Search

Nephrology in Spain has over 60 years of history. Currently, Spain is one of the countries with the longest life expectancy in the world and is expected to top the life expectancy ranking within 20 years. It also leads the ranking of kidney transplantation per million population, and a majority of patients on renal replacement therapy has a functioning kidney graft. However, aging of the population will propel chronic kidney disease-related deaths to second place after Alzheimer’s disease as a cause of death within this century. Thus, a well-prepared, research-oriented Nephrology workforce will be required to tackle the growth of chronic kidney disease and beat expectations.

This chapter introduces an appearance-based approach for topological mapping and localization named FEATMap (Feature-based Mapping). FEATMap relies on a loop closure detection scheme which makes use of local invariant features to describe images. These features are indexed using a set of randomized kd-trees, which permit seeking for matchings between the current and previous images to detect loop closures in a straightforward way. A discrete Bayes filter is added to the solution to obtain loop candidates while ensuring the temporal coherency between consecutive predictions. Finally, FEATMap comprises a method for refining the resulting maps as they are obtained, removing spurious nodes in accordance to the visual information that they contain.

Image mosaicing has gained increasing attention in the last few years, specially for robotic mapping applications. Due to the richness of the sensor data provided, several science fields require the creation of large-area image mosaics for further analysis. In this paper, we propose a novel and generic image mosaicing approach that can produce seamless composites under different configurations in a reasonable amount of time. Our approach is based on a multi-threaded architecture which allows us to execute the different steps of the algorithm simultaneously. To find the topology of the environment, we use a visual index based on a Bag-of-Binary-Words scheme, which is built in an online manner, and thus avoids the classic training step. Our approach is validated under different environments and camera configurations, showing that it can be used on several scenarios producing coherent results in all of them. Furthermore, the implementation of the algorithm is made public to the community.

This chapter describes a novel appearance-based approach for topological mapping called HTMap (Hierarchical Topological Mapping), which is based on a hierarchical decomposition of the environment. Images with similar appearances are grouped together in locations, taking as a representative of the group the average of the PHOG global descriptors of the represented images, as well as the set of their local features, which are indexed by means of OBIndex (which handles them as explained in the previous chapter). As a main innovation, the algorithm proposes a two-level approach to detect loop candidates: first, the global descriptor of the current image is used to determine the most similar location of the map; next, local image features are employed to determine the most likely image within that location.

This chapter introduces a novel method for computing a visual vocabulary online. This binary vocabulary, in combination with an inverted file, conforms an index of images called OBIndex (Online Binary Image Index), which can be used to efficiently retrieve previously seen places. This chapter also presents a topological mapping algorithm called BINMap (Binary Mapping), which makes use of OBIndex as a key component to obtain loop closure candidates during the likelihood computation.

Vessels constitute one of the most cost effective ways of transporting goods around the world. Despite the efforts, maritime accidents still occur, with catastrophic consequences. For this reason, vessels are submitted to periodical inspections for the early detection of cracks and corrosion. These inspections are nowadays carried out at a great cost. In order to contribute to make ship inspections safer and more cost-efficiently, this paper presents a novel Micro-Aerial Vehicle devised as a flying camera that can virtually teleport the human surveyor through the different structures of the vessel hull. The control software has been designed following the Supervised Autonomy paradigm, so that it is in charge of safety related issues such as collision avoidance, while the surveyor, within the main control loop, is supposed to supply displacement commands while he/she is concentrated on the inspection at hand. The paper provides an extensive evaluation of the platform capabilities and usability, both under laboratory conditions and onboard a real vessel, during an inspection campaign.

This paper presents a novel vision-based framework for controlling an Autonomous Underwater Vehicle (AUV). In our application, this AUV is in charge of providing an alternative point of view of a predefined target during a multi-robot intervention mission, where two vehicles cooperate in order to perform the required task. Given this scenario, our framework is based on two main modules: on the one hand, a target detection and tracking module is used to determine the position of the target in the scene; on the other hand, a visual servoing module generates the required velocities for controlling the platform according to the estimated position of the target in the image plane. Results for a set of experiments in different environments are reported and discussed.

Aging is associated with a progressive decrease in glomerular filtration rate, which is associated with an increased cardiovascular mortality risk. Indeed, around 60% of those aged 80 years or older have chronic kidney disease. Thus, population studies in such elderly individuals probably reflect individuals with chronic kidney disease. During aging both systolic blood pressure and pulse pressure progressively increase. It is important to note that there is no consensus among different guidelines for blood pressure targets in the elderly and even less in the elderly with chronic kidney disease. Resistant hypertension is defined as blood pressure above goal despite adherence to a combination of at least three optimally dosed antihypertensive medications, one of which is a diuretic. This is a nonspecific definition, since the precise goal is key to the definition. Despite this, apparent treatment-resistant hypertension is associated with impaired cardiovascular outcomes. We now discuss the management of apparent treatment-resistant hypertension in elderly patients with chronic kidney disease.

Periodic visual inspection of the different surfaces of a vessel hull is typically performed by trained surveyors at great cost, both in time and in economical terms. Assisting them during the inspection process by means of mechanisms capable of automatic or semi-automatic defect detection would certainly decrease the inspection cost. This paper describes a defect detection approach comprising: (1) a Micro-Aerial Vehicle (MAV) which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access; and (2) a coating breakdown/corrosion detector based on a 3-layer feed-forward artificial neural network. The success of the classification process depends not only on the defect detector but also on a number of assistance functions that are provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects are described along the different sections of the paper, as well as the classification performance attained.