80 results about "Mean pressure" patented technology

A method and apparatus for determining the mean arterial blood pressure (MAP) of a subject during tonometric conditions. In one embodiment, the apparatus comprises one or more pressure and ultrasound transducers placed over the radial artery of a human subject's wrist, the latter transmitting and receiving acoustic energy so as to permit the measurement of blood velocity during periods of variable compression of the artery. During compression, the ultrasound velocity waveforms are recorded and processed using time-frequency analysis. The time at which the mean time-frequency distribution is maximal corresponds to the time at which the transmural pressure equals zero, and the mean pressure read by the transducer equals the mean pressure within the artery. In another aspect of the invention, the ultrasound transducer is used to position the transducer over the artery such that the accuracy of the measurement is maximized. In yet another aspect of the invention, a wrist brace useful for measuring blood pressure using the aforementioned apparatus is disclosed.

An optical noninvasive vital sign monitor comprising a reflectance-type optical sensor within a pressurizable capsule retained by a headband, the capsule having an optically transparent or translucent inner wall adapted for placement against a subject's forehead. The optical sensor is mounted on the inside surface of the pressurizable capsule's inner wall, which contacts the subject's forehead during use, and includes a light source and a photodetector aimed toward the inside surface of the inner capsule wall. One embodiment of the vital sign monitor includes optical oscillometric circuit means responsive to an output signal from the optical sensor for determining systolic pressure, mean pressure and diastolic pressure during a transition in capsule pressure between a pressure greater than normal systolic pressure and a pressure less than normal diastolic pressure.

Provided is a non-invasive electronic method and apparatus for measuring blood pressure, in which the data is processed with an algorithm of non-linear fitting for recovering trend envelope of an oscillating PW by a firmware, so that the trend envelope of PW amplitude can be recovered accurately, and the obtained average pressure shows higher degree of agreement with the real situation in clinic. In this apparatus, a 3-way solenoid valve (20) is arranged between a cuff (10) and a first pressure sensor (30), wherein the common port of the 3-way solenoid valve (20) is connected with the first pressure sensor (30), the normally open port thereof connected with the cuff (10), and the normally closed port thereof connected with the air atmosphere during zeroing process. Moreover, an independent timing circuit (45) is provided additionally. In the measurement method of the present invention, the zeroing is performed with the help of the 3-way solenoid valve (20). Once a state of overtime or overpressure occurs, an air bump (50) is immediately closed, and a quick-deflation solenoid valve (60) is opened so that the pressure in the cuff (10) is released to ensure safe application.

A preferred embodiment EGR valve permits exhaust gas to be induced into the intake line downstream of the compressor, while minimizing the need to reduce the size of the turbocharger. The preferred embodiment EGR valve exploits variations around the mean pressure in the EGR passage created by the engine cycle by selectively opening when the pressure in the EGR valve exceeds the pressure in the intake line. Thus, exhaust gas is recirculated even when the engine is running near torque peak. The preferred embodiment EGR valve also exploits the higher mean pressure in the exhaust line relative to the intake line at higher engine speeds by remaining open, in order to minimize the energy consumed in opening and closing the EGR valve.

A method for the automated setting-up of an injection molding machine, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection velocity, including the steps of: manufacturing one of more parts with the machine; determining an injection pressure profile by measuring injection pressure as a function of elapsed injection time with the machine configured with a substantially constant, desired injection velocity; measuring injection velocity as a function of elapsed injection time and determining a profile of the measured injection velocity; defining a mean pressure profile from the pressure profile in a regime of substantially constant measured injection velocity profile; adjusting the velocity profile over at least a portion of an injection velocity phase in response to the pressure profile to reduce differences between the pressure profile and the mean pressure profile, thereby tending to lessen irregularities in the pressure profile.

The invention relates to a method of operating an internal combustion engine operated on gasoline type fuels, more specifically on gasoline, wherein ignition of the fuel-air mixture is initiated spontaneously in at least one operational range of the engine, preferably in the part load range, and wherein a stratified charge is produced in the combustion chamber, preferably in the higher load range. In order to achieve in the simplest possible manner high exhaust quality for an internal combustion engine operated on fuel with poor ignition characteristics in the range of higher mean pressures as well there is provided that combustion is initiated by spontaneous ignition of the fuel in the full load range as well and that preferably the in-cylinder charge temperature is controlled throughout the load range by way of internal exhaust gas recirculation and that, in the full load range, the start of fuel injection occurs after top dead center.

Method of processing data in a vehicle tire monitoring system. For a first given period of time, referred to as the reference period, a device calculates, for each class of temperature supplied, the corresponding mean pressure in a given tire. Then, for at least a second given period of time, the device calculates, for each class of temperature supplied, the corresponding mean pressure and the difference between this mean pressure and the reference mean pressure, and the device calculates the mean value of these differences.