Sliding to predict: vision-based beating heart motion estimation by modeling temporal interactions

Purpose: Technical advancements have been part of modern medical solutions as they promote better surgical alternatives that serve to the benefit of patients. Particularly with cardiovascular surgeries, robotic surgical systems enable surgeons to perform delicate procedures on a beating heart, avoiding the complications of cardiac arrest. This advantage comes with the price of having to deal with a dynamic target which presents technical challenges for the surgical system. In this work, we propose a solution for cardiac motion estimation. Methods: Our estimation approach uses a variational framework that guarantees preservation of the complex anatomy of the heart. An advantage of our approach is that it takes into account different disturbances, such as specular reflections and occlusion events. This is achieved by performing a preprocessing step that eliminates the specular highlights and a predicting step, based on a conditional restricted Boltzmann machine, that recovers missing information caused by partial occlusions. Results: We carried out exhaustive experimentations on two datasets, one from a phantom and the other from an in vivo procedure. The results show that our visual approach reaches an average minima in the order of magnitude of 10-7 while preserving the heart’s anatomical structure and providing stable values for the Jacobian determinant ranging from 0.917 to 1.015. We also show that our specular elimination approach reaches an accuracy of 99% compared to a ground truth. In terms of prediction, our approach compared favorably against two well-known predictors, NARX and EKF, giving the lowest average RMSE of 0.071. Conclusion: Our approach avoids the risks of using mechanical stabilizers and can also be effective for acquiring the motion of organs other than the heart, such as the lung or other deformable objects.Peer ReviewedPostprint (published version

Compactness in Banach space theory - selected problems

We list a number of problems in several topics related to compactness in nonseparable Banach spaces. Namely, about the Hilbertian ball in its weak topology, spaces of continuous functions on Eberlein compacta, WCG Banach spaces, Valdivia compacta and Radon-Nikod\'{y}m compacta

El bienestar psicológico percibido por jóvenes que viven en distintas configuraciones familiares en la zona metropolitana de Guadalajara

El presente documento busca abordar el tema del bienestar psicológico, entendido éste a partir de los múltiples factores intrínsecos y extrínsecos en la vida de un sujeto, por ejemplo: sus emociones (positivas y negativas), relaciones familiares, conductas, pensamientos y relaciones personales. Se parte de la premisa de que el bienestar está relacionado con la configuración familiar, y con base en esta configuración un sujeto puede considerarse con características cualitativamente distintas en las formas de significar el bienestar y el malestar. La metodología utilizada fue la entrevista a profundidad con enfoque autobiográfico y la evaluación de bienestar psicológico aplicada a cada uno de los participantes.ITESO, A.C

The Hubble Diagram of the Calan/Tololo Type Ia Supernovae and the value of Ho

The Calan/Tololo supernova survey has discovered ~30 Type Ia supernovae out to z~0.1. Using BVI data for these objects and nearby SNe Ia, we have shown that there exists a significant dispersion in the intrinsic luminosities of these objects. We have devised a robust chisquare minimization technique simultaneously fitting the BVI light curves to parametrize the SN event as a function of (tb,m, m15(B)) where tb is the time of B maximum, m is the peak BVI magnitude corrected for luminosity variations, and m15(B) is a single parameter describing the whole light curve morphology. When properly corrected for m15(B), SNe Ia prove to be high precision distance indicators,yielding relative distances with errors 7-10%. The corrected peak magnitudes are used to construct BVI Hubble diagrams (HD), and with Cepheid distances recently measured with the HST to four nearby SNe Ia (37C, 72E, 81B, 90N) we derive a value of the Hubble constant of 63.1+/-3.4 (internal) km/s/Mpc. This value is ~10-15% larger than the value obtained by assuming that SNe Ia are perfect standard candles. As we have shown in Paper V, there is now strong evidence that galaxies with younger stellar population appear to host the slowest-declining, and therefore most luminous SNe Ia. Hence, the use of Pop I objects such as Cepheids to calibrate the zero point of the SNe Ia HD can easily bias the results toward luminous SNe Ia, unless the absolute magnitude-decline relation is taken into account.Comment: 32 pages, figures attached, all tables available, to appear in the Astronomical Journa

V-ANFIS for Dealing with Visual Uncertainty for Force Estimation in Robotic Surgery

Accurate and robust estimation of applied forces in Robotic-Assisted Minimally Invasive Surgery is a very challenging task. Many vision-based solutions attempt to estimate the force by measuring the surface deformation after contacting the surgical tool. However, visual uncertainty, due to tool occlusion, is a major concern and can highly affect the results' precision. In this paper, a novel design of an adaptive neuro-fuzzy inference strategy with a voting step (V-ANFIS) is used to accommodate with this loss of information. Experimental results show a significant accuracy improvement from 50% to 77% with respect to other proposals.Peer ReviewedPostprint (published version

Towards retrieving force feedback in robotic-assisted surgery: a supervised neuro-recurrent-vision approach

Robotic-assisted minimally invasive surgeries have gained a lot of popularity over conventional procedures as they offer many benefits to both surgeons and patients. Nonetheless, they still suffer from some limitations that affect their outcome. One of them is the lack of force feedback which restricts the surgeon's sense of touch and might reduce precision during a procedure. To overcome this limitation, we propose a novel force estimation approach that combines a vision based solution with supervised learning to estimate the applied force and provide the surgeon with a suitable representation of it. The proposed solution starts with extracting the geometry of motion of the heart's surface by minimizing an energy functional to recover its 3D deformable structure. A deep network, based on a LSTM-RNN architecture, is then used to learn the relationship between the extracted visual-geometric information and the applied force, and to find accurate mapping between the two. Our proposed force estimation solution avoids the drawbacks usually associated with force sensing devices, such as biocompatibility and integration issues. We evaluate our approach on phantom and realistic tissues in which we report an average root-mean square error of 0.02 N.Peer ReviewedPostprint (author's final draft

A Roller (Coracias garrulus) presumably nesting in a White Stork (Ciconia ciconia) nest

Els llocs escollits per a la instal·lació del niu del gaig blau són molt diversos i estan relacionats amb la seva distinta disponibilitat. Aquí es presenta una observació d'un gaig blau que presumiblement criava en un niu de cigonya en una devesa boscosa de la província de Badajoz on la disponibilitat de nius no era un factor limitant per a la reproducció. Un gaig blau adult es va observar mentre portava una llagosta al bec en el moment que entrava en un forat entre les branques situades a la base del niu. Aquest comportament es podria explicar per la major defensa que les espècies grans fan del seu niu, cosa que donaria al gaig blau un avantatge en la defensa del seu propi niu

The Absolute Luminosities of the Calan/Tololo Type Ia Supernovae

We examine the absolute luminosities of 29 SNe Ia in the Calan/Tololo survey. We confirm a relation between the peak luminosity of the SNe and the decline rate as measured by the light curve, as suggested by Phillips (1993). We derive linear slopes to this magnitude-decline rate relation in BV(I)kc colors, using a sample with Bmax-Vmax < 0.2 mag. The scatter around this linear relation (and thus the ability to measure SNe Ia distances) ranges from 0.13 mag (in the I band) to 0.17 mag (in the B band). We also find evidence for significant correlations between the absolute magnitudes or the decline rate of the light curve, and the morphological type of the host galaxy.Comment: 21 pages, 4 figures, to appear in the Astronomical Journa

Aves limícolas (Charadrii) en un embalse del centro de la Península Ibérica durante el ciclo anual: zonas interiores vs. zonas litorales

The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii.The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii.The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii