HP Innovation Journal Issue 10: Fall 2018 | Page 70

Figure 2
Major components of the HP Labs solution.
RECONSTRUCT
CELL
STRUCTURES
ROTATE
CELLS
Current technologies are expensive and require
extensive training to manipulate. However,
through cell spinning and different visualization
techniques, we can enable biologists to
quickly and easily examine cellular processes.
Additionally, having the ability to spin live
cells and create 3D models of them further
improves understanding of critical cellular
events, including essential processes like cell
division and transient occurrences like endo-
and exocytosis. Furthermore, organelles and
proteins can be fluorescently tagged in a live
cell for visualization of distinct events like
mitochondrial division, nuclear fragmentation,
or trafficking of protein through the
endoplasmic reticulum Golgi, to name a few.
At HP Labs, we have introduced a solution
that rotates cells in a microfluidic chip, then
reconstructs 3D cell structures from the video
sequence of cell spinning, and finally brings
the digital model to physical reality through
3D printing (Figure 2).
Figure 3 (a)
Cell modeling results.
Original video frame.
Innovation Journal Issue Ten
Figure 3 (b)
Reconstructed
3D cell model.
3D PRINT
MODEL
MODELING 3D CELL STRUCTURES
The hardware system consists of an electrode
structure that produces a nonuniform electric
field, which in turn applies a torque to a
cell and rotates it. The spinning cell is then
observed with an optical microscope in
transmission, reflectance, fluorescence, or
other modes, and an attached video camera
records the rotating cells.
As the cells rotate, we can observe them
through multiple viewing angles. Having 2D
object images from multiple observation
angles leads to a 3D reconstruction problem
based on Multi-View Geometry (MVG).
Most existing MVG-based methods only
reconstruct object surfaces. A surface mesh
is then created as a result of obtaining
and interpolating a dense point cloud. The
biological structures we are interested in,
such as cells, are normally transparent. We
can see through the surface and observe
structures within the cell membrane, which
tells more about the cell. As a result, if
Figure 4
Samples of 3D-printed cell
models among assorted designs.