Dispersive return pad with phase change material for active thermal management during an ablation procedure

Patent metadata

Field	Value
Publication number	US-11737822-B2
Application number	US-201816043696-A
Country	US
Kind code	B2
Filing date	Jul 24, 2018
Priority date	Jul 24, 2018
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

A dispersive return pad for a radiofrequency ablation procedure includes a skin material adapted to be worn on a patient's skin, a conductive material positioned adjacent to the skin material, a non-conductive material surrounding the conductive material, and a phase-change material surrounding at least a portion of a side edge of the conductive material. Further, the phase-change material is configured to undergo a phase transition at a target temperature range corresponding to a non-damaging hyperthermic temperature range for the patient's skin. As such, the phase-change material is configured to absorb excess heating from the RF ablation procedure and to prevent burns to the patient's skin.

First claim

What is claimed is:

1. A dispersive return pad for a radiofrequency (RF) ablation procedure, the dispersive return pad comprising:
a skin material adapted to be adhered on a patient's skin;
a conductive material having a top face, a bottom face, and four side edges that are perpendicular to the top face and the bottom face, the bottom face of the conductive material positioned adjacent to the skin material;
a phase-change material surrounding the four side edges of the conductive material, the phase-change material positioned: i) adjacent to and in contact with only the four side edges of the conductive material and ii) on top of the skin material, the phase-change material being configured to undergo a phase transition at a target temperature range corresponding to a non-damaging hyperthermic temperature range for the patient's skin, the phase-change material configured to absorb excess heating from the RF ablation procedure and to prevent burns to the patient's skin; and
a non-conductive material that is different from the skin material, the conductive material, and the phase-change material, the non-conductive material encapsulating the conductive material and the phase-change material.

2. The dispersive return pad of claim 1 , wherein the phase-change material undergoes the phase transition within an ISO IEC 60601 maximum allowable temperature rise of six (6) degrees Celsius (° C.).

3. The dispersive return pad of claim 1 , wherein the target temperature range of the phase transition is less than about 43 degrees Celsius (° C.).

4. The dispersive return pad of claim 3 , wherein the target temperature range of the phase transition ranges from about 40 degrees Celsius (° C.) to about 42° C.

5. The dispersive return pad of claim 1 , wherein the phase-change material further comprises a heat-activated color changing film or pigment incorporated therein that provides a visual indicator of the phase transition.

6. The dispersive return pad of claim 1 , wherein the skin material further comprises one or more insulation layers, and wherein, when in contact with the patient's skin, the skin material equilibrates to a core body temperature of about 37° C. due to the one or more insulation layers.

7. The dispersive return pad of claim 1 , wherein the RF ablation procedure has a maximum duration period of less than three (3) minutes so as to minimize an amount of the phase-change material and mitigate any rising temperature within the duration period.

8. The dispersive return pad of claim 1 , wherein the phase-change material comprises at least one of paraffin wax, non-paraffin organics, hydrated salts, or one or more metallic materials.

9. The dispersive return pad of claim 1 , wherein the conductive material comprises a metallic film at least partially covered with an electrically-conductive gel material.

10. A radiofrequency ablation system for performing a radiofrequency (RF) ablation procedure, comprising:
an energy source for delivering energy to a patient's body;
one or more energy delivery devices electrically coupled to the energy source; and,
a dispersive return pad electrically coupled to the energy source, the dispersive return pad comprising:
a skin material adapted to be worn on a patient's skin;
a conductive material having a top face, a bottom face, and four side edges that are perpendicular to the top face and the bottom face, the bottom face positioned adjacent to the skin material;
a phase-change material surrounding the four side edges of the conductive material, the phase-change material positioned: i) adjacent to and in contact with only the four side edges of the conductive material and ii) on top of the skin material, the phase-change material being configured to undergo a phase transition at a target temperature range corresponding to a non-damaging hyperthermic temperature range for the patient's skin, the phase-change material configured to absorb excess heating from the RF ablation procedure and to prevent burns to the patient's skin; and
a non-conductive material that is different from the skin material, the conductive material, and the phase-change material, the non-conductive material encapsulating the conductive material and the phase-change material.

11. The radiofrequency ablation system of claim 10 , wherein the phase-change material undergoes the phase transition within an ISO IEC 60601 maximum allowable temperature rise of six (6) degrees Celsius (° C.).

12. The radiofrequency ablation system of claim 10 , wherein the target temperature range is less than about 43 degrees Celsius (° C.).

13. The radiofrequency ablation system of claim 10 , wherein the phase-change material further comprises a heat-activated color changing film or pigment incorporated therein that provides a visual indicator of the phase transition.

14. The radiofrequency ablation system of claim 10 , wherein the skin material of the dispersive return pad further comprises one or more insulation layers, and wherein, when in contact with the patient's skin, the skin material equilibrates to a core body temperature of about 37° C. due to the one or more insulation layers.

15. The radiofrequency ablation system of claim 10 , wherein the RF ablation procedure has a maximum duration period of less than three (3) minutes so as to minimize an amount of the phase-change material and mitigate any rising temperature within the duration period.

16. The radiofrequency ablation system of claim 10 , wherein the phase-change material of the dispersive return pad is at least one of paraffin wax, non-paraffin organics, hydrated salts, or one or more metallic materials, and wherein the conductive material is a metallic film at least partially covered with an electrically-conductive gel material.

Assignees

• Avent Inc

Inventors

• Wang Ruoya
• Barrett Jennifer J

Classifications

• A61B18/16 Primary

  Indifferent or passive electrodes for grounding · CPC title

• A61B18/1482

  having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy · CPC title

• A61B2018/00083

  low, i.e. electrically insulating · CPC title

• A61B2018/00577

  Ablation · CPC title

• A61B2018/00714

  Temperature · CPC title