Maximum expiratory flow-volume curve: mathematical model and experimental results

✍ Scribed by S. Abboud; O. Barnea; A. Guber; N. Narkiss; I. Bruderman

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 685 KB
• Volume: 17
• Category: Article
• ISSN: 1350-4533
• DOI: 10.1016/1350-4533(95)97312-d

✦ Synopsis

A rn~t~at~ca~ simu~tion of the m~x~murn ex~.r~to~ fkm+volume (MEFV) curve was beamed using a lumped ~~r~~&~ rno~~. TRe model uses a theoretical ~~~irn~t~~ of an titivation function r~~s~t~ng the hngk ~essure-ualu~ re~t~onsh~p du~ng rn~x~rn~~y forced ex~~r~t~~. The wavef~ obt~~~d by the mo~l wefio compared to the flow-uo~u~ curves recorded from normal subjects and f0-r patients with small airways disease, asthma, and emphysema. We were able to reproduce the flow-volume curves using the model and calculate new parameters that reflect the dependency of airways resistance on expired volume during FVC manoeuvre. These new parameters are based on the entire information presented in the flow-volume curue and on the reduction in flow at all lung volumes. We also calculated the mean slope of the resistance-expired volume curves b obtained from the model by fitting a straight line to the curve, Using r~es~t~t~ve data fw normal cmd COPR patients defect mean slopes of 0.095, 0.13, 0.49 and 1.44 litre-' were obtu~ned for non& su~ect, small airways disease, ~thrn~ and ashy sema bates, r~pe~t~ve~. The rno~~-bred para~t~ may be a~l~c~~ to human studies. Horueuer, further studies in large groups of patients are required to bet& define the true predictive value of the new indices described fw the diagnosis of COPD.