Classifications

• • G—PHYSICS
  • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
  • G16H—HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA
  • G16H20/00—ICT specially adapted for therapies or health-improving plans, e.g. for handling prescriptions, for steering therapy or for monitoring patient compliance
  • G16H20/40—ICT specially adapted for therapies or health-improving plans, e.g. for handling prescriptions, for steering therapy or for monitoring patient compliance relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/06—Respiratory or anaesthetic masks
  • A61M16/0666—Nasal cannulas or tubing
  • A61M16/0672—Nasal cannula assemblies for oxygen therapy
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes operated by electrical means
  • A61M16/022—Control means therefor
  • A61M16/024—Control means therefor including calculation means, e.g. using a processor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/10—Preparation of respiratory gases or vapours
  • A61M16/1005—Preparation of respiratory gases or vapours with O2 features or with parameter measurement
  • A61M16/101—Preparation of respiratory gases or vapours with O2 features or with parameter measurement using an oxygen concentrator
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/10—Preparation of respiratory gases or vapours
  • A61M16/12—Preparation of respiratory gases or vapours by mixing different gases
  • A61M16/122—Preparation of respiratory gases or vapours by mixing different gases with dilution
  • A61M16/125—Diluting primary gas with ambient air
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/20—Valves specially adapted to medical respiratory devices
  • A61M16/201—Controlled valves
• • G—PHYSICS
  • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
  • G16H—HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA
  • G16H40/00—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices
  • G16H40/60—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices for the operation of medical equipment or devices
  • G16H40/63—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices for the operation of medical equipment or devices for local operation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/04—Tracheal tubes
  • A61M16/0402—Special features for tracheal tubes not otherwise provided for
  • A61M16/042—Special features for tracheal tubes not otherwise provided for with separate conduits for in-and expiration gas, e.g. for limited dead volume
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/06—Respiratory or anaesthetic masks
  • A61M16/0666—Nasal cannulas or tubing
  • A61M16/0672—Nasal cannula assemblies for oxygen therapy
  • A61M16/0677—Gas-saving devices therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/08—Bellows; Connecting tubes ; Water traps; Patient circuits
  • A61M16/0875—Connecting tubes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/10—Preparation of respiratory gases or vapours
  • A61M16/14—Preparation of respiratory gases or vapours by mixing different fluids, one of them being in a liquid phase
  • A61M16/16—Devices to humidify the respiration air
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/20—Valves specially adapted to medical respiratory devices
  • A61M16/201—Controlled valves
  • A61M16/202—Controlled valves electrically actuated
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/20—Valves specially adapted to medical respiratory devices
  • A61M16/208—Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
  • A61M2016/003—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
  • A61M2016/0033—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical
  • A61M2016/0039—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical in the inspiratory circuit
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2202/00—Special media to be introduced, removed or treated
  • A61M2202/02—Gases
  • A61M2202/0208—Oxygen
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/50—General characteristics of the apparatus with microprocessors or computers
  • A61M2205/502—User interfaces, e.g. screens or keyboards

Definitions

• the present disclosure pertains to a method and a system for delivery oxygen to a patient.
• the patient When mechanically ventilating patients, the patient is typically attached to a ventilator with a light-weight plastic breathing tube or circuit.
• a passive exhalation valve near the patient, which is essentially just a hole in the patient circuit. This hole continuously exhausts gas from the patient circuit, which allows exhaled CO2 to be removed from the patient circuit to avoid rebreathing. Because of this leak, there is a reasonably large bias flow from the ventilator continuously during use. This leak is fine for normal ventilation, but if an additional gas is added into the bulk flow from the ventilator, much of that presumably important gas is both wasted or diluted or both, because it never reaches the airways of the patient. Two gases of particular interest are supplemental oxygen and water vapor (humidification).
• an oxygen concentrator When an oxygen concentrator is used to deliver a constant flow of oxygen into a low-flow port of the pressure support ventilator, the effective F1O2 delivered to the patient is lowered by the fact that some usually large fraction of the gas is dumped to atmosphere via the exhalation valve. That is, when using the oxygen concentrator with a non-invasive (NIV) mechanical ventilator, gas is delivered into the low-flow port on the ventilator.
• the oxygen concentrator is set to a constant flowrate so that its delivered oxygen mixes with the air from the NIV ventilator.
• Most NIV ventilator circuits are of the passive type, meaning that there is a constant leak from the exhalation valve, resulting in that only a fraction of the oxygen delivered by the ventilator actually is inhaled by the patient. Most of the gas exits the exhalation valve.
