Movers and Shakers: Kinetic Energy Harvesting for the Internet of Things

Numerous energy harvesting wireless devices that will serve as building blocks for the Internet of Things (IoT) are currently under development. However, there is still only limited understanding of the properties of various energy sources and their impact on energy harvesting adaptive algorithms. Hence, we focus on characterizing the kinetic (motion) energy that can be harvested by a wireless node with an IoT form factor and on developing energy allocation algorithms for such nodes. In this paper, we describe methods for estimating harvested energy from acceleration traces. To characterize the energy availability associated with specific human activities (e.g., relaxing, walking, cycling), we analyze a motion dataset with over 40 participants. Based on acceleration measurements that we collected for over 200 hours, we study energy generation processes associated with day-long human routines. We also briefly summarize our experiments with moving objects. We develop energy allocation algorithms that take into account practical IoT node design considerations, and evaluate the algorithms using the collected measurements. Our observations provide insights into the design of motion energy harvesters, IoT nodes, and energy harvesting adaptive algorithms.Comment: 15 pages, 11 figure

Morphology and performance in pentacene

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 57-60).by Ioannis Kymissis.M.Eng

Project-based Learning within a Large-Scale Interdisciplinary Research Effort

The modern engineering landscape increasingly requires a range of skills to successfully integrate complex systems. Project-based learning is used to help students build professional skills. However, it is typically applied to small teams and small efforts. This paper describes an experience in engaging a large number of students in research projects within a multi-year interdisciplinary research effort. The projects expose the students to various disciplines in Computer Science (embedded systems, algorithm design, networking), Electrical Engineering (circuit design, wireless communications, hardware prototyping), and Applied Physics (thin-film battery design, solar cell fabrication). While a student project is usually focused on one discipline area, it requires interaction with at least two other areas. Over 5 years, 180 semester-long projects have been completed. The students were a diverse group of high school, undergraduate, and M.S. Computer Science, Computer Engineering, and Electrical Engineering students. Some of the approaches that were taken to facilitate student learning are real-world system development constraints, regular cross-group meetings, and extensive involvement of Ph.D. students in student mentorship and knowledge transfer. To assess the approaches, a survey was conducted among the participating students. The results demonstrate the effectiveness of the approaches. For example, 70% of the students surveyed indicated that working on their research project improved their ability to function on multidisciplinary teams more than coursework, internships, or any other activity

Wearable toe band system for monitoring of peripheral artery disease

Approximately 8 to 12 million people in the United States suffer from peripheral artery disease (PAD). PAD causes narrowed arteries and reduces blood flow to the lower extremities. People with PAD begin to experience discomfort and pain while walking. Untreated PAD can lead to ulcers, gangrene, and amputation. Before experiencing those severe conditions, detection of narrowing blood vessel enables early diagnosis and treatment. Therefore, accurate and timely diagnosis is necessary. Please click Additional Files below to see the full abstract

Trap States Ruling Photoconductive Gain in Tissue-Equivalent, Printed Organic X-Ray Detectors

Organic semiconductors are excellent candidates for X-ray detectors that can adapt to new applications, with unique properties including mechanical flexibility and the ability to cover large surfaces. Their chemical composition, primarily carbon and hydrogen, makes them human tissue equivalent in terms of radiation absorption. This is a highly desirable property for a radiation dosimeter to be employed in medical diagnostics and therapy, however a low-Z composition limits the absorption of ionizing radiation. The detection efficiency can be enhanced by considering the photoconductive gain (PG) effect, a significant contributor to the ionizing radiation detection mechanism in this class of materials. In this work, a process of controlled solution deposition by nozzle printing and crystallization of an organic semiconductor thin film is demonstrated whereby a flexible, arrayed thin-film X-ray detector with record X-ray sensitivities among flexible radiation detectors (S = (9.0 +/- 0.4) x 10(7) mu C Gy(-1) cm(-3)) is developed. The excitonic peaks responsible for the activation of the PG effect are investigated and identified using a novel technique called photocurrent spectroscopy optical quenching, and the analysis of the changes in trap states is further demonstrated

