screening in eSports

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7601
Author(s):  
Aline Santos Silva ◽  
Miguel Velhote Correia ◽  
Hugo Plácido Silva
Keyword(s):  
Data Collection ◽  
Team Performance ◽  
High Throughput Screening ◽  
Large Scale ◽  
Pearson Correlation ◽  
Physiological Data ◽  
Proof Of Concept ◽  
Signal Loss ◽  
Monitoring Technologies ◽  
Grade Assessment

eSports is a rapidly growing industry with increasing investment and large-scale international tournaments offering significant prizes. This has led to an increased focus on individual and team performance with factors such as communication, concentration, and team intelligence identified as important to success. Over a similar period of time, personal physiological monitoring technologies have become commonplace with clinical grade assessment available across a range of parameters that have evidenced utility. The use of physiological data to assess concentration is an area of growing interest in eSports. However, body-worn devices, typically used for physiological data collection, may constitute a distraction and/or discomfort for the subjects. To this end, in this work we devise a novel “invisible” sensing approach, exploring new materials, and proposing a proof-of-concept data collection system in the form of a keyboard armrest and mouse. These enable measurements as an extension of the interaction with the computer. In order to evaluate the proposed approach, measurements were performed using our system and a gold standard device, involving 7 healthy subjects. A particularly advantageous characteristic of our setup is the use of conductive nappa leather, as it preserves the standard look and feel of the keyboard and mouse. According to the results obtained, this approach shows 3–15% signal loss, with a mean difference in heart rate between the reference and experimental device of −1.778 ± 4.654 beats per minute (BPM); in terms of ECG waveform morphology, the best cases show a Pearson correlation coefficient above 0.99.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

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