Assessment of terminations of a branched lung model using acoustic impedance measurements

Details

• Personal Author:
  Jerabek MA ; Sneckenberger JE ; Stanley CF ; Whitmoyer TB
• Description:
  The measurement of acoustic impedance at frequencies up to 6,400 Hz has been proposed as a diagnostic tool to yield more detailed information about lung condition. A three generation branching system of plastic Y-tubes has been constructed. The impedance of the branched system is measured by an impedance tube using the two-microphone technique. The impedance spectrum is used to calculate the reflection coefficient spectrum, which is converted to an impulse response by an inverse FFT. The area function is extracted from the impulse response by the Ware-Aki algorithm, Measurements of acoustic impedance of the branched system were made for several different end conditions of the eight terminal outlets. The outlets were either blocked with modeling clay, plastic packing material, or aluminum blocks or were unblocked. Six measurements were made of each configuration. In general, the more outlets blocked, the larger the shift to the right of the impedance magnitude peaks for frequencies above 3000 Hz. The impedance magnitude peaks for the plastic packing material were shifted in frequency to the right relative to the peaks of the other system terminations. The impedance magnitude peaks for the clay and aluminum system terminations were significantly different in magnitude but not shifted in frequency. The area functions at the end of the branched system were significantly different (a> 99%) for most of the end conditions. Area functions for the modeled branched lung systems between the end of the impedance tube and the termination outlets of the branched system were similar but distinctively different for the various end conditions. These results indicate that the two-microphone technique can sense small changes in the terminating end conditions of a rigid system of branched tubes and· thus may sense impedance changes due to lung disease in the conducting airways. [Description provided by NIOSH]
• Subjects:
  Lung Lung Diseases Occupational Health Respiratory System Respiratory Tract Diseases Safety
• Keywords:
  Analytical Instruments Analytical Models Analytical Processes Area Function Author Keywords: Acoustic Impedance Lung Disease Lung Disorders Lung Function Lung Model Respiratory Function Respiratory System Disorders

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• ISBN:
  9780873350983
• Publisher:
  Society for Mining, Metallurgy, and Exploration, Inc.
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 3 ; OSHA Region 8 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  139-143
• NIOSHTIC Number:
  nn:20049421
• Citation:
  Respirable dust in the mineral industries, proceedings of the 3rd symposium on respirable dust in the mineral industries, October 17-19, 1990, Pittsburgh, Pennsylvania. Frantz RL, Ramani RV, eds. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 1991 Jan; :139-143
• Contact Point Address:
  T.B. Whitmoyer, Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506
• Editor(s):
  Frantz RL; Ramani RV
• Federal Fiscal Year:
  1991
• Performing Organization:
  West Virginia University
• Peer Reviewed:
  False
• Source Full Name:
  Respirable dust in the mineral industries, proceedings of the 3rd symposium on respirable dust in the mineral industries, October 17-19, 1990, Pittsburgh, Pennsylvania
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5916a6c51e043f24516e1b38f4e0a14ba4a16177b04be36ddfad7cbd5f43fc662191ac680688c27ebc52483e71513b64fe81c95efeb5ea7614bbfb324f863ba4
• Download URL:
  https://stacks.cdc.gov/view/cdc/203869/cdc_203869_DS1.pdf
• File Type:
  [PDF - 3.37 MB ]