1195 results about "Pressure rise" patented technology

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.

A fuel delivery system is provided with a fuel solenoid valve to minimize fuel leakage and evaporative emissions during diurnal cycles by preventing pressure buildup as the temperature of the fuel system rises. The fuel solenoid valve is located between a pressurized side of the delivery system and a fuel tank. In one embodiment, the fuel solenoid valve is closed when the engine is running or when the engine is off and the rail is hot. When the fuel rail cools down, the solenoid valve opens to bleed a desired amount of fuel thereby creating a fuel vapor space. Thereafter, during hot soak conditions of the diurnal cycles when the fuel rail is hot again while the engine is off, the pressure will rise due to the thermal expansion of the fuel and the created fuel vapor space minimizes further rising of the fuel pressure. Further, by adjusting the solenoid valve opening time, the pressure rising limit may be set at a desired pressure to minimize injector leakage.

A system and method determine when fluid is not flowing properly from a secondary infusion source during a secondary infusion. The system includes an upstream pressure sensor and a processor programmed to receive signals from the sensor and analyze the signals to determine if secondary fluid flow is proper. The processor samples the output signals from the upstream pressure sensor and analyzes the sampled signals to determine if a pressure rise in the infusion line has occurred when the secondary infusion is initiated. If a pressure rise, indicating that fluid from the secondary container has begun flowing into the infusion line, has not been detected, the processor is programmed to provide a signal indicating that attention should be given to the infusion set up.

A system and method are provided for determining an index of autonomic nervous system (ANS) or sympathetic nervous system (SNS) activity for use in patient monitoring or therapy delivery control. An ANS or SNS index is calculated as a function of multiple monitored physiological variables that strongly correlate to changes in autonomic or sympathetic tone. These ANS-influenced variables are derived from selected hemodynamic and / or electrical signals and may include variables relating to any of: the maximum rate of pressure rise (dP / dtmax), the maximum rate of pressure decline (dP / dtmin), pulse pressure (PP), pre-ejection time interval (PEI) and / or systolic time interval (STI), heart rate (HR), heart rate variability (HRV), and baro-reflex gain. Changes in the ANS or SNS index may be used to automatically adjust a device delivered therapy.

A multicylinder homogeneous charge compression ignition (HCCI) engine with a control system designed to maintain stable HCCI combustion during engine speed / load transitions by: (1) determining “combustion parameter” values such as the maximum rate of pressure rise for each cycle of each cylinder, (2) adjusting engine operating parameters (such as charge-air intake temperature, intake pressure (boost), or charge-air oxygen concentration) to effect a change in the combustion parameter value, (3) thereafter adjusting an engine “control parameter” (e.g., commanded fuel quantity) to each cylinder to maintain a desired target for the combustion parameter value, and (4) individually adjusting cooling, heating and / or fuel command to deviating cylinders to achieve uniform combustion. Additional strategies such as averaging of combustion parameter values and use of deadband regions in the control of HCCI combustion are also set forth.

A cryopump regeneration method includes a temperature raising step of raising the temperature of a cryopanel so as to vaporize gas molecules condensed on the exhaust surface of the cryopanel, an evacuation step of evacuating a pump vessel, a determination step of determining whether the internal pressure of the pump vessel has reached a set pressure higher than the water vapor pressure at 0 DEG C, a pressure rise test step of stopping the evacuation and performing a pressure rise test, and an observation step of observing residual water based on the internal pressure of the pump vessel.

The invention discloses an electronic thermometric pan with the function of electric generation by temperature differences of a semiconductor refrigeration piece, which mainly consists of a pan body, a handle, a temperature difference power generating system and a thermometric system. The temperature difference power generating system comprises the semiconductor refrigeration piece, a pressure-rising and voltage-stabilizing electronic component and an electric energy storage device. The thermometric system consists of a temperature sensor, a microprocessor, a circuit board and a liquid crystal piece. The temperature sensor is directly arranged at the bottom part of the pan body and the circuit board is arranged in a cavity of the handle. A cavity of the joint of the handle and the pan body is internally provided with the semiconductor refrigeration piece that is in contact with the pan body. The other surface of the semiconductor refrigeration piece is in close contact with a metal radiator. The temperature difference power generating system, the thermometric system and the liquid crystal piece are respectively connected with the circuit board. By utilizing cooking residual heat to generate power, the electronic thermometric pan of the invention realizes the temperature measurement for the bottom of the pan without battery drive, thereby not only becoming a healthy, hygienic and safe cook utensil, but also meeting the requirements of the times of environmental protection and economy; furthermore, the electronic thermometric pan of the invention also has convenient and reliable use, thereby having quite broad application prospect.