The indoor positioning system is now an important technique as part of the Internet-of-Things(IoT)ecosystem.Among indoor positioning techniques,multiple Wi-Fi Access Points(APs)-based positioning systems have been res...The indoor positioning system is now an important technique as part of the Internet-of-Things(IoT)ecosystem.Among indoor positioning techniques,multiple Wi-Fi Access Points(APs)-based positioning systems have been researched a lot.There is a lack of research focusing on the scene where only one Wi-Fi AP is available.This work proposes a hybrid indoor positioning system that takes advantage of the Fine-Timing Measurements(FTM)technique that is part of the IEEE 802.11mc standard,introduced back in 2016.The system uses one single Wi-Fi FTM AP and takes advantage of the built-in inertial sensors of the smartphone to estimate the device’s position.We explore both Loosely Coupled(LC)and Tightly Coupled(TC)integration schemes for the sensors’data fusion.Experimental results show that the proposed methods can achieve an average positioning accuracy of about 1 m without knowing the initial position.Compared with the LC integration method,the median error accuracy of the proposed TC fusion algorithm has improved by more than 52%and 67%,respectively,in the two experiments we set up.展开更多
In a sample of 28 subacute anterior circulation ischemic stroke patients with severe arm paresis, reduced motor cortex excitability (increased motor thresholds, reduced MEP amplitudes, reduced number of active points)...In a sample of 28 subacute anterior circulation ischemic stroke patients with severe arm paresis, reduced motor cortex excitability (increased motor thresholds, reduced MEP amplitudes, reduced number of active points) and a reduced conduction velocity in the corticospinal system were found in the affected hemisphere. At the same time motor cortex topology for the abductor pollicis brevis (APB) representation was comparable for the affected and non-affected hemisphere. Considerable arm motor recovery (Fugl-Meyer test) was observed when assessed four weeks later after a period of rehabilitation intervention. Motor cortex excitability and conduction velocity in the corticospinal system improved in the affected hemisphere. In addition, APB representation showed a medial shift in patients with such a representation at pre test (n = 14). Multiple stepwise regression indicated that of all transcranial magnetic stimulation (TMS) parameters only the medial shift of the motor cortex map predicted motor recovery. Assessing the effect of training time (nonintensified vs. intensified therapy) and type of arm training (Bobath approach vs. Arm BASIS training) with a randomised controlled design revealed that the impairment-oriented Arm BASIS training improved motor control more than the control conditions. In addition, patients of the group receiving the Arm BASIS training with an APB representation at pre test showed a medial shift of the motor cortex map and improved conduction times. In conclusion, changes in motor cortex topology were likely to be relevant for motor recovery and might have been induced by the impairment-oriented training.展开更多
基金supported by the National Key Research and Development Program of China[grant numbers 2016YFB0502200,2016YFB0502201]the NSFC[grant number 91638203]。
文摘The indoor positioning system is now an important technique as part of the Internet-of-Things(IoT)ecosystem.Among indoor positioning techniques,multiple Wi-Fi Access Points(APs)-based positioning systems have been researched a lot.There is a lack of research focusing on the scene where only one Wi-Fi AP is available.This work proposes a hybrid indoor positioning system that takes advantage of the Fine-Timing Measurements(FTM)technique that is part of the IEEE 802.11mc standard,introduced back in 2016.The system uses one single Wi-Fi FTM AP and takes advantage of the built-in inertial sensors of the smartphone to estimate the device’s position.We explore both Loosely Coupled(LC)and Tightly Coupled(TC)integration schemes for the sensors’data fusion.Experimental results show that the proposed methods can achieve an average positioning accuracy of about 1 m without knowing the initial position.Compared with the LC integration method,the median error accuracy of the proposed TC fusion algorithm has improved by more than 52%and 67%,respectively,in the two experiments we set up.
文摘In a sample of 28 subacute anterior circulation ischemic stroke patients with severe arm paresis, reduced motor cortex excitability (increased motor thresholds, reduced MEP amplitudes, reduced number of active points) and a reduced conduction velocity in the corticospinal system were found in the affected hemisphere. At the same time motor cortex topology for the abductor pollicis brevis (APB) representation was comparable for the affected and non-affected hemisphere. Considerable arm motor recovery (Fugl-Meyer test) was observed when assessed four weeks later after a period of rehabilitation intervention. Motor cortex excitability and conduction velocity in the corticospinal system improved in the affected hemisphere. In addition, APB representation showed a medial shift in patients with such a representation at pre test (n = 14). Multiple stepwise regression indicated that of all transcranial magnetic stimulation (TMS) parameters only the medial shift of the motor cortex map predicted motor recovery. Assessing the effect of training time (nonintensified vs. intensified therapy) and type of arm training (Bobath approach vs. Arm BASIS training) with a randomised controlled design revealed that the impairment-oriented Arm BASIS training improved motor control more than the control conditions. In addition, patients of the group receiving the Arm BASIS training with an APB representation at pre test showed a medial shift of the motor cortex map and improved conduction times. In conclusion, changes in motor cortex topology were likely to be relevant for motor recovery and might have been induced by the impairment-oriented training.
