299 results about "Relative pressure" patented technology

A device for performing a surgical procedure on a knee includes an adjustable femoral portion, a tibial portion and at least one sensor coupled with the femoral and/or tibial portions to sense pressure exerted by the femoral and tibial portions against one another. The femoral portion is adapted for removably coupling with a distal end of a femur to adjust tension in soft tissue adjacent the knee and has at least one positioning feature adapted to move relative to the distal end of the femur as the femoral portion is adjusted, thus helping position a femoral prosthetic on the distal end of the femur. The sensor(s) may be adapted to sense pressure at medial and lateral sides of the knee, and relative pressures may be displayed as data on a visual display. Adjustments to the femoral member may be made to balance pressure at flexion and extension of the knee.

An enteral feeding unit or system that minimizes the occurrence of gastro-esophogeal-pharynegal reflux during feeding is described. The enteral feeding unit or device includes an automatable feeding pump with a feedback sensor for sensing a relative pressure in a patient's stomach and esophagus, and a regulator system for controlling or monitoring feeding rate to said patient as a function of said relative gastro-esophageal pressure. The system includes a stomach probe that has a fluid-tight closure of the esophagus. The stomach probe, according to the invention, is characterized by a tampon-bladder for watertight closure of the esophagus, in which the tampon-bladder forms from flexible and/or elastic material at least a closed inner cavity for the reception of a fluid medium, through a means (11) of establishing a prescribed pressure for the medium in the tampon-bladder (16) by an inner lumen forming the actual stomach probe, from which an outer hose-like lumen (18) extending to the tampon-bladder (16) is so arranged that between the outer lumen (18) and the inner lumen (17) a channel is formed connected to the inner cavity of the tampon-bladder (16) arranged on the outer lumen (18) by a number of openings (20), whereby the inner cavity of the tampon-bladder (16) is connected via the canal formed between the inner and outer lumina (17, 18) with the means of production of pressure in the tampon-bladder, that is, with a suitably graded reservoir or equalizing vessel (11) for the liquid medium situated above the tampon-bladder and outside the patient.

This invention provides a printing head which can prevent an increase in the number of block enable signal lines, and can prevent changes in printing ink density caused by interference due to the relative pressures of nozzles generated in ink discharge, and an image printing apparatus using the printing head. For this purpose, an increase in the number of input signal lines along with an increase in the number of blocks is prevented using a block clock signal or the like instead of a block enable signal as an input signal to the printing head. Three ring counters generate signals having different nozzle driving orders. These signals are selectively used by a ring counter selection signal. Ink is not always discharged from the nozzles in the same output order. This can prevent changes in ink density caused by pressure interference.

An enteral feeding unit that reduces the occurrence of gastro-esophogeal-pharynegal reflux during feeding includes an automatable feeding pump with a feedback sensor for sensing a relative pressure in a patient's stomach and esophagus, and a regulator system for controlling and monitoring feeding rate to the patient as a function of the relative gastro-esophageal pressure. The system includes a stomach probe that provides a fluid-tight closure of the esophagus. The stomach probe includes a tampon-bladder for watertight closure of the esophagus, in which the tampon-bladder is formed of flexible and/or elastic material. At least an inner cavity of the bladder is provided for the reception of a fluid medium. A prescribed pressure for the medium in the tampon-bladder (53) is maintained by an inner lumen forming the stomach probe, from which an outer hose-like lumen (62) extending to the tampon-bladder (53) is so arranged that between the outer lumen (62) and the inner lumen (61) a channel is formed connected to the inner cavity of the tampon-bladder (53) arranged on the outer lumen (62) by a number of openings (57). The inner cavity (58) of the tampon-bladder (53) is connected via a canal formed between the inner and outer lumina (62) with a suitably graded reservoir or equalizing vessel for the liquid medium situated above the tampon-bladder and outside the patient.

A pressure sensor has two sensor elements respectively disposed in different pressure spaces A and B. Each of the sensor elements has a semiconductor substrate having a pressure reference chamber therein, a diaphragm formed as a wall defining the pressure reference chamber, and gauges for converting deformation of the diaphragm into an electric signal. The two sensor elements overlap with each other at sides opposite to the respective diaphragms, and close a hole formed in a partition member partitioning the two pressure spaces A and B. A differential pressure between the pressure spaces A and B is detected as a relative pressure by a difference between outputs from the two sensor elements.

