Ablation devices, systems and method for measuring cooling effect of fluid flow
First Claim
1. An ablation catheter for ablating tissue in need of treatment, wherein the tissue is subjected to surface perfusion, comprising:
- a proximal portion and a distal portion, said distal portion having a distal tip;
at least one ablation electrode on the distal tip; and
an anemometer located on an exterior surface of the distal portion, said anemometer being thermally isolated from the distal tip to permit the anemometer to measure a cooling effect of surface perfusion, and wherein the anemometer comprises a bridge circuit having at least one hot wire located on the surface of the distal portion and at least one resistor of the bridge circuit located within the ablation catheter.
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Accused Products
Abstract
Disclosed herein are various catheter and catheter systems that are useful in ablating tissue that is also subject to surface perfusion, for example blood flow across and/or through tissue. A representative embodiment of a catheter useful with the present invention includes an anemometer located on an exterior surface of the distal portion of the catheter. The anemometer is thermally isolated from the distal tip to permit the anemometer to measure the cooling effect of surface perfusion. The ablation catheter may include thermal insulation to insulate the anemometer from the distal tip. Alternatively, and/or in addition, the anemometer may be positioned proximally of the distal tip. The catheter may include one or more temperature sensors thermally coupled to the distal tip to measure the temperature of the distal tip. The distal tip may include one or more spiral grooves, or one or more holes. It is contemplated that the anemometer may be positioned within any such spiral groove or hole using a thermal insulation material, such as a non-conductive adhesive. The catheter may optionally include a contact sensor on the distal portion to assess a degree of contact between the ablation catheter and tissue being treated. Various ablation systems and methods are described herein that utilize catheters as described above.
76 Citations
27 Claims
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1. An ablation catheter for ablating tissue in need of treatment, wherein the tissue is subjected to surface perfusion, comprising:
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a proximal portion and a distal portion, said distal portion having a distal tip; at least one ablation electrode on the distal tip; and an anemometer located on an exterior surface of the distal portion, said anemometer being thermally isolated from the distal tip to permit the anemometer to measure a cooling effect of surface perfusion, and wherein the anemometer comprises a bridge circuit having at least one hot wire located on the surface of the distal portion and at least one resistor of the bridge circuit located within the ablation catheter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An ablation system for ablating tissue in need of treatment, comprising:
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an ablation catheter having; a proximal portion and a distal portion, said distal portion having a distal tip; at least one ablation electrode on the distal tip; and an anemometer located on an exterior surface of the distal portion, said anemometer being thermally isolated from the distal tip to permit the anemometer to measure a cooling effect of surface perfusion and wherein the anemometer comprises a bridge circuit having at least one hot wire located on the surface of the distal portion and at least one resistor of the bridge circuit located within the ablation catheter; a contact assessment device that assesses a degree of contact between the ablation catheter and tissue being treated; a power source coupled to the at least one ablation electrode, said power source being programmable to deliver at least one programmable level of power; a clock to measure a time period during which ablative power is delivered to the tissue being treated; a power monitoring device to monitor the amount of ablation power that is delivered by the ablation catheter; and a lesion analysis processor for estimating lesion formation as a function of at least;
i) an output of the anemometer that provides information on surface perfusion;
ii) an output of the contact assessment device;
iii) an output of the clock; and
iv) an output of the power monitoring device. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of ablating tissue comprising:
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placing an ablation catheter in contact with tissue to be ablated, said catheter having; a proximal portion and a distal portion, said distal portion having a distal tip; an ablation electrode located in the distal tip coupled to an ablation energy source for delivering ablation energy to the tissue; and
andan anemometer located on an exterior surface of the distal portion, said anemometer is positioned to permit the anemometer to measure a cooling effect of surface perfusion and wherein the anemometer comprises a bridge circuit having at least one hot wire located on the surface of the distal portion and at least one resistor of the bridge circuit located within the ablation catheter; activating the ablation energy source to deliver ablation energy to the tissue to be ablated; using an output of the anemometer to estimate lesion formation; and deactivating the ablation energy source when an estimated lesion formation reaches a desired level. - View Dependent Claims (25, 26, 27)
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Specification