316 results about "Differential measurement" patented technology

Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code. The structure and dynamics of sub-cellular constituents cannot be currently studied in their native state using the existing methods and technologies including, for example, x-ray and neutron scattering. In contrast, light based techniques with nanometer resolution enable the cellular machinery to be studied in its native state. Thus, preferred embodiments of the present invention include systems based on principles of interferometry and/or phase measurements and are used to study cellular physiology. These systems include principles of low coherence interferometry (LCI) using optical interferometers to measure phase, or light scattering spectroscopy (LSS) wherein interference within the cellular components themselves is used, or in the alternative the principles of LCI and LSS can be combined to result in systems of the present invention.

Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code. The structure and dynamics of sub-cellular constituents cannot be currently studied in their native state using the existing methods and technologies including, for example, x-ray and neutron scattering. In contrast, light based techniques with nanometer resolution enable the cellular machinery to be studied in its native state. Thus, preferred embodiments of the present invention include systems based on principles of interferometry and/or phase measurements and are used to study cellular physiology. These systems include principles of low coherence interferometry (LCI) using optical interferometers to measure phase, or light scattering spectroscopy (LSS) wherein interference within the cellular components themselves is used, or in the alternative the principles of LCI and LSS can be combined to result in systems of the present invention.

A pacemaker provides multi-chamber pacing with a pacing interval that can be programmed and adapted in response to cardiac output measurements for a given patient. In a typical embodiment, the pacemaker may provide pacing stimuli to both ventricles of a heart. In addition, the invention may include a measurement device that incorporates first and second blood oxygen saturation sensors for deployment in the left and right ventricle. The oxygen saturation sensors provide a differential measurement that can be used to calculate cardiac output in accordance with the Fick method. The oxygen saturation sensors may be carried by a common trans-septal lead that positions one of the sensors proximate the right ventricle and the other sensor proximate the left ventricle. Alternatively, the oxygen saturation sensors may be deployed via separate leads. Whether single or dual leads are used to carry the oxygen saturation sensors, a respective lead may optionally carry electrodes for sensing, pacing, or both.

An acoustic energy-based, non-contact or contact testing approach provides low cost, highly accurate, and reliable information to (a) identify flaws and anomalies and (b) assess the integrity of a particular material. This approach is not hindered by surface conditions or impediments, and indeed, looks beneath the surface of the material by propagating an acoustic wave through the material using two differential transducers. A dynamic differential measurement is made of the material under a load condition and an unloaded condition that allows identification and assessment of various characteristics of the material. Multiple “windows” of information may be generated that permit (a) direct detection of flaws, defects, and anomalies using a scattering technique, (b) detection of crack closure and opening used to assess the stability of the material, (c) determination of strain on the material which relates to its performance, and (d) determination of defect dynamics linked to the defect size and stability.

A calibration system and method for a resistor ladder that employs relative measurement and adjustment between pairs of resistors. The system includes a resistor tree of complementary pairs of programmable resistors coupled to the resistor ladder, a measurement circuit that measures voltage differences between complementary pairs of programmable resistors, and control logic. The control logic controls the measurement circuit to measure a voltage difference between each complementary pair of programmable resistors and adjusts the relative resistance of each complementary pair of programmable resistors to equalize voltage. The measurement is facilitated by a sigma-delta ADC that converts a measured voltage difference into a bit stream. The programmable resistors are implemented with binary weighted resistors that are digitally adjusted one LSB at a time. Lower and upper adjustment thresholds may be employed to avoid unnecessary over-adjustments while maintaining a requisite level of accuracy.

The invention concerns compositions and methods for assay or detection of apolipoprotein-B48 in samples. In particular, it concerns a method for differential measurement of apolipoprotein-B48 (“Apo-B48”) and apolipoprotein-B100 (“Apo-B100”) in biological samples. The invention also concerns synthetic products of Apo-B100, the corresponding antibodies, kits containing same, and their uses for detecting, differentially quantifying and/or recording an amount of Apo-B48 and/or Apo-B100 in a sample, or for quantifying and/or recording atherogenic lipoparticles in a sample. The products, materials and kits hereinabove can also be used for differentially modulating the levels of Apo-B48 and/or Apo-B100 or their activity, in vitro or in vivo, and for regulating lipid metabolism in a subject.

