Tracheostoma filter assembly

摘要

The filter assembly has a housing and filter (2) component movable within the housing in response to breathing. The housing includes a base plate (6) with upstanding flanges (10) and an upstanding ring (12) for engaging the filter. A cap (8) has a lateral flange (14) and a hole (16). The filter comprises one or more layers of filter fabric (22) such as carbon impregnated polyesters. A supporting frame (24) has an upstanding ring (26) with a lateral flange (28) extending from it. The friction between the rings ensures that the inhalation position of the filter is controlled by the pressure differential across the filter layers.