Abstract: A diagnostic device having a nose fitting used without connection to a breathing gas supply for obtaining flow data values at ambient pressure. The nose fitting is connected to a pressure or flow sensor that supplies data values to a microprocessor. The detection and measurement of breathing gas flow is made from a tight sealing nose fitting (mask or prongs) configured with a resistive element inserted in the flow stream as breathing gas exits from and enters into the fitting. The nasal fitting is further provided with a port for connection to a flow or pressure transducer. The resistive element causes a pressure difference to occur between the upstream side and the downstream side when air flows through the element. The data values may be stored in computer memory to be analyzed for flow limitations.

Abstract: In the treatment of obstructive sleep apnea, a method and apparatus are disclosed for optimizing the controlled positive pressure to minimize the flow of air from a flow generator while still ensuring that flow limitation in the patient's airway does not occur. In particular, the invention relates to a breathing device and method of use to adjust a controlled positive pressure to the airway of a patient by detecting flow limitation from analysis of an inspiratory flow waveform. Once the presence of flow limitation has been analyzed, the system determines an action to take for adjustment of the controlled positive pressure. The pressure setting is raised, lowered or maintained depending on whether flow limitation has been detected and on the previous actions taken by the system.

Abstract: A motion transducer is embedded in a section of cable interconnecting a primary medical sensor with associated electronics. By affixing the section containing the transducer to a portion of a patient's anatomy, information relating to the parameter of primary concern as well as the patient's activity can be gathered without the complexity normally associated with instrumenting a patient for the acquisition of such data.

Abstract: A mask and harness system for use in providing breathing oxygen and protection from pollutants for the eyes and respiratory system as might be encountered in high altitude aviation environments. In one preferred embodiment, the mask system has a face seal, a soft flexible lens, a pneumatically-actuated harness, and a regulator with microphone to control the flow of oxygen and to facilitate communications in aircraft flight decks and other aircraft compartments. The system is designed for required five-second donning with one hand and because of the flexible lens, is capable of storage in the relatively preferred on crowded flight decks. It is connected to an oxygen source and, optionally, with aircraft communications. The regulator controls the flow rate of oxygen to the wearer based on altitude and physiological requirements. The regulator includes a valve for purging the condensation-prone moist gases from the lens area and provides positive pressure in the mask.

Abstract: The gas mixing apparatus provides the components of a breathing gas for mixing at approximately ambient atmospheric pressure, and regulates the pressure of a selected gas to approximately ambient atmospheric pressure for mixing with air at ambient atmospheric pressure. The gas mixing apparatus includes a piston disposed within a pump chamber. A flow limiting inlet controls introduction of a first selected gas such as oxygen for mixing with a second selected gas such as air. The pressure of the first selected gas is limited to an acceptable maximum pressure, so that even if a valve for admitting the first selected gas for mixing at ambient pressure fails, breathing gas will not be provided at an excessive pressure.

Abstract: A piston based ventilator for delivering breathing gas to the lungs of a patient, and more particularly a piston based ventilator that delivers breathing gas to a patient upon longitudinal movement of a piston rod and associated piston head within a piston cylinder. The piston rod is centrally located within the cylinder and moves along the cylinder in response to direct drive from a motor to move the piston head within the cylinder and displace a volume of gas to be delivered to the patient.

Abstract: The lung ventilator safety valve circuit includes a normally open, pulse width modulated solenoid safety valve connected to a patient airway of a ventilator system. A pressure sensor monitors pressure in the patient airway, and a control unit maintains the safety valve closed when the pressure is not excessive. The safety valve is opened when the sensed pressure equals or exceeds a maximum airway pressure threshold that can be set by an operator, or in the event of a power failure.

Abstract: An apparatus and method for facilitating the respiration of a patient are disclosed which are particularly useful in treating mixed and obstructive sleep apnea and certain cardiovascular conditions, among others, by increasing nasal air pressure delivered to the patient's respiratory passages just prior to inhalation and by subsequently decreasing the pressure to ease exhalation effort. The preferred apparatus includes a patient-coupled gas delivery device for pressurizing the patient's nasal passages at a controllable pressure, and a controller coupled with the delivery device having a pressure transducer for monitoring the nasal pressure and a microcontroller for selectively controlling the nasal pressure. In operation, the controller determines a point in the patient breathing cycle just prior to inhalation and initiates an increase in nasal pressure at that point in order to stimulate normal inhalation, and subsequently lowers the nasal pressure to ease exhalation efforts.

Abstract: A microphone signal attenuating breathing mask body having a gas port for inhalation of a gas to the wearer in a flow stream therethrough. A demand microphone is mounted to the mask and is coupled to an electromagnetic switch responsive to a predetermined magnetic field for switching from an actuation to an attenuation position to block transmission of sound from the microphone. An air vane is pivotally mounted on the mask body and is formed with an impingement pad positioned in the flow stream and mounts an activating magnet disposed adjacent the switch. The vane is normally disposed in a normal position such that the magnet is in an activating position and the electromagnetic switch is in the actuation position such that the microphone is active for transmission of audio signals.

Abstract: The method and system for controlling airway pressure in a ventilator during the inspiratory cycle involves controlling the flow of breathing gas through a flow supply valve venting the breathing gas at a desired rate of outflow through a relief valve to achieve the desired airway pressure. Measurements of the rates of actual supply flow, the actual outflow through the exhalation/relief valve, and the pressure in the airway are compared with desired values for determination the amount of error for feedback control of the ventilator system.

Abstract: A piston based ventilator for delivering breathing gas to the lungs of a patient, and more particularly a piston based ventilator that delivers breathing gas to a patient upon longitudinal movement of a piston rod and associated piston head within a piston cylinder. The piston rod is centrally located within the cylinder and moves along the cylinder in response to direct drive from a motor to move the piston head within the cylinder and displace a volume of gas to be delivered to the patient.

