Clinical usability, reliability, and repeatability of noncontact scanners in measuring residual limb volume in persons with transtibial amputation.

BACKGROUND: In previous studies, noncontact 3D scanners were found to be the most reliable in measuring volume of the residual limb after a transtibial amputation (TTA). Meanwhile newly developed noncontact scanners became available to measure residual limb volume after TTA but should be tested for clinical usability and reliability. OBJECTIVE: To determine the clinical usability, reliability, and repeatability of noncontact scanners in measuring residual limb volume in persons with a TTA. STUDY DESIGN: Original research report; repeated measurements. METHODS: Three noncontact scanners (Rodin4D, Omega Tracer, and Biosculptor) were used to measure the residual limb volume on two occasions by two observers in 30 persons with an unilateral or bilateral TTA. Clinical usability was assessed as scores of the Post-Study System Usability Questionnaire, participant satisfaction (0-10 scale), and time to take the measurement. RESULTS: The usability score of the Omega Scanner 3D (123.4) and Rodin4D (121.3) was significantly better compared with the Biosculptor (117.8). Participant experience was equal for all. The residual variance was 8.4%, where participant and scanning system explained most of the error variance (80.7%). Repeatability coefficients of the systems were 16.5 cc (Omega Scanner 3D), 26.4 cc (Rodin4D), and 32.8 cc (Biosculptor). The time to perform the measurements was significantly longer (+80 seconds) for the Omega Scanner 3D. CONCLUSIONS: For measuring residual limb volume in TT amputees, Omega software (state version 12.2) combined with the Rodin4D scanner was more usable and reliable than the Rodin 4D or Biosculptor systems, when operated by staff with limited experience and training.

Measurement properties and usability of non-contact scanners for measuring transtibial residual limb volume.

BACKGROUND: Non-contact scanners may have potential for measurement of residual limb volume. Different non-contact scanners have been introduced during the last decades. Reliability and usability (practicality and user friendliness) should be assessed before introducing these systems in clinical practice. OBJECTIVES: The aim of this study was to analyze the measurement properties and usability of four non-contact scanners (TT Design, Omega Scanner, BioSculptor Bioscanner, and Rodin4D Scanner). STUDY DESIGN: Quasi experimental. METHODS: Nine (geometric and residual limb) models were measured on two occasions, each consisting of two sessions, thus in total 4 sessions. In each session, four observers used the four systems for volume measurement. Mean for each model, repeatability coefficients for each system, variance components, and their two-way interactions of measurement conditions were calculated. User satisfaction was evaluated with the Post-Study System Usability Questionnaire. RESULTS: Systematic differences between the systems were found in volume measurements. Most of the variances were explained by the model (97%), while error variance was 3%. Measurement system and the interaction between system and model explained 44% of the error variance. Repeatability coefficient of the systems ranged from 0.101 (Omega Scanner) to 0.131 L (Rodin4D). Differences in Post-Study System Usability Questionnaire scores between the systems were small and not significant. CONCLUSION: The systems were reliable in determining residual limb volume. Measurement systems and the interaction between system and residual limb model explained most of the error variances. The differences in repeatability coefficient and usability between the four CAD/CAM systems were small. Clinical relevance If accurate measurements of residual limb volume are required (in case of research), modern non-contact scanners should be taken in consideration nowadays.