Method to Characterize Exhaled Nitric Oxide from the Airways Using a Sequence of Breathhold Maneuvers
The new breath-hold technique may have potential to characterize airway NO exchange in subjects unable to perform single-breath exhalations.
Researchers at the University of California have developed a new technique to characterize airway NO, which requires a series of progressively increasing breath-hold times followed by exhalation of only the airway compartment. Using our new technique, we determined values (means + SE) in healthy adults (20-38 yr, n = 8) for the airway diffusing capacity [4.5 + 1.6 pl/s-1 parts per billion (ppb)-1], the airway wall concentration (1,340 + 213 ppb), and the maximum airway wall flux (4,350 + 811 pl/s). Relative to previously described single-breath techniques of the current art, our new breath-hold technique has two distinct advantages. First, the exhalation flow need not be controlled, providing a simpler maneuver to complete for both the subject and the investigator or clinician. Second, the technique provides improved accuracy (smaller confidence interval) for estimating DawNO relative to the single-breath technique with a 20-s breath hold and decreasing exhalation flow. Thus, the technique is relatively simple to perform and does not require monitoring or control of exhalation flow, and determined airway NO parameters agree well with a previously described single-breath technique. In addition, the impact of two important physical and anatomical features, neglected for simplicity in previous models, have been included; namely, axial diffusion of NO in the gas phase and an increasing cross-sectional area of the airway tree with axial position (i.e., trumpet shape).
Patent Number: US7427269B2
Application Number: US2006636027A
Inventor: George, Steven C. | Shin, Hye-Won | Condorelli, Peter
Priority Date: 12 Dec 2005
Priority Number: US7427269B2
Application Date: 8 Dec 2006
Publication Date: 23 Sep 2008
IPC Current: A61B000508
US Class: 600532 | 600529 | 600533
Assignee Applicant: The Regents of the University of California
Title: Accurate method to characterize airway nitric oxide using different breath-hold times including axial diffusion of nitric oxide using heliox and breath hold
Usefulness: Accurate method to characterize airway nitric oxide using different breath-hold times including axial diffusion of nitric oxide using heliox and breath hold
Summary: For characterizing NO gas exchange dynamics in human lungs for physiological processes in disease states such as smooth muscle tone in asthma.
Novelty: Nitric oxide (NO) gas exchange dynamics characterization method for physiological processes in e.g. asthma involves measuring airway NO parameters during consecutive breath hold maneuvers and diagnosing disease states of lungs
Biomedical
Medical Device
7427269
Tech ID/UC Case 18826/2005-162-0 Related Cases 2005-162-0
USA
