CAREER: Wearable opto-electronic sensor for quantitative, noninvasive imaging of cerebral blood flow in humans

尽管大脑只占人体质量的2%，但它接受了人体20%的血液供应；这是它所提供的重要功能的真实证明。然而，流向大脑的血液是由一种叫做“自我调节”的机制严格控制的，因为即使是短暂的血液流动中断也会导致中风，而过量的血液流动会导致脑出血。由于这一关键作用，自动调节和脑血流量的定量测量可用于检测脑损伤，监测治疗，甚至预测恢复。不幸的是，目前还没有便携式的、易于使用的仪器，医生可以用它来定量地、连续地对病人床边的脑血流进行成像。为了解决这一技术差距，该项目将开发第一个可穿戴光学成像仪器，用于床边，无创成像人类脑血流和自动调节动力学。除了帮助临床医生处理脑损伤外，这种成像仪器将提高我们对关键脑功能的理解，并有助于识别未确诊的局部脑损伤。这个项目的教育和推广目标是开发和分发模块化的电子乐高套件，这将促进所有年龄段的电子设计的乐趣和体验式学习。脑血管自动调节（CVAR）是一种重要的体内平衡机制，在动脉血压和代谢需求变化过程中控制脑血流量（CBF）。由于这种自主神经过程的破坏是疾病的强烈指示，CVAR动力学的定量测量是脑损伤的功能生物标志物，包括缺血性中风、创伤性脑损伤和阿尔茨海默病。不幸的是，目前的临床监测状态仅限于在头部的几个位置测量CBF，迫使CVAR指标被描述为一个单一的全局数字，忽略了空间分布，可能导致未确诊的局部损伤。为了解决这一技术限制，该项目将开发新的便携式光学技术，用漫射相关光谱（DCS）定量测量脑血流量。具体而言，(1)该项目将构建世界上第一个用于定量监测血流的可穿戴光学设备，其技术创新将DCS血流监测仪的占地面积从一个大公文包大幅缩小到1平方英尺。在。光学探测器。(2)然后，该项目将调整这种可穿戴式血流传感器，用于整个人类头部，对人类的脑血流（CBF）进行无创成像。严格的实验将在模拟组织的幻影和人体上进行，以表征CBF成像仪的准确性、灵敏度和噪声性能。在这个项目中开发的设备对于更广泛的神经影像学社区来说是独一无二的。随着这项技术的适当传播和商业化，这种首个同类CBF成像仪可以帮助广泛的研究大脑的研究人员，包括神经学家、神经科学家、心理学家和行为科学家，也可以适用于其他组织类型。该提案由工程理事会的化学、生物工程、环境和运输系统司（CBET）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The human brain receives up to 20% of the body's blood supply, despite accounting for only 2% of the human body's mass; a true testament to the vital function that it provides. Nevertheless, blood flow to the brain is tightly controlled by a mechanism called autoregulation, because even momentary disruptions in blood flow can lead to strokes, while excess blood flow can result in brain bleeds. Due to this critical role, quantitative measurements of autoregulation and brain blood flow can be used to detect brain injuries, monitor treatment, and even predict recovery. Unfortunately, there is currently no portable, easy-to-use instrument that physicians can use to quantitatively and continuously image brain blood flow at a patient's bedside. To address this technology gap, this project will develop the first wearable optical imaging instrument for bedside, noninvasive imaging of brain blood flow and autoregulation dynamics in humans. In addition to helping clinicians manage brain injuries, this imaging instrument will improve our understanding of critical brain function and will help identify undiagnosed local brain injuries. The educational and outreach goal of this project is to develop and distribute modular electronic-lego kits that will foster fun, experiential learning of electronic design for all ages. Cerebrovascular autoregulation (CVAR) is an important homeostatic mechanism that controls cerebral blood flow (CBF) during changes in arterial blood pressure and metabolic demand. Since disruption of this autonomic process is strongly indicative of disease, quantitative measurements of CVAR dynamics are functional biomarkers for brain injuries including ischemic strokes, traumatic brain injuries and Alzheimer's disease. Unfortunately, the state of current clinical monitoring is limited to CBF measurements at a few locations in the head, forcing CVAR metrics to be characterized as a single global number that ignores spatial distributions, potentially leading to undiagnosed local injuries. To address this technical limitation, this project will develop new portable optical technology to quantitatively measure cerebral blood flow with Diffuse Correlation Spectroscopy (DCS). Specifically, (1) this project will build the world's first wearable optical device for quantitative monitoring blood flow, featuring technical innovations that dramatically shrink the footprint of a DCS blood flow monitor from a large briefcase to a 1 sq. in. optical probe. (2) The project will then adapt this wearable blood flow sensor for use over the entire human head for non-invasive imaging of cerebral blood flow (CBF) in humans. Rigorous experiments will be conducted on tissue-simulating phantoms, and in humans, to characterize the accuracy, sensitivity, and noise performance of the CBF imager. The devices developed in this project are unique for the broader neuroimaging community. With appropriate dissemination and commercialization of this technology, this first-of-its kind CBF imager can help a broad cohort of researchers who study the brain including neurologists, neuroscientists, phycologists, and behavioral scientists, and can also be adapted for other tissue types.The proposal was co-funded by the Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET) in the Directorate of Engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.