Browsing by Author "Smith, Michael"

Now showing 1 - 14 of 14
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    Active Noise Control Simulations using the Transmission Line Matrix Method
    (2016) Gorobets, Militina; Smith, Michael; Nielsen, Jorgen; Manzara, Leonard
    Active noise control (ANC) focuses on removing unwanted sounds or vibrations in an environment with the use of sensors, actuators and a mathematical algorithm. New algorithms are typically evaluated in simulation prior to implementation. Despite the popularity of this research field, simulations tools are limited, and most verifications are performed using scripts that often simplify the propagation environment. This can lead to a strong mismatch between simulation and measurement results. The transmission line matrix method (TLM2) is a wave propagation algorithm that has previously found success in indoor wireless planning due to its ability to easily model complex environments. This thesis proposes an ANC simulator using the TLM2. Extensive capabilities of the simulator are demonstrated with generic wave propagation scenarios and two ANC algorithms. The simulator is implemented on the GPU to improve execution speed. The simulator is interfaced with MATLAB to enhance testability of new algorithms.
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    Advantages of making a SELFIE - Self Evaluation Learning Framework in Exams
    (2015-05-12) Marasco, Emily; Smith, Michael; Gorobets, Mila
    A steep learning curve is introduced by early emphasis on tools and techniques during science and engineering courses needed for hands-on, practical laboratory experiences. Associated discrepancies between a student’s perceived theoretical background and the practical application of that background knowledge leads to different study behaviours during quizzes and exams: 1. Those who have correctly taken into account the complexity level of each course component. 2. Those who believe they have taken the complexity changes into account; but need to study and seek mentoring because they have not. 3. Those who believe they are not coping with the complexity changes but are in fact doing well; perhaps these students should be moving some study time onto other course exams. To assist students in more accurately determining into which category they currently fall, we introduced a Self-Evaluation Learning Framework for use In Exams and quizzes – SELFIE. Following a decade of using an ad-hoc SELFIE and the increased interest in the advantages of self-assessment at the university level [1, 2], we have formalized the approach [3]. We present results from student self-analysis during midterm and final exams. We detail one approach to addressing student concerns about their self-evaluation – a “Make up your own question and answer it” question during final exams. Designed to provide an opportunity to boost marks for students interested in the course material but struggling, the Make-Your-Own Question has proved popular for students who want to be remembered by the instructor and get a good job or internship reference.
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    Discrete Fourier Transform Techniques to Improve Diagnosis Accuracy in Biomedical Applications
    (2018-01-08) Adibpour, Paniz; Smith, Michael; Fear, Elise; Frayne, Richard; Nielsen, John
    Transforming acquired data in time or space is necessary for many applications, due to practical constraints on time-domain sampling at high data rates or the requirement for algorithms to process frequency-domain data during the image reconstruction procedure. Therefore, the discrete Fourier transform (DFT) plays an important role in many fields for preprocessing, reconstruction or data analysis stages of algorithms. The hardware or physical constraints also necessitate acquisition of limited length raw data which results in DFT-imposed distortions after data processing for which low pass filters are considered as general solution. Through this thesis, fundamental DFT properties are investigated and an optimization method is introduced to take advantage of these properties. This method is a potential alternative to low pass filters which impose resolution loss to processed data. The formalized method is examined and validated using preliminary observer metrics for two magnetic resonance imaging reconstruction approaches and a microwave imaging technique.
