1937 results about "Doppler us" patented technology

Aspects of the present disclosure are presented for a surgical instrument having one or more sensors at or a near an end effector and configured to aide in the detection of tissues and other materials and structures at a surgical site. The detections may then be used to aide in the placement of the end effector and to confirm which objects to operate on, or alternatively, to avoid. Examples of sensors include laser sensors used to employ Doppler shift principles to detect movement of objects at the surgical site, such as blood cells; resistance sensors to detect the presence of metal; monochromatic light sources that allow for different levels of absorption from different types of substances present at the surgical site, and near infrared spectrometers with small form factors.

A radar-based physiological motion sensor is disclosed. Doppler-shifted signals can be extracted from the signals received by the sensor. The Doppler-shifted signals can be digitized and processed subsequently to extract information related to the cardiopulmonary motion in one or more subjects. The information can include respiratory rates, heart rates, waveforms due to respiratory and cardiac activity, direction of arrival, abnormal or paradoxical breathing, etc. In various embodiments, the extracted information can be displayed on a display.

A physiological sensing stethoscope suitable for use in high-noise environments is disclosed. The stethoscope is designed to be substantially matched to the mechanical impedance of monitored physiological activity and substantially mismatched to the mechanical impedance of air-coupled acoustic activity. One embodiment of the stethoscope utilizes a passive acoustic system. Another embodiment utilizes an active Doppler system. The passive and active systems can be combined in one stethoscope enabling switching from a passive mode to an active mode suitable for use in very high-noise environments. The stethoscope is suitable for use in environments having an ambient background noise of 100 dBA and higher. The passive includes a head having a housing, a flexural disc mounted with the housing, and an electromechanical stack positioned between the housing and the flexural disc in contact with the skin of a patient. The active system detects Doppler shifts using a high-frequency transmitter and receiver.

Provided herein is a method for use in medical applications that permits (1) affordable three-dimensional imaging of blood flow using a low-profile easily-attached transducer pad, (2) real-time blood-flow vector velocity, and (3) long-term unattended Doppler-ultrasound monitoring in spite of motion of the patient or pad. The pad and associated processor collects and Doppler processes ultrasound blood velocity data in a three dimensional region through the use of a planar phased array of piezoelectric elements. The invention locks onto and tracks the points in three-dimensional space that produce the locally maximum blood velocity signals. The integrated coordinates of points acquired by the accurate tracking process is used to form a three-dimensional map of blood vessels and provide a display that can be used to select multiple points of interest for expanded data collection and for long term continuous and unattended blood flow monitoring. The three dimensional map allows for the calculation of vector velocity from measured radial Doppler.

A thinned array (greater than half-wavelength element spacing of the transducer array) is used to make a device of the present invention inexpensive and allow the pad to have a low profile (fewer connecting cables for a given spatial resolution). The full aperture is used for transmit and receive so that there is no loss of sensitivity (signal-to-noise ratio) or dynamic range. Utilizing more elements (extending the physical array) without increasing the number of active elements increases the angular field of view. A further increase is obtained by utilizing a convex non-planar surface.

The invention discloses a continuous Doppler US imaging system orthogonal intrinsic signal generation device, which comprise a field programmable gate array (FPGA), a crystal oscillator, a first digital-analog converter and a second digital-analog converter. The output end of the field programmable gate array (FPGA) is connected with the input ends of the first digital-analog converter and the second digital-analog converter; the crystal oscillator is respectively connected with the field programmable gate array (FPGA), the first digital-analog converter and the second digital-analog converter; the crystal oscillator is used for supplying synchronizing clock signals to the field programmable gate array (FPGA), the first digital-analog converter and the second digital-analog converter; the field programmable gate array (FPGA) is used for outputting the sine value corresponding to the phase value to the first digital-analog converter according to the input phase value and outputting the cosine value corresponding to the phase value to the second digital-analog converter; the first digital-analog converter is used for converting the sine value into the corresponding analog signals; the second digital-analog converter is used for converting the cosine value into the corresponding analog signals.

Telemedicine systems and methods are described. In a telemedicine system operable to communicate with a remote operations center, communications can be transmitted/received using a transceiver having an antenna. The antenna can include first and second di-pole antenna elements, the first di-pole antenna element being vertically polarized and the second di-pole antenna element being horizontally polarized. A controller of the system can establish, using the transceiver, a telemedicine session with the operations center using a Transport Morphing Protocol (TMP), the TMP being an acknowledgement-based user datagram protocol. The controller can also mask one or more transient network degradations to increase resiliency of the telemedicine session. The telemedicine system can include a 2D and 3D carotid Doppler and transcranial Doppler and/or other diagnostic devices, and provides for real-time connectivity and communication between medical personnel in an emergency vehicle and a receiving hospital for immediate diagnosis and treatment to a patient in need.

