Dataset: Propulsion cost changes of ultra-lightweight manual wheelchairs after one year of simulated use Jacob Misch 1,2 Stephen Sprigle 1,2,3 1 Rehabilitation Engineering and Applied Research Lab, Georgia Institute of Technology, Atlanta, Georgia, United States of America 2 School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America 3 School of Industrial Design, Georgia Institute of Technology, Atlanta, Georgia, United States of America Email contact: rearlab@gatech.edu This project was supported by the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) through grant #: 90IFRE0036-01-02. NIDILRR is a Center within the United States Department of Health and Human Services (HHS) Administration for Community Living (ACL). The contents of this article do not necessarily reflect the views of the Department of Health and Human Services. This work was also supported in part by internal funding from the Rehabilitation Engineering and Applied Research (REAR) Lab. This data was used in the manuscript submitted to ASME Open Journal of Engineering, with manuscript number: AOJE-22-1079 Title: Propulsion cost changes of ultra-lightweight manual wheelchairs after one year of simulated use Authors: Jacob Misch, Stephen Sprigle DOI: The methods of data collection for the main outcome metric (propulsion cost) are summarized in the journal article, with references to more detailed articles. The data analysis methods are described in depth within the journal article associated with this dataset, which is open access. Data was collected between January 2021 to August 2021. This workbook includes a reference worksheet with accelerometer placement and two worksheets with data: "Data" - Data related to the main outcome metric (propulsion cost) as well as geometric measurements of each tested wheelchair. More detailed descriptors of the data and column headers can be found in the worksheet. "Statistical Analysis Results" - Data related to the performance comparisons between folding and rigid frames, as well as pre- and post-simulated use ("New" versus "Worn" conditions). Ratios and corresponding 95% confidence intervals are reported. An example plot is shown to illustrate the 'Superior', 'Inferior', and 'Comparable' performance classifications. Plots of the two main comparisons are also included. "Data" columns: FRAME_TYPE - The style of manual wheelchair for that frame. A total of 4 folding frames and 2 rigid frames were used in this investigation. CONFIGURATION - The identifier given to the wheelchair configuration to represent the unique combination of drive wheel, caster, and caster fork. DRIVE_WHEEL - The name of each tested drive wheel. "Primo Orion" was the make and model of the tire used for all tested chairs in this study. This pneumatic tire was inflated to 75 psi and fitted to a 24"-diameter metal-spoked wheel. CASTER_WHEEL - The name of each tested caster. Each configuration utilized one pair of solid urethane casters (Primo 5x1" solid casters). SYSTEM_MASS - The combined mass of the wheelchair frame, components, and the AMPS, reported in kilograms (kg). The AMPS is constructed to weigh approximately 80 kg and represent the overall size, shape, and weight distribution of a typical wheelchair user. WEIGHT_DISTRIBUTION - The percentage of the total system mass supported by the rear wheels. The nominal or target weight distribution was approximately 70% of the total mass over the rear wheels, with the other 30% supported by the front casters. This was measured individually for each configuration. SURFACE - The surface on which the tests are conducted (Brick, Grates, Sidewalk, and Tile). SIMULATED_USE_STAGE - The phase of simulated usage when the propulsion cost data was measured. "New" indicates the propulsion cost values were taken before the chair was driven on the wheelchair carousel track, and "Worn" indicates the propulsion cost values were measured post-simulated use. PROPULSION COST - The propulsion cost (energy per distance traveled) for the straight maneuver, reported in joules per meter (J/m). "Statistical Analysis Results" columns: COMPARISON - The comparison that is being made using the ratio of interest in the "RATIO" column. For this study, the two options were comparing folding versus rigid frames or comparing new versus worn frames. RATIO - The identifier given to the comparison of interest. (New Folding)/(New Rigid), for example, compares the propulsion costs of the new folding frames against the propulsion costs of new rigid frames. A point estimate value of 1.0000 would indicate those two groupings have identical