DEVICE AND METHOD FOR COUNTING ELEMENTARY PARTICLES EMITTED BY A FLUID IN A CONDUIT

• US 20080315860A1
• Filed: 12/21/2007
• Published: 12/25/2008
• Est. Priority Date: 06/19/2007
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Reymond, Jean-Marc, Mangeot, Philippe, Kerhoas-Cavata, Sophie
• Granted Patent: US 7,821,248 B2
• Time in Patent Office: Days
• US Class Current: 324/71.4
• CPC Class Codes: A61B 2503/40 Animals
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150229 Pumps for assisting the blood sampling
• CPC Class Codes: A61B 5/15087 short range, e.g. between console and disposable using implanted devices A61B5/150877
• CPC Class Codes: A61B 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/508 for non-human patients

Abstract

The invention relates to a device and a method for counting elementary particles emitted by a fluid, the device comprising a line for transferring the fluid and, outside the line, detection means (6a) for detecting the particles that are attenuated by a wall of the line and/or by this fluid.

A counting device according to the invention includes at least one counting portion (4a) of oblong cross section which joins together two adjacent portions of the line having a larger flow section and which has an [internal height (h)/internal width (l)] ratio of 20% or less, in which the internal height and the internal width represent the smallest and largest transverse dimensions respectively of the portion, these being measured along two approximately perpendicular directions, said detection means extending transversely to this portion, facing its entire internal width and on either side thereof.

Claims

1. A particle counting device for counting of elementary particles emitted by a fluid, the device comprising a line for transferring this fluid and, placed outside said line, detection means for detecting these particles, said particles being attenuated by a wall of said line and/or by this fluid, which device includes at least one counting portion of oblong cross section which joins together two adjacent portions of this line having a larger flow section and which has an internal height (h)/internal width (l) ratio of 20% or less, in which the internal height and the internal width represent the smallest and largest transverse dimensions respectively of this portion, these being measured along two approximately perpendicular directions, said detection means extending transversely to this portion, facing its entire internal width and on either side thereof.

2. The particle counting device as claimed in claim 1, wherein said fluid is a liquid and wherein said counting portion has an internal height (h)/internal width (l) ratio of between 5% and 10%.

3. The particle counting device as claimed in claim 1, wherein the ratio of the flow section of the counting portion to that of each adjacent portion is equal to or less than 35%.

4. The particle counting device as claimed in claim 3, wherein said internal height (h) of the counting portion is less than 20% of the internal diameter of each of the adjacent cylindrical portions and wherein said internal width (l) of this portion is greater than 1.3 times this internal diameter.

5. The particle counting device as claimed in claim 1, wherein this counting portion has an approximately rectangular cross section, the long sides and/or the short sides of which are curved with mutually symmetrical curvatures, so that this portion has at least partly a substantially convex or concave external face.

6. The particle counting device as claimed in claim 2, wherein said line is designed for the flow of liquid microsamples, said internal height (h) of the counting portion being between 100 m and 250 m and said internal width of this portion being greater than 1.3 mm, whereas the or each adjacent cylindrical portion has a diameter of between 0.8 mm and 1.2 mm.

7. The particle counting device as claimed in claim 6, wherein the area of the flow section of said counting portion is between 0.15 mm² and 0.25 mm² and wherein this portion has a length of between 30 mm and 40 mm so as to be able to contain a microsample of about 8 μ

l facing said detection means.

8. The particle counting device as claimed in claim 1, wherein said counting portion has a wall thickness e, expressed in μ

m, and a density d, expressed in g/cm³, the product e×

d of which is less than 100, in such a way that the attenuation by this portion of particles to be counted is minimized when these particles are electrons or positrons coming from beta-radioactive radiation emitted by said fluid.

9. The particle counting device as claimed in claim 8, wherein this product e×

d is less than 50.

10. The particle counting device as claimed in claim 8, wherein said counting portion is based on a thermoformed polymer with a density of 1.5 g/cm³ or less, and wherein this portion has a wall thickness of less than 50 m.

11. The particle counting device as claimed in claim 1, wherein said detection means comprise two sets of detectors placed respectively against or in the immediate vicinity of two approximately plane large faces of said counting portion, which faces are separated from each other by said height (h) and are joined together by two small faces of this portion, these sets of detectors overhanging said small faces in the direction of said width (l).

12. The particle counting device as claimed in claim 11, which is placed upstream of a computer-controlled peristaltic pump for sucking up, in bursts, a specified amount of samples to be taken, said large faces of said counting portion each having a slightly convex shape on their external side.

13. device as claimed claim 1, wherein a material that is substantially transparent at the wavelength of the particles emitted by said fluid is chosen for the wall of said counting portion.

14. The particle counting method as claimed in claim 13, characterized in that the particles are photons emitted by fluorescence.

15. The particle counting method as claimed in claim 13, wherein the particles are electrons or positrons emitted by beta-radioactivity, said wall having a thickness e, expressed in μ

m, and a density d, expressed in g/cm³, such that the product e×

d is less than 100 so as to minimize the attenuation of these particles for the purpose of counting them.

16. The particle counting method as claimed in claim 15, wherein said counting portion is based on a thermoformed polymer with a density of 1.5 g/cm³ or less, and wherein this portion has a wall thickness of less than 50 μ

m and preferably less than 30 μ

m.

17. The particle counting method as claimed in claim 15, wherein said fluid consists of blood microsamples that flow in said line, and in the plasma of which microsamples a short-lived beta-radiotracer is diluted.

18. The particle counting method as claimed in claim 17, wherein said microsamples have been taken in succession from a mammal, such as a rat or a mouse, and each has a volume of less than 100 μ

l, the entire volume of each microsample being substantially located within said counting portion facing said detection means, so that these microsamples follow one another in this portion as discrete packets both in space and in time.