Apparatus for orienting generally flat particles for sensing

Abstract

A flow chamber which is particularly useful in slit-scan photometry and which has a predetermined configuration for orienting generally flat oval particles such as squamous cells in the direction of fluid flow such that the maximum cross-sectional area of each particle is substantially normal to a light path traversing the flow of particles at an observing station situated along the flow path of the particles.

What it is desired to be secured by Letters Patent of the United States is: 
     
       1. A flow chamber for orienting sample particles suspended in a sample fluid for .[.observation by slit-scan photometry.]. .Iadd.sensing by interaction with light .Iaddend.said flow chamber having an entrance for receiving the sample fluid and an exit for fluid discharge, said flow chamber being configured so that the ratio of a first dimension of the flow chamber to a second dimension of the flow chamber is monotonically increasing in the direction of sample fluid flow, the first dimension being transverse to the second dimension, and the cross-sectional area of said flow chamber generally normal to the direction of fluid flow is configured to decrease gradually and monotonically in the direction of fluid flow such that fluid flow within said flow chamber is caused to accelerate gradually and monotonically and .[.observation means for transmitting a light beam through said flow chamber located.]. .Iadd.means for producing said light in said flow chamber .Iaddend.at a point prior to said exit. 
     
     
       2. Apparatus for orienting sample particles suspended in a fluid for observation by slit-scan photometry comprising: a flow chamber;   means for introducing the fluid suspension into the axial center of said flow chamber;   means for producing a flow of sheath fluid for surrounding said sample fluid and producing a planar laminar flow;   said flow chamber having walls configured in the direction of fluid flow therethrough such that said fluid suspension is caused to accelerate gradually and monotonically; said walls narrowing to form an exit for said fluid suspension located at a point approximately in the center of the fluid flow, and observation means for transmitting a light beam through the flow chamber located at a point prior to said exit.   
     
     
       3. Apparatus as claimed in claim 2 wherein said flow chamber has an entrance opposite said exit and said exit has an elongated oblong configuration. 
     
     
       4. Apparatus as claimed in claim 3 wherein said flow chamber includes a slit which locates a longitudinal plane thereof which provides a low pressure zone along said longitudinal plane. 
     
     
       5. Apparatus as claimed in claim 4 wherein said exit comprises said slit extending in a first direction across said entrance port and perpendicular to a second direction of said entrance port. 
     
     
       6. Apparatus as claimed in claim 2 wherein said walls taper exponentially in the direction of fluid suspension flow. 
     
     
       7. Apparatus as claimed in claim 2 wherein said means for introducing said fluid suspension includes a sample tube extending into said flow chamber along said axial center. 
     
     
       8. Apparatus as described in claim 7 wherein said means for producing said sheath fluid flow includes means for producing smooth, nonturbulent flow of the sheath fluid through said flow chamber, comprising a plurality of tubes extending in the direction of fluid flow such that said sheath fluid is laminar within the entrance port of said flow chamber. 
     
     
       9. Apparatus for orienting sample particles suspended in a sample fluid for .[.observation by slit-scan photometry.]. .Iadd.sensing by suitable light sensing technique, .Iaddend.comprising: a. flow cell means;   b. conduit means connected to the flow cell means for conducting a fluid flow in the flow cell means;   c. sheath liquid flow means for producing a flow of sheath fluid through the conduit means and the flow means;   d. sample flow means for introducing the sample fluid into the sheath fluid flow;   e. said flow cell means including; a flow chamber having an entrance for receiving the sample fluid and the sheath fluid, and an exit for fluid discharge, said flow chamber configured along a first height axis perpendicular to the flow of said sample fluid through said flow chamber so that said sheath fluid flow is accelerated gradually and monotonically in said flow direction; and   said flow chamber configured along a second width axis perpendicular to both the flow of sample fluid and said first axis forming a slit through said flow chamber such that there is negligible effect upon the flow of said sample fluid by said flow chamber along said second axis;   said flow chamber having walls configured in the direction of sample fluid flow through said flow chamber to narrow along said first axis and form an exit for said sample fluid;   the ratio of said flow chamber's width to height in the direction of sample fluid flow monotonically increasing and the cross-sectional area formed by said height and width decreasing gradually and monotonically in the direction of sample fluid flow; and   .Iadd.light .Iaddend.means for .[.observing.]. .Iadd.sensing .Iaddend.said sample particles in said flow chamber at a point prior to said exit.   
     
     
       10. Apparatus as claimed in claim 9 wherein the entrance of said flow chamber is of an elongated oblong configuration and substantially centered in the sheath fluid flow. 
     
     
       11. Apparatus as claimed in claim 9 including: means for producing smooth, nonturbulent flow of the sheath fluid flow through said flow cell, said means for producing including a plurality of tubes extending in the direction of fluid flow, said sample flow means including a tube extending through the center of said means for producing so that approximate laminar flow is produced as said sheath fluid enters said flow chamber   
     
     
       12. The apparatus as claimed in claim 9 in which the flow chamber configuration along said second width axis is approximately constant. 
     
     
       13. In .[.an.]. .Iadd.a particle-sensing .Iaddend.apparatus .[.for sit-scan photometry.]. wherein generally flat sample particles suspended in a sample fluid are injected through a sample flow tube into the center of a planar laminar flowing fluid .Iadd., .Iaddend.a flow chamber for orienting said particles such that the maximum cross-sectional area of .Iadd.each .Iaddend. .[.the.]. .Iadd.particle is .Iaddend..[.particles are.]. oriented in a direction transverse .Iadd.to .Iaddend. .[.a light beam used in observing.]. .Iadd.light used in sensing .Iaddend.said sample particles, said flow chamber comprising: an entrance;   an exit opposite said entrance in the configuration of a slit extending in a direction across the longitudinal plane of said flow chamber and perpendicular to the width of said entrance;   said flow chamber having walls configured in the direction of sample fluid flow through said flow chamber to narrow such that the laminar flowing fluid is caused to accelerate gradually and monotonically.   
     
     
       14. A flow chamber as described in claim 13 wherein said sample flow tube extends through the center of said entrance of said flow chamber. .Iadd. 15. A flow chamber as claimed in claim 1 in which said light is concentrated into a beam for use in slit-scan photometry..Iaddend..Iadd. 16. The flow chamber as claimed in claim 13 in combination with means to produce said light and direct same transverse of the direction of fluid flow. .Iaddend..Iadd. 17. The combination of claim 16 in which the light is in the form of a beam for use in slit-scan photometry.