The Effect of Electric Cross-Talk in Retinal Neurostimulation

Matteucci, P; Barriga‐Rivera, Alejandro; Eiber, Calvin D.; Lovell, Nigel H.; Morley, John W.; Suaning, Gregg J.

doi:10.1167/iovs.15-18400

Cited by 32 publications

(35 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hexapolar stimulation, where the six electrodes surrounding each stimulating electrode are connected to each other and used a return or ''guard,'' has been shown in previous studies to increase the specificity of activation in the retina and reduce electrical cross-talk. 31,40,41 However, this technique also results in a significant increase in stimulation threshold to elicit a cortical response, 31,32,38,41 which is consistent with studies showing increased perceptual thresholds for cochlear implant patients when receiving bipolar and TP stimulation. 27,33,42 While, at matched current levels, cortical activation has been shown to be reduced with HP stimulation compared to monopolar (MP) stimulation.…”

supporting

confidence: 82%

“…25 It also has been shown that channel interactions can be reduced in the retina using HP stimulation. 40 Further investigation in the use of these current focusing techniques in reducing electrical crosstalk in the retina could be of great benefit.…”

Section: Future Studiesmentioning

confidence: 99%

“…23,31,32 Cochlear implant studies show that the electrode return mode used during stimulation, such as bipolar and tripolar (TP) stimulation, can significantly reduce the spread of neural activation in the cochlea and also can reduce the extent of auditory brain activation. [33][34][35][36][37] Similar approaches have been attempted in the retina, such as the use of bipolar stimulation, 31,38 common ground returns, 31 hexapolar returns (HP), 32,[38][39][40] and quasimonopolar modes 32 with varying levels of success. Hexapolar stimulation, where the six electrodes surrounding each stimulating electrode are connected to each other and used a return or ''guard,'' has been shown in previous studies to increase the specificity of activation in the retina and reduce electrical cross-talk.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Spatial Restriction of Neural Activation Using Focused Multipolar Stimulation With a Retinal Prosthesis

Spencer

Fallon

Thien

et al. 2016

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

Citation: Spencer TC, Fallon JB, Thien PC, Shivdasani MN. Spatial restriction of neural activation using focused multipolar stimulation with a retinal prosthesis. Invest Ophthalmol Vis Sci. 2016;57:3181-3191. DOI:10.1167/ iovs.16-19325 PURPOSE. The resolution provided by present state-of-the-art retinal prostheses is severely limiting for recipients, partly due to the broad spread of activation in the retina in response to monopolar (MP) electrical stimulation. Focused multipolar (FMP) stimulation has been shown to restrict neural activation in the cochlea compared to MP stimulation. We extended the FMP stimulation technique to a two-dimensional electrode array and compared its efficacy to MP and hexapolar (HP) stimulation in the retina.METHODS. Normally-sighted cats (n ¼ 6) were implanted with a suprachoroidal electrode array containing 42 electrodes. Multichannel multiunit spiking activity was recorded from the visual cortex in response to MP, HP, and FMP retinal stimulation.RESULTS. When inferring retinal spread using voltage recordings off the stimulating array, FMP stimulation showed significantly reduced voltages in regions surrounding the primary stimulating electrode. When measuring the retinal and cortical selectivity of neural responses, FMP and HP stimulation showed significantly higher selectivity compared to MP stimulation (separate 2-way ANOVAs, P < 0.05). However, the lowest cortical thresholds for each stimulating electrode were higher for FMP and HP compared to MP stimulation (1-way ANOVA, P < 0.001). No significant differences were observed between FMP and HP stimulation in any measures.CONCLUSIONS. Focused multipolar and HP stimulation using a two-dimensional array are promising techniques to reduce the spread of activation for a retinal prosthesis. Clinical application would be expected to result in smaller phosphenes; thus, reducing phosphene overlap between electrodes and increasing the resolution at the expense of higher thresholds for activation.

show abstract

supporting

confidence: 82%

Section: Future Studiesmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Spatial Restriction of Neural Activation Using Focused Multipolar Stimulation With a Retinal Prosthesis

