Characterisation of the Elasticity of the Human Vocal Fold using
Electromechanical Measurement Techniques
Characterisation of the Elasticity of the Human Vocal Fold using
Electromechanical Measurement Techniques
The Linear Skin Rheometer
The Laryngeal Tensiometer
LSR Principle of Operation
Shear Mode Operation
Force ~ Displacement Graph
-2
0
2
4
6
8
10
12
0 0.5 1 1.5 2 2.5
Indentor Mode
Results from Harvard - AQL 2003
Results from Wisconsin - 2005
Typical Experimental Setup
Vocal Fold Shear Modulus - Shear Model
0
500
1000
1500
2000
2500
3000
3500
4000
0 20 40 60 80 100
Age
Pa
sc
al
Female
Male
Vocal Fold Shear Modulus - Indentometer Model
0
500
1000
1500
2000
2500
3000
0 20 40 60 80 100
Age
Pa
sc
al
female
Male
Male FemaleShear 1008 190 1237 384Indent 1000 230 1332 214
Summary of Shear Modulus Results
The Laryngeal Tensiometer
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Shear Strain
-0.4
-0.2
0
0.2
0.4
0.6
0 50 100 150 200 250 300 350
Time
Fo
rce
gra
ms
Methyl Cellulose Attachment
Suction Attachment
Suction
-1
-0.5
0
0.5
1
1.5
2
2.5
time
Gra
ms
Fo
rce
Age Sex CofV Shear ModulusMean Pascals
36 F 15% 93337 F 19% 77728 F 11% 70170 F - 197228 F 10% 181952 F 27% 90163 M 22% 163755 M 17% 2225
Range of Shear Modulus Obtained from 8Volunteer Patients
First Suction results CofV = 3% & 8%
Spinning
0
0.2
0.4
0.6
0.8
1
1.2
0 50 100 150 200
Angle
DSR
Elastic Variance with angle
Complete Vocal Fold
00.20.40.60.8
11.2
0 50 100 150 200
Angle (90 = transverse)
Stif
fnes
s
Anisotropic Behaviour Study
0
0.2
0.4
0.6
0.8
1
1.2
0 50 100 150 200
Ligament & Muscle
0
0.2
0.4
0.6
0.8
1
1.2
0 50 100 150 200
Muscle Only
Complete 0.38
Ligament 0.53
Muscle 0.61
Ratio of Transverse to Longitudinal Stiffness
Implies LP is inherently anisotropic
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