A method of full-field or “ping-based” Doppler ultrasound imaging allows for detection of Doppler signals indicating moving reflectors at any point in an imaging field without the need to pre-define range gates. In various embodiments, such whole-field Doppler imaging methods may include transmitting a Doppler ping from a transmit aperture, receiving echoes of the Doppler ping with one or more separate receive apertures, detecting Doppler signals and determining the speed of moving reflectors. In some embodiments, the system also provides the ability to determine the direction of motion by solving a set of simultaneous equations based on echo data received by multiple receive apertures.

Ultrasound monitoring systems and components used in ultrasound monitoring systems, such as Transcranial Dopper (TCD) systems, are disclosed. Components include framework systems for mounting, locating and maintaining one or more ultrasound probes in contact with an anatomical surface, adjustable probe mounting systems, and probe interface components providing an acoustically transmissive interface between a probe mounting system and the emissive face of the ultrasound probe.

An apparatus and method for determining the density and fluid-type of a fluid flowing in a capillary tube, the velocity and viscosity of a blood sample flowing in a capillary tube, the erythrocyte sedimentation rate (ESR) of a blood sample after flow has been brought to an abrupt stop in a capillary tube, and/or the zeta sedimentation rate (ZSR) of a blood sample after flow has been brought to an abrupt stop in a capillary tube. These measurements are accomplished by directing a waveform pulse, such as an ultrasound pulse, at a pre-determined frequency transversely across the capillary tube and sample fluid, and by determining the flight of time of the pulse through the capillary tube and sample fluid and/or the Doppler shift of the echo signals reflecting off cells moving forwardly or transversely within a flowing, or stationary, blood sample.

The invention relates to a high precision speed and distance measuring laser radar system and a speed and distance measuring method. The basic principle of the invention is as follows: linear chirp modulation and pseudo-random code modulation of lasers are performed; most lasers after modulation are taken as outgoing lasers and transmitted by a telescope; a small part of the lasers is taken as local oscillator beams and used for coherent detection; laser echo signals are divided into two parts; distance information is obtained after related operation of one part of the laser echo signals and original pseudo-random codes; the frequency difference of the local oscillator beams and echo signal beams is obtained after coherent detection of the other part of the laser echo signals and the local oscillator beams and pulse compression, and simultaneously comprises the distance information and Doppler shift; the Doppler shift is obtained through mathematical manipulation, thereby speed information is obtained. The high precision speed and distance measuring laser radar system and a speed and distance measuring method of the invention is characterized in that the speed information and the distance information of a target can be obtained with high precision.

An indoor ultrasonic location tracking system that can utilize standard audio speakers to provide indoor ranging information to modern mobile devices like smartphones and tablets. The method uses a communication scheme based on linearly increasing frequency modulated chirps in the audio bandwidth just above the human hearing frequency range where mobile devices are still sensitive. The method uses gradual frequency and amplitude changes that minimize human perceivable (psychoacoustic) artifacts derived from the non-ideal impulse response of audio speakers. Chirps also benefit from Pulse Compression, which improves ranging resolution and resilience to both Doppler shifts and multi-path propagation that plague indoor environments. The method supports the decoding of multiple unique identifier packets simultaneously. A Time-Difference-of-Arrival pseudo-ranging technique allows for localization without explicit synchronization with the broadcasting infrastructure. An alternate received signal strength indicator based localization technique allows less accurate localization at the benefit of sparser transmission infrastructure.

A prior application discloses a novel probe geometry that offers a wide field of view in an ultrasonic imaging device. That geometry is referred to as a "thinned array" of transducer elements. The application discloses an improved probe geometry permitting high-resolution imaging of a large volume of the subject's body. In this improved geometry, the array elements are non-uniform in size and spacing. The probe is intended for use, for example, in a method of determining parameters of blood flow, such as vector velocity, blood flow volume, and Doppler spectral distribution, using sonic energy (ultrasound) and a novel thinned array. Also in a method of tracking blood flow and generating a three dimensional image of blood vessel of interest that has much greater resolution than images produced using heretofore known ultrasound devices and methods.

Vector Doppler Imaging (VDI) improves on conventional Color Doppler Imaging (CDI) by giving speed and direction of blood flow at each pixel of a display generated by a computing system. Multiple angles of Plane wave transmissions (PWT) via an ultrasound transducer conveniently give projected Doppler measurements over a wide field of view, providing enough angular diversity to identify velocity vectors in a short time window while capturing transitory flow dynamics. A fast, aliasing-resistant velocity vector estimator for PWT is presented, and VDI imaging of a carotid artery with a 5 MHz linear array is shown using a novel synthetic particle flow visualization method.

