US6071278A
Expired / Lapsed
US
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Tissue heating and ablation systems and methods using porous electrode structures with specified electrical resistivities
Assignee: EP Technologies Inc
•
Filing: 1996-04-12
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Granted: 2000-06-06
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Expires: 2016-04-12
Abstract
Abstract Systems and methods for heating or ablating tissue use a porous electrode. The porous electrode comprises a wall having an interior area that contains an electrically conductive element. At least a portion of the wall comprises a porous material sized to block passage of blood cells while passing ions. The systems and methods position the porous electrode in contact with tissue. The systems and methods couple the electrically conductive element to a source of electrical energy. The systems and methods convey a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrical conducting element through the fluid medium and porous material to ablate tissue. The systems and methods also specify differing electrical resistivities for the porous material based, at least in part, upon achieving differing desired tissue heating or ablation effects.
Inventors
- 👤 Dorin Panescu
- 👤 David K. Swanson
- 👤 James G. Whayne
- 👤 Patrick M. Owens
- 👤 Russell B. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:29
CPC Classifications
A; A61; A61B; A61B18/00; A61B18/04; A61B18/12; A61B18/14; A61B18/1492; A61B2018/00053; A61B2018/00107; A61B2018/00148; A61B2018/00214
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
117 words
A system for ablating body tissue comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying differing electrical resistivities for the porous material to achieve differing desired tissue ablation effects.
Claim 2
Independent Claim
117 words
A system for ablating body tissue comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying differing electrical resistivities for the porous material to achieve differing desired tissue ablation effects.
Claim 3
Independent Claim
150 words
A system for ablating body tissue to form lesions comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying a first electrical resistivity for the porous material to achieve a first tissue lesion characteristic and specifying a second electrical resistivity for the porous material different than the first electrical resistivity to achieve a second tissue lesion characteristic different than the first lesion characteristic.
Claim 4
Independent Claim
150 words
A system for ablating body tissue to form lesions comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying a first electrical resistivity for the porous material to achieve a first tissue lesion characteristic and specifying a second electrical resistivity for the porous material different than the first electrical resistivity to achieve a second tissue lesion characteristic different than the first lesion characteristic.
Claim 5
Independent Claim
144 words
A system for ablating heart tissue to form lesions comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying a first electrical resistivity for the porous material to achieve a deep tissue lesion geometry and specifying a second electrical resistivity for the porous material greater than the first electrical resistivity to achieve a shallow tissue lesion geometry.
Claim 6
Independent Claim
144 words
A system for ablating heart tissue to form lesions comprising a porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, an electrically conducting element for coupling the electrically conductive element to a source of electrical energy, a fluid conducting element for conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, and means for specifying a first electrical resistivity for the porous material to achieve a deep tissue lesion geometry and specifying a second electrical resistivity for the porous material greater than the first electrical resistivity to achieve a shallow tissue lesion geometry.
Claim 7
Dependent Claim
48 words
A system according to claim 1 or 2 or 3 and further including a temperature sensing element carried by the porous electrode, and further including means for specifying delivery of electrical energy to the medium based, at least in part, upon temperature sensed by the temperature sensing element.
Claim 8
Dependent Claim
18 words
A system according to claim 1 or 2 or 3 wherein the porous material comprises a microporous membrane.
Claim 9
Dependent Claim
18 words
A system according to claim 1 or 2 or 3 wherein the porous material comprises an ultrafiltration membrane.
Claim 10
Dependent Claim
39 words
A system according to claim 1 or 2 or 3 wherein the wall includes a distal region and a proximal region, and wherein the porous material occupies more of the distal region of the wall than the proximal region.
Claim 11
Dependent Claim
21 words
A system according to claim 7 wherein at least 1/3rd of the proximal region of the wall is free of pores.
Claim 12
Dependent Claim
34 words
A system according to claim 1 or 2 or 3 wherein the porous portion of the wall comprises at least first and second porous zones spaced apart by a third zone free of pores.
Claim 13
Dependent Claim
31 words
A system according to claim 9 wherein the electrode includes an axis, and wherein the first and second porous zones are circumferentially spaced apart by the third zone about the axis.
Claim 14
Dependent Claim
30 words
A system according to claim 9 wherein the electrode includes an axis, and wherein the first and second porous zones are spaced apart by the third zone along the axis.
Claim 15
Dependent Claim
16 words
A system according to claim 1 or 2 or 3 wherein the wall is electrically conductive.
Claim 16
Dependent Claim
20 words
A system according to claim 1 or 2 or 3 and further including a radiopaque element carried by the electrode.
Claim 17
Dependent Claim
18 words
A system according to claim 1 or 2 or 3 wherein the medium carries a radiopaque contrast substance.
Claim 18
Dependent Claim
27 words
A system according to claim 1 or 2 or 3 wherein the porous portion has a porosity providing an electrical resistivity of at least about 500 ohm·cm.
Claim 19
Dependent Claim
26 words
A system according to claim 1 or 2 or 3 wherein the porous portion has a porosity providing an electrical resistivity less than about 500 ohm·cm.
Claim 20
Dependent Claim
17 words
A system according to claim 1 or 2 or 3 wherein the medium comprises a hypertonic solution.
Claim 21
Dependent Claim
13 words
A system according to claim 17 wherein the hypertonic solution includes sodium chloride.
