USEFULNESS OF RAPID PROTOTYPING IN PLANNING COMPLEX TRAUMA SURGERIES

Orthopaedic trauma surgery is a complex surgical speciality in which anatomy, physiology and physics are mixed. Proper diagnosing and based on that planning and performing surgery is of crucial matter. This article presents usefulness of 3D reconstruction in diagnostics and surgical planning. It focuses on utility of computed tomography reconstruction in trauma surgery. Moreover, two cases in which this technique was used is described. Complex 3D reconstruction proved its usefulness and in future it may become a modality of choice for planning complex trauma procedures in which standard implants and approaches are insufficient.&nbsp

From linguistic innovation in blogs to language learning in adults : what do interaction networks tell us?

Social networks have been found to play an increasing role in human behaviour and even the attainment of individuals. We present the results of two projects applying SNA to language phenomena. One involves exploring the social propagation of ne ologisms in a social software (microblogging service), the other investigating the impact of social network structure and peer interaction dynamics on second-language learning outcomes in the setting of naturally occurring face-to-face interaction. From local, low-level interactions between agents verbally communicating with one another we aim to describe the processes underlying the emergence of more global systemic order and dynamics, using the latest methods of complexity science. In the former study, we demonstrate 1) the emergence of a linguistic norm, 2) that the general lexical innovativeness of Internet users scales not like a power law, but a unimodal, 3) that the exposure thresholds necessary for a user to adopt new lexemes from his/her neighbours concentrate at low values, suggesting that—at least in low-stakes scenarios—people are more susceptible to social influence than may erstwhile have been expected, and 4) that, contrary to common expectations, the most popular tags are characterised by high adoption thresholds. In the latter, we find 1) that the best predictor of performance is reciprocal interactions between individuals in the language being acquired, 2) that outgoing interactions in the acquired language are a better predictor than incoming interactions, and 3) not surprisingly, a clear negative relationship between performance and the intensity of interactions with same-native-language speakers. We also compare models where social interactions are weighted by homophily with those that treat them as orthogonal to each other

ANALYSIS OF THE MINING TORQUE SIGNAL WITH CONTINUOUS WAVELET TRANSFORM

This paper presents an analysis of the excavation torque signal with the use of a Continuous Wavelet Transform. The article also presents results of preliminary research on utilising neural networks to identify excavating cutting tools type used in multi-tool excavating heads of mechanical coal miners.Selected wavelet coefficients were used as data to teach artificial neural network. The research is necessary to identify rock excavating process with a given head, and design adaptation system for control of mining process with such a head. The results of numerical analyses conducted with the use of Neural Networks are presented

The influence of the nucleus pulposus on the stress distribution in the natural and prosthetic intervertebral disc

The aim of this article was to present the results of a preliminary study on the stress distribution in the lumbar intervertebral disc [IVD] under loads induced during daily activities. Basic anatomy, biomechanical analysis of the vertebra and intervertebral disc were introduced. The third and fourth lumbar vertebrae were chosen for the study because they carry considerably higher loads, especially while standing or sitting. The static mechanical analyses using the finite element method (FEM) were conducted for four standard loads reflecting patient’s positions: recumbent, standing, sitting and standing with additional loads, and three models: an intervertebral disc with an inner nucleus pulposus and two prosthetic intervertebral discs, with or without an artificial nucleus. The FEM analysis was performed in the SolidWorks Simulation module on reverse-engineered 3D models of vertebrae and the intervertebral disc, based on a series of computed tomography [CT] scans of the patient’s spine, which had been properly processed in Materialise Mimics software and exported to CAD files. The model of the fourth intervertebral disc, placed between third and fourth vertebra, had been additionally modified to include its inner core, the nucleus pulposus

Usefulness of rapid prototyping in planning complex trauma surgeries

Orthopaedic trauma surgery is a complex surgical speciality in which anatomy, physiology and physics are mixed. Proper diagnosing and based on that planning and performing surgery is of crucial matter. This article presents usefulness of 3D reconstruction in diagnostics and surgical planning. It focuses on utility of computed tomography reconstruction in trauma surgery. Moreover, two cases in which this technique was used is described. Complex 3D reconstruction proved its usefulness and in future it may become a modality of choice for planning complex trauma procedures in which standard implants and approaches are insufficient

Stress distribution in the knee joint in relation to tibiofemoral angle using the finite element method

The article presents the results of a preliminary study on the structural analysis of the knee joint, considering changes in the mechanical properties of the articular cartilage of the joint. Studies have been made due to the need to determine the tension distribution occurring in the cartilage of the human knee. This distribution could be the starting point for designing custom made human knee prosthesis. Basic anatomy, biomechanical analysis of the knee joint and articular cartilage was introduced. Based on a series of computed tomography [CT] scans, the 3D model of human knee joint was reverse-engineered, processed and exported to CAD software. The static mechanical analysis of the knee joint model was conducted using the finite element method [FEM], in three different values of tibiofemoral angle and with varying mechanical properties of the cartilage tissue. Main conclusions of the study are: the capability to absorb loads by articular cartilage of the knee joint is preliminary determined as decreasing with increasing degenerations of the cartilage and with age of a patient. Without further information on changes of cartilage’s mechanical parameters in time it is hard to determine the nature of relation between mentioned capability and these parameters

Stress distribution in the knee joint in relation to tibiofemoral angle using the finite element method

The article presents the results of a preliminary study on the structural analysis of the knee joint, considering changes in the mechanical properties of the articular cartilage of the joint. Studies have been made due to the need to determine the tension distribution occurring in the cartilage of the human knee. This distribution could be the starting point for designing custom made human knee prosthesis. Basic anatomy, biomechanical analysis of the knee joint and articular cartilage was introduced. Based on a series of computed tomography [CT] scans, the 3D model of human knee joint was reverse-engineered, processed and exported to CAD software. The static mechanical analysis of the knee joint model was conducted using the finite element method [FEM], in three different values of tibiofemoral angle and with varying mechanical properties of the cartilage tissue. Main conclusions of the study are: the capability to absorb loads by articular cartilage of the knee joint is preliminary determined as decreasing with increasing degenerations of the cartilage and with age of a patient. Without further information on changes of cartilage’s mechanical parameters in time it is hard to determine the nature of relation between mentioned capability and these parameters

The influence of the nucleus pulposus on the stress distribution in the natural and prosthetic intervertebral disc

The aim of this article was to present the results of a preliminary study on the stress distribution in the lumbar intervertebral disc [IVD] under loads induced during daily activities. Basic anatomy, biomechanical analysis of the vertebra and intervertebral disc were introduced. The third and fourth lumbar vertebrae were chosen for the study because they carry considerably higher loads, especially while standing or sitting. The static mechanical analyses using the finite element method (FEM) were conducted for four standard loads reflecting patient’s positions: recumbent, standing, sitting and standing with additional loads, and three models: an intervertebral disc with an inner nucleus pulposus and two prosthetic intervertebral discs, with or without an artificial nucleus. The FEM analysis was performed in the SolidWorks Simulation module on reverse-engineered 3D models of vertebrae and the intervertebral disc, based on a series of computed tomography [CT] scans of the patient’s spine, which had been properly processed in Materialise Mimics software and exported to CAD files. The model of the fourth intervertebral disc, placed between third and fourth vertebra, had been additionally modified to include its inner core, the nucleus pulposus