Retinitis Pigmentosa
Conditions
Keywords
retinitis pigmentosa, Argus II retinal prosthesis system
Brief summary
The proposed project seeks to provide object recognition as a feature in a retinal implant system. Participants will be able to direct an object recognition application to find a desired object in the field of view of the head-mounted camera, and to direct the participant's view towards it through the presentation of a recognizable icon. A prototype system will be developed and evaluated in human subjects in phase I. A full system implementation and a second phase of the trial will be completed in phase II.
Detailed description
The investigators propose to add an object-finding feature to a retinal prosthesis system. To use this feature, the participant will enable a special mode and input the desired object from a set of pre-programmed object types. Imagery from the visible light camera in the system eyeglasses will be processed using object recognition software as the participant scans their head across the room scene. When the object is identified in the scene by the processor, a flashing icon will be output to the epiretinal array in the appropriate position to guide the participant to the physical location of the object. Once located, the system will track the location of the object. There will be two phases to the human subjects evaluation, each run initially through simulations in sighted human subjects, followed by tests in Argus II participants. In phase 1, system evaluation in human subjects at Johns Hopkins UNiversity (JHU) will explore performance in representative tasks and compare prosthetic visual performance without and with the new object finding feature. An important aspect of the evaluation will be the comparison of different icons and presentation modes to assist participants in locating and reaching objects. In phase 2, the system will be integrated into the Argus II video processing unit (VPU), and JHU will conduct human trials that include functional testing of the integrated prototype in representative environments and optimizing the ergonomics of the system, e.g. simultaneous finding and tracking of multiple objects/icons.
Interventions
DEVICEObject recognition subsystem
The object recognition subsystem is an add-on to the Argus II retinal prosthesis system. in the early stage of the study the subsystem will run on a separate processor; in the later stage the subsystem will run in the Argus II user's video processing unit.
Sponsors
Johns Hopkins University
Second Sight Medical Products
Minnesota HealthSolutions
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DEVICE_FEASIBILITY
Masking
NONE
Intervention model description
This is a small sample open label feasibility study for an object recognition and localization system based on machine learning
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* For healthy volunteers: Vision corrected to 20/25, good general health * For retinitis pigmentosa (RP) patients: End-stage retinitis pigmentosa, recipient of an Argus II retinal prosthesis system
Exclusion criteria
* None
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Performance (Completion Time) Locating a Cell Phone and a Person | Time in seconds to complete task. Stationary task time was time to placing hand on the table with the cell phone and mobility task time was time to handshake with the target person. | This outcome measure compares time to task completion without and with modalities of the subsystem for both a stationary and mobility task. For the stationary task, participants were seated in front of a table and a cell phone was placed randomly at the center of one of ten rectangular zones. Participants were asked to find and put their hand on the location of the cell phone. The time of the response was recorded (and the distance from the cell phone, which is a separate primary outcome). For the mobility task, participants were asked to find a target person in an otherwise empty room with dark walls. Once the participant got within arm's length, the target person would initiate a handshake. The time and number of steps (a separate primary outcome) were recorded. If the person wasn't found within 5 minutes, the task was stopped and scored as incomplete. |
| Accuracy (Distance From Target) | Distance to cell phone required up to 30 minutes per mode and distance to a person required up to 45 minutes per mode. | This outcome measure compares task completion (accuracy to a target) without and with modalities of the subsystem for both a stationary and mobility task. For the stationary task, participants were seated in front of a table and a cell phone was placed randomly at the center of one of ten rectangular zones. Participants were asked to find and put their hand on the location of the cell phone. The distance to the cell phone in centimeters was recorded. For the mobility task, participants were asked to find a target person in an otherwise empty room with dark walls. Once the participant got within arm's length, the target person would initiate a handshake. The number of steps were recorded. If the person wasn't found within 5 minutes, the task was stopped and scored as incomplete. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Argus II Users Blind individuals previously implanted with the Argus II retinal prosthesis system were invited to join the study. Data were collected in 4 participants ranging in age from 61 to 90 years old. One participant was female, all identified as white, non-hispanic. | 4 |
