Functional Evaluation of Handgrip
Signals for Parkinsonian Patients
Gregorio Andria, Filippo Attivissimo, Nicola Giaquinto, Anna Maria Lucia Lanzolla, Livio
Quagliarella, and Nicola Sasanell
IEEE Transaction On Instrumentation And Measurement, Vol.55, No. 5, October 2006
Presenter: Lim Bee Yen
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Outline
Introduction of Parkinson’s disease
Purposes Measurement System
Factors Affecting Grip Strength: A review
Experimental Tests
Results
Discussion and Conclusions
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Introduction of Parkinson’s disease
Degenerative Diseases of the Nervous System
Chronic neurological conditions associated with
progressive loss of neurons.
• No evidence of inflammation.
• No evidence of cellular necrosis.
Examples:
• Alzheimer’s disease.
• Parkinson’s disease.
• Motor neuron disease (ALS).
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Parkinson’s disease(1/3)
2nd most common
neurodegenerative disease.
Mean onset = 57 years of age.
Affects 1-2% of population over
60 years of age.
Etiology is unknown.
Disease progression is highly
variable.
Can be early onset in some
cases.
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Parkinson’s disease(2/3)
Patient’s afflicted with Parkinson’s disease are
described as exhibiting a ‘classic triad’:
– Resting tremor
– Muscle rigidity
– Bradykinesia
Electroencephalograms (EEGs) record some
aspects of brain electrical activity
– not effective in spotting Parkinson’s disease
No diagnostic test that can confirm Parkinson’s
disease
生醫系統整合實驗室 Integrated Biomedical System Laboratory
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Parkinson’s disease(3/3)
Many studies concern gait analysis in Parkinsonian
patients
– high-cost equipment
– problematic test protocols
– experienced operators
Simpler procedures have been used to analyze
reach-to-grasp movements and ballistic movements
with the upper limbs
– high degrees of freedom and the complexity of the
analyzed movements
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Purposes Measurement System
A very simple and versatile system
Able to perform most of the tests indispensable
to hand functionality analysis
Two main parts:
– A handle
– An acquisition system
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A handle
Sensor based on traction
Compression load cells
– TCLZ-100KA-Tokyo Sokki Kenkyujo Company,
supply voltage: 5 V, full scale 100 kg in order to
measure the grip strength
Rendering of the realized prototype equipped
with accessories for different grasp typologies
Prototype realized by Sezione di Ingegneria Biomedica—Università di
Bari, Bari, Italy, in collaboration with the Measurement Group,
Polytechnic of Bari.
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An acquisition system
 Multichannel strain gauge conditioner and amplifier
system:
• Vishay M-M 2100 and 12-bit DAQ Board: PCL-718
Advantech for IBM
 Equipped with management and elaboration
software to permit the complete characterization of
hand motor activities.
 Both the young and the elderly, and the healthy and
pathological people can easily use it.
