Precise 3D Photogrammetry Measurement of Human Body Surface

DESCRIPTION (provided by applicant): Precise 3-Dimensinal (3D) measurement of human body is essential for prostheses and orthoses design and manufacturing. Traditionally, plaster bandage was used for molding and producing negative mold of the residual limb. It is a laborious, time-consuming, and discomfort procedure. The quality of the resultant product is subject to practitioner's experience with poor repeatability and controllability. Recently, laser scanning has been used to provide 3D measurement of the surface and to reconstruct the 3D surface via a reverse engineering approach for its ease of use and high accuracy. However, the long acquisition time (usually around minutes) inevitably introduces movement-related distortion. Also the high cost of laser scanning equipment (usually 30,000-50,000) hinders its wide adoption This STTR Phase I project proposed a non-contact and cost-effective technology based on Close Range Digital Photogrammetry (CRDP) to provide precise 3D measurement of human body surface at a lower cost and shorter acquisition time (in seconds), compared to laser scanning. The proposed method will achieve 1 mm accuracy. In Phase I, the method will be tested experimentally using a breadboard system with measurements taken on a sample human residual limb mold. The system hardware includes commercial grade digital cameras and a light pattern projector, with system cost below 3,000. The CRDP algorithm and software will be developed on Windows PC platform and the results of 3D surface reconstruction will be validated in Phase I. The accuracy of the measurement results will be evaluated by calculating the Root-Mean-Squared error. The system performance will be validated by using standard geometry and by comparison with results from laser scanning. The ultimate goal is to develop a complete 3D computer aided Measurement/Design/Manufacturing flow to substantially improve the productivity of the prosthetic and orthotic service and lower the cost. According to the figures from the American Academy of Orthotists and Prosthetists, About 6,000 prosthetists--medical professionals who design and fit prostheses--served 1.9 million amputees within the United States. A prosthetic device can cost between 2,500 and 50,000 and an adult usually needs to replace it every one to three years. The proposed CRDP technology provides an innovative low-cost solution to address the public health need. The CRDP technology will benefit the 1.9 million people with limb loss. Clinics and private companies can deliver orthotic and prosthetic service at lower cost in a shorter time. PUBLIC HEALTH RELEVANCE: According to federal data estimates, about 6,000 prosthetists served 1.9 million amputees within the United States, A prosthetic device can cost between 2,500 and 50,000 and an adult usually needs to replace it every one to three years. The proposed Close Range Digital Photogrammetry CRDP technology provides an innovative solution with low cost and high efficiency to address the public health need. Clinics and private companies can deliver orthotic and prosthetic service at a much lower cost in a shorter time.