Heat and Moisture Exchanging Filters

摘要

A pleated filter in a housing comprises hydrophobic (10) and hydrophilic (11) sheets, preferably laminated together, and is connected between a patient and a ventilator in an open breathing system, with the hydrophobic sheet nearest to the patient. The hydrophobic sheet comprises resin-bonded ceramic fibres and has an alcohol bubble point of more than 710 mm of H2O to capture micro-organisms. The hydrophilic sheet comprises cellulose, may be continuous or slotted and captures moisture from exhaled breath, allowing it to be picked up again by inhaled air.