Abstract: A breathing assistance device, capable of operating according to several respiratory modes forming a list of possible modes. The device is equipped with a mechanism for selecting a desired mode from a group of modes that can be selected. The device also includes a mechanism for realizing a configuration diagnostic of the device, a mechanism for associating with authorization level with each possible mode, according to the results of the diagnostic, with the lowest authorization level corresponding to unauthorized modes, a mechanism for authorizing only the selection of authorized modes, in such a way that selecting unauthorized modes is impossible.

Abstract: An anesthetic breathing apparatus has a first gas analyzer arranged to provide gas measurement data related to a first sample point to a control unit that is arranged in a servo or feedback control system configured to adjust delivery of a vaporized anesthetic agent from an anesthetic vaporizer to a delivery point in an inspiratory branch of a breathing circuit of the anesthetic breathing apparatus, The first sampling point is arranged in the breathing circuit downstream and close to the delivery point. A second gas analyzer arranged to be operated in a first mode of operation to provide gas measurement data for patient monitoring, and arranged to be operated in a second mode of operation to provide gas measurement data to the control unit. A switch over unit is fluidly connected to the second gas analyzer, and arranged to switch fluid communication of said second gas analyzer between the first sample point for the second mode of operation and a second sample point for the first mode of operation.

Abstract: This disclosure describes systems and methods for compensating for leakage when during delivery of gas to a patient from a medical ventilator in a pressure regulated volume control (PRVC) ventilation mode. The technology described herein includes systems and methods that compensate the delivery of PRVC ventilation for leakage in the patient circuit by using leak-compensated lung flows as well as respiratory mechanics (lung compliance and lung resistance) estimated in a manner that compensates for elastic and inelastic leaks from the ventilation system.

Abstract: A portable resuscitation system is provided. The system includes a housing for enclosing a ventilation device and a vital signs tracking device. The housing is anatomically designed for use as a neck support for opening an airway of a subject in a supine position and optionally includes mechanism for modifying the height or angle of the neck support.

Abstract: Apparatus for respiratory support and non-invasive detection of alveolar recruitment/derecruitment provides air supply to a patient at a base pressure and an additional pressure which can be varied at a frequency of from 5 to 10 Hz and transducers applied to the conduits supplying air to the patient to send electric signals to a computer to obtain a variable positive end-expiratory pressure and a to obtain an end expiratory resistance at varying values of positive end expiratory pressure and defining the state of pulmonary recruitment as the value of the positive end-expiratory pressure which corresponds to a point of maximum expiratory resistance.

Abstract: An apparatus for deploying oxygen masks that includes a pre-packaged modular system that does not require manual repacking of oxygen masks by aircraft technicians. The cartridge is for use with a manifold having a passageway in fluid communication with a source of breathable gas. The cartridge includes an end wall, a sidewall extending from the end wall and terminating at a distal end adjacent to an opening. A flexible member defines a chamber inside the cartridge. The chamber is in fluid communication with the passageway when the cartridge is coupled to the manifold. The flexible member has an outlet. A mask assembly is disposed inside the cartridge. The mask assembly has a hose coupled to the outlet of the flexible member. A cover is removably attached to the distal end of the at least one side wall.

Abstract: A blower includes a housing including an inlet and an outlet, a stationary component provided to the housing, an impeller positioned between the inlet of the housing and the stationary component, and a motor adapted to drive the impeller. The housing and the stationary component cooperate to define a volute that directs air towards the outlet. The housing includes a separating wall constructed and arranged to divide the volute into a high speed airpath region and a low speed airpath region.

