Browsing by Author "Yadid-Pecht, Orly"
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- ItemOpen AccessA CMOS active pixel sensor contact imager for cell detection in biosensing applications(2007) Tam, Terence; Yadid-Pecht, Orly; Jullien, Graham
- ItemOpen AccessA cmos aps image sensor with watermarking(2007) Nelson, Graham; Yadid-Pecht, Orly; Jullien, GrahamA novel idea is proposed for integrating digital watermarking capabilities into complementary metal-oxide semiconductor (CMOS) image sensors. The background of watermarking and previous hardware implementation is given and a simple digital watermarking scheme, ideal for implementation in a CMOS image sensor, is outlined. The watermarking algorithm was analyzed in terms of the effect on image quality, the statistics for successful watermark detection, and its susceptibility to attack. It was found that image quality could be high if less than three watermark bits were added to an image. A trend was also discovered that if the inequality 28 -/'MN 2 2048 is satisfied, where M and N are the dimensions of the image, in pixels, and 8 is the number of bits used for the watermark values, successful detection statistics will be obtained. It was also demonstrated that removing a watermark placed with this particular algorithm is relatively easy using low-pass filters; however, extracting the watermark from a watermarked image for insertion into an unauthorized image was accomplished and represents a greater threat. A device prototype was designed and fabricated and the results are discussed. The design of key components is highlighted in the context of the larger system. The operation of the chip in terms of signals and timing is given. Successful fabrication turned out to be an elusive goal and the difficulties encountered provide valuable information to the next phase of the project, recently submitted for fabrication. Finally, the noise data show conclusively that fixed pattern noise (FP ) is a useful source for key generation. It allows for the unique identification of sensors through the key generation process; however, small changes in the input data can affect the key, if the length of the key is large enough. Keys should be stored in non-volatile memory on the image sensor in order to speed up the image capture process. In summary, a complete system from sensor to key generation to embedding and detection of digital watermarks has been created, and can help provide a much needed boost to image veracity in target applications.
- ItemOpen AccessA cmos image sensor based miniature fluorescence detection system for biosensing applications(2010) Beiderman, Marianna; Yadid-Pecht, Orly
- ItemOpen AccessA Secure, Low Power and Low Hardware Digital Watermarking System for Real-time Surveillance Video Authentication(2013-01-25) Roy, Sonjoy Deb; Yadid-Pecht, Orly; Jacobson, Michael JohnReal-time video authentication is a major concern for surveillance video cameras. In this thesis, we present a secure, low power and low hardware video watermarking system that inserts an invisible semi-fragile watermark into the video stream for real-time surveillance video authentication during the commonly used MPEG-4 encoding process with insignificant video quality degradation. Our watermarking system was prototyped on an Altera® Cyclone FPGA device and was evaluated to ensure the achievement of high processing speed, low power and low hardware goals. In addition, we propose a general threat model for video watermarking system intended for real-time surveillance video authentication. Grain – 128a, a secure stream cipher, was chosen as a source of low hardware cryptographically secure pseudorandom number generator to generate a secure watermark sequence. The system was also assessed based on different recognized watermarking attacks and the proposed threat model to provide evidence for the achievement of the security goals.
- ItemOpen AccessAn Automated Hardware-based Tone Mapping System For Displaying Wide Dynamic Range Images(2013-05-21) Ofili, Chika; Yadid-Pecht, OrlyTone mapping algorithms are used to adapt captured wide dynamic range (WDR) scenes to the limited dynamic range of available display devices. In this thesis, a real-time hardware implementation of an exponent-based tone mapping algorithm is presented. An automatic parameter selector was designed for this algorithm in order to achieve good tone-mapped images without manual reconfiguration of the tone mapping algorithm. Both algorithms were implemented in Verilog and synthesized for an FPGA device. The hardware architecture employed a combination of parallelism and system pipelining so as to achieve a high performance in power consumption, hardware resources usage and processing speed. In addition, modifications to the tone mapping algorithm were implemented so as to increase the image and video quality of the tone-mapped image frames. Objective image quality assessment shows that the improved tone mapping algorithm attains higher image quality scores than the original tone mapping operator.