Spencer

Fallon

Thien

et al. 2016

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

show abstract

“…However, this also poses several problems related mainly with data transmission, since this is one of the key factors limiting the number of electrodes. Thus, if the number of stimulating electrodes is increased, there are often considerable interference and cross-talk problems (Matteucci et al, 2016;Flores et al, 2016;Khalili Moghaddam et al, 2014).…”

Section: Delivering Of Information To Implantsmentioning

confidence: 99%

Development of visual Neuroprostheses: trends and challenges

Fernández

2018

Bioelectron Med

View full text Add to dashboard Cite

Visual prostheses are implantable medical devices that are able to provide some degree of vision to individuals who are blind. This research field is a challenging subject in both ophthalmology and basic science that has progressed to a point where there are already several commercially available devices. However, at present, these devices are only able to restore a very limited vision, with relatively low spatial resolution. Furthermore, there are still many other open scientific and technical challenges that need to be solved to achieve the therapeutic benefits envisioned by these new technologies. This paper provides a brief overview of significant developments in this field and introduces some of the technical and biological challenges that still need to be overcome to optimize their therapeutic success, including long-term viability and biocompatibility of stimulating electrodes, the selection of appropriate patients for each artificial vision approach, a better understanding of brain plasticity and the development of rehabilitative strategies specifically tailored for each patient.

show abstract

“…Acute electrophysiology experimentation is the approach of choice of many areas of research and is particularly common in those fields in which functional models are not available or easily accessible. In the case of visual prosthesis research, a feline model has been traditionally used as it has a highly developed visual system with sufficiently large eye to implant a retinal electrode array . Natural cases of retinal degeneration have been reported in cats, and other researchers have induced it by administering adenosine triphosphate in the vitreous .…”

Section: Introductionmentioning

confidence: 99%

Long‐term anesthetic protocol in rats: feasibility in electrophysiology studies in visual prosthesis

Barriga‐Rivera

Tatarinoff

Lovell

et al. 2017

Veterinary Ophthalmology

Self Cite

View full text Add to dashboard Cite

Electrical stimulation of excitable cells provides therapeutic benefits for a variety of medical conditions, including restoration of partial vision to those blinded via some types of retinal degeneration. To improve visual percepts elicited by the current technology, researchers are conducting acute electrophysiology experiments, mainly in cats. However, the rat can provide a model of a range of retinal diseases and possesses a sufficiently large eye to be used in this field. This article presents a long-term anesthetic protocol to enable electrophysiology experiments to further the development of visual prostheses. Six Long-Evans rats (aged between 14 and 16 weeks) were included in this study. Surgical anesthesia was maintained for more than 15 h by combining constant intravenous infusion of ketamine (24.0-34.5 mg/kg/h), xylazine (0.9-1.2 mg/kg/h), and inhaled isoflurane in oxygen (<0.5%). Overall heart rate, respiratory rate, and body temperature remained between 187-233 beats/min, 45-58 breaths/min, and 36-38 °C, respectively. Neural responses to 200-ms light pulses were recorded from the superior colliculus using a 32-channel neural probe at the beginning and before termination of the experiment. Robust responses were recorded from distinct functional types of retinal pathways. In addition, a platinum electrode was implanted in the retrobulbar space. The retina was electrically stimulated, and the activation threshold was determined to be 5.24 ± 0.24 μC/cm . This protocol may be used not only in the field of visual prosthesis research, but in other research areas requiring longer term acute experiments.

show abstract

The Effect of Electric Cross-Talk in Retinal Neurostimulation

Cited by 32 publications

References 34 publications

Spatial Restriction of Neural Activation Using Focused Multipolar Stimulation With a Retinal Prosthesis

Spatial Restriction of Neural Activation Using Focused Multipolar Stimulation With a Retinal Prosthesis

Development of visual Neuroprostheses: trends and challenges

Long‐term anesthetic protocol in rats: feasibility in electrophysiology studies in visual prosthesis

Contact Info

Product

Resources

About