853 results about "Pulse frequency" patented technology

A one-piece cylindrical bandstop filter for medical lead systems incorporates parallel capacitive and inductive elements in a compact cylindrical configuration. The compact cylindrical configuration of the bandstop filter does not add significantly to the size or weight of the medical lead system. Preferably, the bandstop filters are of biocompatible materials or hermetically sealed in biocompatible containers. The parallel capacitive and inductive elements are placed in series with the medical lead system, and are selected so as to resonate at one or more selected frequencies, typically MRI pulsed frequencies.

The invention relates to a method for automatic inspection of the surface 20 of a moving object, in which a region on the object's surface is illuminated from at least two different illumination directions 13-15. The object's illuminated surface region is imaged with a camera to provide image information for analysis. The light sources in the different illumination directions 13-15 are pulsed to illuminate the object's surface region at different times, the pulsing frequency being >1 kHz The object's illuminated surface region is imaged as lines with a line scan camera 21 in sync with the above pulsing. The invention also relates to an arrangement for inspecting the surface 20 of a moving object, the arrangement comprising at least two light sources 10-12 in at least two different illumination directions 13-15 for illuminating the surface region of the object under inspection; a camera for imaging the object's surface region; and an image analyzer for analyzing the image information acquired from the object's surface 20 by imaging. The light sources 10-12 illuminate the object's surface 20 from the different illumination directions 13-15 at different times, and the camera is a line scan camera 21. The arrangement further comprises a timing controller 18 for synchronous pulsing of the light sources 10-12 and the at least one line scan camera 21, the pulsing frequency of the light sources 10-12 being >1 kHz.

A method for precise working of material, particularly organic tissue, comprises the step of providing laser pulses with a pulse length between 50 fs and 1 ps and with a pulse frequency from 50 kHz to 1 MHz and with a wavelength between 600 and 2000 nm for acting on the material to be worked. Apparatus, in accordance with the invention, for precise working of material, particularly organic tissue comprising a pulsed laser, wherein the laser has a pulse length between 50 fs and 1 ps and with a pulse frequency of from 50 kHz to 1 MHz is also described.

Interference classification with minimal or incomplete information. Receivers in access points and in other network devices on a wireless digital network may be switched to a spectrum monitor mode in which they provide amplitude-versus-frequency information for a chosen part of the spectrum. This may be performed by performing a FFT or similar transform on the signals from the receiver. Receivers are calibrated with known interference sources in controlled environments to determine peaks, pulse frequency, bandwidth, and other identifying parameters of the interference source in best and worst case conditions. These calibrated values are used for matching interference signatures. Calibration is also performed using partial signatures collected over a short period in the order of microseconds. These partial signals may be used to detect interferers while scanning. Another aspect of the invention is to record the variation of noise floor in the presence of interference sources. Multiple interference sources may be detected. While data collection is performed in one or more APs, classification may be performed in the

AP or on other systems associated with the network collecting and processing spectrum information from one or more APs.

Apparatus and methods for treating obesity using chronic cervical vagal nerve stimulation (cVNS) of the left vagus trunk are disclosed. Four men and ten women, average age 46 years (SD±10) were treated with output current typically 0.75 mA, pulse frequency 30 Hz and width 250 or 500 μs, and duty cycle of 30 s power per five minutes. Mean intake weight was 91 kg (SD±27, range 46 to 137 kg) with body mass index (BMI) 43 kg/m² (SD±5, range 18 to 49 kg/mn²). After 6-12 months, obese patients had marked weight loss while normal weights were maintained. Decrease in BMI was consistently proportional to initial BMI. Average weight loss at one year was 7 kg (SD±3, range −6 to +24) with mean drop in BMI of 2 kg/m² (SD±3, range −2 to +8)k. All patients denied any major dieting or exercise.

One or more inductors and one or more capacitors are physically disposed relative to one another in series and are electrically connected to one another in parallel to form a bandstop filter. Chip inductors and chip capacitors having spaced apart conductive terminals are physically arranged in end-to-end abutting relation to minimize electrical potential between adjacent conductive terminals. The bandstop filter may be hermetically sealed within a biocompatible container for use with an implantable lead or electrode of a medical device. The values of the inductors and the capacitors are selected such that the bandstop filter is resonant at one or more selected frequencies, such as an MRI pulsed frequency.

