Method and apparatus for eddy current compensation in a radio frequency probe

• US 7,771,351 B1
• Filed: 05/26/2006
• Issued: 08/10/2010
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Cleveland Clinic Foundation
• Original Assignee: Cleveland Clinic Foundation
• Inventors: Sauer, Brian L., Fleischman, Aaron J., Roy, Shuvo, Talman, James R.
• Primary Examiner(s): Johnson, III; Henry M
• Assistant Examiner(s): SYED, ATIA K
• Application Number:
  US11/441,851
• Time in Patent Office: 1,537 Days
• Field of Search: None
• US Class Current: 600/302
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372

Abstract

Systems and methods are provided for determining a characteristic of an associated in vivo sensor within a living body. A transmit coil produces an excitation signal, having a first orientation, to excite the in vivo sensor to produce a response signal. A receive coil produces a current in response to the response signal. The receive coil is oriented to interact with signals having a second orientation that is substantially orthogonal to first orientation. The probe further comprises at least one eddy current compensation coil that produces a compensation field. A component of the compensation field along the second orientation has a magnitude at the receive coil substantially equal and opposite to a magnitude of a similarly oriented component of a magnetic field associated with eddy currents induced within the body.

Claims

1. A radio frequency (RF) probe assembly for determining a characteristic of an associated in vivo sensor within a living body, comprising:

a transmit coil that produces an excitation signal, having a first orientation, to excite the in vivo sensor to produce a response signal;

a receive coil that produces a current in response to the response signal, the receive coil being oriented to interact with signals having a second orientation that is substantially orthogonal to first orientation;

at least one eddy current compensation coil that produces a compensation field, a component of the compensation field along the second orientation having a magnitude at the receive coil substantially equal and opposite to a magnitude of a similarly oriented component of a magnetic field associated with eddy currents induced within the body; and

a coupling adjustment component that adjusts the position of a given eddy current compensation coil of the at least one eddy compensation coil.

2. The assembly of claim 1, wherein the coupling adjustment component adjusts the position of the given eddy current compensation coil relative to the receive coil as to adjust the magnitude of the compensation field at the receive coil.

3. The assembly of claim 1, wherein the coupling adjustment component adjusts the position of the RF probe relative to the body as to adjust the magnitude of the magnetic field component associated with the induced eddy currents at the receive coil.