Hyperthermia treatment and probe therefor
First Claim
1. A method for effecting treatment in a patient comprising:
- identifying a volume in the patient the whole of which volume is to be heated to a required temperature, the volume being defined by a peripheral surface of the volume;
providing a heat source and applying heat to the volume within the patient by;
providing the heat source on an invasive probe having a longitudinal axis and an end;
inserting the end of the probe into the volume;
arranging the probe to cause directing of heat from the end in a direction at an angle to the longitudinal axis such that a heating effect of the probe lies in a disk surrounding the axis;
arranging the direction of the heat so as to define a heating zone which forms a limited angular orientation of heating within the disk such that, as the probe is rotated, the probe causes heating of different angular segments of the volume within the disk;
with the probe at a fixed axial position, rotating the probe about the axis so that the heating zone lies in a selected segment;
wherein the application of heat by the probe to the selected segment causes heat to be transferred from the segment into parts of the volume outside the segment surrounding the end of the probe;
and applying cooling to the end of the probe so as to extract heat from the parts surrounding the probe by conduction of heat therefrom;
wherein the end of the probe is cooled by;
providing on the probe a supply duct for a cooling fluid extending from a supply to the end of the probe;
providing an expansion zone of reduced pressure at the end of the probe so as to cause the cooling fluid to expand as a gas thus generating a cooling effect;
and providing on the probe a return duct for return of the expanded gas from the end of the probe, wherein the return duct is of larger cross-sectional area than the supply duct by a factor of the order of 200 to 250 times.
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Accused Products
Abstract
A method of using a probe that emits energy to coagulate lesions is disclosed. The probe is constructed and arranged to emit light from its distal end, either at an angle to its longitudinal axis, or along its longitudinal axis. Optionally, an end reflector may be used to direct the energy in a beam to one side of the fiber end. A reinforcing sleeve for the fiber is mounted to a shielded, Piezo-electric motor constructed and arranged to move the fiber both longitudinally and rotationally within an optional elongate cannula. An MRI system is arranged to generate a series of output signals indicative of temperature in the targeted area. The application of energy is stopped when the temperature at the boundary of the lesion reaches the required hyperthermic temperature. Cooling of the tip portion of the probe is effected by expansion of a supplied cooling fluid through a restrictive orifice into an expansion zone at the probe end. The fiber is encased in a stiff tubular titanium probe with a relatively small fluid supply duct inside the probe with the interior of the probe acting as a return duct for the expanded liquid. The temperature of the probe end is monitored by a sensor in the probe end and controlled by controlling the pressure in the supplied cooling fluid.
88 Citations
69 Claims
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1. A method for effecting treatment in a patient comprising:
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identifying a volume in the patient the whole of which volume is to be heated to a required temperature, the volume being defined by a peripheral surface of the volume; providing a heat source and applying heat to the volume within the patient by; providing the heat source on an invasive probe having a longitudinal axis and an end; inserting the end of the probe into the volume; arranging the probe to cause directing of heat from the end in a direction at an angle to the longitudinal axis such that a heating effect of the probe lies in a disk surrounding the axis; arranging the direction of the heat so as to define a heating zone which forms a limited angular orientation of heating within the disk such that, as the probe is rotated, the probe causes heating of different angular segments of the volume within the disk; with the probe at a fixed axial position, rotating the probe about the axis so that the heating zone lies in a selected segment; wherein the application of heat by the probe to the selected segment causes heat to be transferred from the segment into parts of the volume outside the segment surrounding the end of the probe; and applying cooling to the end of the probe so as to extract heat from the parts surrounding the probe by conduction of heat therefrom; wherein the end of the probe is cooled by; providing on the probe a supply duct for a cooling fluid extending from a supply to the end of the probe; providing an expansion zone of reduced pressure at the end of the probe so as to cause the cooling fluid to expand as a gas thus generating a cooling effect; and providing on the probe a return duct for return of the expanded gas from the end of the probe, wherein the return duct is of larger cross-sectional area than the supply duct by a factor of the order of 200 to 250 times. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for effecting treatment in a patient comprising:
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identifying a volume in the patient to be heated to a required temperature; providing a heat source for applying heat to the volume within the patient; providing a probe mounting the heat source allowing invasive insertion of an end of the probe into the patient; providing a position control system for moving the end of the probe to a required position within the patient; inserting the end of the probe into the volume; providing on the probe a supply duct for a cooling fluid extending from a supply to the end of the probe; providing an expansion zone of reduced pressure at the end of the probe so as to cause the cooling fluid to expand as a gas thus generating a cooling effect; and
,providing on the probe a return duct for return of the expanded gas from the end of the probe; wherein the heat source comprises a laser, an optical fiber for communicating light from the laser, and a light directing element at an end of the fiber, wherein the light directing element comprises a chamfered end of the fiber and wherein the chamfered end is located in the gas in the expansion zone. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A probe for use in effecting treatment in a patient comprising:
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a heat source for applying heat to a volume within the patient; a probe body mounting the heat source thereon for allowing invasive insertion of an end of the probe into the patient; a supply duct on the probe body for a cooling fluid extending from a supply to the end of the probe; the probe body being arranged to provide an expansion zone of reduced pressure at the end of the probe body so as to cause the cooling fluid to expand as a gas thus generating a cooling effect; and
,a return duct on the probe body for return of the expanded gas from the end of the probe; wherein the heat source comprises a laser, an optical fiber for communicating light from the laser, and a light directing element at an end of the fiber, wherein the light directing element comprises a chamfered end of the fiber and wherein the chamfered end is located in the gas in the expansion zone. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A method of applying heat to tissue in vivo comprising:
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identifying a quantity of tissue as a target; inserting an elongate transmitting medium percutaneously and feeding said elongate transmitting medium toward said target until a distal end of said elongate transmitting medium is operationally proximate said target; applying energy to said target by sending energy through said elongate transmitting medium, said energy exiting said distal end and heating said target; monitoring said energy application to ensure surrounding non-targeted tissue is not damaged by heat; determining whether the entire targeted area has been heated; if necessary, translating said elongate transmitting medium to an unheated area of said target; applying energy to said unheated area of said target. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
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69. A method of applying heat to tissue in vivo comprising:
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identifying a quantity of tissue as a target; inserting an elongate transmitting medium percutaneously and feeding said elongate transmitting medium toward said target until a distal end of said elongate transmitting medium is operationally proximate said target; applying energy to said target by sending energy through said elongate transmitting medium, said energy exiting said distal end and heating said target; wherein heating said target by sending energy through said elongate transmitting medium comprises directing laser energy through an optical fiber contained within said transmitting medium and deflecting said laser energy off of a chamfered end of said optical fiber; monitoring said energy application to ensure surrounding non-targeted tissue is not damaged by heat; determining whether the entire targeted area has been heated; if necessary, translating said elongate transmitting medium to an unheated area of said target; applying energy to said unheated area of said target; and cooling said distal end of said elongate transmitting medium so as to extract heat from parts of said target surrounding said elongate transmitting medium by conduction of heat therefrom comprising; directing fluid to said distal end of said elongate transmitting medium through a supply duct in said elongate transmitting medium; vaporizing said fluid in an expansion zone of reduced pressure in said distal end of said elongate transmitting medium; and retrieving the gas from said elongate transmitting medium through a return duct in said elongate transmitting medium that is between 200 and 250 times larger in cross-sectional area than said supply duct.
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Specification