264 results about "Acoustic reflection" patented technology

A thin film bulk acoustic wave (BAW) resonator structure and filter which can be fabricated by inexpensive manufacturing techniques and in smaller size than conventional such products are to be provided. The BAW resonator structure and filter have a substrate, a first BAW resonator placed over the substrate, an acoustic reflection layer placed over the first BAW resonator and a second BAW resonator placed over the acoustic reflection layer, and the acoustic reflection layer is electroconductive. Herein, the acoustic reflection layer constitutes a first electrode, and this first electrode electrically connects and acoustically separates the first BAW resonator and the second BAW resonator.

The invention discloses a piezoelectric bulk wave resonator and a manufacturing method thereof. The piezoelectric bulk wave resonator comprises a multilayer structure and a substrate, wherein at least one groove is arranged in the surface of the substrate, the multilayer structure covers the at least one groove, and an acoustic reflection structure of the piezoelectric bulk wave resonator is formed by at least one formed cavity; the multilayer structure is sunken to the bottom of the cavity in each cavity and is not in contact with the bottom of the cavity; or the multilayer structure is raised in a direction which is far away from the bottom of the cavity, and the raised height is greater than or equal to the predetermined raised height. According to the invention, through controlling the downwards sunken degree and the upwards raised height of the multilayer film structure in the piezoelectric bulk wave resonator, good air reflection interfaces are arranged on the upper side and the lower side of the multilayer film structure of the piezoelectric bulk wave resonator, so that a good reflection effect of bulk acoustic wave is ensured, and a value Q is at a high level.

A method and apparatus for enhancing the moveout between a direct wave and a reflected wave. The method involves transmitting imaging signals into a body to be imaged and receiving the resulting signals propagated from the signal source. The step of receiving the propagated signals includes selectively adjusting the distance between the signal source and the signal receivers between successive signals. The method further comprises separating the reflected signals from the total received signals and enhanced stacking of the measured reflected signals.

A piezoelectric resonator includes an acoustic reflective layer including first acoustic impedance sub-layers made of a material with relatively low acoustic impedance and second acoustic impedance sub-layers made of a material with relatively high acoustic impedance. A thin-film laminate is disposed on the acoustic reflective layer. The thin-film laminate includes a piezoelectric thin-film, a first electrode, a second electrode greater than the first electrode, and a mass-adding film. The second electrode is disposed on the acoustic reflective layer. The mass-adding film is disposed in at least one portion of a region outside a piezoelectric vibrational section and extends around the first electrode. The second electrode extends over the piezoelectric vibrational section to a region containing the mass-adding film.

A non-invasive method and apparatus for monitoring changes in intracranial pressure which removes extracranial effects from the measurements. The method and apparatus can include the supplying of a fixed frequency electrical output to a transducer coupled to the patient's head, thereby generating an acoustical tone burst in the patient's head which generates a first echo and a second echo, the first echo reflecting from a first interface in the side of the patient's head coupled to the transducer, and the second echo reflecting from a second interface at the opposite side of the patient's head. The first and second echoes are received by the transducer which can generate a first electrical signal and a second electrical signal, wherein the first and second electrical signals vary in accordance with the corresponding first and second echoes. The counterbalancing phase shifts required to bring about quadrature between each of the first and second electrical signals and the fixed frequency electrical output can be measured, and values for the change in intracranial distance based on the changes in the counterbalancing phase shifts can be obtained.

The present disclosure relates to a system and method for use of acoustic reflectometry information in ventilation devices. The system and method includes a speaker to emit sound waves into an intubated endotracheal tube (“ETT”) and a microphone to detect returning acoustic reflections. In addition, the system and method includes a reflectometry device in communication with a ventilation device for analyzing timings and amplitudes of the returning acoustic reflections to determine a size of a passageway around an ETT tip, location and size of ETT obstructions, and relative movement of the ETT tip within a trachea. The reflectometry device is also configured to determine a resistance parameter representative of resistance to actual flow of air through the ETT based upon a function of the diameter of the ETT, length of the ETT, and percent obstruction of the ETT, where the resistance parameter is used to calculate the tracheal pressure.

The invention discloses a real-time multi-mode photoacoustic human eye imaging system and an imaging method thereof. The imaging system comprises a laser device, a front optical path, a reflecting mirror, a focusing lens, a light-transmitting acoustic reflection device, a scanning mirror, a water trough, an ultrasonic probe, an ultrasonic transmitter-receiver set, an amplifier and a computer. A light-transmitting acoustic reflection film and the scanning mirror are placed in the water trough. The imaging system has a photoacoustic imaging mode and an ultrasonic imaging mode. Mechanical scanning is replaced through the scanning mirror, imaging time is greatly shortened, and pain of a patient is relieved. Meanwhile, due to the optical and ultrasonic confocal design, an existing pure optical focusing imaging mode or an existing pure ultrasonic focusing imaging mode is changed, sensitivity is improved on the basis that the optical resolution is achieved, and full-eye imaging from the front of the eye to the bottom of the eye can be carried out. Due to dual-wavelength use, the limitation that imaging is only carried out on the eye vascular structure at present is broken through, functional imaging of the degree of blood oxygen saturation can be carried out, and early detection of a part of eye diseases is facilitated.

