Environmental Localization Mapping and Guidance for Visual Prosthesis Users
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 26
- 试验地点
- 2
- 主要终点
- Duration of Time to Complete Navigational Tasks as Assessed by the Mean Duration of Travel in Seconds Normalized by the Nominal Path Distance in Meters
研究概览
简要总结
This study is driven by the hypothesis that independent navigation by blind users of visual prosthetic devices can be greatly aided by use of an autonomous navigational aid that provides information about the environment and guidance for navigation through multimodal sensory cues. For this study, the investigators developed a navigation system that uses on-board sensing to map the user's environment and compute navigable paths to desired destinations in real-time. Information regarding obstacles and directional guidance is communicated to the user via a combination of sensory modalities including limited vision (through the user's visual prosthesis), haptic, and audio cues. This study evaluates how effectively this navigational aid improves prosthetic vision users' ability to perform navigational tasks. The participants for this study include both retinal prosthesis users of the Argus II Retinal Prosthesis System (Argus II) and normally sighted individuals who use a virtual reality headset to simulate the limited vision of the Argus II system.
详细描述
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 the users 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 scene recognition technologies.
This study is driven by the hypothesis that independent navigation by blind users of visual prosthetic devices can be greatly aided by use of an autonomous navigational aid that provides information about the environment and guidance for navigation through multimodal sensory cues. The investigators developed a navigation system that uses on-board sensing and SLAM-based algorithms to continuously construct a map of the user's environment and locate the user within that map in real-time. On-board path planning algorithms compute optimal navigation routes to reach desired destinations based on the constructed map. The system then communicates obstacle locations and navigational cues to the user while navigating via a combination of sensory modalities. The participants for this study include blind Argus II users, who use their retinal implant for vision, and normally sighted individuals, who use a virtual reality headset to simulate the limited vision of a retinal prosthesis.
The sensory modalities used by the navigational aid to communicate information back to the user include:
- Limited vision is provided via the user's visual prosthesis, with the Argus II retinal implant supporting an image size of 10 x 6 pixels spanning approximately 18 x 11 degrees field-of-view. Images sent to the visual implant are derived from video frames provided by forward-facing cameras integrated within headgear worn by the user. Three forms of vision feedback are evaluated in this study including: 1) the standard vision output of the Argus II (which uses texture-based processing including difference-of-Gaussian and contrast enhancement filters), 2) an enhanced depth-based vision mode that uses the depth sensing capabilities of the navigational aid to highlight above-ground obstacles, and 3) a high field of view depth-based vision mode that doubles the pixel size and field of view of the visual feedback in each dimension. The depth-vision modes display only above-ground obstacles with increasing brightness relative to decreasing distance from the user; the ground and obstacles beyond a threshold distance are not displayed in order to declutter the visual scene. The high field-of-view depth-vision mode is only utilized by normally sighted participants, as this mode exceeds the vision capabilities of the Argus II implant.
- Haptic cues indicate the direction in which the user should advance in order to follow the path computed by the navigational aid to reach a target destination. The haptic cues are generated by vibrators situated at five positions located left-to-right along the users forehead, which are built into user-worn headgear. The five vibration points indicate for the user to turn in directions: "far left", "slight left", "straight ahead", "slight right", and "far right".
- Audio cues provide an audible alert when the user approaches an obstacle within 1.5 feet and provide verbal updates on the remaining distance to reach the destination along the path computed by the navigational aid.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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.
研究组 & 干预措施
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Argus Vision (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Depth Vision (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Depth Vision with Haptic / Audio (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Haptic / Audio (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: High Field-of-View Depth Vision (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Distance test vision mode: Low Resolution / Low Field-of-View (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Distance test vision mode: Low Resolution / High Field-of-View (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Distance test vision mode: High Resolution / Low Field-of-View (Device)
Evaluation of normally sighted participants using a simulated visual prosthesis
All normally sighted participants will be assigned to this arm of the study. This study group will perform all experiments using a virtual reality headset (Oculus Go) to simulate the limited vision of a retinal prosthesis system. This study group will include all interventions, including those that both match and exceed the visual performance of the Argus II system.