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    Improved Cavitation Monitoring and Detection Methods for Focused Ultrasound Blood-Brain Barrier Disruption
    (2022-01) Khan, Sonia; Curiel, Laura; Curiel, Laura; Smith, Michael; Fear, Elise; Abbasi, Zahra
    Transcranial focused ultrasound (FUS) in combination with microbubbles has demonstrated promising outcomes in treatment of brain disorders by stimulating transient BBB disruption, allowing therapeutics to enter into the brain. Currently, time signals from a hydrophone are transformed into frequency domain to monitor cavitation activity during BBB opening. The area under the curve (AUC) in a 300 Hz bandwidth around the subharmonic is used as a metric to determine cavitation activity. However, given the available frequency resolution, there are very few points within the 300 Hz bandwidth for precisely analysing the AUC. Also, many recorded signals show no detectable subharmonic above the noise as the A/D calibration is overwhelmed due to the strong fundamental. These issues can result in the subject being under treated or over treated. This research aims to better monitor and control the cavitation phenomenon for BBB disruption by developing methods to improve the cavitation spectra. The acoustic signals captured by a hydrophone from the excited microbubble phantom were filtered with a low pass analog filter to improve the system’s dynamics of self-calibration by suppressing the strong fundamental. The acoustic signals were further improved with two proposed signal processing techniques, namely, Fourier interpolation via zero-padding to increase the spectral frequency resolution, and windowing, which allowed us to uncover previously unreported subharmonic side lobes. Additionally, we propose the bandwidth to be wider than the current 300 Hz for AUC to include the useful information in these side bands. Our proposed improvements were validated on animal data. Finally, the performance of our proposed improvements was compared to traditional methods by evaluating metrics for cavitation detection. Previous studies reported a steady increase in the AUC with increase in pressure, whereas our work presented that the AUC would rise drastically at the stable cavitation threshold indicating that maximum energy is concentrated in stable cavitation regime. Then, beyond this threshold, the AUC will drop before rising again, signifying the energy shift towards initiating inertial cavitation. Our findings can be beneficial to enhance cavitation detection metrics and we can actually visualize the different cavitation regimes when the AUC and power are evaluated for subharmonic.
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    Improved Classification of Optic Neuritis Patients Using Brain Visual Network Transfer Functions
    (2017-12-22) Shahrabi Farahani, Ehsan; Smith, Michael; Goodyear, Bradley; Sesay, Abu; Fapojuwo, Abraham
    One method to investigate how information propagates throughout brain networks is the transfer function (TF), which determines the amplification or attenuation of frequency components of signals from one brain region to another. Previous functional magnetic resonance imaging (fMRI) studies have demonstrated a disrupted cortical visual network (CVN) in the presence of optic neuritis (ON), which is often associated with the development of multiple sclerosis (MS). In this thesis, new approaches were developed to optimize TF metrics for resting state fMRI data for the purpose of distinguishing between the CVNs of healthy volunteers and ON patients. TF metrics were validated using receiver operating characteristics. Further development permitted the ability to distinguish CVNs between patients experiencing ON as a clinically isolated syndrome and ON patients with relapsing-remitting multiple sclerosis. Such a distinction has implications for the understanding of MS development and progression. Artificial neural networks were also explored as a potential tool to combine several TF metrics to further increase accuracy.
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    Recommended best practices for acquiring thermal imaging data from in-situ clinical environments and exploratory data analysis of COVID-19 data.
    (2024-09-18) Anderson, Chantelle; Di Martino, Elena; van Marle, Guido; Smith, Michael; Yanushkevich, Svetlana
    This thesis explores the use, process, and outcomes of low-cost, non-invasive, and non-radiating thermal imaging in in-situ clinical environments. The primary objective of the research was to develop best practice guidelines, enhancing the application of thermal imaging in in-situ clinical environments. These recommended best practices introduced a new general approach to acquire thermal images in in-situ clinical settings, which was validated in a COVID-19 clinical setting. A total of 109 participants were recruited from a Level 1 Trauma Center in Calgary, Alberta, Canada. The sample size was reduced to 38 participants (n=38) due to experimental limitations. To facilitate this research, a hand-held commercial medical grade device was designed and built. A tablet was outfitted with a commercial thermal sensor and encased with a 3D printed plastic protective case. The outfitted tablet was used to acquire 3 images from each participants (front, left and right views). Clinical data was also collected and aggregated with the thermal image data. The comprehensive dataset was used to explore potential coronavirus disease-2019 (COVID-19) thermal characteristics in humans. The primary contributions of this thesis include a detailed list of recommendations to acquire thermal imaging data in in-situ clinical environments, providing insights into the challenges, limitations, and nuances of in-situ thermal data collection. The study identified potential underlying patterns, anomalies, and characteristics within the data that could be used to differentiate COVID-19 infections from other infections. The results suggest that using multiple regions of interest has the potential to offer a more accurate indication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection status than single-region measurements, such as forehead thermometer readings. Thus, highlighting the promising potential of thermal imaging for clinical diagnostics, especially during pandemics, while recommending key guidelines to enhance its practical application in real-world medical settings.
