11 research outputs found

    On the automated analysis of preterm infant sleep states from electrocardiography

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    On the automated analysis of preterm infant sleep states from electrocardiography

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    Developing a portable, customizable, single-channel EEG device for homecare and validating it against a commercial EEG device

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    There are several commercial electroencephalography (EEG) devices on the market; however, affordable devices are not versatile for diverse research applications. The purpose of this project was to investigate how to develop a low-cost, portable, single-channel EEG system for a research institute that could be used for neurofeedback-related applications in homecare. A device comparison was intended to examine what system requirements such a system would need to achieve the secondary objective of developing a neurofeedback application that demonstrates the functionalities of the new device. A portable, single-channel EEG device prototype was realized that consisted of an amplifier module called EEG Click, a single-board microcontroller, an electrode cable, some disposable wet electrode pads, and a custom 3D-printed headband. Three pieces of software were developed: firmware for the prototype, two supporting computer applications for data recording, and visual neurofeedback. The neurofeedback application replayed a first-person view roller coaster video at a varying frame rate based on the theta band's mean power spectral density (PSD). The prototype was compared against a commercial device, InteraXon MUSE 2 (Muse). Technical measurements included determining the amplitude-frequency characteristics and signal quality, such as signal-to-noise ratio (SNR), spurious-free dynamic range (SFDR), and total harmonic distortion (THD). Furthermore, four physiological measurements were performed on six human test subjects, aged between 21-31 (mean: 26.0, std: 3.11), to compare the altered brain activity and induced artifacts between the two devices. The four tests were respiratory exercise, head movement exercise, eye movement exercise, and paced auditory serial addition test (PASAT), where each measurement included several epochs with various stimuli. After the recordings, PSD was calculated for each bandpass filtered epoch, then the spectra were split into theta (4-8 Hz), alpha (8-12 Hz), and beta bands (12-30 Hz). The PSD values were averaged within each frequency band, and then these baseline-corrected mean values were the input for the repeated measures ANOVA statistical analysis. Results revealed that the amplitude-frequency characteristic of the prototype was low-pass filter-like and had a smaller slope than Muse's. The prototype's SNR, including and excluding the first five harmonics, was 6 dB higher, while SFDR and THD for the first five harmonics were roughly the same as Muse's. The two devices were comparable in detecting changes in most physiological measurements. Some differences between the two devices were that Muse was able to detect changes in respiratory activity in the beta band (F(8,16) = 2.510, p = .056), while the prototype was more sensitive to eye movement, especially lateral and circular eye movement in theta (F(2,8) = 9.144, p = .009) and alpha (F(2,8) = 6.095, p = .025) bands. A low-cost, portable EEG prototype was successfully realized and validated. The prototype was capable of performing homecare neurofeedback in the theta band. The results indicated it is worth exploring further the capabilities of the prototype. Since the sample size was too small, more complex physiological measurements with more test subjects would be more conclusive. Nevertheless, the findings are promising; the prototype may become a product once

    Development of a Plasmonic On-Chip System to Characterize Changes from External Perturbations in Cardiomyocytes

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    Today’s heart-on-a-chip devices are hoped to be the state-of-the-art cell and tissue characterizing tool, in clinically applicable regenerative medicine and cardiac tissue engineering. Due to the coupled electromechanical activity of cardiomyocytes (CM), a comprehensive heart-on-a-chip device as a cell characterizing tool must encompass the capability to quantify cellular contractility, conductivity, excitability, and rhythmicity. This dissertation focuses on developing a successful and statistically relevant surface plasmon resonance (SPR) biosensor for simultaneous recording of neonatal rat cardiomyocytes’ electrophysiological profile and mechanical motion under normal and perturbed conditions. The surface plasmon resonance technique can quantify (1) molecular binding onto a metal film, (2) bulk refractive index changes of the medium near (nm) the metal film, and (3) dielectric property changes of the metal film. We used thin gold metal films (also called chips) as our plasmonic sensor and obtained a periodic signal from spontaneously contracting CMs on the chip. Furthermore, we took advantage of a microfluidic module for controlled drug delivery to CMs on-chip, inhibiting and promoting their signaling pathways under dynamic flow. We identified that ionic channel activity of each contraction period of a live CM syncytium on a gold metal sensor would account for the non-specific ion adsorption onto the metal surface in a periodic manner. Moreover, the contraction of cardiomyocytes following their ion channel activity displaces the medium, changing its bulk refractive index near the metal surface. Hence, the real-time electromechanical activity of CMs using SPR sensors may be extracted as a time series we call the Plasmonic Cardio-Eukaryography Signal (P-CeG). The P-CeG signal render opportunities, where state-of-the-art heart-on-a-chip device complexities may subside to a simpler, faster and cheaper platform for label-free, non-invasive, and high throughput cellular characterization

    Artistic Modulation of Consciousness by Bioelectromagnetic Stimulation

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    The thesis demonstrates why the application of bioelectromagnetic stimulation as a medium of artistic expression allows for the production of new and unprecedented realisations of integrative art. Furthermore, the modulation of consciousness in human beings relating with such realisations is argued to be the core of a new practice of research resulting from the technological confluence of Philosophy, Art and Science. The Brunelleschi Experiment is examined in order to establish the assumption that one of the fundamental characteristics of Art is to impact consciousness of those interacting with its forms. The aspects of disembodiment of the previously referred experiment, instrumental in provoking such impact, are argued to be consistent with those found in the philosophy and practice of Fernando Pessoa. The practice of the Portuguese philosopher is presented as proto-foundational grounds of the new research practice proposed. The recent findings of Olaf Blanke, specially the ones regarding the induction of out-of-body experiences by bioelectromagnetic stimulation are reassessed as previous technological foundations of the new artistic realisations proposed. The practice of art was an instrumental part of the research and is therefore described as a methodology to access consciousness and generate knowledge, a thinking process. Research was undertaken in the context of two projects: Sensitive Spheres and Collectron. Both projects are representations of the social implications of perceiving human beings as electromagnetic manifestations. In the context of these projects, Bioelectromagnetism is understood as the study of the intersections between biological entities and the electromagnetic spectrum. Each project represents a culture of interactions between biological beings, including their spiritual dimension, in which art plays a fundamental role in creating alternative forms of communication as well as in congregating and mediating consciousnesses at a collective level. In conclusion, Homo Conscientis, an audiovisual integrative experience applying bioelectromagnetics, is presented as the first manifestation of the new practice proposed. Both its technical aspects and the observations resulting from its application have been thoroughly described.Fundacao para a Ciencia e Tecnologia, Portuga

    NASA Tech Briefs, Spring 1977

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    Topics: NASA TU Services: Technology Utilization services that can assist you in learning about and applying NASA technology; New Product Ideas: A summary of sel~ted innovations of value to manufacturers for the development of new products; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences
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