420 results about "Pulse transmission" patented technology

An ultra wideband (UWB) or short-pulse transmission system that enables precise tracking or geolocation of a target over distances of several kilometers. The system includes a set of N (where N>2) untethered UWB transceivers located at fixed positions, an untethered UWB receiver at the target, and a processor at the target for resolving time-of-flight measurement ambiguities of received pulses to determine precise geolocation by solving a set of equations according to time-of-flight measurements and surveyed positions of N-1 transceivers. To eliminate a clock distribution system, self-synchronizing of pulse timing is achieved by generating a start pulse at one of the untethered transceivers. Alternatively, a timing source may be provided by a GPS or other timing generator at the transceivers in order to synchronize emissions of their pulses.

An apparatus and methods for performing a circulatory measurement on an extremity, such as a hand, of a subject. The circulatory measurement results in the derivation of an output circulatory metric that may encompass blood pressure or various other circulatory metrics. An indicator of an input circulatory metric at a locus on the extremity is measured, such as a pulse transit time. To determine the pulse transit time, a first plethysmographic signal may be obtained at a first position on the extremity, while a second plethysmographic signal may be obtained at a second position on the extremity of the subject. A transit time characterizing a circulatory pressure wave is calculated based on the first and second plethysmographic signals, leading to derivation of a wave speed. A calibration is then applied to provide the circulatory measurement based at least on the derived wave speed and a measured indicator of a hydrostatic component of blood pressure. Calibration is provided, in certain described embodiments, by derivation of two calibration parameters, a gain and a pulse transit time at zero pressure. Methods for deriving the calibration parameters include performing measurements under distinct hydrostatic pressure conditions, and based upon a measured derivative with respect to pressure of the pulse wave velocity.

An ultra-wideband pulse modulation system and method is provided. One method of the present invention includes transforming data into a ternary data set with data being represented with states of zero, positive one and negative one. The modulation and pulse transmission method of the present invention enables the simultaneous coexistence of the ultra-wideband pulses with conventional carrier-wave signals. The present invention may be used in wireless and wired communication networks such as hybrid fiber-coax networks. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

An apparatus and methods for adaptive and autonomous calibration of pulse transit time measurements to obtain arterial blood pressure using arterial pressure variation. The apparatus and methods give pulse transit time (PTT) devices an ability to self-calibrate. The methods apply a distributed model with lumped parameters, and may be implemented, for example, using pulse transit time measurements derived from a wearable photoplethysmograph (PPG) sensor architecture with an intervening pressurizing mechanism.

In conventional pulse compression processing, sidelobes from strong return signals may hide correlation peaks associated with weaker return signals. Example embodiments include methods of mitigating this near/far interference by weighting a received return signal or corresponding reference signal based the return signal's time of arrival, then performing pulse compression using the weighted signal to produce a correlation peak that is not hidden by sidelobes from another return. Multi-frequency processing can also be used to reduce the pulse width of the transmitted pulses and received return signals, thereby mitigating near/far interference by decreasing the overlap between signals from nearby targets. Weighting can be combined with multi-frequency pulse transmission and reception to further enhance the fidelity of the processed correlation peak. Weighting and multi-frequency processing also enable higher duty cycles than are possible with conventional pulse compression radars.

The present invention refers to a circuit for current and voltage control in a switching power supply controlled on the primary side, comprising a transformer with a primary-sided and a secondary-sided main winding, wherein energy pulses are transmitted from the primary side to the secondary side. Furthermore, a primary-sided switch switches on an off a primary current through the primary-sided main winding. A primary current comparator determines a switch-off time of the switch depending on the primary current. In order to reduce the load dependency of the output voltage, the control variable is variably amplified by a feedback network and additionally the control variable is reduced depending on the output load through a correction network. To reduce noise generated by the energy-rich pulse transmissions at low frequencies and the waviness of the output voltage, the control variable is fed back to the primary current comparator so that the duration during which the primary current flows through the primary-sided main winding is reduced differently. To reduce the susceptance to failure when determining the switch-on time, a comparator voltage depending on the control variable is generated as reference.

