Catheter location system and method
First Claim
1. A system for determining the location of a catheter within a patient comprisingmeans for applying at least two orthogonal current signals through the patient,a catheter adapted to be disposed within a patient, the catheter having means for sensing the applied at least two orthogonal current signals through the patient, andmeans for calculating from said sensed signal the location of the sensing means relative to the means for applying.
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Abstract
A system and method are provided for catheter location mapping, and related procedures. Three substantially orthogonal alternating signals are applied through the patient, directed substantially toward the area of interest to be mapped, such as patient'"'"'s heart. The currents are preferably constant current pulses, of a frequency and magnitude to avoid disruption with ECG recordings. A catheter is equipped with at least a measuring electrode, which for cardiac procedures is positioned at various locations either against the patient'"'"'s heart wall, or within a coronary vein or artery. A voltage is sensed between the catheter tip and a reference electrode, preferably a surface electrode on the patient, which voltage signal has components corresponding to the three orthogonal applied current signals. Three processing channels are used to separate out the three components as x, y and z signals, from which calculations are made for determination of the three-dimensional location of the catheter tip within the body. An easy calibration procedure, which can be performed separately or during the mapping, is used to calibrate the system and provide the correlations between respective x, y and z sense signals and dimensional locations. The procedure is particularly applicable for catheter mapping prior to ablation, and for repositioning the catheter tip at precise locations for the desired ablations. The procedure is also applicable for other techniques where position must be remembered and re-found with accuracy, such as in mapping coronary stenosis and/or placing stents. Although the invention provides the greatest benefit in 3-dimensional applications, it is also useful for one and two dimensional applications.
908 Citations
34 Claims
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1. A system for determining the location of a catheter within a patient comprising
means for applying at least two orthogonal current signals through the patient, a catheter adapted to be disposed within a patient, the catheter having means for sensing the applied at least two orthogonal current signals through the patient, and means for calculating from said sensed signal the location of the sensing means relative to the means for applying.
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14. A system for use in indicating the location of a catheter within a patient, comprising:
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external signal means for applying at least one electrical alternating current signal to said patient; a catheter adapted to be inserted into said patient'"'"'s body and manipulated to a plurality of locations, said catheter having at least an electrode; and location means connected to said electrode for sensing said at least one alternating current signal and processing said sensed alternating current signal to obtain location signals indicative of the location of said catheter when positioned at respective different body locations. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A method of locating the three-dimensional position of a catheter within a patient, comprising:
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applying respective three-dimensional orthogonal current alternating signals, corresponding substantially to x, y and z directions through said patient; inserting a catheter into said patient, said catheter having an electrode disposed along the catheter and sensing said applied respective three-dimensional orthogonal current alternating signals; measuring the signals sensed at said electrode and corresponding to each of said three dimensional orthogonal current signals; calculating position data of the catheter from said sensed signals; and outputting position data representative of such three-dimensional position. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification