33 results about "Continuous wave doppler" patented technology

A handheld ultrasound instrument is disclosed having enhanced diagnostic modes including pulse/continuous wave Doppler, time-motion analysis, spectral analysis and tissue harmonic imaging. An external electrocardiograph (ECG) recording unit is also disclosed. The ECG unit is adaptable to be used with the handheld ultrasound instrument to provide for ECG monitoring while performing an ultrasound scan in B-mode, Doppler, color Doppler, M-mode, and CW/PW mode. The enhanced handheld ultrasound instrument further includes a security mechanism allowing any combination of the diagnostic modes to be enabled by the manufacturer, and later to enable or disable any one or group of the diagnostic modes. The invention also discloses a method for a manufacturer to maintain a database of handheld ultrasound instrument capabilities after the instruments enter the stream of commerce.

A method of blood flow monitoring for a patient, the method comprising the steps of: a) receiving a first signal indicative of the real time cardiac output for the patient; b) processing the continuous wave Doppler signal to provide an estimate of blood flow velocity as a function of time; c) receiving a pressure measurement indicative of the blood flow resistance through the patient; and d) calculating an Inotropy measure indicative of the potential and kinetic energy of the cardiac output of the patient.

The invention provides a heartbeat frequency detection algorithm of a non-contact vital sign detection system; the steps are: respectively doing bandpass filtering for I and Q two way signals outputted by a continuous wave doppler radar; using a center estimate algorithm to carry out useful dc component recovery; using a complete cluster experience modal decomposition algorithm to separate a heartbeat signal from a human body jitter signal, a breathing signal and environment interference noises; resolving a Hilbert marginal spectrum of each decomposition signal and doing peak value detection; finding out the Hilbert marginal spectrum corresponding to the heartbeat signal according to a marginal spectrum peak position and energy concentration degree close to the spectrum peak; obtaining heartbeat frequency information according to the spectrum peak position. The heartbeat frequency detection algorithm can effectively extract the heartbeat signal under unstable human body and large environment interference noises, thus obtaining accurate heartbeat frequency information, improving anti-interference property of the non-contact vital sign detection system, and satisfying heartbeat frequency detection accuracy demands of medical affairs personnel.

The invention relates to a poly-phase code radar signal waveform automatic identification method based on continuous wave Doppler (CWD) feature and belongs to the technical field of information countermeasures. According to the poly-phase code radar signal waveform automatic identification method based on CWD feature, a discrete sampling type Choi-Williams conversion is used as a basic tool, a CWD image of poly-phase code pulse compression radar signal is used as a feature extraction object, a Pseudo-Zernike moment of the CWD image, a target number of an image, a time position of a peak power in a CWD and a poly-phase code waveform symmetrical property are taken as features to identify a poly-phase code pulse compression radar waveform, and a neural network which is composed of 10 perceptrons and stops in advance of overall average is set up for automatic waveform identification. The poly-phase code radar signal waveform automatic identification method based on CWD feature has the advantages that the identification precision of the poly-phase code radar signal waveform is improved, the requirement of a signal to noise ratio is further decreased, and a new way can be developed for the design of radar signal identification and sorting by popularized and used in a poly-phase code continuous wave radar signal.

Continuous wave Doppler images in a data base comprising cardiac echo studies are processed to separate Doppler frames. The frames are pre-processed to extract envelope curves and their corner shape features. Shape patterns in Doppler images from echo studies of patients with known cardiac (valvular) diseases are employed to infer the similarity in valvular disease labels for purposes of automated clinical decision support. Specifically, similarity in appearance of Doppler images from the same disease class is modeled as a constrained non-rigid translation transform of velocity envelopes embedded in these images. Shape similarity between two Doppler images is then judged by recovering the alignment transform using a variant of dynamic shape warping. Since different diseases appear as characteristic shape patterns in Doppler images, measuring the similarity in the shape pattern conveyed within the velocity region of two Doppler images can infer the similarity in their diagnosis labels.

A Doppler blood flow monitoring system comprises a sensor cuff capable of being secured around an exterior surface of a patient's vessel, at least one transducer attached to the sensor cuff for generating signals into the vessel and for receiving said signals, and a transmitter in communication with the at least one transducer and capable of wirelessly transmitting an RF signal external to the patient's body. The system also comprises a receiver capable of receiving the RF signal from the transmitter and being capable of generating an audible sound or signal commensurate with detected flow. The system can take advantage of pulse wave or continuous wave Doppler technology.

The present invention provides an object motion identification method based on a multi-channel continuous-wave Doppler radar. One antenna is employed to emit electromagnetic wave to irradiate the surface of a motion object to be measured, the reflected signals are received by 2-3 receiving antennas and are subjected to down conversion to a base band, the arcsine algorithm is employed to demodulate the phase information without the phase ambiguity limitation, the distance changing information between each receiving antenna and the motion object is obtained, the track formula is employed to obtain the object's motion track, and the mode identification is performed on the basis of the motion track. The object motion identification method based on the multi-channel continuous-wave Doppler radar can avoid the phase ambiguity problem of the arc tangent class function, is applied to the work condition with high the sampling rate and work condition with the low sampling rate and keeps the accuracy in the condition with the low sampling rate. The mode identification is realized on the basis of location and tracking of the object to be measured. The identification accuracy is high, the anti-interference capability is high, the configuration is simple, and the cost is low, the most of the demodulated motions are the linear relation with no need for the complex data processing process, and the hardware resource is saved.

