380 results about "Breathing circuits" patented technology

A disposable anesthesia face mask suitably sized and configured to engage the nose portion, mouth portion and chin portion of a patient's face comprises a cup-like shell or receptacle member and a flexible inflatable hollow sealing cushion attached to the shell member on a flange thereon and wherein the shell member includes first passageway means for coupling to a breathing circuit, and a second passageway for connection to a flexible tube which, in turn, is adapted to be connected to a CO2 monitoring machine or capnograph. The face mask shell nasal portion has a first width, the face mask shell mouth portion has a second width greater than the first width, and the face mask shell chin portion has a third width greater than the second width. The nasal, mouth and chin portions are continuous and form the cup-like extent of the shell or receptacle member giving it a characteristic “pear” shape. Lateral projections provided on the shell flange are intended to accommodate an elastic head strap that may adjustably be coupled to the projections to hold the mask in place on a patient's face and head.

An apparatus to measure cardiac output (Q) and other parameters such as alveolar ventilation (VA), minute CO₂ elimination from the lung (VCO₂ ), minute oxygen consumption (VO₂), oxygenated mixed venous partial pressure of CO₂, (PvCO₂-oxy), true mixed venous partial pressure of CO₂(PvCO₂), PaCO₂, mixed venous oxygen saturation (SvO₂), pulmonary shunt, and anatomical dead space, consisting of: a) a breathing circuit with characteristics that: i. on exhalation, exhaled gas is kept substantially separate from inhaled gas; ii. oninhalation, when V_E is greater than FGS flow, the subject inhales FGS first and then inhales a gas that is substantially SGS, for the balance of inhalation; b) gas sensor means for monitoring gas concentrations at the patient-circuit interface c) a first gas set (FGS), and a second gas set (SGS), said second gas set which may comprise previously exhaled gases or exogenous gases or both d) a gas flow control means for controlling the rate of FGS flow into the breathing circuit e) means to identify phase of breathing, said means may consist of pressure sensors or analysis of signal generated by gas sensors or other means known to those skilled in the art; f) machine intelligence consisting of a computer or logic circuit capable of controlling the gas flow control means, receiving the output of the gas sensor means and means to identify phased of breathing, and performing the calculations for measuring cardiac output and other parameters as outlined in the disclosure.

A method and system for ventilating a patient that compensates for leaks occurring within the patient breathing circuit while limiting the volume of breathing gas delivered to the patient. During the operation of a ventilator to supply breathing gases to a patient, the ventilator monitors for leak volumes occurring during the inspiratory phase and expiratory phase of the breathing cycle. Based upon the leak volumes sensed, the volume of breathing gas delivered by the ventilator is increased such that the tidal volume delivered to the patient is the desired tidal volume set by a clinician. The ventilator operates to generate a leak alarm when the leak volume exceeds an alarm threshold. If the leak alarm is generated, the tidal volume delivered to the patient is limited to the tidal volume being delivered prior to generation of the leak alarm. During compensation of the breathing gases delivered to the patient, the system and method determines whether the compensated tidal volume exceeds a maximum tidal volume threshold and limits the compensated tidal volume to the maximum tidal volume threshold.

A method of calculating the flux of any gas (x) in a CBC circuit for a ventilated or a spontaneous breathing subject, for example said gas(x) being; a) an anesthetic such as but limited to; i)N₂O; ii) sevoflurane; iii) isoflurane; iv) halothane; v) desflurame; or the like b) Oxygen; c) Carbon dioxide; or the like utilizing the following relationships; Flux of gas(x)=SGF (F_SX−F_EX) wherein SGF=Source of gas flow into the breathing circuit (CBC circuit) in liters/minute as read from the gas flow meter as set by the anesthesiologist; F_SX=Fractional concentration of gas X in the source gas (which is set by the anesthesiologist); F_EX=Fractional concentration of gas X in the end expired gas as determined by a portable gas analyzer, or the like.

A disposable anti-fog airway adapter for use with a mainstream respiratory gas analyzer which provides a measurement of a patient's inhaled and exhaled gases. The airway adapter includes windows that are constructed of a thin, low heat capacity plastic that rapidly equilibrates to the temperature of the warm moist gases in the patient breathing circuit. In addition, the inside of the windows is also coated with an anti-fog surfactant either by laminating an anti-fog film with the window plastic prior to attaching the window to the airway adapter body or by first attaching the window to the airway adapter body and then applying the surfactant to the airway adapter after the window film is bonded in place so that the surfactant coats the entire inside of the adapter. The surfactant functions to increase the critical wetting tension of the surface it covers so that water on the window spreads into a uniform thin layer which does not absorb very much infrared energy and thus does not significantly reduce the signal strength. "Instant on" operation is accomplished because no heater and the like is necessary to warm up the windows to maintain them at an elevated temperature to prevent fogging. Numerous techniques are also provided for adhering the windows to the airway adapter body so that a substantially airtight seal may be obtained.

