A system for measuring a nasal valve collapse of a patient comprising: a facial mask adapted to form a seal with a facial structure of the patient, the facial mask including an endoscope port and an opening to allow air flow; an air flow sensor in fluid communication with the opening of the facial mask configured to measure an air flow across the opening; an endoscope with a camera adapted to pass through the endoscope port in the facial mask for imaging the nasal valve; characterized in that the system comprises a data acquisition module configured to: receive a plurality of images from the camera and a plurality of air flow measurements from the air flow sensor, determine (i) a first image of the plurality of images of the nasal valve taken during inhalation, wherein the first image is synchronized with a non-zero flow measurement of the plurality of air flow measurements and (ii) a second image of the plurality of images of the nasal valve taken during a period between exhalation and inhalation, wherein the second image is synchronized with a zero flow measurement of the plurality of air flow measurements, and determine, based on the first image and the second image, a size difference of the nasal valve during inhalation and during the period between exhalation and inhalation. a facial mask adapted to form a seal with a facial structure of the patient, the facial mask including an endoscope port and an opening to allow air flow; an air flow sensor in fluid communication with the opening of the facial mask configured to measure an air flow across the opening; an endoscope with a camera adapted to pass through the endoscope port in the facial mask for imaging the nasal valve; characterized in that the system comprises a data acquisition module configured to: receive a plurality of images from the camera and a plurality of air flow measurements from the air flow sensor, determine (i) a first image of the plurality of images of the nasal valve taken during inhalation, wherein the first image is synchronized with a non-zero flow measurement of the plurality of air flow measurements and (ii) a second image of the plurality of images of the nasal valve taken during a period between exhalation and inhalation, wherein the second image is synchronized with a zero flow measurement of the plurality of air flow measurements, and determine, based on the first image and the second image, a size difference of the nasal valve during inhalation and during the period between exhalation and inhalation. receive a plurality of images from the camera and a plurality of air flow measurements from the air flow sensor, determine (i) a first image of the plurality of images of the nasal valve taken during inhalation, wherein the first image is synchronized with a non-zero flow measurement of the plurality of air flow measurements and (ii) a second image of the plurality of images of the nasal valve taken during a period between exhalation and inhalation, wherein the second image is synchronized with a zero flow measurement of the plurality of air flow measurements, and determine, based on the first image and the second image, a size difference of the nasal valve during inhalation and during the period between exhalation and inhalation. <EOS>