# US 10,371,656 B2 · Tomography apparatus and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,656 B2 - Document ID: US10371656B2 - Status: Granted - Kind: B2 - Application number: 15/511,132 - Filed: 2015-09-15 - Published: 2017-09-07 - Granted: 2019-08-06 - Earliest claimed: 2014-09-15 - Assignees: University of Leeds - Applicants: University of Leeds - Inventors: Mi Wang; Bishal Karki; Qiang Wang - Web page: https://patentgrep.com/patent/US10371656B2 ## CPC - G01N 27/026: {Dielectric impedance spectroscopy (electrochemical impedance spectroscopy for measuring corrosion G01N17/02)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Tomography apparatus comprises: a plurality of electrodes arranged around a perimeter of a cross section of a sample volume for containing a liquid or mixed-phase sample, each electrode being arranged to be in electrical contact with a sample contained in the sample volume; measurement means adapted to perform a set of measurements, each measurement comprising driving a current between a first respective adjacent pair of said electrodes and measuring a voltage developed across a second respective adjacent pair of said electrodes; and processing means adapted to generate a tomogram indicative of sample conductivity over said cross section from said set of measurements. The processing means is arranged to calculate sample conductivity values of a portion of said cross section from said set of measurements and generate said tomogram from said calculated sample conductivity values of said portion using an assumption of symmetry. ## Claims ### Claim 1 A tomography apparatus comprising: a plurality of electrodes arranged around a perimeter of a cross section of a sample volume for containing a liquid or mixed-phase sample, each electrode being arranged to be in electrical contact with a sample contained in the sample volume; a measurement means adapted to perform a set of measurements, each measurement comprising driving a current between a first respective adjacent pair of said electrodes and measuring a voltage developed across a second respective adjacent pair of said electrodes; and a processing means adapted to generate a tomogram indicative of sample conductivity over said cross section from said set of measurements, wherein the processing means is arranged to calculate sample conductivity values of a portion of said cross section from said set of measurements and generate said tomogram from said calculated sample conductivity values of said portion using an assumption of symmetry. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said plurality of electrodes are distributed asymmetrically around said perimeter. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein said portion is one half of said cross section, and the assumption of symmetry is that sample conductivity over the other half mirrors said one half. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the apparatus further comprises a cylindrical pipe, arranged with its longitudinal axis horizontal, arranged to contain a flowing sample, the sample volume being an interior volume of the pipe, and said cross section being a circular cross section of the pipe interior, in a vertical plane perpendicular to the longitudinal axis. ### Claim 5 (depends on 2) The apparatus of claim 2, wherein said portion is a radial portion extending from a centre of the cross section to the perimeter, and the assumption of symmetry is that sample conductivity over said cross section is a function of radius only. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the apparatus further comprises a cylindrical pipe, arranged with its longitudinal axis vertical, arranged to contain a flowing sample, the sample volume being an interior volume of the pipe, and said cross section being a circular cross section of the pipe interior, in a horizontal plane. ### Claim 7 (depends on 2) The apparatus of claim 2, wherein said plurality of electrodes consists of 8 electrodes, said perimeter is circular, and 6 of said 8 electrodes are distributed around one half of the perimeter, with the remaining 2 of said 8 electrodes being distributed around the other half of the perimeter. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein said plurality of electrodes are distributed uniformly around said perimeter. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein said portion extends across the cross section from one side of the perimeter to an opposite side of the perimeter and includes a centre of the cross section. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein said portion is a band extending diametrically across the cross section. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein said portion consists of a plurality of rows of pixels, each row extending across the cross section, and the rows being parallel to one another. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein said portion consists of a single row of pixels extending across the cross section, along a diameter of the cross section. ### Claim 13 (depends on 8) The apparatus of claim 8, wherein the apparatus further comprises a cylindrical pipe, arranged with its longitudinal axis vertical, arranged to contain a flowing sample, the sample volume being an interior volume of the pipe, and said cross section being a circular cross section of the pipe interior, in a horizontal plane. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the assumption of symmetry is that sample conductivity over said cross section is a function of radius only. ### Claim 15 (depends on 8) The apparatus of claim 8, wherein said perimeter is circular and said set of measurements comprises a first sub-set and a second sub-set, each of the first sub-set of measurements comprising driving a current between a respective pair of adjacent electrodes and measuring a voltage developed across a diametrically opposite pair of electrodes, and each of the second sub-set of measurements comprises driving a current between a respective pair of adjacent electrodes and measuring a voltage developed across an opposite respective pair of electrodes along a respective chord of the circular perimeter, wherein the chords of the second sub-set of measurements are parallel to one another. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the set of measurements consists of the first sub-set, the second sub-set, and a third sub-set, wherein the third subset comprises a plurality of measurements using respective pairs of electrodes at opposite ends of chords extending across the perimeter in a direction at least substantially perpendicular to the chords of the second sub-set. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the third sub-set further comprises a plurality of measurements using respective pairs of electrodes at opposite ends of further chords extending across the perimeter. ### Claim 18 (depends on 1) A flow measurement or monitoring apparatus comprising the tomography apparatus of claim 1. ### Claim 19 A tomography method comprising: arranging a plurality of electrodes around a perimeter of a cross section of a sample volume for containing a liquid or mixed-phase sample, each electrode being arranged to be in electrical contact with a sample contained in the sample volume; performing a set of measurements, each measurement comprising driving a current between a first respective adjacent pair of said electrodes and measuring a voltage developed across a second respective adjacent pair of said electrodes; and generating a tomogram indicative of sample conductivity over said cross section from said set of measurements, wherein the method further comprises calculating sample conductivity values of a portion of said cross section from said set of measurements and generating said tomogram from said calculated sample conductivity values of said portion using an assumption of symmetry.