6584 results about "Gas concentration" patented technology

An indirect calorimeter for measuring the metabolic rate of a subject includes a disposable portion and a reusable portion. The disposable portion includes a respiratory connector configured to be supported in contact with the subject so as to pass inhaled and exhaled gases as the subject breathes. The disposable portion also includes a flow pathway operable to receive and pass inhaled and exhaled gases, having a first end in fluid communication with the respiratory connector and a second end in fluid communication with a source and sink for respiratory gases. The disposable portion is disposed within the reusable portion, which includes a flow meter, a component gas concentration sensor, and a computation unit. The flow meter generates a signal as a function of the instantaneous flow volume of respiratory gases passing through the flow pathway and the component gas concentration sensor generates a signal as a function of the instantaneous fraction of a predetermined component gas in the exhaled gases. The computation unit receives the electrical signals from the flow meter and the concentration sensor and calculates at least one respiratory parameter for the subject as the subject breathes through the calorimeter.

An ozone gas concentration measurement method that can easily measure the concentration of ozone gas. A process gas containing ozone gas is produced from a raw gas containing oxygen gas. The number of moles of gas molecules contained in the process gas is measured. The concentration of the ozone gas contained in the process gas is calculated based on the number of moles of gas molecules contained in the process gas.

A method of determining a respiratory parameter for a subject using an indirect calorimeter is provided. The indirect calorimeter includes a respiratory connector for passing inhaled and exhaled gases, a flow pathway operable to receive and pass inhaled and exhaled gases having a flow tube within the flow pathway through which the inhaled and exhaled gases pass, a flow meter for determining an instantaneous flow volume of the inhaled and exhaled gases, a component gas concentration sensor for determining an instantaneous fraction of a predetermined component gas and a computation unit having a processor and a memory. The method includes the steps of initializing the indirect calorimeter and the subject breathing into the respiratory connector if the indirect calorimeter is initialized, sensing the flow volume of the inhaled and exhaled gases passing through the flow pathway using the flow meter and transmitting a signal representing the sensed flow volume to the computation unit. The method also includes the steps of sensing a concentration of a predetermined component gas as the inhaled and exhaled gases pass through the flow pathway using the component gas sensor, and transmitting a signal representing the sensed concentration of the predetermined component gas to the computation unit. The method further includes the steps of calculating at least one respiratory parameter for the subject as the subject breathes through the calorimeter using the sensed flow volume and the sensed concentration of the predetermined component gas, and providing the subject with the at least one respiratory parameter.

A ventilator (10) for use by a clinician in supporting a patient presenting pulmonary distress. A controller module (20) with a touch-screen display (26) operates a positive or negative pressure gas source (40) that communicates with the intubated or negative pressure configured patient through valved (46) supply and exhaust ports (42, 44). A variety of peripheral, central, and or supply/exhaust port positioned sensors (54) may be included to measure pressure, volumetric flow rate, gas concentration, transducer, and chest wall breathing work. Innovative modules and routines (30) are incorporated into the controller module enabling hybrid, self-adjusting ventilation protocols and models that are compatible with nearly every conceivable known, contemplated, and prospective technique, and which establish rigorous controls configured to rapidly adapt to even small patient responses with great precision so as to maximize ventilation and recruitment while minimizing risks of injury, atelectasis, and prolonged ventilator days.

Gas detection or monitoring apparatus mainly comprising, an optical source unit including a tunable diode laser, an optical detection unit including a light sensitive detector, the source and the detector being arranged so that light from the source propagates through a gas measurement volume prior to being received by the detector, and the source being adapted to scan the light wavelength across one or more expected absorption lines of gases in the measurement volume, a control and processing unit for control and modulation of the source and processing of the detected signal and for calculating at least one digital value representing (a) gas concentrations in the gas measurement volume, wherein said control and processing unit is coupled to the source via a digital-to-analogue (D/A) converter, and the detector output signal is coupled to the input of an analogue-to-digital (A/D) converter, and the output of the A/D converter is coupled to the processing unit.

The invention is directed to a method of fueling gas turbines from natural gas reserves with relatively low methane concentrations. The invention uses such reserves to generate electric power. The invention permits the use of these reserves at significantly lower cost than by producing pipeline natural gas to fuel gas turbines to generate electric power. These reserves currently generally are used only after the removal of impurities to produce pipeline natural gas quality turbine fuel. The latter current technology is capital intensive, and at current natural gas prices, economically unattractive. The process of the invention can remove the impurities from the gas from the natural gas reserve necessary for protection of the environment, and leaves inert gasses in the fuel in an amount which will increase the output of a gas turbine for the generation of power by about 5 to about 20%.

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 apparatus for remote laser-based detection of gas at levels exceeding natural background levels preferably utilizing wavelength modulated tunable diode laser absorption spectroscopy. In a preferred embodiment, background gas and noise are estimated using statistical moving average and variance calculations. Gas concentration length measurements resulting from the spectroscopy are preferably compared in real-time or near-real-time to the sum of the background and noise estimates and an alarm limit to detect gas presence of concern. Gas levels exceeding this detection threshold are preferably indicated by a prolonged output tone with a pitch indicative of the magnitude of the gas measurement, and gas levels below the detection threshold are preferably indicated by silence.