• Waste of the oxygen concentrator is not a problem since the oxygen is just coming from the air in the room anyway.
• a flow rate of, for example, 5 Liters/minute (L/min) is pretty low compared with a typical flow of gas down the passive flow circuit, resulting in a limited F1O2 that can be delivered.
• Increasing the F1O2 would be valuable.
• the pressure support mechanical ventilators may also have an accessory oxygen blending module (OBM) that possesses an oxygen Diameter Index Safety System (DISS) fitting to receive wall or bottled gas at a mean 50 pounds per square inch (psi) supply pressure.
• OBM accessory oxygen blending module
• DISS oxygen Diameter Index Safety System
• the oxygen blending module is then used by the ventilator to maintain a fractional oxygen of all gas that exits the ventilator to a value dialed in by the user.
• the only potential problem with this arrangement is that there is much waste of the oxygen, particularly when using a passive patient circuit that employs a fixed orifice that leaks gas directly to the atmosphere. In such a configuration, oxygen continuously bleeds from the exhalation valve even during the exhalation phase of breathing.
• wall gas is available.
• Oxygen to the Oxygen Blending Module will be supplied from the wall source.
• the wall source In general, because of the plentiful supply of the wall oxygen, there is little concern for oxygen wastage. That is, when using the wall gas, the oxygen waste is not so much of a problem. But, when a patient is being transported within or outside of the hospital and bottled gas is used, the result is fast depletion of the gas bottle. That is, in cases where a patient needs controlled supplemental oxygen at a specific F1O2 while they are being transported and unable to connect to the wall oxygen, the ventilator will be connected to a bottled gas. In such cases, wastage of bottled gas, which is expensive, heavy and occupies a large volume, is highly undesirable and is certainly a source of complaint for many users of such systems.
• the system comprises an oxygen source; a ventilator operatively connected to the oxygen source to receive a supply of oxygen therefrom, the ventilator configured to provide gas including a mixture of the supply of oxygen and air to a patient through a breathing circuit; a valve operatively connected to the ventilator and the oxygen source, the valve having a) an open position in which the ventilator receives the supply of oxygen from the oxygen source and b) a closed position in which the ventilator is not in fluid communication with the oxygen source; and a computer system that comprises one or more physical processors operatively connected with the sensor and the valve, the one or more physical processors being programmed with computer program instructions which, when executed cause the computer system to: determine a volume of gas delivered to the patient during a breath cycle of the patient and an inspiratory volume of gas delivered to the patient during an inspiration phase of the breath cycle by using the breath flow information; and provide input to the valve based on the determined
• the method is implemented by a computer system comprising one or more physical processors executing computer program instructions that, when executed, perform the method.
• the method comprises obtaining, from a sensor, breath flow information for a patient; determining, using the computer system, a volume of gas delivered to the patient during a breath cycle of the patient and an inspiratory volume of gas delivered to the patient during an inspiration phase of the breath cycle by using the breath flow information; and providing, using the computer system input to a valve based on the determined volumes, the provided input causing a movement of the valve between an open position in which a ventilator receives a supply of oxygen from an oxygen source and a closed position in which the ventilator is not in fluid communication with the oxygen source.
• the machine-readable instructions comprise obtaining, from a means for sensing, breath flow information for the patient; determining, using the means for executing, a volume of gas delivered to the patient during a breath cycle of the patient and an inspiratory volume of gas delivered to the patient during an inspiration phase of the breath cycle by using the breath flow information; and providing, using the means for executing, input to a valve based on the determined volumes, the provided input causing a movement of the opening and closing means between the open and closed positions.