| Legally Blind Individuals Individuals with profound visual impairment (best corrected visual acuity worse than 20/500) were invited to join the study. Data were collected in 5 participants ranging in age from 31 to 54 years old. One participant was female, all identified as white, non-hispanic. | 5 |
| Total | 9 |
Baseline characteristics
| Characteristic | Argus II Users | Legally Blind Individuals | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 3 Participants | 0 Participants | 3 Participants |
| Age, Categorical Between 18 and 65 years | 1 Participants | 5 Participants | 6 Participants |
| Age, Continuous | 77 years | 35 years | 54 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 4 Participants | 5 Participants | 9 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 4 Participants | 5 Participants | 9 Participants |
| Region of Enrollment United States | 4 participants | 5 participants | 9 participants |
| Sex: Female, Male Female | 1 Participants | 1 Participants | 2 Participants |
| Sex: Female, Male Male | 3 Participants | 4 Participants | 7 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 4 | 0 / 5 |
| other Total, other adverse events | 0 / 4 | 0 / 5 |
| serious Total, serious adverse events | 0 / 4 | 0 / 5 |
Outcome results
Primary
Accuracy (Distance From Target)
This outcome measure compares task completion (accuracy to a target) without and with modalities of the subsystem for both a stationary and mobility task. For the stationary task, participants were seated in front of a table and a cell phone was placed randomly at the center of one of ten rectangular zones. Participants were asked to find and put their hand on the location of the cell phone. The distance to the cell phone in centimeters was recorded. For the mobility task, participants were asked to find a target person in an otherwise empty room with dark walls. Once the participant got within arm's length, the target person would initiate a handshake. The number of steps were recorded. If the person wasn't found within 5 minutes, the task was stopped and scored as incomplete.
Time frame: Distance to cell phone required up to 30 minutes per mode and distance to a person required up to 45 minutes per mode.
Population: Blind individuals previously implanted with the Argus II retinal prosthesis system were invited to join the study. Data were collected in 4 participants. Individuals with profound visual impairment (best corrected visual acuity worse than 20/500) were invited to join the study. Data were collected in 5 participants.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Argus II Users | Accuracy (Distance From Target) | Stationary, Normal Camera | 7 cm | Standard Deviation 6.6 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Icon | 3 cm | Standard Deviation 1.8 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Tone | 1 cm | Standard Deviation 0.8 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Speech | 2 cm | Standard Deviation 0.7 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Normal Camera plus Tone | 3 cm | Standard Deviation 0.5 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Normal Camera plus Speech | 3. cm | Standard Deviation 1.6 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Tone plus Icon | 1 cm | Standard Deviation 1 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Speech plus Icon | 2 cm | Standard Deviation 1.4 |
| Argus II Users | Accuracy (Distance From Target) | Stationary, Tactile | 0 cm | Standard Deviation 0 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Normal Camera | 52 cm | Standard Deviation 23 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Icon | 17 cm | Standard Deviation 7.3 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Tone | 21 cm | Standard Deviation 8.8 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Speech | 17 cm | Standard Deviation 7.6 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Normal Camera plus Tone | 18 cm | Standard Deviation 8.9 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Normal Camera plus Speech | 16 cm | Standard Deviation 7 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Tone plus Icon | 17 cm | Standard Deviation 7.8 |
| Argus II Users | Accuracy (Distance From Target) | Mobility, Speech plus Icon | 17 cm | Standard Deviation 5 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Speech | 8 cm | Standard Deviation 1.7 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Tone plus Icon | 1 cm | Standard Deviation 0.9 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Tactile | 0 cm | Standard Deviation 0 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Normal Camera | 4 cm | Standard Deviation 7 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Speech plus Icon | 6 cm | Standard Deviation 3.6 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Icon | 4 cm | Standard Deviation 6.1 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Normal Camera | 4 cm | Standard Deviation 4 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Tone | 3 cm | Standard Deviation 1.5 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Normal Camera plus Tone | 4 cm | Standard Deviation 4 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Speech | 2 cm | Standard Deviation 0.9 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Icon | 8 cm | Standard Deviation 7.5 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Normal Camera plus Tone | 1 cm | Standard Deviation 2.4 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Tone plus Icon | 6 cm | Standard Deviation 3.5 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Normal Camera plus Speech | 1 cm | Standard Deviation 1.8 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Tone | 8 cm | Standard Deviation 1.6 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Mobility, Normal Camera plus Speech | 5 cm | Standard Deviation 4.5 |
