RESUMO
In this paper, the development of a copper-chrome-based glass microheater and its integration into a Polymethylmethacrylate (PMMA) microfluidic system are presented. The process highlights the importance of an appropriate characterization, taking advantage of computer-simulated physical methods in the heat transfer process. The presented system architecture allows the integration for the development of a thermal flow sensor, in which the fluid flows through a 1 mm width × 1 mm length microchannel across a 5 mm width × 13 mm length heating surface. Using an electrothermal analysis, based on a simulation and design process, the surface heating behavior curve was analyzed to choose a heating reference point, primarily used to control the temperature point within the fluidic microsystem. The heater was characterized using the theory of electrical instrumentation, with a 7.22% error for the heating characterization and a 5.42% error for the power consumption, measured at 0.69 W at a temperature of 70 °C. Further tests, at a temperature of 115 °C, were used to observe the effects of the heat transfer through convection on the fluid and the heater surface for different flow rates, which can be used for the development of thermal flowmeters using the configuration presented in this work.
RESUMO
Introducción: los defectos del cráneo y las anomalías del hueso craneofacial que requie-ren reconstrucción son comunes en una variedad de procedimientos neuroquirúrgicos. Después de una craniectomía o de fracturas craneofaciales posteriores a traumatismos cráneoencefálicos, los pacientes pueden desarrollar defectos cosméticos importantes. Algunos de estos son la depresión de la piel y un defecto de hundimiento que lleva a una apariencia asimétrica de la cabeza, sin dejar de lado las repercusiones físicas, neu-rológicas y psicológicas que estas lesiones conllevan. La reconstrucción craneofacial y la craneoplastía tienen una larga historia, pero las nuevas técnicas quirúrgicas y una multitud de opciones de materiales han impulsado recientemente el avance en esta área. Los implantes de polimetilmetacrilato (PMMA) han demostrado ser estables, bio-compatibles, no conductores, radiotransparentes y de bajo costo. Es así que se pueden colocar y modificar fácilmente, con lo que se elimina la morbilidad del sitio donante. Presentación del caso: en este artículo presentamos un caso de craneoplastía de defec-to frontal, posterior a traumatismo, cuya reconstrucción fue realizada mediante una prótesis de polimetilmetacrilato (PMMA) en el Hospital General Xoco de la Cuidad de México. Conclusión: se reporta la reducción del tiempo quirúrgico, además de un costo de la prótesis accesible para el paciente; de esta manera, se obtuvieron resultados sa-tisfactorios y mejoras en el contorno estético facial, en tanto se permitió cobertura y protección para el tejido encefálico.
Introduction: Skull defects and craniofacial bone abnormalities that require reconstruction are common in a variety of neurosurgical procedures. After craniectomy or craniofacial fractures following cranioencephalic trauma, patients can develop important cosmetic defects, such as depression of the skin and a sunken flap that can lead to an asymmetrical appearance of the head, without neglecting the physical and psychological repercussions. neurological that these injuries carry. Craniofacial reconstruction and cranioplasty have a long history, but new surgical techniques and a multitude of material options have recently fueled progress in this area. Polymethylmethacrylate (PMMA) implants have proven to be stable, biocompatible, non-conductive, radiolucent, and inexpensive. They can be easily placed and modified and the morbidity of the donor site is eliminated. Clinical case: In this article, we present a case of frontal defect cranioplasty after trauma performed using a polymethylmethacrylate (PMMA) prosthesis at the General Hospital Xoco in Mexico City. Conslusion: The surgical time could be reduced, in addition to the cost of the prosthesis. It was accessible to the patient and obtained satisfactory results such as improvements in the facial aesthetic contour and obtained coverage and protection for the brain tissue.