Stent expansion and apposition sensing

• US 6,179,858 B1
• Filed: 01/08/1999
• Issued: 01/30/2001
• Est. Priority Date: 05/12/1998
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Squire, James C., Rogers, Campell, Edelman, Elazer R.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): LEWIS, WILLIAM W
• Application Number:
  US09/227,555
• Time in Patent Office: 753 Days
• Field of Search: 606/1, 606/108, 606/159, 606/191, 606/192, 606/194, 606/198, 623/1, 623/12, 623/1.1, 623/1.11
• US Class Current: 606/198
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61M 2025/0002 with a pressure sensor at the distal end

Abstract

An apposition sensing system including a stent; a catheter assembly to which the stent is coupled for deployment into a lumen; and a sensor positioned on the catheter assembly adjacent to an end of the stent. The sensor is adapted to provide an electrical parameter which is indicative of apposition of the end of the stent to the inner wall of the lumen. In one aspect of the invention, the sensor includes first and second pressure sensors positioned at proximal and distal portions of the catheter assembly adjacent to proximal and distal ends of the stent. A monitoring unit monitors pressure changes sensed by the sensors. In accordance with an alternative embodiment of the invention, there is provided an expansion sensing system including a stent having an electrically conductive region; an expandable insulating sleeve; a catheter assembly to which the stent is coupled for deployment into a lumen; and at least one electrode associated with the catheter assembly. The sleeve is positioned between the electrode and the conductive region, the electrode and conductive region being adapted to provide an electrical parameter which varies in correspondence with expansion of the stent. In one aspect of the invention, the sleeve positioned between the electrode and the conductive region define a variable capacitor. A monitoring unit monitors variations in capacitance between the electrode and conductive region which is directly proportional to the change in stent diameter.

Claims

1. A system comprising:

an endoluminal device including an endovascular stent;

a catheter assembly to which said device is coupled for deployment into a lumen; and

a sensor positioned on said catheter assembly adjacent to an end of said endoluminal device, said sensor being mechanically coupled to said lumen and adapted to provide an electrical parameter which is indicative of apposition pressure of said end of said endoluminal device to the inner wall of said lumen.

2. The system of claim 1, wherein said catheter assembly comprises a balloon catheter.

4. The system of claim 1, wherein said endoluminal device comprises an endovascular stent.

3. An endoluminal device apposition sensing system comprising:

an endoluminal device;

a catheter assembly to which said endoluminal device is coupled for deployment into a lumen; and

first and second pressure sensors positioned at proximal and distal portions of said catheter assembly adjacent to proximal and distal ends of said endoluminal device; and

a monitoring unit which monitors pressure changes sensed by said sensors which is indicative of apposition of said proximal and distal ends of said endoluminal device to the inner wall of said lumen.

5. The system of claim wherein said catheter assembly comprises a balloon catheter.

6. A system comprising:

an endoluminal device including an electrically conductive region;

an expandable insulating sleeve;

a catheter assembly to which said endoluminal device is coupled for deployment into a lumen; and

at least one electrode associated with said catheter assembly, said expandable insulating sleeve being positioned between said electrode and said conductive region, said electrode and conductive region being adapted to provide an electrical parameter which varies in correspondence with expansion of said endoluminal device.

7. The system of claim 6, wherein said endoluminal device comprises an endovascular stent.

8. The system of claim 6, wherein said catheter assembly comprises a balloon catheter.

9. An endoluminal device expansion sensing system comprising:

an endoluminal device including an electrically conductive region;

an expandable insulating sleeve;

a catheter assembly to which said endoluminal device is coupled for deployment into a lumen;

at least one electrode associated with said catheter assembly, said expandable insulating sleeve being positioned between said at least one electrode and said conductive region so as to define a variable capacitor; and

a monitoring unit which monitors variations in capacitance between said at least one electrode and conductive region which is directly proportional to the change in device diameter.

10. The system of claim 9, wherein said endoluminal device comprises an endovascular stent.

11. The system of claim 9, wherein said catheter assembly comprises a balloon catheter.

12. A method of sensing expansion of a stent within a lumen, said stent being coupled to a catheter assembly for deployment into said lumen, said method comprising:

providing at least one electrode on said catheter assembly and an insulating sleeve between said electrode and an electrically conductive region associated with said stent; and

monitoring changes in an electrical parameter associated with said electrode and said conductive region which varies in correspondence with expansion of said stent.