Carlos Del Pino

Cirugía virtual para pacientes con obstrucción nasal: empleo de un software basado en dinámica de fluidos (MeComLand®, Digbody® & Noseland®) para documentar parámetros objetivos de flujo y optimizar resultados quirúrgicos

INTRODUCTION Computational fluid dynamics (CFD) is a mathematical tool to analyse airflow. We present a novel CFD software package to improve results following nasal surgery for obstruction. METHODS A group of engineers in collaboration with otolaryngologists have developed a very intuitive CFD software package called MeComLand®, which uses the patients cross-sectional (tomographic) images, thus showing in detail results originated by CFD such as airflow distributions, velocity profiles, pressure, or wall shear stress. NOSELAND® helps medical evaluation with dynamic reports by using a 3D endoscopic view. Using this CFD-based software a patient underwent virtual surgery (septoplasty, turbinoplasty, spreader grafts, lateral crural J-flap and combinations) to choose the best improvement in nasal flow. OBJECTIVE To present a novel software package to improve nasal surgery results. To apply the software on CT slices from a patient affected by septal deviation. To evaluate several surgical procedures (septoplasty, turbinectomy, spreader-grafts, J-flap and combination among them) to find the best alternative with less morbidity. RESULTS The combination of all the procedures does not provide the best nasal flow improvement. Septoplasty plus turbinoplasty obtained the best results. Turbinoplasty alone rendered almost similar results to septoplasty in our simulation. CONCLUSIONS CFD provides useful complementary information to cover diagnosis, prognosis, and follow-up of nasal pathologies based on quantitative magnitudes linked to fluid flow. MeComLand®, DigBody® and NoseLand® represent a non-invasive, low-cost alternative for the functional study of patients with nasal obstruction.

Optimal response of Batchelor vortex

The optimal response of the Batchelor vortex is studied by considering the time-harmonically forced problem with frequency ω. High variance levels are sustained in this system under periodic forcing. The optimal response is largest when the input frequency is null in the axisymmetric case (m = 0). In addition, the axial flow does not play a relevant part in determining the optimal response. When considering helical modes |m| = 1, perturbations are excited through a resonance mechanism at moderate and large wavelengths. At smaller wavelengths, a large response is excited by steady forcing. Regarding the axial flow, the response is largest when the axial velocity intensity is near to zero. For perturbations with larger azimuthal wavenumbers |m| > 1, the magnitude of the response is smaller than those for helical modes. Therefore, studying the response for |m| > 1 is of no interest.