Bai Zelin, Li Haocheng, Chen Jingbo, Zhuang Wei, Li Gen, Chen Mingsheng, Xu Jia, Zhao Shuanglin, Liu Yuening, Sun Jian, Wang Feng, Xu Lin, Qin Mingxin, Jin Gui
College of Biomedical Engineering, Third Military Medical University (Army Medical University), Chongqing, China.
School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China.
PeerJ. 2021 Jan 5;9:e10583. doi: 10.7717/peerj.10583. eCollection 2021.
Intracranial hemorrhage (ICH) carrying extremely high morbidity and mortality can only be detected by CT, MRI and other large equipment, which do not meet the requirements for bedside continuous monitoring and pre-hospital first aid. Since the biological tissues have different dielectric properties except the pure resistances, and the permittivity of blood is far larger than that of other brain tissues, here a new method was used to detect events of change at the blood/tissue volume ratio by measuring of the head permittivity. In this paper, we use a self-made parallel plate capacitor to detect the intracranial hemorrhage in rabbits by contactless capacitance measurement. The sensitivity of the parallel-plate capacitor was also evaluated by the physical solution measurement. The results of physical experiments show that the capacitor can distinguish between three solutions with different permittivity, and the capacitance increased with the increase of one solution between two plates. At the next step in the animal experiment, the capacitance changes caused by 2 ml blood injection into the rabbit brain were measured. The results of animal experiments show that the capacitance was almost unchanged before and after the blood injection, but increased with the increase of the blood injection volume. The increase of capacitance caused by blood injection was much larger than that before and after blood injection ( < 0.01). The experiments show that this method is feasible for the detection of intracranial hemorrhage in a non-invasive and contactless manner.
颅内出血（ICH）的发病率和死亡率极高，目前只能通过CT、MRI等大型设备检测，这些设备无法满足床边连续监测和院前急救的需求。由于生物组织除了纯电阻外还具有不同的介电特性，且血液的介电常数远大于其他脑组织，因此本文采用一种新方法，通过测量头部介电常数来检测血液/组织体积比的变化情况。在本文中，我们使用自制的平行板电容器，通过非接触式电容测量来检测家兔颅内出血情况。还通过物理溶液测量评估了平行板电容器的灵敏度。物理实验结果表明，该电容器能够区分三种不同介电常数的溶液，且两板之间一种溶液量增加时电容也随之增加。在动物实验的下一步中，测量了向家兔脑内注射2ml血液所引起的电容变化。动物实验结果表明，注射血液前后电容几乎不变，但随着注射血量增加而增大。注射血液引起的电容增加远大于注射前后的变化（P<0.01）。实验表明，该方法以非侵入性和非接触方式检测颅内出血是可行的。
