Characterization of Novel Fabry Pérot Filter Arrays for Nanospectrometers in Medical Applications

Optische Spektroskopie ist eine sehr wichtige Messtechnik mit einem hohen Potential für zahlreiche Anwendungen in der Industrie und Wissenschaft. Kostengünstige und miniaturisierte Spektrometer z.B. werden besonders für moderne Sensorsysteme “smart personal environments” benötigt, die vor allem in der Energietechnik, Messtechnik, Sicherheitstechnik (safety and security), IT und Medizintechnik verwendet werden. Unter allen miniaturisierten Spektrometern ist eines der attraktivsten Miniaturisierungsverfahren das Fabry Pérot Filter. Bei diesem Verfahren kann die Kombination von einem Fabry Pérot (FP) Filterarray und einem Detektorarray als Mikrospektrometer funktionieren. Jeder Detektor entspricht einem einzelnen Filter, um ein sehr schmales Band von Wellenlängen, die durch das Filter durchgelassen werden, zu detektieren. Ein Array von FP-Filter wird eingesetzt, bei dem jeder Filter eine unterschiedliche spektrale Filterlinie auswählt. Die spektrale Position jedes Bandes der Wellenlänge wird durch die einzelnen Kavitätshöhe des Filters definiert. Die Arrays wurden mit Filtergrößen, die nur durch die Array-Dimension der einzelnen Detektoren begrenzt werden, entwickelt. Allerdings erfordern die bestehenden Fabry Pérot Filter-Mikrospektrometer komplizierte Fertigungsschritte für die Strukturierung der 3D-Filter-Kavitäten mit unterschiedlichen Höhen, die nicht kosteneffizient für eine industrielle Fertigung sind. Um die Kosten bei Aufrechterhaltung der herausragenden Vorteile der FP-Filter-Struktur zu reduzieren, wird eine neue Methode zur Herstellung der miniaturisierten FP-Filtern mittels NanoImprint Technologie entwickelt und präsentiert. In diesem Fall werden die mehreren Kavitäten-Herstellungsschritte durch einen einzigen Schritt ersetzt, die hohe vertikale Auflösung der 3D NanoImprint Technologie verwendet. Seit dem die NanoImprint Technologie verwendet wird, wird das auf FP Filters basierende miniaturisierte Spectrometer nanospectrometer genannt. Ein statischer Nano-Spektrometer besteht aus einem statischen FP-Filterarray auf einem Detektorarray (siehe Abb. 1). Jeder FP-Filter im Array besteht aus dem unteren Distributed Bragg Reflector (DBR), einer Resonanz-Kavität und einen oberen DBR. Der obere und untere DBR sind identisch und bestehen aus periodisch abwechselnden dünnen dielektrischen Schichten von Materialien mit hohem und niedrigem Brechungsindex. Die optischen Schichten jeder dielektrischen Dünnfilmschicht, die in dem DBR enthalten sind, entsprechen einen Viertel der Design-Wellenlänge. Jeder FP-Filter wird einer definierten Fläche des Detektorarrays zugeordnet. Dieser Bereich kann aus einzelnen Detektorelementen oder deren Gruppen enthalten. Daher werden die Seitenkanal-Geometrien der Kavität aufgebaut, die dem Detektor entsprechen. Die seitlichen und vertikalen Dimensionen der Kavität werden genau durch 3D NanoImprint Technologie aufgebaut. Die Kavitäten haben Unterschiede von wenigem Nanometer in der vertikalen Richtung. Die Präzision der Kavität in der vertikalen Richtung ist ein wichtiger Faktor, der die Genauigkeit der spektralen Position und Durchlässigkeit des Filters Transmissionslinie beeinflusst.

Compact Representations for Fast Nonrigid Registration of Medical Images

We develop efficient techniques for the non-rigid registration of medical images by using representations that adapt to the anatomy found in such images. Images of anatomical structures typically have uniform intensity interiors and smooth boundaries. We create methods to represent such regions compactly using tetrahedra. Unlike voxel-based representations, tetrahedra can accurately describe the expected smooth surfaces of medical objects. Furthermore, the interior of such objects can be represented using a small number of tetrahedra. Rather than describing a medical object using tens of thousands of voxels, our representations generally contain only a few thousand elements. Tetrahedra facilitate the creation of efficient non-rigid registration algorithms based on finite element methods (FEM). We create a fast, FEM-based method to non-rigidly register segmented anatomical structures from two subjects. Using our compact tetrahedral representations, this method generally requires less than one minute of processing time on a desktop PC. We also create a novel method for the non-rigid registration of gray scale images. To facilitate a fast method, we create a tetrahedral representation of a displacement field that automatically adapts to both the anatomy in an image and to the displacement field. The resulting algorithm has a computational cost that is dominated by the number of nodes in the mesh (about 10,000), rather than the number of voxels in an image (nearly 10,000,000). For many non-rigid registration problems, we can find a transformation from one image to another in five minutes. This speed is important as it allows use of the algorithm during surgery. We apply our algorithms to find correlations between the shape of anatomical structures and the presence of schizophrenia. We show that a study based on our representations outperforms studies based on other representations. We also use the results of our non-rigid registration algorithm as the basis of a segmentation algorithm. That algorithm also outperforms other methods in our tests, producing smoother segmentations and more accurately reproducing manual segmentations.

