Particle parameter determination system

1. A particle analysis system comprising:

a channel;

a hydrodynamic focusing module connected to the channel;

a projection system proximate to the channel;

a screen having a slit aperture proximate to the channel; and

a dual sensor detector proximate to the slit aperture; and

wherein the slit aperture comprises a first slit and a second slit; and

signals from the first slit and the second slit provide information about speeds of the particles;

wherein a width of the signal provides information about a diameter of the particle; an amplitude of the signal provides information for discriminating different kinds of particles; and/or the amplitude of the signal provides counts of the particles; the width of the signal provides information for discriminating different kinds of particles; the width of the signal provides counts of the particles; a combination of width and amplitude of the signal provides information for discriminating different kinds of particles; and the combination of width and amplitude of the signal provides counts of particles.

2. The system of claim 1 , wherein the channel and the hydrodynamic focusing module are situated in a cartridge.

3. The system of claim 1 , wherein:

the channel is for conveying particles;

the projection mechanism is for displaying an image of the particles in the channel on the screen; and

the detector is for detecting a portion of the image through the slit aperture; and

wherein the detector, upon detecting an image of a particle through the slit aperture, outputs a signal.

4. The system of claim 3 , wherein the particles are blood cells.

5. The system of claim 1 , wherein:

the particles are red blood cells and platelets;

the counts comprise a count of red blood cells and a count of platelets;

diameters of the red blood cells of the count of the red blood cells are approximately determined;

a mean cell volume of the count of the red blood cells is approximately determined;

a red cell distribution width of the count of red blood cells is approximately determined; and/or

a hematocrit is approximately determined from a product of the count of the red blood cells and the red cell distribution width.

6. The system of claim 1 , further comprising;

a hemoglobin module for approximately determining an amount of hemoglobin in a blood sample; and

wherein:

a mean cell hemoglobin is approximately determined by the amount of hemoglobin divided by the count of the red blood cells; and/or

a mean cell hemoglobin concentration is approximately determined by the count of the red blood cells divided by the hematocrit.

7. A method for determining particle parameters comprising:

measuring a flow rate with a flow rate sensor;

hydrodynamically focusing particles of a fluid sample into a single file through a flow channel;

projecting a light through the flow channel;

focusing an image of the particles in the flow channel onto a multiple slit aperture;

detecting obscurations of light from the aperture;

converting the obscurations of light into waveforms representative of the obscurations of light; and

processing the waveforms into data about the particles;

calculating a particle diameter from a product of the calibration factor and the pulse width in distance, and minus the slit width from the product.

8. The method of claim 7 , wherein the data from the detecting comprises:

flow rate;

measurement time;

count of particles;

pulse width in time;

pulse amplitude; and/or

particle transit time.

9. The method of claim 8 , further comprising doing an analysis of the particles to attain a number of first type particles and a number of second type particles in the fluid sample by means of one or more of the following operations:

a histogram of measured particle pulsewidths; or

a histogram of measured particle amplitudes; or

a combined scatter plot of measured particle pulsewidths versus measured particle amplitudes.

10. The method of claim 9 , wherein:

the fluid sample is a blood sample;

the first type particle is a red blood cell; and

the second type particle is a platelet.

11. The method of claim 8 , further comprising:

calculating a first type particle count per volume from a number of first type particles counted divided by a product of a dilution factor, a flow rate and a measurement time; and

calculating a second type particle count per volume from a number of second type particles counted divided by a product of the dilution factor, the flow rate and the measurement time.

12. The method of claim 7 , further comprising:

measuring slit pitch of the multiple slit aperture; and/or

measuring slit width.

13. The method of claim 12 , further comprising:

calculating a flow velocity of the particles from slit pitch divided by particle transit time; and/or

calculating a pulse width in distance from a product of flow velocity and pulse width in time.

14. The method of claim 13 , further comprising determining a calibration factor.

15. The method of claim 7 , further comprising:

obtaining a particle flow rate; and

determining a dilution factor of the fluid sample.

16. The method of claim 7 , further comprising:

calculating a mean particle volume (MCV) from a product of a cube of an average first type particle diameter and π/6; and

calculating a first type particle distribution width (RDW) from a product of standard deviation and a first type particle diameter and π/6, divided by the MCV.

17. The method of claim 16 , further comprising calculating a hematocrit (Hct) from a product of a first type particle count per volume and an MCV.

18. The method of claim 17 , further comprising:

measuring an amount of hemoglobin per unit volume (Hb) of the fluid sample;

calculating a mean cell hemoglobin concentration (MCHC) from the Hb divided by the Hct; and

calculating a mean cell hemoglobin (MCH) as a product of the MCHC and the MCV.