- ItemOpen AccessAn imaging system with watermarking and compression capabilities(2009) Shoshan, Yonatan; Yadid-Pecht, Orly
- ItemOpen AccessAn Integrated, Lensless, Miniature and Portable Contact Imaging System for Fluorescence Spectroscopy(2014-09-15) Blockstein, Lior; Yadid-Pecht, OrlyIn this work, two different contact imaging systems were designed, fabricated and tested. The first system was designed to allow continuous, non-invasive imaging of calcium changes in multiple neurons. This is particularly important for studying brain functionality. First, emission filter for the system was designed, fabricated and tested. The filter used polyvinyl as a chromophore for UV light attenuation and polyvinyl acetate (PVAc) as a chromophore holder. The neurons were loaded with Fura-2 AM, a calcium sensitive fluorescent dye, which has dual excitation wavelengths at 340 nm and 380 nm with ratiometric emission at ~510 nm. Measurements with the PVAc based benzophenone-8 (PVACB-8) filter revealed an attenuation of approximately two and a half orders of magnitude, which was sufficient to collect fluorescence signal from Fura-2 AM loaded neurons. The PVAcB-8 filter was compared with a commercially available dichroic filter and proven more efficient in fluorescent imaging. The developed PVAcB-8 filter was used in the design, fabrication and verification of a novel complementary metal oxide semiconductor (CMOS) imager based miniature lensless contact imaging system. The device consisted of a removable, absorption filter interfaced with a CMOS imaging sensor and an external DG-4 lamp for excitation. The system was used to acquire fluorescent images from live neurons by monitoring calcium changes with Fura-2 AM dye. Fura-2 AM loaded Lymnaea stagnalis neurons were stimulated with dual excitation wavelengths of 340 nm and 380 nm; the image sensor detected 510 nm emission. It was shown that the system was capable of detecting intracellular calcium changes in Fura-2 loaded neurons. Further, this sensor also enabled viewing of multiple neurons over a large surface area simultaneously, an option that is not readily available in conventional light microscopy. The second system was designed to allow continuous, monitoring of chlorophyll and colored dissolved organic matter (CDOM) in an aquatic environment. A continuous assessment of these two water quality parameters can be used for determining the health of a body of water, in anticipation and a possible prevention of harmful phenomena. Design, fabrication and verification of a proof-of-concept miniature fluorometer, for continuous assessment of two parameters for water quality are presented here. The fluorometer system utilized light emitting diodes (LEDs) for fluorescence excitation and absorption filters, for excitation light attenuation. Excitation LED for Chlrorophyll had peak emission at 465nm and excitation LED for colored dissolved organic matter (CDOM) had peak emission at 341nm. The prototype device demonstrates the concept of attaching two different absorption filters, onto a single sensor array, for measuring fluorescence signals from two different fluorescent dyes. The system’s abilities to detect fluorescence from various concentrations of fluorescein as a close simulant and calibration standard for Chlrorophyll; and Quinine sulfate dihydrate (QSD) as a simulant and calibration standard for CDOM were tested. Fluorescent signal for fluorescein between 0.7 nM to 1000 nM and QSD between 2 ppb to 500 ppb was successfully acquired. Both systems demonstrate alternative approach to fluorescent imaging. The field of view in a contact imaging system is defined by the size of the pixel array and can be over 1cm2. The light collection efficiency (LCE) can be as high as 50%, and unlike in a conventional microscope there is no tradeoff between the field of view and the LCE. The pixel array area can be used for a single fluorescent application or divided into multiple sub sections for multiple fluorophores. The proof of concept designs presented in this thesis demonstrate that contact imaging systems are capable to compete against the existing systems and may replace them in the future.
- ItemOpen AccessAn Ultra-Low Noise, Fully Differential Active Reset CMOS Imager with Transistor Based Column Parallel Common Mode Feedback for Spectrally Constructed Background Illumination Rejection(2016) Shahin, Saharnaz; Yadid-Pecht, OrlyAn ultra-low noise, ultra-sensitive fully differential CMOS imager for background illumination rejection is presented. Fabricated by TSMC35 technology, the pixel is able to detect very low light signals and discern them from backgrounds exceeding their intensity. Measurements indicate a common mode rejection ratio (81.6 dB), very high sensitivity (200 V/Lux.s), and noise floor of 4 electrons. Obtained figures agree with theoretical assessments and simulations, proving the pixel to be a basis of a sensing element in ultra-sensitive continuous time or gated applications. As a second contribution, to stabilize the DC output, a transistor based common mode feedback (CMFB) is added (AMSp35 technology). By moving the load and CMFB to column periphery, number of transistors per pixel have reduced to 12, and improvements in pixel size and fill factor are achieved. Simulations promise a functional imager with high gain (50 dB) and noise floor of 98 µV.
