Biomedical Engineering and Bioengineering Commons^™

Polarimetric Imaging Of The Uterine Cervix, Mariacarla Gonzalez

FIU Electronic Theses and Dissertations

Cervical cancer is the fourth most common cancer in women, with more than half a million women diagnosed each year due to persistent human papillomavirus (HPV) infection and a mortality of 311,000 women. According to the World Cancer Research Fund, developing countries have 84% of the global burden of the disease and 80% of the mortality due to a lack of effective screening programs. Several screening techniques have been developed and implemented to aid in low resource setting cervical screening, however, most require physician interpretation of color images. Other modalities utilize contrast agents to highlight pathological tissue but have small …

Correlation Of Acute Radiation Dermatitis To Tissue Oxygenation In Radiation Therapy Treated Breast Cancer Subjects, Edwin Alexander Robledo

FIU Electronic Theses and Dissertations

Over 95% of radiation therapy (RT) treated breast cancer subjects undergo an adverse skin reaction known as radiation dermatitis (RD). Assessment of severity or grading of RD is clinically visual and hence subjective. Our objective is to determine sub-clinical tissue oxygenation (StO₂) changes in response to RT treatment in breast cancer subjects using near-infrared spectroscopic imaging and correlate these changes to RD grading. A WIRB approved 6-8 week longitudinal pilot study was carried out on 10 RT-treated subjects at Miami Cancer Institute. Significant changes (p < 0.05) in StO₂ of irradiated and contralateral chest wall and axilla regions with weeks of …

Penta-Modal Imaging Platform With Oct- Guided Dynamic Focusing For Simultaneous Multimodal Imaging, Arash Dadkhah

FIU Electronic Theses and Dissertations

Complex diseases, such as Alzheimer’s disease, are associated with sequences of changes in multiple disease-specific biomarkers. These biomarkers may show dynamic changes at specific stages of disease progression. Thus, testing/monitoring each biomarker may provide insight into specific disease-related processes, which can result in early diagnosis or even development of preventive measures. Obtaining a comprehensive information of biological tissues requires imaging of multiple optical contrasts, which is not typically offered by a single imaging modality. Thus, combining different contrast mechanisms to achieve simultaneous multimodal imaging is desirable. However, this process is highly challenging due to specific optical and hardware requirements for …

Development Of All-Optical Quantitative Ultrasound Imaging System, Mohamed Abdulrahman Almadi

FIU Electronic Theses and Dissertations

Ultrasound (US) is a well-established deep-tissue imaging modality in biomedicine. It distinguishes different tissue types based on their echogenicity, but this approach provides limited diagnostic sensitivity and accuracy. The majority of the US transducers nowadays rely on lead zirconate titanate (PZT) ceramic elements to transmit and receive ultrasound. Unfortunately, significant limitations arise from these transducers due to their frequency characteristics and complex fabrication process. A recently introduced technique, Quantitative Ultrasound (QUS) Measurement, shows a great promise to improve US-based tissue diagnosis, but it requires a transducer with a large spectrum bandwidth, which is a feature not available in PZT transducers. …

3d Architectural Analysis Of Neurons, Astrocytes, Vasculature & Nuclei In The Motor And Somatosensory Murine Cortical Columns, Jared Leichner

FIU Electronic Theses and Dissertations

Characterization of the complex cortical structure of the brain at a cellular level is a fundamental goal of neuroscience which can provide a better understanding of both normal function as well as disease state progression. Many challenges exist however when carrying out this form of analysis. Immunofluorescent staining is a key technique for revealing 3-dimensional structure, but subsequent fluorescence microscopy is limited by the quantity of simultaneous targets that can be labeled and intrinsic lateral and isotropic axial point-spread function (PSF) blurring during the imaging process in a spectral and depth-dependent manner. Even after successful staining, imaging and optical deconvolution, …

Scalable Profiling And Visualization For Characterizing Microbiomes, Camilo Valdes

FIU Electronic Theses and Dissertations

Metagenomics is the study of the combined genetic material found in microbiome samples, and it serves as an instrument for studying microbial communities, their biodiversities, and the relationships to their host environments. Creating, interpreting, and understanding microbial community profiles produced from microbiome samples is a challenging task as it requires large computational resources along with innovative techniques to process and analyze datasets that can contain terabytes of information.

