The core of the paper is focused on the experimental characterization of four different 3D laser scanners based on Time
of Flight principle, through the extraction of resolution, accuracy and uncertainty parameters from specifically designed
3D test objects. The testing process leads to four results: z-uncertainty, xy-resolution z-resolution and z-accuracy. The
first is obtained by the evaluation of random residuals from the 3D capture of a planar target, the second from the
scanner response to an abrupt z-jump, and the last two from direct evaluation of the image extracted by different
geometric features progressively closer each other. The aim of this research is to suggest a low cost characterization
process, mainly based on calibrated test object easy to duplicate, that allow an objective and reliable comparison between
3D TOF scanner performances.
Resolution analysis represents a 2D imaging topic for the use of particular targets for equipment characterization. These
concepts can be extended in 3D imaging through the use of specific tridimensional target object. The core of this paper is
focused on experimental characterization of seven different 3D laser scanner through the extraction of resolution,
accuracy and uncertainly parameters from 3D target object. The process of every single range map defined by the same
resolution leads to different results as z-resolution, optical resolution, linear and angular accuracy. The aim of this
research is to suggest a characterization process mainly based on resolution and accuracy parameters that allow a reliable
comparison between 3D scanner performances.
The paper presents an innovative approach totally based on digital data to optimize lower limb socket prosthesis design. This approach is based on a stump's detailed geometric model and provides a substitute to plaster cast obtained through the traditional manual methodology with a physical model, realized with Rapid Prototyping technologies; this physical model will be used for the socket lamination. The paper discusses a methodology to reconstruct a 3D geometric model of the stump able to describe with high accuracy and detail the complete structure subdivided into bones, soft tissues,
muscular masses and dermis. Some different technologies are used for stump acquisition: non contact laser technique for external geometry, CT and MRI imaging technologies for the internal structure, the first one dedicated to bones geometrical model, the last for soft tissues and muscles. We discuss problems related to 3D geometric reconstruction: the patient and stump positioning for the different acquisitions, markers' definition on the stump to identify landmarks,
alignment's strategies for the different digital models, in order to define a protocol procedure with a requested accuracy for socket's realization. Some case-studies illustrate the methodology and the results obtained.