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.

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.

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

This single-arm study enrolled 21 participants; 4 did not pass screening, leaving 17 who started the study. Baseline analyses include 12 participants with complete and valid data. Five participants were excluded from analysis, as they were used to refine the study protocol and their data were not collected under consistent conditions and were therefore excluded from the final data analysis.

Each participant completed two laboratory visits (~ 6 hours total). At each visit, one functional task (Drinking or Popcorn) was tested under both control conditions.

Presenting the VGS condition first removed full counterbalancing and may have introduced order effects, such as improved manual performance from task familiarity. Participants were novice users with no prior experience using a robotic arm, which may have influenced performance and subjective feedback. Limited exposure time also restricted their ability to evaluate long-term usability or adaptation effects. The small, heterogeneous sample and controlled lab environment limit generalizability.