Soft tissue modelling through autowaves for surgery simulation

Modelling of soft tissue deformation is of great importance to virtual reality based surgery simulation. This paper presents a new methodology for simulation of soft tissue deformation by drawing an analogy between autowaves and soft tissue deformation. The potential energy stored in a soft tissue as a result of a deformation caused by an external force is propagated among mass points of the soft tissue by non-linear autowaves. The novelty of the methodology is that (i) autowave techniques are established to describe the potential energy distribution of a deformation for extrapolating internal forces, and (ii) non-linear materials are modelled with non-linear autowaves other than geometric non-linearity. Integration with a haptic device has been achieved to simulate soft tissue deformation with force feedback. The proposed methodology not only deals with large-range deformations, but also accommodates isotropic, anisotropic and inhomogeneous materials by simply changing diffusion coefficients

Videocirurgia colorretal com assistência robótica: o próximo passo? Robotic assisted colorrectal surgery

O desenvolvimento de técnicas minimamente invasivas é um dos mais importantes avanços da cirurgia colorretal. A assistência robótica integra o arsenal de técnicas em cirurgia minimamente invasiva, e vem sendo aplicado em cirurgia colorretal por um restrito grupo de cirurgiões em alguns centros ao redor do mundo com resultados iniciais que merecem atenção. O objetivo do presente estudo é analisar os resultados do emprego da assistência robótica em videocirurgia colorretal. Dentre as vantagens associadas ao emprego de robôs em videocirurgia colorretal, figuram o incremento na precisão dos movimentos e a visão tridimensional. A experiência clínica é ainda pequena, e advém de uma série de casos e estudos comparativos com a videocirurgia colorretal sem assistência robótica com ainda pequeno número de casos. A dissecção pélvica com incremento da preservação autonômica parece ser a maior vantagem associada à assistência robótica em videocirurgia colorretal. Somente através do treinamento de um número mais representativo de cirurgiões colorretais, bem como com a expansão da experiência clínica será possível prever com maior precisão o papel da assistência robótica em videocirurgia colorretal.<br>The development of minimally invasive surgical techniques represents an important aspect of modern surgical research. Robot-assisted minimally invasive colorectal surgery represents a way of assisting laparoscopic colorectal procedures. Robotic technology overcomes some of these limitations by successfully providing intuitive motion and enhanced precision and accuracy, in an environment that is much more ergonomic. A restrict number of surgeons in specialized centers around the world have been applying robotics. In this review, current evidence about different technologies and its place in colorectal surgery is evaluated. The feasibility of performing robot-assisted colorectal operations has been demonstrated though case series and small case-controlled trials. The potential for enhancing autonomic nerve preservation during proctectomy may be the most remarkable advantage associated to robotic assistance during laparoscopic colorectal surgery. Colorectal surgeons should seize the opportunity to begin to use surgical robotic systems. Only through widespread surgeon training and increasing clinical experience with these systems, further technological developments, and continuous research, robotic technology will be routinely incorporated into surgical procedures on the colon and rectum