Spirometric device

• US 4,078,554 A
• Filed: 09/15/1976
• Issued: 03/14/1978
• Est. Priority Date: 09/18/1975
• Status: Expired due to Term

• Current Assignee: Synthelabo LLC (Sanofi-Synthélabo SA)
• Original Assignee: Synthelabo (Paris Cedex, FR) (Sanofi-Synthélabo SA)
• Inventors: Cavallo, Roger Paul Charles, Le Maitre, Andre Emmanuel
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/723,343
• Time in Patent Office: 545 Days
• Field of Search: 128/2.08, 128/2.07, 73/198
• US Class Current: 600/539
• CPC Class Codes: A61B 5/09 using an element rotated by the flow toys actuated by air current A63H33/40
• CPC Class Codes: A61B 5/7242 using integration
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit

Abstract

A spirometric device for connection to the respiratory piping system of a patient and wherein a delivery pickup system is situatable on an exhalation branch of the system. The signals transmitted by a pressure pickup included in the device and situated on the respiratory system and those transmitted by the delivery pickup are led to a computing and measuring assembly which integrates the delivery signals while correcting these as a function of the pressure variations and/or of the errors caused by the gas contained in the respiratory system.

Claims

1. A spirometric device for connection to a respiratory piping system of a patient comprising:

a delivery pickup means for location on an exhalation branch of the system and responsive to signals transmitted thereby to generate delivery signals proportional to rate of flow, a pressure pickup means for situation on said system and responsive to signals transmitted thereby to generate pickup signals, a computing and measuring means for integrating the delivery signals and correcting the integrated output as a function of pressure variations to supply a corrected signal, parallel circuit means responsive to said pressure signals for detecting the maximum pressure and the minimum pressure, first subtracting means for obtaining an analogical signal proportional to the difference of said maximum and minimum pressures, and means for supplying the output of said first subtracting means to said computing and measuring means for correcting said integrated output.

2. A device according to claim 1, the computing and measuring means including second subtracting means for subtracting from the integrated signal obtained in the computing and measuring means, the analogical signal proportional to the difference of said maximum and minimum pressures, to thereby correct the measurement as a function of surplus gas volume corresponding to the volume difference of the gas contained in the respiratory system at extreme pressures, when said surplus gas is returned to atmospheric pressure.

3. A device as claimed in claim 2, wherein the first substracting means includes an inverter coupled to one of the parallel circuit means and summation means coupled to said inverter and the other of said parallel circuit means.

4. A device as claimed in claim 3, further including a potentiometric means interposed between said first and second subtracting means to permit adjustment of the pressure difference signal and render said difference signal proportional to the volume of the respiratory system being monitored.

5. A device according to claim 4, wherein said computing and measuring means includes first and second integrators disposed in parallel, the first of said integrators integrates over a given period, and the second of said integrators over a respiratory cycle, dectector means for resetting said second integrator to zero by the signal transmitted by the delivery pickup means, the two integrators being coupled to said second subtracting means, and a multiplier means for multiplying the said signal of the difference of the maximum and minimum pressures by the number of cycles during a given period and means for supplying the multiplied signal to the second subtracting means.

6. A device according to claim 5, further including means for deriving said number of cycles during said given period by counting the zero reset pulses transmitted by the detector means.