Revistas
Revista:
COMPUTERIZED MEDICAL IMAGING AND GRAPHICS
ISSN:
0895-6111
Año:
2014
Vol.:
38
N°:
7
Págs.:
558 - 568
This work presents an automatic method for distortion correction and calibration of intra-operative spine X-ray images, a fundamental step for the use of this modality in computer and robotic assisted surgeries. Our method is based on a prototype calibration drum, attached to the c-arm intensifier during the intervention. The projections of its embedded fiducial beads onto the X-ray images are segmented by the proposed method, which uses its calculated centroids to undo the distortion and, afterwards, calibrate the c-arm. For the latter purpose, we propose the use of a constrained version of the well known Direct Linear Transform (DLT) algorithm, reducing its degrees of freedom from 11 to 3. Experimental evaluation of our method is included in this work, showing that it is fast and more accurate than other existing methods. The low segmentation error level also ensures accurate calibration of the c-arm, with an expected error of 4% in the computation of its focal distance. (C) 2014 Elsevier Ltd. All rights reserved.
Revista:
IEEE TRANSACTIONS ON MEDICAL IMAGING
ISSN:
0278-0062
Año:
2014
Vol.:
33
N°:
5
Págs.:
1044 - 1053
Repetitive and alternating lower limb movements are a specific component of human gait. Due to technical challenges, the neural mechanisms underlying such movements have not been previously studied with functional magnetic resonance imaging. In this study, we present a novel treadmill device employed to investigate the kinematics and the brain activation patterns involved in alternating and repetitive movements of the lower limbs. Once inside the scanner, 19 healthy subjects were guided by two visual cues and instructed to perform a motor task which involved repetitive and alternating movements of both lower limbs while selecting their individual comfortable amplitude on the treadmill. The device facilitated the performance of coordinated stepping while registering the concurrent lower-limb displacements, which allowed us to quantify some movement primary kinematic features such as amplitude and frequency. During stepping, significant blood oxygen level dependent signal increases were observed bilaterally in primary and secondary sensorimotor cortex, the supplementary motor area, premotor cortex, prefrontal cortex, superior and inferior parietal lobules, putamen and cerebellum, regions that are known to be involved in lower limb motor control. Brain activations related to individual adjustments during motor performance were identified in a right lateralized network including striatal, extrastriatal, and fronto-parietal areas.
Revista:
TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES
ISSN:
0968-090X
Año:
2013
Vol.:
33
Págs.:
22 - 36
This paper presents a new mechatronic system that combines the capabilities of the steering wheel, the throttle and brake pedals in a single all-encompassing device. A two degreeof-freedom mechanism allows controlling all driving functionalities together in a very ergonomic and original way. The system uses drive-by-wire technology with haptic feedback for an outstanding driving experience. The device has been tested in a simulation platform, showing similar performance to conventional set of steering wheel and pedals, and very good acceptance among users. This work also surveys current drive-by-wire systems in the automotive industry and the use of haptic technology to assist drivers.
Autores:
de Rosario, Helios; Solaz, José S.; Signes, Elisa; et al.
Revista:
REVISTA DE BIOMECANICA
ISSN:
1575-5622
Año:
2011
Vol.:
56
Págs.:
7-10
Durante los cuatro años del proyecto MARTA, el Instituto de Biomecánica (IBV) ha llevado a cabo para FICOSA International diversos estudios con conductores en un simulador de automóvil. Con la cooperación del Centro de Estudios e Investigaciones Técnicas de Gipuzkoa (CEIT), se han estudiado las sensaciones y reacciones de los usuarios ante el manejo de tecnologías innovadoras basadas en la interacción táctil. De este modo se han analizado alarmas vibrotáctiles de colisión frontal o de somnolencia, integradas en el pedal del acelerador, así como un sistema de control de la climatización en pantalla táctil y un nuevo control manual de conducción semiautomática.