Algorithms and Systems for Electromagnetic and Ultrasound Inverse Problems

这项NSERC发现拨款提案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。两者都是波场成像技术，可以对难以接近的物体或感兴趣的区域的特定属性创建定量图像。当利用电磁波（例如微波）时，对一个区域的介电常数和电导率等特性进行成像，而当使用超声波时，对诸如可压缩性、衰减因子和质量密度等超声波特性进行成像。这些属性图像可以用于各种各样的诊断应用。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。主要的生物医学重点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。这些相同的技术也被纳入储存谷物成像系统，用于监测粮食质量，以便及早发现变质情况。我们在解决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，精确测量区域外的散射场。我们的系统设计研究使这个询问/测量过程的实际表现和我们的软件开发，其中包括成像算法，使我们能够产生财产图像。****科学和技术的挑战限制了使用波场成像获得的图像的准确性和分辨率。这些挑战限制了EWI在乳腺成像中的应用，但有理由相信研究将会带来改进。精度，而不是分辨率，更重要的是谷物成像，没有竞争技术产生的财产图像存在。该研究项目的总体长期重点是改进和适应EWI和USI算法、技术和系统，使这些模式成为乳房成像应用和颗粒成像应用的商业可行模式。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，非破坏性评价）。共有7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.