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Sample records for human circulatory system

  1. Representations of the Human Circulatory System

    ERIC Educational Resources Information Center

    Lopez-Manjon, Asuncion; Angon, Yolanda Postigo

    2009-01-01

    There is no agreement about the robustness of intuitive representations of the circulatory system and their susceptibility to change by instruction. In this paper, we analyse to what extent students with varying degrees of biology instruction and different ages (High School Health Science and Social Science students and first and final year…

  2. Simulation of a human circulatory system.

    PubMed

    Menon, Vinay

    2012-01-01

    This article describes a mathematically based human circulatory model. The model consists of lumped elements made of venous, arterial, peripheral, pulmonary vein and artery segments. A heart model is simulated using 4 chambers (left and right atriums and ventricles). The heart pump mechanism is operated by a simple piston based models for each of the chambers. The simulation consists of 19 (states) first order differential equations. and simulated with Matlab and Simulink. The simulation computes volume, flow rate and pressures in each segment.

  3. Towards a Fast Dynamic Model of the Human Circulatory System

    DTIC Science & Technology

    2011-10-06

    4.5m for the pulmonary vascular tree. According to Guyton & Hall (2000), about 5 L is considered normal for an adult human, and the area distribution...decreases further, and even falls below the equilibrium pressure. Guyton & Hall (2000) reports that normal mean pressures are 100 mmHg in the arteries, 20...the order of 100 times faster than realtime. Five liters is considered a normal volume for an adult human circulatory system ( Guyton & Hall, 2000

  4. Towards a Fast Dynamic Model of the Human Circulatory System

    NASA Astrophysics Data System (ADS)

    Kaplan, Carolyn; Green, Melissa; Boris, Jay; Oran, Elaine

    2011-11-01

    We describe a model for systems-level transport in the human circulatory system that is based on a set of equations for a one-dimensional unsteady elastic pipe flow circuit. The system is collapsed from three spatial dimensions and time to one spatial dimension and time by assuming axisymmetric vessel geometry and a parabolic velocity profile across the cylindrical vessels. To drive the fluid, the contractions of a beating heart are modeled as periodic area changes of the elastic vessels. Two different models are compared, both including and neglecting fluid acceleration. Time-resolved distributions of pressure, velocity and area compare reasonably well with reference data. Increasing the rigidity of the vasculature is found to increase peak arterial pressures on the order of ten percent, and including a distributed vascular contraction to model distributed skeletal muscle contractions monotonically increases time-averaged blood flow in the veins, consistent with human physiological response. The circulatory system model presented here simulates the circulatory system on the order of one hundred times faster than real-time; that is, we can compute thousands of heartbeats per minute of CPU time.

  5. A Simulink model for the human circulatory system.

    PubMed

    Wabel, P; Leonhardt, S

    1998-01-01

    This paper presents the mathematical simulation of the human circulatory system. The model is based on the former work of Coleman and co-workers and has been redesigned for simulation with the Matlab toolbox "Simulink". It includes the heart and the peripheral circulation, the respiratory system, the kidneys and the major neural and hormonal control mechanisms, which are necessary for maintaining homeostasis. The model contains more than 30 blocks with over 200 physiological variables, which can be accessed and plotted during the simulation.

  6. Computational Hemodynamic Simulation of Human Circulatory System under Altered Gravity

    NASA Technical Reports Server (NTRS)

    Kim. Chang Sung; Kiris, Cetin; Kwak, Dochan

    2003-01-01

    A computational hemodynamics approach is presented to simulate the blood flow through the human circulatory system under altered gravity conditions. Numerical techniques relevant to hemodynamics issues are introduced to non-Newtonian modeling for flow characteristics governed by red blood cells, distensible wall motion due to the heart pulse, and capillary bed modeling for outflow boundary conditions. Gravitational body force terms are added to the Navier-Stokes equations to study the effects of gravity on internal flows. Six-type gravity benchmark problems are originally presented to provide the fundamental understanding of gravitational effects on the human circulatory system. For code validation, computed results are compared with steady and unsteady experimental data for non-Newtonian flows in a carotid bifurcation model and a curved circular tube, respectively. This computational approach is then applied to the blood circulation in the human brain as a target problem. A three-dimensional, idealized Circle of Willis configuration is developed with minor arteries truncated based on anatomical data. Demonstrated is not only the mechanism of the collateral circulation but also the effects of gravity on the distensible wall motion and resultant flow patterns.

  7. Development of a mathematical model of the human circulatory system.

    PubMed

    Conlon, Martin J; Russell, Donald L; Mussivand, Tofy

    2006-09-01

    A mathematical lumped parameter model of the human circulatory system (HCS) has been developed to complement in vitro testing of ventricular assist devices. Components included in this model represent the major parts of the systemic HCS loop, with all component parameters based on physiological data available in the literature. Two model configurations are presented in this paper, the first featuring elements with purely linear constitutive relations, and the second featuring nonlinear constitutive relations for the larger vessels. Three different aortic compliance functions are presented, and a pressure-dependent venous flow resistance is used to simulate venous collapse. The mathematical model produces reasonable systemic pressure and flow behaviour, and graphs of this data are included.

  8. Mathematical circulatory system model

    NASA Technical Reports Server (NTRS)

    Lakin, William D. (Inventor); Stevens, Scott A. (Inventor)

    2010-01-01

    A system and method of modeling a circulatory system including a regulatory mechanism parameter. In one embodiment, a regulatory mechanism parameter in a lumped parameter model is represented as a logistic function. In another embodiment, the circulatory system model includes a compliant vessel, the model having a parameter representing a change in pressure due to contraction of smooth muscles of a wall of the vessel.

  9. Students' Achievement in Human Circulatory System Unit: The Effect of Reasoning Ability and Gender.

    ERIC Educational Resources Information Center

    Sungur, Semra; Tekkaya, Ceren

    2003-01-01

    Investigates the effect of gender and reasoning ability on the human circulatory system concepts achievement and attitude toward biology. Reports a statistically significant mean difference between concrete and formal students with regard to achievement and attitude toward biology. (Contains 24 references.) (Author/YDS)

  10. Learning in a Non-Physical Science Domain: The Human Circulatory System.

    ERIC Educational Resources Information Center

    Chi, Michelene T. H.; And Others

    This research explores the moment-by-moment understanding students exhibit in the learning of a non-physical science domain--the human circulatory system. The goal was to understand how students learn by capturing the nature of their initial mental models (naive conceptions), and by seeing how new information gets assimilated into their mental…

  11. Students' Alternative Conceptions of the Human Circulatory System: A Cross-Age Study.

    ERIC Educational Resources Information Center

    Arnaudin, Mary W.; Mintzes, Joel J.

    1985-01-01

    Concept maps and structured/clinical interviews were completed by 25 fourth graders and 25 college freshmen to determine knowledge of the human circulatory system. Students (N=945) at various levels were then measured for misconception frequencies. Student preconceptions appear to be tenacious, but confrontation strategies may assist fundamental…

  12. Facilitating Conceptual Change in Ninth Grade Students' Understanding of Human Circulatory System Concepts

    ERIC Educational Resources Information Center

    Alkhawaldeh, Salem A.

    2007-01-01

    The purpose of this study was to investigate the effectiveness of the conceptual change text oriented instruction over traditionally designed instruction on ninth grade students' understanding of the human circulatory system concepts, and their retention of this understanding. The subjects of this study consist of 73 ninth grade female students…

  13. The Persistence of Misconceptions about the Human Blood Circulatory System among Students in Different Grade Levels

    ERIC Educational Resources Information Center

    Ozgur, Sami

    2013-01-01

    In this paper, it is aimed to investigate the persistence of misconceptions in the topic of the human blood circulatory system among students in different grade levels. For this reason, after discussions with biology educators, two tests consisting of open-ended questions were developed by the researcher and administered to students in four…

  14. Developing seventh grade students' systems thinking skills in the context of the human circulatory system.

    PubMed

    Raved, Lena; Yarden, Anat

    2014-01-01

    Developing systems thinking skills in school can provide useful tools to deal with a vast amount of medical and health information that may help learners in decision making in their future lives as citizen. Thus, there is a need to develop effective tools that will allow learners to analyze biological systems and organize their knowledge. Here, we examine junior high school students' systems thinking skills in the context of the human circulatory system. A model was formulated for developing teaching and learning materials and for characterizing students' systems thinking skills. Specifically, we asked whether seventh grade students, who studied about the human circulatory system, acquired systems thinking skills, and what are the characteristics of those skills? Concept maps were used to characterize students' systems thinking components and examine possible changes in the students' knowledge structure. These maps were composed by the students before and following the learning process. The study findings indicate a significant improvement in the students' ability to recognize the system components and the processes that occur within the system, as well as the relationships between different levels of organization of the system, following the learning process. Thus, following learning students were able to organize the systems' components and its processes within a framework of relationships, namely the students' systems thinking skills were improved in the course of learning using the teaching and learning materials.

  15. [Essence of meridians and collaterals: circulatory conduction system of bio-electricity of human].

    PubMed

    Shang, Zhen-De

    2011-03-01

    The running courses of twelve meridians are explained through the electrical properties of cell membrane, and the phenomenon related with meridians such as mechanism of acupuncture analgesia and acupuncture anesthesia, pause of the propagated sensation along channels, nature of propagated sensation and width of propagated sensation is expounded in this article. As a result, it is held that the meridian system, a circulatory conduction system of bio-electricity of human, is an independent system from the known nine large systems.

  16. Numerical Models of Human Circulatory System under Altered Gravity: Brain Circulation

    NASA Technical Reports Server (NTRS)

    Kim, Chang Sung; Kiris, Cetin; Kwak, Dochan; David, Tim

    2003-01-01

    A computational fluid dynamics (CFD) approach is presented to model the blood flow through the human circulatory system under altered gravity conditions. Models required for CFD simulation relevant to major hemodynamic issues are introduced such as non-Newtonian flow models governed by red blood cells, a model for arterial wall motion due to fluid-wall interactions, a vascular bed model for outflow boundary conditions, and a model for auto-regulation mechanism. The three-dimensional unsteady incompressible Navier-Stokes equations coupled with these models are solved iteratively using the pseudocompressibility method and dual time stepping. Moving wall boundary conditions from the first-order fluid-wall interaction model are used to study the influence of arterial wall distensibility on flow patterns and wall shear stresses during the heart pulse. A vascular bed modeling utilizing the analogy with electric circuits is coupled with an auto-regulation algorithm for multiple outflow boundaries. For the treatment of complex geometry, a chimera overset grid technique is adopted to obtain connectivity between arterial branches. For code validation, computed results are compared with experimental data for steady and unsteady non-Newtonian flows. Good agreement is obtained for both cases. In sin-type Gravity Benchmark Problems, gravity source terms are added to the Navier-Stokes equations to study the effect of gravitational variation on the human circulatory system. This computational approach is then applied to localized blood flows through a realistic carotid bifurcation and two Circle of Willis models, one using an idealized geometry and the other model using an anatomical data set. A three- dimensional anatomical Circle of Willis configuration is reconstructed from human-specific magnetic resonance images using an image segmentation method. The blood flow through these Circle of Willis models is simulated to provide means for studying gravitational effects on the brain

  17. Development and Validation of a Two-Tier Instrument to Examine Understanding of Internal Transport in Plants and the Human Circulatory System

    ERIC Educational Resources Information Center

    Wang, Jing-Ru

    2004-01-01

    This study is intended to develop an assessment instrument to investigate students' understandings about internal transport in plants and human circulatory system. A refined process of a two-tier diagnostic test was used to develop the instrument. Finally, three versions of the Internal Transport in Plants and the Human Circulatory System test…

  18. Relations of Cognitive and Motivational Variables with Students' Human Circulatory System Achievement in Traditional and Learning Cycle Classrooms

    ERIC Educational Resources Information Center

    Sadi, Özlem; Çakiroglu, Jale

    2014-01-01

    This study is aimed at investigating the relationships among students' relevant prior knowledge, meaningful learning orientation, reasoning ability, self-efficacy, locus of control, attitudes toward biology and achievement with the human circulatory system (HCS) using the learning cycle (LC) and the traditional classroom setting. The study was…

  19. The Contribution of Conceptual Change Texts Accompanied by Concept Mapping to Students' Understanding of the Human Circulatory System.

    ERIC Educational Resources Information Center

    Sungur, Semra; Tekkaya, Ceren; Geban, Omer

    2001-01-01

    Investigates the contribution of conceptual change texts accompanied by concept mapping instruction to 10th-grade students' understanding of the human circulatory system. Indicates that the conceptual change texts accompanied by concept mapping instruction produced a positive effect on students' understanding of concepts. Concludes that students…

  20. Students' Visualization of Diagrams Representing the Human Circulatory System: The Use of Spatial Isomorphism and Representational Conventions

    ERIC Educational Resources Information Center

    Cheng, Maurice M. W.; Gilbert, John K.

    2015-01-01

    This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14-15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented…

  1. Photoacoustic detection of metastatic melanoma cells in the human circulatory system.

    PubMed

    Weight, Ryan M; Viator, John A; Dale, Paul S; Caldwell, Charles W; Lisle, Allison E

    2006-10-15

    Detection of disseminating tumor cells among patients suffering from various types and stages of cancer can function as an early warning system, alerting the physician of the metastatic spread or recurrence of the disease. Early detection of such cells can result in preventative treatment of the disease, while late stage detection can serve as an indicator of the effectiveness of chemotherapeutics. The prognostic value of exposing disseminating tumor cells poses an urgent need for an efficient, accurate screening method for metastatic cells. We propose a system for the detection of metastatic circulating tumor cells based on the thermoelastic properties of melanoma. The method employs photoacoustic excitation coupled with a detection system capable of determining the presence of disseminating cells within the circulatory system in vitro. Detection trials consisting of tissue phantoms and a human melanoma cell line resulted in a detection threshold of the order of ten individual cells, thus validating the effectiveness of the proposed mechanism. Results imply the potential to assay simple blood draws, from healthy and metastatic patients, for the presence of cancerous melanoma providing an unprecedented method for routine cancer screening.

  2. Photoacoustic detection of metastatic melanoma cells in the human circulatory system

    NASA Astrophysics Data System (ADS)

    Weight, Ryan M.; Viator, John A.; Dale, Paul S.; Caldwell, Charles W.; Lisle, Allison E.

    2006-10-01

    Detection of disseminating tumor cells among patients suffering from various types and stages of cancer can function as an early warning system, alerting the physician of the metastatic spread or recurrence of the disease. Early detection of such cells can result in preventative treatment of the disease, while late stage detection can serve as an indicator of the effectiveness of chemotherapeutics. The prognostic value of exposing disseminating tumor cells poses an urgent need for an efficient, accurate screening method for metastatic cells. We propose a system for the detection of metastatic circulating tumor cells based on the thermoelastic properties of melanoma. The method employs photoacoustic excitation coupled with a detection system capable of determining the presence of disseminating cells within the circulatory system in vitro. Detection trials consisting of tissue phantoms and a human melanoma cell line resulted in a detection threshold of the order of ten individual cells, thus validating the effectiveness of the proposed mechanism. Results imply the potential to assay simple blood draws, from healthy and metastatic patients, for the presence of cancerous melanoma providing an unprecedented method for routine cancer screening.

  3. Students' Visualization of Diagrams Representing the Human Circulatory System: The use of spatial isomorphism and representational conventions

    NASA Astrophysics Data System (ADS)

    Cheng, Maurice M. W.; Gilbert, John K.

    2015-01-01

    This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14-15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented aspects of the circulatory system. All diagrams used in the interviews had been used by their teacher when teaching the topic. Students' interpretations were expressed by their verbal response and their drawing. Dual coding theory was used to interpret students' responses. There was evidence that one student relied on verbal recall as a strategy in interpreting diagrams. It was found that students might have relied unduly on similarities in spatial features, rather than on deeper meanings represented by conventions, of diagrams when they associated diagrams that represented different aspects of the circulatory system. A pattern of students' understanding of structure-behaviour-function relationship of the biological system was observed. This study suggests the importance of a consistent diagrammatic and verbal representation in communicating scientific ideas. Implications for teaching practice that facilitates learning with diagrams and address students' undue focus on spatial features of diagrams are discussed.

  4. The human heart and the circulatory system as an interesting interdisciplinary topic in lessons of physics and biology

    NASA Astrophysics Data System (ADS)

    Volná, M.; Látal, F.; Kubínek, R.; Richterek, L.

    2014-01-01

    Many topics which are closely related can be found in the national curriculum of the Czech Republic for physics and biology. One of them is the heart and the circulatory system in the human body. This topic was examined cross curriculum, a teaching module was created and the topic was chosen for our research. The task was to determine if the students of bachelor study are aware of connections between physics and biology within this topic and whether we can help them effectively to describe the corresponding physics phenomena in the human body connected, for example, with a heart attack or with the measurement of blood pressure. In this paper, the heart and the circulatory system are presented as suitable topics for an interdisciplinary teaching module which includes both theoretical and experimental parts. The module was evaluated by a group of first-year undergraduate students of physics at the Faculty of Science, Palacký University. The acquired knowledge was compared with another control group through a test. The highest efficiency of the module was evaluated on the basis of questions that covered the calculation problems.

  5. Progression of Mortality due to Diseases of the Circulatory System and Human Development Index in Rio de Janeiro Municipalities

    PubMed Central

    Soares, Gabriel Porto; Klein, Carlos Henrique; Silva, Nelson Albuquerque de Souza e; de Oliveira, Glaucia Maria Moraes

    2016-01-01

    Background Diseases of the circulatory system (DCS) are the major cause of death in Brazil and worldwide. Objective To correlate the compensated and adjusted mortality rates due to DCS in the Rio de Janeiro State municipalities between 1979 and 2010 with the Human Development Index (HDI) from 1970 onwards. Methods Population and death data were obtained in DATASUS/MS database. Mortality rates due to ischemic heart diseases (IHD), cerebrovascular diseases (CBVD) and DCS adjusted by using the direct method and compensated for ill-defined causes. The HDI data were obtained at the Brazilian Institute of Applied Research in Economics. The mortality rates and HDI values were correlated by estimating Pearson linear coefficients. The correlation coefficients between the mortality rates of census years 1991, 2000 and 2010 and HDI data of census years 1970, 1980 and 1991 were calculated with discrepancy of two demographic censuses. The linear regression coefficients were estimated with disease as the dependent variable and HDI as the independent variable. Results In recent decades, there was a reduction in mortality due to DCS in all Rio de Janeiro State municipalities, mainly because of the decline in mortality due to CBVD, which was preceded by an elevation in HDI. There was a strong correlation between the socioeconomic indicator and mortality rates. Conclusion The HDI progression showed a strong correlation with the decline in mortality due to DCS, signaling to the relevance of improvements in life conditions. PMID:27849263

  6. Measurement science in the circulatory system

    PubMed Central

    Jones, Casey M.; Baker-Groberg, Sandra M.; Cianchetti, Flor A.; Glynn, Jeremy J.; Healy, Laura D.; Lam, Wai Yan; Nelson, Jonathan W.; Parrish, Diana C.; Phillips, Kevin G.; Scott-Drechsel, Devon E.; Tagge, Ian J.; Zelaya, Jaime E.; Hinds, Monica T.; McCarty, Owen J.T.

    2014-01-01

    The dynamics of the cellular and molecular constituents of the circulatory system are regulated by the biophysical properties of the heart, vasculature and blood cells and proteins. In this review, we discuss measurement techniques that have been developed to characterize the physical and mechanical parameters of the circulatory system across length scales ranging from the tissue scale (centimeter) to the molecular scale (nanometer) and time scales of years to milliseconds. We compare the utility of measurement techniques as a function of spatial resolution and penetration depth from both a diagnostic and research perspective. Together, this review provides an overview of the utility of measurement science techniques to study the spatial systems of the circulatory system in health and disease. PMID:24563678

  7. The Circulatory System. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

    ERIC Educational Resources Information Center

    National Evaluation Systems, Inc., Amherst, MA.

    This instructional modular unit with instructor's guide provides materials on aspects of one of the major systems of the human body--the circulatory system. Its purpose is to introduce the student to the structures and functions of the human circulatory system--and the interrelationships of the two--and to familiarize the student with some of the…

  8. 78 FR 55081 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... Monitoring System. The CardioMEMS HF System is a permanently implantable pressure measurement system...

  9. 78 FR 11208 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... approval application for the MitraClip Delivery System sponsored by Abbott Vascular. The system consists...

  10. 77 FR 16038 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-19

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... the premarket approval application (PMA) for the HeartWare Ventricular Assist System (HVAS)...

  11. 78 FR 49272 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... outside the body, is used as a temporary substitute for the heart's intrinsic pacing system until...

  12. 77 FR 66847 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... remaining pre-Amendment Class III devices. These systems typically consist of a treatment table,...

  13. 76 FR 56200 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... and are pre-loaded onto 6 or 7 Fr \\1\\ (diameter of 2 or 2.3 mm) delivery systems. Upon deployment,...

  14. 75 FR 7282 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-18

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... recommendations and vote on a PMA for the REVO MRI Pacemaker System sponsored by Medtronic. The REVO MRI...

  15. 76 FR 36548 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... mm and accessories implant system consists of the following: The Edwards SAPIEN Transcatheter...

  16. 76 FR 63928 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of...: ``Medtronic cardiac resynchronization therapy defibrillator (CRT-D) systems are indicated for heart...

  17. 75 FR 81282 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel of... PMA supplement for the RX Acculink Carotid Stent System, sponsored by Abbott Vascular. The RX...

  18. 77 FR 18829 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel...

  19. 78 FR 67365 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Circulatory System Devices Panel of the Medical Devices... (FDA). The meeting will be open to the public. Name of Committee: Circulatory System Devices Panel...

  20. Children's Beliefs about the Human Circulatory System: An Aid for Teachers Regarding the Role Intuitive Beliefs Play in the Development of Formal Concepts in 7-14-Year Olds. Report No. 82:16.

    ERIC Educational Resources Information Center

    Catherall, Robin W.

    This exploratory study was aimed at uncovering children's beliefs and ideas about the human circulatory system. Thirty-two subjects, aged 7 to 14 years, were interviewed using a modification of Piaget's clinical method. The data were analyzed by developing a conceptual inventory of beliefs for each of five research questions. It was found that the…

  1. A pacemaker powered by an implantable biofuel cell operating under conditions mimicking the human blood circulatory system--battery not included.

    PubMed

    Southcott, Mark; MacVittie, Kevin; Halámek, Jan; Halámková, Lenka; Jemison, William D; Lobel, Robert; Katz, Evgeny

    2013-05-07

    Biocatalytic electrodes made of buckypaper were modified with PQQ-dependent glucose dehydrogenase on the anode and with laccase on the cathode and were assembled in a flow biofuel cell filled with serum solution mimicking the human blood circulatory system. The biofuel cell generated an open circuitry voltage, Voc, of ca. 470 mV and a short circuitry current, Isc, of ca. 5 mA (a current density of 0.83 mA cm(-2)). The power generated by the implantable biofuel cell was used to activate a pacemaker connected to the cell via a charge pump and a DC-DC converter interface circuit to adjust the voltage produced by the biofuel cell to the value required by the pacemaker. The voltage-current dependencies were analyzed for the biofuel cell connected to an Ohmic load and to the electronic loads composed of the interface circuit, or the power converter, and the pacemaker to study their operation. The correct pacemaker operation was confirmed using a medical device - an implantable loop recorder. Sustainable operation of the pacemaker was achieved with the system closely mimicking human physiological conditions using a single biofuel cell. This first demonstration of the pacemaker activated by the physiologically produced electrical energy shows promise for future electronic implantable medical devices powered by electricity harvested from the human body.

  2. Permanent circulatory support systems at the Pennsylvania State University.

    PubMed

    Weiss, W J; Rosenberg, G; Snyder, A J; Cleary, T J; Gaumond, R P; Geselowitz, D B; Pierce, W S

    1990-02-01

    Permanent circulatory support systems are required for patients in whom myocardial damage is irreversible and cardiac transplantation is not possible. Two systems are described which provide long term circulatory support: the left ventricular assist system and the total artificial heart. These systems are based on the design of a pusher plate actuated blood pump, driven by a small brushless dc electric motor and rollerscrew driver. An implantable motor controller maintains suitable physiologic flow rates for both systems and controls left-right balance in the total artificial heart. Other parts of the system include an intra-thoracic compliance chamber, transcutaneous energy and data transmission system, and internal and external batteries.

  3. [The diseases of circulatory system in employees of railway transport].

    PubMed

    Molodtsov, R N; Shemetova, G N

    2013-01-01

    The article presents the epidemiologic and medical social aspects of diseases of circulatory system in employees of railway transport in 2000-2010 exemplified by Privolzhskiy railroad. The established tendencies in prevalence of pathology of cardio-vascular system in railroad workers makes the issues of practical implementation of priority of prevention in the organization of medical care to this group of patients to come to foreground. The main directions for complex prevention of diseases of circulatory system in employees of railway transport are presented.

  4. Influence of compliance on flow rate waveforms in hydraulic circuits for in vitro modeling the human circulatory system.

    PubMed

    He, Wenbo; Wang, Yuan; Gong, Xiaoyan

    2014-01-01

    Generating an artificial blood flow in a circle system is an important step in hemodynamic research; thus, the influence of circle system components on the pulsatile flow wave forms should be investigated. In this study, a circle system was built, in which two solenoid valves were controlled by a timer to transform a constant flow into a pulsatile one, and two customized compliances with five different aeration volumes were set up upstream and downstream of the test chamber, achieving twenty-five different wave forms. Then, the influence of the compliance settings on the flow rate wave form was investigated. From the experimental data, it can be concluded that the absolute value of the maximum value and the minimum value of the wave forms increases along the aeration of the downstream compliance but decreases along the aeration of the upstream compliance. For the second maximum value and the offset between the maximum value and the minimum value, remarkable differences were obtained between runs with aeration of zero compliance and nonzero compliance. Finally, an emulational flow was achieved with the up- and downstream aeration volume equaling 360 mL and 180 mL, respectively, which fit the realistic wave form well.

  5. Monoacylglycerol-enriched oil increases EPA/DHA delivery to circulatory system in humans with induced lipid malabsorption conditions.

    PubMed

    Cruz-Hernandez, Cristina; Destaillats, Frédéric; Thakkar, Sagar K; Goulet, Laurence; Wynn, Emma; Grathwohl, Dominik; Roessle, Claudia; de Giorgi, Sara; Tappy, Luc; Giuffrida, Francesca; Giusti, Vittorio

    2016-12-01

    It was hypothesized that under induced lipid malabsorption/maldigestion conditions, an enriched sn-1(3)-monoacylglycerol (MAG) oil may be a better carrier for n-3 long-chain PUFAs (LC-PUFAs) compared with triacylglycerol (TAG) from fish oil. This monocentric double blinded clinical trial examined the accretion of EPA (500 mg/day) and DHA (300 mg/day) when consumed as TAG or MAG, into the erythrocytes, plasma, and chylomicrons of 45 obese (BMI ≥30 kg/m(2) and ≤40 kg/m(2)) volunteers who were and were not administered Orlistat, an inhibitor of pancreatic lipases. Intake of MAG-enriched oil resulted in higher accretion of LC-PUFAs than with TAG, the concentrations of EPA and DHA in erythrocytes being, respectively, 72 and 24% higher at 21 days (P < 0.001). In addition, MAG increased the plasma concentration of EPA by 56% (P < 0.001) as compared with TAG. In chylomicrons, MAG intake yielded higher levels of EPA with the area under the curve (0-10 h) of EPA being 55% greater (P = 0.012). In conclusion, in obese human subjects with Orlistat-induced lipid maldigestion/malabsorption conditions, LC-PUFA MAG oil increased LC-PUFA levels in erythrocytes, plasma, and chylomicrons to a greater extent than TAG. These results indicate that MAG oil might require minimal enzymatic digestion prior to intestinal uptake and transfer across the epithelial barrier.

  6. From Head to Toe: Respiratory, Circulatory, and Skeletal Systems. Book 3.

    ERIC Educational Resources Information Center

    Wiebe, Arthur, Ed.; And Others

    Designed to supplement curricular programs dealing with the human body, this booklet offers an activity-based, student-oriented approach for middle school teachers and students. Twelve activities focus on principles and skills related to the respiratory, circulatory, and skeletal systems. Each activity consists of student sheets and a teacher's…

  7. NUCLEAR-FUELED CIRCULATORY SUPPORT SYSTEMS IV: RADIOLOGIC PERSPECTIVES

    PubMed Central

    Huffman, F. N.; Norman, J. C.

    1974-01-01

    If an implantable artificial heart can be developed, it should prove beneficial to a significant group of patients. A variety of energy sources, such as biologic, electromagnetic, and nuclear, are under evaluation. Currently, biologic fuel cell technology is not sufficiently advanced to permit its extrapolation to the power levels required for implantable circulatory support systems. Electromagnetic systems have the disadvantage of heavy batteries of considerable bulk requiring frequent recharging. Radioisotope-fueled thermal engine systems have the potential of providing degrees of freedom not possible with rechargeable units. However, radiosotope circulatory support systems subject their recipients to prolonged intracorporeal radiation, add to environmental background radiation, and constitute an exceedingly small, but finite, hazard due to possible violation of fuel containment. PMID:15215965

  8. [Caffeine and adaptive changes in the circulatory system during pregnancy].

    PubMed

    Cendrowska-Pinkosz, Monika; Dworzański, Wojciech; Krauze, Magdalena; Burdan, Franciszek

    2017-01-23

    Adaptive physiological changes that occur in pregnant women can fluctuate with the intake of substances with proven, adverse biological effect on the body. Due to the fact that caffeine is one of the most chronically used xenobiotics, the impact of consuming caffeine on adaptive processes in the circulatory system of a pregnant women required a research. Many researchers emphasise its negative effect on the circulatory system of the mother and her offspring. However, in spite of years of observation, there is no clear answer to what extent dose or in what period of time the caffeine modulates the adaptive processes during pregnancy. Because of the potential risk the supply of caffeine during pregnancy should be subjected to considerable restrictions.

  9. Functional stability of cerebral circulatory system

    NASA Technical Reports Server (NTRS)

    Moskalenko, Y. Y.

    1980-01-01

    The functional stability of the cerebral circulation system seems to be based on the active mechanisms and on those stemming from specific of the biophysical structure of the system under study. This latter parameter has some relevant criteria for its quantitative estimation. The data obtained suggest that the essential part of the mechanism for active responses of cerebral vessels which maintains the functional stability of this portion of the vascular system, consists of a neurogenic component involving central nervous structures localized, for instance, in the medulla oblongata.

  10. I.4. Biofluid mechanics & the circulatory system.

    PubMed

    Verdonck, Pascal; Dumont, Kris

    2010-01-01

    A fluid is a medium which deforms, or undergoes motion, continuously under the action of a shearing stress and includes liquids and gases. Applying biofluid mechanics to the cardiovascular system requires knowledge of anatomy and geometry, pressure data and blood flow, volume and velocity measurements. A good example is the assessment of the haemodynamics of biological and mechanical heart valves.

  11. The role of brain gaseous transmitters in the regulation of the circulatory system.

    PubMed

    Ufnal, Marcin; Sikora, Mariusz

    2011-09-01

    A number of neurotransmitters, including biologically active gases namely, nitric oxide (NO), hydrogen sulfide (H2S) and carbon monoxide (CO) have been postulated to play an important role in the control of the cardiovascular system by the brain. The attention of researchers has been focused on NO in particular. It has been shown that pharmacological manipulation of NO concentration in the brain produces significant changes in circulatory parameters. Furthermore, significant alterations in the brain NO system have been found in animal models of human cardiovascular diseases. These findings imply that NO in the brain may become a promising target for new treatment strategies. Although H2S and CO have also been proved to serve as transmitters in the central nervous system, their role in the neurogenic regulation of the cardiovascular system remains more obscure. Interestingly, increased synthesis of NO, H2S and CO is found in inflammation and it appears that the gases mediate some of the circulatory responses to inflammatory stimuli. In this review we discuss the role of brain gaseous transmitters in the control of the circulatory system in health and disease.

  12. Bonghan circulatory system as an extension of acupuncture meridians.

    PubMed

    Soh, Kwang-Sup

    2009-06-01

    The Bonghan system is a newly-discovered circulatory system, which corresponds to classical acupuncture meridians and was discovered in the early 1960s by Bonghan Kim. Despite its potential importance in biology and medicine, it has been ignored or forgotten for a long time. Only recently have most of its significant parts, such as the Bonghan system (BHS) inside blood or lymph vessels, on the surfaces of internal organs, and in brain ventricles, been confirmed. For this, novel methods using modern technology were necessary because Bonghan Kim did not describe his methods. For example, Among other methods, the discovery of a BHS-specific dye, trypan blue, was one of the most important original contributions that made BHS observation possible. With this technique, the BHS in adipose tissue became traceable, and the BHS was discovered on the fascia surrounding tumor tissues, a finding which may have great significance in relation to serious health problems in modern society, namely, obesity and cancer.

  13. Adhesion Molecules: Master Controllers of the Circulatory System.

    PubMed

    Schmidt, Eric P; Kuebler, Wolfgang M; Lee, Warren L; Downey, Gregory P

    2016-03-15

    This manuscript will review our current understanding of cellular adhesion molecules (CAMs) relevant to the circulatory system, their physiological role in control of vascular homeostasis, innate and adaptive immune responses, and their importance in pathophysiological (disease) processes such as acute lung injury, atherosclerosis, and pulmonary hypertension. This is a complex and rapidly changing area of research that is incompletely understood. By design, we will begin with a brief overview of the structure and classification of the major groups of adhesion molecules and their physiological functions including cellular adhesion and signaling. The role of specific CAMs in the process of platelet aggregation and hemostasis and leukocyte adhesion and transendothelial migration will be reviewed as examples of the complex and cooperative interplay between CAMs during physiological and pathophysiological processes. The role of the endothelial glycocalyx and the glycobiology of this complex system related to inflammatory states such as sepsis will be reviewed. We will then focus on the role of adhesion molecules in the pathogenesis of specific disease processes involving the lungs and cardiovascular system. The potential of targeting adhesion molecules in the treatment of immune and inflammatory diseases will be highlighted in the relevant sections throughout the manuscript.

  14. Design of a hydraulic analog of the circulatory system for evaluating artificial hearts.

    PubMed

    Donovan, F M

    1975-01-01

    A major problem in improving artificial heart designs is the absence of methods for accurate in vitro testing of artificial heart systems. A mock circulatory system has been constructed which hydraulically simulates the systemic and pulmonary circulations of the normal human. The device is constructed of 1/2 in. acrylic sheet and has overall dimensions of 24 in. wide, 16 in. tall, and 8 in. deep. The artificial heart to be tested is attached to the front of the device, and pumps fluid from the systemic venous chamber into the pulmonary arterial chamber and from the pulmonary venous chamber into the systemic arterial chamber. Each of the four chambers is hermetically sealed. The compliance of each chamber is determined by the volume of air trapped above the fluid in that chamber. The pulmonary and systemic resistances are set automatically by bellows-operated valves to simulate the barroreceptor response in the systemic arteries and the passive pulmonary resistance response in the pulmonary arteries. Cardiac output is measured by a turbine flowmeter in the systemic circulation. Results using the Kwan-Gett artificial heart show a good comparison between the mock circulatory system response and the calf response.

  15. Endoglin regulates mural cell adhesion in the circulatory system.

    PubMed

    Rossi, Elisa; Smadja, David M; Boscolo, Elisa; Langa, Carmen; Arevalo, Miguel A; Pericacho, Miguel; Gamella-Pozuelo, Luis; Kauskot, Alexandre; Botella, Luisa M; Gaussem, Pascale; Bischoff, Joyce; Lopez-Novoa, José M; Bernabeu, Carmelo

    2016-04-01

    The circulatory system is walled off by different cell types, including vascular mural cells and podocytes. The interaction and interplay between endothelial cells (ECs) and mural cells, such as vascular smooth muscle cells or pericytes, play a pivotal role in vascular biology. Endoglin is an RGD-containing counter-receptor for β1 integrins and is highly expressed by ECs during angiogenesis. We find that the adhesion between vascular ECs and mural cells is enhanced by integrin activators and inhibited upon suppression of membrane endoglin or β1-integrin, as well as by addition of soluble endoglin (SolEng), anti-integrin α5β1 antibody or an RGD peptide. Analysis of different endoglin mutants, allowed the mapping of the endoglin RGD motif as involved in the adhesion process. In Eng (+/-) mice, a model for hereditary hemorrhagic telangectasia type 1, endoglin haploinsufficiency induces a pericyte-dependent increase in vascular permeability. Also, transgenic mice overexpressing SolEng, an animal model for preeclampsia, show podocyturia, suggesting that SolEng is responsible for podocytes detachment from glomerular capillaries. These results suggest a critical role for endoglin in integrin-mediated adhesion of mural cells and provide a better understanding on the mechanisms of vessel maturation in normal physiology as well as in pathologies such as preeclampsia or hereditary hemorrhagic telangiectasia.

  16. Evaluation of exercise-respiratory system modifications and preliminary respiratory-circulatory system integration scheme

    NASA Technical Reports Server (NTRS)

    Gallagher, R. R.

    1974-01-01

    The respiratory control system, functioning as an independent system, is presented with modifications of the exercise subroutine. These modifications illustrate an improved control of ventilation rates and arterial and compartmental gas tensions. A very elementary approach to describing the interactions of the respiratory and circulatory system is presented.

  17. A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

    PubMed

    Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

    2017-02-14

    The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

  18. Mortality from Circulatory System Diseases and Malformations in Children in the State of Rio de Janeiro

    PubMed Central

    Salim, Thais Rocha; Soares, Gabriel Porto; Klein, Carlos Henrique; de Oliveira, Glaucia Maria Moraes

    2016-01-01

    Background The epidemiological profile of mortality in a population is important for the institution of measures to improve health care and reduce mortality Objective To estimate mortality rates and the proportional mortality from cardiovascular diseases and malformations of the circulatory system in children and adolescents. Methods This is a descriptive study of mortality from cardiovascular diseases, malformations of the circulatory system, from all causes, ill-defined causes and external causes in children and adolescents in the state of Rio de Janeiro from 1996 to 2012. Populations were obtained from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística - IBGE) and deaths obtained from the Department of Informatics of the Unified Health System (DATASUS)/Ministry of Health. Results There were 115,728 deaths from all causes, 69,757 in males. The annual mortality from cardiovascular diseases was 2.7/100,000 in men and 2.6/100,000 in women. The annual mortality from malformations of the circulatory system was 7.5/100,000 in men and 6.6/100,000 in women. Among the specific causes of circulatory diseases, cardiomyopathies had the highest rates of annual proportional mortality, and from malformations of the circulatory system, it occurred due to unspecified malformations of the circulatory system, at all ages and in both genders. Conclusion Mortality from malformations of the circulatory system was most striking in the first years of life, while cardiovascular diseases were more relevant in adolescents. Low access to prenatal diagnosis or at birth probably prevented the proper treatment of malformations of the circulatory system. PMID:27192384

  19. Gut Bacteria and Hydrogen Sulfide: The New Old Players in Circulatory System Homeostasis.

    PubMed

    Tomasova, Lenka; Konopelski, Piotr; Ufnal, Marcin

    2016-11-17

    Accumulating evidence suggests that gut bacteria play a role in homeostasis of the circulatory system in mammals. First, gut bacteria may affect the nervous control of the circulatory system via the sensory fibres of the enteric nervous system. Second, gut bacteria-derived metabolites may cross the gut-blood barrier and target blood vessels, the heart and other organs involved in the regulation of the circulatory system. A number of studies have shown that hydrogen sulfide (H₂S) is an important biological mediator in the circulatory system. Thus far, research has focused on the effects of H₂S enzymatically produced by cardiovascular tissues. However, some recent evidence indicates that H₂S released in the colon may also contribute to the control of arterial blood pressure. Incidentally, sulfate-reducing bacteria are ubiquitous in mammalian colon, and H₂S is just one among a number of molecules produced by the gut flora. Other gut bacteria-derived compounds that may affect the circulatory system include methane, nitric oxide, carbon monoxide, trimethylamine or indole. In this paper, we review studies that imply a role of gut microbiota and their metabolites, such as H₂S, in circulatory system homeostasis.

  20. The Circulatory System [and] Instructor's Guide: The Circulatory System. Health Occupations Education Module: Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

    ERIC Educational Resources Information Center

    National Evaluation Systems, Inc., Amherst, MA.

    This module on the circulatory system is one of 17 modules designed for individualized instruction in health occupations education programs at both the secondary and postsecondary levels. It is part of an eight-unit subset on anatomy and physiology within the set of 17 modules. Following a preface which explains to the student how to use the…

  1. The Pulsed Flow Algorithm (PFA) Applied to Coupled Respiratory and Circulatory Systems

    NASA Astrophysics Data System (ADS)

    Staples, A.; Oran, E.; Boris, J.; Kaplan, C.; Kailasanath, K.

    2007-11-01

    The Pulsed Flow Equations (PFE) are a set of coupled partial differential equations designed to capture features particularly relevant to internal flows through flexible elastic channels, such as flows in physiological systems in biological organisms, and hydraulics systems. The equations are an extension of the standard one-dimensional fluid flow equations that, in addition, are able to capture two-dimensional diffusion, branching, transport, viscous, and other effects. A limiting case of the equations is the standard one-dimensional fluid flow equations. The equations are discretized and solved partially using an asymptotic solution, after which they reduce to tridiagonal form. The solution formalism can be applied to many types of complex networks of internal flows, and solves these problems, including some important two-dimensional effects, at the cost of a one-dimensional tridiagonal computation. Here we apply the PFA to describe a coupled circulatory and respiratory system calibrated to the average human body.

  2. Noninvasive optoacoustic system for rapid diagnostics and management of circulatory shock

    NASA Astrophysics Data System (ADS)

    Esenaliev, Rinat O.; Petrov, Irene Y.; Petrov, Yuriy; Kinsky, Michael; Prough, Donald S.

    2012-02-01

    Circulatory shock is lethal, if not promptly diagnosed and effectively treated. Typically, circulatory shock resuscitation is guided by blood pressure, heart rate, and mental status, which have poor predictive value. In patients, in whom early goaldirected therapy was applied using central venous oxygenation measurement, a substantial reduction of mortality was reported (from 46.5% to 30%). However, central venous catheterization is invasive, time-consuming and often results in complications. We proposed to use the optoacoustic technique for noninvasive, rapid assessment of central venous oxygenation. In our previous works we demonstrated that the optoacoustic technique can provide measurement of blood oxygenation in veins and arteries due to high contrast and high resolution. In this work we developed a novel optoacoustic system for noninvasive, automatic, real-time, and continuous measurement of central venous oxygenation. We performed pilot clinical tests of the system in human subjects with different oxygenation in the internal jugular vein and subclavian vein. A novel optoacoustic interface incorporating highly-sensitive optoacoustic probes and standard ultrasound imaging probes were developed and built for the study. Ultrasound imaging systems Vivid i and hand-held Vscan (GE Healthcare) as well as Site-Rite 5 (C.R. Bard) were used in the study. We developed a special algorithm for oxygenation monitoring with minimal influence of overlying tissue. The data demonstrate that the system provides precise measurement of venous oxygenation continuously and in real time. Both current value of the venous oxygenation and trend (in absolute values and for specified time intervals) are displayed in the system. The data indicate that: 1) the optoacoustic system developed by our group is capable of noninvasive measurement of blood oxygenation in specific veins; 2) clinical ultrasound imaging systems can facilitate optoacoustic probing of specific blood vessels; 3) the

  3. Bilingual Skills Training Program. Barbering/Cosmetology. Module 10.0: Circulatory System.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on the circulatory or vascular system is the tenth of ten (CE 028 308-318) in the barbering/cosmetology course of a bilingual skills training program. (A Vocabulary Development Workbook for modules 6-10 is available as CE 028 313.) The course is designed to furnish theoretical and laboratory experience. Module objectives are for…

  4. [Procedure for coding the causes of death in some circulatory system diseases].

    PubMed

    Kakorina, E P; Aleksandrova, G A; Frank, G A; Mal'kov, P G; Zaĭratians, O V; Vaĭsman, D Sh

    2014-01-01

    The paper deals with the unification of requirements for coding the causes of death in circulatory system diseases, by taking into account the recently updated ICD-10 and the Consensus of the Expert Council Task Force on Pathological Anatomy, Ministry of Health of the Russian Federation (27 February 2014).

  5. The Decapod Crustacean Circulatory System: A Case That Is neither Open nor Closed

    NASA Astrophysics Data System (ADS)

    McGaw, Iain J.

    2005-02-01

    Historically, the decapod crustacean circulatory system has been classed as open. However, recent work on the blue crab, Callinectes sapidus, suggests the circulatory system may be more complex than previously described. Corrosion casting techniques were refined and used to map the circulatory system of a variety of crab species (order: Decapoda; family: Cancridae) to determine if the complexity observed in the blue crab was present in other species. Seven arteries arose from the single chambered heart. The anterior aorta, the paired anterolateral arteries, and the paired hepatic arteries exited from the anterior aspect of the heart. The small-diameter posterior aorta exited posteriorly from the heart. Exiting from the ventral surface of the heart, the sternal artery branched to supply the legs and mouthparts of the crab. These arteries were more complex than previously described, with arterioles perfusing all areas of the body. The arterioles split into fine capillary-like vessels. Most of these capillaries were blind ending. However, in several areas (antennal gland, supraesophageal ganglion) complete capillary beds were present. After passing through the capillary-like vessels, blood drained into a series of sinuses. However, rather than being arbitrary spaces as previously described, scanning electron micrographs showed the sinuses to be distinct units. Most of the sinuses formed a series of flattened membrane-bound lacunae. This complexity may qualify the decapod crustacean circulatory system as one that is "partially closed" rather than open.

  6. Toward a Theory of the Primo Vascular System: A Hypothetical Circulatory System at the Subcellular Level

    PubMed Central

    Lee, Byung-Cheon; Park, Sang Hyun; Yoon, Seung Zhoo

    2013-01-01

    This paper suggests a theoretical framework for the primo vascular system (PVS), a hypothetical circulatory system, in which extracellular DNA microvesicles interact to form and break down cell structures. Since Bonghan Kim reported the existence of Bonghan ducts and the SNU research team reinvestigated and named it the PVS, there has been series of studies trying to examine its structure and functions. In this paper, we hypothesize that the PVS is the network system in which extracellular DNA microvesicles circulate and interact at the subcellular level, forming and breaking down cell structures. This idea integrates A. Béchamp's idea of microzymas and Bonghan Kim's idea of sanals. A proof of this idea may complement modern medical theory, perhaps providing an essential clue for an alternative solution dealing with modern healthcare problem. PMID:23853665

  7. Toward a theory of the primo vascular system: a hypothetical circulatory system at the subcellular level.

    PubMed

    Lee, Byung-Cheon; Yoon, Ji Woong; Park, Sang Hyun; Yoon, Seung Zhoo

    2013-01-01

    This paper suggests a theoretical framework for the primo vascular system (PVS), a hypothetical circulatory system, in which extracellular DNA microvesicles interact to form and break down cell structures. Since Bonghan Kim reported the existence of Bonghan ducts and the SNU research team reinvestigated and named it the PVS, there has been series of studies trying to examine its structure and functions. In this paper, we hypothesize that the PVS is the network system in which extracellular DNA microvesicles circulate and interact at the subcellular level, forming and breaking down cell structures. This idea integrates A. Béchamp's idea of microzymas and Bonghan Kim's idea of sanals. A proof of this idea may complement modern medical theory, perhaps providing an essential clue for an alternative solution dealing with modern healthcare problem.

  8. Global solution to a hyperbolic problem arising in the modeling of blood flow in circulatory systems

    NASA Astrophysics Data System (ADS)

    Ruan, Weihua; Clark, M. E.; Zhao, Meide; Curcio, Anthony

    2007-07-01

    This paper considers a system of first-order, hyperbolic, partial differential equations in the domain of a one-dimensional network. The system models the blood flow in human circulatory systems as an initial-boundary-value problem with boundary conditions of either algebraic or differential type. The differential equations are nonhomogeneous with frictional damping terms and the state variables are coupled at internal junctions. The existence and uniqueness of the local classical solution have been established in our earlier work [W. Ruan, M.E. Clark, M. Zhao, A. Curcio, A hyperbolic system of equations of blood flow in an arterial network, J. Appl. Math. 64 (2) (2003) 637-667; W. Ruan, M.E. Clark, M. Zhao, A. Curcio, Blood flow in a network, Nonlinear Anal. Real World Appl. 5 (2004) 463-485; W. Ruan, M.E. Clark, M. Zhao, A. Curcio, A quasilinear hyperbolic system that models blood flow in a network, in: Charles V. Benton (Ed.), Focus on Mathematical Physics Research, Nova Science Publishers, Inc., New York, 2004, pp. 203-230]. This paper continues the analysis and gives sufficient conditions for the global existence of the classical solution. We prove that the solution exists globally if the boundary data satisfy the dissipative condition (2.3) or (3.2), and the norms of the initial and forcing functions in a certain Sobolev space are sufficiently small. This is only the first step toward establishing the global existence of the solution to physiologically realistic models, because, in general, the chosen dissipative conditions (2.3) and (3.2) do not appear to hold for the originally proposed boundary conditions (1.3)-(1.12).

