US3844280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Medical ventilator including a fail-safe device
Assignee: US Philips Corp
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Filing: 1972-08-18
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Granted: 1974-10-29
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Expires: 1992-08-18
Abstract
Abstract A time-cycled medical ventilator which includes a source of respiratory gas and hermetically driven bellows for supplying required pressure to move the gas to the patient. Operating means driven by a driving gas under control of control means operates to distend and compress the bellows in accordance with the time cycle. An inspiratory gas valve is connected on its inlet side to the source of respiratory gas for controlling the flow of gas to the patient through an inspiration gas passage. An expiratory gas valve is connected by an expiration gas passage to the patient for controlling flow of respiratory gas away from the patient. Electrically driven valve operating means are connected to each of the gas valves for controlling their operation. A pressure relief valve is connected to the inspiration gas passage so as to provide venting to atmosphere of said gas passage in order to relieve excess gas pressure from said gas passage when the gas pressure therein reaches a predetermined value. Detecting means are arranged responsive to the driving gas pressure so that when the driving gas pressure falls to atmospheric pressure means connected to said pressure relief valve will be operated to open said valve and provide a connection from atmosphere to said inspiration gas passage so as to allow the patient to breathe independent of the ventilator.
Inventors
- 👤 G Smythe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:10
CPC Classifications
A; A61; A61M; A61M16/00; A61M16/021; A61M16/0057; A61M16/0075
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
324 words
A time-cycled medical ventilator comprising a source of respiratory gas to be supplied to a patient, pneumatically driven bellows connected to said source of respiratory gas for supplying the pressure required to move said respiratory gas into the lungs of the patient, operating means connected to said bellows for causing said bellows to alternately distend and compress in accordance with the time cycle, control means connected to said operating means for controlling flow of driving gas in accordance with said time-cycle to said operating means to effect operation thereof, a source of driving gas for supplying said driving gas at higher than atmospheric pressure to said control means, an inspiration gas passage for supplying respiratory gas to a patient, an inspiratory gas valve connected on an inlet side thereof to said source of respiratory gas for controlling the flow of respiratory gas to the patient through said inspiration gas passage connected on the outlet side of said inspiratory gas valve, an expiration gas passage for receiving respiratory gas from a patient, an expiratory gas valve connected on the inlet side thereof to said expiration gas passage for controlling flow of respiratory gas from the patient, electrically driven valve operating means connected to each of said gas valves for controlling operation thereof, a pressure relief valve connected to said inspiration gas passage on the outlet side of said inspiratory gas valve arranged for opening so as to vent said passage to atmosphere and relieve excess pressure in said inspiratory gas passage when the gas pressure therein reaches a predetermined value, detecting means responsive to the pressure of said driving gas, means connected to said detecting means for opening said pressure relief valve when the pressure of said driving gas drops to atmospheric pressure for a period of time in excess of a predetermined period so as to connect said inspiration gas passage to the atmosphere and allow the patient to breathe independent of the ventilator.
Claim 2
Dependent Claim
324 words
A time-cycled medical ventilator comprising a source of respiratory gas to be supplied to a patient, pneumatically driven bellows connected to said source of respiratory gas for supplying the pressure required to move said respiratory gas into the lungs of the patient, operating means connected to said bellows for causing said bellows to alternately distend and compress in accordance with the time cycle, control means connected to said operating means for controlling flow of driving gas in accordance with said time-cycle to said operating means to effect operation thereof, a source of driving gas for supplying said driving gas at higher than atmospheric pressure to said control means, an inspiration gas passage for supplying respiratory gas to a patient, an inspiratory gas valve connected on an inlet side thereof to said source of respiratory gas for controlling the flow of respiratory gas to the patient through said inspiration gas passage connected on the outlet side of said inspiratory gas valve, an expiration gas passage for receiving respiratory gas from a patient, an expiratory gas valve connected on the inlet side thereof to said expiration gas passage for controlling flow of respiratory gas from the patient, electrically driven valve operating means connected to each of said gas valves for controlling operation thereof, a pressure relief valve connected to said inspiration gas passage on the outlet side of said inspiratory gas valve arranged for opening so as to vent said passage to atmosphere and relieve excess pressure in said inspiratory gas passage when the gas pressure therein reaches a predetermined value, detecting means responsive to the pressure of said driving gas, means connected to said detecting means for opening said pressure relief valve when the pressure of said driving gas drops to atmospheric pressure for a period of time in excess of a predetermined period so as to connect said inspiration gas passage to the atmosphere and allow the patient to breathe independent of the ventilator.
Claim 3
Dependent Claim
30 words
The medical ventilator according to claim 1 further comprising a spring connected to said expiratory gas control valve for opening said valve when said valve operating means is not driven.
Claim 4
Dependent Claim
66 words
The medical ventilator according to claim 1 further comprising at least one non-return valve connecting said detecting means to said driving gas allowing passage of driving gas to said detecting means only when said driving gas pressure is above atmospheric pressure, said detecting means including a pneumatic time constant device which is chargeable by the driving gas passed to said detecting means by said non-return valve.
Claim 5
Dependent Claim
60 words
The medical ventilator according to claim 3 wherein said time constant device includes an expansible chamber for receiving and storing driving gas passed by the non-return valve, and a gas discharge path arranged to discharge gas from the chamber at a rate slower than the rate at which driving gas can be fed to the chamber via the non-return valve.
Claim 6
Dependent Claim
45 words
The medical ventilator according to claim 4 wherein said means connected to said detecting means for opening said pressure relief valve comprises mechanical linkage to said pressure relief valve so that said pressure relief valve is opened when the chamber is fully discharged of gas.
Claim 7
Dependent Claim
66 words
The medical ventilator according to claim 5 wherein said chamber comprises a cylinder having a spring-restored piston tHerein so that driving gas admitted to the cylinder drives the piston against the restoring force of the spring, and wherein said mechanical linkage comprises a piston rod, carried by said piston arranged to open the pressure relief valve when the driving gas is fully discharged from the cylinder.
Claim 8
Dependent Claim
18 words
The medical ventilator according to claim 1 wherein said control means comprises at least one solenoid-operated control valve.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |