550 research outputs found

    Advanced sensors technology survey

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    This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

    An assessment of some possible neurological applications of electrical impedance tomography

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    Electrical impedance tomography (EIT) is a recently developed technique which produces reconstructed images of the internal distribution of the impedance of an object from measurement with external electrodes. It was assessed for its possible application in imaging intra-cranial disorders non- invasively with the use of scalp electrodes. Cerebral impedance increases of 12-55% were measured by a four electrode method at 50 kHz during global cerebral ischaemia or cortical spreading depression (CSD) in anaesthetized rats. Measured with scalp electrodes in two pairs 2-26 mm apart, impedance increased by 1.8-5.9% during global cerebral ischaemia for 5 or 15 min; the changes correlated in duration with cortical impedance changes, but increased more gradually. Increases of about 2% still were observed when the effects of variations in temperature and local scalp impedance were excluded. A finite element model was used to predict the attenuation of a signal due to cerebral anoxic depolarization by the extracerebral layers. These residual impedance changes were compatible with this, but their cause by other mechanisms related to the method of production of cerebral ischaemia could not be ruled out. An unexpected decrease of 0.8% was observed during CSD with electrodes 0.5mm apart on the scalp. This became undetectable when scalp temperature was kept constant. The model predicted that impedance changes of about 1% could be measured during CSD with scalp electrodes spaced further apart. Images were then collected using a prototype EIT system operating at 51 kHz during the same model of cerebral ischaemia. Test objects in a medium of constant resistivity could be accurately localized, but spatial resolution of intracranial impedance changes was substantially degraded when recorded with scalp electrodes. EIT has the potential for imaging various cerebral physiological or pathological changes, but improvements to the reconstruction algorithm are needed if regional intracerebral changes are to be discriminated during recording with scalp electrodes

    Communications Biophysics

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    Contains research objectives and summary of research.National Institutes of Health (Grant 5 PO1 GM14940-07)National Institutes of Health (Grant 1 RO1 NS11000-01)Clarence J. LeBel FundNational Institutes of Health (Grant 1 RO1 NS10737-01)National Aeronautics and Space Administration (Grant NGL 22-009-304)Boston City Hospital Purchase Order 1176-21335B-D Electrodyne Division, Becton Dickinson and Company (Grant)Chicago Musical Instrument Company (Grant

    A wearable mechatronic device for extracorporeal blood ultrafiltration

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    The interest in the design of portable and wearable medical devices is related to both the relevant clinical and social benefits for patients and the potential economic savings for national health services. Biomedical technologies are improving at a very fast rate and represent an extraordinary means to develop innovative portable and wearable devices which can help people live in a prosperous way, in particular reducing sorrow in case of disease. This leads to a widespread effort to develop devices which can execute at home therapies that are usually performed in hospitals. This thesis presents a new wearable and portable device for extracorporeal blood ultrafiltration, named WUF (Wearable UltraFiltration device), able to remove excess fluids from fluid overload patients with chronic kidney disease and/or congestive heart failure. The design requirements that a modern wearable device for extracorporeal ultrafiltration must meet have been identified thanks to a thorough literature review on previous similar proposals followed by an extensive risk analysis. The design of the WUF prototype has faced several difficulties, ranging from the identification or conceivement of safe and reliable components to the design of a compact and neat layout. For most components it was possible to identify commercial (off-the-shelf) products meeting the requirements, nonetheless for some others, specific investigations, studies and developments were needed and led to the design of customized solutions or the formulation of original approaches. The design of an effective, efficient, safe and reliable control architecture, based on two microcontrollers and one microcomputer, the implementation of the control logic and of a graphical user interface have been carried out too being essential features of such a mechatronic device. A backpack/trolley design has been chosen as the layout for the device, since such a solution guarantees the best tradeoff between miniaturization and ergonomics. The design introduces an original positioning of the vast majority of components in three independent planar panels: one for disposable components, one for non-disposable devices and one for electronic boards and controllers. This arrangement of components can drastically simplify and speed up the in-hospital operations needed before and after a therapy with the WUF

    Advances of Italian Machine Design

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    This 2028 Special Issue presents recent developments and achievements in the field of Mechanism and Machine Science coming from the Italian community with international collaborations and ranging from theoretical contributions to experimental and practical applications. It contains selected contributions that were accepted for presentation at the Second International Conference of IFToMM Italy, IFIT2018, that has been held in Cassino on 29 and 30 November 2018. This IFIT conference is the second event of a series that was established in 2016 by IFToMM Italy in Vicenza. IFIT was established to bring together researchers, industry professionals and students, from the Italian and the international community in an intimate, collegial and stimulating environment

    Design and construction of a laboratory system for neuromuscular stimulation of the lower extremities during cycling

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    Functional Neuromuscular Stimulation (FNS) is a method by which paralyzed muscles are stimulated electrically in order to produce a useful movement. The design and testing of a laboratory system for the modulated control of the lower extremities during FNS-induced cycling on an exercising device (Paracycle) is described. The system hardware, which is designed around a standard IBM compatible Personal Computer, features six independent stimulation channels. Waveform characteristics such as pulse frequency, width and amplitude are defined as a function of the crank position of the Paracycle for each channel. An extensive software package allows programmability of the waveform parameters and supports the user in the definition of stimulation sequences. The effective performance of the complete FNS-controller/ Paracycle system has been demonstrated during a controlled case study with two paraplegic subjects

    Aerospace medicine and biology: A cumulative index to a continuing bibliography (supplement 345)

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    This publication is a cumulative index to the abstracts contained in Supplements 333 through 344 of Aerospace Medicine and Biology: A Continuing Bibliography. Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number, and accession number

    Aerospace Medicine and Biology. A continuing bibliography with indexes

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    This bibliography lists 244 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1981. Aerospace medicine and aerobiology topics are included. Listings for physiological factors, astronaut performance, control theory, artificial intelligence, and cybernetics are included

    Progress Report No. 14

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    Progress report of the Biomedical Computer Laboratory, covering period 1 July 1977 to 30 June 1978
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