Droplets Produced by Medical Nebulizers: Methods (Part 2)
The concentration of sodium chloride in the aerosol droplets generated by the jet nebulizers was measured for different, constant, nebulizer solution temperatures. The lowest temperature used for each nebulizer was approximately the value reached after running the nebulizer without heating to a steady temperature Ts, determined as described previously. The nebulizer bowl, containing 5 ml normal saline solution, was cooled to a nominated temperature by immersion in a cold water bath. buy antibiotics online
The aerosol was then generated and the nebulizer solution temperature kept at the nominated value by immersion in a warm water bath. The temperature of the nebulizer solution was monitored with the miniature esophageal thermistor probe. The temperature was controlled to ± 0.3 degrees during a generation time of 10 to 25 min and generated volume of 1 to 3 ml. The aerosol was passed via a short length of tubing (30 cm) through the last two stages of a cascade impactor (DCI6, Deiron, Columbus, OH) and collected in a small container of similar dimensions to a cascade impactor slide. The flow through the impactor stages was 12.5 L/min, and the dilution air necessary to supplement the flow through the nebulizer was supplied either at ambient temperature (23 to 24°C) and humidity (65 to 75 percent) or fully humidified at ambient temperature via a Douglas bag.