Thermal defogging system and method

An optical instrument comprising:

• an optical element for transmission of optical signals;
• a primary housing that houses the optical element, the primary housing comprising a head configured for insertion into a patient oral cavity, the head of the primary housing defining an aperture for transmission of the optical signals;
• a defogging element coupled to the head of the primary housing, the defogging element comprising:
• a transparent element positioned within the aperture, at least one side of the transparent element facing an external environment;
• and
• a transparent conductive layer covering an area on a surface of the transparent element;
• and
• a removable secondary housing coupled to and covering the head of the primary housing, the removable secondary housing defining a second aperture for transmission of the optical signals, wherein the removable secondary housing comprises an additional transparent element in the second aperture, the additional transparent element lacking a conductive layer, wherein an air gap separates the additional transparent element from the transparent element, and wherein responsive to application of electrical power to the transparent conductive layer, the transparent conductive layer generates heat that is thermally communicated across the air gap to a side of the additional transparent element facing the external environment.

An optical scanning device comprising:

• an optical element for transmission of optical signals;
• a primary housing that houses the optical element, the primary housing comprising a head that is to be inserted into a patient cavity, the head of the primary housing defining an aperture for transmission of the optical signals;
• and
• a defogging element mounted to the primary housing, the defogging element comprising:
• a transparent element positioned within the aperture, at least one side of the transparent element facing an external environment;
• and
• a transparent conductive layer covering at least a portion of the transparent element;
• and
• a secondary housing coupled to and covering the head of the primary housing, wherein the secondary housing protects the optical scanning device from contact with the patient cavity, the secondary housing comprising:
• an additional aperture that aligns with the aperture;
• and
• an additional transparent element in the additional aperture;
• wherein an air gap separates the additional transparent element from the transparent element, and wherein responsive to application of electrical power to the transparent conductive layer, the transparent conductive layer generates heat that is thermally communicated across the air gap to the additional transparent element to defog the additional transparent element of the secondary housing.