Retinal prostheses have the potential to restore vision to blind patients that have retinitis pigmentosa or similar hereditary degenerative disorders, by electrically stimulating surviving retinal neurons through implanted electrode arrays. Current retinal prostheses provide limited visual acuity and one challenge is to spatially control neural activation following electrical stimulation. Most of the retinal prostheses are either epi-retinal - in front of the retinal ganglion cell layer, or sub-retinal - behind photoreceptor layer. In this study, we performed calcium imaging of ganglion cells from whole mounted retinas and compared the spread of neural activation between epi-retinal stimulation with a fiber electrode and sub-retinal stimulation with a disk electrode. We investigated the effects of phase durations on the spatial resolution of biphasic stimulation. Our results suggest that with fiber electrode epi-retinal stimulation, the axon bundles activation can lead to significant spread of stimulation, and cannot be avoided simply by changing the phase durations. However, sub-retinal stimulation with very short pulses (phase duration 0.033ms) can effectively confine the activation of retinal ganglion cells.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/EMBC.2019.8857347 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Efficacy of Chewing Xylitol Gum on Restoring Postoperative Bowel Activity After Laparoscopic Cholecystectomy: A Three-arm Randomized Controlled Trial.
J Perianesth Nurs
January 2025
Medical Faculty, Department of Anesthesia and Reanimation, Giresun Üniversitesi, Giresun, Türkiye. Electronic address:
Purpose: The aim in the present study was to evaluate the effects of chewing postoperative xylitol gum on gastrointestinal functional recovery after laparoscopic cholecystectomy.
Design: A three-arm randomized controlled trial.
Methods: After a baseline assessment, participants were randomly assigned in three groups.
Hospital attendance, malaria prevalence and self-medication with an antimalarial drug before and after the start of COVID-19 pandemic in a sentinel site for malaria surveillance in Gabon.
Malar J
January 2025
Department of Parasitology-Mycology and Tropical Medicine, Université Des Sciences de La Santé de Libreville, BP 4009, Libreville, Gabon.
Background: The negative impact of COVID-19 pandemic on healthcare service utilization has been reported in several countries. In Gabon, data on the preparedness for future pandemic are lacking. The aim of the present study was to assess the trends of hospital attendance, malaria and self-medication prevalences as well as ITN use before and during Covid-19 first epidemic waves in a paediatric wards of a sentinel site for malaria surveillance, in Libreville, Gabon.
View Article and Find Full Text PDFEncorafenib, cetuximab and chemotherapy in BRAF-mutant colorectal cancer: a randomized phase 3 trial.
Nat Med
January 2025
Vall d'Hebron Hospital Campus and Vall d'Hebron Institute of Oncology (VHIO), University of Vic - Central University of Catalonia, Barcelona, Spain.
Encorafenib + cetuximab (EC) is approved for previously treated BRAF V600E-mutant metastatic colorectal cancer (mCRC) based on the BEACON phase 3 study. Historically, first-line treatment of BRAF V600E-mutant mCRC with chemotherapy regimens has had limited efficacy. The phase 3 BREAKWATER study investigated EC+mFOLFOX6 versus standard of care (SOC) in patients with previously untreated BRAF V600E mCRC.
View Article and Find Full Text PDFFast single atom imaging for optical lattice arrays.
Nat Commun
January 2025
Department of Physics, Harvard University, Cambridge, MA, USA.
High-resolution fluorescence imaging of ultracold atoms and molecules is paramount to performing quantum simulation and computation in optical lattices and tweezers. Imaging durations in these experiments typically range from a millisecond to a second, significantly limiting the cycle time. In this work, we present fast, 2.
View Article and Find Full Text PDFIntroducing and establishing birth companionship in labour ward of a tertiary care centre in North India: a quality improvement journey through and beyond COVID-19 pandemic.
BMJ Open Qual
January 2025
Professor Department of Obstetrics and Gynaecology, Lady Hardinge Medical College, New Delhi, India.
Background: Allowing a birth companion is the basic right of a mother and is identified as an important component of respectful maternity care. The implementation of this intervention has been a challenge in heavy-load public health facilities in India.
Local Problem: Despite the proven benefits of the presence of birth companions on maternal-fetal outcomes, there was no policy of allowing birth companions in our hospital.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!