  9. Disparity in regional and systemic circulatory capacities: do they affect the regulation of the circulation?

    PubMed

    Calbet, J A L; Joyner, M J

    2010-08-01

    In this review we integrate ideas about regional and systemic circulatory capacities and the balance between skeletal muscle blood flow and cardiac output during heavy exercise in humans. In the first part of the review we discuss issues related to the pumping capacity of the heart and the vasodilator capacity of skeletal muscle. The issue is that skeletal muscle has a vast capacity to vasodilate during exercise [approximately 300 mL (100 g)(-1) min(-1)], but the pumping capacity of the human heart is limited to 20-25 L min(-1) in untrained subjects and approximately 35 L min(-1) in elite endurance athletes. This means that when more than 7-10 kg of muscle is active during heavy exercise, perfusion of the contracting muscles must be limited or mean arterial pressure will fall. In the second part of the review we emphasize that there is an interplay between sympathetic vasoconstriction and metabolic vasodilation that limits blood flow to contracting muscles to maintain mean arterial pressure. Vasoconstriction in larger vessels continues while constriction in smaller vessels is blunted permitting total muscle blood flow to be limited but distributed more optimally. This interplay between sympathetic constriction and metabolic dilation during heavy whole-body exercise is likely responsible for the very high levels of oxygen extraction seen in contracting skeletal muscle. It also explains why infusing vasodilators in the contracting muscles does not increase oxygen uptake in the muscle. Finally, when approximately 80% of cardiac output is directed towards contracting skeletal muscle modest vasoconstriction in the active muscles can evoke marked changes in arterial pressure.

  10. Burden of Circulatory System Diseases and Ignored Barriers of Knowledge Translation

    PubMed Central

    Ghafouri, Hamed-Basir; Saravani, Shahzad; Shokraneh, Farhad

    2012-01-01

    Circulatory system disease raise third highest disability-adjusted life years among Iranians and ischemic cardiac diseases are main causes for such burden. Despite available evidences on risk factors of the disease, no effective intervention was implemented to control and prevent the disease. This paper non-systematically reviews available literature on the problem, solutions, and barriers of implementation of knowledge translation in Iran. It seems that there are ignored factors such as cultural and motivational issues in knowledge translation interventions but there are hopes for implementation of started projects and preparation of students as next generation of knowledge transferors. PMID:24250994

  11. Perturbation analysis of internal balancing for lightly damped mechanical systems with gyroscopic and circulatory forces

    NASA Technical Reports Server (NTRS)

    Blelloch, P. A.; Mingori, D. L.; Wei, J. D.

    1987-01-01

    Approximate expressions are developed for internally balanced singular values corresponding to the modes of mechanical systems with gyroscopic forces, light damping, and small circulatory forces. A brief overview is first given of the balanced realization model reduction method, including a discussion of recent work. The models considered are defined, and a perturbation analysis is used to show that the modal representation becomes asymptotically balanced as damping reduces to zero. The approximate balanced singular values are calculated, and a simple example of a flexible, dual-spin spacecraft is given as an illustration of the results.

  12. AB-180 circulatory support system: summary of development and phase I clinical trial.

    PubMed

    Griffin, W P; Savage, E B; Clark, R E; Pacella, J J; Johnson, G A; Magovern, J A; Magovern, G J

    1998-01-01

    The AB-180 Circulatory Support System (AB-180 CSS; Cardiac Assist Technologies, Pittsburgh, PA) is a left ventricular assist system for investigational use in patients with postcardiotomy cardiogenic shock who are refractory to standard treatment with an intra-aortic balloon pump, pharmacologic treatment, or both. The intent of the AB-180 CSS is to provide temporary (up to 14 days) mechanical circulatory support until the heart recovers adequate mechanical function. The system consists of a small implantable centrifugal pump and a controller. A unique infusion system produces a hydrodynamic bearing between rotational and stationary components of the AB-180 CSS pump. This infusion system also provides a source of heparin for localized anticoagulation. Extensive bench and animal work has illustrated anticoagulation requirements, established operating guidelines, and demonstrated safety and efficacy. An investigational device exemption has been granted for a Phase I, five patient feasibility study at Allegheny General Hospital in Pittsburgh, Pennsylvania. To date, the pump has been implanted in one patient. The results from this first case are presented here.

  13. Noninvasive optoacoustic system for rapid diagnosis and management of circulatory shock

    NASA Astrophysics Data System (ADS)

    Petrov, Irene Y.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. N.; Seeton, Roger; Esenaliev, Rinat O.; Prough, Donald S.

    2013-03-01

    Circulatory shock can lead to death or severe complications, if not promptly diagnosed and effectively treated. Typically, diagnosis and management of circulatory shock are guided by blood pressure and heart rate. However, these variables have poor specificity, sensitivity, and predictive value. Early goal-directed therapy in septic shock patients, using central venous catheterization (CVC), reduced mortality from 46.5% to 30%. However, CVC is invasive and complication-prone. We proposed to use an optoacoustic technique for noninvasive, rapid assessment of peripheral and central venous oxygenation. In this work we used a medical grade optoacoustic system for noninvasive, ultrasound image-guided measurement of central and peripheral venous oxygenation. Venous oxygenation during shock declines more rapidly in the periphery than centrally. Ultrasound imaging of the axillary [peripheral] and internal jugular vein [central] was performed using the Vivid e (GE Healthcare). We built an optoacoustic interface incorporating an optoacoustic transducer and a standard ultrasound imaging probe. Central and peripheral venous oxygenations were measured continuously in healthy volunteers. To simulate shock-induced changes in central and peripheral oxygenation, we induced peripheral vasoconstriction in the upper extremity by using a cooling blanket. Central and peripheral venous oxygenations were measured before (baseline) and after cooling and after rewarming. During the entire experiment, central venous oxygenation was relatively stable, while peripheral venous oxygenation decreased by 5-10% due to cooling and recovered after rewarming. The obtained data indicate that noninvasive, optoacoustic measurements of central and peripheral venous oxygenation may be used for diagnosis and management of circulatory shock with high sensitivity and specificity.

  14. Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education.

    PubMed

    Abram, Sean R; Hodnett, Benjamin L; Summers, Richard L; Coleman, Thomas G; Hester, Robert L

    2007-06-01

    We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop.

  15. Transcutaneous energy transmission for mechanical circulatory support systems: history, current status, and future prospects.

    PubMed

    Slaughter, Mark S; Myers, Timothy J

    2010-07-01

    A totally implantable mechanical circulatory support system would be very desirable for destination therapy. However, implanting all components of a pulsatile total artificial heart (TAH) or left ventricular assist device (LVAD) is complex because of the requirement for a continuous electrical power supply and the need for volume compensation. Implantable compliance chambers were developed for early LVAD designs, and although they functioned properly during initial laboratory tests, air loss by diffusion and the development of fibrous tissue around the sac eventually rendered them ineffective. Because these problems have not yet been overcome, volume displacement LVADs are currently designed with either a direct communication to an external drive console or an atmospheric vent. Transcutaneous energy transmission systems (TETSs) were also developed, but because the skin was being penetrated for volume compensation, it seemed more efficient to transmit electrical power through wires incorporated into the venting apparatus. More recently, TETSs were used clinically for both a pulsatile TAH and LVAD in a small number of patients, but for reasons unrelated to the TETS, neither of these devices is presently in use. Because the newer continuous-flow LVADs do not require a compliance chamber, they present a potential future application for TETS technology, because infections of the percutaneous tube continue to be one of the most important limitations of long-term circulatory support. A totally implantable LVAD with an incorporated TETS for destination therapy could become an important advance in the treatment of end-stage heart failure.

  16. [Comparison of a rural town and a fishing town: diet and circulatory system diseases].

    PubMed

    Liang, H; Ozasa, K; Higashi, A; Watanabe, Y; Hayashi, K; Aoike, A; Kawai, K

    1993-10-01

    We report a comparative study of the Standardized Mortality Ratio (SMR) for circulatory system diseases and diet in a rural town and a fishing town in Kyoto Prefecture. SMR was assessed during the 5-year period from 1983 through 1987, and compared with the standard age- and sex-adjusted demographic and mortality statistics compiled by the National Census Bureau of Japan in 1985. A food frequency questionnaire in which the respondents evaluated their food consumption during the previous 1-year period was used to assess diet. The questionnaire was administered during February 1989 in the rural town and during February 1990 in the fishing town. In comparison with the standard statistics, SMR was higher in the rural town and lower in the fishing town. The inhabitants of the fishing town more frequently consumed low-fat and low-sodium foods, such as fish, potatoes, tofu, and green, yellow and other vegetables, and less frequently consumed high-fat and high-sodium foods, such as meat, fried food, pickles, than did the inhabitants of the rural town. The residents of the fishing town also consumed a greater variety of foods in one week. The two towns differ in geography and economic structure, and their inhabitants have different life-styles and eating habits. The lower SMR for circulatory system diseases in the fishing town may be related to the greater consumption of fish and vegetables with lower meat and salt intake, as well as the balanced of diet.

  17. A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics.

    PubMed

    Knoops, Paul G M; Biglino, Giovanni; Hughes, Alun D; Parker, Kim H; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

    2016-12-07

    A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the

  18. Non-Intrusive Device for Real-Time Circulatory System Assessment with Advanced Signal Processing Capabilities

    NASA Astrophysics Data System (ADS)

    Pinheiro, E.; Postolache, O.; Girão, P.

    2010-01-01

    This paper presents a device that uses three cardiography signals to characterize several important parameters of a subject's circulatory system. Using electrocardiogram, finger photoplethysmogram, and ballistocardiogram, three heart rate estimates are acquired from beat-to-beat time interval extraction. Furthermore, pre-ejection period, pulse transit time (PTT), and pulse arrival time (PAT) are computed, and their long-term evolution is analyzed. The system estimates heart rate variability (HRV) and blood pressure variability (BPV) from the heart rate and PAT time series, to infer the activity of the cardiac autonomic system. The software component of the device evaluates the frequency content of HRV and BPV, and also their fractal dimension and entropy, thus providing a detailed analysis of the time series' regularity and complexity evolution, to allow personalized subject evaluation.

  19. Stability of circulatory elastic systems in the presence of magnetic damping.

    NASA Technical Reports Server (NTRS)

    Smith, T. E.; Herrmann, G.

    1971-01-01

    The effect of a type of magnetic damping on the stability of equilibrium of some circulatory elastic systems is examined. A simple system with two degrees of freedom is considered first, and a destabilization is found to be caused by the magnetic field. The nature of the destabilization, however, is not identical to that caused by internal viscous damping. The differences and similarities between the two effects are discussed, and the results are also compared with those of linear external viscous damping. A continuous cantilever bar subjected to a follower force at its free end is then examined. It is found that the critical load is independent of the strength of the magnetic field, and is considerably lower than the corresponding critical load in the absence of a magnetic field. Finally, the continuous cantilever is treated approximately by Galerkin's procedure and also by using a two-degree-of-freedom model of the cantilever; the results obtained are qualitatively the same.

  20. The circulatory system: blood procurement, AIDS, and the social body in China.

    PubMed

    Erwin, Kathleen

    2006-06-01

    The market for blood thrived in China for more than a decade, preying on rural villagers desperate for cash. Profit motives and unhygienic collection created an AIDS epidemic, where now up to 80 percent of adults in some villages are HIV infected. Today, illegal blood banks continue to operate in some areas. Moreover, better screening and blood testing do little to address the underlying cultural reluctance to give blood. This article examines what is at stake for blood donors in the circulation of blood through both the physical and the social bodies in China today. I argue that public health and social policy solutions require consideration of the symbolic meanings of blood and the body, kin relations, and gift exchange. China's HIV-contaminated blood procurement crisis demands a critical reexamination of the hidden processes embedded in a "circulatory system" that has inseparably bound the "gift of life" and a "commodity of death".

  1. Effect of 5E Instructional Model in Student Success in Primary School 6th Year Circulatory System Topic

    ERIC Educational Resources Information Center

    Cardak, Osman; Dikmenli, Musa; Saritas, Ozge

    2008-01-01

    The aim of this study is to research the effect of the 5E instructional model on primary (sixth grade) student success during the circulatory system unit. This study was conducted with 38 students in two different classes by the same researcher in 2006-2007. One of the classes was assigned as the control group and the other as the experimental…

  2. Viscoelasticity of blood and viscoelastic blood analogues for use in polydymethylsiloxane in vitro models of the circulatory system.

    PubMed

    Campo-Deaño, Laura; Dullens, Roel P A; Aarts, Dirk G A L; Pinho, Fernando T; Oliveira, Mónica S N

    2013-01-01

    The non-Newtonian properties of blood are of great importance since they are closely related with incident cardiovascular diseases. A good understanding of the hemodynamics through the main vessels of the human circulatory system is thus fundamental in the detection and especially in the treatment of these diseases. Very often such studies take place in vitro for convenience and better flow control and these generally require blood analogue solutions that not only adequately mimic the viscoelastic properties of blood but also minimize undesirable optical distortions arising from vessel curvature that could interfere in flow visualizations or particle image velocimetry measurements. In this work, we present the viscoelastic moduli of whole human blood obtained by means of passive microrheology experiments. These results and existing shear and extensional rheological data for whole human blood in the literature enabled us to develop solutions with rheological behavior analogous to real whole blood and with a refractive index suited for PDMS (polydymethylsiloxane) micro- and milli-channels. In addition, these blood analogues can be modified in order to obtain a larger range of refractive indices from 1.38 to 1.43 to match the refractive index of several materials other than PDMS.

  3. Viscoelasticity of blood and viscoelastic blood analogues for use in polydymethylsiloxane in vitro models of the circulatory system

    PubMed Central

    Campo-Deaño, Laura; Dullens, Roel P. A.; Aarts, Dirk G. A. L.; Pinho, Fernando T.; Oliveira, Mónica S. N.

    2013-01-01

    The non-Newtonian properties of blood are of great importance since they are closely related with incident cardiovascular diseases. A good understanding of the hemodynamics through the main vessels of the human circulatory system is thus fundamental in the detection and especially in the treatment of these diseases. Very often such studies take place in vitro for convenience and better flow control and these generally require blood analogue solutions that not only adequately mimic the viscoelastic properties of blood but also minimize undesirable optical distortions arising from vessel curvature that could interfere in flow visualizations or particle image velocimetry measurements. In this work, we present the viscoelastic moduli of whole human blood obtained by means of passive microrheology experiments. These results and existing shear and extensional rheological data for whole human blood in the literature enabled us to develop solutions with rheological behavior analogous to real whole blood and with a refractive index suited for PDMS (polydymethylsiloxane) micro- and milli-channels. In addition, these blood analogues can be modified in order to obtain a larger range of refractive indices from 1.38 to 1.43 to match the refractive index of several materials other than PDMS. PMID:24404022

  4. Pumping Rate Study of a Left Ventricular Assist Device in a Mock Circulatory System.

    PubMed

    Zhuang, Xiaoqi; Yang, Ming; Xu, Liang; Ou, Wenchu; Xu, Zihao; Meng, Fan; Huang, Huan

    2016-01-01

    The aim of this work was to investigate the hemodynamic influence of the change of pump rate on the cardiovascular system with consideration of heart rate and the resonant characteristics of the arterial system when a reliable synchronous triggering source is unavailable. Hemodynamic waveforms are recorded at baseline conditions and with the pump rate of left ventricular assist device (LVAD) at 55, 60, 66, and 70 beats per minute for four test conditions in a mock circulatory system. The total input work (TIW) and energy equivalent pressure (EEP) are calculated as metrics for evaluating the hemodynamic performance within different test conditions. Experimental results show that TIW and EEP achieve their maximum values, where the pump rate is equal to the heart rate. In addition, it demonstrates that TIW and EEP are significantly affected by changing pump rate of LVAD, especially when the pump rate is closing to the natural frequency of the arterial system. When a reliable synchronous triggering source is not available for LVAD, it is suggested that selecting a pump rate equal to the resonant frequency of the arterial system could achieve better supporting effects.

  5. Development of an in-vitro circulatory system with known resistance and capacitance

    NASA Technical Reports Server (NTRS)

    Offerdahl, C. D.; Schaub, J. D.; Koenig, S. C.; Swope, R. D.; Ewert, D. L.; Convertino, V. A. (Principal Investigator)

    1996-01-01

    An in-vitro (hydrodynamic) model of the circulatory system was developed. The model consisted of a pump, compliant tubing, and valves for resistance. The model is used to simulate aortic pressure and flow. These parameters were measured using a Konigsburg Pressure transducer and a Triton ART2 flow probe. In addition, venous pressure and flow were measured on the downstream side of the resistance. The system has a known compliance and resistance. Steady and pulsatile flow tests were conducted to determine the resistance of the model. A static compliance test was used to determine the compliance of the system. The aortic pressure and flow obtained from the hydrodynamic model will be used to test the accuracy of parameter estimation models such as the 2-element and 4-element Windkessel models and the 3-element Westkessel model. Verifying analytical models used in determining total peripheral resistance (TPR) and systemic arterial compliance (SAC) is important because it provides insight into hemodynamic parameters that indicate baroreceptor responsiveness to situations such as changes in gravitational acceleration.

  6. NASA Models of Space Radiation Induced Cancer, Circulatory Disease, and Central Nervous System Effects

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Chappell, Lori J.; Kim, Myung-Hee Y.

    2013-01-01

    The risks of late effects from galactic cosmic rays (GCR) and solar particle events (SPE) are potentially a limitation to long-term space travel. The late effects of highest concern have significant lethality including cancer, effects to the central nervous system (CNS), and circulatory diseases (CD). For cancer and CD the use of age and gender specific models with uncertainty assessments based on human epidemiology data for low LET radiation combined with relative biological effectiveness factors (RBEs) and dose- and dose-rate reduction effectiveness factors (DDREF) to extrapolate these results to space radiation exposures is considered the current "state-of-the-art". The revised NASA Space Risk Model (NSRM-2014) is based on recent radio-epidemiology data for cancer and CD, however a key feature of the NSRM-2014 is the formulation of particle fluence and track structure based radiation quality factors for solid cancer and leukemia risk estimates, which are distinct from the ICRP quality factors, and shown to lead to smaller uncertainties in risk estimates. Many persons exposed to radiation on earth as well as astronauts are life-time never-smokers, which is estimated to significantly modify radiation cancer and CD risk estimates. A key feature of the NASA radiation protection model is the classification of radiation workers by smoking history in setting dose limits. Possible qualitative differences between GCR and low LET radiation increase uncertainties and are not included in previous risk estimates. Two important qualitative differences are emerging from research studies. The first is the increased lethality of tumors observed in animal models compared to low LET radiation or background tumors. The second are Non- Targeted Effects (NTE), which include bystander effects and genomic instability, which has been observed in cell and animal models of cancer risks. NTE's could lead to significant changes in RBE and DDREF estimates for GCR particles, and the potential

  7. 38 CFR 4.62 - Circulatory disturbances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances. The circulatory disturbances, especially of the lower extremity following injury in the popliteal... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Circulatory...

  8. 38 CFR 4.62 - Circulatory disturbances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances. The circulatory disturbances, especially of the lower extremity following injury in the popliteal... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Circulatory...

  9. 38 CFR 4.62 - Circulatory disturbances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances. The circulatory disturbances, especially of the lower extremity following injury in the popliteal... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Circulatory...

  10. 38 CFR 4.62 - Circulatory disturbances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances. The circulatory disturbances, especially of the lower extremity following injury in the popliteal... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Circulatory...

  11. 38 CFR 4.62 - Circulatory disturbances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances. The circulatory disturbances, especially of the lower extremity following injury in the popliteal... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Circulatory...

  12. In vitro cardiovascular system emulator (bioreactor) for the simulation of normal and diseased conditions with and without mechanical circulatory support.

    PubMed

    Ruiz, Paula; Rezaienia, Mohammad Amin; Rahideh, Akbar; Keeble, Thomas R; Rothman, Martin T; Korakianitis, Theodosios

    2013-06-01

    This article presents a new device designed to simulate in vitro flow rates, pressures, and other parameters representing normal and diseased conditions of the human cardiovascular system. Such devices are sometimes called bioreactors or "mock" simulator of cardiovascular loops (SCVLs) in literature. Most SCVLs simulate the systemic circulation only and have inherent limitations in studying the interaction of left and right sides of circulation. Those SCVLs that include both left and right sides of the circulation utilize header reservoirs simulating cycles with constant atrial pressures. The SCVL described in this article includes models for all four chambers of the heart, and the systemic and pulmonary circulation loops. Each heart chamber is accurately activated by a separate linear motor to simulate the suction and ejection stages, thus capturing important features in the perfusion waveforms. Four mechanical heart valves corresponding to mitral, pulmonary, tricuspid, and aortic are used to control the desired unidirectional flow. This SCVL can emulate different physiological and pathological conditions of the human cardiovascular system by controlling the different parameters of blood circulation through the vascular tree (mainly the resistance, compliance, and elastance of the heart chambers). In this study, four cases were simulated: healthy, congestive heart failure, left ventricular diastolic dysfunction conditions, and left ventricular dysfunction with the addition of a mechanical circulatory support (MCS) device. Hemodynamic parameters including resistance, pressure, and flow have been investigated at aortic sinus, carotid artery, and pulmonary artery, respectively. The addition of an MCS device resulted in a significant reduction in mean blood pressure and re-establishment of cardiac output. In all cases, the experimental results are compared with human physiology and numerical simulations. The results show the capability of the SCVL to replicate various

  13. Head capsule, chephalic central nervous system and head circulatory system of an aberrant orthopteran, Prosarthria teretrirostris (Caelifera, Hexapoda).

    PubMed

    Baum, Eileen; Hertel, Wieland; Beutel, Rolf Georg

    2007-01-01

    The head capsule, the circulatory system and the central nervous system of the head of Prosarthria teretrirostris (Proscopiidae) is described in detail, with special consideration of modifications resulting from the aberrant head shape. The transformations of the head are completely different from those found in phasmatodeans, which are also characterised by twig mimesis. The circulatory system is distinctly modified. A hitherto undescribed additional structure in the posterior head region very likely functions as a pulsatile organ. The cephalic central nervous system is strongly elongated, with changes in the position of the suboesophageal ganglion, the corpora cardiaca and the course of the nervus mandibularis. Three-dimensional reconstructions of these two organ systems in combination with the pharynx were made using Alias Maya 6.0 software. Comparisons with other representatives of Caelifera suggest a clade comprising Proscopiidae and Morabinae. The presence of a transverse muscle connecting the antennal ampullae in Prosarthria shows that this structure likely belongs to the groundplan of Orthoptera, even though it is missing in different representatives of this group. The transverse ampullary muscle is a potential synapomorphy of Orthoptera, Phasmatodea and Dictyoptera.

  14. A hybrid mock circulatory system: development and testing of an electro-hydraulic impedance simulator.

    PubMed

    Kozarski, M; Ferrari, G; Clemente, F; Górczyńska, K; De Lazzari, C; Darowski, M; Mimmo, R; Tosti, G; Guaragno, M

    2003-01-01

    Mock circulatory systems are used to test mechanical assist devices and for training and research purposes; when compared to numerical models, however, they are not flexible enough and rather expensive. The concept of merging numerical and physical models, resulting in a hybrid one, is applied here to represent the input impedance of the systemic arterial tree, by a conventional windkessel model built out of an electro-hydraulic (E-H) impedance simulator added to a hydraulic section. This model is inserted into an open loop circuit, completed by another hybrid model representing the ventricular function. The E-H impedance simulator is essentially an electrically controlled flow source (a gear pump). Referring to the windkessel model, it is used to simulate the peripheral resistance and the hydraulic compliance, creating the desired input impedance. The data reported describe the characterisation of the E-H impedance simulator and demonstrate its behaviour when it is connected to a hybrid ventricular model. Experiments were performed under different hemodynamic conditions, including the presence of a left ventricular assist device (LVAD).

  15. Computer modeling of interactions of an electric motor, circulatory system, and rotary blood pump.

    PubMed

    Xu, L; Fu, M

    2000-01-01

    The innovative ventricular assist systems (IVAS) is the next generation ventricular assist device for use as a permanent implantable device. Its practical application depends upon control of the electric motor and interactions of the electric motor, blood pump, and circulatory system. Computer modeling and simulation are necessary to investigate and evaluate the interactions and feasibility of sophisticated control algorithms. In this paper, a computer model of the complete system, including the cardiovascular system, blood pump, and electric motor, is proposed. The model is obtained based on an electric circuit model of the cardiovascular system, a parametric model of the blood pump, and a dynamic model of the electric motor. The cardiovascular system uses nonlinear parameters to simulate the time-varying property of the ventricles, and the cannula collapse effect caused by over-pumping. The blood pump model can be obtained either from pump design data, or test data. The motor control can be operated with closed-loop regulation, depending upon physiologic requirements. Different operation modes (current or speed) of the electric motor can be simulated. The computer model is implemented using MATLAB. Various motor operation modes are simulated and their effects are evaluated. By adjusting the motor input, the pump can achieve proper output so that normal physiology can be obtained. In addition to evaluating existing operation modes and their effect on the physiologic system, the computer simulation results show that this computer model can contribute significantly to the development of new physiologic control algorithms. It is demonstrated that, using this motor-pump-physiology interaction model, development of an innovative ventricular assist system can be greatly facilitated.

  16. [Nursing diagnoses and outcomes related to the circulatory-system terms (ICNP®) represented in an ontology].

    PubMed

    Cubas, Marcia Regina; Brondani, Arianny Macedo; Malucelli, Andreia

    2013-10-01

    The aim of the present study was to develop titles of Nursing Diagnoses and Outcomes (ND/NO) through the relationship between the terms of the Focus axis, limited to the Circulatory System Process, and the terms of other ICNP® axes and to integrate these terms into an ontology. Titles were developed linking 17 terms of the focus axis, which were evaluated by expert nurses in five Brazilian cities. Titles whose use concordance was above 0.80 were included in the ontology. In total, 89 titles for ND/NO were supported in the literature, and 19 were not supported; 37 were assessed as eligible for use in healthcare practice and were included in the ontology. The construction of ND/NO titles based on the ICNP® and using a formal representation of knowledge is a task that requires deepening concepts used for nursing and adequate classification revisions. The elaborated titles will facilitate the composition of diagnostics that are more consistent with practice.

  17. [Trans isomers of unsaturated fatty acids increase the risk of atherosclerosis-related circulatory system diseases].

    PubMed

    Perova, N V; Metel'skaia, V A; Boĭtsov, S A

    2013-01-01

    The paper provides a review of the literature on a relevant non-drug prevention problem, namely the negative effect of trans isomers of unsaturated fatty acids (trans-UFA) on the risk of circulatory system diseases (CSD) and other chronic noncommunicable diseases. It gives data on the specific features of the structure and ability of trans-UFA to elevate the plasma levels of atherogenic low-density lipoproteins and to lower those of non/antiatherogenic high-density lipoproteins. The natural sources of their moderate content in the animal fats from ruminants and those of their redundant content in the margarines manufactured by hydrogenation of liquid vegetable oils are described. A new technology for preparing soft margarines (spreads) is presented, which can produce fatty products that do not virtually contain trans-UFA. There is evidence that trans-UFA can considerably raise the risk of CSD and their acute complications. It is concluded that the manufacture of fatty products with low and even no trans-UFA levels should be expanded in Russia to improve its population's health.

  18. A hybrid mock circulatory system: testing a prototype under physiologic and pathological conditions.

    PubMed

    Ferrari, Gianfranco; De Lazzari, Claudio; Kozarski, Maciej; Clemente, Fabrizio; Górczyńska, Krystyna; Mimmo, Rita; Monnanni, Eliana; Tosti, Giancarlo; Guaragno, Marco

    2002-01-01

    Hydraulic models of circulation are used to test mechanical heart assist devices and for research and training purposes. However, when compared with numerical models, they are rather expensive and often not sufficiently flexible or accurate. Flexibility and accuracy can be improved by merging numerical models with physical models, thus obtaining a hybrid model where numerical and physical sections are connected by an electrohydraulic interface. This concept is applied here to represent left ventricular function. The resulting hybrid model is inserted into the existing closed loop model of circulation. The hybrid model reproduces ventricular function by a variable elastance numerical model. Its interaction with the hydraulic sections is governed by measuring left atrial and systemic arterial pressures and computing the left ventricular output flow by the resolution of the corresponding equations. This signal is used to control a flow generator reproduced by a gear pump driven by a DC motor. Results obtained under different circulatory conditions demonstrate the behavior of the ventricular model on the pressure-volume plane and report the trend of the main hemodynamic variables.

  19. User's instructions for the Guyton circulatory dynamics model using the Univac 1110 batch and demand processing (with graphic capabilities)

    NASA Technical Reports Server (NTRS)

    Archer, G. T.

    1974-01-01

    The model presents a systems analysis of a human circulatory regulation based almost entirely on experimental data and cumulative present knowledge of the many facets of the circulatory system. The model itself consists of eighteen different major systems that enter into circulatory control. These systems are grouped into sixteen distinct subprograms that are melded together to form the total model. The model develops circulatory and fluid regulation in a simultaneous manner. Thus, the effects of hormonal and autonomic control, electrolyte regulation, and excretory dynamics are all important and are all included in the model.

  20. Receptor-mediated oral delivery of a bioencapsulated green fluorescent protein expressed in transgenic chloroplasts into the mouse circulatory system

    PubMed Central

    Limaye, Arati; Koya, Vijay; Samsam, Mohtashem; Daniell, Henry

    2012-01-01

    Oral delivery of biopharmaceutical proteins expressed in plant cells should reduce their cost of production, purification, processing, cold storage, transportation, and delivery. However, poor intestinal absorption of intact proteins is a major challenge. To overcome this limitation, we investigate here the concept of receptor-mediated oral delivery of chloroplast-expressed foreign proteins. Therefore, the transmucosal carrier cholera toxin B-subunit and green fluorescent protein (CTB-GFP), separated by a furin cleavage site, was expressed via the tobacco chloroplast genome. Polymerase chain reaction (PCR) and Southern blot analyses confirmed site-specific transgene integration and homoplasmy. Immunoblot analysis and ELISA confirmed expression of monomeric and pentameric forms of CTB-GFP, up to 21.3% of total soluble proteins. An in vitro furin cleavage assay confirmed integrity of the engineered furin cleavage site, and a GM1 binding assay confirmed the functionality of CTB-GFP pentamers. Following oral administration of CTB-GFP expressing leaf material to mice, GFP was observed in the mice intestinal mucosa, liver, and spleen in fluorescence and immunohistochemical studies, while CTB remained in the intestinal cell. This report of receptor-mediated oral delivery of a foreign protein into the circulatory system opens the door for low-cost production and delivery of human therapeutic proteins. PMID:16603603

  1. Interdisciplinary studies on the development of nuclear-fueled circulatory support systems: Collaboration of industry and academe

    NASA Technical Reports Server (NTRS)

    Norman, J. C.

    1974-01-01

    The purpose of this report is to acquaint the Houston community with specific areas of available technology, both public and private, to demonstrate to industry how this technology may be acquired and put to use to provide new and useful services for man. Much of the technology utilized in the development of nuclear-fueled circulatory support systems in our laboratories has evolved from industry, NASA, and AEC; our projects involve radiation biology, thermodynamics, energy transfers, hemodynamics, hematology, pathology, and surgery.

  2. A LabVIEW model incorporating an open-loop arterial impedance and a closed-loop circulatory system.

    PubMed

    Cole, R T; Lucas, C L; Cascio, W E; Johnson, T A

    2005-11-01

    While numerous computer models exist for the circulatory system, many are limited in scope, contain unwanted features or incorporate complex components specific to unique experimental situations. Our purpose was to develop a basic, yet multifaceted, computer model of the left heart and systemic circulation in LabVIEW having universal appeal without sacrificing crucial physiologic features. The program we developed employs Windkessel-type impedance models in several open-loop configurations and a closed-loop model coupling a lumped impedance and ventricular pressure source. The open-loop impedance models demonstrate afterload effects on arbitrary aortic pressure/flow inputs. The closed-loop model catalogs the major circulatory waveforms with changes in afterload, preload, and left heart properties. Our model provides an avenue for expanding the use of the ventricular equations through closed-loop coupling that includes a basic coronary circuit. Tested values used for the afterload components and the effects of afterload parameter changes on various waveforms are consistent with published data. We conclude that this model offers the ability to alter several circulatory factors and digitally catalog the most salient features of the pressure/flow waveforms employing a user-friendly platform. These features make the model a useful instructional tool for students as well as a simple experimental tool for cardiovascular research.

  3. [The influence of the length of work on the adaptation of the circulatory system of male teachers of different specialities].

    PubMed

    Kirilina, V M; Goranskiĭ, A I

    2010-01-01

    The problem of human adaptation to the social and biological conditions of the existence is placed at the center of attention of many natural and social sciences studying vital activity of a person in all forms it displays. The basis of the existence of the human population is considered to be a social and labor activity of people. Recently, the importance of researches has increased, which enables to evaluate the functional state of a person under the circumstances of adaptation to a particular occupation. These researches are the theoretical foundation to develop methods for improving the efficiency of people in many kinds of professions, and especially it is important for elderly people. The results of social and hygienic researches among the middle-aged and elderly people involved in different trades vary and are stipulated generally by the conditions of the working environment, difficulties and intensity of work processes. The study of the features of the circulatory system of a person in the process of working activities is a significant issue in physiology. It is found that the greatest changes in the functional parameters of the blood circulation are observed in young and elderly people. In the same way, it is shown that it depends on the type of adaptation, age characteristics, work experience which result in slowing down the rate of the processes of the nervous system, the regulation of blood circulation becomes inert, the level of physical health reduces, and age displacements accelerate. These changes are considered as a result of increased spending of physiological reserves of the organism in various environmental conditions.

  4. [THE CHARACTERISTIC OF SOMATOTYPE AND FUNCTIONAL STATE OF CIRCULATORY SYSTEM OF STUDENT YOUTH OF THE NORTHEAST OF RUSSIA].

    PubMed

    Timofeieva, A V; Klimova, T M; Mikhailova, A E; Zakharova, R N; Vinokurova, S P; Timofeiev, L F

    2015-01-01

    The article considers results of single-step study in random sampling of female students of the M.K. Ammosov north-east federal university (n=456). The study was carried out to investigate somatotype and functional state of circulatory system. The standard technique was applied to measure height, body mass, chest circumference, level of arterial pressure and rate of heart beats. The type of somatotype was established using Pignet index. The tone of vegetative system was determined using Kérdö index. The adaptation potential of circulatory system was determined using functional changes index. The results of study established that in 61% of examined female students the type of constitution corresponds to normosthenic one. The percentage of persons with asthenic and hypersthenic type of constitution amounted to 27% and 12% correspondingly. The signs of increasing oftone ofsympathetic nervous system are observed in 89% of girls. The functional condition of circulatory system is evaluated as "tension of adaptation mechanisms" that is apparently related to period of adaptation to new conditions. The prolonged preservation of such states results in exhaustion offunctional resources of organism and can promote development of diseases. In conditions of impacting of unfavorable ecological factors the deconditionning disorders can significantly contribute to health disturbances and decreasing of life quality. To preserve youth's health during period of education the comprehensive strategy is to be implemented such components as dynamic monitoring of health, organization of adequate diet, explanation of necessity of observance of sleep and rest pattern, development of conditions for active aerobic physical exertion and activities on correction of risk factors of development of diseases are to be included.

  5. Twelve-hour reanimation of a human heart following donation after circulatory death.

    PubMed

    Rosenfeldt, Franklin; Ou, Ruchong; Woodard, John; Esmore, Donald; Marasco, Silvana

    2014-01-01

    Despite increasing use of donation after cardiac death (DCD) and encouraging results for non-cardiac transplants, DCD cardiac transplantation has not been widely adopted because, (1) the DCD heart sustains warm ischaemic injury during the death process and (2) conventional static cold storage significantly adds to the ischaemic injury. We have developed a simple system for perfusion of the DCD heart with cold crystalloid solution using gravity-feed that can reduce ischaemic injury and potentially render the heart suitable for transplantation. This report describes the first application of this technique to a human DCD heart with good functional metabolic recovery over 12h on an ex vivo rig.

  6. Some embryological aspects of cholinergic innervation in the cardiovascular system--a close association with the subintestinal circulatory channel.

    PubMed

    Shigei, Tatsuro; Tsuru, Hiromichi; Ishikawa, Naohisa; Yoshioka, Koichi

    2010-01-01

    A series of our studies on the dog venous system revealed that cholinergic excitatory innervation was localized in a group of veins: the portal, mesenteric, and hepatic veins and the middle segment of the inferior vena cava. Our studies on pharmacological responsiveness of dog veins also revealed that they could be divided into two groups: the visceral and somatic parts, and the cholinergic excitatory innervation localized to the visceral part. Considering these results and some relevant literature, a hypothesis is proposed on the classification of muscles of the cardiovascular system and some embryological aspects of the parasympathetic cholinergic innervation in the circulatory system are discussed. The embryonic circulatory system of vertebrates can be divided into two parts: somatic and visceral. The body of an embryo is regarded as a double tube and vessels of the visceral part and the heart belong to the inner tube. The muscle of these vessels and the heart are derived from visceral mesoderm, either the coelomic epithelium or mesenchymal cells, in common with muscle of the digestive tube; and thus the parasympathetic cholinergic nerves innervating the muscle of the digestive tube also distribute to these vessels and the heart. The heart and vascular muscles in the visceral part are structures developed early in the course of evolution in invertebrates. Their primary function is to propel the body fluid, and the chief structure containing them is the subintestinal circulatory channel (ventral aorta - heart - subintestinal vein). They exhibit spontaneous, rhythmic activity, showing characteristics of a single unit muscle, and receive parasympathetic cholinergic innervation. On the other hand, the vascular muscles in the somatic part are endothelium-associated muscles developed anew in the vertebrate; do not contract spontaneously, being classified as a multiunit muscle; and lack parasympathetic cholinergic innervation.

  7. Atmospheric pressure fluctuations in the far infrasound range and emergency transport events coded as circulatory system diseases

    NASA Astrophysics Data System (ADS)

    Didyk, L. A.; Gorgo, Yu. P.; Dirckx, J. J. J.; Bogdanov, V. B.; Buytaert, J. A. N.; Lysenko, V. A.; Didyk, N. P.; Vershygora, A. V.; Erygina, V. T.

    2008-09-01

    This study examines whether a relation exists between rapid atmospheric pressure fluctuations, attributed to the far infrasound frequency range (APF), and a number of emergency transport events coded as circulatory system diseases (EEC). Over an entire year, the average integral amplitudes of APF in the range of periods from 3 s to 120 s over each hour (HA) were measured. Daily dynamics of HA averaged over the year revealed a wave shape with smooth increase from night to day followed by decrease from day to night. The total daily number of EEC within the city of Kiev, Ukraine, was related to the daily mean of HA (DHA) and to the ratio of HA averaged over the day time to HA averaged over the night time (Rdn), and was checked for confounding effects of classical meteorological variables through non-parametric regression algorithms. The number of EEC were significantly higher on days with high DHA (3.72 11.07 Pa, n = 87) compared to the low DHA (0.7 3.62 Pa, n = 260, p = 0.01), as well at days with low Rdn (0.21 1.64, n = 229) compared to the high Rdn (1.65 7.2, n = 118, p = 0.03). A difference between DHA and Rdn effects on the emergency events related to different categories of circulatory diseases points to a higher sensitivity of rheumatic and cerebro-vascular diseases to DHA, and ischaemic and hypertensive diseases to Rdn. Results suggest that APF could be considered as a meteorotropic factor capable of influencing circulatory system diseases.

  8. Systemic activation of the transient receptor potential vanilloid subtype 4 channel causes endothelial failure and circulatory collapse: Part 2.

    PubMed

    Willette, Robert N; Bao, Weike; Nerurkar, Sandhya; Yue, Tian-Li; Doe, Chris P; Stankus, Gerald; Turner, Gregory H; Ju, Haisong; Thomas, Heath; Fishman, Cindy E; Sulpizio, Anthony; Behm, David J; Hoffman, Sandra; Lin, Zuojun; Lozinskaya, Irina; Casillas, Linda N; Lin, Min; Trout, Robert E Lee; Votta, Bartholomew J; Thorneloe, Kevin; Lashinger, Erin S R; Figueroa, David J; Marquis, Robert; Xu, Xiaoping

    2008-08-01

    The transient receptor potential (TRP) vanilloid subtype 4 (V4) is a nonselective cation channel that exhibits polymodal activation and is expressed in the endothelium, where it contributes to intracellular Ca2+ homeostasis and regulation of cell volume. The purpose of the present study was to evaluate the systemic cardiovascular effects of GSK1016790A, a novel TRPV4 activator, and to examine its mechanism of action. In three species (mouse, rat, and dog), the i.v. administration of GSK1016790A induced a dose-dependent reduction in blood pressure, followed by profound circulatory collapse. In contrast, GSK1016790A had no acute cardiovascular effects in the TRPV4-/- null mouse. Hemodynamic analyses in the dog and rat demonstrate a profound reduction in cardiac output. However, GSK1016790A had no effect on rate or contractility in the isolated, buffer-perfused rat heart, and it produced potent endothelial-dependent relaxation of rodent-isolated vascular ring segments that were abolished by nitric-oxide synthase (NOS) inhibition (N-nitro-L-arginine methyl ester; L-NAME), ruthenium red, and endothelial NOS (eNOS) gene deletion. However, the in vivo circulatory collapse was not altered by NOS inhibition (L-NAME) or eNOS gene deletion but was associated with (concentration and time appropriate) profound vascular leakage and tissue hemorrhage in the lung, intestine, and kidney. TRPV4 immunoreactivity was localized in the endothelium and epithelium in the affected organs. GSK1016790A potently induced rapid electrophysiological and morphological changes (retraction/condensation) in cultured endothelial cells. In summary, inappropriate activation of TRPV4 produces acute circulatory collapse associated with endothelial activation/injury and failure of the pulmonary microvascular permeability barrier. It will be important to determine the role of TRPV4 in disorders associated with edema and microvascular congestion.

  9. The artificial ventricle: A conceptual design for a novel mechanical circulatory support system.

    PubMed

    Sherif, Hisham M F

    2009-01-01

    We describe a novel design for a new mechanical circulatory support pump which can be utilized for single or biventricular support in a completely internal configuration. The device has a long projected service life, a totally implantable, readily available and off-the-shelf energy source. The proposed device is a pulsatile, positive-displacement blood pump composed of a conically-shaped compliance chamber, constructed of a biocompatible material and attached to two bioprosthetic valves (an inlet valve and an outlet valve), surrounded by radially-arranged contractile elements, made of an electro-active polymer and connected to a common stimulating electrode connected to an implantable permanent pacemaker. The entire assembly is housed in a hermetically sealed biologically inert shell. The energy output from the pacemaker will cause the deformation of the contractile elements and thus compression of the compliance chamber, effecting ejection of the blood through the outlet valve. Based on a design emulating the natural anatomic configuration, the device shall be able to provide clinically significant mechanical assistance and/or replacement of the native heart function and thus a means of supporting the failing ventricle(s) or replacing the failing heart for an extended period of time. The proposed design offers a new pulsatile, positive displacement mechanical circulatory support or replacement for one or both ventricles, is completely implantable, is composed of readily available materials, has minimal energy requirements and an extended service life on internal power supply.

  10. [The comparison of the two Ottoman books of anatomy (17-19th centuries) with regard to the circulatory system].

    PubMed

    Uluçam, E; Gökçe, N

    2000-01-01

    17th and 19th centuries were particularly important for the development of the Ottoman medicine. Westernization which had already started in the 17th century continued along the 19th and the early 20th centuries. Turkish physicians began to contact with their European colleagues and in this period Latin medical terminology began to appear in the Ottoman medical literature. Sirvanli Semseddin Itaki's work of the 17th century, the Teşrihü'l Ebdan ve Tercüman-i Kibale-i Feylesufan, is the first illustrated Turkish manuscript of anatomy. The illustrations are qualified as developed examples, compared with the medical literature and knowledge of the period. In the 19th century, Sanizade Mehmet Ataullah Efendi (1771-1826) wrote a modern book of anatomy for the Ottoman medical doctors. Miyarü'l Etibba was one of the earliest printed medical books in Turkish. The second volume of Sanizade's Hamse, Miratü'l Ebdan fi Teşrih-i Azai'l Insan is the first printed Ottoman book on anatomy. In Usulü't-Tabia, the third volume of Hamse, the circulatory system is discussed. In this article, we studied the circulatory system described in Semseddin Itaki's Teşrih-ül Ebdan ve Tercüman-i Kibale-i Feylesufan and in Sanizade's Usulü't-Tabia and compared them.

  11. Mortality from Circulatory System Diseases among French Uranium Miners: A Nested Case-Control Study.

    PubMed

    Drubay, Damien; Caër-Lorho, Sylvaine; Laroche, Pierre; Laurier, Dominique; Rage, Estelle

    2015-05-01

    A significant association has been observed between radon exposure and cerebrovascular disease (CeVD) mortality among French uranium miners, but risk factors for circulatory system diseases (CSD) have not been previously considered. We conducted new analyses in the recently updated (through 2007) French cohort of uranium miners (n = 5,086), which included 442 deaths from CSD, 167 of them from ischemic heart disease (IHD) and 105 from CeVD. A nested case-control study was then set up to collect and investigate the influence of these risk factors on the relationships between mortality from CSD and occupational external gamma ray and internal ionizing radiation exposure (radon and long-lived radionuclides) in this updated cohort. The nested case-control study included miners first employed after 1955, still employed in 1976 and followed up through 2007. Individual information about CSD risk factors was collected from medical files for the 76 deaths from CSD (including 26 from IHD and 16 from CeVD) and 237 miners who had not died of CSD by the end of follow-up. The exposure-risk relationships were assessed with a Cox proportional hazard model weighted by the inverse sampling probability. A significant increase in all CSD and CeVD mortality risks associated with radon exposure was observed in the total cohort [hazard ratios: HRCSD/100 working level months (WLM) = 1.11, 95% confidence interval (1.01; 1.22) and HRCeVD/100 WLM = 1.25 (1.09; 1.43), respectively]. A nonsignificant exposure-risk relationship was observed for every type of cumulative ionizing radiation exposure and every end point [e.g., HRCSD/100WLM = 1.43 (0.71; 2.87)]. The adjustment for each CSD risk factor did not substantially change the exposure-risk relationships. When the model was adjusted for overweight, hypertension, diabetes, hypercholesterolemia and smoking status, the HR/100WLM for CSD, for example, was equal to 1.21 (0.54; 2.75); and when it was adjusted for risk factors selected with the

  12. Relationships between Digestive, Circulatory, and Urinary Systems in Portuguese Primary Textbooks

    ERIC Educational Resources Information Center

    Carvalho, Graça S.; Clèment, Pierre

    2007-01-01

    In this study, 63 Portuguese primary schoolbooks (1920-2005) were analyzed. The analysis focused on text information (reference to blood absorption and association of the digestive system to other human systems) and on information from images (presence or absence of image "confusion" (when the sequence of the digestive tract is not…

  13. Mean arterial pressure nonlinearity in an elastic circulatory system subjected to different hematocrits.

    PubMed

    Branigan, Tom; Bolster, Diogo; Vázquez, Beatriz Y Salazar; Intaglietta, Marcos; Tartakovsky, Daniel M

    2011-07-01

    The level of hematocrit (Hct) is known to affect mean arterial pressure (MAP) by influencing blood viscosity. In the healthy population, an increase in Hct (and corresponding increase in viscosity) tends to raise MAP. However, data from a clinical study of type 2 diabetic patients indicate that this relationship is not universal. Instead, individuals in the lower levels of Hct range display a decrease in MAP for a given rise in Hct. After reaching a minimum, this trend is reversed, so that further increases in Hct lead to increases in MAP. We hypothesize that this anomalous behavior occurs due to changes in the circulatory autoregulation mechanism. To substantiate this hypothesis, we develop a physically based mathematical model that incorporates autoregulation mechanisms. Our model replicates the anomalous U-shaped relationship between MAP and Hct found in diabetic patients in the same range of Hct variability.

  14. Long-term allergen exposure induces adipose tissue inflammation and circulatory system injury.

    PubMed

    Jung, Chien-Cheng; Su, Huey-Jen

    2016-05-01

    The purpose of this study was to study whether allergen exposure can induce inflammation and lower the anti-inflammation levels in serum and in adipose tissues, and further develop cardiovascular injury. Our data showed that heart rate was significantly higher in the OVA-challenged mice compared to control mice. Moreover, there were higher expressions of pro-inflammation genes in the OVA-challenged mice in adipose tissues, and the expressions of anti-inflammation genes were lower. The levels of inflammation mediators were associated in serum and adipose tissues. The level of circulatory injury lactate dehydrogenase was significantly associated with the levels of E-selectin, resistin and adiponectin in the serum. The hematoxylin and eosin and immunohistochemistry stains indicated the OVA-challenged mice had higher levels of inflammation. In summary, the current study demonstrated allergen exposure can cause cardiovascular injury, and inflammatory mediators in adipose tissues play an important role in the pathogenesis of cardiovascular injury.

  15. Experimental evidence for the existence of the passive antitumor defense system formed by the synergistic action of certain small substances of the circulatory system.