• FIG. 3 shows an exemplary ventilator with a low-flow inlet port in
• FIG. 8 shows an exemplary model of a ventilator, an exhaust valve and a lung showing anatomic deadspace volume in accordance with an embodiment of the present patent application
• FIG.10 shows volume and flow traces for one breath in accordance with an embodiment of the present patent application
• FIG.14 shows an exemplary schematic of patient circuit hardware and flow paths in accordance with an embodiment of the present patent application
• FIG.15 shows flow signals corresponding to equation (7) described in the specification in accordance with an embodiment of the present patent application
• FIG. 18 shows an exemplary graphical representation of total patient circuit flow, where a location and quantification of V nsp within breath cycle is shown, in accordance with an embodiment of the present patent application;
• FIG. 21 shows an exemplary graphical representation of total patient circuit flow, in which delivery of the inspiratory volume, V nsp , is illustrated as starting at turn on and stopping at turn off, in accordance with an embodiment of the present patent application;
• FIG. 22 shows an exemplary graphical representation of total patient circuit flow with a margin added to the turn on in accordance with an embodiment of the present patent application
• FIG. 27 shows an exemplary graphical representation of percentage of water saved with a variation in Inspiratory positive air pressure (IPAP) in accordance with an embodiment of the present patent application
• FIG. 28 shows an exemplary graphical representation of percentage of water saved with a variation in Expiratory positive air pressure (EPAP) pressure in accordance with an embodiment of the present patent application
• FIG. 29 shows an exemplary graphical representation of percentage of water saved with a variation in tidal volume in accordance with an embodiment of the present patent application
• FIG. 30 shows an exemplary graphical representation of percentage of water saved with breath rate in accordance with an embodiment of the present patent application
• the present patent application provides a system 100 for delivering
• Valve 108 has a) an open position in which the ventilator 104 receives the supply of oxygen from oxygen source 102 and b) a closed position in which the ventilator 104 is not in fluid communication with oxygen source 102.
• Sensor 112 is configured to measure breath flow information for the patient.
• Computer system 114 comprises one or more physical processors 116 operatively connected with the sensor 112 and valve 108.
• system 100 includes an accumulator 110 that is configured to accumulate the supply of oxygen from oxygen source 102 when valve 108 is in the closed position and to provide the supply of oxygen to ventilator 104 when valve 108 is in the open position.
• accumulator 110 is functionally only needed to enhance F1O2 when using oxygen concentrator 102 (as the oxygen source) through a low-flow port 124 of ventilator 104.
• computer system 114 is further configured to: obtain a tube volume, V tU be, and determine a volume difference between the volume of the gas delivered to the patient during the breath cycle of the patient, V to t and the tube volume, Vtube.
• computer system 114 is configured to provide input to the valve causing the movement of valve 108 to the open position when the determined volume difference is delivered to the patient from a start of a next breath cycle.
• computer system 114 is configured to maintain valve 108 in the open position until the inspiratory volume of gas delivered to the patient during the inspiration phase of the breath cycle and provide input to valve 108 causing the movement of valve 108 to the closed position after the inspiratory volume of gas is delivered to the patient.
• system 100 provides a flow of gas, such as oxygen, to a non-invasive ventilator (i.e., a ventilator with a passive exhalation port) at a location that is not on the patient circuit and that uses valve 108 to control the delivery of the gas to ventilator 104.
• a non-invasive ventilator i.e., a ventilator with a passive exhalation port
• system 100 is configured to increase or improve a desired fraction of inspired oxygen (F1O2) from oxygen concentrator 102 to ventilator 104. In some embodiments, system 100 is configured to enhance F102 from oxygen concentrator 102 to ventilator 104. In some embodiments, system 100 is configured to improve the limited F1O2 associated with use of oxygen concentrator 102 input to low- flow port 124 (e.g., see FIGS. 2 and 3) of pressure support ventilator 104.
• F1O2 inspired oxygen
• system 100 is configured to improve the limited F1O2 associated with use of oxygen concentrator 102 input to low- flow port 124 (e.g., see FIGS. 2 and 3) of pressure support ventilator 104.
• the present patent application provides valve 108 operating in concert with the breathing phase of patient P via ventilator 104.
• Valve 108 is used to shut off the oxygen flow to ventilator 104 and accumulate this oxygen gas in accumulator 110 to be delivered during the next time valve 108 is opened to deliver the oxygen gas into ventilator 104.
• the present patent application also provides an algorithm (as described in great detail below) that is used in ventilator 104 to drive valve 108 to allow delivery of the oxygen gas so that the oxygen gas only enters the ventilator 104 if the oxygen gas is going to be delivered to patient P during the inspiratory phase of patient P.
• the algorithm is provided in ventilator 104.
• the algorithm is provided in a stand-alone system other than ventilator 104.
• accumulator or high-pressure hose 110 takes
• oxygen concentrator 102 ultimately delivers gas at a pressure of about 8 psi. This pressure never reaches low -flow port 124 of ventilator 104 because the flow is unobstructed to and through ventilator 104. With valve 108 though, the flow can be stopped, which allows the pressure to build up inside accumulator or high-pressure hose 110 up to 8 psi. This allows high-pressure hose 110 to act as an accumulator where excess oxygen is stored in the compliance of this tubing while valve 108 is closed. Once valve 108 opens, this excess oxygen gas is released. If it happens quickly, all of the excess oxygen gas can be delivered during the inspiratory phase of patient P, which has the effect of increasing the effective F1O2 as compared with the normal constant flow of oxygen.
