Continuous assessment of nasal airflow resistance by adaptive modeling.
A method to assess nasal airflow resistance is presented that provides a continuous resistance value and applies a novel minimally obtrusive measurement technique. Instead of calculating the resistance once for each breathing cycle conventionally, it is calculated for each signal sample at any sampling frequency. The continuous pressure recording is produced with a nasopharyngeal catheter inserted 8 cm deep along the floor of the other nasal cavity and the flow recording is produced with respiratory effort bands. A least-mean-square (LMS) extension for the resistance model of Broms is developed that dynamically adapts to the time-varying characteristics of the nasal functioning and produces the continuous resistance values. Experimental results are shown that demonstrate the uniqueness and applicability of the new technique in assessing quickly changing resistance in a histamine/xylometatsolin challenges, the differences between normal and symptomatic patients, and the effect of nasal treatment of patients.
Department of Electrical and Information Engineering, University of Oulu, Oulu, Finland. tapio.seppanen@ee.oulu.fi
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D000328:Adult; D000368:Aged; D000403:Airway Resistance / Q000502:physiology*; D002000:Bronchospirometry / Q000295:instrumentation / Q000379:methods; D002406:Catheterization, Peripheral / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D009296:Nasal Cavity / Q000502:physiology*; D009305:Nasopharynx / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology*; D012220:Rhinitis / Q000175:diagnosis / Q000503:physiopathology; D055815:Young Adult