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- All Subjects: Biosensors
Description
Demand for biosensor research applications is growing steadily. According to a new report by Frost & Sullivan, the biosensor market is expected to reach $14.42 billion by 2016. Clinical diagnostic applications continue to be the largest market for biosensors, and this demand is likely to continue through 2016 and beyond. Biosensor technology for use in clinical diagnostics, however, requires translational research that moves bench science and theoretical knowledge toward marketable products. Despite the high volume of academic research to date, only a handful of biomedical devices have become viable commercial applications. Academic research must increase its focus on practical uses for biosensors. This dissertation is an example of this increased focus, and discusses work to advance microfluidic-based protein biosensor technologies for practical use in clinical diagnostics. Four areas of work are discussed: The first involved work to develop reusable/reconfigurable biosensors that are useful in applications like biochemical science and analytical chemistry that require detailed sensor calibration. This work resulted in a prototype sensor and an in-situ electrochemical surface regeneration technique that can be used to produce microfluidic-based reusable biosensors. The second area of work looked at non-specific adsorption (NSA) of biomolecules, which is a persistent challenge in conventional microfluidic biosensors. The results of this work produced design methods that reduce the NSA. The third area of work involved a novel microfluidic sensing platform that was designed to detect target biomarkers using competitive protein adsorption. This technique uses physical adsorption of proteins to a surface rather than complex and time-consuming immobilization procedures. This method enabled us to selectively detect a thyroid cancer biomarker, thyroglobulin, in a controlled-proteins cocktail and a cardiovascular biomarker, fibrinogen, in undiluted human serum. The fourth area of work involved expanding the technique to produce a unique protein identification method; Pattern-recognition. A sample mixture of proteins generates a distinctive composite pattern upon interaction with a sensing platform consisting of multiple surfaces whereby each surface consists of a distinct type of protein pre-adsorbed on the surface. The utility of the "pattern-recognition" sensing mechanism was then verified via recognition of a particular biomarker, C-reactive protein, in the cocktail sample mixture.
ContributorsChoi, Seokheun (Author) / Chae, Junseok (Thesis advisor) / Tao, Nongjian (Committee member) / Yu, Hongyu (Committee member) / Forzani, Erica (Committee member) / Arizona State University (Publisher)
Created2011
Description
Human breath is a concoction of thousands of compounds having in it a breath-print of physiological processes in the body. Though breath provides a non-invasive and easy to handle biological fluid, its analysis for clinical diagnosis is not very common. Partly the reason for this absence is unavailability of cost effective and convenient tools for such analysis. Scientific literature is full of novel sensor ideas but it is challenging to develop a working device, which are few. These challenges include trace level detection, presence of hundreds of interfering compounds, excessive humidity, different sampling regulations and personal variability. To meet these challenges as well as deliver a low cost solution, optical sensors based on specific colorimetric chemical reactions on mesoporous membranes have been developed. Sensor hardware utilizing cost effective and ubiquitously available light source (LED) and detector (webcam/photo diodes) has been developed and optimized for sensitive detection. Sample conditioning mouthpiece suitable for portable sensors is developed and integrated. The sensors are capable of communication with mobile phones realizing the idea of m-health for easy personal health monitoring in free living conditions. Nitric oxide and Acetone are chosen as analytes of interest. Nitric oxide levels in the breath correlate with lung inflammation which makes it useful for asthma management. Acetone levels increase during ketosis resulting from fat metabolism in the body. Monitoring breath acetone thus provides useful information to people with type1 diabetes, epileptic children on ketogenic diets and people following fitness plans for weight loss.
