US 12,352,678 B2
Counting method and counting apparatus
Rui Hiraoka, Osaka (JP); and Satoshi Arimoto, Shiga (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Oct. 6, 2022, as Appl. No. 17/938,375.
Application 17/938,375 is a continuation of application No. PCT/JP2021/013180, filed on Mar. 29, 2021.
Claims priority of application No. 2020-078982 (JP), filed on Apr. 28, 2020.
Prior Publication US 2023/0028960 A1, Jan. 26, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 15/04 (2006.01); G01N 15/06 (2006.01); G01N 15/1404 (2024.01); G01N 15/14 (2006.01)
CPC G01N 15/06 (2013.01) [G01N 15/1404 (2013.01); G01N 2015/1486 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A counting method comprising:
aggregating particles in a sample by applying a first alternating current having a first frequency to an electrode set, the electrode set including (i) a first electrode including a first base extending in a first direction, two first convex portions protruding from the first base in a second direction perpendicular to the first direction, and a first concave portion formed between the two first convex portions and (ii) a second electrode including a second base extending in the first direction, two second convex portions protruding from the second base in the second direction perpendicular to the first direction, and a second concave portion formed between the two second convex portions, the first electrode and the second electrode being arranged such that the two first convex portions of the first electrode face the two second convex portions of the second electrode,
wherein the applying the first alternating current having the first frequency to the electrode set causes the particles to aggregate and overlap in a space between one of the two first convex portions of the first electrode and one of the two second convex portions of the second electrode by action of a first-direction dielectrophoretic force exerted by a first electric field gradient generated by the application of the first alternating current having the first frequency to the electrode set, the one of the two first convex portions of the first electrode and the one of the two second convex portions of the second electrode facing each other,
wherein the counting method further comprises dispersing the aggregated particles by applying a second first alternating current having a second frequency to the electrode set, the second frequency being higher than the first frequency,
wherein the applying the second alternating current having the second frequency to the electrode set suppresses the overlap of the aggregated particles by dispersing aggregated particles to one of first concave portion of the first electrode or the second concave portion of the second electrode by action of a second-direction dielectrophoretic force exerted by a second electric field gradient generated by the application of the second alternating current having the second frequency to the electrode set, the second-direction dielectrophoretic force being different from the first-direction dielectrophoretic force, and
wherein the counting method further comprises:
capturing a dispersion image including the particles after being dispersed to one of first concave portion of the first electrode or the second concave portion of the second electrode by action of the second-direction dielectrophoretic force; and
determining a number of the particles on a basis of the dispersion image.