| Legally Blind Individuals | Accuracy (Distance From Target) | Stationary, Speech plus Icon | 2 cm | Standard Deviation 1.4 |
Primary
Performance (Completion Time) Locating a Cell Phone and a Person
This outcome measure compares time to task completion without and with modalities of the subsystem for both a stationary and mobility task. For the stationary task, participants were seated in front of a table and a cell phone was placed randomly at the center of one of ten rectangular zones. Participants were asked to find and put their hand on the location of the cell phone. The time of the response was recorded (and the distance from the cell phone, which is a separate primary outcome). For the mobility task, participants were asked to find a target person in an otherwise empty room with dark walls. Once the participant got within arm's length, the target person would initiate a handshake. The time and number of steps (a separate primary outcome) were recorded. If the person wasn't found within 5 minutes, the task was stopped and scored as incomplete.
Time frame: Time in seconds to complete task. Stationary task time was time to placing hand on the table with the cell phone and mobility task time was time to handshake with the target person.
Population: Blind individuals previously implanted with the Argus II retinal prosthesis system were invited to join the study. Data were collected in 4 participants. Individuals with profound visual impairment (best corrected visual acuity worse than 20/500) were invited to join the study. Data were collected in 5 participants.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Speech | 19 time (s) | Standard Deviation 4.7 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tactile | 6 time (s) | Standard Deviation 2 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera | 47 time (s) | Standard Deviation 16.6 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera | 135 time (s) | Standard Deviation 3.7 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera plus Tone | 24 time (s) | Standard Deviation 1.7 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Icon | 37 time (s) | Standard Deviation 10.2 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tone | 26 time (s) | Standard Deviation 6.6 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Tone | 35 time (s) | Standard Deviation 0.9 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Speech | 28 time (s) | Standard Deviation 6.6 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera plus Speech | 27 time (s) | Standard Deviation 5.6 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera plus Tone | 29 time (s) | Standard Deviation 9.1 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tone plus Icon | 27 time (s) | Standard Deviation 2.9 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera plus Speech | 27 time (s) | Standard Deviation 11.4 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Tone plus Icon | 36 time (s) | Standard Deviation 1.6 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Icon | 30 time (s) | Standard Deviation 6.1 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Speech plus Icon | 38 time (s) | Standard Deviation 10.5 |
| Argus II Users | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Speech plus Icon | 27 time (s) | Standard Deviation 5.1 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Speech plus Icon | 12 time (s) | Standard Deviation 8.8 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Tone | 17 time (s) | Standard Deviation 4.3 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera plus Speech | 9 time (s) | Standard Deviation 9.1 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera | 11 time (s) | Standard Deviation 13.5 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Icon | 23 time (s) | Standard Deviation 9.7 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tone | 21 time (s) | Standard Deviation 10.4 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Speech | 26 time (s) | Standard Deviation 18.1 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera plus Tone | 16 time (s) | Standard Deviation 17.3 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tone plus Icon | 22 time (s) | Standard Deviation 10.7 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Speech plus Icon | 35 time (s) | Standard Deviation 33.1 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Tactile | 6 time (s) | Standard Deviation 2 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera | 9 time (s) | Standard Deviation 15.6 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Icon | 44 time (s) | Standard Deviation 86.1 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Speech | 15 time (s) | Standard Deviation 1.9 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Mobility, Normal Camera plus Tone | 6 time (s) | Standard Deviation 6.4 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Tone plus Icon | 8 time (s) | Standard Deviation 4.9 |
| Legally Blind Individuals | Performance (Completion Time) Locating a Cell Phone and a Person | Stationary, Normal Camera plus Speech | 12 time (s) | Standard Deviation 9.4 |