Research Of Integrated Dry Powder Inhaler Based On Ergonomics

In the past30years, the dry powder inhaler as a kind of pulmonary drugdelivery devices has broad prospect in the treatment of lung disease such as asthma,chronic obstructive pulmonary disease. This paper proposes a kind of integrated drypowder inhaler using compressed gas as drive energy to disperse pharmaceutical,with functions of pumping, automatical feeding of pharmaceutical, device triggeringby inhalation and coordinating between pharmaceutical dispersion and patient’sinspiratory, and analyzes its characteristics using parametric simulation and fluidsimulation, providing theoretical basis for the structure design of dry powderinhaler products and improvement of the clinical efficacy of inhalation therapy.Based on the ergonomics including safety, work efficiency, flexibility, andmaterial properties, we analyze the advantages and disadvantages of existing drypowder inhalers, study the functional elements of ideal dry powder inhalers, and putforward a design of integrated dry powder inhaler; based on the description of theworking mechanism of the inhaler, combined with gas transmission theory, we buildup the mathematical model of gas state parameters and force parameters in theinhaler.Based on mathematical model of the inhaler, we establish control model of theinhaler using proportion link, integral link, and relational operator link in Simulink,and determine the adjustment goals including the time of inhalation triggering, thetimes and the input force of pumping, and the delay time according to the functionalelements of the inhaler based on ergonomics; based on empirical parameters of thereference product, we set up the initial structure parameters for the parametricsimulation, and adjust them in the submodules of control model to obtain structureparameters in line with the adjustment goals and the feasibility of inhaler; then weput the adjusted parameters into the whole control model to obtain the characteristiccurves of the outputs in submodules.Based on multidimensional gas dynamics, we analyze the characteristics of airturbulence in the dispersion pipe of the inhaler; using the computational fluiddynamics software, CFX, we research the influence on the airflow field in thedispersion pipe by changing length and diameter of the dispersion pipe and the inlet pipe; then we contrast and improve the dispersion pipe structure, evaluating effectsof the pharmaceutical diffusion and dispersion in the pipe; finally we operate theparticle tracking simulation in the dispersion pipe, and achieve the particledispersion trace and the change of apparent velocity, concentration and force of thepharmaceutical particles.