A method of acoustically rendering a virtual environment is described. The method includes receiving a subset of polygons derived for an acoustic display from a set of polygons generated for a graphical display. Acoustic reflections are determined from a sound source that bounce off of polygons in the subset of polygons to a listener position in the virtual environment. It is determined whether a polygon in the subset of polygons causes an occlusion of the sound source at the listener position, and a play list of sounds is generated based on the reflections and occlusions.

For use in acoustic micro imaging, a method (and implementing apparatus) is disclosed for creating a 4D virtual sample data memory. The method comprises employing a pulsed ultrasonic microscope probe to interrogate a sample at three-dimensionally varied locations in the sample. Data developed by the microscope probe includes for each location interrogated a digitized A-scan for that location. The developed data is stored in a data memory.

Disclosed is an ultrasound probe which outputs ultrasound on a basis of a drive signal which is to be received. The ultrasound probe including a composite piezoelectric layer in which a piezoelectric material and a polymer material are arranged alternately in a one-dimensional array or in a two-dimensional array, an acoustic reflection layer which has an acoustic impedance higher than an acoustic impedance of the composite piezoelectric layer and an adhesion layer which bonds the composite piezoelectric layer and the acoustic reflection layer wherein in a bonding surface of the composite piezoelectric layer that bonds with the acoustic reflection layer, a polymer material part is concaved in a direction opposite to an acoustic reflection layer side comparing to an piezoelectric material part.

A surface acoustic wave device includes a micro-machined pressure transducer for monitoring tire pressure. The device is configured having a micro-machined cavity that is sealed with a flexible conductive membrane. When an external tire pressure equivalent to the cavity pressure is detected, the membrane makes contact with ridges on the backside of the surface acoustic wave device. The ridges are electrically connected to conductive fingers of the device. When the detected pressure is correct, selected fingers on the device will be grounded producing patterned acoustic reflections to an impulse RF signal. When the external tire pressure is less than the cavity reference pressure, a reduced reflected signal to the receiver results. The sensor may further be constructed so as to identify itself by a unique reflected identification pulse series.

The invention relates to the field of communication, and provides an acoustic resonator comprising an annular convex beam eave structure, a filter and an electronic device, and the resonator comprisesa top electrode, a piezoelectric layer, a bottom electrode, an acoustic reflection structure and a substrate which are sequentially connected in position relation. The edge of the top electrode is provided with an eave structure, the eave structure is located in the effective area of the acoustic resonator, and an air gap is formed between the eave structure and the piezoelectric layer. The edgeof the top electrode is further provided with a beam structure, one part of the beam structure is located in the effective area of the acoustic resonator, and an air gap is formed between the beam structure and the piezoelectric layer. A first protruding structure is arranged at the position corresponding to the eave structure, and a second protruding structure is arranged at the position corresponding to the beam structure. Compared with the prior art, the quality factor or the parallel impedance of the acoustic resonator can be effectively improved.

The invention relates to the technical field of a film bulk acoustic wave resonator and specifically relates to a preparation method for the film bulk acoustic wave resonator. According to the method, wafer bonding is carried out through adoption of polymer; SiO<2> hydrophilic bonding frequently used by a traditional ion injection stripping method is replaced; an electrode covered by the polymer can be patterned according to a design of the film bulk acoustic wave resonator. The polymer has fluidity, so the polymer can be flattened under the effect of pressure in a wafer bonding process; and the patterned electrode can be nested into the polymer and the stripping of LiNbO<3> single crystal film is not influenced, so the problem that the electrode is difficult to pattern in a bonding transfer process of the single crystal film is solved. The polymer is taken as an acoustic reflection layer of the film bulk acoustic wave resonator, the problem that an air resonant cavity is low in structure strength and a Bragg acoustic reflection cavity is high in preparation difficulty is solved, a preparation technology of a device is simple, and the prepared device is high in structure strength.

The invention relates to an anchor rod nondestructive testing method based on multi-source information fusion. A testing platform of the method comprises small hammers which are made of more than four materials, an acoustic sensor, a data acquisition device and a computer, wherein the acoustic sensor is arranged on an anchor head at an exposed end of an anchor rod to be tested; the data acquisition device is connected with the acoustic sensor; the computer is connected with the data acquisition device; when the method is used for nondestructive testing of the anchor rod, the anchor head of the anchor rod is knocked by the small hammers of more than four materials respectively, so that more than four excitation signals are generated, an acoustic reflection signal of the bottom end of the anchor rod is transmitted to the data acquisition device through the acoustic sensor, then data acquired by the data acquisition device is subjected to data processing and recognition computation based on multi-source information fusion through the computer, and the nondestructive testing is performed on the anchor rod; and the nondestructive testing comprises length measurement of the anchor rod and/or pouring defect testing. By the method, the defects of weak excitation energy of a single signal, difficulty in recognition, severe field testing conditions and poor stability can be overcome, so that the reflection information is easy to recognize and has high testing accuracy.

