519 results about "Amplitude ratio" patented technology

Apparatus and method for noninvasively determining cardiac performance parameters including 1) lengths of systolic time intervals, (2) contractility index, (3) pulse amplitude ratios while performing the Valsalva maneuver, (4) cardiac output index, and (5) a pulse wave velocity index. A catheter having at least one balloon is inserted into the esophagus and pressurized and positioned adjacent the aortic arch to sense aortic pressure. The effects of aortic pressure on the balloon are utilized to determine at least one of the cardiac performance parameters. The catheter may include a second balloon which is spaced from the aortic balloon a distance such that when the second balloon is in a position adjacent the left atrium to sense left atrial pressure the aortic balloon is in a position adjacent the aortic arch to sense aortic pressure, this distance being related to the distance between the left atrium and aortic arch in most adult persons.

A method for estimating systolic and diastolic pressure is disclosed herein. The method includes obtaining a predetermined type of blood pressure data from a patient, and providing previously acquired blood pressure data obtained from a plurality of different subjects. The method also includes implementing the previously acquired blood pressure data to select systolic and diastolic amplitude ratios that most closely correlate with the predetermined type of blood pressure data obtained from the patient. The selected systolic and diastolic amplitude ratios are adapted to compensate for the effects of arterial compliance. The method also includes implementing the selected systolic and diastolic amplitude ratios to generate a systolic and diastolic blood pressure estimates.

The present invention relates to a device for the location of passive intermodulation faults in a coaxial cable network. The test apparatus (100) according to one embodiment of the present invention utilises a pair of high-power, frequency-synthesised, unmodulated RF carriers v₁(t) (101) and v₂(t) (102) are generated inside the HPA module of the apparatus. The power and frequency of v₁(t) (101) and v₂(t) (102) can be independently set to a range of values, v₁(t), v₂(t) are combined inside the instrument and then applied to the input of the device under test (DUT). The PIM signals (107,108,109) generated in the DUT are combined to produce the primary PIM signal v_IM(t) (103). The apparatus also includes two receivers (110,111,112,113,114,115) for the detection of v_IM(t) 103 and v_REF(t) (104). These signals are downconverted to 455 kHz. The two 455 kHz waveforms are digitised with a dual- channel A/D converter (116,117) and the amplitude ratio and phase offset between the digitised waveforms are calculated and stored.

The invention discloses a rolling bearing failure diagnostic method based on a multi-characteristic parameter, which comprises the following steps of: (1) pre-processing the collected vibrating signals, and removing the interference of the noise and other vibrating sources; (2) extracting a time domain statistical parameter capable of reflecting different working conditions of the rolling bearing from the vibrating signals; (3) figuring out the envelope signal of the pre-processed vibrating signals, decomposing the envelope signal through an improved empirical mode decomposition method to obtain a series of intrinsic mode functions; (4) selecting multiple intrinsic mode functions concentrating most part of energy, and calculating an energy torque; (5) performing envelope spectrum analysis on the first decomposed intrinsic mode function, and calculating the failure characteristic amplitude ratio; and (6) serving a plurality of characteristic parameters extracted in the step as input vector of a BP neural network, and outputting the diagnosis result through the network. The rolling bearing failure diagnostic method disclosed by the invention can fully reflect the operation condition of the rolling bearing, improve the diagnosis accuracy and facilitate realization of the online monitoring of the rolling bearing.

A stylus includes a pressure detector for detecting applied pressure, a first signal generator for generating a signal of a first frequency, a second signal generator for generating a signal of a second frequency, and a controller for adjusting at least one of the first and second signal generators to control an amplitude ratio of the signal of the first frequency to the signal of the second frequency according to the applied pressure detected by the pressure detector.

A control device has a unit for preparing a pattern having first and second periods by comparing a triangular wave and a sine wave having an amplitude ratio set at each value of a modulation factor, and selecting one pattern corresponding to an instructed modulation factor, and a unit for applying a controlled voltage, set at low and high levels in response to first and second periods of the selected pattern, to a generator. The triangular wave has a cycle duration obtained by dividing the cycle duration of the generator by product of 3 and odd number, a crest having a level higher than the sine wave at a timing of each first period, and a trough having a level lower than the sine wave at a timing of each second period.

An antenna device has a divider producing first and second signals, and amplifiers amplifying the signals at a changeable amplitude ratio of the first signal to the second signal. A Rotman lens gives first phase differences to first high frequency waves, produced from the first amplified signal at an input port and transmitted to output ports, and gives second phase differences to second high frequency waves produced from the second amplified signal at another input port and transmitted to the output ports. An antenna forms a beam composed of electromagnetic waves, having the first phase differences and electric power corresponding to the first amplified signal on an antenna surface, and electromagnetic waves, having the second phase differences and electric power corresponding to the second amplified signal on the antenna surface, and radiates the beam in a particular direction corresponding to the phase differences and the amplitude ratio.

