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US3759249A Expired / Lapsed US ⏱️ 0.0 years remaining

Respiratory analysis system and method

Assignee: National Aeronautics and Space Administration
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Filing: 1971-08-19
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Granted: 1973-09-18
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Expires: 1991-08-19
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Abstract

Abstract A system for monitoring the respiratory process wherein the gas flow rate and the frequency of respiration and expiration cycles can be determined on a real time basis. A face mask is provided with one-way inlet and outlet valves where the gas flow is through independent flowmeters and through a mass spectrometer. The opening and closing of a valve operates an electrical switch, and the combination of the two switches produces a low frequency electrical signal of the respiratory inhalation and exhalation cycles. During the time a switch is operated, the corresponding flowmeter produces electric pulses representative of the flow rate, the electrical pulses being at a higher frequency than that of the breathing cycle and combined with the low frequency signal. The high frequency pulses are supplied to a conventional analyzer computer which also receives temperature and pressure inputs and computes mass flow rate and totalized mass flow of gas. From the mass spectrometer, components of the gas are separately computed as to flow rate as well. The electrical switches cause operation of up-down inputs of a reversible counter. To measure a real time, a 1-minute clock pulse is used to operate the counter. The occurrence of a pulse alerts the counter, and the next succeeding reverse from down to up in the breathing cycle causes an electrical sequence to occur in which the counter is momentarily inhibited while the count therein is transferred to a printer. The electrical sequence is complete before the next up-to-down reverse in the breathing cycle occurs, so that there is no loss in the counting of cycles. Thus, the number of cycles closest to one-minute time are measured. The respective up and down cycles can be individually monitored and combined for various respiratory measurements.

Inventors

  • 👤 J Fletcher

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 17:29
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/08; A61B5/0816; A61B5/087

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 176 words
Apparatus for monitoring the respiratory function comprising: respiratory means for receiving inhalation and exhalation gas flow, said respiratory means having inhalation and exhalation valve means respectively operative for opening in response to inhalation and expiration, said respiratory means including means for developing electrical signals representative of the respiratory functions; first computing means connected to the output of the respiratory means and also receiving signals indicative of absolute pressure and temperatures for providing a signal indicative of mass flow rate; analyzing means determining the partial pressures of selected respiratory gases; summing means receiving the partial pressures from the analyzing means and providing a signal representative of total pressure; second computing means connected to the output of first computing means, the signal of partial pressure of a selected gas and the signal from the summing means to provide a signal representing mass flow of selected respiratory gas; and first counter means connected to the second computing means and also receiving signals of inhalation and exhalation cycles to produce a signal indicative of net difference of selected respiratory gas.
Claim 2
Dependent Claim 176 words
Apparatus for monitoring the respiratory function comprising: respiratory means for receiving inhalation and exhalation gas flow, said respiratory means having inhalation and exhalation valve means respectively operative for opening in response to inhalation and expiration, said respiratory means including means for developing electrical signals representative of the respiratory functions; first computing means connected to the output of the respiratory means and also receiving signals indicative of absolute pressure and temperatures for providing a signal indicative of mass flow rate; analyzing means determining the partial pressures of selected respiratory gases; summing means receiving the partial pressures from the analyzing means and providing a signal representative of total pressure; second computing means connected to the output of first computing means, the signal of partial pressure of a selected gas and the signal from the summing means to provide a signal representing mass flow of selected respiratory gas; and first counter means connected to the second computing means and also receiving signals of inhalation and exhalation cycles to produce a signal indicative of net difference of selected respiratory gas.
Claim 3
Dependent Claim 125 words
The apparatus of claim 1 wherein there is a second counter means connected to the first counter means; timing means for controlling the second counter means by providing timing signals, said timing signals defining a finite time reference for the respiratory function; means responsive to said timing signals for stopping the measurement of the respiratory function and nearly simultaneously reinitiating a new measurement of the next respiratory function; and means for transferring the counted data from said counter means to a storage means without affecting the measurement then underway thereby synchronizing the unrythmic respiratory phenomenon to a finite timing means so that each measurement begins and ends at the beginning of a respiratory function after the occurrence of the timing signal from the timing means.
Claim 4
Dependent Claim 20 words
The apparatus of claim 2 including a free running, high frequency clock to provide discrete time elements to the measurement.
Claim 5
Dependent Claim 23 words
The apparatus of claim 2 and further including means operative during the inhibition time period for printing the output of said counter means.
Claim 6
Dependent Claim 36 words
The apparatus of claim 1 wherein said valve means includes a flow passage and a pressure differential operated diaphragm in said flow passage, and means responsive to movement of said diaphragm for generating an electrical signal.
Claim 7
Independent Claim 151 words
A method for monitoring the respiratory process wherein the gas flow rate and the frequency of inhalation and exhalation cycles are determined on a real time basis, said method comprising: deriving alternating low frequency signals of the inhalation and exhalation cycles; measuring as pulse rate signals the flow rate during the inhalation and exhalation cycles; converting the pulse rate signals and frequency signals to up and down signals representing inhalation and exhalation flow rate; supplying the up and down signals to a continuous counter; and providing to the counter a timing signal defining a finite time which alerts the counter to be synchronized with the respiratory function whereby upon the next transition of the respiratory cycle the counter commences counting and continues to count until the next similar transition of the respiratory cycle after the succEeding timing signal at which time the counted data is transferred while the count is continued.
Claim 8
Independent Claim 151 words
A method for monitoring the respiratory process wherein the gas flow rate and the frequency of inhalation and exhalation cycles are determined on a real time basis, said method comprising: deriving alternating low frequency signals of the inhalation and exhalation cycles; measuring as pulse rate signals the flow rate during the inhalation and exhalation cycles; converting the pulse rate signals and frequency signals to up and down signals representing inhalation and exhalation flow rate; supplying the up and down signals to a continuous counter; and providing to the counter a timing signal defining a finite time which alerts the counter to be synchronized with the respiratory function whereby upon the next transition of the respiratory cycle the counter commences counting and continues to count until the next similar transition of the respiratory cycle after the succEeding timing signal at which time the counted data is transferred while the count is continued.
Claim 9
Dependent Claim 18 words
The method specified in claim 6 wherein a free-running, high-frequency clock signal is applied to the counted data.

References Cited (Backward Citations)

US3396719A Cited
US3309684A Cited
US3465103A Cited
US3577984A Cited
US3507146A Cited
US3523529A Cited
US3611801A Cited
US3572331A Cited
US3645133A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-09-17 1977-03-19 1977-09-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-09-17 1981-03-19 1981-09-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-09-17 1985-03-19 1985-09-18 $7700.00 Window Closed / Lapsed

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