Pattern Recognition with the Optic Nerve Visual Prosthesis

Abstract

A volunteer with retinitis pigmentosa and no residual vision was chronically implanted with an optic nerve electrode connected to an implanted neurostimulator and antenna. An external controller with telemetry was used for electrical activation of the nerve which resulted in phosphene perception. Open-loop stimulation allowed the collection of phosphene attributes and the ability to elicit perception of simple geometrical patterns. Low perception thresholds allowed for large current intensity range within safety limits. In a closed-loop paradigm, the volunteer was using a head-worn video camera to explore a projection screen. The volunteer underwent performance evaluation during the course of a training program with 45 simple patterns. After learning, the volunteer reached a recognition score of 63% with a processing time of 60 s. Mean performance in orientation discrimination reached 100% with a processing time of 8 s.

Electrically Evoked Responses in the Rabbit Cortex Induced by Current Steering With Penetrating Optic Nerve Electrodes

“…5,14 Among them, the ON approach may potentially achieve artificial vision over a relatively large area of the visual field. Veraat et al 5,29 first proposed using the ON as a prosthetic target for a iovs.arvojournals.org j ISSN: 1552-5783 blind patient and successfully implanted a cuff electrode with four surface stimulating sites. A similar method was adopted by our group to target the ON in animal experiments, but used a penetrating electrode array as the neural interface.…”

Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses

“…1,[4][5][6] On the contrary, AVS 2 is directly and immediately applicable to any ͑artifi-cial͒ vision-providing/stimulating system that is based on an external ͑e.g., eyeglass-mounted͒ or internal ͑e.g., intraocular camera͒ video-camera system as the first step in the stimulation/processing cascade, such as optic nerve implants, [10][11][12] cortical implants, [13][14][15][16] electric tongue stimulators, [17][18][19][20] and tactile stimulators ͑both electrical and mechanical [21][22][23] ͒. In addition, AVS 2 can interface to infrared ͑IR͒ camera systems to augment the visual cues with thermal information, allowing for "supervision" at night and during adverse weather conditions such as fog.…”

Implantable CMOS biomedical devices

“…According to the site at which the retinal stimulator is placed, the retinal prosthesis device is classified into three categories: epi-retinal stimulation [18][19][20][21], sub-retinal stimulation [22][23][24][25], and suprachoroidal transretinal stimulation (STS) [25,26], which has recently been developed. The stimulation site may be located not only in retinal cells, but also in the pathways to the brain, such as the optic nerves [27], which are the transmission lines of visual information, and, of course, in the visual cortex [28], which is the terminal of the visual information. Figure 5 shows the arrangement of these elements.…”