Abstract: A single-chip solution for multi-modal imaging with every pixel capable of electrostatic, ultrasonic and optical imaging. The device can be configured in as much modality configurations as possible based on the types of the transducers included in the system.

Abstract: The present disclosure provides a device for ultrasonic sensing, which includes a driver circuit configured to generate an ultrasonic signal, a piezoelectric element having a first electrode and a second electrode, a blocking transistor configured to connect the piezoelectric element with the second electrode to a fixed bias voltage, and a source rectifier including a gate, a drain, and a source electrically connected to the piezoelectric element and the blocking transistor. The piezoelectric element is coupled with the driver circuit with the first electrode. The blocking transistor includes a gate for receiving a blocking control signal, a drain electrically connected to the second electrode of the piezoelectric element, and a source electrically connected to the fixed bias voltage, wherein, in response to the blocking signal, the blocking transistor is configured to be turned on within a transmission period and to be turned off within a receiving period.

Abstract: The present disclosure relates to a method for compressing an evaluation curve, which is recorded during a radar-based fill level measurement of a filling material located in a container, and to a corresponding fill level measurement device for carrying out the method. Corresponding to the compression method according to the present disclosure, the present disclosure comprises a corresponding method for decompressing the compressed evaluation curve. The compression method is characterized in that the compression occurs using linear prediction, by corresponding estimation coefficients and an error curve being created. This makes use of the finding according to the present disclosure that evaluation curves can be compressed for diagnostic purposes, in particular in the case of FMCW-based fill level measurement, efficiently and without data loss using the model of linear prediction.

Abstract: An ultrasonic diagnostic imaging system acquires different kinds of pilot images showing different characteristics of a region of a body where shearwave measurements are performed. The pilot images are analyzed by a push pulse locator to adaptively generate push pulses at locations in the body which minimize or avoid shearwave travel through blood vessels, through regions of stiffness inhomogeneities in the body, or at times when shearwaves are adversely affected by tissue motion.

Abstract: Systems and methods for dewatering slurries having relatively high solids content such as earthen slurries are disclosed. In some embodiments, one or more transducer devices configured for acoustic spectroscopy and/or electroacoustic spectroscopy are used to determine a parameter related to the particle size distribution (e.g., specific surfaced area) and/or zeta potential of the slurry.

Abstract: The invention relates to measuring devices or display devices and a method for operating these devices, in particular instruments for level measurement, for level detection, for detecting the topology of a product surface or for displaying the measured values of these instruments. A measuring device or display device has an RFID unit. The RFID unit is set up to exchange data with a memory on an external command from an external communication device, to switch a controllable switch on and off, and/or to transfer energy to an energy storage device.

Abstract: Provided is a vehicle control device capable of realizing fuel-efficient traveling of an own vehicle. Therefore, a vehicle control device 100 includes a limiting factor determination unit 101 that determines whether there are a limiting factor on an own lane that limits traveling of an own vehicle in the own lane and a limiting factor on an adjacent lane that limits the traveling of the own vehicle in a lane adjacent to the own lane, a lane selection unit 102 that selects a lane in which the own vehicle travels based on a determination result of the limiting factor determination unit 101, and a driving force control unit 103 that controls a driving force of the own vehicle based on the lane selected by the lane selection unit 102.

Abstract: A multi-dimensional data acquisition and analysis system for placenta tissue is provided, including a preparation area, a sampling area, a tension cable, a mobile platform, a tray, a mobile cabin door, a cabin door motor, a motor, a motor controller, binocular vision cameras, a laser point cloud detector, a hyperspectral camera, an ultrasonic ranging, a lifting motor, a lifting guide rail, ring light sources, an infrared sensor, a two-dimensional code area and a two-dimensional code identification camera. The technical scheme of the disclosure is adopted to solve the problem of lack of effective technical means for placenta detection at present.

Abstract: Within the field of elastography, a new approach analyzes the limiting case of shear waves established as a reverberant field. In this framework, it is assumed that a distribution of shear waves exists, oriented across all directions in 3D (e.g. 2D space+time). The simultaneous multi-frequency application of reverberant shear wave fields can be accomplished by applying an array of external sources that can be excited by multiple frequencies within a bandwidth, for example 50, 100, 150, . . . 500 Hz, all contributing to the shear wave field produced in the liver or other target organ. This enables the analysis of the dispersion of shear wave speed as it increases with frequency, indicating the viscoelastic and lossy nature of the tissue under study. Furthermore, dispersion images can be created and displayed alongside the shear wave speed images.

