Method of locating the tip of a central venous catheter

• US 8,858,455 B2
• Filed: 08/16/2013
• Issued: 10/14/2014
• 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:
  US13/969,265
• Publication Number:
  US 20130338517A1
• Time in Patent Office: 424 Days
• Field of Search: 600508-510, 600/424, 607/28, 607/122
• US Class Current: 600/508
• 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 5/065 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 5/287 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
• CPC Class Codes: A61B 5/353 Detecting P-waves
• CPC Class Codes: A61B 5/6852 Catheters

Abstract

A method of locating a tip of a central venous catheter (“CVC”) having a distal and proximal pair of electrodes disposed within the superior vena cava, right atrium, and/or right ventricle. The method includes obtaining a distal and proximal electrical signal from the distal and proximal pair of electrodes and using those signals to generate a distal and proximal P wave, respectively. A deflection value is determined for each of the P waves. A ratio of the deflection values is then used to determine a location of the tip of the CVC. Optionally, the CVC may include a reference pair of electrodes disposed within the superior vena cava from which a reference deflection value may be obtained. A ratio of one of the other deflection values to the reference deflection value may be used to determine the location of the tip of the CVC.

Claims

1. A method of locating a tip of a central venous catheter having a portion disposed within the superior vena cava, the catheter comprising a distal pair of electrodes and a proximal pair of electrodes spaced longitudinally from the distal pair of electrodes, the method comprising:

obtaining a distal electrical signal from the distal pair of electrodes;

generating a first P wave from the distal signal;

determining a first deflection value of the first P wave;

obtaining a proximal electrical signal from the proximal pair of electrodes;

generating a second P wave from the proximal signal;

determining a second deflection value of the second P wave;

calculating a first ratio from the first and second deflection values;

obtaining a superior vena cava deflection value;

calculating a second ratio of one of the first deflection value and the second deflection value to the superior vena cava deflection value; and

without advancing or withdrawing the tip of the central venous catheter, either determining that the tip of the central venous catheter is located in a desired location when the first ratio and second ratio are both approximately one, or that the tip of the central venous catheter has been inserted too far when the second ratio is greater than a maximum predefined threshold value, when the first ratio is greater than the maximum predefined threshold value, or when the first ratio is less than a minimum predefined threshold value.

2. The method according to claim 1, wherein the maximum predefined threshold value is two, and the minimum predefined threshold value is one half.