75 results about "Thermoacoustic imaging" patented technology

A method and system for examining biological tissue includes the steps of radiating a tissue region with a plurality of microwave radiation pulses. The microwave pulses are swept across a range of microwave frequencies. In response to the swept frequency microwave pulses, the tissue region emits a plurality of thermoacoustic signals. At least one image of the tissue region is formed from the plurality of thermoacoustic signals. The signals can be ultrawideband signals.

Methods and systems to analyze soft tissue or vasculature in a subject, form images with enhanced soft tissue contrast, determine blood flow parameters in soft tissue or vasculature, and to aid in the diagnosis of disease using thermoacoustic methods. Pulsed electromagnetic energy is administered to tissue to excite a thermoacoustic signal in the soft tissue or vasculature. An acoustic receiver or receiver array is coupled to a subject to detect and record the thermoacoustic signals produced. Thermoacoustic data are acquired after administration of a physiologically-tolerable tracer or contrast agent. The acquired data may be analyzed to produce images of the soft tissue and vasculature (angiogram), to determine blood flow parameters, and/or to diagnose disease in a subject.

The invention discloses an ultrashort pulse microwave thermoacoustic imaging method and an ultrashort pulse microwave thermoacoustic imaging device. The device comprises an ultrashort pulse microwave generator, an ultrasonic detector and a data acquisition and image reconstruction device. The method comprises the following steps of: fixing an object to be detected in a coupling tank containing deionized water; making the ultrashort pulse microwave generator output ultrashort pulse microwaves under the control of a trigger circuit, making the ultrashort pulse microwaves uniformly irradiate theobject to be detected through a pulse transmitting antenna, and exciting to obtain thermoacoustic signals; and receiving the thermoacoustic signals by using the ultrasonic detector, making signals output by the trigger circuit trigger a data acquisition card to acquire the thermoacoustic signals, and recording and saving the thermoacoustic signals and reconstructing images by using a computer. The ultrashort pulse microwave generator with ns-level pulse width excites the thermoacoustic signals, the thermoacoustic signal exciting efficiency can be greatly improved, and a sample to be detected is subjected to high-resolution tomography. The device has high imaging resolution, simple structure and low cost, and is convenient to operate and easily promoted and applied in the field of nondestructive testing.

The present disclosure provides systems and methods for combining photoacoustic/thermoacoustic imaging with power Doppler signal processing. More particularly, the disclosed systems and methods involve use of encoded Doppler signals in order to detect and image in vivo blood flow. The disclosed flow detection systems and methods may be used in photoacoustic imaging using PD to achieve, inter alia, enhanced signal-to-noise (SNR) and sensitivity performances. A method for detecting flow in a target region may involve (i) obtaining a encoded signal containing photoacoustic imaging data for the target region using a photoacoustic imaging system, (ii) decoding the encoded signal, (iii) passing the decoded signal through a demodulator and a low-pass filter, resulting in a base-band signal, (iv) passing the base-band signal through a wall filter, resulting in an uncluttered signal; and (iv) estimating the Ro value by integrating the power spectrum of the uncluttered signal.

Apparatus comprising at least one transducer comprising a displacement component that is configured to move upon application of an electrical signal; a cavity in communication with the at least one transducer; and at least one thermodynamic member within the cavity configured to readily exchange heat with a cavity gas or fluid, wherein the transducer is configured to generate a standing wave within the cavity to transfer heat along the thermodynamic member.

The invention discloses a system and a method for measuring temperature in real time based on thermoacoustic effect. A thermoacoustic signal of a detected material is detected by using thermoacoustic imaging equipment; a relation parameter of the temperature of the detected material and the thermoacoustic signal amplitude value is obtained by data fitting; during actual temperature measurement, by using the known fitting parameters and through the relation of the temperature of the detected material and the thermoacoustic signal, the temperature of the detected material is obtained by reversely deducing and analyzing by using a one-dimensional thermoacoustic signal; and finally a temperature distribution figure is displayed on a computer in real time. Combined with the advantages of thermoacoustic technology, the system and the method for measuring the temperature in real time based on the thermoacoustic effect have high accuracy and high spatial resolution, and can quickly obtain temperature change parameters and the temperature distribution figure in real time under the condition of no damage, wherein the temperature measurement accuracy can reach 0.2 DEG C, so a reliable monitoring method and a system device are provided for real-time and nondestructive measurement of material temperature.

The invention relates to a method for using thermal sound image to detect foreign material and relative device. Said device is formed by a microwave generator, a rotational scanning element, a sound signal collector, a computer, a sample fixer, and a sound coupler, while the microwave generator, sound signal collector, and the computer are electrically connected; the rotationally scanning element is electrically connected with the computer; the sample fixer is in the sound coupler; and the sample fixer is connected with the rotational scanning element. The invention has high positioning accuracy, high resolution and the application for supplying clear image to the foreign material detecting technique, with low cost.

