Detection of neonatal ventricular hemorrhage using EIT

描述(由申请人提供)： 新生儿脑室出血是早产的常见后果。目前使用超声波、核磁共振或CT扫描对其进行评估。这些模式不适合对婴儿进行持续监测，而且涉及大量人员或设备费用。由于血液相对于其他头颅组织具有较高的电阻率对比度，因此可以使用电阻抗方法来检测和监控血液的外观。在这项提案中，电阻抗断层成像(EIT)成像技术被提议作为这些成像方式的非侵入性、低成本监测的替代方案。EIT有可能测量出血率并大致定位出血部位。这项建议涉及开发一种系统，用于捕获和重建头部的阻抗图像，并从背景噪声中提取与出血相关的阻抗变化信息。从头部的二维和三维有限元模型收集的结果将用于测试头骨模型的重建方法。类似于体内测量预期的噪声将被模拟并添加到合成数据中，以确定速率估计中的近似不确定性。将设计和建造电路，以捕获磁头内部的电阻率和电导率的相位准确数据。电路和重建方法将首先在球形水箱模型中进行测试，然后在胎儿头骨模型上进行测试。我们将比较胎儿头骨模型对不同补血量的敏感度，并与球罐中的敏感度进行比较。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呼吸，并将心电和呼吸数据与EIT数据同步记录。在监测和检查这些过程产生的伪影水平之后，当血液被输入侧脑室时，信号将被收集。这些数据将被分析以确定将形状变化和其他身体阻抗变化产生的伪影从出血过程中分离出来的最佳方式。

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.