First image data and second image data are generated by capturing a subject image at a CCD. The first image data captured over a first exposure time manifest a relatively small extent of image blur. The second image data are captured over a second exposure time set longer than the first exposure time. A spatial frequency analysis is implemented on the first image data and the second image data to calculate the amplitude ratio and the phase difference of the high-frequency components in the two sets of image data. Based upon the amplitude ratio and the phase difference of the high-frequency components thus calculated, the spatial frequency component of the second image data is corrected to generate third image data in which any image blur has been corrected.

Received quality detecting section 108 detects a received quality, bit determining section 111 determines whether a TPC bit is 0 or 1, amplitude reading section 112 reads a ratio of an amplitude of a signal other than the TPC bit and an amplitude of the TPC bit, accumulating section 113 determines an increase or decrease of transmit power and an amount of the increase and decrease of the transmit power using a symbol of the TPC bit for the increase or decrease, and an amplitude ratio for the amount of the increase and decrease to instruct to transmission amplifier 104, and multiplying section 114 multiplies the amplitude of the signal other than the TPC bit by a correction value corresponding to the received quality to determine the amplitude of the TPC bit.

The invention establishes a prediction method for the multi-axial high-cycle fatigue life of a plastic metal material based on a critical plane approach. According to the invention, a fatigue failure mode of the plastic metal material under the condition of combined loading of tension and torsion is taken into consideration, influence of a stress amplitude ratio and phase difference on the multi-axial high-cycle fatigue life under the condition of multi-axial loading is also considered, a fatigue life prediction model for prediction of the multi-axial high-cycle fatigue life is established by using linear combination of a maximum principal stress peak value and a maximum shear stress range on the basis of critical plane criteria of multi-axial fatigue and used for predicating the life of the plastic metal material bearing multi-axial high-cycle fatigue load, and the prediction method for the multi-axial high-cycle fatigue life of the plastic metal material based on the critical plane approach is eventually brought forward. The model established in the invention is based on the critical plane criteria capable of revealing damage of a physical mechanism multi-axial fatigue and takes influence of the stress amplitude ratio and phase difference on multi-axial high-cycle fatigue failure under the condition of multi-axial loading into consideration, and small dispersity and high accuracy of prediction results of the model are realized.

Techniques are provided for detecting pulmonary edema based on a comparison of impedance-based respiratory patterns and impedance-based cardiac patterns, i.e. patterns derived from thoracic impedance signals. In one example, a numerical ratio is calculated between average peak-to-peak amplitudes of the respiratory patterns and average peak-to-peak amplitudes of the cardiac patterns. Pulmonary edema is detected if the amplitude ratio falls below a pulmonary edema detection threshold. Techniques are also provided for controlling operation of an impedance-based reduced respiration detector, i.e. a detector which seeks to detect apnea, hypopnea, or the like, based on analysis of respiratory patterns derived from a thoracic impedance signal. If the numerical ratio falls below a minimum reliability threshold, then the reduced respiration detector is deactivated because episodes of reduced respiration cannot then reliably be derived from an analysis of respiration patterns obtained from the thoracic impedance signals.

The invention discloses a method and device for checking scales of a resistivity logging instrument, and the method comprises a resistivity logging instrument calibrating step and a resistivity logging instrument checking step, wherein the resistivity logging instrument calibrating step is as follows: measuring the amplitude ratio R0 and the phase difference D0 of signals when the resistivity logging instrument is exposed in air, measuring the amplitude ratio Rn and the phase difference Dn of the signals when simulated formations with different resistivities are placed around the resistivity logging instrument, and confirming the amplitude ratio response function relationship and the phase difference response function relationship according to R0, D0, Rn and Dn; and the resistivity logging instrument checking step is as follows: measuring the amplitude ratio R and the phase difference D of the signals when a simulated formation with resistivity Rho is placed nearby the logging instrument, calculating the amplitude ratio resistivity and the phase difference resistivity as per R, D, the amplitude response function relationship and the phase difference response function relationship, and calculating difference values of the amplitude ratio resistivity and the phase difference resistivity with the resistivity Rho. If the difference values of the amplitude ratio resistivity and the phase difference resistivity with the resistivity Rho are both less than a preset measuring error of the instrument, the resistivity logging instrument passes through the checking.

