RESUMEN
The effects of systemic sclerosis (SSc)--a disease of the connective tissue causing blood flow problems that can require amputation of the fingers--can be observed indirectly by imaging the capillaries at the nailfold, though taking quantitative measures such as blood flow to diagnose the disease and monitor its progression is not easy. Optical flow algorithms may be applied, though without ground truth (i.e. known blood flow) it is hard to evaluate their accuracy. We propose an image model that generates realistic capillaroscopy videos with known flow, and use this model to quantify the effect of flow rate, cell density and contrast (among others) on estimated flow. This resource will help researchers to design systems that are robust under real-world conditions.
Asunto(s)
Algoritmos , Simulación por Computador , Angioscopía Microscópica/métodos , Uñas/irrigación sanguínea , Flujo Sanguíneo Regional , Capilares/fisiopatología , Dedos/fisiopatología , Humanos , Procesamiento de Imagen Asistido por ComputadorRESUMEN
This paper presents an intuitive approach to the programming of Functional Electrical Stimulation (FES) hardware. A stimulation sequence is defined as a Finite State Machine (FSM) that is created and modified via an easy-to-use interface. Using a USB-equipped stimulator, data from an internal accelerometer are streamed to a PC whilst the subject undergoes the motion of interest. Simultaneously, the clinician labels the collected data via a number of key presses in order to train a sequence of simple classifiers. The 'optimal' (in a quantitative sense) parameters are then uploaded directly back to the stimulator for immediate stand-alone operation.
Asunto(s)
Inteligencia Artificial , Terapia por Estimulación Eléctrica/métodos , Trastornos del Movimiento/rehabilitación , Reconocimiento de Normas Patrones Automatizadas/métodos , Programas Informáticos , Terapia Asistida por Computador/métodos , Interfaz Usuario-Computador , Terapia por Estimulación Eléctrica/instrumentación , Humanos , Trastornos del Movimiento/diagnóstico , Análisis y Desempeño de Tareas , Terapia Asistida por Computador/instrumentaciónRESUMEN
Given the increased use of accelerometers in movement analysis, validation of such inertial sensors against conventional 3D camera systems and performance comparisons of different sensors have become important topics in biomechanics. This paper evaluates and compares linear acceleration trajectories obtained from two different 3D accelerometers and derived from Vicon position data for an upper limb "reach & grasp" task. Overall, good correspondence between the three measurement systems was obtained. Sources of error are discussed.
