Oral inhalation of aerosolized drugs has be widely applied in healing the affected body organs including lesions of the throat and lungs and it is more effiicient than those conventional therapies,such as intravenous ...Oral inhalation of aerosolized drugs has be widely applied in healing the affected body organs including lesions of the throat and lungs and it is more effiicient than those conventional therapies,such as intravenous drip,intramuscular injection and external topical administration in the aspects of the dosage reduction and side effects of drugs.Never-theless,the traditional atomization devices always exhibit many drawbacks.For example,non-uniformed atomization particle distribution,the instability of transient atomization quantity and difficulties in precise energy control would seriously restrict an extensive use of atomization inhalation therapy.In this study,the principle of intra-hole fluctua-tion phenomenon occurred in the hole is fully explained,and the produced volume change is also estimated.Addi-tionally,the mathematical expression of the atomization rate of the atomizing device is well established.The mecha-nism of the micro-pump is further clarified,and the influence of the vibration characteristics of the atomizing film on the atomization behavior is analyzed theoretically.The curves of sweep frequency against the velocity and amplitude of the piezoelectric vibrator are obtained by the Doppler laser vibrometer,and the corresponding mode shapes of the resonance point are achieved.The influence of vibration characteristics on atomization rate,atomization height and atomization particle size are also verified by experiments,respectively.Both the experimental results and theoretical calculation are expected to provide a guidance for the design of this kind of atomization device in the future.展开更多
Traditional atomization devices always exhibit many drawbacks,such as non-uniform atomization particle sizes,instability of transient atomization quantity and uncontrollability of precise energy,which seriously restri...Traditional atomization devices always exhibit many drawbacks,such as non-uniform atomization particle sizes,instability of transient atomization quantity and uncontrollability of precise energy,which seriously restrict further practical application of atomization inhalation therapy.The formation and separation process of droplets belongs to a microphenomenon of atomization.The investigation of the droplet formation and separation process will be favorable for understanding the atomization mechanism.In present work,the Conservative Level Set Method(CLSM)is successfully applied on the simulation of the formation and separation of droplets in a medical piezoelectric atomization device induced by intra-hole fluctuation.The intra-hole fluctuation mechanism is systematically explored and analyzed,and also the expression of the volume change in the micro cone hole is built and evaluated.Both the control equation and simulation model of droplet formation and separation process have been well established by meshing the simulation model,and thereby the process of droplet formation and separation is simulated.The corresponding results demonstrate that the breaking time of droplets is decreased with the inlet velocity and liquid temperature rising,while enhanced with the liquid concentration increasing.Meanwhile,the volume of droplet is decreased with the inlet velocity and liquid concentration increasing,but increased with the liquid temperature rising.The velocity of droplet is enhanced with the inlet velocity and liquid temperature rising,and reduced with the increase of liquid concentration.When the large side diameter of micro-cone hole is set as 79μm,the breaking time of the droplet reaches a minimum value of 38.7μs,whereas the volume and the velocity of droplet reach a maximum value of 79.8 pL and 4.46 m/s,respectively.This study provides theoretical guidance for the design of medical piezoelectric atomization devices and contributes to the promotion of inhalation therapy in practical use.展开更多
基金Supported by Open Fund of State Key Laboratory of Remote Sensing Science of China(Grant No.OFSLRSS 201913)Guangdong Provincial Basic and Applied Basic Research Foundation of China(Grant No.2019B151520017).
文摘Oral inhalation of aerosolized drugs has be widely applied in healing the affected body organs including lesions of the throat and lungs and it is more effiicient than those conventional therapies,such as intravenous drip,intramuscular injection and external topical administration in the aspects of the dosage reduction and side effects of drugs.Never-theless,the traditional atomization devices always exhibit many drawbacks.For example,non-uniformed atomization particle distribution,the instability of transient atomization quantity and difficulties in precise energy control would seriously restrict an extensive use of atomization inhalation therapy.In this study,the principle of intra-hole fluctua-tion phenomenon occurred in the hole is fully explained,and the produced volume change is also estimated.Addi-tionally,the mathematical expression of the atomization rate of the atomizing device is well established.The mecha-nism of the micro-pump is further clarified,and the influence of the vibration characteristics of the atomizing film on the atomization behavior is analyzed theoretically.The curves of sweep frequency against the velocity and amplitude of the piezoelectric vibrator are obtained by the Doppler laser vibrometer,and the corresponding mode shapes of the resonance point are achieved.The influence of vibration characteristics on atomization rate,atomization height and atomization particle size are also verified by experiments,respectively.Both the experimental results and theoretical calculation are expected to provide a guidance for the design of this kind of atomization device in the future.
基金Guangdong Basic and Applied Basic Research Foundation(Grant No.2019B1515120017).
文摘Traditional atomization devices always exhibit many drawbacks,such as non-uniform atomization particle sizes,instability of transient atomization quantity and uncontrollability of precise energy,which seriously restrict further practical application of atomization inhalation therapy.The formation and separation process of droplets belongs to a microphenomenon of atomization.The investigation of the droplet formation and separation process will be favorable for understanding the atomization mechanism.In present work,the Conservative Level Set Method(CLSM)is successfully applied on the simulation of the formation and separation of droplets in a medical piezoelectric atomization device induced by intra-hole fluctuation.The intra-hole fluctuation mechanism is systematically explored and analyzed,and also the expression of the volume change in the micro cone hole is built and evaluated.Both the control equation and simulation model of droplet formation and separation process have been well established by meshing the simulation model,and thereby the process of droplet formation and separation is simulated.The corresponding results demonstrate that the breaking time of droplets is decreased with the inlet velocity and liquid temperature rising,while enhanced with the liquid concentration increasing.Meanwhile,the volume of droplet is decreased with the inlet velocity and liquid concentration increasing,but increased with the liquid temperature rising.The velocity of droplet is enhanced with the inlet velocity and liquid temperature rising,and reduced with the increase of liquid concentration.When the large side diameter of micro-cone hole is set as 79μm,the breaking time of the droplet reaches a minimum value of 38.7μs,whereas the volume and the velocity of droplet reach a maximum value of 79.8 pL and 4.46 m/s,respectively.This study provides theoretical guidance for the design of medical piezoelectric atomization devices and contributes to the promotion of inhalation therapy in practical use.