How to improve the formal analytic reasoning and scientific motivation in the intellectual training of medical students

A review article of the The New England Journal of Medicine refers that almost a century ago, Abraham Flexner, a research scholar at the Carnegie Foundation for the Advancement of Teaching, undertook an assessment of medical education in 155 medical schools in operation in the United States and Canada. Flexner’s report emphasized the nonscientific approach of American medical schools to preparation for the profession, which contrasted with the university-based system of medical education in Germany. At the core of Flexner’s view was the notion that formal analytic reasoning, the kind of thinking integral to the natural sciences, should hold pride of place in the intellectual training of physicians. This idea was pioneered at Harvard University, the University of Michigan, and the University of Pennsylvania in the 1880s, but was most fully expressed in the educational program at Johns Hopkins University, which Flexner regarded as the ideal for medical education. (...)

A Multiagent System for Coordinating Ambulances for Emergency Medical Services

To coordinate ambulances for emergency medical services, a multiagent system uses an auction mechanism based on trust. Results of tests using real data show that this system can efficiently assign ambulances to patients, thereby reducing transportation time. Emergency transportation on specialized vehicles is needed when a person's health is in risk of irreparable damage. A patient can't benefit from sophisticated medical treatments and technologies if she or he isn't placed in a proper healthcare center with the appropriate medical team. For example, strokes are neurological emergencies involving a limited amount of time in which treatment measures are effective

Anatomy of a medical journal article

This tutorial reviews the common elements that all journal articles contain (abstract, methods, etc.) and what can be learned from each element. In addition, the tutorial distinguishes between scholarly journal articles and other publications. The Health Education Assets Library (HEAL) is a digital library that provides freely accessible digital teaching resources of the highest quality that meet the needs of today's health sciences educators and learners.

The Sociology of the Web

A sociologist's description of the Web as a socially constructed/discovered/encountered piece of technology.

La educational sociology y su incidencia en el desarrollo de la sociología de la educación.

Resumen tomado de la publicación

Influencia de las creencias religiosas cristianas en la decisión de realizar suicidio asistido al final de la vida

El suicidio asistido como una posible opción al final de la vida, es una idea que hasta ahora está siendo considerada, ya que existen argumentaciones a favor y en contra que han generado controvertidos debates a su alrededor. Algunos de los argumentos en contra están basados en los principios de las instituciones religiosas de orden cristiano, las cuales defienden el valor sagrado de la vida de las personas y la aceptación del sufrimiento como un acto de amor profundo y sumisión a los mandatos de Dios, el creador. Mientras del lado contrario, se encuentran quienes defienden el procedimiento, impulsando la autonomía y la autodeterminación que cada persona tiene sobre su vida. La revisión de la literatura realizada no sólo permite ampliar los argumentos de estas dos posiciones, sino que también permite conocer la historia del suicidio asistido, la posición que este procedimiento tiene en diferentes países del mundo, incluyendo a Colombia, y finalmente se presentan las contribuciones de la psicología entorno al procedimiento en discusión.

Legal Sociology Reformulated: the Transformation of Law in Globalization and New Citizenship

This article seeks to demonstrate how Law inter-related with Economy, constitutes in modern societies one of the main instruments for the construction of citizen consensus or the construction of political hegemony in modern societies. If we consider this affirmation —as is argued here— the transformations suffered in recent decades by Law as a consequence of the new phase of capitalistic globalization, have played an important role in the constitution of a new subjectivity (“single thought”) in the population.

