Detection of neonatal ventricular hemorrhage using EIT

描述（由申请人提供）： 新生儿脑室内出血是早产的常见后果。目前使用超声、MRI或CT扫描进行评估。这些模式不适合于婴儿的连续监测，并且涉及大量的人员或设备成本。由于血液相对于其他颅骨组织具有高电阻率对比度，因此可以使用电阻抗方法检测和监测其外观。在该提议中，电阻抗断层成像（EIT）的成像技术被提议作为这些成像模式的非侵入性、低成本监测替代方案。EIT有可能测量出血率并大致定位出血部位。该建议涉及开发用于捕获和重建头部阻抗图像的系统，并从背景噪声中提取关于出血相关阻抗变化的信息。从头部的二维和三维有限元模型收集的结果将用于测试颅骨模型上的重建方法。将模拟与体内测量预期相似的噪声，并将其添加到合成数据中，以确定速率估计的大致不确定性。电路将被设计和建造，以捕捉电阻率和电导率的头部内的相位准确的数据。电路和重建方法将首先在球形罐模型中进行测试，然后在胎儿颅骨模型中进行测试。将比较胎儿颅骨体模对不同量添加血液的灵敏度与球形罐中的灵敏度。最后，该系统将在新生猪模型上进行测试。将对仔猪进行麻醉和机械通气，并将ECG和通气数据与EIT数据同步记录。在监测和检查这些过程产生的伪影水平后，将在血液输入侧脑室时收集信号。将对这些数据进行分析，以确定将形状变化和其他身体阻抗变化产生的伪影与出血过程分离的最佳方法。

DESCRIPTION (provided by applicant): Cerebral intraventricular hemorrhage in neonatal human infants is common consequence of pre-term delivery. It is currently assessed using ultrasound, MRI or CT scan. These modalities are not suitable for continuous monitoring of infants and involve large personnel or equipment costs. Because blood has a high electrical resistivity contrast relative to other cranial tissue, it appearance can be detected and monitored using electrical impedance methods. In this proposal, the imaging technique of Electrical Impedance Tomography (EIT) is proposed as a non-invasive, low-cost monitoring alternative to these imaging modalities. EIT has the potential to measure bleeding rate and approximately localize the bleeding site. This proposal involves development of a system for capturing and reconstructing impedance images of the head, and extracting information about bleeding-related impedance changes from background noise. Results gathered from two- and three-dimensional finite element models of the head will be used to test reconstruction methods on a skull model. Noise similar to that expected from in-vivo measurements will be simulated and added to synthetic data to determine the approximate uncertainty in rate estimations. Circuits will be designed and constructed to capture phase-accurate data of resistivity and conductivity inside the head. The circuitry and reconstruction methods will be tested first in a spherical tank model and then on a fetal skull phantom. Sensitivity in the fetal skull phantom to different amounts of added blood will be compared with that found in the spherical tank. Finally, the system will be tested on a neonatal pig model. Piglets will be anesthetized and mechanically ventilated and ECG and ventilation data will be recorded synchronously with EIT data. After monitoring and examining the level of artifact produced by these processes, signals will be collected as blood is transfused into a lateral ventricle. These data will be analyzed to determine the best way of separating artifacts produced by shape changes and other body impedance changes from the bleeding process.