Abstract: A portable, compact closed circuit ventilation device for manual ventilation of a patient undergoing a surgical or medical procedure that requires sedation as well as emergency management of respiratory failure. One example embodiment includes a closed breathing circuit having a manually squeezable bag, a carbon dioxide absorption canister, a plurality of valves, a gas port and a plurality of sensors for measuring Tidal Volume (TV), Peak Airway Pressure (PAP) and End Tidal CO2 (ETCO2). Another example embodiment includes an open breathing circuit having a bag, valves and sensors. A monitor displays the sensor measurements during the respiratory phases. In a spontaneously breathing patient the device may be used to assess the adequacy of patient's respiratory efforts. During manual or assisted ventilation, the monitor assures safe and efficacious ventilation by the closed breathing circuit.

Abstract: An assembly for modifying patient airflow into a nasopharyngeal airway or trachea. A valve assembly having a valve seal is adapted to attach to an airflow generator. The valve seal is connected to and operable by a motor means. A controller circuit is connected to the motor means for operating the motor means incrementally such that pressurized air from the airflow generator continuously enters the interior feed tube from the inlet but passes out of the outlet only when the motor means causes the valve seal to move in relation to the exit tube to at least partially unblock the outlet such that the pressurized air is converted into a single, repeatable burst exiting the outlet. In one embodiment, instead of a motor, the valve assembly can include a shaft. A butterfly valve seal is attached to the shaft. A nickel titanium wire is in conductive communication with the shaft.

Abstract: Systems and methods for providing respiratory therapy with varying flow rates are disclosed. A system comprises a source of breathing gas, a patient interface, and a flow control device. The flow control device is configured to automatically change a rate of the flow of breathing gas. The flow control device may vary the rate of the flow of breathing gas at a frequency slower than a frequency of breathing of the patient. A method comprises coupling a patient interface to the patient, providing the flow of breathing gas to an inlet port of the patient interface, and automatically changing a rate of the flow of breathing gas with a flow control device in communication with the flow of breathing gas. The method may also comprise varying the rate of the flow of breathing gas at a frequency slower than a frequency of breathing of the patient.

Abstract: Disclosed is an apparatus for treating a respiratory disorder, configured to compute a measure of typical recent ventilation such that a rate of adjustment of the measure of typical recent ventilation is reduced as a measure of recent uncompensated leak increases. Also disclosed is an apparatus for treating a respiratory disorder, configured to compute a target ventilation from a product of a measure of typical recent ventilation and a target fraction, wherein the target fraction is dependent on the recent pressure support.

Abstract: Medical techniques include systems and methods for administering a positive pressure ventilation, a positive end expiratory pressure, and a vacuum to a person. Approaches also include treating a person with an intrathoracic pressure regulator so as to modulate or upregulate the autonomic system of the person, and treating a person with a combination of an intrathoracic pressure regulation treatment and an intra-aortic balloon pump treatment.

Abstract: The invention relates to a system for providing emergency oxygen and therapeutic oxygen in an aircraft, said system having an oxygen source, an oxygen conduction system comprising a second oxygen outlet, a device for providing emergency oxygen comprising a second oxygen inlet, a device for providing therapeutic oxygen, having a first oxygen inlet and a first oxygen outlet. According to the invention, the second oxygen outlet can be coupled to the first oxygen inlet, the first oxygen outlet can be coupled to the second oxygen inlet and the second oxygen outlet can be coupled to the second oxygen inlet.

Abstract: Oxygen supply elevator which supplies oxygen to an internal space of the elevator or a separate oxygen mask provided in the elevator, thereby allowing a user to easily breathe and removing smoke or the like. The oxygen supply elevator includes: an oxygen containing unit which is provided in a facility mounting space formed on the elevator and contains oxygen at pressure higher than atmospheric pressure; an oxygen supply unit which is connected with the oxygen containing unit through at least one communication channel and supplies oxygen to an oxygen supply space in the elevator; a valve unit which is provided on the communication channel and adjusts a flow rate of oxygen discharged from the oxygen containing unit; and a control unit which is connected to the valve unit and adjusts whether to open or close the valve unit or an opening amount of the valve unit.

