Limits...
Temperature modulation of electric fields in biological matter.

Daniels CS, Rubinsky B - PLoS ONE (2011)

Bottom Line: This second study demonstrates that in this probe configuration the temperature induced changes in electrical properties of tissue substantially reduce the electric fields in the cooled regions.This novel treatment can potentially be used to protect sensitive tissues from the effect of the PEF.Perhaps the most important conclusion of this investigation is that temperature is a powerful and accessible mechanism to modulate and control electric fields in biological tissues and can therefore be used to optimize and control PEF treatments.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of California, Berkeley, California, United States of America. daniels.charlotte@gmail.com

ABSTRACT
Pulsed electric fields (PEF) have become an important minimally invasive surgical technology for various applications including genetic engineering, electrochemotherapy and tissue ablation. This study explores the hypothesis that temperature dependent electrical parameters of tissue can be used to modulate the outcome of PEF protocols, providing a new means for controlling and optimizing this minimally invasive surgical procedure. This study investigates two different applications of cooling temperatures applied during PEF. The first case utilizes an electrode which simultaneously delivers pulsed electric fields and cooling temperatures. The subsequent results demonstrate that changes in electrical properties due to temperature produced by this configuration can substantially magnify and confine the electric fields in the cooled regions while almost eliminating electric fields in surrounding regions. This method can be used to increase precision in the PEF procedure, and eliminate muscle contractions and damage to adjacent tissues. The second configuration considered introduces a third probe that is not electrically active and only applies cooling boundary conditions. This second study demonstrates that in this probe configuration the temperature induced changes in electrical properties of tissue substantially reduce the electric fields in the cooled regions. This novel treatment can potentially be used to protect sensitive tissues from the effect of the PEF. Perhaps the most important conclusion of this investigation is that temperature is a powerful and accessible mechanism to modulate and control electric fields in biological tissues and can therefore be used to optimize and control PEF treatments.

Show MeSH

Related in: MedlinePlus

The electric field distributions along a transection at the diameter of the sample for Case 2.a) Control, b) cold probe 4 cm from center, c) cold probe 2 cm from center, and d) cold probe 0 cm from center. These images indicate that in this configuration, resistance in parallel, cooling can be used to protect particular regions in the domain from electric fields. By comparing Figure 7 b, c and d to Figure 7a, it is clear that the cooling temperatures applied lower the electric field in the region of low temperature in this geometry.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3113852&req=5

pone-0020877-g007: The electric field distributions along a transection at the diameter of the sample for Case 2.a) Control, b) cold probe 4 cm from center, c) cold probe 2 cm from center, and d) cold probe 0 cm from center. These images indicate that in this configuration, resistance in parallel, cooling can be used to protect particular regions in the domain from electric fields. By comparing Figure 7 b, c and d to Figure 7a, it is clear that the cooling temperatures applied lower the electric field in the region of low temperature in this geometry.

Mentions: Figure 7 illustrates the electric field along a transection through the center of the electrodes and cooling probe for various locations of the cooling probe. Figure 7a shows the control case and Figure 7b shows the cooling case at 4 cm from the center of the domain. It is clear that in the configuration described here the increased electrical resistance due to the cold region acts as a current path of high electrical resistance in parallel to the higher temperature path of lower resistance. This configuration, in contrast to the trends identified in Case 1, results in a substantial decrease in the electric field in the cooled region. In fact, the electric field reaches 0 V/m in the location of the cold probe.


Temperature modulation of electric fields in biological matter.

Daniels CS, Rubinsky B - PLoS ONE (2011)

The electric field distributions along a transection at the diameter of the sample for Case 2.a) Control, b) cold probe 4 cm from center, c) cold probe 2 cm from center, and d) cold probe 0 cm from center. These images indicate that in this configuration, resistance in parallel, cooling can be used to protect particular regions in the domain from electric fields. By comparing Figure 7 b, c and d to Figure 7a, it is clear that the cooling temperatures applied lower the electric field in the region of low temperature in this geometry.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3113852&req=5

pone-0020877-g007: The electric field distributions along a transection at the diameter of the sample for Case 2.a) Control, b) cold probe 4 cm from center, c) cold probe 2 cm from center, and d) cold probe 0 cm from center. These images indicate that in this configuration, resistance in parallel, cooling can be used to protect particular regions in the domain from electric fields. By comparing Figure 7 b, c and d to Figure 7a, it is clear that the cooling temperatures applied lower the electric field in the region of low temperature in this geometry.
Mentions: Figure 7 illustrates the electric field along a transection through the center of the electrodes and cooling probe for various locations of the cooling probe. Figure 7a shows the control case and Figure 7b shows the cooling case at 4 cm from the center of the domain. It is clear that in the configuration described here the increased electrical resistance due to the cold region acts as a current path of high electrical resistance in parallel to the higher temperature path of lower resistance. This configuration, in contrast to the trends identified in Case 1, results in a substantial decrease in the electric field in the cooled region. In fact, the electric field reaches 0 V/m in the location of the cold probe.

Bottom Line: This second study demonstrates that in this probe configuration the temperature induced changes in electrical properties of tissue substantially reduce the electric fields in the cooled regions.This novel treatment can potentially be used to protect sensitive tissues from the effect of the PEF.Perhaps the most important conclusion of this investigation is that temperature is a powerful and accessible mechanism to modulate and control electric fields in biological tissues and can therefore be used to optimize and control PEF treatments.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of California, Berkeley, California, United States of America. daniels.charlotte@gmail.com

ABSTRACT
Pulsed electric fields (PEF) have become an important minimally invasive surgical technology for various applications including genetic engineering, electrochemotherapy and tissue ablation. This study explores the hypothesis that temperature dependent electrical parameters of tissue can be used to modulate the outcome of PEF protocols, providing a new means for controlling and optimizing this minimally invasive surgical procedure. This study investigates two different applications of cooling temperatures applied during PEF. The first case utilizes an electrode which simultaneously delivers pulsed electric fields and cooling temperatures. The subsequent results demonstrate that changes in electrical properties due to temperature produced by this configuration can substantially magnify and confine the electric fields in the cooled regions while almost eliminating electric fields in surrounding regions. This method can be used to increase precision in the PEF procedure, and eliminate muscle contractions and damage to adjacent tissues. The second configuration considered introduces a third probe that is not electrically active and only applies cooling boundary conditions. This second study demonstrates that in this probe configuration the temperature induced changes in electrical properties of tissue substantially reduce the electric fields in the cooled regions. This novel treatment can potentially be used to protect sensitive tissues from the effect of the PEF. Perhaps the most important conclusion of this investigation is that temperature is a powerful and accessible mechanism to modulate and control electric fields in biological tissues and can therefore be used to optimize and control PEF treatments.

Show MeSH
Related in: MedlinePlus