Coherent hemodynamics spectroscopy for cerebral autoregulation and blood flow

项目概述：本项目旨在开发一种新的非侵入性技术，相干血流动力学 光谱（CHS），用于局部测量脑灌注和微血管自动调节 水平这种新技术由三部分组成：（1）基于扩散近场的实验方法， 红外光谱（NIRS），以无创地收集微循环水平的脑灌注数据;（2）轻度 全身平均动脉压的扰动引起脑内的振荡或瞬变 （3）应用一种新的血流动力学模型对脑组织近红外光谱（NIRS）测量结果进行分析 将血液动力学转化为生理和功能量的测量。具体而言，这项提案 着重于动态脑自动调节（dCA）和毛细血管通过时间（CTT）的CHS测量， 其产生绝对脑血流量（CBF）。CHS测量局部CTT、CBF和dCA的能力 将通过开发空间分辨CHS（用于脑映射）和深度分辨CHS（用于 脑外组织和脑组织的区分）。我们计划在塔夫茨医疗中心的两个单位进行临床试验， 即透析病房和神经重症监护病房，以证明CHS的临床潜力。的 第一个临床试验，对糖尿病血液透析患者，旨在验证CHS测量CBF和dCA的， 与年龄匹配的健康对照进行比较研究，并证明CHS检测 血液透析期间脑灌注减少。第二个临床试验，对患有 蛛网膜下腔出血（aSAH）和创伤性脑损伤（TBI），将直接考验临床 CHS在监测脑灌注和自动调节缺陷中的潜力。其主要目标是 应用是一种新的工具，用于定量，非侵入性评估局部 微循环水平的脑血管血流动力学。CHS提供了一个显着的临床潜力， 这是由于其能够非侵入性地评估和监测脑组织灌注的能力，脑组织灌注在各种 临床状况，包括蛛网膜下腔出血、创伤性脑损伤、血液透析治疗， 缺血性中风和心肺分流术

Project Summary: This project aims to develop a novel non-invasive technique, coherent hemodynamics spectroscopy (CHS), for the local measurement of brain perfusion and autoregulation at the microvascular level. This new technique consists of three components: (1) An experimental method based on diffuse near- infrared spectroscopy (NIRS) to non-invasively collect brain perfusion data at the microcirculation level; (2) Mild perturbations in the systemic mean arterial pressure to evoke oscillations or transients in the cerebral hemodynamics; (3) The application of a new hemodynamic model to translate NIRS measurements of cerebral hemodynamics into measurements of physiological and functional quantities. Specifically, this proposal focuses on CHS measurements of dynamic cerebral autoregulation (dCA) and capillary transit time (CTT), which yields absolute cerebral blood flow (CBF). The capability of CHS to measure local CTT, CBF, and dCA will be capitalized by developing spatially-resolved CHS (for brain mapping) and depth-resolved CHS (for discrimination of extracerebral and brain tissues). We plan clinical tests at two units at the Tufts Medical Center, namely the dialysis unit and the neurological critical care unit, to demonstrate the clinical potential of CHS. The first clinical test, on diabetic hemodialysis patients, aims to validate CHS measurements of CBF and dCA in a comparative study with age-matched healthy controls, and to demonstrate the potential of CHS to detect a reduction in cerebral perfusion during hemodialysis. The second clinical test, on patients who suffered from aneurysmal Subarachnoid Hemorrhage (aSAH) and Traumatic Brain Injury (TBI), will directly test the clinical potential of CHS in monitoring cerebral perfusion and autoregulation deficits. The broad objective of this application is the development of a new tool for the quantitative, non-invasive assessment of local cerebrovascular hemodynamics at the microcirculation level. CHS offers a significant clinical potential as a result of its ability to non-invasively assess and monitor brain tissue perfusion, which is impaired in a variety of clinical conditions, including subarachnoid hemorrhage, traumatic brain injury, hemodialysis treatment, ischemic stroke, and cardiopulmonary bypass.