Advisor(s)

Charles A. DiMarzio

Contributor(s)

Dana H. Brooks, Anthony J. Devaney

Date of Award

2009

Date Accepted

1-2009

Degree Grantor

Northeastern University

Degree Level

Ph.D.

Degree Name

Doctor of Philosophy

Department or Academic Unit

College of Engineering. Department of Electrical and Computer Engineering.

Keywords

Optical quadrature microscopy (OQM), Embryo viability, Electrical and Computer Engineering

Subject Categories

Microscopy--Technological innovations, Noise control

Disciplines

Engineering

Abstract

Since 1978 in vitro fertilization (IVF) procedures have resulted in the birth of over three million babies. Yet, despite the plethora of qualitative viability markers utilized in various embryo scoring methods, IVF procedures in the United States had a live birth rate of only 34% in 2005, with 32% of these successful pregnancies resulting in multiple births. These multiple pregnancies were directly attributed to the transfer of multiple embryos to increase the probability that a single, healthy embryo was included, because the current qualitative measures are inadequate to measure embryo viability reliably. The use of quantitative, three dimensional viability measures could create a definitive method of embryo scoring that will produce a successful pregnancy from the transfer of a single embryo. Optical quadrature microscopy (OQM) was invented at Northeastern University to measure the amplitude and phase of an optically transparent sample. Since its conception, OQM has been built into the Keck 3D Fusion Microscope that combines brightfield, differential interference contrast (DIC), epi-fluorescence, OQM, confocal fluorescence, confocal reflectance, and two-photon on a single microscope stage, and has been used in conjunction with DIC to create the phase-subtraction cell-counting method that has counted the number of cells in live mouse embryos accurately beyond the developmental stage at which DIC can be used alone. In this dissertation, we derive a thorough signal-to-noise ratio analysis that provides the minimum phase error in the current system, and present the ability of OQM to measure accurate phase for spherical objects that are much larger than the depth of field. We also provide an overview of multimodal imaging of mouse embryos and describe how the rate of development, cell size, symmetry, and fragmentation, and oocyte mitochondrial distribution measurements could be quantified with the extension of the phase-subtraction cell count and the measurement of relative dry mass. If verified with human embryos, these methodologies could provide the means to determine which viability measures are truly indicative of embryo health. Supplementary File 1 shows a brightfield time-lapse of embryos developing from the 2-cell to the morula stage and Supplementary File 2 provides a visualization of the phase-subtraction cell-counting method.

Document Type

Dissertation

Rights Holder

William C. Warger II


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Additional Files

growth.wmv (4567 kB)
Growth
25cell.avi (247 kB)
Cell counting simulation

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