Experimental study on thermal field in the vicinity of arterial bifurcation in microwave ablation therapy

Figures & data

Figure 1. Experimental system (A), structure of blood vessel (B).

Figure 2. Structure of the antenna and water circulation.

Table I.  Properties of phantom and liver.

	ε	σ(s/m)	ρ(kg/m^3)	C(J/kg•°C)	K(W/m•°C)
Phantom	45	2.2	1070	3700	0.535
Liver	45	2.2	1020	3628	0.42 ∼ 0.57

ε, Dielectric constant; σ, Electrical conductivity; ρ, Density; C, specific heat; K, thermal conductive.

Figure 3. Positions of the microwave antenna.

Figure 4. Positions of antenna and TCs. (A) D, 10 mm; (B) D, 15 mm; (C) D, 20 mm.

Figure 5. Experimental temperature curves for distance between antenna and vessel D = 10 mm (A) TC No.1; (B) TC No.8; (C) TC No.15; (D) TC No.21; (E) TC No.27.

Figure 6. The maximum temperature of the tissue in the recirculation along the branching vessel.

Figure 7. Experimental temperature contours (54°C) after 60 s, 120 s, 180 s, 240 s and 300 s of heating for different distances D between the antenna and the blood vessel with a blood flow of 42.39 mL/min. (A) D = 10 mm; (B) D = 15 mm; (C) D = 20 mm.

Figure 8. Simulated temperature contours (54°C) for different distances, D, between the antenna and the blood vessel with a blood flow of 42.39 mL/min. (A) D = 10 mm; (B) D = 15 mm; (C) D = 20 mm.

Table II.  Comparison of the coagulation region.

Distance D (mm)	Experimental (X × Y) mm	Numerical (X × Y) mm
D = 10	26.5 × 33.5	27.8 × 37.2
D = 15	35.3 × 35.8	34.2 × 37.6
D = 20	35.5 × 36.3	34.5 × 38.2

Figure 9. Experimental temperature profiles along the blood vessel for different distances D between the antenna and the blood vessel.

Figure 10. Experimental and simulated temperature profiles along the blood vessel with a blood flow of 42.39 mL/min for D = 10 mm.

Figure 11. Experimental temperature contours (54°C) after 300 s for different distances D between the antenna and the blood vessel with a blood flow of 42.39 mL/min. Position 1: D = 10 mm, Position 2: D = 15 mm, Position 3: D = 20 mm.

Figure 12. Simulated temperature contours (54°C) after 300 s for different distances D between the antenna and the blood vessel with a blood flow of 42.39 mL/min and 70.79 mL/min. (A) D = 10 mm; (B) D = 15 mm.

Figure 13. Experimental no-flow temperature of TC No.15 and TC No.16 with D = 10 mm.

Figure 14. Experimental left-most daughter blocked temperature of TC No.1 and TC No.27 under the condition of 42.39 mL/min with D = 10 mm.