Structure Comparison And Optimization Of Children’s Atomizing Masks Based On Drug Utilization

The form and development of children’s body systems and organs are immature,their physiological functions are not perfect,their resistance is relatively low,and they are easy to be invaded by external germs,among which respiratory diseases are the most prominent.Aerosol inhalation has become a widely used medical treatment for children with respiratory diseases.Nebulizing involves dispersing drugs into tiny droplets or particles that are suspended in a gas and enter the respiratory tract as the patient breathes in to relieve bronchospasm and dilate the bronchus.In the process of using medical atomizing masks,children’s compliance is poor and they do not cooperate with treatment due to reasons such as stuffy breathing,drug odor,wearing foreign body sensation and loud noise of atomizer,resulting in poor atomizing treatment effect and a large amount of liquid medicine waste.In order to improve the utilization rate of drugs in the process of atomizing inhalation and improve the sense of respiratory distress,four kinds of mask structures（forward intake type,down intake type,inner short tube type and outer short tube type）were proposed based on the existing structures of children’s atomizing masks in the market.The numerical simulation method was adopted.The structure was compared and optimized in terms of drug utilization rate,residual CO₂in the hood,particle movement status,diameter and velocity of drug delivery inlet.The results show that:（1）When the drug delivery speed is 1.2m/s,the diameter of the drug delivery port is15mm,and the diameter of the air outlet balance hole is 7mm,compared with the four mask structures,Outer short tube type>Front intake type>Inner short tube type>Lower intake type.（2）Under the same conditions,the residual concentration of CO₂in the mask of the four types of masks at the end of expiratory breath is Front intake type<Inner short tube type<Lower intake type<Outer short tube type.That is,the short tube type mask is more likely to cause congestion in the process of atomization than the other three models.Considering the drug utilization rate and residual concentration of CO₂,the forward intake model is recommended for children’s atomization.（3）For the front intake model mask,by comparing the performance of the mask under the same flow,different delivery speeds and diameters,it was found that the drug utilization rate could be better improved by controlling the delivery speed below0.7m/s and not less than 0.3m/s.However,as the delivery speed decreases,the atomization time will be extended correspondingly.Without considering the medication time,the diameter of drug delivery inlet can be set to 7mm,and the drug utilization rate can reach 60%.Under the premise of the same drug delivery flow,reducing the drug delivery speed is more significant than reducing the inlet diameter to improve drug utilization.