    PubMed

    Kulcsár, Gyula

    2003-12-01

    In AIDS, only a few types of tumors (mainly Kaposi's sarcoma and non-Hodgkin's lymphoma) increase in incidence despite global abnormalities in the immune system. In addition, the reason for the higher incidence of these tumors is not immunosuppression but other agents. This shows that the immune system has no absolute role in the prevention of tumors. Consequently, the fact that tumors do not develop in the majority of the population during their lifetime, indicates the existence of other defense system(s). We demonstrated previously that a mixture of 16 substances (selected experimentally out of 89 compounds of the circulatory system using the synergistic tumor cell-killing effect as criteria) had a cytotoxic effect (inducing apoptosis) in vitro and in vivo on tumor cell lines, but not on normal cells in vitro or animals. In our hypothesis these substances (L-tryptophan, L-tyrosine, L-methionine, L(-)malate, L-ascorbate, L-arginine, L-phenylalanine, L-histidine, 2-deoxy-D-ribose, d-biotin, pyridoxine, adenine, riboflavin, D(+)-mannose, orotate, and hippurate) are the active agents of a passive antitumor defense system (PADS). On the basis of the results, a tablet and a cream were developed, and an infusion is in preclinical phase. In this study we demonstrate that the above-mentioned substances can kill tumor cells when the experimental protocols, concentrations, and cell numbers are chosen to be comparable to the physiological conditions that exist in the living system when these substances fight against arising cancer cells. The results of our experiments demonstrate that the PADS really works in the human body.

  16. Additional N-glycosylation in the N-terminal region of recombinant human alpha-1 antitrypsin enhances the circulatory half-life in Sprague-Dawley rats.

    PubMed

    Chung, Hye-Shin; Kim, Ji-Sun; Lee, Sang Mee; Park, Soon Jae

    2016-04-01

    Glycosylation affects the circulatory half-lives of therapeutic proteins. However, the effects of an additional N-glycosylation in the unstructured region or the loop region of alpha-1 antitrypsin (A1AT) on the circulatory half-life of the protein are largely unknown. In this study, we investigated the role of an additional N-glycosylation site (Q4N/D6T, Q9N, D12N/S14T, A70N, G148T, R178N, or V212N) to the three naturally occurring N-glycosylation sites in human A1AT. A single-dose (445 μg/kg) pharmacokinetic study using male Sprague-Dawley rats showed that, among the seven recombinant A1AT (rA1AT) mutants, Q9N and D12N/S14T showed the highest serum concentration and area under the curve values, as well as similar circulatory half-lives that were 2.2-fold higher than plasma-derived A1AT and 1.7-fold higher than wild-type rA1AT. We further characterized the Q9N mutant regarding the N-glycan profile, sialic acid content, protease inhibitory activity, and protein stability. The results indicate that an additional N-glycosylation in the flexible N-terminal region increases the circulatory half-life of rA1AT without altering its protease inhibitory activity. Our study provides novel insight into the use of rA1AT for the treatment of emphysema with an increased injection interval relative to the clinically used plasma-derived A1AT.

  17. In vivo 3D visualization of peripheral circulatory system using linear optoacoustic array

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey A.; Brecht, Hans-Peter; Fronheiser, Matthew P.; Nadvoretsky, Vyacheslav; Su, Richard; Conjusteau, Andre; Oraevsky, Alexander A.

    2010-02-01

    In this work we modified light illumination of the laser optoacoustic (OA) imaging system to improve the 3D visualization of human forearm vasculature. The computer modeling demonstrated that the new illumination design that features laser beams converging on the surface of the skin in the imaging plane of the probe provides superior OA images in comparison to the images generated by the illumination with parallel laser beams. We also developed the procedure for vein/artery differentiation based on OA imaging with 690 nm and 1080 nm laser wavelengths. The procedure includes statistical analysis of the intensities of OA images of the neighboring blood vessels. Analysis of the OA images generated by computer simulation of a human forearm illuminated at 690 nm and 1080 nm resulted in successful differentiation of veins and arteries. In vivo scanning of a human forearm provided high contrast 3D OA image of a forearm skin and a superficial blood vessel. The blood vessel image contrast was further enhanced after it was automatically traced using the developed software. The software also allowed evaluation of the effective blood vessel diameter at each step of the scan. We propose that the developed 3D OA imaging system can be used during preoperative mapping of forearm vessels that is essential for hemodialysis treatment.

  18. Effect of micro mist sauna bathing on thermoregulatory and circulatory functions and thermal sensation in humans

    NASA Astrophysics Data System (ADS)

    Iwase, Satoshi; Kawahara, Yuko; Nishimura, Naoki; Sugenoya, Junichi

    2016-05-01

    moderate and effective thermal effect during micro mist sauna bathing than the conventional mist sauna bathing. In addition, micro mist sauna is as effective for heating the human subjects as bathtub bathing as well as more moderate thermal and sweating sensations.

  19. Effect of micro mist sauna bathing on thermoregulatory and circulatory functions and thermal sensation in humans.

    PubMed

    Iwase, Satoshi; Kawahara, Yuko; Nishimura, Naoki; Sugenoya, Junichi

    2016-05-01

    more moderate and effective thermal effect during micro mist sauna bathing than the conventional mist sauna bathing. In addition, micro mist sauna is as effective for heating the human subjects as bathtub bathing as well as more moderate thermal and sweating sensations.

  20. A fast building and effective hydraulic pediatric mock circulatory system for the evaluation of a left ventricular assist device.

    PubMed

    Huang, Feng; Ruan, Xiaodong; Zou, Jun; Qian, Wenwei; Fu, Xin

    2013-01-01

    A mock circulatory system (MCS) has been proven a useful tool in the development of a ventricular assist device. Nowadays a MCS aimed at the evaluation of pediatric blood pumps, which require many different considerations compared with that of adults, has become an urgent need. This article presents the details on how the dynamic process of the left ventricle, which is described in terms of the pressure-volume loop (P-V loop), and the properties of the circulation such as compliance and resistance are simulated by hydraulic elements. A simple control method is introduced to reproduce the physiological afterload and preload sensitivities of the mock ventricle for the first time. Hemodynamic performance of the system is obtained by medical sensors to validate the similarity of the device to the native cardiovascular system. The actual sensitivities of the mock ventricle are obtained intuitively from the changes of the P-V loops. The aortic input impedance of the MCS is also obtained and compared with the data from previous medical reports. At last a pediatric left ventricular assist device (LVAD) prototype is introduced for testing to further verify the effectiveness of the MCS. The experimental results indicate that this pediatric MCS is capable of reproducing basic hemodynamic characteristics of a child in both normal and pathological conditions and it is sufficient for testing a pediatric LVAD. Besides, most components constituting the main hydraulic part of this MCS are inexpensive off-the-shelf products, making the MCS easy and fast to build.

  1. Influence of apnoeic oxygenation in respiratory and circulatory system under general anaesthesia.

    PubMed

    Kolettas, Alexander; Grosomanidis, Vasilis; Kolettas, Vasilis; Zarogoulidis, Paul; Tsakiridis, Kosmas; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Kiougioumtzi, Ioanna; Machairiotis, Nikolaos; Drylis, Georgios; Kesisis, Georgios; Beleveslis, Thomas; Zarogoulidis, Konstantinos

    2014-03-01

    Apnoeic oxygenation is an alternative technique of oxygenation which is recommended in the consecutive oxygen administration with varying flows (2-10 lt/min) through a catheter which is positioned over the keel of the trachea. Apnoeic oxygenation maintains for a significant period of time the oxygenation of blood in breathless conditions. This technique was first applied in 1947 by Draper, Whitehead, and Spencer and it was studied sporadically by other inventors too. However, the international literature shows few studies that have examined closely apnoeic oxygenation and its effects on Hemodynamic image and the respiratory system of the human body. Recently they have begun to arise some studies which deal with the application of this technique in several conditions such as difficult tracheal intubation, ventilation of guinea pigs in campaign conditions where the oxygen supply is limited and calculable, the application of this technique in combination with the use of extracorporeal removal of carbon dioxide (CO2). All the above indicate, the clinical use of this technique.

  2. Influence of apnoeic oxygenation in respiratory and circulatory system under general anaesthesia

    PubMed Central

    Kolettas, Alexander; Grosomanidis, Vasilis; Kolettas, Vasilis; Tsakiridis, Kosmas; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Kiougioumtzi, Ioanna; Machairiotis, Nikolaos; Drylis, Georgios; Kesisis, Georgios; Beleveslis, Thomas; Zarogoulidis, Konstantinos

    2014-01-01

    Apnoeic oxygenation is an alternative technique of oxygenation which is recommended in the consecutive oxygen administration with varying flows (2-10 lt/min) through a catheter which is positioned over the keel of the trachea. Apnoeic oxygenation maintains for a significant period of time the oxygenation of blood in breathless conditions. This technique was first applied in 1947 by Draper, Whitehead, and Spencer and it was studied sporadically by other inventors too. However, the international literature shows few studies that have examined closely apnoeic oxygenation and its effects on Hemodynamic image and the respiratory system of the human body. Recently they have begun to arise some studies which deal with the application of this technique in several conditions such as difficult tracheal intubation, ventilation of guinea pigs in campaign conditions where the oxygen supply is limited and calculable, the application of this technique in combination with the use of extracorporeal removal of carbon dioxide (CO2). All the above indicate, the clinical use of this technique. PMID:24672687

  3. Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

    PubMed

    Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

    Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

  4. Changes in the central and peripheral circulatory system in response to the cold: own studies using impedance plethysmography and Doppler ultrasound.

    PubMed

    Łastowiecka-Moras, Elżbieta; Kozyra-Pydyś, Eliza

    2016-12-01

    The aim of the study was to determine the cardiovascular response to continuous (4 °C for 60 min) and intermittent (10 min at 4 °C and 10 min at room temperature alternately) exposure to the cold in 30 healthy young men. The subjects were equipped with a set of identical clothing (insulation 2.1 clo) and during the stay in the chamber and outside performed the same activities, i.e., walking on a treadmill at a speed of 0.5 km/h. The tests included assessing the central circulatory system using the Holter system and assessing the peripheral circulatory system using impedance plethysmography and Doppler ultrasound. The analysis of the parameters that describe the central and peripheral circulation poses a difficulty in determining which variant of exposure constitutes a greater load on the circulatory system. It should be noted that even the conditions used in the study may cause adverse effects in the cardiovascular system.

  5. A new method of providing pulsatile flow in a centrifugal pump: assessment of pulsatility using a mock circulatory system.

    PubMed

    Herreros, Jesús; Berjano, Enrique J; Sales-Nebot, Laura; Más, Pedro; Calvo, Irene; Mastrobuoni, Stefano; Mercé, Salvador

    2008-06-01

    Previous studies have demonstrated the potential advantages of pulsatile flow as compared with continuous flow. However, to date, physiologic pumps have been technically complex and their application has therefore remained in the experimental field. We have developed a new type of centrifugal pump, which can provide pulsatile as well as continuous flow. The inner wall of a centrifugal pump is pulsed by means of a flexible membrane, which can be accurately controlled by means of either a hydraulic or pneumatic driver. The aim of this study was to assess the hydraulic behavior of the new pump in terms of surplus hemodynamic energy (SHE). We conducted experiments using a mock circulatory system including a membrane oxygenator. No differences were found in the pressure-flow characteristics between the new pump and a conventional centrifugal pump, suggesting that the inclusion of the flexible membrane does not alter hydraulic performance. The value of SHE rose when systolic volume was increased. However, SHE dropped when the percentage of ejection time was reduced and also when the continuous flow (programmed by the centrifugal console) increased. Mean flow matched well with the continuous flow set by the centrifugal console, that is, the pulsatile component of the flow was exclusively controlled by the pulsatile console, and was therefore independent of the continuous flow programmed by the centrifugal console. The pulsatility of the new pump was approximately 25% of that created with a truly pulsatile pump.

  6. Stagnation point flow and heat transfer on a thin porous sheet: Applications to flow dynamics of the circulatory system

    NASA Astrophysics Data System (ADS)

    Misra, J. C.; Sinha, A.; Mallick, B.

    2017-03-01

    The paper is concerned with the modeling and analysis of stagnation point flow and heat transfer on a thin porous sheet under the action of an induced magnetic field. The fluid is considered to be incompressible viscous and electrically conducting. The study is motivated towards exploring some interesting phenomena in the micro-circulatory system. Heat transfer is considered to be governed by the heat equation. In order to take care of the induced magnetism that affects the flow process, the flow equations are coupled with magnetic field variables. The analysis has been performed under the purview of the boundary layer theory, together with the use of similarity transformation. The transformed equations are solved by developing an appropriate numerical method. Numerical results have been computed for a typical situation of the fluid in motion. The results are displayed graphically/in tabular form, which depict the distribution of velocity and temperature under the action of the induced magnetic field and permeability of the porous sheet. The study shows that the flow of the fluid reduces, as the strength of the induced magnetic field increases. However, the reduction in velocity is accompanied by an enhancement of the temperature field.

  7. A biplane roentgen videometry system for dynamic /60 per second/ studies of the shape and size of circulatory structures, particularly the left ventricle.

    NASA Technical Reports Server (NTRS)

    Ritman, E. L.; Sturm, E.; Wood, E. H.; Heintzen, P. H.

    1971-01-01

    A roentgen-television digital-computer technique and a display system developed for dynamic circulatory structure studies are described. Details are given for a videoroentgenographic setup which is used for obtaining biplane roentgen silhouettes of a left ventricle. A 60 per sec measurement of the shape and volume of angiographically outlined cardiac chambers can be made by this technique along with simultaneous ECG, pressure, and flow measurements accessible for real-time digital computer processing and analysis.

  8. Effects of alfapump system on kidney and circulatory function in patients with cirrhosis and refractory ascites.

    PubMed

    Solà, Elsa; Sanchez-Cabús, Santiago; Rodriguez, Ezequiel; Elia, Chiara; Cela, Raquel; Moreira, Rebeca; Pose, Elisa; Sánchez-Delgado, Jordi; Cañete, Nuria; Morales-Ruiz, Manuel; Campos, Francisco; Balust, Jaume; Guevara, Mónica; García-Valdecasas, Juan Carlos; Ginès, Pere

    2017-03-20

    The alfapump system has been proposed as a new treatment for the management of refractory ascites. The system removes ascites from the peritoneal cavity to urinary bladder, producing a continuous low-volume paracentesis.

  9. [Effects of kavergal on indices of lipid peroxidation and the condition of the antioxidant system in patients with rheumatic heart disease presenting with circulatory insufficiency].

    PubMed

    Abdullaev, S F; Inoiatova, F Kh; Inoiatov, F Sh

    2002-01-01

    132 patients with rheumatic heart disease presenting with circulatory insufficiency displayed increased LPO both in the blood plasma and red cells, decline in the antioxidant enzymes activity varying with the circulatory insufficiency functional class degree of severity. Basic therapy with making use of antiinflammatory drugs, cardiac glycosides, diuretics together with drugs endowed with an antiarrhythmic activity and nitroglycerin (where indicated) was found to have practically no effect on LPO level or activity of the antioxidant system. The use of the drug kavergal, 1 g three times daily (total daily dosage being 3 g) in the complex therapy, has been shown to significantly decrease hyperlipoperoxidation both in the blood plasma and red cells increasing the activity of enzymes of the antioxidant defence.

  10. Active musculoskeletal structures equipped with a circulatory system and a network of ionic polymeric gel muscles

    SciTech Connect

    Shahinpoor, M.; Mojarrad, M.

    1994-12-31

    Presented are descriptions of design and fabrication of an active musculoskeletal structure composed of an artificial human skeleton of 5.3 feet in height. This skeletal structure is further equipped with an artificial heart in the form of a multi-channel computer-controlled fluid pump. The fluid pump may be programmed to selectively pump either an acid, a base or de-ionized water to a network of veins that feed a network of pairs of antagonist contractile synthetic muscles. These muscles are manufactured in the laboratory from polyacrylonitrile (PAN) fiber bundles that are specially designed and packaged inside flexible, hyperelastic latex membranes. Each pair of muscles act as a pair of antagonist actuator similar to the biceps and triceps muscles of the human arm. The initial fabrication indicates that it is possible to dynamically control such active musculoskeletal structures. A model is also presented for the dynamic control of such antagonist muscles. The model is intended to be used to study the human musculoskeletal dynamics.

  11. 76 FR 58019 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... fibrillation in patients who are undergoing open concomitant cardiac surgery. The AtriCure Synergy Ablation... of atrial fibrillation. The system consists of the following: The Pulmonary Vein Ablation...

  12. On the destabilizing effect of damping on discrete and continuous circulatory systems

    NASA Astrophysics Data System (ADS)

    Luongo, Angelo; D`Annibale, Francesco

    2014-12-01

    The 'Ziegler paradox', concerning the destabilizing effect of damping on elastic systems loaded by nonconservative positional forces, is addressed. The paper aims to look at the phenomenon in a new perspective, according to which no surprising discontinuities in the critical load exist between undamped and damped systems. To show that the actual critical load is found as an (infinitesimal) perturbation of one of the infinitely many sub-critically loaded undamped systems. A series expansion of the damped eigenvalues around the distinct purely imaginary undamped eigenvalues is performed, with the load kept as a fixed, although unknown, parameter. The first sensitivity of the eigenvalues, which is found to be real, is zeroed, so that an implicit expression for the critical load multiplier is found, which only depends on the 'shape' of damping, being independent of its magnitude. An interpretation is given of the destabilization paradox, by referring to the concept of 'modal damping', according to which the sign of the projection of the damping force on the eigenvector of the dual basis, and not on the eigenvector itself, is the true responsible for stability. The whole procedure is explained in detail for discrete systems, and successively extended to continuous systems. Two sample structures are studied for illustrative purposes: the classical reverse double-pendulum under a follower force and a linear visco-elastic beam under a follower force and a dead load.

  13. Mock circulatory system of the Fontan circulation to study respiration effects on venous flow behavior.

    PubMed

    Vukicevic, Marija; Chiulli, John A; Conover, Timothy; Pennati, Giancarlo; Hsia, Tain Yen; Figliola, Richard S

    2013-01-01

    We describe an in vitro model of the Fontan circulation with respiration to study subdiaphragmatic venous flow behavior. The venous and arterial connections of a total cavopulmonary connection (TCPC) test section were coupled with a physical lumped parameter (LP) model of the circulation. Intrathoracic and subdiaphragmatic pressure changes associated with normal breathing were applied. This system was tuned for two patients (5 years, 0.67 m2; 10 years, 1.2 m2) to physiological values. System function was verified by comparison to the analytical model on which it was based and by consistency with published clinical measurements. Overall, subdiaphragmatic venous flow was influenced by respiration. Flow within the arteries and veins increased during inspiration but decreased during expiration, with retrograde flow in the inferior venous territories. System pressures and flows showed close agreement with the analytical LP model (p < 0.05). The ratio of the flow rates occurring during inspiration to expiration were within the clinical range of values reported elsewhere. The approach used to set up and control the model was effective and provided reasonable comparisons with clinical data.

  14. Reproduction of Consistent Pulse-Waveform Changes Using a Computational Model of the Cerebral Circulatory System

    PubMed Central

    Connolly, Mark; He, Xing; Gonzalez, Nestor; Vespa, Paul; DiStefano, Joe; Hu, Xiao

    2014-01-01

    Due to the inaccessibility of the cranial vault, it is difficult to study cerebral blood flow dynamics directly. A mathematical model can be useful to study these dynamics. The model presented here is a novel combination of a one-dimensional fluid flow model representing the major vessels of the circle of Willis (CoW), with six individually parameterized auto-regulatory models of the distal vascular beds. This model has the unique ability to simulate high temporal resolution flow and velocity waveforms, amenable to pulse-waveform analysis, as well as sophisticated phenomena such as auto-regulation. Previous work with human patients has shown that vasodilation induced by CO2 inhalation causes 12 consistent pulse-waveform changes as measured by the Morphological Clustering and Analysis of Intracranial Pressure algorithm. To validate this model, we simulated vasodilation and successfully reproduced 9 out of the 12 pulse-waveform changes. A subsequent sensitivity analysis found that these 12 pulse-waveform changes were most affected by the parameters associated with the shape of the smooth muscle tension response and vessel elasticity, providing insight into the physiological mechanisms responsible for observed changes in the pulse-waveform shape. PMID:24389244

  15. Reproduction of consistent pulse-waveform changes using a computational model of the cerebral circulatory system.

    PubMed

    Connolly, Mark; He, Xing; Gonzalez, Nestor; Vespa, Paul; DiStefano, Joe; Hu, Xiao

    2014-03-01

    Due to the inaccessibility of the cranial vault, it is difficult to study cerebral blood flow dynamics directly. A mathematical model can be useful to study these dynamics. The model presented here is a novel combination of a one-dimensional fluid flow model representing the major vessels of the circle of Willis (CoW), with six individually parameterized auto-regulatory models of the distal vascular beds. This model has the unique ability to simulate high temporal resolution flow and velocity waveforms, amenable to pulse-waveform analysis, as well as sophisticated phenomena such as auto-regulation. Previous work with human patients has shown that vasodilation induced by CO2 inhalation causes 12 consistent pulse-waveform changes as measured by the morphological clustering and analysis of intracranial pressure algorithm. To validate this model, we simulated vasodilation and successfully reproduced 9 out of the 12 pulse-waveform changes. A subsequent sensitivity analysis found that these 12 pulse-waveform changes were most affected by the parameters associated with the shape of the smooth muscle tension response and vessel elasticity, providing insight into the physiological mechanisms responsible for observed changes in the pulse-waveform shape.

  16. Teaching Bio-inspired design using heart and circulatory system as a model

    NASA Astrophysics Data System (ADS)

    Gharib, Morteza

    2007-11-01

    Cardiovasculr system is an open book of design for an engineer searching for innovation in the particular area of efficient fluid transport. But the routs of technology transfer from nature's technology to engineering science are not always so obvious. The main challenge is how to train our future students to find these hidden innovations and apply them based on sound engineering and scientific principles. As part of a 3 quarter course at Caltech that is called ``Physiology for Bioengineers,'' we try to discuss examples of such cases by introducing students to the critical thinking that is required for model development. In this talk, I will give two examples from the third quarter of this course where students are asked to develop a physics-based model to describe the efficient pumping of blood in embryonic and adult hearts.

  17. Changes in the levels of coenzyme Q homologues, alpha-tocopherol and malondialdehyde in human tissue during the course of circulatory shock.

    PubMed

    Corbucci, G G; Gasparetto, A; Antonelli, M; Bufi, M; De Blasi, R A

    1986-01-01

    Following our previous findings on mitochondrial oxidative damage during the course of circulatory shock in human muscular tissue, in the present work we examined the pathogenic connections between the electron-transport-chain enzymic activity and the ubiquinone metabolism. The effects of the oxidative damage on the alpha-tocopherol content and malondialdehyde (MDA) levels were also studied. The results reveal an involvement of cytochrome oxidase and coenzyme Q10 in the oxidative damage due to shock; alpha-tocopherol seems to show a particularly increased antioxidant activity contemporary with the marked increase in MDA levels. These findings suggest that the significant fall in the mitochondrial oxidative capacity could generate an oxygen free-radical production with subsequent peroxidative damage of the mitochondrial inner-membrane bilayer.

  18. Numerical modeling of the fetal blood flow in the placental circulatory system

    NASA Astrophysics Data System (ADS)

    Shannon, Alexander; Gallucci, Sergio; Mirbod, Parisa

    2015-11-01

    The placenta is a unique organ of exchange between the growing fetus and the mother. It incorporates almost all functions of the adult body, acting as the fetal lung, digestive and immune systems, to mention a few. The exchange of oxygen and nutrients takes place at the surface of the villous tree. Using an idealized geometry of the fetal villous trees in the mouse placenta, in this study we performed 3D computational analysis of the unsteady fetal blood flow, gas, and nutrient transport over the chorionic plate. The fetal blood was treated as an incompressible Newtonian fluid, and the oxygen and nutrient were treated as a passive scalar dissolved in blood plasma. The flow was laminar, and a commercial CFD code (COMSOL Multiphysics) has been used for the simulation. COMSOL has been selected because it is multi-physics FEM software that allows for the seamless coupling of different physics represented by partial differential equations. The results clearly illustrate that the specific branching pattern and the in-plane curvature of the fetal villous trees affect the delivery of blood, gas and nutrient transport to the whole placenta.

  19. Development of a Deprivation Index and its relation to premature mortality due to diseases of the circulatory system in Hungary, 1998-2004.

    PubMed

    Juhász, Attila; Nagy, Csilla; Páldy, Anna; Beale, Linda

    2010-05-01

    An association between health and socio-economic status is well known. Based on international and national studies, the aims of this study were to develop a multi-dimensional index at the municipality level, to provide information about socio-economic deprivation in Hungary and to investigate the association between socio-economic status and the spatial distribution of premature mortality due to diseases of the circulatory system. Seven municipality level socio-economic indicators were used from the National Information System of Spatial Development (income, low qualification, unemployment, one-parent families, large families, density of housing and car ownership). After normalisation and standardisation, indicator weights were evaluated using factor analysis. A risk analysis study was conducted using the Rapid Inquiry Facility software to evaluate the association between deprivation and the spatial distribution of premature mortality due to diseases of the circulatory system for the years 1998-2004. Areas of significantly high deprivation were identified in the northeastern, eastern and southwestern parts of Hungary. A statistically significant association was found between premature cardiovascular mortality and deprivation status in both genders. The Deprivation Index is the first composite index at the municipality level in Hungary and includes key factors that affect socio-economic status. The identified association highlighted the fact that inequalities in socio-economic status may reflect the spatial distribution of health status in a population. The results can be used to inform prevention strategies and help plan local health promotion programs aimed at reducing health inequalities.

  20. The Circulatory and Metabolic Responses to Hypoxia in Humans – With Special Reference to Adipose Tissue Physiology and Obesity

    PubMed Central

    Heinonen, Ilkka H. A.; Boushel, Robert; Kalliokoski, Kari K.

    2016-01-01

    Adipose tissue metabolism and circulation play an important role in human health. It is well-known that adipose tissue mass is increased in response to excess caloric intake leading to obesity and further to local hypoxia and inflammatory signaling. Acute exercise increases blood supply to adipose tissue and mobilization of fat stores for energy. However, acute exercise during systemic hypoxia reduces subcutaneous blood flow in healthy young subjects, but the response in overweight or obese subjects remains to be investigated. Emerging evidence also indicates that exercise training during hypoxic exposure may provide additive benefits with respect to many traditional cardiovascular risk factors as compared to exercise performed in normoxia, but unfavorable effects of hypoxia have also been documented. These topics will be covered in this brief review dealing with hypoxia and adipose tissue physiology. PMID:27621722

  1. Radiation and circulatory disease.

    PubMed

    Little, Mark P

    Exposure to therapeutic doses of ionizing radiation is associated with damage to the heart and coronary arteries. However, only recently have studies with high-quality individual dosimetry data allowed this risk to be quantified while also adjusting for concomitant chemotherapy, and medical and lifestyle risk factors. At lower levels of exposure the evidence is less clear. In this article I review radiation-associated risks of circulatory disease in groups treated with radiotherapy for malignant and non-malignant disease, and in occupationally- or environmentally-exposed groups receiving rather lower levels of radiation dose, also for medical diagnostic purposes. Results of a meta-analysis suggest that excess relative risks per unit dose for various types of heart disease do not exhibit statistically significant (p>0.2) heterogeneity between studies. Although there are no marked discrepancies between risks derived from the high-dose therapeutic and medical diagnostic studies and from the moderate/low dose occupational and environmental studies, at least for ischemic heart disease and stroke there are indications of larger risks per unit dose for lower dose rate and fractionated exposures. Risks for stroke and other types of circulatory disease are significantly more variable (p<0.0001), possibly resulting from confounding and effect-modification by well known (but unobserved) risk factors. Adjustment for any of mean dose, dose fractionation or age at exposure results in the residual heterogeneity for cerebrovascular disease becoming non-significant. The review provides strong evidence in support of a causal association between both low and high dose radiation exposure and most types of circulatory disease.

  2. Peripheral circulatory failure.

    PubMed

    Lodha, Rakesh; Kapoor, Vishal

    2003-02-01

    Shock is a syndrome arising from any of several initiating causes, resulting in inadequate tissue perfusion. Untreated shock due to any cause can lead to irreversible cellular damage. Early diagnosis and intervention are, therefore, key to improved outcomes. In children, hypotension is not a sensitive marker for diagnosing peripheral circulatory failure. A detailed evaluation to assess perfusion particularly estimating capillary refill time and end organ perfusion is required. Septic shock is a complex condition with varying contribution of hypovolemia, cardiac dysfunction and distributive shock. Aggressive fluid therapy in the early stages is essential to recovery. Understanding the pathophysiology will help in judicious use of vasoactive drugs. Newer modalities of treatment for severe sepsis and septic shock still need evaluation in children.

  3. Deep hypothermic circulatory arrest

    PubMed Central

    Ziganshin, Bulat A.

    2013-01-01

    Effective cerebral protection remains the principle concern during aortic arch surgery. Hypothermic circulatory arrest (HCA) is entrenched as the primary neuroprotection mechanism since the 70s, as it slows injury-inducing pathways by limiting cerebral metabolism. However, increases in HCA duration has been associated with poorer neurological outcomes, necessitating the adjunctive use of antegrade (ACP) and retrograde cerebral perfusion (RCP). ACP has superseded RCP as the preferred perfusion strategy as it most closely mimic physiological perfusion, although there exists uncertainty regarding several technical details, such as unilateral versus bilateral perfusion, flow rate and temperature, perfusion site, undue trauma to head vessels, and risks of embolization. Nevertheless, we believe that the convenience, simplicity and effectiveness of straight DHCA justifies its use in the majority of elective and emergency cases. The following perspective offers a historical and clinical comparison of the DHCA with other techniques of cerebral protection. PMID:23977599

  4. Influence of Mechanical Circulatory Support on Endothelin Receptor Expression in Human Left Ventricular Myocardium from Patients with Dilated Cardiomyopathy (DCM)

    PubMed Central

    Gärtner, Florian; Abraham, Getu; Kassner, Astrid; Baurichter, Daniela; Milting, Hendrik

    2017-01-01

    Background In terminal failing hearts ventricular assist devices (VAD) are implanted as a bridge to transplantation. Endothelin receptor (ETR) antagonists are used for treatment of secondary pulmonary hypertension in VAD patients. However, the cardiac ETR regulation in human heart failure and during VAD support is incompletely understood. Methods In paired left ventricular samples of 12 dilated cardiomyopathy patients we investigated the density of endothelin A (ETA) and B (ETB) receptors before VAD implantation and after device removal. Left ventricular samples of 12 non-failing donor hearts served as control. Receptor quantification was performed by binding of [125I]-ET-1 in the presence of nonselective and ETA selective ETR ligands as competitors. Additionally, the ETR mRNA expression was analyzed using quantitative real-time-PCR. Results The mRNA of ETA but not ETB receptors was significantly elevated in heart failure, whereas total ETR density analyzed by radioligand binding was significantly reduced due to ETB receptor down regulation. ETA and ETB receptor density showed poor correlation to mRNA data (spearman correlation factor: 0.43 and 0.31, respectively). VAD support had no significant impact on the density of both receptors and on mRNA expression of ETA whereas ETB mRNA increased during VAD. A meta-analysis reveals that the ETA receptor regulation in human heart failure appears to depend on non-failing hearts. Conclusions In deteriorating hearts of patients suffering from dilated cardiomyopathy the ETA receptor density is not changed whereas the ETB receptor is down regulated. The mRNA and the proteins of ETA and ETB show a weak correlation. Non-failing hearts might influence the interpretation of ETA receptor regulation. Mechanical unloading of the failing hearts has no impact on the myocardial ETR density. PMID:28095452

  5. Whole body hyperthermia, but not skin hyperthermia, accelerates brain and locomotor limb circulatory strain and impairs exercise capacity in humans.

    PubMed

    Trangmar, Steven J; Chiesa, Scott T; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2017-01-01

    Cardiovascular strain and hyperthermia are thought to be important factors limiting exercise capacity in heat-stressed humans, however, the contribution of elevations in skin (Tsk) versus whole body temperatures on exercise capacity has not been characterized. To ascertain their relationships with exercise capacity, blood temperature (TB), oxygen uptake (V̇O2), brain perfusion (MCA Vmean), locomotor limb hemodynamics, and hematological parameters were assessed during incremental cycling exercise with elevated skin (mild hyperthermia; HYPmild), combined core and skin temperatures (moderate hyperthermia; HYPmod), and under control conditions. Both hyperthermic conditions increased Tsk versus control (6.2 ± 0.2°C; P < 0.001), however, only HYPmod increased resting TB, leg blood flow and cardiac output (Q̇), but not MCA Vmean Throughout exercise, Tsk remained elevated in both hyperthermic conditions, whereas only TB was greater in HYPmod At exhaustion, oxygen uptake and exercise capacity were reduced in HYPmod in association with lower leg blood flow, MCA Vmean and mean arterial pressure (MAP), but similar maximal heart rate and TB The attenuated brain and leg perfusion with hyperthermia was associated with a plateau in MCA and two-legged vascular conductance (VC). Mechanistically, the falling MCA VC was coupled to reductions in PaCO2, whereas the plateau in leg vascular conductance was related to markedly elevated plasma [NA] and a plateau in plasma ATP These findings reveal that whole-body hyperthermia, but not skin hyperthermia, compromises exercise capacity in heat-stressed humans through the early attenuation of brain and active muscle blood flow.

  6. Teaching Integrative Physiology Using the Quantitative Circulatory Physiology Model and Case Discussion Method: Evaluation of the Learning Experience

    ERIC Educational Resources Information Center

    Rodriguez-Barbero, A.; Lopez-Novoa, J. M.

    2008-01-01

    One of the problems that we have found when teaching human physiology in a Spanish medical school is that the degree of understanding by the students of the integration between organs and systems is rather poor. We attempted to remedy this problem by using a case discussion method together with the Quantitative Circulatory Physiology (QCP)…

  7. The first organ-based free ontology for arthropods (Ontology of Arthropod Circulatory Systems - OArCS) and its integration into a novel formalization scheme for morphological descriptions.

    PubMed

    Wirkner, Christian S; Göpel, Torben; Runge, Jens; Keiler, Jonas; Klussmann-Fricke, Bastian-Jesper; Huckstorf, Katarina; Scholz, Stephan; Mikó, Istvan; Yoder, Matt; Richter, Stefan

    2017-01-25

    Morphology, the oldest discipline in the biosciences, is currently experiencing a renaissance in the field of comparative phenomics. However, morphological/phenotypic research still suffers on various levels from a lack of standards. This shortcoming, first highlighted as the "linguistic problem of morphology", concerns the usage of terminology but also the need for formalization of morphological descriptions themselves, something of paramount importance not only to the field of morphology but also when it comes to the use of phenotypic data in systematics and evolutionary biology. We therefore argue, that for morphological descriptions, the basis of all systematic and evolutionary interpretations, ontologies need to be utilized which are based exclusively on structural qualities/properties and which in no case include statements about homology and/or function. Statements about homology and function constitute interpretations on a different or higher level. Based on these 'anatomy ontologies', further ontological dimensions (e.g. referring to functional properties or homology) may be exerted for a broad use in evolutionary phenomics. To this end we present the first organ-based ontology for the most species-rich animal group, the Arthropoda. Our Ontology of Arthropod Circulatory Systems (OArCS) contains a comprehensive collection of 383 terms (i.e. sups) tied to 296 concepts (i.e. definitions) collected from the literature on phenotypic aspects of circulatory organ features in arthropods. All of the concepts used in OArCS are based exclusively on structural features, and in the context of the ontology are independent of homology and functional assumptions. We cannot rule out that in some cases, terms are used which in traditional usage and previous accounts might have implied homology and/or function, e.g. heart, sternal artery. Concepts are composed of descriptive elements that are used to classify observed instances into the organizational framework of the

  8. Vascular and Immunobiology of the Circulatory Sphingosine 1-Phosphate Gradient.

    PubMed

    Yanagida, Keisuke; Hla, Timothy

    2017-02-10

    Vertebrates are endowed with a closed circulatory system, the evolution of which required novel structural and regulatory changes. Furthermore, immune cell trafficking paradigms adapted to the barriers imposed by the closed circulatory system. How did such changes occur mechanistically? We propose that spatial compartmentalization of the lipid mediator sphingosine 1-phosphate (S1P) may be one such mechanism. In vertebrates, S1P is spatially compartmentalized in the blood and lymphatic circulation, thus comprising a sharp S1P gradient across the endothelial barrier. Circulatory S1P has critical roles in maturation and homeostasis of the vascular system as well as in immune cell trafficking. Physiological functions of S1P are tightly linked to shear stress, the key biophysical stimulus from blood flow. Thus, circulatory S1P confinement could be a primordial strategy of vertebrates in the development of a closed circulatory system. This review discusses the cellular and molecular basis of the S1P gradients and aims to interpret its physiological significance as a key feature of the closed circulatory system.

  9. US FDA perspective on regulatory issues affecting circulatory assist devices.

    PubMed

    Sapirstein, Wolf; Chen, Eric; Swain, Julie; Zuckerman, Bram

    2006-11-01

    There has been a rapid development in mechanical circulatory support systems in the decade since the US FDA first approved a mechanical device to provide the circulatory support lacking from a failing heart. Devices are presently approved for marketing by the FDA to replace a failing ventricle, the Ventricular Assist Device or the entire heart, Total Artificial Heart. Contemporaneous with, and permitted by, improvement in technology and design, devices have evolved from units located extracorporeally to paracorporeal systems and totally implanted devices. Clinical studies have demonstrated a parallel improvement in the homeostatic adequacy of the circulatory support provided. Thus, while the circulatory support was initially tolerated for short periods to permit recovery of cardiac function, this technology eventually provided effective circulatory support for increasing periods that permitted the FDA to approve devices for bridging patients in end-stage cardiac failure awaiting transplant and eventually a device for destination therapy where patients in end-stage heart failure are not cardiac transplant candidates. The approved devices have relied on displacement pumps that mimic the pulsatility of the physiological system. Accelerated development of more compact devices that rely on alternative pump mechanisms have challenged both the FDA and device manufacturers to assure that the regulatory requirements for safety and effectiveness are met for use of mechanical circulatory support systems in expanded target populations. An FDA regulatory perspective is reviewed of what can be a potentially critical healthcare issue.

  10. Circulatory responses to hypoxia in experimental myocardial infarction.

    NASA Technical Reports Server (NTRS)

    Schroll, M.; Robison, S. C.; Harrison, D. C.

    1971-01-01

    Three levels of decreased arterial oxygen saturation elicited a graded circulatory response in dogs, manifested by stepwise increases in cardiac output, left ventricular dp/dt, and stroke volume, and decreases in systemic vascular resistance. Responses to similar hypoxia challenges after experimental myocardial infarction were qualitatively similar but quantitatively less. Although the circulatory compensation for hypoxia was less effective after myocardial infarction, no further deterioration of the haemodynamics was noted.

  11. Pathophysiological roles of peroxynitrite in circulatory shock.

    PubMed

    Szabó, Csaba; Módis, Katalin

    2010-09-01

    Peroxynitrite is a reactive oxidant produced from nitric oxide and superoxide, which reacts with proteins, lipids, and DNA, and promotes cytotoxic and proinflammatory responses. Here, we overview the role of peroxynitrite in various forms of circulatory shock. Immunohistochemical and biochemical evidences demonstrate the production of peroxynitrite in various experimental models of endotoxic and hemorrhagic shock both in rodents and in large animals. In addition, biological markers of peroxynitrite have been identified in human tissues after circulatory shock. Peroxynitrite can initiate toxic oxidative reactions in vitro and in vivo. Initiation of lipid peroxidation, direct inhibition of mitochondrial respiratory chain enzymes, inactivation of glyceraldehyde-3-phosphate dehydrogenase, inhibition of membrane Na+/K+ ATPase activity, inactivation of membrane sodium channels, and other oxidative protein modifications contribute to the cytotoxic effect of peroxynitrite. In addition, peroxynitrite is a potent trigger of DNA strand breakage, with subsequent activation of the nuclear enzyme poly(ADP-ribose) polymerase, which promotes cellular energetic collapse and cellular necrosis. Additional actions of peroxynitrite that contribute to the pathogenesis of shock include inactivation of catecholamines and catecholamine receptors (leading to vascular failure) and endothelial and epithelial injury (leading to endothelial and epithelial hyperpermeability and barrier dysfunction), as well as myocyte injury (contributing to loss of cardiac contractile function). Neutralization of peroxynitrite with potent peroxynitrite decomposition catalysts provides cytoprotective and beneficial effects in rodent and large-animal models of circulatory shock.

  12. The Abdominal Circulatory Pump

    PubMed Central

    Aliverti, Andrea; Bovio, Dario; Fullin, Irene; Dellacà, Raffaele L.; Lo Mauro, Antonella; Pedotti, Antonio; Macklem, Peter T.

    2009-01-01

    Blood in the splanchnic vasculature can be transferred to the extremities. We quantified such blood shifts in normal subjects by measuring trunk volume by optoelectronic plethysmography, simultaneously with changes in body volume by whole body plethysmography during contractions of the diaphragm and abdominal muscles. Trunk volume changes with blood shifts, but body volume does not so that the blood volume shifted between trunk and extremities (Vbs) is the difference between changes in trunk and body volume. This is so because both trunk and body volume change identically with breathing and gas expansion or compression. During tidal breathing Vbs was 50–75 ml with an ejection fraction of 4–6% and an output of 750–1500 ml/min. Step increases in abdominal pressure resulted in rapid emptying presumably from the liver with a time constant of 0.61±0.1SE sec. followed by slower flow from non-hepatic viscera. The filling time constant was 0.57±0.09SE sec. Splanchnic emptying shifted up to 650 ml blood. With emptying, the increased hepatic vein flow increases the blood pressure at its entry into the inferior vena cava (IVC) and abolishes the pressure gradient producing flow between the femoral vein and the IVC inducing blood pooling in the legs. The findings are important for exercise because the larger the Vbs the greater the perfusion of locomotor muscles. During asystolic cardiac arrest we calculate that appropriate timing of abdominal compression could produce an output of 6 L/min. so that the abdominal circulatory pump might act as an auxiliary heart. PMID:19440240

  13. Combination of optoacoustics and ultrasound imaging for non-invasive, rapid assessment, and management of circulatory shock

    NASA Astrophysics Data System (ADS)

    Petrov, Yuriy; Petrov, Irene Y.; Esenaliev, Rinat O.; Kinsky, Michael; Prough, Donald S.

    2011-03-01

    We developed a noninvasive, optoacoustic diagnostic platform for monitoring of multiple physiologic variables in inpatients and outpatients. One of the most important applications of this platform is noninvasive, rapid assessment and management of circulatory shock, a common condition in critically ill patients. At present, monitoring of circulatory shock requires measurement of central venous blood oxygenation using invasive procedures such as insertion of catheters in central veins. Hemoglobin saturation below 70% in central veins indicates circulatory shock that requires immediate treatment. We built a portable optoacoustic system for noninvasive measurement of central venous oxygenation. In this study we used the optoacoustic system and clinical ultrasound imaging systems for rapid optoacoustic probing of these veins. The optoacoustic system utilizes a custom-made, sensitive optoacoustic probe that was developed in our laboratory for monitoring of blood oxygenation in deep blood vessels. The studies were performed in human subjects with different geometry (depth, size) of the veins. The ultrasound imaging systems permitted rapid identification of specific blood vessels for optoacoustic probing. We developed a novel algorithm for continuous, realtime, and precise measurement of blood oxygenation in blood vessels. Precision of central venous oxygenation measurement obtained in the study was very high: 1%. Our results indicate that the combination of optoacoustics and ultrasound imaging systems can provide more rapid and accurate assessment and management of the circulatory shock.

  14. A mock circulatory system to assess the performance of continuous-flow left ventricular assist devices (LVADs): does axial flow unload better than centrifugal LVAD?

    PubMed

    Sénage, Thomas; Février, Dorothée; Michel, Magali; Pichot, Emmanuel; Duveau, Daniel; Tsui, Steven; Trochu, Jean Noel; Roussel, Jean Christian

    2014-01-01

    Hemodynamic performances comparisons between different types of left ventricular assist devices (LVADs) remain difficult in a clinical context. The aim of this study was to create an experimental model to assess and compare two types of LVAD under hemodynamic conditions that simulated physical effort and pulmonary hypertension. An experimental mock circulatory system was created to simulate the systemic and pulmonary circulations and consisted of pulsatile left and right cardiac simulators (cardiowest pump), air/water tanks to model compliances, and tubes to model the venous and arterial resistances. Two types of continuous-flow ventricular assist devices were connected to this pulsated model: an axial flow pump, Heartmate II (HTM II), and a centrifugal pump, VentrAssist (VTA). The hemodynamic conditions at rest and during exercise were replicated. Mean aortic pressures were not significantly different at rest and during effort but mean flow under maximum pump speed was higher with HTM II (13 L vs. 10 L, p = 0.02). Left atrial pressure was lower at rest and during effort for the HTM II (11 mm Hg vs. 3 mm Hg, p = 0.02 and 9 mm Hg vs. 2 mm Hg, p = 0.008) than with the VTA, but with greater risk of left-ventricle suck-down for the axial flow. Power consumption for a similar flow was lower with the VTA during rest (4.7 W vs. 6.9 W, p = 0.002) and during effort (4.3 W vs. 6.6 W, p = 0.008). In case of high pulmonary vascular resistance with preserved right ventricular function, lower right ventricular pressure was obtained with HTM II (21 mm Hg vs. 28 mm Hg, p = 0.03). Observed results are in favor of a better discharge of the left and right cavities with the HTM II compared to the VTA yet with a higher risk of left cavity collapse occurrence.

  15. Risks of circulatory diseases among Mayak PA workers with radiation doses estimated using the improved Mayak Worker Dosimetry System 2008.

    PubMed

    Moseeva, Maria B; Azizova, Tamara V; Grigoryeva, Evgenia S; Haylock, Richard

    2014-05-01

    The new Mayak Worker Dosimetry System 2008 (MWDS-2008) was published in 2013 and supersedes the Doses-2005 dosimetry system for Mayak Production Association (PA) workers. It provides revised external and internal dose estimates based on the updated occupational history data. Using MWDS-2008, a cohort of 18,856 workers first employed at one of the main Mayak PA plants during 1948-1972 and followed up to 2005 was identified. Incidence and mortality risks from ischemic heart disease (IHD) (International Classification of Diseases (ICD)-9 codes 410-414) and from cerebrovascular diseases (CVD) (ICD-9 codes 430-438) were examined in this cohort and compared with previously published risk estimates in the same cohort based on the Doses-2005 dosimetry system. Significant associations were observed between doses from external gamma-rays and IHD and CVD incidence and also between internal doses from alpha-radiation and IHD mortality and CVD incidence. The estimates of excess relative risk (ERR)/Gy were consistent with those estimates from the previous studies based on Doses-2005 system apart from the relationship between CVD incidence and internal liver dose where the ERR/Gy based on MWDS-2008 was just over three times higher than the corresponding estimate based on Doses-2005 system. Adjustment for smoking status did not show any effect on the estimates of risk from internal alpha-particle exposure.

  16. The influence of the winter North Atlantic Oscillation index on hospital admissions through diseases of the circulatory system in Lisbon, Portugal

    NASA Astrophysics Data System (ADS)

    Almendra, Ricardo; Santana, Paula; Vasconcelos, João; Silva, Giovani; Gonçalves, Fábio; Ambrizzi, Tércio

    2017-02-01

    The aim of this paper is to analyze the relationship between North Atlantic Oscillation (NAO), meteorological variables, air pollutants, and hospital admissions due to diseases of circulatory systems in Lisbon (Portugal) during winter months (2003-2012). This paper is one of the few studies analyzing the impact of NAO on health through its influence on thermal stress and air pollution and is the first to be conducted in Lisbon. This study uses meteorological data (synthetized into a thermal comfort index), air pollutant metrics, and the NAO index (all clustered in 10-day cycles to overcome daily variability of the NAO index). The relationship between morbidity, thermal comfort index, NAO index, and air pollutants was explored through several linear models adjusted to seasonality through a periodic function. The possible indirect effect between the NAO index and hospital admissions was tested, assuming that NAO (independent variable) is affecting hospital admissions (outcome variable) through thermal discomfort and/or pollution levels (tested as individual mediators). This test was conducted through causal mediation analysis and adjusted for seasonal variation. The results from this study suggest a possible indirect relationship between NAO index and hospital admissions. Although NAO is not significantly associated with hospital admissions, it is significantly associated with CO, PM2.5, NO, and SO2 levels, which in turn increase the probability of hospitalization. The discomfort index (built with temperature and relative humidity) is significantly associated with hospital admissions, but its variability is not explained by the NAO index. This study highlights the impacts of the atmospheric circulation patterns on health. Furthermore, understanding the influence of the atmospheric circulation patterns can support the improvement of the existing contingency plans.

  17. [Peculiarities of systemic on regional circulatory dynamics at a pseudoexfoliative syndrome and pseudoexfoliative glaucoma (review of literature)].

    PubMed

    Brezhnev, A Iu; Kuroedov, A V; Aleksandrov, A S

    2010-05-01

    The article presents results of searches, devoted to haemodynamic damages against wide-spread ophthalmo-pathology--pseudoexfoliative syndrome and pseudoexfoliative glaucoma. Changes, appearing on different levels, confirm hypothesis about systemic character of the disease and prove the necessity of further examination of role of syndrome in development of different forms of vascular disease.

