United States Patent n<>] ni] Patent Number: 5,307,808
Dumoulin et al. [45] Date of Patent: May 3, 1994
[54] TRACKING SYSTEM AND PULSE
SEQUENCES TO MONITOR THE POSITION
OF A DEVICE USING MAGNETIC
RESONANCE
[75] Inventors: Charles L. Dumoulin, Ballston Lake,
N.Y.; Steven P. Souza,
Williamstown, Mass.; Robert D.
Darrow, Scotia, N.Y.
[73] Assignee: General Electric Company,
Schenectady, N.Y.
[21] Appl. No.: 861,718
[22] Filed: Apr. 1,1992
[51] Int. CU A61B 5/055
[52] U.S. Q 128/653.2; 128/653.5;
128/658
[58] Field of Search 128/653.2, 653.5, 899,
128/658
[56] References Cited
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FOREIGN PATENT DOCUMENTS
0385367 9/1990 European Pat. Off. .
3937052 5/1990 Fed. Rep. of Germany .
Primary Examiner—William E. Kamm
Assistant Examiner—Brian L. Casler
Attorney, Agent, or Firm—Lawrence P. Zale; Marvin
Snyder
[57] ABSTRACT
A tracking system employs magnetic resonance signals to monitor the position of a device such as a catheter within a subject. The device has a receiver coil which is sensitive to magnetic resonance signals generated in the subject. These signals are detected in the presence of magnetic field gradients and thus have frequencies which are substantially proportional to the location of the coil along the direction of the applied gradient. Signals are detected responsive to sequentially applied mutually orthogonal magnetic gradients to determine the position of the device in several dimensions. The position of the device as determined by the tracking system is superimposed upon independently acquired medical diagnostic images.
15 Claims, 9 Drawing Sheets
