A Signal Actuated Nebulizer for Use with Breathing Machines

Publisher Website
Google Scholar
Abstract
A nebulizer system has been developed to provide aerosol therapy for seriously ill patients whose breathing is being assisted by mechanical ventilators or breathing machines. This system uses an electrical valve operated Vortran nebulizer nozzle, a 250 mL reservoir (with temperature bath) for protracted operation, and an intermittent electrical signal obtained from the breathing machine for synchronization. There is a built-in air-operated magnetic stlrrer in the nebulizer reservoir to provide uniform nebulization over extended periods of operation for suspensions, colloids, and liposomes in aqueous preparations. This Vortran Intermittent Signal Actuated Nebulizer (VISAN) operates using compressed air or oxygen-enriched air (50 psig) nebulization of respirable droplets (smaller than 3.5 pm MMAD) with concentrations up to 35 μL/L at flow rates up to 300 mL/s, for operating periods as short as 0.5 s. Triple nozzle units can be used to achieve flows up to 800 mL/s. The VISAN generates aerosol only when actuated during the inhalation phase of the breathing cycle, so that the aerosol generation, ventilator flow, and patient inhalation are perfectly synchronized. The airflow from the ventilator passes through the nebulizer system and serves to carry the aerosol to the patient. Up to about 50% of the tidal volume is usually supplied by the nebulizer to maximize total dosage of medication during each tidal breath. The establishment of the desired operating conditions for the nebulizer depends upon the inspiratory time, tidal volume, and appropriate aerosol and ventilator shares of the volume. Inspiratory time and tidal volume are related to the desired breathing rate, the proportion of the breathing cycle associated with inspiration, and the minute volume.

This publication has 2 references indexed in Scilit: