SYSTEM AND METHOD FOR ESTIMATING TISSUE HEATING OF A TARGET ABLATION ZONE FOR ELECTRICAL-ENERGY BASED THERAPIES

• US 20150088120A1
• Filed: 12/02/2014
• Published: 03/26/2015
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Virginia Tech Intellectual Properties, Inc.
• Original Assignee: Virginia Tech Intellectual Properties, Inc.
• Inventors: Garcia, Paulo A., Arena, Christopher B., Davalos, Rafael V., Sano, Michael B.
• Granted Patent: US 10,117,707 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00613 Irreversible electroporation reversible electroporation A61N1/327
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00886 Duration
• CPC Class Codes: A61B 2018/00892 Voltage
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 2034/104 Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• CPC Class Codes: A61B 2034/256 having a database of accessory information, e.g. including context sensitive help or scientific articles
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: C12N 13/00 Treatment of microorganisms or enzymes with electrical or wave energy, e.g. magnetism, sonic waves

Abstract

Systems and methods are provided for modeling and for providing a graphical representation of tissue heating and electric field distributions for medical treatment devices that apply electrical treatment energy through one or a plurality of electrodes. In embodiments, methods comprise: providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to tissue through a plurality of electrodes; modeling electric and heat distribution in the tissue based on the parameters; and displaying a graphical representation of the modeled electric and heat distribution. In another embodiment, a treatment planning module is adapted to generate an estimated target ablation zone based on a combination of one or more parameters for an irreversible electroporation protocol and one or more tissue-specific conductivity parameters.

Claims

1. A method of treating a tissue with a medical treatment device that applies electrical treatment energy through one or more electrodes defining a target treatment area of the tissue and comprises a display device, the method comprising:

providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to a tissue through one or more electrodes;

modeling heat distribution and/or electric field distribution in a tissue surrounding the electrodes based on the one or more parameters;

displaying a graphical representation of the heat and/or electric field distribution based on the modeled heat distribution in the display device;

modifying one or more of the parameters of the treatment protocol based on the graphical representation of the heat distribution; and

implanting the electrodes in the tissue and delivering one or more electrical pulses to the tissue through the electrodes by way of a voltage pulse generator based on the one or more modified parameters.

2. The method of claim 1, wherein the one or more parameters are chosen from one or more of voltage, electrode spacing, electrode length, treatment duration, number of pulses, pulse width, electric field intensity, electrode diameter, a baseline conductivity for the target treatment area, a change in conductivity for the target treatment area, or a conductivity for a specific tissue type.

3. A method of treatment planning for medical therapies involving administering electrical treatment energy, the method comprising:

providing one or more parameters of a treatment protocol for delivering one or more electrical pulses to tissue through one or more electrodes;

modeling heat and/or electric field distribution in the tissue based on the parameters; and

displaying a graphical representation of the modeled heat and/or electric field distribution.

4. The method of claim 3, wherein the heat distribution is modeled to estimate the Joule heating in the tissue and is calculated as:

5. The method of claim 3, further comprising specifying a cutoff heat distribution value and providing a graphical representation of the heat and/or electric field distribution curve as an isocontour line.

6. The method of claim 3, further comprising:

modeling an electrical damage and/or a thermal damage in the tissue based on the parameters;

displaying a graphical representation of the modeled electrical damage and/or thermal damage.

7. The method of claim 6, wherein the electric field distribution is calculated as:

∇

²φ

=0

where φ

is the electric potential, this equation is solved with boundary) conditions;

{right arrow over (n)}·

{right arrow over (J)}=0 at the boundaries

φ

=V_in at the boundary of the first electrode

φ

=0 at the boundary of the second electrode

wherein {right arrow over (n)} is the normal vector to the surface, {right arrow over (J)} is the electrical current and V_in is the electrical potential applied.

8. The method of claim 6, further comprising specifying a cutoff electrical field distribution value and providing a graphical representation of the electrical field distribution value as an isocontour line.

9. The method of claim 3, wherein the parameters are chosen from one or more of voltage, electrode spacing, electrode diameter, electrode length, number of pulses, treatment duration, pulse width, electric field intensity, a baseline conductivity for the target treatment area, a change in conductivity for the target treatment area, or a conductivity for a specific tissue type.

10. The method of claim 8, further comprising one or more databases comprising a plurality of sets of parameters for treatment protocols stored in the database.

11. The method of claim 10, wherein the graphical representations of the modeled heat and electrical field distributions are derived from Cassini oval calculations.

20. The method of claim 6, wherein the graphical representation of the modeled thermal damage and/or electrical damage is derived from Cassini oval calculations.

21. The method of claim 3, further comprising:

modeling one or more of a thermally damaged region, IRE necrotic region, IRE apoptotic region, reversible electroporation region, and region where there is no effect in the tissue based on the parameters; and

displaying a graphical representation of the modeled regions.

22. The method of claim 3, further comprising:

modeling one or more of a thermally damaged region, an electroporation region, and a region where there is no effect in the tissue based on the parameters; and

displaying a graphical representation of the modeled regions.

12. A system for treatment planning for medical therapies involving administering electrical treatment energy, the system comprising:

a computer comprising;

a memory;

a display device;

a processor coupled to the memory and the display device; and

a treatment planning module stored in the memory and executable by the processor, the treatment planning module adapted to;

receive as input one or more parameters of a treatment protocol for delivering electrical pulses to tissue through one or more electrodes;

model heat and/or electric field distribution in the tissue based on the parameters;

display a graphical representation of the modeled heat and/or electric field distribution on the display device.

13. The system of claim 12, further comprising one or more databases comprising a plurality of sets of parameters for treatment protocols stored in the databases.

14. The system of claim 12, wherein the inputs are chosen from one or more of voltage, electrode spacing, treatment duration, pulse width, electric field intensity, a baseline conductivity for the target treatment area, a change in conductivity for the target treatment area, or a conductivity for a specific tissue type.

15. The system of claim 14, wherein the change in conductivity is expressed as a ratio of the baseline conductivity to the maximum conductivity of the tissue that is reached during treatment.

16. The system of claim 14, wherein the conductivity for a specific tissue type is provided in a database for a plurality of tissues.

17. The system of claim 12, wherein the one or more electrodes is provided by one or more bipolar probes.

18. The system of claim 12, wherein the one or more electrodes are provided by one or more single needle electrodes.

19. The system of claim 15, wherein the change in conductivity is calculated in real-time based on measured voltages and currents before, during, and/or after pulse delivery.