US3768468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ventilators
Assignee: BOC Group Ltd
•
Filing: 1971-01-18
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Granted: 1973-10-30
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Expires: 1991-01-18
Abstract
Abstract A lung ventilator in which the volume of respirable gas passing to the patient per unit time is continuously measured and the flow stopped, to mark the end of the inspiratory phase and the start of the expiratory phase, when a chosen volume has passed through the meter.
Inventors
- 👤 L Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:31
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/72; A61B5/7235; A61B5/7242; A61B5/08; A61B5/091; A61M; A61M16/00; A61M16/0051; A61M16/021; A61M16/022; A61M16/024; A61B2560/00; A61B2560/02; A61B2560/0266; A61B2560/0276; Y; Y10; Y10S; Y10S137/00; Y10S137/908
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
A lung ventilator adapted to control the volume of respirable gas supplied to a patient irrespective of the duration of the inspiratory phase of the patient''s respiratory cycle, of the patient''s airway pressure, or of variations in the rate at which gas flows to the patient, including an inhalation passageway connected at one end to a supply of pressurized respirable gas, and at the other end to the patient; an exhalation passageway connected to the patient; a gas flow control valve in said inhalation passageway; a gas flow sensitive transducer in said inhalation passageway and said exhalation passageway adapted to generate signals of which the frequency is proportional to the gas flow rate; means integrating said flow rate signals to produce a signal which is a measure of the volume of gas flowing therethrough; means for closing the said valve when the said integrated signal from said gas flow sensitive transducer in said inhalation passageway reaches a chosen value, and means for reopening the valve and rendering the transducer effective at the beginning of the next inspiratory phase.
Claim 2
Dependent Claim
178 words
A lung ventilator adapted to control the volume of respirable gas supplied to a patient irrespective of the duration of the inspiratory phase of the patient''s respiratory cycle, of the patient''s airway pressure, or of variations in the rate at which gas flows to the patient, including an inhalation passageway connected at one end to a supply of pressurized respirable gas, and at the other end to the patient; an exhalation passageway connected to the patient; a gas flow control valve in said inhalation passageway; a gas flow sensitive transducer in said inhalation passageway and said exhalation passageway adapted to generate signals of which the frequency is proportional to the gas flow rate; means integrating said flow rate signals to produce a signal which is a measure of the volume of gas flowing therethrough; means for closing the said valve when the said integrated signal from said gas flow sensitive transducer in said inhalation passageway reaches a chosen value, and means for reopening the valve and rendering the transducer effective at the beginning of the next inspiratory phase.
Claim 3
Dependent Claim
62 words
A lung ventilator as claimed in claim 1, including a two-position, multiple-port valve movable between a ''manual'' and an ''automatic'' position, the valve having two of its ports connected to the inspiration and expiration passageways of the ventilator, two ports adapted to be connected to a patient, and the remaining port or ports adapted to be connected to a manual rebreathing device.
Claim 4
Dependent Claim
44 words
A lung ventilator as claimed in claim 2, in which the said multiple-port valve is connected to means for displacing it into the manual position when the pressure of oxygen or other selected gas supplied to the ventilator falls below a chosen minimum value.
Claim 5
Dependent Claim
70 words
A lung ventilator as claimed in claim 1, in which the signals corresponding to the inspiratory volume flow are fed to an integrator of which the output is fed to a comparator for comparison with like signals corresponding to the desired volume flow, equalisation of the two signals being effective to cause the comparator to generate a changeover signal stopping the inspiratory flow and allowing the expiratory flow to start.
Claim 6
Dependent Claim
44 words
A lung ventilator as claimed in claim 4, in which the outlet of the comparator is connected to a device controlling both a valve in the inspiratory flow passageway and aN auxiliary valve controlling the position of a valve in the expiratory flow passageway.
Claim 7
Dependent Claim
50 words
A lung ventilator as claimed in claim 4, in which operation of the control device is adapted to start a timer when the comparator generates the said changeover signal and which, after a chosen time has elapsed, causes the comparator to be reset and the inspiratory valve to be opened.
Claim 8
Dependent Claim
19 words
A lung ventilator as claimed in claim 1, including a minute volume indicator connected to said exhalation integrating means.
Claim 9
Dependent Claim
34 words
A lung ventilator as claimed in claim 7, in which connected to the minute volume indicator is an alarm device adapted to operate when the minute volume goes beyond chosen minimum and maximum values.
Claim 10
Dependent Claim
19 words
A lung ventilator as claimed in claim 4, including a tidal volume indicator connected to the inspiratory flow integrator.
Claim 11
Dependent Claim
34 words
A lung ventilator as claimed in claim 1, in which couplied to the inspiratory flow passageway is a meter for indicating the oxygen content of the gas supplied to the outlet of the ventilator.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |