US3902481A - System and device for exploration of the intrathoracic ventilatory mechanism - Google Patents

System and device for exploration of the intrathoracic ventilatory mechanism Download PDF

Info

Publication number
US3902481A
US3902481A US454711A US45471174A US3902481A US 3902481 A US3902481 A US 3902481A US 454711 A US454711 A US 454711A US 45471174 A US45471174 A US 45471174A US 3902481 A US3902481 A US 3902481A
Authority
US
United States
Prior art keywords
signal
supplying
intrathoracic
oscilloscope
subject
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US454711A
Other languages
English (en)
Inventor
Daniel E L Bargeton
Paul A A Monzein
Jean Y V Durand
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institut National de la Sante et de la Recherche Medicale INSERM
Original Assignee
Institut National de la Sante et de la Recherche Medicale INSERM
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institut National de la Sante et de la Recherche Medicale INSERM filed Critical Institut National de la Sante et de la Recherche Medicale INSERM
Application granted granted Critical
Publication of US3902481A publication Critical patent/US3902481A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/08—Measuring devices for evaluating the respiratory organs
    • A61B5/087—Measuring breath flow

Definitions

  • ABSTRACT A system and process for exploration of the intrathoracic ventilatory mechanism producing a signal y (V )tdV/dt) in which V the volume displaced in the mouth of a patient, and A is an adjustable parameter.
  • the signal y is recorded on an oscilloscope in dependence on A p which is a signal indicating variations in oesophageal pressure.
  • the parameter A is adjusted at the oscilloscope so that the loop representing y is closed in a straight line with the slope of the straight line giving compliance C and A/C giving the intrathoracic resistance.
  • the present invention relates to a system and process for exploration of the intrathoracic vontilatory mechanism, and a corresponding device for applying the sys tem.
  • the exploration is based on the following considerations:
  • Ventilatory mechanics considers the ventilatory system as a linear system of the second order.
  • E is the intrathoracic elastance
  • R is the intrathoracic resistance
  • Vp is the pulmonary volume
  • Vr is the relaxation volume.
  • a p the variations is oesophageal pressure, as given by a small balloon or gas-bag, and for the volume V displaced at the mouth:
  • V being the pulmonary volume at the beginning of inhalation.
  • the signal dV/dt is provided by a pneumotachograph (PTG), which signal integrated with respect to time provides V.
  • a conventional process comprises recording, in respect of time, A p
  • Another conventional process comprises recording on a track, V in dependence on A p; and on another track dV/dt in dependence on A p.
  • V On the loop in respect of V, the two points at zero flow are determined by means of their horizontal tangents, and compliance is the slope of their diameter; while on the loop in respect of dV/dt the two points of equal volume are taken, which makes it possible to calculate R.
  • the aim of the invention is to overcome the above mentioned disadvantages.
  • the system and process according to the invention employs a signal and v is recorded in dependence on A p on an oscilloscope with A being a regulatable parameter which is regulated on the oscilloscope so that the loop representing v is closed in a straight line, and then A RC, and the slope of the straight line gives C, hence It will be noted that closing a loop in a straight line is a particularly straight-forward and precise phenomenon in oscilloscopy. Moreover, it is sufficient to regulate to zero to produce a loop whose surface area measures the intrathoracic ventilatory work per cycle.
  • the invention also includes means for permitting gain regulation, calibration and separate observation of the two phases of respiration.
  • the PTG supplies a signal which is proportional to the flow (IV/d1, the calibration factor being proportional to the viscosity of the gaseous mixture which passes through it.
  • This viscosity depends on temperature and the water vapor content, and is therefore not the same for inhaled air and for exhaled gas which is water-vapor saturated at the temperature of the body. It is impossible to know beforehand the temperature of the gas in the PTG, because of the heat exchanges which occur between the gas and the walls. In addition, as viscosity is not an additive property, it is impossible to deduce the viscosity of the gaseous mixture from the viscosities of its components. It is therefore impossible to envisage beforehand how the calibration factor of the PTO is going to vary as between inhalation and exhalation.
  • a cylindrical vessel contains water which is maintained at a temperature of 37 by means of a thermostat.
  • a turbine provides for heat and moisture exchanges between the water and the air which it contains.
  • a plunger piston varies the volume of the vessel.
  • the pneumotachograph to be calibrated is mounted on a pipe which is fixed to the cover of the vessel, so that ambient air passes through the pneumotachograph during inhalation when the piston is moved downwardly, while gas under alveolar conditions passes through the pneumotachograph during exhalation" when the piston is raised.
  • FIGURE illustrates an apparatus for applying the system and process according to the invention, given by way of non-limiting example.
