Ji Linhong

The clinical application of the upper extremity compound movements rehabilitation training robot

In order to estimate the effect of neural rehabilitation robot for improving the upper extremity motor function, 23 hemiplegia patients who are BrunnstromTII at least receive clinical rehabilitation training by the upper extremity compound movements rehabilitation training robot. The assistance models of the neural rehabilitation robot and the programming of the clinical rehabilitation training are studied in this dissertation. The clinical assessment results make clear that after a period of rehabilitation treatment, the function of most patients, which could be assessed by Fugl-Meyer method, improved to a certain extent, and the rehabilitation effect is better than the traditional rehabilitation training. The outcome indicates that, the upper extremity compound movements rehabilitation training robot has a significant application prospect in clinical rehabilitation.

Two-dimensional simulation of inductively coupled plasma based on COMSOL and comparison with experimental data

A two-dimensional axisymmetric inductively coupled plasma (ICP) model, and its implementation in the COMSOL multiphysical software, is described. The simulations are compared with the experimental results of argon discharge from the gaseous electronics conference RF reference cell in the inductively coupled plasma mode. The general trends of the number density and temperature of electrons with radial scanning are approximately correct. Finally, we discuss the reasons why the comparisons are not in agreement, and then propose an improvement in the assumptions of the Maxwellian electron energy distribution function and reaction rate.

Fluid model of inductively coupled plasma etcher based on COMSOL

Fluid dynamic models are generally appropriate for the investigation of inductively coupled plasmas. A commercial ICP etcher filled with argon plasma is simulated in this study. The simulation is based on a multiphysical software, COMSOL™, which is a partial differential equation solver. Just as with other plasma fluid models, there are drift–diffusion approximations for ions, the quasi-neutrality assumption for electrons movements, reduced Maxwell equations for electromagnetic fields, electron energy equations for electron temperatures and the Navier–Stokes equation for neutral background gas. The two-dimensional distribution of plasma parameters are shown at 200 W of power and 1.33 Pa (10 mTorr) of pressure. Then the profile comparison of the electron number density and temperature with respect to power is illustrated. Finally we believe that there might be some disagreement between the predicted values and the real ones, and the reasons for this difference would be the Maxwellian eedf assumption and the lack of the cross sections of collisions and the reaction rates.

Finite element analysis on factors influencing the clamping force in an electrostatic chuck

As one of the core components of IC manufacturing equipment, the electrostatic chuck (ESC) has been widely applied in semiconductor processing such as etching, PVD and CVD. The clamping force of the ESC is one of the most important technical indicators. A multi-physics simulation software COMSOL is used to analyze the factors influencing the clamping force. The curves between the clamping force and the main parameters such as DC voltage, electrode thickness, electrode radius, dielectric thickness and helium gap are obtained. Moreover, the effects of these factors on the clamping force are investigated by means of orthogonal experiments. The results show that the factors can be ranked in order of voltage, electrode radius, helium gap and dielectric thickness according to their importance, which may offer certain reference for the design of ESCs.

Double visual feedback in the rehabilitation of upper limb

Stroke patients may have limb paralysis or disturbance of consciousness. In the rehabilitation system, the main task of human-computer interaction focused on visual interaction. In this study, it has been confirmed that the visual feedback system in the rehabilitation has played an important role. This robotic system combines a dual video to meet training needs. In the experiment, trainees trains in accordance with the planned trajectory. Through the combined visual system, motion analysis feeds back to trainees in real time. iIn comparing to traditional training without feedback, the combination of Visual feedback can enhance the trainees consciousness of balance, train the neural sensitivity of the brain and nerve system, and can restore the movement ability.

Lower-limb robot-assisted therapy in rehabilitation of acute and subacute stroke patients

Robot-assisted therapy has been proved more effective for treating neurological conditions than conventional therapy. It is known that early training can enhance motor learning and improve functional abilities more than chronicphase training. But there is almost no such lower-limb rehabilitation robot for patients within three months after stroke in clinical. This article introduces such a new robot for acute and subacute stroke patients, which can increase joint flexibility, prevent muscle disuse atrophy, help neural plasticity, enhance motor learning and improve functional abilities by providing patients simulating-gait-training. We did randomized controlled trials including total 8 subjects (4 healthy, 4 patients). At the end of rehabilitation training, the patients’ conditions were assessed by nursing and training staff using the Fugl-Meyer Assessment score. After four weeks of robot-assisted therapy, experimental results showed that the patients’ score and their activities of daily living improved a lot. It is proved that the lower-limb rehabilitation robot for acute and subacute patients is effective.

