PARTICLE ANALYSIS METHOD AND APPARATUS WHEREIN LIQUID CONTAINING PARTICLES IS SUCKED INTO A CONSTRICTED FLOW PATH

• US 3,810,010 A
• Filed: 11/27/1972
• Issued: 05/07/1974
• Est. Priority Date: 11/02/1968
• Status: Expired due to Term

• Current Assignee: Reinhard Thom
• Original Assignee: Reinhard Thom
• Inventors: Thom, Reinhard
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US05/309,662
• Time in Patent Office: 526 Days
• Field of Search: 324/71R,71CP 73/432PS
• US Class Current: 324/71.1
• CPC Class Codes: G01N 15/134 Devices using two or more apertures

Abstract

An apparatus for determining the relative quantities of different sized particles contained in a liquid, for example the relative number of red and white blood corpuscles, by measuring the electrical changes which occur as said particles pass through a capillary passage, is improved by providing a second capillary passage which directs the fluid medium containing the particles to be tested into the center of the first capillary passage.

Claims

1. In an arrangement for deriving values corresponding to the quantities of different size particles contained in a liquid to be tested, which arrangement comprises, in combination:

a. a first vessel for holding liquid, b. a second vessel for holding liquid, c. means including a first capillary tube connected to each of said vessels for causing a flow of liquids from the first vessel to the second vessel, d. electrode means in each vessel, e. means for applying a voltage across said electrodes so that ion movement caused by the voltage across the electrodes occurs through said first capillary tube, and f. current measuring means for detecting temporary changes in the current between the electrodes with respect to its amplitude and for indicating the number of current changes separately according to amplitudes, the improvement which comprises;

g. a second capillary tube for supplying a liquid having the different size particles to be tested suspended therein, said second capillary tube having an opening positioned co-axially with said first capillary tube, the distance between the outlet opening of said second capillary tube and the inlet of said first capillary tube being such that flow of liquids from the first vessel to the second vessel sucks liquid out of said second capillary tube and injects it directly into said first capillary tube, whereby values corresponding to quantities of different size particles contained in the liquid sucked from said second capillary tube may be determined.

2. The improvement defined in claim 1, wherein the opening of said first capillary tube into which the said liquid stream from the second capillary tube enters has rounded edges.

3. The improvement of claim 1, wherein said first capillary tube has a funnel shape starting at the inlet opening and extending over at least a portion of its axial length.

4. The improvement defined in claim 3, wherein said funnel walls are of substantially paraboloidal shape.

5. The improvement defined in claim 1, wherein the opening of said second capillary tube is approximately two-thirds the size of the opening of said first capillary tube.

6. The improvement defined in claim 1, wherein said second capillary passage narrows in the direction towards its outlet opening in the form of a funnel.

7. The improvement defined in claim 1, wherein the inner surface of said second capillary passage is provided with a coating which reduces the surface tension between said passage and said liquid.

8. The improvement defined in claim 7, wherein said coating is silicone.

9. The improvement defined in claim 1, wherein said first capillary tube is formed in a partition separating said first and second vessels and has a funnel shaped portion of substantially paraboloidal shape extending from said first vessel through a portion of its axial length to a minimum diameter portion having rounded edges leading to said second vessel, and wherein the interior of said second capillary tube has a silicone coating and narrows in the direction towards its outlet opening in the form of a funnel.

10. In an arrangement for studying the physical properties of particles suspended in a fluid medium of different conductivity than the particles, which arrangement comprises:

a. means for holding a quantity of the fluid medium, b. Means defining a constricted flow path for the fluid with the particles suspended therein, c. means for producing an electrical field and an electrical current along said constricted flow path and d. means for detecting changes in said electrical current caused by passage of suspended particles through said constricted flow path, the improvement comprising means for sucking a quantity of the fluid medium containing the particles to be tested into that area of said constricted flow path, in which area said electrical field is approximately homogeneous.

11. In an arrangement for studying the physical properties of particles suspended in a fluid medium of different conductivity than the particles, which arrangement comprises:

a. means for holding a quantity of the fluid medium, b. means defining a constricted flow path for the fluid with the particles suspended therein, c. means for producing an electrical current along said constricted flow path and d. means for detecting changes in said electrical current caused by passage of suspended particles through said constricted flow path, the improvement comprising means for sucking a quantity of the fluid medium containing the particles to be tested into the center of said constricted flow path.

12. In an arrangement for deriving values corresponding to the quantities of different size particles contained in a liquid to be tested, which arrangement comprises, in combination:

a. a first vessel for holding liquid, b. a second vessel for holding liquid, c. means including a first capillary tube connected to each of said vessels for causing a flow of liquids from the first vessel to the second vessel, d. electrode means in each vessel, e. means for applying a voltage across said electrodes so that an electric field caused by the voltage across the electrodes makes ions move through said first capillary tube, and f. current measuring means for detecting temporary changes in the current between the electrode with respect to its amplitude and for indicating the number of current changes separately according to amplitudes, the improvement which comprises;

g. a second capillary tube for supplying a liquid having the different size particles to be tested suspended therein, said second capillary tube having an opening positioned co-axially with said first capillary tube, the distance between the outlet opening of said second capillary tube and the inlet of said first capillary tube being such that flow of liquids from the first vessel to the second vessel sucks liquid out of said second capillary tube and injects it directly into said first tube as a stream flowing through that area of said first tube, in which area said electric field is approximately homogeneous.

13. The method of using an arrangement for deriving values corresponding to the quantities of different size particles contained in a liquid to be tested, which arrangement comprises, in combination:

a. a first vessel for holding liquid, b. a second vessel for holding liquid, c. means including a first capillary tube connected to each of said vessels for causing a flow of liquids from the first vessel to the second vessel, d. electrode means in each vessel, e. means for applying a voltage across said electrodes so that ion movement caused by the voltage across the electrodes occurs through said first capillary tube, f. current measuring means for detecting temporary changes in the current between the electrodes with respect to its amplitude and for indicating the number of current changes separately according to amplitudes, and g. a second capillary tube for supplying a liquid having the different size particles to be tested suspended therein, said second capillary tube having an opening positioned co-axially with said first capillary tube, The distance between the outlet opening of said second capillary tube and the inlet of said first capillary tube being such that the flow of liquids from the first vessel to the second vessel sucks liquid out of said second capillary tube and injects it directly into said first capillary tube, whereby values corresponding to quantities of different size particles contained in the liquid sucked from said second capillary tube may be determined, which method comprises the steps of placing electrolyte in said second vessel, placing particle-free electrolyte in said first vessel, placing particle-containing liquid in said second capillary tube, and sucking particle-containing liquid out of said second capillary tube and injecting it directly into said first capillary tube by flowing said particle-free electrolyte from said first vessel through said first capillary tube itnto said second vessel.

14. An arrangement as claimed in claim 1, wherein said outlet opening has a diameter of 50 microns, said inlet has a smallest diameter of 70 microns, and said distance is 50 microns.

15. An arrangement as claimed in claim 1, wherein said distance, the diameter of said outlet opening, and the smallest diameter of said inlet are all of the same order of magnitude.

16. The method of using an arrangement as claimed in claim 13, wherein said outlet opening has a diameter of 50 microns, said inlet has a smallest diameter of 70 microns, and said distance is 50 microns.

17. The method of using an arrangement as claimed in claim 13, wherein said distance, the diameter of said outlet opening, and the smallest diameter of said inlet are all of the same order of magnitude.