Systems and methods for a multiple angle light scattering (MALS) instrument having two-dimensional detector array

• US 20070046938A1
• Filed: 06/13/2006
• Published: 03/01/2007
• Est. Priority Date: 05/02/2005
• Status: Active Grant

• Current Assignee: JMAR LLC
• Original Assignee: JMAR Research Inc. (JMAR Technologies, Inc.)
• Inventors: Hemberg, Oscar, Bloom, Scott, Spivey, Brett, Gottlieb, Joseph, Adams, John, Chan, Victor, Lyon, John, Crousore, Kristina
• Granted Patent: US 7,616,311 B2
• Time in Patent Office: Days
• US Class Current: 356/343
• CPC Class Codes: G01N 15/1433 using image recognition
• CPC Class Codes: G01N 15/1434 Optical arrangements
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 15/1463 using image analysis for extracting features of the particle
• CPC Class Codes: G01N 15/147 the analysis being performed on a sample stream
• CPC Class Codes: G01N 15/1475 using image analysis for extracting features of the particle
• CPC Class Codes: G01N 2015/0088 Biological contaminants; Fouling
• CPC Class Codes: G01N 2015/019 Biological contaminants; Fouling

Abstract

A particle detection system uses a reflective optic comprising a curved surface to detect high angle scattered light generated by a particle in a liquid medium, when a laser beam is incident on the particle. When the particles transit the laser beam, light is scattered in all directions and is described by MIE scattering theory for particles about the size of the wavelength of light and larger or Rayleigh Scattering when the particles are smaller than the wavelength of light. By using the reflective optic, the scattered light can be detected over angles that are greater than normally obtainable.

Claims

1. A system for detecting and identifying a particle in a liquid, the system comprising:

a target zone;

a light source configured to generate a light beam and direct the light beam through the target zone;

an optic configured to collect and reflect light scattered by a particle in the target zone; and

a 2-dimensional detector camera configured to detect the reflected light.

2. The system of claim 1, wherein the 2-dimensional detector camera provides a frame rate from about 1000 frames per second to 10000 frames per second.

3. The system of claim 1, wherein the 2-dimensional detector camera comprises a square array of photodiodes.

4. The system of claim 3, wherein the square array of photodiodes comprises 256 active elements arranged in a 16×

16 square grid.

5. The system of claim 4, wherein each of the 256 active elements comprises a size of approximately 1.1 mm².

6. The system of claim 5, wherein the 256 active elements comprise a layout having about 1.5 mm center-to-center spacing between elements.

7. The system of claim 3, wherein the 2-dimensional detector camera further comprises a signal conditioning and digitizing board connected to the array of photodiodes.

8. The system of claim 7, wherein the board comprises a plurality of trans-impedance amplifiers, wherein a plurality of photodiodes are connected to each trans-impedance amplifier.

9. The system of claim 8, wherein each of the pluralities of photodiodes are connected to their respective trans-impedance amplifier via a multiplexer.

10. The system of claim 1, wherein the target zone comprises a liquid medium, the particle carried in the path of the beam by the liquid medium.

11. The system of claim 10, wherein the optic comprises a reflective optic having a curved reflecting surface, the reflective optic index coupled with the liquid medium in the target zone, the reflective optic configured to collect and reflect light scattered by a particle in the liquid medium in the target zone;

12. The system of claim 11, wherein the reflective optic is a second surface curved mirror.

13. The system of claim 12, wherein the reflective optic allows light scattered through an angle of 90°

to be captured by the detector.

14. The system of claim 10, wherein the light beam is incident at an angle, and wherein the light beam is internally reflected by the interface of the liquid medium with the atmosphere, thus eliminating the need for a beam stop to deflect the light beam after it has traveled through the target zone.

15. The system of claim 1, further comprising a beam stop configured to deflect the light beam after it has passed through the target zone.

16. A system for detecting and identifying a particle in a liquid, the system comprising:

a flowcell comprising a flowing liquid media and a target zone;

a light source configured to generate a light beam and direct the light beam through the target zone;

an interface optic;

a reflective optic configured to collect and reflect light scattered by a particle carried by the liquid media through the target zone; and

a 2-dimensional detector camera configured to detect the reflected light.

17. The system of claim 16, wherein the 2-dimensional detector camera provides a frame rate from about 1000 frames per second to 10000 frames per second.

18. The system of claim 16, wherein the 2-dimensional detector camera comprises a square array of photodiodes.

19. The system of claim 16, wherein the interface optic is integral to the flowcell.

20. The system of claim 16, wherein the reflective optic is integral to the flowcell.