The invention belongs to the thermoacoustic imaging technology field, in particular to an image reconstruction algorithm of the sound velocity uneven medium thermoacoustic imaging. The method modifies the time domain reconstruction method of the sound velocity uneven medium thermoacuostic imaging, which leads to that the propagation time of acoustic waves between two points in medium is no longer proportional to the distance and is worked out through the estimated sound velocity distribution. Currently, the prior knowledge of the sound velocity distribution is mostly required by the reconstruction algorithm on the sound velocity uneven medium thermoacuostic imaging. And an iterative method is adopted for the calculation and the speed is slow. The invention does not require the prior knowledge of the sound velocity distribution in the medium and is a direct inverse approach. The invention can rapidly reconstruct a whole thermoacoustic image.

A method of identifying a flaw in a part is provided that includes vibrating a part to induce heat. The heat originates in any flaws in the part. A thermal image is obtained using, for example, an infrared camera. A mathematical representation of the thermophysics, such as the heat conduction or thermal energy equations using the boundary element method or finite element method is used to identify a source and an intensity of the heat identified with the thermal image. Using the source and intensity of the heat, flaw characteristics for the part can be determined. The method is employed using an inspection system that includes a vibration device for vibrating the part. An imaging device, such as an infrared camera, measures temperature on the surface of the part. An assumption is made or additional measurements are taken to obtain values for surface flux or surface heat transfer coefficients. A processor communicates with the imaging device for receiving the surface temperature. The processor includes computer memory having part characteristics and mathematical equations. The processor uses the measured surface temperature, assumed or measured heat flux or heat transfer coefficients, part characteristics and mathematical equations to determine the flaw characteristics in the part.

The invention discloses an early-stage breast cancer nondestructive screening and imaging system, which mainly comprises circular gears, an annular ultrasonic array, a bowl-shaped annular shell, ultrasonic coupling liquid, a protective film, a horn antenna, a waveguide tube, a microwave generator, a frequency divider, a data acquisition circuit, a preprocessing circuit, a stepping motor, a driver, a digital I/O card, a computer and a display. The working process of the system is that: detected mammary glands are radiated by pulse microwaves to generate thermo-acoustic signals which are received by the annular ultrasonic array and are finally acquired by the computer; the driver drives the annular ultrasonic array to rotate to a next position around detected biological tissues; and the steps of acquisition and rotation are repeated until the thermo-acoustic signals of enough positions are received, and the computer re-establishes three-dimensional thermo-acoustic images of the detectedtissues. The early-stage breast cancer nondestructive screening and imaging system can quickly and nondestructively realize the three-dimensional thermo-acoustic imaging of the detected mammary glands to provide one of important bases for the diagnosis of early-stage breast cancer.

The invention relates to a close-contact ultrasonic coupling adaptive device for photoacoustic/thermoacoustic mammary gland imaging detection, and belongs to the technical field of photoacoustic/thermoacoustic imaging. The adaptive device comprises a detection cup, a coupling liquid spray device and an air pressure regulating device, wherein a to-be-detected breast is placed in the detection cup with the shape and the size corresponding to the breast; the coupling liquid spray device is connected with the detection cup, and can spray ultrasonic coupling liquid between the to-be-detected breast and the detection cup; and the air pressure regulating device is connected with the detection cup by an air guide tube, and inhales or deflates between the to-be-detected breast and the detection cup. The adaptive device has the advantages that the adaptive device is good in matching degree, safe, comfortable, easy to replace, and high in automation degree.

A three-dimensional thermoacoustic imaging system uses dye markers. Thermoacoustic signals are produced by the dye markers when light from an external source is absorbed by the dye. Thermoacoustic images with and without dye stimulation may be generated using excitation frequencies both inside and outside the frequency band of fluorescence of the dye marker, and these may be combined, and/or combined with conventional ultrasound images for image enhancement. An apparatus for carrying out this method on mice, uses a commercially available array of transducers positioned opposite to the body of the mouse, which is immersed in a coupling media. A source of illumination such as a laser directs light to the mouse through the coupling media, and resulting acoustic waves are captured by the array and reconstructed to form an image.

The present invention is directed to a method and system of TCT imaging whereupon an exact inversion formula is used for reconstruction of TCT data. The present invention utilizes inversion formulae that are of the filtered backprojection and ρ-filter types.

The invention discloses a magnetic thermoacoustic imaging conductivity reconstruction method based on a linear Poisson's equation. An exciting coil generates an electromagnetic thermoacoustic signal on a conductive object; an ultrasonic transducer receives the electromagnetic thermoacoustic signal; an ultrasonic signal processing and acquiring subsystem acquires and processes the signal; and a control circuit controls the synchronization of a current excitation source, the ultrasonic transducer and the ultrasonic signal processing and acquiring subsystem. The method comprises the following steps: performing circular fault scanning on the electromagnetic thermoacoustic signal by virtue of the ultrasonic transducer, acquiring an electromagnetic ultrasonic signal on the circumference of each fault, and finally combining an image reconstruction algorithm to realize the conductivity image reconstruction. The conductivity image reconstruction method comprises the following steps: firstly defining an objective function meeting a thermoacoustic source, the conductivity, a primary magnetic dislocation spatial component and an electric scalar potential spatial component, giving the initial value of the conductivity, solving the electric scalar potential spatial component according to a current continuity theorem under the condition that the thermoacoustic source distribution is known, substituting the electric scalar potential spatial component and magnetic dislocation spatial component into the objective function, and reconstructing the conductivity distribution.

