Bond Graph modeling of the human esophagus and analysis considering the interference in the fullness of an individual by reducing mechanical esophageal flow

INTRODUCTION: This paper shows a proposal for the mathematical modeling of the human esophagus using Bond Graph formalism and the interference in the satiation of an individual by way of an Esophageal Flow Controller (EFC). Therefore, it was evaluated that there is a significant change in fall time that affects the process of human satiety when the diameter of the esophagus is reduced. METHODS: As a first study, the analysis did not consider all hypothetical influences; only the most important variables were considered. RESULTS: As a result, the order of the final equation was x ∈ ℜ10. Furthermore, the designed model can be classified as linear, established and time invariant. CONCLUSION: The simulation results allow us to conclude that using the EFC in order to reduce the esophageal diameter in the upper esophageal sphincter area of 3cm by 1 cm implies that the system response will be slower; and consequently this reduction will interfere with satiety.

Electronic temperature monitoring during the decompression surgery of the facial nerve.

Despite of its apparent protection by being located deep in a bony canal, the facial nerve is a cranial pair of nerves more vulnerable to traumatic injuries. The surgical accidents are the most frequent causes of intratemporal complications of the facial nerve. Among the postoperative sequelae, the thermal injuries are common due to overheating of the otologic burr resulting in facial paralysis. For the prevention of thermal injuries in the facial nerve was designed a data acquisition board to obtain the temperature measured by thermocouples using a PC and parallel communication. The signals from the temperature sensors passed through conditioning for amplification and analog to digital data conversion. Afterwards, they were stored on a computer for the statistical analysis and the visualization of the curves of variation of the measured temperatures. These curves provide the verification of the facial nerve temperature ascending and descending time during surgery steps to access the nerve. These data provide a substantial safe working margin to the surgeon.