Now showing items 1-18 of 18

    • Binocular open-view system to perform estimations of aberrations and scattering in the human eye 

      García Guerra, Carlos Enrique; Aldaba Arévalo, Mikel; Pujol Ramo, Jaume; Arjona Carbonell, Mª Montserrat (2015-11-10)
      Article
      Open Access
      We present a system that integrates a double-pass (DP) instrument and a Hartmann-Shack (HS) wavefront sensor to provide information not only on aberrations, but also on scattering occurring in the human eye. A binocular ...
    • Implementation of the frequency scatter index in clinical commercially available double-pass systems 

      Sánchez, Roberto F; García Guerra, Carlos Enrique; Martínez Roda, Juan Antonio; De Paul, Aníbal; Issolio, Luis A.; Pujol Ramo, Jaume (2022-03)
      Article
      Open Access
      A previous work has reported a methodology to quantify intraocular scattering using a high sensitivity double-pass instrument with a robust index, the frequency scatter index. The purpose of our study was to evaluate an ...
    • Influence of power and the time of application of fogging lenses on accommodation 

      Turull Mallofré, Aina; García Guerra, Carlos Enrique; Mestre Ferrer, Clara; Vilaseca Ricart, Meritxell; Pujol Ramo, Jaume; Aldaba Arévalo, Mikel (2023-09-27)
      Article
      Open Access
      Fogging is a non-invasive technique based on the use of positive spherical power lenses to relax accommodation during refraction that is commonly used as an alternative to cycloplegic drugs. Although the mechanism of the ...
    • Method to reduce undesired multiple fundus scattering effects in double-pass systems 

      García Guerra, Carlos Enrique; Martínez Roda, Juan Antonio; Aldaba Arévalo, Mikel; Díaz Douton, Fernando; Vilaseca Ricart, Meritxell; Vohnsen, Brian; Pujol Ramo, Jaume (2019-04-29)
      Article
      Open Access
    • Multimodal eye's optical quality (MEOQ) 

      García Guerra, Carlos Enrique (Universitat Politècnica de Catalunya, 2016-07-29)
      Doctoral thesis
      Open Access
      Covenantee:   Karlsruher Institut für Technologie
      Within the visual system, the optics of the eye is responsible for forming images of external objects on the ocular fundus for its photo-reception and neural interpretation. However, the eye is not perfect and its capabilities ...
    • New compact open-field double-pass system with asymmetric focus 

      Giner Tort, Anna; Arjona Carbonell, Mª Montserrat; Díaz Douton, Fernando; Aldaba Arévalo, Mikel; García Guerra, Carlos Enrique; Sanabria Ortega, Fernando Guillermo; Pujol Ramo, Jaume (2018-01-01)
      Article
      Open Access
      Every day more people are using multifocal systems to correct presbyopia, as for example contact lenses or intraocular lenses. As a consequence, the necessity to do an appropriate characterization of their optical quality ...
    • Quantification of forward scattering based on the analysis of double-pass images in the frequency domain 

      Martínez Roda, Juan Antonio; García Guerra, Carlos Enrique; Díaz Douton, Fernando; Pujol Ramo, Jaume; Salvador, Antoni; Vilaseca Ricart, Meritxell (Oxford University Press, 2019-11)
      Article
      Open Access
    • Real time 100 GHz MST imaging retina 

      Alonso del Pino, María; Garg, V.; García Guerra, Carlos Enrique; Romeu Robert, Jordi; Llombart, Nuria; Jofre Roca, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      Conference report
      Restricted access - publisher's policy
      A real time tomographic imaging system at 100 GHz based on a retina and Modulated Scattered Technique (MST) is presented in this paper. It consists in applying a low frequency modulation to each probe of an array of antennas ...
    • Reducing speckle in double-pass systems using focus tunable lenses 

      García Guerra, Carlos Enrique; Aldaba Arévalo, Mikel; Arjona Carbonell, Mª Montserrat; Pujol Ramo, Jaume (2014)
      Conference report
      Restricted access - publisher's policy
      Speckle arises in double-pass systems when coherent light is reflected by the retina. Since it degrades the images that are used to characterize the eye, there is special attention in reducing speckle when working with ...
    • Response for light scattered in the ocular fundus from double-pass and Hartmann–Shack estimations 