干预措施: Distance test vision mode: High Resolution / High Field-of-View (Device)
Evaluation of blind participants using the Argus II retinal prosthesis
All blind participants who have been implanted with the Argus II Retinal Prosthesis System will be assigned to this arm of the study. This study group will be limited to performing a subset of the interventions including only those that do not exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Argus Vision (Device)
Evaluation of blind participants using the Argus II retinal prosthesis
All blind participants who have been implanted with the Argus II Retinal Prosthesis System will be assigned to this arm of the study. This study group will be limited to performing a subset of the interventions including only those that do not exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Depth Vision (Device)
Evaluation of blind participants using the Argus II retinal prosthesis
All blind participants who have been implanted with the Argus II Retinal Prosthesis System will be assigned to this arm of the study. This study group will be limited to performing a subset of the interventions including only those that do not exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Depth Vision with Haptic / Audio (Device)
Evaluation of blind participants using the Argus II retinal prosthesis
All blind participants who have been implanted with the Argus II Retinal Prosthesis System will be assigned to this arm of the study. This study group will be limited to performing a subset of the interventions including only those that do not exceed the visual performance of the Argus II system.
干预措施: Navigation system mode: Haptic / Audio (Device)
Evaluation of blind participants using the Argus II retinal prosthesis
All blind participants who have been implanted with the Argus II Retinal Prosthesis System will be assigned to this arm of the study. This study group will be limited to performing a subset of the interventions including only those that do not exceed the visual performance of the Argus II system.
干预措施: Distance test vision mode: Low Resolution / Low Field-of-View (Device)
结局指标
主要结局
Duration of Time to Complete Navigational Tasks as Assessed by the Mean Duration of Travel in Seconds Normalized by the Nominal Path Distance in Meters
时间窗: Up to 7 minutes for each navigation task, on Day 1 or Day 2
Participants will be asked to complete the navigation tasks of crossing an obstacle field approximately 6 meters in length and navigating to a target destination located about 20 - 30 meters away. The normalized duration of time to complete each navigation task will be measured in seconds. To account for variability in the path distances of different trials, the measured time will be normalized by a reference (nominal) path distance in meters associated with the configuration of each trial. The mean normalized time across all trials will be computed for each intervention.
Distance Traversed to Complete Navigational Tasks as Assessed by the Mean Distance Traveled in Meters Normalized by the Nominal Path Distance in Meters
时间窗: Up to 7 minutes for each navigation task, on Day 1 or Day 2
Participants will be asked to complete the navigation tasks of crossing an obstacle field approximately 6 meters in length and navigating to a target destination located about 20 - 30 meters away. The normalized distance traversed to complete each navigation task will be measured. To account for variability in the path distances of different trials, the measured distance will be normalized by a reference (nominal) path distance in meters associated with the configuration of each trial. The mean normalized distance across all trials will be computed for each intervention.
Obstacle Avoidance While Completing Navigational Tasks as Assessed by the Mean Number of Contacts With Obstacles Normalized by the Nominal Path Distance in Meters
时间窗: Up to 7 minutes for each navigation task, on Day 1 or Day 2
Participants will be asked to complete the navigation tasks of crossing an obstacle field approximately 6 meters in length and navigating to a target destination located about 20 - 30 meters away. The number of contacts with obstacles encountered while completing each navigation task will be measured. To account for variability in the path distances of different trials, the number of contacts will be normalized by a reference (nominal) path distance in meters associated with the configuration of each trial. The mean normalized number of contacts with obstacles across all trials will be computed for each intervention.
Success in Completing Navigational Tasks as Assessed by the Mean Percentage of Trials Where Participants Successfully Reached the Intended Destination
时间窗: Up to 7 minutes for each navigation task, on Day 1 or Day 2
Participants will be asked to navigate to a target destination located about 20 - 30 meters away. We will measure success rate as the mean number of trials for which each participants successfully reached the intended destination divided by the total number of trials performed by that participant for each intervention.
Accuracy of Relative Distance Judgments as Assessed by the Percentage of Correct Responses
时间窗: Up to 60 seconds for each discrimination task, on Day 1 or Day 2
Participants will be presented with two physical objects and asked to identify which of the objects is the nearer one after walking a controlled distance down a centerline oriented between the objects. We will measure accuracy as the percentage of correct responses (the total number of correct responses divided by the total number of trials times 100).
次要结局
未报告次要终点