  18. A Multi-Scale Model of the Circulatory System for the Study of Left Ventricular Assist Devices

    NASA Astrophysics Data System (ADS)

    Gohean, J. R.; Moser, R. D.; Bazilevs, Y.; Hughes, T. J. R.

    2006-11-01

    A computer model of the cardiovascular system has been developed to study the hemodynamic effects of a non-pulsatile axial flow left ventricular assist device (LVAD). The model is multi-scale and consists of a distributed quasi-one-dimensional arterial tree, based on integrated Navier-Stokes with a pressure/area state equation representing the compliance of the arteries; and lumped parameter models for the systemic return, pulmonary circulation, coronary circulation, and heart. Physiologically consistent aortic pressure and flow histories have been obtained by including a dynamic aortic valve model that allows back-flow by representing leaflet motion. In addition, a three-dimensional finite element model of the aorta with nonlinear elastic arterial walls can be integrated with the quasi-one-dimensional and lumped parameter models, with the lower fidelity models providing boundary conditions for the detailed model. The three dimensional model allows investigation of the detailed flow characteristics induced by the LVAD. The effect of an LVAD and its implant configuration on the hemodynamics of the cardiovascular system and coronary perfusion are studied for various patient conditions and levels of assist.

  19. Understanding circulatory shock. Is it hypovolemic, cardiogenic, or vasogenic?

    PubMed

    Teba, L; Banks, D E; Balaan, M R

    1992-05-15

    Circulatory shock comprises a group of complex circulatory syndromes that result from a variety of conditions. It alters the function of most organ systems and has very high mortality. Identification of the type of shock (hypovolemic, cardiogenic, vasogenic, or a combination) and optimal treatment are aided by hemodynamic monitoring, including determination of preload, cardiac output, and systemic vascular resistance. Experimental studies and isolation of bioactive substances have improved understanding of the mechanisms involved in shock. Restoration of intravascular volume, cardiac contractility, and vascular tone and control of the underlying septic process when applicable are the basis of current therapy. Close monitoring and support of the affected organ systems in an intensive care environment facilitate recovery. Encouraging results with new treatments indicate improved chances for a satisfactory outcome in patients with circulatory shock.

  20. Mechanical circulatory support in pediatrics.

    PubMed

    Steffen, Robert J; Miletic, Kyle G; Schraufnagel, Dean P; Vargo, Patrick R; Fukamachi, Kiyotaka; Stewart, Robert D; Moazami, Nader

    2016-05-01

    End-stage heart failure affects thousands of children yearly and mechanical circulatory support is used at many points in their care. Extracorporeal membrane oxygenation supports both the failing heart and lungs, which has led to its use as an adjunct to cardiopulmonary resuscitation as well as in post-operative cardiogenic shock. Continuous-flow ventricular assist devices (VAD) have replaced pulsatile-flow devices in adults and early studies have shown promising results in children. The Berlin paracorporeal pulsatile VAD recently gained U.S. Food and Drug Administration approval and remains the only VAD approved in pediatrics. Failing univentricular hearts and other congenitally corrected lesions are new areas for mechanical support. Finding novel uses, improving durability, and minimizing complications are areas of growth in pediatric mechanical circulatory support.

  1. Structures with Reconfigurable Circulatory Systems

    DTIC Science & Technology

    2008-05-16

    precedent for the general concept and aims, it was naturally disappointing not to be the first to report this chemistry. In parallel with the...polymerization in reverse. Thiol compounds, such as glutathione, cysteine and homocysteine are a natural reservoir of reductive capacities of the cells...Cysteine, an amino acid, is a critical substrate in biosynthesis of proteins, glutathione, taurine sulfate and the exceptionally metabolically active

  2. Mass Spectrometry Based Metabolomics Comparison of Liver Grafts from Donors after Circulatory Death (DCD) and Donors after Brain Death (DBD) Used in Human Orthotopic Liver Transplantation

    PubMed Central

    Laing, Richard; Kirwan, Jennifer; Silva, Michael A.; Richards, Douglas A.; Murphy, Nick; Mirza, Darius F.; Viant, Mark R.

    2016-01-01

    Use of marginal liver grafts, especially those from donors after circulatory death (DCD), has been considered as a solution to organ shortage. Inferior outcomes have been attributed to donor warm ischaemic damage in these DCD organs. Here we sought to profile the metabolic mechanisms underpinning donor warm ischaemia. Non-targeted Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry metabolomics was applied to biopsies of liver grafts from donors after brain death (DBD; n = 27) and DCD (n = 10), both during static cold storage (T1) as well as post-reperfusion (T2). Furthermore 6 biopsies from DBD donors prior to the organ donation (T0) were also profiled. Considering DBD and DCD together, significant metabolic differences were discovered between T1 and T2 (688 peaks) that were primarily related to amino acid metabolism, meanwhile T0 biopsies grouped together with T2, denoting the distinctively different metabolic activity of the perfused state. Major metabolic differences were discovered between DCD and DBD during cold-phase (T1) primarily related to glucose, tryptophan and kynurenine metabolism, and in the post-reperfusion phase (T2) related to amino acid and glutathione metabolism. We propose tryptophan/kynurenine and S-adenosylmethionine as possible biomarkers for the previously established higher graft failure of DCD livers, and conclude that the associated pathways should be targeted in more exhaustive and quantitative investigations. PMID:27835640

  3. Mass Spectrometry Based Metabolomics Comparison of Liver Grafts from Donors after Circulatory Death (DCD) and Donors after Brain Death (DBD) Used in Human Orthotopic Liver Transplantation.

    PubMed

    Hrydziuszko, Olga; Perera, M Thamara P R; Laing, Richard; Kirwan, Jennifer; Silva, Michael A; Richards, Douglas A; Murphy, Nick; Mirza, Darius F; Viant, Mark R

    2016-01-01

    Use of marginal liver grafts, especially those from donors after circulatory death (DCD), has been considered as a solution to organ shortage. Inferior outcomes have been attributed to donor warm ischaemic damage in these DCD organs. Here we sought to profile the metabolic mechanisms underpinning donor warm ischaemia. Non-targeted Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry metabolomics was applied to biopsies of liver grafts from donors after brain death (DBD; n = 27) and DCD (n = 10), both during static cold storage (T1) as well as post-reperfusion (T2). Furthermore 6 biopsies from DBD donors prior to the organ donation (T0) were also profiled. Considering DBD and DCD together, significant metabolic differences were discovered between T1 and T2 (688 peaks) that were primarily related to amino acid metabolism, meanwhile T0 biopsies grouped together with T2, denoting the distinctively different metabolic activity of the perfused state. Major metabolic differences were discovered between DCD and DBD during cold-phase (T1) primarily related to glucose, tryptophan and kynurenine metabolism, and in the post-reperfusion phase (T2) related to amino acid and glutathione metabolism. We propose tryptophan/kynurenine and S-adenosylmethionine as possible biomarkers for the previously established higher graft failure of DCD livers, and conclude that the associated pathways should be targeted in more exhaustive and quantitative investigations.

  4. State of the Art of Mechanical Circulatory Support

    PubMed Central

    Mallidi, Hari R.; Anand, Jatin; Cohn, William E.

    2014-01-01

    Mechanical circulatory support of the failing heart has become an important means of treating end-stage heart disease. This rapidly growing therapeutic field has produced impressive clinical outcomes and has great potential to help thousands of otherwise terminal patients worldwide. In this review, we examine the state of the art of mechanical circulatory support: current practice, totally implantable systems of the future, evolving biventricular support mechanisms, the potential for myocardial recovery and adjunctive treatment methods, and miniaturized devices with expanded indications for therapy. PMID:24808767

  5. [Circulatory assist devices in cardiology].

    PubMed

    Ferrari, M; Figulla, H R

    2005-03-24

    One out of 13 patients with an acute myocardial infarction is endangered of cardiogenic shock. In addition, acute valvular leakage, shunt vitiae, and acute myocarditis can lead to acute myocardial failure. As a therapeutic option, mechanical assist devices offer cardiac support and hemodynamic stabilization under these circumstances. The following minimal-invasive devices are used in cardiology and intensive care medicine: intra-aortic balloon pulsation (IABP), intra-vascular axial screw pumps, extra-corporal centrifugal pumps with and without additional membrane oxygenator. The IABP improves left ventricular function by a systolic reduction of the after-load, and an increase of diastolic blood pressure dependent on myocardial function. In contrast, axial screw pumps and centrifugal pumps can provide circulatory support independently of myocardial function. Mechanical assist devices can prevent irreversible damage not only by offering a reduction of myocardial work load, but also by improving organ perfusion in cardiogenic shock situations. Another indication for mechanical circulatory support depicts high-risk coronary angioplasty if the left ventricular ejection fraction is severely reduced or the target vessel supplies more than 50 % of vital myocardium. In case of irreversible heart failure, turbine pumps or centrifugal pumps offer a stabilization for the patient's transfer to a cardiac surgery center. They can also be used for bridging to heart transplantation in acute situations. Technical improvements will enhance the use of mechanical assist devices in the near future. Especially the development of portable emergency devices will enrich therapeutic possibilities in cardiology and intensive care medicine.

  6. Overview of the 2011 Food and Drug Administration Circulatory System Devices Panel of the Medical Devices Advisory Committee Meeting on the CardioMEMS Champion Heart Failure Monitoring System.

    PubMed

    Loh, Joshua P; Barbash, Israel M; Waksman, Ron

    2013-04-16

    The CardioMEMS Champion Heart Failure Monitoring System (CardioMEMS, Atlanta, Georgia) is a permanently implantable pressure measurement system designed to wirelessly measure and monitor pulmonary artery (PA) pressure and heart rate in heart failure (HF) patients to guide ambulatory HF management and to reduce HF hospital stays. On December 8, 2011, the Food and Drug Administration (FDA) Circulatory System Device Panel reviewed the CardioMEMS Champion HF Monitoring System premarket approval (PMA) application. The majority of Panel members agreed that that the discussed monitoring system is safe for use in the indicated patient population. However, new information reported by the FDA with regard to preferential support in management of patients in the treatment group raised concerns among the Panel members with regard to potential bias in analyzing the efficacy of the device itself. Additionally, Panel members raised concerns with regard to the efficacy of the device in certain patient subpopulations. Hence, most Panel members decided that there was not reasonable assurance that the discussed monitoring system is effective. This summary aims to describe the discussions and recommendations made during this meeting.

  7. [Importance of mechanical assist devices in acute circulatory arrest].

    PubMed

    Ferrari, Markus Wolfgang

    2016-03-01

    Mechanical assist devices are indicated for hemodynamic stabilization in acute circulatory arrest if conventional means of cardiopulmonary resuscitation are unable to re-establish adequate organ perfusion. Their temporary use facilitates further diagnostic and therapeutic options in selected patients, e.g. coronary angiography followed by revascularization.External thorax compression devices allow sufficient cardiac massage in case of preclinical or in-hospital circulatory arrest, especially under complex transfer conditions. These devices perform standardized thorax compressions at a rate of 80-100 per minute. Invasive mechanical support devices are used in the catheter laboratory or in the intensive care unit. Axial turbine pumps, e.g. the Impella, continuously pump blood from the left ventricle into the aortic root. The Impella can also provide right ventricle support by pumping blood from the vena cava into the pulmonary artery. So-called emergency systems or ECMO devices consist of a centrifugal pump and a membrane oxygenator allowing complete takeover of cardiac and pulmonary functions. Withdrawing blood from the right atrium and vena cava, oxygenated blood is returned to the abdominal aorta. Isolated centrifugal pumps provide left heart support without an oxygenator after transseptal insertion of a venous cannula into the left atrium.Mechanical assist devices are indicated for acute organ protection and hemodynamic stabilization for diagnostic and therapeutic measures as well as bridge to myocardial recovery. Future technical developments and better insights into the pathophysiology of mechanical circulatory support will broaden the spectrum of indications of such devices in acute circulatory arrest.

  8. Hemodynamics of Mechanical Circulatory Support.

    PubMed

    Burkhoff, Daniel; Sayer, Gabriel; Doshi, Darshan; Uriel, Nir

    2015-12-15

    An increasing number of devices can provide mechanical circulatory support (MCS) to patients with acute hemodynamic compromise and chronic end-stage heart failure. These devices work by different pumping mechanisms, have various flow capacities, are inserted by different techniques, and have different sites from which blood is withdrawn and returned to the body. These factors result in different primary hemodynamic effects and secondary responses of the body. However, these are not generally taken into account when choosing a device for a particular patient or while managing a patient undergoing MCS. In this review, we discuss fundamental principles of cardiac, vascular, and pump mechanics and illustrate how they provide a broad foundation for understanding the complex interactions between the heart, vasculature, and device, and how they may help guide future research to improve patient outcomes.

  9. Cell-Mediated Delivery of Nanoparticles: Taking Advantage of Circulatory Cells to Target Nanoparticles

    PubMed Central

    Anselmo, Aaron C.; Mitragotri, Samir

    2014-01-01

    Cellular hitchhiking leverages the use of circulatory cells to enhance the biological outcome of nanoparticle drug delivery systems, which often suffer from poor circulation time and limited targeting. Cellular hitchhiking utilizes the natural abilities of circulatory cells to: (i) navigate the vasculature while avoiding immune system clearance, (ii) remain relatively inert until needed and (iii) perform specific functions, including nutrient delivery to tissues, clearance of pathogens, and immune system surveillance. A variety of synthetic nanoparticles attempt to mimic these functional attributes of circulatory cells for drug delivery purposes. By combining the advantages of circulatory cells and synthetic nanoparticles, many advanced drug delivery systems have been developed that adopt the concept of cellular hitchhiking. Here, we review the development and specific applications of cellular hitchhiking-based drug delivery systems. PMID:24747161

  10. Hypoglycaemic bradycardia and circulatory collapse in a dog and a cat.

    PubMed

    Little, C J L

    2005-09-01

    Hypoglycaemia was accompanied by sinus bradycardia and circulatory collapse in a dog and a cat. In each case, when the hypoglycaemia was corrected by intravenous infusion of a glucose solution the bradycardia and circulatory failure were soon abolished, indicating that these abnormalities were caused by the hypoglycaemia. Similar observations have been made in human patients. To the author's knowledge, this is the first report documenting hypoglycaemic bradycardia in veterinary medicine.

  11. [Oral contraception and circulatory risks].

    PubMed

    Wingrave, S J

    1984-10-01

    The longterm prospective study of health effects of oral contraceptives (OCs) conducted by the Royal College of General Practitioners compared 23,000 OC users with 23,000 controls matched for age and marital status. As of 1981, 55 deaths attributable to circulatory problems had occurred in ever-users of OCs, ciompared to 10 in controls, giving a relative risk of 4.2 for OC users. No relation was found between duration of use and mortality risk among users, although mortality risks were greater at all durations of use than for nonusers. Parity was related to mortality risk among users but not among controls. The most significant factors affecting the relation between pill use and circulatory risk were age and smoking. Among users who smoked, the risk ratios were 3.4 for those aged 25-34, 4.2 for those aged 35-44, 7.4 for those aged 45 and over, and 5.1 for the entire group. Among nonsmoking pill users, the ratios were 1.6 for those aged 25-34, 3.3 for those aged 35-44, 4.6 for those 45 and over, and 3.2 for the total sample. Among smokers, the rates of excess deaths were 1 in 10,000 for users aged 15-34, 1 in 2000 for those aged 35-44, and 1 in550 for those aged 45 and over. Among nonsmokers, the rates were 1 in 50,000 users for those aged 25-34, 1 in 6700 for those aged 35-44, and 1 in 2500 for those aged 45 and over. The majority of deaths were attributed to ischemic cardiac problems and to sub-arachnoid hemorrhages, and risks appeared to be elevated in former as well as current users. The total incidence of circulatory effects in former users appears to be elevated only for cerebrovascular disorders, but the suggestion of residual effects requires further study before conclusions can be drawn. Smokers who developed cardiovascular or cerebrovascular problems were at 2-3 times greater risk of dying than were other women. The percentages of fatal cases of ischemic heart and cerebrovascular diseases were 22.8% among ever-users who smoked, 10.9% among controls who

  12. Subject-specific estimation of central aortic blood pressure via system identification: preliminary in-human experimental study.

    PubMed

    Fazeli, Nima; Kim, Chang-Sei; Rashedi, Mohammad; Chappell, Alyssa; Wang, Shaohua; MacArthur, Roderick; McMurtry, M Sean; Finegan, Barry; Hahn, Jin-Oh

    2014-10-01

    This paper demonstrates preliminary in-human validity of a novel subject-specific approach to estimation of central aortic blood pressure (CABP) from peripheral circulatory waveforms. In this "Individualized Transfer Function" (ITF) approach, CABP is estimated in two steps. First, the circulatory dynamics of the cardiovascular system are determined via model-based system identification, in which an arterial tree model is characterized based on the circulatory waveform signals measured at the body's extremity locations. Second, CABP waveform is estimated by de-convolving peripheral circulatory waveforms from the arterial tree model. The validity of the ITF approach was demonstrated using experimental data collected from 13 cardiac surgery patients. Compared with the invasive peripheral blood pressure (BP) measurements, the ITF approach yielded significant reduction in errors associated with the estimation of CABP, including 1.9-2.6 mmHg (34-42 %) reduction in BP waveform errors (p < 0.05) as well as 5.8-9.1 mmHg (67-76 %) and 6.0-9.7 mmHg (78-85 %) reductions in systolic and pulse pressure (SP and PP) errors (p < 0.05). It also showed modest but significant improvement over the generalized transfer function approach, including 0.1 mmHg (2.6 %) reduction in BP waveform errors as well as 0.7 (20 %) and 5.0 mmHg (75 %) reductions in SP and PP errors (p < 0.05).

  13. Outline of the International Organization for Standardization Standard for Circulatory Support Devices (ISO 14708-5).

    PubMed

    Imachi, Kou; Mussivand, Tofy

    2010-09-01

    The rapid progress of artificial heart and circulatory support devices enables us to apply them to severe heart failure patients. Many types of circulatory support devices have been developed in the United States, Europe, and Japan. This situation urged the establishment of an International Organization for Standardization (ISO) Standard for the circulatory support devices. A new work, "Cardiac Ventricular Assist Devices," was proposed to the ISO/TC150/SC6 (TC150: Technical Committee of Implants for Surgery, SC6: Sub-committee of Active Implants) in 2000, and the work was finalized for publication at a 2009 meeting of the ISO/TC150 in Kyoto. In this article, the authors would like to introduce the ISO system and the outline of the ISO Standard for Circulatory Support Devices.

  14. Post-exercise leg and forearm flexor muscle cooling in humans attenuates endurance and resistance training effects on muscle performance and on circulatory adaptation.

    PubMed

    Yamane, Motoi; Teruya, Hiroyasu; Nakano, Masataka; Ogai, Ryuji; Ohnishi, Norikazu; Kosaka, Mitsuo

    2006-03-01

    The influence of regular post-exercise cold application to exercised muscles trained by ergometer cycling (leg muscles) or handgrip exercise using a weight-loaded handgrip ergometer (forearm flexor muscles) was studied in human volunteers. Muscle loads were applied during exercise programs three to four times a week for 4-6 weeks. Besides measuring parameters characterizing muscle performance, femoral and brachial artery diameters were determined ultrasonographically. Training effects were identified by comparing pre- and post-training parameters in matched groups separately for the trained limbs cooled after exercise by cold-water immersion and the corresponding trained limbs kept at room temperature. Significant training effects were three times more frequent in the control than in the cold group, including increases in artery diameters in the control but not in the cold group. It is concluded that training-induced molecular and humoral adjustments, including muscle hyperthermia, are physiological, transient and essential for training effects (myofiber regeneration, muscle hypertrophy and improved blood supply). Cooling generally attenuates these temperature-dependent processes and, in particular, hyperthermia-induced HSP formation. This seems disadvantageous for training, in contrast to the beneficial combination of rest, ice, compression and elevation in the treatment of macroscopic musculo-tendinous damage.

  15. Human Systems Integration Introduction

    NASA Video Gallery

    This lecture provides an overview of Human Systems Integration (HSI), its implementation cost and return on investment, HSI domains, how HSI fits into the NASA organization structure, HSI roles and...

  16. Human immune system variation

    PubMed Central

    Brodin, Petter; Davis, Mark M.

    2017-01-01

    The human immune system is highly variable between individuals but relatively stable over time within a given person. Recent conceptual and technological advances have enabled systems immunology analyses, which reveal the composition of immune cells and proteins in populations of healthy individuals. The range of variation and some specific influences that shape an individual’s immune system is now becoming clearer. Human immune systems vary as a consequence of heritable and non-heritable influences, but symbiotic and pathogenic microbes and other non-heritable influences explain most of this variation. Understanding when and how such influences shape the human immune system is key for defining metrics of immunological health and understanding the risk of immune-mediated and infectious diseases. PMID:27916977

  17. Effect of Kampo formulations (traditional Chinese medicine) on circulatory parameters.

    PubMed

    Xu, F H; Uebaba, K

    1999-01-01

    The pharmacological action of 6 main Kampo formulations (1.Mao -to: [Japanese pictograph see text] MA HUANG TANG; 2. Shimbu -to: [Japanese pictograph see text]: ZHEN WU TANG; 3. Ninjin -to: [Japanese pictograph see text] : REN SHEN TANG; 4.Shigyaku-san: [Japanese pictograph see text] : SI NI SAN; 5.Keishi-to: Japanese pictograph see text] : GUI ZHI TANG; 6. Shimotsu - to: [Japanese pictograph see text] : SI WU TANG) on circulatory and autonomic nervous system were studied. 7 healthy adult males( age, 22.3 +/- 1.8 years old ) had 6 basic Kampo formulations, followed by noninvasive measurement of systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO ), cardiacindex (CI), total peripheral resistance (TPR) by means of systolic area method of brachialsphygmography, every 30 minutes for 2 hours. As results, Mao - to induced an increase of BP,HR,SV,CO and CI, but a decrease of TPR. Keishi - to induced an increase of SBP and SV, and Shimotsu-to induced an increase of DBP and MBP, HR was slowed during former period after oral administration of Shigyaku - san, and later period after oral administration of Shimbu-to and Shimotsu-to. Regarding autonomic activity, Mao-to(former period of experiment ), Shimbu - to and Shimotsu-to induced supression of sympathetic activity, on the other hand, Mao-to (later period of experiment ) and Shiyaku - san showed a tendency of parasympathomimetic action. Mao -to induced the strongest activation of circulatory system of 6 main farmulations, and showed change of autonomic nervous activity, however, the change of circulatory and automonic nervous activity were not coincident each other. It was speculated that comprehensive mechanism of Mao-to were not only dependent of ephedrin, main active constituent of Mao, but also dependent on Keishi's vasodilatory action in it. Ninjin -to showed no actions on circulatory or autonomic system. This is indicated

  18. Spaceflight Human System Standards

    NASA Technical Reports Server (NTRS)

    Holubec, Keith; Tillman, Barry; Connolly, Jan

    2009-01-01

    NASA created a new approach for human system integration and human performance standards. NASA created two documents a standard and a reference handbook. The standard is titled NASA Space Flight Human-System Standard (SFHSS) and consists of two-volumes: Volume 1- Crew Health This volume covers standards needed to support astronaut health (medical care, nutrition, sleep, exercise, etc.) Volume 2 Human Factors, Habitability and Environmental Health This volume covers the standards for system design that will maintain astronaut performance (ie., environmental factors, design of facilities, layout of workstations, and lighting requirements). It includes classic human factors requirements. The new standards document is written in terms so that it is applicable to a broad range of present and future NASA systems. The document states that all new programs prepare system-specific requirements that will meet the general standards. For example, the new standard does not specify a design should accommodate specific percentiles of a defined population. Rather, NASA-STD-3001, Volume 2 states that all programs shall prepare program-specific requirements that define the user population and their size ranges. The design shall then accommodate the full size range of those users. The companion reference handbook, Human Integration Design Handbook (HIDH), was developed to capture the design consideration information from NASA-STD-3000, and adds spaceflight lessons learned, gaps in knowledge, example solutions, and suggests research to further mature specific disciplines. The HIDH serves two major purposes: HIDH is the reference document for writing human factors requirements for specific systems. HIDH contains design guidance information that helps insure that designers create systems which safely and effectively accommodate the capabilities and limitations of space flight crews.

  19. Mechanical circulatory devices in acute heart failure.

    PubMed

    Teuteberg, Jeffrey J; Chou, Josephine C

    2014-07-01

    Cardiogenic shock remains a leading cause of mortality despite advances in the treatment of myocardial infarction and advanced heart failure. Medical therapy can be inadequate, and patients may need mechanical circulatory support (MCS). The proper application of MCS requires knowledge of the underlying cause of acute heart failure, familiarity with the circulatory support devices, and the potential benefits and limitations of device therapy. This article describes the most commonly used temporary ventricular assist devices and their use in the various causes of cardiogenic shock.

  20. Prime Time for Temporary Mechanical Circulatory Support.

    PubMed

    Eckman, Peter M; Hryniewicz, Katarzyna

    2015-07-01

    Cardiovascular care has witnessed a paradigm shift toward widespread use of mechanical circulatory support (MCS). In this context, the 2015 SCAI/ACC/HFSA/STS Clinical Expert Consensus Statement on the use of percutaneous mechanical circulatory support devices in cardiovascular care is a timely and welcome addition to the literature. This consensus statement is an important summary of the state of the field and a valuable method for all who participate in cardiovascular care to ensure up-to-date understanding of the treatment options available.

  1. Continuous cerebral hemodynamic measurement during deep hypothermic circulatory arrest

    PubMed Central

    Busch, David R.; Rusin, Craig G.; Miller-Hance, Wanda; Kibler, Kathy; Baker, Wesley B.; Heinle, Jeffrey S.; Fraser, Charles D.; Yodh, Arjun G.; Licht, Daniel J.; Brady, Kenneth M.

    2016-01-01

    While survival of children with complex congenital heart defects has improved in recent years, roughly half suffer neurological deficits suspected to be related to cerebral ischemia. Here we report the first demonstration of optical diffuse correlation spectroscopy (DCS) for continuous and non-invasive monitoring of cerebral microvascular blood flow during complex human neonatal or cardiac surgery. Comparison between DCS and Doppler ultrasound flow measurements during deep hypothermia, circulatory arrest, and rewarming were in good agreement. Looking forward, DCS instrumentation, alone and with NIRS, could provide access to flow and metabolic biomarkers needed by clinicians to adjust neuroprotective therapy during surgery. PMID:27699112

  2. Human Factors in Human-Systems Integration

    NASA Technical Reports Server (NTRS)

    Fitts, David J.; Sandor, Aniko; Litaker, Harry L., Jr.; Tillman, Barry

    2008-01-01

    Any large organization whose mission is to design and develop systems for humans, and train humans needs a well-developed integration and process plan to deal with the challenges that arise from managing multiple subsystems. Human capabilities, skills, and needs must be considered early in the design and development process, and must be continuously considered throughout the development lifecycle. This integration of human needs within system design is typically formalized through a Human-Systems Integration (HSI) program. By having an HSI program, an institution or organization can reduce lifecycle costs and increase the efficiency, usability, and quality of its products because human needs have been considered from the beginning.

  3. On a basic model of circulatory, fluid, and electrolyte regulation in the human system based upon the model of Guyton

    NASA Technical Reports Server (NTRS)

    White, R. J.

    1973-01-01

    A detailed description of Guyton's model and modifications are provided. Also included are descriptions of several typical experiments which the model can simulate to illustrate the model's general utility. A discussion of the problems associated with the interfacing of the model to other models such as respiratory and thermal regulation models which is prime importance since these stimuli are not present in the current model is also included. A user's guide for the operation of the model on the Xerox Sigma 3 computer is provided and two programs are described. A verification plan and procedure for performing experiments is also presented.

  4. Human Balance System

    MedlinePlus

    ... and vision problems, and difficulty with concentration and memory. What is balance? Balance is the ability to maintain the body’s center of mass over its base of support. 1 A properly functioning balance system allows humans to see clearly while moving, identify orientation with ...

  5. Bodily systems and the spatial-functional structure of the human body.

    PubMed

    Smith, Barry; Munn, Katherine; Papakin, Igor

    2004-01-01

    The human body is a system made of systems. The body is divided into bodily systems proper, such as the endocrine and circulatory systems, which are subdivided into many sub-systems at a variety of levels, whereby all systems and subsystems engage in massive causal interaction with each other and with their surrounding environments. Here we offer an explicit definition of bodily system and provide a framework for understanding their causal interactions. Medical sciences provide at best informal accounts of basic notions such as system, process, and function, and while such informality is acceptable in documentation created for human beings, it falls short of what is needed for computer representations. In our analysis we will accordingly provide the framework for a formal definition of bodily system and of associated notions.

  6. Integration and control of circulatory function.

    PubMed

    Guyton, A C; Cowley, A W; Young, D B; Coleman, T G; Hall, J E; DeClue, J W

    1976-01-01

    In this chapter we have emphasized especially the intrinsic controls of the circulation, such as the autoregulation mechanism for control of local blood flow, automatic control of cardiac output, long-term control of arterial pressure, long-term control of blood volume, and automatic distribution of fluids between the circulation and the interstitial spaces. The reasons for emphasizing these mechanisms are several: first, many experiments have now shown that the intrinsic mechanisms can provide highly stable long-term control of the circulation. Second, the value of the nervous and hormonal controls have probably been greatly overemphasized in the past. And, third, there are special complexities of the intrinsic controls--such as nonlinearities, delay in responses, and other effects--that have made these difficult to understand; it is probably these difficulties that have led to their underemphasis. However, we have not meant to take from the nervous and hormonal systems their true importance in circulatory control. For instance, intrinsic mechanisms have almost no capability for acute arterial pressure control (only for long-term control), and they have no mechanism for providing the drive necessary to make the animal ingest water and electrolytes. These require the nervous controls. Also, nervous reflexes are important in enhancing the effectiveness of blood volume control and control of cardiac pumping. Among the hormonal mechanisms, the renin-angiotensin system can provide a modest degree of arterial pressure control when the pressure falls below normal by eliciting a vasoconstrictor response in the peripheral blood vessels. However, this system seems to have an even more important renal function, a direct effect on kidneys to cause fluid retention; this in turn increases the body fluid volume and in this way increases the arterial pressure. Finally, the roles of ADH and aldosterone in the control of blood volume have probably been greatly overemphasized. On

  7. [The prevention of transfusion-associated circulatory overload].

    PubMed

    Ozier, Y

    2014-11-01

    Hydrostatic pulmonary edema is a frequent and severe complication of blood transfusion. Recent epidemiological studies open the way for a better prevention of Transfusion-Associated Circulatory Overload. Preventive measures rely solely on the medical and nursing staff. Mitigation strategies include a careful identification of patients and conditions at-risk, a single-unit transfusion policy in patients with chronic anemia, the use of slow infusion rates, the careful monitoring of patient vital signs (particularly systemic arterial blood pressure). Peritransfusion IV diuretics use is likely to be helpful, although optimal prescribing patterns have not been defined.

  8. Bleeding following deep hypothermia and circulatory arrest in children.

    PubMed

    Mossad, Emad B; Machado, Sandra; Apostolakis, John

    2007-03-01

    Deep hypothermic circulatory arrest (DHCA) is a technique of extracorporeal circulation commonly used in children with complex congenital heart defects undergoing surgical repairs. The use of profound cooling (20 degrees C) and complete cessation of circulation allow adequate exposure and correction of these complex lesions, with enhanced cerebral protection. However, the profound physiologic state of DHCA results in significant derangement of the coagulation system and a high incidence of postoperative bleeding. This review examines the impact of DHCA on bleeding and transfusion requirements in children and the pathophysiology of DHCA-induced platelet dysfunction. It also focuses on possible pharmacologic interventions to decrease bleeding following DHCA in children.

  9. Splanchnic vasodilation and hyperdynamic circulatory syndrome in cirrhosis.

    PubMed

    Bolognesi, Massimo; Di Pascoli, Marco; Verardo, Alberto; Gatta, Angelo

    2014-03-14

    Portal hypertension is a clinical syndrome which leads to several clinical complications, such as the formation and rupture of esophageal and/or gastric varices, ascites, hepatic encephalopathy and hepato-renal syndrome. In cirrhosis, the primary cause of the increase in portal pressure is the enhanced resistance to portal outflow. However, also an increase in splanchnic blood flow worsens and maintains portal hypertension. The vasodilatation of arterial splanchnic vessels and the opening of collateral circulation are the determinants of the increased splanchnic blood flow. Several vasoactive systems/substances, such as nitric oxide, cyclooxygenase-derivatives, carbon monoxide and endogenous cannabinoids are activated in portal hypertension and are responsible for the marked splanchnic vasodilatation. Moreover, an impaired reactivity to vasoconstrictor systems, such as the sympathetic nervous system, vasopressin, angiotensin II and endothelin-1, plays a role in this process. The opening of collateral circulation occurs through the reperfusion and dilatation of preexisting vessels, but also through the generation of new vessels. Splanchnic vasodilatation leads to the onset of the hyperdynamic circulatory syndrome, a syndrome which occurs in patients with portal hypertension and is characterized by increased cardiac output and heart rate, and decreased systemic vascular resistance with low arterial blood pressure. Understanding the pathophysiology of splanchnic vasodilatation and hyperdynamic circulatory syndrome is mandatory for the prevention and treatment of portal hypertension and its severe complications.

  10. Biplane roentgen videometric system for dynamic, 60/sec, studies of the shape and size of circulatory structures, particularly the left ventricle.

    NASA Technical Reports Server (NTRS)

    Ritman, E. L.; Sturm, R. E.; Wood, E. H.

    1973-01-01

    An operator interactive video system for the measurement of roentgen angiographically outlined structures is described. Left ventricular volume and three-dimensional shapes are calculated from up to 200 pairs of diameters measured from ventriculograms at the rate of 60 pairs of biplane images per second. The accuracy and reproducibility of volumes calculated by the system were established by analysis of roentgenograms of inanimate objects of known volume and by comparison of left ventricular stroke volumes calculated by the system with the stroke volumes calculated by an indicator-dilution technique and an aortic root electromagnetic flowmeter. Computer-generated display of the large amounts of data obtained by the videometry system is described.

  11. Human portable preconcentrator system

    DOEpatents

    Linker, Kevin L.; Bouchier, Francis A.; Hannum, David W.; Rhykerd, Jr., Charles L.

    2003-01-01

    A preconcentrator system and apparatus suited to human portable use wherein sample potentially containing a target chemical substance is drawn into a chamber and through a pervious screen. The screen is adapted to capture target chemicals and then, upon heating, to release those chemicals into the chamber. Chemicals captured and then released in this fashion are then carried to a portable chemical detection device such as a portable ion mobility spectrometer. In the preferred embodiment, the means for drawing sample into the chamber comprises a reversible fan which, when operated in reverse direction, creates a backpressure that facilitates evolution of captured target chemicals into the chamber when the screen is heated.

  12. Quantitative three-dimensional dynamic imaging of structure and function of the cardiopulmonary and circulatory systems in all regions of the body

    NASA Technical Reports Server (NTRS)

    Sturm, R. E.; Ritman, E. L.; Wood, E. H.

    1975-01-01

    The background for, and design of a third generation, general purpose, all electronic spatial scanning system, the DSR is described. Its specified performance capabilities provide dynamic and stop action three dimensional spatial reconstructions of any portion of the body based on a minimum exposure time of 0.01 second for each 28 multiplanar 180 deg scanning set, a maximum scan repetition rate of sixty 28 multiplane scan sets per second, each scan set consisting of a maximum of 240 parallel cross sections of a minimum thickness of 0.9 mm, and encompassing a maximum cylindrical volume about 23 cm in length and up to 38 cm in diameter.

  13. Feasibility of a TinyPump system for pediatric CPB, ECMO, and circulatory assistance: hydrodynamic performances of the modified pump housing for implantable TinyPump.

    PubMed

    Yokoyama, Naoyuki; Suzuki, Masaaki; Hoshi, Hideo; Ohuchi, Katsuhiro; Fujimoto, Tetsuo; Takatani, Setsuo

    2007-01-01

    The TinyPump is a miniature centrifugal blood pump with an extremely small priming volume of 5 ml, allowing blood transfusion free cardiopulmonary bypass as well as extracorporeal membrane oxygenation in pediatric patients. In this study, a new pump housing with the angled inlet port (25 degrees toward impeller center with respect to the flow axis) was designed to optimize the pump displaced volume and to extend the application of the TinyPump to implantable support The fluid dynamic performance analysis revealed that the head pressure losses increased from 3 to 17 mm Hg in comparison with straight port design as the pump rotational speed increased from 2,000 to 4,000 rpm. This was probably caused by perturbed flow patterns at the site of the inlet bent port area and streamline hitting the off-center of the impeller. No significant effect on pumping efficiency was observed because of modification in inlet port design. Modification in the inflow and outflow port designs together with the drive mechanism reduces the height of the pump system, including the motor, to 27 mm yielding the displaced volume of 68 ml in comparison with 40 mm of the paracorporeal system with the displaced volume of 105 ml. Further analysis in terms of hemolytic as well as antithrombogenic performance will be carried out to finalize the housing design for the implantable version of the TinyPump.

  14. Normal behaviour of circulatory parameters during exercise. Reference values for heart rate and systemic blood pressure. The ECCIS Project data. Epidemiologia e Clinica della Cardiopatia Ischemica Silente.

    PubMed

    Menghini, F; Dally, L; Fazzini, P F; Menotti, A; Prati, P L; Rovelli, F; Antoniucci, D; Seccareccia, F

    1995-08-01

    The study of simultaneous variations in heart rate (HR) and systemic blood pressure is of great interest in ergometric practice complementing the analysis of the ST segment by ECG. This paper examines data proceeding from 500 consecutive, normal, exercise stress tests with the aim of offering reference values on the step-by-step behaviour of HR, systolic and diastolic blood pressure (SBP, DBP) during exercise in a normal population. The sample comes from a large epidemiological study (ECCIS Project) conducted on 4842 healthy, working men, aged 40-59, which proposes to identify, by a 3 stage procedure, subjects with totally asymptomatic coronary artery disease (type I silent ischemia). A further aim of our paper is to examine the influence of some physiological variables (age, height, weight, body mass index, resting HR, SBP and DBP) on the response to effort of HR, SBP and DBP; reciprocal HR/SBP adjustment during exercise; maximal attained workload and recovery time. Due to a preliminary observation that the rate of step-by-step increase in HR and SBP is inversely related to total duration, the population was split into 4 groups according to exercise tolerance (defined by maximal attained workload) to elaborate reference values. Furthermore our data demonstrate that: 1) SBP increases more rapidly with respect to HR for older and heavier subjects; 2) Exercise tolerance is inversely related to age, baseline HR and SBP, and directly related to weight and height; 3) return to baseline conditions, during recovery, is quicker for subjects with better exercise tolerance and lower baseline HR, SBP and weight.

  15. Human portable preconcentrator system

    DOEpatents

    Linker, Kevin L.; Brusseau, Charles A.; Hannum, David W.; Puissant, James G.; Varley, Nathan R.

    2003-08-12

    A preconcentrator system and apparatus suited to human portable use wherein sample potentially containing a target chemical substance is drawn into a chamber and through a pervious screen. The screen is adapted to capture target chemicals and then, upon heating, to release those chemicals into the chamber. Chemicals captured and then released in this fashion are then carried to a portable chemical detection device such as a portable ion mobility spectrometer. In the preferred embodiment, the means for drawing sample into the chamber comprises a reversible fan which, when operated in reverse direction, creates a backpressure that facilitates evolution of captured target chemicals into the chamber when the screen is heated. The screen can be positioned directly in front of the detector prior to heating to improve detection capability.

  16. A contemporary review of mechanical circulatory support.

    PubMed

    Patel, Chetan B; Cowger, Jennifer A; Zuckermann, Andreas

    2014-07-01

    Mechanical circulatory support has seen numerous advances in the recent years, with important observations made to guide patient selection for the therapy, indications for use, and management of devices after implantation. There is rapid growth in the use of left ventricular assist device therapy (LVAD) for advanced heart failure, with a movement to pursue device intervention earlier in the disease spectrum before comorbidities escalate. With this increase in LVAD use have come new challenges, including unanticipated adverse events and high readmission rates. Simultaneously, complications encountered during LVAD support and an increased number of patients supported with a goal for transplant have had an important effect on the allocation of cardiac allografts. Still, the field continues to evolve and address these challenges in systematic fashion to provide novel solutions and meet the needs of a growing population with advanced heart failure. This has led to an extensive body of literature, ranging from case reports to multicenter clinical trials, which will enhance the future of LVAD technology and patient outcomes. This review summarizes important publications in mechanical circulatory support during the past 24 months.

  17. Human-System Technology

    DTIC Science & Technology

    2005-11-10

    Computing, this multidisciplinary field exploits advances in cognitive research together with those in computer science and related areas to optimize the...deep understanding of human cognition, perception, and/or locomotion; the relevant areas of computer science ; and the nature of the human activity to be

  18. Donation after circulatory death: burying the dead donor rule.

    PubMed

    Rodríguez-Arias, David; Smith, Maxwell J; Lazar, Neil M

    2011-08-01

    Despite continuing controversies regarding the vital status of both brain-dead donors and individuals who undergo donation after circulatory death (DCD), respecting the dead donor rule (DDR) remains the standard moral framework for organ procurement. The DDR increases organ supply without jeopardizing trust in transplantation systems, reassuring society that donors will not experience harm during organ procurement. While the assumption that individuals cannot be harmed once they are dead is reasonable in the case of brain-dead protocols, we argue that the DDR is not an acceptable strategy to protect donors from harm in DCD protocols. We propose a threefold alternative to justify organ procurement practices: (1) ensuring that donors are sufficiently protected from harm; (2) ensuring that they are respected through informed consent; and (3) ensuring that society is fully informed of the inherently debatable nature of any criterion to declare death.

  19. Circulatory Estrogen Level Protects Against Breast Cancer in Obese Women

    PubMed Central

    Suba, Zsuzsanna

    2013-01-01

    Literary data suggest apparently ambiguous interaction between menopausal status and obesity-associated breast cancer risk based on the principle of the carcinogenic capacity of estrogen. Before menopause, breast cancer incidence is relatively low and adiposity is erroneously regarded as a protective factor against this tumor conferred by the obesity associated defective estrogen-synthesis. By contrast, in postmenopausal cases, obesity presents a strong risk factor for breast cancer being mistakenly attributed to the presumed excessive estrogen-production of their adipose-tissue mass. Obesity is associated with dysmetabolism and endangers the healthy equilibrium of sexual hormone-production and regular menstrual cycles in women, which are the prerequisites not only for reproductive capacity but also for somatic health. At the same time, literary data support that anovulatory infertility is a very strong risk for breast cancer in young women either with or without obesity. In the majority of premenopausal women, obesity associated insulin resistance is moderate and may be counteracted by their preserved circulatory estrogen level. Consequently, it is not obesity but rather the still sufficient estrogen-level, which may be protective against breast cancer in young adult females. In obese older women, never using hormone replacement therapy (HRT) the breast cancer risk is high, which is associated with their continuous estrogen loss and increasing insulin-resistance. By contrast, obese postmenopausal women using HRT, have a decreased risk for breast cancer as the protective effect of estrogen-substitution may counteract to their obesity associated systemic alterations. The revealed inverse correlation between circulatory estrogen-level and breast cancer risk in obese women should advance our understanding of breast cancer etiology and promotes primary prevention measures. New patents recommend various methods for the prevention and treatment of obesity

  20. Umbilical arterial S-nitrosothiols in stressed newborns: role in perinatal circulatory transition.

    PubMed

    Gaston, B; Fry, E; Sears, S; Heroman, W M; Ignarro, L; Stamler, J S

    1998-12-30

    S-Nitrosothiols are potent endogenous vasodilators recently found to be in greater concentrations in fetal umbilical venous than arterial blood. We hypothesized that neonatal increases in SNOs may be involved in the normal human perinatal circulatory transition. Paired human umbilical artery and vein plasma samples were collected after birth. S-Nitrosothiol concentrations were measured as NO after photolysis--and NO3- after reduction in vanadium chloride--by chemiluminescence. Normal umbilical arterial serum SNO levels were nearly twice those of matched venous samples but were low in infants who did not transition normally to neonatal circulation. There was no difference in the concentration of NO3- between the normal and depressed infants. The parallel failure of some fetuses to switch both to a normal arteriovenous SNO relationship and a normal clinical post-partum state suggests that SNOs may be involved in the perinatal circulatory transition.

  1. Options for temporary mechanical circulatory support

    PubMed Central

    Saffarzadeh, Areo

    2015-01-01

    Temporary mechanical circulatory support (MCS) refers to a group of devices generally used for less than 30 days to maintain adequate organ perfusion by compensating for a failure of the pumping mechanism of the heart. The increased availability and rapid adoption of new temporary MCS strategies necessitate physicians to become familiar with devices placed both percutaneously and via median sternotomy. This review will examine the different options for commonly used temporary MCS devices including intra-aortic balloon pumps (IABPs), veno-arterial-extracorporeal membrane oxygenation (VA-ECMO), TandemHeart® (CardiacAssist, Pittsburg, PA, USA) Impella® and BVS 5000® (both Abiomed Inc., Danvers, MA, USA), CentriMag® and Thoratec percutaneous ventricular assist device (pVAD)® (both Thoratec Corporation, Pleasanton, CA, USA). A specific emphasis will be made to describe relevant mechanisms of action, standard placement strategies, hemodynamic effects, relevant contraindications and complications, and important daily management considerations. PMID:26793330

  2. Mechanical circulatory support in heart failure

    PubMed Central

    Szczurek, Wioletta; Suliga, Kamil; Rempega, Grzegorz; Rajwa, Paweł

    2016-01-01

    The increasing number of end-stage heart failure patients eligible for heart transplant and the disproportionately low number of donor hearts have led to increased interest in ventricular assist devices (VAD). These devices can be used as a bridge to decision, bridge to recovery, or bridge to candidacy. The main advantage of mechanical circulatory support (MCS) is the improvement of organ perfusion and function, which leads to better quality of life and survival. The MCS can also be used as a destination therapy in end-stage heart failure patients who are not eligible for heart transplant. It should be remembered that, despite the tangible benefits, VAD implantation may also be associated with the risk of serious complications, such as bleeding, infection, arrhythmias, blood clots, right ventricular failure, and cardiovascular events. This study presents an up-to-date overview of the current knowledge on the role of MCS in modern medicine. PMID:27516785

  3. Disorder in Complex Human System

    NASA Astrophysics Data System (ADS)

    Akdeniz, K. Gediz

    2011-11-01

    Since the world of human and whose life becomes more and more complex every day because of the digital technology and under the storm of knowledge (media, internet, governmental and non-governmental organizations, etc...) the simulation is rapidly growing in the social systems and in human behaviors. The formation of the body and mutual interactions are left to digital technological, communication mechanisms and coding the techno genetics of the body. Deconstruction begins everywhere. The linear simulation mechanism with modern realities are replaced by the disorder simulation of human behaviors with awareness realities. In this paper I would like to introduce simulation theory of "Disorder Sensitive Human Behaviors". I recently proposed this theory to critique the role of disorder human behaviors in social systems. In this theory the principle of realty is the chaotic awareness of the complexity of human systems inside of principle of modern thinking in Baudrillard's simulation theory. Proper examples will be also considered to investigate the theory.

  4. Circulatory Failure During Noninhaled Forms of Cyanide Intoxication.

    PubMed

    Haouzi, Philippe; Tubbs, Nicole; Rannals, Matthew D; Judenherc-Haouzi, Annick; Cabell, Larry A; McDonough, Joe A; Sonobe, Takashi

    2017-03-01

    Our objective was to determine how circulatory failure develops following systemic administration of potassium cyanide (KCN). We used a noninhaled modality of intoxication, wherein the change in breathing pattern would not influence the diffusion of CN into the blood, akin to the effects of ingesting toxic levels of CN. In a group of 300 to 400 g rats, CN-induced coma (CN i.p., 7 mg/kg) produced a central apnea within 2 to 3 min along with a potent and prolonged gasping pattern leading to autoresuscitation in 38% of the animals. Motor deficits and neuronal necrosis were nevertheless observed in the surviving animals. To clarify the mechanisms leading to potential autoresuscitation versus asystole, 12 urethane-anesthetized rats were then exposed to the lowest possible levels of CN exposure that would lead to breathing depression within 7 to 8 min; this dose averaged 0.375 mg/kg/min i.v. At this level of intoxication, a cardiac depression developed several minutes only after the onset of the apnea, leading to cardiac asystole as PaO2 reached value approximately 15 Torr, unless breathing was maintained by mechanical ventilation or through spontaneous gasping. Higher levels of KCN exposure in 10 animals provoked a primary cardiac depression, which led to a rapid cardiac arrest by pulseless electrical activity (PEA) despite the maintenance of PaO2 by mechanical ventilation. These effects were totally unrelated to the potassium contained in KCN. It is concluded that circulatory failure can develop as a direct consequence of CN-induced apnea but in a narrow range of exposure. In this "low" range, maintaining pulmonary gas exchange after exposure, through mechanical ventilation (or spontaneous gasping), can reverse cardiac depression and restore spontaneous breathing. At higher level of intoxication, cardiac depression is to be treated as a specific and spontaneously irreversible consequence of CN exposure, leading to a PEA.