Abstract: The lung compliance of a subject that is at least partially self-ventilating is determined. The quantification of lung compliance may be an estimation, a measurement, and/or an approximate measurement. The quantification of lung compliance may be enhanced over conventional techniques and/or systems for quantifying lung compliance of self-ventilating subjects in the lung compliance may be quantified relatively accurately without an effort belt or other external sensing device that directly measures diaphragmatic muscle pressure, and without requiring the subject to manually control diaphragmatic muscle pressure. Quantification of lung compliance may be a useful tool in evaluating the health of the subject, including detection of fluid retention associated with developing acute congestive heart failure.

Abstract: A ventilatory system for providing ventilatory support to a patient without the need for an external source of pressurized drive gas. The ventilatory system comprises a drive pump and a controller such that the drive pump collects ambient air and may pressurize it to a pressure determined by the controller. The controller may signal to the drive pump to pressurize the collected ambient air to a first pressure for delivering ventilatory support to a patient and a second pressure for providing PEEP support to a patient. The controller may signal to the drive pump to deliver a targeted flow and/or volume of collected ambient air to the bellows to provide volumetric ventilatory support during inhalation and a PEEP support during exhalation.

Abstract: The present invention provides a method and apparatus for providing continuous positive airway pressure for treating sleep apnea. The method comprises the steps of providing a breathing gas flow to a subject, measuring a respiratory characteristic of the subject, determining or estimating a preferable breathing gas flow for the subject based on wavelet analysis utilizing in part the respiratory characteristic of the subject, and preferably adjusting the breathing gas flow if the determined or estimated preferable breathing gas flow is different. This method and apparatus can be used in a number of applications including both clinical and home use in the form of CPAP for the treatment of sleep apnea or less preferably as a ventilator to assist in patient breathing.

Abstract: Exhalation valve including a diaphragm for opening and closing an outlet of an exhalation flow path for guiding exhaled air to the outside air, a back chamber provided opposite the exhalation flow path in the diaphragm and forming a space together with the diaphragm, and a pump unit fixed to the circumference of the back chamber for adjusting the air pressure inside the back chamber by feeding and discharging of air to and from the back chamber. The diaphragm closes the outlet of the exhalation flow path when the air pressure inside the exhalation flow path is lower than the air pressure inside the back chamber, and opens the outlet of the exhalation flow path when the air pressure inside the exhalation flow path is higher than the air pressure inside the back chamber.

Abstract: A system for managing a supplemental gas supply in a breathing assistance system configured to provide breathing assistance to a patient includes a temperature sensor and a control system. The temperature sensor is configured to measure a temperature associated with a breathing assistance system configured to deliver a first gas and a supplemental gas toward a patient. The control system is configured to automatically control the flow of the supplemental gas based at least on the monitored temperature.

Abstract: A method is provided for automatically controlling a ventilation or breathing system with a ventilation unit (7), which is controlled by a control unit (5), in order to deliver an assist pressure preset by the control unit, wherein the current values of the tidal volume flow Flow(t) and those of the volume V(t) are detected in the control unit. The control unit (5) may carry out a proportionally assisting ventilation method (PAV: Proportional Assist Ventilation) by a factor for a degree of compensation (PPSp) being selected by the control unit and by the parameters for the volume assist (VA) and the flow assist (FA) being determined by: VA=PPSp·?E FA=PPSp·?R, wherein ?E is the deviation of a measured or assumed elastance (Emeasured) of the patient from an ideal elastance (Eideal) and ?R is the deviation of a measured or assumed resistance (Rmeasured) of the patient from an ideal resistance (Rideal).

Abstract: A user interface for respiratory apparatus comprises a combination of a menu display (302), push buttons (304, 308, 310) and a rotary control dial (306). The user interface may include a menu control for detecting at least one parameter from the user's operation of the controls to navigate the menu and applying this to subsequent operation of the user interface controls. The user parameter may be a direction of operation of the rotary control dial which the user associates with a particular direction of navigation within the menu.

