repetitive control based tremor suppression using electrical stimulation
DESCRIPTION
Repetitive Control Based Tremor Suppression Using Electrical Stimulation. Engin Hasan Copur Dr. Bing Chu, Dr. Christopher Freeman, Dr. Dina Shona Laila University of Southampton. Outline. What is a tremor? Tremor Suppression Techniques Objective Simulation Results - PowerPoint PPT PresentationTRANSCRIPT
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Repetitive Control Based Tremor Suppression Using Electrical
Stimulation
Engin Hasan Copur Dr. Bing Chu, Dr. Christopher Freeman,
Dr. Dina Shona Laila University of Southampton
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Outline What is a tremor? Tremor Suppression Techniques Objective Simulation Results Conclusion and Future Work
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What is a tremor? Tremor is an approximately rhythmic, roughly
sinusoidal involuntary movement
1.5 million patients in Europe have essential tremor (Sullivan et al., 2004)
Of these 1.5 million as many as one in three may have intention tremor (Louis et al., 2009)
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Tremor Suppression Techniques Invasive Methods:
Stereotactic Thalamotomy
Deep Brain Stimulation (DBS)
Non-invasive Methods:
Pharmacological treatment
Non-pharmacological treatment
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Functional Electrical Stimulation (FES) Previous treatment methods have some limitations
FES is potentially more effective and less dangerous than the others
An open challenge of using FES for tremor suppression is to employ a most effective closed-loop control algorithm in FES applications.
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Objective
In my study, repetitive control is used and compared with some other methods to examine whether repetitive control has more potential than the others for suppressing tremor or not.
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Simulation Results
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0 0.5 1 1.5 2 2.5 3 3.5-4
-3
-2
-1
0
1
2
3
4
5
6 x 10 -3
Time (s)
Tremo
r Amp
litude
Closed-loop SystemOpen-loop System
0 0.5 1 1.5 2 2.5 3 3.5-4
-3
-2
-1
0
1
2
3
4
5
6 x 10 -3
Time (s)
Tremo
r Amp
litude
Closed-loop SystemOpen-loop System
Time responses of output of closed-loop system with high-pass and band-pass filters
F
G
c
-+
�
V oluntar y motion signal, r T r emor signal, d
+Wrist Model
FilterGain
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Simulation Results
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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.03
-0.02
-0.01
0
0.01
0.02
0.03
Time(s)
Outpu
t of C
losed
-Loop
Syste
m
F s = 45Hz
Open-loop SystemRC w/o inner feedback systemRC with inner feedback system
0 2 4 6 8 10 12 14 16 18 20-0.02
-0.015
-0.01
-0.005
0
0.005
0.01
0.015
0.02
T ime (s )Tre
mor A
mplitu
de
Gradient-based RC w/o inner loopGradient-based RC with inner loopOpen-Loop System
Time responses of output of closed-loop system with different repetitive control algortihms
Wrist Model
Repetitive Controller
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Conclusion or summary or future work Conclusion
Filters are able to remove tremor signal very slightly RC is more efficient than filters However both methods have some limitations
Future Work All simulations in this study will be tested experimentally The identification method of wrist model will be checked The studies will be expanded to design a more robust control
algorithm All methods may be tested on MS patients diagnosed with intention
tremor
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Thank you!
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References Louis, E. D., Frucht, S. J., and Rios, E. (2009).
Intention tremor in essential tremor: Prevalence and association with disease duration. Movement Disorders, 24(4):626–627. 4
Sullivan, K. L., Hauser, R. A., and Zesiewicz, T. A. (2004). Essential tremor: Epidemiology, diagnosis, and treatment. The Neurologist, 10(5):250–258.
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