System and method for assessing dimensions and eccentricity of valve annulus for trans-catheter valve implantation

Patent metadata

Field	Value
Publication number	US-9867556-B2
Application number	US-201514615996-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Feb 7, 2014
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A system for detecting the dimensions and geometry of a native valve annulus for trans-catheter valve implantation includes a compliant balloon and a shaft within the balloon. One or more drive electrodes may be affixed to a surface of the balloon, and one or more sense electrodes may be affixed to the shaft. After insertion of the balloon into the native valve annulus, the drive electrodes may be energized with a predetermined voltage. Using a trained statistical model and the voltages measured at the sense electrodes, initial estimates of the cross-section of the valve annulus may be obtained. The initial estimates may then be provided to an optimization model of the valve annulus to obtain a highly accurate prediction of the cross-section of the valve annulus.

First claim

The invention claimed is:

1. A system for determining the dimensions and geometry of a native valve annulus for trans-catheter valve implantation, the system comprising:
a balloon extending in a longitudinal direction and having an interior surface;
a shaft extending in the longitudinal direction within the balloon;
a first pair of electrodes on the interior surface of the balloon and configured to produce a first electrical field based on a first predetermined current;
a second pair of electrodes on the interior surface of the balloon and configured to produce a second electrical field based on a second predetermined current;
a first sense electrode pair on the shaft and configured to detect the first and second electrical fields; and
a second sense electrode pair on the shaft and configured to detect the first and second electrical fields.

2. The system of claim 1 , wherein the balloon is an insulative material such that the first electrical field and the second electrical field are confined to an area inside the balloon.

3. The system of claim 1 , wherein the first sense electrode pair is at a midpoint of a length of the shaft within the balloon.

4. The system of claim 1 , wherein:
an electrode of the first pair of electrodes is positioned at an angle of about 90° in a circumferential direction of the balloon from an electrode of the second pair of electrodes; and
the second sense electrode pair is positioned at an angle of about 90° in the circumferential direction of the balloon from the first sense electrode pair.

5. The system of claim 1 , further comprising:
a third pair of electrodes on the shaft, one electrode of the third pair of electrodes being positioned a predetermined distance in a first direction along the shaft from the first sense electrode pair and the other electrode of the third pair of electrodes being positioned the predetermined distance in a second direction along the shaft from the first sense electrode pair, the second direction being opposite the first direction, the third pair of electrodes being configured to produce a third electrical field based on a third predetermined current; and
a third sense electrode pair on the shaft and configured to detect the third electrical field.

6. A method for determining the dimensions and geometry of a native valve annulus for trans-catheter valve implantation, the method comprising:
loading a balloon catheter in a delivery system, the balloon catheter comprising:
a balloon extending in a longitudinal direction and having an interior surface;
a shaft extending in the longitudinal direction within the balloon;
a first pair of drive electrodes on the interior surface of the balloon;
a second pair of drive electrodes on the interior surface of the balloon;
a first sense electrode pair on the shaft; and
a second sense electrode pair on the shaft;

delivering the balloon catheter to the native valve annulus;
deploying the balloon catheter within the native valve annulus so that the balloon conforms to a surface of the native valve annulus;
applying a first current to the first pair of electrodes to produce a first electrical field;
applying a second current to the second pair of electrodes to produce a second electrical field;
detecting the first electrical field with the first and second sense electrode pair;
detecting the second electrical field with the first and second sense electrode pair; and
determining one or more dimensions of the native valve annulus based at least on the detected first electrical field and the detected second electrical field.

7. The method of claim 6 , wherein the balloon is an insulative material such that the first electrical field and the second electrical field are confined to an area inside the balloon.

8. The method of claim 6 , wherein the first sense electrode pair is at a midpoint of a length of the shaft within the balloon.

9. The method of claim 6 , wherein the electrodes that comprise the first and second pairs of drive electrodes are affixed about 180° apart on the interior surface such that the electrodes of the first and the second drive electrode pairs are about 90° degrees apart on the interior surface; and
the electrodes that comprise the first and sense electrode pairs are affixed about 180° apart on the shaft such that the electrodes of the first and the second sense electrode pairs are about 90° apart on the shaft.

10. The method of claim 6 , wherein the balloon catheter further comprises:
a third pair of electrodes on the shaft, one electrode of the third pair of electrodes being positioned a predetermined distance in a first direction along the shaft from the first sense electrode pair and the other electrode of the third pair of electrodes being positioned the predetermined distance in a second direction along the shaft from the first sense electrode pair, the second direction being opposite the first direction; and
a third sense electrode pair on the shaft; and
the method further comprises:
applying a third current to the third pair of electrodes to produce a third electrical field;
detecting the third electrical field with the third sense electrode pair; and
further determining the one or more dimensions of the native valve annulus based at least on the detected third electrical field.

11. A method for determining the dimensions and geometry of a native valve annulus for trans-catheter valve implantation, the method comprising:
receiving, with one or more processors, first voltage values from a first sense electrode pair on a shaft of a balloon catheter, the first sense electrode pair being configured to detect a first electrical field produced by a first pair of drive electrodes and a second electrical field produced by a second pair of drive electrodes;
receiving, with the one or more processors, second voltage values from a second sense electrode pair on the shaft of the balloon catheter, the second sense electrode pair being configured to detect the first electrical field and the second electrical field;
determining, with the one or more processors, a major axis length of the native valve annulus based on the first and second voltage values;
determining, with the one or more processors, a minor axis length of the native valve annulus based on the first and second voltage values; and
determining, with the one or more processors, an eccentricity of the native valve annulus based on the determined major axis length and the determined minor axis length.

12. The method of claim 11 , further comprising:
determining, with the one or more processors, an estimated major axis length of the native valve annulus by providing the first and second voltage values to a statistical model of the native valve annulus;
wherein the step of determining the major axis length of the native valve annulus includes applying an optimization model of the native valve annulus to the estimated major axis length.

13. The method of claim 11 , further comprising:
determining, with the one or more processors, at least one offset value associated with the balloon catheter based on the received first and second voltage values, wherein the at least one offset value identifies an amount of offset of an axis of the balloon catheter relative to an axis of the native valve annulus.

14. A method for determining the dimensions and geometry of a native valve annulus for trans-catheter valve implantation, the method comprising:
loading a balloon catheter in a delivery system, the balloon catheter comprising:
a balloon extending in a longitudinal direction;
a shaft extending in the longitudinal direction wi

Assignees

• St Jude Medical Cardiology Div Inc

Inventors

• Balachandran Ram Kumar
• Venkatasubramanian Ramji T
• Hill Anthony David
• Hauck John
• Saikrishnan Neelakantan
• Thao Riki

Classifications

• A61B5/1076 Primary

  for measuring dimensions inside body cavities, e.g. using catheters (A61B3/1005 takes precedence) · CPC title

• A61B5/6853

  with a balloon · CPC title

• A61B5/6869

  Heart · CPC title

• A61F2/2496

  Devices for determining the dimensions of the prosthetic valve to be implanted, e.g. templates, sizers · CPC title

• A61B2560/0252

  using ambient temperature · CPC title