Research on the deposition of inhaled particles in human pulmonary acinus region is important to the pathogenesis investigation, prevention and treatment of lung diseases. Most of the current research focus on the final deposition fraction of inhaled particles in human acinar region, but little is involved in their dynamic deposition characteristics. In this paper, five multi-alveolar models, G3-G7, were built. The evaluation parameter 1/4 deposition time was introduced to study the particle deposition speed. The deposition characteristics of particles in the diameter ranging 0.1-5 μm were numerically simulated and summarized under the influence of factors such as the generation and structure of model, particle diameter and respiratory mode, shedding some new light on the further research of transport of inhaled particles. The results showed that the generation and structure of model had a significance effect on the deposition of particles. 0.1 μm particles were dominated by Brownian diffusion, which experienced a high deposition fraction, a fast deposition speed and a logarithmic deposition curve, while 5 μm particles were dominated by gravitational sedimentation, with a high deposition fraction, a fast deposition speed and an S-shaped deposition curve. The deposition of 0.3-1 μm particles were influenced greatly by convention and varied with the change of respiratory mode. The research methods and results in this paper can provide theoretical basis and data support for the further exploration of the mechanism, prevention and treatment of lung diseases.
Aerosols ; Computer Simulation ; Humans ; Lung ; Models, Biological ; Particle Size

The inhalation and deposition of particles in human pulmonary acinus region can cause lung diseases. Numerical simulation of the deposition of inhaled particles in the pulmonary acinus region has offered an effective gateway to the prevention and clinical treatment of these diseases. Based on some important affecting factors such as pulmonary acinar models, model motion, breathing patterns, particulate characteristics, lung diseases and ages, the present research results of numerical simulation in human pulmonary acinus region were summarized and analyzed, and the future development directions were put forward in this paper, providing new insights into the further research and application of the numerical simulation in the pulmonary acinus region.
Aerosols ; Computer Simulation ; Humans ; Lung ; physiology ; Models, Biological ; Particle Size ; Pulmonary Alveoli ; physiology

Research on the deposition of inhalable particles in the alveoli of the lungs is important to the causes, development for common respiratory diseases such as emphysema, and even the optimization of clinical treatment and prevention programs of them. In this paper, an experimental model was established to simulate the deposition of terminal bronchioles and pulmonary acinus particles. The deposition rate of inhalable particles with different particle sizes in the pulmonary acinus was studied under different functional residual capacity. The results showed that the particle diameter was an important factor affecting the deposition of particles in the lung alveoli. Particles with 1 μm diameter had the highest deposition rate. With the functional residual capacity increasing, particulate deposition rate significantly reduced. The results of this study may provide data support and optimization strategy for target inhalation therapy of respiratory diseases such as emphysema and pneumoconiosis. The established model may also provide a feasible experimental model for studying the deposition of inhalable particles in the pulmonary alveoli.

Objective To investigate the transportation of chemico-biological particles(CBP) through the micropassage inside the human body in order to improve chemico-biological protection.Methods Dissipative particle dynamics (DPD) method was used to study CBP transportation through micropassages inside the human body.Results The Poiseuille flow could be ensured by imposing boundary conditions including pressure gradient and no-slip.The axial velocity between fluid particles and CBPs was well matched except the area close to the passage wall.However, CBPs tended to accumulate and the density of CBPs slightly increased, leading to the jam effect and producing particle accumulation.Conclusion The characteristic of CBP transportation is better understood,which can help develop some chemico-biological protection devices according to movement of CBPs and improve the performance of CBPs during chemico-biological protection.

The research on cycle change form of the pressure and the wall shear in human upper respiratory tract can strengthen understanding of the characteristics of the airflow in the place and provide us with a scientific basis for analyzing the diffusion, transition and deposition patterns of aerosol there. In our study, we used large eddy simulation to emulate the pressure and wall shear in human upper respiratory tract in conditions of the low intensive respiratory patterns, and discussed the distributing disciplinarian of the pressure and wall shear in mouth-throat model and trachea-triple bifurcation. The results showed that the pressure gradient variation in human upper respiratory tract was mainly fastened from root of epiglottis to trachea. The minimum pressure at the interim of inspiration was a duplication of the interim of expiration, and located on the posterior wall of the glottis. The pressure gradient variation was evident on trachea and its fork. The wall shear changed with the velocity of the air flow, and its direction changed periodically with breath cycle.
Biomechanical Phenomena ; Bronchi ; physiology ; Computer Simulation ; Epiglottis ; physiology ; Humans ; Mouth ; physiology ; Nose ; physiology ; Pharynx ; physiology ; Pressure ; Pulmonary Ventilation ; physiology ; Respiratory Mechanics ; physiology ; Respiratory Physiological Phenomena ; Respiratory System ; Shear Strength ; Stress, Mechanical ; Trachea ; physiology

With the development of technology and the deterioration of environment,more and more attention was attracted to the research on fluid dynamics in human upper respiratory tract.In this paper,the methods of research on fluid dynamics in human upper respiratory tract were introduced,and the mechanical models of human upper respiratory tract which were constructed by the scholars in the resent years were summarized.In addition,the current status of research on the airflow movements,the transportation and deposition of the particles in human upper respiratory tract was analyzed.The developing trend of this field was prospected as well.

Obiective To study the compartment environmental quality of ambulance against biological contamination for safe and comfortable transportation and treatment of patients. Methods The experimental research and numerical simulation were carried to master the state of compartment environmental quality, Results Compartment environment indexes excel technology demands, such as overpressure/negative-pressure, temperature, biological contamination, vibration and shock as well as noise and luminance, Conclusion The compartment environmental quality of this ambulance is in a good state.

The technology of info-visualization is recommended.The main research of info-visualization system of medical equipment is proposed and the key technologies involved in that system are discussed.

S95-100field mobile medical system is a field mobile hospital composed of such function cells as medical shelters,tents,special vehicles and transportable containers.Several logistic functions of the cells are introduced including patients checking and sorting,surgery,pre-operation preparation,emergency,clinical laboratory,medical supply,X-ray diagnosis,sterilization,medical command and communication,patient holding ward,logistic technical support and connection.The whole system assignments by different modules clipping and transformations,the application tests and widen tryouts in the army are alsopresented.

Based on the structure characteristics of the stretcher base of WCY2000field ambulance,this paper sets up a finite element analysis model with twotypes of beam elements.The accuracies under twotypes of elements are discussed and model method of the same structure is presented.