An apparatus and method for injecting gas within a plasma reactor and tailoring the distribution of an active species generated by the remote plasma source over the substrate or wafer. The distribution may be uniform, wafer-edge concentrated, or wafer-center concentrated. A contoured plate or profiler modifies the distribution. The profiler is an axially symmetric plate, having a narrow top end and a wider bottom end, shaped to redistribute the gas flow incident upon it. The method for tailoring the distribution of the active species over the substrate includes predetermining the profiler diameter and adjusting the profiler height over the substrate. A coaxial injector tube, for the concurrent injection of activated and non-activated gas species, allows gases to be delivered in an axially symmetric manner whereby one gas can be excited in a high density RF plasma, while the other gas can be prevented from excitation and/or dissociation caused by exposure to the plasma or heated surfaces in the source apparatus. The profiler is used in conjunction with the coaxial injector tube for redistributing the excited gases emerging from the injector tube, while allowing the non-excited gases to pass through its center.

A method for analyzing gas concentration using doubly resonant photoacoustic spectroscopy, and a doubly resonant photaoacoustic gas detector comprising: i) a continuous wave light beam whose wavelength coincides with an absorption wavelength of a gaseous analyte; ii) a closed path optical cavity having at least two reflective surfaces; iii) an acoustic resonator chamber contained within said optical cavity, and comprising an acoustic sensor for detecting sound waves generated by a gaseous analyte present within said chamber, the light beam passing sequentially into, through and out of said chamber, and being repeatedly reflected back and forth through said chamber, and being modulated at a frequency which is equal to or equal to one-half of an acoustic resonance frequency of said acoustic resonator chamber.

A fiber gas sensor includes a fiber core with first and second refractive index periodic modulated grating structures having different amplitude modulation profiles positioned about the fiber core. A fiber cladding is positioned about the first and second refractive index periodic modulated grating structures. A sensing layer is positioned about the fiber cladding of one of the refractive index periodic modulated grating structures. The sensing layer includes a sensing material made of a Pd-based alloy, such as nano-PdOx, nano-Pd(x)Au(y)Ni(1-x-y) or nano-Pd/Au/WOx. The fiber gas sensor provides a measurement of localized, temperature-corrected gas concentration and composition from a combustion environment. A reflection-based or a transmission-based sensing system with an array of one or more fiber gas sensors is also described.

A system for determining gas compositions includes a probe, inserted into a source of gaseous material, the probe having a gas permeable sensor tip and being capable of sending and receiving light to and from the gaseous material, a sensor body, connected to the probe, situated outside of the source and a fiber bundle, connected to the sensor body and communicating light to and from the probe. The system also includes a laser source, connected to one portion of the fiber bundle and providing laser light to the fiber bundle and the probe a Raman spectrograph, connected to another portion of the fiber bundle, receiving light from the probe and filtering the received light into specific channels and a data processing unit, receiving and analyzing the received light in the specific channels and outputting concentration of specific gas species in the gaseous material based on the analyzed received light.

Devices, systems, and methods for diagnosing physiological parameters of the lungs and treating associated medical conditions are disclosed herein. In particular, certain embodiments permit detection of air flow in lung passageways, air leaks, gas concentration (in particular oxygen), and temperature measurements. Measurements obtained using the devices, systems, and methods disclosed herein may also be used to determine optimal treatment sites for medical conditions such as emphysema, COPD, or lung volume reduction.

An oxygen concentration apparatus (300) according to the present invention has: pressure swing adsorption type oxygen concentration means (310); and a control means (350) that controls switching means (316) that switches between intake of pressurized air into an adsorption column (312) and exhaust from the adsorption column. The switching means is controlled based on pressure in oxygen concentrated gas in the conduit measured by pressure measuring means to adjust a cycle of adsorption and regeneration processes of the oxygen concentration means so that pressure at the upstream of flow rate adjusting means (340) can be controlled and, as a result, the need for a mechanical pressure regulating valve, that has been needed conventionally, can be eliminated. Further, there is also shown a gas supply apparatus that comprises ultrasonic type gas concentration and flow rate measuring means that comprises, in turn, two ultrasonic transducers that is disposed in an opposed manner in the conduit through which product gas flows so that a concentration value measured when the product gas output is stopped is determined to be a product gas concentration.

The invention relates to a fire-fighting robot for a transformer substation. The fire-fighting robot comprises a routing-inspection robot, a gas detection device, an infrared temperature measurement device, a fire extinguishing device and a main control computer, wherein the routing-inspection robot is arranged in the transformer substation, a routing-inspection route is painted at the ground of a working space of the routing-inspection robot, and a plurality of radio frequency cards for positioning are mounted at ground key points. The fire-fighting robot has the beneficial effects that the automatic routing inspection can be carried out based on routing-inspection route marks and a navigation device; the gas detection device is utilized for monitoring the characteristic gas concentration of an early-stage fire disaster in a production place of the transformer substation in real time and pre-warning the concentration overrun condition in a grading manner; the infrared temperature measurement device is utilized for collecting infrared temperature images of production devices, and pre-warning over-temperature conditions of the devices in a grading manner and positioning fault points; the fire extinguishing device is utilized for rapidly extinguishing the sudden fire, controlling the fire propagation in an initial stage and earning time for the rescue operation. Therefore, the precaution and the fighting of the early-stage fire disaster are strengthened, and the fire safety situation of the transformer substation is effectively improved.

A reactor of a chemical vapor deposition system is equipped with a gas feeder for blowing dopant gas to plural semiconductor wafers supported by a wafer boat at intervals, and the gas feeder has a gas passage gradually reduced in cross section and gas outlet holes equal in diameter and arranged along the wafer boat for keeping the doping gas concentration substantially constant around the semiconductor wafers, whereby the dopant is uniformly introduced in material deposited on all the semiconductor wafers.

A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded, and a second more serious alarm condition when either a second, higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.