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Bioengineering Theses - Archive

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Full-Text Articles in Biomedical Engineering and Bioengineering

Registration Of Beta-Cit Dopamine Transporter Spect Images, Abhinay Dilip Joshi May 2006

Registration Of Beta-Cit Dopamine Transporter Spect Images, Abhinay Dilip Joshi

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This work outlines a method for quantification of nigrostriatal dopaminergic neurons by means of SPECT using the cocaine derivative [123I] β-CIT (123I-labelled 2β-carbomethoxy-3β-(4-iodophenyl) tropane (β-CIT))as a radiotracer which binds with high affinity to the dopamine receptors. It has been validated (1) that the calculation of a simple ratio of specific/non-specific displaceable binding during a period of binding-equilibrium in the striatum about 20 hrs after the administration of a bolus injection of the tracer gives a strong and reliable index of the binding potential of dopamine uptake sites. Previous studies [2] have shown that the dopaminergic deficit in patients with Parkinson's …

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Phenotypic Differences In The Behavior Of Immortalized Human Bronchial Epithelial Cells In Three Dimensional Culture Systems, Anusha Sridharan May 2006

Phenotypic Differences In The Behavior Of Immortalized Human Bronchial Epithelial Cells In Three Dimensional Culture Systems, Anusha Sridharan

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Human Bronchial Epithelial Cells (HBECS) immortalized with viral oncoproteins E6/E7, are potentially malignant due to numerous chromosomal aberrations. Recently a model system was established in which HBECS were immortalized with Cyclin-dependent-kinase-4 (Cdk4) and human Telomerase Reverse Transcriptase (hTERT). These cells were shown to have intact p53 checkpoints and had well expressed differentiation markers. HBECS are non-tumorigenic as they do not form tumors in nude mice or colonies in soft agar. The purpose of this research was to establish the differences in phenotypic behavior between HBECS immortalized with E6/E7 viral oncoproteins and HBECS immortalized with Cdk4/hTERT. A three dimensional culture model …

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Development Of A Multi-Channel Handheld Probe Designed For Near Infrared Spectroscopy And An Exploration Into Its Clinical Applications, Pradheep Raman May 2006

Development Of A Multi-Channel Handheld Probe Designed For Near Infrared Spectroscopy And An Exploration Into Its Clinical Applications, Pradheep Raman

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Near Infrared (NIR) spectroscopy and imaging has become popular in research fields for the past 2 decades. My research focuses on the development of a handheld, multi-channel, multi-separation probe for the low-cost, compact, NIR spectroscopy (LCC-NIRS) system and also on the exploration into its possible clinical applications. The work is divided into three parts. The first part deals with the development of the multi-separation probe with source-detector separation of 3.8 cm, 3.3 cm, 3.0 cm, and 2.3 cm. The probe is designed to work as a tri-wavelength system for the LCC-NIRS, which was developed earlier, consisting of one light emitting …

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High Precision Spatial And Temporal Control Of Neural Circuitry Using Semi-Automated, Multiwavelength Nanopatterning System, Nagasandhya Mitnala May 2006

High Precision Spatial And Temporal Control Of Neural Circuitry Using Semi-Automated, Multiwavelength Nanopatterning System, Nagasandhya Mitnala

Bioengineering Theses - Archive

The ideal way to manipulate neurons would be to reversibly activate and inactivate neuronal firing and thus enable a bi-directional control. Many attempts have been made in the past to have such a tool. The traditional approach for controlling neural circuits is to generate a local electric field which has been shown to be highly effective at triggering action potentials in neurons [53]. Although the timing of the electrode stimulation is very precise, its specificity and spatial control are poor. Also, silencing neuronal activity is as important as stimulating it. Ed Boyden described a protein that switches off nerve firing …

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Optimization Of Methods For In-Vitro Expansion And Cryopreservation Of Mammalian Stem Cells, Harikrishnan Balachandran May 2006

Optimization Of Methods For In-Vitro Expansion And Cryopreservation Of Mammalian Stem Cells, Harikrishnan Balachandran