  5. The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): first annual report.

    PubMed

    de By, Theo M M H; Mohacsi, Paul; Gummert, Jan; Bushnaq, Hasan; Krabatsch, Thomas; Gustafsson, Finn; Leprince, Pascal; Martinelli, Luigi; Meyns, Bart; Morshuis, Michiel; Netuka, Ivan; Potapov, Evgenij; Zittermann, Armin; Delmo Walter, Eva Maria; Hetzer, Roland

    2015-05-01

    The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on 10 December 2009 with the initiative of Roland Hetzer (Deutsches Herzzentrum Berlin, Berlin, Germany) and Jan Gummert (Herz- und Diabeteszentrum Nordrhein-Westfalen, Bad Oeynhausen, Germany) with 15 other founding international members. It aims to promote scientific research to improve care of end-stage heart failure patients with ventricular assist device or a total artificial heart as long-term mechanical circulatory support. Likewise, the organization aims to provide and maintain a registry of device implantation data and long-term follow-up of patients with mechanical circulatory support. Hence, EUROMACS affiliated itself with Dendrite Clinical Systems Ltd to offer its members a software tool that allows input and analysis of patient clinical data on a daily basis. EUROMACS facilitates further scientific studies by offering research groups access to any available data wherein patients and centres are anonymized. Furthermore, EUROMACS aims to stimulate cooperation with clinical and research institutions and with peer associations involved to further its aims. EUROMACS is the only European-based Registry for Patients with Mechanical Circulatory Support with rapid increase in institutional and individual membership. Because of the expeditious data input, the European Association for Cardiothoracic Surgeons saw the need to optimize the data availability and the significance of the registry to improve care of patients with mechanical circulatory support and its potential contribution to scientific intents; hence, the beginning of their alliance in 2012. This first annual report is designed to provide an overview of EUROMACS' structure, its activities, a first data collection and an insight to its scientific contributions.

  6. Heat produces uteroplacental circulatory disturbance in pregnant rats through action of corticotropin releasing hormone (CRH).

    PubMed

    Nakamura, H; Nagase, H; Ogino, K; Hatta, K; Matsuzaki, I

    2000-01-01

    There is some evidence showing an existence of corticotropin releasing hormone (CRH) and opioid peptides, including beta-endorphin (betaEP), in human placenta, whereas physiological roles of the placental peptides in response to stress remain to be elucidated. To clarify the involvement of CRH and opioid system in the uteroplacental circulation in the pregnant rats exposed to heat, we examined the effects of heat and intravenous administration of CRH receptor antagonist alpha-helical CRH (9-41) on the uteroplacental blood flow, as well as blood CRH, and blood and placental betaEP in pregnant rats. Heat did not change uterine blood flow in virgin rats, but reduced uteroplacental blood flow in pregnant rats. The reduced uteroplacental blood flow induced by heat in pregnant rats was reversed by the administration of alpha-helical CRH. Independent of the status of pregnancy, heat increased blood CRH, which was not reversed by alpha-helical CRH. Although heat did not change placental betaEP, alpha-helical CRH reduced blood and placenta betaEP in pregnant rats. These results suggest that the uteroplacental circulatory disturbance caused by heat is mediated by CRH, possibly through the involvement of CRH receptor in rat placenta. The placental opioid system seems unlikely to be involved in the mediation of uteroplacental circulation.

  7. Circulatory response and autonomic nervous activity during gum chewing.

    PubMed

    Hasegawa, Yoko; Sakagami, Joe; Ono, Takahiro; Hori, Kazuhiro; Zhang, Min; Maeda, Yoshinobu

    2009-08-01

    Mastication has been proven to enhance the systemic circulation, with circulatory responses seeming to be largely regulated by autonomic nervous activity via a more complex regulatory system than those of other activities. However, few studies have examined the relationships between changes in autonomic nervous activity and the systemic circulation that are induced by masticatory movement. We investigated changes in the systemic circulation and autonomic nervous activity during gum chewing to clarify the influence of mastication. Electrocardiograms, arterial blood pressure, and masseter electromyograms were taken while chewing gum continuously as indicators of systemic circulation in 10 healthy subjects with normal dentition. Cardiac sympathetic activity and vagus nervous activity, as well as vasomotor sympathetic nervous activity, were evaluated by fluctuation analysis of heart rate and blood pressure. Repeated analysis of variance and multiple comparisons were performed to determine chronological changes in each indicator during gum chewing. Gum chewing increased the heart rate and the mean arterial pressure. Although cardiac sympathetic activity and vagus nervous activity showed significant changes, vasomotor sympathetic nervous activity did not. These results suggest that changes in the autonomic nervous activity of the heart are mainly involved in the enhancement of systemic circulation with gum chewing. This explains some characteristics of autonomic nervous regulation in masticatory movement.

  8. Human Systems Modeling and Simulation

    DTIC Science & Technology

    2005-12-01

    individuals, organizations, and other social forms as systems of practices. A rereading of the propositional and system forms shows that they make no... social inter-dependencies that underwrite human behavior: designing, prototyping, testing and delivering extensions to Synergia’s ACCORD technology for...also and primarily the cognitive and social inter-dependencies that underwrite human behavior. • Develop technology for the computational specification

  9. Human Message Systems.

    ERIC Educational Resources Information Center

    Hopper, Robert

    A long-standing dispute over the best way to teach communication involves two major positions: teaching communication through practice/performance and teaching communication through theories and principles. This book describes both theories and practices, offering ideas within a systems framework so that each chapter introduces interacting…

  10. Human Systems Integration Requirements

    DTIC Science & Technology

    2009-09-01

    conditions? (Night, All Weather) 5. Is there special gear required that may impact task performance (Mission Oriented Protective Posture (MOPP...or from personal protective equipment? 21. Does the system meet vibration and shock requirements under all operational conditions? 22. Are there...11. Is the system’s ability to distinguish between friendly and enemy targets compatible with mission oriented protective posture level IV (MOPP

  11. Evolving experience with mechanical circulatory support.

    PubMed Central

    Kormos, R L; Borovetz, H S; Armitage, J M; Hardesty, R L; Marrone, G C; Griffith, B P

    1991-01-01

    Since 1985 total mechanical circulatory support for mortally ill transplant candidates has been progressively integrated into the authors' program. During this period 379 patients underwent transplantation. Of this group of patients, 62 required some form of mechanical support other than the intra-aortic balloon pump. Because intra-aortic balloon pump assist was limited in therapeutic effect and was associated with patient immobility and line-related sepsis, the next logical step toward support was the artificial heart. Of 20 patients implanted with the Jarvik heart, 17 underwent transplantation, but only 9 of these survived to discharge. In 1988, the authors abandoned the preferential use of the total artificial heart because of excessive cumulative probability of death from wound infection. They began to use the Novacor electrical assist device with the percutaneous power cord because they believed that univentricular support would be adequate for most patients, because its heterotopic position would reduce the likelihood of infection, and because it had the potential for chronic implantation. Twenty-three patients with biventricular failure (right ventricular ejection fraction less than 20%, 18/23) received the electrical assist device for an average of 50.4 days (range 1-193 days). All 17 transplanted patients survived until discharge. Only one of the five deaths that occurred after implantation, but without transplantation, was due to infection (candidiasis). Remarkably, all patients who survived the perioperative period ultimately survived with univentricular support alone. Based on this experience, survival of mechanically supported patients is now comparable to that of those less mortally ill. Images Fig. 3. PMID:1953099

  12. Summary of the British Transplantation Society guidelines for transplantation from donors after deceased circulatory death.

    PubMed

    Andrews, Peter A; Burnapp, Lisa; Manas, Derek

    2014-02-15

    The second edition of the British Transplantation Society Guidelines for Transplantation from Donors after Deceased Circulatory Death was published in June 2013. The guideline has been extensively revised since the previous edition in 2004 and has used the GRADE system to rate the strength of evidence and recommendations. This article summarizes the Statements of Recommendation contained in the guideline, which provide a framework for transplantation after deceased circulatory death in the U.K. and may be of wide international interest. It is recommended that the full guideline document is consulted for details of the relevant references and evidence base. This may be accessed at: http://www.bts.org.uk/MBR/Clinical/Guidelines/Current/Member/Clinical/Current_Guidelines.aspx.

  13. NASA Space Flight Human System Standards

    NASA Technical Reports Server (NTRS)

    Tillman, Barry; Pickett, Lynn; Russo, Dane; Stroud, Ken; Connolly, Jan; Foley, Tico

    2007-01-01

    NASA has begun a new approach to human factors design standards. For years NASA-STD-3000, Manned Systems Integration Standards, has been a source of human factors design guidance for space systems. In order to better meet the needs of the system developers, NASA is revising its human factors standards system. NASA-STD-3000 will be replaced by two documents: set of broad human systems specifications (including both human factors and medical topics) and a human factors design handbook

  14. Description, validation, and modification of the Guyton model for space-flight applications. Part A. Guyton model of circulatory, fluid and electrolyte control. Part B. Modification of the Guyton model for circulatory, fluid and electrolyte control

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1985-01-01

    The mathematical model that has been a cornerstone for the systems analysis of space-flight physiological studies is the Guyton model describing circulatory, fluid and electrolyte regulation. The model and the modifications that are made to permit simulation and analysis of the stress of weightlessness are described.

  15. Human System Integration: Regulatory Analysis

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This document was intended as an input to the Access 5 Policy Integrated Product team. Using a Human System Integration (HIS) perspective, a regulatory analyses of the FARS (specifically Part 91), the Airman s Information Manual (AIM) and the FAA Controllers Handbook (7110.65) was conducted as part of a front-end approach needed to derive HSI requirements for Unmanned Aircraft Systems (UAS) operations in the National Airspace System above FL430. The review of the above aviation reference materials yielded eighty-four functions determined to be necessary or highly desirable for flight within the Air Traffic Management System. They include categories for Flight, Communications, Navigation, Surveillance, and Hazard Avoidance.

  16. Development of a hybrid (numerical-hydraulic) circulatory model: prototype testing and its response to IABP assistance.

    PubMed

    Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Tosti, G; Darowski, M

    2005-07-01

    Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters)are developed in LabVIEW environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.

  17. Human Factors Considerations in System Design

    NASA Technical Reports Server (NTRS)

    Mitchell, C. M. (Editor); Vanbalen, P. M. (Editor); Moe, K. L. (Editor)

    1983-01-01

    Human factors considerations in systems design was examined. Human factors in automated command and control, in the efficiency of the human computer interface and system effectiveness are outlined. The following topics are discussed: human factors aspects of control room design; design of interactive systems; human computer dialogue, interaction tasks and techniques; guidelines on ergonomic aspects of control rooms and highly automated environments; system engineering for control by humans; conceptual models of information processing; information display and interaction in real time environments.

  18. Circulatory contributors to the phenotype in hereditary hemorrhagic telangiectasia

    PubMed Central

    Shovlin, Claire L.

    2015-01-01

    Hereditary hemorrhagic telangiectasia (HHT) is mechanistically and therapeutically challenging, not only because of the molecular and cellular perturbations that generate vascular abnormalities, but also the modifications to circulatory physiology that result, and are likely to exacerbate vascular injury. First, most HHT patients have visceral arteriovenous malformations (AVMs). Significant visceral AVMs reduce the systemic vascular resistance: supra-normal cardiac outputs are required to maintain arterial blood pressure, and may result in significant pulmonary venous hypertension. Secondly, bleeding from nasal and gastrointestinal telangiectasia leads to iron losses of such magnitude that in most cases, diet is insufficient to meet the ‘hemorrhage adjusted iron requirement.’ Resultant iron deficiency restricts erythropoiesis, leading to anemia and further increases in cardiac output. Low iron levels are also associated with venous and arterial thromboses, elevated Factor VIII, and increased platelet aggregation to circulating 5HT (serotonin). Third, recent data highlight that reduced oxygenation of blood due to pulmonary AVMs results in a graded erythrocytotic response to maintain arterial oxygen content, and higher stroke volumes and/or heart rates to maintain oxygen delivery. Finally, HHT-independent factors such as diet, pregnancy, sepsis, and other intercurrent illnesses also influence vascular structures, hemorrhage, and iron handling in HHT patients. These considerations emphasize the complexity of mechanisms that impact on vascular structures in HHT, and also offer opportunities for targeted therapeutic approaches. PMID:25914716

  19. High-risk medical devices, children and the FDA: regulatory challenges facing pediatric mechanical circulatory support devices.

    PubMed

    Almond, Christopher S D; Chen, Eric A; Berman, Michael R; Less, Joanne R; Baldwin, J Timothy; Linde-Feucht, Sarah R; Hoke, Tracey R; Pearson, Gail D; Jenkins, Kathy; Duncan, Brian W; Zuckerman, Bram D

    2007-01-01

    Pediatric mechanical circulatory support is a critical unmet need in the United States. Infant- and child-sized ventricular assist devices are currently being developed largely through federal contracts and grants through the National Heart, Lung, and Blood Institute (NHLBI). Human testing and marketing of high-risk devices for children raises epidemiologic and regulatory issues that will need to be addressed. Leaders from the US Food and Drug Administration (FDA), NHLBI, academic pediatric community, and industry convened in January 2006 for the first FDA Workshop on the Regulatory Process for Pediatric Mechanical Circulatory Support Devices. The purpose was to provide the pediatric community with an overview of the federal regulatory process for high-risk medical devices and to review the challenges specific to the development and regulation of pediatric mechanical circulatory support devices. Pediatric mechanical circulatory support present significant epidemiologic, logistic, and financial challenges to industry, federal regulators, and the pediatric community. Early interactions with the FDA, shared appreciation of challenges, and careful planning will be critical to avoid unnecessary delays in making potentially life-saving devices available for children. Collaborative efforts to address these challenges are warranted.

  20. Circulatory death determination in uncontrolled organ donors: a panel viewpoint.

    PubMed

    Bernat, James L; Bleck, Thomas P; Blosser, Sandralee A; Bratton, Susan L; Capron, Alexander M; Cornell, Danielle; DeVita, Michael A; Fulda, Gerard J; Glazier, Alexandra K; Gries, Cynthia J; Mathur, Mudit; Nakagawa, Thomas A; Shemie, Sam D

    2014-04-01

    One barrier for implementing programs of uncontrolled organ donation after the circulatory determination of death is the lack of consensus on the precise moment of death. Our panel was convened to study this question after we performed a similar analysis on the moment of death in controlled organ donation after the circulatory determination of death. We concluded that death could be determined by showing the permanent or irreversible cessation of circulation and respiration. Circulatory irreversibility may be presumed when optimal cardiopulmonary resuscitation efforts have failed to restore circulation and at least a 7-minute period has elapsed thereafter during which autoresuscitation to restored circulation could occur. We advise against the use of postmortem organ support technologies that reestablish circulation of warm oxygenated blood because of their risk of retroactively invalidating the required conditions on which death was declared.

  1. H2S during circulatory shock: Some unresolved questions

    PubMed Central

    McCook, Oscar; Radermacher, Peter; Volani, Chiara; Asfar, Pierre; Ignatius, Anita; Kemmler, Julia; Möller, Peter; Szabó, Csaba; Whiteman, Matthew; Wood, Mark E.; Wang, Rui; Georgieff, Michael; Wachter, Ulrich

    2014-01-01

    Numerous papers have been published on the role of H2S during circulatory shock. Consequently, knowledge about vascular sulfide concentrations may assume major importance, in particular in the context of “acute on chronic disease”, i.e., during circulatory shock in animals with pre-existing chronic disease. This review addresses the questions i) of the “real” sulfide levels during circulatory shock, and, ii) to which extent injury and pre-existing co-morbidity may affect the expression of H2S producing enzymes under these conditions. In the literature there is a huge range on sulfide blood levels during circulatory shock, in part as a result of the different analytical methods used, but also due to the variable of the models and species studied. Clearly, some of the very high levels reported should be questioned in the context of the well-known H2S toxicity. As long as “real” sulfide levels during circulatory shock are unknown and/or undetectable “on line” due to the lack of appropriate techniques, it appears to be premature to correlate the measured blood levels of hydrogen sulfide with the severity of shock or the H2S therapy-related biological outcomes. The available data on the tissue expression of the H2S-releasing enzymes during circulatory shock suggest that a “constitutive” CSE expression may play a crucial role of for the maintenance of organ function, at least in the kidney. The data also indicate that increased CBS and CSE expression, in particular in the lung and the liver, represents an adaptive response to stress states. PMID:24650697

  2. Human-system Interfaces for Automatic Systems

    SciTech Connect

    OHara, J.M.; Higgins,J.; Fleger, S.; Barnes V.

    2010-11-07

    Automation is ubiquitous in modern complex systems, and commercial nuclear- power plants are no exception. Automation is applied to a wide range of functions including monitoring and detection, situation assessment, response planning, and response implementation. Automation has become a 'team player' supporting personnel in nearly all aspects of system operation. In light of its increasing use and importance in new- and future-plants, guidance is needed to conduct safety reviews of the operator's interface with automation. The objective of this research was to develop such guidance. We first characterized the important HFE aspects of automation, including six dimensions: levels, functions, processes, modes, flexibility, and reliability. Next, we reviewed literature on the effects of all of these aspects of automation on human performance, and on the design of human-system interfaces (HSIs). Then, we used this technical basis established from the literature to identify general principles for human-automation interaction and to develop review guidelines. The guidelines consist of the following seven topics: automation displays, interaction and control, automation modes, automation levels, adaptive automation, error tolerance and failure management, and HSI integration. In addition, our study identified several topics for additional research.

  3. Is moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion superior to deep hypothermic circulatory arrest in elective aortic arch surgery?

    PubMed

    Poon, Shi Sum; Estrera, Anthony; Oo, Aung; Field, Mark

    2016-09-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether moderate hypothermia circulatory arrest with selective antegrade cerebral perfusion (SACP) is more beneficial than deep hypothermic circulatory arrest in elective aortic arch surgery. Altogether, 1028 papers were found using the reported search, of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There were four retrospective observational studies, one prospective randomized controlled trial and one meta-analysis study. There were no local or neuromuscular complications related to axillary arterial cannulation reported. In the elective setting, four studies showed that the in-hospital mortality for moderate hypothermia is consistently low, ranging from 1.0 to 4.3%. In a large series of hemiarch replacement comparing 682 cases of deep hypothermia with 94 cases of moderate hypothermia with SACP, 20 cases (2.8%) of permanent neurological deficit were reported, compared to 3 cases (3.2%) in moderate hypothermia. Three observational studies and a meta-analysis study did not identify an increased risk of postoperative renal failure and dialysis following either deep or moderate hypothermia although a higher incidence of stroke was reported in the meta-analysis study with deep hypothermia (12.7 vs 7.3%). Longer cardiopulmonary bypass time and circulatory arrest time were reported in four studies for deep hypothermia, suggesting an increased time required for systemic cooling and rewarming in that group. Overall, these findings suggested that in elective aortic arch surgery, moderate hypothermia with selective antegrade cerebral perfusion adapted to the duration of circulatory arrest can be performed safely with acceptable mortality and morbidity outcomes. The risk of spinal cord

  4. A Human Body Analysis System

    NASA Astrophysics Data System (ADS)

    Girondel, Vincent; Bonnaud, Laurent; Caplier, Alice

    2006-12-01

    This paper describes a system for human body analysis (segmentation, tracking, face/hands localisation, posture recognition) from a single view that is fast and completely automatic. The system first extracts low-level data and uses part of the data for high-level interpretation. It can detect and track several persons even if they merge or are completely occluded by another person from the camera's point of view. For the high-level interpretation step, static posture recognition is performed using a belief theory-based classifier. The belief theory is considered here as a new approach for performing posture recognition and classification using imprecise and/or conflicting data. Four different static postures are considered: standing, sitting, squatting, and lying. The aim of this paper is to give a global view and an evaluation of the performances of the entire system and to describe in detail each of its processing steps, whereas our previous publications focused on a single part of the system. The efficiency and the limits of the system have been highlighted on a database of more than fifty video sequences where a dozen different individuals appear. This system allows real-time processing and aims at monitoring elderly people in video surveillance applications or at the mixing of real and virtual worlds in ambient intelligence systems.

  5. Optical spectroscopic assessment of free flap circulatory impairment

    NASA Astrophysics Data System (ADS)

    Sowa, Michael G.; Payette, Jeri R.; Kohlenberg, Elicia; Leonardi, Lorenzo; Pabbies, Arone; Kerr, Paul

    2004-10-01

    Free flaps are used to reconstruct tissue damaged by injury. Circulatory impairment of the free flap is the leading cause of a failed flap surgery. This study demonstrates that optical spectroscopy can detect early signs of circulatory impairment and distinguish between arterial or venous blockage. An epigastric flap model is used to mimic conditions of both arterial and venous circulatory impairment. Animals were divided into three groups 1.) arterial occlusion (n=5), 2.) venous occlusion (n=4), and 3.) control (n=5). A classifier was applied to the reflectance data to determine whether there were consistent differences between the three study groups. The classifier was able to distinguish between arterial occlusion, venous occlusion and healthy flaps with a 95% accuracy. Measures of hemoglobin oxygen saturation and blood volume were derived from the same reflectance data. Oxygenation of the flap was significantly lower during venous or arterial occlusion compared to control flaps. Blood volume of the free flap went up significantly following venous blockage while blockage of the artery cause a significant drop in blood volume. Combining the predictions of the classifier and examining the oxygenation and blood volume parameters reliably detected circulatory impairment of the free flap.

  6. Mechanical circulatory support for elderly heart failure patients.

    PubMed

    Butler, Craig R; Jugdutt, Bodh I

    2012-09-01

    End-stage systolic heart failure is an increasingly common problem in elderly patients and is associated with high cost, poor quality of life, and poor outcomes. Mechanical circulatory support is a promising therapy as both a bridge to transplantation and destination therapy. Elderly patients are frequently ineligible for heart transplantation because of their age and comorbidities, and the application of mechanical circulatory support for destination therapy in this population is not well defined. A review of the literature was undertaken to better characterize our experience to date with mechanical circulatory support in older heart failure populations. Mechanical circulatory support is being employed increasingly for destination therapy indications in older patients. The newer continuous flow devices appear to have disproportionate advantage in elderly patients, which has translated into marked improvement in 1- and 2-year survival. The rational implementation of MCS devices in elderly heart failure patients needs to focus on (1) continuous flow devices that appear to have particular benefit in this population, (2) extensive pre-MCS assessment including variables relating to frailty, and (3) intervening before these patients develop cardiogenic shock. More data are needed on the cost-benefit analysis of routine use of CF devices as destination therapy in elderly patients with heart failure.

  7. [Cerebral oximetry in pulmonary thromboendarterectomy with circulatory arrest].

    PubMed

    Catalán Escudero, P; González Román, A; Serra Ruiz, C N; Barbero Mielgo, M; García Fernández, J

    2014-02-01

    Pulmonary thromboendarterectomy is an uncommon procedure and should be performed with circulatory arrest. One of the major concerns is the postoperative central neurological injuries. Perioperative brain oxygen monitoring is advisable in this surgical procedure for the early detection of brain hypoperfusion episodes and their intensity as well as any other postoperative episodes that can deteriorate the neurological outcome.

  8. Mechanical circulatory support for infants and small children.

    PubMed

    Gournay, Véronique; Hauet, Quentin

    2014-01-01

    The number of children in need of mechanical circulatory support has increased substantially over the last two decades, due to the technological progress made in surgery and intensive care, leading to improved survival of patients with congenital heart disease. In addition, primary myocardial dysfunction related to myocarditis or dilated cardiomyopathy may cause end-stage cardiac failure in children or infants, although not as frequently as in adults. The need for mechanical circulatory support may be either temporary until spontaneous myocardial recovery, as in postcardiotomy cardiac failure, or prolonged until heart transplantation in the absence of recovery. Two types of mechanical circulatory devices are suitable for the paediatric population: extracorporeal membrane oxygenation for short-term support; and ventricular assist devices for long-term support as a bridge to transplantation. The aim of this review is to describe the specific issues related to paediatric mechanical circulatory support and the different types of devices available, to report on their rapidly growing use worldwide and on the outcomes for each indication and type of device, and to provide a perspective on the future developments and remaining challenges in this field.

  9. Circulatory disease mortality in the Massachusetts tuberculosis fluoroscopy cohort study.

    PubMed

    Little, Mark P; Zablotska, Lydia B; Brenner, Alina V; Lipshultz, Steven E

    2016-03-01

    High-dose ionizing radiation is associated with circulatory disease. Risks from lower-dose fractionated exposures, such as from diagnostic radiation procedures, remain unclear. In this study we aimed to ascertain the relationship between fractionated low-to-medium dose radiation exposure and circulatory disease mortality in a cohort of 13,568 tuberculosis patients in Massachusetts, some with fluoroscopy screenings, between 1916 and 1961 and follow-up until the end of 2002. Analysis of mortality was in relation to cumulative thyroid (cerebrovascular) or lung (all other circulatory disease) radiation dose via Poisson regression. Over the full dose range, there was no overall radiation-related excess risk of death from circulatory disease (n = 3221; excess relative risk/Gy -0.023; 95% CI -0.067, 0.028; p = 0.3574). Risk was somewhat elevated in hypertensive heart disease (n = 89; excess relative risk/Gy 0.357; 95% CI -0.043, 1.030, p = 0.0907) and slightly decreased in ischemic heart disease (n = 1950; excess relative risk/Gy -0.077; 95% CI -0.130, -0.012; p = 0.0211). However, under 0.5 Gy, there was a borderline significant increasing trend for all circulatory disease (excess relative risk/Gy 0.345; 95% CI -0.032, 0.764; p = 0.0743) and for ischemic heart disease (excess relative risk/Gy 0.465; 95% CI, -0.032, 1.034, p = 0.0682). Pneumolobectomy increased radiation-associated risk (excess relative risk/Gy 0.252; 95% CI 0.024, 0.579). Fractionation of dose did not modify excess risk. In summary, we found no evidence of radiation-associated excess circulatory death risk overall, but there are indications of excess circulatory death risk at lower doses (<0.5 Gy). Although consistent with other radiation-exposed groups, the indications of higher risk at lower doses are unusual and should be confirmed against other data.

  10. APPLICATION OF OPTIMAL CONTROL THEORY TO CARDIO-CIRCULATORY ASSIST DEVICES.

    DTIC Science & Technology

    The objective of the investigation is the application of, and where necessary, extension of optimal control theory to the synthesis of controllers for such cardio-circulatory assist devices. In particular, the concept of set of attainability is extended to include linear, periodic, bounded control systems and the maximum principle applied to obtain necessary and sufficient conditions for various problems. In addition to several numerical examples, the results of a large-scale hybrid simulation for a cardiovascular model and particular assist device are presented.

  11. Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability.

    PubMed

    Wang, Jake X; Smith, Joshua R; Bonde, Pramod

    2014-04-01

    Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources.

  12. Addressing Consent Issues in Donation After Circulatory Determination of Death.

    PubMed

    Overby, Kim J; Weinstein, Michael S; Fiester, Autumn

    2015-01-01

    Given the widening gap between the number of individuals on transplant waiting lists and the availability of donated organs, as well as the recent plateau in donations based on neurological criteria (i.e., brain death), there has been a growing interest in expanding donation after circulatory determination of death. While the prevalence of this form of organ donation continues to increase, many thorny ethical issues remain, often creating moral distress in both clinicians and families. In this article, we address one of these issues, namely, the challenges surrounding patient and surrogate informed consent for donation after circulatory determination of death. First we discuss several general concerns regarding consent related to this form of organ donation, and then we address additional issues that are unique to three different patient categories: adult patients with medical decision-making capacity or potential capacity, adult patients who lack capacity, and pediatric patients.

  13. Architecting Systems for Human Space Flight

    NASA Technical Reports Server (NTRS)

    Wocken, Gerald

    2002-01-01

    Human-system interactions have been largely overlooked in the traditional systems engineering process. Awareness of human factors (HF) has increased in the past few years, but the involvement of HF specialists is still often too little and too late. In systems involving long-duration human space flight, it is essential that the human component be properly considered in the initial architectural definition phase, as well as throughout the system design process. HF analysis must include not only the strengths and limitations of humans in general, but the variability between individuals and within an individual over time, and the dynamics of group interactions.

  14. Ocular circulatory responses to exhaustive exercise in humans.

    PubMed

    Ikemura, Tsukasa; Hayashi, Naoyuki

    2012-09-01

    It is unclear whether exhaustive dynamic exercise increases ocular blood flow, although we have reported that submaximal exercise increases ocular blood flow. We hypothesized that ocular blood flow decreases at exhaustion, since exhaustion causes hyperventilation, which induces a reduction in PaCO(2). To test this hypothesis, ocular blood flow, blood pressure, and respiratory measurements were made in 12 healthy male subjects during cycle ergometer exercise at 75% of maximal heart rate, until exhaustion. Blood flows in the retinal and choroidal vasculature (RCV), the superior temporal retinal arteriole (STRA), and the superior nasal retinal arteriole (SNRA) were measured with the aid of laser-speckle flowgraphy every 3 min during the exercise. The conductance index (CI) in the ocular vasculature was calculated by dividing the blood flow by the mean arterial pressure (MAP). The mean arterial partial pressure of CO(2) (PaCO(2)) was estimated from tidal volume and end-tidal CO(2) partial pressure. MAP significantly increased from the resting baseline throughout the exercise, while PaCO(2) was significantly decreased at exhaustion and during the recovery period. By 6 min after the onset of exercise, blood flow velocity in the RCV significantly increased by 32 ± 6% (mean ± SD) from the resting baseline value. At exhaustion, blood flow velocity in the RCV did not differ significantly from the resting baseline value, and the STRA blood flow was significantly decreased by 13 ± 4%. The CIs in the RCV, STRA, and SNRA were significantly decreased compared to baseline at exhaustion. These findings suggest that ocular blood flow is increased by submaximal exercise, whereas it is suppressed by the hypocapnia associated with exhaustion.

  15. Circulatory shear flow alters the viability and proliferation of circulating colon cancer cells

    NASA Astrophysics Data System (ADS)

    Fan, Rong; Emery, Travis; Zhang, Yongguo; Xia, Yuxuan; Sun, Jun; Wan, Jiandi

    2016-06-01

    During cancer metastasis, circulating tumor cells constantly experience hemodynamic shear stress in the circulation. Cellular responses to shear stress including cell viability and proliferation thus play critical roles in cancer metastasis. Here, we developed a microfluidic approach to establish a circulatory microenvironment and studied circulating human colon cancer HCT116 cells in response to a variety of magnitude of shear stress and circulating time. Our results showed that cell viability decreased with the increase of circulating time, but increased with the magnitude of wall shear stress. Proliferation of cells survived from circulation could be maintained when physiologically relevant wall shear stresses were applied. High wall shear stress (60.5 dyne/cm2), however, led to decreased cell proliferation at long circulating time (1 h). We further showed that the expression levels of β-catenin and c-myc, proliferation regulators, were significantly enhanced by increasing wall shear stress. The presented study provides a new insight to the roles of circulatory shear stress in cellular responses of circulating tumor cells in a physiologically relevant model, and thus will be of interest for the study of cancer cell mechanosensing and cancer metastasis.

  16. Feedbacks in human-landscape systems.

    PubMed

    Chin, Anne; Florsheim, Joan L; Wohl, Ellen; Collins, Brian D

    2014-01-01

    This article identifies key questions and challenges for geomorphologists in investigating coupled feedbacks in human-landscape systems. While feedbacks occur in the absence of human influences, they are also altered by human activity. Feedbacks are a key element to understanding human-influenced geomorphic systems in ways that extend our traditional approach of considering humans as unidirectional drivers of change. Feedbacks have been increasingly identified in Earth-environmental systems, with studies of coupled human-natural systems emphasizing ecological phenomena in producing emerging concepts for social-ecological systems. Enormous gaps or uncertainties in knowledge remain with respect to understanding impact-feedback loops within geomorphic systems with significant human alterations, where the impacted geomorphic systems in turn affect humans. Geomorphology should play an important role in public policy by identifying the many diffuse and subtle feedbacks of both local- and global-scale processes. This role is urgent, while time may still be available to mitigate the impacts that limit the sustainability of human societies. Challenges for geomorphology include identification of the often weak feedbacks that occur over varied time and space scales ranging from geologic time to single isolated events and very short time periods, the lack of available data linking impact with response, the identification of multiple thresholds that trigger feedback mechanisms, the varied tools and metrics needed to represent both physical and human processes, and the need to collaborate with social scientists with expertise in the human causes of geomorphic change, as well as the human responses to such change.

  17. Human Factors Interface with Systems Engineering for NASA Human Spaceflights

    NASA Technical Reports Server (NTRS)

    Wong, Douglas T.

    2009-01-01

    This paper summarizes the past and present successes of the Habitability and Human Factors Branch (HHFB) at NASA Johnson Space Center s Space Life Sciences Directorate (SLSD) in including the Human-As-A-System (HAAS) model in many NASA programs and what steps to be taken to integrate the Human-Centered Design Philosophy (HCDP) into NASA s Systems Engineering (SE) process. The HAAS model stresses systems are ultimately designed for the humans; the humans should therefore be considered as a system within the systems. Therefore, the model places strong emphasis on human factors engineering. Since 1987, the HHFB has been engaging with many major NASA programs with much success. The HHFB helped create the NASA Standard 3000 (a human factors engineering practice guide) and the Human Systems Integration Requirements document. These efforts resulted in the HAAS model being included in many NASA programs. As an example, the HAAS model has been successfully introduced into the programmatic and systems engineering structures of the International Space Station Program (ISSP). Success in the ISSP caused other NASA programs to recognize the importance of the HAAS concept. Also due to this success, the HHFB helped update NASA s Systems Engineering Handbook in December 2007 to include HAAS as a recommended practice. Nonetheless, the HAAS model has yet to become an integral part of the NASA SE process. Besides continuing in integrating HAAS into current and future NASA programs, the HHFB will investigate incorporating the Human-Centered Design Philosophy (HCDP) into the NASA SE Handbook. The HCDP goes further than the HAAS model by emphasizing a holistic and iterative human-centered systems design concept.

  18. Fundamentals of systems ergonomics/human factors.

    PubMed

    Wilson, John R

    2014-01-01

    Ergonomics/human factors is, above anything else, a systems discipline and profession, applying a systems philosophy and systems approaches. Many things are labelled as system in today's world, and this paper specifies just what attributes and notions define ergonomics/human factors in systems terms. These are obviously a systems focus, but also concern for context, acknowledgement of interactions and complexity, a holistic approach, recognition of emergence and embedding of the professional effort involved within organization system. These six notions are illustrated with examples from a large body of work on rail human factors.

  19. What Research Says: The Cardiovascular System: Children's Conceptions and Misconceptions.

    ERIC Educational Resources Information Center

    Arnaudin, Mary W.; Mintzes, Joel J.

    1986-01-01

    Reports findings of a study on children's perceptions and alternate conceptions about the human circulatory system. Summarizes the responses of fifth and eighth grade students on questions dealing with the heart and blood. Offers examples of hands-on activities and confrontation strategies that address common misconceptions on circulation. (ML)

  20. Circulatory response to hyperthermia during acute normovolaemic haemodilution

    NASA Astrophysics Data System (ADS)

    Talwar, Anita; Fahim, M.

    Cats anaesthetized with a mixture of chloralose and urethane were exposed to heat stress in two groups. In the first group (n=10) of control animals, the effect of heat stress on haemodynamic variables was recorded at control haematocrit (HCT) of 42.0+/-1.0%. In a second group, the effect of heat stress was studied after induction of acute normovolaemic haemodilution (HCT of 13.0+/-1.0%). Haemodilution was induced to a maximum of 60% replacement of blood with dextran (mol.wt. 150000). Heat stress was induced by surface heating and core body temperature was raised from 37° C to 42° C. The effect of heat stress and haemodilution on various haemodynamic variables, viz. left ventricular pressure (LVP), left ventricular contractility (LVdP/dtmax), heart rate (HR), cardiac output (CO), arterial blood pressure (ABP), right atrial pressure (RAP), and arterial blood PO2, PCO2 and pH was examined. Haemodilution produced significant (P<0.05) increases in HR and CO but there were no significant (P>0.05) changes in ABP, RAP, LVdP/dtmax and total peripherial resistance (TPR). Hyperthermia caused a significant fall (P<0.05) in TPR. However, the percentage fall in TPR was higher in the control group. On exposure to heat stress, there were significant (P<0.05I increases in HR and CO in both the groups; however, HR and CO values were significantly (P<0.05) higher in the haemodiluted group compared to the control. The latter findings could be due either to the higher basal values of these variables with the fall in HCT or to inefficient cardiovascular regulatory mechanisms. The lack of efficient regulatory control under such severe stress conditions makes the cardiovascular system of anaemic animals more vulnerable to heat stress. In conclusion, the results of the present study showed deleterious effects of heat stress in both the groups. The higher values of HR and CO in the haemodiluted group may be responsible for circulatory failure at low HCT values, indicating a higher risk

  1. Circulatory Shock. Volume 27, Number 4, 1989

    DTIC Science & Technology

    1990-02-01

    19107. Recent reports suggest that circulating endogenous opiates may influence cardiac function. We have investigated the presence of beta -endorphin...cardiac BE to its precursor, beta -lipotropin4 (BLPH), was significantly elevated for AC rats (1.691-0.06 vs 1.1710.06, AC vs So, respectively, pɘ.001). The... glucan ) or saline infusion (control). TABLE. Effect of Macrophage DAYS POST-G/UCAN CHALLENGE 1 2 3 4 5 Activation on systemic host- BLOOD MONONUCLEAR

  2. [Effect of noise on circulatory disorders].

    PubMed

    Reinharez, D

    1989-01-01

    The author reports a dramatic case of severe functional and trophic disorders of the lower limbs which proved to be entirely caused by noise. This case led him to study noise and its repercussions on the vascular system: physical characteristics, methods of measurement, epidemiology of this environmental nuisance, general and vascular diseases produced by the traumatic-vibration syndrome, and study of its mechanism of action. He concludes by calling for interdisciplinary action to combine fundamental research, screening and prevention of the disorders caused by noise.

  3. Recent advances in computational methodology for simulation of mechanical circulatory assist devices

    PubMed Central

    Marsden, Alison L.; Bazilevs, Yuri; Long, Christopher C.; Behr, Marek

    2014-01-01

    Ventricular assist devices (VADs) provide mechanical circulatory support to offload the work of one or both ventricles during heart failure. They are used in the clinical setting as destination therapy, as bridge to transplant, or more recently as bridge to recovery to allow for myocardial remodeling. Recent developments in computational simulation allow for detailed assessment of VAD hemodynamics for device design and optimization for both children and adults. Here, we provide a focused review of the recent literature on finite element methods and optimization for VAD simulations. As VAD designs typically fall into two categories, pulsatile and continuous flow devices, we separately address computational challenges of both types of designs, and the interaction with the circulatory system with three representative case studies. In particular, we focus on recent advancements in finite element methodology that has increased the fidelity of VAD simulations. We outline key challenges, which extend to the incorporation of biological response such as thrombosis and hemolysis, as well as shape optimization methods and challenges in computational methodology. PMID:24449607

  4. Do the Spatial Features of an Adjunct Display that Readers Complete while Reading Affect Their Understanding of a Complex System?

    ERIC Educational Resources Information Center

    McCrudden, Matthew T.; McCormick, Montana K.; McTigue, Erin T.

    2011-01-01

    We varied the spatial features of adjunct displays that depicted a complex scientific system (i.e. human circulatory system). University students (n = 47), who were assigned randomly to a display condition before reading, selected relevant information from the text and wrote it (a) next to a list of definitions (list condition), (b) inside boxes…

  5. (PCG) Protein Crystal Growth Human Serum Albumin

    NASA Technical Reports Server (NTRS)

    1989-01-01

    (PCG) Protein Crystal Growth Human Serum Albumin. Contributes to many transport and regulatory processes and has multifunctional binding properties which range from various metals, to fatty acids, hormones, and a wide spectrum of therapeutic drugs. The most abundant protein of the circulatory system. It binds and transports an incredible variety of biological and pharmaceutical ligands throughout the blood stream. Principal Investigator on STS-26 was Larry DeLucas.

  6. The Human-Robot Interaction Operating System

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Kunz, Clayton; Hiatt, Laura M.; Bugajska, Magda

    2006-01-01

    In order for humans and robots to work effectively together, they need to be able to converse about abilities, goals and achievements. Thus, we are developing an interaction infrastructure called the "Human-Robot Interaction Operating System" (HRI/OS). The HRI/OS provides a structured software framework for building human-robot teams, supports a variety of user interfaces, enables humans and robots to engage in task-oriented dialogue, and facilitates integration of robots through an extensible API.

  7. Epigenetic Systems View of Human Development.

    ERIC Educational Resources Information Center

    Gottlieb, Gilbert

    1991-01-01

    Discusses the history of the hierarchical epigenetic systems view as applied to human development and offers examples of its implementation. Notes the agreement by many authors that the multilevel systems view is the right model for developmental psychology in both human and animal studies. (BC)

  8. Recommendations for donation after circulatory death kidney transplantation in Europe.

    PubMed

    van Heurn, L W Ernest; Talbot, David; Nicholson, Michael L; Akhtar, Mohammed Z; Sanchez-Fructuoso, Ana I; Weekers, Laurent; Barrou, Benoit

    2016-07-01

    Donation after circulatory death (DCD) donors provides an invaluable source for kidneys for transplantation. Over the last decade, we have observed a substantial increase in the number of DCD kidneys, particularly within Europe. We provide an overview of risk factors associated with DCD kidney function and survival and formulate recommendations from the sixth international conference on organ donation in Paris, for best-practice guidelines. A systematic review of the literature was performed using Ovid Medline, Embase and Cochrane databases. Topics are discussed, including donor selection, organ procurement, organ preservation, recipient selection and transplant management.

  9. Parking Assistance Systems using Human Guidance

    NASA Astrophysics Data System (ADS)

    Wada, Massaki; Yoon, Kang Sup; Hashimoto, Hideki

    This paper dicusses the problem of parking assistance system development. Firstly, we propose the driver assistance systems general architecture based on path planning and human interface modules. A path generation method based on parking possibility area is developed for the parking assistance systems. The human interface designed for the parking assistance systems is then described. A prototype of the parking assistance systems based on the proposed architecture and approaches have been constructed. Proposed algorithms and implementation solutions in the prototype construction are described. The lane and row parking experimental results obtained with the prototype systems are also shown.

  10. Human Systems Integration in the Federal Government

    NASA Technical Reports Server (NTRS)

    Jones, Patricia M.; Graves, Gaye L.; Allard, Terry; Blackhurst, Jack; Fitts, David J.; Peters, Sean; Piccione, Dino; Shattuck, Lawrence G.

    2010-01-01

    Human Systems Integration principles and methods can be used to help integrate people, technology, and organizations in an effective and efficient manner. Over the past decade, a wide range of tools, techniques, and technologies have been developed by federal agencies to achieve significant cost and performance benefits. In this discussion, we will explore trends in military human systems integration and learn about the critical role being played by human performance and effectiveness research. We will also examine case studies on the planning and design of future human space flight vehicles, the national air space system and the first nuclear reactors to be built in the United States in over 30 years. And with an eye toward sustaining the discipline s principles and methods, we ll take a look at educating and training the next generation of human systems integration practitioners.

  11. Stupid Tutoring Systems, Intelligent Humans

    ERIC Educational Resources Information Center

    Baker, Ryan S.

    2016-01-01

    The initial vision for intelligent tutoring systems involved powerful, multi-faceted systems that would leverage rich models of students and pedagogies to create complex learning interactions. But the intelligent tutoring systems used at scale today are much simpler. In this article, I present hypotheses on the factors underlying this development,…

  12. Human System Drivers for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Kundrot, Craig E.; Steinberg, Susan; Charles, John B.

    2010-01-01

    Evaluation of DRM4 in terms of the human system includes the ability to meet NASA standards, the inclusion of the human system in the design trade space, preparation for future missions and consideration of a robotic precursor mission. Ensuring both the safety and the performance capability of the human system depends upon satisfying NASA Space Flight Human System Standards.1 These standards in turn drive the development of program-specific requirements for Near-earth Object (NEO) missions. In evaluating DRM4 in terms of these human system standards, the currently existing risk models, technologies and biological countermeasures were used. A summary of this evaluation is provided below in a structure that supports a mission architecture planning activities. 1. Unacceptable Level of Risk The duration of the DRM4 mission leads to an unacceptable level of risk for two aspects of human system health: A. The permissible exposure limit for space flight radiation exposure (a human system standard) would be exceeded by DRM4. B. The risk of visual alterations and abnormally high intracranial pressure would be too high. 1

  13. Feedbacks in human-landscape systems

    NASA Astrophysics Data System (ADS)

    Chin, Anne

    2015-04-01

    As human interactions with Earth systems intensify in the "Anthropocene", understanding the complex relationships among human activity, landscape change, and societal responses to those changes is increasingly important. Interdisciplinary research centered on the theme of "feedbacks" in human-landscape systems serves as a promising focus for unraveling these interactions. Deciphering interacting human-landscape feedbacks extends our traditional approach of considering humans as unidirectional drivers of change. Enormous challenges exist, however, in quantifying impact-feedback loops in landscapes with significant human alterations. This paper illustrates an example of human-landscape interactions following a wildfire in Colorado (USA) that elicited feedback responses. After the 2012 Waldo Canyon Fire, concerns for heightened flood potential and debris flows associated with post-fire hydrologic changes prompted local landowners to construct tall fences at the base of a burned watershed. These actions changed the sediment transport regime and promoted further landscape change and human responses in a positive feedback cycle. The interactions ultimately increase flood and sediment hazards, rather than dampening the effects of fire. A simple agent-based model, capable of integrating social and hydro-geomorphological data, demonstrates how such interacting impacts and feedbacks could be simulated. Challenges for fully capturing human-landscape feedback interactions include the identification of diffuse and subtle feedbacks at a range of scales, the availability of data linking impact with response, the identification of multiple thresholds that trigger feedback mechanisms, and the varied metrics and data needed to represent both the physical and human systems. By collaborating with social scientists with expertise in the human causes of landscape change, as well as the human responses to those changes, geoscientists could more fully recognize and anticipate the coupled

  14. The French airbridge for circulatory support in the Carribean†

    PubMed Central

    Lebreton, Guillaume; Sanchez, Bruno; Hennequin, Jean-Luc; Resière, Dabor; Hommel, Didier; Léonard, Christian; Mehdaoui, Hossein; Roques, François

    2012-01-01

    OBJECTIVES We report the assessment and the activities for the first year of our airborne circulatory support mobile unit (CSMU) in the French Caribbean. METHODS From January 2010 to June 2011, 12 patients (mean age = 35.7 years; range: 15–62 years; sex ratio = 1:1) were attended outside Martinique by our CSMU and transferred to our unit by air. RESULTS Eight patients had acute respiratory distress syndrome and were assisted by veno-venous extra corporeal membrane oxygenation (ECMO) four had refractory cardiogenic shock, assisted by extra corporeal life support (ECLS). The average air transfer distance for patients was 912 km (range: 198–1585 km). The average flying time was 124 min (range: 45–255 min). The aircraft used were heliciopter, military transport or private jet. The setting-up of assistance devices and transfer of patients was uneventful. One patient subsequently benefited from heart transplantation after long-term circulatory support. One patient died under ECMO support after 51 days of assistance and another died on the 60th day after withdrawal of ECLS. CONCLUSIONS CSMUs can be very efficient in providing support to patients in refractory shock, when remote from a cardiac surgery centre. The airborne transfer of patients on ECMO/ECLS can be achieved safely, even over long distances. PMID:22659268

  15. Development of an implantable centrifugal blood pump for circulatory assist.

    PubMed

    Wakisaka, Y; Taenaka, Y; Chikanari, K; Okuzono, Y; Endo, S; Takano, H

    1997-01-01

    An implantable centrifugal pump (ICP) for prolonged circulatory assist has been developed, at 320 ml and 830 g. A central balancing hole was made in its impeller for better antithrombogenicity. Waterproofing and histocompatibility were supported by a silicone seal and a casing made of titanium and acrylic resin. Overall efficiency was 30% and normalized index of homolysis was 0.003 mg/dl, the same value as the BP-80, at a flow rate of 5 L/min and a head of 100 mmHg. Antithrombogenicity and hemolytic properties of the ICP were investigated in paracorporeal implantation in three goats (61-71 kg). Exothermicity, anatomic fit, and water tightness of the ICP were evaluated in intrathoracic implantation in an adult goat (66 kg). The ICP could run paracorporeally for 50, 200, and 381 days. There was no thrombus in the ICP after 381 days' pumping, and the ICP could run in the chest cavity for 40 days. The temperature of the motor rose 1.8 +/- 0.3 degrees C from that of the pleura. Moisture content of the seal remained normal. The ICP was completely covered with smooth fibrous tissue. Although a small area of atelectasis was found in the lingula, neither lung adhesion nor necrosis of the chest wall was observed. The ICP has satisfactory antithrombogenicity, hemolytic property, water tightness, anatomic fit, and exothermicity for use as an implantable circulatory assist device.

