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射频和微波技术的新的医疗诊断模式。为了支持这项研究，我们请求为频率范围高达40 GHz的矢量网络分析仪(VNA)提供资金。它提供高频器件和电路的散射参数的扫频测量，以及两个附加功能：频率转换测量和时域测量。所要求的仪器将取代现在出现故障和过时的两个虚拟核供应器。我们的旧VNA出现的问题使实验工作陷入停顿，这对我们学员的进步和我们研究项目的成功至关重要。有三个研究项目在很大程度上依赖于所要求的仪器。首先，我们正处于开发用于乳腺癌筛查的微波成像原型的高级阶段。它将提供一种亟需的非电离替代乳房X光检查，具有同等或更好的诊断准确性、更广泛的可及性、更低的成本、更高的检查频率和更好的患者安全性。它的模块一直在用乳房组织模体进行测试，为病人的试验做准备，但这些测试现在被搁置了。这还包括开发一种新的超宽带(UWB)接收器芯片，将其集成到乳房成像传感器阵列的每个天线中。芯片的流片生产预计将在2022年进行，其表征将需要使用VNA进行频率转换测量。其次，我们正在为7T磁共振成像(MRI)扫描仪和活体核磁共振(核磁共振)波谱设计新的线圈。7T磁共振波谱将显著提高对脑肿瘤和周围神经肿瘤、癫痫、多发性硬化症等神经退行性疾病的诊断准确率。磁共振线圈测试需要使用VNA进行测量，以调整线圈并验证线圈阻抗匹配和耦合。我们还追求电子自旋共振(ESR)谱在生物医学上的应用，它需要在X波段(10 GHz，0.33T)和Q波段(35 GHz，1.25T)进行测量。第三，我们致力于新的辐射计，以克服目前线性差和精度有限的限制。医用辐射计之所以有吸引力，是因为它们的被动性质--它们不照射患者；它们只感知来自身体的自然热辐射。它们被用来监测热疗和热消融治疗期间的深层体温。高灵敏度辐射计被用于新兴的组织热像成像，用于检测恶性肿瘤。这些以实验为基础的研究对于通过上述项目实现高影响力的创新至关重要。它不仅是开发具有新功能的硬件所必需的，也是支持开发图像重建和处理、异常检测以及利用机器学习进行自动诊断的新方法所必需的。