Lihong Wang - Creve Coeur MO, US Konstantin Maslov - Affton MO, US
Assignee:
Washington University - St. Louis MO
International Classification:
A61B 8/00
US Classification:
600437, 600459, 600476
Abstract:
A confocal photoacoustic microscopy system includes a laser configured to emit a light pulse, a focusing assembly configured to receive the light pulse and to focus the light pulse into an area inside an object, an ultrasonic transducer configured to receive acoustic waves emitted by the object in response to the light pulse, and an electronic system configured to process the acoustic waves and to generate an image of the area inside the object. The focusing assembly is further configured to focus the light pulse on the object in such a way that a focal point of the focusing assembly coincides with a focal point of the at least one ultrasonic transducer.
Method, System And Apparatus For Dark-Field Reflection-Mode Photoacoustic Tomography
Lihong Wang - College Station TX, US Konstantin Maslov - College Station TX, US
Assignee:
The Texas A&M University System - College Station TX
International Classification:
A61B 6/00
US Classification:
600476000
Abstract:
The present invention provides a method, system and apparatus for reflection-mode microscopic photoacoustic imaging using dark-field illumination that can be used to characterize a target within a tissue by focusing one or more laser pulses onto a surface of the tissue so as to penetrate the tissue and illuminate the target, receiving acoustic or pressure waves induced in the target by the one or more laser pulses using one or more ultrasonic transducers that are focused on the target and recording the received acoustic or pressure waves so that a characterization of the target can be obtained. The target characterization may include an image, a composition or a structure of the target. The one or more laser pulses are focused with an optical assembly of lenses and/or mirrors that expands and then converges the one or more laser pulses towards the focal point of the ultrasonic transducer.
Lihong Wang - Creve Coeur MO, US Hui Fang - Saint Louis MO, US Konstantin Maslov - Affton MO, US
Assignee:
WASHINGTON UNIVERSITY IN ST. LOUIS - St. Louis MO
International Classification:
G01F 1/20
US Classification:
702 48
Abstract:
A method for measuring a fluid flow includes employing small light-absorbing particles as tracers that flow at the same speed as the fluid, measuring the photoacoustic Doppler shifts of the photoacoustic signals produced by these tracer particles, and determining, from the measurements, information about the flow including one or more of the flow speed, flow profile, and flow direction.
Reflection-Mode Photoacoustic Tomography Using A Flexibly-Supported Cantilever Beam
Lihong Wang - Creve Coeur MO, US Konstantin Maslov - Affton MO, US
Assignee:
WASHINGTON UNIVERSITY IN ST. LOUIS - St. Louis MO
International Classification:
A61B 5/05
US Classification:
600407
Abstract:
Noninvasively imaging biological tissue using a handheld device. A light pulse is focused into a predetermined area inside an object using a flexibly mounted cantilever beam, acoustic waves emitted by the object in response to the at least one light pulse are detected by a transducer, and an image of the predetermined area inside the object is generated based on a signal generated by the transducer representative of the acoustic waves.
Miniaturized Photoacoustic Imaging Apparatus Including A Rotatable Reflector
Lihong Wang - Creve Coeur MO, US Konstantin Maslov - Affton MO, US Joon-Mo Yang - St. Louis MO, US
Assignee:
WASHINGTON UNIVERSITY IN ST. LOUIS - St. Louis MO
International Classification:
A61B 1/00 A61B 6/00
US Classification:
600104
Abstract:
A reflection-mode photoacoustic endoscope includes a light source configured to emit a light pulse, a signal detection or transmission unit configured to detect or emit an ultrasonic pulse, and a rotatable reflector. The rotatable reflector is configured to reflect at least one of the light pulse and the ultrasonic pulse into a target area of an object, and reflect a response signal to the signal detection unit. The response signal is one of a photoacoustic wave generated by the object responsive to the light pulse and an ultrasonic pulse echo generated by the object responsive to the ultrasonic pulse.
Confocal Photoacoustic Microscopy With Optical Lateral Resolution
A method for determining a ratio of hemoglobin absorption within a biological tissue using a handheld device is provided. The method includes focusing at least one light pulse into a predetermined area inside an object using at least one excitation wavelength, wherein a fluorescence signal is based on at least a local excitation optical fluence and properties of fluorophores in the predetermined area. The method further includes receiving a photoacoustic signal emitted by the object in response to the at least one light pulse, the photoacoustic signal being a product of the local excitation optical fluence, an optical absorption coefficient of hemoglobin, and an acoustic detection sensitivity. The method further includes determining the ratio of hemoglobin absorption based on a hemoglobin absorption coefficient that is based at least partially on the fluorescence signal and the photoacoustic signal.
Method Of Photoacoustic Microscopy With Lateral Resolution Of Microvasculature
- St. Louis MO, US Konstantin Maslov - Affton MO, US
International Classification:
A61B 5/00 A61B 5/02
Abstract:
A method for obtaining a 3-D OR-PAM image of microvasculature within a region of interest of a subject is provided. The method includes: focusing a first light pulse at a first depth beneath a first surface position within the region of interest; receiving a first PA signal in response to the first light pulse; focusing a second light pulse at a second depth beneath the first surface position within the region of interest; receiving a second PA signal in response to the second light pulse; and forming the 3-D OR-PAM image by combining the first PA signal and the second PA signal.