Biomedical Engineering and Bioengineering Commons^™

Biosensing Enhancement Of Dengue Virus Using Microballoon Mixers On Centrifugal Microfluidic Platforms

Faculty of Engineering University of Malaya

Dengue is the current leading cause of death among children in several Latin American and Asian countries. Due to poverty in areas where the disease is prevalent and the high cost of conventional diagnostic systems, low cost devices are needed to reduce the burden caused by dengue infection. Centrifugal microfluidic platforms are an alternative solution to reduce costs and increase the availability of a rapid diagnostic system. The rate of chemical reactions in such devices often depends on the efficiency of the mixing techniques employed in their microfluidic networks. This paper introduces a micromixer that operates by the expansion and …

Development Of Novel Passive Check Valves For The Microfluidic Cd Platform

Faculty of Engineering University of Malaya

Microfluidic CD platforms are utilized to perform different biological processes and chemical analyses. In general, a microfluidic CD implements the centrifugal force that is created by the spinning of the platform to pump liquid through the microfluidic network of chambers and channels. Over the last few decades, a wide range of active and passive valving methods were proposed and tested on various microfluidic platforms. Most of the presented valves are too complex to design and involve lengthy fabrication processes. In this paper, easy to fabricate air and liquid check valves for centrifugal microfluidic platforms are presented: a Terminal Check Valve …

Ultrasound-Based Tissue Characterization And Classification Of Fatty Liver Disease: A Screening And Diagnostic Paradigm

Faculty of Engineering University of Malaya

Fatty Liver Disease (FLD) is a progressively prevalent disease that is present in about 15% of the world population. Normally benign and reversible if detected at an early stage, FLD, if left undetected and untreated, can progress to an irreversible advanced liver disease, such as fibrosis, cirrhosis, liver cancer and liver failure, which can cause death. Ultrasound (US) is the most widely used modality to detect FLD. However, the accuracy of US-based diagnosis depends on both the training and expertise of the radiologist. US-based Computer Aided Diagnosis (CAD) techniques for FLD detection can improve accuracy, speed and objectiveness of the …

Performance Comparison Of Windowing Techniques For Ecg Signal Enhancement, Innovative Research Publications Irp India, K.Sravan Kumar, Babak Yazdanpanah, Dr.G.S.N Raju

Innovative Research Publications IRP India

Electrocardiogram (ECG) signal is generally corrupted by various artifacts like baseline wander, power line interference (50/60 Hz) and electromyography noise and these must be removed before diagnosis. The task propounded in this article is removal of low frequency interference i.e. baseline wandering and high frequency noise i.e. electromyography in ECG signal and digital filters are implemented to delete it. The digital filters accomplished are FIR with various windowing methods as of Rectangular, Hann, Blackman, Hamming, and Kaiser. The results received are at order of 300,450,600.The signal taken of the MIT-BIH database which contains the normal and abnormal waveforms. The work …

Correlation Between Energy Distribution Profile And Lev El Of Consciousness, D. K. Chaturvedi Dr.

D. K. Chaturvedi Dr.

The purpose of this experimental study was to determine the energy levels corresponding to the different focal points (Chakras or centers) of the body, which is related with consciousness. In this experiment, the energy level is measured at four different centers, namely, the navel center, the heart center, the throat center and the eye center of the Human beings. The measurements have been taken using Energy Measurement System (EMS) developed at Department of Electrical Engineering, Dayalbagh Education Institute, Dayalbagh, Agra, India, which works on the principle of tissue resistance of body. The probe was placed at different centers and subsequent …

At89c51 Microcontroller Based Control Model For Hybrid Assistive Limb (Knee ), Suresh L

suresh L

In this paper, a controlling system is implemented for a wearable walking supporting device so called as Hybrid Assistive Limb. The control circuit is implemented without considering the biological signals of the human body for the knee part, which is based on the knee joint moment from the human body model. The control and a driving circuit s are implemented to assistive the knee as for the requir ement of knee joint dynamics.

Microfabricated Nanotopological Surfaces For Study Of Adhesion-Dependent Cell Mechanosensitivity, Weiqiang Chen, Yubing Sun, Jianping Fu

Weiqiang Chen

Cells exhibit high sensitivity and diverse responses to the intrinsic nanotopography of the extracellular matrix through their nanoscale cellular sensing machinery. A simple microfabrication method for precise control and spatial patterning of the local nanoroughness on glass surfaces by using photolithography and reactive ion etching is reported. It is demonstrated that local nanoroughness as a biophysical cue could regulate a diverse array of NIH/3T3 fi broblast behaviors, including cell morphology, adhesion, proliferation, migration, and cytoskeleton contractility. The capability to control and further predict cellular responses to nanoroughness might suggest novel methods for developing biomaterials mimicking nanotopographic structures in vivo for …

Surface-Micromachined Microfiltration Membranes For Efficient Isolation And Functional Immunophenotyping Of Subpopulations Of Immune Cells, Weiqiang Chen, Nien-Tsu Huang, Boram Oh, Raymond H. W. Lam, Rong Fan, Timothy T. Cornell, Thomas P. Shanley, Katsuo Kurabayashi, Jianping Fu

