A design and evaluation of wearable p300 brain-computer interface system based on Hololens2 / 生物医学工程学杂志

Patients with amyotrophic lateral sclerosis ( ALS ) often have difficulty in expressing their intentions through language and behavior, which prevents them from communicating properly with the outside world and seriously affects their quality of life. The brain-computer interface (BCI) has received much attention as an aid for ALS patients to communicate with the outside world, but the heavy device causes inconvenience to patients in the application process. To improve the portability of the BCI system, this paper proposed a wearable P300-speller brain-computer interface system based on the augmented reality (MR-BCI). This system used Hololens2 augmented reality device to present the paradigm, an OpenBCI device to capture EEG signals, and Jetson Nano embedded computer to process the data. Meanwhile, to optimize the system's performance for character recognition, this paper proposed a convolutional neural network classification method with low computational complexity applied to the embedded system for real-time classification. The results showed that compared with the P300-speller brain-computer interface system based on the computer screen (CS-BCI), MR-BCI induced an increase in the amplitude of the P300 component, an increase in accuracy of 1.7% and 1.4% in offline and online experiments, respectively, and an increase in the information transfer rate of 0.7 bit/min. The MR-BCI proposed in this paper achieves a wearable BCI system based on guaranteed system performance. It has a positive effect on the realization of the clinical application of BCI.

Short-term voluntary exercise enhances the activation of endogenous neural stem cells inintracerebral hemorrhage mice with hyperlipidemia / 西安交通大学学报(医学版)

【Objective】 To investigate the improvement of motor function recovery and the activation of endogenous neural stem cells (eNSCs) via voluntary exercise in mice with hyperlipidemia after intracerebral hemorrhage (ICH). 【Methods】 Four-month-old male Nestin-CreERT2: tdTomato transgenic mice were fed with high-fat diet (HFD) for eight weeks. Type Ⅳ collagenase was micro-injected into the corpus striatum to construct mouse ICH model with the help of stereotaxic apparatus. Voluntary exercise (wheel running) was initiated on the second day after ICH and monitored daily for seven days. Neurological severity score (NSS) and beam walking test were applied to evaluate motor function and coordination. Liver and brain tissues were collected at day 9 after ICH and sliced for staining. Then the Nestin-labeled cells, Ki67+, and doublecortin (DCX)+ in subventricular zone (SVZ) were counted to evaluate eNSCs activation. 【Results】 ① Compared with those of mice fed by chow diet (CD), the body weight, blood glucose level, concentration of lipid metabolism factors and the number of Nile Red positive cells in liver tissue were significantly higher in HFD-fed mice, confirming hyperlipidemia. ② Compared with the sham group, NSS score increased and the distance of cross-beam walking of ICH mice significantly decreased, showing the deficiency of motor function. It could be rescued by 7-day wheel running, as shown by a lower NSS score and a longer cross-beam walking distance. ③ Compared with the sham group, the number of Nestin+/Ki67+ cells decreased and Nestin+/DCX+ cells increased after ICH. After 7-day voluntary exercise, the number of Nestin+/Ki67+ cells decreased but that of Nestin+/DCX+ cells further increased significantly. However, compared with ICH, the increase of Nestin+/DCX+ cells in ICH+Ex was not significant. 【Conclusion】 Short-term voluntary exercise during the acute stage of ICH improved the recovery of motor function and enhance the proliferation of eNSCs in mice with hyperlipidemia. This provides a new idea for further developing ICH accelerated rehabilitation strategy based on eNSCs.