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    Reliable Embedded Systems Development
    (2014-01-20) Deng, Dongcheng; Smith, Michael
    With software defects reducing profits in many fields, it is worthwhile to consider moving key defect reducing strategies from one development area into another. A considerable amount of effort has been contributed to adapt and adopt the success of Agile methods into the embedded domain as defect-reduction methods. However, limited efficient and effective tools constrain the applicability of the Agile philosophy. Moreover, little studies have been reported to summarize the current state of the Agile-inspired embedded software development (AIESD) domain. The implications of an overview of AIESD generated from a systematic mapping study are discussed. An Agile test support (ATS) co-processor was proposed to provide low-overhead test insertion capability to embedded processors. The performance of the ATS was compared to existing hardware-assisted test insertion techniques. A demonstration application shows the use of ATS co-processor in multi-threaded environment.
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    Shape Memory Alloy-based Whole Blood Glucose Monitoring Device: The e-Mosquito
    (2017) Wang, Gang; Mintchev, Martin; Yadid-Pecht, Orly; Smith, Michael; Yanushkevich, Svetlana; Murari, Kartikeya; Gavrilova, Marina; Kaminska, Bozena
    Diabetes Mellitus (DM) is a systemic disorder that results in elevated blood glucose levels in the body, leading to many secondary complications. Presently, manual fingerpicking tests remain the most popular method of blood glucose monitoring (BGM). However, the tests are often ignored by DM patients due to the pain and inconvenience. This thesis aims at addressing a growing demand for replacing the fingerpricking tests by presenting a wearable microsystem for minimally invasive, autonomous and pseudo-continuous blood glucose monitoring, the e-Mosquito. The proposed design of the e-Mosquito device aims to extract whole blood sample from a small lanced skin wound using a novel shape memory alloy (SMA)-based microactuator and directly measure the blood glucose level from this sample. A completely functional prototype of the e-Mosquito was developed. The prototype was first tested in-vitro on a custom-designed mechanical test station. Measurements showed that the output force and depth met the minimum requirements for reaching subcutaneous blood capillaries. The microactuation mechanism was also evaluated by extracting blood samples from the wrist of four human volunteers. 19 out of 23 actuations successfully reached capillary vessels below the wrist producing blood droplets on the surface of the skin. The integrated potentiostat-based glucose sensing circuit of the e-Mosquito device also showed a good linear correlation (R^2=0.9733) with measurements using standard BGM technology. These proof-of-concept studies demonstrated the feasibility of the SMA-based e-Mosquito device for replacing the fingerpricking tests in DM management.
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    Sound Ecology and Acoustic Health, Part 1: Developing a basic Android Application
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-07) Gaspard, Adrian; Smith, Michael; Lepine, Nicholas
    Introduction to periodical article: A background level of urban noise is, unfortunately, one of those inconveniences that we must put up with to live in a community. You and your neighbour can sympathize with each other at a BBQ about being awakened by the dawn chorus of birds or early morning commuter traffic noise. You can band together to solve that problem with a joint big win on the local lottery and buy new houses elsewhere. Sometimes, the noise can be such an issue across a wide community that even federal politicians can be stirred from their comfortable seat to assist in the investigation as in the case of the Windsor Hum (2009 - 2014, zugislanddocumentary.com). However, as mentioned in our urban noise article Circuit Cellar issues, the BBQ conversation might go along these lines. You say “That noise at 2 a.m. every night last week, hasn’t it been driving you crazy?” and your neighbour responds “What noise?” After such a conversation, it is worthwhile getting your hearing tested. There are conditions affecting the ears, such as Tinnitus or “ringing in the ears”, which could be alleviated with professional help. However, with that issue ruled out, you now have a noise in your house that nobody else in your neighborhood seems to have. It’s time to become a noise detective. There are apps to record your prowess in “singing in the shower” and those, to a limited degree, would be useful in capturing the noise. If your neighbour agrees, check at their house or in their garden. Everybody’s hearing is different and there’s a possibility that the noise you are hearing is there and they are just not sensitive to it. Recording is good - it confirms that something physical is present in several locations. However we want a little more than that. We have been working with local Acoustics firms who have suggested that people should look out for “home resonances” as playing a role in noise nuisances you hear and your neighbour does not. We have all seen neighbourhood kids playing with resonances - tiny, gentle kicks of their legs at just the right time can cause a playground swing to reach great heights. In a similar way, parts of your house - wall, basement concrete pad, or heating duct - can be constructed in such a way that they sympathetically vibrate with, and amplify, some tiny, gentle, totally insignificant incoming vibration through the air or ground. To analyze the frequency response of your house including resonances we need a “recording app” with a number of custom DSP extensions for resonance identification. Rather than undergoing the hassle of trying to gain access to - and then modify - the source code of an existing app, we took a more pragmatic approach. If the local teenagers can build their own Android apps, surely we can too! To build our own recording app, we would customize from online Android tutorials (developer.android.com/training). Fig. 1A outlines our plan for our first Android activity built without any teenage assistance necessary. When this WAT_AN_APP is finished we will be able to record and playback an audio .3GPP file using a modified Android MediaRecorder app and be able to better show to others that the noise problem we hear physically exists. However we also want to be able to use our own DSP experience from work to add any special analysis feature. In future articles we will look at using a different Android activity approach that allows us to capture sound into an uncompressed data buffer. Fig. 1B demonstrates that goal of using some DSP “spectral” analysis to identify an unwelcome “spectral” presence, a ghost. We extend the app to do more sophisticated analysis that uses graphics to display the presence of home resonances that might be impacting the acoustic health of your home.
