Laser microstructured diamond electrode arrays for bionic eye applications (Conference Presentation)

2018 ◽  
Author(s):  
Steven Prawer ◽  
David Garrett
Keyword(s):  
Electrode Arrays ◽  
Diamond Electrode ◽  
Bionic Eye

scholarly journals Micro-Fabrication of Components for a High-Density Sub-Retinal Visual Prosthesis

Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 944 ◽  
Author(s):  
Douglas Shire ◽  
Marcus Gingerich ◽  
Patricia Wong ◽  
Michael Skvarla ◽  
Stuart Cogan ◽  
...  
Keyword(s):  
High Density ◽  
Visual Prosthesis ◽  
Massachusetts Institute Of Technology ◽  
Electrode Arrays ◽  
Retinal Implant ◽  
Micro Fabrication ◽  
Bionic Eye ◽  
Startup Company ◽  
Problems And Solutions ◽  
Institute Of Technology

We present a retrospective of unique micro-fabrication problems and solutions that were encountered through over 10 years of retinal prosthesis product development, first for the Boston Retinal Implant Project initiated at the Massachusetts Institute of Technology and at Harvard Medical School’s teaching hospital, the Massachusetts Eye and Ear—and later at the startup company Bionic Eye Technologies, by some of the same personnel. These efforts culminated in the fabrication and assembly of 256+ channel visual prosthesis devices having flexible multi-electrode arrays that were successfully implanted sub-retinally in mini-pig animal models as part of our pre-clinical testing program. We report on the processing of the flexible multi-layered, planar and penetrating high-density electrode arrays, surgical tools for sub-retinal implantation, and other parts such as coil supports that facilitated the implantation of the peri-ocular device components. We begin with an overview of the implantable portion of our visual prosthesis system design, and describe in detail the micro-fabrication methods for creating the parts of our system that were assembled outside of our hermetically-sealed electronics package. We also note the unique surgical challenges that sub-retinal implantation of our micro-fabricated components presented, and how some of those issues were addressed through design, materials selection, and fabrication approaches.

Simultaneous Square-Wave Voltammetric Determination of Paracetamol, Caffeine and Orphenadrine in Pharmaceutical Formulations Using a Cathodically Pretreated Boron-Doped Diamond Electrode

2013 ◽  
Vol 25 (7) ◽  
pp. 1734-1741 ◽  
Author(s):  
Ana Paula Pires Eisele ◽  
Débora Nóbile Clausen ◽  
César Ricardo Teixeira Tarley ◽  
Luiz Henrique Dall'Antonia ◽  
Elen Romão Sartori
Keyword(s):  
Pharmaceutical Formulations ◽  
Voltammetric Determination ◽  
Boron Doped Diamond ◽  
Square Wave ◽  
Diamond Electrode ◽  
Boron Doped ◽  
Boron Doped Diamond Electrode

scholarly journals A deep convolutional visual encoding model of neuronal responses in the LGN

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Eslam Mounier ◽  
Bassem Abdullah ◽  
Hani Mahdi ◽  
Seif Eldawlatly
Keyword(s):  
Firing Rate ◽  
Visual Information ◽  
Visual Stimulation ◽  
Neuronal Population ◽  
Neuronal Firing ◽  
Electrode Arrays ◽  
Deep Convolutional Neural Networks ◽  
Firing Rates ◽  
Spatiotemporal Representation

AbstractThe Lateral Geniculate Nucleus (LGN) represents one of the major processing sites along the visual pathway. Despite its crucial role in processing visual information and its utility as one target for recently developed visual prostheses, it is much less studied compared to the retina and the visual cortex. In this paper, we introduce a deep learning encoder to predict LGN neuronal firing in response to different visual stimulation patterns. The encoder comprises a deep Convolutional Neural Network (CNN) that incorporates visual stimulus spatiotemporal representation in addition to LGN neuronal firing history to predict the response of LGN neurons. Extracellular activity was recorded in vivo using multi-electrode arrays from single units in the LGN in 12 anesthetized rats with a total neuronal population of 150 units. Neural activity was recorded in response to single-pixel, checkerboard and geometrical shapes visual stimulation patterns. Extracted firing rates and the corresponding stimulation patterns were used to train the model. The performance of the model was assessed using different testing data sets and different firing rate windows. An overall mean correlation coefficient between the actual and the predicted firing rates of 0.57 and 0.7 was achieved for the 10 ms and the 50 ms firing rate windows, respectively. Results demonstrate that the model is robust to variability in the spatiotemporal properties of the recorded neurons outperforming other examined models including the state-of-the-art Generalized Linear Model (GLM). The results indicate the potential of deep convolutional neural networks as viable models of LGN firing.

