Spinal Cord Injury/Disorder
Conditions
Keywords
Assistive devices, Wheelchairs, Activities of daily living, Assistive robotic manipulators
Brief summary
The purpose of this study is to evaluate a new control (i.e., the vision-guided shared (VGS) control) for a wheelchair-mounted assistive robotic manipulator among powered wheelchair users. This study consists of a questionnaire about general demographics, health information, and previous experience with assistive technology. Several tests are also administered to test upper extremity function and ability as well as to test spatial orientation and visualization ability. Participants till then undergo a training phase with the assistive robotic manipulator mounted on a table to assess if they are eligible for participation in the study. Eligible participants will move on to a second training phase where they are asked to learn and practice slightly more complex tasks while using the vision-guided shared controller. After this training, participants are asked to complete two everyday tasks each comprising multiple steps using the VGS control and default teleoperation using a joystick. At the conclusion of the study, researchers conduct a brief semi-structured interview with each participant and obtain more insight on how participants perceive the ease-of-use and usefulness of the vision-guided shared control.
Detailed description
Veterans who use powered mobility devices including those with high-level spinal cord injury (SCI), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS) often experience serious upper extremity impairments. Management and care of upper extremity impairments often involve a range of assistive solutions. However, product availability and technological advancement for manipulation assistance fall far behind those for mobility. Many of these individuals, despite their independent mobility, cannot reach for a glass of water, make a simple meal, and pick up a tooth brush. They still require assistance from a personal caregiver for essential activities of daily living (ADLs) involving reaching and object handling/manipulation. With the rapid advancement of robotics technology, assistive robotic manipulators (ARMs) emerge as a viable solution for assisting Veterans with upper extremity impairments to complete daily tasks involving reaching, object handling, and manipulation. ARMs are often equipped with many degrees of freedom (DOF), but users cannot control all of the DOFs at the same time with a conventional joystick, and need to switch modes quite often to complete even simple manipulation tasks, especially when an ARM gets close to the target and need to be aligned appropriately for manipulation. Thus existing ARMs suffer from the lack of efficiency and effectiveness especially in an unstructured environment. The goal of this project is to develop and evaluate a vision-guided shared (VGS) control to address the effectiveness and efficiency of ARMs for real-world use. The VGS control uses fiducial markers on objects or adaptive tools to make vision-based tracking robust and reliable for real-world applications. It allows a user to initiate any task by moving an ARM close to a tagged object, and the ARM to take over fine manipulation upon detecting the target. This project is to evaluate the new control among powered wheelchair users to complete a set of everyday manipulation tasks. Participants complete two multi-step manipulation tasks using the new VGS control method and the default teleoperation method. Researchers collect outcome measures in terms of efficiency (i.e., task completion time), effectiveness (i.e., task completion success rate), and usability, i.e., NASA Task Load Index (NASA TLX), and System Usability Scale (SUS). Investigators expect to improve manipulation functions of Veterans with upper limb impairments through a more practical and usable implementation of vision-based robotic control and human-robot interaction technologies.
Interventions
DEVICECompare two control methods for a wheelchair-mounted robotic manipulator
Participants will pay one visit to the lab where they will be asked to complete a set of manipulation tasks using a wheelchair-mounted robotic manipulator first using the new custom vision-guided shared (VGS) control, and after a break, using default joystick or switch control. The sequence of the two control methods are fixed.
Sponsors
VA Office of Research and Development
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Intervention model description
All participants receive both interventions sequentially: VGS control followed by default teleoperation control. The study uses a non-randomized, within-subject design, allowing each participant to serve as their own control when comparing outcomes across interventions. We chose not to randomize the order of interventions because findings from pilot testing indicated that completing the study in a randomized order imposed excessive cognitive and physical demands on participants. Pilot participants reported that beginning with the VGS control facilitated learning and adjustment to the subsequent teleoperation control, reducing frustration and fatigue. Additionally, the primary purpose of this study is not to directly compare the two control methods, but rather to explore how VGS may offer advantages in usability, efficiency, and user confidence. Although this fixed sequence may introduce potential order effects, prioritizing participant comfort and ensuring meaningful insights.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 18 years of age and older * using a power wheelchair as primary means of mobility * having self reported difficulties in performing everyday manipulation tasks such as reaching for a glass of water, opening a refrigerator, and picking up a toothbrush
Exclusion criteria
* people with impaired vision * people with pressure ulcers that prevent them from sitting continuously for an extended period of time
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Task Completion Time | 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). | 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. |
| Success Rate | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| NASA Task Load Index (TLX) | 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. |
| System Usability Scale (SUS) | 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. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORDan Ding, PhD
VA Pittsburgh Healthcare System University Drive Division, Pittsburgh, PA
Participant flow
Recruitment details
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.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 52.4 years STANDARD_DEVIATION 18.9 |
| Diagnosis Cerebral Palsy | 3 Participants |
| Diagnosis Muscular Dystrophy | 2 Participants |
| Diagnosis Other | 3 Participants |
| Diagnosis Spinal Cord Injury | 4 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 12 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 11 Participants |
| Sex: Female, Male Female | 3 Participants |
| Sex: Female, Male Male | 9 Participants |
| Spinal Cord Injury (SCI) Functional Index (FI) | 50 T-score (standardized score) STANDARD_DEVIATION 10 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 12 |
| other Total, other adverse events | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 |
Outcome results
None listed