Dynamic Vibration Absorber for Suppression of Tremor of Hand in Parkinson

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Dynamic Vibration Absorber for Suppression of
Tremor of Hand in Parkinsons Diseases

• Zaidi Mohd Ripin,
• School of Mechanical Engineering, Universiti
  Sains Malaysia
• 16/12/2008

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Parkinsons disease

• Parkinson's disease (also known as Parkinson
  disease or PD) is a degenerative disorder of the
  central nervous system that often impairs the
  sufferer's motor skills, speech, and other
  functions. 1

1 Jankovic J (April 2008). "Parkinson's
disease clinical features and diagnosis". J.
Neurol. Neurosurg. Psychiatr. 79 (4) 36876.
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• Hashemi et al. (2004) proposed a tuned vibration
  absorber (TVA) on a two degrees of freedom
  hand-arm model.
• Based on their studies, the vibration absorber
  was designed, tested both analytically and
  experimentally.
• Experimental investigations indicated that
  optimum control performance was related to the
  position of the controller and the excitation
  frequency (varies from 2 to 10 Hz).
• With a distance of 160 mm from the end of
  forearm, the TVA was found to have the best
  performance, and, for different tremor
  frequencies, the vibration of the experimental
  model was reduced by more than 80.

Vibration absorber
Analytical model
Vibration absorber
Experimental model
Hashemi, S.M., Golnaraghi, M.F., and Patla, A.E.,
(2004) A Tuned Vibration Absorber (TVA) for
Suppression of Rest Tremor in Parkinsons
Disease, Journal of Medical Biological
Engineering Computing. Vol. 41, pp. 61-70.
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• Cherian et al. (1996) contributes to model
  development of a five DOF biomechanical model,
  which represents the viscoelastic and inertia
  properties of human hand-arm.
• They proposed a 0.5 kg flow divider attached to a
  5 DOF hand-arm model.
• The overall weighted acceleration of the hand
  decreased by 22, while the forearm and the upper
  arm increases by 13 and 10 respectively.

Flow divider
Schematic of 5DOF hand-arm model with flow divider
Cherian, T., Rakheja, S. and Bhat, R.B. (1996).
An analytical investigation of an energy flow
divider to attenuate hand-transmitted vibration.
Journal of Industrial Ergonomics. 17455-467.
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Principle of a vibration absorber

• A simple vibration absorber consists of a mass
  and a spring.
• When a primary system is excited by a harmonic
  force, its vibration can be suspended by
  attaching a vibration absorber.

An absorber attached to primary system
Animation
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• The vibration absorber has been used in many
  application since it was invented in 1909.
• Applications range from small handheld tools, to
  giant structures such as bridges to large moving
  structures, such as aircraft.

The collapse of Tacoma Narrows Bridge
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• However, passive vibration absorber has their
  shortcomings, example narrow band treatment.
• The alternative to passive vibration absorbers
  is active vibration absorber.
• An active vibration absorber has an active
  element U (the actuator).
• Active vibration absorbers have higher
  effectiveness and can re-tuned via their
  electronics/software (manually or automatically).
  

An active dynamic absorber/tuned mass damper
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• Hand-held gyroscopic device

• The device is held against the back side of the
  human hand to reduce or eliminate essential
  tremor or other tremor. driven by an electric
  motor with batteries mounted near the periphery
  of the gyroscope to enhance the gyroscopic
  action.

Reference United States Patent 5058571
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Research Potential

• Tremor quantification (magnitude, direction,
  parts (eg finger, hand, arm, elbow)
• Modeling of tremor in hand-arm system (internal
  forces?, verification)
• Parametric studies introduction of devices to
  the model , identify possible reduction,
  optimization
• Design drawing, detail components PATENT
• Prototype development and field testing

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New Technology

• Piezo-electric devices for gyroscopic motion
  high speed low mass acceptable inertia
• Active DVA gyro system coupled with
  accelerometer with feedback system to REACT
• Form factor Location (no bigger than wristwatch
  not to interfere with hand function)

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New Technology

• Piezo-electric devices for gyroscopic motion
  high speed low mass acceptable inertia
• Active DVA gyro system coupled with
  accelerometer with feedback system to REACT
• Form factor Location (no bigger than wristwatch
  not to interfere with hand function)

EXTREMELY DIFFICULT TO REALIZE !
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SKILLS

• Medical what can and cannot
• Mechanical to model, measure
• Control - to solve
• Leader to inspire us and get the money

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• Thank you