Trial Outcomes & Findings for The Perceptual Experience of Argus II Users (NCT NCT05285618)
NCT ID: NCT05285618
Last Updated: 2025-01-01
Results Overview
Number of phosphenes perceived in response to paired-electrode stimulation across 5 spatial distances and 7 temporal interpulse delays. Phosphenes are brief sensations of light or visual flashes that occur in the absence of an external light source. A response is counted as a phosphene if the participant reports any visual sensation consistent with a flash of light.
COMPLETED
NA
6 participants
during single-session testing
2025-01-01
Participant Flow
Participant milestones
| Measure |
Argus II Users
This Basic Experimental Studies Involving Humans (BESH) study investigates phosphene perception and performance factors in blind participants implanted with the Argus II retinal prosthesis system. Using paired-electrode stimulation, we analyze how phosphene shape and number are influenced by neuroanatomical factors, stimulus parameters, and spatial offsets. Additionally, we examine the causes of high current thresholds and limited spatial resolution, which impede pattern vision in Argus II devices. This research aims to provide insights for optimizing stimulation strategies and improving retinal prosthesis design.
Argus II: Participants used the Argus II retinal prosthesis system in both experiments to perform visual perception tasks.
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|---|---|
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Overall Study
STARTED
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6
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Overall Study
COMPLETED
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6
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Overall Study
NOT COMPLETED
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0
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Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
The Perceptual Experience of Argus II Users
Baseline characteristics by cohort
| Measure |
Argus II Users
n=6 Participants
Blind individuals previously implanted with the Argus II retinal prosthesis system participated in two experiments. The first experiment tested phosphene perception by varying the spatial offsets and temporal delays between pairs of electrodes. The second experiment tested the effect of gamification on circle localization and motion discrimination tasks.
Argus II: Participants used the Argus II retinal prosthesis system in both experiments to perform visual perception tasks.
Gamification: Participants performed gamified versions of circle localization and motion discrimination tasks designed to improve engagement and task performance.
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Age, Categorical
<=18 years
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0 Participants
n=5 Participants
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Age, Categorical
Between 18 and 65 years
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3 Participants
n=5 Participants
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Age, Categorical
>=65 years
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3 Participants
n=5 Participants
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Sex: Female, Male
Female
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1 Participants
n=5 Participants
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Sex: Female, Male
Male
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5 Participants
n=5 Participants
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Race (NIH/OMB)
American Indian or Alaska Native
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0 Participants
n=5 Participants
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Race (NIH/OMB)
Asian
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0 Participants
n=5 Participants
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Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
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0 Participants
n=5 Participants
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Race (NIH/OMB)
Black or African American
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0 Participants
n=5 Participants
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Race (NIH/OMB)
White
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6 Participants
n=5 Participants
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Race (NIH/OMB)
More than one race
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0 Participants
n=5 Participants
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Race (NIH/OMB)
Unknown or Not Reported
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0 Participants
n=5 Participants
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Region of Enrollment
United States
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6 participants
n=5 Participants
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PRIMARY outcome
Timeframe: during single-session testingPopulation: Data were collected in 6 participants ranging in age from 45 to 88 years old. One participant was female. All identified as white, non-hispanic.
Number of phosphenes perceived in response to paired-electrode stimulation across 5 spatial distances and 7 temporal interpulse delays. Phosphenes are brief sensations of light or visual flashes that occur in the absence of an external light source. A response is counted as a phosphene if the participant reports any visual sensation consistent with a flash of light.
Outcome measures
| Measure |
Argus II Users
n=6 Participants
Blind individuals previously implanted with the Argus II retinal prosthesis system were invited to join the study.
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|---|---|
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Number of Phosphenes Perceived
Delay 0
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1.09 number of phosphenes
Standard Deviation 0.910
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Number of Phosphenes Perceived
Delay 4ms
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1.43 number of phosphenes
Standard Deviation 0.555
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Number of Phosphenes Perceived
Delay 12ms
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1.46 number of phosphenes
Standard Deviation 0.538
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Number of Phosphenes Perceived
Delay 29ms
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1.41 number of phosphenes
Standard Deviation 0.570
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Number of Phosphenes Perceived
Delay 50ms
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1.48 number of phosphenes
Standard Deviation 0.511
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Number of Phosphenes Perceived
Delay 178ms
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1.37 number of phosphenes
Standard Deviation 0.544
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Number of Phosphenes Perceived
Delay 419ms
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1.36 number of phosphenes
Standard Deviation 0.639
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Number of Phosphenes Perceived
Distance (808 - 1834um)
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1.24 number of phosphenes
Standard Deviation 0.642
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Number of Phosphenes Perceived
Distance (1835 - 2856um)
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1.44 number of phosphenes
Standard Deviation 0.685
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Number of Phosphenes Perceived
Distance (2857 - 3877um)
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1.31 number of phosphenes
Standard Deviation 0.622
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Number of Phosphenes Perceived
Distance (3878 - 4898um)
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1.41 number of phosphenes
Standard Deviation 0.663
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Number of Phosphenes Perceived
Distance (4899 - 5920um)
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1.45 number of phosphenes
Standard Deviation 0.631
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Adverse Events
Argus II Users
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Michael Beyeler
University of California, Santa Barbara
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place