  • the pneumotachograph 1 supplies the signal +dV/dt to a gain regulating potentiometer 3 having a slider which supplies a signal to a circuit 5 for detecting the sign of dV/zlL'During inhalation, the circuit 5 closes its switch contacts 7 which, by way of a switch 9, feeds a relay 11.
  • the slider of the potentiometer 3 also supplies the signal to a potentiometer 13 for correction of gain upon exhalation, its effect upon inhalation being nullified by being bridged by a working contact 15 of the relay II.
  • the slider of the potentiometer l3 feeds an operational amplifier 17 connected as an integratorinverter, at whose output the signal V is produced.
  • the slider of the potentiometer 13 also supplies the signal to a single-pole change-over switch 19 having three positions which acts as a gain change-over means and which supplies the signal with gain 0, or with gain 1, or with gain 10, to an inverter amplifier 21 which supplies a potentiometer 23 for displaying the regulatable parameter A.
  • a single-pole change-over switch 19 having three positions which acts as a gain change-over means and which supplies the signal with gain 0, or with gain 1, or with gain 10
  • an inverter amplifier 21 which supplies a potentiometer 23 for displaying the regulatable parameter A.
  • the signal passes either by way of a rest contact 27 of the relay 11 and a cut-out switch 29, or a working contact 31 and a cut-out switch 33, and passes to the vertical active plate Y of an oscilloscope 35.
  • the gasbag 37 passes the signal A p to the horizontal active plate X of the oscilloscope 35, which oscilloscope may be of the type having a long-persistance screen, provided with a so-called Polaroid immediate photographic apparatus, etc.
  • the PTG 1 is mounted on a calibration pump (not shown), and calibration is effected not with respect to flow but with respect to volume, the integrator 17 having a time-constant of I second.
  • the switch 19 having suppressed the input into the summing means 25 of the signal (1V M1, enables V to be registered with respect to time on the oscilloscope 35.
  • the sign detector 5 cuts in the potentiometer 13 onto the signal dV/dt for exhalation, and short circuits it for inhalation.
  • the cut-out switches 29 and 33 are closed so as to record inhalation and exhalation.
  • the calibration pump neither produces nor consumes gas, the same mass of air passes through the PTG during inhalation under conditions ATPS and during exhalation under conditions BTPS.
  • the potentiometer I3 is acted upon so that the mean value of the signal is zero. This calibration correction is much more precise by observing volume than by observing flow, as any inequality in calibration is integrated in each cycle, and is rendered visible even if it is small. The potentiometer 3 is then acted upon, to produce the desired value of the deflection observed for a known volume (500, 750 or 1000 ccm).
  • the resistance is substantially the same for inhalation and for exhalation, at least in the rest condition.
  • this may be different, and there may therefore be an advantage in observing inhalation and exhalation separately.
  • This is permitted by the switches 27 and 31 associated with the relay 11 which is actuated by the detector circuit 5.
  • substantial values of R can be observed.
  • the changeover switch 19 makes it possible to use the inverter 21 with a gain of 10, and it is therefore possible to observe time constants RC ranging up to seconds, which covers all the needs arising in pathological investigation.
  • the eye is very sensitive to the motion of a straight line and, on a noisy signal, can much better determine a straight line than a curve or a loop.
  • a system for exploring the intrathoracic ventilator mechanism of a subject comprising means for supply ing a signal A p of the variations in oesophageal pressure, pneumotachograph means for supplying a signal dV/dt of the derivative with respect to time of the vol ume V displaced at the mouth of the subject, integrating circuit means for receiving the signal dV/tlt and supplying a signal V, summing circuit means for receiving the signal dV/dt and the signal V for supplying a signal in which A is a regulatable parameter, and oscilloscope means having a horizontal input for receiving the signal A p and a vertical input for receiving the signal y, the parameter A being regulated so that the loop displayed on the screen of the oscilloscope means is closed in a straight line, the slope of the straight line giving the compliance C and the quotient of the division of the parameter A by the compliance C giving the intrathoracic resistance R, and further comprising gain regulating potentiometer means for receiving the signal dVdr from
  • oscillo scope means displays on the screen a loop in which the surface of the loop for the value zero in the parameter A is a measure of the intrathoracic ventilatory work per cycle of the subject.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Pulmonology (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Physiology (AREA)
  • Physics & Mathematics (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
US454711A 1973-03-23 1974-03-25 System and device for exploration of the intrathoracic ventilatory mechanism Expired - Lifetime US3902481A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7310597A FR2222065B1 (enrdf_load_stackoverflow) 1973-03-23 1973-03-23

Publications (1)

Publication Number Publication Date
US3902481A true US3902481A (en) 1975-09-02

Family

ID=9116803

Family Applications (1)

Application Number Title Priority Date Filing Date
US454711A Expired - Lifetime US3902481A (en) 1973-03-23 1974-03-25 System and device for exploration of the intrathoracic ventilatory mechanism

Country Status (9)

