High resolution two-dimensional resistance tomography

Patent metadata

Field	Value
Publication number	US-12357188-B2
Application number	US-201917295318-A
Country	US
Kind code	B2
Filing date	Nov 29, 2019
Priority date	Nov 28, 2018
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

The disclosed 2-D and 3-D tomographic resistance imaging method improves tomographic resistance image resolution by adopting an orthogonal basis with the maximum number of elements N to describe the maximum resolution resistivity map ρ(r), where this number of elements N is set according to the number of electrodes Q; by defining the orthogonal basis according to any known constraints in the problem, thereby enhancing the resolution where it is needed; by positioning electrodes to be sensitive to these basis functions; and by choosing current I and voltage V contact electrode pairs that maximize signal-to-noise ratio.

First claim

We claim:

1. A computer implemented method for mapping a tomographic image over a surface, comprising:
defining a surface area of a resistive sensing membrane having Q periphery contact electrodes attached along a periphery of the defined surface area of the resistive sensing membrane, wherein Q comprises an integer higher than or equal to five, wherein the resistive sensing membrane comprises a plurality of local area resistances (r ABCD ) i to (r ABCD ) N , wherein the plurality of local area resistances (r ABCD ) i to (r ABCD ) N vary when an applied contact pressure is applied over the defined surface area of the resistive sensing membrane, wherein the applied contact pressure causes a two-dimensional (2-D) resistance variation;
mapping a 2-D resistance tomographic image over the defined surface area of the resistive sensing membrane according to the plurality of local area resistances of the applied contact pressure to the defined surface area of the resistive sensing membrane, wherein the 2-D resistance tomographic image mapping comprises:
measuring a respective tetra-polar resistance of the plurality of local area resistances (r ABCD ) i to (r ABCD ) N sequentially, wherein i=1 to N, and N represents a maximum number of independent tetra-polar measurements,
wherein each respective tetra-polar resistance corresponds to a respective voltage and current ratio r( ABCD ) i =V CD /I AB , such that a respective voltage V CD is established across a first periphery contact electrode pair CD when a respective current I AB is simultaneously passed across a second periphery contact electrode pair AB, wherein the first periphery contact electrode pair CD is different from the second periphery contact electrode pair AB, wherein the respective tetra-polar resistance reflects a local area resistance variation in a resistivity map ρ(r) of the 2-D resistance tomographic image;
wherein the resistivity map ρ(r) is related to orthogonal basis polynomial functions ϕ i (r) by an equation of ρ(r)=Σ i a i ϕ i (r), and the resistivity map ρ(r) is formed by superimposing the orthogonal basis polynomial functions ϕ i (r) having a resolution that increases with index i whose upper limit N is the same as a maximum number of independent tetra-polar resistance measurements, wherein a=(a 1 , a 2 , . . . a i , . . . ) are ordered vector of coefficients; and
displaying the 2-D resistance tomographic image through the resistivity map ρ(r) on the defined surface.

2. The computer implemented method according to claim 1 , wherein the defined surface area of the resistive sensing membrane is an arbitrary shape, and in a case when the defined surface area is circular, the orthogonal basis polynomial functions ϕ i (r) are a priori polynomial basis functions described by the Zernike polynomial equations:

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;

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Assignees

• Univ Northwestern

Inventors

• Grayson Matthew Allen
• Wang Chulin
• Onsager Claire Cecelia
• Aygen Can Cenap
• Costakis Charles M
• Lang Lauren E
• Tzavelis Andreas
• Rogers John Ashley

Classifications

• A61B5/0073

  by tomography, i.e. reconstruction of 3D images from 2D projections (A61B5/0066 takes precedence) · CPC title

• A61B5/0536 Primary

  Impedance imaging, e.g. by tomography · CPC title

• A61B5/0044 Primary

  for the heart · CPC title