OVERVIEW
Four ablations will be done in ex vivo bovine for each flow rate. There will be three different flow rates: 0 mL/min, 860 mL/min, and 1000 mL/min. These flow rate were chosen based on hepatic flow rates of humans in the supine position (Brown et al. 1989; Leen et al. 1992). Each ablation will be performed at 40 watts for 2 minutes for a total of 12 ablations. The average area of a 30ºC and 50 ºC contour at the end of the ablation will be used to characterize the size of the ablation zone for each flow rate.
LIVER PREPARATION Approximately 300mL of bovine liver was homogenized to create the test medium. Heterogeneity of liver tissue can lead to inconsistent ablations due to the different thermal properties of the different cell types. …show more content…
The temperature was monitored with fiber optic thermistors (Neoptix, Canada). The liver was then degassed with a vacuum, see Figure 3. The degassing process removes air from the blended liver tissue. It is important to remove air from the liver tissue because air has a different dielectric constant compared to liver. The difference in dielectric constant can result in inconsistent ablations; thus, degassing creates a more homogenous liver leading to more consist ablations. The blended liver should be degassed for one minute five …show more content…
The applicator will be connected to the Certus also from Nuewave Medical. The Certus controls the amount of power applied to the applicator as well as the amount of time the power is applied to the applicator. Before placing the applicator in the ablation apparatus, the applicator must be tested to ensure the cooling system of the applicator is operating correctly. Follow the procedure in Appendix A to properly test the applicator. Using a third arm, see Figure 7, the applicator should be placed in the ablation apparatus. Once the applicator has been placed in the notch of the ablation apparatus the time and power should be set using the Certus. The ablations will be performed at 40 watts for 2 minutes. This power and time is chosen to allow for any possible heat transfer to be observed. If the time is too short no heat transfer will occur and if the power is too low the ablation zone will be so small that the fluid flow will be too far from the zone too observe any sort of impact from the fluid flow. FLOW VESSEL
Four ablations will be done in ex vivo bovine for each flow rate. There will be three different flow rates: 0 mL/min, 860 mL/min, and 1000 mL/min. These flow rate were chosen based on hepatic flow rates of humans in the supine position (Brown et al. 1989; Leen et al. 1992). Each ablation will be performed at 40 watts for 2 minutes for a total of 12 ablations. The average area of a 30ºC and 50 ºC contour at the end of the ablation will be used to characterize the size of the ablation zone for each flow rate.
LIVER PREPARATION Approximately 300mL of bovine liver was homogenized to create the test medium. Heterogeneity of liver tissue can lead to inconsistent ablations due to the different thermal properties of the different cell types. …show more content…
The temperature was monitored with fiber optic thermistors (Neoptix, Canada). The liver was then degassed with a vacuum, see Figure 3. The degassing process removes air from the blended liver tissue. It is important to remove air from the liver tissue because air has a different dielectric constant compared to liver. The difference in dielectric constant can result in inconsistent ablations; thus, degassing creates a more homogenous liver leading to more consist ablations. The blended liver should be degassed for one minute five …show more content…
The applicator will be connected to the Certus also from Nuewave Medical. The Certus controls the amount of power applied to the applicator as well as the amount of time the power is applied to the applicator. Before placing the applicator in the ablation apparatus, the applicator must be tested to ensure the cooling system of the applicator is operating correctly. Follow the procedure in Appendix A to properly test the applicator. Using a third arm, see Figure 7, the applicator should be placed in the ablation apparatus. Once the applicator has been placed in the notch of the ablation apparatus the time and power should be set using the Certus. The ablations will be performed at 40 watts for 2 minutes. This power and time is chosen to allow for any possible heat transfer to be observed. If the time is too short no heat transfer will occur and if the power is too low the ablation zone will be so small that the fluid flow will be too far from the zone too observe any sort of impact from the fluid flow. FLOW VESSEL