The community profiles are critical because they provide information about what microorganisms are present in the sample, and in what proportions. This is particularly important as many human diseases and environmental disasters …

Visible Optical Coherence Tomography Based Multimodal Imaging For Quantification Of Retinal Lipofuscin, Zahra Nafar

FIU Electronic Theses and Dissertations

Retinal degeneration is the leading cause of irreversible low vision and blindness in the world, that describes conditions characterized by progressive loss of photoreceptors. Retinal Pigment Epithelium (RPE) is located under photoreceptors’ outer segments and plays an important role in the maintenance of photoreceptors by completing the visual cycle and phagocytosis of shed photoreceptor outer segments. Lipofuscin, a byproduct of the visual cycle, is a nondegradable compound that accumulates in the RPE cells and eventually damages the RPE cells and inevitably causes photoreceptor degeneration. Lipofuscin is the major cause of fundus fluorescence that can be detected by Fundus Autofluorescent (FAF) …

Measuring Collagen Arrangement And Its Relationship With Preterm Birth Using Mueller Matrix Polarimetry, Joseph James Chue-Sang

FIU Electronic Theses and Dissertations

Preterm birth (PTB) is defined as delivery prior to 37 weeks of gestation. It is the leading cause of infant death worldwide, responsible for infant neurological disorders, long-term cognitive impairment, as well as chronic health issues involving the auditory, visual, digestive, and respiratory systems. In expectant mothers, causes for PTB can include infection, inflammation, vascular disease, short intervals between pregnancies, multiple gestations and genetic factors. In the U.S., PTB occurs in over 11% of births and at an elevated 18.1% in Miami-Dade County, FL; while in the developing world the incidence of PB is over 15%. Early identification of at-risk …

Quantitative Yttrium-90 Bremsstrahlung Spect/Ct And Pet/Ct Study For 3d Dosimetry In Radiomicrosphere Therapy, Senait Aknaw Debebe

FIU Electronic Theses and Dissertations

Liver cancer ranks the third most common cause of cancer related mortality worldwide. Radiomicrosphere therapy (RMT), a form of radiation therapy, involves administration of Yttrium-90 (90Y) microspheres to the liver via the hepatic artery. 90Y microspheres bremsstrahlung SPECT/CT or PET/CT imaging could potentially identify an extrahepatic uptake. An early detection of such an uptake, thus, could initiate preventative measures early on. However, the quantitative accuracy of bremsstrahlung SPECT/CT images is limited by the wide and continuous energy spectrum of 90Y bremsstrahlung photons. 90Y PET/CT imaging is also possible but limited by the extremely small internal pair production decay. These limitation …

The Effect Of Hyperthermia On Doxorubicin Therapy And Nanoparticle Penetration In Multicellular Ovarian Cancer Spheroids, Abhignyan Nagesetti

FIU Electronic Theses and Dissertations

The efficient treatment of cancer with chemotherapy is challenged by the limited penetration of drugs into the tumor. Nanoparticles (10 – 100 nanometers) have emerged as a logical choice to specifically deliver chemotherapeutics to tumors, however, their transport into the tumor is also impeded owing to their bigger size compared to free drug moieties. Currently, monolayer cell cultures, as models for drug testing, cannot recapitulate the structural and functional complexity of in-vivo tumors. Furthermore, strategies to improve drug distribution in tumor tissues are also required. In this study, we hypothesized that hyperthermia (43°C) will improve the distribution of silica nanoparticles …

Optical Coherence Photoacoustic Microscopy (Oc-Pam) For Multimodal Imaging, Xiaojing Liu

FIU Electronic Theses and Dissertations

Optical coherence tomography (OCT) and Photoacoustic microscopy (PAM) are two noninvasive, high-resolution, three-dimensional, biomedical imaging modalities based on different contrast mechanisms. OCT detects the light backscattered from a biological sample either in the time or spectral domain using an interferometer to form an image. PAM is sensitive to optical absorption by detecting the light-induced acoustic waves to form an image. Due to their complementary contrast mechanisms, OCT and PAM are suitable for being combined to achieve multimodal imaging.