• system 100 is configured to conserve oxygen.
• the present patent application proposes an improved way to deliver oxygen to patient P that is also using a non-invasive ventilator that minimizes the loss (waste) of oxygen.
• the present patent application was conceived and developed in response to the fact that an inspiratory-only delivery of oxygen from an Oxygen Blending Module (OBM) has nearly no application for home ventilation. This is because home ventilator patients use the oxygen concentrators, which use low-flow port 124, not the OBM.
• OBM Oxygen Blending Module
• the primary issue with use of the oxygen concentrator is that it has a limited output (F1O2), unlike the OBM, which provides all of the oxygen necessary to provide the user-specified F1O2 (21-100%) up to very high flow rates.
• ventilator 104 is configured to provide ventilatory support to patient P.
• ventilator 104 includes a gas flow generator for providing a flow of gas to patient P and conduit 106 for delivery of the gas flow to an airway of patient P.
• ventilator 104 is configured to handle the software associated with turning valve 108 on and off, and a means of providing power to activate solenoid valve 108.
• ventilator 104 may also be referred to as means for providing gas (to patient P through breathing circuit means 106).
• the gas includes a mixture of air and the supply of oxygen from means 102 for supplying oxygen or oxygen source 102.
• the oxygen blending module is a high-pressure oxygen blending module.
• breathing circuit 106 is referred to as patient
• sensor 1 12 includes a transmitter for sending
• sensor 1 12 may provide the breath flow information to a computer system (e.g., comprising server 1 14) over a network (e.g., network 150) for processing.
• sensor 1 12 may process the obtained breath flow information, and provide processed breath flow information to the computer system (e.g., comprising server 1 14) over a network (e.g., network 150).
• ventilator 108 when valve 108 is in the open position, ventilator
• the breath cycle of patient P includes inspiration phase and expiration phase.
• valve 108 is a servo valve. In some embodiments, valve 108 is a servo valve at low-flow port 124 of pressure support ventilator 104. In some embodiments, servo valve is used when oxygen source includes an oxygen blending module.
• accumulator 100 typically has a length of high pressure hose that provides a conduit connecting oxygen concentrator 102 to valve 108.
• tube volume subsystem 216 is configured to
• system 100 includes valve turn on margin
• valve turn on margin determination subsystem is configured to determine a margin for turning on valve 108.
• determined valve turn on margin is shown and described in detail with respect to FIG. 22 and also with respect to equations (20)-(23).
• ventilator 104 port/connection on ventilator 104, or it could be just signaled by ventilator 104 while receiving power from some other source.
• System 100 used with bottled gas 102 includes solenoid valve 108 that is ideally controlled by ventilator 104 and located at the inlet of low-flow port 124, and a length of high pressure hose/accumulator 110 that provides a conduit connecting gas bottle 102 to valve 108. Other associated connectors on either end of this arrangement are necessary as well. Ventilator 104 is also configured to be able to handle the software associated with turning valve 108 on and off, and a means of providing power to active solenoid valve 108.
• the algorithm of the present patent application has the following goals 1) do not inject oxygen during retrograde flow back up the patient circuit; 2) do not add oxygen into the final 1/3 of G-, representing anatomic deadspace; 3) do not add oxygen during the expiratory phase; 4) minimize oxygen that simply exits the exhaust valve; and 5) make sure that there is fully oxygenated gas at the very beginning of inspiration.
• FIG. 10 is used to develop the math associated with the algorithm of the present patent application.
• FIG. 10 shows volume and flow traces for one breath cycle. The dot in FIG. 10 indicates the location of 2/3 of V T .
• V Um tube volume
• Qc is the stored flow value at count i ;
• count k is the backward count from t tng until V sum 3 V tube .
• Humidified gas during the inspiratory phase can then be delivered.
• the volume delivery flow pattern into the patient circuit used to load the inhaled volume will not correspond with the actual volume delivered during the inspiratory phase unless the patient happens to start inspiration at exactly the same time that the tube starts being loaded from the humidifier.
• the tubing loading cannot be simply turned on for the same duration as the inspiratory time. Therefore, the circuit flow volume delivered during the inspiratory phase is to be measured so as to deliver that specific volume into the tube. To measure this volume, equation (9) is used. Equation (9)
• Vmsp flow volume delivered during the inspiratory phase
• n count at the following t cycle .
