95 results about "Photoacoustic tomography" patented technology

A system and method for photoacoustic tomography of a sample, such as a mammalian joint, includes a light source configured to deliver light to the sample, an ultrasonic transducer disposed adjacent to the sample for receiving photoacoustic signals generated due to optical absorption of the light by the sample, a motor operably connected to at least one of the sample and the ultrasonic transducer for varying a position of the sample and the ultrasonic transducer with respect to one another along a scanning path, and a control system in communication with the light source, the ultrasonic transducer, and the motor for reconstructing photoacoustic images of the sample from the received photoacoustic signals.

Photoacoustic imaging is enhanced by scanning (61) the sensor array (10) used in photoacoustic imaging laterally relative to the tissue being imaged, gathering multiple tissue images (70, 71, 72, 73) at multiple relative lateral positions, and generating a photoacoustic image (80) of the tissue by combining the images taken at multiple relative lateral positions.

A measurement method of measuring a spectroscopic characteristic inside of a scattering medium includes

a first step of measuring the spectroscopic characteristic of the scattering medium by using diffuse optical tomography by irradiating light into the scattering medium, a second step of measuring the spectroscopic characteristic of the scattering medium by using acousto-optical tomography or photo acoustic tomography by irradiating light into the scattering medium, and a third step of making an assumption of a distribution of the spectroscopic characteristic inside of the scattering medium and of changing the assumption such that a difference between a predicted value of the spectroscopic characteristic derived from the assumption and a measured value obtained in the first step can fall upon a permissible range. The third step uses data obtained in the second step for at least one of the parameter: an initial value, a constraint condition, or a boundary condition.

Provided herein is an optoacoustic imaging system configured to produce images of one or more objects in a body using at least a maximum angular amplitude probability algorithm to reconstruct the optoacoustic images of the body. In addition the optoacoustic imaging system may be configured to produce 3D maps from the reconstructed optoacoustic images of the body. Also, provided is a method for diagnosing a pathophysiological condition characterized by abnormal optical properties of tissues in a body from maps so produced.

Accurately quantifying optical absorption coefficient using acoustic spectra of photoacoustic signals. Optical absorption is closely associated with many physiological parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of non-fluorescent molecules. A sample is illuminated by, for example, a pulsed laser and following the absorption of optical energy, a photoacoustic pressure is generated via thermo-elastic expansion. The acoustic waves then propagate and are detected by a transducer. The optical absorption coefficient of the sample is quantified from spectra of the measured photoacoustic signals. Factors, such as system bandwidth and acoustic attenuation, may affect the quantification but are canceled by dividing the acoustic spectra measured at multiple optical wavelengths.

The biological tissue photoacoustic tomography method includes the following steps: (1). making pulse laser come into the biological tissue to produce photoacoustic signal; (2). making a beam of detection focus ultrasonic wave come into the photoacoustic zone, and interacting with photoacoustic signal to form superposition of the above-mentioned two signal; (3). receiving and measuring the superimposed signal; (4) making frequency spectrum separation by using computer, extracting and storing photoacoustic signal; and (5). making filtering and integration treatment of the photoacoustic signal,and utilizing the leaner projection algorithm to implement tissue chromatographic imaging. Said equipment includes laser, ultrasonic wave generator component, acoustic sgnal measuring component, signal amplifier, data collecting card, three-D electric rotating platform and computer.

Systems and methods for improving limited-view photoacoustic tomography using an acoustic reflector are described. In particular, an acoustic reflector and ultrasonic transducer array are integrated to provide a virtual array that enhances the field of view of the ultrasonic transducer array, thereby improving the quality of photoacoustic tomography images obtained using the systems and methods described herein.

A method and system for remote sensing. The method includes applying an orbital angular momentum (OAM) mode on a light beam to generate an OAM light beam having an optical OAM spectrum, exposing a target object to the OAM light beam such that the target object absorbs energy of the OAM light beam to generate ultrasonic emissions, the ultrasonic emissions having a reflected OAM spectrum associated with the target object, and generating a high resolution image of the target object based on the reflected OAM spectrum.

The invention relates to a double-focusing ultrasonic probe and sparse array photoacoustic tomography imaging system. Each probe comprises a concave detection face. The numerical value hole diameter of each concave detection face in the first direction is larger than that of the concave detection face in the second direction. A signal receiving angle of each concave detection face in the first direction is larger than that of the concave detection face in the second direction. The focused region length of each concave detection face in the second direction is larger than that of the concave detection face in the first direction. The first direction is perpendicular to the second direction. Each probe has a large signal receiving angle on an imaging fracture surface, and therefore the quality of an image reconstructed by a compressed sensing image reconstructing method under a low sampling rate can be improved. Meanwhile, an annular probe array can be formed in a sparse distribution mode, and cost of the imaging system can be reduced. Data acquisition amount needed by image reconstruction can be reduced, and therefore data acquisition speed and imaging speed are increased.

