The major therapy for ischemic stroke is thrombolytic treatment, but severe consequences occur when this method is used to treat hemorrhagic stroke. Currently, computed tomography and magnetic resonance imaging are used to differentiate between two types of stroke, but these two methods are ineffective for pre-hospital care. We developed a new brain diagnostic device for rabbits based on electromagnetic induction to non-invasively differentiate two types of stroke. The device includes two coils and a phase difference measurement system that detects the magnetic inductive phase shift (MIPS) value to reflect the tissue’s condition. The hemorrhage model was established through the injection of autologous blood into the internal capsule of a rabbit’s brain. Ischemia was induced in the brain of a rabbit by bilateral carotid artery occlusion. Two types of animal models were measured with our device. The MIPS value gradually decreased with increasing injected blood and increased with ischemia time. The MIPS changes induced by the two types of strokes were exact opposites, and the absolute values of MIPS variation in the hemorrhagic and the ischemic groups were significantly larger than those of the normal control group (P < 0.05). The tested technique can differentiate ischemic stroke from hemorrhagic stroke on rabbit brain in a non-invasive, continuous, and bulk monitoring manner by using a simple and inexpensive apparatus.

Cerebral edema (CE) is a non-specific pathological swelling of the brain secondary to any type of neurological injury. The real-time monitoring of focal CE mostly found in early stage is of great significance to reduce mortality and disability. Magnetic Induction Phase Shift (MIPS) is expected to achieve non-invasive continuous monitoring of CE. However, most existing MIPS sensors are made of hard materials which makes it difficult to accurately retrieve CE information. In this article, we designed a conformal two-coil structure and a single-coil structure, and studied their sensitivity map using finite element method (FEM). After that, the conformal MIPS sensor that is preferable for local CE monitoring was fabricated by flexible printed circuit (FPC). Next, physical experiments were conducted to investigate its performance on different levels of simulated CE solution volume, measurement distance, and bending. Subsequently, 14 rabbits were chosen to establish CE model and another three rabbits were selected as controls. The 24-hour MIPS real-time monitoring experiments was carried out to verify that the feasibility. Results showed a gentler attenuation trend of the conformal two-coil structure, compared with the single-coil structure. In addition, the novel flexible conformal MIPS sensor has a characteristic of being robust to bending according to the physical experiments. The results of animal experiments showed that the sensor can be used for CE monitoring. It can be concluded that this flexible conformal MIPS sensor is desirable for local focusing measurement of CE and subsequent multidimensional information extraction for predicting model. Also, it enables a much more comfortable environment for long-time bedside monitoring.

As a very common secondary disease after Traumatic brain injury (TBI), brain edema can lead to increased intracranial water content and elevated intracranial pressure (ICP), which makes the patient suffer a less favorable prognosis outcome such as hemiplegia, aphasia, dysgnosia and even death. Its real-time monitoring is of great significance for improving the therapeutic condition of TBI and reducing the mortality and disability rate. Magnetic induction phase shift (MIPS) has the advantages of non-invasive, non-contact, strong penetration and real-time bedside monitoring. In this work, 34 rabbits divided into experimental group (n=26) and control group (n=8) were used to carry out 24-hour MIPS monitoring in brain edema. Meanwhile, intracranial pressure (ICP) and brain water content (BWC) were chosen as the references. MIPS of rabbits in the experimental group decreased continuously in 24 hours, while the ICP and BWC increased. Furthermore, MIPS detection sensitivity became lower and lower within the development of brain edema. The weights of ICP and BWC estimated by MIPS in three different stage were calculated to get the BESI, which can evaluate the severity of brain edema. The BSEI of rabbits in the experimental group increased over time, ranging from 0 to 1. The 0 reflect normal and the 1 represents severe brain edema. The first stage of BESI changed from 0 to 0.43, the second stage from 0.43 to 0.917 and the third stage from 0.917 to 1. The BESI of rabbits in the control group did not increase obviously within time. There were significant differences among them. Through the comparative experimental study of MIPS, ICP and BWC on rabbits with brain edema, a more effective and direct parameter was found, which can promote the application value of MIPS in real-time bedside monitoring of brain edema.