propulsion costs. A point estimate below 1.0000 indicates the group in the numerator (New Folding, in this example) has lower propulsion costs, or superior performance, than the group in the denominator. SURFACE - The surface on which the tests are conducted (Concrete or Carpet). POINT_ESTIMATE - The point estimate of the ratio (test mean / reference mean), calculated as indicated in the "RATIO" column. LOWER_BOUND - The lower extent of the 95% confidence interval built around the point estimate. UPPER_BOUND - The upper extent of the 95% confidence interval built around the point estimate. CLASSIFICATION - One of three outcomes (superior, inferior, comparable). The extents of each 95% confidence interval are compared against equivalence limits (±5% for propulsion cost, or 0.95 to 1.05). Confidence intervals that are completely below 0.95 are considered 'Superior' as the test configuration (group in the numerator) experienced lower propulsion costs the reference configuration (group in the denominator). Similarly, confidence intervals completely above 1.05 are considered 'Inferior' as the test configuration experienced higher propulsion costs, reflecting worse or inferior performance. Confidence intervals that cross one or both limits, or that reside completely within the limits, are considered 'Comparable' as the test and reference groups both exhibited similar performances. Methods: The objective of this study was to measure the propulsion efficiency of folding and rigid manual wheelchairs equipped with standardized components (drive wheels, tires, and casters) and loading conditions (occupant mass, weight distribution). A wheelchair-propelling robot [1] was used to propel the wheelchair with standardized propulsion characteristics. Mechanical energy expenditure and travel distance were measured with sensors integrated within the robotic propulsion device. These methods are similar to those used to capture propulsion efficiency as described in [2,3]. Six aluminum ultra-lightweight manual wheelchair frames were used in this study, including four folding (Cougar by Drive Medical; Catalyst 5 by Ki Mobility; Flexx by Karman Healthcare; Champion by Küschall) and two rigid (Quickie 5R by Sunrise Medical; K-Series by Küschall) frames. Each configuration was equipped with 24x1-3/8" tires inflated to 75 psi on metal-spoked wheels, with solid 5x1" urethane casters and rigid aluminum caster forks. The Anatomical Model Propulsion System (AMPS), the wheelchair-propelling robot, propelled the wheelchair (in each configuration) in a straight line approximately 10 meters forward, at a speed of 1 meter per second, across two common surfaces: smooth concrete and low-pile carpet. Ten of these over-ground trials were run per surface for each configuration, resulting in 120 total AMPS trials. Propulsion costs were calculated by summing the energy supplied by the AMPS to the wheelchair, and dividing that value by the total distance traveled during the trial. These values were used to compare the propulsion efficiencies between configurations. A carousel-like circle track tester was used to drive each "new" chair approximately 511 kilometers at a speed of 1 meter per second with a wheelchair dummy (mass of 80 kilograms) loaded into the seat. This simulated approximately one year of everyday travel over common surfaces. AMPS-based performance testing was then conducted on each "worn" (post-simulated use) wheelchair for an additional 120 AMPS trials. The "new" and "worn" propulsion costs were compared to assess the impact of everyday usage on the performance of ultra-lightweight aluminum wheelchairs in general, and propulsion costs were additionally compared between rigid and folding frames to assess the impact of frame style on overall propulsion efficiency. (More detailed methods can be found in the associated article in ASME Open Journal of Engineering.) References in Methods: [1] Liles, H.; Huang, M.; Caspall, J.; & Sprigle, S. (2014). "Design of a Robotic System to Measure Propulsion Work of Over-Ground Wheelchair Maneuvers". IEEE Transactions on Neural Systems and Rehabilitation Engineering, Vol. 23, no.6, pp. 983-991, 2014. [2] Misch, J.; & Sprigle, S. (2022). "Estimating whole-body vibration limits of manual wheelchair mobility over common surfaces". Rehabil Assist Technol Eng, 2022. doi: 10.1177/20556683221092322. [3] Misch, J.; & Sprigle, S. (2021) "Effects of wheels and tires on high-strength lightweight wheelchair propulsion cost using a robotic wheelchair tester". Disabil Rehabil: Assist Technol, 2021. doi: 10.1080/17483107.2021.2012274.