Breating pattern by inductive plethysmography in relatidon to bronchial obstruction in asthma
1993 (English)Licentiate thesis, comprehensive summary (Other academic)
This work aimed at improving a method for "non-invasive" ventilatory monitoring (the respiratory inductive plethysmography; RIP), and at assessing whether RIP can be used for detection and monitoring of bronchial obstruction in asthma.
The RIP measures the changes in rib cage and abdominal cross-sectional areas during breathing. These movements are translated into lung volume estimates via RIP calibration against e.g. a pneumotachometer. The commercially available RIP device (Respitrace®) was exploited.
New PC software for RIP data acquisition, calibration, validation and on-Iine display of RIP derived breathing parameters was developed. This software has considerably increased the ease of RIP data acquisition and analysis.
The software was used for evaluation of three models of the ventilatory system: an original linear model; an alternative linear mode!; anda non-linear model of second degree.
The original linear mode! for the ventilatory system, which relates lung volume changes from the start of inspiration or expiration to rib cage and abdominal excursion from the start of respiratory motion, had the best accuracy. When using the original linear mode! for RIP calibration, the errors for tidal volume estimation were ≤ 10% <luring normal tidal volume breathing, and ≤ 20% <luring !arge tidal volume breathing in all subjects.
The new RIP system was used to see if the natura! breathing pattem changes consistently among asthmatic subjects when FEV 1 has fallen at least 20% during a bronchial histamine challenge. Only 4 of the 8 patients showed a significant increase in minute ventilation (mean 72%) and mean inspiratory flow (mean 80% ). It was concluded that breathing pattem analysis is nota adequate method for airway obstruction monitoring during bronchial challenge.
Place, publisher, year, edition, pages
Linköping: Linköpings universitet , 1993. , 35 + 2 papers p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 373
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-29509Local ID: LiU-Tek-Lic-1993: 15ISBN: 91-7871-113-4OAI: oai:DiVA.org:liu-29509DiVA: diva2:250324
1993-06-01, Administrationsbyggnadens aula, Campus US, Linköpings universitet, Linköping, 13:15 (English)