Automated pulmonary function testing apparatus

• US 4,034,743 A
• Filed: 10/24/1975
• Issued: 07/12/1977
• Est. Priority Date: 10/24/1975
• Status: Expired due to Term

• Current Assignee: Airco, Inc.
• Original Assignee: Airco, Inc.
• Inventors: Greenwood, James R., Miller, Philip M., Whitacre, Thomas S.
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US05/625,791
• Time in Patent Office: 627 Days
• Field of Search: 128/2.07, 128/2.08
• US Class Current: 600/538
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence

Abstract

Automated pulmonary function testing apparatus includes a spirometer responsive to the breathing efforts of a patient for producing electrical signals which vary in accordance with volumes of breathed gas and central processing means for calculating one or more pulmonary function parameters associated with such volumes. Display means are adapted to visually display information supplied from the central processing means to an operator and/or a patient under test. In addition, keyboard means coupled to the central processing means are also provided such that upon operation of a particular key, tests may be selected and volumes or other calculated parameters may be visually displayed and/or printed on a permanent record medium.

Claims

1. Automated pulmonary function testing apparatus comprising spirometer means responsive to the breathing efforts of a patient under test for producing electrical signals varying in magnitude in accordance with volumes of breathed gas, said spirometer means having a potentiometer to which an excitation signal is supplied, a central processing unit having an arithmetic unit therein;

means for supplying digital representations of said electrical signals to said central processing unit for calculation in said arithmetic unit of one or more pulmonary function parameters;

patient display means and operator display means both coupled to said central processing unit for visually displaying to the patient during a pulmonary function test instructions defining breathing efforts required of the patient, and for visually displaying the results of said test to said operator, respectively;

keyboard means coupled to said central processing unit and having a plurality of test keys each of which corresponds to a particular pulmonary function test to be conducted and parameter key means associated with each of said test keys such that after a particular test is conducted, operation of said parameter key means enables calculation in said arithmetic unit, and display on said operator display means, of the parameter corresponding to said operated parameter key means, said keyboard means comprising means for supplying signals representing ambient temperature to said central processing unit for calculation in said arithmetic unit of spirometer potentiometer excitation signals corrected for difference between the water vapor partial pressure of (1) the exhaled breath of a patient under test and (2) the air in said spirometer means; and

means for coupling said central processing unit to said spirometer potentiometer such that corrected excitation signals are supplied to said spirometer potentionmeter and subsequent correction of said electrical signals produced by said spirometer means for said difference in water partial pressure is rendered unnecessary.

2. Apparatus as defined in claim 1 wherein said spiromter means comprises a spirometer servo motor and servo motor control means coupled to said central processing means and to said spirometer servo motor for supplying signals to said servo motor effective to adjust the initial position of said spirometer prior to commencing pulmonary function testing of a patient.