The invention relates to a novel optical fiber Fabry-Perot pressure sensor and a fabrication method thereof. The optical fiber Fabry-Perot pressure sensor is used for detecting the relative pressure and absolute pressure of liquid and gas as well as sound wave signals, ultrasonic wave signals and the like. The structure of the optical fiber Fabry-Perot pressure sensor mainly comprises an optical fiber, an elastic diaphragm, a sensor body and a miniature spring. Two methods and an alternative method can be adopted to form a Fabry-Perot cavity and fabricate the sensor. The elastic diaphragm and the sensing optical fiber are tightly contacted in a plane-sphere point contact manner; when the outside pressure is changed to cause the deformation of the elastic diaphragm, the diaphragm can drive the optical fiber to axially move in the sensor body, so that the length of the Fabry-Perot cavity of the optical fiber is changed; after a broadband light source is connected, by scanning the spectrum of the light passing through the optical fiber Fabry-Perot pressure sensor or extracting low-coherence interference fringes, the change of the cavity length can be extracted, and thereby pressure information can be obtained. The structure can avoid the defect that the diaphragm of the conventional optical fiber Fabry-Perot pressure sensor cannot be over-deformed, and can obtain higher measurement precision.

A crankcase ventilation system for an internal combustion engine has an engine driven pump pumping scavenged separated oil from the oil outlet of an air-oil separator to the crankcase, preferably using engine generated pulsating oscillatory positive and negative relative pressure pulses.

Provided is a relative pressure control system has a simple configuration, but enables accurate regulation of a division ratio of an operation gas, and concurrently makes it possible to securely drain the operation gas from an operation gas pipeline in case of emergency. The system includes a plurality of air operated valves of a normally open type that are connected to an operation gas pipeline supplied with an operation gas; pressure sensors that are series connected to the respective air operated valves and that detect output pressures of the respective air operated valves; a controller that controls operation pressures of the respective air operated valves in accordance with the pressures detected by the pressure sensors; and a hard-interlock solenoid valve that correlates the plurality of air operated valves to one another so that at least one of the plurality of air operated valves is normally opened. In the configuration, an opening of a specified one of the plurality of air operated valves is regulated, the operation gas is output at a predetermined division ratio.

An improved heterogeneous catalyst for catalyzing the reaction of gaseous reactants, comprising a high performance catalyst particle with a diameter to height ratio in the range between about 0.5:1 to 1.0:1.0, the high performance catalyst particle has a Relative Particle Size Parameter (RPSP) and a Geometric Surface Area (GSA), wherein the high performance catalyst particle has a higher GSA for a particular RPSP than a prior art catalyst particle. In another embodiment the improved heterogeneous catalyst with a diameter to height ratio in the range between about 0.5:1 to 1.0:1.0 has a Relative Particle Size Parameter (RPSP), a Geometric Surface Area (GSA), and an associated Relative Pressure Drop (RPD), wherein the high performance catalyst particle has a higher GSA for a particular RPSP or alternately a lower RPD for a particular GSA than a prior art catalyst particle.

The invention discloses a method for full-dimension representation and analysis of dense reservoir pore throats. The method comprises the following steps of 1, data optimization: (a) preparing a dense oil rock sample; (b) using a high-pressure mercury injection apparatus Pore Master to perform mercury injection experiment on a rock sample; (c) using an automatic isothermal adsorption instrument to perform low-temperature nitrogen experiment at the temperature of 77.35K and relative pressure of 0.01-1MPa; (d) according to adsorption type pore throat distribution frequency, accumulating a distribution frequency chart, and performing interpolating on the accumulated distribution frequency chart; (e) connecting the mercury injection type pore throat distribution frequency and the converted adsorption type pore throat distribution frequency at 25nm; 2, data check. The representation method has the advantages that the steps are simple; the pore throat distribution rules of different reservoirs can be analyzed, and the more accurate and deeper evaluation is performed on different dimensions of space microstructures by crossing multiple orders of magnitude.

