1,720,990 research outputs found
A 30 μW 30 fps 110 × 110 Pixels Vision Sensor Embedding Local Binary Patterns
No full textWe present a 110 × 110 pixel vision sensor that computes the Local Binary Patterns (LBPs) of an imaged scene with a power consumption of 30 μW at 30 fps. The LBP of a given pixel is a binary vector, encoding the direction and sign of image contrast with respect to its neighbors. Each LBP provides a visual description of an image's local structure that is widely used for texture and object recognition. In the sensor proposed here, each pixel detects its corresponding LBP with respect to its four neighboring pixels and saves this information into a digital map using 6 bits to encode each pixel. The operation is executed during the exposure time and requires 83 pW/pixel · frame to be computed. The chip is implemented in a 0.35 μm CMOS featuring 34 T square pixels with 26 μm pitch. We illustrate some examples of image description based on the LBPs output by the sensor
A Video Game-Integrated Electromyography Biofeedback Device for Use in Physical Therapy
Full text linkWe present a novel system to be used in the rehabilitation of patients with forearm injuries. The system uses surface electromyography (sEMG) recordings from a wireless sleeve to control video games designed to provide engaging biofeedback to the user. An integrated hardware/software system uses a neural net to classify the signals from a user’s muscles as they perform one of a number of common forearm physical therapy exercises. These classifications are used as input for a suite of video games that have been custom-designed to hold the patient’s attention and decrease the risk of noncompliance with the physical therapy regimen necessary to regain full function in the injured limb. The data is transmitted wirelessly from the on-sleeve board to a laptop computer using a custom-designed signal-processing algorithm that filters and compresses the data prior to transmission. We believe that this system has the potential to significantly improve the patient experience and efficacy of physical therapy using biofeedback that leverages the compelling nature of video games
MODELING POWER CONSUMPTION AND OPERATION IN A BISTABLE ELECTROWETTING-BASED DISPLAY
Full text linkGemstone Team VOLTAGETeam VOLTAGE is an undergraduate research team based in University of Maryland’s Gemstone research program. Their objective is to advance research related to modeling e-paper technologies. Experimentation with electrowetting display fabrication techniques, followed by modeling based on measured parameters is performed. Both numerical and circuit-based simulations are performed. Numerical simulations demonstrate correlations between pixel size, alpha constant, actuation voltage, and power consumption. Circuit-based simulations demonstrate a method for determining power consumption of an electrowetting-based display and give an accurate power consumption for a specified display
Lab-on-CMOS-Capacitance Sensor Array for Real-Time Cell Viability Measurements
No full textThis project addresses the need to enhance the functionality and reusability of existing CMOS chips for monitoring cell viability and facilitating visual inspection. The primary challenge tackled is the reduction of research downtime due to inefficient sensor replacement and the improvement of data collection methods.
To achieve this, the project integrates PCB design software, CAD software, and programming languages, including VHDL, C, and MATLAB. PCB design is utilized to create strategic board configurations aimed at streamlining the data collection process and ensuring the creation of a reliable and replaceable cell viability measurement device. These methods synergistically enhance CMOS chip functionality and usability, with a focus on streamlining packaging, facilitating hot-swappable system development, and establishing a data readout system.
Key achievements encompass the development of a hot-swappable system for effortless CMOS chip replacement, streamlined packaging to bolster chip longevity, and the establishment of a real-time data readout system. These advancements notably enhance research efficiency and data quality by minimizing downtime and improving the correlation of capacitance measurements with direct visual observations of cell behavior.
