Surgical mask

Claim 1

A SURGICAL MASK COMPRISING: A UNITARY CUP-SHAPED MASK OF IMPERMEABLE MOLDED CONSTRUCTION HAVING A CENTRAL PORTION OF A SIZE AND SHAPE TO COVER THE MOUTH AND NOSTRILS OF A PERSON WEARING THE SAME, AND SUFFICIENTLY FLEXIBLE TO CONFORM WITH ITS EDGE REGION GENERALLY TO THE OUTLINE OF THE PERSON''S FACE ABOUT THE NOSE; AND MASK HAVING INTEGRAL MOLDED CHANNEL PORTIONS DEFINING THE EXTERIOR WALLS OF AIR PASSAGES EXTENDING FROM THE CENTRAL PORTION OF SAID MASK REARWARDLY ALONG EACH SIDE OF SAID MASK, SAID AIR PASSAGES FLARING OUTWARDLY TOWARD THE REAR SO AS TO OPEN SUBSTANTIALLY ADJACENT THE CHECK OF THE PERSON WEARING SAID MASK AND IN A DIRECTION FACING POSTERIORLY OF THE HEAD OF THE PERSON WEARING SAID MASK; SUBSTANTIALLY FLAT PLATE-LIKE MEANS DEFINING THE INTERIOR WALLS OF SAID AIR PASSAGES, SAID PLATE-LIKE MEANS EXTENDING REARWARDLY BEYOND THE EDGE OF SAID MASK AND LYING ADJACENT THE CHEEK OF THE PERSON WEARING SAID MASK SO AS TO PREVENT THE CKEEKS OF THE PERSON FROM OBSTRUCTING SAID AIR PASSAGES, THE SIZE OF SAID CENTRAL PORTION BEING SUCH THAT THE VOLUME ENCLOSED BETWEEN THE FACE OF THE PERSON WEARING THE MASK AND SAID CENTRAL PORTION IS SUBSTANTIALLY EQUAL TO THE COMBINED VOLUME OF SAID AIR PASSAGES; AND STRAP MEANS JOINED TO SAID MASK FOR SUPPORTING THE LATTER ABOUT THE PERSON''S HEAD, WHEREBY EXHALED AIR IS EXHAUSTED FROM SAID CUP-SHAPED MASK THROUGH SAID AIR PASSAGES IN A DIRECTION POSTERIORLY OF THE HEAD OF THE PERSON WEARING SAID MASK AND A SUBSTANTIALLY COMPLETE EXCHANGE OF AIR WITHIN SAID MASK OCCURS WITH EACH INHALATION AND EXHALATION.