Abstract: A method, apparatus, and system are provided for mucous membrane therapy. The method includes receiving at least one body signal from a patient; detecting a condition of the patient based on the body signal; and administering the therapy to at least one of a mucous membrane or a serous membrane of the patient. A medical device system configured to implement the method is provided. A computer-readable storage device for storing instructions that, when executed by a processor, perform the method is also provided.

Abstract: A bi-directional gas flow generation system (10), the system comprising: (a) a pressure generator (14) comprising an inlet (40) and an outlet (42), (b) a flow member (16) comprising an outlet port (50), an inlet port (52), a respiratory circuit port (54) and a flow path (60), (c) a first valve (18), (d) a second valve (20), and (e) a processor (24) configured to selectively control the first valve and the second valve to operate in (i) a first mode in which gas flows from the flow member inlet port (52) to the respiratory circuit port (54), thereby creating a positive pressure at the respiratory circuit port (54) to insufflate the subject; and (ii) a second mode in which gas flows from the respiratory circuit port (54) to the flow member outlet port (50), thereby facilitating gas flow out from the airway of the subject to exsufflate the subject.

Abstract: An flight-safe indicator for a battery displays the flight-safety state of a battery to be transported by an aircraft. The indicator can be easily recognized by ground personnel anywhere regardless of the language they speak or read. The indicator comprises an icon indicating that the battery is safe for flight and would be easily recognized by personnel at an airport. The icon would be placed on the battery or on the battery packaging prior to loading on the aircraft. When the magnitude of power stored on the battery exceeds a safety threshold, the icon changes to an indication that the battery is not safe for transporting by aircraft and the operator may discharge the battery using a load until it reaches a safe level.

Abstract: An air delivery system is provided. The air delivery system includes a PAP device having a flow generator, a patient interface, a processor and a connector, and at least a removable sensing device having at least a sensor, a front-end analog circuit and a connector. The sensor is integrated with the patient interface to measure a respiratory characteristic in a path between the patient's upper airway and the flow generator. When the removable sensing device is separated from the PAP device, the PAP device enters a first operation mode to perform a first preset air delivery behavior, and when the removable sensing device is coupled to the PAP device through the connectors respectively thereof, the PAP device enters a second operation mode to perform a second air delivery behavior for adjusting the treatment pressure in accordance with the respiratory characteristic.

Abstract: Systems and methods for estimating a leak flow in a breathing assistance system including a ventilation device connected to a patient are provided. Data of a flow waveform indicating the flow of gas between the ventilation device and the patient is accessed. A specific portion of the flow waveform is identified, and a linear regression of the identified portion of the flow waveform is performed to determine an estimated leak flow in the breathing assistance system.

Abstract: Components of a CPAP or other patient ventilation apparatus have a remotely-readable identification tag encoded with component identification data. The flow generator controller is programmed to receive data derived from the identification tag from a tag reader, and to adapt functions of the flow controller to coordinate with the component.

Abstract: A pressure support device implements compensation for variations in air density of its operating environment. A pressurized flow of breathable gas is generated for delivery to the airway of a subject. One or more parameters associated with the ambient environment of the pressure support device are determined. These parameters can include one or more of an ambient barometric air pressure, an ambient air temperature, or ambient air humidity. In some embodiments, one or more assumed parameters associated with the ambient environment of the pressure support device are determined based on typical sleeping conditions of the subject. An ambient air density of the ambient environment of the pressure support device is estimated based on one or more of the parameters and/or assumed parameters. A flow rate of the pressurized flow of breathable gas is adjusted based on the estimated ambient air density of the ambient environment of the pressure support device.

Abstract: A breathing apparatus includes a filter, a motor and a blower driven by the motor. The filter is disposed ahead of the blower and the blower is configured to generate an air volume flow over the filter. A data storage unit has calibration curves for the air volume flow stored therein and the calibration curves are provided in characteristic line fields referenced to a known ambient pressure (p0, p1). Each of the characteristic line fields has a reference calibration curve referred to a predetermined operating state. A control unit is connected to the motor and the data storage unit. The control unit is configured to extrapolate one of the characteristic line fields for the operation of the motor by comparing a calibration curve ({dot over (V)}ox) for an unknown ambient pressure (px) recorded at a predetermined operating state with a reference calibration curve.