Methods and devices are provided for suppressing reverberations within an ultrasound transducer with a backing whereby the backing may not sufficiently attenuate the acoustic energy by means of acoustic absorption and scattering alone. At least a portion of a surface of the backing is segmented into a plurality of levels defined by surface segments. The levels may be are spatially offset so that acoustic reflections from the segmented surface are spread out in time, thereby decreasing the net amplitude of the internally reflected waves as they interact with the piezoelectric layer. Adjacent (neighbouring) levels may be spatially offset by a longitudinal distance equaling approximately an odd number multiple of a quarter of an operational wavelength of the transducer, so that destructive interference occurs from acoustic waves reflected from adjacent levels. Various example configurations of segmented surfaces are described, and methods for selecting a profile of a segmented surface are provided.

A system and method are provided for monitoring bladder distention. Independently controllable acoustic transmitters are coupled to the surface of a user's abdomen region in a spaced-apart fashion. Each transmitter can introduce a broadband acoustic signal into a portion of the abdomen region. Acoustic receivers are also coupled to the surface of the abdomen region to detect acoustic reflections generated when the acoustic signals are introduced into the abdomen region. A controller is positioned on the user and is correlated to an orientation of the user. The controller stores a profile indicative of anatomical features of the user. The controller initiates periodic activations of selected ones of the transmitters based upon the profile and the orientation of the user. The controller uses a weighted combination of all of the acoustic reflections to determine bladder distention of the user. The weighted combination is defined by at least the profile and orientation of the user.

A lithotripsy system capable of 3D tracking monitors the acoustic reflection from the stone in order to focus the shock wave on the stone regardless of shock wave displacement or stone movement. The tracking and focusing is based on a phased array concept, allowing the lithotripsy head to remain stationary and well coupled to the body. An alternate shock wave steering is based on refraction by a variable liquid wedge.

The invention discloses a method for testing bonding defects of a shell of a wine turbine blade and a web plate by using ultrasonic nondestructive testing means. According to the method, the defect of a hungry joint existing in the bonding process of the shell of the wine turbine blade and the web plate can be effectively detected. The method comprises the following parts: detection of preparation work, detection of an implementation process, and a defect judgment criterion. The wine turbine blade is detected by using an ultrasonic flaw detection technology; the internal acoustic reflection situation of the blade can be objectively reflected; and the internal defects of the blade can be effectively judged.

A lithotripsy system capable of 3D tracking monitors the acoustic reflection from the stone in order to focus the shock wave on the stone regardless of shock wave displacement or stone movement. The tracking and focusing is based on a phased array concept, allowing the lithotripsy head to remain stationary and well coupled to the body.

Disclosed is a high Q-value bulk acoustic wave resonator, and the wave resonator comprises a substrate; a piezoelectric stack structure which is located on the substrate, wherein an acoustic reflection structure is arranged between the piezoelectric stack structure and the substrate; one or more high acoustic impedance annular convex structures; one or more low acoustic impedance annular convex structures; wherein the high-acoustic-impedance annular bulge structures and the low-acoustic-impedance annular bulge structures alternately surround the boundary of the piezoelectric stack structure top electrode. According to the invention, through arranging the multiple circles of annular projection structures on the boundary of the top electrode, the transverse leakage of sound waves can be effectively reduced, thereby improving the Q value of the bulk acoustic wave resonator.

A film bulk acoustic resonator includes a substrate; an acoustic reflector portion formed on the substrate; and an acoustic resonator portion including a lower electrode, a piezoelectric film, and an upper electrode which are sequentially stacked on the acoustic reflector portion, An uppermost layer of the acoustic reflector portion which is in contact with the acoustic resonator portion has a root-mean-square roughness of approximately 1 nm or less.

The present invention is for a triangular cross section symmetrical engine exhaust muffler for an internal combustion engine. Its internal design provides baffles symmetrically disposed about a plane centrally located equidistant from the ends of a tube having a triangular cross section. The design has three baffles spaced to minimize backpressure but angled to enhance acoustic reflections within the chamber formed by the tube having a triangular cross section, baffles, and the affixed endplates including the inlet/exhaust ports. These acoustic reflections serve to modify the sound emanating from the exhaust manifold or manifolds of the internal combustion engine. The muffler chamber also serves to smooth out the pulsating gas flow emanating from the engine as a result of the combustion cycle.