Harmonic motion is produced in a subject using vibro-acoustography. An ultrasonic imaging system repetitively interrogates the subject and the Doppler shift in the reflected echo signals is analyzed to measure the phase and amplitude of harmonic motion produced in the subject at different prescribed frequencies. Shear wave propagation through the subject is determined from this information and mechanical properties related to “stiffness” of the subject are determined. A Kalman filter is employed in the phase and amplitude measurement to extract the harmonic motion information from background noise.

Apparatus and methods of use are provided for complex flow imaging and analysis that is non-invasive, accurate, and time-resolved. It is particularly useful in imaging of vascular flow with spatiotemporal fluctuations. This apparatus is an ultrasound-based framework called vector projectile imaging (VPI) that can dynamically render complex flow patterns over an imaging view at millisecond time resolution. The VPI apparatus and methods comprise: (i) high-frame-rate broad-view data acquisition (based on steered plane wave firings); (ii) flow vector estimation derived from multi-angle Doppler analysis (coupled with data regularization and least-squares fitting); and (iii) dynamic visualization of color-encoded vector projectiles (with flow speckles displayed as adjunct).

A moving target detection imaging method of a dual-channel frequency modulation continuous wave SAR system comprises the steps of recording echo data by a radar system, performing residual video phase removing processing on the echo data, performing Doppler frequency shift compensation on the data, performing phase deviation compensation on two-channel conversion data, and performing subtraction processing on the two-channel data; performing migration correction and direction dechirping processing on an image with clutter cancellation to realize the rough imaging of a target, and detecting the moving target and extracting one by one; performing inverse transformation on the extracted targets to an original data domain, estimating motion parameters to construct a precise direction dechirping function of the moving target, performing residual video phase removing processing, precise direction dechirping processing and distance migration correction, constructing a fuzzy function for compensation, and then performing Keystone transformation to finish the precise image of the moving target. The moving target detection imaging method solves the imaging problem of the fast moving target when motion parameters are unknown under the continuous wave system, so the signal-to-noise rate and the target detection probability are greatly improved.

The invention provides a frequency offset estimation method for high-dynamic large-frequency-offset burst signals. The estimation method comprises burst frame capturing, estimation and correction of Doppler changing rate, basic frequency offset estimation, and Doppler frequency offset estimation, a burst signal frame is formed by a pilot frequency segment and a data segment, and a receiver employs the pilot frequency segment to realize frequency offset estimation. Firstly, the burst frame capturing is realized via a threshold comparison method; then the segmentation of pilot frequency data is realized, a DFT-assistant hierarchical iteration method is employed to estimate the Doppler changing rate, and the estimation value of the Doppler changing rate is used for dynamic compensation of the pilot frequency segment; later, DFT-assistant basic frequency offset estimation of signals after dynamic correction is realized; and finally, the estimation value of the Doppler changing rate and the basic frequency offset estimation value are combined to estimate the frequency offset of each symbol in the burst signal frame. According to the frequency offset estimation method, the data segment is compensated by the adoption of the frequency offset estimation result so that the data segment has small frequency changing rate and residual frequency offset, and bit synchronization, frame synchronization, and carrier synchronization can be realized.

The invention discloses a distance-speed synchronous pull-off deception jamming recognition algorithm based on gradient projection, and belongs to the field of radar anti-jamming. According to a PD radar, the radar is generally jammed through distance-speed synchronous pull-off jamming, the deception jamming can conduct pull-off jamming on distance information and speed information at the same time, and thus the difficulty for accurately choosing and tracking a target of the PD radar is increased. The method comprises the following steps that (1) signals received by the radar are sampled, and a complete atom library is established according to the time-variant characteristic of a distance-speed synchronous jamming echo; (2) when the AGC voltages and the target number of a receiver are suddenly changed, it is judged that the target is jammed; (3) the Doppler frequency of the target is obtained through a gradient projection method, then the target speed is figured out, and accordingly anti-jamming is performed according to the target speed. The distance-speed synchronous pull-off deception jamming recognition algorithm based on gradient projection is high in jamming recognition capability, easy in engineering realization, high in engineering application value and large in popularization prospect.

The invention provides an underwater robot object detection device and a detection method. The device comprises a PC/104 computer, a single-beam forward looking sonar equipment sensor, a Doppler log, a depth gauge, an altimeter and a relay element. When in an underwater state, after the computer is electrified, an equipment control program is started automatically, controls a relay to open the sensor through a DI/O digital board, collects the environment information in the advancing direction with a single-beam forward looking sonar, calibrates the data with the information of the Doppler log, classifies the data through the depth information, obtains underwater object point plane information through processing algorithm, and estimates the object underwater depth information based on the information of the depth gauge, so as to detect an underwater object. The invention prevents the space occupation problem of the multi-beam forward looking sonar and the three-dimensional sonar, effectively solves the problem that the single-beam forward looking sonar can only obtain the underwater object two-dimensional detection information, and is more applicable to the underwater object detection application of an underwater unmanned submarine.