DOI QR코드

DOI QR Code

Computational Analysis of Airflow in Upper Airway for Drug Delivery of Asthma Inhaler

천식 흡입기의 약물전달을 위한 상기도내의 유동해석

  • Received : 2014.02.10
  • Accepted : 2014.04.29
  • Published : 2014.09.01

Abstract

Drug delivery in human upper airway was studied by the numerical simulation of oral airflow. We created an anatomically accurate upper airway model from CT scan data by using a medical image processing software (Mimics). The upper airway was composed of oral cavity, pharynx, larynx, trachea, and second generations of branches. Thin sliced CT data and meticulous refinement of model surface under the ENT doctor's advice provided more sophisticated nasal cavity models. With this 3D upper airway models, numerical simulation was conducted by ANSYS/FLUENT. The steady inspiratory airflows in that model was solved numerically for the case of flow rate of 250 mL/s with drug-laden spray(Q= 20, 40, 60 mL/s). Optimal parameters for mechanical drug aerosol targeting of predetermined areas was to be computed, for a given representative upper airways. From numerical flow visualization results, as flow-rate of drug-laden spray increases, the drag spray residue in oral cavity was increased and the distribution of drug spray in trachea and branches became more homogeneous.

상기도 내의 약물 전달을 알아보기 위하여 구강 호흡 시 공기유동에 대한 수치해석을 수행하였다. 상기도는 구강과 후두, 기관과 기관지로 구성되어 있다. 정밀 촬영한 CT 데이터로부터 의료영상 소프트웨어(Mimics)를 이용한 구분(segmentation)과 세심한 표면처리를 통하여 해부학적으로 정확한 모델을 만들 수 있었다. 이 3차원 컴퓨터 모델을 이용하여, 구강에서 기관지의 2번째 분지까지 이르는 유로의 수치 모델을 제작하였다. 수치해석은 상용 소프트웨어인 ANSYS/Fluent를 이용하여 계산하였다. 본 연구에 사용된 모델은 노즐이 부착되지 않은 상태에서 초당 250 mL를 흡입하는 정상 구강호흡 모델과 입구에 각각 20 mL/s, 40 mL/s, 60 mL/s의 유량을 갖는 노즐을 장착한 모델을 사용하였다. 전산 유동가시화 결과로부터, 노즐의 유량을 증가시킬수록 선회류의 발생 정도가 증가하여 구강 내 약물의 잔류 량은 증가하지만, 기관/기관지에 약물 도표는 균일하게 나타났다.

Keywords

References

  1. Korea National Statistical Office, "Prevalence of Asthma Among Adults 19 Years of Age and Over, by Sex(Internet)," Daejeon: National Statistical Office; c2011. Available from: http://www.kosis.kr
  2. Kim, S. M., Jeong, J. H., Lee, J. H. and Rho, S. G., 2009, "Efficiency test Evaluation Method for Nebulizer & Medical Nonventialatory Nebulizer," Journal of Biomedical Engineering Research : the Official Journal of the Korean Society of Medical & Biological Engineering, Vol. 30, No. 5, pp. 438-443.
  3. Chung, S. K. and Kim, S. K., 2008, "Digital Particle Imagevelocimetry Studies of Nasal Airflow," Respir. Physiol. Neurobiol., Vol. 163, pp. 111-120. https://doi.org/10.1016/j.resp.2008.07.023
  4. Chung, S. K., Son, Y., Shin, S. and Kim, S. K., 2006 "Nasal Airflow During Respiratory Cycle," Am. J. Rhinol., Vol. 20, No. 4, pp. 379-384. https://doi.org/10.2500/ajr.2006.20.2890
  5. Kim, S. K. and Chung, S. K. 2009a, "Investigation on the Respiratory Airflow in Human Airway by PIV," J. Visualization 6(4), pp. 274-281.
  6. Geoghegan, P. H., Buchmann, N. A., Spence, C. J. T., Moore, S. and Jermy, M., 2012, "Fabrication of Rigid and Flexible Refractive-Index-Matched Flow Phantoms for Flow Visualization and Optical Flow Measurements," Exp Fluids 52, pp. 1331-1347. https://doi.org/10.1007/s00348-011-1258-0
  7. Kim, S. K. and Son, Y. R., 2002, "Particle Image Velocimetry Measurements in Nasal Airflow," Trans. Korean Soc. Mech. Eng. B, 26(6), pp. 566-569.
  8. Johnstone, A., Uddin, M., Pollad, A., Heeman, A. F. and Finaly, W. H., 2004, "The Flow Inside an Idealized Form of the Human Extra-Thoracic Airway," Experiments in Fluids, Vol. 37, pp. 673-689. https://doi.org/10.1007/s00348-004-0857-4
  9. Ryan, G., Dolovich, M, B., Omminski, G., Cockcroft, D, W., Juniper, E. and Hargreave, F, E., 1981, "Influence of Nebulizer Output, Particle Size, and Method of Inhalation," J. Allergy Clin Immunol, Vol. 67, pp. 156-161. https://doi.org/10.1016/0091-6749(81)90012-9
  10. Barry, P. W., O'Callaghan. 1999, "An in Vitro Analysis of the Output of Budesonide from Different Nebulizer," J. Allergy Clin Immunol, Vol. 104, pp. 1168-1178. https://doi.org/10.1016/S0091-6749(99)70009-6
  11. Doorly, D. J., Franke, V., Gambarruto, A., Taylor, D. J., Schroter, R. C. 2006," Nasal Airflow:Computational and Experimental Modeling," 5th World Congress of Biomechanics, Munich, S270.
  12. Kim, S. K. and Shin, S. J., 2005, "An Investigation on Oscillatory Airflow in Human Airway During Nose Breathing by Tomographic PIV," Trans. Korean Soc. Mech. Eng. B, Vol. 23, No. 5, pp. 137-145.
  13. Woo, S. H. and Kim, K. H., 2008, "Knowledge Related to Disease, Awareness and Practice of Inhaler Use in Asthmatic Patients," J. Korean Acad Fundam Nurs, Vol. 15, No. 4, pp. 418-427.
  14. Lee, J. K. and Yang, Y. H., 2010, "Correct Use of Inhalers in Patients with Obstructive Pulmonary Disease," J. Korean Acad Fundam Nurs Edu, Vol. 16, No. 1, pp. 111-120. https://doi.org/10.5977/JKASNE.2010.16.1.111
  15. Kleinstreuer, C., Zhang, Z. and Li, Z., 2008, "Modeling Airflow and Particle Transport/Deposition in Pulmonary Airways," J. Respiratory Physiology & Neurobiology, Vol. 163, pp. 128-138. https://doi.org/10.1016/j.resp.2008.07.002