Background: 3D scanners used to obtain the three dimensional (3D) shapes of body parts offering an alternative to the traditional custom techniques such as casting with a variety of potential advantages. However, 3D scanners are normally very expensive and not affordable and accessible for most orthotists and prosthetists especially in the developing countries. Therefore, the aim of this study was to evaluate the validity and reliability of a low-cost handheld and affordable 3D scanner (3Dsystems, sense) for use in orthotics and prosthetics.
Methods: The validity and reliability of the 3D Sense scanner was assessed through the repeated scanning and measurements of the predefined circumferences of the stumps of 4 transtibial amputees and 8 body cast models. Two assessors performed digital scanning and tape measurements in 2 different days, each consisting three trials per condition/day. Reliability of the 3D sense scanner was assessed by investigating between trials, assessors and day’s reliability using Intraclass Correlation Coefficients. Standard error of measurement (SEM) were also calculated to assess measurement error. Validity of the 3D sense scanner was assessed using correlation analysis, mean percentage error (the mean differences between scanner and tape measures) and Bland-Altman statistics.
Results: The 3D Sense scanner provides stumps and body cast models measurements with similar reliability to the tape measurement. Reliability coefficients for the 3D scanner are relatively high (ICC). The ICCs all are near 1.0 and SEMs all are ranging from 0.06 to 0.10. The 3D Sense scanner demonstrated an excellent validity. There were a significant positive correlations between the 3D scanner and tape measures for both stumps and body cast models measurements (r > 0.850; p < 0.0001). The measurement error between the 3D scanner and tape is very low as indicated by mean differences close to zero.
Conclusions: This study introduces a low-cost handheld and affordable 3D scanner which proven to be a valid and reliable clinical tool in orthotics and prosthetics. This 3D scanner would have enormous and powerful clinical applicability resulting in valid and reliable digital information of body segments for computer-aided design of orthotics and prosthetics.