86,543 research outputs found
Novel devices and strategies to investigate and counteract pain: an engineer’s point of view on pain and how to fight against it
No full textPain is a gift; it is a fundamental adaptive mechanism to protect ourselves from injuries and illnesses. While usually pain is perceived as debilitating and intolerable and researchers are focusing on how to suppress it, its presence has a great survival value, which becomes evident in its absence. Contrary to the common belief, insensitivity to pain is a curse, which sometimes is an ill-fated consequence of some conditions, such as alcoholism, multiple sclerosis, diabetes and leprosy. Pain warns us of dangers, impeding us to continue adding insult to an injury causing more serious issues; it forces us to rest and protect the affected body part until the latter has recovered completely. As
such, pain represents an "unpleasant sensory and emotional experience" but "associated with actual or potential tissue damage", thus necessary to avoid further repercussions. When a high-intensity stimulus that can damage tissues is applied onto the human skin, it activates pain receptors, called nociceptors; information reaches the brain through myelinated A and un-myelinated C nerve fibers and the pain is experienced. If pain is certainly a gift, complications arise when its natural mechanisms do not perform correctly and the unpleasant painful sensations become incessant, interfering drastically with the person’s quality of life. This is not a rare event: as an example,
more than 100 million adults in the United States only are affected by chronic pain.
In such cases, pain loses its role as a warning against more critical injuries and simply becomes a medical problem, requiring medical treatment. Costs of these treatments are not negligible: they range from 635 billion of US dollars per year, combining the health care cost and the productivity estimates. Therefore pain has to be investigated, to be better understood and counteracted, if necessary. Easy? Not at all: pain is difficult to ascertain, is primarily assessed by means of self-report and experiments on pain suffer from a lack of reproducibility and accuracy.
The result is that many relevant neuro-physiological aspects on pain still remain unclear.
Here is where the engineer work becomes essential: medicine needs engineering to design, develop and implement reliable and precise devices whose features help pain research. Furthermore, when possible, the engineer should propose solutions that are inexpensive, portable, easy-to-assemble and customizable to suit diverse experimental requirements, ready to be employed into different researches. A complex challenge, without a doubt, but fundamental: the reader will find throughout this thesis, final report of my PhD in Electronic Engineering, a dissertation on the development of brand new devices and strategies to study and counteract the feeling of pain. Particularly, this thesis is made of two distinct engineering projects, devoted to these two aspects respectively.
Part I - Pain Counteraction: PROVIRT PLP project has the aim to improve the rehabilitation of upper limb amputees who suffer from Phantom Limb Pain syndrome, a chronic pain condition, with a technology based on pattern recognition and virtual reality. A promising discover made by Ramachandran showed how restoring the visual feedback of the amputated limb may have a primary importance in the pain counteraction, thus I implemented a device to maximise such illusion. PROVIRT PLP is able to read surface electromyographic signals from the amputee’s stump and coherently convert them into the movement of an avatar in a virtual reality environment. This part describes the project requisites, the design and implementation of the electronics, the observation regarding the classifiers and the pattern recognition stage and the software application that commands the virtual reality module. The system is then further improved by the means
of three experimental in-vivo tests, namely Test A - Optimization of EMG-based hand gesture recognition: Supervised vs. unsupervised data preprocessing on healthy subjects and transradial amputees, Test B - Evaluating the influence of subject-related variables on EMG-based hand gesture classification and Test C - Tuning parameters and performance evaluation. The project has been funded by INAIL (Italian government agency for the insurance against work-related injuries) and can be considered a successful compromise between gesture/intention of movement classification accuracy and ease of use for both health professionals and amputees. To date, Test D - Therapy
effectiveness that will eventually shed some light on PROVIRT PLP suitability for PLP counteraction is ongoing, with promising partial results.