Abstract: A mask and harness system for use in providing breathing oxygen and protection from pollutants for the eyes and respiratory system as might be encountered in high altitude aviation environments. In one preferred embodiment, the mask system has a face seal, a soft flexible lens, a pneumatically-actuated harness, and a regulator with microphone to control the flow of oxygen and to facilitate communications in aircraft flight decks and other aircraft compartments. The system is designed for required five-second donning with one hand and because of the flexible lens, is capable of storage in the relatively preferred on crowded flight decks. It is connected to an oxygen source and, optionally, with aircraft communications. The regulator controls the flow rate of oxygen to the wearer based on altitude and physiological requirements. The regulator includes a valve for purging the condensation-prone moist gases from the lens area and provides positive pressure in the mask.

Abstract: The gas mixing apparatus provides the components of a breathing gas for mixing at approximately ambient atmospheric pressure, and regulates the pressure of a selected gas to approximately ambient atmospheric pressure for mixing with air at ambient atmospheric pressure. The gas mixing apparatus includes a piston disposed within a pump chamber. A flow limiting inlet controls introduction of a first selected gas such as oxygen for mixing with a second selected gas such as air. The pressure of the first selected gas is limited to an acceptable maximum pressure, so that even if a valve for admitting the first selected gas for mixing at ambient pressure fails, breathing gas will not be provided at an excessive pressure.

Abstract: The system and method for flow triggering pressure supported ventilation include a source of a predetermined, preinspiratory, constant flow of breathing gas to a patient, one or more flow sensors for measuring the rate of gas flow in a flow path communicating with the patient, means for determining when inhalation from the flow path has occurred, and means for generating pressure support in the delivered gas flow in response to inhalation by the patient, means to terminate pressure support when inspiratory phase concludes, and means to reestablish the predetermined, preinspiratory, continuous flow of breathing prior to the patient's next inspiratory effort. A plurality of individual gas sources preferably provide a controlled mixture of breathing gas. In combination with pressure support to the patient during the inspiration effort, the flow triggering strategy of the invention offers significant improvements in providing breath support to patients having weakened respiratory capabilities.

Abstract: Patient airway baseline pressure levels are controlled in a ventilator having a pneumatically controlled exhalation valve without an external supply of pilot pressure, by supplying an internal source of controllable pilot pressure for operating the exhalation valve. The pressure of pressurized air supplied by an internal pump can be electrically controlled by pulse width modulation of a variable pulse duration signal. A second source of pressurized air for pilot pressure is provided, and in one embodiment is a reservoir provided for receiving pressurized air from the pump and from the exhalation circuit. A valve is connected to the pump means and the reservoir for receiving pressurized air from the pump in a first position, and for receiving pressurized air from the reservoir in a second position. When the valve means is in the second position, pressurized air is delivered at a pressure which is the greater of the pressurized air supplied by the pump means or the gas flow from the exhalation circuit.

Abstract: A microphone signal attenuating breathing mask body having a gas port for inhalation of a gas to the wearer in a flow stream therethrough. A demand microphone is mounted to the mask and is coupled to an electromagnetic switch responsive to a predetermined magnetic field for switching from an actuation to an attenuation position to block transmission of sound from the microphone. An air vane is pivotally mounted on the mask body and is formed with an impingement pad positioned in the flow stream and mounts an activating magnet disposed adjacent the switch. The vane is normally disposed in a normal position such that the magnet is in an activating position and the electromagnetic switch is in the actuation position such that the microphone is active for transmission of audio signals.

Abstract: The lung ventilator safety valve circuit includes a normally open, pulse width modulated solenoid safety valve connected to a patient airway of a ventilator system. A pressure sensor monitors pressure in the patient airway, and a control unit maintains the safety valve closed when the pressure is not excessive. The safety valve is opened when the sensed pressure equals or exceeds a maximum airway pressure threshold that can be set by an operator, or in the event of a power failure.

Abstract: The invention is a compact multi-camera closed circuit video television system for use in commercial aircraft. The arrangement of the cameras and the construction of the system are arranged to allow installation within either the pressurized or unpressurized portions of the aircraft, and the video cameras are arranged to provide multiple views of the exterior of the aircraft under the control of the flight crew.

Abstract: An apparatus and method for facilitating the respiration of a patient are disclosed which are particularly useful in treating mixed and obstructive sleep apnea and certain cardiovascular conditions, among others, by increasing nasal air pressure delivered to the patient's respiratory passages just prior to inhalation and by subsequently decreasing the pressure to ease exhalation effort. The preferred apparatus includes a patient-coupled gas delivery device for pressurizing the patient's nasal passages at a controllable pressure, and a controller coupled with the delivery device having a pressure transducer for monitoring the nasal pressure and a microcontroller for selectively controlling the nasal pressure. In operation, the controller determines a point in the patient breathing cycle just prior to inhalation and initiates an increase in nasal pressure at that point in order to stimulate normal inhalation, and subsequently lowers the nasal pressure to ease exhalation efforts.

Abstract: The piston ventilators include a double acting reciprocating piston, in which the piston motion delivering breathing gas to a patient receiving assistance from the ventilator simultaneously draws in breathing gas from a source of breathing gas, and a single acting piston ventilator, in which only the delivery end of the cylinder is provided with inlet and exhaust valves. In the double acting piston ventilator, breathing gas is supplied to both ends of the piston cylinder through two intake valves, and exhausting breathing gas through two exhaust valves. Both intake valves of the cylinder are ducted to the breathing gas supply, and the two exhaust valves of the cylinder are ducted to a gas delivery limb of the ventilator connected to the patient's airway.