School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China.
Department of Neurosurgery, Southwest Hospital, Army Medical University, Chongqing, China.
Biomed Eng Online. 2022 Mar 27;21(1):20. doi: 10.1186/s12938-022-00991-y.
Early diagnosis and continuous monitoring are the key to emergency treatment and intensive care of patients with acute ischemic stroke (AIS). Nevertheless, there has not been a fully accepted method targeting continuous assessment of AIS in clinical.
Near-field coupling (NFC) sensing can obtain the conductivity related to the volume of intracranial components with advantages of non-invasiveness, strong penetrability and real-time monitoring. In this work, we built a multi-parameter monitoring system that is able to measure changes of phase and amplitude in the process of electromagnetic wave (EW) reflection and transmission. For investigating its feasibility in AIS detection, 16 rabbits were chosen to establish AIS models by bilateral common carotid artery ligation and then were enrolled for monitoring experiments.
During the 6 h after AIS, the reflection amplitude (RA) shows a decline trend with a range of 0.69 dB and reflection phase (RP) has an increased variation of 6.48° . Meanwhile, transmission amplitude (TA) and transmission phase (TP) decrease 2.14 dB and 24.29° , respectively. The statistical analysis illustrates that before ligation, 3 h after ligation and 6 h after ligation can be effectively distinguished by the four parameters individually. When all those parameters are regarded as recognition features in back propagation (BP) network, the classification accuracy of the three different periods reaches almost 100%.
These results prove the feasibility of multi-parameter NFC sensing to assess AIS, which is promised to become an outstanding point-of-care testing method in the future.
急性缺血性脑卒中（AIS）的急救和重症监护的关键是早期诊断和连续监测。然而，目前还没有一种被完全接受的方法可以对 AIS 进行连续评估。
近场耦合（NFC）感应可以获得与颅内成分体积相关的电导率，具有非侵入性、强穿透性和实时监测的优点。在这项工作中，我们构建了一个多参数监测系统，能够测量电磁波（EW）反射和传输过程中相位和幅度的变化。为了研究其在 AIS 检测中的可行性，选择了 16 只兔子通过双侧颈总动脉结扎建立 AIS 模型，并进行监测实验。
在 AIS 发生后 6 小时内，反射幅度（RA）呈下降趋势，范围为 0.69dB，反射相位（RP）的变化增加了 6.48°。同时，传输幅度（TA）和传输相位（TP）分别下降了 2.14dB 和 24.29°。统计分析表明，在结扎前、结扎后 3 小时和结扎后 6 小时，这四个参数可以有效地进行区分。当将所有这些参数作为反向传播（BP）网络的识别特征时，三个不同时期的分类准确率几乎达到 100%。
这些结果证明了多参数 NFC 感应评估 AIS 的可行性，有望成为未来一种出色的即时检测方法。