  16. Ethical controversies in organ donation after circulatory death.

    PubMed

    2013-05-01

    The persistent mismatch between the supply of and need for transplantable organs has led to efforts to increase the supply, including controlled donation after circulatory death (DCD). Controlled DCD involves organ recovery after the planned withdrawal of life-sustaining treatment and the declaration of death according to the cardiorespiratory criteria. Two central ethical issues in DCD are when organ recovery can begin and how to manage conflicts of interests. The "dead donor rule" should be maintained, and donors in cases of DCD should only be declared dead after the permanent cessation of circulatory function. Permanence is generally established by a 2- to 5-minute waiting period. Given ongoing controversy over whether the cessation must also be irreversible, physicians should not be required to participate in DCD. Because the preparation for organ recovery in DCD begins before the declaration of death, there are potential conflicts between the donor's and recipient's interests. These conflicts can be managed in a variety of ways, including informed consent and separating the various participants' roles. For example, informed consent should be sought for premortem interventions to improve organ viability, and organ procurement organization personnel and members of the transplant team should not be involved in the discontinuation of life-sustaining treatment or the declaration of death. It is also important to emphasize that potential donors in cases of DCD should receive integrated interdisciplinary palliative care, including sedation and analgesia.

  17. NASA Human System Risk Assessment Process

    NASA Technical Reports Server (NTRS)

    Francisco, D.; Romero, E.

    2016-01-01

    NASA utilizes an evidence based system to perform risk assessments for the human system for spaceflight missions. The center of this process is the multi-disciplinary Human System Risk Board (HSRB). The HSRB is chartered from the Chief Health and Medical Officer (OCHMO) at NASA Headquarters. The HSRB reviews all human system risks via an established comprehensive risk and configuration management plan based on a project management approach. The HSRB facilitates the integration of human research (terrestrial and spaceflight), medical operations, occupational surveillance, systems engineering and many other disciplines in a comprehensive review of human system risks. The HSRB considers all factors that influence human risk. These factors include pre-mission considerations such as screening criteria, training, age, sex, and physiological condition. In mission factors such as available countermeasures, mission duration and location and post mission factors such as time to return to baseline (reconditioning), post mission health screening, and available treatments. All of the factors influence the total risk assessment for each human risk. The HSRB performed a comprehensive review of all potential inflight medical conditions and events and over the course of several reviews consolidated the number of human system risks to 30, where the greatest emphasis is placed for investing program dollars for risk mitigation. The HSRB considers all available evidence from human research and, medical operations and occupational surveillance in assessing the risks for appropriate mitigation and future work. All applicable DRMs (low earth orbit for 6 and 12 months, deep space for 30 days and 1 year, a lunar mission for 1 year, and a planetary mission for 3 years) are considered as human system risks are modified by the hazards associated with space flight such as microgravity, exposure to radiation, distance from the earth, isolation and a closed environment. Each risk has a summary

  18. CRESST Human Performance Knowledge Mapping System

    DTIC Science & Technology

    2002-12-01

    team processes and team outcomes. Computers in Human Behavior , 15, 463-494. 0 Herl, H. E. (1995). Construct validation of an approach to modeling...system to measure content understanding. Computers in Human Behavior , 15, 315-334. Johnson, R.F. (2001). Statistical measures of marksmanship (ARI...problem-solving. Computers in Human Behavior , 15, 403-418. West, C. D., Pomeroy, J. R., Park, J. K., Gerstenberger, E. A., & Sandoval, J. (2000

  19. Modeling of Embedded Human Systems

    DTIC Science & Technology

    2013-07-01

    reduces to solving an initial value HJ PDE. Let the system dynamics be given by ẋ = f(x, u), where f is bounded and Lipschitz continuous in x. Choose the...Sprinkle, “Synthesizing executable simulations from structural models of component- based systems,” Electronic Communications of the European Association

  20. 9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic...

  1. Urine proteomes of healthy aging humans reveal extracellular matrix (ECM) alterations and immune system dysfunction.

    PubMed

    Bakun, M; Senatorski, G; Rubel, T; Lukasik, A; Zielenkiewicz, P; Dadlez, M; Paczek, L

    2014-02-01

    Aging is a complex physiological process that poses considerable conundrums to rapidly aging societies. For example, the risk of dying from cardiovascular diseases and/or cancer steadily declines for people after their 60s, and other causes of death predominate for seniors older than 80 years of age. Thus, physiological aging presents numerous unanswered questions, particularly with regard to changing metabolic patterns. Urine proteomics analysis is becoming a non-invasive and reproducible diagnostic method. We investigated the urine proteomes in healthy elderly people to determine which metabolic processes were weakened or strengthened in aging humans. Urine samples from 37 healthy volunteers aged 19-90 years (19 men, 18 women) were analyzed for protein expression by liquid chromatography-tandem mass spectrometry. This generated a list of 19 proteins that were differentially expressed in different age groups (young, intermediate, and old age). In particular, the oldest group showed protein changes reflective of altered extracellular matrix turnover and declining immune function, in which changes corresponded to reported changes in cardiovascular tissue remodeling and immune disorders in the elderly. Thus, urinary proteome changes in the elderly appear to reflect the physiological processes of aging and are particularly clearly represented in the circulatory and immune systems. Detailed identification of "protein trails" creates a more global picture of metabolic changes that occur in the elderly.

  2. Systems biology of human atherosclerosis.

    PubMed

    Shalhoub, Joseph; Sikkel, Markus B; Davies, Kerry J; Vorkas, Panagiotis A; Want, Elizabeth J; Davies, Alun H

    2014-01-01

    Systems biology describes a holistic and integrative approach to understand physiology and pathology. The "omic" disciplines include genomics, transcriptomics, proteomics, and metabolic profiling (metabonomics and metabolomics). By adopting a stance, which is opposing (yet complimentary) to conventional research techniques, systems biology offers an overview by assessing the "net" biological effect imposed by a disease or nondisease state. There are a number of different organizational levels to be understood, from DNA to protein, metabolites, cells, organs and organisms, even beyond this to an organism's context. Systems biology relies on the existence of "nodes" and "edges." Nodes are the constituent part of the system being studied (eg, proteins in the proteome), while the edges are the way these constituents interact. In future, it will be increasingly important to collaborate, collating data from multiple studies to improve data sets, making them freely available and undertaking integrative analyses.

  3. An advanced computational bioheat transfer model for a human body with an embedded systemic circulation.

    PubMed

    Coccarelli, Alberto; Boileau, Etienne; Parthimos, Dimitris; Nithiarasu, Perumal

    2016-10-01

    In the present work, an elaborate one-dimensional thermofluid model for a human body is presented. By contrast to the existing pure conduction-/perfusion-based models, the proposed methodology couples the arterial fluid dynamics of a human body with a multi-segmental bioheat model of surrounding solid tissues. In the present configuration, arterial flow is included through a network of elastic vessels. More than a dozen solid segments are employed to represent the heat conduction in the surrounding tissues, and each segment is constituted by a multilayered circular cylinder. Such multi-layers allow flexible delineation of the geometry and incorporation of properties of different tissue types. The coupling of solid tissue and fluid models requires subdivision of the arterial circulation into large and small arteries. The heat exchange between tissues and arterial wall occurs by convection in large vessels and by perfusion in small arteries. The core region, including the heart, provides the inlet conditions for the fluid equations. In the proposed model, shivering, sweating, and perfusion changes constitute the basis of the thermoregulatory system. The equations governing flow and heat transfer in the circulatory system are solved using a locally conservative Galerkin approach, and the heat conduction in the surrounding tissues is solved using a standard implicit backward Euler method. To investigate the effectiveness of the proposed model, temperature field evolutions are monitored at different points of the arterial tree and in the surrounding tissue layers. To study the differences due to flow-induced convection effects on thermal balance, the results of the current model are compared against those of the widely used modelling methodologies. The results show that the convection significantly influences the temperature distribution of the solid tissues in the vicinity of the arteries. Thus, the inner convection has a more predominant role in the human body heat

  4. Human Systems Integration (HSI) in Acquisition

    DTIC Science & Technology

    2009-08-01

    Cost/Risk Drivers The numbers in the Activities boxes correspond to the numbers In the Inputs and Outputs boxes. Tools: ● CATIA ● HSI Requirements...Technology Development Phase (Inputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME References: ● DODI 5000.02 & DODD 5000.01 ● DAG ● CJCSI...Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME Activities for Each Output: 1.0 Incorporate domain considerations into baseline

  5. Mechanical ventilation and thoracic artificial lung assistance during mechanical circulatory support with PUCA pump: in silico study.

    PubMed

    De Lazzari, Claudio; Genuini, Igino; Quatember, Bernhard; Fedele, Francesco

    2014-02-01

    Patients assisted with left ventricular assist device (LVAD) may require prolonged mechanical ventilatory assistance secondary to postoperative respiratory failure. The goal of this work is the study of the interdependent effects LVAD like pulsatile catheter (PUCA) pump and mechanical ventilatory support or thoracic artificial lung (TAL), by the hemodynamic point of view, using a numerical simulator of the human cardiovascular system. In the simulator, different circulatory sections are described using lumped parameter models. Lumped parameter models have been designed to describe the hydrodynamic behavior of both PUCA pump and thoracic artificial lung. Ventricular behavior atrial and septum functions were reproduced using variable elastance model. Starting from simulated pathological conditions we studied the effects produced on some hemodynamic variables by simultaneous PUCA pump, thoracic artificial lung or mechanical ventilation assistance. Thoracic artificial lung was applied in parallel or in hybrid mode. The effects of mechanical ventilation have been simulated by changing mean intrathoracic pressure value from -4 mmHg to +5 mmHg. The hemodynamic variables observed during the simulations, in different assisted conditions, were: left and right ventricular end systolic (diastolic) volume, systolic/diastolic aortic pressure, mean pulmonary arterial pressure, left and right mean atrial pressure, mean systemic venous pressure and the total blood flow. Results show that the application of PUCA (without mechanical ventilatory assistance) increases the total blood flow, reduces the left ventricular end systolic volume and increases the diastolic aortic pressure. Parallel TAL assistance increases the right ventricular end diastolic (systolic) volume reduction both when PUCA is switched "ON" and both when PUCA is switched "OFF". By switching "OFF" the PUCA pump, it seems that parallel thoracic artificial lung assistance produces a greater cardiac output (respect to

  6. The pathophysiologic role of myocardial depressant factor as a mediator of circulatory shock.

    PubMed

    Lefer, A M

    1982-07-15

    Myocardial Depressant Factor (MDF) is a small peptide circulating in the blood of all mammalian species tested in a variety of shock states including endotoxic, hemorrhagic, cardiogenic, bowel ischemic, acute pancreatitis, burn, and traumatic shock. MDF is produced by the action of proteolytic enzymes released by the ischemic pancreas. MDF acts to depress myocardial contractility, constrict the splanchnic arteries and impair reticuloendothelial system phagocytosis. Several pharmacologic agents prevent the formation of MDF including membrane stabilizers (e.g., glucocorticoids), protease inhibitors (e.g., aprotinin), converting enzyme inhibitors (e.g., captopril), prostaglandins (e.g., PGE1 and PGI2), thromboxane synthetase inhibitors (e.g., imidazole, PTA2) and local anesthetics (e.g., lidocaine). Prevention of MDF formation or action improves survival. Thus, MDF is an important mediator of shock pathophysiology and should be considered in the therapy of circulatory shock states.

  7. A case for human systems neuroscience.

    PubMed

    Gardner, J L

    2015-06-18

    Can the human brain itself serve as a model for a systems neuroscience approach to understanding the human brain? After all, how the brain is able to create the richness and complexity of human behavior is still largely mysterious. What better choice to study that complexity than to study it in humans? However, measurements of brain activity typically need to be made non-invasively which puts severe constraints on what can be learned about the internal workings of the brain. Our approach has been to use a combination of psychophysics in which we can use human behavioral flexibility to make quantitative measurements of behavior and link those through computational models to measurements of cortical activity through magnetic resonance imaging. In particular, we have tested various computational hypotheses about what neural mechanisms could account for behavioral enhancement with spatial attention (Pestilli et al., 2011). Resting both on quantitative measurements and considerations of what is known through animal models, we concluded that weighting of sensory signals by the magnitude of their response is a neural mechanism for efficient selection of sensory signals and consequent improvements in behavioral performance with attention. While animal models have many technical advantages over studying the brain in humans, we believe that human systems neuroscience should endeavor to validate, replicate and extend basic knowledge learned from animal model systems and thus form a bridge to understanding how the brain creates the complex and rich cognitive capacities of humans.

  8. The New Era of the Lymphatic System: No Longer Secondary to the Blood Vascular System

    PubMed Central

    Choi, Inho; Lee, Sunju; Hong, Young-Kwon

    2012-01-01

    The blood and lymphatic systems are the two major circulatory systems in our body. Although the blood system has been studied extensively, the lymphatic system has received much less scientific and medical attention because of its elusive morphology and mysterious pathophysiology. However, a series of landmark discoveries made in the past decade has begun to change the previous misconception of the lymphatic system to be secondary to the more essential blood vascular system. In this article, we review the current understanding of the development and pathology of the lymphatic system. We hope to convince readers that the lymphatic system is no less essential than the blood circulatory system for human health and well-being. PMID:22474611

  9. Human Rating the Orion Parachute System

    NASA Technical Reports Server (NTRS)

    Machin, Ricardo A.; Fisher, Timothy E.; Evans, Carol T.; Stewart, Christine E.

    2011-01-01

    Human rating begins with design. Converging on the requirements and identifying the risks as early as possible in the design process is essential. Understanding of the interaction between the recovery system and the spacecraft will in large part dictate the achievable reliability of the final design. Component and complete system full-scale flight testing is critical to assure a realistic evaluation of the performance and reliability of the parachute system. However, because testing is so often difficult and expensive, comprehensive analysis of test results and correlation to accurate modeling completes the human rating process. The National Aeronautics and Space Administration (NASA) Orion program uses parachutes to stabilize and decelerate the Crew Exploration Vehicle (CEV) spacecraft during subsonic flight in order to deliver a safe water landing. This paper describes the approach that CEV Parachute Assembly System (CPAS) will take to human rate the parachute recovery system for the CEV.

  10. Transient Decrease in Circulatory Testosterone and Homocysteine Precedes the Development of Metabolic Syndrome Features in Fructose-Fed Sprague Dawley Rats

    PubMed Central

    Sakamuri, Anil; Pitla, Sujatha; Putcha, Uday Kumar; Jayapal, Sugeedha; Pothana, Sailaja; Vadakattu, Sai Santosh

    2016-01-01

    Background. Increased fructose consumption is linked to the development of metabolic syndrome (MS). Here we investigated the time course of development of MS features in high-fructose-fed Sprague Dawley rats along with circulatory testosterone and homocysteine levels. Methods. Rats were divided into control and experimental groups and fed with diets containing 54.5% starch and fructose, respectively, for 4, 12, and 24 weeks. Plasma testosterone and homocysteine levels were measured along with insulin, glucose, and lipids. Body composition, insulin resistance, and hepatic lipids were measured. Results. Increase in hepatic triglyceride content was first observed in metabolic disturbance followed by hypertriglyceridemia and systemic insulin resistance in fructose-fed rats. Hepatic lipids were increased in time-dependent manner by fructose-feeding starting from 4 weeks, but circulatory triglyceride levels were increased after 12 weeks. Fasting insulin and Homeostatis Model Assessment of Insulin Resistance (HOMA-IR) were increased after 12 weeks of fructose-feeding. Decreased visceral adiposity, circulatory testosterone, and homocysteine levels were observed after 4 weeks of fructose-feeding, which were normalized at 12 and 24 weeks. Conclusions. We conclude that transient decrease in circulatory testosterone and homocysteine levels and increased hepatic triglyceride content are the earliest metabolic disturbances that preceded hypertriglyceridemia and insulin resistance in fructose-fed SD rats. PMID:27818793

  11. Respiratory and Circulatory Systems, Science (Experimental): 5363.04.

    ERIC Educational Resources Information Center

    Weiss, Alan; And Others

    This biology course is especially recommended for students interested in a vocation in nursing, medical technology, dental hygiene or other para-medical areas. In part, it is considered a second course in biology. The course includes an intensive in-depth study of the respiratory structures, nerve and chemical control of breathing, gas exchange,…

  12. Deep hypothermic circulatory arrest: real-life suspended animation.

    PubMed

    Chau, Katherine H; Ziganshin, Bulat A; Elefteriades, John A

    2013-01-01

    Deep hypothermic circulatory arrest (DHCA) is a cerebral protection technique that was developed in the 1950s and popularized in the 1970s. It has become one of the three most common cerebral protection techniques currently used in aortic arch surgeries, with the other two being antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). At our institution, DHCA has been the cerebral protection technique of choice for over a quarter century. Our clinical experience with DHCA has been very positive, and our clinical studies have shown DHCA to have outcomes equal to (and sometimes better than) those of ACP and RCP, and DHCA to be very effective at preserving neurocognitive function. Other institutions, however, prefer ACP or RCP to DHCA. Each technique has its own set of pros and cons, and the question regarding which technique is the superior method for cerebral protection is hotly debated.

  13. The prevention of transfusion-associated circulatory overload.

    PubMed

    Alam, Asim; Lin, Yulia; Lima, Ana; Hansen, Mark; Callum, Jeannie L

    2013-04-01

    Transfusion-associated circulatory overload (TACO) is an important and potentially injurious complication of transfusion that is underappreciated by clinicians. Risk factors for TACO include being at an extreme of age, having preexisting cardiac and/or (potentially) renal dysfunction, acute myocardial infarction, and individuals receiving plasma. Keys to preventing TACO, aside from identifying high-risk individuals, should be multifaceted. We advocate for the widespread use of pretransfusion checklists and implementation of nonemergent transfusion protocols. We suggest the regular use of pretransfusion diuretics in high-risk individuals. When a transfusion is required, we believe that "critical" nursing supervision and leadership are instrumental in the coordination of slow transfusion rates on computerized infusion pumps and ensuring patients are appropriately monitored. We believe that using these methodologies on a global scale will prevent many TACO events and minimize the severity when it does occur.

  14. Improved mechanism for capturing muscle power for circulatory support.

    PubMed

    Trumble, Dennis R; Melvin, David B; Byrne, Mark T; Magovern, James A

    2005-09-01

    Although it is now understood that trained skeletal muscle can generate enough steady-state power to provide significant circulatory support, there are currently no means by which to tap this endogenous energy source to aid the failing heart. To that end, an implantable muscle energy converter (MEC) has been constructed and its function has been improved to optimize durability, anatomic fit, and mechanical efficiency. Bench tests show that MEC transmission losses average less than 10% of total work input and that about 85% of this muscle power is successfully transferred to the working fluid of the pump. Results from canine implant trials confirm excellent biocompatibility and demonstrate that contractile work of the latissimus dorsi muscle-measured to 290 mJ/stroke in one dog-can be transmitted within the body at levels consistent with cardiac assist requirements. These findings suggest that muscle-powered cardiac assist devices are feasible and that efforts to further develop this technology are warranted.

  15. System for Odorless Disposal of Human Waste

    NASA Technical Reports Server (NTRS)

    Jennings, Dave; Lewis, Tod

    1987-01-01

    Conceptual system provides clean, hygienic storage. Disposal system stores human wastes compactly. Releases no odor or bacteria and requires no dangerous chemicals or unpleasant handling. Stabilizes waste by natural process of biodegradation in which microbial activity eventually ceases and ordors and bacteria reduced to easily contained levels. Simple and reliable and needs little maintenance.

  16. Policy Interactions in Human-Landscape Systems

    NASA Astrophysics Data System (ADS)

    Gerlak, Andrea K.

    2014-01-01

    Given the heightened pace and extent of human interactions with landscapes, there is increasing recognition of the interdependence of hydrogeomorphological, ecological, and human systems in understanding human-landscape interactions. There is also widespread agreement for greater integration across disciplinary boundaries to generate new knowledge urgently needed for theory building to understand, predict, and respond to rapidly changing human-landscape systems. The development of new conceptual frameworks, methods, tools, and collaborations linking across the natural and social sciences are key elements to such integration. In an effort to contribute to a broader conceptual framework for human-landscape systems, this paper describes how environmental policy research has contributed to four integrative themes—thresholds and tipping points; spatial scales and boundaries; feedback loops; and time scales and lags—developed by participants in an NSF-sponsored interdisciplinary workshop. As a broad and heterogeneous body of literature, environmental policy research reflects a diversity of methodological and theoretical approaches around institutions, actors, processes, and ideas. We integrate across multiple subfields and research programs to help identify complementarities in research that may support future interdisciplinary collaborative work. We conclude with a discussion of future research questions to help advance greater interdisciplinary research around human-landscape systems.

  17. Human circulating dopamine-beta-hydroxylase and epilepsy.

    PubMed

    Warter, J M; Coquillat, G; Kurtz, D

    1975-01-01

    The activity of circulatory dopamine-beta-hydroxylase (DBH) in humans is shown to be lower in some epileptic subjects than in normal subjects. The activity of the enzymes was found to be dramatically low in subjects who experienced an epileptic seizure 24 hrs before DBH activity was determined. The activity varied through the course of epileptic seizures induced by a convulsant drugs and these variations might be due to the "en masse" changes of the sympathetic nervous system.

  18. 21 CFR 862.1370 - Human growth hormone test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Human growth hormone test system. 862.1370 Section... Systems § 862.1370 Human growth hormone test system. (a) Identification. A human growth hormone test system is a device intended to measure the levels of human growth hormone in plasma. Human growth...

  19. 21 CFR 862.1370 - Human growth hormone test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Human growth hormone test system. 862.1370 Section... Systems § 862.1370 Human growth hormone test system. (a) Identification. A human growth hormone test system is a device intended to measure the levels of human growth hormone in plasma. Human growth...

  20. [Human resources for local health systems].

    PubMed

    Linger, C

    1989-01-01

    The economic and social crises affecting Latin America have had a profound social and political effect on its structures. This paper analyzes this impact from 2 perspectives: 1) the impact on the apparatus of the state, in particular on its health infra-structures; and 2) the direction of the democratic process in the continent and the participatory processes of civil societies. The institutionalization of the Local Health Systems (SILOS) is an effort to analyze the problem from within the health sector and propose solutions. This paper discusses the issues of human resource development in health systems; training in human resource development and human resource development in local health care systems. There are 3 strategies used to change health systems: 1) The judicial-political system: The state's apparatus 2) The political-administrative system: the national health care system; and 3) the political-operative system: local health care systems. To assure implementation of SILOS there are 4 steps to be followed: 1) create political conditions that allow the transformation and development of local health systems; 2) development of high-level institutional and political initiatives to develop health care networks; 3) offer key players institutional space and social action to develop the SILOS process; 4) rapidly develop SILOS in regions to assure its integration with other development efforts. The labor force in the health sector and organized communities play critical roles in proposing and institutionalizing health programs.

  1. Human Systems Integration (HSI) Practitioner's Guide

    NASA Technical Reports Server (NTRS)

    Zumbado, Jennifer Rochlis

    2015-01-01

    The NASA/SP-2015-3709, Human Systems Integration (HSI) Practitioner's Guide, also known as the "HSIPG," provides a tool for implementing HSI activities within the NASA systems engineering framework. The HSIPG is written to aid the HSI practitioner engaged in a program or project (P/P), and serves as a knowledge base to allow the practitioner to step into an HSI lead or team member role for NASA missions. Additionally, this HSIPG is written to address the role of HSI in the P/P management and systems engineering communities and aid their understanding of the value added by incorporating good HSI practices into their programs and projects. Through helping to build a community of knowledgeable HSI practitioners, this document also hopes to build advocacy across the Agency for establishing strong, consistent HSI policies and practices. Human Systems Integration (HSI) has been successfully adopted (and adapted) by several federal agencies-most notably the U.S. Department of Defense (DoD) and the Nuclear Regulatory Commission (NRC)-as a methodology for reducing system life cycle costs (LCCs). These cost savings manifest themselves due to reductions in required numbers of personnel, the practice of human-centered design, decreased reliance on specialized skills for operations, shortened training time, efficient logistics and maintenance, and fewer safety-related risks and mishaps due to unintended human/system interactions. The HSI process for NASA establishes how cost savings and mission success can be realized through systems engineering. Every program or project has unique attributes. This HSIPG is not intended to provide one-size-fits-all recommendations for HSI implementation. Rather, HSI processes should be tailored to the size, scope, and goals of individual situations. The instructions and processes identified here are best used as a starting point for implementing human-centered system concepts and designs across programs and projects of varying types, including

  2. Sex differences in the human visual system.

    PubMed

    Vanston, John E; Strother, Lars

    2017-01-02

    This Mini-Review summarizes a wide range of sex differences in the human visual system, with a primary focus on sex differences in visual perception and its neural basis. We highlight sex differences in both basic and high-level visual processing, with evidence from behavioral, neurophysiological, and neuroimaging studies. We argue that sex differences in human visual processing, no matter how small or subtle, support the view that females and males truly see the world differently. We acknowledge some of the controversy regarding sex differences in human vision and propose that such controversy should be interpreted as a source of motivation for continued efforts to assess the validity and reliability of published sex differences and for continued research on sex differences in human vision and the nervous system in general. © 2016 Wiley Periodicals, Inc.

  3. Development of Human System Integration at NASA

    NASA Technical Reports Server (NTRS)

    Whitmore, Mihriban; McGuire, Kerry; Thompson, Shelby; Vos, Gordon

    2012-01-01

    Human Systems Integration seeks to design systems around the capabilities and limitations of the humans which use and interact with the system, ensuring greater efficiency of use, reduced error rates, and less rework in the design, manufacturing and operational deployment of hardware and software. One of the primary goals of HSI is to get the human factors practitioner involved early in the design process. In doing so, the aim is to reduce future budget costs and resources in redesign and training. By the preliminary design phase of a project nearly 80% of the total cost of the project is locked in. Potential design changes recommended by evaluations past this point will have little effect due to lack of funding or a huge cost in terms of resources to make changes. Three key concepts define an effective HSI program. First, systems are comprised of hardware, software, and the human, all of which operate within an environment. Too often, engineers and developers fail to consider the human capacity or requirements as part of the system. This leads to poor task allocation within the system. To promote ideal task allocation, it is critical that the human element be considered early in system development. Poor design, or designs that do not adequately consider the human component, could negatively affect physical or mental performance, as well as, social behavior. Second, successful HSI depends upon integration and collaboration of all the domains that represent acquisition efforts. Too often, these domains exist as independent disciplines due to the location of expertise within the service structure. Proper implementation of HSI through participation would help to integrate these domains and disciplines to leverage and apply their interdependencies to attain an optimal design. Via this process domain interests can be integrated to perform effective HSI through trade-offs and collaboration. This provides a common basis upon which to make knowledgeable decisions. Finally

  4. Human System Risk Management for Space Flight

    NASA Technical Reports Server (NTRS)

    Davis, Jeffrey

    2015-01-01

    This brief abstract reviews the development of the current day approach to human system risk management for space flight and the development of the critical components of this process over the past few years. The human system risk management process now provides a comprehensive assessment of each human system risk by design reference mission (DRM) and is evaluated not only for mission success but also for long-term health impacts for the astronauts. The discipline of bioastronautics is the study of the biological and medical effects of space flight on humans. In 1997, the Space Life Sciences Directorate (SLSD) initiated the Bioastronautics Roadmap (Roadmap) as the "Critical Path Roadmap", and in 1998 participation in the roadmap was expanded to include the National Space Biomedical Research Institute (NSBRI) and the external community. A total of 55 risks and 250 questions were identified and prioritized and in 2000, the Roadmap was base-lined and put under configuration control. The Roadmap took into account several major advisory committee reviews including the Institute of Medicine (IOM) "Safe Passage: Astronaut care for Exploration Missions", 2001. Subsequently, three collaborating organizations at NASA HQ (Chief Health and Medical Officer, Office of Space Flight and Office of Biological & Physical Research), published the Bioastronautics Strategy in 2003, that identified the human as a "critical subsystem of space flight" and noted that "tolerance limits and safe operating bands must be established" to enable human space flight. These offices also requested a review by the IOM of the Roadmap and that review was published in October 2005 as "A Risk Reduction Strategy for Human Exploration of Space: A Review of NASA's Bioastronautics Roadmap", that noted several strengths and weaknesses of the Roadmap and made several recommendations. In parallel with the development of the Roadmap, the Office of the Chief Health and Medical Officer (OCHMO) began a process in

  5. Structural design of a newly developed pediatric circulatory assist device for Fontan circulation by using shape memory alloy fiber.

    PubMed

    Shiraishi, Y; Sugai, T K; Tanaka, A; Yoshizawa, M; Yambe, T; Yamada, A; Omran, M H; Shiga, T; Kitano, T; Kamiya, K; Mochizuki, S; Miura, H; Homma, D; Yamagishi, M

    2011-01-01

    Total cavopulmonary connection (TCPC) is commonly applied for the surgical treatment of congenital heart disease such as single ventricle in pediatric patients. Patients with no ventricle in pulmonary circulation are treated along with Fontan algorithm, in which the systemic venous return is diverted directly to the pulmonary artery without passing through subpulmonary ventricle. In order to promote the pulmonary circulation after Fontan procedure, we developed a newly designed pulmonary circulatory assist device by using shape memory alloy fibers. We developed a pulmonary circulatory assist device as a non-blood contacting mechanical support system in pediatric patients with TCPC. The device has been designed to be installed like a cuff around the ePTFE TCPC conduit, which can contract from outside. We employed a covalent type functional anisotropic shape memory alloy fiber (Biometal, Toki Corporation, Tokyo Japan) as a servo actuator of the pulmonary circulatory assist device. The diameter of this fiber was 100 microns, and its contractile frequency was 2-3 Hz. Heat generation with electric current contracts these fibers and the conduit. The maximum contraction ratio of this fiber is about 7% in length. In order to extend its contractile ratio, we fabricated and installed mechanical structural units to control the length of fibers. In this study, we examined basic contractile functions of the device in the mock system. As a result, the internal pressure of the conduit increased to 63 mmHg by the mechanical contraction under the condition of 400 msec-current supply in the mock examination with the overflow tank of 10 mmHg loading.

  6. Human performance modeling for system of systems analytics.

    SciTech Connect

    Dixon, Kevin R.; Lawton, Craig R.; Basilico, Justin Derrick; Longsine, Dennis E.; Forsythe, James Chris; Gauthier, John Henry; Le, Hai D.

    2008-10-01

    A Laboratory-Directed Research and Development project was initiated in 2005 to investigate Human Performance Modeling in a System of Systems analytic environment. SAND2006-6569 and SAND2006-7911 document interim results from this effort; this report documents the final results. The problem is difficult because of the number of humans involved in a System of Systems environment and the generally poorly defined nature of the tasks that each human must perform. A two-pronged strategy was followed: one prong was to develop human models using a probability-based method similar to that first developed for relatively well-understood probability based performance modeling; another prong was to investigate more state-of-art human cognition models. The probability-based modeling resulted in a comprehensive addition of human-modeling capability to the existing SoSAT computer program. The cognitive modeling resulted in an increased understanding of what is necessary to incorporate cognition-based models to a System of Systems analytic environment.

  7. Hemocompatibility of Axial Versus Centrifugal Pump Technology in Mechanical Circulatory Support Devices.

    PubMed

    Schibilsky, David; Lenglinger, Matthias; Avci-Adali, Meltem; Haller, Christoph; Walker, Tobias; Wendel, Hans Peter; Schlensak, Christian

    2015-08-01

    The hemocompatible properties of rotary blood pumps commonly used in mechanical circulatory support (MCS) are widely unknown regarding specific biocompatibility profiles of different pump technologies. Therefore, we analyzed the hemocompatibility indicating markers of an axial flow and a magnetically levitated centrifugal device within an in vitro mock loop. The HeartMate II (HM II; n = 3) device and a CentriMag (CM; n = 3) adult pump were investigated in a human whole blood mock loop for 360 min using the MCS devices as a driving component. Blood samples were analyzed by enzyme-linked immunosorbent assay for markers of coagulation, complement system, and inflammatory response. There was a time-dependent activation of the coagulation (thrombin-antithrombin complexes [TAT]), complement (SC5b-9), and inflammation system (polymorphonuclear [PMN] elastase) in both groups. The mean value of TAT (CM: 4.0 μg/L vs. 29.4 μg/L, P < 0.001; HM II: 4.5 μg/L vs. 232.2 μg/L, P < 0.05) and PMN elastase (CM: 53.4 ng/mL vs. 253.8 ng/mL, P < 0.05; HM II: 28.0 ng/mL vs. 738.8 ng/mL, P < 0.001) significantly increased from baseline until the end of the experiments (360 min). After 360 min, TAT and PMN values were significantly higher in the HM II group compared with the values in the CM adult group. The values of SC5b-9 increased from baseline to 360 min in the CM group (CM: 141.8 ng/mL vs. 967.9 ng/mL, P < 0.05) and the HM II group. However, the increase within the HM II group (97.3 vs. 2462.0, P = 0.06) and the comparison of the 360-min values between CM group and HM II group did not reach significance (P = 0.18). The activation of complement, coagulation, and inflammation system showed a time-dependent manner in both devices. The centrifugal CM device showed significantly lower activation of coagulation and inflammation than that of the HM II axial flow pump. Both HM II and CM have demonstrated an acceptable

  8. A new skeletal muscle linear-pull energy convertor as a power source for prosthetic circulatory support devices [corrected].

    PubMed

    Farrar, D J; Hill, J D

    1992-01-01

    Previous studies show that stimulated skeletal muscle wrapped around the heart or a blood pumping pouch can provide partial circulatory assistance. However, skeletal muscle is accustomed to pulling in direct tension, and power obtained from using the muscle in wraparound configurations is very inefficient. Therefore we have developed a new skeletal muscle-powered, linear-pull energy convertor for powering a wide range of implanted devices, including circulatory support blood pumps such as counterpulsation devices or complete prosthetic ventricles. This energy convertor system is powered by a skeletal muscle such as the latissimus dorsi, which is stimulated with a pulse generator. With the muscle left intact and in situ as much as possible, its insertion at the humerus is removed and reattached to a small-cylinder hydraulic energy convertor that is firmly attached to the ribs. Mechanical force in direct tension from the muscle is converted to high-pressure, low displacement; hydraulic energy (at approximately 200 psi). The output of this hydraulic energy convertor is connected by a small-diameter tube to a hydraulic actuator to drive the pusher plate of an implantable ventricular assist device located in the thoracic cavity or abdomen or another suitable blood pump. Preliminary in vitro tests from an engineering model of the Thoratec muscle-powered ventricular assist device show flow outputs of 5.2 L/min at a mean arterial pressure of 99 mm Hg. The muscle-powered ventricular assist device is a specific application designed to provide completely implantable circulatory support as an alternative to heart transplantation. It will enable patients to experience a quality of life free from batteries and the electrical power-conditioning hardware required with electromechanical systems.

  9. The human brain intracerebral microvascular system: development and structure

    PubMed Central

    Marín-Padilla, Miguel

    2012-01-01

    The capillary from the meningeal inner pial lamella play a crucial role in the development and structural organization of the cerebral cortex extrinsic and intrinsic microvascular compartments. Only pial capillaries are capable of perforating through the cortex external glial limiting membrane (EGLM) to enter into the nervous tissue, although incapable of perforating the membrane to exit the brain. Circulatory dynamics and functional demands determine which capillaries become arterial and which capillaries become venous. The perforation of the cortex EGLM by pial capillaries is a complex process characterized by three fundamental stages: (1) pial capillary contact with the EGLM with fusion of vascular and glial basal laminae at the contact site, (2) endothelial cell filopodium penetration through the fussed laminae with the formation of a funnel between them that accompanies it into the nervous tissue while remaining open to the meningeal interstitium and, (3) penetration of the whole capillary carrying the open funnel with it and establishing an extravascular Virchow-Robin Compartment (V-RC) that maintains the perforating vessel extrinsic (outside) the nervous tissue through its entire length. The V-RC is walled internally by the vascular basal lamina and externally by the basal lamina of joined glial cells endfeet. The VRC outer glial wall appear as an extension of the cortex superficial EGLM. All the perforating vessels within the V-RCs constitute the cerebral cortex extrinsic microvascular compartment. These perforating vessels are the only one capable of responding to inflammatory insults. The V-RC remains open (for life) to the meningeal interstitium permitting the exchanges of fluid and of cells between brain and meninges. The V-RC function as the brain sole drainage (prelymphatic) system in both physiological as well as pathological situations. During cortical development, capillaries emerge from the perforating vessels, by endothelial cells growing sprouts

  10. Interactions between human behaviour and ecological systems

    PubMed Central

    Milner-Gulland, E. J.

    2012-01-01

    Research on the interactions between human behaviour and ecological systems tends to focus on the direct effects of human activities on ecosystems, such as biodiversity loss. There is also increasing research effort directed towards ecosystem services. However, interventions to control people's use of the environment alter the incentives that natural resource users face, and therefore their decisions about resource use. The indirect effects of conservation interventions on biodiversity, modulated through human decision-making, are poorly studied but are likely to be significant and potentially counterintuitive. This is particularly so where people are dependent on multiple natural resources for their livelihoods, when both poverty and biodiversity loss are acute. An inter-disciplinary approach is required to quantify these interactions, with an understanding of human decision-making at its core; otherwise, predictions about the impacts of conservation policies may be highly misleading. PMID:22144389

  11. Deployment of human-machine dialogue systems.

    PubMed Central

    Roe, D B

    1995-01-01

    The deployment of systems for human-to-machine communication by voice requires overcoming a variety of obstacles that affect the speech-processing technologies. Problems encountered in the field might include variation in speaking style, acoustic noise, ambiguity of language, or confusion on the part of the speaker. The diversity of these practical problems encountered in the "real world" leads to the perceived gap between laboratory and "real-world" performance. To answer the question "What applications can speech technology support today?" the concept of the "degree of difficulty" of an application is introduced. The degree of difficulty depends not only on the demands placed on the speech recognition and speech synthesis technologies but also on the expectations of the user of the system. Experience has shown that deployment of effective speech communication systems requires an iterative process. This paper discusses general deployment principles, which are illustrated by several examples of human-machine communication systems. Images Fig. 1 PMID:7479719

  12. Human Transportation System (HTS) study: Executive summary

    NASA Technical Reports Server (NTRS)

    Lance, N.; Geyer, M. S.; Gaunce, M. T.

    1993-01-01

    Work completed under the Human Transportation System Study is summarized. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems as well as proposed systems to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are the following: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

  13. Human Transportation System (HTS) study, volume 1

    NASA Technical Reports Server (NTRS)

    Lance, N.; Geyer, M. S.; Gaunce, M. T.

    1993-01-01

    Work completed under the Human Transportation System Study is summarized. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems as well as proposed systems to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are the following: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

  14. Morphogenesis of the human excretory lacrimal system

    PubMed Central

    de la Cuadra-Blanco, C; Peces-Peña, M D; Jáñez-Escalada, L; Mérida-Velasco, J R

    2006-01-01

    The aim of this study was to determine the principal developmental stages in the formation of the excretory lacrimal system in humans and to establish its morphogenetic period. The study was performed using light microscopy on serial sections of 51 human specimens: 33 embryos and 18 fetuses ranging from 8 to 137 mm crown–rump length (CR; 5–16 weeks of development). Three stages were identified in the morphogenesis of the excretory lacrimal system: (1) the formative stage of the lacrimal lamina (Carnegie stages 16–18); (2) the formative stage of the lacrimal cord (Carnegie stages 19–23); and (3) the maturative stage of the excretory lacrimal system, from the 9th week of development onward. A three-dimensional reconstruction of the excretory lacrimal system was performed from serial sections of an embryo at the end of the embryonic period (27 mm CR). PMID:16879594

  15. Hot-water heating system having an air eliminator

    SciTech Connect

    Pompei, F.

    1984-06-26

    An improved forced-liquid flow, circulatory system for removing gas entrained or dissolved in the liquid. The system includes a circulatory liquid-flow network and means for forcing the liquid to flow through the circulatory network. A by-pass line is situated around the region where the lowest gas solubility in the liquid occurs in the circulatory network. Such lowest gas solubility occurs at the point of generally highest temperature and lowest pressure, as determined most precisely by Henry's Law. Gas-liquid separator means is located in the by-pass line. The separator means separates the gas from the liquid and expels the gas from the circulatory network.

  16. Optoacoustic measurement of central venous oxygenation for assessment of circulatory shock: clinical study in cardiac surgery patients

    NASA Astrophysics Data System (ADS)

    Petrov, Irene Y.; Prough, Donald S.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Esenaliev, Rinat O.

    2014-03-01

    Circulatory shock is a dangerous medical condition, in which blood flow cannot provide the necessary amount of oxygen to organs and tissues. Currently, its diagnosis and therapy decisions are based on hemodynamic parameters (heart rate, blood pressure, blood gases) and mental status of a patient, which all have low specificity. Measurement of mixed or central venous blood oxygenation via catheters is more reliable, but highly invasive and associated with complications. Our previous studies in healthy volunteers demonstrated that optoacoustic systems provide non-invasive measurement of blood oxygenation in specific vessels, including central veins. Here we report our first results of a clinical study in coronary artery bypass graft (CABG) surgery patients. We used a medical-grade OPO-based optoacoustic system developed in our laboratory to measure in real time blood oxygenation in the internal jugular vein (IJV) of these patients. A clinical ultrasound imaging system (GE Vivid e) was used for IJV localization. Catheters were placed in the IJV as part of routine care and blood samples taken via the catheters were processed with a CO-oximeter. The optoacoustic oxygenation data were compared to the CO-oximeter readings. Good correlation between the noninvasive and invasive measurements was obtained. The results of these studies suggest that the optoacoustic system can provide accurate, noninvasive measurements of central venous oxygenation that can be used for patients with circulatory shock.

  17. First Human Systemic Infection Caused by Spiroplasma

    PubMed Central

    Aquilino, Ana; López, Pilar; Galiana, Antonio J.; Tovar, Juan; Andrés, María; Gutiérrez, Félix

    2014-01-01

    Spiroplasma species are organisms that normally colonize plants and insects. We describe the first case of human systemic infection caused by Spiroplasma bacteria in a patient with hypogammaglobulinemia undergoing treatment with biological disease-modifying antirheumatic agents. Spiroplasma turonicum was identified through molecular methods in several blood cultures. The infection was successfully treated with doxycycline plus levofloxacin. PMID:25428150

  18. How to Bootstrap a Human Communication System

    ERIC Educational Resources Information Center

    Fay, Nicolas; Arbib, Michael; Garrod, Simon

    2013-01-01

    How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified…

  19. The Human Resources Management System: Part 1.

    ERIC Educational Resources Information Center

    Ceriello, Vincent R.

    1982-01-01

    Presents a systematic and disciplined approach to planning for the development and implementation of an information system which will collect, store, maintain, and report human resources data. Discusses guidelines, priorities, training requirements, security, auditing, interface with payroll, and personnel reporting. (CT)

  20. A Novel Human Autonomy Assessment System

    PubMed Central

    Munstermann, Marco; Stevens, Torsten; Luther, Wolfram

    2012-01-01

    This article presents a novel human autonomy assessment system for generating context and discovering the behaviors of older people who use ambulant services. Our goal is to assist caregivers in assessing possibly abnormal health conditions in their clients concerning their level of autonomy, thus enabling caregivers to take countermeasures as soon as possible. PMID:22969374

  1. Visuals and Visualisation of Human Body Systems

    ERIC Educational Resources Information Center

    Mathai, Sindhu; Ramadas, Jayashree

    2009-01-01

    This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…

  2. Separation of craniopagus Siamese twins using cardiopulmonary bypass and hypothermic circulatory arrest.

    PubMed

    Cameron, D E; Reitz, B A; Carson, B S; Long, D M; Dufresne, C R; Vander Kolk, C A; Maxwell, L G; Tilghman, D M; Nichols, D G; Wetzel, R C

    1989-11-01

    Occipitally joined craniopagus Siamese twins were separated with the use of cardiopulmonary bypass and hypothermic circulatory arrest. The 7-month-old infants shared a large sagittal venous sinus that precluded conventional neurosurgical approach because of risk of exsanguination and air embolism. After craniotomy and preliminary exposure of the sinus, each twin underwent sternotomy and total cardiopulmonary bypass with deep hypothermia. Hypothermic circulatory arrest allowed safe division and subsequent reconstruction of the sinus remnants. Several unusual problems were encountered, including transfusion of a large blood volume from one extracorporeal circuit to the other through the common venous sinus, deleterious warming of the exposed brain during circulatory arrest, and thrombosis of both pump oxygenators. Both infants survived, although recovery was complicated in each by neurologic injury, cranial wound infection, and hydrocephalus. This case demonstrates the valuable supportive role of cardiopulmonary bypass and hypothermic circulatory arrest in the management of complex surgical problems of otherwise inoperable patients.

  3. Microfluidic Emulation of Mechanical Circulatory Support Device Shear-Mediated Platelet Activation

    PubMed Central

    Dimasi, A.; Rasponi, M.; Sheriff, J.; Chiu, W.-C.; Bluestein, D.; Tran, P.L.; Slepian, M. J.; Redaelli, A.

    2016-01-01

    Thrombosis of ventricular assist devices (VADs) compromises their performance, with associated risks of systemic embolization, stroke, pump stop and possible death. Anti-thrombotic (AT) drugs, utilized to limit thrombosis, are largely dosed empirically, with limited testing of their efficacy. Further, such testing, if performed, typically examines efficacy under static conditions, which is not reflective of actual shear-mediated flow. Here we adopted our previously developed Device Thrombogenicity Emulation methodology to design microfluidic platforms able to emulate representative shear stress profiles of mechanical circulatory support (MCS) devices. Our long-term goal is to utilize these systems for point-of-care (POC) personalized testing of AT efficacy under specific, individual shear profiles. First, we designed different types of microfluidic channels able to replicate sample shear stress patterns observed in MCS devices. Second, we explored the flexibility of microfluidic technology in generating dynamic shear stress profiles by modulating the geometrical features of the channels. Finally, we designed microfluidic channel systems able to emulate the shear stress profiles of two commercial VADs. From CFD analyses, the VAD-emulating microfluidic systems were able to replicate the main characteristics of the shear stress waveforms of the macroscale VADs (i.e. shear stress peaks and duration). Our results establish the basis for development of a lab-on-chip POC system able to perform device-specific and patient-specific platelet activation state assays. PMID:26578003

  4. Clinical outcome and circulatory effects of fetal cardiac arrhythmia.

    PubMed

    Lingman, G; Lundström, N R; Marsál, K

    1986-01-01

    By means of abdominal fetal ECG and non-invasive ultrasound blood flow studies 113 cases of fetal cardiac arrhythmia were classified according to the origin of arrhythmia. Pregnancy outcome was characterized by an increased frequency of fetal distress and heart malformation, and increased fetal and neonatal mortality. The following types of arrhythmia were identified: supraventricular extrasystoles (n = 84), paroxysmal tachycardia (n = 6), sinus bradycardia (n = 3), atrial flutter (n = 1), ventricular extrasystoles (n = 14), and atrioventricular block (n = 5). In 37 cases the combined Doppler and real-time ultrasound technique was used to measure fetal aortic blood flow as a means of studying the circulatory effects of the arrhythmia. Increased peak velocity, rising slope and acceleration were found in the first post-pausal beat after a supraventricular extrasystole or a missed beat; this supports the validity of Frank-Starling law for the fetal heart and suggests that a strong relationship exists between these variables and myocardial contractility. In two cases of intra-uterine heart failure, the effect of digoxin treatment in utero on the fetal aortic flow variables was studied, results indicating a positive inotropic effect of the drug on the fetal myocardium. The estimation of fetal aortic volume blood flow in cases of fetal cardiac arrhythmia is useful for early detection of fetal cardiac failure, and for monitoring the effects of intra-uterine treatment.

  5. Contemporary mechanical circulatory support therapy for postcardiotomy shock.

    PubMed

    Fukuhara, Shinichi; Takeda, Koji; Garan, Arthur Reshad; Kurlansky, Paul; Hastie, Jonathan; Naka, Yoshifumi; Takayama, Hiroo

    2016-04-01

    Significant progress has been made in the use of mechanical circulatory support (MCS), particularly in the clinical success in durable left ventricular assist device. Short-term MCS has also advanced in the form of venoarterial extracorporeal membrane oxygenation, external centrifugal VADs as well as percutaneous VADs. Postcardiotomy shock (PCS) is a rare clinical entity associated with substantial morbidity and mortality. It is characterized by heart failure that either results in an inability to wean from cardiopulmonary bypass or that occurs in the immediate postoperative period, accounting for the most common indication for MCS. The reported in-hospital mortality of the PCS patients remains high, consistently over 50%, despite ongoing refinements of MCS technology. The optimization of selection criteria and the prompt institution of MCS are likely the keys to improving this persistently high mortality rate. Unfortunately, the lack of a clear definition for PCS in the literature limits scientific analyses and comparison of the existing evidence. To establish the treatment strategy and appropriately manage this challenging disease, substantial and fundamental effort by the cardiovascular society is imperative.

  6. Improved Mechanism for Capturing Muscle Power for Circulatory Support

    PubMed Central

    Trumble, Dennis R.; Melvin, David B.; Byrne, Mark T.; Magovern, James A.