The Role of Race in Admission to a Dual Diagnosis Unit Versus General Inpatient Psychiatric Unit in those with Active Substance Use

Psychiatric disorders are highly comorbid with substance use disorders, and the presence of co-occurring conditions increases severity of illness and complicates recovery. Those with comorbid mental illness and substance use disorders may benefit from specialized services, specifically integrated dual diagnosis treatment. Admission to a dual diagnosis unit requires health care providers to consider a number of factors, including severity of illness, psychiatric history, bed availability, and providers’ perceived likelihood of benefit of specialized services. Ideally, decisions regarding the necessity of substance use treatment are made independent of race, and yet, racial disparities exist among those who are offered substance use treatment. The aim of this study was to evaluate the demographic differences of patients who are identified as having active substance use admitted from the comprehensive psychiatric emergency program (CPEP) to a dual diagnosis unit versus those admitted to a general inpatient psychiatric unit. Our study consists of a retrospective analysis of patients, aged 18–90 (n = 100), admitted to either a dual diagnosis unit (8B) or general psychiatric unit (6K) at Mount Sinai Beth Israel (MSBI), a private metropolitan hospital in New York City, between November 1st to November 30th, 2020. We hypothesized that there are racial disparities in unit assignments while accounting for a variety of potentially relevant demographic and clinical variables. The primary outcome was a comparison of demographic factors, particularly racial composition, of those admitted to the dual diagnosis unit versus those admitted to the general psychiatric unit. After accounting for 6 clinical and 3 other demographic variables, patients of Black race were over 5 times more likely (adjusted odds ratio 5.31; P = 0.011) to be assigned to 8B than patients of White, Asian, or Other race. Additional contributors to 8B assignment were male gender, IM or IV PRNs, and documented substance use ('Table 1'). There were no significant differences between Black and Non-Black patients in rates of substance use detected on toxicology ('Table 2'). These findings suggest that race may be a driving factor in unit assignment, and unconscious racial bias may potentially confound admission decision-making, limiting access to available resources and services for some populations. More research is needed to understand factors contributing to racial disparities in substance use treatment

An Implantable Piezofilm Middle Ear Microphone: Performance in Human Cadaveric Temporal Bones

Purpose: One of the major reasons that totally implantable cochlear microphones are not readily available is the lack of good implantable microphones. An implantable microphone has the potential to provide a range of benefits over external microphones for cochlear implant users including the filtering ability of the outer ear, cosmetics, and usability in all situations. This paper presents results from experiments in human cadaveric ears of a piezofilm microphone concept under development as a possible component of a future implantable microphone system for use with cochlear implants. This microphone is referred to here as a drum microphone (DrumMic) that senses the robust and predictable motion of the umbo, the tip of the malleus. Methods: The performance was measured of five DrumMics inserted in four different human cadaveric temporal bones. Sensitivity, linearity, bandwidth, and equivalent input noise were measured during these experiments using a sound stimulus and measurement setup. Results: The sensitivity of the DrumMics was found to be tightly clustered across different microphones and ears despite differences in umbo and middle ear anatomy. The DrumMics were shown to behave linearly across a large dynamic range (46 dB SPL to 100 dB SPL) across a wide bandwidth (100 Hz to 8 kHz). The equivalent input noise (0.1-10 kHz) of the DrumMic and amplifier referenced to the ear canal was measured to be 54 dB SPL and estimated to be 46 dB SPL after accounting for the pressure gain of the outer ear. Conclusion: The results demonstrate that the DrumMic behaves robustly across ears and fabrication. The equivalent input noise performance was shown to approach that of commercial hearing aid microphones. To advance this demonstration of the DrumMic concept to a future prototype implantable in humans, work on encapsulation, biocompatibility, connectorization will be required