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The recent advances in the field of Tissue Engineering have given rise to the need for a tremendous quantity of cells. The search for and use of an appropriate multipotent or pluripotent stem cells in tissue engineering is an emerging concept. Mesenchymal stem cells hold a very great deal of promise because of their capacity to self-renew and to differentiate into various lineages. These cells are very low in number in the body but their in vitro expansion capacity is very unique. Taking into consideration the lack of uniform approach for expansion of these MSCs and storing these cells for …

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Implantable Drug Delivery System With In-Plane Micropump, Amit A. Mhatre Jan 2006

Implantable Drug Delivery System With In-Plane Micropump, Amit A. Mhatre

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A MEMS based Implantable Drug Delivery System (IDDS) is discussed. The heart of the system is an in-plane MEMS micropump enables us to make a compact, inexpensive system. A conceptual IDDS design is proposed. This design consists of an implantable unit which houses the micropump, electronic and power circuitry. This implantable unit is connected to a subcutaneous port via a silicone catheter. The subcutaneous port acts as a refillable reservoir. This leads to a reduction in unit volume and makes the system customizable. The IDDS pumps drug into surrounding tissue with the help of a MEMS-based micropump. The force generated …

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High Resolution Optical Coherence Tomography (Oct) System For Integration With A Multimodal Optical Imaging Workstation, Kapil Bharati Langer Dec 2005

High Resolution Optical Coherence Tomography (Oct) System For Integration With A Multimodal Optical Imaging Workstation, Kapil Bharati Langer

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Development and construction of a high resolution Optical Coherence Tomography (OCT) system is described. OCT is one of the modalities in an integrated multimode optical imaging workstation built around an inverted Differential Interference Contrast (DIC) microscope in our laboratory, to image cells and tissue samples. The design and construction of the OCT sample path is dictated by its integration to the optical imaging workstation. The OCT system is controlled via a DAC card, interfaced using LabVIEW to the computer. The image of the sample under observation is constructed from the raster scan data acquired by the DAQ. Ti-Sapphire broadband laser …

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Fabrication And Mechanical Characterization Of A Two-Ply Cross Fiber Stent And Fibers Comprising Blends Of Poly(L-Lactic Acid), Sushma Gampa Dec 2005

Fabrication And Mechanical Characterization Of A Two-Ply Cross Fiber Stent And Fibers Comprising Blends Of Poly(L-Lactic Acid), Sushma Gampa

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Recent studies indicate that stabilization of vulnerable atherosclerotic plaques is critical for minimizing acute coronary syndromes. In this regard a new biodegradable stent design, the Two-ply cross fiber stent, has been developed to reduce stent-imposed stresses on such plaque and to provide increased drug reservoir capability. A comparative study of the mechanical properties of Two-ply and Single-ply stent designs was performed. Fibers comprising PLLA blends were developed and their thermal and mechanical properties were determined. Lateral spreading of helical fibers upon deployment of the Two ply design was observed that, in theory, may reduce stresses on the plaque surface. The …

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Parametric And Non-Parametric Analysis Of Carotid Sinus Baroreflex System Using Electrically Induced Muscle Contraction, Sheetal D. Deshmukh Dec 2005

Parametric And Non-Parametric Analysis Of Carotid Sinus Baroreflex System Using Electrically Induced Muscle Contraction, Sheetal D. Deshmukh

Bioengineering Theses - Archive

The arterial pressure is an important physiological parameter which if not maintained at desired level may lead to fatal disorders or in worst situations even death. The physiological feedback control mechanism in order to regulate the arterial pressure is performed by the baroreceptors. In this study the dynamic characteristics of carotid sinus baroreceptor are identified to obtain the open-loop characteristics of the carotid sinus pressure (CSP, mmHg) to the renal sympathetic nerve activity (RSNA, Arbitrary unit), RSNA to systemic arterial pressure (SAP, mmHg), CSP to SAP and CSP to heart rate (HR, bpm).The purpose of this study was to know …

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Analysis Of The Dynamics Of Vasomotion Using Laser Doppler Flow, Shruthi Raj Aug 2005

