Field gradient-based remote imaging

Patent metadata

Field	Value
Publication number	US-12059240-B2
Application number	US-202318110914-A
Country	US
Kind code	B2
Filing date	Feb 17, 2023
Priority date	Aug 17, 2017
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

Systems and method for remote field measurement-based mapping of anatomical structures (e.g., using impedance image of electrical fields) are described. In some embodiments, an image of features within a target region is produced by analysis of a spatial pattern of field measurements made in a measurement region remote from the target region features; for example, but not exclusively, by treating the spatial arrangement of field measurements in some portion of the measurement region as indicating the spatial (e.g., angular and/or distance) arrangement of features (e.g., anatomical structure of topography and/or tissue type) in the target region.

First claim

What is claimed is:

1. A system for imaging using measurements of at least one electrical field made within a first region of a body, the system comprising: a processor and memory storing instructions which instruct the processor to:
for each of the at least one electrical fields:
receive a plurality of measurements of voltages of the electrical field measured using an intrabody probe at different positions within the first region, and
map voltage gradients of the electrical field to the first region, using the voltage measurements;

analyze the mapped voltage gradients to identify distortions in the at least one electrical field;
determine positions of apertures in a tissue wall located outside of the first region using the identified distortions as indications of the presence of the apertures at said positions; and
use the determined positions to produce an image showing the tissue wall and the apertures.

2. The system of claim 1 , wherein the processor is instructed to access data associating the received voltage measurements with particular electrodes of a plurality of electrodes of the intrabody probe, to access known distances of the plurality of electrodes along the intrabody probe, and to map the voltage gradients indicated by the voltage measurements using the voltage measurements, their associations with particular electrodes, and the known distances.

3. The system of claim 1 , wherein the processor produces the image using voltage gradients from near a periphery of the first region, the near periphery being defined by the instructions to exclude voltage gradients from a central portion of the first region.

4. The system of claim 3 , wherein the processor is instructed to determine positions of the apertures by setting distances from the first region to portions of the tissue wall surrounding the apertures as a function of gradient strength near the periphery of the first region.

5. The system of claim 4 , wherein the processor is instructed to produce the image by setting distances from the first region to features of the image using a map of voltage gradient strength near the periphery as a function of solid angle.

6. The system of claim 3 , wherein the processor is instructed to produce the image by setting distances from the first region to features of the image as a function of a decay of a distortion in voltage gradients with distance.

7. The system of claim 1 , wherein the processor is instructed to access data associating the voltage measurements to respective heartbeat phases during which they were measured, and to produce a plurality of images corresponding respectively to different heartbeat phases.

8. The system of claim 1 , wherein the processor is instructed to:
access contact measurements measured while the probe contacts the tissue wall; and
to identify a feature of the image which indicates an anatomical structure located behind the tissue wall, using a mismatch between the position of the surface as measured by the contact measurements and a position of said surface as indicated in the image.

9. The system of claim 1 , wherein the processor is instructed to produce the image showing the tissue wall and the apertures by producing a plurality of portions of an image of the tissue wall, each corresponding to a respective portion of the first region, wherein each portion of the plurality of portions of the image of the tissue wall has in common with the respective portion of the first region an angular position with respect to a reference location.

10. The system of claim 9 , wherein each of the plurality of portions of the first region is between the reference location and the respective imaged portion of the tissue wall.

11. The system of claim 1 , wherein the processor is instructed to produce the image so that a plurality of respective portions of the first region and of the image are in correspondence, such that each image portion is respectively indicated by measurements from a respective corresponding portion of the first region.

12. The system of claim 1 , wherein the processor is instructed to determine the positions of structural features of the tissue wall comprising relatively raised and/or recessed features; and to produce the image to show said structural features.

13. The system of claim 1 , wherein the image shows features of the topography of the tissue wall.

14. The system of claim 1 , wherein the tissue wall surrounding the apertures is at a distance from the first region of at least 1 cm.

15. The system of claim 1 , wherein the at least one electrical fields comprise at least three electrical fields crossing within the first region; and the processor is instructed to used identified distortions in each of the at least three electrical fields as indications of the presence of the apertures.

16. The system of claim 1 , wherein each of the different positions of the probe within the first region is away from a first one of the apertures, said first aperture having a first side facing the first region and second side facing away from the first region, the different positions being on the first side of the first aperture, and the image produced by the processor shows a region on the second side of the first aperture.

17. The system of claim 16 , wherein the processor is instructed to produce the image by setting distances from the first region to the first aperture as a function of a decay of a distortion in voltage gradients with distance.

18. The system of claim 1 , wherein the voltage gradients comprise a plurality of different local voltage gradients, each at a different one of the different positions.

19. The system of claim 1 , wherein the tissue wall shown in the image is a wall of a cardiovascular lumen.

20. The system of claim 19 , wherein at least one of the apertures shown in the image is an ostium of a pulmonary vein or a mitral valve.

21. The system of claim 2 , comprising the intrabody probe having the plurality of electrodes at known distances, and configured for use in measuring the voltages of the at least one electrical fields.

Assignees

• Navix Int Ltd

Inventors

• Ben-Haim Shlomo

Classifications

• A61B5/0538 Primary

  invasively, e.g. using a catheter · CPC title

• A61B5/283

  Invasive · CPC title

• A61B5/4233

  oesophagus · CPC title

• A61B5/063

  using impedance measurements · CPC title

• A61B5/6852

  Catheters · CPC title