ContributorsPrabhakar, Amlendu (Author) / Tao, Nongjian (Thesis advisor) / Forzani, Erica (Committee member) / Lindsay, Stuart (Committee member) / Arizona State University (Publisher)
Created2013
Description
Advances in miniaturized sensors and wireless technologies have enabled mobile health systems for efficient healthcare. A mobile health system assists the physician to monitor the patient's progress remotely and provide quick feedbacks and suggestions in case of emergencies, which reduces the cost of healthcare without the expense of hospitalization. This work involves development of an innovative mobile health system with adaptive biofeedback mechanism and demonstrates the importance of biofeedback in accurate measurements of physiological parameters to facilitate the diagnosis in mobile health systems. Resting Metabolic Rate (RMR) assessment, a key aspect in the treatment of diet related health problems is considered as a model to demonstrate the importance of adaptive biofeedback in mobile health. A breathing biofeedback mechanism has been implemented with digital signal processing techniques for real-time visual and musical guidance to accurately measure the RMR. The effects of adaptive biofeedback with musical and visual guidance were assessed on 22 healthy subjects (12 men, 10 women). Eight RMR measurements were taken for each subject on different days under same conditions. It was observed the subjects unconsciously followed breathing biofeedback, yielding consistent and accurate measurements for the diagnosis. The coefficient of variation of the measured metabolic parameters decreased significantly (p < 0.05) for 20 subjects out of 22 subjects.
ContributorsKrishnan, Ranganath (Author) / Tao, Nongjian (Thesis advisor) / Forzani, Erica (Committee member) / Yu, Hongyu (Committee member) / Arizona State University (Publisher)
Created2012
Description
The world of healthcare can be seen as dynamic, often an area where technology and science meet to consummate a greater good for humanity. This relationship has been working well for the last century as evident by the average life expectancy change. For the greater of the last five decades the average life expectancy at birth increased globally by almost 20 years. In the United States specifically, life expectancy has grown from 50 years in 1900 to 78 years in 2009. That is a 76% increase in just over a century. As great as this increase sounds for humanity it means there are soon to be real issues in the healthcare world. A larger older population will need more healthcare services but have fewer young professionals to provide those services. Technology and science will need to continue to push the boundaries in order to develop and provide the solutions needed to continue providing the aging world population sufficient healthcare. One solution sure to help provide a brighter future for healthcare is mobile health (m-health). M-health can help provide a means for healthcare professionals to treat more patients with less work expenditure and do so with more personalized healthcare advice which will lead to better treatments. This paper discusses one area of m-health devices specifically; human breath analysis devices. The current laboratory methods of breath analysis and why these methods are not adequate for common healthcare practices will be discussed in more detail. Then more specifically, mobile breath analysis devices are discussed. The topic will encompass the challenges that need to be met in developing such devices, possible solutions to these challenges, two real examples of mobile breath analysis devices and finally possible future directions for m-health technologies.
ContributorsLester, Bryan (Author) / Forzani, Erica (Thesis advisor) / Xian, Xiaojun (Committee member) / Trimble, Steve (Committee member) / Arizona State University (Publisher)
Created2012
Description
Air pollution is one of the biggest challenges people face today. It is closely related to people's health condition. The agencies set up standards to regulate the air pollution. However, many of the pollutants under the regulation level may still result in adverse health effect. On the other hand, it is not clear the exact mechanism of air pollutants and its health effect. So it is difficult for the health centers to advise people how to prevent the air pollutant related diseases. It is of vital importance for both the agencies and the health centers to have a better understanding of the air pollution. Based on these needs, it is crucial to establish mobile health sensors for personal exposure assessment. Here, two sensing principles are illustrated: the tuning fork platform and the colorimetric platform. Mobile devices based on these principles have been built. The detections of ozone, NOX, carbon monoxide and formaldehyde have been shown. An integrated device of nitrogen dioxide and carbon monoxide is introduced. Fan is used for sample delivery instead pump and valves to reduce the size, cost and power consumption. Finally, the future work is discussed.
ContributorsWang, Rui (Author) / Tao, Nongjian (Thesis advisor) / Forzani, Erica (Committee member) / Zhang, Yanchao (Committee member) / Karam, Lina (Committee member) / Arizona State University (Publisher)
Created2012
Description
The project is mainly aimed at detecting the gas flow rate in Biosensors and medical health applications by means of an acoustic method using whistle based device. Considering the challenges involved in maintaining particular flow rate and back pressure for detecting certain analytes in breath analysis the proposed system along with a cell phone provides a suitable way to maintain the flow rate without any additional battery driven device. To achieve this, a system-level approach is implemented which involves development of a closed end whistle which is placed inside a tightly fitted constant back pressure tube. By means of experimentation pressure vs. flowrate curve is initially obtained and used for the development of the particular whistle. Finally, by means of an FFT code in a cell phone the flow rate vs. frequency characteristic curve is obtained. When a person respires through the device a whistle sound is generated which is captured by the cellphone microphone and a FFT analysis is performed to determine the frequency and hence the flow rate from the characteristic curve. This approach can be used to detect flow rate as low as low as 1L/min. The concept has been applied for the first time in this work to the development and optimization of a breath analyzer.