In the broader context of lab-on-a-chip technology and sensor development, these achievements deepen our understanding of cell behavior and expedite progress in drug screening, disease diagnostics, and tissue engineering. The integrated approach presented in this research marks a significant advancement in pushing the boundaries of lab-on-a-chip technology and its applications in biomedical research.National Science Foundatio
EMG Biofeedback Videogame System for the Gait Rehabilitation of Hemiparetic Individuals
Full text linkGemstone Team CHIPWe report a novel approach to electromyographic (EMG) biofeedback for post-stroke hemiparetic gait rehabilitation, using a videogame. An integrated hardware/software system facilitates gameplay of Tiger Woods PGA Tour 2004 in driving range mode by performing rehabilitation exercises. Real-time visual EMG biofeedback is provided as the patient performs exercises. Custom-built bioamplifiers and software collect, amplify, and filter the surface EMG signals from six lower-limb muscles, and score them by feature extraction. The ball is driven a distance proportional to each score. Exercises are scored by comparing the patient's EMG activation with target profiles. The user-friendly system is controlled by prompts on a personal computer. We envision two major benefits from this system. First, the biofeedback is offered in real-time, in a clear, intuitive form, and coupled with task-specific motions. Second, we hypothesize that adopting rehabilitation exercises to control a fun videogame will lead to greater adherence to the exercise regime, with accompanying improvements in gait
Low cost mobile EEG for characterization of cortical auditory responses
No full textWe report a low cost mobile EEG system for characterizing cortical auditory responses. The system is built using commercial off-the-shelf components and each unit costs less than $200. It measures seven EEG channels plus one audio channel (envelope only), and communicates the data to external devices via Bluetooth. A novel implementation was pursued in order to support local signal compression using compressed sensing. At the same time, it provides a low cost solution that is useful for recording cortical auditory responses and extracting clinically relevant features of the waveform. This system has been designed with the eventual goal of long term monitoring of the brain activity of schizophrenic patients outside a clinical setting, in order to better understand auditory hallucinations and manage their ongoing treatment. In this preliminary study we obtained simultaneous audio and cortical recordings of evoked auditory responses from normal healthy subjects wearing the EEG for several hours in duration. We report evoked auditory responses for 2 Hz and 40 Hz click trains. We also report alpha wave responses, demonstrating stable and high quality recordings over a five hour period
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Label-Free Detection of DNA
Full text linkIn recent years, developing more efficient DNA detection methods has been the center of interest in the growing field of molecular biology. Improved DNA detection methods can benefit the fields of forensic science, risk assessment, medical diagnostics, and genetics, along with a multitude of other technological fields. We are striving to detect the presence of a strand of DNA without the use of any labels. To do so, we must first be able to place DNA on a chiphich is the goal of my summer research project. This project is an excellent example of how the fields of microelectronics and biology are quickly merging into one. The success of this project will result in the creation of a parallel system that will allow us to analyze of various characteristics of a particular strand of DNA at the same time. The standard method currently used in molecular biology studies to analyze DNA binding involves fluorescent labeling. Basically, once the strand of DNA in question is labeled with the proper fluorescent tag, it is added to the chip surface, where it binds with the capture, or known strand of DNA that is bound to the surface. If the oligonucleotide in question is complimentary to the capture DNA, hybridization will occur and they will bind to one another. Fluorescence will be observed when the substrate surface is viewed under a fluorescence microscope. Although highly sensitive and widely available, fluorescence markers are photochemically unstable and require expensive optical devices for analysis. In addition, they can provide researchers with a false-positive result. For instance, a 25 mer oligonucletide that is complimentary to the capture DNA with the exception of one or two base pairs will still bind to the DNA on the substrate even though it will result in a mismatch error. Fluorescence will be observed regardlesseading the scientist to believe that the two strands are complimentary. Since both the chemical and electrical characteristics of the substrate will change upon binding of the DNA strand in question, we propose to approach the problem from an electrical standpoint by using Mr. Som Prakash capacitance sensor to measure the amount of binding between the two strands. We will initially follow the current protocol that uses fluorescence to measure the presence of DNA. We plan to test fully complementary and non-complementary DNA strands as well as strands containing 1, 5, or 10 mismatches. We will then measure fluorescence and capacitance levels. The fluorescence method is used purely as a control in this experiment. The purpose of this experiment is to determine whether or not the label-free, electrical approach is more accurate than the current chemical approach. We hope that the capacitance sensor will be able to detect changes in the strength of the bonds present between the purines and the pyrimidines of the double helix formed. Even if the proposed method is just as accurate as the chemical method, it could be used as the method of choice in the future since it is more efficient and will remove the need for optical instruments and fluorescent labeling
Low-power EEG monitor based on compressed sensing with compressed domain noise rejection
Full text linkWireless sensor nodes capable of acquiring and transmitting biosignals are increasingly important to address future needs in healthcare monitoring. One of the main issues in designing these systems is the unavoidable energy constraint due to the limited battery lifetime, which strictly limits the amount of data that may be transmitted. Compressed Sensing (CS) is an emerging technique for introducing low-power, real-time compression of the acquired signals before transmission. The recently developed rakeness approach is capable of further increasing CS performance. In this paper we apply the rakeness-CS technique to enhance compression capabilities for electroencephalographic (EEG) signals, and particularly for Evoked Potentials (EP), which are recordings of the neural activity evoked by the presentation of a stimulus. Simulation results demonstrate that EPs are correctly reconstructed using rakeness-CS with a compression factor of 16. Additionally, some interesting denoising capabilities are identified: the high-frequency noise components are rejected and the 60 Hz power line noise is decreased by more than 20 dB with respect to the state-of-the-art filtering when rakeness-CS techniques are applied to the EEG data stream
- …