- ItemOpen AccessCatheter-Based Acoustic Interrogation Device for Monitoring Motility Dynamics of the Lower Esophageal Sphincter(2015-09-30) Lu, Qian; Mintchev, Martin; Yadid-Pecht, OrlyDysfunction of the lower esophageal sphincter (LES) could result in various gastrointestinal disorders.However, minimally-invasive technology for direct, long-term, ambulatory monitoring of the dynamics of the LES is lacking. This thesis aims at filling this void by presenting a novel, catheter-based acoustic interrogation device for real-time monitoring the motility dynamics of the LES. The device was first tested in-vitro on a custom-designed LES simulator. Measurements showed statistically significant Pearson correlation coefficients (p<0.05). In a pilot test on a canine model, the device successfully detected an episode in which the LES was forced opened and closed by a transoral endoscope, which was monitored by a second, transpyloric endoscope positioned in the distal stomach. The dynamics of the LES was independently confirmed by frame-by-frame endoscopic video analysis. The proposed acoustic catheter has the potential for facilitating the diagnosis of LES-related diseases.
- ItemOpen AccessCMOS Laser Diode Drivers for Supercontinuum Generation(2016) He, Yuting; Yadid-Pecht, Orly; Barclay, Paul; Belostotski, LeonidThere have been intense research efforts on developing compact and low-cost supercontinuum generation (SCG) systems, which have various application areas including telecommunications, spectroscopy, and optical coherence tomography. This research employs complementary metal–oxide–semiconductor (CMOS) technology to design and implement two integrated laser diode drivers for reducing the size and cost of SCG systems. A continuous-wave CMOS driver with a maximum output current of 600 mA is developed for driving a laser diode in an erbium-doped fiber amplifier (EDFA). A picosecond pulsed CMOS driver is designed and applied for gain-switching a laser diode to produce optical pulses with a pulse width of 200 ps and a repetition rate of 5.6 MHz. The gain-switched laser diode output is amplified by an EDFA and then launched into a highly nonlinear fiber for SCG. The generated supercontinuum has an average power of 62 mW and a spectral bandwidth of 806 nm.
- ItemOpen AccessCompact Optical Sensing Systems for pH and Other Substances Detection - Theory and Implementation(2016) Cao, Muyun; Yadid-Pecht, Orly; Yadid-Pecht, Orly; Murari, Kartikeya; Chodavarapu, VamsyChemical detection is of importance in research and industry. Optical sensors based on contact imaging realize the chemical detection in compact, efficient and inexpensive ways. In the first project real-time optical pH sensor based on complementary metal–oxide–semiconductor (CMOS) contact imaging and microfluidics, an optical contact imaging sensor for pH detection with capillary microfluidics is proposed. The CMOS array detects the changes of light intensity after absorption by phenol red doped sol-gel filters while the level of absorbance corresponds to a pH value of the analyte. Deposition methods of sol-gel are optimized and compared. In the second project, real-time optical concentration sensor based on Raman scattering, CMOS contact imaging is presented. This biochemical optical sensor is designed for detecting the concentration of solutions. It is built with a laser diode, an optical filter, a sample holder and a commercial CMOS sensor.
- ItemOpen AccessDual Extension CMOS Imager and Peripherals for Biomedical Applications(2012-09-27) Dattner, Yonathan; Yadid-Pecht, OrlyA dual extension CMOS imager, also known as a High and Low Light Imager (HALLI), and peripherals for biomedical applications is presented in this thesis. The HALLI utilizes a single column parallel partitioned pixel amplifier with variable topology for the detection of both high and low light levels in the same frame. For fluorescence detection the fabrication of a low cost poly-acrylic acid (PAA) based emission filter integrated with the CMOS contact imager is introduced. An additional peripheral proposed in this research is a rail-to-rail differential difference amplifier which can be integrated as part of the imager architecture and will allow for high resolution analog-to-digital conversion using a newly developed expanding technique. The HALLI and peripherals are key components towards achieving a lab-on-a-chip device for biomedical applications.
