Recent advances in wavefront shaping techniques for biomedical applications

Yu, Hyeonseung; Park, Jongchan; Lee, KyeoReh; Yoon, Jonghee; Kim, KyungDuk; Lee, Shinwha; Park, YongKeun

doi:10.1016/j.cap.2015.02.015

Cited by 217 publications

(134 citation statements)

References 131 publications

Supporting

Mentioning

133

Contrasting

Order By: Relevance

“…Therefore, the choosing of a wavefront modulator is usually a trade-off between the speed, the modulation efficiency, the pixel number, and the cost, among many other requirements from the specific application. Since the initial implementation, wavefront shaping has seen many exciting advancements and has been explored for wide applications, which has been well reviewed [19,[79][80][81] and, thus, will not be reiterated herein. However, it must be pointed out that most efforts in the community have centered on three aspects: to improve the focal intensity enhancement ratio (R), to shorten the optimization process, and to seek appropriate noninvasive guide star to produce the feedback signal.…”

Section: Wavefront Shapingmentioning

confidence: 99%

Wavefront Shaping and Its Application to Enhance Photoacoustic Imaging

Lai

2017

Applied Sciences

View full text Add to dashboard Cite

Abstract:Since its introduction to the field in mid-1990s, photoacoustic imaging has become a fast-developing biomedical imaging modality with many promising potentials. By converting absorbed diffused light energy into not-so-diffused ultrasonic waves, the reconstruction of the ultrasonic waves from the targeted area in photoacoustic imaging leads to a high-contrast sensing of optical absorption with ultrasonic resolution in deep tissue, overcoming the optical diffusion limit from the signal detection perspective. The generation of photoacoustic signals, however, is still throttled by the attenuation of photon flux due to the strong diffusion effect of light in tissue. Recently, optical wavefront shaping has demonstrated that multiply scattered light could be manipulated so as to refocus inside a complex medium, opening up new hope to tackle the fundamental limitation. In this paper, the principle and recent development of photoacoustic imaging and optical wavefront shaping are briefly introduced. Then we describe how photoacoustic signals can be used as a guide star for in-tissue optical focusing, and how such focusing can be exploited for further enhancing photoacoustic imaging in terms of sensitivity and penetration depth. Finally, the existing challenges and further directions towards in vivo applications are discussed.

show abstract

Section: Wavefront Shapingmentioning

confidence: 99%

Wavefront Shaping and Its Application to Enhance Photoacoustic Imaging

Lai

2017

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…The detailed specifications, costs, and pros and cons of each type of SLMs are summarized elsewhere. 8 Measurements of full scattering matrices are, however, still very challenging. Owing to the inherent complexity of the turbid media, there are no general relations between the elements in a matrix.…”

Section: B Scattering Matrixmentioning

confidence: 99%

“…Further information about the scattering properties in specific biological tissues can be found elsewhere. 8,14 …”

Section: Introductionmentioning

confidence: 99%

Perspective: Wavefront shaping techniques for controlling multiple light scattering in biological tissues: Toward in vivo applications

Park

Lee

et al. 2018

APL Photonics

Self Cite

View full text Add to dashboard Cite

Multiple light scattering has been regarded as a barrier in imaging through complex media such as biological tissues. Owing to recent advances in wavefront shaping techniques, optical imaging through intact biological tissues without invasive procedures can now be used for direct experimental studies, presenting promising application opportunities in in vivo imaging and diagnosis. Although most of the recent proof of principle breakthroughs have been achieved in the laboratory setting with specialties in physics and engineering, we anticipate that these technologies can be translated to biological laboratories and clinical settings, which will revolutionize how we diagnose and treat a disease. To provide insight into the physical principle that enables the control of multiple light scattering in biological tissues and how recently developed techniques can improve bioimaging through thick tissues, we summarize recent progress on wavefront shaping techniques for controlling multiple light scattering in biological tissues.

show abstract

“…Recently, the active control of light transport through complex media by shaping an impinging wavefront has been demonstrated, and gained significant interest [1][2][3][4].Such phenomena, governed by the interference of multiply scattered waves, can be well formulated with a scattering matrix (SM). A SM describes a linear relationship between input and output complex fields.…”

mentioning

confidence: 99%

“…Recently, the active control of light transport through complex media by shaping an impinging wavefront has been demonstrated, and gained significant interest [1][2][3][4].…”

mentioning

confidence: 99%

Energy leakage in partially measured scattering matrices of disordered media

Lee

Park

2016

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Light transport through complex media is a fundamentally important physical problem and also has implications in various applications. Recently, the active control of light transport through complex media by shaping an impinging wavefront has been demonstrated, and gained significant interest [1][2][3][4].Such phenomena, governed by the interference of multiply scattered waves, can be well formulated with a scattering matrix (SM). A SM describes a linear relationship between input and output complex fields. A SM consists of two transmission matrices (TM) and two reflection matrices (RM), and considers illuminations from both sides. Because a SM contains the full optical information about light transport through a turbid medium, it has been exploited in various studies, including image reconstruction through a scattering layer [5] One of the most important questions in light transport though turbid media concerns energy transport. Theoretically, the existence of perfect transmission channels, also known as open channels, have been predicted even in highly scattering media, by the random matrix theory [19,20] and particularly the DMPK equation [21,22]. The transmission eigenvalues of ideal TMs or RMs, manifesting energy transmittance, follow a bimodal distribution when wave propagation is in the diffusive regime, which indicates the existence of perfect transmission channels regardless of sample thicknesses.Unfortunately, attempts to enhance energy delivery through turbid media via open channels have not been fully explored in experimental conditions. Recently, several works have demonstrated enhancements of energy delivery [23,24]. However, the demonstrated enhancements were far below the theoretically expected ones, mainly due to the limited number of optical modes for measurements and controls. More recently, it was shown that the limited numerical apertures (NAs) of lenses in optical systems prevent them from accessing information about open channels, and thus enhanced energy delivery through turbid media will be significantly limited [25,26]. Although the accessible information in experimental conditions has been well described, uncollected information which is beyond the capability of a measurement system, and its effect on energy transmission, have never been previously considered.Recently, several methods have been developed to enhance energy delivery via reflection measurements [27,28]. However, transmission was restricted to only about 3-fold enhancements in these studies. In addition, the ultimate limit of the enhancement was not clarified, particularly in relation to practical experimental conditions. Importantly, controlling energy transmission by monitoring reflected fields also has potential for biomedical applications because it does not require an invasive scheme.In this letter, we investigate energy leaky modes which originate from partial measurements of a SM, using numerical simulations. When a TM or RM of a medium is completely measured, incident energy can be fully delivered to the output si...

show abstract

Recent advances in wavefront shaping techniques for biomedical applications

Cited by 217 publications

References 131 publications

Wavefront Shaping and Its Application to Enhance Photoacoustic Imaging

Wavefront Shaping and Its Application to Enhance Photoacoustic Imaging

Perspective: Wavefront shaping techniques for controlling multiple light scattering in biological tissues: Toward in vivo applications

Energy leakage in partially measured scattering matrices of disordered media

Contact Info

Product

Resources

About