Vector Network Analyzer for Medical Imaging Research

用于医学成像研究的矢量网络分析仪

• 批准号: RTI-2022-00407
• 负责人: Nikolova, Natalia
• 金额: $ 10.93万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743062
• 关键词: Vector; Network; Analyzer; Medical; Imaging

Our research focuses on new medical diagnostic modalities using RF and microwave technologies. In support of this research, we request funding for a vector network analyzer (VNA) with a frequency range up to 40 GHz. It provides frequency-sweep measurements of the scattering parameters of high-frequency devices and circuits along with two additional functionalities: frequency-conversion measurements and time-domain measurements. The requested instrument will replace two VNAs that are now malfunctioning and obsolete. The problems with our old VNAs brought to a halt experimental work, which is critical to the progress of our trainees and the success of our research projects.    There are three research programs that depend critically on the requested instrument. First, we are in the advanced stages of developing a microwave-imaging prototype for breast-cancer screening. It will provide a much needed non-ionizing alternative to mammography with equivalent or better diagnostic accuracy, wider accessibility, reduced cost, increased check-up frequency, and improved patient safety. Its modules have been undergoing tests with breast-tissue phantoms in preparation for trials with patients but these tests are now on hold. This also includes the development of a new ultra-wideband (UWB) receiver chip, to be integrated within each antenna in the breast-imaging sensor array. The chip tape-out is expected in 2022 and its characterization will require frequency-conversion measurements with a VNA.    Second, we are working on novel coil designs for a 7T magnetic resonance imaging (MRI) scanner and in vivo nuclear magnetic resonance (NMR) spectroscopy. 7T MR spectroscopy will significantly enhance the diagnostic accuracy for brain and peripheral nerve tumors, epilepsy, multiple sclerosis and other neurodegenerative diseases. MRI coil testing requires measurements with a VNA for coil tuning and to validate the coil impedance match and coupling. We also pursue the biomedical applications of electron spin resonance (ESR) spectroscopy, which requires measurements at the X-band (10 GHz, 0.33 T) and the Q-band (35 GHz, 1.25 T).    Third, we work on new radiometers to overcome the current limitations of poor linearity and limited accuracy. Medical radiometers are attractive due to their passive nature - they do not irradiate the patient; they only sense the natural thermal radiation from the body. They are used to monitor the deep-body temperature during hyperthermia and thermal-ablation therapies. High-sensitivity radiometers are used in the emerging thermographic imaging of tissue for the detection of malignancies.    Experiment-based research is critical in achieving high-impact innovation through the projects described above. It is needed not only for the development of hardware with new functionalities but also to support the development of new methods for image reconstruction and processing, anomaly detection, and automated diagnostics exploiting machine learning.

我们的研究重点是使用RF和微波技术的新医学诊断方式。为了支持这项研究，我们要求对矢量网络分析仪（VNA）的资金，其频率范围高达40 GHz。它提供了高频设备和电路的散射参数的频率测量以及两个其他功能：频率转换测量和时间域测量值。请求的仪器将替换两个现在正在发生故障和过时的VNA。我们旧的VNA的问题引起了一项停顿的实验工作，这对于我们的培训的进步和研究项目的成功至关重要。有三个研究计划批判性地取决于所请求的工具。首先，我们处于开发用于乳腺癌筛查的微波图像原型的高级阶段。它将提供急需的非电源替代乳房X线摄影术，具有等效或更好的诊断准确性，广泛的可及性，降低的成本，增加的检查频率以及改善患者的安全性。它的模块一直在使用乳房组织幻象进行测试，以准备与患者进行试验，但这些测试现在已搁置。这还包括开发新的超宽带（UWB）接收器芯片，该芯片将集成在胸腔成像传感器阵列中的每个天线中。预计将在2022年将芯片胶带插入，其表征将需要使用VNA进行频率转换测量。其次，我们正在研究7T磁共振成像（MRI）扫描仪和体内核磁共振（NMR）光谱的新型线圈设计。 7T MR光谱法将显着提高大脑和周围神经肿瘤，癫痫，多发性硬化症和其他神经退行性疾病的诊断准确性。 MRI线圈测试需要使用VNA进行测量，以进行线圈调整并验证线圈阻抗匹配和耦合。我们还追求电子自旋共振（ESR）光谱的生物医学应用，该光谱需要在X波段（10 GHz，0.33 T）和Q波段（35 GHz，1.25 T）处进行测量。第三，我们使用新的辐射仪来克服线性差和准确性有限的当前局限性。医疗辐射仪由于其被动性而具有吸引力 - 它们不会照射患者；他们只感知体内的天然热辐射。它们用于监测高温和热燃烧疗法期间的深体温度。高敏性辐射仪用于组织的新兴热量成像，以检测恶性肿瘤。基于实验的研究对于通过上述项目实现高影响力创新至关重要。不仅需要开发具有新功能的硬件，还需要支持开发图像重建和处理，处理，异常检测以及利用机器学习的自动化诊断方法的开发。