A method and apparatus for thermal treatment of tissue by irradiating the skin with electromagnetic energy is disclosed. Sources of electromagnetic energy include radio frequency (RF) generators, lasers, and flashlamps. The apparatus includes either a positional sensor or a dosage evaluation sensor, or both types of sensors. These sensors provide feedback to a controller. The controller may control the electromagnetic source parameters, the electromagnetic source activation, and/or the sensor measurement parameters. An additional scanning delivery unit may be operably coupled to the controller or to the sensors to provide a controlled distribution of electromagnetic energy to the target region of the skin. The use of positional measurement sensors and dosage evaluation sensors permits the controller to automatically determine the proper electromagnetic source parameters including, for example, pulse timing and pulse frequency.

A device for treating diseases and chronic ailments of the human body by inducing powerful, short duration magnetic pulses in close proximity to a region of the body. The device comprises an electromagnetic coil or inductor energized by an electric circuit and a power source, pulsed between 1 and 25 pulses per second for therapeutic means and use as an alternative medical treatment. The device comprises an electric circuit that transmits pulsating current to an induction coil placed within a handheld stylus device for introducing a high energy, pulsed magnetic field to target locations on the body. The stylus is placed against the human body and introduces the pulsating magnetic field into and through body tissue, bone and the bloodstream. The stylus is completely noninvasive and provides a means to direct magnetic energy to a specific part of the body. The device is an advancement in the art, and one that provides increased magnetic energy and pulse frequency without the use of Xenon flash tubes that consume large quantities of power.

A laser beam source and an operating method thereof is provided for a directional infrared countermeasures (DIRCM) weapon system for defensively countering guided missiles having infrared seeking heads, by directing an infrared laser beam at the guided missile so as to disorient, saturate, or irreversibly destroy the IR detectors and circuitry arranged in the target seeking head. The power, pulse frequency and spectral composition of the laser beam is adjustable and selectable as required to adapt to any particular defensive engagement. To achieve this, the laser beam source comprises an Nd:YAG pumping laser and an optical parametric oscillator including an oscillator crystal arranged in a resonator cavity. The crystal includes a plurality of different periodically polarized crystal zones having different lattice constants. The adjacent zones can be grouped together into selectable crystal zone groups. The beam cross-section of the pumping laser beam corresponds to the cross-section of a single crystal zone or of a crystal zone group encompassing plural zones. The crystal is arranged on a slide table that is slidably displaceable by a servomotor, to move a selected crystal zone or group into the path of the pumping laser beam. Thereby the wavelength components and the relative intensities thereof of the output laser beam can easily be selectively adjusted.

Driving of a pulse motor is controlled in such a manner that a rotating body driven by the pulse motor rotates at a uniform angular velocity. Angular displacement of the rotating body is detected, a difference between a detection value of the angular displacement and a target value of angular displacement set in advance is calculated, and a drive pulse frequency of a drive pulse signal to be used for driving the pulse motor is calculated based on the difference and a reference drive pulse frequency. Whether the difference is added to the reference drive pulse can be selected.

A frequency jittering control circuit for a PFM power supply includes a pulse frequency modulator to generate a frequency jittering control signal to switch a power switch to generate an output voltage. The frequency jittering control circuit jitters an input signal or an on-time or off-time of the pulse frequency modulator to jitter the switching frequency of the power switch to thereby improve EMI issue.

A method and a device for airborne laser scanning flying height change real-time compensation can eliminate adverse effect of flying height change to a laser scanning point cloud distribution area and cloud density of a laser scanning point. When the flying height of an airborne platform is changed, a flying height change value is acquired by a global position system(GPS)/ inertial navigation system(INS)integrated measurement device, the value of a scan field angle which can keep the width of a scanning stripe unchanged and the value of a laser pulse frequency which can keep the laser scanning point cloud density unchanged are calculated in a flying height compensation controller. A rotating prism photoelectric shaft angle encoder measures and obtains a real time rotating angle of a rotating prism and offers the real time rotating angle of the rotating prism to the flying height compensation controller, a square signal which is identical with an expect laser pulse frequency value is outputted only within a scope of the required scan field angle and offered to a laser pulse transmitter, thus a laser transmitter can launch a laser pulse of the corresponding frequency. By using the compensation method, the flying height change of the airborne platform can not affect the laser scanning point cloud distribution area and cloud density of a laser scanning point permanently.

An anti-plugging oscillating shear valve system for generating pressure fluctuations in a flowing drilling fluid comprising a stationary stator and an oscillating rotor, both with axial flow passages. The rotor oscillates in close proximity to the stator, at least partially blocking the flow through the stator and generating oscillating pressure pulses. The rotor passes through two zero speed positions during each cycle, facilitating rapid changes in signal phase, frequency, and/or amplitude facilitating enhanced data encoding. The rotor is driven by a electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. In one embodiment, a torsional spring is attached to the motor and the resulting spring mass system is designed to be near resonance at the desired pulse frequency. The torsion spring may be a solid torsion bar or a magnetic spring.