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    Sound Ecology and Acoustic Health, Part 2: An Android Application for Recording Noise Nuisances
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-08) Gaspard, A; Smith, Michael
    Introduction to periodical: In our last month’s article, CC Issue 300, we light-heartily discussed a supposed back yard BBQ discussion between neighbours about urban noise nuisances. Unfortunately noise nuisances are real in some of our local Calgary Communities, and we are looking for some simple, inexpensive approaches to help people investigate and reduce the problem. We demonstrated the first steps of our solution - the development of an Android project with basic code to generate a main screen with a button that generated a welcome screen when pressed. We called this a WAT_AN_APP, meaning we were able to develop it Without Any Teenager Assistance being Necessary. In this article we want to extend our basic WAT_AN_APP project to recording and playing-back audio .3GPP files as shown in Fig. 1A. This will allow us to record any physical noises present that are less easily heard by others in your house or need more study as they are less noticeable during the day as they are hidden under traffic noise. In this article, we want to take a more adult approach – use a JEAC process that uses Just Enough Additional Code to make the new recording activity work
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    Sound Ecology and Acoustic Health, Part 2: An Android Application for Recording Noise Nuisances
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-08) Gaspard, Adrian; Smith, Michael
    Introduction to periodical: In our last month’s article, CC Issue 300, we light-heartily discussed a supposed back yard BBQ discussion between neighbours about urban noise nuisances. Unfortunately noise nuisances are real in some of our local Calgary Communities, and we are looking for some simple, inexpensive approaches to help people investigate and reduce the problem. We demonstrated the first steps of our solution - the development of an Android project with basic code to generate a main screen with a button that generated a welcome screen when pressed. We called this a WAT_AN_APP, meaning we were able to develop it Without Any Teenager Assistance being Necessary. In this article we want to extend our basic WAT_AN_APP project to recording and playing-back audio .3GPP files as shown in Fig. 1A. This will allow us to record any physical noises present that are less easily heard by others in your house or need more study as they are less noticeable during the day as they are hidden under traffic noise. In this article, we want to take a more adult approach – use a JEAC process that uses Just Enough Additional Code to make the new recording activity work.
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    Sound Ecology and Acoustic Health, Part 3: A Quantitative Ghost Hunting Application
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-09) Gaspard, Adrian; Smith, Michael
    Introduction to periodical: After CC Issues 300 and 301, we could boast to our local teenager that “WE” have developed an Android application. Last month, CC Issue # we added “just enough additional code” (JEAC) to record and play-back .3GPP files so we could show our neighbour at a back-yard BBQ that – “I am not imagining things -- look there are really local urban noise nuisances” (Fig. 1A). This time we are going quantitative with an audio record and analysis update of the WAT_AN_APP application for “Things that Go Boom at Night” – TGBN. This will either enable us to request lots of commiseration as the community noise are really bad or boast that we have more ghosts going “BOO(m)” at night than anybody else! QUICK RECAP: The idea is to leave the TGBN device running over a weekend. We are going to capture a 7 seconds sound recording if the community noise sound level gets above background level. When the sound stays high in intensity, a warning message (Android toast) will appear on our device’s screen. As a precaution, a scary “Boo” kind of sound will be outputted to intimidate any ghosts that MIGHT be present as we head off in the opposite direction.