The invention relates to a reproducing repair experiment platform and particularly relates to a brush electroplating repair experiment platform for an oil cylinder barrel. By adjusting four main parameters, which affect brush electroplating plating performances, such as brush electroplating voltage, relative movement speed of a workpiece and a plating pen, plating liquor flow rate, and relative pressure of the workpiece and the plating pen, optimal brush electroplating parameter value of the inner surface of the oil cylinder barrel can be obtained; the oil cylinder barrel is repaired through the obtained parameter value, so that dimension requirements and using performances can be satisfied well. According to the platform, a vertical structure is adopted, a plating brush adopts an inverter pulse power supply which is high in thickness measuring precision, and moreover, various parameters such as voltage are adjustable; the relative motion of the workpiece and the plating pen is decomposed into two major motions of linear feeding and rotation of the plating pen; each process step of the brush electroplating is automatically controlled by a PLC (Programmable Logic Controller); each of all different plating liquors has a respective specified plating liquor pump and a plating liquor box for realizing automatic applying and recycling. Besides, the brush electroplating repair experiment platform disclosed by the invention is simple and stable in structure, strong in practicability, high in automation degree, convenient to measure each parameter and capable of carrying out brush electroplating experiments, teaching and machining on the inner surface of a cylindrical workpiece.

The invention relates to a measuring method and a device for measuring optical fiber multipoint temperature and pressure of an intelligent well, belonging to the technical field of intelligent wells. The measuring method comprises that a plurality of optical fiber temperature sensors and optical fiber pressure sensors are arranged on an optical cable, wherein reversed lights which are reflected by the optical fiber temperature sensors and the optical fiber pressure sensors are respectively transformed into spectroscopic data which is transmitted to a processor, thereby respectively obtaining reflectance spectrums of all sensors, and a wave length value which is relative to the largest reflection rate is used as characteristic parameter of relative temperature sensors, the length of the cavity of each pressure sensor is calculated to be used as characteristic parameter of relative pressure sensors, and then the characteristic parameters of relative temperature and relative pressure sensors are compared with the characteristic parameter calibration curve to gain temperature reading or pressure reading of the optical fiber sensors. The device comprises a broad band light source, a modularized optical spectrometer, a data transmission line, a data processor, a first section optical fiber and a second section optical fiber, a optical fiber coupling, an optical cable, and a two-parameter sensor group of optical fiber temperature and optical fiber pressure. The invention solves the problems of pressure float and temperature crossfire when optical fiber grating technology is applied to a pressure sensor.

The invention relates to a verifying unit which comprises a high-low temperature thermostat, and a to-be-tested relay mounting rack, a temperature sensor, an adjusting cylinder, and an SF6 and SF6 mixed gas cylinder which are arranged inside the high-low temperature thermostat, as well as an absolute pressure transducer, a relative pressure transducer, an SF6 gas cylinder, an N2 or CF4 gas cylinder, a vacuum pump and a control device which are arranged outside the high-low temperature thermostat, wherein the control device is respectively connected with the temperature sensor, a to-be-tested gas density replay, the absolute pressure transducer and the relative pressure transducer; and the control device is used for data processing, control command outputting, and verification result data display. The verifying unit is used for realizing the full-temperature accurate test to the SF6 gas density relay, and meanwhile realizes the full-temperature accurate test to the SF6 mixed gas density relay.

A pressure indicating device for self contained breathing apparatus includes a piston arrangement which is responsive to the relative pressures of the supply and the pressure at the outlet of the first stage regulator to assume several different positions in the containment housing. Piston position is recognized by electronic circuitry and an LED display is lighted accordingly to provide a series of unique signals to the user, of the remaining quantity of breathing fluid. In one embodiment of the invention, plural, graduated-size pistons provide a progressive indication of the air supply. In another embodiment, a single, stepped piston effects progressive electrical contact at various positions in the travel of the piston.

Belonging to the technical field of lithium ion battery recovery, the invention discloses a method and device for collection of a waste lithium ion battery electrolyte solution. The method comprises the steps of: (1) placing a waste lithium ion battery obliquely for 12-72h to round up the electrolyte solution so as to be convenient for export; (2) incising the battery in step (1), then tilting the battery incision downward and placing the battery in a vacuum environment with a relative pressure ranging from -0.05 to -0.09MPa, keeping the pressure for 2-20min, and collecting the effluent electrolyte solution; and (3) taking out an electrical core from the battery in step (2), extruding the electrical core to collect the electrolyte solution, and combining the electrolyte solution with the electrolyte solution from step (2). According to the method and devoce provided by the invention, a vacuum pumping-extrusion process is employed to collect the electrolyte solution, the process is simple, practical and efficient, and is easy to control, has industrial reproducibility, and can realize batch and continuous production.