## CFD

It is an acronym for Computational Fluid Dynamics. Fluid Dynamics is the science that describes the motion of a fluid (gas or liquid) by means of mathematical equations. These equations, when solved, give the values of all quantities which describe the fluid motion, like velocity, pressure, temperature. The attribute Computational indicates that these equations are solved by means of numerical methods. So, basically, CFD is a numerical method that can be implemented on a computer that, solving mathematical equations,

describes the behavior of a given fluid in a given condition. CFD is used in a wide set of fields, here some examples: to describe the air motion around a vehicle, the fluid motion inside a valve, the smoke dispersion inside a parking lot or the airflow of the nasal cavities.

CFD – https://conself.com/blog/common-cfd-terms-explained/

## Virtual Surgery

It refers to the virtual simulation of surgical procedures with the objective of training medical professionals, without the need of a patient, cadaver or animal. Flowgy integrates and combines different virtual surgery technologies that allow to modify, either on the CT Scan or on a three-dimensional model of the patient’s own nasal cavity, the anatomical structure allowing the simulation of a surgical procedure.

Virtual Surgery – https://www.sciencedirect.com/science/article/abs/pii/S001048251830129X?via%3Dihub

## Fluid mechanics

It is the branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas) and the forces on them. It has applications in a wide range of disciplines, including mechanical, civil, chemical and biomedical engineering, geophysics, oceanography, meteorology, astrophysics, and biology.

Fluid mechanics – https://en.wikipedia.org/wiki/Fluid_mechanics

## Rhinomanometry

It measures nasal pressure and airflow during breathing. It gives a functional measure of the pressure- flow relationships during the respiratory cycle, is accepted as the standard technique for measuring nasal airway resistance and assessing the patency of the nose.

Rhinomanometry – https://www.sciencedirect.com/topics/medicine-and-dentistry/rhinomanometry

## Acoustic rhinometry

It uses a reflected sound signal to measure the cross-sectional area and volume of the nasal passage. Acoustic rhinometry gives an anatomic description of a nasal passage.

Acoustic rhinometry – https://www.sciencedirect.com/topics/medicine-and-dentistry/rhinomanometry

## CT Scan

A CT scan or computed tomography scan (formerly known as computed axial tomography or CAT scan) is a medical imaging technique used in radiology to get detailed images of the body non-invasively for diagnostic purposes. The personnel that perform CT scans are called radiographers or radiology technologists.

CT Scan – https://en.wikipedia.org/wiki/CT_scan

## Image Segmentation

It is the process by which a digital image is partitioned into multiple segments (pixels), and whose objective is to simplify the representation of the image for a more efficient analysis.

Image Segmentation – https://en.wikipedia.org/wiki/Image_segmentation

## Convergence

The Fluid Dynamics equations are solved by means of numerical methods, that are generally iterative. The number of iterations needed to obtain the correct solution varies. It is possible to measure how far one is from the correct solution, and to use that measure to stop the iterative method when the correct solution is reached. When it happens, the analysis is said to be Converged or to have reached Convergence, which simply means that the obtained solution is correct.

Convergence – https://conself.com/blog/common-cfd-terms-explained/

## Non- Dimensional Estimators

The Non-Dimensional parameters are used by Flowgy to quantitatively measure the grade of nasal cavity obstruction. The first mathematical estimator Φ is a function of geometric features and possible asymmetries between the nostrils, whereas the second estimator R represents in fluid mechanics terms the total nasal resistance corresponding to the atmosphere-channel pressure drop.

Non-Dimensional Estimators – https://onlinelibrary.wiley.com/doi/10.1002/cnm.2906