scholarly journals Improvement in resolution of fiber-laser photoacoustic tomography based on a virtual-point concept

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xue Bai ◽  
Xu Li ◽  
Jun Ma ◽  
Bai-Ou Guan
Keyword(s):  
Fiber Laser ◽  
Image Resolution ◽  
Photoacoustic Tomography ◽  
Time Resolved ◽  
Tomography System ◽  
Flexible Fiber ◽  
Arc Shape ◽  
Virtual Point ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique

AbstractIn this study, a virtual-point concept was introduced into fiber-laser photoacoustic tomography to improve the elevational image resolution. The flexible fiber laser was bent into an arc shape to conform to the ultrasound wavefront, which formed an ultrasound focus at the center of the arc. The synthetic aperture focusing technique was utilized to reconstruct the images; as a result, the elevational resolution particularly within the out-of-focus region was considerably improved compared to the resolution of an image retrieved by multiplexing the PA time-resolved signals with sound velocity. The all-optical fiber-laser photoacoustic tomography system with a high spatial resolution has potential for various applications, including biomedical research and preclinical/clinical diagnosis.

ULTRASONIC IMAGING SYSTEM USING A 2D ENVELOPE BEAMFORMING TECHNIQUE: IN-HOMOGENEITIES LOCATION

2004 ◽  
Vol 12 (04) ◽  
pp. 571-585
Author(s):  
L. MEDINA ◽  
E. MORENO
Keyword(s):  
Imaging System ◽  
Side Lobe ◽  
Ultrasonic Pulse ◽  
Image Resolution ◽  
Synthetic Aperture ◽  
Water Tank ◽  
Synthetic Aperture Focusing ◽  
Longitudinal Resolution ◽  
Synthetic Aperture Focusing Technique ◽  
Beamforming Technique

An algorithm has been developed to implement synthetic aperture focusing technique for B-scan. This is made at a several transmitter/receiver locations to form a map of ultrasonic reflectivity on the insonified region, considering the path travelled by the ultrasonic pulse from the transducer to the target and back again. To reconstruct the image, a time domain beam-former is applied to the envelope of the detected signals. This method minimizes the side-lobe amplitude and the restriction of λ/2 distance between two adjacent transducer positions can be neglected without loosing image resolution. The present work is focused on the location of the in-homogeneities, caused by the presence of a phantom immersed in a water tank. The results are presented when the distance between two adjacent transducer positions are varied from 0.5λ to 2.5λ showing that the longitudinal resolution is not affected but the lateral resolution becomes poorer when the distance is about 2λ. The error in the longitudinal location of in-homogeneities is within the minimum detectable distance of the system, while the lateral location error is increased when the distance between any two adjacent transducer positions is larger than 1.5λ.

scholarly journals Photoacoustic Tomography System for Roughly Painted Micro Objects

2019 ◽  
Vol 19 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Andreas Setiawan ◽  
Fransiscus Dalu Setiaji ◽  
Gunawan Dewantoro ◽  
Nur Aji Wibowo
Keyword(s):  
Photoacoustic Tomography ◽  
Tomography System

Photoacoustic microscopy by scanning mirror-based synthetic aperture focusing technique

2015 ◽  
Vol 13 (10) ◽  
pp. 101101-101104 ◽  
Author(s):  
De Cai De Cai ◽  
Zhongfei Li Zhongfei Li ◽  
Sung-Liang Chen Sung-Liang Chen
Keyword(s):  
Synthetic Aperture ◽  
Photoacoustic Microscopy ◽  
Scanning Mirror ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique
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