Natural Polymers as Heat and Moisture Exchange Devices for Medical Applications

Abstract

In recent decades, Heat and Moisture Exchange (HME) devices have been employed increasingly for short-term use in anaesthesia and long-term use in intensive care units. These devices work as heat exchangers, accumulating the patient’s expired heat and moisture and returning them to the patient during the inhalation phase. Porous matrices obtained from freeze-drying of blends of natural polymers exhibit high open and interconnected porosity and water vapour intake characteristics which make them possible candidates for HME devices. Preliminary tests were conducted on specimens made of gelatine blended with chitosan and treated with a non-toxic cross-linking agent. The tests were carried out in cyclic flow conditions with saturated and dried air. Results show water vapour retention comparable with accepted standards for HME devices.