Medical Student’s Use of Time During Clinical Clerkships and the Credits Based System

Introduction: Comprehensive undergraduate education in clinical sciences is grounded on activities developed during clerkships. To implement the credits system we must know how these experiences take place. Objectives: to describe how students spend time in clerkships, how they assess the educative value of activities and the enjoyment it provides. Method: We distributed a form to a random clustered sample of a 100 students coursing clinical sciences, designed to record the time spent, and to assess the educative value and the grade of enjoyment of the activities in clerkship during a week. Data were registered and analyzed on Excel® 98 and SPSS. Results: mean time spent by students in clerkship activities on a day were 10.8 hours. Of those, 7.3 hours (69%) were spent in formal education activities. Patient care activities with teachers occupied the major proportion of time (15.4%). Of the teaching and learning activities in a week, 28 hours (56%) were spent in patient care activities and 22.4 hours (44.5%) were used in independent academic work. The time spent in teaching and learning activities correspond to 19 credits of a semester of 18 weeks. The activities assessed as having the major educational value were homework activities (4.6) and formal education activities (4.5). The graded as most enjoyable were extracurricular activities, formal educational activities and independent academic work. Conclusion: our students spend more time in activities with patients than the reported in literature. The attending workload of our students is greater than the one reported in similar studies.

Medical Students Circadian Sleep Rhythms and Academic Performance

Objective: to evaluate, with a preliminary study, the distribution of circadian rhythms, sleep schedule patterns and their relationship with academic performance on medical students. Methodology: in this descriptive study, a 10 item original questionnaire about sleep rhythms and academic performance was applied to medical students from different semesters. Week (class time) and weekend schedules, preferences, daytime somnolence and academic performance were asked. Three chronotypes (morningness, intermediate and eveningness) were defined among waking-sleeping preference, difficulty to sleep early, exam preparation preference hour and real sleep schedule. The sleep hour deficit per week night was also calculated. Results: Of the 318 medical students that answered the questionnaire, 62.6% corresponded to intermediate chronotypes, 8.8% to evening-type and 28.7% to morning-type. Significant difference was found among the two chronotype tails (p=0.000, Chi-square 31.13). No correlation was found between academic performance and age, sex, chronotype, week sleep deficit and sleep hours in week and weekends. A 71.1% of the students slept 6 or fewer hours during class time and 78% had a sleep deficit (more frequent in the evening chronotype). Conclusions: No relation was found between sleep chronotype and academic performance. Students tend to morningness. Few studies have been made on equatorial zones or without seasons

Medical Evaluation Processes in Clinical settings. Qualitative Analysis through the Experience of Teachers and Studens

Evaluation processes in clinical practice have not been well, being their study focused on the technical issues concerning these processes. This study tried an approach to the evaluation processes through the analysis of perceptions from teachers and students about the methodology of evaluation considering the teachinglearning processes performed in a clinical practice of the Medicine Program –Universidad El Bosque from Bogota. With this purpose we conducted interviews with teachers and students searching the manner in which the evaluative, learning and teaching processes are done; then we analyzed the perception from both agents concerning the way these processes are related. The interviews were categorized bath deductively and inductively, and then contrasted with some current theories of learning, teaching and evaluation in medicine. The study showed that nowadays the evaluation and, in general, the educative processes are affected by several factors which are associated to the manner the professional practice is developed, and the educative process of the current teachers. We concluded there is no congrency between the approach of the evaluation, mainly conductivist, and the learning and teaching strategies mainly constructivist. This fact cause dissent in teachers and students.

Experience of the Flexible Internship in University of Rosario-Medical School

Objective: To evaluate the flexible program implemented for the medical internship at School of Medicine, Universidad del Rosario during the period 1997-2002. Methodology: A descriptive study was performed to summarize the choices of medical clerkships made by the interns during the whole studied period. The coincidence with the further choice of a determined medical specialty was assessed. Conclusions: Most of the last year’s students remain preferring a conservative approach to their career, by choosing clerkships in a basic area, such as internal medicine, pediatrics, gynecology and obstetrics or general surgery. The coincidence between the type of internship or clerkships a student performs and the future election of a specialty is high.

Colombian Medical Education System: A Hundred Years Behind

Almost one hundred years ago the Carnegie Foundation for the Advancement of Teaching authorized a study and report about the medical education of the United States and Canada directed by Mr. Abraham Flexner an education expert of the time. This report turned out to be one of the most important documents of the medical education revolution that took place by that time in North America and that led it to become what it is today. Almost a century after that, Colombian medical education has reached an outstanding similarity to the system described in the Flexner report. The present article highlights the parallel between North America’s medical education situation a hundred years ago and Colombia’s actual medical education situation. We present here some notions about the actual education system based on what was described on 1910 and which we consider, constitutes the current medical education situation on our country and possibly on many Latin American countries.