| 摘要 |
<p>In one aspect, the present invention is directed to a nose filter adapted to be inserted into a nostril, the nose filter comprising: a housing having an external shape corresponding to the nostril, for enforcing breathed air to pass through the housing; filtering membrane(s), for filtering inhaled air; a first air passageway(s), through the filtering membrane(s); a second air passageway(s), bypassing the filtering membrane(s); and valve(s), for enforcing inhaled air to pass through the filtering membrane(s), and bypass the filtering membrane(s) upon exhalation; wherein the valve(s) are operative to block the second air passageway(s) upon inhalation, and operative to open the second passageway(s) upon exhalation.</p> |
