Method of forming an electromagnetic sensing coil in a medical instrument

• US 8,359,730 B2
• Filed: 07/01/2011
• Issued: 01/29/2013
• Est. Priority Date: 10/17/2003
• Status: Active Grant

• Current Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Navigation Incorporated (Medtronic Plc)
• Inventors: Burg, Bruce M., Dukesherer, John H., Jascob, Bradley A., Kessman, Paul
• Primary Examiner(s): Kim, Paul D
• Application Number:
  US13/175,087
• Publication Number:
  US 20110258843A1
• Time in Patent Office: 578 Days
• Field of Search: 296/021, 296/05, 296/06, 298/32, 298/41, 298/55, 298/58, 298/83, 336/176, 336/200, 336/212, 336/229, 336/232, 336/233, 600/414, 600/424, 600/426, 600/431, 600/433
• US Class Current: 29/606
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/207 Divots for calibration
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2034/256 having a database of accessory information, e.g. including context sensitive help or scientific articles
• CPC Class Codes: A61B 2090/365 augmented reality, i.e. correlating a live optical image with another image
• CPC Class Codes: A61B 2090/367 creating a 3D dataset from 2D images using position information
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• 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: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/4423 related to hygiene or sterilisation
• CPC Class Codes: A61B 6/4441 : the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/541 : involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 8/4245 : involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 8/543 : involving acquisition triggered by a physiological signal
• CPC Class Codes: H01F 2005/027 : wound on formers for receiving several coils with perpendicular winding axes, e.g. for antennae or inductive power transfer
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49071 : by winding or coiling
• CPC Class Codes: Y10T 29/49073 : by assembling coil and core
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49171 : with encapsulating

Abstract

A surgical navigation system for navigating a region of a patient includes a non-invasive dynamic reference frame and/or fiducial marker, sensor tipped instruments, and isolator circuits. The dynamic reference frame may be repeatably placed on the patient in a precise location for guiding the instruments. The instruments may be precisely guided by positioning sensors near moveable portions of the instruments. Electrical sources may be electrically isolated from the patient.

Claims

1. For a surgical navigation system, a method of forming an electromagnetic sensing coil in a medical instrument, comprising:

forming a core from at least a conductive material, wherein forming the core includes forming a guidable portion of a stylet, a suction tube, a core for a probe, a core for a catheter, a core for an ablation tip, a core for a lens, and combinations thereof;

positioning a first layer of dielectric material over the core;

forming a first coil and a second coil about the core after positioning the first layer of material, wherein the first layer of material is configured to isolate the coils from the conductive material of the core and the first coil is spaced apart a predetermined distance from the second coil;

providing a compensation circuit to compensate for any error between a sensed signal from the first coil relative to a sensed signal from the second coil;

connecting respective ends of the first and second coils to an appropriate portion of the medical instrument;

covering the coil and at least a portion of the first layer of a material with a second layer of material after connecting the respective ends of the coils, the second material configured to isolate the coil from an exterior environment; and

sealing a terminal end portion of the core, a portion of the first layer adjacent the terminal end portion and a portion of the second layer adjacent the terminal end portion.