Country Link
US (1) US3902481A (enrdf_load_stackoverflow)
BE (1) BE812536A (enrdf_load_stackoverflow)
CH (1) CH587042A5 (enrdf_load_stackoverflow)
DE (1) DE2413988A1 (enrdf_load_stackoverflow)
FR (1) FR2222065B1 (enrdf_load_stackoverflow)
GB (1) GB1448347A (enrdf_load_stackoverflow)
IT (1) IT1011144B (enrdf_load_stackoverflow)
LU (1) LU69684A1 (enrdf_load_stackoverflow)
NL (1) NL7403955A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4005702A (en) * 1974-05-22 1977-02-01 Institut National De La Sante Et De La Recherche Medical System and method for exploration of the intrathoracic ventilatory mechanism
US4031885A (en) * 1975-10-15 1977-06-28 Puritan-Bennett Corporation Method and apparatus for determining patient lung pressure, compliance and resistance
US4036222A (en) * 1974-05-08 1977-07-19 Soram S.A. Automatic electronic apparatus for measuring the bronchial resistance and the elastance of the pulmonary tissue
US20030196663A1 (en) * 2002-04-20 2003-10-23 Ullrich Wenkebach Process and device for controlling the breathing gas supply

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3480006A (en) * 1964-09-28 1969-11-25 Hellige & Co Gmbh F Physiological volume-pressure diagram recording device
US3713436A (en) * 1970-10-23 1973-01-30 Spearhead Inc Method and apparatus for measuring mechanical properties of the respiratory system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1508303A (fr) * 1966-11-23 1968-01-05 Appareil de mesure pour l'étude de la mécanique ventilatoire pulmonaire

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3480006A (en) * 1964-09-28 1969-11-25 Hellige & Co Gmbh F Physiological volume-pressure diagram recording device
US3713436A (en) * 1970-10-23 1973-01-30 Spearhead Inc Method and apparatus for measuring mechanical properties of the respiratory system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4036222A (en) * 1974-05-08 1977-07-19 Soram S.A. Automatic electronic apparatus for measuring the bronchial resistance and the elastance of the pulmonary tissue
US4005702A (en) * 1974-05-22 1977-02-01 Institut National De La Sante Et De La Recherche Medical System and method for exploration of the intrathoracic ventilatory mechanism
US4031885A (en) * 1975-10-15 1977-06-28 Puritan-Bennett Corporation Method and apparatus for determining patient lung pressure, compliance and resistance
US20030196663A1 (en) * 2002-04-20 2003-10-23 Ullrich Wenkebach Process and device for controlling the breathing gas supply
US6820613B2 (en) * 2002-04-20 2004-11-23 Dräger Medical AG & Co. KGaA Process and device for controlling the breathing gas supply

Also Published As

Publication number Publication date
GB1448347A (en) 1976-09-02
DE2413988A1 (de) 1974-09-26
FR2222065B1 (enrdf_load_stackoverflow) 1975-10-31
BE812536A (fr) 1974-07-15
IT1011144B (it) 1977-01-20
CH587042A5 (enrdf_load_stackoverflow) 1977-04-29
FR2222065A1 (enrdf_load_stackoverflow) 1974-10-18
LU69684A1 (enrdf_load_stackoverflow) 1974-07-17
NL7403955A (enrdf_load_stackoverflow) 1974-09-25

Similar Documents

Publication Publication Date Title
Stocks et al. A new apparatus for the accurate measurement of airway resistance in infancy
DuBois et al. A new method for measuring airway resistance in man using a body plethysmograph: values in normal subjects and in patients with respiratory disease
US4034743A (en) Automated pulmonary function testing apparatus
DuBois et al. A rapid plethysmographic method for measuring thoracic gas volume: a comparison with a nitrogen washout method for measuring functional residual capacity in normal subjects
JP3102898B2 (ja) 個人用の肺活量計
JP3475207B2 (ja) 代謝分析装置および代謝率分析装置
US3659590A (en) Respiration testing system
US5386833A (en) Method for calibrating a carbon dioxide monitor
Webb et al. An instrument for continuous measurement of oxygen consumption.
US3857385A (en) Direct indicating devices for measuring respiratory resistance
Johanson Jr et al. A noninvasive technique for measurement of airway conductance in small animals.
CN112516541B (zh) 一种用于mr及ct检查前的辅助训练系统
Wrigge et al. Determination of functional residual capacity (FRC) by multibreath nitrogen washout in a lung model and in mechanically ventilated patients: accuracy depends on continuous dynamic compensation for changes of gas sampling delay time
US3902481A (en) System and device for exploration of the intrathoracic ventilatory mechanism
US5857459A (en) Boxless measurement of thoracic gas volume
WO2001076476A2 (en) Method and apparatus for measurement of in vivo air volumes
US4535780A (en) Apparatus for measuring xenon concentration in xenon cerebral blood-flow studies
Linnarsson et al. Breath-by-breath measurement of respiratory gas exchange using on-line analog computation
Jonson A method for determination of pulmonary elastic recoil and resistance at a regulated flow rate
Lind et al. Microcomputer-assisted on-line measurement of breathing pattern and occlusion pressure
Cox et al. Clinical evaluation of a new electronic spirometer
US5584300A (en) Measurement of lung air capacity
Brunner et al. Compensation for Unavoidable Error
Shephard Pneumotachographic measurement of breathing capacity
US3703893A (en) Method and apparatus for determining work of breathing