System and method for immune activity determination

1. A method for determining a trajectory parameter associated with blood cells of a subject, comprising:

receiving a plurality of blood cells of the subject at a microfluidic channel;

aligning and focusing the plurality of blood cells at an inertial focusing region of the microfluidic channel;

for each cell of the plurality of blood cells:

applying a stress to the cell at a deformation region of the microfluidic channel, wherein the deformation region is downstream of the focusing region;

with an image acquisition system, acquiring an optical dataset of the cell as the cell passes through the deformation region; and

measuring a trajectory of the cell passing through the deformation region, wherein the trajectory comprises a series of discrete positions of the cell as the cell passes through the deformation region, wherein the trajectory comprises an oscillation of a centroid of the cell; and

determining one or more trajectory parameters associated with the subject, wherein the trajectory parameters comprise at least one of a difference, sum, amplitude, maximum, and average value of one or more positions of the trajectory.

2. The method of claim 1 , wherein the oscillation is in a position orthogonal to the flow direction and the trajectory parameter comprises an average amplitude of the oscillation.

3. The method of claim 2 , wherein the trajectory parameter is determined based on a ternary, quaternary, and quintenary cycle of the oscillation.

4. The method of claim 2 , wherein the trajectory parameter is determined without using the first oscillation cycle.

5. The method of claim 1 , wherein the trajectory parameter is associated with an immune activation state of the subject.

6. The method of claim 1 , wherein the optical dataset comprises at least ten images of the cell within the deformation region.

7. The method of claim 1 , wherein a fluid flow through the microfluidic device is at a Reynolds number of at least 100.

8. The method of claim 1 , wherein the deformation region comprises an extensional flow region.

9. A method for diagnosing immune activation state of a patient, comprising:

receiving a plurality of blood cells of the patient at a microfluidic channel of a flow guide;

for each cell of the plurality of blood cells:

applying a stress to the cell at a deformation region of the flow guide, wherein the stress is configured to deform the cell;

with an image acquisition system, acquiring an optical dataset of the cell comprising a plurality of images of the cell before, during, and after the stress is applied to the cell;

determining a structural parameter associated with the cell, wherein the structural parameter is determined using the plurality of images; and

determining a trajectory parameter associated with a trajectory of the cell during and after the stress is applied to the cell, wherein the trajectory parameter comprises an oscillation of a centroid of the cell, wherein the trajectory parameter is determined based on the plurality of images;

based on a model correlating the trajectory parameters and the structural parameters to an immune state, determining an index associated with the patient; and

diagnosing the immune activation state of the user based on the index.

10. The method of claim 9 , wherein for each cell wherein the trajectory parameter comprises an amplitude of the oscillation.

11. The method of claim 10 , wherein for each cell, the trajectory parameter is determined based on an amplitude of a ternary, quaternary, and quintenary cycle of the oscillation.

12. The method of claim 9 , further comprising determining a leukocyte count of the plurality of blood cells, wherein the index is further determined based on the leukocyte count.

13. The method of claim 9 , wherein receiving the plurality of blood cells comprises receiving at least 100 cells per second at the flow guide.

14. The method of claim 9 , wherein determining the trajectory parameter comprises:

detecting an object within each image of the plurality of images;

segmenting each image of the plurality of images into a foreground and a background; and

extracting a feature from the foreground, wherein the feature is associated with at least one of a cell shape and the trajectory.

15. The method of claim 14 , wherein segmenting each image comprises segmenting each image using a convolutional neural network.

16. The method of claim 9 , further comprising lysing red blood cells of the plurality of blood cells using a formic acid lysis system.

17. The method of claim 9 , wherein the diagnosis is determined within 10 minutes of receiving the plurality of blood cells at the flow guide.

18. The method of claim 9 , wherein the immune activation state comprises a sepsis-related condition.

19. The method of claim 9 , wherein the model is a linear logistic regression.

20. The method of claim 19 , further comprising determining a set of parameters of the linear logistic regression using a training dataset corresponding to a patient set comprising a high sepsis incidence.