CAREER: Synthetic Ultra-Wideband Millimeter-Wave Imaging for Tissue Diagnostics

建议的工作将产生应用毫米波技术在生物医学成像应用所需的基础和技术知识。尽管这种低成本技术在生物医学成像环境中具有各种优势，包括高图像对比度和合适的穿透深度，但它尚未应用于任何此类应用。主要原因是它在为诊断目的提供足够分辨率方面的局限性。该方案提供了一种新的方法，通过该方法可以合成任何传统设计方法无法实现的超宽成像带宽。这将提高图像分辨率到以前未达到的值。该提案的主要重点是开发一种便携式低成本皮肤成像设备，该设备可以以高分辨率对组织层进行深度成像，同时提供恶性组织和正常组织之间令人满意的对比。通过在早期阶段诊断皮肤肿瘤，该设备将节省大量的时间和精力，减少患者的不适，并为个体患者和国家医疗保健系统显著降低成本。拟议的研究将结合各种教育和推广工作，旨在让研究生、本科生和高中生参与拟议的研究，提高他们对生物电磁学和生物医学成像的兴趣。PI将具体追求以下主要目标：1)通过自由科学中心的“科学伙伴”项目吸引高中生，2)通过史蒂文斯研究所的暑期学者研究项目招收本科生，特别是女性和少数族裔的本科生，并激励他们继续攻读研究生，3)参加史蒂文斯医疗保健创新中心组织的活动和研讨会，4)在史蒂文斯建立电磁学生物医学应用课程，5)在专业会议和技术期刊上传播研究成果。“合成”超宽带毫米波成像，这是一种探索超宽成像带宽的新方法。这是任何传统的设计方法都无法实现的，因此是“综合”组装的，从而显著提高了获取图像的分辨率。通过将所需带宽划分为若干相邻子带或信道来实现合成增益。每个信道包含一个天线单元，该天线单元被优化为在该特定子频带内运行。子带天线依次放置在目标前方，发射目标信号，并记录目标的后向散射响应。然后对这些响应进行处理和组合以合成一个集成信号，就好像它是从虚拟等效超宽带天线收集的一样。通过使用这一概念，在毫米波频段实现高性能超宽带天线的挑战得到了缓解，因为每个天线都在有限的带宽内进行了优化。基于这种方法，将开发一种成像系统，用于在离体组织测量中检测皮肤肿瘤。该系统将通过开发用于多静态传感器阵列的新型宽带小型化贴片天线来优化和小型化。最终的成像设置将很容易适用于护理点和手持成像设备。“合成”超宽带成像方法将导致使用常规成像方法无法实现的图像分辨率。该方法是通用的，因为通道的数量和位置可以根据具体应用的需要调整以覆盖任何频率范围。这些功能为毫米波成像系统带来了全新的功能水平，并使目前不可行的应用成为可能。此外，新型宽带、小型化贴片天线将为最终成像装置的小型化和优化而开发，这对于毫米波范围内的各种通信和成像应用是非常理想的。

The proposed work will generate the required fundamental and technological knowledge for applying the millimeter-wave technology to biomedical imaging applications. Despite the various advantages of this low-cost technology in a biomedical imaging context including high image contrasts and suitable penetration depths, it has not been applied to any such application. The main reason is its limitation in providing sufficient resolutions for diagnostic purposes. This proposal offers a novel approach by which an ultra-wide imaging bandwidth that cannot be realized by any conventional design method is assembled synthetically. This will improve image resolutions to values previously unattained. The main focus of this proposal is the development of a portable and low-cost skin imaging device that can image tissue layers over their depths with high resolutions while offering satisfactory contrasts between malignant and normal tissues. By diagnosing skin tumors at an early stage, the device will save tremendous amounts of time, effort, and patient discomfort and provide significant cost reductions for both the individual patient and the nation's healthcare system. The proposed research will be combined with various educational and outreach efforts aimed at involving graduate, undergraduate, and high school students in the proposed research and raising their interests in bio-electromagnetics and bio-medical imaging. The PI will specifically pursue the following main goals: 1) engaging high school students through the Liberty Science Center's "Partners in Science" program, 2) recruiting undergraduate students, especially from female and minority groups, through the Summer Scholars Research Program at Stevens Institute and motivating them to continue towards graduate studies, 3) participating in the events and seminars organized by the Center for Healthcare Innovation at Stevens, 4) establishing a course on biomedical applications of electromagnetics at Stevens, and 5) disseminating the results of the research at professional conferences and technical journals. "Synthetic" ultra-wideband millimeter-wave imaging, a novel approach in which an ultra-wide imaging bandwidth will be explored. This cannot be realized by any conventional design method and is therefore assembled "synthetically", resulting in significant improvements in the resolution of acquired images. The synthetic increase is achieved by dividing the desired bandwidth into a number of adjacent sub-bands or channels. Each channel contains an antenna unit which is optimized for operation within that specific sub-band. The sub-band antennas are successively placed in front of the target, transmit their signals, and record the backscattered responses. The responses are then processed and combined to synthesize an integrated signal as if it were collected from a virtual equivalent ultra-wideband antenna. By using this concept, the challenges of realizing high-performance ultra-wideband antennas in the millimeter-wave regime are alleviated as each antenna is optimized within a limited bandwidth. An imaging system will be developed based on this approach for the detection of skin tumors in ex-vivo tissue measurements. The system will be optimized and miniaturized through developing a new class of wideband, miniaturized patch antennas for use in multi-static sensor arrays. The final imaging setup will be readily applicable to point-of-care and hand-held imaging devices. The "synthetic" ultra-wideband imaging approach will lead to image resolutions which are unachievable using conventional imaging methods. The approach is versatile, as the number and position of the channels can be adjusted to cover any frequency range as required for the specific application. These capabilities bring a whole new level of functionality to millimeter-wave imaging systems and enable applications that are not currently feasible. Furthermore, the new class of wideband, miniaturized patch antennas which will be developed for the miniaturization and optimization of the final imagining setup will be highly desirable for a variety of communication and imaging applications in the millimeter-wave regime.