      García Guerra, Carlos Enrique; Aldaba Arévalo, Mikel; Arjona Carbonell, Mª Montserrat; Díaz Douton, Fernando; Martínez Roda, Juan Antonio; Pujol Ramo, Jaume (2016-10-06)
      Article
      Open Access
      Double-pass (DP) and Hartmann--Shack (HS) are complementary techniques based on reflections of light in the ocular fundus that may be used to estimate the optical properties of the human eye. Under conventional data ...
    • Speckle reduction in double-pass retinal images 

      Halpaap Halpaap, Herbert Donatus; García Guerra, Carlos Enrique; Vilaseca Ricart, Meritxell; Masoller Alonso, Cristina (Nature, 2019-03-14)
      Article
      Open Access
    • Speckle reduction in double-pass retinal images using variable-focus lenses 

      García Guerra, Carlos Enrique; Aldaba Arévalo, Mikel; Arjona Carbonell, Mª Montserrat; Pujol Ramo, Jaume (2015-01-01)
      Article
      Open Access
      Speckle arises in double-pass images when coherent light is scattered by the retina. Since this noise degrades the images that are used to characterize the eye, there is special attention in reducing speckle when working ...
    • System for objective assessment of the accommodation response during subjective refraction 

      García Guerra, Carlos Enrique; Martínez Roda, Juan Antonio; Ondategui Parra, Juan Carlos; Turull Mallofré, Aina; Aldaba Arévalo, Mikel; Vilaseca Ricart, Meritxell (Association for Research in Vision and Ophthalmology (ARVO), 2023-05)
      Article
      Open Access
      Purpose: To evaluate a system based on a Hartmann–Shack wavefront sensor attached to a phoropter that allows the user to obtain real-time information about the refractive state of the eye and the accommodation response ...
    • Tear film stability assessment by corneal reflex image degradation 

      Aldaba Arévalo, Mikel; Mira Agudelo, Alejandro; Barrera, John Fredy; García Guerra, Carlos Enrique; Pujol Ramo, Jaume (2019-04-01)
      Article
      Open Access
    • Tear film stability assessment by corneal reflex image degradation 

      Aldaba Arévalo, Mikel; Mira Agudelo, Alejandro; Barrera, John Fredy; García Guerra, Carlos Enrique; Pujol Ramo, Jaume (2018)
      Conference lecture
      Restricted access - publisher's policy
      A method for tear film break up measurements based on the degradation of corneal reflex images caused by dry spots is presented. The experimental setup, which is based on recording the corneal reflex image or the first ...
    • Technical improvements applied to a double-pass setup for performance and cost optimization 

      Sanabria Ortega, Fernando Guillermo; Aldaba Arévalo, Mikel; Díaz Douton, Fernando; García Guerra, Carlos Enrique; Pujol Ramo, Jaume (2014-06-01)
      Article
      Open Access
      We have studied the possibility of improving the performance, simplifying, and reducing the cost of a double-pass system by the use of alternative technologies. The system for correcting the spherical correction has been ...
    • Use of spectral information for red scale pest control 

      García Guerra, Carlos Enrique; Burgos Fernández, Francisco Javier; Canals Pascual, Eloi; Díaz Douton, Fernando; Zaragoza, Abel; Virgili, Albert; Vilaseca Ricart, Meritxell (2021)
      Conference lecture
      Open Access
      Decreasing the use of pesticides is one of the main goals of current agriculture, which requires fast, precise and continuous assessments of crop pests. Citrus pests cause a lot of damage worldwide and the techniques to ...
    • X-Band Imaging Retinas 

      García Guerra, Carlos Enrique (Universitat Politècnica de Catalunya, 2010-07)
      Master thesis
      Open Access
      Systems at 10GHz based on the use of horn antennas and slotted-waveguide antennas are studied along this work. The importance of this study relies on the fact that these antennas can be employed for imaging applications ...