Abstract: A comfortable low-leak mask assembly for use with Non-Invasive Positive Pressure Ventilation (NIPPV) is provided to improve patient compliance and/or treatment. The mask system may include headgear having straps that are substantially inextensible and/or micro-adjustable; and/or a mask and/or cushion that includes various structures to allow enhanced/tailored sealing and/or fit at selected locations on the patient's face.

Abstract: A ventilation apparatus for treating sleep apnea is provided. A ventilator controlled by a control system may deliver ventilation gas through a ventilation gas delivery circuit to a ventilation catheter and a distal tip on the ventilation catheter. One or more sensors may detect a breathing cycle and the control system may operate the ventilator in synchrony with the breathing cycle. The distal tip may deliver the ventilation gas superiorly from the transtracheal ventilation catheter towards an upper airway, inferiorly from the transtracheal ventilation catheter towards a lung, or a combination of both. The ventilation catheter may be a transtracheal catheter, a trans-oral catheter or a trans-nasal catheter.

Abstract: The invention is directed to a positive airway pressure (PAP) system with a head mounted harness assembly with a housing and a head position sensor located within or secured to the housing that detects the position of a patient's head, and communicates this head position information to a controller of the system which may be disposed within the housing having the position sensor or a second housing. The controller varies the output pressure of the pressure source, e.g. a rotary compressor, based, at least in part, on the head position information provided by the head position sensor. In a preferred embodiment, the position sensor is an accelerometer.

Abstract: A flow cassette has a housing with an inlet and an outlet and a passage therebetween. The flow cassette also has a temperature sensor disposed within the passage and configured to measure the temperature of a fluid flowing through the passage, a flow rate sensor disposed within the passage and configured to measure a flow rate of the fluid flowing through the passage, and a processor coupled to the temperature sensor and flow rate sensor. The processor is configured to accept measurements of temperature and flow rate from the temperature sensor and flow rate sensor, respectively, and provide a compensated flow rate.

Abstract: The present invention relates to a method of delivering gas during ventilation of a patient using a system for breath delivery. The method of gas delivery includes real-time compensation of gas compression losses, in the current breath delivery phase, and gas leakage losses. The present invention further relates to a system for breath delivery. Still further, the present invention relates to a computer implemented method adapted of delivering gas during ventilation of a patient using a system for breath delivery.

Abstract: The invention is directed to a positive airway pressure (PAP) system with a head mounted harness assembly with a housing and a head position sensor located within or secured to the housing that detects the position of a patient's head, and communicates this head position information to a controller of the system which may be disposed within the housing having the position sensor or a second housing. The controller varies the output pressure of the pressure source, e.g. a rotary compressor, based, at least in part, on the head position information provided by the head position sensor. In a preferred embodiment, the position sensor is an accelerometer.

Abstract: A respiratory treatment apparatus provides respiratory treatment with improved power management control to permit more efficient power consumption and power supply units, such as battery powered operation. In one embodiment, power management prioritizes the flow generator (104) over other accessories such as the heating elements (111, 135) of a humidifier (112) and/or a delivery tube. The flow generator may control operations of the heating elements as a function of a detected respiratory cycle. For example, the timing of operation of the heating elements may be interleaved with the portion of an inspiratory phase of the respiratory cycle to permit the flow generator to operate during a peak power operation without a power drain or with a lower power drain from these components. Operations of distinct sets of components of the system (e.g., different heating elements) may also be interleaved to prevent simultaneous peak power operations.

