Clinical and in vitro evaluation of membrane humidifier that does not require addition of water

Abstract

It is well known that conventional bubbling humidifiers are capable of producing micro-aerosols contaminated with bacteria. We developed a unique humidifier, named a membrane humidifier, that does not require an external water supply. This new system obtains moisture from room air. We investigated the clinical and in vitro evaluation of the membrane humidifier. Ten patients with chronic pulmonary disease participated in the study. We evaluated the partial pressure of oxygen in arterial blood (PaO2) of 10 patients who used the new device. We conducted an in vitro study to determine whether the device could prevent the bacterial contamination of humidified-oxygen. We passed compressed air contaminated with Pseudomonas aeruginosa outside the hollow fibres of the membrane humidifier, and the humidified-oxygen passed inside the hollow fibres was sampled into nutrient broth periodically for 10 days. We also compared the relative humidity of oxygen humidified by a membrane humidifier with that of oxygen humidified by a bubbling humidifier. There was no significant difference between measured PaO2 while breathing oxygen humidified using a membrane humidifier and that while breathing oxygen humidified using a bubbling humidifier. Cultures of the humidified-oxygen passed through the hollow fibres were negative for bacteria. The membrane humidifier could produce good humidification. The new device appeared to prevent bacterial contamination, and may help to reduce the risk of infection in patients at hospital and home.

Telemonitoring of Home Oxygen Therapy: A Review of the State of the Art and Introduction of a New Cloud-based System

“…In Japan, new functions have been added to oxygen concentrators so that patients can use HOT comfortably. 32 Interviews during outpatient hospital visits are not sufficient for confirming in adequate detail the usage conditions of oxygen concentrators at home, and research has shown the difficulties associated with determining whether oxygen is inhaled at an appropriate flow rate during HOT. 33 To solve these problems, we have developed an analytical system that allows health care providers to use their own computers to analyze the usage conditions of oxygen concentrators and integrated time-series data consisting of pulse rates and SpO 2 values measured by patients themselves with a dedicated pulse oximeter.…”