RESPIRATION TESTING SYSTEM

• US 3,659,590 A
• Filed: 10/13/1969
• Issued: 05/02/1972
• Est. Priority Date: 10/13/1969
• Status: Expired due to Term

• Current Assignee: Joseph Mailen Kootsey, William C. Jones
• Original Assignee: Joseph Mailen Kootsey, William C. Jones
• Inventors: Jones, William C., Kootsey, Joseph Mailen
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Howell, Kyle L.
• Application Number:
  US04/865,754
• Time in Patent Office: 932 Days
• Field of Search: 128/2.07,2.08 73/23,421.5
• US Class Current: 600/538
• CPC Class Codes: A61B 5/0803 Recording apparatus specially adapted therefor

Abstract

In a system for measuring the various desired parameters of a person'"'"''"'"'s respiratory system, the person breathes into a closed volume of gas having a known concentration of helium until the concentration of helium in the enclosure and his lungs reaches an equilibrium. A helium analyzer is included in the system; and when the subject'"'"''"'"'s breathing reaches the end of a resting expiration, a valve is turned to switch his breathing out of the closed system. A solenoid is also energized to maintain the volume of gas in the analyzer at a constant value; and computation circuitry receives the analyzer signal which is representative of the new helium concentration in the closed system to compute the various desired respiratory parameters of the subject'"'"''"'"'s respiratory system including Functional Residual Capacity, Total Lung Capacity, or Residual Volume as called for by the operator. Further, the circuitry will compute the percentage of any of these parameters relative to a norm value for that parameter; and all computation results are preferably displayed on a digital voltmeter for facility of reading and recording.

Claims

1. In combination, a respiratory testing apparatus including means for recording the breathing cycle of a subject, container means for confining the breath of the patient in a predetermined volume containing a known amount of helium, analyzer means for generating a signal representative of the concentration of helium in said known volume, first circuit means for generating a signal representative of said known amount of helium, divider circuit means receiving the output signals of said analyzer means and said first circuit means for generating a quotient signal representative of the quotient of said two received signals, second circuit means for generating a signal representative of the sum of the dead space in said container means and said initial volume of helium and for subtracting said last-named signal from said quotient signal to generate a signal representative of the Functional Residual Capacity of said subject.

2. The system of claim 1 further comprising display means for displaying a received electrical signal in digital form, and first switch means for selectively coupling said signal representative of Function Residual Capacity of said patient to said display means.

3. The system of claim 2 further comprising second switch means for selectively coupling said signal representative of the concentration of helium in said known volume to said display means to display the same exclusive of said signal representative of Functional Residual Capacity.

4. The system of claim 3 further comprising adjustable circuit means associated with said first circuit means for varying said generated signal thereof to a predetermined value on said display means representative of a known initial concentration of helium.

5. The system of claim 1 further comprising third circuit means for generating a signal representative of Inspiratory Capacity, and third switch means for selectively adding said last-named signal to said signal representative of Functional ResidUal Capacity thereby to generate a signal representative of Total Lung Capacity.

6. The system of claim 1 further comprising fourth circuit means for generating a signal representative of Expiratory Reserve Volume, and fourth switch means for selectively subtracting said signal representative of Expiratory Reserve Volume from said signal representative of Functional Residual Capacity to generate a signal representative of Residual Volume.

7. The system of claim 1 further comprising settable fifth circuit means adjustable to have an impedance value representative of a norm or predicted value of a pulmonary parameter, and fifth switch means for selectively feeding said signal representative of said Functional Residual Capacity to said fifth circuit means to generate a signal representative of the percentage of said measured Functional Residual Capacity signal is relative to said norm signal.

8. The system of claim 7 further comprising a digital voltmeter adapted to selectively display said computed signals representative of Function Residual Capacity and said percentage when said first and fifth switching means are actuated respectively.