Abstract: Ultrasound signal processing device including: transmitter causing transmission array composed of all or some transducer elements of ultrasound probe to transmit ultrasound; reception aperture setter designating reception array having center position corresponding to center position of transmission array; transmission time calculator calculating, for each of measurement points arranged within area of reach of ultrasound, transmission time from transmission of ultrasound until arrival of ultrasound at measurement point; reception time calculator calculating reception time from reflection of ultrasound at measurement point until arrival of ultrasound at reception transducer element; delay amount calculator calculating total propagation time being sum of transmission time and reception time, and calculating delay amount for reception transducer element based on total propagation time; delay processor specifying reception signal value corresponding to delay amount, from reception signal sequence corresponding to

Abstract: A method for assisting a maneuvering procedure of a motor vehicle in a parking garage is disclosed, wherein the motor vehicle moves within the parking garage during the maneuvering procedure from a drop-off site in the parking garage to a predetermined position in the parking garage, wherein the maneuvering procedure of the motor vehicle is monitored by at least one sensor of the motor vehicle, comprising the steps: establishing a communication link between a controller of the motor vehicle and a vehicle-external unit of the parking garage; transmitting climate-specific measured data that are acquired by at least one measuring point in the parking garage from the at least one measuring point to the vehicle-external unit, and calibrating the at least one sensor of the motor vehicle depending on the climate-specific measured data.

Abstract: An apparatus for testing a transducer module includes a test signal generator coupled to a common-mode terminal common to a plurality of transducers, and a signal processing circuit configured to receive output signal from each of said transducers and to produce an output signal. If the transducers are well matched to one another, the output signal will have little or no output amplitude. If there is a mismatch between the transducers, however, the output signal will have an amplitude proportional to the mismatch. The amplitude of the output signal may be compared to a predetermined threshold in order to produce a mismatch output signal indicating the existence of, and/or the degree of, mismatch between the transducers.

Abstract: An apparatus for detecting and recording insect flying activities, such as outside a bee hive, with a Doppler radar is described. Also described is a system including a plurality of apparatuses for detecting and recording insect flying activities, such as outside a bee hive, with a Doppler radar.

Abstract: A vehicular door control system responsive to object detection includes a radar unit disposed at a vehicle that has a field of sensing adjacent to and exterior a door of the vehicle and that transmits radar signals and receives reflected radar signals representative of an object. A scanning actuator coupled to the radar unit moves the radar unit relative to the door to create a variation between the transmitted radar signals and the reflected radar signals. An electronic control unit (ECU) operates the radar unit to transmit the radar signals. While the radar unit is transmitting the radar signals and receiving the reflected radar signals, the ECU operates the scanning actuator to move the radar unit relative to the door. The ECU processes the received reflected radar signals to determine presence of the object and operates an electrically powered actuator coupled to the door to open and close the door.

Abstract: A method, apparatus, and a non-transitory computer-readable storage medium for event detection are provided. The method may be applied to an electronic device. The electronic device may transmit a detection signal. The electronic device may receive an echo signal of the detection signal. The electronic device may acquire a feature value of the echo signal. The electronic device may calculate a decision parameter based on the feature value, and may determine, based on the decision parameter, that the electronic device is moving towards or away from a target object.

Abstract: A method for transceiving signals and a transceiver using the same are provided. The method includes: configuring a transmitting circuit to transmit a transmitting signal via a first transmitting channel of the transmitting circuit during a transmitting period of the transmitting signal; configuring a switch module to connect the first transmitting channel to a first transducer element of a probe during the transmitting period; and configuring the switch module to disconnect the first transmitting channel form the first transducer element and to connect the first transmitting channel to a second transducer element of the probe during the transmitting period.

Abstract: Method and system for ultrasonic characterization of a medium Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix Rui(t) defined between the emission basis (i) as input and a reception basis (u) as output, determining a focused reflection matrix RFoc(rin, rout, at) of the medium between an input virtual transducer (Win) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TVout) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TVout) being obtained at a time instant that is shifted by an additional delay 6t relative to a time instant of the responses of the input virtual transducer (TVin).