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A standard calibration procedure
A progression of known weights
Varying in the range of 5–55 kg
A step of 5 kg and applied in ascending and
descending orders
Suspended from the handle device, maintaining
it in the vertical side
The calibration cycle has been repeated three
times
For each applied weight, the handle extension
has been measured
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A standard calibration procedure
Relationship between the applied weights and the recorded
strain of the handle of the developed measurement instrument
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Factors affecting grip strength:
A review(1/3)
Effects of Body Position
 A standardized testing body position is important to compare
different test results
 “The patient seated with his shoulder adducted and neutrally
rotated, the elbow flexed at 90◦, and the forearm and wrist in
neutral position.” -ASHT
Effects of Multiple Trials
 Motor performances and the greatest grip strength usually
occur in the earlier trials
 Fatigue does not affect the hand strength measurements
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生醫系統整合實驗室 Integrated Biomedical System Laboratory
Factors affecting grip strength:
A review (2/3)
 Effects of Duration of Contraction Time
 Isometric contraction can cause potentially dangerous increases in
blood pressure and pulse rate
 A duration of contraction phase equal to or less than 3 s is
recommended
 Effects of Age
 Age is an important variable in the measurement of grip strength
 Grip strength has a nonlinear relationship to age(6~19, 20~50)
 Effects of Sex
 The hand strength of males is stronger than females
 In the range of 14–20 years, the differences between males and
females increase rapidly
生醫系統整合實驗室 Integrated Biomedical System Laboratory
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Factors affecting grip strength:
A review(3/3)
Effects of Hand Dominance
 Some have found that the grip strength of a dominant hand is
approximately 10% greater than that of the nondominant
Effects of Body Weight and Height
 There is a positive relationship between hand strength and the
variables of weight and height
 Grip strength has a nonlinear relationship to age(6~19, 20~50)
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Experimental Tests (1/5)
44 people:
 20 are healthy(11 men and nine women, averaging in age of
61 ± 4 years)
 24 are pathological (15 men and nine women, averaging in
age of 68 ± 6 years)
Standard body position:
 Modified the standard body position described because for
some Parkinsonian patients were not able to maintain the
elbow flexed at 90∘
 The proposed protocol is simple to understand, not requiring
complicated adjustments of the subject position.
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Experimental Tests (2/5)
Analysis:
 Using the Stokes suggestions to eliminate the trials that are
suspected as fictitious loss of grip.
Five successive trials:
 For each patient and for both hands, five successive trials
have been carried out, recoding the relevant score every time.
 The procedure of test requests an initial contraction, which
takes about 3 s , and a successive release phase. The global
time duration of each trial is 6 s.
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Experimental Tests (3/5)
 Beginning and end of the test:
 Two different sounds identified the beginning and end of the
test.
 When the patient heard the first sound, he should exercise the
maximum strength on the handle, keeping the grasp until the
perception of the second sound.
A suitable acquisition system:
 IBM PLC-718 with an accuracy of 0.01% reading ± 1 bit) that
uses a sampling frequency = 110 Hz.
 The obtained signal can be divided into five main phases [4]:
reaction, contraction, maintenance, release, and relaxation
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Experimental Tests (4/5)
Signal relevant to the healthy patient test
Signal relevant to the Parkinsonian patient test
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Experimental Tests (5/5)
Signal relevant to Parkinsonian patients
(continuous line) and the relative filtered
signal (circle marker).
Filtered signal relevant to Parkinsonian patients
(continuous line), the relative derivative signal
(dotted line), and the relative area signal
(dashed line).
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Results (1/3)
 No differences of sex and age were considered
because our sample of patients was
characterized by individuals aged over 50 years
old.
The parameters that high-light in a clear way
meaningful differences between healthy and
Parkinsonian patients were “fall speed” and
“area signal.”
The release phase is less fatiguing and less
difficult with respect to the contraction one.
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Results (2/3)
The area parameter takes into account all the main
char- acteristics of grip strength behavior
(contraction phase, maximum strength, and release
phase).
The velocities (in the rise and fall phase) represent
the ratio between strength variation and time
variation, giving information about the dynamics
of the analyzed phenomena.
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Results (3/3)
Fall speed values relevant to the
Parkinsonian (continuous line) and
healthy (line with the plus marker)
patients with relative average values and
standard uncertainty.
Area signal values relevant to the
Parkinsonian (continuous line) and
healthy (line with plus marker)
patients with relative average values
and standard uncertainty.
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Conclusions
The applicability of a new analysis method for
characterization of the motor activities of limbs has
been investigated.
Objective evaluation relevant to Parkinson’s
disease and represents the first attempt to identify
some criteria for estimating the impairment
produced by Parkinson’s disease.
The analysis concerns patients under treatment
ON-state so that a confirmation of the results must
be given by the tests made on the Parkinsonian
patients in OFF-state.
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Thank you for your attention!
http://faculty.stust.edu.tw/~terrydu/
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