Dynamic properties of body plethysmographs and effects on physiological parameters

J. John, B. Drefeldt, Varsha Surendranath Taskar, C. Mansson, B. Jonson

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

A model incorporating compliance, resistance, inertia, and the thermal time constant of plethysmographs is used to describe the effect of its dynamic properties on measured respiratory parameters. Using numerical simulation we studied the effect of distortion of flow signals from 13 infants in whom flow and esophageal pressure had been recorded. The distortion in amplitude, shape, and timing of the recorded flow patterns was dependent on the dynamic properties of the plethysmograph. For constant- volume 'pressure' plethysmographs, errors of derived parameters such as compliance and resistance are very important if the thermal time constant is short. These errors are not corrected by calibrating the plethysmograph at the breathing frequency. Time correction of the flow signals in volume- displacement plethysmographs gives accurate results when the plethysmograph resistance and compliance are low. Overall, a volume-displacement plethysmograph with moderately high resistance of the flowmeter, corrected for internal pressure and inertia, gives the best possible results.

Original languageEnglish (US)
Pages (from-to)152-159
Number of pages8
JournalJournal of Applied Physiology
Volume77
Issue number1
DOIs
StatePublished - Jan 1 1994
Externally publishedYes

Fingerprint

Compliance
Pressure
Hot Temperature
Flowmeters
Respiration

Keywords

  • body plethysmography
  • inertia
  • pressure correction
  • thermal time constant
  • time correction

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Dynamic properties of body plethysmographs and effects on physiological parameters. / John, J.; Drefeldt, B.; Taskar, Varsha Surendranath; Mansson, C.; Jonson, B.

In: Journal of Applied Physiology, Vol. 77, No. 1, 01.01.1994, p. 152-159.

Research output: Contribution to journalArticle

John, J. ; Drefeldt, B. ; Taskar, Varsha Surendranath ; Mansson, C. ; Jonson, B. / Dynamic properties of body plethysmographs and effects on physiological parameters. In: Journal of Applied Physiology. 1994 ; Vol. 77, No. 1. pp. 152-159.
@article{d95a2310dc4343449f810cec30016ace,
title = "Dynamic properties of body plethysmographs and effects on physiological parameters",
abstract = "A model incorporating compliance, resistance, inertia, and the thermal time constant of plethysmographs is used to describe the effect of its dynamic properties on measured respiratory parameters. Using numerical simulation we studied the effect of distortion of flow signals from 13 infants in whom flow and esophageal pressure had been recorded. The distortion in amplitude, shape, and timing of the recorded flow patterns was dependent on the dynamic properties of the plethysmograph. For constant- volume 'pressure' plethysmographs, errors of derived parameters such as compliance and resistance are very important if the thermal time constant is short. These errors are not corrected by calibrating the plethysmograph at the breathing frequency. Time correction of the flow signals in volume- displacement plethysmographs gives accurate results when the plethysmograph resistance and compliance are low. Overall, a volume-displacement plethysmograph with moderately high resistance of the flowmeter, corrected for internal pressure and inertia, gives the best possible results.",
keywords = "body plethysmography, inertia, pressure correction, thermal time constant, time correction",
author = "J. John and B. Drefeldt and Taskar, {Varsha Surendranath} and C. Mansson and B. Jonson",
year = "1994",
month = "1",
day = "1",
doi = "10.1152/jappl.1994.77.1.152",
language = "English (US)",
volume = "77",
pages = "152--159",
journal = "Journal of Applied Physiology Respiratory Environmental and Exercise Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Dynamic properties of body plethysmographs and effects on physiological parameters

AU - John, J.

AU - Drefeldt, B.

AU - Taskar, Varsha Surendranath

AU - Mansson, C.

AU - Jonson, B.

PY - 1994/1/1

Y1 - 1994/1/1

N2 - A model incorporating compliance, resistance, inertia, and the thermal time constant of plethysmographs is used to describe the effect of its dynamic properties on measured respiratory parameters. Using numerical simulation we studied the effect of distortion of flow signals from 13 infants in whom flow and esophageal pressure had been recorded. The distortion in amplitude, shape, and timing of the recorded flow patterns was dependent on the dynamic properties of the plethysmograph. For constant- volume 'pressure' plethysmographs, errors of derived parameters such as compliance and resistance are very important if the thermal time constant is short. These errors are not corrected by calibrating the plethysmograph at the breathing frequency. Time correction of the flow signals in volume- displacement plethysmographs gives accurate results when the plethysmograph resistance and compliance are low. Overall, a volume-displacement plethysmograph with moderately high resistance of the flowmeter, corrected for internal pressure and inertia, gives the best possible results.

AB - A model incorporating compliance, resistance, inertia, and the thermal time constant of plethysmographs is used to describe the effect of its dynamic properties on measured respiratory parameters. Using numerical simulation we studied the effect of distortion of flow signals from 13 infants in whom flow and esophageal pressure had been recorded. The distortion in amplitude, shape, and timing of the recorded flow patterns was dependent on the dynamic properties of the plethysmograph. For constant- volume 'pressure' plethysmographs, errors of derived parameters such as compliance and resistance are very important if the thermal time constant is short. These errors are not corrected by calibrating the plethysmograph at the breathing frequency. Time correction of the flow signals in volume- displacement plethysmographs gives accurate results when the plethysmograph resistance and compliance are low. Overall, a volume-displacement plethysmograph with moderately high resistance of the flowmeter, corrected for internal pressure and inertia, gives the best possible results.

KW - body plethysmography

KW - inertia

KW - pressure correction

KW - thermal time constant

KW - time correction

UR - http://www.scopus.com/inward/record.url?scp=0028277767&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028277767&partnerID=8YFLogxK

U2 - 10.1152/jappl.1994.77.1.152

DO - 10.1152/jappl.1994.77.1.152

M3 - Article

C2 - 7961228

AN - SCOPUS:0028277767

VL - 77

SP - 152

EP - 159

JO - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

JF - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology

SN - 8750-7587

IS - 1

ER -