The invention discloses a roll angle measuring method based on a grating and a device thereof, which belongs to the technical field of photoelectric detection. A laser lases and emerges directly, or emerges after collimation through a collimating lens; the light is directly incident on a one-dimensional plane transmission grating, or reversely incident on the grating through a retrodirective reflector; plus-minus first stage diffracted light from the grating is focused to form two diffracted light points through a lens; a photodetector is used to detect the variations in positions of the two focused light points, thus figuring out a roll angle. The optical structure of the device is compact and simple, and brings convenience to practice; in addition, the accuracy, the stability and the economical efficiency are also high. The grating is used as a sensitive device; error separation is achieved, and the interference-free feature is improved by using the differential measurement of double diffracted beams; few optical devices are used; and the power of the light source is low; the cost is low; mobile parts do not require to be provided with cables; the angle measurement distinguishability is as high as 0.5 and even higher; different requirements of measurement accuracy can be met just by replacing the grating with gratings having different numbers of lines.

Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code. The structure and dynamics of sub-cellular constituents cannot be currently studied in their native state using the existing methods and technologies including, for example, x-ray and neutron scattering. In contrast, light based techniques with nanometer resolution enable the cellular machinery to be studied in its native state. Thus, preferred embodiments of the present invention include systems based on principles of interferometry and/or phase measurements and are used to study cellular physiology. These systems include principles of low coherence interferometry (LCI) using optical interferometers to measure phase, or light scattering spectroscopy (LSS) wherein interference within the cellular components themselves is used, or in the alternative the principles of LCI and LSS can be combined to result in systems of the present invention.

The invention discloses a full optical path drift compensation high-precision roll angle measuring method and a device, and belongs to the technical field of photovoltaic testing. By using a pair of retro-reflector as sensitive device, the roll angle information is obtained through the parallel two-beam differential measurement, in which the parallel beam through a set of double pentagonal prism and a pentagonal prism splitting the collimated laser beam after splitting obtained by the dual beam parallelism prism precision guaranteed without adjustment, greatly enhance the feasibility and practicability of measurement methods; by using a rectangular prism as beam translation and reverse means that two beams measuring light path completely overlap, and the light path direction reciprocal use This feature, in twice while improving measurement resolution, combined with a total path of the light drift compensation method, can achieve all-optical laser beam path is completely drift compensation, to resolve the current measuring method using laser collimation of the laser beam cannot completely eliminate the drift angle the impact of the common problems that can achieve the roll angle measurement resolution of better than 0.1 'accuracy of better than 1'; compact optical structure of the present invention, the adjustment is simple, no more freedom crosstalk error, moving parts without cable, easy on-site measurement .

A tire pressure monitoring system is provided that includes a switched capacitor circuit having a clock with two non-overlapping clock phases that control a state of analog switches of the switched capacitor circuit. The system uses tire pressure sensor MEMS capacitors that are measured differentially. A capacitance-to-voltage converter is connected to the MEMS sense capacitor, and a sigma-delta converter having a comparator with a first digital output state and a second digital output state is used. The first output state is a sum of reference voltages and the second output state is a difference of the reference voltages. An average value of the capacitance-to-voltage converter output is driven to a zero value and a digital output is provided of the average output states that is equal to a difference between the MEMS capacitors divided by their sum multiplied by a ratio of the reference voltages.

The invention discloses a static two sides weight differential measurement method of lift coefficient of balance according to the lift balance coefficient formula (I)through measuring the weight differential Wg=(W-G) of the pair weight and the sedan wing and gives the lift rated load capacity Q then calculates the balance coefficient K. The method is that: at the condition of lift with no-load layouts the force transducer at the bottom of well corresponding with the pair weight and the pair weight falls down to the bottom of well and contacts with the force transducer then measures the weight differential Wg1 of the pair weight side and the sedan wing side; installs the poise with the carrying capacity QP in the sedan wing (QP is greater than the one-half of the lift rated carrying capacity) layouts the force transducer at the bottom of well corresponding with the sedan wing the sedan wing falls down to the bottom of well and contacts with the force transducer then measures the weight differential Wg2 of the sedan wing side and the pair weight side and calculates the balance coefficient K according to the formula(II)following the weight differentia Wg1, Wg2, the lift rated carrying capacity Q, and the bearing capacity QP. According to this method develop the lift balance coefficient test device which can measure the lift balance coefficient directly, accurately, and rapidly at the static case.

A power control system and method for a wireless telephone employs an open loop technique for relatively low power levels and a closed loop technique at higher power levels. In the open loop technique, a wireless telephone (104, 106, 108) stores a phasing table of automatic power control (APC) values for the power levels (which are used to control upconverter gain levels measured at different channels. In operation, a power controller (322) reads the power level and reads the APC value in the table. Another table stores the APC value for one power level as the channel and temperature are varied. This value is interpolated, as needed, during operation. The APC value for the open loop approach is determined by reading the input channel; finding the closest higher and closest lower channels in the temperature-channel table; interpolating between APC values for the temperature column of the closest lower temperature, to get the actual value. The difference between this value and the APC value for the actual power level in the phasing table is then obtained.

