Digital fluidic ventilator
First Claim
1. A respiratory ventilator comprising:
- source means providing gas to be administered to a patient'"'"'s lungs;
valve means connected to said source means and normally preventing the flow of gas to the patient;
fluid conveying means for conveying gas from said valve means to the patient when said valve means is activated;
exhalation valve means connected to said fluid conveying means for exhausting gas exhaled from the patient;
a fluid flipflop having a set state and a reset state;
means connecting said flipflop to said valve means to actuate said valve means when said flipflop is in said set state;
bias means for applying a continuous bias signal of fixed magnitude to said flipflop tending to switch it to said set state;
first means connected to said fluid conveying means and said flipflop for transmitting a negative inspiratory pressure in said fluid conveying means to said flipflop if the patient begins to inhale, said negative pressure tending to aid said bias signal in switching said flipflop to said set state; and
,second means connected to said fluid conveying means and said fluid flipflop for transmitting the positive pressure in said fluid conveying means to said flipflop to switch it to said reset state when a predetermined positive pressure is present in said fluid conveying means.
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Accused Products
Abstract
A single fluidic flipflop serves as the primary control element in a respiratory ventilator, the flipflop selectively controlling an interface valve to intermittently interrupt the flow of gas from a source to the lungs of a patient through a flow line. In a pressure-limited embodiment positive and negative pressures in the flow line control the flipflop whereas in a volume limited embodiment a negative pressure provides one control for the flipflop and the second control is digitally derived from the volume of gas flowing to the patient. The ventilator is operable in the assist, control and intermittent mandatory ventilation modes. It may operate as an intermittent positive pressure breathing device or a positive end expiratory pressure device, depending upon a manually adjustable bias signal applied to the flipflop. Provision is made for both a manual and an automatic sigh control, and for selectively inflating an endotracheal cuff.
36 Citations
19 Claims
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1. A respiratory ventilator comprising:
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source means providing gas to be administered to a patient'"'"'s lungs; valve means connected to said source means and normally preventing the flow of gas to the patient; fluid conveying means for conveying gas from said valve means to the patient when said valve means is activated; exhalation valve means connected to said fluid conveying means for exhausting gas exhaled from the patient; a fluid flipflop having a set state and a reset state; means connecting said flipflop to said valve means to actuate said valve means when said flipflop is in said set state; bias means for applying a continuous bias signal of fixed magnitude to said flipflop tending to switch it to said set state; first means connected to said fluid conveying means and said flipflop for transmitting a negative inspiratory pressure in said fluid conveying means to said flipflop if the patient begins to inhale, said negative pressure tending to aid said bias signal in switching said flipflop to said set state; and
,second means connected to said fluid conveying means and said fluid flipflop for transmitting the positive pressure in said fluid conveying means to said flipflop to switch it to said reset state when a predetermined positive pressure is present in said fluid conveying means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A respiratory ventilator comprising:
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source means providing gas to be administered to a patient'"'"'s lungs; valve means connected to said source means and normally preventing the flow of gas to the patient; fluid conveying means for conveying gas from said valve means to the patient when said valve means is activated; exhalation valve means connected to said fluid conveying means for exhausting gas exhaled from the patient; a fluid flipflop having a set state and a reset state; means connecting said flipflop to said valve means to actuate said valve means when said flipflop is in said set state; bias means for applying a continuous bias signal of fixed magnitude to said flipflop tending to switch it to said set state; first means connected to said fluid conveying means and said flipflop for transmitting a negative inspiratory pressure from said fluid conveying means to said flipflop when the patient begins to inhale, said negative pressure tending to aid said bias signal in switching said flipflop to said set state; and
,second means connected to said fluid conveying means and said fluid flipflop for applying a signal to said flipflop switch it to its reset state after a predetermined volume of gas has flowed through said fluid conveying means. - View Dependent Claims (17, 18, 19)
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Specification