Transcranial electrical stimulation (TES) is a non-invasive neuromodulation technique with great potential. Electrode optimization methods based on simulation models of individual TES field could provide personalized stimulation parameters according to individual variations in head tissue structure, significantly enhancing the stimulation accuracy of TES. However, the existing electrode optimization methods suffer from prolonged computation times (typically exceeding 1 d) and limitations such as disregarding the restricted number of output channels from the stimulator, further impeding their clinical applicability. Hence, this paper proposes an efficient and practical electrode optimization method. The proposed method simultaneously optimizes both the intensity and focality of TES within the target brain area while constraining the number of electrodes used, and it achieves faster computational speed. Compared to commonly used electrode optimization methods, the proposed method significantly reduces computation time by 85.9% while maintaining optimization effectiveness. Moreover, our method considered the number of available channels for the stimulator to distribute the current across multiple electrodes, further improving the tolerability of TES. The electrode optimization method proposed in this paper has the characteristics of high efficiency and easy operation, potentially providing valuable supporting data and references for the implementation of individualized TES.
Objective To review the advances of functional electrical stimulation(FES) in treatment of peripheral nerve injuries. Methods By index of recent literature, the measures of stimulation, the mechanisms of FES and unsolved problems were evaluated and analyzed. Results Great advances have been made in the treatment of peripheral nerve injuries. It can not only enhance the regeneration of injured peripheral nerve, but also prevent muscular atrophy. Conclusion FES is an effective treatment for peripheral nerve injuries.
ObjectivesTo systematically review the efficacy of pelvic floor electrical stimulation on urinary dysfunction.MethodsPubMed, EMbase, The Cochrane Library, CBM, CNKI, VIP and WanFang Data databases were searched to collect randomized controlled trials (RCTs) on the efficacy of pelvic floor electrical stimulation on urinary dysfunction from inception to August 2018. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies; then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 9 RCTs involving 559 patients were included. The results of meta-analysis showed that the pelvic floor electrical stimulation group was superior to the control group in bladder volume before and after treatment(MD=79.25, 95%CI 40.36 to 118.15, P<0.000 1), residual urine volume (MD=35.50, 95%CI 7.60 to 63.41, P=0.01), maximum detrusor pressure (MD=5.19, 95%CI 2.11 to 8.27, P<0.001), number of leaks (RR=1.95, 95%CI 1.39 to 2.52, P<0.000 01), daily average urination frequency (RR=2.64, 95%CI 1.97 to 3.31, P<0.000 01), and international lower urinary tract score (MD=5.07, 95%CI 2.17 to 7.96, P=0.000 6).ConclusionsCurrent evidence shows that pelvic floor electrical stimulation is an effective therapy for urinary dysfunction. Due to limited quality and quantity of the included studies, more high quality-studies are required to verify the above conclusion.
Neuromuscular electrical stimulation (NMES) has been proven to promote human balance, but research on its impact on motor ability mainly focuses on external physical analysis, with little analysis on the intrinsic neural regulatory mechanisms. This study, for the first time, investigated the effects of NMES on cortical activity and cortico-muscular functional coupling (CMFC) during standing balance. Twelve healthy subjects were recruited in bilateral NMES training, with each session consisting of 60 electrically induced isometric contractions. Electroencephalogram (EEG) signals, electromyogram (EMG) signals, and center of pressure (COP) signals of the foot sole were collected before stimulation, two weeks after stimulation, and four weeks after stimulation while the subjects maintained standing balance. The results showed that NMES training improved subjects' postural stability during standing balance. Additionally, based on the EMG power spectral density (PSD), the κ frequency band was defined, and EEG-EMG time-frequency maximal information coefficients (TFMIC) were calculated. It was found that NMES enhanced functional connectivity between the cortex and lower limb muscles, with varying degrees of increase in β-κ and γ-κ frequency band CMFC after stimulation. Furthermore, sample entropy (SE) of EEG signals also increased after training. The results of this study confirm that NMES training can enhance CMFC and brain activation during standing balance. This study, from the perspective of physiological electrical signals, validates the effectiveness of NMES for balance training and provides objective assessment metrics for the training effects of NMES.
Existing neuroregulatory techniques can achieve precise stimulation of the whole brain or cortex, but high-focus deep brain stimulation has been a technical bottleneck in this field. In this paper, based on the theory of negative permeability emerged in recent years, a simulation model of magnetic replicator is established to study the distribution of the induced electric field in the deep brain and explore the possibility of deep focusing, which is compared with the traditional magnetic stimulation method. Simulation results show that a single magnetic replicator realized remote magnetic source. Under the condition of the same position and compared with the traditional method of stimulating, the former generated smaller induced electric field which sharply reduced with distance. By superposition of the magnetic field replicator, the induced electric field intensity could be increased and the focus could be improved, reducing the number of peripheral wires while guaranteeing good focus. The magnetic replicator model established in this paper provides a new idea for precise deep brain stimulation, which can be combined with neuroregulatory techniques in the future to lay a foundation for clinical application.
