Surgical sealing surfaces and methods of use
First Claim
1. A method of applying controlled energy to treat tissue, the method comprising:
- engaging tissue with an electrosurgical surface, the surface coupled to a matrix comprising a positive temperature coefficient of resistance (PTCR) material and a heat exchange material disposed within an interior of the matrix, the PTCR material having a substantially conductive state and a substantially non-conductive state;
delivering Rf current to tissue so as to ohmically heat tissue; and
modulating the delivery of Rf current to tissue wherein the Rf current flows at least partly through the matrix and the heat exchange material removes heat from the PTCR material to substantially prevent tissue charring or arcing in tissue.
1 Assignment
0 Petitions
Accused Products
Abstract
Various embodiments provide compositions that exhibit positive temperature coefficient of resistance (PTCR) properties for use in thermal interactions with tissue—including thermal sensing and I2R current-limiting interactions. Embodiments also provide tissue-engaging surfaces having PTCR materials that provide very fast switching times between low resistance and high, current-limiting resistance. One embodiment provides a matrix for an electrosurgical energy delivery surface comprising a PTCR material and a heat exchange material disposed within an interior of the matrix. The PTCR material has a substantially conductive state and a substantially non-conductive state. The heat exchange material has a structure configured to have an omni-directional thermal diffusivity for exchanging heat with the PTCR material to cause rapid switching of the PTCR material between the conductive state and non-conductive state. Preferably, the structure comprises a graphite foam having an open cell configuration. The matrix can be carried by tissue contacting surfaces of various electrosurgical devices.
259 Citations
15 Claims
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1. A method of applying controlled energy to treat tissue, the method comprising:
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engaging tissue with an electrosurgical surface, the surface coupled to a matrix comprising a positive temperature coefficient of resistance (PTCR) material and a heat exchange material disposed within an interior of the matrix, the PTCR material having a substantially conductive state and a substantially non-conductive state; delivering Rf current to tissue so as to ohmically heat tissue; and modulating the delivery of Rf current to tissue wherein the Rf current flows at least partly through the matrix and the heat exchange material removes heat from the PTCR material to substantially prevent tissue charring or arcing in tissue. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of applying controlled energy to treat tissue, the method comprising:
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engaging tissue with an electrosurgical energy delivery surface including a matrix of a positive temperature coefficient of resistance (PTCR) material and a heat exchange material disposed within an interior of the matrix; engaging tissue with the surface; delivering Rf energy to tissue so as to ohmically heat at least a portion of the engaged tissue; and utilizing the heat exchange material to remove heat from the PTCR material to cause rapid switching of the PTCR material between substantially conductive and substantially non-conductive states. - View Dependent Claims (8, 9, 10)
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11. A method of delivering energy to treat tissue, the method comprising:
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engaging tissue with an electrosurgical energy delivery surface including a matrix comprising a positive temperature coefficient of resistance (PTCR) material and a heat exchange material disposed within an interior of the matrix, the PTCR material having a substantially conductive state and a substantially non-conductive state; delivering Rf energy to tissue so as to ohmically heat tissue in a target tissue volume; spatially modulating the delivery of Rf energy to tissue utilizing the heat exchange material to exchange heat with the PTCR material to cause rapid switching of the PTCR material between the substantially conductive and substantially non-conductive states; and producing a substantially uniform thermal effect in the target tissue volume. - View Dependent Claims (12, 13, 14, 15)
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Specification