http://hdl.handle.net/2117/3393 2013-05-25T17:52:37Z http://hdl.handle.net/2117/19389 Title: Temporal stability in the perception of dry eye ocular disconfort symptoms Authors: Cardona Torradeflot, Genís; Marcellán, Concepción; Fornieles Deu, Albert; Vilaseca Ricart, Meritxell; Quevedo Junyent, Luisa Jesus Abstract: Purpose. A prospective longitudinal study was designed to investigate the ability of patients with tear deficiency to correctly recall their past symptoms. The ultimate goal of the study was to contribute to the ongoing research concerning the lack of association between dry eye symptomatology and clinical tests of tear film evaluation. Methods. A total of 26 subjects with ages ranging from 29 to 61 years participated in the study. All subjects reported symptoms associated with tear deficiency, although none had been diagnosed with dry eye disease. Subjects were instructed to grade their symptoms on two different occasions, at the precise moment they were experiencing them, by means of a home questionnaire, and through a recall questionnaire, which was administered within a maximum interval of 10 days from the first questionnaire. Tear evaluation tests were performed at this second time. Non-parametric statistical analyses were used to investigate the relationship between present and recalled symptoms and between symptoms and signs, as well as between the different dry eye tests. The contributions of age, gender, and recall period were also evaluated. Results. With the exception of irritation (p 0.029) and scratchiness (p 0.025), no statistically significant difference was encountered between home and recall questionnaires, although females were found to recall their symptoms slightly better than males (p 0.048). An increase in the severity of the symptoms was associated with a better recollection (p 0.007). Symptoms (home or recalled) and clinical signs were not correlated, although the recalled symptom of scratchiness presented moderately strong correlations with several dry eye tests. Conclusions. Although the lack of correlation between dry eye tests and symptoms mirrored previous research, symptoms recall was found to follow certain interesting patterns, similar to those published in pain research literature. 2013-05-24T07:33:54Z http://hdl.handle.net/2117/18415 Title: Efectos de la elección del conjunto de entrenamiento en la reconstrucción de firmas espectrales con dispositivo CCD Authors: Gor, Sergio; Sandoval, José; Vilaseca Ricart, Meritxell 2013-03-19T15:50:03Z http://hdl.handle.net/2117/18334 Title: One-shot focusing using the entropy as a merit function Authors: Suc, Vicent; Royo Royo, Santiago; Jordan, Andres; Bakos, G.; Penev, K. 2013-03-15T09:45:27Z http://hdl.handle.net/2117/18179 Title: Strategy to obtain initial configurations for free form reflectors design Authors: Tomás Corominas, Núria; Arasa Marti, Jose 2013-03-11T15:14:03Z http://hdl.handle.net/2117/17842 Title: Comparison of B-spline and Zernike fitting techniques in complex wavefront surfaces Authors: Ares Rodríguez, Miguel; Royo Royo, Santiago; Caum Aregay, Jesús; Pizarro Bondia, Carlos Editor: Osten, Wolfgang; Gorecki, Christophe; Novak, Erik L. 2013-02-18T14:47:58Z http://hdl.handle.net/2117/17831 Title: Application of matched digital filters to noisy fringe-patterns from complex wavefronts Authors: Caum Aregay, Jesús; Arasa Marti, Jose; Royo Royo, Santiago; Ares Rodríguez, Miguel Editor: Osten, Wolfgang; Gorecki, Christophe; Novak, Erik L. 2013-02-18T13:23:04Z http://hdl.handle.net/2117/17443 Title: Measuring the accommodative response with a double-pass system: Comparison with the Hartmann-Shack technique Authors: Aldaba Arévalo, Mikel; Vilaseca Ricart, Meritxell; Díaz-Doutón, Fernando; Arjona Carbonell, Mª Montserrat; Pujol Ramo, Jaume 2013-01-21T15:11:53Z http://hdl.handle.net/2117/17436 Title: Analysis and control of speckle effects in self-mixing interferometry Authors: Atashkhooei, Reza; Royo Royo, Santiago; Azcona Guerrero, Francisco Javier; Zabit, U 2013-01-21T13:26:57Z http://hdl.handle.net/2117/17187 Title: Iris color evaluation through multispectral systems Authors: Herrera Ramírez, Jorge Alexis; Vilaseca Ricart, Meritxell; Pujol Ramo, Jaume; Arjona Carbonell, Mª Montserrat; de