Experimental and Clinical Studies of Retinal Stimulation
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- University of Michigan
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Change in shape perception
Study Overview
Brief Summary
The study will evaluate new methods of retinal stimulation and training with the goal of improving the visual ability of retinal prosthesis participants.
Detailed Description
The study will test new ways to make the retinal prosthesis visual perception easier with auditory-visual training and how to make the retinal prosthesis work better at perceiving shapes.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Other
- Masking
- None
Eligibility Criteria
- Ages
- 25 Years to 89 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Must be implanted with an Argus II Retinal Prosthesis system.
- •Have 5 or more electrodes that create a perception with stimulation.
- •Must be willing and able to comply with the protocol testing requirements.
Exclusion Criteria
- •Subjects participating in another investigatory drug or device study
- •Any disease or condition that prevents understanding or communication of informed consent, study demands, and testing protocols.
Arms & Interventions
Retinal stimulation
Alternative stimulus patterns will be tested (vs. baseline). The intervention is the alternative stimulus pattern. The intervention will be tested only in the clinic vs. baseline. The subject will go home with baseline settings. The two alternative stimulus patterns to be tested are asymmetric waveforms and bipolar stimulus.
Intervention: New visual processing unit (VPU) with asymmetric waveforms (Device)
Retinal stimulation
Alternative stimulus patterns will be tested (vs. baseline). The intervention is the alternative stimulus pattern. The intervention will be tested only in the clinic vs. baseline. The subject will go home with baseline settings. The two alternative stimulus patterns to be tested are asymmetric waveforms and bipolar stimulus.
Intervention: New VPU with bipolar stimulation (Device)
Outcomes
Primary Outcomes
Change in shape perception
Time Frame: Baseline, 8 hours
As measured by elongation ratio. The elongation ratio is the ratio of major axis length to minor axis length of an ellipse. Subjects will draw shapes on a touch screen and these shapes will be fit to an ellipse.
Percent change in stimulus thresholds
Time Frame: Baseline, 8 hours
Compare baseline threshold with threshold of modified stimulus parameters. Threshold is measured in microCoulumbs ( the product of stimulus duration and stimulus amplitude).
Secondary Outcomes
No secondary outcomes reported
Investigators
James Weiland
Professor of Biomedical Engineering
University of Michigan