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Creators/Authors contains: "Thompson, David E."

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  1. Heart rate variability (HRV) features support several clinical applications, including sleep staging, and ballistocardiograms (BCGs) can be used to unobtrusively estimate these features. Electrocardiography is the traditional clinical standard for HRV estimation, but BCGs and electrocardiograms (ECGs) yield different estimates for heartbeat intervals (HBIs), leading to differences in calculated HRV parameters. This study examines the viability of using BCG-based HRV features for sleep staging by quantifying the impact of these timing differences on the resulting parameters of interest. We introduced a range of synthetic time offsets to simulate the differences between BCG- and ECG-based heartbeat intervals, and the resulting HRV features are used to perform sleep staging. Subsequently, we draw a relationship between the mean absolute error in HBIs and the resulting sleep-staging performances. We also extend our previous work in heartbeat interval identification algorithms to demonstrate that our simulated timing jitters are close representatives of errors between heartbeat interval measurements. This work indicates that BCG-based sleep staging can produce accuracies comparable to ECG-based techniques such that at an HBI error range of up to 60 ms, the sleep-scoring error could increase from 17% to 25% based on one of the scenarios we examined.

     
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  2. P300-based Brain-Computer Interface (BCI) performance is vulnerable to latency jitter. To investigate the role of latency jitter on BCI system performance, we proposed the classifier-based latency estimation (CBLE) method. In our previous study, CBLE was based on least-squares (LS) and stepwise linear discriminant analysis (SWLDA) classifiers. Here, we aim to extend the CBLE method using sparse autoencoders (SAE) to compare the SAE-based CBLE method with LS- and SWLDA-based CBLE. The newly-developed SAE-based CBLE and previously used methods are also applied to a newly-collected dataset to reduce the possibility of spurious correlations. Our results showed a significant (p<0.001) negative correlation between BCI accuracy and estimated latency jitter. Furthermore, we also examined the effect of the number of electrodes on each classification technique. Our results showed that on the whole, CBLE worked regardless of the classification method and electrode count; by contrast the effect of the number of electrodes on BCI performance was classifier dependent. 
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  3. The Project-Based Scientific Research is a new interdisciplinary course developed by the National Science Foundation (NSF - IUSE) funded STEM center at _______ State University. The implementation of this new course was one of the major three goals for this five year grant to strengthen the STEM undergraduate research community at ______ State University by helping undergraduates who are interested in hands-on and/or scientific research. The course is designed to introduce undergraduate junior and senior science, engineering technology and math students to the vibrant world of real research; to build foundational skills for research; to help STEM students meet potential mentors whose research labs they might join with the goal of gaining experimental research experience while on campus. On top of course content and requirements the following goals are aimed for the student and faculty mentors to strengthen the research community; (1) helping undergraduate students who are interested in research connect with faculty partners who are committed to mentoring undergraduates in research, (2) to guide students in reading through papers that introduce the type of research being carried out in a faculty partners lab, (3) to guide students in drafting a mini-review of 5 papers relevant to that research, (4) to guide students in identifying and writing up a research proposal which they will complete in the lab of the faculty partner. The learning objectives for the students in this course are summarized as; (a) by the end of this course, all students build a foundational understanding of the principles of STEM research through the exploration and discussion of important historical interdisciplinary projects; (b) interact with faculty researchers who perform projects across STEM disciplines; (c) be able to describe the similarities and differences between experimental and theoretical STEM research; (d) explore and present several possibilities for future research topics; (e) design and present a research prospectus, complete with a review of some of the relevant literature; (f) and be prepared to continue a research project with a chosen faculty mentor or mentors. First year, six academic departments out of eight participated this new course by offering a cross-listed course for their students under one major course taught by one of the PIs at the STEM Center. All the details such as challenges faced, outcomes, resources used, faculty involved, student and faculty feedback etc. for this course will be shared with academia in the paper. 
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  4. null (Ed.)