The invention provides an injection current type thermoacoustic imaging method. The injection current type thermoacoustic imaging method is characterized by: through an electrode, injecting a current into an imaging target, generating Joule heat in the imaging target body, causing thermal expansion, generating an ultrasonic signal, utilizing an ultrasonic probe to detect the ultrasonic signal, and reconstructing conductivity distribution of a sound source and a target body according to the detected ultrasonic signal. The injection current type thermoacoustic imaging method can be used for electric impedance imaging with high-resolution, and is used for early diagnosis of diseases.

A thermoacoustic imaging device is provided having a transmitter configured to provide an electromagnetic transmit signal (e.g. a continuous sinusoidal signal) to an object being imaged. The transmit signal is a modulated continuous-wave signal based on a carrier frequency signal f_c modulated at a modulation frequency at or near f_m. The detector is further configured to receive an acoustic signal from the object being imaged, and is responsive to acoustic frequencies at or near 2f_m. A non-linear thermoacoustic effect in the object being imaged generates the acoustic signal from the object being imaged. Spectroscopic maps could be generated and imaged object could be analyzed. The device enhances signal-to-noise ratio of the reconstructed image and reduces the requirement of peak power in thermoacoustic imaging systems. In addition, the generated pressure of the imaged object is separated from microwave leakage and feedthrough in frequency through the nonlinear thermoacoustic effect.

Disclosed is a magneto-thermoacoustic tomographic method and system. According to the method, linear frequency modulated magnetic field is applied to a conductive object (7), an induction electric field is generated in the conductive object (7), joule heat is generated, and the conductive object (7) is excited to generate a thermoplastic ultrasonic signal, the thermoplastic ultrasonic signal is detected, and reconstructing of acoustic field and electric field inverse problems is performed to acquire a conductivity distribution image. The system comprises an excitation module, a detection module, a water tank, a control module and an upper computer; the excitation module is mainly composed of a signal generator, a power amplifier and an excitation coil; the detection module is mainly composed of an ultrasonic transducer, a signal conditioning circuit and a signal acquisition circuit; the control module is used for motion control, excitation source control, acquisition control and image reconstruction control; the upper computer is used for implementing an image reconstruction function and a control function of the control module.

The invention discloses a thermoacoustic imaging system for lymphedema imaging as well as a control method thereof, and belongs to field of medical treatment. The thermoacoustic imaging system for lymphedema imaging comprises a pulsed microwave source, an ultrasonic transducer, a thermoacoustic signal processing unit, a data acquisition unit and a computer, wherein the pulsed microwave source is used for exciting thermoacoustic effect in a lymphedema region to generate a thermoacoustic signal; the ultrasonic transducer is used for receiving the thermoacoustic signal; the thermoacoustic signalprocessing unit comprises an amplifier and a filter which are correspondingly used for amplifying and filtering the thermoacoustic signal; the data acquisition unit is used for performing A/D conversion on the amplified and filtered thermoacoustic signal to acquire a digitized thermoacoustic signal; the computer is used for controlling the pulsed microwave source, performing image reconstruction on the digitized thermoacoustic signal to acquire an thermoacoustic image and performing color coding on the thermoacoustic image to realize the prominent imaging of lymphedema.

The invention discloses a sealed breathing mask for a rat, and relates to an animal experimental device, in particular to a breathing mask for a rat. The sealed breathing mask for the rat aims to effectively fix the head of the rat and prevent leakage of gas in the mask. The sealed breathing mask for the rat consists of a special-bowl-shaped shell, a special-shaped silica gel sealing ring, a toothed rod, a silica gel ring and a packing ring. By combination of the special-bowl-shaped shell and the silica gel sealing ring, the mask can be attached to the face of the rat, while being connected with the rat and the breathing mask, the toothed rod can further serve as a gas outlet channel of the mask, and while the packing ring can effectively fix the toothed rod, a gas outlet can be sealed bythe packing ring. By good airtightness, an experimenter can be effectively prevented from being exposed in dangerous gas, gas (liquid) of the outside is prevented from entering the mask, experiments such as photoacoustic imaging and thermoacoustic imaging can be met, and after the rat submerges into water, experimental requirements for guaranteeing free breathing of the rat can further be met.

A cancer detection system may comprise at least two imaging systems, each of which implements a different imaging modality, and each of which provides sampled image data. The system may further include, for each imaging modality, a modeling unit to produce modeled image data based on a common set of biophysical parameters. The system may also include a joint non-linear inversion module to receive information from each modeling unit and reconstruct a set of joint biophysical properties. The system may include a scaling unit to revise the common set of biophysical parameters based on the set of joint biophysical properties. The system may include a comparator to compare the sampled image data from each of the imaging systems to the corresponding modeled image data to determine a difference between the sampled image data and the modeled image data, and to determine when the difference is less than a threshold difference.