The invention pertains to the pipeline monitoring technology, particularly a fiber pipeline monitoring system. The system is composed of an optical transmitter module, an optical interferometer module, a monitoring line, a modulator module, an optical receiver module and a signal processing module. The system can get two signals corresponding to different optical path positions of the same vibration though multiplexing a fiber interference system, compare the spectrum characteristics of the two signals, and eliminate the interference of the position information caused by the vibration information so as to obtain the accurate vibration position information under the condition that the system adds no photoelectric detector. The position information is obtained through the medium value of the spectrum amplitude ratio of the two signals, and the difference caused by the instability of the detection signal is eliminated, thus the accuracy of the location is greatly improved. The location function is realized with single-core fiber under the condition of not constituting a loop, thus the location monitoring can be realized by paving equal-distance main line along the petroleum pipe line, which has strong environmental applicability.

The present invention discloses a dual-channel phase and amplitude modulation synchronous DDS device, which comprises two channels on the basis of the prior art, wherein, an adder is added between a phase accumulator and a sinusoidal look-up table unit in the sine wave output channel of the first channel, to add the phase value from the phase accumulator with the phase control word of the first channel and output a shifted phase value, so as to shift the phase of the output waveform. In addition, a divider is added between the sinusoidal look-up table unit and a D/A converter in the sine wave output channel of the first channel, to divide the amplitude from the sinusoidal look-up table unit of the first channel by the amplitude ratio coefficient of the divider of the first channel, so as to accomplish amplitude modulation for the output waveform. In that way, phase difference and amplitude ratio functions are implemented, in relation to the second channel. The output from the phase accumulator is connected to both channel, and the synchronization control for the phase accumulator and the two channels is implemented by means of the same system clock signal; therefore, the two channels of signals are completely synchronous.

The invention provides a high non-linear optical fiber excited Brillouin scattering effect and amplitude ratio based microwave frequency measurement method and device and belongs to the technical field of microwave photonics. The device provided by the invention is composed of a tunable laser, a coupler, a phase modulator, a strength modulator, a vector network analyzer, an opto-isolator, a high non-linear optical fiber, a circulator, an erbium-doped optical fiber amplifier, a microwave signal source, a DC voltage stabilizing power source and a photoelectric detector. The frequency range of to-be-detected microwave signals can be enlarged through increasing bandwidths of the strength modulator and the phase modulator and enlarging the scanning range of the vector network analyzer and measurement precision can be improved through reducing noise in optical links and increasing the magnitude of energy transfer of excited Brillouin scattering effect. According to the invention, an amplitude ratio function curve is constructed based on the high non-linear optical fiber excited Brillouin scattering effect and a frequency value of to-be-detected microwave signals is obtained through the amplitude ratio function curve. Therefore, the measurement precision is improved.

Disclosed herein is a functional electrical stimulation (FES) device and system. In one embodiment, sequential bipolar pulse stimulation may be provided to an area of a living body via one or more electrode leads applied to the area via a FES device comprising a current pulse generating circuit comprising output nodes for operative coupling to the one or more electrode leads, and configured for operative coupling to a voltage supply. The current pulse generating circuit generally comprises positive and negative stimulation paths drawing from the voltage supply to respectively apply positive and negative currents through the area via the one or more electrode leads. In one example, the stimulation paths comprise respective capacitive elements, a capacitance ratio of which dictating, at least in part, an amplitude ratio of the positive and negative currents, wherein periodic alternative activation of the stimulation paths provides the sequential bipolar pulse stimulation. In another example, each path comprises a respective charging element and a respective activation switch, wherein each respective charging element is charged by the voltage supply and discharged upon activation of the respective activation switch to generate positive and negative current pulses respectively, such that a pulse rise time of the positive and negative current pulses is predominantly dictated by a switching speed of each respective switch. Systems and uses for these devices, and FES in general, are also described.

There is provided a technique for securing a large examination space in a tunnel type MRI device without inviting increase of manufacturing cost and without significantly reducing irradiation efficiency or uniformity of the irradiation intensity distribution in an imaging region. Between rungs of a partially cylindrical RF coil, which coil corresponds to a cylindrical RF coil of which part is removed, there are disposed half-loops generating magnetic fields, which are synthesized with magnetic fields generated by loops constituted by adjacent rungs of the partially cylindrical RF coil and rings connecting the rungs to generate a circularly polarized or elliptically polarized magnetic field. Further, high-frequency signals of the same reference frequency having a desired amplitude ratio and phase difference are supplied to the partially cylindrical RF coils and half-loops.

