Intermittent positive pressure breathing device
First Claim
1. A positive pressure ventilator comprising:
- a. a source of breathing gas;
b. a normally closed first valve means (40) for directing the breathing gas from said source to the patient;
c. A first bistable means (32) for controlling said first valve means, said first bistable means having a first set of opposed control inputs;
d. a first time delay means (28), and a second time delay means (30), each independently adjustable in time delay;
e. means responsive to said first time delay means to operate one of said first inputs of said first bistable means to open said first valve means, and to trip said second time delay means, and to initiate the inhalation action; and
f. means responsive to the operation of said second time delay means to operate a second one of said first inputs of said first bistable means to close said first valve means and to trip said first time delay means and initiate the exhalation action; and
includingg. between said source of breathing gas and said first valve means a pressure controller (38) for maintaining a constant supply pressure to said valve; and
h. between said first valve means and said patient a flow rate control valve (R5);
whereby a selected constant value of flow rate of gas is supplied to said patient when said first valve means is open; and
includingnon-rebreathing valve means having an open and a closed position, includingi. spring means to open said non-rebreathing valve in the absence of operating pressure, said non-rebreathing valve connected to the supply line of breathing gas for the patient and includingj. fluidic OR gate means for applying pressure to close said non-rebreathing valve during the inhalation phase, and to open said non-rebreathing valve during the exhalation phase.
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Accused Products
Abstract
A ventilator implemented completely with fluidic devices provides independent control of inhalation time, exhalation time and breathing gas flow rate. The basic fluidic system comprises a low frequency oscillator which in the form of a flip flop is controlled in its two stable states by means of independently controlled time delay relays. The output of the flip flop is amplified by a digital amplifier and operates an on-off valve which is used to direct breathing gas from the source to the patient. Independent control of the flow rate of the breathing gas is by means of a needle valve. With this basic fluidic system, there are seven other features of the apparatus. One is a maximum pressure control which on inhalation is responsive to the patient'"'"'s breathing air pressure. The second feature is a sensitivity control, which during exhalation is responsive to the patient inspiratory effort. The third feature is a positive end exhalation pressure control. The fourth is an intermittent mandatory ventilation control which permits breathing rates as low as one breath per minute. The fifth feature is a manual control which allows the termination of the exhalation phase and initiation of the inhalation phase manually. The sixth feature is a sensor which is responsive to the breathing gas pressure at the patient. If the apparatus becomes detached from the patient, pressure cycling is modified and an alarm system sensitive to this pressure is activated. The seventh feature is a safety valve which allows the patient to breathe atmospheric air when the supply pressure of the source gas fails.
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Citations
19 Claims
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1. A positive pressure ventilator comprising:
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a. a source of breathing gas; b. a normally closed first valve means (40) for directing the breathing gas from said source to the patient; c. A first bistable means (32) for controlling said first valve means, said first bistable means having a first set of opposed control inputs; d. a first time delay means (28), and a second time delay means (30), each independently adjustable in time delay; e. means responsive to said first time delay means to operate one of said first inputs of said first bistable means to open said first valve means, and to trip said second time delay means, and to initiate the inhalation action; and f. means responsive to the operation of said second time delay means to operate a second one of said first inputs of said first bistable means to close said first valve means and to trip said first time delay means and initiate the exhalation action; and
includingg. between said source of breathing gas and said first valve means a pressure controller (38) for maintaining a constant supply pressure to said valve; and h. between said first valve means and said patient a flow rate control valve (R5); whereby a selected constant value of flow rate of gas is supplied to said patient when said first valve means is open; and
includingnon-rebreathing valve means having an open and a closed position, including i. spring means to open said non-rebreathing valve in the absence of operating pressure, said non-rebreathing valve connected to the supply line of breathing gas for the patient and including j. fluidic OR gate means for applying pressure to close said non-rebreathing valve during the inhalation phase, and to open said non-rebreathing valve during the exhalation phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A positive pressure ventilator comprising:
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a. a source of breathing gas; b. a normally closed first valve means for directing the breathing gas from said source to the patient; c. a first bistable means for controlling said first valve means, said first bistable means having a first set of opposed control inputs; d. a first and a second time delay means, each independently adjustable in time delay; e. means responsive to said first time delay means to operate one of said first inputs of said first bistable means to open said first valve means, and to trip said second time delay means, and to initiate the inhalation action; f. means responsive to the operation of said second time delay means to operate a second one of said first inputs of said first bistable means to close said first valve means and to trip said first time delay means and initiate the exhalation action; and
further includingg. diaphragm valve means responsive to the patient pressure, said patient pressure being positive, and of sufficient magnitude during the inhalation phase to close said diaphragm valve means; a second bistable means having a set of opposed control inputs back pressure switch means responsive to the closing of said diaphragm valve means to apply fluid pressure to a first input of a second bistable means, a second input to said second bistable means connected through a resistance to the output of a digital amplifier responsive to said first bistable means, an output of said second bistable means connected to a first input of a first monostable means, a second input of said first monostable means connected to said output of said digital amplifier, the pressure on said first input keeping the output of said first monostable means a logical zero; and i. alarm means responsive to a logical one on said output of said first monostable means; whereby when the patient is disconnected from said breathing apparatus, said patient pressure never gets high enough to close said diaphragm valve, whereby said back pressure switch never operates and said second input resets said second bistable means, taking said pressure at said first input off of said first monostable means and permitting output of said first monostable means to change to a logical one and activate an alarm.
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17. A positive pressure ventilator comprising;
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a. a source of breathing gas; b. a normally closed first valve means (40) for directing the breathing gas from said source to the patient; c. a first bistable means (32) for controlling said first valve means, said first bistable means having a first set of opposed control inputs; d. a first time delay means (28), and a second time delay means (30), each independently adjustable in time delay; e. means responsive to said first time delay means to operate one of said first inputs of said first bistable means to open said first valve means, and to trip said second time delay means, and to initiate the inhalation action; and f. means responsive to the operation of said second time delay means to operate a second one of said first inputs of said first bistable means to close said first valve means and to trip said first time delay means and initiate the exhalation action; and
includingg. between said source of breathing gas and said first valve means a pressure controller (38) for maintaining a constant supply pressure to said valve; and h. between said first valve means and said patient a flow rate control valve (R5); whereby a selected constant value of flow rate of gas is supplied to said patient when said first valve means is open; and
includingmeans responsive to the pressure in the breathing gas line to the patient for activating an alarm when the patient pressure is less than a selected value during said inhalation action, comprising; i. diaphragm valve means responsive to said patient pressure; j. back pressure switch means responsive to said diaphragm valve means; k. second bistable means responsive to said back pressure switch means; l. fluidic NOR gate means responsive to said second bistable means and m. alarm means responsive to said fluidic NOR gate means. - View Dependent Claims (18, 19)
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Specification