Weiqiang Chen

An accurate measurement of the immune status in patients with immune system disorders is critical in evaluating the stage of diseases and tailoring drug treatments. The functional cellular immunity test is a promising method to establish the diagnosis of immune dysfunctions. The conventional functional cellular immunity test involves measurements of the capacity of peripheral blood mononuclear cells to produce pro-inflammatory cytokines when stimulated ex vivo. However, this “bulk” assay measures the overall reactivity of a population of lymphocytes and monocytes, making it difficult to pinpoint the phenotype or real identity of the reactive immune cells involved. In this research, we …

Nanoroughened Surfaces For Efficient Capture Of Circulating Tumor Cells Without Using Capture Antibodies, Weiqiang Chen, Shinuo Weng, Feng Zhang, Steven Allen, Xiang Li, Liwei Bao, Raymond H. W. Lam, Jill A. Macoska, Sofia D. Merajver, Jianping Fu

Weiqiang Chen

Circulating tumor cells (CTCs) detached from both primary and metastatic lesions represent a potential alternative to invasive biopsies as a source of tumor tissue for the detection, characterization and monitoring of cancers. Here we report a simple yet effective strategy for capturing CTCs without using capture antibodies. Our method uniquely utilized the differential adhesion preference of cancer cells to nanorough surfaces when compared to normal blood cells and thus did not depend on their physical size or surface protein expression, a significant advantage as compared to other existing CTC capture techniques.

Nanotopography Influences Adhesion, Spreading, And Self-Renewal Of Human Embryonic Stem Cells, Weiqiang Chen, Luis G. Villa-Diaz, Yubing Sun, Shinuo Weng, Jin Koo Kim, Raymond H. W. Lam, Lin Han, Rong Fan, Paul H. Krebsbach, Jianping Fu

Weiqiang Chen

Human embryonic stem cells (hESCs) have great potentials for future cell-based therapeutics. However, their mechanosensitivity to biophysical signals from the cellular microenvironment is not well characterized. Here we introduced an effective microfabrication strategy for accurate control and patterning of nanoroughness on glass surfaces. Our results demonstrated that nanotopography could provide a potent regulatory signal over different hESC behaviors, including cell morphology, adhesion, proliferation, clonal expansion, and self-renewal. Our results indicated that topological sensing of hESCs might include feedback regulation involving mechanosensory integrin-mediated cell matrix adhesion, myosin II, and E-cadherin. Our results also demonstrated that cellular responses to nanotopography were cell-type …

Development Of A Novel Methodology For Indoor Emission Source Identification, Kwanghoon Han

Kwanghoon Han

The objective of this study was to develop and evaluate a methodology to identify individual sources of emissions based on the measurements of mixed air samples and the emission signatures of individual materials previously determined by Proton Transfer Reaction-Mass Spectrometry (PTR-MS), an on-line analytical device. The methodology based on signal processing principles was developed by employing the method of multiple regression least squares (MRLS) and a normalization technique. Samples of nine typical building materials were tested individually and in combination, including carpet, ceiling material, gypsum board, linoleum, two paints, polyolefine, PVC and wood. Volatile Organic Compound (VOC) emissions from each …

Determination Of Material Emission Signatures By Ptr-Ms And Their Correlations With Odor Assessments By Human Subjects, Kwanghoon Han

Kwanghoon Han

The objectives of this study were to determine volatile organic compound (VOC) emission signatures of nine typical building materials by using proton transfer reaction-mass spectrometry (PTR-MS) and to explore the correlation between the PTR-MS measurements and the measurements of acceptability by human subjects. VOC emissions from each material were measured in a 50-l small-scale chamber. Chamber air was sampled by PTR-MS to determine emission signatures. Sorbent tube sampling and TD-GC/MS analysis were also performed to identify the major VOCs emitted and to compare the resulting data with the PTR-MS emission signatures. The data on the acceptability of air quality assessed …

Model Omnibus Privacy Statute, Sam S. Han Ph.D.

Sam Han

One of today’s major concerns is how easily digital information can be copied and disseminated. Thus, when one’s private information becomes publicly available in digital format, that information can be readily duplicated and distributed across the globe within seconds. If the disseminated information includes credit card numbers or Social Security numbers, then there is a heightened exposure to identity theft and a host of other privacy-related crimes.

Given the existence of such a digital landmine, laws have been promulgated for various sectors (e.g., financial, healthcare, government, etc.) to protect personally-identifiable information. However, due to differing needs of the various sectors, …

Microfluidic Devices For Terahertz Spectroscopy Of Biomolecules, P. A. George, W. Hui, F. Rana, Benjamin G. Hawkins, A. E. Smith, B. J. Kirby

Benjamin G. Hawkins

We demonstrate microfluidic devices for terahertz spectroscopy of biomolecules in aqueous solutions. The devices are fabricated out of a plastic material that is both mechanically rigid and optically transparent with near-zero dispersion in the terahertz frequency range. Using a low-power terahertz time-domain spectrometer, we experimentally measure the absorption spectra of the vibrational modes of bovine serum albumin from 0.5–2.5 THz and find good agreement with previously reported data obtained using large-volume solutions and a high-power free-electron laser. Our results demonstrate the feasibility of performing high sensitivity terahertz spectroscopy of biomolecules in aqueous solutions with detectable molecular quantities as small as …