A health management apparatus includes a first pulse wave measuring unit that measures a first pulse wave of a subject during sleep; and a second pulse wave measuring unit that measures a second pulse wave of the subject during sleep. The second pulse wave is different from the first pulse wave in propagation time from the heart of the subject. The apparatus also includes a pulse transmission time calculating unit that calculates a pulse transmission time indicating a time difference between the first and second pulse waves; a pulse interval calculating unit that calculates a pulse interval based on at least one of the first and second pulse waves; an autonomic nerve index calculating unit that calculates an autonomic nerve index based on the pulse transmission time and the pulse interval; and a health determining unit that determines the condition of health of the subject based on the autonomic nerve index.

An electrosurgical system is disclosed. The electrosurgical system includes an electrosurgical instrument configured to generate a first and second data streams and a transmission circuit configured to convert the first and second data streams into a pulsed transmission signal. The first signal property of the transmission signal is representative of the first data stream and the second signal property of the transmission signal is representative of the second data stream. The transmission circuit is further configured to process the transmission signal to decode the first signal property into the first data stream and the second signal property into the second data stream.

A medical ultrasound imaging pulse transmission method transmits at least three pulses, including at least two pulses of different amplitude and at least two pulses of differing phase. The larger-amplitude pulse is transmitted with a larger aperture and the smaller-amplitude pulses are transmitted with respective smaller subapertures. The subapertures are arranged such that the sum of the subapertures used for the smaller-amplitude pulses is equal to the aperture used for the larger-amplitude pulse. In this way, pulses of differing amplitudes are obtained without varying the power level of individual transducer elements, and precise control over pulse amplitude is provided.

Apparatus, method, and software for electrocardiogram-assisted non-invasive arterial blood pressure d stiffness measurement is disclosed including brachial cuff with flexible electrodes, control box with rigid electrodes, and associated hardware/software. Cuff is wrapped around upper arm while electrodes on device are touched with fingers of other hand. Device acquires simultaneous ECG/oscillometric data during cuff deflation. Processing unit determines ECG R-peak positions to isolate arterial pulses and calculate pulse transit time. Change in pulse amplitude as function of cuff pressure is used for constructing oscillometric envelope and calculating blood pressure using empirical coefficients. Change in pulse transit time as function of cuff pressure is used independently for constructing pulse transit time envelopes and finding blood pressure with/without empirical coefficients. Fusion algorithm combines results for robust blood pressure and vessel stiffness evaluation. Device sends physiological information to personal computer/smartphone wirelessly, for further analysis. Computer/smartphone transmits information to third party for patient management.

The invention discloses an obstacle information acquisition method, a laser pulse transmission method and a laser pulse transmission device. The laser pulse transmission method comprises the steps of:transmitting a first laser pulse at a first moment; and transmitting a second laser pulse at a second moment, wherein peak power of the first laser pulse is less than that of the second laser pulse,a time interval between the second moment and the first moment is longer than T, and the T is a time length from a moment that the laser pulse is transmitted to a moment that a laser pulse echo signalreflected by a near-field obstacle is received. By adopting the obstacle information acquisition method, the laser pulse transmission method and the laser pulse transmission device, since the power of the first laser pulse is small, stray light cannot cause voltage saturation of a detection circuit, thus the first laser pulse reflected by the near-field obstacle can be detected, thereby effectively solving the problem of measurement blind area of the near-field obstacle caused by the stray light inside a laser radar at low cost; and since the signal intensity of the second laser pulse is high, normal detection of a far-field obstacle can be guaranteed.

The invention discloses a laser ranging system and method based on waveform time domain matching. The laser ranging system includes software and hardware, and is characterized in that an FPGA sends a control signal to a laser narrow pulse transmission circuit; the transmission circuit controls a laser transmitter to transmit pulse laser; an object reflection laser beam transmits an echo wave optical signal to a photo-translating system through an optical alignment system and a spike filter; the photo-translating system converts an optical signal into an echo wave electric signal, and then the echo wave electric signal becomes a fixed amplitude echo wave analog signal through an analog amplification circuit and enters a signal integration system; when the FPGA transmits a control signal to control laser transmission, at the same time, the FPGA transmits a time reference pulse to the signal integration system; the signal integration system integrates the time reference pulse and the fixed amplitude echo wave analog signal into an echo wave signal with time reference; the echo wave signal with time reference is quantified as a digital detection signal in an ADC sampling system, and then is transmitted to the FPGA for data analysis; and a ranging result is output from the FPGA by means of analysis of waveform time domain matching of the software part.

