| Dental high-speed handpieces and other oral diagnostic and therapeutic equipment generate a large amount of microbiological aerosols containing bacteria,viruses,and other microorganisms during high-speed drilling,grinding,and ultrasonic high-frequency vibration therapy,which have a high risk of infection and pathogenicity.In response to the urgent need to address the special requirements for the treatment of oral microbial aerosols and to block the transmission routes of oral microbial aerosols in the context of the COVID-19 pandemic,this thesis uses Image J’s image stack feature pattern matching to study the propagation characteristics of microbial aerosols and reveal their diffusion rules.The DPM model in FLUENT fluid simulation software is used to simulate the aerosol diffusion process,and multi-channel adsorption mouthpieces with negative pressure adsorption are studied based on this to achieve real-time and reliable adsorption of microbial aerosols generated during oral treatment.Plasma component aerodynamic layout and key component aerodynamic acoustic optimization are carried out to reduce flow losses and turbulent noise,improve aerodynamic efficiency,and reduce operating noise,thereby reducing the threat of noise in the clinic.The reliability of the theoretical research of the equipment is verified through equipment adsorption experiments.The main research content of this thesis is as follows:(1)Study on the diffusion characteristics of microbial aerosols.Based on the real-time target capture and fast image recording principles of high-speed cameras,images of the diffusion of aerosols and other splatter materials in the near-field small-scale space during oral treatment are captured.The image stack feature pattern matching of the Image J image recognition and processing software is used to track and sequentially label the continuous flow of aerosols in the images,synthesize the aerosol motion trajectory map,and measure the aerosol diffusion distance,diffusion angle,and flow velocity in different oral regions through aerosol tracking and diffusion angle measurement.(2)Study on the multi-channel adsorption characteristics of the equipment.The FLUENT discrete phase DPM model is used to simulate the diffusion process of oral aerosols,and the adsorption process of the aerosol diffusion by the adsorption device’s suction port is analyzed through simulation.By adjusting the negative pressure value and the number of suction ports,the optimal adsorption scheme is explored to achieve efficient adsorption of aerosols generated during oral treatment,providing a theoretical basis for the structural design of the adsorption device.(3)Design of adsorption equipment structure and optimization of equipment component layout.By analyzing the functional requirements of the adsorption equipment and clarifying the working principle of the equipment,the selection of key components is determined,and a three-dimensional model of the adsorption equipment is established using SOLIDWORKS 3D modeling software.Meanwhile,under the premise of ensuring the coupling mechanism between the working efficiency and energy efficiency of the components,the influence of different layout forms of the plasma generator components inside the equipment on the aerodynamic and acoustic performance of the equipment is compared,and the plasma generator layout is optimized to reduce the airflow loss and operating noise of the equipment.(4)Aerodynamic and acoustic optimization of key components of the adsorption equipment.The centrifugal fan is an important power source and noise source of the equipment,which affects the efficiency of aerosol adsorption and the safety of noise in the clinic.In order to improve the aerodynamic efficiency of the fan and reduce the aerodynamic noise,the blade structure of the fan was optimized.By adjusting the perforation form,diameter,and perforation rate of the blades,the aerodynamic performance of the centrifugal fan was improved by 11%,and the acoustic performance was improved by 3%.Finally,porous media materials were filled inside the blades,and the acoustic performance of the equipment was improved to 5.3%.By optimizing the centrifugal fan,the adsorption efficiency of the equipment was improved,and the impact of overall operating noise on medical staff and patients was reduced.(5)Prototype production and experimental verification of the adsorption equipment.Based on the design scheme and 3D model of the adsorption equipment,a prototype is produced and the adsorption performance of the equipment is experimentally verified using a oral diagnosis and treatment model.Fluorescein is used to track the diffusion of aerosol particles,and control experiments with and without the adsorption equipment are set up to verify the adsorption effect by detecting the number and particle size distribution of the collected fluorescein points.This thesis investigates the diffusion laws of microbial aerosols and develops a multi-channel adsorption device.The aerodynamic layout optimization of the device components and the aerodynamic and acoustic optimization of key components ensure efficient adsorption and low-noise operation of the adsorption device.This effectively prevents the diffusion of microbial aerosols in the clinic,which is of great significance in preventing the spread of epidemics and protecting the diagnosis and treatment safety of dental patients and medical personnel. |
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