US 6,850,804 B2Granted

System method and apparatus for localized heating of tissue

AssigneeCalfacior Corporation

InventorsPhilip E. Eggers, John L. Ridihalgh

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Abstract

System method and apparatus for accurately carrying out the in situ heating of a targeted tissue. Small implants are employed with the targeted tissue which exhibit an abrupt change of magnetic permeability at an elected Curie temperature. The permeability state of the implant is monitored utilizing a magnetometer. The implants may be formed as a setpoint temperature determining component combined with a non-magnetic heater component to enhance the tissue heating control of the system. With the system, a very accurate quantum of heat energy can be supplied to a neoplastic lesion or tissue carrying infectious disease so as to maximize the induction of heat shock proteins. The system also may be utilized in conjunction with non-magnetic arterially implanted stents for the hyperthermia therapy treatment of restenosis and in conjunction with the mending of boney tissue.

Claims40

Dependent claims

A method for thermally treating a target tissue volume within the body of a patient comprising the steps of:

(a) determining temperature value and treatment interval therapy data for carrying out said treatment of said target tissue volume;
(b) providing an untethered implant with a ferrite component formulated with oxides of Fe, Mn and Zn to exhibit a Curie point temperature corresponding with said temperature value and exhibiting a permeability attribute at temperatures below said Curie point temperature;
(c) providing an alternating current field based heating assembly having an on-state and an off-state and controllable for the generation of heat at said target tissue volume from an application component located externally of said body;
(d) providing a detector assembly having a magnetometer-based pick-up component positionable externally of said body and, when enabled, having a first detector output in the presence of magnetic flux lines of a magnetic field encountering said implant when exhibiting said permeability attribute and a second detector output in the absence of said permeability attribute;
(e) locating said untethered implant at an intra-body location effective for response to temperatures at the location of said target tissue;
(f) positioning said detector assembly pick-up at a location externally of said body effective for monitoring magnetic flux lines of said magnetic field encountering said implant;
(g) monitoring said detector assembly for the presence of said first and second detector outputs;
(h) controlling said heating assembly to have said on-state in response to said first detector output and to have said off-state in response to said second detector output;
and
(i) controlling said heating assembly to terminate said generation of heat at said target tissue at the expiration of said determined treatment interval.

7 more elements

A system for thermally treating a target tissue within the body of a patient comprising:

a tetherless implant located internally within said patient, positioned in thermally responsive relationship with said target tissue, having a ferrite component formulated with oxides of Fe, Mn and Zn to exhibit a Curie point temperature selected for carrying out said thermal treatment at a target temperature level, said ferrite component exhibiting a permeability of value perturbing the flux lines of a magnetic field at temperatures below said Curie point temperature;
a heating assembly actuable to apply alternating field based heat-inducing energy to said target tissue to an extent effective to elevate the temperature of said target tissue toward said target temperature level and de-actuable to terminate said application of thermal energy;
an implant monitor comprising a magnetometer with a pick-up located externally of said body in general adjacency with said target tissue, and, when enabled, having a first monitor condition in response to the perturbation of magnetic flux lines encountering said ferrite component when exhibiting said permeability at said value and having a second monitor condition in the substantial absence of said permeability at said value;
and
a control assembly responsive to said first and second monitor conditions to actuate said heating assembly in a manner effective in a manner effective to attain said target temperature level at said target tissue.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/310,475Filed 5 Dec 2002 · continuation in part
Priority: 18 Jan 2002
Published: US 2003/0139787 A124 Jul 2003
Granted: 1 Feb 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

G01K 7/38
Using magnetic elements, e.g. magnets, coils: the variations of temperature influencing the magnetic permeability
A61B 18/04
Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body: by heating
A61F 7/12
Heating or cooling appliances for medical or therapeutic treatment of the human body: devices for heating or cooling internal body cavities
A61B 18/18
Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body: by applying electromagnetic…

Family

Application60/349,593Us provisional application · filed 18 Jan 2002
Application10/201,363Parent of this continuation-in-part · filed 23 Jul 2002
Application10/246,347Parent of this continuation-in-part · filed 18 Sep 2002
US 2003/0139788 A1Pre-grant publication · published 24 Jul 2003
US 2003/0139787 A1Published application
US 2003/0163177 A1Published application
US 6,993,394 B2Related patent
US 6,850,804 B2This patent

From the US filing history. Foreign family members aren’t listed.