Abstract: A CPAP or other ventilation system includes a mask, a flow generator, a positive or high pressure line to provide positive or high pressure air from the flow generator to the mask and a vacuum or return line provided to actively extract exhaled gas from the breathing chamber and/or the air delivery conduit of the mask. The vacuum or return line includes a vent outlet preferably positioned remote from the mask.

Abstract: A ventilation device for non-invasive positive pressure ventilation (NIPPV) or continuous positive airway pressure (CPAP) treatment of a patient has a gas flow generator, a gas delivery circuit optionally including a humidifier, a controller and sensors monitoring values of operational parameters of the device. The device further includes one or more relationships stored in data storage of the controller relating combinations of parameter values as being indicative of fault conditions of the device operation, the sensors and/or the fault detection process.

Abstract: A method and apparatus for facilitating breathing using a mechanical breathing gas ventilator is presented. The patient effort is deduced from a measured flow signal and analyzed with respect to the energy in the breathing system comprising the mechanical ventilator and the patient. When a predetermined energy threshold has been reached the ventilator responds to the breathing pattern change.

Abstract: Gas leakage from a ventilator circuit and patient interface is estimated by a method that relies on breath-by-breath or time-to-time variability in the pattern of pressure delivery by the ventilator, comprising generating signals that correspond to pressure (PCIRCUIT) and flow rate (Flow) in the ventilator circuit, integrating flow (Integrated Flow), measuring the change in Integrated Flow (?V) over an INTERVAL extending from a selected point in the expiratory phase of a ventilator cycle to a selected point during the expiratory phase of a nearby ventilator cycle, repeating the measurement of ?V for at least two said INTERVALs, processing PCIRCUIT to produce an index or indices that reflect(s) the pattern of pressure delivery by the ventilator during each of said INTERVALs, applying statistical methods to determine the relation between the differences in ?V among 1NTERVALs and the corresponding differences in said index or indices of PCIRCUIT, and establishing from said relation the leak rate at specified PCI

Abstract: A control system for a high frequency oscillating ventilator (HFOV) includes an oscillator controller and a mean airway pressure (MAP) controller. The HFOV includes a reciprocating piston which is adapted to generate positive and negative pressure waves for delivery to a patient airway. The oscillator controller comprises a pair of closed loop control circuits including an oscillator pressure loop and a centering loop which are collectively adapted to regulate frequency and amplitude of piston reciprocations and centering of the piston. The MAP controller comprises a closed loop control circuit that is adapted for regulating MAP at the patient utilizing feedback in the form of patient circuit pressure. Likewise, the oscillator controller utilizes patient circuit pressure as well as piston displacement feedback in order to regulate movement of the piston.

Abstract: A low-cost CPAP apparatus in which, upon detection of the transition from inhalation to exhalation, the blower motor is de-energized to allow it to freewheel. When the pressure in the patient mask (or whatever interface is utilized) reaches a minimum pressure level during exhalation, the motor is re-energized and its speed is controlled so to maintain the pressure at a level suitable for exhalation. Upon detection of the transition from exhalation to inhalation, the motor speed is increased to provide higher pressures in the patient mask suitable for inhalation.

Abstract: A method of operating a CPAP apparatus in which the interface pressure is controlled to rapidly drop at the start of expiration by an expiratory relief pressure (ERP) that is independent of instantaneous respiratory flow, following which the pressure rises to an inspiratory level at or shortly before the end of expiration, or at the onset of an expiratory pause, if any. The ERP is an increasing function of the inspiratory pressure. The expiratory pressure follows a template that is a function of the expected expiration time, the magnitude of the template being equal to the ERP. The current estimated proportion of expiration is determined by comparing the expiration time of the breath in progress to low-pass filtered expiratory durations measured for a number of the preceding breaths.

