Method of locating the tip of a central venous catheter

• US 8,774,907 B2
• Filed: 01/09/2013
• Issued: 07/08/2014
• Est. Priority Date: 10/23/2006
• Status: Active Grant

• Current Assignee: BARD Access Systems Incorporated (Becton, Dickinson & Co)
• Original Assignee: BARD Access Systems Incorporated (Becton, Dickinson & Co)
• Inventors: Rothenberg, Peter M.
• Primary Examiner(s): Patel, Niketa
• Assistant Examiner(s): LEVICKY, WILLIAM J
• Application Number:
  US13/737,806
• Publication Number:
  US 20130123597A1
• Time in Patent Office: 545 Days
• Field of Search: 600508-510, 607/28, 607/122
• US Class Current: 600/509
• 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 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle

Abstract

Methods of locating a tip of a central venous catheter (“CVC”) relative to the superior vena cava, sino-atrial node, right atrium, and/or right ventricle using electrocardiogram data. The CVC includes at least one electrode. In particular embodiments, the CVC includes two or three pairs of electrodes. Further, depending upon the embodiment implemented, one or more electrodes may be attached to the patient'"'"'s skin. The voltage across the electrodes is used to generate a P wave. A reference deflection value is determined for the P wave detected when the tip is within the proximal superior vena cava. Then, the tip is advanced and a new deflection value determined. A ratio of the new and reference deflection values is used to determine a tip location. The ratio may be used to instruct a user to advance or withdraw the tip.

Claims

1. A method of determining a location of a tip of a central venous catheter having a lumen filled with an electrolytic material, a portion disposed inside the superior vena cava, a second electrode attached to the skin of a subject, and a first electrode in communication with the electrolytic material, the tip having an opening in communication with the lumen that exposes the electrolytic material inside the lumen to the electrical environment outside the tip, the method comprising:

obtaining a reference electrical signal comprising the voltage difference between the first electrode and the second electrode;

generating a reference P wave from the reference electrical signal;

determining a reference deflection value of the reference P wave;

after the tip of the central venous catheter has been moved to a new position, obtaining a new electrical signal comprising the voltage difference between the first electrode and the second electrode;

generating a new P wave from the new electrical signal;

determining a new deflection value of the new P wave;

calculating a ratio of the new deflection value to the reference deflection value;

comparing the ratio to a threshold value; and

indicating the tip should be withdrawn based on the comparison of the ratio to the threshold value.