Catheter positioning system

United States Patent [w]

Nardella et al.

US006050267A [ii] Patent Number: [45] Date of Patent:

6,050,267 Apr. 18,2000

[54] CATHETER POSITIONING SYSTEM

[75] Inventors: Paul C. Nardella, Wareham; Thomas A. Wrublewski, Sharon, both of Mass.

[73] Assignee: American Cardiac Ablation Co. Inc.,

Taunton, Mass.

[21] Appl. No.: 09/018,435 [22] Filed: Feb. 4, 1998

Related U.S. Application Data

[63] Continuation-in-part of application No. 08/847,684, Apr. 28, 1997.

[51] Int. C I. A61B 19/00

[52] U.S. CI 128/899; 600/547

[58] Field of Search 128/899; 600/547,

600/373, 382

[56] References Cited

U.S. PATENT DOCUMENTS

5,201,900 4/1993 Nardella 606/157

5,293,868 3/1994 Nardella 128/642

5,295,484 3/1994 Marcus et al 128/660.03

5,341,807 8/1994 Nardella 128/642

5,357,956 10/1994 Nardella 128/642

5,364,392 11/1994 Warner et al 606/34

5,383,917 1/1995 Desai et al 607/702

5,409,000 4/1995 Imran 128/642

5,417,687 5/1995 Nardella et al 606/32

5,443,489 8/1995 Ben-Haim 607/115

5,447,529 9/1995 Marchlinski et al 607/99

5,514,130 5/1996 Baker 606/41

5,536,267 7/1996 Edwards et al 606/41

5,540,655 7/1996 Edwards et al 604/22

5,540,679 7/1996 Fram et al 606/27

A system for detecting the position of a catheter in a patient includes three sets of excitation electrodes, with one set disposed in each of three intersecting axes. A signal processor measures a voltage indicative of impedance between a detection electrode disposed on the catheter and each of the three sets of excitation signals in order to determine the X coordinate, Y coordinate and Z coordinate of the catheter. The detected position of the catheter is recorded and the detection of subsequent catheter positions is performed relative to the recorded catheter position. The difference between subsequent catheter positions and the recorded position relative to the X, Y and Z axes is displayed in order to facilitate repositioning of the catheter at the recorded position. Excitation electrode embodiments utilizing as few as four excitation electrodes are disclosed. The excitation electrodes may be surface, subcutaneous or intracardiac electrodes.

21 Claims, 16 Drawing Sheets