Design, fabrication, and testing of a dual-band photoacoustic transducer

Jian-Hung Liu; Chen-Wei Wei; Yae-Lin Sheu; Yu-Tsung Tasi; Yu-Hsin Wang; Pai-Chi Li

doi:10.1117/12.809954

12 February 2009 Design, fabrication, and testing of a dual-band photoacoustic transducer

Jian-Hung Liu, Chen-Wei Wei, Yae-Lin Sheu, Yu-Tsung Tasi, Yu-Hsin Wang, Pai-Chi Li

Proceedings Volume 7177, Photons Plus Ultrasound: Imaging and Sensing 2009; 717712 (2009) https://doi.org/10.1117/12.809954
Event: SPIE BiOS, 2009, San Jose, California, United States

Abstract

The absorption coefficients in most biological tissues range from 1 cm-1 to 10 cm-1, which produce photoacoustic signal with peak frequency lower than 5 MHz. However, the lower operating frequencies mean equivalently larger wavelengths, which are incapacitation to resolve smaller objects. In order to obtain the excellent performance of images in both sensitivity and resolution, this study discusses the design and fabrication of the dual frequencies photoacoustic transducer (DFPT) with 36°-rotated, Y-cut lithium niobate (LiNbO3) material. The DFPT had a diameter of 6 mm and comprised two concentric rings of equal area with center frequency of the outer and inner elements as 4.9 MHz and 14.8 MHz, respectively. Moreover, there was a 0.65 mm hole in the DFPT surface for insertion of an optical fiber, which solved conventional light-placing problem. The experiment was performed with an agarose phantom which mixed glass beads with various concentration of black stain to create different optical absorptions. The absorption coefficients of absorbers are 5.6 cm-1 and 11.8 cm-1, respectively. The mean amplitude between the two absorbers differs by 0.5 dB at band 0-5 MHz, while the difference increases to 5.9 dB at band 6-15 MHz. The results show that the DFPT not only provides high ultrasonic resolution but also enhances the contrast based on higher frequency subbands for photoacoustic imaging. The potential of improving the contrast between biological tissues and contrast agent with a significant higher absorption is revealed. In the future, the DFPT will be applied to in vivo investigation with gold nanoparticles. Bioconjugated gold nanoparticles have been used as a photoacoustic contrast agent as well as a molecular probe to target cancer cells in a small animal model. The denseness of targeted gold nanoparticles on tumor results in a higher absorptions, which means higher frequency signals comparing to those of surrounding tissues. Thus, DFPT will assist in recognizing the tumor region for a better diagnosis.

Citation Download Citation

Jian-Hung Liu, Chen-Wei Wei, Yae-Lin Sheu, Yu-Tsung Tasi, Yu-Hsin Wang, and Pai-Chi Li "Design, fabrication, and testing of a dual-band photoacoustic transducer", Proc. SPIE 7177, Photons Plus Ultrasound: Imaging and Sensing 2009, 717712 (12 February 2009); https://doi.org/10.1117/12.809954

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available