Part II - Pain Investigation: PUSH project has the aim to define objective measures
of pain, by means of robust and consistent patterns of noxious stimuli and innocuous
touch. The project wants to develop a device, able to allow for reliable non-invasive
investigation of the peripheral and central mechanisms related to the sense of pain, towards
the definition of biomarkers for its quantitative assessment. Since fMRI is the standard
tool in advanced brain research, PUSH is developed to be completely MR-compatible.
This part describes the idea of a pneumatic-driven system to elicit pain, the design and
implementation of the electronics, the characterization of the system and a fMRI in-vivo
experiment on an adult volunteer to validate it. The project can be considered as a
brand new interesting prototype for any kind of fMRI- and EEG-based work on painful
mechanical stimulation, and a technical paper that describes its details
Support vector machines to detect physiological patterns for EEG and EMG-based human-computer interaction:a review
No full textSupport vector machines (SVMs) are widely used classifiers for detecting physiological patterns in human-computer interaction (HCI). Their success is due to their versatility, robustness and large availability of free dedicated toolboxes. Frequently in the literature, insufficient details about the SVM implementation and/or parameters selection are reported, making it impossible to reproduce study analysis and results. In order to perform an optimized classification and report a proper description of the results, it is necessary to have a comprehensive critical overview of the applications of SVM. The aim of this paper is to provide a review of the usage of SVM in the determination of brain and muscle patterns for HCI, by focusing on electroencephalography (EEG) and electromyography (EMG) techniques. In particular, an overview of the basic principles of SVM theory is outlined, together with a description of several relevant literature implementations. Furthermore, details concerning reviewed papers are listed in tables and statistics of SVM use in the literature are presented. Suitability of SVM for HCI is discussed and critical comparisons with other classifiers are reported
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Optimization of EMG-based hand gesture recognition: supervised vs. unsupervised data preprocessing on healthy subjects and transradial amputees
No full texttWe propose a methodological study for the optimization of surface EMG (sEMG)-based hand gestureclassification, effective to implement a human–computer interaction device for both healthy subjectsand transradial amputees. The widely commonly used unsupervised Principal Component Analysis (PCA)approach was compared to the promising supervised common spatial pattern (CSP) methodology toidentify the best classification strategy and the related tuning parameters. A low density array of sEMGsensors was built to record the muscular activity of the forearm and classify five different hand gestures.Twenty healthy subjects were recruited to compute optimized parameters for (“within” analysis) and tocompare between (“between” analysis) the two strategies. The system was also tested on a transradialamputee subject, in order to assess the robustness of the optimization in recognizing disabled users’gestures.Results show that RMS-WA/ANN is the best feature vector/classifier pair for the PCA approach (accu-racy 88.81 ± 6.58%), whereas M-RMS-WA/ANN is the best pair for the CSP methodology (accuracy of89.35 ± 6.16%). Statistical analysis on classification results shows no significant differences between thetwo strategies. Moreover we found out that the optimization computed for healthy subjects was provento be sufficiently robust to be used on the amputee subject. This motivates further investigation of theproposed methodology on a larger sample of amputees. Our results are useful to boost EMG-based handgesture recognition and constitute a step toward the definition of an efficient EMG-controlled system foramputees
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Sensory-Glove-Based Open Surgery Skill Evaluation
No full textManual dexterity is one of the most important surgical skills, and yet there are limited instruments to evaluate this ability objectively. In this paper, we propose a system designed to track surgeons’ hand movements during simulated open surgery tasks and to evaluate their manual expertise. Eighteen participants, grouped according to their surgical experience, performed repetitions of two basic surgical tasks, namely single interrupted suture and simple running suture. Subjects’ hand movements were measured with a sensory glove equipped with flex and inertial sensors, tracking flexion/extension of hand joints, and wrist movement. The participants’ level of experience was evaluated discriminating manual performances using linear discriminant analysis, support vector machines, and artificial neural network classifiers. Artificial neural networks showed the best performance, with a median error rate of 0.61% on the classification of single interrupted sutures and of 0.57% on simple running sutures. Strategies to reduce sensory glove complexity and increase its comfort did not affect system performances substantially
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
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