ContributorsRavichandran, Balaje Dhanram (Author) / Forzani, Erica (Thesis advisor) / Xian, Xiaojun (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2012
Description
Obesity has consistently presented a significant challenge, with excess body fat contributing to the development of numerous severe conditions such as diabetes, cardiovascular disease, cancer, and various musculoskeletal disorders. In this study, different methods are proposed to study substrate utilization (carbohydrates, proteins, and fats) in the human body and validate the biomarkers enabling to investigation of weight management and monitor metabolic health. The first technique to study was Indirect calorimetry, which assessed Resting Energy Expenditure (REE) and measured parameters like oxygen consumption (VO2) and carbon dioxide production (VCO2). A validation study was conducted to study the effectiveness of the medical device Breezing Med determining REE, VO2, and VCO2. The results were compared with correlation slopes and regression coefficients close to 1. Indirect Calorimetry can be used to determine carbohydrate and fat utilization but it requires additional correction for protein utilization. Protein utilization can be studied by analyzing urinary nitrogen. Therefore, a secondary technique was studied for identifying urea and ammonia concentration in human urine samples. Along this line two methods for detecting urea were explored, a colorimetric technique and it was validated against the Ion-Selective method. The results were then compared by correlation analysis of urine samples measured with both methods simultaneously curves. The equations for fat, carb, and protein oxidation, involving VO2, VCO2 consumption, and urinary nitrogen were implemented and validated, using the above-described methods in a human subject study with 16 subjects. The measurements included diverse diets (normal vs. high fat/protein) in normal energy balance and pre-/post interventions of exercise, fasting, and a high-fat meal. It can be concluded that the indirect calorimetry portable method in conjunction with urine urea methods are important to help the understanding of substrate utilization in human subjects, and therefore, excellent tools to contribute to the treatments and interventions of obesity and overweighted populations.
ContributorsPradhan, Ayushi (Author) / Forzani, Erica (Thesis advisor) / Lind, Mary Laura (Committee member) / Wang, Shaopeng (Committee member) / Arizona State University (Publisher)
Created2023
Description
Realtime understanding of one’s complete metabolic state is crucial to controlling weight and managing chronic illnesses, such as diabetes. This project represents the development of a novel breath acetone sensor within the Biodesign Institute’s Center for Bioelectronics and Biosensors. The purpose is to determine if a sensor can be manufactured with the capacity to measure breath acetone concentrations typical of various levels of metabolic activity. For this purpose, a solution that selectively interacts with acetone was embedded in a sensor cartridge that is permeable to volatile organic compounds. After 30 minutes of exposure to a range of acetone concentrations, a color change response was observed in the sensors. Requiring only exposure to a breath, these novel sensor configurations may offer non-trivial improvements to clinical and at-home measurement of lipid metabolic rate.
