Ernesto De la Cruz Sánchez

MODELADO VIRTUAL DE UNA ESTRUCTURA BIOLOGICA: LA CORNEA HUMANA

ABSTRACT: The cornea is the most important part of the anterior segment of the human eye. In a natural scenario, the tissue that forms part of the corneal architecture presents a stable geometrical morphology, while in a pathological scenario a morphological alteration that affects to the geometry of its architecture is detected. The use of virtual models of biologic structures in the field of Biomedical Engineering has been demonstrated to be very useful in clinical practice for diagnosis and surgical reconstruction. This paper presents the virtual modelling of the human cornea as a technique for the diagnosis of the corneal pathology named keratoconus. After generating the virtual model of the cornea, several geometric variables are then extracted and analyzed, permitting to differentiate between healthy and keratoconic corneas. The obtained results have been clinically validated and demonstrate the functionality of the methodology applied, being possible to extend this methodology to other geometric variables. Keywords: geometric modelling, keratoconus, corneal disease, virtual model.

Validity of an inertial system to measure sprint time and sport task time: a proposal for the integration of photocells in an inertial system

This study presents a proposal for the integration of photocell data (time) into an inertial system. We divert the signal emitted by the infrared cell (ChronoJump, Spain) towards the inertial device (WIMU PRO, RealTrack System, Almeria, Spain) by an ANT + transmitter to make a mark that is later visualised in S PRO software (RealTrack System, Almeria, Spain). The objective of this study is to show the validity of an inertial system to measure sprint and sport task time by integrating photocells into an inertial system. For this purpose, we compared the time of 108 runs (at 20, 150 and 400 m) between inertial software and photocell software (gold standard). The results of the validity in this study were satisfactory and had a bias .0006 ± .0018 s. To conclude, the time measurements between photocells and an inertial system using ANT + are accurate and the proposal presented in this manuscript could make this sport activity monitoring more efficient.Abstract This study presents a proposal for the integration of photocell data (time) into an inertial system. We divert the signal emitted by the infrared cell (ChronoJump, Spain) towards the inertial device (WIMU PRO, RealTrack System, Almeria, Spain) by an ANT + transmitter to make a mark that is later visualised in S PRO software (RealTrack System, Almeria, Spain). The objective of this study is to show the validity of an inertial system to measure sprint and sport task time by integrating photocells into an inertial system. For this purpose, we compared the time of 108 runs (at 20, 150 and 400 m) between inertial software and photocell software (gold standard). The results of the validity in this study were satisfactory and had a bias .0006 ± .0018 s. To conclude, the time measurements between photocells and an inertial system using ANT + are accurate and the proposal presented in this manuscript could make this sport activity monitoring more efficient.

Sports graduate capabilities and competencies: a comparison of graduate and employer perceptions in six EU countries

Abstract The graduate employment market faces ever-increasing socio-economic and political pressures. Higher Education Institutions and the sport sector in the EU have an important role in contributing to graduate employment. The aims of the study were: (1) to assess general perceptions of employability, and (2) to assess sports graduates’ and employers’ perceptions of specific capabilities and competencies in order to identify possible improvements for sports graduate employability programmes. A cross-sectional survey of sports graduates and employers was administered in six EU countries including the UK, France, Germany, Spain, Greece and the Czech Republic to assess graduate and employer perceptions. A graduate capabilities and competencies framework was devised to assess personal, interpersonal, cognitive, role-specific and generic skills. Responses were elicited from 1132 sports graduates and 327 employers. There was generally a wide difference of opinion between employers and sports graduates in terms of the importance and possession of a number of capabilities and competencies. There is a need for the Higher Education sector and employers to take responsibility in ensuring that work experience, work placement and volunteering opportunities are embedded in curricula and to ensure the fitness of purpose of what and how graduate capabilities and competencies are assessed.

Accuracy, intra- and inter-unit reliability, and comparison between GPS and UWB-based position-tracking systems used for time–motion analyses in soccer

Abstract There is interest in the accuracy and inter-unit reliability of position-tracking systems to monitor players. Research into this technology, although relatively recent, has grown exponentially in the last years, and it is difficult to find professional team sport that does not use Global Positioning System (GPS) technology at least. The aim of this study is to know the accuracy of both GPS-based and Ultra Wide Band (UWB)-based systems on a soccer field and their inter- and intra-unit reliability. A secondary aim is to compare them for practical applications in sport science. Following institutional ethical approval and familiarization, 10 healthy and well-trained former soccer players (20 ± 1.6 years, 1.76 ± 0.08 cm, and 69.5 ± 9.8 kg) performed three course tests: (i) linear course, (ii) circular course, and (iii) a zig–zag course, all using UWB and GPS technologies. The average speed and distance covered were compared with timing gates and the real distance as references. The UWB technology showed better accuracy (bias: 0.57–5.85%), test–retest reliability (%TEM: 1.19), and inter-unit reliability (bias: 0.18) in determining distance covered than the GPS technology (bias: 0.69–6.05%; %TEM: 1.47; bias: 0.25) overall. Also, UWB showed better results (bias: 0.09; ICC: 0.979; bias: 0.01) for mean velocity measurement than GPS (bias: 0.18; ICC: 0.951; bias: 0.03).There is interest in the accuracy and inter-unit reliability of position-tracking systems to monitor players. Research into this technology, although relatively recent, has grown exponentially in t...

Early Keratoconus Detection Enhanced by Modern Diagnostic Technology

This chapter describes how to employ a geometrical analysis of the human cornea in order to detect differences in a sample with healthy corneas and corneas with abnormal corneal topography. We obtained geometrical data from a total of 120 patients divided into two groups: healthy (89) and subclinical keratoconic (31) corneas. The proposed detection method generates a virtual 3D solid custom model of the cornea employing Computer-Aided Geometric Design tools and using raw data from a discrete and finite set of spatial points representative of both sides of the corneal surface provided by a corneal topographer. Determined geometric variables are then extracted from the model and statistically analyzed to detect any corneal deformation. The predictive value of the modeled variables was established through a ROC analysis, achieving the Posterior apex deviation variable the best results. This accurate characterization of the human cornea enables new paths in the detection of this type of corneal pathology and offers a new and more integrated tool that facilitates a better diagnosis and follow-up of keratoconus.

Geometrical Analysis of Corneal Topography

The complexity of the structure and shape of the ocular globe, and specially the architecture of the cornea, supposes a particular challenge when a personalised geometric model of the cornea is searched with the aim of representing any morphological alteration when changing from a natural scenario to a pathological case. Therefore, it is essential to know the geometry of the anterior and posterior corneal surfaces to diagnose any pathology related to corneal morphology alteration and thus decide the posterior corrective treatment. With this aim, this chapter proposes a new concept of geometrical analysis of the cornea obtained from a personalised virtual solid model of the cornea, which is generated from a discrete and finite set of spatial points representative of both sides of the corneal surfaces provided by a corneal topographer.

Diagnostic Approach of Corneal Topography Maps

Corneal topography is in charge of performing the study of corneal morphology in both a balanced scenario and in a scenario where a deformation of the tissues that conform the corneal architecture is present. The current state of the art has evolved with the incorporation of a higher number of measuring points of the cornea as new and advanced measuring devices are developed, which leads to a better knowledge of its morphology and to an adequate characterization from the analytic point of view. This chapter presents several new diagnosis approaches of the most important ectatic disease, the keratoconus. These new diagnosis criteria are based on univariate and multivariate quantitative detection systems, systems based on geometric variables obtained by the aid of graphical geometry, systems based on mathematical models and systems based on neural networks.