Particle analyzer

Claim 2

A particle analyzer according to claim 1, further comprising a second light source (36) for producing a second light beam, and second imaging means (38) for capturing two-dimensional still images of particles in the liquid specimen flow, wherein: a one-dimensional imaging region (56) of the one dimensional image sensor (22) is located in a two-dimensional imaging region (54) of the second imaging means (38); and the signal processing means (25) is arranged to detect the presence of a particle on the basis of the image signals from the one-dimensional image sensor (22) and then to operate the second light source (36) to capture a two-dimensional still image of that particle.

Claim 3

A particle analyzer according to claim 1 or 2, wherein the signal processing means (24, 25) is arranged to determine whether the image signals from the one-dimensional image sensor (22) indicate the presence of a plurality of particles and, in response to a positive determination, to instruct that data concerning scattered light and/or fluorescent light from the particles is ignored.

Claim 4

A particle analyzer according to any one of claims 1 to 3, wherein the signal processing means (24, 25) is arranged to determine particle morphological information and/or absorption information on the basis of the image signals from the one-dimensional image sensor (22).

Claim 5

A particle analyzer according to claim 4, wherein the morphological information is one or more of the cell area, cell circumferential length, nucleus area, cell width, cell complexity, cell roundness, and nucleus area fraction.

Claim 6

A particle analyzer according to claim 4 or 5, wherein the absorption information is one or more of the absorption quantity and the degree of absorption.

Claim 7

A particle analyzer comprising: a light source (210) for directing a light beam at particles in a liquid specimen (217) forming part of a sheath flow; a one-dimensional image sensor (222) which is positionable to extend transversely of the particle flow direction for having focused thereon particle image(s) produced by the light beam and is arranged to produce for every scan cycle an image signal corresponding to the particle image(s) focused on the image sensor ( 222 ); and signal processing means (224) for determining characteristics of individual particles by processing the image signals, and analyzing the particles on the basis of the determined characteristics; wherein the signal processing means comprises: background correction processing means (242) for processing each image signal (Sb(i)) to obtain a corrected signal (Sc(i)) by calculating the difference between the image signal (Sb(i)) and a background signal (Sa) obtained in the absence of any particles in an imaging region (234) of the image sensor (222); binarizing processing means (244) for processing each corrected signal (Sc(i)) to obtain a binary signal (Sd(i)) indicating a particular portion of a particle, the binary signal (Sd(i)) being produced by comparing the corrected signal (Sc(i)) with specified threshold data (Th); binary signal processing means (246) for performing logical operation(s) on the binary signal (Sd(i)); and arithmetical processing means (245, 248, 250, 252, 254, 256) for calculating the characteristics of particles from the signals produced by one or more of the previous three means (242, 244, 246).

Claim 8

A particle analyzer according to claim 7, wherein the arithmetical processing means comprises: first processing means (248, 250) for, in respect of each scan cycle, obtaining an AND signal (S3(i)) by performing a logical AND operation on the binary signal (S2(i)) of the scan cycle (i) and the binary signal (S2(i-1) of the preceding scan cycle (i-1); and means (256) for multiplying the sum of the widths of the AND signals corresponding to one particle by the distance (L) moved by the particle in one scan period, thereby to obtain the area of the particle.

Claim 9

A particle analyzer according to claim 7 or 8, wherein the arithmetical processing means comprises: second processing means (248, 250) for, in respect of each scan cycle, obtaining an EXOR signal (S6(i)) by performing an exclusive-or operation on the binary signal (S2(i)) of the scan cycle (i) and the binary signal (S2(i-1)) of the preceding scan cycle (i-1); and means (256) for, in respect of each particle, calculating the width of each EXOR signal, calculating the square root of the sum of the square of each EXOR signal width and the square of the distance (L) moved by the particle in one scan period, and calculating the cumulative sum of the square roots, thereby to obtain the circumferential length of the particle.

Claim 10

A particle analyzer according to any one of claims 7 to 9, wherein the arithmetical processing means comprises: second processing means (248, 250) for, in respect of each scan cycle, obtaining an EXOR signal (S6(i)) by performing an exclusive-or operation on the binary signal (S2(i)) of the scan cycle (i) and the binary signal (S2(i-1)) of the preceding scan cycle (i-1); and means (256) for dividing by 2 the sum of the widths of the EXOR signals corresponding to one particle, thereby to obtain the width of the particle in the direction perpendicular to the direction of movement of the particle.

Claim 11

A particle analyzer according to any one of claims 7 to 10, wherein the arithmetical processing means comprises: means (252) for obtaining the cumulative sum of the corrected signals (S1(i)) corresponding to one particle, thereby to obtain the absorption quantity of the particle.

Claim 12

A particle analyzer according to any one of claims 7 to 11, wherein the arithmetical processing means comprises: third processing means (248, 250) for, in respect of each scan cycle, obtaining an AND signal (S3(i)) by performing a logical AND operation on the binary signal (S2(i)) of the scan cycle (i) and the binary signal (S2(i-1)) of the preceding scan cycle (i-1), and obtaining an ANEX signal (S7(i)) by performing an exclusive-or operation on the AND signal (S3(i)) of the scan cycle (i) and the AND signal (S3(i-1)) of the preceding scan cycle (i-1); and means (256) for, in respect of each particle, calculating the width of each ANEX signal, calculating the square root of the sum of the square of each ANEX signal width and the square of the distance (L) moved by the particle in one scan period, and calculating the cumulative sum the square roots, thereby to obtain the circumferential length of the particle.

Claim 13

A particle analyzer according to any one of claims 7 to 12, wherein the arithmetical processing means comprises: third processing means (248, 250) for, in respect of each scan cycle, obtaining an AND signal (S3(i)) by performing a logical AND operation on the binary signal (S2(i)) of the scan cycle (i) and the binary signal (S2(i-1)) of the preceding scan cycle (i-1), and obtaining an ANEX signal (S7(i)) by performing an exclusive-or operation on the AND signal (S3(i)) of the scan cycle (i) and the AND signal (S3(i-1)) of the preceding scan cycle (i-1); and means (256) for dividing by 2 the sum of the widths of the ANEX signals corresponding to one particle, thereby to obtain the width of the particle in the direction perpendicular to the direction of movement of the particle.

Claim 14

A particle analyzer according to claim 8, further comprising a second such signal processing means (224) using different specified threshold data (Th2) in order to determine characteristics of the nuclei of particles instead of the characteristics of the entire particles, the second signal processing means (224) including means for dividing the nucleus area of a particular particle by the particle area of that particle thereby to obtain the nucleus area fraction.

Claim 15

A particle analyzer according to claim 14, wherein the second signal processing means (224) includes means (252) for obtaining the cumulative sum of the corrected signals (S1(i)) corresponding to the nucleus of one particle, thereby to obtain the absorption quantity of that nucleus.

Claim 16

A particle analyzer according to claim 8, wherein the arithmetical processing means further comprises: differentiating means (245) for obtaining the difference between successive corrected signals (S1(i)); and means (254) for calculating the sum of the differences corresponding to one particle, or the sum of the square of the differences, and dividing the sum by the area of the particle, thereby to obtain the complexity per unit area.

Claim 17

A particle analyzer according to claim 9 or 12, wherein the arithmetical processing means further comprises means for squaring the circumferential length and dividing by the area, thereby to obtain the roundness of the particle.

Claim 18

A particle analyzer according to any one of claims 7 to 17, wherein each signal processing means (224) comprises a plurality of arithmetical processing means so that characteristics may be calculated simultaneously if a plurality of particles simultaneously cross the imaging region (234) of the one-dimensional image sensor (222).