A direct digital synthesizer (DDS) drives a receive sampling gate at a frequency that is offset from a transmit pulse frequency to produce an expanded time sampled echo signal. The frequency offset generates a smoothly slipping phase between realtime received echoes and the sampling gate that stroboscopically expands the apparent time of the sampled echoes with an exemplary factor of 1-million and a range accuracy of 1-centimeter. The flexibility and repeatability of the digitally synthesized timing system is a quantum leap over analog prior art. The rock solid stability of the DDS allows further accuracy improvement via an error correction table.

The invention discloses a method for controlling brittleness Laves phases in the laser additive manufacturing process of a nickel-based high-temperature alloy. Firstly, laser additive manufacturing technological parameters are initially optimized, and a cooling medium is adopted for cooling the bottom of a base material; then a laser modulation technology is used for modulating a laser source, and superior laser modulation parameters are obtained, wherein the peak power of square waves ranges from 600 W to 1000 W, the pulse frequency of the square waves ranges from 10 HZ to 100 HZ, and the duty ratio of the square waves ranges from 0.3 to 0.6; the wave peak power of sawtooth waves ranges from 600 W to 1200 W, the wave trough power of the sawtooth waves is 0 W, and the pulse frequency of the sawtooth waves ranges from 10 HZ to 100 HZ; and according to the parameters of sine waves, the wave peak power ranges from 600 W to 1000 W, the wave trough is 0 W, and the pulse frequency ranges from 10 HZ to 100 HZ; and finally, laser additive manufacturing and forming of the nickel-based high-temperature alloy are conducted according to the above parameters, and a formed part with all small equiaxial dendritic structures and small discrete Laves phases is obtained. By means of the laser modulation method, the precipitation behavior of the Laves phases in the laser additive manufacturing process of the nickel-based high-temperature alloy can be effectively controlled, the cracking sensibility of parts obtained through laser additive manufacturing is reduced, and the microstructure is improved.

A magnetic resonance system, comprising at least one SQUID, configured to receive a radio frequency electromagnetic signal, in a circuit configured to produce a pulsatile output having a minimum pulse frequency of at least 1 GHz which is analyzed in a processor with respect to a timebase, to generate a digital signal representing magnetic resonance information. The processor may comprise at least one rapid single flux quantum circuit. The magnetic resonance information may be image information. A plurality of SQUIDs may be provided, fed by a plurality of antennas in a spatial array, to provide parallel data acquisition. A broadband excitation may be provided to address a range of voxels per excitation cycle. The processor may digitally compensate for magnetic field inhomogeneities.

The invention discloses a method for preparing an antisepsis and antiwear ceramics coating layer on the surface of alloy through microarc oxidation. The method includes three steps of collocating electrolyte, arranging power electric parameters and microarc oxidation treatment; wherein, the component concentrations of the electrolyte are sodium silicate of 20 to 100g/L, sodium hydroxide of 5 to 10g/L and organic amine additive of 5 to 15ml/L; the current density of unit area is 50 to 100A/centiare; the pulse frequency is 100 to 700Hz; the pulse dutyfactor is 20 to 90 percent; the temperature of the electrolyte in the microarc oxidation treatment is not higher than 45 DEG C. The method needs lower unit power density and has fast film forming speed to prepare the ceramics coating layer on the surface of aluminum and magnesium alloys; the method adopts 100KVA power which can treat at least 2 centiares of the surface area of the aluminum alloy for one time; the growing speed of the ceramics coating layer can reach 1 to 1.5 micron/min. The formed ceramics coating layer is uniform and compact; the rigidity of the aluminum alloy can reach 1200 to 1300Hv.

The invention is directed to an arrangement for generating extreme ultraviolet radiation from a plasma generated by an energy beam with high conversion efficiency, particularly for application in radiation sources for EUV lithography. It is the object of the invention to find a novel possibility for generating EUV radiation by means of a plasma induced by an energy beam that permits a more efficient conversion of the energy radiation into EUV radiation in the wavelength region of 13.5 nm and ensures a long lifetime of the optical components and the injection device. According to the invention, this object is met by using a mixture of particles with a carrier gas and the target feed device has a gas liquefaction chamber, wherein the target material is supplied to the injection unit as a mixture of solid particles in liquefied carrier gas, and a droplet generator is provided for generating a defined droplet size and series of droplets, wherein means which are controllable in a frequency-dependent manner and which are triggered by the pulse frequency of the energy beam are connected to the injection unit for the series of droplets.