In the treatment of drug-refractory epilepsy in children, surgical treatment has a good clinical effect. However, for children whose surgical site is difficult to determine and who cannot undergo resectional surgery, neuromodulation techniques are one of the treatments that can be considered. At present, new neuromodulation technologies in children mainly include transcutaneous vagus nerve stimulation (transcutaneous auricular vagus nerve stimulation, ta-VNS), deep brain stimulation (deep brain stimulation, DBS), reactive nerve stimulation (responsive neurostimulation, RNS), transcranial magnetic stimulation (transcranial magnetic stimulation, TMS), transcranial direct current stimulation (transcranial direct current stimulation, TDCS) and transcranial alternating current stimulation (transcranial alternating current stimulation, TACS). This article briefly discussed the clinical efficacy and safety of various currently available neuromodulation technologies, so as to provide a reference for the rational selection and application of neuromodulation technologies, and improve the clinical efficacy and quality of life of children with drug-refractory epilepsy.
Artificial prosthesis is an important tool to help amputees to gain or partially obtain abled human limb functions. Compared with traditional prosthesis which is only for decoration or merely has feedforward control channel, the perception and feedback function of prosthesis is an important guarantee for its normal use and self-safety. And this includes the information of position, force, texture, roughness, temperature and so on. This paper mainly summarizes the development and current status of artificial prostheses in the field of perception and feedback technology in recent years, which is derived from two aspects: the recognition way of perception signals and the feedback way of perception signals. Among the part of recognition way of perception signals, the current commonly adopted sensors related to perception information acquisition and their application status in prosthesis are overviewed. Additionally, from the aspects of force feedback stimulation, invasive/non-invasive electrical stimulation, and vibration stimulation, the feedback methods of perception signals are summarized and analyzed. Finally, some problems existing in the perception and feedback technology of artificial prosthesis are proposed, and their development trends are also prospected.
Transcranial magneto-acoustic electrical stimulation (TMAES) is a novel method of brain nerve regulation and research, which uses induction current generated by the coupling of ultrasound and magnetic field to regulate neural electrical activity in different brain regions. As the second special envoy of nerve signal, calcium plays a key role in nerve signal transmission. In order to investigate the effect of TMAES on prefrontal cortex electrical activity, 15 mice were divided into control group, ultrasound stimulation (TUS) group and TMAES group. The TMAES group received 2.6 W/cm2 and 0.3 T of magnetic induction intensity, the TUS group received only ultrasound stimulation, and the control group received no ultrasound and magnetic field for one week. The calcium ion concentration in the prefrontal cortex of mice was recorded in real time by optical fiber photometric detection technology. The new object recognition experiment was conducted to compare the behavioral differences and the time-frequency distribution of calcium signal in each group. The results showed that the mean value of calcium transient signal in the TMAES group was (4.84 ± 0.11)% within 10 s after the stimulation, which was higher than that in the TUS group (4.40 ± 0.10)% and the control group (4.22 ± 0.08)%, and the waveform of calcium transient signal was slower, suggesting that calcium metabolism was faster. The main energy band of the TMAES group was 0−20 Hz, that of the TUS group was 0−12 Hz and that of the control group was 0−8 Hz. The cognitive index was 0.71 in the TMAES group, 0.63 in the TUS group, and 0.58 in the control group, indicating that both ultrasonic and magneto-acoustic stimulation could improve the cognitive ability of mice, but the effect of the TMAES group was better than that of the TUS group. These results suggest that TMAES can change the calcium homeostasis of prefrontal cortex nerve clusters, regulate the discharge activity of prefrontal nerve clusters, and promote cognitive function. The results of this study provide data support and reference for further exploration of the deep neural mechanism of TMAES.
Median nerve electrical stimulation is a common peripheral nerve electrical stimulation treatment technology in clinic. With simple operation, it has been widely used in clinical to promote coma after craniocerebral trauma, relieve pain, improve cognition, Parkinson’s disease and so on. However, its mechanism has always been a hot topic and difficult part. At present, there are a large number of clinical efficacy studies and animal experiments of median nerve electrical stimulation at home and abroad. This article reviews the clinical application and animal experiments of median nerve electrical stimulation in recent years, and summarizes its mechanism, hoping to contribute to relevant clinical applications and research.
Objective To systematically evaluate the orthotic effect of functional electrical stimulation (FES) on the improvement of walking in stroke patients with foot drop. Methods The randomized controlled trials (RCTs) that investigated the orthotic effect of FES on walking in stroke patients with foot drop were electronically searched in the databases such as PubMed, Web of Science, The Cochrane Library (Issue 1, 2013), EMbase, CBM, CNKI, VIP and WanFang Data from January 2000 to January 2013, and the relevant references of included papers were also manually searched. Two reviewers independently screened the trials according to the inclusion and exclusion criteria, extracted the data, and assessed the methodology quality. The meta-analyses were performed using RevMan 5.1 software. Results A total of 8 RCTs involving 255 patients were included. The results of meta-analyses on 4 RCTs showed that, compared with the conventional rehabilitation intervention, the functional electrical stimulation could significantly improve the walking speed, with significant difference (MD=0.09, 95%CI 0.00 to 0.18, P=0.04). The other indicators were only descriptively analyzed due to the incomplete data. Conclusions Functional electrical stimulation is effective in improving walking speed, but it is uncertain of other therapeutic indicators. So it should be further proved by conducting more high quality, large sample and multi-center RCTs.