Detection Of Electrical Impedance In Early Brain Edema Development

Craniocerebral injury is one of the major diseases of death in China.The secondary brain edema caused by various traumatic brain injury is the main reasons for the death or disability of patients with craniocerebral injury after admission in clinic.The main risk of brain edema is that brain edema will cause local brain tissue volume swelling,due to limited intracranial space compensation,resulting in the surrounding brain tissue extrusion,and then causes the surrounding brain tissue ischemia.If not promptly intervene,it may cause brain edema-cerebral ischemia-rebleeding,as a vicious cycle of ischemia.The vicious cycle of ischemia can be avoided if early cerebral edema could be detected and treatment could be timely in clinic.The current clinical diagnostic techniques,however,are unable to achieve early detection of brain edema.CT and other imaging techniques can only diagnose brain edema with significant changes in brain(such as brain line deviation,ventricular deformation,etc.)and the patients with primary cerebral edema are further compromised by secondary brain edema.Therefore,the early detection of cerebral edema has important clinical value and there is a clinical need for a new method to detect early brain edema.Early basic research suggests that bioelectrical impedance technology is expected to play a role in early brain edema detection.The process of brain edema is the process of changes of free ions and water molecules in the intercellular fluid,intracellular fluid of the brain tissue,that is,the process of the distribution of electrolyte solution in brain tissue,which is accompanied by brain tissue conduction changes in characteristics.Since,the electrical impedance of the development of brain edema has a very high sensitivity.At present,most of the studies on the electrical impedance of the brain are mainly focused on the measurement of electrical impedance of primary brain injury,but from primary brain injury to early secondary disease due to the difficulty of capturing secondary edema in animal models changes in electrical impedance during brain edema have not been studied at home and abroad.Since,this paper studied the electricity impedance changes of the brain from primary brain injury to early secondary brain edema based on the establishment of two types of primary brain injury(ischemic brain injury and hemorrhagic brain injury)animal model and analyzed the possible mechanism of brain tissue electrical impedance changes during brain edema combined with histomorphological changes in the initial.Following research has been done:(1)Study on the Change of Electrical Impedance in the Process of Ischemic Brain Damage to Brain EdemaIn the study,first of all,observe the degree of brain edema from the perspective of histomorphological and extract part of the histomorphological parameters.Then the electrical impedance of the brain tissue after brain ischemia was measured both in vivo and in vitro and the change of electrical impedance was observed and analyzed.On the basis of this,we analyzed the possible mechanism of changes of electrical impedance in brain tissue during the development of cerebral edema during the development of cerebral edema.The results showed that early edema of cerebral edema(expressed as cytotoxic brain edema)in ischemic brain injury caused the increase of electrical impedance in brain tissue and the electrical impedance of brain tissue showed a decreasing trend with the development of cerebral edema.(2)Study on the Change of Electrical Impedance in Hemorrhagic Brain Injury to Brain EdemaIn the study,first of all,observe the degree of brain edema from the perspective of histomorphological and extract part of the histomorphological parameters.Then the electrical impedance of the brain tissue after intracerebral hemorrhage was measured both in vivo and in vitro and the change of electrical impedance was observed and analyzed.On the basis of this,we analyzed the possible mechanism of changes of electrical impedance in brain tissue during the development of cerebral edema during the development of cerebral edema.The results showed that early edema of cerebral edema(expressed as vasogenic brain edema)in intracerebral hemorrhage caused the decrease of electrical impedance in brain tissue and the electrical impedance of brain tissue showed a increasing trend with the development of cerebral edema.Combining with the results in two parts of the study,it is not difficult to find that the brain electrical impedance changes of the secondary cerebral edema of ischemic brain injury and hemorrhagic brain injury are different.This initially confirmed that bioelectrical impedance technology can distinguish different types of early cerebral edema and is expected to provide early guidance for the treatment of early cerebral edema.The main innovations of this study are:(1)Detected the changes of electrical impedance from the development of primary brain injury to brain edema in animal models for the first time;(2)We studied the occurrence of secondary cerebral edema and the changes of electrical impedance and the difference between the two groups,and the relationship between the change of histopathological changes and the changes of histomorphology for the first time.We distinguished the bioelectrical impedance between different types of early cerebral edema and provide guidance for the diagnosis and treatment of clinical brain edema;(3)The results of this study provide important experimental support for the establishment of early detection methods of cerebral edema electrical impedance.