In this dissertation, an optical coherence photoacoustic microscopy (OC-PAM) system was developed for in vivo multimodal retinal imaging with a pulsed broadband …

Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, Dennis Toledo

FIU Electronic Theses and Dissertations

Cobalt Ferrite has important, size-dependent magnetic properties. Consequently, an overview of particle size is important. Co-precipitation in air was the fabrication method used because it is comparatively simple and safe. The effects of three different reaction times including 1, 2, 3 hour(s) on particle size were compared. Also, the effectiveness of three different capping agents (Oleic Acid, Polyvinylpyrollidone (PVP), and Trisodium Citrate) in reducing aggregation and correspondingly particle size were examined. Using Welch’s analysis of variance (ANOVA) and the relevant post hoc tests, there was no significant difference (p=0.05) between reaction times of 1 hour and 2 hours, but there …

Label-Free Surface-Enhanced Raman Spectroscopy-Linked Immunosensor Assay (Slisa) For Environmental Surveillance, Vinay Bhardwaj

FIU Electronic Theses and Dissertations

The contamination of the environment, accidental or intentional, in particular with chemical toxins such as industrial chemicals and chemical warfare agents has increased public fear. There is a critical requirement for the continuous detection of toxins present at very low levels in the environment. Indeed, some ultra-sensitive analytical techniques already exist, for example chromatography and mass spectroscopy, which are approved by the US Environmental Protection Agency for the detection of toxins. However, these techniques are limited to the detection of known toxins. Cellular expression of genomic and proteomic biomarkers in response to toxins allows monitoring of known as well as …

Intraoperative Guidance For Pediatric Brain Surgery Based On Optical Techniques, Yinchen Song

FIU Electronic Theses and Dissertations

For most of the patients with brain tumors and/or epilepsy, surgical resection of brain lesions, when applicable, remains one of the optimal treatment options. The success of the surgery hinges on accurate demarcation of neoplastic and epileptogenic brain tissue. The primary goal of this PhD dissertation is to demonstrate the feasibility of using various optical techniques in conjunction with sophisticated signal processing algorithms to differentiate brain tumor and epileptogenic cortex from normal brain tissue intraoperatively.

In this dissertation, a new tissue differentiation algorithm was developed to detect brain tumors in vivo using a probe-based diffuse reflectance spectroscopy system. The system …

Funtional Near Infrared Spectroscopy Study Of Language, Joint Attention And Motor Skills, Ujwal Chaudhary

FIU Electronic Theses and Dissertations

Near infrared spectroscopy (NIRS) is an emerging non-invasive optical neuro imaging technique that monitors the hemodynamic response to brain activation with ms-scale temporal resolution and sub-cm spatial resolution. The overall goal of my dissertation was to develop and apply NIRS towards investigation of neurological response to language, joint attention and planning and execution of motor skills in healthy adults. Language studies were performed to investigate the hemodynamic response, synchrony and dominance feature of the frontal and fronto-temporal cortex of healthy adults in response to language reception and expression. The mathematical model developed based on granger causality explicated the directional flow …

Multifunctional Nanoparticles In Cancer: In Vitro Characterization, In Vivo Distribution, Tingjun Lei

FIU Electronic Theses and Dissertations

A novel biocompatible and biodegradable polymer, termed poly(Glycerol malate co-dodecanedioate) (PGMD), was prepared by thermal condensation method and used for fabrication of nanoparticles (NPs). PGMD NPs were prepared using the single oil emulsion technique and loaded with an imaging/hyperthermia agent (IR820) and a chemotherapeutic agent (doxorubicin, DOX). The size of the void PGMD NPs, IR820-PGMD NPs and DOX-IR820-PGMD NPs were approximately 90 nm, 110 nm, and 125 nm respectively. An acidic environment (pH=5.0) induced higher DOX and IR820 release compared to pH=7.4. DOX release was also enhanced by exposure to laser, which increased the temperature to 42°C. Cytotoxicity of DOX-IR820-PGMD …