Environmental Localization Mapping and Guidance for Visual Prosthesis Users (SLAM)

This study is driven by the hypothesis that navigation for users of retinal prosthetics can be greatly improved by incorporating Spatial Localization and Mapping (SLAM) and object recognition technology conveying environmental information via a retinal prosthesis and auditory feedback. The investigators will study how effectively the SLAM technology enables the visual prosthesis system to construct a map of the user's environment and locate the user within that map. The technology will be tested both with normally sighted individuals donning a virtual reality headset and with retinal prosthesis users (Argus II).

Study Overview

• Status: Recruiting
• Conditions: Retinitis Pigmentosa; Visual Impairment; Visual Prosthesis
• Intervention / Treatment: Device: Navigation System for Users of a Visual Prosthesis

Detailed Description

About 1.3 million Americans aged 40 and older are legally blind, a majority because of diseases with onset later in life, such as glaucoma and age-related macular degeneration. Second Sight Medical Products (SSMP) has developed the world's first FDA approved retinal implant, Argus II, intended to restore some functional vision for people suffering from retinitis pigmentosa (RP). In this era of smart devices, generic navigation technology, such as GPS mapping apps for smartphones, can provide directions to help guide a blind user from point A to point B. However, these navigational aids do little to enable blind users to form an egocentric understanding of the surroundings, are not suited to navigation indoors, and do nothing to assist in avoiding obstacles to mobility. The Argus II, on the other hand, provides blind users with a limited visual representation of their surroundings that improves users' ability to orient themselves and traverse obstacles, yet lacks features for high-level navigation and semantic interpretation of the surroundings. The proposed study aims to address these limitations of the Argus II through a synergy of state-of-the-art simultaneous localization and mapping (SLAM) and object recognition technologies.

This study is driven by the hypothesis that navigation for users of retinal prosthetics can be greatly improved by incorporating SLAM and object recognition technology conveying environmental information via a retinal prosthesis and auditory feedback. SLAM enables the visual prosthesis system to construct a map of the user's environment and locate the user within that map. The system then provides object location and navigational cues via appropriate sensory modalities enabling the user to mentally form an egocentric map of the environment. Investigators will develop and test a visual prosthesis system which 1) constructs a map of unfamiliar environments and localizes the user using SLAM technology 2) automatically identifies navigationally-relevant objects and landmarks using object recognition and 3) provides sensory feedback for navigation, obstacle avoidance, and object/landmark identification.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Seth Billings, Ph.D.; Phone Number: 4437787462; Email: seth.billings@jhuapl.edu
• Study Contact Backup: Name: Francesco Tenore, Ph.D.; Phone Number: 4437789774; Email: francesco.tenore@jhuapl.edu

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21205
      • Recruiting
      • Johns Hopkins Medicine - Wilmer Eye Institute
      • Contact: Gislin Dagnelie, PhD; Phone Number: 410-614-4822; Email: gislin@lions.med.jhu.edu
      • Principal Investigator: Gislin Dagnelie, PhD
    • Laurel, Maryland, United States, 20723
      • Recruiting
      • Johns Hopkins Applied Physics Laboratory
      • Contact: Seth Billings, Ph.D.; Phone Number: 443-778-7462; Email: seth.billings@jhuapl.edu
      • Principal Investigator: Seth Billings, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Criteria for inclusion of normally sighted individuals:

• Subject speaks English;
• Subjects must be an adult (at least 18 years of age);
• Subject has the cognitive and communication ability to participate in the study (i.e., follow spoken directions, perform tests, and give feedback);
• Subject is willing to conduct psychophysics testing up to 4-6 hours per day of testing on 3-5 consecutive days;
• Subject has visual acuity of 20/40 or better (corrected);
• Subject is capable of understanding participant information materials and giving written informed consent.
• Subject is able to walk unassisted

Criteria for inclusion of Argus II users:

The inclusion criteria for the study are the following:

• Subject is at least 25 years of age;
• Subject has been implanted with the Argus II system;
• Subject's eye has healed from surgery and the surgeon has cleared the subject for programming;
• Subject has the cognitive and communication ability to participate in the study (i.e., follow spoken directions, perform tests, and give feedback);
• Subject is willing to conduct psychophysics testing up to 4-6 hours per day of testing on 3-5 consecutive days;
• Subject is capable of understanding patient information materials and giving written informed consent;
• Subject is able to walk unassisted.

Exclusion criteria for all subjects is the following:

• Subject is unwilling or unable to travel to testing facility for at least 3 days of testing within a one-week timeframe;
• Subject does not speak English;
• Subject has language or hearing impairment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Navigation system for users of a visual prosthesis; This intervention will assess the feasibility of using a navigation system to aid blind users of a visual prosthesis with navigation tasks, by using the navigation system to provide navigational cues through multiple sensory modalities including vision and audition. The navigation system will be designed and developed as part of the proposed research and will interface with the Argus II retinal prosthesis system, which is an FDA approved visual prosthesis. Existing blind users of the Argus II device will be recruited for this study, and the navigation system will interface with these subjects' existing Argus II systems. Sighted subjects will also be recruited for this study, in which case the navigation system will interface with a head-mounted display (such as the Oculus Rift) worn by the sighted subjects that simulates the visual sensory information experienced by blind users of the Argus II retinal implant.

Device: Navigation System for Users of a Visual Prosthesis; We use common psychophysical judgments such as the following: discriminating between two alternatives by saying which is present in the field of view, touching a tablet computer to indicate the apparent location of a target in the frontal plane, and looking for targets by rotating the head and pointing when one is found. We will compare user performance using the Basic system with user performance using the Augmented and Augmented + Modal systems where contextual information associated with the task is conveyed to users via enhanced visual, auditory, and haptic modalities.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy as assessed as ratio of target identification success to total trials	The participant will be asked to identify intended targets in a closed environment, as well as to navigate to intended targets. We will measure accuracy as the total number of successes divided by the total number of trials.	Up to 5 minutes
Trial Time as assessed by mean time duration to identify target	This will be assessed by the mean duration of time to identify intended target (in seconds). For successful trials, the shorter the amount of time to conduct a task, the better the performance on said task.	Up to 5 minutes
Success in psychophysical judgments	This will be assessed by the metric error in distance judgment, that is, the correctness of identification of judgments of target features. Measurement in meters.	Trial Duration: estimated at up to one minute.

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Collaborators: National Eye Institute (NEI); Carnegie Mellon University
• Investigators: Principal Investigator: Seth Billings, Ph.D., Johns Hopkins University

Study record dates

Study Major Dates

• Study Start (Actual): March 16, 2021
• Primary Completion (Estimated): July 30, 2024
• Study Completion (Estimated): July 30, 2024

Study Registration Dates

• First Submitted: April 21, 2020
• First Submitted That Met QC Criteria: April 21, 2020
• First Posted (Actual): April 24, 2020

Study Record Updates

• Last Update Posted (Estimated): June 13, 2023
• Last Update Submitted That Met QC Criteria: June 12, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Retinal Prosthesis; Argus II
• Additional Relevant MeSH Terms: Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Retinal Degeneration; Retinal Diseases; Genetic Diseases, Inborn; Eye Diseases, Hereditary; Retinal Dystrophies; Sensation Disorders; Retinitis; Retinitis Pigmentosa; Vision, Low; Vision Disorders
• Other Study ID Numbers: IRB00228932; 1R01EY029741-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Results from this study will be disseminated through conference presentations and peer-reviewed publications. However, IPD will not be shared outside the study team.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes