E. Ewertowska , V. Muñoz , A. Ivorra , M. Trujillo , E ... · 3 Neurotherm Spain , 4 Serra Húnter...
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E. Ewertowska 1 , B. Mercadal 2 , V. Muñoz 3 , A. Ivorra 2,4 , M. Trujillo 5 , E. Berjano 1 1 Department of Electronic Engineering, Universitat Politècnica de València, Spain; 2 Department of Information and Communication Technologies, Universitat Pompeu Fabra, Spain; 3 Neurotherm Spain, 4 Serra Húnter Fellow Programme, Generalitat de Catalunya, Spain; 5 Instituto Universitario de Matemática Pura y Aplicada, Universitat Politècnica de València, Spain;
Transcript of E. Ewertowska , V. Muñoz , A. Ivorra , M. Trujillo , E ... · 3 Neurotherm Spain , 4 Serra Húnter...
E . E w er tow ska 1 , B . M e r c ada l 2 , V. M u ñ o z 3 , A . I vo r r a 2 , 4 , M . Tr u j i l l o 5 , E . B e r j a n o 1
1 D e p a r t me n t o f E l e c t ron i c E n g i n e e r i ng , U n i ve r s i t a t P o l i t è c n i c a d e Va l è n c i a , S p a i n ;2 D e p a r t me n t o f I n f o r ma t i on a n d C o m m u n i c a t i on Te c h no lo g i es , U n i ve r s i t a t P o m p e u F a b r a , S p a i n ;
3 N e u r o t he rm S p a i n , 4 S e r r a H ú n t e r F e l l o w P r o g ram me , G e n e ra l i t a t d e C a t a l unya , S p a i n ; 5 I n s t i t u t o U n i ve r s i t a r i o d e M a t e m á t i c a P u r a y A p l i c ad a , U n i ve r s i t a t P o l i t è c n i c a d e Va l è n c i a , S p a i n ;
Overview
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1. THEORY
2. MOTIVATION
3. COMPUTER MODELLING WITH COMSOL
4. RESULTS
5. CONCLUSIONS
COMSOL Conference 2016 Munich
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Minimally invasive technique for long-term pain relief in peripheral nerve injury
Radiofrequency heating
1. Theory COMSOL Conference 2016 Munich
PRF
Neuromodulation
through electric field
Analgesic method
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Pulsed radiofrequency (PRF)
Short, high – voltage pulses with high
frequency current
Reduces thermal lesion restricting temperatures to 42ºC
RFA
Heating due to
an electro-mechanical
friction
Neurotomy
Chua et. al., 2011
1. Theory COMSOL Conference 2016 Munich
Comparable electric dose
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Pulse protocols for PRF
A B C D
Pulse duration [ms] 20 20 5 5
Repetition frequency [Hz] 2 2 5 5
Voltage [V] 45 45 55 55
Temperature controller
(TC)- + - +
3. Computer modelling with COMSOL COMSOL Conference 2016 Munich
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Computational validation of two different pulse protocols for pulsedradiofrequency used in clinical pain management
Analysis of thermal and electric performance in function of pulse characteristics
Assessment of temperature control on electric effect in tissue
Motivation
2. Motivation COMSOL Conference 2016 Munich
2D extruded model
2D model
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COMSOL – model geometry
3. Computer modelling with COMSOL COMSOL Conference 2016 Munich
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COMSOL – model assumptions
3. Computer modelling with COMSOL
Materialσ
S/m
k
W/(m∙K)
ρ
kg/m3
c
J/(kg∙K)
Tissue 0.28 0.49 1090 3421
Plastic 105 0.026 70 1045
Electrode 7.4105 15 8103 480
Homogeneous tissue
Constant thermal conductivity, k
COMSOL Conference 2016 Munich
)37(015.028.0 Te
Temperature dependent electrical conductivity, σ
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COMSOL – coupled physics
Electric Problem 0))(( VT
2)( ETq VE
PQqTkt
Tc
)(
)( TTcQ aP
Heaviside function: flc2hs(T, scale)
3. Computer modelling with COMSOL
6.4,0
6.4,1
COMSOL Conference 2016 Munich
Thermal Problem
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Pulse protocols for PRF
3. Computer modelling with COMSOL
Ts
Temperature controller
CT
CT
s
S
42,0
42,1
ii vtv )(
COMSOL Conference 2016 Munich
dsAet RT
E
0
)(Thermal damage
No temperature controller
Maximal temperature reduced by 5ºC
No change in minimal temperature
distribution (~49ºC)
A B C D
Pulse duration [ms] 20 20 5 5
Repetition frequency [Hz] 2 2 5 5
Voltage [V] 45 45 55 55
Temperature controller
(TC)- + - +
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Thermal performance
4. Results COMSOL Conference 2016 Munich
Temperature controller
Minimal temperatures maintained at
~42ºC
Temperature range unchanged
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Thermal damage
A B C D
Thermal damage of 63%, Ω = 1
No thermal damage
4. Results COMSOL Conference 2016 Munich
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Electrical performance
Higher magnitude of electric fieldfor higher voltaje independently ontemperature control
No change in electric fieldmagnitude in the presence oftemperature controller
4. Results COMSOL Conference 2016 Munich
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Conclusions
Determination of changing material properties (σ(T)) and other parameters by means of specific functions (flc2hs)
Pulse of shorter duration implies tissue temperature reduction and benefits the electric effect in tissue
Temperature controller is needed to avoid the risk of thermal lesion
5. Conclusions COMSOL Conference 2016 Munich
E . E w er tow ska 1 , B . M e r c ada l 2 , V. M u ñ o z 3 , A . I vo r r a 2 , 4 , M . Tr u j i l l o 5 , E . B e r j a n o 1
1 D e p a r t me n t o f E l e c t ron i c E n g i n e e r i ng , U n i ve r s i t a t P o l i t è c n i c a d e Va l è n c i a , S p a i n ;2 D e p a r t me n t o f I n f o r ma t i on a n d C o m m u n i c a t i on Te c h no lo g i es , U n i ve r s i t a t P o m p e u F a b r a , S p a i n ;
3 N e u r o t he rm S p a i n , 4 S e r r a H ú n t e r F e l l o w P r o g ram me , G e n e ra l i t a t d e C a t a l unya , S p a i n ; 5 I n s t i t u t o U n i ve r s i t a r i o d e M a t e m á t i c a P u r a y A p l i c ad a , U n i ve r s i t a t P o l i t è c n i c a d e Va l è n c i a , S p a i n ;
