Ultrasound waveguiding of light deep into scattering media

一般来说，光学技术对于生物医学应用（如成像和治疗）具有吸引力。然而，光在生物组织中的大量散射阻止了光有效地穿透到组织中超过几毫米，从而极大地限制了光用于生物医学应用的潜力。因此，迫切地寻求抑制或规避散射的方法。在这些概念中，使用超声波通过声光效应改变光路似乎特别有前途。因此，本项目的目的是系统地评估超声波导如何促进光传输深入散射组织，并通过增加穿透深度实现生物医学组织的光学和光声成像。基于我们的初步研究，我们建立了散射介质中超声和光传播的数值模型，以及超声介导的光波导。有了这些模型，我们得到的实验配置的最佳设置。因此，这些设置将实施和系统的实验分析与散射幻影和解决方案。最后，我们结合联合收割机的优化概念与光声成像和开发的概念，在更大的穿透深度，由于超声介导的光引导的光声成像。总而言之，我们有两个主要目标：1。 全面理解散射介质中超声诱导光波导的物理效应2。 在光声成像中通过超声诱导波导实现高穿透深度

In general, optical technologies are attractive for biomedical applications such as imaging and treatment. However, the massive scattering of light in biological tissue prevents an efficient penetration of light deeper than a few millimeters into the tissue and thus dramatically limits the potential of light for biomedical applications. Therefore, approaches to suppress or circumvent the scattering are desperately sought for. Among those concepts, the use of ultrasound for alteration of the light path via the acoustooptical effect seems particularly promising. Therefore, the aim of this project is to evaluate systematically how ultrasound waveguiding can promote light delivery deep into scattering tissue and by that enable optical and photoacoustic imaging of biomedical tissue with increased penetration depth. Based on our preliminary studies, we develop numerical models for ultrasound and light propagation in scattering media as well as for the ultrasound mediated light waveguiding. With those models, we derive optimum settings for experimental configurations. Consequently, these settings will be implemented and systematically experimentally analyzed with scattering phantoms and solutions. Finally, we combine the optimized concept with photoacoustic imaging and develop concepts for photoacoustic imaging at larger penetration depth due to ultrasound mediated light guiding. In summary, we have two main goals: 1. A comprehensive understanding of the physical effects underlying the ultrasound induced light waveguiding in scattering media 2. Demonstration of high penetration depth via ultrasound induced waveguiding in photoacoustic imaing