Analysis Of The Dynamics Of Vasomotion Using Laser Doppler Flow, Shruthi Raj

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Vasomotion is a phenomenon caused by changes in the diameters of blood vessels. It is due to the contractile activity of small arteries and arterioles resulting in periodic changes of blood flow in the skin. These flow variations in the arteries are reflected by the Laser Doppler Flowmeter. The goal of the skin blood flow (blood perfusion) study is to establish a method to analyze and quantify the pattern of vasomotion as detected using Laser Doppler Flow (LDF). Spectral analysis of the LDF signal reveals the presence of periodic components in the vascular system. The study involves twelve subjects of …

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Vascular Stent Analysis, Tre Raymond Welch Aug 2005

Vascular Stent Analysis, Tre Raymond Welch

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It is important for cardiologist to understand the stresses and strains the stent experiences during deployment. We created a 3-D model of the coiled stent which is exported into ANSYS creating the finite element model. The stent material is Poly-L-Lactic Acid (PLLA) fiber with a Young's modulus of 7043(MPa) and a Poisson's ratio of 0.35. A nonlinear material analysis simulates the material behavior through plastic deformation during expansion from 1(atm) to 14(atm). The von Mises stresses, principal stresses, and principal strains are analyzed to determine the yielding of the PLLA fiber. Also, the effect of different material properties including Young's …

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Near Infrared Spectroscopy: A Study Of Cerebral Hemodynamics During Breathholding And Development Of A System For Hot Flash Measurement, Vikrant Sharma Aug 2005

Near Infrared Spectroscopy: A Study Of Cerebral Hemodynamics During Breathholding And Development Of A System For Hot Flash Measurement, Vikrant Sharma

Bioengineering Theses - Archive

Near Infrared (NIR) spectroscopy and imaging has become popular in research fields for the past 2-3 decades. My research focuses on the continuous wave near infrared imaging technique. The work consists of two main parts. In the first part, an existing commercial system, an LEDI (Light Emitting Diode Imager), is used to study the cerebral hemodynamics during breath holding. The aim was to evaluate the ability of an LED-based continuous wave imager to capture changes in hemodynamics occurring inside the skull induced by breath holding. The study involved 15 human subjects. It was found that the total hemoglobin concentration (in …

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Dynamic Modeling Of Cerebral Blood Flow Autoregulation Using Arx And Windkessel Models, Piyush Gehalot Aug 2005

Dynamic Modeling Of Cerebral Blood Flow Autoregulation Using Arx And Windkessel Models, Piyush Gehalot

Bioengineering Theses - Archive

Linear lumped parameter models like ARX and Windkessel models are simple, easy to solve, and find their application in real time modeling. The present study is focused on employing single input single output ARX and Windkessel models to beat-to-beat mean arterial blood pressure (MABP, mmHg) considered as input to the model, and cerebral blood flow velocity (CBFV, cm/sec) considered as output of the model. For some models and modeling methodologies, the data consisted of cerebral perfusion pressure (CPP, mmHg, estimated from MABP) and CBFV. The data was measured from 10 healthy normal subjects while the subjects performed Valsalva maneuver with …

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Biomechanical Properties Of Anterior Vaginal Wall Tissue In Post-Menopausal Women, Aradhana Bhatt Aug 2005

Biomechanical Properties Of Anterior Vaginal Wall Tissue In Post-Menopausal Women, Aradhana Bhatt

Bioengineering Theses - Archive

Cystocele repair in post-menopausal women suffering from urinary incontinence and associated vaginal prolapse is a common method of palliation. In this method, there is surgical reduction of vaginal tissue and the weak cross-sections are often supported with a synthetic sling fashioned from polymer mesh material. Some sling-supported and unsupported repairs fail over the years. The reasons for these failures are unclear, due in part to a lack of fundamental knowledge of the mechanisms associated with cystocele and vaginal prolapse. The aim of this study was to understand the mechanisms of tissue failure by biomechanical and ultrastructural studies. We take advantage …

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