Method and apparatus for particle image analysis using flow cell

• US 6,317,511 B1
• Filed: 02/20/1997
• Issued: 11/13/2001
• Est. Priority Date: 02/22/1996
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Horiuchi, Hideyuki
• Primary Examiner(s): Johns, Andrew W.
• Application Number:
  US08/803,230
• Time in Patent Office: 1,727 Days
• Field of Search: 382/133, 382/134, 382/286, 702/21, 702/128, 356/23, 356/39, 356/335, 250/461.2
• US Class Current: 382/133
• CPC Class Codes: G01N 15/1433 using image recognition
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream

Abstract

A sample is flowed through a flow cell, the passage of particles is detected by a laser light beam, a flash lamp is turned on in response to the detection, still images of the particles are picked up by a TV camera, and the images are image-processed. A particle detection unit adjusting unit calculates the anticipated number of image-processed particles from the total number of detected particles, compares it with the number of actually image-processed particles, and changes a particle detection condition such that the calculated value is equal to the actual measurement value. In actual sample measurement, an operation condition of the apparatus can be determined and measurement result can be corrected using those parameters.

Claims

1. A particle image analysis method for picking up still images of particles as the particles flowing in a flow cell are detected and analyzing the picked-up still images of the particles, comprising the steps of:

a) flowing fluid having particles suspended therein to the flow cell;

b) counting the number of still images of particles having larger sizes than a predetermined size, of the still images of particles obtained for the fluid;

c) counting the number of particles having larger detection signals than a predetermined level, of the particles detected for the fluid;

d) calculating the anticipated number of particles to be image-processed based on the counted number of particles; and

e) comparing the counted number of still images and the calculated number of particles.

2. A particle image analysis method according to claim 1 wherein the predetermined level of the detection signal is a width of the detection signal and/or a level of the detection signal.

3. A particle image analysis method according to claim 2 further comprising the step of:

changing at least one of the particle size, the width of the detection signal and the level of the detection signal as limiting conditions such that the counted number of still images and the calculated number of particles substantially match.

4. A particle image analysis method according to claim 3 further comprising the step of:

flowing the fluid sample to be measured to the flow cell after the substantial match of the counted number of still images and the calculated number of particles.

5. A particle image analysis method according to claim 1 further comprising the step of:

turning on a flash lamp in response to the detection of particles flowing in the flow cell and counting the number of times of turn-on of the flash lamp during the measurement time of the fluid.

6. A particle image analysis method according to claim 5 further comprising the steps of:

calculating the anticipated number of times of turn-on of the flash lamp based on the counted number of particles; and

comparing the calculated anticipated number of times of turn-on with the counted number of times of turn-on.

7. A particle image analysis apparatus for executing the method according to claim 1.

12. A particle image analysis apparatus for executing the method according to claim 2.

13. A particle image analysis apparatus for executing the method according to claim 3.

14. A particle image analysis apparatus for executing the method according to claim 4.

15. A particle image analysis apparatus for executing the method according to claim 5.

16. A particle image analysis apparatus for executing the method according to claim 6.

8. A particle image analysis apparatus having particle detection means for detecting particles in a sample flowing in a flow cell, a light source for emitting a pulsive light in response to the detection of the particle, means for picking up still images of the particles in response to light emission and means for analyzing the picked-up still images of particles;

comprising;

detection condition adjusting unit for receiving a particle detection signal from said particle detection means,

characterized in that said detection condition adjusting unit including;

a) size setting means for setting a lower limit of a size of particle to be image-processed;

b) count means for counting the number of still images of particles having larger sizes than the setting set by said size setting means;

c) detection signal setting means for setting a magnitude of a signal to be limited, of the output signal from said particle detection means;

d) signal count means for counting the number of signals larger than the setting set by said detection signal setting means;

e) calculation means for calculating the anticipated number of particles to be image-processed based on information from said signal count means; and

f) compare means for comparing the counted number of still images with the calculated number of particles.

9. A particle image analysis apparatus according to claim 8 wherein said size setting means or said detection signal setting means changes the setting such that the counted number of still images and the calculated number of particles substantially match.

10. A particle image analysis apparatus according to claim 8 wherein said detection signal setting means includes means for setting a level of the output signal and means for setting a width of the output signal.

11. A particle image analysis apparatus according to claim 8 further comprising:

count means for counting the number of times of turn-on of said light source during the measurement time of the fluid having particles suspended therein.