Abstract: Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix Rui(t) defined between the emission basis (i) as input and a reception basis (u) as output, and determining a focused reflection matrix RFoc(rin, rout, ?t) of the medium between an input virtual transducer (TVin) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TVout) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TVout) being obtained at a time instant that is shifted by an additional delay ?t relative to a time instant of the responses of the input virtual transducer (TVin).

Abstract: Techniques are disclosed for systems and methods to provide perimeter ranging for navigation of mobile structures. A navigation control system includes a logic device, a perimeter ranging system, one or more actuators/controllers, and modules to interface with users, sensors, actuators, and/or other elements of a mobile structure. The logic device is configured to receive perimeter sensor data from ultrasonic perimeter ranging sensor assemblies of the perimeter ranging system and generate an obstruction map based on the received perimeter sensor data. The logic device determines a range to and/or a relative velocity of a navigation hazard based on the received perimeter sensor data. The logic device determines navigation control signals based on the range and/or relative velocity of the navigation hazard. Control signals may be displayed to a user and/or used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.

Abstract: A sound velocity profile inversion method based on an inverted multi-beam echometer.

Abstract: Methods, apparatus, systems and articles of manufacture to detect changes in a physical environment are disclosed. An example apparatus includes a descriptor generator to generate a first descriptor, the descriptor generator including: a chirp producer to emit a chirp into the environment, a chirp recorder to record a response to the chirp from the environment, and a chirp response encoder to generate an encoding of the response to the chirp; a descriptor similarity generator to generate a similarity value, the similarity value to compare the first descriptor to a second descriptor; and a physical change indicator to, in response to the similarity value exceeding a similarity threshold, indicate that a physical change has occurred in the environment.

Abstract: A sonar survey system including a multibeam echo sounder using plural transmit projectors and plural receive hydrophones, wherein beams with associated magnitudes are received such that the largest magnitude beam(s) are identified as characterizing beam(s) and data associated with these characterizing beam(s) is used as a compressed characterization of the ensonified space.

Abstract: An ultrasound detection device comprising: an ultrasound receiver configured to generate a signal indicative of a pressure of ultrasound that impinges on the receiver; and a coded mask comprising an ultrasound-blocking material perforated by an array of a plurality of apertures, the apertures arranged such that when the coded mask is placed over the receiver between the receiver and a source of ultrasound in a predetermined lateral position, the ultrasound is transmitted from the ultrasound source to the receiver via a known unique pattern of active apertures of the plurality of apertures such that the signal that is generated by the receiver is a multiplexed signal.

Abstract: Disclosed embodiments include illustrative piezoelectric element array assemblies, methods of fabricating a piezoelectric element array assembly, and systems and methods for shearing cellular material. Given by way of non-limiting example, an illustrative piezoelectric element array assembly includes at least one piezoelectric element configured to produce ultrasound energy responsive to amplified driving pulses. A lens layer is bonded to the at least one piezoelectric element. The lens layer has a plurality of lenses formed therein that are configured to focus ultrasound energy created by single ones of the at least one piezoelectric element into a plurality of wells of a microplate disposable in ultrasonic communication with the lens layer, wherein more than one of the plurality of lenses overlie single ones of the at least one piezoelectric element.

Abstract: The present disclosure relates to a mapping system adapted for detecting objects in an environmental scene, by scanning an environmental scene with propagating energy, and receiving reflected energy back from objects present in the environmental scene, in a prioritized manner, for later use. The system may comprise an imaging subsystem which includes a detection and ranging subsystem for initially identifying primitive objects in the environmental scene. The imaging subsystem may also include an identification and mapping subsystem for prioritizing the primitive objects for further scanning and analysis, to ultimately identify one or more of the primitive objects as one or more abstract objects. An environmental model, updated in real time, is used to maintain a map of the primitive objects and the known abstract objects within the environmental scene, as new primitive objects and new abstract objects are obtained with repeated scans of the environmental scene.

Abstract: Within the field of elastography, a new approach analyzes the limiting case of shear waves established as a reverberant field. In this framework, it is assumed that a distribution of shear waves exists, oriented across all directions in 3D (e.g. 2D space+time). The simultaneous multi-frequency application of reverberant shear wave fields can be accomplished by applying an array of external sources that can be excited by multiple frequencies within a bandwidth, for example 50, 100, 150, . . . 500 Hz, all contributing to the shear wave field produced in the liver or other target organ. This enables the analysis of the dispersion of shear wave speed as it increases with frequency, indicating the viscoelastic and lossy nature of the tissue under study. Furthermore, dispersion images can be created and displayed alongside the shear wave speed images.