A method, device and system for determining a DOA of a signal are described. Determination of the DOA of the signal may include receiving first and second UWB waveforms of the signal at one or more antennas of a UWB transceiver. A window may be defined in the first and second UWB waveforms such that the window is defined in a leading portion of the signal. First and second amplitude values of the respective first and second UWB waveforms in the window may be calculated. An amplitude ratio may be calculated with the first and second amplitude values and compared with calibration data to determine the DOA of the signal.

A noise-attenuating neonate incubator (NANI) comprising sound attenuating module (SAM) configured to decrease the ratio, (AmpRatt_i), of the sound's amplitude at a time, t_i, to a reference amplitude, to a critical amplitude ratio value of said sound measured over a predetermined time, At, (AmpR_QVΔt) or less. The SAM comprises passive noise attenuating, active noise attenuating or both. A method for sound attenuating a neonate incubator, characterized by: (a) obtaining a noise-attenuating neonate incubator (NANI) comprising sound attenuating module (SAM) configured to decrease AmpRatt_i to AmpR_QVΔt or less; (b) accommodating said neonate in said NANI; and, (c) attenuating said noise by said at least one SAM, thereby changing the sound signature.

The invention discloses a polarization calibration method for an antenna system with an automatic polarization adjustment function, and relates to a polarization calibration method in the field of communication. The antenna system with the automatic polarization adjustment function comprises a horizontally polarized antenna, a vertically polarized antenna, an automatic polarization adjustment module and a polarization control circuit, wherein the automatic polarization adjustment module consists of a first amplifier, a second amplifier, match circuits of the first amplifier and the second amplifier, a first numerical control phase shifter, a second numerical control phase shifter, a first numerical control attenuator, a second numerical control attenuator and a combiner/shunt; the automatic polarization adjustment function is completed by automatically adjusting an amplitude ratio of an orthogonal double-line polarization unit; and the polarization calibration process is completed by an automatic calibration method. The method has the advantages that the adjustment speed is high, the adjustment from time to time can be realized, the adjustment effect is good, and antenna outlines are not changed. The method is suitable for manufacturing the antennas with the polarization adjustment functions in satellite communication or other communication systems, in particular to low-outline satellite communication antennas of mobile carriers.

The invention provides a plate structure impact load positioning method based on a distributed fiber bragg grating sensing network, and belongs to the field of impact monitoring of structure firmness monitoring. The method includes the steps of firstly, arranging the distributed fiber bragg grating sensing network; secondly, collecting an impact response signal; thirdly, extracting feature information and analyzing sensitive characteristics of an FBG sensor; fourthly, positioning the position of an impact point through the association algorithm of the maximum peak amplitude ratio of the impact response signal and position information. The positioning algorithm is simple, rapid, convenient and reliable and is high in instantaneity.

The invention discloses a method for detecting a single channel synthetic aperture radar (SAR) ground motion target, which includes conducting clutter locking estimation on original echo data to obtain clutter Doppler center frequency, converting the original echo data into direction spectrum, dividing the direction spectrum into positive frequency spectrum and negative frequency spectrum with the clutter Doppler center frequency as a boundary, obtaining a first auxiliary look complex image and a second auxiliary look complex image respectively through the positive frequency spectrum and the negative frequency spectrum, conducting direction rectification on the first auxiliary look complex image and the second auxiliary look complex image, obtaining a first auxiliary look amplitude image and a second auxiliary look amplitude image through the first auxiliary look complex image and the second auxiliary look complex image which receives the direction rectification, conducting amplitude comparison on corresponding pixels of the first auxiliary look amplitude image and the second auxiliary look amplitude image. The pixel position corresponds to a movable target if the amplitude ratio is larger than the set detection threshold, otherwise, the pixel position corresponds to the clutter background, so that the movable target detection result can be obtained. The method can effectively restrain clutter and detect ground low speed motion targets.

A method of scaling soft symbols of an uplink E-DCH is provided, where the E-DCH is received from a user in a network for processing in a base station receiver in the network employing a log-MAP turbo decoding algorithm to process the E-DCH. The E-DCH includes an E-DPDCH from which the soft symbols are generated at the base station receiver, and an E-DPCCH used to transmit control information associated with the E-DPDCH, which along with configuration information from a radio network controller (RNC) of the network enables the base station receiver to determine a reference amplitude ratio linked to the actual power offset of the E-DPDCH from the legacy DPCCH. In the method, an estimated E-DPDCH to DPCCH amplitude ratio that represents a scaling factor for the soft symbols is determined, and the soft symbols are scaled by the scaling factor to enable the soft symbols to be processed by the log-MAP turbo decoding algorithm in the base station receiver.