Biomedical Engineering and Bioengineering Commons^™

Design Of Asic Based Electrical Impedance Tomography Microendoscopic System For Prostate Cancer Surgical Marginal Assessment, Mohsen Shahghasemi

Dartmouth College Ph.D Dissertations

Prostate cancer is the second most common cancer in the United States. It is typically treated by surgically excising the cancerous section of the prostate. Because there is not always a visible distinction between the healthy and cancerous sections, surgery often leaves some cancerous tissue behind. This is referred to as a positive surgical margin and it requires adjuvant treatment with adverse side effects. Electrical impedance tomography (EIT) is a low-cost low-form-factor method that can be used to assess surgical marginal intraoperatively to ensure that no cancerous tissue is left behind. EIT-based surgical margin assessment works on the principle that …

System-Characterized Artificial Intelligence Approaches For Cardiac Cellular Systems And Molecular Signature Analysis, Ziqian Wu

Dartmouth College Ph.D Dissertations

The dissertation presents a significant advancement in the field of cardiac cellular systems and molecular signature systems by employing machine learning and generative artificial intelligence techniques. These methodologies are systematically characterized and applied to address critical challenges in these domains. A novel computational model is developed, which combines machine learning tools and multi-physics models. The main objective of this model is to accurately predict complex cellular dynamics, taking into account the intricate interactions within the cardiac cellular system. Furthermore, a comprehensive framework based on generative adversarial networks (GANs) is proposed. This framework is designed to generate synthetic data that faithfully …

Intraoperative Quantification Of Bone Perfusion In Lower Extremity Injury Surgery, Xinyue Han

Dartmouth College Ph.D Dissertations

Orthopaedic surgery is one of the most common surgical categories. In particular, lower extremity injuries sustained from trauma can be complex and life-threatening injuries that are addressed through orthopaedic trauma surgery. Timely evaluation and surgical debridement following lower extremity injury is essential, because devitalized bones and tissues will result in high surgical site infection rates. However, the current clinical judgment of what constitutes “devitalized tissue” is subjective and dependent on surgeon experience, so it is necessary to develop imaging techniques for guiding surgical debridement, in order to control infection rates and to improve patient outcome.

In this thesis work, computational …

Advancing Fluorescent Contrast Agent Recovery Methods For Surgical Guidance Applications, Brook Kennedy Byrd

Dartmouth College Ph.D Dissertations

Fluorescence-guided surgery (FGS) utilizes fluorescent contrast agents and specialized optical instruments to assist surgeons in intraoperatively identifying tissue-specific characteristics, such as perfusion, malignancy, and molecular function. In doing so, FGS represents a powerful surgical navigation tool for solving clinical challenges not easily addressed by other conventional imaging methods. With growing translational efforts, major hurdles within the FGS field include: insufficient tools for understanding contrast agent uptake behaviors, the inability to image tissue beyond a couple millimeters, and lastly, performance limitations of currently-approved contrast agents in accurately and rapidly labeling disease. The developments presented within this thesis aim to address such …

Multimodal Ultrasound Imaging For Improved Metastatic Lymph Node Detection, Sidhartha Jandhyala

Dartmouth College Ph.D Dissertations

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and is complex in nature due to the variety of organs located in the head and neck region. Knowing the metastatic state of the lymph nodes is paramount in accurately staging and treating HNSCC patients. Currently, metastatic lymph node detection involves the use of magnetic resonance imaging and/or x-ray computed tomography, followed by biopsies for histological confirmation. The main diagnostic criteria is the size of the nodes; however, current imaging methods are not 100% accurate due natural lymph node variability. Ultrasound imaging is able to provide …

Phase-Changing Nanodroplets As Nanotheranostic Platform For Combination Cancer Therapy, Catalina-Paula Spatarelu

Dartmouth College Ph.D Dissertations

Cancer is a cluster of diseases, and 1.8 million Americans are newly diagnosed each year. Treatment issues such as drug instability, the occurrence of severe side effects, as well as resistance make the need for solutions to improve conventional methods, like chemotherapy, apparent. Nano-sized drug-delivery platforms, particles loaded with therapeutic molecules that escape the immune system clearance and accumulate at the tumor site, were proposed as one of these solutions. Despite the expansion of the field, several aspects still need to be addressed: inconsistent delivery of the drugs, inability of measuring the effective dose being delivered to the tumor, lack …

Advancing Combined Radiological And Optical Scanning For Breast-Conserving Surgery Margin Guidance, Samuel Stewart Streeter

Dartmouth College Ph.D Dissertations

Breast cancer is one of the most common types of cancer worldwide, and standard-of-care for early-stage disease typically involves a lumpectomy or breast-conserving surgery (BCS). BCS involves the local resection of cancerous tissue, while sparring as much healthy tissue as possible. State-of-the-art methods for intraoperatively evaluating BCS margins are limited. Approximately 20% of BCS cases result in a tissue resection with cancer at or near the resection surface (i.e., a positive margin). A two-fold increase in ipsilateral breast cancer recurrence is associated with the presence of one or more positive margins. Consequently, positive margins often necessitate costly re-excision procedures to …