Abstract: The invention relates to a method and to a device for sorting particles of a material flow into at least two fractions, the particles in the material flow being observed by means of at least one detector, particles being subjected to acoustic pressure on the basis of the properties determined by the detector so that they are supplied to different fractions.

Abstract: An ultrasound (US) system is discloses and includes a plurality of transducer elements forming a one-dimensional array and a plurality of bias voltage circuits. Each bias voltage circuit is in communication with a respective first set of the transducer elements and configured to apply a bias voltage to its respective first set of the transducer elements. The US system also included a second plurality of transmit and receive circuits. Each transmit and receive circuit is in communication with a respective second set of transducer elements and configured to stimulate signal transmission or reception of the respective second set of transducer elements.

Abstract: An ultrasonic recognition module, a driving method thereof, and a display device. Multiple receiving electrodes are divided into multiple receiving groups. Pulse signal input ends of driving circuits corresponding to the receiving electrodes in the same receiving group are electrically connected to a same pulse signal input line, and pulse signal input ends of driving circuits corresponding to the receiving electrodes in the different receiving groups are electrically connected to different pulse signal input lines.

Abstract: A wideband sonar receiver is provided that includes: a selectable bandpass filter adapted to filter a received sonar signal to produce a filtered signal and a correlator adapted to correlate the baseband samples with baseband replica samples to provide a correlated signal. In addition, the wideband sonar receiver may include a shaping filter to shape unshaped received pulses. Finally, a variety of sonar processing algorithms are described with regard to reducing clutter and interference, target detection, and bottom detection.

Abstract: A system, method, and device for monitoring a parameter downhole. The system comprises a conveyance string locatable in the wellbore, a sensor and a recorder located on the conveyance string, and a processor in communication with the recorder. The recorder comprises a sampler in communication with the sensor, and the sampler is operable to sample the measured parameter at a sampling rate of 150 kHz to 10 MHz. The recorder also comprises an information storage device in communication with the sampler and operable to store the samples acquired by the sampler. The processor is operable to monitor the parameter based on the samples collected by the sampler.

Abstract: An acoustic bidirectional reflectance distribution function (BRDF) measurement system utilizing metamaterials and compressive sensing for measuring scattering acoustic profiles (e.g., over large angular regions, such as hemispherical scattering/emitting into two ? steradians or even spherical scattering/emitting over four ? steradians). The measurement system includes one or more acoustic waveguides having a curved receiving surface and made from an acoustic metamaterial configured to encode as a sound signal a frequency and directionality of a sound input received from a sample. Each acoustic waveguide includes an acoustic sensor for detecting the encoded sound signal from the metamaterial.

Abstract: Aspects of the technology described herein relate to sensing a fingerprint of a subject via an ultrasound fingerprint sensor. Certain aspects relate to transmitting and receiving ultrasound data at multiple different frequencies to provide sensing data from different depths within the skin of the subject. Since different ultrasound frequencies are expected to penetrate a subject's skin to different degrees, sensing a finger at multiple ultrasound frequencies may provide information on different physical aspects of the finger. For instance, sound ultrasound frequencies may sense a surface of the skin, whereas other ultrasound frequencies may penetrate through one or more of the epidermal, dermal or subcutaneous layers. The ultrasound fingerprint apparatus may have utility in various applications, including but not limited to mobile electronic devices, such as mobile phones or tablet computers, a laptop computer or biometric access equipment.

Abstract: An ultrasonic transducer positionable in a wellbore environment may include a piezoelectric material layer, a protective layer, and connecting plate positioned between the piezoelectric material layer and the protective layer. The piezoelectric material layer may be formed as a plurality of columns of piezoelectric material for detecting a characteristic of the wellbore environment during a drilling operation. The protective layer may be positionable between the piezoelectric material layer and an acoustic medium in the wellbore environment. The connecting plate may be positioned between the piezoelectric material layer and the protective layer. The connecting plate may have a coefficient of thermal expansion (CTE) in a range between the CTE of the piezoelectric material layer and that of the protective layer, and an acoustic impedance in a range between the acoustic impedance of the piezoelectric material layer and that of the protective layer.