The invention relates to a method and apparatus for processing substrates, such as glass and semiconductor wafers. The method comprises directing to the substrate from a laser source a plurality of sequential focused laser pulses having a predetermined duration, pulsing frequency and focal spot diameter, the pulses being capable of locally melting the substrate, and moving the laser source and the substrate with respect to each other at a predetermined moving velocity so that a structurally modified zone is formed to the substrate. According to the invention, the pulse duration is in the range of 20-100 ps, pulsing frequency at least 1 MHz and moving velocity adjusted such that the distance between successive pulses is less than ⅕ of the diameter of the focal spot. The invention can be utilized, for example, for efficient dicing, scribing and welding of materials which are normally transparent.

The invention discloses a system for measuring network clock synchronization, is applied to the communication and smart grid fields. The system comprises a pulse countering module, a time counting module, a clock reference module and a synchronization calculation module, wherein the pulse counting module calculates pulse frequency difference between a master clock and a slave clock, the master clock is synchronous with a remote reference clock, and the slave clock is synchronous with the master clock through a network so as to be synchronous with the remote reference clock; the time counting module measures the time difference between the master clock and the slave clock; the clock reference module inputs a reference clock, and the reference clock is synchronous with the remote reference clock; and the synchronization calculating module is used for calculating network clock synchronization parameters according to the time difference and the pulse frequency difference and outputting time synchronization parameters. The system disclosed by the invention can be used for evaluating the clock frequency synchronization accuracy and the time synchronization accuracy which can be reached at each node by an IEEE1588PTP (Institute of Electrical and Electronics Engineers 1588 Peer To Peer) clock synchronous network, and important reference data is provided for clock synchronization network optimization, and performance prediction on application and equipment depending on clock synchronization.

What is disclosed is a system and method for recovering a patient's cardiac pulse rate from a sequence of video images recording of that patient. In one embodiment, a reference signal of a particular frequency is generated at predetermined frequency intervals and a constrained source separation is performed on the source data to obtain an estimation of the source signal intended to be recovered. The reference signal is updated and constrained source separation is again performed. These operations are repeated for all frequencies of the reference signal. The frequency at which a minimum error is achieved is determined to be the subject's recovered cardiac pulse frequency. In such a manner, the source signal is extracted and recovered reliably from captured multi-channel RGB signals or multispectral signals. The teachings hereof find their uses in a variety of medical solutions including various military, security and telemedicine applications. Various embodiments are disclosed.

The invention provides a tissue engineering nerve graft based on a biological printing technology and a preparation method thereof. The tissue engineering nerve graft comprises an outer tube and a tube inside scaffolds, wherein trophic factors and/or cells can cover the inner surface and the outer surface. A high-fidelity printing operation is performed according to the actual nerve shape demand by utilizing the biological printing technology, a polymer solution is printed into the specified nerve graft in a three-dimensional way by using an ink-jet printer by adjusting the sizes and the quantity of the jet nozzles of the ink-jet printer, the distances from the jet nozzles to a bottom layer and the pulse frequency of a supercharger and writing a control program of specific printing, and the specified nerve graft is applied to treatment of peripheral nerve defect and spinal cord injury.

A computerized wagering game system has a gaming module comprising a processor and gaming code which is operable when executed on the processor to conduct a wagering game on which monetary value can be wagered, and an audio module comprising a digital audio amplifier, the audio module operable to receive digital audio signals and to amplify them to produce an amplified digital audio signal. In some embodiments, the digital amplifier produces a pulse width modulated amplified digital audio signal, which is in further embodiments also pulse frequency modulated.

An electromagnetic radiation treatment regime includes identifying a target area of a patient. In one embodiment, the target area is the vagus nerve. An electromagnetic radiation source, for example, a low frequency and/or radio frequency electromagnetic radiation source, is selected, along with treatment session parameters, such as, pulse frequency, pulse duration, electrical current, magnetic flux density, and/or treatment session exposure time. An amount of electromagnetic radiation is applied to the target area, and a response to the electromagnetic radiation in the target area is measured. Based on an evaluation of the measured response, the treatment parameters may be modified for one or more subsequent electromagnetic radiation treatment session.

