Development and Characterization of Pathway Measurement Tool (PathMeT)

Over 3.6 million Americans use a wheelchair as a primary means of mobility. Many of these people have active lives and use pedestrian pathways as travel routes. Many of these common pathways cause dangerous whole body vibrations for wheelchair users, so it is important to characterize these surfaces to eliminate pathways that are too rough. A Pathway Measurement Tool, PathMeT, is needed to characterize pathways according to the Americans with Disabilities Act (ADA) standards and regulations. Such aspects to be measured include cross slope, running slope, level change, and a new upcoming regulation, roughness. This paper describes the design, development, testing, and characterization PathMeT with respect to roughness and level change. PathMeT is a manually propelled rolling profiler that uses a laser displacement measurement device and an encoder to create a surface profile. Two testing protocols were developed to assess the precision of PathMeT. The first protocol had three users propel PathMeT over three different surfaces to determine the inter- and intra- reliability of the device using the interclass correlation coefficient (ICC). The inter-rater and intra-rater reliability based on the ICC was found to be .983 and .993, respectively. The second protocol investigated laser placement on the device by propelling PathMeT over a one inch level change and altering the laser location with respect to the back axle. It was observed that the placement had a large effect on the surface profile. As a result, PathMeT is reliable between and within users, and laser placement should undergo further consideration.