Abstract: An acoustic biometric touch scanner device and method is disclosed. In one aspect, an acoustic fingerprint sensing device includes an array of ultrasonic transducers configured to transmit an ultrasound signal having a frequency in a range from 50 megahertz (MHz) to 500 MHz. The acoustic fingerprint ultrasonic transducers include a piezoelectric film. The acoustic fingerprint sensing device further includes a receiving surface configured to receive a finger. The acoustic fingerprint sensing device further includes a processor configured to generate an image of at least a portion of a fingerprint of the finger based on a reflection of the ultrasound signal from the finger.

Abstract: An ultrasonic flow meter is disclosed, including a switching unit for switching electrical transmission signals between a signal generator and at least two ultrasonic transducers and for switching electrical reception signal between the transducers and a receiver circuit, wherein the switching unit is coupled to an output terminal of an operational amplifier of the signal generator and to an inverting input terminal of an operational amplifier of the receiver circuit. Furthermore, a method for characterizing an ultrasonic transducer is disclosed, including the step of determining directly from one or more supply current signals for an active component of a signal generator one or more quantities useful for characterizing the transducer. Furthermore, a method for determining the time delay of an ultrasonic signal in a flow path of an ultrasonic flow meter is disclosed, including the step of comparing physically transmitted, delayed and received signals with simulated non-delayed signals.

Abstract: Noise present in ultrasonic tests applied by an ultrasonic test system to test objects, e.g., production parts, is reduced to provide more accurate results and to reduce waste, e.g., by reducing the number of test objects inaccurately identified as faulty. To that end, a noise signature is obtained for an ultrasonic test applied by the ultrasonic test system to a known object having the same dimensions and the same material composition as the test objects. The noise present in the output of the ultrasonic test applied by the ultrasonic test system to one or more of the test objects is then reduced responsive to the obtained noise signature to improve the accuracy of the ultrasonic test.

Abstract: A mobile computing device includes: a beacon transmitter; a receiver; a controller connected with the beacon transmitter and the receiver, the controller configured to: control the beacon transmitter to broadcast a lost device signal, the lost device signal configured for locating the mobile computing device and including an indicator of a designated reception window; during the designated reception window, enable the receiver; and in response to receiving a discovery command from a searching device, control the beacon transmitter to transmit a response signal for locating the mobile computing device.

Abstract: A vibration sensor with monitoring function is provided, which includes a substrate, a microelectromechanical vibration sensor chip and an application-specific integrated circuit chip. The microelectromechanical vibration sensor chip is disposed on the substrate and detects a vibration applied to an object to generate a plurality of vibration signals. The application-specific integrated circuit chip is disposed on the substrate and electrically connected to the microelectromechanical vibration sensor chip, which includes a sampling module, a transform module and an analysis module. The sampling module receives and converts the vibration signals into a plurality of digital signals, and filters the digital signals to generate a plurality of time-domain data. The transform module transforms the time-domain data into a frequency-domain data according to a predetermined number.

Abstract: Provided is an electronic apparatus for detecting information about a target object by using an ultrasound wave. The electronic apparatus includes: a transmitter configured to emit an ultrasound wave modulated based on a predetermined code signal; a receiver configured to receive a reflected signal corresponding to the emitted ultrasound wave reflected from a target object; and a controller configured to acquire a reception signal from the received reflected signal and detect information about the target object based on a difference between correlation values corresponding to a plurality of predetermined periods of the reception signal and the predetermined code signal.

Abstract: A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.

Abstract: A system for monitoring a remote underwater location using an unmanned underwater vessel (5). The system includes an unmanned surface vessel (8), a communication unit (7) for submerged location and connected to the unmanned surface vessel (8) and in which the unmanned surface vessel has a position tracking control system for controlling the position of that vessel on a body of water and relative to the unmanned underwater vehicle (5). The communication unit (7) has a first wireless communication arrangement for communication with the unmanned underwater vehicle, a second wired communication arrangement (10) for communication with the unmanned surface vessel and the unmanned surface vessel has a third communication arrangement for communication with an operator or observer (1) remote from the unmanned surface vessel and the unmanned underwater vehicle.

