Development and testing of new upper-limb prosthetic devices:Research designs for usability testing Linda Resnik, PT, PhD, OCS
Study Aim • Describe usability testing and designs and methods of usability testing research related to upper-limb prosthetics. • Relevance • Upper-limb prostheses must meet users’ needs or will likely be abandoned. • Participants in 2006 State of the Science Meeting in Prosthetics and Orthotics identified development and evaluation of new, better devices as a high priority.
Concepts • Usability Research • Helps ensure that products are designed, developed, and optimized to meet user needs. • User Testing Studies • Provide feedback on device performance and perceived usability from user’s perspective. Methods include− • Observations of user interacting with device. • User satisfaction reports. • Evaluation of usability of specific device features. • Collection of standardized usability metrics.
Usability Study Design • Designs • Single case studies or case series (most common). • Crossover designs or quasi-experimental studies. • Typically involve small, purposeful, and convenience samples. • Should represent important subsets of users. • Often involves qualitative and quantitative assessments. • Quantitative assessments require reliable and valid measures appropriate for stage of prosthetic development.
Prosthesis Development Cycle Development cycle of prostheses (black). International Classification of Functioning, Disability, and Health components of assessment and their location within cycle (gray). Adapted from Hill W, Stavdahl O, Hermansson LN, Kyberd P, Swanson S, Hubbard S. Functional outcomes in the WHO-ICF model: Establishment of the Upper Limb Prosthetic Outcome Measures Group. J Prosthet Orthot. 2009;21(2):115–19. DOI: 10.1097JPO0b013e3181a1d2dc
Conclusions • Usability research helps ensure that products are designed, developed, and optimized to meet user needs. • Testing method depends on usability attributes being assessed. • Usability testing new to many in prosthetics research, but complements other study types necessary to advance research and practice in upper-limb prosthetics.