Holographic microscope slide in a spatio-temporal imaging modality for reliable 3D cell counting

Area of Science:

• Microfluidics
• Holographic Microscopy
• Digital Holography

Background:

• Miniaturization and simplification are key trends in imaging flow cytometry.
• Lab-on-a-Chip (LoC) microfluidic devices offer innovative and cost-effective solutions.
• Existing systems often face limitations in field-of-view and depth of focus.

Purpose of the Study:

• To present a novel microfluidic platform integrating holographic microscope slides (HMS) and space-time digital holography (STDH).
• To utilize a 1D linear sensor array (LSA) for simplified and cost-effective cell counting.
• To enhance diagnostic capabilities by enabling reliable cell quantification with reduced optical components.

Main Methods:

• Integration of microfluidics, computational methods, and holography.
• Application of STDH utilizing sample motion within a microfluidic channel.
• Employment of a 1D linear sensor array (LSA) instead of traditional 2D cameras.
• Leveraging numerical refocusing for volumetric imaging.

Main Results:

• Achieved reliable cell counting without requiring highly accurate flow control.
• Obtained an unlimited field-of-view along the flow direction due to STDH.
• Enabled imaging and visualization of the entire channel volume via numerical refocusing.
• Demonstrated a system with a reduced number of optical components.

Conclusions:

• The proposed LoC platform offers a cost-effective and innovative solution for imaging flow cytometry.
• The combination of HMS and STDH with LSA enhances cell counting reliability and throughput.
• This technology opens new perspectives for 3D volumetric imaging in microfluidic devices, improving diagnostic potential.