# US 11,906,412 B2 · Particle characterisation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,412 B2 - Document ID: US11906412B2 - Status: Granted - Kind: B2 - Application number: 17/531,021 - Filed: 2021-11-19 - Published: 2022-10-13 - Granted: 2024-02-20 - Earliest claimed: 2017-03-23 - Assignees: Malvern Panalytical Limited - Applicants: Malvern Panalytical Limited - Inventors: Jason Corbett; Alex Malm - Web page: https://patentgrep.com/patent/US11906412B2 ## CPC - G01N 15/0211: {Investigating a scatter or diffraction pattern} - G01N 2015/0053: {in liquids, e.g. trouble} - G01N 2015/0222: {from dynamic light scattering, e.g. photon correlation spectroscopy} - 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 A method of characterising particles in a sample, comprising: obtaining a scattering measurement comprising a time series of measurements of scattered light from a detector, the scattered light produced by the interaction of an illuminating light beam with the sample; producing a corrected scattering measurement, comprising compensating for scattering contributions from contaminants by reducing a scattering intensity in at least some time periods of the scattering measurement; determining a particle characteristic from the corrected scattering measurement. ## Claims ### Claim 1 A method of characterising particles in a sample, comprising: obtaining a plurality of scattering measurements, each scattering measurement comprising a time series of measurements of scattered light from a detector, the scattered light produced by the interaction of an illuminating light beam with the sample; identifying contaminated scattering measurements, in which a contaminant was contributing to the scattered light; and determining a particle characteristic from scattering measurements that have not been identified as contaminated scattering measurements by: determining an autocorrelation function for each scattering measurement that has not been identified as a contaminated scattering measurement; combining the autocorrelation functions to produce an average autocorrelation function from which the particle characteristic is derived. ### Claim 2 (depends on 1) The method of claim 1, wherein identifying contaminated scattering measurements comprises identifying scattering measurements within a predetermined time window from a time when the scattered light intensity exceeds a threshold. ### Claim 3 (depends on 2) The method of claim 2, wherein the threshold is determined after a measurement. ### Claim 4 (depends on 3) The method of claim 3, wherein the threshold is determined from the ensemble characteristics of the scattering measurements. ### Claim 5 (depends on 4) The method of claim 4, wherein the threshold is derived from an average intensity taken across the scattering measurements. ### Claim 6 (depends on 2) The method of claim 2, wherein the threshold is determined dynamically as the measurements are taken. ### Claim 7 (depends on 1) The method of claim 1, wherein identifying contaminated scattering measurements comprises identifying scattering measurements within a predetermined time window from a time when fluctuations in the time series of measurements have a frequency below a cut-off frequency. ### Claim 8 (depends on 1) The method of claim 1, wherein identifying contaminated scattering measurements comprises identifying scattering measurements within a predetermined time window from a time when the scattered light intensity exceeds a threshold and fluctuations in the time series of measurements have a frequency below a cut-off frequency. ### Claim 9 (depends on 1) The method of claim 1, wherein identifying contaminated scattering measurements comprises; partitioning the scattering measurements, determining a comparative particle characteristic for each partitioned portion, and identifying partitioned portions where the comparative particle characteristic exceeds a threshold. ### Claim 10 (depends on 9) The method of claim 9, wherein the comparative particle characteristic is particle size. ### Claim 11 (depends on 9) The method of claim 9, wherein the comparative particle characteristic is polydispersity index. ### Claim 12 (depends on 11) The method of claim 11, wherein the threshold is determined from a best fit normal distribution. ### Claim 13 (depends on 12) The method of claim 12, wherein the threshold is three standard deviations from the average value determined from the best fit normal distribution. ### Claim 14 (depends on 9) The method of claim 9, wherein the plurality of measurements is taken until a convergence criterion is met. ### Claim 15 An apparatus for characterising particles, comprising: a light source, a sample cell, a detector and a processor; wherein the light source is operable to illuminate a sample within the sample cell with a light beam so as to produce scattered light by interactions of the light beam with the sample; the detector is configured to detect the scattered light and produce a time series of measurements; and the processor is configured to: obtain a scattering measurement comprising a time series of measurements of the scattered light from the detector; identify contaminated scattering measurements, in which a contaminant was contributing to the scattered light; and determine a particle characteristic from scattering measurements that have not been identified as contaminated scattering measurements by: determining an autocorrelation function for each scattering measurement that has not been identified as a contaminated scattering measurement; combining the autocorrelation functions to produce an average autocorrelation function from which the particle characteristic is derived.