A ONE WAY VALVE FOR A DISPOSABLE MOUTHPIECE

摘要

A one way valve (26) for a disposable mouthpiece (28) used by a person to exhale into a respiratory instrument (30), the one way valve (26) comprising a body (32), a through bore in the body (32), and a valve member (36) which extends across the through bore (34), the valve member (36) being flexible and arranged such that it bends when the person exhales in order to allow the passage of the exhaled air from the person into the respiratory instrument and such that it seals when the person inhales in order to prevent the passage of inhaled air from the respiratory instrument into the person and thereby to prevent the person becoming infected with any infection that may be in the respiratory instrument as a result of the respiratory instrument having previously been used by a person who had an infection, characterised in that the valve member (36) is secured to the valve body at a peripheral portion of the valve member (36) and the valve member (36) bends about the peripheral portion when the person exhales.