Device and method for heating tissue in a patient's body
First Claim
1. Device for heating tissue, comprisinga chamber constructed for insertion into a patient'"'"'s body,an electrically conductive fluid preselected for resistive heating for filling the chamber,a plurality of spaced electrical contacts enclosed within the chamber and a corresponding plurality of conductors for connecting the electrical contacts to a power supply for applying a radio frequency electrical potential between the contacts, said contacts being exposed to the fluid-containing space of said chamber so that said radio frequency electrical potential can cause current to flow through fluid between the contacts, said chamber and said contacts being cooperatively constructed and arranged to cause said current to be confined to said fluid within the chamber,whereby on the basis of I2 R losses of said radio frequency electric current flowing between the electrical contacts, the fluid can be heated and the fluid in turn can heat the surrounding tissue by thermal conduction through a wall of the chamber.
5 Assignments
0 Petitions
Accused Products
Abstract
Device and method for heating tissue, the device having a catheter shaft for insertion into a patient'"'"'s body, a chamber formed by a collapsible balloon mounted on the catheter shaft and filled with an electrically conductive fluid, two or more electrical contacts enclosed within the chamber, a power supply for applying an electrical potential to the contacts, and a two or more conductors for connecting each of the contacts to the power supply. The fluid is heated on the basis of I2 R losses by a radio frequency electric current flowing between the electrodes, and the fluid in turn heats the surrounding tissue by heat transfer through the wall of the chamber. According to the method, the apparatus is inserted into the patient'"'"'s body, the chamber is filled with an electrically conductive fluid, and an electrical potential is applied to the contacts. The apparatus functions as a temperature source. A thermister sensor in the balloon or in contact with tissue responds to the heating effect to control the application of the current. Advantageously, by periodic sensing of temperature, and application of controlled rf power, a preset constant temperature is maintained at the selected sensing point, either at the internal body site or the liquid within the balloon. In this way carefully controlled therapy can be conducted at constant temperature.
-
Citations
27 Claims
-
1. Device for heating tissue, comprising
a chamber constructed for insertion into a patient'"'"'s body, an electrically conductive fluid preselected for resistive heating for filling the chamber, a plurality of spaced electrical contacts enclosed within the chamber and a corresponding plurality of conductors for connecting the electrical contacts to a power supply for applying a radio frequency electrical potential between the contacts, said contacts being exposed to the fluid-containing space of said chamber so that said radio frequency electrical potential can cause current to flow through fluid between the contacts, said chamber and said contacts being cooperatively constructed and arranged to cause said current to be confined to said fluid within the chamber, whereby on the basis of I2 R losses of said radio frequency electric current flowing between the electrical contacts, the fluid can be heated and the fluid in turn can heat the surrounding tissue by thermal conduction through a wall of the chamber.
-
21. A method for heating tissue, comprising inserting into a patient'"'"'s body a chamber containing electrically conductive fluid preselected for resistive heating, there being a plurality of spaced electrical contacts encodes within the chamber and a corresponding plurality of conductors for connecting the electrical contacts to a power supply for applying a radio frequency electrical potential to the contacts, said contacts being exposed to the fluid-containing space of said chamber so that said radio frequency electrical potential can cause current to flow through fluid between the contacts,
said chamber and said contacts being cooperatively constructed and arranged to cause said current to be confined to said fluid within the chamber, and applying radio frequency potential between said electrical contacts, whereby on the basis of I2 R losses of said radio frequency electric current flowing between the electrical contacts, the fluid is heated and the fluid in turn heats the surrounding tissue by thermal conduction through a wall of the chamber.
-
24. A method of constant temperate heating, comprising inserting into a patient'"'"'s body a chamber containing electrically conductive fluid preselected for resistive heating, there being a plurality of electrical contacts enclosed within the chamber and a corresponding plurality of conductors for connecting the electrical contacts to a power supply for applying a radio frequency electrical potential to the contacts, said contacts being exposed to the fluid-containing space of said chamber so that said radio frequency electrical potential can cause current to flow through fluid between the contacts,
said chamber and said contacts being cooperatively constructed and arranged to cause said current to be confined to said fluid within the chamber, applying radio frequency potential, between said electrical contacts, monitoring temperature at a point influenced by the temperature of said liquid and in response thereto controlling the radio frequency energy applied to said electrical contacts to maintain said temperature constant, whereby on the basis of I2 R losses of said controlled radio frequency electric current flowing between the electrical contacts, the fluid is heated and the fluid in turn heats the surrounding tissue by thermal conduction through a wall of the chamber.
Specification