Trial Outcomes & Findings for Evaluation of Vision-Guided Shared Control for Assistive Robotics Manipulators (NCT NCT04323449)
NCT ID: NCT04323449
Last Updated: 2026-02-17
Results Overview
Each task consisted of multiple predefined steps (six for the Drinking Task and ten for the Popcorn Task). Participants performed two trials per task. The time of completion was defined as the total time (in seconds) required to complete all steps, measured from the start cue to task completion. Each step had a 5-minute limit; if not completed within that time, the step was considered failed and assigned the maximum 5-minute duration before proceeding to the next step. Task completion times were summarized using descriptive statistics, with average times calculated across all trials, including failed steps assigned the maximum 5-minute duration.
COMPLETED
NA
21 participants
Two lab visits (<3 hours each). At each visit (drinking; popcorn), task completion time was recorded after each trial for default manual control and for VGS control (2 trials per control; 4 measurements per visit).
2026-02-17
Participant Flow
The investigators recruited participants through three Institutional Review Board (IRB) approved registries. The investigators have also recruited through distributing the recruitment flyer to rehab facilities throughout the VA Pittsburgh Healthcare System and the Center for Assistive Technology at the University of Pittsburgh Medical Center. Four participants did not complete the baseline questionnaire and subsequent visit.
Participant milestones
| Measure |
Single Group: Voice-Guided System (VGS) Followed by Default Teleoperation Control
All participants receive Intervention A (VGS) during Phase 1, followed by Intervention B (Teleoperation Control) during Phase 2.
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|---|---|
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Enrollment/Screening
STARTED
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21
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Enrollment/Screening
COMPLETED
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17
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Enrollment/Screening
NOT COMPLETED
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4
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Interventions/Study Period
STARTED
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17
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Interventions/Study Period
COMPLETED
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12
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Interventions/Study Period
NOT COMPLETED
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5
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Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Evaluation of Vision-Guided Shared Control for Assistive Robotics Manipulators
Baseline characteristics by cohort
| Measure |
Vision-guided Control vs Default Control
n=12 Participants
New custom control method vs default control method
Compare two control methods for a wheelchair-mounted robotic manipulator: Participants pay two visits to the lab where they are asked to complete two multi-step manipulation tasks using a wheelchair-mounted robotic manipulator first using the new custom vision-guided control and then default teleoperation (joystick or switch) control.
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|---|---|
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Age, Continuous
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52.4 years
STANDARD_DEVIATION 18.9 • n=25 Participants
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Sex: Female, Male
Female
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3 Participants
n=25 Participants
|
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Sex: Female, Male
Male
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9 Participants
n=25 Participants
|
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Ethnicity (NIH/OMB)
Hispanic or Latino
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0 Participants
n=25 Participants
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Ethnicity (NIH/OMB)
Not Hispanic or Latino
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12 Participants
n=25 Participants
|
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Ethnicity (NIH/OMB)
Unknown or Not Reported
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0 Participants
n=25 Participants
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Race (NIH/OMB)
American Indian or Alaska Native
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0 Participants
n=25 Participants
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Race (NIH/OMB)
Asian
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1 Participants
n=25 Participants
|
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Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
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0 Participants
n=25 Participants
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Race (NIH/OMB)
Black or African American
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0 Participants
n=25 Participants
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Race (NIH/OMB)
White
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11 Participants
n=25 Participants
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Race (NIH/OMB)
More than one race
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0 Participants
n=25 Participants
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Race (NIH/OMB)
Unknown or Not Reported
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0 Participants
n=25 Participants
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Diagnosis
Spinal Cord Injury
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4 Participants
n=25 Participants
|
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Diagnosis
Cerebral Palsy
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3 Participants
n=25 Participants
|
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Diagnosis
Muscular Dystrophy
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2 Participants
n=25 Participants
|
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Diagnosis
Other
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3 Participants
n=25 Participants
|
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Spinal Cord Injury (SCI) Functional Index (FI)
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50 T-score (standardized score)
STANDARD_DEVIATION 10 • n=25 Participants
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PRIMARY outcome
Timeframe: Two lab visits (<3 hours each). At each visit (drinking; popcorn), task completion time was recorded after each trial for default manual control and for VGS control (2 trials per control; 4 measurements per visit).Population: The first five participants were used to refine the study protocol. As procedural adjustments were made during this early phase, their data were not collected under consistent conditions and were therefore excluded from the final analysis
Each task consisted of multiple predefined steps (six for the Drinking Task and ten for the Popcorn Task). Participants performed two trials per task. The time of completion was defined as the total time (in seconds) required to complete all steps, measured from the start cue to task completion. Each step had a 5-minute limit; if not completed within that time, the step was considered failed and assigned the maximum 5-minute duration before proceeding to the next step. Task completion times were summarized using descriptive statistics, with average times calculated across all trials, including failed steps assigned the maximum 5-minute duration.