The invention relates to a liquid surface tension testing method based on mechanical vibration of a liquid droplet. The method specifically comprises the following steps: placing a hydrophobic substrate on a Doppler ultrasonic probe, and generating a liquid droplet on the hydrophobic substrate; vibrating a triggering device to freely vibrate the liquid droplet; converting free vibration of capillary waves on the surface of the liquid droplet into an ultrasonic Doppler frequency shift signal through the ultrasonic probe by using a non-focusing continuous wave Doppler method, and amplifying theultrasonic Doppler frequency shift signal; acquiring a free vibration characteristic diagram of the liquid droplet from the ultrasonic Doppler frequency shift signal by using a computer signal processing module, performing Fourier transform so as to obtain a vibration frequency characteristic diagram, analyzing the vibration frequency characteristic diagram, and reading frequency of a second harmonic generation peak; by taking the reciprocal of the mass of the liquid droplet as a transverse coordinate, and the square of the frequency of the second harmonic generation peak as a longitudinal coordinate, drawing diagrams, fitting straight lines, calculating a straight slope, and further calculating the surface tension of the liquid droplet. The method based on ultrasonic Doppler frequency shifting is capable of carrying out frequency measurement on ultrasonic signals, and has the advantages of reagent conservation, high performance cost ratios and portability.

The invention provides a method and apparatus for brain blood flow dynamic analysis, wherein a continuous wave Doppler blood flow rate waveform detecting module is utilized to carotid artery blood flow rate waveform and value, a pulse type supersonic carotid artery caliber detecting module is employed to detect the blood vessel diameter of the carotid artery, an arm type electronic blood pressure measurement module is used to obtain the human body blood pressure readings, and a simplified method is employed to calculate and analyze the cerebrovascular dynamic parameters. The invention can substantially improve the detecting and analyzing speed for the brain hemodynamic parameters, and greatly reduce the volume of the apparatus.

The present invention relates to a synthesis method of anolog wave beam in continuous wave Doppler module and its device. The described device includes a delay line LC network formed from inductor and capacitor and a resistor series-connected with the input end of the described delay line LC network for making magnitude compensation of inputted signal. The low-noise outputted multi-channel voltage signals are passed through the resistor series-connected with delay line to make signal magnitude compensation, after having been compensated said signals can be added into the LC network of delay line from different taps to make signal delay and signal accumulation, finally a wave beam synthesized signal can be outputted from output end of LC network.

The invention provides a non-contact accurate heartbeat detection method based on a Doppler radar. The method comprises the following steps: firstly, capturing frequency shift caused by weak chest displacement due to human heart beating by adopting the principle of continuous wave Doppler radar sign detection, namely transmitting T(t) to a subject through a transmission end by Radar, and modulating the phase of the T (t) signal by the chest wall movement x (t) of the subject, and capturing a reflected signal by a radar receiving end; secondly, passing the reflection signal through a front-end low-noise amplifier to obtain a baseband signal, demodulating the baseband signal by adopting an orthogonal mixer, and acquiring a chest wall signal through arc tangent demodulation and winding calculation after the reflection signal passes through a gain amplifier; and finally, passing the chest wall analog signal through an analog-to-digital converter to obtain a digital signal x (t), processing the digital signal x(t), separating and extracting a heart signal at a PC end through a Marithan algorithm and a matched filtering algorithm, and performing FTPR-TWV algorithm to obtain a heartbeat spectrum result.

A system for determining peripheral artery disease and method of use for determining the presence or absence of peripheral vascular disease and the severity of the disease in particular vascular segments. The System for determining peripheral artery disease and method of use includes a continuous wave Doppler transceiver which generates a digitized version of quadrature detected stereo audio and is coupleable to a waveform converter and processor. The waveform converter and processor provides filtering, time domain to frequency domain conversion, gain control, and statistical processing of the converted Doppler Stereo audio and is operationally coupled to a display for presenting results to a technician.

The invention provides a non-contact accurate heart rate detection method based on a 77GHz millimeter wave radar. The method comprises the steps that firstly, the frequency shift caused by weak thoracic cavity displacement caused by human body heart beating is captured by adopting the continuous wave Doppler radar sign detection principle, that is, the radar transmits T (t) to a subject through a transmitting end; then the phase of a T (t) signal is modulated by the chest wall movement x (t) of the subject, and a reflected signal is captured by a radar receiving end; secondly, the reflected signal passes through a low-noise amplifier at the front end to obtain a baseband signal, the baseband signal is demodulated by adopting an orthogonal mixer, and after the baseband signal passes through a gain amplifier, a chest wall signal can be obtained through arc tangent demodulation and winding calculation; finally, a chest wall analog signal passes through an analog-digital converter to obtain a digital signal x (t), and after the digital signal is processed, a heartbeat spectrum result is obtained through a heartbeat signal extraction algorithm VMD and a heartbeat spectrum estimation algorithm CZT at a PC end.