Abstract: Provided is a method including steps: (a) storing in a database an eigenvector and an eigenvalue for each recognizable gesture, with respect to a first signal input through a radar apparatus and a second signal resulting from removing background information from the first signal: (b) receiving a third signal from which to determine a gesture, as an input, from the radar apparatus: (c) removing background information from the third signal from which to determine the gesture to obtain a fourth signal: (d) computing an inner product of the eigenvector and a signal matrix relating to each of the third signal from which to determine the gesture and the fourth signal resulting from removing the background information from the third signal: and (e) comparing the computed inner product with the eigenvalue in the database, in which the eigenvector is extracted from signals of all recognizable gestures and the eigenvalue, and the eigenvalue for each recognizable gesture is an inner product of the eigenvector and the si

Abstract: The disclosed technology provides a computing device with a slot antenna assembly including a slot formed in a metal exterior surface of a computing device case; an acoustic transceiver positioned to transmit an acoustic wave out through the slot and to receive a reflected portion of the acoustic wave in through the slot when the acoustic wave is reflected by an object; a proximity detector coupled to the acoustic transceiver that determines a physical separation between the object and the slot antenna based on a temporal separation between transmission of the acoustic wave and receipt of the reflected portion of the acoustic wave; and a transmission power controller that adjusts transmission power of the slot antenna based on the determined physical separation.

Abstract: Natural frequencies of vibration of objects, such as aerial vehicles, are identified based on imaging data captured while the objects are subjected to excitation. The imaging data is captured using high-speed cameras, and changes in intensities of pixels corresponding to surfaces of the object are used to determine a spectral diagram of the vibrations from which natural frequencies of vibration (e.g., vibration modes) are determined. The visibility of the vibrating objects is enhanced by providing video images to band-pass filters within small bands around the natural frequencies, and magnifying the vibration based on the amplitudes or phases determined from each of the video images. A stream of the modified video images may be used to determine a mode shape corresponding to the vibration of the objects at or around a natural frequency of vibration.

Abstract: The descried techniques may support a sensing scheme for reducing background signals in imaging sensors. A device may include a sensor configured to determine ridges and valleys of a fingerprint. The sensor may include a pixel array with each pixel of the pixel array having a set of electrodes. To reduce the background signals, the device may sense, e.g., during a transmit mode, a first set of signals associated with the pixel array using at least one electrode of the set of electrodes, and sense, e.g., during a receive mode, a second set of signals associated with the pixel array using the at least one electrode. The device may reduce a background signal associated with the sensor according to the sensing of the first set of signals and the second set of signals.

Abstract: A method to actuate a locking element for a vehicle including detecting a movement of an object using an optical sensor, activating an ultrasound sensor in accordance with the detected movement, detecting a gesture using the ultrasound sensor, and actuating the locking element in accordance with the detected gesture.

Abstract: An ultrasonic sensor includes a piezoelectric body including a transmission region for an ultrasonic wave and a reception region for a reflected wave of the ultrasonic wave, a common electrode in the transmission region and the reception region, a transmission electrode in the transmission region, a reception electrode in the reception region; and a semiconductor element that is electrically connected to the transmission electrode and the reception electrode and switches an electrical path between a conductive state and a non-conductive state. The semiconductor element puts the path into the conductive state after application of the alternating-current voltage is stopped. Thus, a reverberation signal, output from the reception region in accordance with a reverberant vibration of the ultrasonic wave, is fed back to the transmission electrode.

Abstract: A system and method for classifying body activities through an on-body antenna measuring changes in reflected power and the resulting reflection coefficients, in contrast to two antenna systems that measure transmission power therebetween. A single on-body antenna can be attached or held in close proximity to the body. The antenna can be calibrated based on changes in the reflection coefficients for various calibration activities for the location at which the antenna is placed on the body. Magnitude changes and patterns of the reflection coefficients at a given frequency for a given activity can be compared with calibrated data to correlate a given activity. Further accuracy can be gained by comparing both magnitude and phase changes and patterns at a given frequency with calibrated data for a given activity. The antenna can use power losses from a transmitted signal to measure the changes in the reflected power to minimize power requirements.

Abstract: In an apparatus for multi-pole acoustic logging while drilling, a N-cycle sinusoidal wave signal is generated by utilizing a signal processor, and amplified into a high-voltage sinusoidal excitation signal by utilizing a power amplifier, and output to a transmitting transducer. The signal processor simultaneously generates an enable signal. The enable signal includes a transient discharge enable signal. The power amplifier is connected with a transient discharge circuit. After the signal processor generates N cycles of a sinusoidal wave, the transient discharge enable signal enables the transient discharge circuit to discharge to release an energy storage current of a power transformer so as to eliminate a high-voltage ringing effect and improve an excitation efficiency of the transducer.