Algorithms and Systems for Electromagnetic and Ultrasound Inverse Problems

NSERC的这项发现拨款计划旨在推进构成定量电磁波成像(EWI)和超声成像(USI)基础的核心科学知识和实用技术。这两种技术都是波场成像技术，可以创建不可接近的对象或感兴趣区域的特定属性的定量图像。当使用电磁波(例如，微波)时，诸如区域的介电常数和导电性的属性被成像，而当使用超声波时，诸如可压缩性、衰减系数和质量密度的超声属性被成像。这些属性图像可用于各种诊断应用中。在我的指导下，马尼托巴大学的电磁成像实验室对特定的EWI和USI算法做出了重大贡献，我们已经建立了适用于各种生物医学和工业应用的成像系统。生物医学的主要重点一直是建立检测乳腺癌以及经常监测乳腺癌治疗的系统和技术。这些同样的技术也被纳入用于监测粮食质量的储粮成像系统中，以便及早发现变质。我们在求解非线性逆散射问题的基础上提出的定量波场成像技术，可以在成像应用中引入波型能量作为询问场，并精确测量区域外的散射场。我们的系统设计研究使这一询问/测量过程得以实际表现，我们的软件开发结合了成像算法，使我们能够产生属性图像。*科学和技术挑战限制了使用波场成像获得的图像的精度和分辨率。这些挑战限制了EWI用于乳房成像的采用，但有理由相信，研究将导致改进。对于颗粒成像来说，更重要的是精度，而不是分辨率，因为没有与之竞争的产生属性图像的技术。这项研究计划的总体长期重点是改进和调整EWI和USI算法、技术和系统，使这些模式成为商业上可行的模式，既适用于乳房成像应用，也适用于颗粒成像应用。主要的方法论主题是在开发、整合和利用有助于成像过程的系统设计特征的同时，开发算法的进步。这项研究的成功将开辟新的生物医学和新的工业应用(例如，无损评估)。共有七名研究生将参与这项研究。

This NSERC Discovery Grant proposal aims to advance the core scientific knowledge and practical technologies that form the foundation of quantitative electromagnetic wave imaging (EWI) and ultrasound imaging (USI). Both are wavefield imaging techniques that create quantitative images of particular properties of an inaccessible object or region of interest. Properties such as the permittivity and conductivity of a region are imaged when one utilizes electromagnetic waves, e.g., microwaves, whereas ultrasonic properties, such as the compressibility, attenuation factor, and mass density, are imaged when using ultrasound waves. These property images can be utilized in a wide variety of diagnostic applications. Under my direction, the Electromagnetic Imaging Laboratory at the U. of Manitoba has made significant contributions to particular EWI and USI algorithms and we've built imaging systems applicable to various biomedical and industrial applications. The primary biomedical focus has been on building systems and technologies for the detection of breast cancer as well as for the frequent monitoring of breast cancer treatment. These same techniques have also been incorporated into stored-grain imaging systems that are used for the monitoring of grain quality so as to provide the early detection of spoilage. The quantitative wavefield imaging techniques we've advanced, based on solving the nonlinear inverse scattering problem, can be utilized in imaging applications wherein wave-type energy can be introduced as an interrogating field and the scattered-field outside the region can be accurately measured. Our system design research enables the practical manifestation of this interrogation/measurement process and our software development, which incorporates the imaging algorithms, allows us to produce the property images.****Scientific and technological challenges limit the accuracy and resolution of images obtained using wavefield imaging. These challenges have limited the adoption of EWI for breast imaging but there is reason to believe that research will lead to improvements. Accuracy, rather than resolution, is more important for grain imaging where no competing technology that produces property images exists. The overall long-term focus of this research program is to improve and adapt EWI and USI algorithms, technologies, and systems to the point where these modalities become commercially viable modalities for both the breast imaging application as well as for the grain-imaging application. The main methodological theme is to simultaneously develop algorithmic advances while developing, incorporating, and utilizing system design features that aid the imaging process. The success of this research will open-up new biomedical and novel industrial applications (e.g., non-destructive evaluation). A total of seven graduate students will be involved in this research.