ABSTRACT
The study of temperature profiles and heat transport within the human body when subjected to electromagnetic waves is crucial for development and improvement of radiofrequency cardiac ablation treatments (radio frequency ablation). The present study provides an analytical solution for computing the temperature profiles for blood and tissue for various biological media along with heat transfer behavior during various ablation processes. The local thermal nonequilibrium model is used to characterize the bioheat transport through the biological medium. The two energy equation model for tissue and blood phase is considered. To understand the effects induced by imposed electromagnetic field, the specific absorption rate of body tissues is also studied. The results obtained have been validated against the pertinent numerical results in the literature. This study provides benchmark analytical solutions for heat transport through biological media, thereby helping in understanding the thermophysiologic response of human body toward imposed electromagnetic radiation.
Nomenclature
atb | = | specific surface area between vascular and extravascular region (m2/m3) |
Bi | = | Biot number (–) |
cp | = | specific heat capacity (J/kg°C) |
E | = | electric field intensity (V/m) |
f | = | frequency of EM wave (Hz) |
htb | = | heat transfer coefficient between lumen and tissue (W/m2°C) |
H | = | height of the biological medium (m) |
k0 | = | free space wave number (m−1) |
K | = | thermal conductivity (W/m°C) |
L | = | length of biological medium (m) |
P | = | power of EM wave (W) |
qs | = | heat flux at surface (W/m2) |
Q | = | heat source (W/m3) |
T | = | temperature (°C) |
u | = | lumen velocity (m/s) |
x | = | longitudinal coordinate (m) |
y | = | transverse coordinate (m) |
Greek symbols | = | |
ε | = | porosity (ratio of volume fraction of vascular to extravascular space) (–) |
η | = | dimensionless coordinate (–) |
Φ | = | dimensionless heat generation (–) |
κ | = | ratio of effective blood thermal conductivity to tissue thermal conductivity (-) |
ρ | = | density (kg/m3) |
θ | = | dimensionless temperature (–) |
μ | = | magnetic permeability (H/m) |
γ | = | permittivity (F/m) |
σ | = | electric conductivity (S/m) |
Subscripts | = | |
b | = | blood phase |
c | = | cutoff |
ev | = | effective value |
em | = | external |
met | = | metabolic |
r | = | relative |
s | = | surface |
t | = | tissue phase |
Nomenclature
atb | = | specific surface area between vascular and extravascular region (m2/m3) |
Bi | = | Biot number (–) |
cp | = | specific heat capacity (J/kg°C) |
E | = | electric field intensity (V/m) |
f | = | frequency of EM wave (Hz) |
htb | = | heat transfer coefficient between lumen and tissue (W/m2°C) |
H | = | height of the biological medium (m) |
k0 | = | free space wave number (m−1) |
K | = | thermal conductivity (W/m°C) |
L | = | length of biological medium (m) |
P | = | power of EM wave (W) |
qs | = | heat flux at surface (W/m2) |
Q | = | heat source (W/m3) |
T | = | temperature (°C) |
u | = | lumen velocity (m/s) |
x | = | longitudinal coordinate (m) |
y | = | transverse coordinate (m) |
Greek symbols | = | |
ε | = | porosity (ratio of volume fraction of vascular to extravascular space) (–) |
η | = | dimensionless coordinate (–) |
Φ | = | dimensionless heat generation (–) |
κ | = | ratio of effective blood thermal conductivity to tissue thermal conductivity (-) |
ρ | = | density (kg/m3) |
θ | = | dimensionless temperature (–) |
μ | = | magnetic permeability (H/m) |
γ | = | permittivity (F/m) |
σ | = | electric conductivity (S/m) |
Subscripts | = | |
b | = | blood phase |
c | = | cutoff |
ev | = | effective value |
em | = | external |
met | = | metabolic |
r | = | relative |
s | = | surface |
t | = | tissue phase |