Outcome measures
| Measure |
Vision-guided Control vs Default Control
n=12 Participants
New custom control method (VGS) vs default method
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|---|---|
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Task Completion Time
Drinking Task using VGS Control
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333.7 seconds
Standard Deviation 211.3
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Task Completion Time
Drinking Task with Default Control
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604.7 seconds
Standard Deviation 368.9
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Task Completion Time
Popcorn Task Using VGS Control
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748.5 seconds
Standard Deviation 204.3
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Task Completion Time
Popcorn Task Using Default Control
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1128.9 seconds
Standard Deviation 389.6
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PRIMARY outcome
Timeframe: Two lab visits (<3 hours each). At each visit (drinking; popcorn), success rate was recorded after each trial for default manual control and for VGS control (2 trials per control; 4 measurements per visit).Success rate was defined as the number of task steps successfully completed within the 5-minute limit, out of a total of 12 trials (6 steps performed twice) for drinking task and 20 trials (10 steps performed twice) for popcorn task. Each trial not completed within 5 minutes was counted as a failure.
Outcome measures
| Measure |
Vision-guided Control vs Default Control
n=12 Participants
New custom control method (VGS) vs default method
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|---|---|
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Success Rate
Drinking Task using VGS Control
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95.8 Percentage of successful steps
Standard Deviation 6.6
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Success Rate
Drinking Task with Default Control
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86.1 Percentage of successful steps
Standard Deviation 8.9
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Success Rate
Popcorn Task Using VGS Control
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93.8 Percentage of successful steps
Standard Deviation 5.7
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Success Rate
Popcorn Task Using Default Control
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89.2 Percentage of successful steps
Standard Deviation 10.2
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SECONDARY outcome
Timeframe: Two lab visits (<3 hours each). At each visit (drinking; popcorn), participants completed 2 default manual control and 2 VGS control trials; NASA-TLX was completed once per control method after both trials (2 per visit).The NASA Task Load Index (NASA-TLX) assesses participants' subjective workload after completing all tasks under each control method. It includes six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration. Each dimension is rated from 0 to 100, with higher scores indicating greater perceived workload. The overall task load index is calculated as the average of the six dimension scores, resulting in a total score ranging from 0 to 100, where higher scores represent greater overall task load.
Outcome measures
| Measure |
Vision-guided Control vs Default Control
n=12 Participants
New custom control method (VGS) vs default method
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|---|---|
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NASA Task Load Index (TLX)
Drinking Task using VGS Control
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25.8 Score (0-100)
Standard Deviation 17.7
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NASA Task Load Index (TLX)
Drinking Task with Default Control
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41.3 Score (0-100)
Standard Deviation 22.3
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NASA Task Load Index (TLX)
Popcorn Task Using VGS Control
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30 Score (0-100)
Standard Deviation 14.7
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NASA Task Load Index (TLX)
Popcorn Task Using Default Control
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42.4 Score (0-100)
Standard Deviation 19.2
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SECONDARY outcome
Timeframe: Two lab visits (<3 hours each). At each visit (drinking; popcorn), participants completed 2 default manual control and 2 VGS control trials; SUS was completed once per control method after both trials (2 per visit).The System Usability Scale (SUS) is a 10-item questionnaire assessing perceived usability. Each item is rated on a 5-point scale, and the total SUS score is converted to a 0-100 scale, with higher scores indicating better usability.
Outcome measures
| Measure |
Vision-guided Control vs Default Control
n=12 Participants
New custom control method (VGS) vs default method
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|---|---|
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System Usability Scale (SUS)
Drinking Task using VGS Control
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72.1 Score (0-100)
Standard Deviation 19.7
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System Usability Scale (SUS)
Drinking Task with Default Control
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65.6 Score (0-100)
Standard Deviation 19.2
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System Usability Scale (SUS)
Popcorn Task Using VGS Control
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69.2 Score (0-100)
Standard Deviation 22.9
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System Usability Scale (SUS)
Popcorn Task using Default Control
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64.6 Score (0-100)
Standard Deviation 27.9
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Adverse Events
Vision-guided Control vs Default Teleoperation Control
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place