Lasarte, Marta 2012-12-21T18:36:41Z http://hdl.handle.net/2117/15996 Title: Spectral signatures : a way to identify species and conditions of vegetables Authors: Sandoval, José; Gor, Sergio; Ramallo, Jacqueline; Sfer, Ana; Colombo, Elisa; Vilaseca Ricart, Meritxell; Pujol Ramo, Jaume Abstract: Confirming the statement from Shlens (2009), that is, that the goal of PCA is to identify the most meaningful basis to reexpress a dataset, the results obtained in this work show that the careful selection and suitable preparation of samples together with the precise collection of spectral signature data and the application of an adequate statistical analysis like PCA conform a powerful and reliable technique to recognize and classify plants, allowing us to identify the origin of a given vegetable sample. That technique could be considerably improved by developing a database of standardized spectral signatures of the main crops in each stage and status. This could be the basis for higher level of plant and crop analysis, allowing us the prediction, diagnosis, and solution of different health and phenologic affections of plants. 2012-06-09T10:47:59Z http://hdl.handle.net/2117/15748 Title: Optics of astigmatism and retinal image quality Authors: Vilaseca Ricart, Meritxell; Díaz-Doutón, Fernando; Luque, Sergio Oscar; Aldaba Arévalo, Mikel; Arjona Carbonell, Mª Montserrat; Pujol Ramo, Jaume Abstract: In the first part of this chapter, the optical condition of astigmatism is defined. The main causes and available classifications of ocular astigmatism are briefly described. The most relevant optical properties of image formation in an astigmatic eye are analysed and compared to that of an emmetropic eye and an eye with spherical ametropia. The spectacle prescription and axis notation for astigmatism are introduced, and the correction of astigmatism by means of lenses is briefly described. The formation of the retinal image for extended objects and the related blurring are also analysed, and the real limits of tolerance of uncorrected astigmatism are provided. Simulations of retinal images in astigmatic eyes, obtained by means of commercial optical design software, are also presented. Finally, the clinical assessment of retinal image quality by means of wavefront aberrometry and double-pass systems in eyes with astigmatism is presented, and current trends in research related to this topic are highlighted. 2012-04-19T12:02:39Z http://hdl.handle.net/2117/15038 Title: Measure of roughness of paper using speckle Authors: Pino, Abdiel; Pladellorens Mallofré, Josep 2012-02-09T15:02:59Z http://hdl.handle.net/2117/14635 Title: Determinación de propiedades superficiales del papel utilizando el análisis de la textura del patrón de speckle Authors: Pladellorens Mallofré, Josep 2012-01-18T10:20:20Z http://hdl.handle.net/2117/14553 Title: Optical quality after myopic photorefractive keratectomy and laser in situ keratomileusis: Comparison using a double-pass system Authors: Ondategui Parra, Juan Carlos; Vilaseca Ricart, Meritxell; Arjona Carbonell, Mª Montserrat; Montasell, Ana; Cardona Torradeflot, Genís; Güell, José L.; Pujol Ramo, Jaume 2012-01-16T10:22:55Z http://hdl.handle.net/2117/14446 Title: Use of light-emitting diodes in multispectral systems design: variability of spectral power distribution according to angle and time of usage Authors: Martínez, Oscar; Vilaseca Ricart, Meritxell; Arjona Carbonell, Mª Montserrat; Pizarro Bondia, Carlos; Pujol Ramo, Jaume Abstract: Multispectral systems allow the spectral and color characterization of objects using images obtained from several acquisition channels with different spectral sensitivities. Light sources based on light-emitting diodes have started to be used in multispectral systems, mainly to develop low-cost devices for the industry. In this study, the authors examine the variability of spectral power distribution according to the viewing angle of white and single color light-emitting diodes, which can have a significant impact on spectral and color accuracy. This must be taken into account if they are to be used in multispectral systems design. The spectrum drift according to the time of usage of white light-emitting diodes is also analyzed. 2012-01-10T12:07:34Z