A means to accommodate residual limb movement during optical scanning: a technical note

Area of Science:

• Biomedical Engineering
• Prosthetics and Orthotics
• Medical Imaging

Background:

• Accurate imaging of residual limbs is crucial for prosthetic research and development.
• Subject movement during scanning can introduce significant artifacts, compromising data integrity.
• Existing imaging techniques may not adequately address motion in transtibial amputees.

Purpose of the Study:

• To develop and evaluate a novel technique for correcting subject motion during the imaging of transtibial amputee residual limbs.
• To improve the accuracy of high-resolution shape and volume measurements of the residual limb.
• To enhance the utility of imaging in prosthetics research concerning residual limb changes.

Main Methods:

• A motion correction technique using small reflective markers placed on the residual limb.
• Tracking marker motion with two stationary cameras during a 1.5-second scan interval.
• Generating translational and rotational transformation matrices to correct for detected limb motion.

Main Results:

• The technique demonstrated good performance in correcting moderate (2-4 mm) to high (5-8 mm) motion.
• Motion correction reduced the difference in mean absolute cross-sectional area by approximately 50% compared to uncorrected scans.
• The algorithm showed limitations with exaggerated motion (>= 9 mm), especially outside the marker-defined region.

Conclusions:

• The developed motion correction method is effective for improving imaging accuracy in prosthetics research.
• This technique is valuable for studies investigating residual limb shape or volume changes in transtibial amputees.
• Further refinement may be needed to address extreme motion scenarios for comprehensive application.