中国物理B ›› 2018, Vol. 27 ›› Issue (3): 34301-034301.doi: 10.1088/1674-1056/27/3/034301

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Random phase screen influence of the inhomogeneous tissue layer on the generation of acoustic vortices

Zhiyao Ma(马致遥), Jun Ma(马骏), Dong Zhang(章东), Juan Tu(屠娟)   

  1. 1 Tsien Hsue-shen College, Nanjing University of Science and Technology, Nanjing 210094, China;
    2 School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
    3 Institute of Acoustics, Nanjing University, Nanjing 210093, China
  • 收稿日期:2017-11-04 修回日期:2017-12-01 出版日期:2018-03-05 发布日期:2018-03-05
  • 通讯作者: Jun Ma, Dong Zhang E-mail:majun@njust.edu.cn;dzhang@nju.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61575095, 11374155, and 11674173).

Random phase screen influence of the inhomogeneous tissue layer on the generation of acoustic vortices

Zhiyao Ma(马致遥)1, Jun Ma(马骏)2, Dong Zhang(章东)3, Juan Tu(屠娟)3   

  1. 1 Tsien Hsue-shen College, Nanjing University of Science and Technology, Nanjing 210094, China;
    2 School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
    3 Institute of Acoustics, Nanjing University, Nanjing 210093, China
  • Received:2017-11-04 Revised:2017-12-01 Online:2018-03-05 Published:2018-03-05
  • Contact: Jun Ma, Dong Zhang E-mail:majun@njust.edu.cn;dzhang@nju.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61575095, 11374155, and 11674173).

摘要:

The influence of the inhomogeneous tissue layer on the generation of acoustic vortices (AV) is studied theoretically and experimentally based on the phase screen model. By considering the time-shift of a random phase screen, the formula of acoustic pressure for the AV beam generated by a circular array of eight planar piston sources is derived. With the actual correlation length of the abdominal wall, numerical simulations before and after the insertion of the inhomogeneous tissue layer are conducted, and also demonstrated by experimental measurements. It is proved that, when the thickness variation of the phase screen is less than one wavelength, no significant influence on the generation of AVs can be produced. The variations of vortex nodes and antinodes in terms of the location, shape, and size of AVs are not obvious. Although the circular pressure distribution might be deformed by the phase interference with a larger thickness variation, AVs can still be generated around the center axis with perfect phase spirals in a reduced effective radius. The favorable results provide the feasibility of AV generation inside the human body and suggest the application potential of AVs in object manipulation for biomedical engineering.

关键词: acoustic vortices, random phase screen, phase spiral, correlation length

Abstract:

The influence of the inhomogeneous tissue layer on the generation of acoustic vortices (AV) is studied theoretically and experimentally based on the phase screen model. By considering the time-shift of a random phase screen, the formula of acoustic pressure for the AV beam generated by a circular array of eight planar piston sources is derived. With the actual correlation length of the abdominal wall, numerical simulations before and after the insertion of the inhomogeneous tissue layer are conducted, and also demonstrated by experimental measurements. It is proved that, when the thickness variation of the phase screen is less than one wavelength, no significant influence on the generation of AVs can be produced. The variations of vortex nodes and antinodes in terms of the location, shape, and size of AVs are not obvious. Although the circular pressure distribution might be deformed by the phase interference with a larger thickness variation, AVs can still be generated around the center axis with perfect phase spirals in a reduced effective radius. The favorable results provide the feasibility of AV generation inside the human body and suggest the application potential of AVs in object manipulation for biomedical engineering.

Key words: acoustic vortices, random phase screen, phase spiral, correlation length

中图分类号:  (Radiation pressure?)

  • 43.25.Qp
43.60.Fg (Acoustic array systems and processing, beam-forming) 43.38.Hz (Transducer arrays, acoustic interaction effects in arrays)