Essential tremor suppression by a novel self-balancing device.

BACKGROUND: There are many associated devices using impedance method. However, they cannot completely suppress tremor. Other methods using active vibration control have been a challenging problem for industrial and academic researchers. Potential applications of the latter for tremor patients are still not realized.
OBJECTIVES: This article presents a novel method for suppressing human lower arm tremor in essential tremor by using a self-balancing technique. STUDY
DESIGN: In this article, a rotating unbalanced mass actuator was used to imitate an arm tremor with the same frequency range obtained from clinical sources. A novel counter-balance device was designed to attach the fictitious arm. The tremor reduction is expecting quantitatively.
METHODS: A Proportional-Integral-Derivative controller and an algorithm programmed in LabVIEW are proposed to control a rotating unbalanced mass actuator, anti-shaker, in order to counter the tremor. The self-balancing system for the new approach was obtained when both amplitudes and frequencies of anti-shaker and tremor are the same.
RESULTS: The results show that this method can reduce vibration of tremor in the order of 0.001 rad/s(2).
CONCLUSION: This method can suppress the vibration and can also auto-tune to counter the tremor in a range of 4-12 Hz bandwidth. CLINICAL RELEVANCE: The therapy of arm tremor was associated with using counter-devices to palliate the vibration magnitude. Conventional methods such as physical surgery and drugs cannot completely eliminate tremor. The novel counter-device is an alternative technique with promising application for clinical uses for tremor patients without involving harmful surgery. © The International Society for Prosthetics and Orthotics 2014.