Breathable medical circuit components and materials and methods for forming these components are disclosed. These components incorporate breathable foamed materials that are permeable to water vapor and substantially impermeable to liquid water and the bulk flow of gases. The disclosed materials and methods can be incorporated into a variety of components, including tubes, Y-connectors, catheter mounts, and patient interfaces and are suitable for use in a variety of medical circuits, including insufflation, anesthesia, and breathing circuits.

A compact and wearable metabolic analyzer transducer comprising a housing containing a plurality of analog sensors, an A/D converter, a microcontroller, and a power source operatively coupled thereto where the microcontroller is programmed to compute minute ventilation, O₂ uptake, and CO₂ production of a subject. The transducer and its contents are of a size and weight that can either be easily supported from a facemask worn by a subject or incorporated in a respiratory circuit. The measured values can be wirelessly transmitted or transmitted, via a cable, to a remote personal computer, a personal digital assistant (PDA), or other display devices such as digital watches or image projectors.

An electronic controller having at least one microprocessor controls the solenoid operated valve adding oxygen to the breathing loop of a closed circuit mixed gas rebreather with carbon dioxide scrubbing in maintenance of an oxygen set point in the rage of 0.13-0.50 without any need for monitoring or interpretation of signal data by the operator. The controller receives signals from at least one oxygen sensor located in the breathing loop and sends signals to an indicator: visual, aural, or tactile; during operation providing only intuitively understood normal functioning, limited time remaining, and bail out indications. Automatic diagnosis including oxygen sensor calibration, indication of actions required such as scrubber replacement, and confirmation of an action taken with signals from an action sensor are provided.

An arrangement and method for detecting spontaneous respiratory effort of a patient receiving ventilatory support by a breathing circuit. The nasal cannula control system includes a nasal cannula assembly having two distinct lumens. A different pressure sensor is positioned to detect the pressure difference between each of the two lumens, thereby determining the differential pressure from within the patient's nostrils and within a breathing mask. The nasal cannula control system includes a gas sampling system such that the amount of a monitored gas discharged or exhaled by the patient can be monitored using the same nasal cannula assembly used to generate the differential pressure signal.

A simple breathing circuit is designed to be added to a standard anesthetic circuit to hasten recovery of patients administered vapor anesthetic prior to an operation and also to method of treatments of a patient to hasten recovery from administration of vapor anesthetic prior to surgical procedures.

A limb for a breathing circuit manufactured from very thin walled polymer materials has an elongate axial reinforcing spine lying freely inside the conduit and fixed to each end connector. The spine is laterally compliant but axially stiff. The spine provides resistance to tensile and compressive loads on the conduit, including that induced by prevailing internal pressures.

The invention is directed to an oxygen sensor arrangement 8 for sensing the oxygen in a breathing loop 29 of a breathing apparatus 100. The sensor arrangement 8 comprises at least one primary oxygen sensor 30 arranged to operatively measure the oxygen in the breathing loop 29, and a control arrangement 40 for obtaining measures from said oxygen sensor. A test channel arrangement 15, 362 is adapted to operatively provide a first gas having a first fraction of oxygen from a first supply 20 to said primary oxygen sensor 30 at a position 267 adjacent to or directly adjacent to said primary oxygen sensor. A first test valve arrangement 41 is arranged to operatively open and close the flow of said first gas through said test channel arrangement 15, 362. Said a control arrangement 40 is arranged to operatively actuate said first test valve arrangement 41 so as to provide an amount of said first gas to said primary oxygen sensor 30 via said test channel arrangement 15, 362.

In a first aspect, the invention relates to an apparatus for inducing or maintaining a target end tidal concentration of a gas in a subject comprising a breathing circuit, a source of gas flow into the circuit, means for controlling the rate of the source of gas flow into the circuit and means for controlling the concentration of gases in the source gas flow independently from each other. In another aspect, the invention relates to a method of preparing an apparatus for inducing or maintaining a target end tidal concentration of a gas X in a subject comprising selecting a rate of a source gas flow into a breathing circuit, selecting the concentration of at least one constituent gas of a component gas making up the source gas to a level corresponding to the end tidal concentration of the gas X, whereby the apparatus is adapted to administer a source gas having a first gas composition