The invention discloses a system and method for diffused optical tomography and photoacoustic tomography combined measurement. The system comprises a diffused optical tomography measurement part (1), an imitating CT space scanning system (2), a photoacoustic tomography measurement part (3) and an industrial control computer (4), wherein the diffused optical tomography measurement part (1) and the photoacoustic tomography measurement part (3) are jointly connected with the imitating CT space scanning system (2) to form an integrated multi-mode measurement system, and system automatic control software of the industrial control computer (4) is used for achieving automatic detection and data collection of a diffused optical signal and a photoacoustic signal. Compared with the prior art, by means of the system and method for the diffused optical tomography and photoacoustic tomography combined measurement, the defects of an existing single-mode imaging technique are overcome, the defect that for the prior art, the spatial resolution and the quantitative feature cannot be achieved simultaneously is overcome, the imaging method can achieve the spatial resolution of the photoacoustic tomography technique and the quantitative precision of the diffused optical tomography technique, and therefore the high-quality optical parameter imaging function is achieved.

A method and apparatus are provided for performing photoacoustic tomography with respect to a sample that receives a pulse of excitation electromagnetic radiation and generates an acoustic field in response to said pulse. One embodiment provides an apparatus comprising an acoustically sensitive surface, wherein the acoustic field generated in response to said pulse is incident upon said acoustically sensitive surface to form a signal. The apparatus further comprises a source for directing an interrogation beam of electromagnetic radiation onto said acoustically sensitive surface so as to be modulated by the signal; means for applying a sensitivity pattern to the interrogation beam; and a read-out system for receiving the interrogation beam from the acoustically sensitive surface and for determining a value representing a spatial integral of the signal across the acoustically sensitive surface, wherein said spatial integral is weighted by the applied sensitivity pattern. The apparatus is configured to apply a sequence of sensitivity patterns to the interrogation beam and to determine a respective sequence of values for said weighted spatial integral for generating a photoacoustic image.

The invention discloses a tri-modal breast imaging system and an imaging method thereof.A testing system of the tri-modal breast imaging system comprises a frame, first, second and third lifting platforms, a pressing plate, a transparent plate, an X-ray source, an X-ray detector, an ultrasonic array, a laser, a data collection card, a computer, a refractive divergence component and a motion platform or a transfer platform. By means of integration among three modals including photoacoustic tomography, X-ray breast imaging and ultrasonic imaging, one piece of imaging equipment is adopted for tri-modal breast imaging without changing positions of tissue to be tested. The three modals differ in imaging contrast sources and complement with one another in terms of information. Therefore, non-invasive imaging among the structure, physiological and pathological features and the metabolic function of mammary tissue is carried out after images are filtered, projected and fused so that position and size of a tumor can be accurately determined. The tri-modal breast imaging system is particularly suitable for early detection and continuous monitoring of treatment effect of a breast cancer.

The invention discloses a photoacoustic tomography system combined with an acoustical transmission reflector and an imaging method of the photoacoustic tomography system combined with the acoustical transmission reflector. The photoacoustic tomography system comprises a laser light source, a conscope body, the acoustical transmission reflector, an animal platform, a water tank, a detector and a computer. The acoustical transmission reflector is utilized, and a metal-coated LDPE (Low-Density Polyethylene) material is adopted as the material of the acoustical transmission reflector, so that acoustic impedance similar to that of water is obtained, and further, remarkable ultrasonic reflection is not generated at a water-medium interface; and the material is thin, so that attenuation of ultrasonic waves in the material is lower, loss of the acoustical transmission reflector on the ultrasonic waves is very small, and the transmission of the ultrasonic waves is more convenient. Further, the conscope body is combined with an inverted cone-shaped acoustical transmission reflector, light is focused in a horizontal plane and irradiated onto an animal body to form 360-degree horizontal and uniform irradiation on the animal body, and a uniform and stable light field can be formed in the animal body, so that a reconstructed image can more accurately reflect physiological structure function information in the animal body when the detector is used for detection.

A method of noninvasively imaging tissue within a body includes irradiating the tissue using an imaging laser including a Raman-based laser tuner, the radiation including a plurality of laser pulses, each having energy greater than 100 mJ; receiving an acoustic signal generated by vibrational energy in the tissue, wherein the vibrational energy is a result of selective overtone excitation of molecules in the tissue by the radiation; and automatically converting the acoustic signal to an image representative of the tissue using a processor. An imaging system includes an imaging laser configured to irradiate tissue with a plurality of laser pulses using a Raman-based laser tuner. An ultrasonic transducer receives an acoustic signal generated by vibrational energy in the tissue due to overtone excitation by the radiation. A processor is configured to automatically produce an image representative of the tissue using the received acoustic signal.

A molecular probe marked with a color center material is used as a photoacoustic imaging agent to obtain an acoustic signal of practically adequate intensity using weak near-infrared light, which has good in vivo penetration depth but has small excitation energy, and is within the maximum permissible exposure, in photoacoustic tomography (PAT) diagnosis of a living body.

Provided is a display data obtaining apparatus capable of, in photoacoustic tomography, reducing a fluctuation in sensitivity which depends on location for image reconstruction even in a limited measurement condition in which a photoacoustic wave generated in the entire subject cannot be obtained in a sufficient range. The display data obtaining apparatus includes: an acoustic wave detecting unit for detecting an acoustic wave generated from a subject irradiated with pulsed light to obtain a signal; a first data deriving unit for deriving first data exhibiting an optical characteristic distribution of the subject based on the obtained signal obtained by the acoustic wave detecting unit; a memory for storing spatial sensitivity distribution data specific to the display data obtaining apparatus; and a second data deriving unit for deriving second data exhibiting the optical characteristic distribution of the subject using the first data and the spatial sensitivity distribution data.