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    Sound Ecology and Acoustic Health, Part 4: Time Domain Analysis
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-10) Gaspard, Adrian; Smith, Michael
    Introduction to periodical article: We have spent the last while working towards a mobile phone application to help identify a local noise nuisance problem. We joked with Mike’s neighbour’s kids that the record and play-back .3GPP file WAT_AN_APP application, Fig. 1A, was to impress them that “Without Any Teenage Assistance Necessary, we could write an Android APP” CC Issues ###. We then added just enough additional code (JEAC) to store an audio record for later analysis CC Issues ###. To continue the friendly tease in CC Issues ###, we pretended that the project code was actually designed to detect – “Things that Go BOOm at Night+ - how many “TGBN ghosts” there are in the neighbourhood (Fig. 1B). As they say “Be careful what you wish for!” Our neighbours got interested in the community noise issues we were really trying to measure. They had their teenagers explore the acoustic health of their home using our work-in-progress. Late yesterday, a knock on the door revealed our neighbours asking for help. Their eldest teenager had gone to the University of Pennsylvania. According to the Penn Arts and Sciences website sites.sas.upenn.edu/ghosts-healing, a group of scholars from literature, art history, nursing, archaeology, religious studies, science and medicine wants to take research on ghosts seriously. So our neighbour’s kid decided to volunteer with this group. This turned into a term project -- working on analysing room acoustics as a possible source of “that friendly spectral feeling”. Hence the frantic email message they wanted to pass on -- Term’s nearly over! Could you please get Mike to hurry up and fulfill his promise in that first CC article of providing enough information to do some “real” digital signal processing (DSP) analysis? While he was at it – could he get Adrien to add some graphics’ capability to display the frequency characteristics of the sounds in a room to make my term report more interesting! In Canada, it always good to keep on the right side of the neighbour’s kids as they are a good (inexpensive) labour source for shovelling snow off sidewalks. So we decide to write a RoomAcoustics Analysis Capability addition. Actually we wanted to be able to say that we had Penn-ed some code (sorry for the pun ( :-). ). First we will explain how to reliably excite a room resonance that can be captured by our existing TGBN detector code. We will graphically display the room audio signal to give us a first chance to compare resonance characteristics in different rooms. We found that looking for small differences in the captured signals displayed as a function of time meant working (slowly) with a lot of data. So we added a way to generate frequency information signal of captured signals using a discrete Fourier transform (DFT) algorithm code we grabbed from the web. Fig 2A shows the background noise recorded in our university lab. Having noticed a possible small 727 Hz ghost sleeping next to our desk, we tried to move around the room to better record its characteristic, Fig. 2B. The frequency characteristics of our two records look too similar for us to be sure that we have a non-snoring ghost close by. We decided to wake it up by outputting a three second Chirp, a sound burst from 50 to 1000 Hz. Fig. 2C show the frequency response of the Chirp signal, but there is not much there other than measuring the poor low frequency of our phone’s speaker. However, we accidently got close enough that we woke up the sleeping ghost which significantly changed the frequency response of the room, Fig 2D.
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    Sound Ecology and Acoustic Health, Part 5: Frequency Domain Analysis
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-11) Gaspard, Adrian; Smith, Michael
    Introduction from periodical article:; Last month we explained how finishing our mobile phone application for identifying community noise nuisance problem had suddenly become a “must complete” project for one of Mike’s neighbour’s kids at University. The eldest teenager had volunteered with a group of scholars from literature, art history, nursing, archaeology, religious studies, science and medicine wants to take research on ghosts seriously -- sites.sas.upenn.edu/ghosts-healing. The project involved working on analysing room acoustics as a possible source of “that friendly spectral feeling”. Fig. 1 B Last month we started working on fulfilling the promise from our first CC article to “provide enough information to do some “real” digital signal processing (DSP) analysis” We talked about grabbing the audio information and preparing it for display. This month we will handle the last part of our neighbour’s frantic email “Get Adrien to add some graphics’ capability to display the frequency characteristics of the sounds in a room to make my term report more interesting! The things we Canadians will do to stay on the right side of the neighbour’s kids so they will shovel snow!