Date of Graduation

5-2016

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering (MSBME)

Degree Level

Graduate

Department

Biomedical Engineering

Advisor/Mentor

Muldoon, Timothy J.

Committee Member

Fritsch, Ingrid

Second Committee Member

Balachandran, Kartik

Keywords

Applied sciences; Biomedical imaging; Confocal fluorescence microscopy; Image cytometry; Leukocytes; Linear sensors; Push broom translation

Abstract

There exists a need for research of optical methods capable of image cytometry suitable for point-of-care technology. To propose am optical approach with no moving parts for simplification of mechanical components for the further development of the technology to the poin-of-care, a linear sensor with push broom translation method. Push broom translation is a method of moving objects by the sensor for an extended field of view. A polydimethylsiloxane (PDMS) microfluidic chamber with a syringe pump was used to deliver objects by the sensor. The volumetric rate of the pump was correlated to the integration time of the sensor to ensure images were realistically being formed, termed aspect ratio. An electro-chemical microfluidic system was then also investigated, redox-magnetohydrodynamics (R-MHD), to eliminate the mechanical syringe pump which showed deviations in linear speeds at the specimen plane. To image with adequate signal to background ratio within the deep chamber of the R-MHD device, an epitaxial light sheet confocal microscope (e-LSCM) was used to improve axial resolution. The linear sensor, having small pixels, blocked out-of-plane light while eliminating the need for a mechanical aperture which is used for traditional point-scanning confocal microscopy. The particular linear sensor used has binning modes that were used to vary the axial resolution by increasing the sensor aperture. This approach was validated by using a mirror translated in the axial direction and measuring remitted light intensity. The resulting curve estimated the real axial resolution of the microscope, which compared favorably to theoretical values. The R-MHD and the e-LSCM were then synchronized to perform continuous imaging of fluorescent microspheres and cells in suspension. This study combines epitaxial light sheet confocal microscopy and electro-chemical microfluidics as a robust approach which could be used in future point-of-care image cytometry applications.

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