Resumen Contexto: Los cirujanos de intervenciones mínimamente invasivas requieren ampliar la información para realizar las rutas de intervención, este artículo describe un prototipo de realidad mixta de carácter educativo o pre quirúrgico que hace uso del Casco Metavision Meta II. Se crearon objetos 3D de estructuras morfológicas para neurocirugía y laparoscopia a partir de imágenes obtenidas de resonancia magnética MRI y TAC de un paciente real, con el fin de simular el acceso al cerebro y hacer reconocimiento del área abdominal. Métodos: Este prototipo tiene un enfoque educativo cuyo objetivo es incentivar el reconocimiento de esquemas morfológicos de órganos, para lo cual se diseñaron tres pruebas. Estas pruebas consistieron en la búsqueda de tumores a través de la navegación y la interacción con un objeto exhibido en el casco de realidad mixta Meta 2. Para el área neurológica se dedicaron dos de las tres pruebas, en las dos primeras pruebas se midió el tiempo de búsqueda con cinco tumores, y para el área abdominal se realizó también una prueba para la búsqueda de dos tumores, diseñándose diversas interacciones en el recorrido espacial del objeto 3D generado, usando pantallas con despliegues de los cortes tomados de imágenes de tomografía computarizada. Posterior al desarrollo de las tres pruebas se realizó un proceso de medición de inmersión a partir del uso de un cuestionario. Resultados: El 100% de los usuarios encontró altamente interesante la aplicación, en tanto que el 90% expresó que intentó fijar su foco de atención en el desarrollo exitoso de la prueba, indicador del nivel de absorción de la aplicación. También el 70% de los usuarios describió su experiencia como de alto nivel de inmersión. Conclusiones: Las pruebas demostraron que el prototipo es usable, absorbente y tiene un nivel de inmersión aceptable.

Abstract Context: This article describes an educational or pre-surgical mixed-reality prototype using the Metavision Meta II headset. 3D objects of morphological structures for neurosurgery and laparoscopy were created from MRI and CT images of a real patient in order to simulate the access to the brain and conduct a reconnaissance of the abdominal area. Method: This prototype has an educational approach whose objective is to encourage the recognition of morphological schemes of organs, for which three tests were designed. These tests consisted of searching for tumors through navigation and interaction with an object displayed in the Meta 2 mixed-reality headset. Two of the three tests were dedicated to the neurological area, in which the search time was measured with five tumors, and a test was conducted for the abdominal area regarding the search of two tumors, designing various interactions in the spatial path of the generated 3D object. An immersion measurement process was conducted which was based on the use of a questionnaire. Results: 100% of users found the application highly interesting, while 90% expressed that they tried to focus their attention on the successful completion of the test, an indicator of the level of absorption of the application. Furthermore, 70% of users described their experience as highly immersive. Conclusions: Tests showed the prototype to be usable, absorbent, and has an acceptable level of immersion.

Abstract The aim of this study was to compare the post-thaw distribution of motile sperm subpopulations, following simple or colloid centrifugation. A new analysis was used to evaluate the available number of sperm from each subpopulation after each centrifugation protocol. Frozen/thawed semen samples were divided into the following after-thawing treatments: uncentrifuged control (UDC), sperm washing (SW) and two colloid centrifugation procedures (Equipure, SLC-E, and Androcoll, SLC-A). Percentage of total and progressive motility (TM and PM), as well as sperm motility kinematics, distribution of motile sperm subpopulations, and recovery rates, were statistically compared among treatments. The SLC treatments showed higher (P < 0.001) TM and PM than UDC and SW. Following each SLC procedure, different percentages of the subpopulation with the most vigorous and progressive sperm (sP4) were obtained. SLC-A recovered a larger number of sperm belonging to sP4 than SLC-E, but not significantly higher than SW. From a practical point of view, sperm washing, the standard centrifugation procedure for equine semen processing, recovered the same amount of fast and progressive sperm as colloid centrifugation, apparently the best treatment according to traditional analysis. In conclusion, samples processed by SLC have higher motility percentages than SW and UDC but, after combining the available number of sperm, SLC and SW techniques are equally efficient in recovering sperm from the most vigorous, fast and progressive motile subpopulation (sP4).