- ItemOpen AccessEfficient Multiparty Computation from Lossy Threshold Encryption(2019-09-26) Nargis, Isheeta; Eberly, Wayne; Jacobson, Michael S.; Safavi-Naini, Reihaneh S.; Fong, Philip W. L.; Reardon, Joel; Yadid-Pecht, Orly; Wei, RuizhongThis dissertation includes four contributions concerning secure multiparty computation. The first contribution is a new lossy threshold encryption scheme. This is the first encryption scheme that is both a lossy and a threshold encryption scheme. The second contribution is a new oblivious transfer protocol secure against erasure-free one-sided active adaptive adversaries. The third contribution is a new two-party computation protocol for the evaluation of boolean circuits that is secure against erasure-free one-sided active adaptive adversaries. As a building block of this protocol, a new cut-and-choose oblivious transfer protocol is designed. The fourth contribution is a new multiparty computation protocol for the evaluation of arithmetic circuits that is secure against covert adversaries. Protocols that are part of the second, third and fourth contributions improve the communication complexity, the number of public key encryption operations and the number of exponentiation operations over existing protocols for the same problems that provide the same or higher levels of security.
- ItemOpen AccessElectromechanical Shape Memory Alloy Actuators for Blood Extraction(2017) Berka, Martin; Mintchev, Martin; Yadid-Pecht, Orly; Maundy, Brent; Dalton, ColinThis thesis concerns the design, prototyping and testing of a series of compact electromechanical actuators for drawing capillary blood for analysis by the e-Mosquito wearable, autonomous glucose monitoring system for diabetes. All the designs used contracting shape memory alloy wires, fixed geometry and millimetre-scale moving parts, primarily to extend a disposable lancet needle from the device and into the skin. The lancet was to enter the skin at an acute angle that increased to 90° at full extension, with the goal of increasing blood flow. Attention was paid to isolation and replaceability of external parts, improving manufacturability and increasing actuator power. Satisfactory control and extension of the lancet along the intended path were achieved, leading to the conclusion that the increased elastic response of skin makes angled needle insertion impractical and to the investigation of other techniques for blood sampling with autonomous devices.
- ItemOpen AccessEnhanced Electrogastrography Using Transcutaneous Intraluminal Impedance Measurements (TIIM)(2016) Poscente, Michael Dennis; Mintchev, Martin; Yadid-Pecht, Orly; Bartley, Norman; Matyas, John; Murari, Kartikeya; Andrews, ChristopherGastric motility and gastric emptying rates have been implicated in the symptoms of functional dyspepsia and gastroparesis. The current gold standard to assess gastric emptying is scintigraphy, which is limited by standardization and radiation concerns. This highlights the need for a novel method of assessing gastric motility. Transcutaneous Intraluminal Impedance Measurement (TIIM) is a novel method of assessing gastric motility. By measuring the dynamics of a known signal emitted from a battery-powered gastric retentive oscillator within the stomach, gastric motility can be quantified. In an eight-dog sham comparison study, TIIM was compared to force transducers implanted on the stomach. Two assessment metrics demonstrated statistically significant Pearson correlation coefficients between active TIIM pills and the force transducers (p<0.01, p<0.05), but not when TIIM pills were replaced by sham deactivated pills (p>0.1, p>0.1). A novel portable TIIM receiver was also proposed and tested in the lab to facilitate future ambulatory studies.
- ItemOpen AccessExtremely Low Frequency Detection for Biometric Sensing(2023-09-10) White, Oliver; Yadid-Pecht, Orly; Donev, Jason; Fear, Elise; Curiel, LauraHuman detection is an important aspect of security and surveillance and is a highly researched area, typically using cameras, infrared sensors, or radar. Extremely Low Frequency (ELF) electromagnetic waves, ranging from 0.03 Hz to 300 Hz, offer unique advantages for human detection due to their ability to penetrate various materials, including walls and obstacles. The human body generates a weak magnetic field due to various physiological processes and is measurable within the ELF range. The goal of this thesis is to detect ELF signals emitted by human subjects using an ELF magnetometer and to rapidly distinguish the presence of a human from background noise. A large air-core magnetic induction coil is designed and constructed in conjunction with a low-noise, high-impedance amplification circuit to independently measure the ELF signals from background noise and two human subjects in a semi-remote, non-shielded location. A sampling frequency of 44.1 kHz was used, and the power spectrum density (PSD) was computed for each 3-second data segment. Using a Recurrent Neural Network (RNN) structure, several binary classification models were trained with supervised learning on the PSD sequences between 0.3 and 30 Hz to distinguish background data from human data. The candidate RNN models achieved an average accuracy of above 80% using K-Fold cross-validation on the limited dataset. Overall, the performance of the RNNs was high for one subject, and low for the other subject. It was found that a significant factor in distinguishing a human from background noise was the change in diurnal ELF background power levels between measurements. The results indicate the use of ELF data from humans has the potential for rapid human detection, however, requires a larger dataset for further consideration as a biometric device.