scholarly journals Stretchable, Fully Polymeric Electrode Arrays for Peripheral Nerve Stimulation

2021 ◽  
pp. 2004033
Author(s):  
Estelle A. Cuttaz ◽  
Christopher A. R. Chapman ◽  
Omaer Syed ◽  
Josef A. Goding ◽  
Rylie A. Green
Keyword(s):  
Peripheral Nerve ◽  
Nerve Stimulation ◽  
Peripheral Nerve Stimulation ◽  
Electrode Arrays

scholarly journals Hydraulic insertions of cochlear implant electrode arrays into the human cadaver cochlea: preliminary findings

2021 ◽  
Author(s):  
M. Geraldine ◽  
Thomas Lenarz ◽  
Thomas S. Rau
Keyword(s):  
Cochlear Implant ◽  
Outcome Measurement ◽  
Round Window ◽  
Handling Time ◽  
Human Cadaver ◽  
Hydraulic Actuator ◽  
Electrode Arrays ◽  
Non Invasive ◽  
Insertion Tool ◽  
Set Up

Abstract Objectives (1) To evaluate the feasibility of a non-invasive, novel, simple insertion tool to perform automated, slow insertions of cochlear implant electrode arrays (EA) into a human cadaver cochlea; (2) to estimate the handling time required by our tool. Methods Basic science study conducted in an experimental OR. Two previously anonymized human cadaver heads, three commercially available EAs, and our novel insertion tool were used for the experiments. Our tool operates as a hydraulic actuator that delivers an EA at continuous velocities slower than manually feasible. Intervention(s): the human cadaver heads were prepared with a round-window approach for CI surgery in a standard fashion. Twelve EA insertion trials using our tool involved: non-invasive fixation of the tool to the head; directing the tool to the round window and EA mounting onto the tool; automated EA insertion at approximately 0.1 mm/s driven by hydraulic actuation. Outcome measurement(s): handling time of the tool; post-insertion cone-beam CT scans to provide intracochlear evaluation of the EA insertions. Results Our insertion tool successfully inserted an EA into the human cadaver cochlea (n = 12) while being attached to the human cadaver head in a non-invasive fashion. Median time to set up the tool was 8.8 (7.2–9.4) min. Conclusion The first insertions into the human cochlea using our novel, simple insertion tool were successful without the need for invasive fixation. The tool requires < 10 min to set up, which is clinically acceptable. Future assessment of intracochlear trauma is needed to support its safety profile for clinical translation.

scholarly journals The Importance of Intraoperative Plain Radiographs during Cochlear Implant Surgery in Patients with Normal Anatomy

2021 ◽  
Vol 11 (9) ◽  
pp. 4144
Author(s):  
Ohad Cohen ◽  
Jean-Yves Sichel ◽  
Chanan Shaul ◽  
Itay Chen ◽  
J. Thomas Roland ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Cost Effective ◽  
X Rays ◽  
Normal Anatomy ◽  
Electrode Arrays ◽  
Plain Radiographs ◽  
Hearing Function ◽  
Tertiary Center ◽  
Cochlear Implant Surgery

Although malpositioning of the cochlear implant (CI) electrode array is rare in patients with normal anatomy, when occurring it may result in reduced hearing outcome. In addition to intraoperative electrophysiologic tests, imaging is an important modality to assess correct electrode array placement. The purpose of this report was to assess the incidence and describe cases in which intraoperative plain radiographs detected a malpositioned array. Intraoperative anti-Stenver’s view plain X-rays are conducted routinely in all CI surgeries in our tertiary center before awakening the patient and breaking the sterile field. Data of patients undergoing 399 CI surgeries were retrospectively analyzed. A total of 355 had normal inner ear and temporal bone anatomy. Patients with intra or extracochlear malpositioned electrode arrays demonstrated in the intraoperative X-ray were described. There were four cases of electrode array malposition out of 355 implantations with normal anatomy (1.1%): two tip fold-overs, one extracochlear placement and one partial insertion. All electrodes were reinserted immediately; repeated radiographs were normal and the patients achieved good hearing function. Intraoperative plain anti-Stenver’s view X-rays are valuable to confirm electrode array location, allowing correction before the conclusion of surgery. These radiographs are cheaper, faster, and emit much less radiation than other imaging options, making them a viable cost-effective tool in patients with normal anatomy.

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