Central nervous system (CNS) injury, induced by ischemic/hemorrhagic or traumatic damage, is one of the most common causes of death and long-term disability worldwide. Reactive oxygen and nitrogen species (RONS) resulting in oxidative/nitrosative stress play a critical role in the pathological cascade of molecular events after CNS injury. Therefore, by targeting RONS, antioxidant therapies have been intensively explored in previous studies. However, traditional antioxidants have achieved limited success thus far, and the development of new antioxidants to achieve highly effective RONS modulation in CNS injury still remains a great challenge. With the rapid development of nanotechnology, novel nanomaterials provided promising opportunities to address this challenge. Within these, nanoceria has gained much attention due to its regenerative and excellent RONS elimination capability. To promote its practical application, it is important to know what has been done and what has yet to be done. This review aims to present the opportunities and challenges of nanoceria in treating CNS injury. The physicochemical properties of nanoceria and its interaction with RONS are described. The applications of nanoceria for stroke and neurotrauma treatment are summarized. The possible directions for future application of nanoceria in CNS injury treatment are proposed.

A novel method was developed based on near-field coupling phase shift (NFCPS) to perform non-contact and bedside monitoring of cerebral edema in the intensive care unit (ICU). A total of 17 subjects were selected to conduct real-time NFCPS monitoring of cerebral edema and divided into surgical group, conservative group and control group. The data were collected at an interval of 12 h, until the patients left the ICU for various reasons, such as being transferred to the general ward or discharged from the hospital. Continuous collection was conducted for 15 min at each time point and then the phase shift was recorded as the NFCPS value. The computed tomography (CT) images of the surgical group and the conservative group were obtained at the same time points. The surgical group had the most drastic changes (-3.42 ± 6.0 degrees, at 12 h; -12.85 ± 10.58 degrees, at 24 h; -5.04 ± 2.65 degrees, at 36 h; 0.05 ± 5.74 degrees, at 48 h). The overall brain conductivity may show a decreasing trend at first and then a rising trend in patients who suffer from a hemorrhagic stroke. The comparative analysis of NFCPS and CT images revealed that NFCPS can also reflect the pathophysiological changes of the brain. This research demonstrates the robust clinical feasibility of NFCPS in the non-invasive real-time monitoring of cerebral edema. In addition, the change characteristics of the overall brain conductivity in hemorrhagic stroke patients provide guidance for subsequent research.

Timely reperfusion of ischemic tissues and hemodynamic reconstruction are key to the treatment of acute ischemic stroke. The low temporal resolution of current imaging methods commonly used in clinical practice have the risk of diagnostic delay. In this study, a noninvasive cerebral blood flow (CBF) monitoring device was established based on inductive sensing technology, aiming at rapid and real-time assessment of ischemic tissue blood flow reperfusion to improve the treatment conditions and assess the prognostic outcome of acute ischemic stroke. The noninvasive CBF monitoring device was constructed using an inductive sensor and the LDC1612 evaluation module. Based on a homemade physical model of CBF pulsation and a healthy volunteer test, the depth and range of the sensor were evaluated by the time-domain amplitude and frequency-domain variation characteristics of resonant frequency. The monitoring results were processed using wavelet transform, high and low pass filtering, and cubic spline interpolation to remove the baseline and extract the CBF signal components. Based on the cardiogenic CBF pulsation mechanism, the periodic amplitude and area of CBF signals in resting and carbon dioxide inhalation states were extracted from healthy volunteers, and the feasibility of noninvasive monitoring of CBF by inductive sensing technology was evaluated. The experimental results showed that the method can evaluate the periodic pulsation of CBF and the changes of CBF in real-time with high accuracy. Thus, the present study verifies that the noninvasive CBF monitoring device based on inductive sensing technology can effectively detect the cardiac pulsations of CBF, which is expected to break the time window effect caused by the imaging examination and provide a new technology for noninvasive real-time monitoring of CBF perfusion changes.