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Forced Oscillation Technique (FOT) and Expiratory Flow Limitation (EFL)

This study has been completed.
Information provided by:
Medical Center Alkmaar Identifier:
First received: July 10, 2007
Last updated: June 5, 2008
Last verified: June 2008
The aim of this study is to distinguish COPD patients with expiratory flow limitation in body plethysmography (open loop) from the patients without expiratory flow limitation in body plethysmography (closed loop) with the obtained FOT parameters.


Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Diagnosing Expiratory Flow Limitation in COPD Patients With the Forced Oscillation Technique Using Linear Regression in the Time Frequency Domain

Further study details as provided by Medical Center Alkmaar:

Estimated Enrollment: 60
Study Start Date: November 2006
Study Completion Date: April 2008
Primary Completion Date: April 2008 (Final data collection date for primary outcome measure)
Detailed Description:
In daily practice the expiratory flow limitation is measured by body plethysmography. An open loop in body plethysmography shows expiratory flow limitation in COPD patients. But body plethysmography requires that the patient quietly sits in a closed box and is not able to follow changes breath by breath. The goal of this study is to validate the Forced oscillation technique (FOT) for measuring expiratory flow limitation in COPD patients.30 COPD patients with an open loop in body plethysmography are compared to 30 COPD patients with a closed loop. The methods used in this study are the maximal overlap discrete short time Fourier transform (MODFT) combined with a total least squares analysis. It is hypothesized that the obtained FOT parameters are able to distinguish the patients with expiratory flow limitation in body plethysmography from the patients without expiratory flow limitation in body plethysmography.Secondary study questions are: 1) to what extend are the FOT parameters distorted by breathing artifacts and measurement noise. 2)What changes can be detected by FOT in expiratory flow limitation after administration of salbutamol.

Ages Eligible for Study:   50 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
Stable GOLD 2-4 COPD patients

Inclusion Criteria:

  • Presenting to the outpatient clinic
  • Age 50-80 years
  • Diagnosed with COPD according to the standard criteria
  • Gold Stage II to IV COPD
  • Current or ex-smokers (at least 10 PY)
  • Stable disease (No current exacerbation or exacerbation during the 4 weeks previous to the inclusion)

Exclusion Criteria:

  • History of exacerbation of COPD in the preceding month
  • Upper airway obstruction
  • Allergic Asthma
  • OSAS (obstructive sleep apnea syndrome)
  • Extreme obesity (BMI>35)
  • Clinically manifest cardiac disease (for example clinically relevant congestive heart failure, unstable angina pectoris)
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Please refer to this study by its identifier: NCT00499304

Medical Center Alkmaar
Alkmaar, Netherlands, 1815JD
Sponsors and Collaborators
Medical Center Alkmaar
Principal Investigator: Dewi Tjiong, drs Medical Center Alkmaar
  More Information Identifier: NCT00499304     History of Changes
Other Study ID Numbers: NL13873.09406
Study First Received: July 10, 2007
Last Updated: June 5, 2008

Keywords provided by Medical Center Alkmaar:
Forced oscillation Technique (FOT)
Expiratory flow limitation (EFL)
Breathing artifacts
COPD processed this record on May 22, 2017