Fluid cooled and perfused tip for a catheter

A catheter tip for use in cardiac signal measurement, comprising:

• a) a tip structure on a distal end of a catheter, the tip structure having an interior and comprising a porous material;
• b) a plurality of randomly disposed interstitial spaces formed within the porous material of the tip structure and in fluid communication with a source of fluid in the interior of the tip structure, the interstitial spaces directing a flow of fluid from the source of fluid in the interior of the tip structure over the exterior surface of the tip structure to provide a fluid protective layer surrounding the tip structure to minimize the contact of the tip with biological materials;
• and
• c) a monitoring device within the tip structure for measurement of electrical potentials in a biological tissue.

An ablation catheter which reduces the coagulation of biological materials on a tip of the catheter, reduces the impedance rise of tissue in contact with the catheter tip, and maximizes the energy transfer to the tissue, thereby allowing an increase in lesion size, the ablation catheter comprising:

• a) a proximal end, a distal end, and a central lumen;
• tip means having an exterior surface, the tip means being positioned at the distal end of the catheter for monitoring electrical potentials and applying energy to a biological tissue;
• c) fluid source means positioned at the proximal end of the catheter body for supplying a fluid flow through the catheter to the tip means;
• d) means formed within the tip means for directing the fluid flow through a plurality of passages which direct the fluid flow from the central lumen over the exterior surface of the tip to form a protective fluid layer around the tip means to minimize contact of the tip means with biological fluids, reduce the coagulation of biological materials on the tip means and reduce tire resistance of energy transfer to the tissue;
• e) monitoring means within the tip means for measurement of electrical potentials in a biological tissue;
• and
• f) ablation means within the tip means for application of energy to the biological tissue, the means for directing the fluid flow being formed within the ablation means.

A method of reducing coagulation of biological materials on a catheter tip, minimizing the resistance to energy transfer to tissue, and maximizing the energy transfer to the tissue in communication with the catheter tip, thereby allowing for an increase of lesion size, comprising the steps of:

• a) positioning a catheter having a tip within the body, the tip having a plurality of randomly disposed passages therethrough;
• b) directing a fluid flow through the catheter;
• c) passing the fluid flow through the randomly disposed passages in the catheter tip in an approximately radial direction to produce a fluid flow originating within the catheter over the exterior surface of the tip;
• and
• d) forming a fluid layer around the catheter tip to maintain biological materials at a distance from the catheter tip and minimize contact of the catheter tip with the biological materials, so as to reduce the coagulation of biological materials on the catheter tip and minimize the resistance to energy transfer to tissue in communication with the catheter tip.

An ablation catheter which reduces the coagulation of biological materials on a tip of the catheter, reduces the impedance rise of tissue in contact with the catheter tip, and maximizes the energy transfer to the tissue, thereby allowing an increase in lesion size, comprising:

• a) a catheter including a proximal end, a distal end, and a central lumen;
• b) tip means having an exterior surface, the tip means being positioned at the distal end of the catheter for monitoring electrical potentials, and applying energy to a biological tissue;
• c) fluid source means positioned at the proximal end of the catheter body for supplying a fluid flow through the catheter to the tip means;
• d) directional channel means formed within the tip means for directing the fluid flow through a plurality of passages which direct the fluid flow from the central lumen over the exterior surface of the tip means to form a protective fluid layer around the tip means to minimize contact of the tip with biological fluids, reduce the coagulation of biological materials on the tip means and reduce the resistance to energy transfer to the tissue, wherein the directional channel means is a microporous structure;
• e) monitoring means within the tip means for measurement of electrical potentials in a biological tissue;
• and
• f) ablation means within the tip means for application of energy to the biological tissue.