Lower Limb Rehabilitation Robots: A Review

It is generally accepted that early treatment is an effective way in improving body’s function of the stroke patients. This paper reviews the background of the rehabilitation theory and some typical products of lower limb rehabilitation robots. Lower limb rehabilitation robots have been drawn into rehabilitation training. Researchers have done large amounts of rehabilitation training experiments based on these rehabilitation robots. This paper reviews some representative articles. Abundant clinical trials show that robot-assisted rehabilitation therapy is more effective than conventional therapy in Functional Ambulatory Capacity (FAC), walking speed, step length, etc. However, there are few lower limb rehabilitation robots directing at patients in early stage (the first 3 months after illness) in the domestic and international markets. Therefore, lower limb rehabilitation robot for acute and subacute stroke patients is a promising research area in the future.

Simulation of cold plasma in a chamber under high- and low-frequency voltage conditions for a capacitively coupled plasma

The characteristics of cold plasma, especially for a dual-frequency capacitively coupled plasma (CCP), play an important role for plasma enhanced chemical vapor deposition, which stimulates further studies using different methods. In this paper, a 2D fluid model was constructed for N2 gas plasma simulations with CFD-ACE+, a commercial multi-physical software package. First, the distributions of electric potential (Epot), electron number density (Ne), N number density (N) and electron temperature (Te) are described under the condition of high frequency (HF), 13.56 MHz, HF voltage, 300 V, and low-frequency (LF) voltage, 0 V, particularly in the sheath. Based on this, the influence of HF on Ne is further discussed under different HF voltages of 200 V, 300 V, 400 V, separately, along with the influence of LF, 0.3 MHz, and various LF voltages of 500 V, 600 V, 700 V. The results show that sheaths of about 3 mm are formed near the two electrodes, in which Epot and Te vary extensively with time and space, while in the plasma bulk Epot changes synchronously with an electric potential of about 70 V and Te varies only in a small range. N is also modulated by the radio frequency, but the relative change in N is small. Ne varies only in the sheath, while in the bulk it is steady at different time steps. So, by comparing Ne in the plasma bulk at the steady state, we can see that Ne will increase when HF voltage increases. Yet, Ne will slightly decrease with the increase of LF voltage. At the same time, the homogeneity will change in both x and y directions. So both HF and LF voltages should be carefully considered in order to obtain a high-density, homogeneous plasma.

Gene Transcription and Translation in Design

An organism grows from very small to the whole body, while an engineering product is assembled from elements. An organism is formed autonomously and adaptable to his/her/its environment, while an engineering product can only execute very limited actions. The formation of a product determines its functionality. Nature is the best teacher for learning how structures are formed for specific functionality. This paper compares the design process with the developmental process of embryo and proposes a qualitative development framework that simulates the gene transcription and translation in biology. The key step in design is transforming behaviors to structures. This is a process from information to the form and it bears some similarity with the process from DNA to the protein in embryogenesis. Three basic steps are required from DNA to the protein: gene transcription, transport and protein synthesis, which is named as gene expression. Key mechanisms contributing to this transformation process are investigated and a qualitative development framework are constructed for a growth design process. Simple examples are presented for illustration of proposed methods.Copyright

Evaluation of sEMG on contralateral upper limb physiological characteristic evaluation methodology

Quantitative evaluation for estimating motor function is a prerequisite for clinical application of rehabilitation robot. The current clinical evaluations, such as Fugl-Meyer assessment, still have some deficiency. The study provided an innovative evaluation method, which contrasted the physiological character of impaired limb with the contralateral upper limb of post stroke hemiplegic patients, and investigate the comparability of surface Electromyography (sEMG) between patients and healthy persons during robot-assisted motor recovery training possess similar track and equivalent velocity. There is much comparability of sEMG characteristic in healthy limb of patients compare with healthy person, yet less comparability exist in the impaired limb. The results in the study imply that the method depend on contralateral limb sEMG characteristic have potential capacity in clinical quantitative evaluation of rehabilitation and may competent to associate with other physiological character.