Claim 22
Dependent Claim
19 words
A system according to claim 18 wherein the sodium chloride is present in a concentration at or near saturation.
Claim 23
Dependent Claim
23 words
A system according to claim 18 wherein the sodium chloride is present in a concentration of up to about 9% weight by volume.
Claim 24
Dependent Claim
13 words
A system according to claim 17 wherein the hypertonic solution includes potassium chloride.
Claim 25
Dependent Claim
21 words
A system according to claim 1 or 2 or 3 wherein the medium has a resistivity lower than about 150 ohm·cm.
Claim 26
Dependent Claim
17 words
A system according to claim 22 wherein the medium has a resistivity lower than about 10 ohm·cm.
Claim 27
Dependent Claim
17 words
A system according to claim 22 wherein the medium has a resistivity lower than about 5 ohm·cm.
Claim 28
Dependent Claim
23 words
A system according to claim 1 or 2 or 3 wherein the medium includes a material whose presence increases viscosity of the medium.
Claim 29
Dependent Claim
26 words
A system according to claim 1 or 2 or 3 wherein the medium includes at least one ionic material whose presence increases viscosity of the medium.
Claim 30
Dependent Claim
17 words
A system according to claim 26 wherein the at least one ionic material comprises a radiopaque substance.
Claim 31
Dependent Claim
24 words
A system according to claim 1 or 2 or 3 wherein the medium includes a nonionic material whose presence increases viscosity of the medium.
Claim 32
Dependent Claim
12 words
A system according to claim 28 wherein the nonionic material includes glycerol.
Claim 33
Dependent Claim
12 words
A system according to claim 28 wherein the nonionic material includes mannitol.
Claim 34
Dependent Claim
38 words
A system according to claim 1 or 2 or 3 and further including means for specifying ionic transport through the porous material at a desired rate based, at least in part, upon a desired physiological effect upon tissue.
Claim 35
Dependent Claim
18 words
A system according to claim 1 or 2 or 3 wherein the porous material comprises an ultrafiltration membrane.
Claim 36
Dependent Claim
18 words
A system according to claim 1 or 2 or 3 wherein the porous section comprises a microporous membrane.
Claim 37
Dependent Claim
33 words
A system according to claim 1 or 2 or 3 and further including means for specifying the viscosity of the medium based, at least in part, upon a desired physiological effect upon tissue.
Claim 38
Dependent Claim
14 words
A system according to claim 1 wherein the porous material comprises a hydrophilic material.
Claim 39
Dependent Claim
14 words
A system according to claim 1 wherein the porous material has a hydrophilic coating.
Claim 40
Dependent Claim
14 words
A system according to claim 2 wherein the porous material comprises a hydrophilic material.
Claim 41
Dependent Claim
14 words
A system according to claim 2 wherein the porous material has a hydrophilic coating.
Claim 42
Dependent Claim
14 words
A system according to claim 3 wherein the porous material comprises a hydrophilic material.
Claim 43
Dependent Claim
14 words
A system according to claim 3 wherein the porous material has a hydrophilic coating.
Claim 44
Independent Claim
123 words
A method for ablating tissue comprising the steps of positioning a porous electrode in contact with tissue, the porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, coupling the electrically conductive element to a source of electrical energy, conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, specifying differing electrical resistivities for the porous material based, at least in part, upon achieving differing desired tissue ablation effects, and ablating the tissue.
Claim 45
Independent Claim
123 words
A method for ablating tissue comprising the steps of positioning a porous electrode in contact with tissue, the porous electrode comprising a wall having an interior area, an electrically conductive element in the interior area, at least a portion of the wall comprising a porous material sized to block passage of blood cells while passing ions, coupling the electrically conductive element to a source of electrical energy, conveying a fluid medium containing ions into the interior area to enable ionic transfer of electrical energy from the electrically conductive element through the fluid medium and porous material to ablate tissue, specifying differing electrical resistivities for the porous material based, at least in part, upon achieving differing desired tissue ablation effects, and ablating the tissue.
Claim 46
Dependent Claim
56 words
A method according to claim 41 wherein the specifying step includes specifying a first electrical resistivity for the porous material to achieve a first tissue lesion characteristic and specifying a second electrical resistivity for the porous material different than the first electrical resistivity to achieve a second tissue lesion characteristic different than the first lesion characteristic.
Claim 47
Dependent Claim
50 words
A method according to claim 41 wherein the specifying step includes specifying a first electrical resistivity for the porous material to achieve a deep tissue lesion geometry and specifying a second electrical resistivity for the porous material greater than the first electrical resistivity to achieve a shallow tissue lesion geometry.
Claim 48
Dependent Claim
49 words
A method according to claim 41 or 42 or 37 and further including the steps of sensing temperature using a temperature sensing element carried by the porous electrode, specifying delivery of electrical energy to the medium based, at least in part, upon temperature sensed by the temperature sensing element.
Claim 49
Dependent Claim
39 words
A method according to claim 41 or 42 or 37 and further including the step of specifying ionic transport through the porous material at a desired rate based, at least in part, upon a desired physiological effect upon tissue.
Claim 50
Dependent Claim
22 words
A method according to claim 45 wherein the step of specifying ionic transport specifies constituting the medium to have a desired viscosity.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-06-06 | 2003-12-06 | 2004-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-06 | 2007-12-06 | 2008-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-06 | 2011-12-06 | 2012-06-06 | $7700.00 | Window Closed / Lapsed |