Flowgy Documentation

Everything you need to know about Flowgy to extraordinarily improve medical diagnosis and nasal surgery.

FLOWGY — the power of medical efficiency
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CT Display

Point Tracking System

Real-time synchronization of the three visualization planes (coronal, sagittal and axial)

Segmented image synchronization

Synchronized display of the segmented image from the CT with the original CT Scan.

Scanning and analysis of DICOM files

Automatic scanning of local directories for DICOM files for selection, preview and upload to Flowgy.

X, Y, Z coordinate tracking on images

When you set a point in the coronal view and scroll sideways, Flowgy updates the images in the sagittal view automatically; if you scroll vertically, Flowgy will update the images in the coronal view.

Brightness and Contrast

Manual adjustment of brightness and contrast in CT images for easy viewing.

2 and 3D formats

Flowgy supports the following formats: NRRD, JPG, PNG, TIFF, STL, OBJ, DICOM


Image capture of each of the 3 views and storage on hard disk in JPG or similar image format.

Segmentation & Surgery

Automatic paranasal sinus identification

Flowgy automatically and selectively identifies and removes sinuses.

Automatic segmentation

The segmentation algorithms are automatically applied to the CT Scan.

Segmentation filters

The filters allow the user to modify the view of the segmentation adapting it to his needs.

Import of segmentations

Flowgy supports segmentations made with other segmentation software for your virtual surgery and airflow analysis.


All CT Scans are automatically resampled in order to maintain the aspect ratio and increase their quality and definition.

2D Surgery Brush Tool

The user selects the size of the scalpel with which, by moving the mouse over each CT image, the interior of the shape of the scalpel is transformed into solid material or air, depending on the user's selection. The newly created material/air can be synchronized with a previously generated virtual surgical 3D model.

2D Surgery Polyline Tool

The user can create closed polylines with as many points as necessary. These polylines can be applied to other CT images. At the same time, a spline is generated according to the point distribution of the polyline. The inside/outside of the polylines or their corresponding splines can be filled with material or air.

2D Surgery Polyline Contour Tool

By creating a minimum number of polylines, Flowgy generates by interpolation a sequence of polylines in the remaining CT images. This set of polylines will be used to create the deformable surfaces that will be seen later.

3D Surface Surgery

Selection of the diameter of the scalpel with which, by moving the mouse over the surface of the three-dimensional model, a certain number of layers are removed. This number of layers is configurable by the user.

Volumetric 3D Surgery

Selection of the shape and size of a three-dimensional scalpel which, once positioned on the 3D model, allows its interior to be filled with solid/air.

3D synchronization

3D surgery (superficial or volumetric) synchronized with CT images and vice versa. In such a way that all surgery performed on the 3D model will be updated and shown on the 2D model and vice versa, as can be seen in this image.

Surface Deformation Surgery 2 and 3D

By means of the selection of polylines, different work areas are established, forming a 3D work model, which can be deformed and filling with air or solid the hollows or areas that are outside or inside this volume, thus allowing the surgery to be performed by deforming the 2D and 3D models.


Removal and/or creation of material/air using various systems, either 2D or 3D surgeries.

Visualization effects

Flowgy presents different views of the 3D model, either Smooth in which we see the completely solid model or points with which we visualize the model in the form of points allowing us to see the inside of the model.

Visualization Plans

These planes can be parallel to the axial, coronal and sagittal planes, and inclined.

Measurement tools

Measurements of distances, areas and volumes on the 3D models.


Flowgy allows the creation of structures in addition to those that come by default in order to be able to block or use those that we need; thanks to this system a new selection can be created and a new type of structure can be assigned to it in such a way that at the time of operating only that structure is operated or in its defect this structure is invariable.

Point Tracking 2 and 3D

Flowgy is able to identify a point in the 3D model and update the segmented image or CT scan in real time, allowing the marked point to be visualized. In this way it is very easy to locate and follow in real time, which part you are modifying in the surgery.

Surgery over the CT Scan

Ability to use the segmented view as the CT view to perform virtual surgery, showing the changes in real time.

Surgery over other 3D formats

3D surgery on STL models or similar (without the need for their transformation prior to a DICOM or similar).


Superficial mesh

It consists of the distribution of surface elements or cells (triangles and squares) over the entire surface of the geometry.

Volume meshing

It consists of the distribution of volume elements (tetrahedrons, prisms, hexahedrons and pyramids) inside the volume enclosed by the surface mesh.

Meshing for boundary layer resolution

This is a volumetric mesh composed of a series of layers of prisms and with a distribution of heights much smaller than the size of the base.

Automatic CFD mesh

Fully automatic CFD meshing of the surface and volume of the nasal cavity including the patient's face, as well as the assignment of CFD contour conditions and mask or nasal cavity exterior, to the direct result of the segmentation.

CFD compatibility

Export and import of the CFD surface to other formats (STL, OBJ, ...)

Optimization of the surface mesh

Automatic closure of holes in the surface mesh and automatic detection of intersections of surface and volume elements. Algorithms for surface mesh improvement (elimination of high-grade nodes, needles, improved aspect ratio, ...)

Checking the mesh

Mesh checks to validate volumetric and surface meshing.

Mesh calculation and modification tools

Calculation of curvatures and thicknesses, assignment tools for the establishment and manipulation of boundary conditions, refining and collapsing of elements with different criteria (curvature, thicknesses, ...) re-meshing of flat surfaces defined by the user, cuts of the surface mesh with predefined planes, with separation and closure of the result of the cut and the establishment of different types of computer domains (mask, infinity ...)


Visualization of fluid variables

Visualization of fluid variables (Temperature, Pressure, Speed, ...) To facilitate the visualization of these fluid variables, Flowgy uses a plane creation system, in order to create a plane that cuts the computational volume and to be able to visualize the flow inside the computational field.

Analysis and calculation

Analysis, calculation and storage of the R and Phiestimators, along with the rest of the fluid and geometric parameters of the patient. Calculation of magnitudes in selected areas (areas, perimeters, volumes, flows), as well as curvatures and thickness fields (the result is analogous to an Acoustic Rhinometry)

Technical visualization

Visualization of isolines and vector fields.

Current lines

Calculation, visualization and disk storage of current lines.

Detailed study of the airflow

Cuts of the nasal cavity with axial, sagittal, coronal and inclined planes, which allow the visualization of the internal air flow.