The invention discloses a quasi-continuous laser metal 3D printing method capable of realizing regulation of nickel base alloy crystallographic texture. Laser output is set as a quasi-continuous lasermode, and then a laser metal 3D printing technical window is preliminarily optimized. The temperature field of a molten bath under the preliminarily optimized parameter is calculated by using a finite element heat transfer model; the temperature gradient G and the cooling rate xi of the moving boundary of the molten bath during closing of laser in a single pulse period are extracted, and the growth length L of a single pulse internal columnar dendrite is worked out according to a structure growth theoretical model; the laser parameter is optimized according to the matching rule that the ratioof the scanning speed V to pulse frequency f is 0.5-0.8L, and finally 3D printing forming is conducted according to the optimized parameter, so that a formed part with the consistent crystallographicorientation height is obtained. By regulating the heat source output mode, an effective remelting mechanism for mixed crystal or isometric crystal is introduced in the scanning direction, all columnar dendrite growth is obtained, and the consistency of grain orientation is remarkably improved.

Disclosed a nitric oxide supply system of respiratory failure rescue device belongs to the disease therapy apparatus, which avoids the high concentration NO gas cylinder, the high concentration dry gas cylinder and the nitrogen-oxygen mixed gas cylinder. The invention uses the air as raw material for attaining the NO at any time without the storage and via controlling the electric discharge condition, generates NO gas at most with least NO2 harmful gas to attain the low ratio of NO2/NO. While the concentration of NO ranges from 0-200 ppm in the pulse frequency of 1-90 Hz. The invention comprises an air pump connected in series to the gas passage, a clean-dry air generating device, a flow counter, a pulse generate and control circuit, a arc discharge reactor, a particle filter film, a NO2 catalytic reduction conversion apparatus, a cooler, a particle filter film, a selective absorber and a gas monitor.

In a multi-phase power converter using a phase-locked loop (PLL) arrangement for interleaving of pulse frequency modulated (PFM) pulses of the respective phases, improved transient response, improved stability of high bandwidth output voltage feedback loop, guaranteed stability of the PLL loop and avoidance of jittering and phase cancellation issues are achieved by anchoring the bandwidth at the frequency of peak phase margin. This methodology is applicable to multi-phase power conveners of any number of phases and any known or foreseeable topology for individual phases and is not only applicable to power converters operating under constant on-time control, but is extendable to ramp pulse modulation (RPM) control and hysteresis control. Interleaving of pulses from all phases is simplified through use of phase managers with a reduced number of PLLS using hybrid interleaving arrangements that do not exhibit jittering even when ripple is completely canceled.

A heterodyne detection technique for highly localized IR spectroscopy based on an AFM. A pulsed IR source illuminates a sample and causes contact resonance of an AFM probe, which is a function of localized absorption. The probe is operated in intermittent contact mode and is therefore oscillated at a resonance frequency. A secondary oscillation is mixed in to the probe oscillation such that the sum of the secondary oscillation and the IR source pulse frequency is near another harmonic of the probe. A mixing effect causes measurable probe response at the other harmonic allowing data to be taken away from the pulse frequency, resulting in background effect rejection and improved spatial resolution.

Decrease in a voltage supplied to a load caused by load fluctuations is minimized. A pulse frequency modulated signal generating unit 13 outputs a signal PFMOUT having a pulse frequency modulated according to a voltage supplied to the load 20. A pulse width modulated signal generating unit 14 outputs a signal PWMOUT having a pulse width modulated according to a voltage supplied to the load 20. In a state where the signal PFMOUT is selected, a selection unit 17 refers to a determination result of a frequency determining unit 15 and selects the signal PWMOUT as on/off signal for a semiconductor switch 11 when a low-level period in one cycle of the signal PFMOUT is not more than a predetermined time period. In a state where the signal PWMOUT is selected, the selection unit 17 selects the signal PFMOUT as on/off signal for the semiconductor switch 11 when a voltage determining unit 16 detects that a DC voltage (VOUT) at the load 20 exceeds a predetermined voltage.

A direct digital frequency synthesizer having a multi-modulus divider, a numerically controlled oscillator and a programmable delay generator. The multi-modulus divider receives an input clock having an input pulse frequency f_osc and outputs some integer fraction of those pulses at an instantaneous frequency f_Vp that is some integer fraction (1/P) of the input frequency. The multi-modulus divider selects between at least two ratios of P (1/P or 1/P+1) in response to a signal from the numerically controlled oscillator. The numerically controlled oscillator receives a value which is the accumulator increment (i.e. the number of divided pulse edges) required before an overflow occurs that causes the multi-modulus divider to change divider ratios in response to receiving an overflow signal. The numerically controlled oscillator also outputs both the overflow signal and a delay signal to the delay generator. The delay signal contains phase-dithering noise that is induced by input into the accumulator of an increment generated from a pseudo-random noise generator. The delay signal further controls the frequency of the multi-modulus divider output signal (V_p) to provide an output signal (V_D) with an f_OUT that has improved phase and timing jitter performance over prior art direct digital frequency synthesizer architectures.