Exploratory Innovations in Electrical Impedance Tomography

描述（由申请人提供）：电阻抗断层扫描（EIT）是一种相对较新的功能成像技术，其中电极放置在身体表面，并在电极上施加低幅度，低频电流。这导致电极上的电压分布，然后可以测量。从这些电压中，形成一个图像，反映感兴趣区域内的电导率和/或介电常数分布。由于EIT是一种安全、便携的技术，没有破坏性的副作用，因此特别适合长期监测患者。该项目是长期目标的一部分，旨在开发一种大幅改进的EIT系统，用于实时成像心肺功能，诊断肺部病变并监测各自的治疗。本方案重点探索重建算法和硬件设计的创新，并研究重建的临床实用性。一个完全非线性的算法重建电导率和介电常数在一个横截面区域将开发和实现。目前，还没有实现直接的非线性算法来重建电阻抗数据。这些图像可能为诊断胸腔积液、气胸和肺不张提供关键信息。到目前为止，处于商业原型状态的EIT设备非常少，而且没有一个能够获得本文提出的创新所需的数据。因此，将设计和构建一个EIT系统，以获取载流和非载流电极上的单端和相电压数据。算法将在模拟和实验数据上进行测试，包括来自猪实验性肺损伤模型的数据，该数据将用于评估其在临床环境中的适用性。

DESCRIPTION (provided by applicant): Electrical impedance tomography (EIT) is relatively new functional imaging technique in which electrodes are placed on the surface of the body, and low amplitude, low frequency current is applied on the electrodes. This results in a voltage distribution on the electrodes which can then be measured. From these voltages, an image is formed that reflects the conductivity and/or permittivity distribution within the region of interest. Since EIT is a safe and portable technology with no damaging side effects, it is particularly suitable for long-term patient monitoring. This project is part of a long term goal to develop a substantially improved EIT system for imaging heart and lung function in real-time and diagnosing lung pathologies and monitoring their respective treatments. This proposal focuses on the exploration of innovations in the reconstruction algorithm and hardware design, and a study of the clinical usefulness of the reconstructions. A fully nonlinear algorithm for reconstructing conductivity and permittivity in a cross-sectional region will be developed and implemented. Currently, no direct nonlinear algorithms have been implemented for the reconstruction of permittivity data for EIT. The images may provide pivotal information for the diagnosis of pleural effusion, pneumothorax, and atelectasis. To date there are very few EIT devices in the commercial prototype state, and none that acquire the data needed for the innovations proposed here. Thus, an EIT system will be designed and built that acquires single-ended and phasic voltage data on both current-carrying and noncurrent-carrying electrodes. The algorithms will be tested on simulated and experimental data, including data from an experimental lung injury model in pigs that will be used to assess the applicability in a clinical setting. PUBLIC HEALTH RELEVANCE: Improving EIT technology can benefit the public health by expediting the diagnosis of certain lung pathologies, and by providing a bedside monitoring and diagnosis technique for patients in the intensive care unit with acute respiratory distress syndrome (ARDS), a life-threatening condition with a death rate of 20 to 30 % in which inflammation of lungs and fluid in the air sacs (alveoli) lead to low blood oxygen levels. Side effects of the treatment for patients with ARDS, which is mechanical ventilation through an endotracheal tube, include ventilator-induced pneumonia and lung damage, both of which can be prevented provided the proper ventilator settings are applied. Studies indicate that EIT may be useful for determining the optimal ventilator settings, monitoring reinflation procedures, determining information about alveolar collapse, and diagnosis of pleural effusion, pneumothorax, and atelectasis.