• Equation (10) Equation (10)
• V sum 2 instantaneous value of integrated flow
• equations (9) and ( 10) appear to be identical, but equation (9) is used only to calculate the volume of gas consumed by the patient ( V msp ) and equation (10) is used to set the delivery of gas volume into the tube (done when V sum2 > V insp ) starting at k steps (i.e., where k is obtained from equation (8)] prior to the next value of .
• Tvtube period over which the tube volume is delivered by the ventilator
• i index of current or past breath cycle
• V in spi inspired volume in breath i
• Tv tubei period over which the tube volume is delivered during breath i.
• FIGS. 17-22 are used to explain this approach. The first is just a realistic record of a set of patient flow and pressure signals, which can be used because the robustness of the algorithm derived above, as well as the new one here obviates the need to have a simple harmonic breathing signal that was used before.
• FIG. 17 shows typical patient flow and pressure signals.
• the top most solid curve is total circuit flow, Q c , the dashed curve from the top is leak flow, O, , the second solid curve from the top is actual patient flow, Q p , and the third solid curve from the top is delivered pressure, P p (corresponds to the ordinate on the right).
• the pressure data is shown on the right hand side Y-axis of the graph in FIG. 17, while the flow data is shown on the left hand side Y-axis of the graph in FIG. 17.
• the pressure data is measured in centimeters of FLO (cm FLO).
• the flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 17. The time is measured in seconds.
• FIG. 18 shows location and quantification of V insp within the breath cycle.
• FIG. 18 shows total patient circuit flow signal, Q c .
• the flow data is shown on the left hand side Y-axis of the graph in FIG. 18.
• the flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 18.
• the time is measured in seconds.
• the total inspiratory volume by integrating from beginning to end of an inspiratory phase, Vinsp is the shaded area in FIG. 18.
• the next step is to integrate the total flow to obtain the volume delivered during the entire breath cycle. For now, what happens if exhalation flow exceeds leak flow is ignored, resulting in retrograde flow in the patient circuit back toward the ventilator.
• the volume of total flow over the breath cycle is highlighted in yellow in FIG. 19.
• FIG. 19 shows location and quantification of the total breath volume, V tot , for one breath cycle.
• FIG. 19 shows total patient circuit flow signal, Q c .
• the flow data is shown on the left hand side Y-axis of the graph in FIG. 19. The flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 19. The time is measured in seconds.
• the total volume over one breath phase, Vtot is the shaded area in FIG. 19.
• V tot total volume delivered by the vent during a breath
• N count at the end of the cycle, or that corresponding to .
• FIG. 20 shows volume encompassed by the difference between tube volume, V tube , and total volume, V tot .
• the tube volume described above, V tube is shown in FIG. 20.
• V tube is input by the user.
• V tube is calculated by the ventilator.
• FIG. 20 shows total patient circuit flow signal, Q c .
• the flow data is shown on the left hand side Y -axis of the graph in FIG. 20.
• the flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 20.
• the time is measured in seconds.
• FIG. 21 shows delivery of the inspiratory volume, V insp , starting at turn on and stopping at turn off.
• FIG. 21 shows the total patient circuit flow signal, Q c .
• the flow data is shown on the left hand side Y -axis of the graph in FIG. 21.
• the flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 21.
• the time is measured in seconds.
• FIG. 22 shows adding a margin to turn on.
• FIG. 22 shows total patient circuit flow signal, Q c .
• the flow data is shown on the left hand side Y -axis of the graph in FIG. 22.
• the flow data is measured in Liters/minute (L/min).
• the time is shown on X-axis of the graph in FIG. 22.
• the time is measured in seconds.
• Equation (15) Equation (15)
• V tot total volume delivered by the vent for a given breath
• Q c total patient circuit flow
• i time step that starts at the beginning of a breath cycle
• N number of time steps in a full breath
• m number of full breaths, and its value is reached when
• V tube includes various things depending on the circuit configuration and the entity being controlled.
• Humidification is a very simple case because the only volume for which compensation is necessary is that between the humidifier outlet and the patient. It will be assumed that this is simply the patient circuit tubing.
• the equation (16) shows the tube volume equals the patient circuit tubing volume.
• V circuit patient circuit tubing volume.
