Apparatus and method for improved optical detection of particles in fluid

Abstract

A number of fluidic-photonic devices for allowing optical detection, systems employing such devices, and related methods of operation and fabrication of such devices are disclosed herein. In at least some embodiments, the devices can serve as flow cytometry devices and/or employ microfluidic channels. Also, in at least some embodiments, the devices are fluidic-photonic integrated circuit (FPIC) devices that employ both fluidic channels and one or more waveguides capable of receiving and/or delivering light, and that can be fabricated using polymeric materials. The fluidic-photonic devices in at least some embodiments are capable of functionality such as on-chip excitation, time-of-flight measurement, and can experience enhanced fluorescence detection sensitivity. In at least some embodiments, the devices employ detection waveguides that are joined by way of a waveguide demultiplexer. In additional embodiments, a variety of techniques can be used to process information received via the waveguides, including an iterative cross-correlation process.

What is claimed is: 
     
         1 . A device, comprising:
 a processor; and   a memory comprising processor executable code, the processor executable code when executed by the processor configures the device to:   receive at least one signal produced by at least one detection device, the signal corresponding to an interaction between scattered or fluorescent light and at least one particle suspended in a fluid within a fluidic channel, the scattered or fluorescent light having been produced upon illumination of the fluid and the at least one particle as the at least one particle flows through the fluidic channel from first position within the fluidic channel to a second position within the fluidic channel;   perform a calculation based upon the at least one signal and one or more transit times required for the at least one particle to proceed between the first and the second positions within the fluidic channel, wherein the at least one signal includes a plurality of signals, and wherein the calculation comprises determining a product of a plurality of values corresponding respectively to the plurality of time-shifted signals; and   produce information indicative of at least one characteristic of the at least one particle.   
     
     
         2 . The device of  claim 1 , wherein the plurality of time-shifted signals are shifted relative to one another by the one or more transit times. 
     
     
         3 . The device of  claim 2 , wherein the one or more transit times are obtained prior to obtaining the at least one signal. 
     
     
         4 . The device of  claim 1 , wherein the at least one particle has a diameter of approximately 1 micrometer. 
     
     
         5 . The device of  claim 1 , wherein the at least one signal comprises two or more signals that are received from two or more detection devices configured to detect the scattered or fluorescent light when the at least one particle is at two or more positions within the fluidic channel. 
     
     
         6 . A device, comprising:
 a processor; and   a memory comprising processor executable code, the processor executable code when executed by the processor configures the device to:   receive at least one signal produced by at least one detection device, the signal corresponding to an interaction between scattered or fluorescent light and at least one particle suspended in a fluid within a fluidic channel, the scattered or fluorescent light having been produced upon illumination of the fluid and the at least one particle as the at least one particle flows through the fluidic channel from first position within the fluidic channel to a second position within the fluidic channel;   perform a calculation based upon the at least one signal and one or more transit times required for the at least one particle to proceed between the first and the second positions within the fluidic channel, wherein the calculation comprises iteratively performing two or more calculations based upon the at least one signal and the one or more transit times, wherein each additional iteration of the calculation results in a respective additional piece of information.   
     
     
         7 . The device of  claim 6 , wherein the processor executable code when executed by the processor further configures the device to determine whether a threshold number of successive ones of the respective additional pieces of information have been determined to be substantially equal to zero and, if so, cease to perform the additional iterations. 
     
     
         8 . The device of  claim 6 , wherein the processor executable code when executed by the processor further configures the device to calculate a sum of the information and the additional pieces of information, and output at least one of: the information, the sum, and derivative information based upon at least one of the information and the sum. 
     
     
         9 . A device, comprising:
 a processor; and   a memory comprising processor executable code, the processor executable code when executed by the processor configures the device to:   receive at least one signal produced by at least one detection device, the signal corresponding to an interaction between scattered or fluorescent light and at least one particle suspended in a fluid within a fluidic channel, the scattered or fluorescent light having been produced upon illumination of the fluid and the at least one particle as the at least one particle flows through the fluidic channel from first position within the fluidic channel to a second position within the fluidic channel;   perform a calculation based upon the at least one signal and one or more transit times required for the at least one particle to proceed between the first and the second positions within the fluidic channel, wherein the calculation comprises computing a product between a time-varying intensity function of the at least one signal and a time shifted version of the time-varying intensity function of the at least one signal.   
     
     
         10 . The device of  claim 9 , wherein the one or more transit times are obtained prior to obtaining the at least one signal. 
     
     
         11 . The device of  claim 9 , wherein the at least one particle has a diameter of approximately 1 micrometer. 
     
     
         12 . A device, comprising:
 a processor; and   a memory comprising processor executable code, the processor executable code when executed by the processor configures the device to:   receive at least one signal produced by at least one detection device, the signal corresponding to an interaction between scattered or fluorescent light and at least one particle suspended in a fluid within a fluidic channel, the scattered or fluorescent light having been produced upon illumination of the fluid and the at least one particle as the at least one particle flows through the fluidic channel from first position within the fluidic channel to a second position within the fluidic channel;   perform a calculation based upon the at least one signal and one or more transit times required for the at least one particle to proceed between the first and the second positions within the fluidic channel, wherein the processor executable code when executed by the processor further configures the device to perform the calculation by at least:   (a) assuming a time value for each of the one or more transit times; and   (b) performing a cross-correlation computation on the at least one signal based on the assumed time value(s);   (c) upon determination that the cross-correlation computation result is not below a threshold value, assuming a new time value for at least one of the one or more transit times and performing the cross-correlation computation based on the new assumed transit time value(s); and   (d) upon determination that the cross-correlation computation result is below the threshold value, obtaining the information.   
     
     
         13 . The device of  claim 12 , wherein steps (a) through (c) are carried out iteratively for up to a maximum number of times. 
     
     
         14 . The device of  claim 12 , wherein step (d) further comprises:
 producing a count as to the number of times the cross-correlation computation result has remained below the threshold value; and   obtaining the information if the count is greater than or equal to a predetermined count, obtaining the information.   
     
     
         15 . The device of  claim 12 , wherein step (d) further comprises computing a sum of all cross-correlation results obtained in steps (c) and (d). 
     
     
         16 . The device of  claim 12 , wherein the cross-correlation computation result is representative of number of particles that are suspended within the fluid as the fluid and particles suspended therein flow through the fluidic channel. 
     
     
         17 . The device of  claim 12 , wherein the processor executable code when executed by the processor further configures the device to control or monitor an operation of the at least one detection device. 
     
     
         18 . The device of  claim 12 , wherein the threshold value is zero.