Mechanical Improvement of Gas Monitoring System in Monoplace Hyperbaric Chamber to Advance the Safety and Efficacy.

Introduction: A Monoplace hyperbaric chamber delivers oxygen to the patient's tissues through breathing. Gas monitoring inside the chamber is important because oxygen (O₂) is consumed, and carbon dioxide (CO₂) is increased because treatment is performed in a closed volume. This study aimed to advance the safety and efficacy of the monoplace hyperbaric chamber (MHC) through mechanical improvement in a gas monitoring system (GMS).

Methods: First, as the oxygen supply method was changed to the direction of the patient's face, it was compared the values of O₂, CO₂, humidity, and temperature were measured in the MHC and the GMS when operating at 2.0 atmosphere absolute (ATA) and 3.0 ATA. Second, to evaluate the effects of variables across measuring time, it was analyzed in a 3-way repeated measure ANOVA (10 min.×20 min.×30 min.). Lastly, the values before and after the optimization of the MHC were compared by applying a cooler to prevent temperature rise inside the MHC.

Results: In 2.0 ATA, the average humidity was higher in the MHC than in the GMS (p<0.001). Also, the average temperature was lower in the MHC than in the GMS (p<0.001). In 3.0 ATA, the average CO₂ and humidity were higher in the MHC than in the GMS, respectively (p<0.001, p=0.004). The 3-way repeated measures ANOVA revealed a significant difference in most main and interacted factors (p<0.05). O₂ and temperature, comparing before and after MHC optimization, revealed a significant difference (p<0.05).

Conclusion: Few studies have verified safety and effectiveness by evaluating the pressure, oxygen concentration, etc. of a monoplace hyperbaric chamber. Further research is expected to verify the effectiveness of providing comfort to patients receiving hyperbaric oxygen treatment and increase the treatment effect.