Though conventional implants have a capability of pressure regulation, they cannot maintain the intra-ocular pressure (IOP) desired for different patients. To solve these problems, an active glaucoma implant which consists of the valve actuator, pressure sensor, controller, and power supply, has been developed. In this paper, we first analyse of the operation of the conventional implant using a bond graph, and show its defects and limitations of the conventional valve analytically. Next, we design and analyze an electromagnetically driven valve actuator composed of a membrane, air-core solenoid, permanent magnet, and covering frame. To save the electrical power for operating the valve actuator, appropriate actuating methods are suggested and an optimal design of the valve actuator is carried out. Finally, using simulations, the possibility of the proposed valve actuator is investigated.

In this paper, a haptic device is developed for PC video games, considering such specifications as bandwidth and resolution of human hand, workspace, and back-drivability. It has two degrees-of-freedom of rotation using a gimbal mechanism. For force reflection, two DC motors are used, and for torque amplification, cable transmission is used. For sensing of the reflected torque, a current sensor is used instead of high-cost force/torque sensor, using the property that the torque is linearly proportional to the current in the DC motor. For a joystick angle sensor, a potentiometer is used due to low-cost and enough resolution for torque reflection. It is analyzed that the torque reflection required to achieve motion realization for the video games are the spring torque and damping torque, which are implemented. The time and frequency response of the haptic joystick are demonstrated experimentally. The result will be presented. Additionally, simple dynamic programs which have the force reflection capability are implemented. The proposed haptic joystick is shown to be feasible in the applications of the haptic joystick for PC video games.