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Paramétrages

Paramétrages

1. WO2005065284 - ABLATION DE TISSU AVEC ELECTROPORATION IRREVERSIBLE

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CLAIMS
That which is claimed is:

1. A method of ablating tissue, comprising the steps of:
(a) identifying tissue to be ablated;
(b) placing a first electrode and a second electrode such that the identified tissue is positioned between the first and second electrodes;
(c) applying electrical pulses between the first and second electrodes in an amount sufficient to induce irreversible electroporation of cells of the tissue;
(d) allowing the irreversibly electroporated cells to be removed by internal systems of an organism comprised of the tissue.

2. The method of claim 1 , wherein the electrical pulses are applied for a duration in a range of from about 5 microseconds to about 62 seconds.

3. The method of claim 1, wherein the electrical pulses are applied for a period of about 100 microseconds, ± about 10 microseconds, (note our experiment for other times and voltages)

4. The method of claim 1, wherein from about 1 to about 15 pulses are applied.

5. The method of claim 1 , wherein about eight pulses of about 100
microseconds each in duration are applied.

6. The method of claim 1 , wherein the pulses produce a voltage gradient in a range of from about 50 volt/cm to about 8000 volt/cm.

7. The method of claim 1 , wherein the first electrode is placed at about 5mm to 10 cm from the second electrode.

8. The method of claim 1, wherein the first electrode and second electrode are circular in shape.

9. The method of claim 1, wherein the first electrode and the second electrode each have a surface area of about 1 square centimeter.

10. The method of claim 1 , further comprising:
monitoring temperature of the identified tissue and adjusting the electrical pulses to maintain the temperature at 100°C or less.

11. The method of claim 10, wherein the temperature is maintained at 50°C or less.

12. A method of claim 1 , further comprising:
adjusting the applied voltage, length of the pulses, and number of pulses to obtain irreversible electroporation averaged over the biological cells, thereby achieving irreversible electroporation of the biological cells in the tissue at a level which minimizes damage to non-target tissue.

13. The method of claim 1 , wherein:
adjusting duration of the applied voltage is in accordance with the current-to-voltage ratio to achieve irreversible electroporation of identified tissue cells whereby cell membranes are disrupted in a manner resulting in cell death.

14. The method of claim 13, wherein the current-to-voltage ratio is adjusted based on temperature to maintained target tissue temperature at 100°C or less.

15. The method of claim 13, wherein the current-to-voltage ratio is adjusted based on temperature to maintained target tissue temperature at 50°C or less.

16. A method of ablating tissue, comprising:
(a) identifying a grouping of biological cells in a tissue of a living mammal as being cancer cells and applying a voltage across the cells;
(b) continuously detecting a ratio of electric current through the cells to voltage across the cells as an indication of degree of electroporation of the biological cells; and
(c) adjusting a determined magnitude of the applied voltage in accordance with changes in detected magnitude of the current-to-voltage ratio to achieve irreversible electroporation of the grouping of cells identified as being cancer cells.

17. The method of claim 16, wherein step (b) comprises continuously detecting the current-to-voltage ratio in an indication of onset of electroporation of biological cells, and step (c) comprises adjusting the duration of the applied voltage in accordance with continuously detected cunent-to-voltage ratio to achieve ineversible electroporation of the grouping of cells identified as being cancer cells.

18. The method of claim 16, wherein the cunent-to-voltage ratio is an indication of degree of electroporation averaged over the cells identified as cancer cells, achieving ineversible electroporation of the cancer cells.

19. The method of claim 16, wherein the voltage is applied between two microelectrodes positioned with the grouping of biological cells in between.

20. A method, comprising:
(a) removing a tissue sample from a cancerous tumor;
(b) placing the tissue in an electrically conductive medium and applying a voltage across the medium;
(c) continuously detecting the ratio of electric cunent through the medium to voltage across the medium as an indication of degree of electroporation of cells of the biological tissue; and
(d) adjusting a magnitude of the applied voltage in accordance with changes in magnitude of the cunent-to-voltage ratio to achieve irreversible electroporation of cells of the biological tissue.

21. The method of claim 20, further comprising:
applying the voltage of (d) to cancerous tissue in the tumor to obtain ineversible electroporation of cells in the tumor.

22. The method of claim 20, wherein the tumor is in a mammal.

23. The method of claim 22, wherein the mammal is a human.

24. A method for performing ineversible electroporation, comprising:
(a) applying a voltage across a target tissue comprising a plurality of biological cells;
(b) continuously detecting the ratio of electric cunent through the target tissue to voltage across the tissue as an indication of degree of electroporation of the biological cells; and
(c) adjusting the applied voltage in accordance with changes in current-to-voltage ratio to achieve irreversible electroporation averaged over the biological cells, thereby achieving irreversible electroporation of the biological cells in the tissue at a level which minimizes damage to non-target tissue.

25. The method of claim 24, wherein:
step (b) comprises continuously detecting the cunent-to-voltage ratio as an indication of an onset of electroporation of the biological cells, and
step (c) comprises adjusting duration of the applied voltage in accordance with the cunent-to-voltage ratio to achieve ineversible electroporation of target tissue cells.

26. The method of claim 24, wherein:
voltage is applied between two electrodes inserted in a mammal, and the electrodes are positioned to apply voltage across a target tissue;
step (b) comprises further conelating the cunent-to-voltage ratio with the temperature of the target tissue; and
step (c) comprises adjusting the magnitude of the voltage while the biological cells are between the electrodes based on an averaged degree of electroporation of the biological cells in the tissue.

27. The method of claim 26, wherein the cunent-to-voltage ratio is adjusted based on temperature to maintained target tissue temperature at 60°C or less.

28. The method of claim 27, wherein the cunent-to-voltage ratio is adjusted based on temperature to maintained target tissue temperature at 50°C or less.

29. A method of ablating tissue, comprising the steps of: identifying a tissue zone to be treated;
placing first and second electrodes such that an identified tissue zone is positioned between the first and second electrodes;
applying a predetermined electric field to the identified tissue zone for a time sufficient to perform ineversible electroporation to kill substantially all of the cells in the identified tissue zone.

30. The method of claim 29, wherein the irreversible electroporation results in a fatal disruption the cells' normal controlled flow of material across a membrane of the cell.

31. A device for ablating tissue, comprising:
first and second electrodes that position a tissue zone to be treated therebetween;
a voltage generator means that applies a voltage between the first and second electrodes in a manner which provides a predetermined electric field around the tissue zone for a time sufficient to perform ineversible electroporation to kill substantially all of the cells in the identified tissue zone.

32. The device of claim 31 , wherein the generator means generates pulses of 100 microseconds ± about 10 microseconds at a voltage gradient in a range of from about 50 volt/cm to about 8000 volt/cm.

33. The device of claim 31 , further comprising:
a means for adjusting the voltage and pulse duration of the generator means to obtain ineversible electroporation of cells in the tissue zone while minimizing damage to cells not in the tissue zone.