• the value of the tube volume V tube is a bit more complex because it encompasses a number of different things that may or may not be present in the circuit. These include a) patient circuit tubing, V circmt , (i.e., always present); b) humidifier bowl, V bawl , (i.e., optional but likely present) 3) humidifier connection tube, V connect , (i.e., always with humidifier ⁇ 175 cc); 4) Oxygen Blending Module Volume, V OBM , (i.e., always present - XX cc) and 5) the ventilator internal flow path volume, V vent . If all components listed above are present, the tube volume V tube is shown by equation (17) below.
• VOBM oxygen blending module volume
• F connect humidifier connection tube volume
• V d cuit patient circuit tubing volume
• V vent ventilator internal flow path volume.
• V volume of interest, in this case, V tube .
• P tot absolute pressure in the volume of interest, in this case
• Vmargin margin volume
• V m ⁇ in is simply added to V tube when calculating V tot ⁇ V tube .
• the volume for turn on is calculated as shown in equation (21) below.
• V ! ! total breath volume
• V jnsp inspiratory volume
• anatomic deadspace comprises about 150 cubic
• centimeter(cc), or just under 1/3 of any breath in tidal breathing This means that the last third or so of gas provides no ventilatory benefit to the patient, but is simply a space filler. For humidification, it would be important to keep deadspace gas humidified so as not to allow the upper airways to dry out.
• the patient circuit must contain gas with the following characteristics 1) it must be an uninterrupted slug residing in the patient circuit tube; 2) the gas entire gas slug must be enriched to the same level; 3) the delivered gas slug must have a volume equal to V insp ; 4) the algorithm cannot account for re breathing if the ventilation is insufficient to drive off excess CO2; and 5) as long as leak is > 0, on average, the volume of negative flow, V neg must be less than V insp .
• the cases for consideration include 1) no retrograde flow; 2) enrichment starts after retrograde flow has ceased; 3) enrichment is started, retrograde flow begins after this point, but retrograde volume does not exceed V uv , which is the volume upstream from the enrichment point; and 4) enrichment is started, retrograde flow begins after this point, retrograde flow exceeds V uv .
• V insp-start 3 V neg 1) start volume delivery at the appropriate point; 2) measure the volume of positive gas flow from the time at which V insp is started, until the beginning of retrograde flow. This will be designated V insp-start ; 3) when the quantity of volume equal to (V insp _ start - V neg ) has been delivered into the patient circuit, stop delivery of enrichment and stop the volume delivery integration but retain its value; 4) once flow becomes negative start the negative flow integrator; and 5) once flow changes direction, restart enrichment and restart the volume delivery integrator. If V insp start ⁇ V neg , 1) don’t start gas delivery until positive flow recovers; and 2) then use the case in which there is no retrograde flow above.
• the prediction for water savings is based on a simple model that describes water added to gas as it travels through the humidifier then down the patient circuit. This model is based on the idea that flow from exhalation valve EV is only a function of circuit pressure and is represented by a model for inspiration and one for expiration as shown in FIG. 24. [202] In FIG. 24, the left figure shows the gas volume movement during the inspiratory phase, while that on the right (in FIG. 24) shows the gas volume movement during the expiratory phase.
• volume that passes through the humidifier during the expiratory phase V exp is equal to difference between of the total volume that leaves the exhalation valve during the expiratory phase, F / , and the tidal volume, V t .
• F / , total volume that leaves the exhalation valve during the inspiratory phase
• F / , total volume that leaves the exhalation valve during the expiratory phase.
• CPAP Continuous Positive Airway Pressure
• BiPAP Bilevel Positive Airway Pressure
• system 100 employs its own low -flow port so low- flow port 124 may not even be necessary on ventilator 104.
• Such a stand-alone device allows this present patent application to be used on any ventilator.
• a method 700 for delivery of oxygen is provided.
• Method 700 is implemented by computer system 114 that comprises one or more physical processors 116 executing computer program instructions that, when executed, perform method 700.
• subsystems 212-220 (as shown in FIG. 7) may provide more or less functionality than is described.
• additional subsystems may be programmed to perform some or all of the functionality attributed herein to subsystems 212-220 (as shown in FIG. 7).
• system 100 may also include a communication interface that is configured to send the determined valve turn on and valve turn off through an appropriate wireless communication method (e.g., Wi-Fi, Bluetooth, internet, etc.) to valve 108 or systems for further processing.
• system 100 may include a recursive tuning subsystem that is configured to recursively tune its intelligent decision making subsystem using available data or information to provide better overall valve turn on and valve turn off
• intelligent decision making subsystem, communication interface and recursive tuning subsystem may be part of computer system (comprising server 102).

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• 2019
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