This paper presents the design and simulation of a handheld device for people with hand tremor, such as Parkinson and Essential tremor patients. This device can be used as a pen for smartphones or as a spoon. The designed system includes two links, which are connected to two servo motors, which are mounted in orthogonal directions. To attenuate the effect of hand tremor on the tip of device, PID and Computed Torque methods are used to actively control the system. These controllers are used to control the rotation of the motors for moving the links in opposite directions of the hand tremor. Performance of the device with mentioned controllers is studied for different applications and finally, the results of both controllers are discussed and compared. Based on the presented results in this study, the designed device is able to suppress the hand tremor up to 75% during eating and 65% during following a spiral pattern.

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