Ventilation apparatus and anesthesia delivery system

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of gas within said circulation loop, said blower having an intake side and an exhaust side;
• a proportional flow control valve located in said circulation loop between said airway device and the intake side of said blower;
• a gas storage reservoir located in said circulation loop between said proportional flow control valve and the intake side of said blower;
• a controller operatively connected to said proportional flow control valve, said controller being effective to selectively move said proportional flow control valve to a position to alternatively create a pressure at said airway device which permits gas to flow into said airway device, and then a pressure at said airway device which permits gas to flow out of said airway device.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• an endotracheal tube for intubating a patient, said endotracheal tube having a proximal end and a distal tip which is positionable near the carina of a patient;
• a circulation loop connectable to said endotracheal tube;
• a blower operative to circulate a flow of gas within said circulation loop, said blower having an intake side and an exhaust side;
• a pressure sensor operative to produce a signal representative of the pressure at said distal tip of said endotracheal tube;
• a proportion flow control valve located in said circulation loop between said endotracheal tube and the intake side of said blower;
• and
• a controller operatively connected to said proportion flow control valve, said controller being effective in response to receipt of said signal from said pressure sensor to selectively move said proportion flow control valve to a position to alternatively create a pressure at said proximal end of said endotracheal tube which permits gas to flow into said endotracheal tube and then a pressure at said proximal end which permits gas to flow out of said endotracheal tube.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of intermixed oxygen, a second gas and at least one anesthetic within said circulation loop;
• a multi-gas sensor having an input located at a distal tip of a endotracheal tube, said multi-gas sensor being effective to sense the presence of oxygen, anesthetic gas, carbon dioxide and other gases within said flow and produce signals representative of the concentration of each gas;
• first, second and third supply means for introducing oxygen, said second gas and said at least one anesthetic, respectively, into said circulation loop;
• a controller operatively connected to each of said first, second and third supply means and to said multi-gas sensor, said controller being effective upon receipt of said signals from said multi-gas sensor to selectively control the operation of said first, second and third supply means to obtain the desired, relative concentration of oxygen, said second gas and said at least one anesthetic within said circulation loop.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of gas within said circulation loop;
• a supply device for introducing gas into said circulation loop;
• a bellows having a hollow interior communicating with said circulation loop, said bellows being movable from a baseline position when the volume of gas within said circulation loop changes;
• a sensor device for sensing the extent of movement of said bellows from said baseline position, and for producing a signal representative of said movement;
• a controller operatively connected to said supply device, said controller being effective in response to receipt of said signal from said sensor device to open said supply device so that fresh gas is introduced into said circulation loop at a total flowrate proportional to the extent of movement of said bellows from said baseline position.

Apparatus for use as a ventilator and/or anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of gas within said circulation loop;
• a supply for introducing gas into said circulation loop;
• a heating/cooling device for selectively heating or cooling the gas circulating within said circulation loop, said heating/cooling device including at least one temperature sensor operative to sense the temperature thereof and produce a signal representative of said temperature;
• a controller operatively connected to said heater/cooler device and to said temperature sensor thereof, said controller being effective to operate said heater/cooler device to heat the circulating gas and adjust the heating operation thereof dependent on said signal, said controller being effective to operate said heater/cooler device to cool the circulating gas and adjust the cooling operation thereof dependent on said signal.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of gas within said circulation loop, said blower having an intake side and an exhaust side;
• a purge valve connected to said circulation loop downstream from the airway device, said purge valve being movable between an open position wherein gas is discharged from said circulation loop, and a closed position;
• a proportional flow control valve located in said circulation loop between said purge valve and the intake side of said blower, said proportional flow control valve including:
• (i) a valve body having a hollow interior, an inlet and an outlet;
• (ii) a conduit extending from said inlet of said valve body into said interior thereof, said conduit being formed with a discharge opening having a cross sectional area;
• and
• (iii) a valve closure member movable with respect to said conduit to vary the effective cross sectional area of said discharge opening thereof;
• a controller operatively connected to said proportional flow control valve, said controller being effective to move said valve closure member in a direction toward said discharge opening of said conduit to reduce the effective cross sectional area thereof and create a pressure at the airway device which permits a flow of gas into the airway device, said controller being effective to move said valve closure member in a direction away from said discharge opening of said conduit to increase the effective cross sectional area thereof and create a pressure at the airway device to permit a flow of gas out of the airway device.

In an apparatus for use as a ventilator and/or anesthesia delivery system including an airway device to which a patient can be connected, a proportional flow control valve comprising:

• a valve body having a hollow interior, an inlet and an outlet, said inlet of said valve body communicating with a source of gas and the airway device;
• a conduit extending from said inlet of said valve body into said interior thereof, said conduit being formed with a discharge opening having a cross sectional area;
• and
• a valve closure member movable with respect to said conduit to vary the effective cross sectional area of said discharge opening thereof, said valve closure member being movable in a direction toward said discharge opening of said conduit to reduce the effective cross sectional area thereof and create a pressure at the airway device which permits a flow of gas from the source into the airway device, and said valve closure member being movable in a direction away from said discharge opening of said conduit to increase the effective cross sectional area thereof and create a pressure at the airway device to permit a flow of gas out of the airway device.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of gas within said circulation loop;
• a purge valve connected to said circulation loop downstream from the airway device, said purge valve being movable between an open position wherein gas is discharged from said circulation loop, and a closed position;
• a scavenging system connected by a discharge line to said purge valve, said scavenging system including:
• (i) a manifold having an inlet connected to said discharge line, and an outlet;
• (ii) a sensor device for producing a signal representative of the pressure within said manifold;
• and
• (iii) a proportional flow control valve connected to said manifold between said inlet and said outlet thereof, said proportional flow control valve being proportionately movable between open and closed positions;
• a controller operatively connected to said proportional flow control valve and to said sensor device said controller being effective in response to receipt of said signal from said sensor device to selectively move said proportional flow control valve between said open and closed positions to maintain a substantially constant pressure within the manifold.

Apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device with which a patient can be intubated;
• a blower operative to circulate a flow of gas within said circulation loop;
• oxygen supply device for introducing oxygen into said circulation loop, including:
• (i) at least one tank containing oxygen;
• (ii) a gas make-up valve connected to said recirculation loop;
• (iii) a transfer line interconnecting said tank and said gas make-up valve, said transfer line mounting a one-way valve and a pressure reducing device for supplying oxygen to said transfer line at a predetermined pressure, said pressure reducing device being located between said gas make-up valve and said one-way valve;
• (iv) a pressure gauge connected to said transfer line between said one-way valve and said tank;
• a controller operative to open and close said gas make-up valve to selectively introduce oxygen into said circulation loop.

An anesthetic delivery system, comprising:

• a circulation loop connectable to an endotracheal tube with which a patient can be intubated, said endotracheal tube having a proximal end and a distal tip which is positionable near the carina of the patient;
• a blower operative to circulate a flow of gas within said circulation loop, said blower having an intake side and an exhaust side;
• a supply device for introducing a volatile anesthetic into said circulation loop, said supply device being located at the exhaust side of said blower;
• a first device for introducing oxygen into said circulation loop, and second device for introducing another clinical gas into said circulation loop, said first and second device being located on the intake side of said blower;
• a carbon dioxide absorber connected to said circulation loop to receive the flow of gas therethrough, and means for permitting the flow of gas within said circulation loop to bypass said carbon dioxide absorber;
• a bacterial filter connected to said circulation loop between said blower and the endotracheal tube;
• a heater/cooler connected to said circulation loop;
• a manual breathing bag connected to said circulation loop upstream from the endotracheal tube;
• at least one pressure sensor located at said distal tip of said endotracheal tube, said pressure sensor producing a signal representative of the pressure at said distal tip;
• a multi-gas sensor having an input located at said distal tip of said endotracheal tube, said multi-gas sensor being effective to produce individual signals representative of the respective concentration of oxygen, volatile anesthetic, nitrous oxide and carbon dioxide within said flow of gas;
• a flow sensor located at said proximal end of said endotracheal tube, said flow sensor being effective to produce a first signal representative of the direction of flow of gas into or out of said endotracheal tube and a second signal representative of the magnitude of gas flow into or out of said endotracheal tube;
• a purge valve having an inlet connected to said circulation loop downstream from said endotracheal tube and an outlet, said purge valve being movable between an open position and a closed position;
• a scavenging system connected to said outlet of said purge valve;
• a proportional flow control valve located in said circulation loop between said purge valve and the intake side of said blower;
• a bellows having a hollow interior communicating with said circulation loop, said bellows being located between said proportional flow control valve and the intake side of said blower;
• a room air entrainment valve connected to said circulation loop at said intake side of said blower;
• and
• a controller operatively connected to said blower, said supply device, said first and second devices, said heater/cooler, said at least one pressure sensor, said multi-gas sensor, said flower sensor, said purge valve, said scavenging system, said proportional flow control valve and said room air entrainment valve.

A method of ventilating a patient, comprising:

• providing a source of positive pressure and a source of negative pressure;
• circulating a flow of gas within a circulation loop connectable to a patient by an airway device with the positive and negative pressures, respectively;
• positioning a control device having a variable-sized orifice within the circulation loop between the patient airway device and the source of negative pressure;
• operatively connecting a controller to said control device and selectively using the controller to cause the variable-sized orifice to alternatively create a pressure at the airway device which permits a flow of gas into the airway device, and then a pressure at the airway device which permits gas to flow out of the airway device.

An apparatus for use as a ventilator and/or an anesthesia delivery system, comprising:

• a circulation loop connectable to an airway device to which a patient can be connected;
• a blower operative to circulate a flow of intermixed oxygen, a second gas and at least one anesthetic within said circulation loop;
• a multi-gas sensor having an input located at a distal tip of an endotracheal tube, said multi-gas sensor being effective to sense the presence of at least oxygen, anesthetic gas and carbon dioxide;
• first, second and third supply means for introducing oxygen, the second gas and the at least one anesthetic, respectively, into said circulation loop, said third supply means being a motorized anesthetic syringe pump connected to said circulation loop, said syringe pump including a pump body having an interior carrying a movable plunger, a needle connected at one end to said interior of said pump body, and a sintered metal insert carried within a copper block located in said circulation loop, said needle being connected to said sintered metal insert to deliver liquid anesthetic therein where it is vaporized and carried by said circulation loop to a lung of the patient;
• and
• a controller operatively connected to each of said first, second and third supply means and to said multi-gas sensor, said controller being effective upon receipt of signals from said multi-gas sensor to selectively control the operation of said first, second and third supply means to obtain the desired, relative concentration of oxygen, the second gas and said the at least one anesthetic within said circulation loop.