Comparative study on the accuracy of Biosculptor’s Bioscanner system in transtibial residual limb circumference measurement

Purpose: This study aimed to examine the accuracy and validity of the Biosculptor’s Bioscanner shape capturing system as a portable measuring device by analysing the changes in transtibial residual limb circumference parameters while walking. Assessment on an amputee could also allow for the clinical usability of the digital scanner to be studied. Methods: To verify the accuracy of the system, the Bioscanner method was compared to the widely used standard anthropometric manual measurement technique (i.e., tape measure). One transtibial prosthetic user was recruited to conduct a walking activity at a normal walking pace for 5 to 15 minutes. Circumferential profiles of the participant were obtained digitally and manually during 2–5 minutes of resting walking intervals. The mean differences between the two methods were compared and percentage differences were calculated. The means were used to calculate the standard error measurement (SEM) and the 95% confidence intervals. Study of the limit of agreement between the two method was also used to validate the accuracy of Bioscanner. Results: The findings showed that both measurements gave a general comparable linear pattern. The averaged results from both methods resulted in only small distinctive differences especially at circumference near the mid-patella tendon. Similarly, the pressure-sensitive areas of the limb resulted in only an average of 2.28% differences between the two measurement techniques. The system showed high reliability and SEM with 0.9. Conclusions: Bioscanner appeared to be comparable with the standard manual method. The Biosculptor system provides the portability, fast, reliable, and high accuracy measurements of the transtibial residual limb circumference, thus, it can be considered as a valuable tool for daily measurement of amputee’s residual limb and pre-prosthetic training.