Abstract
This paper presents a path planning method for pick-and-place operations with obstacles in the work environment. The method developed is designed to plan the motion of an anthropomorphic manipulator in cluttered environments. The graph search algorithm A* applied to the configuration free space is used to calculate the shortest path between two points avoiding collisions with obstacles and joint limitations. Applying this algorithm in a six dimension space presents some constraints related to memory consumption and processing time, which were tackled using configuration space partition and selecting neighbourhood cells, respectively. Using the configuration space makes it possible for the entire robot body to avoid collisions with obstacles. Moreover, the system implemented proves that applying A* in high dimension configuration spaces is possible with admissible results.

Abstract
Ao longo dos anos, a espessura da camada de plasma tem sido determinada com o auxílio de métodos manuais. Apesar destes métodos serem bastante fiáveis, estes são morosos e podem introduzir erros do utilizador nos dados. No presente trabalho, foi desenvolvido um método automático de processamento de imagem para a determinação da espessura camada de plasma de uma forma automática.

Abstract
Blood is an opaque, heterogeneous, non-Newtonian fluid composed by a yellowish homogeneous fluid – the plasma – and a series of cellular elements. Red blood cells (RBCs) in microvessels and microchannels has tendency to undergo axial migration due to the parabolic velocity profile which results in a high shear stress around wall that forces the RBCs to move towards the center induced by the tank treading motion of the RBC membrane [1]. As a result there is a formation of a cell free layer (CFL) with extremely low concentration of cells around the walls of the microchannel [1-3]. This phenomenon is commonly observed in both in vitro [2, 3] and in vivo [4] experiments and has been extensively studied in small straight glass tubes [2, 5]. However, to the best of our knowledge, there are very few quantitative studies on the effect of complex geometries (such as bifurcations and confluences) on the CFL flow behaviour. The main objective of this study is to develop a MatLab script able to measure automatically the RBCs trajectories, at the CFL interface, and CFL thickness in microchannels containing series of bifurcations.

Abstract

Abstract
Most of the original image feature detectors are not able to cope with large photometric variations, and their extensions that should improve detection eventually increase the computational cost and introduce more noise to the system. Here we extend the original SURF algorithm increasing its invariance to illumination changes. Our approach uses the local space average color descriptor as working space to detect invariant features. A theoretical analysis demonstrates the impact of distinct photometric variations on the response of blob-like features detected with the SURF algorithm. Experimental results demonstrate the effectiveness of the approach in several illumination conditions including the presence of two or more distinct light sources, variations in color, in offset and scale.

Abstract
Intelligent wheelchairs can become an important solution to assist physically impaired individuals who find it difficult or impossible to drive regular powered wheelchairs. However, when designing the hardware architecture several projects compromise the user comfort and the wheelchair normal usability in order to solve robotic problems. In this paper we describe the main concepts regarding the design of the IntellWheels intelligent wheelchair. Our approach has a user-centered perspective, in which the needs and limitations of physically impaired users are given extensive attention at each stage of the design process. Finally, our design was evaluated through a public opinion assessment. A statistical analysis suggested that the design was effective to mitigate the visual and ergonomic impacts caused by the addition of sensorial and processing capabilities on the wheelchair. © 2013 IEEE.