This invention relates to an apparatus for making highly sensitive differential measurements of acceleration. The vibration sensor includes the use of moveable gate field effect transistors to sense the motion of a cantilever beam relative to the motion sensed by a reference structure, it also includes an actuator element formed by a pair of electrodes actuating electrostatically on the beam. A feedback control loop is also included for force balance operation resulting in a very wide dynamic range for the sensor.

The invention belongs to the technical field of petroleum engineering, and particularly relates to a gas migration monitoring device based on annulus pressure differential measurement while drilling in the drilling process. The gas migration monitoring device based on annulus pressure differential measurement while drilling comprises a nipple for gas migration monitoring while drilling, a central processing unit and a computer terminal; the two ends of the nipple for gas migration monitoring while drilling are connected with a drill collar and a drill pipe, and the two ends of the central processing unit are connected with a gas migration monitoring device body and the computer terminal; the computer terminal sends a measuring signal to the central processing unit through a data connection bus, the measuring signal is transmitted to the nipple for gas migration monitoring while drilling through an armored cable, a sensor group immediately conducts measurement work, the pressure P, the temperature T and the depth H of a corresponding position are obtained, the actual drilling fluid density is obtained through calculation, and if a difference between the actual drilling fluid density and theoretical density is larger than a gas migration discriminant value, well control prevention measures are started. The gas migration monitoring device is high in monitoring accuracy and extremely high in real-time performance, matching with the drill pipe is simple and convenient, the professional requirement on operation is low, the stability is good, and the automation degree is high.

Sensor systems and methods are disclosed, which generally incorporate isolation between the sensor's electronics and the sensed media. The sensor's electronic circuit can incorporate one or more application specific integrated circuit (ASIC) that processes and outputs the signal for both absolute and differential measurements. Such a sensor can be adapted for use in exhaust gas re-circulation (EGR) systems utilized with automotive gasoline engines. Such a sensor can also be utilized for measuring differential pressure across diesel particular filters and/or applications in which differential pressure is required for system control and/or monitoring purposes. The absolute pressure sensor disclosed herein can therefore sense the exhaust pressure on automotive engines and other mechanical and/or electromechanical devices and machines.

Disclosed is an optical sensing device, which comprises a light source emitting a light; a beam splitter; an SPR sensor unit comprising a sensing surface; and a detecting mechanism; and a converting unit converting the first beam and the second beam from the optical device into a two-dimensional interference fringe pattern. From the above-mentioned configuration, an extra phase shift of a detection beam in SPR phase measurement is obtained. The differential measurement approach has shown to achieve a sensitivity figure significantly better than the best result that can be obtained from the prior art in the field of the measurement based on an SPR sensor.

The invention provides a method and a device for simultaneously measuring five degrees-of-freedom errors based on light beam drift compensation. The method and the device are used for solving the problems of low measurement precision, small measurement range and poor anti-interference capability of the existing high-precision simultaneous measurement method for guide rail five degrees-of-freedom. A collimating lens, a prism assembly, a polarization beam splitting prism and a quarter-wave plate are arranged between a laser device and a right-angle prism plated with a beam splitting film, so as to realize processing of incident light and reflected light, information of the reflected light and transmitted light after beam splitting is received and measured by means of a four-quadrant detector and a position sensitive detector, and the measurement of pitch angle, deflection angle and rolling angle errors, horizontal straightness errors, vertical straightness errors and light drift compensation are realized. The method and the device utilize double beam differential measurement to realize error separation, enhance the anti-interference capability, employ few optical devices and are low in light source power and cost; the optical structure is simple, the operation is convenient, the moving parts are not required to be provided with cables, and the field measurement is facilitated; and the angle measurement resolution is high.

A current sensing approach makes use of two shunts in series, embedded in a switching fabric, each shunt the object of a differential measurement of voltage drop across the shunt. Methodical make-before-break cycling of the switches in the switching fabric permit real-time or very near-real-time measurement of nearly all of the errors such as offset errors present in each differential-measurement path. Additional differential measurement paths can be connected with the shunts, with RFI filtering at shorter time constants to serve electronic fuse needs.

Embodiments of the present invention are directed towards systems, methods, and computer readable media for performing multiport vector network analysis. Embodiments of the present invention relate to a multiport network analysis that is derived from a family of two port calibration techniques including Thru/Reflect/Line(TRL), Thru/Reflect/Match(TRM), Line/Reflect/Line (LRL), Line/Reflect/Match (LRM) and several others. An improved calibration method enables the use of a simplified switch matrix to perform accurate vector network analysis in communications and networking systems. After determining some characteristics through conventional methods, a two tier load match correction is performed on the results. The improved correction mechanism enables the system to perform comparably to systems with more complicated switch matrices.