UM File # 3952
Ten million people in the U.S. alone suffer from essential tremor. People diagnosed with this tremor can have trouble performing necessary functions. Additionally, individuals affected by tremor who work in occupations requiring fine muscle control (e.g. artists, surgeons, musicians, drafters) are often forced to retire as a result. Despite current treatment options, many patients possess tremor that is not curable or they may decline treatment because they consider the risks and side-effects to be too great. One approach for this group is the use of tremor suppression devices that physically force a person’s tremor to cease. One significant disadvantage of these devices is user discomfort or pain that occurs when relatively large forces are applied to an affected limb. Another problem is that these devices typically do not distinguish between intended and unintended motions. Therefore, patients encounter resistance to all regular directed movements making the experience of wearing the device awkward and obtrusive.
Researchers at the University of Michigan have developed a handheld active cancellation device for tremor management. This handheld device uses a shape memory alloy (SMA)-actuated platform acting between the user’s hand and the object to be stabilized. Sensing the user’s tremor, the handheld device provides force and displacement to the object in a 2 degree-freedom (DOF) plane counteracting any unintended motions while allowing the user’s hand to move freely. This approach heightens user comfort and aids intuitive operation as intended motions can be distinguished from unintended tremor in the handheld device. Tremor cancellation requires less force than tremor suppression because it does not fight the user’s muscle action.
Applications • Physical rehabilitation • Improve quality of life for patients with essential tremor
Advantages • Inexpensive materials and design • Displacements in each direction may be separately controlled
Assistive Device for Tremor ReductionTechnology #3952
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UM File # 3952