System of providing medical treatment

• US 6,337,627 B1
• Filed: 10/27/2000
• Issued: 01/08/2002
• Est. Priority Date: 10/27/2000
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation, Johns Hopkins University
• Original Assignee: International Business Machines Corporation
• Inventors: Anderson, James H., McAllister, Scott J., Ziegler, Matthias D., Ziegler, James F., Von Gutfeld, Robert J., Murphy, John C.
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): Nguyen, Tai T.
• Application Number:
  US09/699,183
• Time in Patent Office: 438 Days
• Field of Search: 340/572.1, 340/572.2, 340/551, 340/572.4, 340/540, 424/111, 424/9.1, 324/326, 324/207.12
• US Class Current: 340/572.1
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00

Abstract

The invention describes methods for locating a treatment device disposed within a living body by means of magnetic fields that are produced by Barkhausen jumps, principally from amorphous tag wires with high permeability that exhibit reentrant flux reversal. When wires of this type are attached to concealed treatment devices such as catheters, interrogation or scanning of the tag wire by a low frequency ac magnetic field affords an accurate means for locating the treatment devices using a sensor coil to detect the magnetic field signal from the wire locating tag. The strength of the field detected by the position of a sensor coil with respect to the locator tag is used to determine the location of the tag. A favorable signal to noise detection ration is obtained as the signal emitted by the wire is at a very high frequency compared to that of the frequency of the interrogation field.

Claims

1. A system for providing medical treatment to a living body with a treatment device, said system comprising:

a) a said treatment device disposed within said living body,

b) an element attached to said treatment device, wherein said element comprises a magnetic material and is capable of emitting a non-linear magnetic signal in response to an applied ac magnetic field,

c) a magnetic field generator for irradiating said element and a juxtaposed region of said living body with an applied ac magnetic field,

d) a movable magnetic field sensor operable to detect said non-linear magnetic signal from a plurality of selected mutually displaced positions to produce a corresponding plurality of element-locating signals,

e) a computing apparatus for converting said element-locating signals to a location image of said treatment device, and

f) a controller device for controlling the position and treatment action of said treatment device in synchronism with said location image.

2. A system as set forth in claim 1, wherein said element comprises an amorphous magnetic material, said non-linear magnetic signal being characterized by Barkhausen jumps in response to said applied ac magnetic field.

3. A system as set forth in claim 2, wherein said treatment device is a catheter.

4. A system as set forth in claim 2, wherein said treatment device is a surgical instrument.

5. A system as set forth in claim 1, wherein said element comprises an amorphous magnetic wire characterized by a magnetization which is reversible in direction in response to said applied ac field.

6. A system as set forth in claim 1, wherein said treatment device is a catheter.

7. A system as set forth in claim 1, wherein said treatment device is a surgical instrument.

8. A method for providing medical treatment to a living body with a treatment device concealed therein, comprising the steps of:

a) attaching, to said treatment device, an element comprising a magnetic material, said magnetic material being capable of emitting a non-linear magnetic signal in response to an applied ac magnetic field,

b) irradiating said element with an applied ac magnetic field,

c) moving a magnetic field sensor in spaced adjacency to said element to detect said non-linear magnetic signal from a plurality of selected mutually displaced positions to represent a corresponding plurality of element-locating signals,

d) converting said element-locating signals to a location image of said treatment device, and

e) controlling the position and treatment action of said treatment device in synchronism with said location image.

9. A method as set forth in claim 8, wherein said element comprises an amorphous magnetic material, said non-linear magnetic signal being characterized by Barkhausen jumps in response to said applied ac magnetic field.

10. A method as set forth in claim 9, wherein said treatment device is a catheter.

11. A method as set forth in claim 9, wherein said treatment device is a surgical device.

12. A method as set forth in claim 9, wherein said treatment device is a hollow brachytherapy tube holding at least one radioactive particle.