Peep control for bellows ventilator
First Claim
1. A ventilator system for providing a breath to a patient and for receiving exhaled gases from the patient, said system comprising a ventilator, a bellows canister containing a compressible bellows, a conduit fluidly connecting said ventilator to said bellows canister, said ventilator supplying a quantity of drive gas through said conduit to compress said bellows within said canister to provide a breath to the patient, means to vent said conduit to relieve the pressure within said bellows container to allow exhaled gasses from the patient to enter the interior of said bellows, a pop-off valve, said pop-off valve having a control chamber communicating with the pressure in said conduit and an exhaust chamber communicating with the gasses exhaled from the patient, said pop-off valve being responsive to the differential pressures between said control chamber and said exhaust chamber to open said pop-off valve to exhaust gases from the patient through said exhaust chamber through an exhaust outlet, the improvement comprising means to control the pressure in said exhaust outlet to a variable positive pressure above atmospheric pressure.
1 Assignment
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Accused Products
Abstract
An improved system for the control of PEEP in a medical ventilator system having a ventilator and a bellows contained within a bellows canister. A pop-off valve that normally vents excess pressure within the bellows to atmosphere is modified such that its exhaust is vented to a predetermined pressure above atmospheric pressure, such as the PEEP pressure. In the preferred embodiment, that predetermined pressure is the pressure within the ventilator drive gas conduit that transmits the gas from the ventilator to drive the bellows and the exhaust from the pop-off is effectively isolated from that drive gas conduit to avoid contaminating the gas within that drive gas conduit.
26 Citations
16 Claims
- 1. A ventilator system for providing a breath to a patient and for receiving exhaled gases from the patient, said system comprising a ventilator, a bellows canister containing a compressible bellows, a conduit fluidly connecting said ventilator to said bellows canister, said ventilator supplying a quantity of drive gas through said conduit to compress said bellows within said canister to provide a breath to the patient, means to vent said conduit to relieve the pressure within said bellows container to allow exhaled gasses from the patient to enter the interior of said bellows, a pop-off valve, said pop-off valve having a control chamber communicating with the pressure in said conduit and an exhaust chamber communicating with the gasses exhaled from the patient, said pop-off valve being responsive to the differential pressures between said control chamber and said exhaust chamber to open said pop-off valve to exhaust gases from the patient through said exhaust chamber through an exhaust outlet, the improvement comprising means to control the pressure in said exhaust outlet to a variable positive pressure above atmospheric pressure.
- 7. A ventilator system for providing a breath to a patient fluidly connected to a patient circuit during an inspiratory cycle and for receiving exhaled gases from the patient during an exhalation cycle, said system comprising a ventilator, a bellows canister containing a compressible bellows, a drive conduit fluidly connecting said ventilator to said bellows canister, said ventilator supplying a quantity of gas through said drive conduit to compress said bellows within said canister to provide a breath to the patient, said ventilator further having means to provide and maintain a selectable positive pressure within the patient circuit during the expiratory cycle, means to vent said drive conduit to relieve the pressure within said bellows container to allow exhaled gasses from the patient to enter the interior of said bellows, a pop-off valve, said pop-off valve having a control chamber communicating with the pressure in said drive conduit and an exhaust chamber communicating with the gasses exhaled from the patient and a flexible diaphragm separating said chambers, said pop-off valve being responsive to the differential pressures between said control chamber and said exhaust chamber to move said diaphragm to open said pop-off valve to exhaust gases from the patient through said exhaust chamber through an exhaust outlet, and means to control the pressure in said exhaust outlet to track said selectable positive pressure within the patient circuit.
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14. A method of controlling a pop-off valve used in a medical ventilation system supplying a breathing gas to a patient connected to a patient breathing circuit comprising the steps of:
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providing a medical ventilator to administer a breath to a patient during an inhalation cycle and to receive exhaled breath from the patient during an exhalation cycle; establishing and maintaining a positive, controllable pressure in the patient circuit during at least one of the exhalation and inhalation cycles, providing a pop-off valve in communication with the patient circuit to vent excess pressure through an exhaust conduit, and controlling the pressure in the exhaust conduit of the pop-off valve at a pressure above atmospheric pressure. - View Dependent Claims (15, 16)
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Specification