Method of forming an image of cilium and cilia

A method of forming an image of detailed cilium wrapped by mucus which exists in the epithelial layer of a cellular structure inside of a bronchus, the method comprising the steps of:

• irradiating an illumination light to the epithelial layer from a direction inclined 45 degrees or more with respect to an optical axis of an image pick-up optical system;
• generating a Fresnel reflected light according to a refractive index difference of between the mucus and the cilium;
• irradiating the Fresnel reflected light as a halation light for the image pick-up optical system provided on an upper part of the epithelial layer;
• enlarging the Fresnel reflected light by the image pick-up optical system;
• scanning at a velocity which is more than the velocity of motion of the cilium and with resolving power by which the image pick-up element can recognize the cilium;
• transmitting an electrical signal from the image pick-up element to a television monitor;
• and
• performing a scanning display at a velocity which is more than the velocity of motion of the cilium and with resolving power by which the television monitor can recognize the cilium.