    2016-01-01

    Although it is now understood that trained skeletal muscle can generate enough steady-state power to provide significant circulatory support, there are currently no means by which to tap this endogenous energy source to aid the failing heart. To that end, an implantable muscle energy converter (MEC) has been constructed and its function has been improved to optimize durability, anatomic fit, and mechanical efficiency. Bench tests show that MEC transmission losses average less than 10% of total work input and that about 85% of this muscle power is successfully transferred to the working fluid of the pump. Results from canine implant trials confirm excellent biocompatibility and demonstrate that contractile work of the latissimus dorsi muscle—measured to 290 mJ/stroke in one dog—can be transmitted within the body at levels consistent with cardiac assist requirements. These findings suggest that muscle-powered cardiac assist devices are feasible and that efforts to further develop this technology are warranted. PMID:16143010

  7. [Circulatory effects of stellate ganglion block in idiopathic facial palsy].

    PubMed

    Murakawa, K; Ishimoto, E; Noma, K; Ishida, K; Nishijima, M; Izumi, R

    1994-03-01

    The circulatory effects of stellate ganglion block (SGB) on the blood flow through the common carotid artery were determined in 35 patients in acute phase of idiopathic facial palsy (Bell's palsy). SGB was performed by para-tracheal approach with 8 ml of 1% mepivacaine. The blood flow was measured with an ultrasonic blood flowmeter before and 30 minutes after SGB at both sides of the common carotid artery in 20 cases. Measurement was performed continuously for 90 minutes on the palsy side in the other 15 patients. Before SGB, there were no significant differences between the blood flow of the palsy side and the intact side. Thirty minutes after SGB, the blood flow markedly increased to 169.4 +/- 6.2% on the performed side with no change on the non-performed side in 20 cases. In the other 15 patients, the blood flow increased significantly 5 minutes after SGB and reached its peak of 179.7 +/- 11.1% at 20 minutes later. This increase continued for 75 minutes after SGB. It is well known that impaired microcirculation in the facial nerve has an important role in the pathophysiology of Bell's palsy. In view of the fact that the nutrient arteries for the facial nerve are the peripheral branches of the external carotid artery, we believe that SGB which causes significant increase in the blood flow through the common carotid artery is an effective treatment in Bell's palsy.

  8. Kidney donation after circulatory death (DCD): state of the art.

    PubMed

    Summers, Dominic M; Watson, Christopher J E; Pettigrew, Gavin J; Johnson, Rachel J; Collett, David; Neuberger, James M; Bradley, J Andrew

    2015-08-01

    The use of kidneys from controlled donation after circulatory death (DCD) donors has the potential to markedly increase kidney transplants performed. However, this potential is not being realized because of concerns that DCD kidneys are inferior to those from donation after brain-death (DBD) donors. The United Kingdom has developed a large and successful controlled DCD kidney transplant program that has allowed for a substantial increase in kidney transplant numbers. Here we describe recent trends in DCD kidney donor activity in the United Kingdom, outline aspects of the donation process, and describe donor selection and allocation of DCD kidneys. Previous UK Transplant Registry analyses have shown that while DCD kidneys are more susceptible to cold ischemic injury and have a higher incidence of delayed graft function, short- and medium-term transplant outcomes are similar in recipients of kidneys from DCD and DBD donors. We present an updated, extended UK registry analysis showing that longer-term transplant outcomes in DCD donor kidneys are also similar to those for DBD donor kidneys, and that transplant outcomes for kidneys from expanded-criteria DCD donors are no less favorable than for expanded-criteria DBD donors. Accordingly, the selection criteria for use of kidneys from DCD donors should be the same as those used for DBD donors. The UK experience suggests that wider international development of DCD kidney transplantation programs will help address the global shortage of deceased donor kidneys for transplantation.

  9. Ion transport in circulatory and/or septic shock

    SciTech Connect

    Sayeed, M.M.

    1987-05-01

    This review surveys investigations of membrane ion transport in animals in hemorrhagic, endotoxic, or bacteremic shock. The focus of the review is on ion transport studies in the skeletal muscle and liver. Skeletal muscle Na/sup +/-K/sup +/ transport alterations have been shown during the induction of shock via hemorrhage, endotoxin, or live Gram-negative bacteria in the rodent, canine, and primate species. These alterations include impairment of active cellular K/sup +/ accumulation, increased permeability to /sup 24/Na/sup +/ and Cl/sup -/, and membrane depolarization. The ion transport alterations in the skeletal muscle are compatible with movement of extracellular fluid into the intracellular compartment. Such fluid movements can potentially lead to decreases in circulating plasma volume and thus to circulatory deficits in shock. Studies in the liver of rats subjected to hemorrhagic or endotoxic shock indicated the failure of electrogenic Na/sup +/ pump. Although the hepatic cellular membrane permeability to Na/sup +/ relative to permeability to K/sup +/ appeared unaltered in hemorrhagic shock, endotoxic shock caused an increase in permeability to Na/sup +/. Hepatic cellular /sup 45/Ca/sup +/ regulation also appeared to be adversely affected during endotoxic shock. Alterations in hepatic Na/sup +/-K/sup +/ transport and Ca/sup +/ regulation could contribute to impairment in hepatic glucose production during shock. Although mechanisms of altered membrane ion transport during shock states remain unknown, such changes could occur prior to any substantial loss of cellular metabolic energy.

  10. Noncardiac surgery in patients on mechanical circulatory support.

    PubMed

    Taghavi, Sharven; Beyer, Carl; Vora, Halley; Jayarajan, Senthil N; Toyoda, Yoshiya; Dujon, Jay; Sjoholm, Lars O; Pathak, Abhijit; Santora, Thomas A; Goldberg, Amy J; Rappold, Joseph F

    2014-01-01

    This study examined outcomes in patients with left ventricular assist device (LVAD) and extracorporeal membrane oxygenation (ECMO) requiring noncardiac surgical procedures and identified factors that influence outcomes. All patients with mechanical circulatory support (MCS) devices at our institution from 2002 to 2013 undergoing noncardiac surgical procedures were reviewed. There were 148 patients requiring MCS during the study period, with 40 (27.0%) requiring 62 noncardiac surgical procedures. Of these, 29 (72.5%) had implantable LVAD and 11 (27.5%) were supported with ECMO. The two groups were evenly matched with regard to age (53.6 vs. 54.5 years, p = 0.87), male sex (71.4 vs. 45.5%, p = 0.16), and baseline creatinine (1.55 vs. 1.43 mg/dl, p = 0.76). Patients on ECMO had greater demand for postoperative blood products (0.8 vs. 2.8 units of packed red blood cells, p = 0.002) and greater postoperative increase in creatinine (0.07 vs. 0.44 mg/dl, p = 0.047). Median survival was markedly worse in ECMO patients. Factors associated with mortality included ECMO support, history of biventricular assist device, and postoperative blood transfusion. Preoperative aspirin was associated with survival. These findings demonstrate the importance of careful surgical hemostasis and minimizing perioperative blood transfusions in patients on MCS undergoing noncardiac surgical procedures. In addition, low-dose antiplatelet therapy should be continued perioperatively.

  11. Palatability of tastes is associated with facial circulatory responses.

    PubMed

    Kashima, Hideaki; Hamada, Yuka; Hayashi, Naoyuki

    2014-03-01

    To examine whether various types of taste stimuli in the oral cavity elicit unique changes in facial skin blood flow (SkBF) according to the palatability perceived by an individual, the facial SkBF was observed by laser speckle flowgraphy in 15 healthy subjects (11 males and 4 females) before and during the ingestion of bitter tea, chilli sauce, coffee, orange juice, soup, and a water control. The heart rate, mean arterial pressure (MAP), and SkBF in the index finger were recorded continuously. Subjects reported their subjective palatability and taste intensity scores after each stimulus. The vascular conductance indexes (CIs) in the face and finger were calculated as ratios of SkBF to MAP. CI in the eyelid increased significantly in response to chilli sauce, orange juice, and soup, whereas CIs in the forehead, nose, and cheek decreased in response to bitter tea. There was a significant correlation between the palatability scores and CI values in the eyelid when changes induced by chilli sauce were excluded. These results suggest that the facial circulatory response reflects the degree of palatability of a foodstuff.

  12. The NATO Unmanned Aircraft System Human Systems Integration Guidebook

    DTIC Science & Technology

    2012-11-01

    training, refresher training, and core competency-based training • Teamwork /crew resource management • Balance of live flying training, embedded...architecture framework. Its purpose is to visualize and facilitate understanding of the human dimension in relation to operational demands and system...anthropometric/medical data; reach data; range of motion data; physical strength data; human sensory (e.g., visual , auditory, tactile, propioceptive

  13. Glucuronidation does not suppress the estrogenic activity of quercetin in yeast and human breast cancer cell model systems.

    PubMed

    Ruotolo, Roberta; Calani, Luca; Brighenti, Furio; Crozier, Alan; Ottonello, Simone; Del Rio, Daniele

    2014-10-01

    Several plant-derived molecules, referred to as phytoestrogens, are thought to mimic the actions of endogenous estrogens. Among these, quercetin, one of the most widespread flavonoids in the plant kingdom, has been reported as estrogenic in some occasions. However, quercetin occurs in substantial amounts as glycosides such as quercetin-3-O-glucoside (isoquercitrin) and quercetin-3-O-rutinoside (rutin) in dietary sources. It is now well established that quercetin undergoes substantial phase II metabolism after ingestion by humans, with plasma metabolites after a normal dietary intake rarely exceeding nmol/L concentrations. Therefore, attributing phytoestrogenic activity to flavonoids without taking into account the fact that it is their phase II metabolites that enter the circulatory system, will almost certainly lead to misleading conclusions. With the aim of clarifying the above issue, the goal of the present study was to determine if plant-associated quercetin glycosides and human phase II quercetin metabolites, actually found in human biological fluids after intake of quercetin containing foods, are capable of interacting with the estrogen receptors (ER). To this end, we used a yeast-based two-hybrid system and an estrogen response element-luciferase reporter assay in an ER-positive human cell line (MCF-7) to probe the ER interaction capacities of quercetin and its derivatives. Our results show that quercetin-3-O-glucuronide, one of the main human phase II metabolites produced after intake of dietary quercetin, displays ERα- and ERβ-dependent estrogenic activity, the functional consequences of which might be related to the protective activity of diets rich in quercetin glycosides.

  14. Project ATHENA Creates Surrogate Human Organ Systems

    SciTech Connect

    MacQueen, Luke; Knospel, Fanny; Sherrod, Stacy; Iyer, Rashi

    2015-06-15

    The development of miniature surrogate human organs, coupled with highly sensitive mass spectrometry technologies, could one day revolutionize the way new drugs and toxic agents are studied. “By developing this ‘homo minutus,’ we are stepping beyond the need for animal or Petri dish testing: There are huge benefits in developing drug and toxicity analysis systems that can mimic the response of actual human organs,” said Rashi Iyer, a senior scientist at Los Alamos National Laboratory. ATHENA, the Advanced Tissue-engineered Human Ectypal Network Analyzer project team, is nearing the full integration of four human organ constructs — liver, heart, lung and kidney — each organ component is about the size of a smartphone screen, and the whole ATHENA “body” of interconnected organs will fit neatly on a desk. A new video available on the Los Alamos National Laboratory YouTube channel updates the ATHENA project as it begins to integrate the various organ systems into a single system (link to video here). Some 40 percent of pharmaceuticals fail their clinical trials and there are thousands of chemicals whose effects on humans are simply unknown. Providing a realistic, cost-effective and rapid screening system such as ATHENA with high-throughput capabilities could provide major benefits to the medical field, screening more accurately and offering a greater chance of clinical trial success. ATHENA is funded by the Defense Threat Reduction Agency (DTRA) and is a collaboration of Los Alamos National Laboratory, Harvard University, Vanderbilt University, Charité Universitätsmedizin, Berlin, Germany, CFD Research Corporation, and the University of California San Francisco.

  15. Project ATHENA Creates Surrogate Human Organ Systems

    ScienceCinema

    MacQueen, Luke; Knospel, Fanny; Sherrod, Stacy; Iyer, Rashi

    2016-07-12

    The development of miniature surrogate human organs, coupled with highly sensitive mass spectrometry technologies, could one day revolutionize the way new drugs and toxic agents are studied. “By developing this ‘homo minutus,’ we are stepping beyond the need for animal or Petri dish testing: There are huge benefits in developing drug and toxicity analysis systems that can mimic the response of actual human organs,” said Rashi Iyer, a senior scientist at Los Alamos National Laboratory. ATHENA, the Advanced Tissue-engineered Human Ectypal Network Analyzer project team, is nearing the full integration of four human organ constructs — liver, heart, lung and kidney — each organ component is about the size of a smartphone screen, and the whole ATHENA “body” of interconnected organs will fit neatly on a desk. A new video available on the Los Alamos National Laboratory YouTube channel updates the ATHENA project as it begins to integrate the various organ systems into a single system (link to video here). Some 40 percent of pharmaceuticals fail their clinical trials and there are thousands of chemicals whose effects on humans are simply unknown. Providing a realistic, cost-effective and rapid screening system such as ATHENA with high-throughput capabilities could provide major benefits to the medical field, screening more accurately and offering a greater chance of clinical trial success. ATHENA is funded by the Defense Threat Reduction Agency (DTRA) and is a collaboration of Los Alamos National Laboratory, Harvard University, Vanderbilt University, Charité Universitätsmedizin, Berlin, Germany, CFD Research Corporation, and the University of California San Francisco.

  16. An Empirical Methodology for Engineering Human Systems Integration

    DTIC Science & Technology

    2009-12-01

    Human factors engineering HFI ...................................... Human factors integration HMI .................................... Human...AIRPRINT AFRL/RH INCOSE Defense Acquisition Guide MANPRINT IEEE SMC ACM UK HFI Program Manpower X X X X X X X Personnel X X X “Personal...systems engineering human systems integration NATO, some use USAF, ISO HFI Human factors integration Confused with HSI, but only the interface

  17. Human eye color difference threshold measurement system

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Zhou, Taogeng

    2013-12-01

    The human eye has the ability to distinguish millions of colors, with this feature we can identify very subtle color differences, and the measurement of human eye color difference threshold can provide a visual function diagnosis for testee. In recent years, people begin to focus on studies on visual threshold diagnostic equipment. This paper proposes a human eye color difference threshold measurement system which is based on dual integrating sphere. The system includes two pairs of dual integrating sphere and color control module. Dual integrating sphere uses to mix and produce color, and palette unit which produces primary colors (red (R), green (G), blue (B)) is embedded in dual integrating sphere. At the same time, the embedded palette unit which produces cyan (C), magenta (M), and yellow (Y) expands color area that the system can generate. One optical path based on dual integrating sphere generates standard color, the other path produces the matching color which is similar to a standard color. In the high-precision closed-loop color control module, photoelectric switch records stepper motor's origin position and limits move displacement. Precision stepper motor pushes the light-blocking panel of the palette unit to a predetermined position, while real-time monitoring the position of the light-blocking panel and mixing the ideal controllable color. Two colors that the system generates are projected onto the same target area. Subjects make a judgment on color difference threshold by observing the target eventually.

  18. Human factors in high consequence manufacturing systems

    SciTech Connect

    Forsythe, C.; Grose, E.

    1997-11-01

    A high consequence system is often defined as one in which the potential exists for severe or catastrophic accidents. Familiar examples include nuclear power plants, airline and other mass transportation, dams and reservoirs, and large-scale food processing. Many manufacturing systems also qualify as high consequence systems. Much of the authors` experience with high consequence systems derives from work associated with the surveillance and dismantlement of nuclear weapons for the US Department of Energy. With such operations, there exists a risk of high explosive detonation accompanied by radiological dispersal and, potentially, nuclear detonation. Analysis of major industrial accidents such as Three Mile Island, Chernobyl and Bhopal have revealed that these incidents were not attributable to a single event or direct cause, but were the result of multiple factors that combined to create a condition ripe for an accident. In each case, human error was a critical factor contributing to the accident. Consequently, many authors have emphasized the need for greater appreciation of systematic factors and in particular, human activities. This paper discusses approaches used in hazard analysis of US nuclear weapons operations to assess risk associated with human factors.

  19. Human performance modeling for system of systems analytics :soldier fatigue.

    SciTech Connect

    Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

    2005-10-01

    The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

  20. Dynamics of coupled human-landscape systems

    NASA Astrophysics Data System (ADS)

    Werner, B. T.; McNamara, D. E.

    2007-11-01

    A preliminary dynamical analysis of landscapes and humans as hierarchical complex systems suggests that strong coupling between the two that spreads to become regionally or globally pervasive should be focused at multi-year to decadal time scales. At these scales, landscape dynamics is dominated by water, sediment and biological routing mediated by fluvial, oceanic, atmospheric processes and human dynamics is dominated by simplifying, profit-maximizing market forces and political action based on projection of economic effect. Also at these scales, landscapes impact humans through patterns of natural disasters and trends such as sea level rise; humans impact landscapes by the effect of economic activity and changes meant to mitigate natural disasters and longer term trends. Based on this analysis, human-landscape coupled systems can be modeled using heterogeneous agents employing prediction models to determine actions to represent the nonlinear behavior of economic and political systems and rule-based routing algorithms to represent landscape processes. A cellular model for the development of New Orleans illustrates this approach, with routing algorithms for river and hurricane-storm surge determining flood extent, five markets (home, labor, hotel, tourism and port services) connecting seven types of economic agents (home buyers/laborers, home developers, hotel owners/ employers, hotel developers, tourists, port services developer and port services owners/employers), building of levees or a river spillway by political agents and damage to homes, hotels or port services within cells determined by the passage or depth of flood waters. The model reproduces historical aspects of New Orleans economic development and levee construction and the filtering of frequent small-scale floods at the expense of large disasters.

  1. Beyond the VAD: Human Factors Engineering for Mechanically Assisted Circulation in the 21st Century.

    PubMed

    Throckmorton, Amy L; Patel-Raman, Sonna M; Fox, Carson S; Bass, Ellen J

    2016-06-01

    Thousands of ventricular assist devices (VADs) currently provide circulatory support to patients worldwide, and dozens of heart pump designs for adults and pediatric patients are under various stages of development in preparation for translation to clinical use. The successful bench-to-bedside development of a VAD involves a structured evaluation of possible system states, including human interaction with the device and auxiliary component usage in the hospital or home environment. In this study, we review the literature and present the current landscape of preclinical design and assessment, decision support tools and procedures, and patient-centered therapy. Gaps of knowledge are identified. The study findings support the need for more attention to user-centered design approaches for medical devices, such as mechanical circulatory assist systems, that specifically involve detailed qualitative and quantitative assessments of human-device interaction to mitigate risk and failure.

  2. Integrating Spaceflight Human System Risk Research

    NASA Technical Reports Server (NTRS)

    Mindock, Jennifer; Lumpkins, Sarah; Anton, Wilma; Havenhill, Maria; Shelhamer, Mark; Canga, Michael

    2016-01-01

    NASA is working to increase the likelihood of human health and performance success during exploration missions as well as to maintain the subsequent long-term health of the crew. To manage the risks in achieving these goals, a system modelled after a Continuous Risk Management framework is in place. "Human System Risks" (Risks) have been identified, and approximately 30 are being actively addressed by NASA's Human Research Program (HRP). Research plans for each of HRP's Risks have been developed and are being executed. Inter-disciplinary ties between the research efforts supporting each Risk have been identified; however, efforts to identify and benefit from these connections have been mostly ad hoc. There is growing recognition that solutions developed to address the full set of Risks covering medical, physiological, behavioural, vehicle, and organizational aspects of exploration missions must be integrated across Risks and disciplines. This paper discusses how a framework of factors influencing human health and performance in space is being applied as the backbone for bringing together sometimes disparate information relevant to the individual Risks. The resulting interrelated information enables identification and visualization of connections between Risks and research efforts in a systematic and standardized manner. This paper also discusses the applications of the visualizations and insights into research planning, solicitation, and decision-making processes.

  3. Integrating Spaceflight Human System Risk Research

    NASA Technical Reports Server (NTRS)

    Mindock, J.; Lumpkins, S.; Anton, W.; Havenhill, M.; Shelhamer, M.; Canga, M.

    2016-01-01

    NASA is working to increase the likelihoods of human health and performance success during exploration missions, and subsequent crew long-term health. To manage the risks in achieving these goals, a system modeled after a Continuous Risk Management framework is in place. "Human System Risks" (Risks) have been identified, and approximately 30 are being actively addressed by NASA's Human Research Program (HRP). Research plans for each of HRP's Risks have been developed and are being executed. Ties between the research efforts supporting each Risk have been identified, however, this has been in an ad hoc fashion. There is growing recognition that solutions developed to address the full set of Risks covering medical, physiological, behavioral, vehicle, and organizational aspects of the exploration missions must be integrated across Risks and disciplines. We will discuss how a framework of factors influencing human health and performance in space is being applied as the backbone for bringing together sometimes disparate information relevant to the individual Risks. The resulting interrelated information is allowing us to identify and visualize connections between Risks and research efforts in a systematic and standardized way. We will discuss the applications of the visualizations and insights to research planning, solicitation, and decision-making processes.

  4. Biotransport in the human respiratory system.

    PubMed

    Elad, D

    1999-01-01

    The human respiratory system is an 'open' organ, which is designed to exchange oxygen and carbon dioxide between the circulating blood and the external environment. This gas exchange is successfully accomplished via a set of transport phenomena comprised of oscillatory air flow, heat and water vapor exchange, mucus transport and air-blood gas exchange all of which take place in a complex geometry that undergoes large changes. These transport phenomena occur simultaneously to supply the body's need for oxygen in different physiological conditions and/or environments, while defending it from external hazards. The need for better comprehension of the mechanisms involved in pulmonary diseases and for advanced techniques for both diagnosis and intervention stimulated numerous studies of the different biotransport processes that take place in the human respiratory system.

  5. Human Frontal Lobes and AI Planning Systems

    NASA Technical Reports Server (NTRS)

    Levinson, Richard; Lum, Henry Jr. (Technical Monitor)

    1994-01-01

    Human frontal lobes are essential for maintaining a self-regulating balance between predictive and reactive behavior. This paper describes a system that integrates prediction and reaction based on neuropsychological theories of frontal lobe function. In addition to enhancing our understanding of deliberate action in humans' the model is being used to develop and evaluate the same properties in machines. First, the paper presents some background neuropsychology in order to set a general context. The role of frontal lobes is then presented by summarizing three theories which formed the basis for this work. The components of an artificial frontal lobe are then discussed from both neuropsychological and AI perspectives. The paper concludes by discussing issues and methods for evaluating systems that integrate planning and reaction.

  6. HSI Prototypes for Human Systems Simulation Laboratory

    SciTech Connect

    Jokstad, Håkon; McDonald, Rob

    2015-09-01

    This report describes in detail the design and features of three Human System Interface (HSI) prototypes developed by the Institutt for Energiteknikk (IFE) in support of the U.S. Department of Energy’s Light Water Reactor Sustainability Program under Contract 128420 through Idaho National Laboratory (INL). The prototypes are implemented for the Generic Pressurized Water Reactor simulator and installed in the Human Systems Simulation Laboratory at INL. The three prototypes are: 1) Power Ramp display 2) RCS Heat-up and Cool-down display 3) Estimated time to limit display The power ramp display and the RCS heat-up/cool-down display are designed to provide good visual indications to the operators on how well they are performing their task compared to their target ramp/heat-up/cool-down rate. The estimated time to limit display is designed to help operators restore levels or pressures before automatic or required manual actions are activated.

  7. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Human placental lactogen test system. 862.1585 Section 862.1585 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental...

  8. 21 CFR 862.1370 - Human growth hormone test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Human growth hormone test system. 862.1370 Section 862.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1370 Human growth hormone test system. (a) Identification. A human growth hormone...

  9. 21 CFR 862.1370 - Human growth hormone test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Human growth hormone test system. 862.1370 Section 862.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1370 Human growth hormone test system. (a) Identification. A human growth hormone...

  10. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Human placental lactogen test system. 862.1585 Section 862.1585 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental...

  11. 21 CFR 862.1585 - Human placental lactogen test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Human placental lactogen test system. 862.1585 Section 862.1585 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Systems § 862.1585 Human placental lactogen test system. (a) Identification. A human placental...

  12. [Multi-value regulatory systems for extracorporeal circulation].

    PubMed

    Meyrowitz, G; Schmidt, T; Naujokat, E; Albers, J; Kiencke, U; Vahl, C F; Hagl, S

    2002-01-01

    Extracorporeal perfusion is the standard technique in cardiac surgery. It is controlled by perfusionists on the basis of their clinical experience and on the available data collected pre- and intra-operatively. But in spite of intensive monitoring postoperative complications occur. An appropriate control of the heart-lung machine (HLM) using an "autopilot" might improve the quality of heart-surgery and decrease postoperative complications. Hence, a mathematical model of a human circulatory system has been developed which provides much more information about haemodynamics, blood gases and acid-base status than standard monitoring. It has been implemented on a system which is capable of integrating measured data as input parameters in real-time in the simulation. Now, soft- and hardware control concepts based on the human circulatory system have to be developed which are able to control the HLM.

  13. Organ donation after circulatory death in a university teaching hospital.

    PubMed

    Sidiropoulos, S; Treasure, E; Silvester, W; Opdam, H; Warrillow, S J; Jones, D

    2016-07-01

    Although organ transplantation is well established for end-stage organ failure, many patients die on waiting lists due to insufficient donor numbers. Recently, there has been renewed interest in donation after circulatory death (DCD). In a retrospective observational study we reviewed the screening of patients considered for DCD between March 2007 and December 2012 in our hospital. Overall, 148 patients were screened, 17 of whom were transferred from other hospitals. Ninety-three patients were excluded (53 immediately and 40 after review by donation staff). The 55 DCD patients were younger than those excluded (P=0.007) and they died from hypoxic brain injury (43.6%), intraparenchymal haemorrhage (21.8%) and subarachnoid haemorrhage (14.5%). Antemortem heparin administration and bronchoscopy occurred in 50/53 (94.3%) and 22/55 (40%) of cases, respectively. Forty-eight patients died within 90 minutes and proceeded to donation surgery. Associations with not dying in 90 minutes included spontaneous ventilation mode (P=0.022), absence of noradrenaline infusion (P=0.051) and higher PaO2:FiO2 ratio (P=0.052). The number of brain dead donors did not decrease over the study period. The time interval between admission and death was longer for DCD than for the 45 brain dead donors (5 [3-11] versus 2 [2-3] days; P<0.001), and 95 additional patients received organ transplants due to DCD. Introducing a DCD program can increase potential organ donors without reducing brain dead donors. Antemortem investigations appear to be acceptable to relatives when included in the consent process.

  14. Steady and disturbed flow effects on human umbilical vein endothelial cells (HUVECs) in vascular system: an experimental study.

    PubMed

    Arslan, Nurullah; Isik, Sevim; Uykan, Ozge

    2010-01-01

    Coronary artery disease is still one of the most important reasons of the death in the world. The endothelium is the membrane of special cells which lines the interior surface of blood vessels forming an interface between circulating blood in the lumen and the rest of the vessel wall. Endothelial cells (ECs) line the entire circulatory system, from the heart to the smallest capillary. ECs dysfunction has been linked with atherosclerosis through their response to fluid forces. ECs change their morphology when exposed to mechanical stresses. The morphological responses include reorientation, elongation, and rearrangement of adhering molecules. Atherosclerotic lesions are formed in specific arterial regions, where low and oscillatory endothelial shear stress (ESS) occur. In this study, the effects of steady and disturbed flow over human umbilical vein endothelial cells (HUVECs) at different flow rates and periods were determined. Steady flow experiments were performed at flow rate of 1000 cm3/min for twenty four hours. Disturbed flow experiments simulating the flow in branching regions of arterial systems were carried out at flow rates of 250 cm3/min for five hours. The results obtained testified to the morphological changes easily observed. The directional alignment of the cells was determined in the steady flow experiments. Under disturbed flow conditions we observed not only the cell movement at the stagnation point but also the polygonal cell shape downstream the flow field.

  15. Association between Previously Diagnosed Circulatory Conditions and a Dietary Inflammatory Index

    PubMed Central

    Wirth, Michael D.; Shivappa, Nitin; Hurley, Thomas G.; Hébert, James R.

    2016-01-01

    Inflammation is a key contributor to the development or recurrence of circulatory disorders. Diet is a strong modifier of inflammation. It was hypothesized that more pro-inflammatory diets, as indicated by higher Dietary Inflammatory Index (DII) scores, would be associated with self-reported previously diagnosed circulatory disorders using National Health and Nutrition Examination Survey (NHANES) data. This analysis included NHANES respondents from 2005–2010 (n=15,693). The DII was calculated from micro and macronutrients derived from a single 24-hour recall. Logistic regression, stratified by sex and adjusted for important covariates, was used to determine the odds of previous circulatory disorder diagnoses by quartile of DII scores. Excluding hypertension, which had a prevalence of 30%, the prevalence of any circulatory disorder was 8%. Those in DII quartile 4 were 1.30 (95%CI=1.06–1.58) times more likely to have a previous circulatory disorder (excluding hypertension) compared to those in DII quartile 1. Similar findings were observed for specific CVDs including congestive heart failure, stroke, and heart attack. Participants in DII quartile 4 were more likely to have a diagnosis of hypertension compared to those in DII quartile 1 (prevalence odds ratio=1.19, 95%CI=1.05–1.34). Results tended to be stronger among females. Individuals with a previous circulatory disorder diagnosis from NHANES appear to have more pro-inflammatory diets compared to those without a previous diagnosis. Because inflammation is an important factor related to recurrence of circulatory disorders, the DII could be used in treatment programs to monitor dietary modulators of inflammation among individuals with these conditions. PMID:26923509

  16. Human Transportation System (HTS) study, volume 2

    NASA Technical Reports Server (NTRS)

    Lance, N.; Geyer, M. S.; Gaunce, M. T.

    1993-01-01

    This report summarizes work completed under the Human Transportation System Study. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems (e.g., Shuttle, Titan, etc. ) as well as proposed systems (e.g., PLS, Single-Stage-to-Orbit, etc.) to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

  17. An Overview of the Human Systems Integration Division

    NASA Technical Reports Server (NTRS)

    Gore, Brian F.

    2015-01-01

    This presentation will provide an overview of the Human Systems Integration Division, and will highlight some of the human performance modeling efforts undertaken in previously presented MIDAS human performance modeling efforts.

  18. The interactive evolution of human communication systems.

    PubMed

    Fay, Nicolas; Garrod, Simon; Roberts, Leo; Swoboda, Nik

    2010-04-01

    This paper compares two explanations of the process by which human communication systems evolve: iterated learning and social collaboration. It then reports an experiment testing the social collaboration account. Participants engaged in a graphical communication task either as a member of a community, where they interacted with seven different partners drawn from the same pool, or as a member of an isolated pair, where they interacted with the same partner across the same number of games. Participants' horizontal, pair-wise interactions led "bottom up" to the creation of an effective and efficient shared sign system in the community condition. Furthermore, the community-evolved sign systems were as effective and efficient as the local sign systems developed by isolated pairs. Finally, and as predicted by a social collaboration account, and not by an iterated learning account, interaction was critical to the creation of shared sign systems, with different isolated pairs establishing different local sign systems and different communities establishing different global sign systems.

  19. Introduction to human factors considerations in system design

    NASA Technical Reports Server (NTRS)

    Chapanis, A.

    1983-01-01

    A definition for human factors or ergonomics and its industrial and domestic application is presented. Human factors engineering, which discovers and applies information about human abilities, limitations, and other characteristics to the design of tools, machines, systems, tasks, jobs, and environments for safe, comfortable, and effective human use, is outlined. The origins of human factors and ergonomics, the philosophy of human factors, goals and objectives, systems development and design, are reviewed.

  20. Impact of obesity and bariatric surgery on metabolism and coronary circulatory function.

    PubMed

    Valenta, Ines; Dilsizian, Vasken; Quercioli, Alessandra; Jüngling, Freimut D; Ambrosio, Giuseppe; Wahl, Richard; Schindler, Thomas H

    2014-01-01

    Increases in intra-abdominal visceral adipose tissue have been widely appreciated as a risk factor for metabolic disorders such as dyslipidemia, hypertension, insulin resistance, and type 2 diabetes, whereas this is not the case for peripheral or subcutaneous obesity. While the underlying mechanisms that contribute to these differences in adipose tissue activity remain uncertain, increases in visceral fat commonly induce metabolic dysregulation, in part because of increased venous effluent of fatty acids and/or adipokines/cytokines to the liver. Increased body weight, paralleled by an increase in plasma markers of the insulin-resistance syndrome and chronic inflammation, is independently associated with coronary circulatory dysfunction. Recent data suggest that plasma proteins originating from the adipose tissue, such as endocannabinoids (EC), leptin, and adiponectin (termed adipocytes) play a central role in the regulation and control of coronary circulatory function in obesity. Positron emission tomography (PET) in concert with tracer kinetic modeling is a well established technique for quantifying regional myocardial blood flow at rest and in response to various forms of vasomotor stress. Myocardial flow reserve assessed by PET provides a noninvasive surrogate of coronary circulatory function. PET also enables the monitoring and characterization of coronary circulatory function in response to gastric bypass-induced weight loss in initially morbidly obese individuals, to medication and/or behavioral interventions related to weight, diet, and physical activity. Whether the observed improvement in coronary circulatory dysfunction via weight loss may translate to diminution in cardiovascular events awaits clinical confirmation.

  1. How to bootstrap a human communication system.

    PubMed

    Fay, Nicolas; Arbib, Michael; Garrod, Simon

    2013-01-01

    How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified items to a partner using repeated non-linguistic vocalization, repeated gesture, or repeated non-linguistic vocalization plus gesture (but without using their existing language system). Gesture proved more effective (measured by communication success) and more efficient (measured by the time taken to communicate) than non-linguistic vocalization across a range of item categories (emotion, object, and action). Combining gesture and vocalization did not improve performance beyond gesture alone. We experimentally demonstrate that gesture is a more effective means of bootstrapping a human communication system. We argue that gesture outperforms non-linguistic vocalization because it lends itself more naturally to the production of motivated signs.

  2. Ecosocietal Restoration: Reestablishing Humanity's Relationship with Natural Systems.

    ERIC Educational Resources Information Center

    Cairns, John, Jr.

    1995-01-01

    Examines the need for ecological and societal restoration to mitigate the consequences of historical changes in the relationship between human societies and natural systems. Ecosocietal restoration, or the process of reexamining human society's relationship with natural systems, is discussed. (LZ)

  3. [Pathogenic role of intracellular energy insufficiency (hypoenergy) in the development of circulatory collapse (hemodynamic shock)].

    PubMed

    Kovac, Z

    1995-06-01

    Hemodynamic shock syndrome represents an acute circulatory failure due to a decrease of arteriovenous pressure gradient. Three unrelated groups of processes, cardiogenic, vasohypotonic and hypovolemic mechanisms, are possible starting points of the shock syndrome pathogenesis. The basic features of those principal pathogenic steps are outlined in the paper. In addition, clinical practice very often encounters a complex forms of the syndrome, which include two or all three basic pathogenic mechanisms simultaneously. Direct consequence of arteriovenous pressure gradient loss is diminishing perfusion of tissues. Tissue hypoperfusion causes a progressive depletion of cellular energy rich compounds. Such lowering of cellular ATP concentration (cellular hypoenergosis), very often less than 0.1 mmol/L, plays an important pathogenic role in the conversion of homeostatic regulation processes from a negative into a positive feedback mode. Positive feedback regulation amplifies deterioration of arteriovenous blood pressure gradient loss, which reversely intensifies the degree of energy depletion in tissues. Individual cell death decreases a tissue adjustment capacity to hypoperfusion. The critical step leading to a decompensation (systemic failure) or progressive phase of the shock is the reversal of the homeostasis into the positive feedback mode of action. Final outcome of the syndrome reflects a degree of compensation capacity loss as well as irreversible tissue alterations. Clinical manifestations correlate with the underlying pathogenic processes. Short summary of clinical correlative relations with the pathogenic processes, at the cellular, molecular and/or energy level, is given in the paper.

  4. A Review of Non-Cancer Effects, Especially Circulatory and Ocular Diseases1

    PubMed Central

    Little, Mark P.

    2014-01-01

    There is a well-established association between high doses (> 5 Gy) of ionizing radiation exposure and damage to the heart and coronary arteries, although only recently have studies with high quality individual dosimetry been conducted that would enable quantification of this risk adjusting for concomitant chemotherapy. The association between lower dose exposures and late occurring circulatory disease has only recently begun to emerge in the Japanese atomic bomb survivors and in various occupationally-exposed cohorts, and is still controversial. Excess relative risks per unit dose in moderate and low dose epidemiological studies are somewhat variable, possibly a result of confounding and effect modification by well known (but unobserved) risk factors. Radiation doses of 1 Gy or more are associated with increased risk of posterior subcapsular cataract. Accumulating evidence from the Japanese atomic bomb survivors, Chernobyl liquidators, US astronauts and various other exposed groups suggest that cortical cataracts may also be associated with ionizing radiation, although there is little evidence that nuclear cataracts are radiogenic. The dose response appears to be linear, although modest thresholds (of no more than about 0.6 Gy) cannot be ruled out. A variety of other non-malignant effects have been observed after moderate/low dose exposure in various groups, in particular respiratory and digestive disease and central nervous system (and in particular neuro-cognitive) damage. However, because these are generally only observed in isolated groups, or because the evidence is excessively heterogeneous, these associations must be treated with caution. PMID:23903347

  5. Dental orthopantomogram biometrics system for human identification.

    PubMed

    Singh, Sandeep; Bhargava, Darpan; Deshpande, Ashwini

    2013-07-01

    Fingerprinting is the most widely accepted method of identification of people. But in cases of disfigured, decomposed, burnt or fragmented bodies, it is of limited value. Teeth and dental restorations on the other hand are extremely resistant to destruction by fire. They retain a number of their original characteristics, which are often unique and hence offer a possibility of rather accurate and legally acceptable identification of such remains. This study was undertaken to evaluate the utility of orthopantomography for human identification and propose a coding system for orthopantomogram (OPG), which can be utilized as an identification tool in forensic sciences.

  6. Guidance for Human-system Interfaces to Automatic Systems

    SciTech Connect

    O'Hara, J.M.; Higgins, J.; Stephen Fleger; Valerie Barnes

    2010-09-27

    Automation is ubiquitous in modern complex systems, and commercial nuclear- power plants are no exception. Automation is applied to a wide range of functions, including monitoring and detection, situation assessment, response planning, and response implementation. Automation has become a 'team player' supporting personnel in nearly all aspects of system operation. In light of its increasing use and importance in new- and future-plants, guidance is needed to conduct safety reviews of the operator's interface with automation. The objective of this research was to develop such guidance. We first characterized the important HFE aspects of automation, including six dimensions: Levels, functions, processes, modes, flexibility, and reliability. Next, we reviewed literature on the effects of all of these aspects of automation on human performance, and on the design of human-system interfaces (HSIs). Then, we used this technical basis established from the literature to identify general principles for human-automation interaction and to develop review guidelines. The guidelines consist of the following seven topics: Automation displays, interaction and control, automation modes, automation levels, adaptive automation, error tolerance and failure management, and HSI integration.

  7. The effects of space flight on the cardiopulmonary system

    NASA Technical Reports Server (NTRS)

    Nicogossian, Arnauld E.; Gaffney, F. Andrew; Garshnek, Victoria

    1989-01-01

    Alterations of the human cardiopulmonary system in space flight are examined, including fluid shifts, orthostatic intolerance, changes in cardiac dynamics and electromechanics, and changes in pulmonary function and exercise capacity. Consideration is given to lower body negative pressure data from Skylab experiments and studies on the Space Shuttle. Also, echocardiography, cardiac dysrhythmias during spaceflight, and the role of neural mechanisms in circulatory control after spaceflight are discussed.

  8. Human productivity in space and systems costs

    NASA Astrophysics Data System (ADS)

    Miller, R. H.

    Human productivity during assembly operations in-orbit is dependent on limits set by fatigue, metabolic rates, learning, and assembly techniques. In order to quantify these effects, tests were conducted in the NASA MSFC Neutral Buoyancy Simulator, in the NASA KC-135 in parabolic flight, and in space with the EASE program during the Shuttle Atlantis mission 61-B. A separate program attempted to relate productivity to system costs. Because of the surprisingly high productivity which had been demonstrated in orbit, it was shown that assembly operations would have only a small effect on system costs at the present level of launch costs. The results of these continuing studies have been reported in a recent paper(1). They will be briefly summarized here and the results updated to include additional cost elements and to examine the effects of reductions in transportation costs, resulting from advances in technology and from increased demand, on system costs. It is shown that, as launch costs are reduced, the assembly costs could become an increasingly important component of the total system costs.

  9. Success rates of long-term circulatory assist devices used currently for bridge to heart transplantation.

    PubMed

    Arabia, F A; Smith, R G; Rose, D S; Arzouman, D A; Sethi, G K; Copeland, J G

    1996-01-01

    Circulatory assist devices as bridge to heart transplantation have become more important as the number of possible recipients has increased and the number of donors remains stable. The number of patients successfully bridged and discharged home after transplantation was determined for the Novacor Left Ventricular Assist System (Baxter Healthcare Corp., Oakland, CA) (LVAS), console and wearable; the TCI Left Ventricular Assist Device (Thermo Cardio Systems Inc., Woburn, MA) (LVAD), pneumatic and electric; the Thoratec LVAD and Biventricular Assist Device (Thoratec Lab Co., Berkeley, CA) (BIVAD); and the CardioWest total artificial heart (CardioWest Tech. Inc., Tuscon, AZ) (TAH). A total of 1,286 devices (14% Novacor console, 14% Novacor wearable, 35% TCI pneumatic, 4% TCI electric, 10% thoratec LVAD, 19% Thoratec BIVAD, and 4% CardioWest TAH) were implanted worldwide since 1984. A total of 776 (60%) patients reached heart transplantation and 687 patients (88.5% of those transplanted) were discharged home. The individual success rate for each device to bridge a patient to heart transplantation and be discharged home is as follows: Novacor LVAS console, 90%; Novacor LVAS wearable, 92%; TCI LVAD pneumatic, 89%; TCI LVAD electric, 89%; Thoratec LVAD, 93%; Thoratec BIVAD, 81%; and CardioWest TAH, 92%. The success rate with all the available systems to bridge a patient to heart transplantation and be discharged home is similar for all devices. The criteria used to determine which system to be used should be individualized for each patient. Some of the factors that should be considered in making a decision on which device to use should include anticoagulation, univentricular vs biventricular failure, mobility, protocol to discharge home, and size of the patient.

  10. 1988 workshop on human-machine symbiotic systems

    SciTech Connect

    Parker, L.E.; Weisbin, C.R.

    1988-01-01

    This report presents the proceedings of the 1988 Workshop on Human-Machine Symbiotic Systems. Held December 5-6, 1988 in Oak Ridge, Tennessee, the workshop served as a forum for the discussion of several critical issues in human-machine symbiosis: human-machine communication, autonomous task planning and execution monitoring for heterogeneous agents, dynamic task allocation, human-machine system architecture, and machine learning via experience and human observation.

  11. Unifying Human Centered Design and Systems Engineering for Human Systems Integration

    NASA Technical Reports Server (NTRS)

    Boy, Guy A.; McGovernNarkevicius, Jennifer

    2013-01-01

    Despite the holistic approach of systems engineering (SE), systems still fail, and sometimes spectacularly. Requirements, solutions and the world constantly evolve and are very difficult to keep current. SE requires more flexibility and new approaches to SE have to be developed to include creativity as an integral part and where the functions of people and technology are appropriately allocated within our highly interconnected complex organizations. Instead of disregarding complexity because it is too difficult to handle, we should take advantage of it, discovering behavioral attractors and the emerging properties that it generates. Human-centered design (HCD) provides the creativity factor that SE lacks. It promotes modeling and simulation from the early stages of design and throughout the life cycle of a product. Unifying HCD and SE will shape appropriate human-systems integration (HSI) and produce successful systems.

  12. Dendrimer brain uptake and targeted therapy for brain injury in a large animal model of hypothermic circulatory arrest.

    PubMed

    Mishra, Manoj K; Beaty, Claude A; Lesniak, Wojciech G; Kambhampati, Siva P; Zhang, Fan; Wilson, Mary A; Blue, Mary E; Troncoso, Juan C; Kannan, Sujatha; Johnston, Michael V; Baumgartner, William A; Kannan, Rangaramanujam M

    2014-03-25

    Treatment of brain injury following circulatory arrest is a challenging health issue with no viable therapeutic options. Based on studies in a clinically relevant large animal (canine) model of hypothermic circulatory arrest (HCA)-induced brain injury, neuroinflammation and excitotoxicity have been identified as key players in mediating the brain injury after HCA. Therapy with large doses of valproic acid (VPA) showed some neuroprotection but was associated with adverse side effects. For the first time in a large animal model, we explored whether systemically administered polyamidoamine (PAMAM) dendrimers could be effective in reaching target cells in the brain and deliver therapeutics. We showed that, upon systemic administration, hydroxyl-terminated PAMAM dendrimers are taken up in the brain of injured animals and selectively localize in the injured neurons and microglia in the brain. The biodistribution in other major organs was similar to that seen in small animal models. We studied systemic dendrimer-drug combination therapy with two clinically approved drugs, N-acetyl cysteine (NAC) (attenuating neuroinflammation) and valproic acid (attenuating excitotoxicity), building on positive outcomes in a rabbit model of perinatal brain injury. We prepared and characterized dendrimer-NAC (D-NAC) and dendrimer-VPA (D-VPA) conjugates in multigram quantities. A glutathione-sensitive linker to enable for fast intracellular release. In preliminary efficacy studies, combination therapy with D-NAC and D-VPA showed promise in this large animal model, producing 24 h neurological deficit score improvements comparable to high dose combination therapy with VPA and NAC, or free VPA, but at one-tenth the dose, while significantly reducing the adverse side effects. Since adverse side effects of drugs are exaggerated in HCA, the reduced side effects with dendrimer conjugates and suggestions of neuroprotection offer promise for these nanoscale drug delivery systems.

  13. Circulatory osmotic desalination driven by a mild temperature gradient based on lower critical solution temperature (LCST) phase transition materials.

    PubMed

    Mok, Yeongbong; Nakayama, Daichi; Noh, Minwoo; Jang, Sangmok; Kim, Taeho; Lee, Yan

    2013-11-28

    Abrupt changes in effective concentration and osmotic pressure of lower critical solution temperature (LCST) mixtures facilitate the design of a continuous desalination method driven by a mild temperature gradient. We propose a prototype desalination system by circulating LCST mixtures between low and high temperature (low T and high T) units. Water molecules could be drawn from a high-salt solution to the LCST mixture through a semipermeable membrane at a temperature lower than the phase transition temperature, at which the effective osmotic pressure of the LCST mixture is higher than the high-salt solution. After transfer of water to the high T unit where the LCST mixture is phase-separated, the water-rich phase could release the drawn water into a well-diluted solution through the second membrane due to the significant decrease in effective concentration. The solute-rich phase could be recovered in the low T unit via a circulation process. The molar mass, phase transition temperature, and aqueous solubility of the LCST solute could be tuneable for the circulatory osmotic desalination system in which drawing, transfer, release of water, and the separation and recovery of the solutes could proceed simultaneously. Development of a practical desalination system that draws water molecules directly from seawater and produces low-salt water with high purity by mild temperature gradients, possibly induced by sunlight or waste heat, could be attainable by a careful design of the molecular structure and combination of the circulatory desalination systems based on low- and high-molar-mass LCST draw solutes.

  14. Are Human and Natural Systems Decoupling?

    NASA Astrophysics Data System (ADS)

    Ehrlich, P. R.; Ehrlich, A. H.

    2012-12-01

    Typically, studies of coupled human and natural systems focus on reciprocating interactions and feedbacks between social systems and their biophysical environments. A major challenge today for CHANS scholars is to determine whether significant coupling remains or whether society is simply plunging ahead without reacting effectively to the deterioration of the environment. Thresholds for serious climate disruption are passing, toxification of Earth is proceeding apace and producing worrying symptoms, losses of vital biodiversity are at a 65 million-year high with serious consequences for ecosystem services, the epidemiological environment is deteriorating and a race is building to control water flows and extract the last high-quality resources, increasing the chances of ending civilization in an environment-wrecking nuclear war. The social system has attempted to respond to this perfect storm of problems. In the 1960s, building on much earlier work, scientists began assessing the consequences of an ever-growing human population and expanding consumption, overuse of pesticides, radioactive fallout, air and water pollution, and other environmental issues - and to recommend ameliorative steps. In the mid-1980s, biologists formed the discipline of conservation biology with the explicit purpose of stemming the hemorrhage of biodiversity. In the late 1980s, perhaps the single most important reaction to the worsening environmental situation was the development of the Montreal Protocol to preserve the vital stratospheric ozone layer. Around the same time, it dawned on the scientific community that climate disruption was going to be more immediate and dangerous than previously thought, but attempts by the world community to take mitigating steps have been pathetic. Action to deal with other dimensions of the environmental dilemma has been utterly inadequate. To see the growing disconnect, one only has to consider the attention paid in public discourse to the relatively

  15. Launch Pad Escape System Design (Human Spaceflight)

    NASA Technical Reports Server (NTRS)

    Maloney, Kelli

    2011-01-01

    A launch pad escape system for human spaceflight is one of those things that everyone hopes they will never need but is critical for every manned space program. Since men were first put into space in the early 1960s, the need for such an Emergency Escape System (EES) has become apparent. The National Aeronautics and Space Administration (NASA) has made use of various types of these EESs over the past 50 years. Early programs, like Mercury and Gemini, did not have an official launch pad escape system. Rather, they relied on a Launch Escape System (LES) of a separate solid rocket motor attached to the manned capsule that could pull the astronauts to safety in the event of an emergency. This could only occur after hatch closure at the launch pad or during the first stage of flight. A version of a LES, now called a Launch Abort System (LAS) is still used today for all manned capsule type launch vehicles. However, this system is very limited in that it can only be used after hatch closure and it is for flight crew only. In addition, the forces necessary for the LES/LAS to get the capsule away from a rocket during the first stage of flight are quite high and can cause injury to the crew. These shortcomings led to the development of a ground based EES for the flight crew and ground support personnel as well. This way, a much less dangerous mode of egress is available for any flight or ground personnel up to a few seconds before launch. The early EESs were fairly simple, gravity-powered systems to use when thing's go bad. And things can go bad very quickly and catastrophically when dealing with a flight vehicle fueled with millions of pounds of hazardous propellant. With this in mind, early EES designers saw such a passive/unpowered system as a must for last minute escapes. This and other design requirements had to be derived for an EES, and this section will take a look at the safety design requirements had to be derived for an EES, and this section will take a look at

  16. A systems engineering view of the human in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1987-01-01

    A model of the human as an 'engineered' system provides a starting point for determining human requirements and performance on an equivalent basis with technological systems. The human as an engineered system with performance requirements is defined to consist of four subsystems: cognitive, psychological, biomechanical, and biomedical. It is suggested that the treatment of the psychological subsystem as one that modulates the efficiency and quality of human performance offers a particular approach for examining and characterizing psychological effects.

