CATHETER ASSEMBLY INCLUDING ECG SENSOR AND MAGNETIC ASSEMBLIES

• US 20100222664A1
• Filed: 08/21/2009
• Published: 09/02/2010
• Est. Priority Date: 08/22/2008
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Bown, Matthew W., Lemon, Ryan R.
• Granted Patent: US 9,901,714 B2
• Time in Patent Office: Days
• US Class Current: 600/409
• CPC Class Codes: A61B 2017/00044 Sensing electrocardiography, i.e. ECG
• CPC Class Codes: A61B 2017/00331 with preformed bends
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61M 2025/09116 Design of handles or shafts or gripping surfaces thereof for manipulating guide wires
• CPC Class Codes: A61M 2025/09141 made of shape memory alloys which take a particular shape at a certain temperature
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 2025/09183 having tools at the distal tip
• CPC Class Codes: A61M 2205/3507 with implanted devices, e.g. external control
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

A stylet for use in guiding a distal tip of a catheter to a predetermined location within the body of a patient. In one embodiment the stylet is configured for use within a lumen of the catheter and comprises a core wire, an ECG sensor, and a magnetic assembly. The ECG sensor senses an ECG signal of a patient when the stylet is disposed within the lumen of the catheter and the catheter is disposed within the body of the patient. The magnetic assembly includes at least one element capable of producing a magnetic or electromagnetic field for detection by a sensor external to the patient. In another embodiment, the stylet includes a pre-shaped distal segment that is deflected with respect to a more proximal portion of the stylet, which in turn causes a distal segment of the catheter to be deflected when the stylet is received within the lumen.

Claims

1. A catheter assembly, comprising:

a catheter defining at least one longitudinally extending lumen; and

a stylet including a pre-shaped distal segment that is deflected with respect to a longitudinal axis of a portion of the stylet proximal to the distal segment, the pre-shaped distal segment of the stylet causing a distal segment of the catheter to be deflected with respect to the longitudinal axis when the stylet is received within the at least one lumen.

2. The catheter assembly as defined in claim 1, wherein the stylet includes a memory shape material, and wherein the pre-shaped distal segment of stylet defines an arc shape.

3. The catheter assembly as defined in claim 2, wherein the stylet includes nitinol, and wherein the stylet further includes a handle to axially rotate the stylet, wherein axial rotation of the stylet causes the pre-shaped distal segment to axially rotate.

4. The catheter assembly as defined in claim 1, wherein the stylet includes a core wire, wherein the pre-shaped distal segment includes the core wire, and wherein the distal segment of the core wire defines a reduced diameter with respect to portions of the stylet proximal thereto.

5. The catheter assembly as defined in claim 1, wherein the longitudinal axis of the stylet is substantially linear.

6. A stylet for use within a longitudinally extending lumen of a catheter, the stylet comprising:

an elongate core wire;

an ECG sensor for sensing an ECG signal of a patient when the stylet is disposed within the lumen of the catheter and the catheter is disposed within a body of the patient; and

a magnetic assembly including at least one element capable of producing a magnetic or electromagnetic field for detection by a sensor external to the patient.

7. The stylet as defined in claim 6, wherein the ECG sensor is in operable communication with a conductive pathway for passing the ECG signal externally with respect to a patient when the catheter is disposed within a patient.

8. The stylet as defined in claim 7, wherein the ECG sensor includes a distal portion of the core wire, and wherein the conductive pathway includes portions of the core wire proximal to the distal portion.

9. The stylet as defined in claim 6, wherein the stylet further includes a tubing portion covering a portion of the core wire.

10. The stylet as defined in claim 9, wherein the ECG sensor includes at least one of the following:

an annular ring disposed on the tubing portion of the stylet; and

a conductive epoxy, at least a portion of the conductive epoxy being covered by the tubing portion.

11. The stylet as defined in claim 6, wherein the tubing portion defines at least a portion of the ECG sensor.

12. The stylet as defined in claim 9, wherein the tubing portion includes a conductive coil that covers at least a portion of the magnetic assembly.

13. The stylet as defined in claim 6, wherein the ECG sensor includes a conductive wire that is separate from the core wire.

14. A method of guiding a catheter internally within a patient, the catheter defining at least one lumen in which a stylet including a magnetic assembly and an ECG sensor is removably disposed, the method comprising:

introducing the catheter with the stylet disposed therein into the patient body;

detecting data relating to the magnetic assembly by an external sensor during advancement of the catheter within the patient body; and

monitoring ECG signals sensed by the ECG sensor of the stylet during advancement of the catheter so as to position the catheter in a desired location within the patient.

15. The method of guiding as defined in claim 14, wherein monitoring ECG signals further comprises:

monitoring ECG signals sensed by the ECG sensor of the stylet during advancement of the catheter through a vasculature of the patient so as to position the catheter proximate an SA node of the heart of the patient.

16. The method of guiding as defined in claim 14, further comprising:

withdrawing the stylet from the at least one lumen of the catheter after the catheter has been positioned in a desired location.

17. A catheter assembly, comprising:

a catheter defining a lumen; and

a stylet for removable placement in the lumen, the stylet comprising;

a core wire including a distal segment, the portion of the core wire distal segment defining a reduced diameter with respect to the core wire proximal to the distal segment, the core wire capable of sensing an ECG signal of the patient when the stylet is disposed within the lumen of the catheter and the catheter is disposed within a vasculature of the patient;

a tubing portion covering the distal segment of the core wire, the tubing portion being attached to the core wire; and

at least one magnetic element included adjacent the core wire distal segment and covered by the tubing portion.

18. The catheter assembly as defined in claim 17, wherein the core wire includes nitinol and a hydrophilic coating, and wherein the catheter assembly further comprises:

an electrically conductive feature included at a distal end of the sleeve, the electrically conductive feature in electrical communication with the core wire to enable the electrically conductive feature to detect an electrical impulse from a heart of a patient when a distal portion of the stylet is disposed within a vasculature of the patient.

19. The catheter assembly as defined in claim 18, wherein the at least one magnetic element includes a plurality of permanent magnets interposed between the core wire and the tubing portion, and wherein the electrically conductive feature includes a conductive metal, an epoxy, and a tip weld material.

20. The catheter assembly as defined in claim 19, wherein a distal end of the core wire extends substantially to a distal end of the stylet, wherein the electrically conductive feature includes a conductive epoxy that is electrically connects proximate the distal end of the core wire, and wherein the core wire defines a conductive pathway for the passage of the ECG signal to a point exterior to the catheter.