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In this paper, we evaluate the clinical practicality of our hemiplegic upper limb rehabilitation system. This system consists of a selective DOF constrainable mechanism and a facilitative stimulation timing and duration control system. The selective DOF constrainable mechanism enables the separation of synergic movement during shoulder flexion and elbow extension training by constraining each individual joint to target the training exercise. Furthermore, the facilitative stimulation timing and duration control system allow for controlled intervention timing and duration of shrinkable electrical stimulation (SES) and vibratory stimulation according to the training joint angle and angular velocity. In addition, this rehabilitation system is economical and convenient, because it enables training movements of both the elbow and shoulder using a single device. Moreover, this system is safe because there are no actuators. Clinical trials for stroke patients were carried out using this system. As a result, maximal angular velocities of shoulder flexion and elbow extension training improved significantly in most subjects. In addition, the research suggests that the effectiveness of a combination of SES and vibratory stimulation is better than vibratory stimulation alone. Therefore, clinical experiments demonstrate the clinical practicality of this system.

In this paper, rehabilitation aid system by selectable DOF constraintable mechanism and NMES (Neuromuscular Electrical Stimulation) for hemiplegic upper limbs was developed. By using this mechanism, it became possible to separate synergic movement while flexion-extension training of shoulder and elbow by constraining each individual joints. As the clinical trial result by using this mechanism and NMES, the shoulder-elbow UE-FMA sub-scores improved significantly. In this research, NMES timing control system and quantitative evaluation method for sensing the flexion-extension movement of the elbow and shoulder joints are proposed.

As sequelae of stroke, hemiplegia is a typical symptom, where paralysis occurs in the half the body because of brain damage. In this study, we have developed selectable constraint mechanism for hemiplegic upper limb training. By using this mechanism, it became possible to separate synergic movement while flexion-extension training of shoulder and elbow by constraining each individual joints. As the clinical trial result, the shoulder-elbow UE-FMA sub-scores improved significantly. In addition, we proposed NMES timing control system and evaluation method for sensing the flexion-extension movement of the elbow and shoulder joints.

As sequelae of stroke, hemiplegia is a typical symptom, where paralysis occurs in the half the body because of brain damage. In this study, we have developed a rehabilitation aid device with selectable DOF (degree of freedom) constraint mechanism for hemiplegie arm. By using this device, patients became possible to separate synergic movement of shoulder and elbow flexion-extension training by constraining each individually joints, while using Neuromuscular Electrical Stimulation to reduce the side effects, spasticity and pain, and to assist the voluntary movement of hemiplegie arm. In addition, this device can also supports the left and right side upper limb movement. As the clinical trial result, the shoulder-elbow UE-FMA sub-scores improved significantly.

To clarify the origin of the superior field emission characteristics of carbon coated emitters, we investigated the field enhancement at a triple junction and work functions as calculated by ab initio simulations. The electric field near the triple junction is one order of magnitude higher than at other places. Based on ab initio calculation, we found that (1) the work functions of diamond and graphite dramatically decrease to 3 - 3.6 eV upon hydrogen termination, and (2) the effective work functions of some models decrease to 2 eV by applying an external electric field. We also estimated the field emission current from the potential distribution and local density of states under the external electric field applied.

Emission distribution simulation on the cathode surface under ion bombardment shows greater ion bombardment damage on the cathode center than on the periphery. For example, for a klystron gun (5 × 10−8 Torr CO), 46% emission decay occurred on the cathode center, although total emission decayed only 2%.

This paper presents an improved method of voltage utility factor from 50% to 86.6% for a five-leg inverter when two induction motors are driven in vector control and in a condition that a frequency of two motors isn't extremely different, and the improved method of voltage utility factor is theoretically shown. The five-leg inverter is a single inverter that can drive two motors independently and consists of five legs. U and v phases of both motors are connected in each leg respectively whereas w phase of both motors is connected in a common leg. In the five-leg inverter, because w phase of the motors are connected in the common leg, it causes difference from a switching pattern of w phase in two motors. For this reason, the modulation methods for a three leg inverter can't use for the five-leg inverter. Many modulation methods for the five-leg inverter have been proposed, but voltage utility factor is 50% in these methods. From the reason a maximum voltage utility factor of the three leg inverter is 100%, the voltage utility factor of the five-leg inverter is lower than one of the three leg inverter

In this paper, we summarize our activities on X-band RF power source development for the Japan Linear Collider (JLC) project. First, we have designed and tested a solenoid-focused klystron at 11.424 GHz with a pulse length of 1.5 /spl mu/s and with an efficiency of 47%. A periodic permanent magnet (PPM) klystron, the first in that kind at KEK, is also under development. In parallel to this activity, another PPM klystron has been developed and remodeled in collaboration with BINP. Second, a new RF window with 100-MW power-handling capability has been designed and tested. It utilizes the TW mixed mode (TE11 and TM11 modes) to reduce the surface field at the brazing edge of the ceramic. The cold model test shows a low electric field at the brazing point as predicted by HFSS calculations. The high power model is now in manufacturing and the testing will start soon. Third, the Blumlein modulator was upgraded to produce a pulse with 2 /spl mu/s flat top and 200 ns rise time at 550 kV output voltage. Fourth, the multi-mode 2/spl times/2 DLDS (Delay Line Distribution System) pulse compression system has been designed, and its basic unit was manufactured and tested for proof of the principle. The measurement results show that the system works well with a high power distribution efficiency. The so-called mode stability experiment is also under preparation in the ATF linac tunnel in collaboration with SLAC. This experiment is aimed for examination of the stability of linearly polarized TE12 mode in a 55 m long waveguide, a key issue in the present configuration of multi-mode DLDS. Details of these developments and measurement results are presented.

X-band klystrons (XB-72K) designed for the Next Linear Collider (NLC) are described. Klystrons having traveling-wave output structures in order to reduce the electric fields and an RF output power of around 70 MW have been obtained. A new klystron-simulation code using "MAGIC" has been developed at KEK, and the simulation results agree well with the experimental data. The next klystron was designed using the code; an RF output of 120 MW is obtained in the simulation. The klystron is being manufactured and it will be tested this November.

In this paper, we summarize the status of X-band PPM klystron development for the Japan Linear Collider (JLC) project. The periodic permanent magnet (PPM) klystrons are under development in the two-stage/two-year project with Toshiba. The goal is to produce 50 MW output power with efficiency >50% at 1.5 /spl mu/s pulse length at the first klystron and then to advance to 75 MW with efficiency =55% at the second one. The first PPM klystron has been tested, and it achieved 56 MW power with 50% efficiency at the standard 1.5 /spl mu/s pulse length. Neither oscillation of the parasitic mode nor gun oscillations were observed. The particle transmission was found to be 100% when no RF signal is applied. The second PPM klystron is currently under high-power testing. It has improved water cooling system of a PPM circuit and the output cavity for 150 Hz operation. The RF system was also revised for a higher efficiency. To date (June 6, 2001), the PPM-2 klystron produced 73.2 MW at 1.4 /spl mu/s pulse length and 70 MW at 1.5 /spl mu/s pulse length with the efficiency of 54.5%. The maximum efficiency reached 56% at the specified cathode voltage. The high-power testing will be continued to attain a 75 MW output power with a standard 1.5 /spl mu/s pulse. Details of these developments and measurement results are presented.