Endoscopic measurement using radial metrology with digital correlation

Anisotropic and hyperelastic identification of in vitro human arteries from full-field optical measurements

“…The combination of 3-D deformation measurements (Rastogi, 1999;Foster, 1978;Viotti et al, 2008;Matthys et al, 1991;Genovese, 2007Genovese, , 2009Sutton et al, 2007) and inverse approaches is now very common in solid mechanics but it is still under-employed for identifying the anisotropic hyperelastic properties of the arterial tissues (Seshaiyer and Humphrey, 2003;Einstein et al, 2005). Moreover, the virtual fields method (Gré diac et al, 2006), which is an inverse method specifically dedicated to full-field data, has never been used for the mechanical identification of arterial tissues although it has very relevant assets: insensitivity to the uncertainty of boundary conditions (Gré diac et al, 2006), robustness (Avril et al, 2004), fast convergence (Avril and Pierron, 2007).…”

Improvement in design of panoramic annular lens using cemented lenses

“…However, Greguss did not make further research on the relationship between the field and the geometric shapes of PAL's refractive and reflecting surfaces in his patent. Matthys, Gilbert and Greguss proposed the imaging principle of PAL: Flat Cylinder Perspective (FCP) [2] in 1991. Powell analyzed the structure of PAL thoroughly later in 1994 [3], and proposed the idea of using spherical reflecting surfaces instead of parabolic ones.…”

A video-optical system for time-resolved whole-body measurement on vascular segments

“…Both concave and convex conical mirrors, and endoscopic probes have been used in combination with standard optical techniques such as Ligtenberg moiré [25], white light interferometry [26], and digital image correlation [27] for investigating both inner and outer surfaces of axisymmetrical parts. The present work introduces a very straightforward radial metrology-based approach that exploits geometrical optics, and computer vision concepts.…”