Accession Number:

ADA454946

Title:

Prevention of Facial Cold Injury with a Passive Heat and Moisture Exchanger

Descriptive Note:

Conference paper

Corporate Author:

JOZEF STEFAN INST LJUBLJANA (SLOVENIA) DEPT OF AUTOMATION

Personal Author(s):

Report Date:

2005-05-01

Pagination or Media Count:

5.0

Abstract:

The present study evaluated the thermodynamic characteristics of a prototype respiratory heat and moisture exchanger HME, particularly its ability to prevent cold injury to the face. The HME comprised a thermally insulated oro-nasal mask with a cylindrical heat and moisture exchanger protruding from the centre of the mask. The heat exchanging unit contained an aluminium honeycomb structure providing a surface area of 478.5 sq cm for exchange of heat and moisture between the inspired and expired air. A breathing simulator was used to simulate the temperature and humidity of the expired air. The HME was strapped to the head of a manikin, whose mouth was connected to the respiratory simulator. The entire arrangement was placed in a climatic chamber. We evaluated the efficiency of the HME at two different rates of ventilation and at five different ambient conditions -24, -14, -4, 8, and 22 C. The efficiency of the HME was evaluated by determining the performance coefficient PC under each condition. In all subzero ambient conditions, the HME was able to maintain the temperature within the oro-nasal mask above 20 C. By maintaining mask temperature above 20 C in subzero temperatures, the HME can effectively eliminate the risk of freezing cold injury FCI of the facial region.

Subject Categories:

  • Stress Physiology
  • Protective Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE