Systems and methods for orientation independent sensing

Patent metadata

Field	Value
Publication number	US-10194994-B2
Application number	US-201615152496-A
Country	US
Kind code	B2
Filing date	May 11, 2016
Priority date	May 12, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an Ė value at each of a plurality of time intervals, compute an initial estimate of ŵ from a cross product of E and the Ė value for each of the plurality of time intervals, average the initial estimate of ŵ from each of the plurality of time for a best estimate of ŵ, determine a plurality of â(θ) values and using the corresponding {circumflex over (n)}(θ) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

First claim

What is claimed is:

1. A system for obtaining an OIS coordinate frame within a heart, comprising:
a catheter comprising a plurality of closely spaced electrodes; and
an electronic control unit configured to:
receive a plurality of signals from the plurality of closely spaced electrodes;
determine a local 3D electric field loop;
create a zero mean version of E(t) over a depolarization interval;
compute an Ė value at each of a plurality of time intervals;
compute an initial estimate of ŵ from a cross product of E and the Ė value for each of the plurality of time intervals;
average the initial estimate of ŵ from each of the plurality of time for an estimate of ŵ;
determine a plurality of â(θ) values and choosing a corresponding {circumflex over (n)}(θ) value for each of the plurality of â(θ) values;
compute a composite match score; and
choose at least one value for â and a value for {circumflex over (n)}
outputting at least one of the estimate of ŵ and at least one value for â and a value for {circumflex over (n)}.

2. The system of claim 1 , wherein the electronic control unit is further configured to compute at least one of OIS omnipole signals comprising E n , E a , and E w .

3. The system of claim 2 , wherein the electronic control unit is further configured to compute at least one amplitude from the at least one OIS omnipole signals.

4. The system of claim 3 , wherein the electronic control unit is further configured to compute a conduction velocity vector from the at least one OIS omnipole signals and the at least one amplitude.

5. The system according to claim 1 , wherein the electronic control unit is further configured to filter all of a plurality of unipolar signals, a plurality of catheter bipoles, and the 3D E-field loop before determining the local 3D electric field loop and the OIS coordinate fame of {circumflex over (n)}, â, and ŵ.

6. The system according to claim 1 , wherein the electronic control unit is further configured to determine a catheter force related surface distension through the value for {circumflex over (n)}.

7. The system according to claim 1 , wherein the electronic control unit is further configured to determine whether a high quality OIS signal is present within the local 3D electric field loop.

8. The system according to claim 1 , wherein the electronic control unit is further configured to weight a plurality of points within the local 3D electric field loop.

9. A method for obtaining an OIS coordinate frame within a heart, comprising:
receiving a plurality of signals from a plurality of closely spaced electrodes
determining a local 3D electric field loop;
creating a zero mean version of E(t) over a depolarization interval;
computing an Ė value at each of a plurality of time intervals;
computing an initial estimate of ŵ from a cross product of E and the Ė value for each of the plurality of time intervals;
averaging the initial estimate of ŵ from each of the plurality of time for an estimate of ŵ;
determining a plurality of â(θ) values and choosing a corresponding {circumflex over (n)}(θ) value for each of the plurality of â(θ) values;
computing a composite match score; and
choosing at least one value for â and a value for {circumflex over (n)}.

10. The method of claim 9 , further comprising computing at least one of OIS omnipole signals comprising E n , E a , and E w .

11. The method of claim 10 , further comprising computing at least one amplitude from the at least one OIS omnipole signals.

12. The method of claim 11 , further comprising computing a conduction velocity vector from the at least one OIS omnipole signals and the at least one amplitude.

13. The method according to claim 9 , further comprising filtering all of a plurality of unipolar signals, a plurality of catheter bipoles, and the 3D E-field loop before determining the local 3D electric field loop.

14. The method according to claim 9 , wherein the electronic control unit is further configured to determine a catheter force related surface distension through the value for {circumflex over (n)}.

15. The method according to claim 9 , wherein the electronic control unit is further configured to determine whether a high quality OIS signal is present within the local 3D electric field loop.

16. A system for obtaining an OIS coordinate frame within a heart, comprising:
a catheter comprising a plurality of closely spaced electrodes; and
an electronic control unit configured to:
receive a plurality of signals from the plurality of closely spaced electrodes;
determine a local 3D electric field loop;
compute a composite match score for how well {dot over (φ)} matches an inner product of E and â(θ) and −φ matches an inner product of E and {circumflex over (n)};
choose a value for â and a value for {circumflex over (n)}; and
determine a value for ŵ by a right hand rule and a cross product ŵ={circumflex over (n)}×â
outputting at least one of the value for ŵ and the value for â and a value for {circumflex over (n)}.

17. The system of claim 16 , wherein the electronic control unit is further configured to compute at least one of OIS omnipole signals comprising E n , E a , and E w .

18. The system of claim 17 , wherein the electronic control unit is further configured to compute at least one amplitude from the at least one OIS omnipole signals.

19. The system of claim 18 , wherein the electronic control unit is further configured to compute a conduction velocity vector from the at least one OIS omnipole signals and the at least one amplitude.

20. The system according to claim 16 , wherein the electronic control unit is further configured to filter all of a plurality of unipolar signals, a plurality of catheter bipoles, and the 3D E-field loop before determining the local 3D electric field loop.

Assignees

• St Jude Medical Cardiology Div Inc

Inventors

• Deno D Curtis
• Balachandran Ram K
• Massé Stéphane

Classifications

• A61B2018/00577

  Ablation · CPC title

• A61B2090/064

  for measuring force, pressure or mechanical tension · CPC title

• A61B2017/00053

  Mapping · CPC title

• A61B34/20 Primary

  Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis · CPC title

• A61B2018/00648

  using more than one sensed parameter · CPC title