Abstract: An oxygen concentrator system includes a portable unit and a base unit. The portable unit includes an air separation device. The base unit includes a vacuum pump. The portable unit is moveable with respect to the base unit between a connected position, in which the vacuum pump of the base unit is connected to the air separation device of the portable unit for applying vacuum pressure at the air separation device of the portable unit, and a disconnected position, in which the vacuum pump is not connected to the air separation device of the portable unit. The air separation device operates using a vacuum pressure swing adsorption (VPSA) cycle when the portable unit is in the connected position. The air separation device operates using a pressure swing adsorption (PSA) cycle when the portable unit is in the disconnected position.

Abstract: A valve is provided for relieving a gaseous pressure of a branching unit in flow communication with lungs of a subject. The valve comprises an inlet port in flow communication with the branching unit, an outlet port configured to release pressure by discharging a gas flow from the inlet port, and a valve seat in flow communication with the inlet port. The valve further comprises a valve member configured to close a gas discharge between the inlet port and the outlet port when forced against the valve seat, and to facilitate gas discharge between the inlet port and the outlet port when not forced against the valve seat. The valve further comprises a closing spring configured to direct a predetermined closing force to the valve member and an actuator configured to increase and decrease the closing force directed to the valve member.

Abstract: Methods and systems for delivering a pharmaceutical gas to a patient. The methods and systems provide a known desired quantity of the pharmaceutical gas to the patient independent of the respiratory pattern of the patient over a plurality of breaths every nth breath, where n is greater than or equal to 1. The pharmaceutical gases include CO and NO, both of which are provided as a concentration in a carrier gas. The gas control system determines the delivery of the pharmaceutical gas to the patient to result in the known desired quantity (e.g. in molecules, milligrams or other quantified units) of the pharmaceutical gas being delivered. Upon completion of that known desired quantity of pharmaceutical gas over a plurality of breaths, the system can either terminate, continue, activate and alarm, etc.

Abstract: A system for controlling medical devices, wherein this system can comprise a device having at least one wireless or cellular based communication module. The module can be in the form of a GPRS module associated with a SIM card, or a CDMA module. The SIM card can be adapted such that it contains additional memory for storing a program for controlling the device or the system. Multiple cellular communication modules can also be installed in this system. Additional communication modules such as wireless modules including but not limited to Bluetooth, IRDA, RF, or any other wireless module can also be incorporated into the system. Wired modules can also be used, for example these wired modules can be RS-232 modules, USB, Serial adapters, phone and fax modem.

Abstract: Methods and apparatus for determining leak and respiratory airflow are disclosed. A pressure sensor (34) and a differential pressure sensor (32) have connection with a pneumotach (24) to derive instantaneous mask pressure and airflow respectively. A microcontroller (38) estimates a non-linear conductance of any leak path occurring at a mask (12) as being the low pass filtered instantaneous airflow divided by the low pass filtered square root of the instantaneous pressure. The instantaneous leak flow is then the conductance multiplied by the square root of the instantaneous pressure, and the respiratory airflow is calculated as being the instantaneous airflow minus the instantaneous leak flow. The time constants for the low pass filtering performed by the microcontroller (38) can be dynamically adjusted dependent upon sudden changes in the instantaneous leak flow.

Abstract: A method of relieving pain resulting from breathing in a patient with fractured ribs, wherein the pain interrupts the sleeping of the patient. A positive airway pressure machine is attached to the nose or nose and mouth of the patient. The patient turns the machine on to produce a positive airway pressure in the airways of the lungs and adjusts the positive airway pressure to a level where the patient feels that the pain is reduced or eliminated. The method allows a patient with fractured ribs to sleep comfortably without the pain associated with breathing in and out, and without interruption of sleep. The method also promotes the healing and recovery of the fractured ribs.

Abstract: An input device for a clinician to control and modify the operation of a mechanical ventilator comprises a graphical display, a representation of a respiratory therapy trajectory to be delivered to a patient, at least one data point associated with the trajectory, and a data input means for the clinician to select a data point and to modify the value of the trajectory at that data point. The present invention provides for the creation and modification of a respiratory therapy trajectory, wherein the ventilator provides a medical gas waveform to a patient according to the respiratory therapy trajectory.