The invention provides a non-sinusoidal time domain orthogonal modulation method which is non-sinusoidal wave modulation based on orthogonal pulse transmission information. Signals to be transmitted are modulated onto a time domain orthogonal impulse group and impulse parameters are regulated to realize the spectrum shifting and the spectrum control of the modulated signals. The modulated signals are band-limited signals, the spectrum characteristic of which can be controlled. The modulated signals can be applied to any communication frequency band. Communication with relative large bandwidth or broadband communication can be realized, and communication with relative small bandwidth or narrowband communication can be realized. In spectrum management, the method can be compatible with an existing frequency band-division and channel-division communication mode of a relative small bandwidth communication system. And the frequency band utilization rate of the system can infinitely approach Nyquist rate with the increase of orthogonal impulses.

In a PWM communication system, a sensor unit transmits as reference pulses transmission signals, which exhibit duty cycles of 100% and 0%, respectively, prior to transmission of a transmission signal, which has data items compressed thereinto by a signal processing circuit. An input capture circuit of an ECU measures the duty time and the PWM cycle of the transmission signal according to a timer clock of a timer circuit. A signal processing circuit of the ECU produces a duty cycle correction factor k based on the measured duty times and PWM cycles of the reference pulses, produces receiving data based on the duty time and the PWM cycle of the transmission signal, and the duty cycle correction factor, and separates the receiving data into sensor output values of a pressure sensor and a temperature sensor.

A terrain aided navigation using multi-channel monopulse radar imaging to provide a navigation position update. The monopulse radar transmits a single RF pulse transmission or multiple quick RF pulse train bursts to generate a monopulse radar image that can be correlated with a digital terrain segment to provide navigation updates when requested. The radar has monopulse and off-axis capability that allows for selection of a terrain segment within the radar's search area that will provide a good terrain correlation. The radar measurements are made on a range/Doppler cell-by-cell basis that includes angle information. The cells in the range/Doppler map corresponding to the antenna main beam return are converted into a high resolution (x,y,z) image and correlated to the selected terrain segment in the data base reference frame to provide an updated navigation position estimate.

A reset pulse generating section applies the total of voltages of a positive voltage source and two constant-voltage sources from a high side ramp wave generating section to a high side scan switching device as the upper limit of a reset voltage pulse, and applies the ground potential from a low side ramp wave generating section to a low side scan switching device as the lower limit of the reset voltage pulse. A sustaining pulse generating section applies the upper and lower limits of a sustaining voltage pulse through a common sustaining pulse transmission path to the low side scan switching device.

A radar device includes: a frequency modulating unit for modulating a frequency of a transmission signal by a triangular wave; a transmitting unit for pulsing the frequency modulated transmission signal to transmit the pulsed transmission signal as a transmission pulse; a receiving unit for generating a beat signal based on a frequency difference between a frequency modulated transmission signal and a reflected received pulse; a range gate setting unit for setting a range gate that determines a sampling timing of the received pulse based on a transmitting timing of the transmission pulse; a sampling unit for sampling the beat signal in each of range gates; a distance and relative velocity calculating unit for calculating a distance to a target and a relative velocity based on the sampled beat signal; and a control unit for controlling a transmission pulse width and a range gate width depending on a subject vehicle velocity.

By pulsing transmission radio waves of continuous wave radar, clutter components included in a reception signal are suppressed.

In a radar system that emits into space pulsed transmission radio waves being generated based on a frequency-modulated reference continuous waveform, acquires a reception signal by receiving the pulsed transmission radio waves reflected from an external object, and computes distance thereto and velocity thereof from the frequency of a beat signal obtained by mixing the acquired reception signal with the reference continuous waveform, the radar system includes a frequency-band selector 19 for classifying, on the basis of a spectral spread corresponding to the pulse width of the pulsed transmission radio waves, frequency components of the beat signal, and a distance/velocity calculator 20 for computing, on the basis of the classified results from the frequency-band selector 19, relative distance to and velocity of a moving object, or relative distance to a stationary object.