VIRTUAL ENDOSCOPIC DIAGNOSTIC TECHNIQUE IN DACRYOCYSTITIS Russian patent published in 2013 - IPC A61F9/00 A61B6/03 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, specifically ophthalmology and endoscopic diagnostics. The technique consists in creating a post processing 4D rhinoendoscopy record derived from a combination of two surveying records: a helical computed tomography (HCT) of facial bones and an optical rhinoendoscopy. The findings are used to construct a 3D model of a nasal cavity and an individual manual 3D model of lachrymal passages. The centre of a lachrymal sac, a junction region of the sac and naso-lachrymal duct, and an entry of the duct output into the inferior nasal meatus are marked on the 3D model using a software token. That is followed by integrating the derived 3D model of the sac and naso-lachrymal duct into the 3D pseudoendoscopic model of the nasal cavity. A degree of transparency of the bone structures is specified 25-30%; that provides a basis to construct a dynamic mode of the nasal cavity and lachrymal passages. The above are created within the 3D polar coordinate system with a conical field of vision by displacing a cone point in the 3D model of the nasal cavity from a nasal vestibule to front edges of a middle concha. Thereafter, a video sequence is DVD-recorded thereby creating the virtual rhinoendoscopy record. Then, the derived virtual rhinoendoscopy record is correlated with the real optical rhinoendoscopy record, the derived data are DVD-recorded. Using the given invention enables modeling the position of the lachrymal passages in relation to the intranasal structures by combining the two surveying records those are the optical endoscopy of the nasal cavity and the helical computed tomography of the facial bones.

EFFECT: diagnosing involves no contrast substances to be used, presenting the actual position of the lachrymal sac and a configuration of the surrounding structures that enables choosing an optimal surgical approach, particularly a dacryocystorhinostoma location so that providing the post-operative reliable effective function of the lachrymal passages.

2 cl, 1 ex