Microfluidic device for counting biological particles

Abstract

A particle counter for analyzing blood has features which provide for automatic operation and preferably, also provide for portable use in a low resource setting. In a preferred embodiment, preferred embodiment, the device is used to obtain CD4 counts for AIDS diagnosis.

1 - 12 . (canceled) 
     
     
         13 . A portable blood component analysis device, comprising:
 a microfluidic unit with a sample chamber;   the sample chamber having a surface augmentation features with biospecific surface configured to capture particles from blood; and   an analyzer component having a signal detector and a receiving slot configured to receive the microfluidic unit and align the sample chamber with the signal detector.   
     
     
         14 . The device of  claim 13 , wherein the surface augmentation features include a packed bead bed with glass beads. 
     
     
         15 . The device of  claim 13 , wherein the surface augmentation features include a packed bead bed with glass beads with a diameter between 50 and 100 μm and the first longitudinal channel contains a narrow portion with a minimum dimension of less than the diameter of the glass beads. 
     
     
         16 . The device of  claim 13 , further comprising a pump, a controller and a solar power source connected to power the pump and controller. 
     
     
         17 . The device of  claim 13 , wherein the microfluidic unit includes a tube containing at least one wash, and at least one air bubble, the tube being reversibly sealed at both ends and configured to connect with the second longitudinal channel. 
     
     
         18 . The device of  claim 13 , further comprising a pump, a controller and a solar power source connected to power the pump and controller, wherein the microfluidic unit includes a tube containing at least one wash, and at least one air bubble, the tube being reversibly sealed at both ends and configured to connect with the second longitudinal channel and wherein the controller is configured automatically to pump fluids from the tube through the sample chamber and through the second longitudinal channel. 
     
     
         19 . The device of  claim 13 , wherein the blood particles include CD4 cells. 
     
     
         20 . The device of  claim 13 , further comprising a battery. 
     
     
         21 . The device of  claim 13 , further comprising a controller and wherein the signal detector is a light intensity detector and the controller is configured to derive a cell count from a light intensity signal without imaging. 
     
     
         22 . The device of  claim 21 , wherein the controller is configured to derive the cell count from a calibration lookup table correlating cell count against total light intensity from the sample chamber. 
     
     
         23 . The device of  claim 18 , further comprising a display configured to output a cell count. 
     
     
         24 . The device of  claim 23 , further comprising a controller and wherein the signal detector is a light intensity detector and the controller is configured to derive a cell count from a light intensity signal without imaging. 
     
     
         25 . The device of  claim 24 , wherein the controller is configured to derive the cell count from a calibration lookup table correlating cell count against total light intensity from the sample chamber. 
     
     
         26 . The device of  claim 13 , further comprising a pump, a controller and a solar power source connected to power the pump and controller, wherein the microfluidic unit includes a tube containing at least one wash, and an a chemiluminescence activator, the tube being reversibly sealed at both ends and configured to connect with the second longitudinal channel and wherein the controller is configured automatically to pump fluids from the tube through the sample chamber and through the second longitudinal channel. 
     
     
         27 . The device of  claim 18 , wherein the pump is controlled to vary a pumping rate depending on a sample or reagent passing through the sample chamber. 
     
     
         28 . The device  claim 13 , wherein the analyzer includes a pump configured to generate a vacuum of at least 10 kPa.