Improved electrical impedance tomography based on the giant magnetoimpedance effect as a low-cost medical monitoring tool

电阻抗断层成像（EIT）是一种非侵入性的医学成像技术，目前用于生物医学研究，并逐渐被用于临床应用，如机械通气患者的肺功能监测。EIT系统相对较低的购置成本和非常低的运营成本使其特别适合于实时长期监测的情况。然而，当前的EIT仪器需要在患者身体上仔细定位多达32个电极。非接触式EIT方法将是该技术的重大改进，显著扩展其应用领域。该项目的目标是证明非接触式EIT的可行性，并评估其作为临床工具的潜力。我们提出的非接触式EIT方法利用了我们小组在低成本超灵敏巨磁阻抗（GMI）磁强计开发方面的最新进展。这些将与感应激励线圈结合使用，用于感兴趣区域的电导率变化的非接触式映射;最初，在物理体模上。申请的资金将主要用于支持三名研究生的研究，他们将由团队成员共同监督。该项目的一个重要里程碑是开发和优化巨磁阻抗磁力计的灵敏度，以在非屏蔽环境中实现亚pT检测。根据我们在该项目这一部分的成功，新版本的磁力计可以应用于专门设计用于监测癫痫患者的EIT系统，这些患者是脑外科手术以移除癫痫病灶的候选人。灵敏度的增加也可以使脑磁图达到GMI磁力测量的范围。

Electrical impedance tomography (EIT) is a non-invasive medical imaging technique, presently used in biomedical research, and which is gradually being adopted for clinical applications such as lung function monitoring of mechanically ventilated patients. The relatively low acquisition and very low operation costs of EIT systems makes them particularly suited to real-time long-term monitoring situations. However, current EIT instruments require careful positioning of up to 32 electrodes upon the patient's body. A contactless EIT approach would be a major improvement of the technique, significantly extending its field of applications. The goal of this project is to demonstrate the feasibility of contactless EIT and to assess its potential as a clinical tool. The approach we propose to contactless EIT takes advantage of our group's recent advances in the development of low-cost ultra-sensitive giant magnetoimpedance (GMI) magnetometers. These will be used in conjunction with inductive excitation coils for contactless mapping of the conductivity changes in a region of interest; initially, on physical phantoms. The funds requested will mainly support the research of three graduate students who will be co-supervised by the team members. The development and optimization of the sensitivity of GMI magnetometers to reach sub-pT detection in an unshielded environment is an important milestone of the project. Depending upon our success in this part of the project, a new version of the magnetometer could be applied to EIT systems specifically designed to monitor epileptic patients, candidates for brain surgery to remove an epileptic focus. The increased sensitivity could also put magneto-encephalography within reach of GMI magnetometry.