ContributorsDenham, Landon (Author) / Forzani, Erica (Thesis director) / Mora, Sabrina Jimena (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2022-05
Description
Pervaporation is a membrane process suited to complex and highly contaminated wastewaters. Pervaporation desalination is an emerging area of study where the development of high-performance membranes is necessary to propel the field forward. This research demonstrated that sulfonated block polymer membranes (Nexar™)show excellent permeance (water passage normalized by driving force) of as much as 135.5 ± 29 kg m-2 hr-1 bar-1, with salt removal values consistently equal to or greater than 99.5%. Another challenging water management scenario is in spaceflight situations, such as on the International Space Station (ISS). Spaceflight wastewaters are highly complex, with low pH values, and high levels of contaminants. Current processes produce 70% wastewater recovery, necessitating the handling and processing of concentrated brines. Since recoveries of 85% are desired moving forward, further efforts in water recovery are desirable. An area of concern in these ISS water treatment systems is scalant deposition, especially of divalent ions such as calcium species. Zwitterions are molecules with localized positive and negative charges, but an overall neutral charge. Zwitterions have been used to modify the surface of membranes have shown to decrease fouling. Building a copolymer between zwitterions and other polymers, creates zwitterion layer on top of previously studied Nexar™ membranes. This coating demonstrates great promise to combat scaling, as it increases the hydrophilicity of the membrane surface measured via contact angle. The zwitterion membranes experienced reduced scaling, with the greatest difference being between 1617 ± 241 wt% on control membranes, to 317 ± 87 wt% on zwitterion coated membranes in the presence of CaCl2. In treating spaceflight wastewater, these zwitterion membranes are effective at retaining the acid in the feed, going from a pH value of 2 to 7 and reducing the contamination level of the feed, with a removal value of 99.3 ± 0.4%, measured through conductivity. These membranes also perform well in separation processes that do not require extreme vacuum and can be operated passively. By optimizing both membrane material properties and process conditions, achieving increased high levels of water recovery from spaceflight wastewaters is attainable.
ContributorsThomas, Elisabeth (Author) / Lind, Mary Laura (Thesis advisor) / Forzani, Erica (Committee member) / Perreault, Francois (Committee member) / Walker, W. Shane (Committee member) / Williamson, Jill P (Committee member) / Arizona State University (Publisher)
Created2023
Description
This study uses Computational Fluid Dynamics (CFD) modeling to analyze the
dependence of wind power potential and turbulence intensity on aerodynamic design of a
special type of building with a nuzzle-like gap at its rooftop. Numerical simulations using
ANSYS Fluent are carried out to quantify the above-mentioned dependency due to three
major geometric parameters of the building: (i) the height of the building, (ii) the depth of
the roof-top gap, and (iii) the width of the roof-top gap. The height of the building is varied
from 8 m to 24 m. Likewise, the gap depth is varied from 3 m to 5 m and the gap width
from 2 m to 4 m. The aim of this entire research is to relate these geometric parameters of
the building to the maximum value and the spatial pattern of wind power potential across
the roof-top gap. These outcomes help guide the design of the roof-top geometry for wind
power applications and determine the ideal position for mounting a micro wind turbine.
From these outcomes, it is suggested that the wind power potential is greatly affected by
the increasing gap width or gap depth. It, however, remains insensitive to the increasing
building height, unlike turbulence intensity which increases with increasing building
height. After performing a set of simulations with varying building geometry to quantify
the wind power potential before the installation of a turbine, another set of simulations is
conducted by installing a static turbine within the roof-top gap. The results from the latter
are used to further adjust the estimate of wind power potential. Recommendations are made
for future applications based on the findings from the numerical simulations.
dependence of wind power potential and turbulence intensity on aerodynamic design of a
special type of building with a nuzzle-like gap at its rooftop. Numerical simulations using
ANSYS Fluent are carried out to quantify the above-mentioned dependency due to three
major geometric parameters of the building: (i) the height of the building, (ii) the depth of
the roof-top gap, and (iii) the width of the roof-top gap. The height of the building is varied
from 8 m to 24 m. Likewise, the gap depth is varied from 3 m to 5 m and the gap width
from 2 m to 4 m. The aim of this entire research is to relate these geometric parameters of
the building to the maximum value and the spatial pattern of wind power potential across
the roof-top gap. These outcomes help guide the design of the roof-top geometry for wind
power applications and determine the ideal position for mounting a micro wind turbine.
From these outcomes, it is suggested that the wind power potential is greatly affected by
the increasing gap width or gap depth. It, however, remains insensitive to the increasing
building height, unlike turbulence intensity which increases with increasing building
height. After performing a set of simulations with varying building geometry to quantify
the wind power potential before the installation of a turbine, another set of simulations is
conducted by installing a static turbine within the roof-top gap. The results from the latter
are used to further adjust the estimate of wind power potential. Recommendations are made
for future applications based on the findings from the numerical simulations.
ContributorsKailkhura, Gargi (Author) / Huang, Huei-Ping (Thesis advisor) / Rajagopalan, Jagannathan (Committee member) / Forzani, Erica (Committee member) / Arizona State University (Publisher)
Created2017