The invention discloses a signal processing method for calibrating direct-current offset of a single-frequency continuous-wave Doppler rada. The method comprises steps of determining the sampling frequency of a Doppler radar signal, and obtaining an IQ signal of the Doppler radar; performing down-sampling processing on the original data of the IQ signals of the Doppler radar in parallel to obtain radar data after down-sampling; performing signal real-time calibration based on an improved gradient descent algorithm on the down-sampled radar data, and when IQ direct current offset in a set error range is met, calibrating the radar data by using a Gramer-Schmidt orthogonalization formula to obtain calibrated arc data; phase information related to target motion being recovered from the calibrated IQ signal through an arc tangent demodulation algorithm; and obtaining the motion information of the target object according to the recovered phase information related to the target motion.

The invention discloses a Doppler radar low-speed measurement method. The Doppler radar low-speed measurement method is mainly used for solving the problem that an existing continuous wave Doppler radar cannot measure the speed when an aerial carrier hovers and flies at the low speed. According to the realization scheme, the Doppler radar low-speed measurement method comprises the steps that 1, anantenna cover of a Doppler radar is thickened, the selected position of the edge of the antenna cover of the Doppler radar is coated with a matched wave-absorbing material, and the standing-wave ratio of a microstrip antenna and radio frequency transceiver cross-linking interface is controlled; 2, the wave-absorbing material is pasted on the upper part of a radio frequency transceiver of the Doppler radar; 3, an amplifying circuit in an intermediate-frequency receiver of the Doppler radar is adjusted, and the intermediate-frequency receiver is optimized; 4, the intermediate-frequency receiveris subjected to AGC control in a mode of combining a PID algorithm and a linear algorithm; 5, the radar wave beam switching period is prolonged; and 6, a low-speed signal of the aerial carrier is measured under the clearance measuring environment through the Doppler radar improved by the steps 1-5. According to the Doppler radar low-speed measurement method, the low-speed measurement ability of the continuous wave Doppler radar is improved, and the Doppler radar low-speed measurement method can be used for stale speed measurement during hovering or low-speed flying of an aircraft.

A method of optimizing the performance of a cardiac prosthetic pacing device including monitoring, optionally transcutaneously or non-invasively, the flow output from the heart; optionally using a continuous wave Doppler ultrasound device, followed by adjusting the timing of said cardiac prosthetic pacing device so as to optimize the flow from the heart under operational condition, optionally including different pharmacological conditions.

The invention relates to a Doppler full-process quantitative analysis method and device, electronic equipment and a storage medium. The method comprises the following steps: receiving an input user interface image of Doppler spectrum imaging; determining a modal recognition result and a part recognition result of the user interface image; performing quantitative analysis of motion information on the user interface image according to the modal recognition result and the part recognition result; wherein the modal identification result comprises one of pulse wave Doppler, continuous wave Doppler and tissue Doppler. According to the embodiment of the invention, the accuracy of the target object motion information obtained through analysis can be improved, and the full-process automatic quantitative analysis of the Doppler image is realized.

A stand-alone continuous wave (CW) Doppler probe (CW probe) comprises a scanning end that has a single transmit element and a single receive element. A connector has probe connecting elements configured to interface with port connecting elements of a probe port that is provided on an ultrasound system. The port connecting elements are configured to connect with system channels of the ultrasound system. Transmit circuitry connects a first set of the probe connecting elements in parallel, and the transmit circuitry is interconnected with the transmit element. Receive circuitry connects a second set of the probe connecting elements in parallel, and the receive circuitry is interconnected with the receive element.

The invention discloses a double-frequency continuous wave Doppler radar circuit structure for inhibiting direct-current bias. A receiving antenna is connected with a fourth power divider; one path ofan output end of the fourth power divider is serially connected with a first band-pass filter, a first low-noise amplifier, a first mixer, a fifth band-pass filter and a first analog-to-digital converter, and the other path of the output end of the fourth power divider is serially connected with a second band-pass filter, a second low-noise amplifier, a second mixer, a sixth band-pass filter anda second analog-to-digital converter; the first analog-to-digital converter and the second analog-to-digital converter both are connected to a field-programmable gate array; a transmitting antenna isserially connected with a power amplifier and a second power divider; an input end of the second power divider is connected with a third power divider; a first power divider is connected to a first local oscillator, and one path of an output end of the first power divider is connected to the second power divider, and the other path of the output end of the first power divider is connected to the first mixer via a third band-pass filter; and the third power divider is connected to a second local oscillator, and one path of an output end of the third power divider is connected to the second power divider, and the other path of the output end of the third power divider is connected to the second mixer via the fourth band-pass filter.

An event-driven medical treatment data notification system is disclosed. Embodiments are directed to a treatment protocol for detecting Return of Spontaneous Circulation by employing a Doppler effect analysis on a signal transmitted at a patient's heart. A reflected signal is evaluated to determine if the patient's heart is moving, thereby indicating that the patient's heart is beating and, therefore, that blood is flowing.