title: An alternative approach to the monitoring of respiration by dynamic air-pressure sensor.
abstract: Monitoring and assessing of patient respiratory function during conscious sedation are important because many drugs used for conscious sedation produce respiratory depression and subsequent hypoventilation. The purpose of this study is to assess the value of a dynamic air-pressure sensor for respiratory monitoring of clothed patients. Eight clothed adult volunteers were reclined on a dental chair positioned horizontally. The air bag for measuring air-pressure signals corresponding to respiration was placed on the seat back of the dental chair in the central lumbar area of the subject. The subject breathed through a face mask with a respirometer attached for measuring expiratory tidal volume. The air-pressure signals corresponding to respiration were obtained and the time integration values for air pressure during each expiration (integral P(exp)) were calculated. The expiratory tidal volume (TV(exp)) was measured simultaneously by respirometer. The relationship between TV(exp) and integral P(exp) for each subject was assessed by a Pearson correlation coefficient. A strong correlation between TV(exp) and integral P(exp) was observed in all subjects. Measuring integral P(exp) by dynamic air-pressure sensor makes it possible to estimate respiratory volume breath by breath, and the respiratory pressure-time integral waveform was useful in visually monitoring the respiration pattern. We believe that in the future this device will be used to monitor respiratory physiology in clothed patients, contributing to safer sedative procedures.
authors.affiliation: Department of Dental Anesthesiology, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan. takarada@hiroshima-u.ac.jp
authors.forename: Tohru
authors.initials: T
authors.lastname: Takarada
authors.forename: Michio
authors.initials: M
authors.lastname: Kawahara
authors.forename: Masahiro
authors.initials: M
authors.lastname: Irifune
authors.forename: Chie
authors.initials: C
authors.lastname: Endo
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Keiko
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Keiko
authors.initials: K
authors.lastname: Sakata
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Kikuchi
authors.forename: Takuya
authors.initials: T
authors.lastname: Saida
authors.forename: Chiori
authors.initials: C
authors.lastname: Onizuka
mesh_terms: D000328:Adult; D000399:Air Pressure; D004867:Equipment Design; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008397:Masks; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D012119:Respiration; D013147:Spirometry / Q000295:instrumentation; D013990:Tidal Volume / Q000502:physiology; D014160:Transducers, Pressure