- ItemOpen AccessFluorescence-based gluten detection using aptamer hybrid(2019-04-05) Vastarey, Nikhil Suresh; Yadid-Pecht, Orly; Turner, Raymond Joseph; Murari, Kartikeya; Birss, Viola I.This thesis describes different facets of the Gluten detection project. This interdisciplinary project contains aptamer bio-chemistry, sol-gel based optical filters and has explored immobilization techniques for gluten sensing. The aptamer biochemistry contains a single stranded oligonucleotide in combination with PEG and Graphene oxide to enable fluorogenic sensing of gluten. Different food matrices are explored where changes in gluten detection ability can be seen with different aptamer hybrids. The protocol for optimizing the aptamer assay, establishing standard gliadin standards and extraction procedures were optimized. On optimizing the assay parameters, the aptamer sensor is then evolved through different strategies, and its effects are seen on food sample testing. To move towards a strategy for room temperature storage and microfluidic-integration, different immobilization strategies are explored. These include sol-gel based aptamer encapsulation, and aptamer immobilization on an amine-based sol-gel hybrid. The efficiency of binding is gauged through fluorescent experiments on epi-fluorescent microscope. To miniaturize the instrumentation related to fluorescence detection, this thesis implements droplet-based absorbance filters using sol-gel polymerization technique. In accordance with the Beer-Lambert’s law, different dyes are used to obtain absorbance spectra to enable fluorescence transmission into the CMOS imager. A dye is eventually selected, and aptamer-gliadin binding experiments illustrate the miniaturized optical system’s ability to differentiate gluten’s concentration
- ItemOpen AccessHardware implementation of a digital video watermarking system(2010) Li, Xin; Yadid-Pecht, Orly
- ItemOpen AccessHigh-Performance CMOS Image Sensor and System for Imaging Tissue Hemodynamics(2014-09-23) Zhang, Xiao; Murari, Kartikeya; Yadid-Pecht, OrlyMonitoring changes in tissue oxygenation and blood volume is an important aspect of understanding the mechanisms of many diseases and creating corresponding therapeutic interventions. Spectroscopic imaging is adopted in my research to provide a non-contact recording method. Traditionally, such imaging is performed in anesthetized and restrained animals using benchtop instrumentation or miniaturized systems connecting to benchtop instruments through optical fibers or electrical cables, which limits the design and scope of studies. To create a miniaturized imaging system that realizes stand-alone operation on awake and freely-moving rats, I designed and implemented an imaging system, consisting of a miniaturized optical system, a high-performance complementary metal oxide semiconductor (CMOS) image sensor and a storage circuit. The system was electrically and optically characterized and proved to be capable of imaging reflectance changes related to tissue hemodynamics in response to deep brain stimulation (DBS).
- ItemOpen AccessLeakage Prevention and Detection in Pipelines Utilizing a Wireless Information and Communication Network(2018-01-03) Valentin de Oliveira, Thiago; Mintchev, Martin P.; Gemma Lu, Qingye; Onen, Denis; Yadid-Pecht, Orly; Mintchev, Martin P.Major environmental concerns have arisen due to a series of pipeline leakage incidents. Several systems have been proposed to identify and locate leakages; however, incidents still persist and pipeline acceptance from the public has become compromised. In order to address the need for early leakage detection, as well as leakage prevention, a novel pipeline system is proposed. This concept builds on the already existing pipe-in-pipe design, by segmenting the pipeline system with segmentation rings and embedding a wireless network in the annular airgap between the two pipe layers. Presence of fluid in the case of a leakage causes degradation of the wireless network. The leak is detected in real time by an external central unit connected to the wireless network, as demonstrated with a 6'8'' experimental pipeline setup. An analysis of the US pipeline system is provided, along with a cost estimate of implementing such technology.