  17. Sex differences in the human olfactory system.

    PubMed

    Garcia-Falgueras, Alicia; Junque, Carme; Giménez, Mónica; Caldú, Xavier; Segovia, Santiago; Guillamon, Antonio

    2006-10-20

    The olfactory system (accessory) implicated in reproductive physiology and behavior in mammals is sexually dimorphic. These brain sex differences present two main characteristics: they are seen in neural circuits related to sexual behavior and sexual physiology and they take one of two opposite morphological patterns (male>female or female>male). The present work reports sex differences in the olfactory system in a large homogeneous sample of men (40) and women (51) using of voxel-based morphology. Gray matter concentration showed sexual dimorphism in several olfactory regions. Women have a higher concentration in the orbitofrontal cortex involving Brodmann's areas 10, 11 and 25 and temporomedial cortex (bilateral hippocampus and right amygdala), as well as their left basal insular cortex. In contrast, men show a higher gray matter concentration in the left entorhinal cortex (Brodmann's area 28), right ventral pallidum, dorsal left insular cortex and a region of the orbitofrontal cortex (Brodmann's area 25). This study supports the hypothesis that the mammalian olfactory system is a sexually dimorphic network and provides a theoretical framework for the morphofunctional approach to sex differences in the human brain.

  18. Sympathetic nervous system behavior in human obesity.

    PubMed

    Davy, Kevin P; Orr, Jeb S

    2009-02-01

    The sympathetic nervous system (SNS) plays an essential role in the regulation of metabolic and cardiovascular homeostasis. Low SNS activity has been suggested to be a risk factor for weight gain and obesity development. In contrast, SNS activation is characteristic of a number of metabolic and cardiovascular diseases that occur more frequently in obese individuals. Until recently, the relation between obesity and SNS behavior has been controversial because previous approaches for assessing SNS activity in humans have produced inconsistent findings. Beginning in the early 1990s, many studies using state of the art neurochemical and neurophysiological techniques have provided important insight. The purpose of the present review is to provide an overview of our current understanding of the region specific alterations in SNS behavior in human obesity. We will discuss findings from our own laboratory which implicate visceral fat as an important depot linking obesity with skeletal muscle SNS activation. The influence of weight change on SNS behavior and the potential mechanisms and consequences of region specific SNS activation in obesity will also be considered.

  19. The human as supervisor in automated systems

    NASA Technical Reports Server (NTRS)

    Mitchell, C. M.

    1983-01-01

    This hierarchical approach to information display forces the development of a set of human oriented system models which will guide the design of the displays. If the appropriate information is provided at the appropriate time, it is likely that less information will be displayed at any given time, and the quality of the displayed information will require less operator effort to integrate into an assimilatable form. A problem with contemporary control rooms is that there is too much information for an operator to be able to assimilate quickly, easily, and accurately. It is suggested that necessary direction for research in the area of automated control room design is to develop displays which provide active decision aiding for the modern controller. Displays are needed which provide information compatible with the operator's current internal model, filter out irrelevant information, and summarize and condense lower level information.

  20. Human language is a culturally evolving system.

    PubMed

    Steels, Luc

    2017-02-01

    It is well accepted that languages change rapidly in a process of cultural evolution. But some animal communication systems, in particular bird song, also exhibit cultural change. So where exactly is the difference? This article argues that the main selectionist pressure on human languages is not biological-that is, related to survival and fecundity-but instead is linked to producing enough expressive power for the needs of the community, maximizing communicative success, and reducing cognitive effort. The key question to be answered by an "evolutionary linguistics" approach to language is, What are the causal mechanisms sustaining an evolutionary dynamic based on these selection criteria? In other words, what cognitive mechanisms and social interaction patterns are needed, and how do they allow a language to emerge and remain shared, despite profound variation and never-ending change?

  1. [Viral infections of human central nervous system].

    PubMed

    Agut, Henri

    2016-01-01

    The viruses that can infect the central nervous system of humans are numerous and form a heterogeneous group with respect to their structural, functional and epidemiological properties. The pathophysiological mechanisms leading to associated neurological diseases, mainly meningitis and encephalitis, also are complex and often intertwined. Overall, neurological clinical symptoms correspond either to acute viral diseases associated with primary infections or to acute, subacute or chronic diseases associated with persistent viral infections. The frequent severity of the clinical situation requires in all cases the practice of virological diagnosis for which the PCR techniques applied to cerebrospinal fluid samples occupy a prominent place. The severity of clinical manifestations justifies the use of prophylactic vaccination when available and antiviral treatment as soon as the causative virus is identified or suspected.

  2. The physiology of dinosaurs: circulatory and respiratory function in the largest animals ever to walk the earth.

    PubMed

    Pierson, David J

    2009-07-01

    The cardiopulmonary physiology of dinosaurs-and especially of the long-necked sauropods, which grew much larger than any land animals before or since-should be inherently fascinating to anyone involved in respiratory care. What would the blood pressure be in an animal 12 m (40 ft) tall? How could airway resistance and dead space be overcome while breathing through a trachea 9 m (30 ft) long? The last decade has seen a dramatic increase in evidence bearing on these questions. Insight has come not only from new fossil discoveries but also from comparative studies of living species, clarification of evolutionary relationships, new evaluation techniques, computer modeling, and discoveries about the earth's ancient atmosphere. Pumping a vertical column of blood 8 m (26 ft) above the heart would probably require an arterial blood pressure > 600 mm Hg, and the implications of this for cardiac size and function have led to the proposal of several alternative cardiopulmonary designs. Diverse lines of evidence suggest that the giant sauropods were probably warm-blooded and metabolically active when young, but slowed their metabolism as they approached adult size, which diminished the load on the circulatory system. Circulatory considerations leave little doubt that the dinosaurs had 4-chambered hearts. Birds evolved from dinosaurs, and the avian-type air-sac respiratory system, which is more efficient than its mammalian counterpart, may hold the answer to the breathing problems posed by the sauropods' very long necks. Geochemical and other data indicate that, at the time the dinosaurs first appeared, the atmospheric oxygen concentration was only about half of what it is today, and development of the avian-type respiratory system may have been key in the dinosaurs' evolutionary success, enabling them to out-compete the mammals and dominate the land for 150 million years.

  3. Systems biology of human benzene exposure

    PubMed Central

    Zhang, Luoping; McHale, Cliona M.; Rothman, Nathaniel; Li, Guilan; Ji, Zhiying; Vermeulen, Roel; Hubbard, Alan E.; Ren, Xuefeng; Shen, Min; Rappaport, Stephen M.; North, Matthew; Skibola, Christine F.; Yin, Songnian; Vulpe, Christopher; Chanock, Stephen J.; Smith, Martyn T.; Lan, Qing

    2010-01-01

    Toxicogenomic studies, including genome-wide analyses of susceptibility genes (genomics), gene expression (transcriptomics), protein expression (proteomics), and epigenetic modifications (epigenomics), of human populations exposed to benzene are crucial to understanding gene-environment interactions, providing the ability to develop biomarkers of exposure, early effect and susceptibility. Comprehensive analysis of these toxicogenomic and epigenomic profiles by bioinformatics in the context of phenotypic endpoints, comprises systems biology, which has the potential to comprehensively define the mechanisms by which benzene causes leukemia. We have applied this approach to a molecular epidemiology study of workers exposed to benzene. Hematotoxicity, a significant decrease in almost all blood cell counts, was identified as a phenotypic effect of benzene that occurred even below 1ppm benzene exposure. We found a significant decrease in the formation of progenitor colonies arising from bone marrow stem cells with increasing benzene exposure, showing that progenitor cells are more sensitive to the effects of benzene than mature blood cells, likely leading to the observed hematotoxicity. Analysis of transcriptomics by microarray in the peripheral blood mononuclear cells of exposed workers, identified genes and pathways (apoptosis, immune response, and inflammatory response) altered at high (>10ppm) and low (<1ppm) benzene levels. Serum proteomics by SELDI-TOF-MS revealed proteins consistently down-regulated in exposed workers. Preliminary epigenomics data showed effects of benzene on the DNA methylation of specific genes. Genomic screens for candidate genes involved in susceptibility to benzene toxicity are being undertaken in yeast, with subsequent confirmation by RNAi in human cells, to expand upon the findings from candidate gene analyses. Data on these and future biomarkers will be used to populate a large toxicogenomics database, to which we will apply bioinformatic

  4. Measurement of Human Blood and Plasma Volumes

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Szalkay, H. G. H.

    1987-01-01

    Report reviews techniques for measuring blood-plasma volume in humans. Common technique of using radioactive iodine isotope to label plasma albumin involves unwarranted risks from low-level radiation. Report emphasizes techniques using Evans-blue-dye (T-1824) labeling of albumin, hematocrit or hemoglobin/hematocrit measurements, or blood densitometry. In Evans-blue-dye technique, plasma volume determined from decrease in dye concentration occurring after small amount of dye solution injected into circulatory system. Subjection of Evans blue dye to test for carcinogenicity gave negative results.

  5. Coupled Human-Atmosphere-System Thinking

    NASA Astrophysics Data System (ADS)

    Schmale, Julia; Chabay, Ilan

    2014-05-01

    minimize atmospheric release, but rather only complies with either climate or air quality requirements. Nor do current narratives promote behavioral change for the overall reduction of emissions (e.g., you can drive your diesel SUV as long as it has a low fuel consumption). This divide and thinking has not only been manifested in policy and regulations and hence media coverage, but has also shaped the public's general perception of this issue. There is no public conceptual understanding regarding humanity's modification of the atmosphere through the continuously and simultaneously released substances by almost any kind of activity and resulting impacts. Here, we propose a conceptual framework that provides a new perspective on the coupled human-atmosphere-system. It makes tangible the inherent linkages between the socio-economic system, the atmospheric physico-chemical changes and impacts, and legal frameworks for sustainable transformations at all levels. To implement HAS-thinking in decision and policy making, both salient disciplinary and interdisciplinary research and comprehensive science-society interactions in the form of transdisciplinary research are necessary. Societal transformations for the sake of a healthy human-atmosphere relationship are highly context dependent and require discussions of normative and value-related issues, which can only be solved through co-designed solutions. We demonstrate the importance of HAS-thinking by examples of sustainable development in the Arctic and Himalayan countries.

  6. The innate immune system in human systemic lupus erythematosus.

    PubMed

    Weidenbusch, Marc; Kulkarni, Onkar P; Anders, Hans-Joachim

    2017-04-25

    Although the role of adaptive immune mechanisms, e.g. autoantibody formation and abnormal T-cell activation, has been long noted in the pathogenesis of human systemic lupus erythematosus (SLE), the role of innate immunity has been less well characterized. An intricate interplay between both innate and adaptive immune elements exists in protective anti-infective immunity as well as in detrimental autoimmunity. More recently, it has become clear that the innate immune system in this regard not only starts inflammation cascades in SLE leading to disease flares, but also continues to fuel adaptive immune responses throughout the course of the disease. This is why targeting the innate immune system offers an additional means of treating SLE. First trials assessing the efficacy of anti-type I interferon (IFN) therapy or modulators of pattern recognition receptor (PRR) signalling have been attempted. In this review, we summarize the available evidence on the role of several distinct innate immune elements, especially neutrophils and dendritic cells as well as the IFN system, as well as specific innate PRRs along with their signalling pathways. Finally, we highlight recent clinical trials in SLE addressing one or more of the aforementioned components of the innate immune system.

  7. 9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected,...

  8. 9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected,...

  9. 9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected,...

  10. 9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected,...

  11. Sulfide intoxication induced circulatory failure is mediated by a depression in cardiac contractility

    PubMed Central

    Sonobe, Takashi; Haouzi, Philippe

    2015-01-01

    Hydrogen sulfide (H2S) intoxication produces a rapid cardio-circulatory failure leading to cardiac arrest. In non-lethal forms of sulfide exposure, the presence of a circulatory shock is associated with long-term neurological sequelae. Our aim was to clarify the mechanisms of H2S-induced circulatory failure. In anesthetized paralyzed and mechanically ventilated rats, cardiac output, arterial pressure and ventricular pressures were determined while NaHS was infused to increase arterial concentration of soluble H2S (CgH2S) from undetectable to levels leading to circulatory failure. Compared to control/saline infusion, blood pressure started to decrease significantly along with a modest drop in peripheral vascular resistance (-19 ± 5%, P<0.01), when CgH2S reached about 1 microM. As CgH2S exceeded 2-3 microM, parameters of ventricular contractility diminished with no further reduction in peripheral resistance. Whenever H2S exposure was maintained at a higher level (CgH2S over 7 microM), a clear inhibition of cardiac contractility was observed, leading to asystole within minutes, but with no evidence of peripheral vasoplegia. The immediate and long-term neurological effects of specifically counteracting sulfide induced cardiac contractility depression following H2S exposure remain to be investigated. PMID:25616319

  12. Lung transplantation from donors after circulatory death using portable ex vivo lung perfusion

    PubMed Central

    Bozso, Sabin; Vasanthan, Vishnu; Luc, Jessica GY; Kinaschuk, Katie; Freed, Darren; Nagendran, Jayan

    2015-01-01

    BACKGROUND: Donation after circulatory death is a novel method of increasing the number of donor lungs available for transplantation. Using organs from donors after circulatory death has the potential to increase the number of transplants performed. METHODS: Three bilateral lung transplants from donors after circulatory death were performed over a six-month period. Following organ retrieval, all sets of lungs were placed on a portable ex vivo lung perfusion device for evaluation and preservation. RESULTS: Lung function remained stable during portable ex vivo perfusion, with improvement in partial pressure of oxygen/fraction of inspired oxygen ratios. Mechanical ventilation was discontinued within 48 h for each recipient and no patient stayed in the intensive care unit longer than eight days. There was no postgraft dysfunction at 72 h in two of the three recipients. Ninety-day mortality for all recipients was 0% and all maintain excellent forced expiratory volume in 1 s and forced vital capacity values post-transplantation. CONCLUSION: The authors report excellent results with their initial experience using donors after circulatory death after portable ex vivo lung perfusion. It is hoped this will allow for the most efficient use of available donor lungs, leading to more transplants and fewer deaths for potential recipients on wait lists. PMID:25379654

  13. 'In parallel' interconnectivity of the dorsal longitudinal anastomotic vessels requires both VEGF signaling and circulatory flow.

    PubMed

    Zygmunt, Tomasz; Trzaska, Sean; Edelstein, Laura; Walls, Johnathon; Rajamani, Saathyaki; Gale, Nicholas; Daroles, Laura; Ramírez, Craig; Ulrich, Florian; Torres-Vázquez, Jesús

    2012-11-01

    Blood vessels deliver oxygen, nutrients, hormones and immunity factors throughout the body. To perform these vital functions, vascular cords branch, lumenize and interconnect. Yet, little is known about the cellular, molecular and physiological mechanisms that control how circulatory networks form and interconnect. Specifically, how circulatory networks merge by interconnecting 'in parallel' along their boundaries remains unexplored. To examine this process we studied the formation and functional maturation of the plexus that forms between the dorsal longitudinal anastomotic vessels (DLAVs) in the zebrafish. We find that the migration and proliferation of endothelial cells within the DLAVs and their segmental (Se) vessel precursors drives DLAV plexus formation. Remarkably, the presence of Se vessels containing only endothelial cells of the arterial lineage is sufficient for DLAV plexus morphogenesis, suggesting that endothelial cells from the venous lineage make a dispensable or null contribution to this process. The discovery of a circuit that integrates the inputs of circulatory flow and vascular endothelial growth factor (VEGF) signaling to modulate aortic arch angiogenesis, together with the expression of components of this circuit in the trunk vasculature, prompted us to investigate the role of these inputs and their relationship during DLAV plexus formation. We find that circulatory flow and VEGF signaling make additive contributions to DLAV plexus morphogenesis, rather than acting as essential inputs with equivalent contributions as they do during aortic arch angiogenesis. Our observations underscore the existence of context-dependent differences in the integration of physiological stimuli and signaling cascades during vascular development.

  14. The environmental light influences the circulatory levels of retinoic acid and associates with hepatic lipid metabolism.

    PubMed

    Pang, Wenqiang; Li, Chunying; Zhao, Yue; Wang, Shiming; Dong, Wei; Jiang, Pengjiu; Zhang, Jianfa

    2008-12-01

    Environmental light is involved in the regulation of photochemical reaction in mouse retina. It remains unclear whether light-mediated increase in all-trans retinoic acid (ATRA) synthesis in retina will result in altering the circulatory levels of ATRA and regulating downstream gene expression and physiological function. Here we showed circulatory levels of ATRA decreased in mice under constant darkness and elevated by light exposure. Fat gene pancreatic lipase-related protein 2 (mPlrp2) and its partner procolipase (mClps), but not hepatic lipase (mHl), activated in livers for responding to lack of light illuminating. Light-triggered alterations in circulatory ATRA levels regulated ecto-5'-nucleotidase gene expression by retinoic acid receptor retinoic acid receptor-alpha and modulated 5'-AMP levels in blood and were associated with mPlrp2 and mClps expression in the livers. Mice deficient in adenosine receptors displayed mPlrp2 and mClps expression in livers under 12-h light, 12-h dark cycles. Caffeine blocked adenosine receptors and induced hepatic mPlrp2 and mClps expression in wild-type mice. Mice activated in hepatic mPlrp2 and mClps expression lowered hepatic and serum lipid levels and markedly elevated circulatory levels of all-trans retinol. Our results suggest environmental light influence hepatic lipid homeostasis by light-modulated retinoic acid signaling associated with mPlrp2 and mClps gene expression in livers.

  15. Study report on modification of the long term circulatory model for the simulation of bed rest

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.; Grounds, D. J.

    1977-01-01

    Modifications were made of the circulatory, fluid, and electrolyte control model which was based on the model of Guyton. The modifications included separate leg compartments and the addition of gravity dependency. It was found that these modifications allowed for more accurate bed rest simulation by simulating changes in the orthostatic gradient and simulating the response to the fluid shifts associated with bed rest.

  16. [Disorders of mental function in patients with circulatory encephalopathy due to hypertension and atherosclerosis].

    PubMed

    Voloshin, P V; Kryzhenko, T V; Mishchenko, T S; Shestopalova, L F

    1989-07-01

    The authors described the dynamics of disorders of memory, attention and thinking in the course of treatment of patients with circulatory encephalopathy. It was shown that treatment resulted a prevailing regression of neurodynamic disorders of the higher psychic functions that was more productive at early stages of cerebrovascular insufficiency.

  17. Thirty-Five Years of Mechanical Circulatory Support at the Texas Heart Institute

    PubMed Central

    Gemmato, Courtney J.; Forrester, Matthew D.; Myers, Timothy J.; Frazier, O. H.; Cooley, Denton A.

    2005-01-01

    Since the 1960s, the Texas Heart Institute has been intimately involved in the development of mechanical circulatory support devices (for example, ventricular assist devices, aortic counterpulsation pumps, and total artificial hearts) for both short- and long-term use. Here, we review the varied clinical experience with these technologies at the Texas Heart Institute over the last 35 years. PMID:16107108

  18. On the circulatory subsonic flow of a compressible fluid past a circular cylinder

    NASA Technical Reports Server (NTRS)

    Bers, Lipman

    1945-01-01

    The circulatory subsonic flow around an infinite circular cylinder is computed using the linearized pressure-volume relation, by a method developed in a previous report. Formulas and graphs are given for the velocity and pressure distributions, the circulation, the lift, and the dependence of the critical Mach number upon the position of the stagnation point.

  19. Human factors/ergonomics as a systems discipline? "The human use of human beings" revisited.

    PubMed

    Hollnagel, Erik

    2014-01-01

    Discussions of the possible future of Human factors/ergonomics (HFE) usually take the past for granted in the sense that the future of HFE is assumed to be more of the same. This paper argues that the nature of work in the early 2010s is so different from the nature of work when HFE was formulated 60-70 years ago that a critical reassessment of the basis for HFE is needed. If HFE should be a systems discipline, it should be a soft systems rather than a hard systems discipline. It is not enough for HFE to seek to improve performance and well-being through systems design, since any change to the work environment in principle alters the very basis for the change. Instead HFE should try to anticipate how the nature of work will change so that it can both foresee what work will be and propose what work should be.

  20. Building a Human Rights Youth Justice System

    ERIC Educational Resources Information Center

    Wyles, Paul

    2009-01-01

    The Australian Capital Territory's Human Rights Act 2004 and the establishment of an ACT Human Rights Commission have begun to create a human rights culture in the ACT. This paper highlights the influence of this culture on the design and build of the ACT's new youth justice centre. (Contains 2 figures.)

  1. Reorganization of the human central nervous system.

    PubMed

    Schalow, G; Zäch, G A

    2000-10-01

    The key strategies on which the discovery of the functional organization of the central nervous system (CNS) under physiologic and pathophysiologic conditions have been based included (1) our measurements of phase and frequency coordination between the firings of alpha- and gamma-motoneurons and secondary muscle spindle afferents in the human spinal cord, (2) knowledge on CNS reorganization derived upon the improvement of the functions of the lesioned CNS in our patients in the short-term memory and the long-term memory (reorganization), and (3) the dynamic pattern approach for re-learning rhythmic coordinated behavior. The theory of self-organization and pattern formation in nonequilibrium systems is explicitly related to our measurements of the natural firing patterns of sets of identified single neurons in the human spinal premotor network and re-learned coordinated movements following spinal cord and brain lesions. Therapy induced cell proliferation, and maybe, neurogenesis seem to contribute to the host of structural changes during the process of re-learning of the lesioned CNS. So far, coordinated functions like movements could substantially be improved in every of the more than 100 patients with a CNS lesion by applying coordination dynamic therapy. As suggested by the data of our patients on re-learning, the human CNS seems to have a second integrative strategy for learning, re-learning, storing and recalling, which makes an essential contribution of the functional plasticity following a CNS lesion. A method has been developed by us for the simultaneous recording with wire electrodes of extracellular action potentials from single human afferent and efferent nerve fibres of undamaged sacral nerve roots. A classification scheme of the nerve fibres in the human peripheral nervous system (PNS) could be set up in which the individual classes of nerve fibres are characterized by group conduction velocities and group nerve fibre diameters. Natural impulse patterns

  2. Human Factors in Command-and-Control System Procurement,

    DTIC Science & Technology

    1985-12-01

    requirement for the equipment designer to take account of the human operator in the design and development of systems. Accordingly, human factors...they fail to take account of software development and the flow of information between the human and the machine. There has been a growing awareness... account of the human operator in the design and development of systems. Meister and Rabideau (1965) indicated that the concern centred on the ability

  3. Analysis of Dose Response for Circulatory Disease After Radiotherapy for Benign Disease

    SciTech Connect

    Little, Mark P.; Kleinerman, Ruth A.; Stovall, Marilyn; Smith, Susan A.; Mabuchi, Kiyohiko

    2012-12-01

    Purpose: To assess the shape of the dose-response for various circulatory disease endpoints, and modifiers by age and time since exposure. Methods and Materials: This was an analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by circulatory disease endpoint (ischemic heart, cerebrovascular, other circulatory disease). Results: There were significant excess risks for all circulatory disease, with an excess relative risk Gy{sup -1} of 0.082 (95% CI 0.031-0.140), and ischemic heart disease, with an excess relative risk Gy{sup -1} of 0.102 (95% CI 0.039-0.174) (both p = 0.01), and indications of excess risk for stroke. There were no statistically significant (p > 0.2) differences between risks by endpoint, and few indications of curvature in the dose-response. There were significant (p < 0.001) modifications of relative risk by time since exposure, the magnitude of which did not vary between endpoints (p > 0.2). Risk modifications were similar if analysis was restricted to patients receiving radiation, although the relative risks were slightly larger and the risk of stroke failed to be significant. The slopes of the dose-response were generally consistent with those observed in the Japanese atomic bomb survivors and in occupationally and medically exposed groups. Conclusions: There were excess risks for a variety of circulatory diseases in this dataset, with significant modification of risk by time since exposure. The consistency of the dose-response slopes with those observed in radiotherapeutically treated groups at much higher dose, as well as in lower dose-exposed cohorts such as the Japanese atomic bomb survivors and nuclear workers, implies that there may be little sparing effect of fractionation of dose or low-dose-rate exposure.

  4. Blood-gas and circulatory changes during total knee replacement. Role of the intramedullary alignment rod.

    PubMed

    Fahmy, N R; Chandler, H P; Danylchuk, K; Matta, E B; Sunder, N; Siliski, J M

    1990-01-01

    The use of an intramedullary alignment rod in the distal part of the femur is an important step in performing total knee-replacement arthroplasty. On the basis of our observation of a sudden decrease in oxygen saturation in some patients after insertion of the rod, a prospective study was done of the circulatory and blood-gas changes that were associated with insertion in thirty-five patients. We examined the effects of the use of an eight-millimeter solid alignment rod, with and without venting; an eight-millimeter fluted alignment rod, with venting; and an eight-millimeter fluted or solid alignment rod, inserted through a 12.7-millimeter drill-hole, but without other venting. A statistically significant reduction in oxygen saturation, arterial oxygen tension (PaO2), and end-tidal carbon-dioxide tension (PETCO2) occurred after insertion of both solid and fluted eight-millimeter alignment rods through an eight-millimeter hold in both vented and unvented femoral canals, in association with a significant increase (p less than 0.01) in intramedullary pressure. Bone-marrow contents and fat were retrieved from samples of blood from the right atrium, indicating that embolization of marrow contents had occurred during insertion of the alignment rod. A small decrease in systemic blood pressure and heart rate also occurred. These changes were completely eliminated by the use of a 12.7-millimeter drill-hole as the entry site of the eight-millimeter fluted rod. We concluded that insertion of an intramedullary alignment rod in the femur causes embolization of marrow contents, which decreases arterial oxygen tension, oxygen saturation, end-tidal carbon-dioxide tension, arterial blood pressure, and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Risk of mortality from circulatory diseases in Mayak workers cohort following occupational radiation exposure.

    PubMed

    Azizova, T V; Grigorieva, E S; Hunter, N; Pikulina, M V; Moseeva, M B

    2015-09-01

    Mortality from circulatory diseases (CD) (ICD-9 codes 390-459) was studied in an extended Mayak worker cohort, which included 22,377 workers first employed at the Mayak Production Association in 1948-1982 and followed up to the end of 2008. The enlarged cohort and extended follow-up as compared to the previous analyses provided an increased number of deaths from CD and improved statistical power of this mortality study. The analyses were based on dose estimates provided by a new Mayak Worker Dosimetry System 2008 (MWDS-2008). For the first time in the study of non-cancer effects in this cohort quantitative smoking data (smoking index) were taken into account. A significant increasing trend for CD mortality with increasing dose from external gamma-rays was found after having adjusted for non-radiation factors; the excess relative risk per unit dose (ERR/Gy) was 0.05 (95% confidence interval (CI):  >0, 0.11). Inclusion of an additional adjustment for dose from internal alpha-radiation to the liver resulted in a two-fold increase of ERR/Gy = 0.10 (95% CI: 0.02, 0.21). A significant increasing trend in CD mortality with increasing dose from internal alpha-radiation to the liver was observed (ERR/Gy = 0.27, 95% CI: 0.12, 0.48). However the ERR/Gy decreased and lost its significance after adjusting for dose from external gamma-rays. Results of the current study are in good agreement with risk estimates obtained for the Japanese LSS cohort as well as other studies of cohorts of nuclear workers.

  6. Development of a preclinical model of donation after circulatory determination of death for translational application

    PubMed Central

    2014-01-01

    Background Extracorporeal membranous oxygenation is proposed for abdominal organ procurement from donation after circulatory determination of death (DCD). In France, the national Agency of Biomedicine supervises the procurement of kidneys from DCD, specifying the durations of tolerated warm and cold ischemia. However, no study has determined the optimal conditions of this technique. The aim of this work was to develop a preclinical model of DCD using abdominal normothermic oxygenated recirculation (ANOR). In short, our objectives are to characterize the mechanisms involved during ANOR and its impact on abdominal organs. Methods We used Large White pigs weighing between 45 and 55 kg. After 30 minutes of potassium-induced cardiac arrest, the descending thoracic aorta was clamped and ANOR set up between the inferior vena cava and the abdominal aorta for 4 hours. Hemodynamic, respiratory and biochemical parameters were collected. Blood gasometry and biochemistry analysis were performed during the ANOR procedure. Results Six ANOR procedures were performed. The surgical procedure is described and intraoperative parameters and biological data are presented. Pump flow rates were between 2.5 and 3 l/min. Hemodynamic, respiratory, and biochemical objectives were achieved under reproducible conditions. Interestingly, animals remained hemodynamically stable following the targeted protocol. Arterial pH was controlled, and natremia and renal function remained stable 4 hours after the procedure was started. Decreased hemoglobin and serum proteins levels, concomitant with increased lactate dehydrogenase activity, were observed as a consequence of the surgery. The serum potassium level was increased, owing to the extracorporeal circulation circuit. Conclusions Our ANOR model is the closest to clinical conditions reported in the literature and will allow the study of the systemic and abdominal organ impact of this technique. The translational relevance of the pig will permit

  7. Safety Metrics for Human-Computer Controlled Systems

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy G; Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems.This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  8. [The environment and human respiratory system].

    PubMed

    Nikodemowicz, Marian

    2008-01-01

    The process of gas exchange that is breathing is an important element of any person's relation with the environment. What decides about our health and life are the respiratory systems responsible for the breathing process and the quality of the air we breathe. On an average through a person's life 400 millions liters of air flows which carries pollution in the form of constant gases and liquid particles. Particles of about PM-2.5 size get into the deepest structures of the respiratory system from which they are being spread into the whole organism through circulation exerting thier toxic effect on all tissues and organs. The outdoor pollution diffuses but in certain local circumstances it increases. It was so in big ecological disasters such as in 1930 in the Mozy valley in Belgium, in 1948 in the Donory region in the USA and in 1952 smog pollution in London. On an average any human being spends indoors about 60-80% of his time. The increased concentration of pollution occurs indoors and there is a possibility of exposing oneself to ETS- Environmental Tobacco Smoke. The biggest concentration of inhaled pollution takes place when smoking tobacco. Pollution of air causes diseases of the respiratory system, cardiovascular system, tumours and others. Frequent occurrence of COPD in certain areas correlates with the level of air pollution and it significantly increases in tobacco smokers. The number and frequency of bronchial asthma and the need for hospitalization depends on air pollution. Lung cancer cases were rarely described in literature before the area of industrialization and wide spread custom of tobacco smoking. Now it is the most frequently occurred cancer in the whole world. There is an interdependence of the density of population, of the number of smoked cigarettes and of density of pollution with the number lung cancer cases. It is hoped that in the future, smoking habits will be eliminated, the use of crude oil and coal will be replaced by hydroelectric

  9. Three mixed venous saturation catheters in patients with circulatory shock and respiratory failure.

    PubMed

    Rouby, J J; Poète, P; Bodin, L; Bourgeois, J L; Arthaud, M; Viars, P

    1990-10-01

    Thirty-one critically ill patients with acute respiratory failure and circulatory shock were divided into three groups. Group 1 included 11 patients with an inserted mixed venous saturation (SvO2) catheter using three-reference wavelengths and characterized by one transmitting and one detecting fiberoptic filament (Oximetrix opticath catheter); group 2 included eight patients with an inserted SvO2 catheter using two-reference wavelengths and characterized by one transmitting and one detecting fiberoptic filament; (Edwards sat-one catheter); group 3 included 12 patients with an inserted SvO2 catheter using two-reference wavelengths and characterized by one transmitting and two detecting fiberoptic filaments. Once calibration procedures were performed, SvO2 measured by the catheter and by an hemoximeter OSM 3 (reference value) were compared following each therapeutic intervention. Over a period of 1.5 to 6 hours during which the hematocrit value remained unchanged, 119 measurements were obtained in group 1, 91 in group 2 and 181 in group 3. The dispersion of SvO2 values was much more pronounced with the two-reference wavelength systems using either one or two detecting fiber optic filaments, and the correlation coefficient was significantly higher with the three-reference wavelength system (r = 0.970 for the Oximetrix catheter vs r = 0.855 for the Edwards catheter and r = 0.826 for the Spectramed catheter, p less than 0.001). After 24 hours, the spontaneous drifts in the two-reference wavelength systems, using either one or two detecting fiber optic filaments (expressed as the SvO2 value measured by the catheter minus the reference SvO2 value) were significantly higher than the spontaneous drift in the three-reference wavelength system (9.3 +/- 7 percent for the Edwards catheter and +/- 6 +/- 4.1 percent for the Spectramed catheter vs 3.3 +/- 3.1 percent for the Oximetrix catheter, p less than 0.05). This study shows that a three-wavelength system is more accurate

  10. Effects of Particulate Matter and Its Chemical Constituents on Elderly Hospital Admissions Due to Circulatory and Respiratory Diseases

    PubMed Central

    Ferreira, Tatiane Morais; Forti, Maria Cristina; de Freitas, Clarice Umbelino; Nascimento, Felipe Parra; Junger, Washington Leite; Gouveia, Nelson

    2016-01-01

    Various fractions of particulate matter have been associated with increased mortality and morbidity. The purpose of our study is to analyze the associations between concentrations of PM2.5, PM2.5–10, PM10 and their chemical constituents (soluble ions) with hospital admissions due to circulatory and respiratory diseases among the elderly in a medium-sized city in Brazil. A time series study was conducted using Poisson regression with generalized additive models adjusted for confounders. Statistically significant associations were identified between PM10 and PM2.5–10 and respiratory diseases. Risks of hospitalization increased by 23.5% (95% CI: 13.5; 34.3) and 12.8% (95% CI: 6.0; 20.0) per 10 μg/m3 of PM2.5-10 and PM10, respectively. PM2.5 exhibited a significant association with circulatory system diseases, with the risk of hospitalization increasing by 19.6% (95% CI: 6.4; 34.6) per 10 μg/m3. Regarding the chemical species; SO42−, NO3−, NH4+ and K+ exhibited specific patterns of risk, relative to the investigated outcomes. Overall, SO42− in PM2.5–10 and K+ in PM2.5 were associated with increased risk of hospital admissions due to both types of diseases. The results agree with evidence indicating that the risks for different health outcomes vary in relation to the fractions and chemical composition of PM10. Thus, PM10 speciation studies may contribute to the establishment of more selective pollution control policies. PMID:27669280

  11. The human cardiovascular system during space flight

    NASA Astrophysics Data System (ADS)

    Grigoriev, A. I.; Kotovskaya, A. R.; Fomina, G. A.

    2011-05-01

    Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.

  12. [Reperfusion therapy and mechanical circulatory support in patients in cardiogenic shock].

    PubMed

    Scholz, K H

    1999-10-01

    Cardiogenic shock is a state of inadequate tissue perfusion due to cardiac dysfunction, which is most commonly caused by acute myocardial infarction. The pathophysiology of cardiogenic shock is characterized by a downward spiral: ischemia causes myocardial dysfunction, which, in turn, augments the ischemic damage and the energetical imbalance. With conservative therapy, mortality rates for patients with cardiogenic shock are frustratingly high reaching more than 80%. Additional thrombolytic therapy has not been shown to significantly improve survival in such patients. Emergency cardiac catheterization and coronary angioplasty, however, seem to improve the outcome in shock-patients, which most probably is due to rapid and complete revascularization generally reached by angioplasty. In addition to interventional therapy with rapid coronary revascularization, the use of mechanical circulatory support may interrupt the vicious cycle in cardiogenic shock by stabilizing hemodynamics and the metabolic situation. Different cardiac assist devices are available for cardiologists and cardiac surgeons: 1. intraaortic balloon counterpulsation (IABP), 2. implantable turbine-pump (Hemopump), 3. percutaneous cardiopulmonary bypass support (CPS), 4. right heart, left heart, or biventricular assist devices placed by thoracotomy, and 5. intra- and extrathoracic total artificial hearts. Since percutaneous application is possible with IABP, Hemopump and CPS, these devices are currently used in interventional cardiology. The basic goals of the less invasive intraaortic balloon counterpulsation (IABP; Figure 1) are to stabilize circulatory collapse, to increase coronary perfusion and myocardial oxygen supply, and to decrease left ventricular workload and myocardial oxygen demand (Figure 2). Since the advent of percutaneous placement, IABP has been used by an increasing number of institutions (Figure 3). In addition to cardiogenic shock, the system may be of use in a variety of other

  13. Linking Humans and Systems in Nuclear Power

    SciTech Connect

    Jacques Hugo

    2013-02-01

    Traditional engineering methods do not make provision for the integration of human considerations, while traditional human factors methods do not scale well to the complexity of large-scale nuclear power plant projects. Although the need for up-to-date human factors engineering processes and tools is recognised widely in industry, so far no formal guidance has been developed. This article proposes such a framework.

  14. Complex Systems and Human Performance Modeling

    DTIC Science & Technology

    2013-12-01

    human communication patterns can be implemented in a task network modeling tool. Although queues are a basic feature in many task network modeling...time. MODELING COMMUNICATIVE BEHAVIOR Barabasi (2010) argues that human communication patterns are “bursty”; that is, the inter-event arrival...Having implemented the methods advocated by Clauset et al. in C3TRACE, we have grown more confident that the human communication data discussed above

  15. Central circulatory hemodynamics as a function of gravitational stress

    NASA Technical Reports Server (NTRS)

    Latham, Rick D.; White, C. D.; Fanton, J. W.; Owens, R. W.; Barber, J. F.; Lewkowski, B. E.; Goff, O. T.

    1991-01-01

    This study focuses on an evaluation of the central hemodynamics in a nonhuman primate model to variations in gravitational states. The baboon, phylogenectically close to man, was chosen as the human surrogate. The study environments selected are head-down and head-up tilt in the physiology laboratory, centrifugation to test hypergravic stress, and parabolic flights to test transient acute responses to microgravity.

  16. Evaluating Models of Human Performance: Safety-Critical Systems Applications

    NASA Technical Reports Server (NTRS)

    Feary, Michael S.

    2012-01-01

    This presentation is part of panel discussion on Evaluating Models of Human Performance. The purpose of this panel is to discuss the increasing use of models in the world today and specifically focus on how to describe and evaluate models of human performance. My presentation will focus on discussions of generating distributions of performance, and the evaluation of different strategies for humans performing tasks with mixed initiative (Human-Automation) systems. I will also discuss issues with how to provide Human Performance modeling data to support decisions on acceptability and tradeoffs in the design of safety critical systems. I will conclude with challenges for the future.

  17. Towards Human Centred Manufacturing Systems in the Next Generation

    NASA Astrophysics Data System (ADS)

    Anezaki, Takashi; Hata, Seiji

    Nowadays agile market is in common, and the fundamental technology supporting next-generation production system requires further development of machine and information technologies to establish “human friendly technology" and a bridging of these technologies together. IMS-HUTOP project proposes a new product life cycle that respects the human nature of individuals, and establishes the elemental technologies necessary for acquiring, modelling and evaluating various human factors in an effort to achieve the HUTOP cycle. In this paper we propose a human centred and human friendly manufacturing system, which has been proposed in the IMS-HUTOP project.

  18. Considerations of human's long stay in closed systems.

    PubMed

    Ashida, A

    1994-07-01

    Conditions for long stay of human in closed systems with material circulation, such as space stations and lunar bases, are discussed compared with the current human's life style on earth in the light of human cultural history. Impact on the life-style in the closed ecological system lies on meals and hygiene systems. A key to resolve problems in a new life-style in a closed system lies on mental aspects relating to a new life culture. Necessary items to be developed are shown in order to realize comfortable life in the closed system.

  19. High School Students' Understanding of the Human Body System

    ERIC Educational Resources Information Center

    Assaraf, Orit Ben-Zvi; Dodick, Jeff; Tripto, Jaklin

    2013-01-01

    In this study, 120 tenth-grade students from 8 schools were examined to determine the extent of their ability to perceive the human body as a system after completing the first stage in their biology curriculum--"The human body, emphasizing homeostasis". The students' systems thinking was analyzed according to the STH thinking model, which roughly…

  20. Human factors issues for resolving adverse effects of human work underload and workload transitions in complex human-machine systems

    SciTech Connect

    Ryan, T.G.

    1995-10-01

    A workshop was conducted whose specific purpose was to build on earlier work of the United States National Research Council, United States Federal government agencies, and the larger human factors community to: (1) clarify human factors issues pertaining to degraded performance in advanced human-machine systems (e.g., nuclear production, transportation, aerospace) due to human work underload and workload transition, and (2) develop strategies for resolving these issues. Recent history demonstrates that: (1) humans often react adversely to their diminishing roles in advanced human-machine systems, and therefore (2) new allocation models and strategies are required if humans are to be willing and able to assume diminishing and shifting roles assigned to them in these systems, and are to accept new technologies making up these systems. Problems associated with theses diminishing and shifting human roles are characterized as work underload and workload transitions. The workshop affirmed that: (1) work underload and workload transition are issues that will have to be addressed by designers of advanced human-machine systems, especially those relying on automation, if cost, performance, safety, and operator acceptability are to be optimized, (2) human machine allocation models, standards, and guidelines which go beyond simple capability approaches will be needed to preclude or seriously diminish the work underload and workload transition problems, and (3) the 16 workload definition, measurement, situational awareness, and trust issues identified during the workshop, need resolution if these models, standards, and guidelines are to be achieved.

  1. Human factors systems approach to healthcare quality and patient safety

    PubMed Central

    Carayon, Pascale; Wetterneck, Tosha B.; Rivera-Rodriguez, A. Joy; Hundt, Ann Schoofs; Hoonakker, Peter; Holden, Richard; Gurses, Ayse P.

    2013-01-01

    Human factors systems approaches are critical for improving healthcare quality and patient safety. The SEIPS (Systems Engineering Initiative for Patient Safety) model of work system and patient safety is a human factors systems approach that has been successfully applied in healthcare research and practice. Several research and practical applications of the SEIPS model are described. Important implications of the SEIPS model for healthcare system and process redesign are highlighted. Principles for redesigning healthcare systems using the SEIPS model are described. Balancing the work system and encouraging the active and adaptive role of workers are key principles for improving healthcare quality and patient safety. PMID:23845724

  2. Human Centered Autonomous and Assistant Systems Testbed for Exploration Operations

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Mount, Frances; Carreon, Patricia; Torney, Susan E.

    2001-01-01

    The Engineering and Mission Operations Directorates at NASA Johnson Space Center are combining laboratories and expertise to establish the Human Centered Autonomous and Assistant Systems Testbed for Exploration Operations. This is a testbed for human centered design, development and evaluation of intelligent autonomous and assistant systems that will be needed for human exploration and development of space. This project will improve human-centered analysis, design and evaluation methods for developing intelligent software. This software will support human-machine cognitive and collaborative activities in future interplanetary work environments where distributed computer and human agents cooperate. We are developing and evaluating prototype intelligent systems for distributed multi-agent mixed-initiative operations. The primary target domain is control of life support systems in a planetary base. Technical approaches will be evaluated for use during extended manned tests in the target domain, the Bioregenerative Advanced Life Support Systems Test Complex (BIO-Plex). A spinoff target domain is the International Space Station (ISS) Mission Control Center (MCC). Prodl}cts of this project include human-centered intelligent software technology, innovative human interface designs, and human-centered software development processes, methods and products. The testbed uses adjustable autonomy software and life support systems simulation models from the Adjustable Autonomy Testbed, to represent operations on the remote planet. Ground operations prototypes and concepts will be evaluated in the Exploration Planning and Operations Center (ExPOC) and Jupiter Facility.

  3. Apparatus and methods for a human de-amplifier system

    DOEpatents

    Kress, Reid L.; Jansen, John F.

    2000-01-01

    A human de-amplifier system for interfacing a human operator and a physical object through a physical plant, wherein the physical object has dimensions in the range of 1 micrometer to 1 mm. The human de-amplifier system uses an inner-feedback loop to increases the equivalent damping of the operating system to stabilize the system when it contacts with the environment and reduces the impact of the environment variation by utilizing a high feedback gain, determined by a root locus sketch. Because the stability of the human de-amplifier system of the present invention is greatly enhanced over that of the prior art, the de-amplifier system is able to manipulate the physical object has dimensions in the range of 1 micrometer to 1 mm with high stability and accuracy. The system also has a monitoring device to monitor the motion of the physical object under manipulation.

  4. Self-Powered Human-Interactive Transparent Nanopaper Systems.

    PubMed

    Zhong, Junwen; Zhu, Hongli; Zhong, Qize; Dai, Jiaqi; Li, Wenbo; Jang, Soo-Hwan; Yao, Yonggang; Henderson, Doug; Hu, Qiyi; Hu, Liangbing; Zhou, Jun

    2015-07-28

    Self-powered human-interactive but invisible electronics have many applications in anti-theft and anti-fake systems for human society. In this work, for the first time, we demonstrate a transparent paper-based, self-powered, and human-interactive flexible system. The system is based on an electrostatic induction mechanism with no extra power system appended. The self-powered, transparent paper device can be used for a transparent paper-based art anti-theft system in museums or for a smart mapping anti-fake system in precious packaging and documents, by virtue of the advantages of adding/removing freely, having no impairment on the appearance of the protected objects, and being easily mass manufactured. This initial study bridges the transparent nanopaper with a self-powered and human-interactive electronic system, paving the way for the development of smart transparent paper electronics.

  5. Mechanical Circulatory Support Devices for Pediatric Patients With Congenital Heart Disease.

    PubMed

    Chopski, Steven G; Moskowitz, William B; Stevens, Randy M; Throckmorton, Amy L

    2017-01-01

    The use of mechanical circulatory support (MCS) devices is a viable therapeutic treatment option for patients with congestive heart failure. Ventricular assist devices, cavopulmonary assist devices, and total artificial heart pumps continue to gain acceptance as viable treatment strategies for both adults and pediatric patients as bridge-to-transplant, bridge-to-recovery, and longer-term circulatory support alternatives. We present a review of the current and future MCS devices for patients having congenital heart disease (CHD) with biventricular or univentricular circulations. Several devices that are specifically designed for patients with complex CHD are in the development pipeline undergoing rigorous animal testing as readiness experiments in preparation for future clinical trials. These advances in the development of new blood pumps for patients with CHD will address a significant unmet clinical need, as well as generally improve innovation of the current state of the art in MCS technology.

  6. Is heart transplantation after circulatory death compatible with the dead donor rule?

    PubMed

    Nair-Collins, Michael; Miller, Franklin G

    2016-05-01

    Dalle Ave et al (2016) provide a valuable overview of several protocols for heart transplantation after circulatory death. However, their analysis of the compatibility of heart donation after circulatory death (DCD) with the dead donor rule (DDR) is flawed. Their permanence-based criteria for death, which depart substantially from established law and bioethics, are ad hoc and unfounded. Furthermore, their analysis is self-defeating, because it undercuts the central motivation for DDR as both a legal and a moral constraint, rendering the DDR vacuous and trivial. Rather than devise new and ad hoc criteria for death for the purpose of rendering DCD nominally consistent with DDR, we contend that the best approach is to explicitly abandon DDR.

  7. Durable Mechanical Circulatory Support versus Organ Transplantation: Past, Present, and Future

    PubMed Central

    Anand, Jatin; Singh, Steve K.; Antoun, David G.; Cohn, William E.; Frazier, O. H. (Bud); Mallidi, Hari R.

    2015-01-01

    For more than 30 years, heart transplantation has been a successful therapy for patients with terminal heart failure. Mechanical circulatory support (MCS) was developed as a therapy for end-stage heart failure at a time when cardiac transplantation was not yet a useful treatment modality. With the more successful outcomes of cardiac transplantation in the 1980s, MCS was applied as a bridge to transplantation. Because of donor scarcity and limited long-term survival, heart transplantation has had a trivial impact on the epidemiology of heart failure. Surgical implementation of MCS, both for short- and long-term treatment, affords physicians an opportunity for dramatic expansion of a meaningful therapy for these otherwise mortally ill patients. This review explores the evolution of mechanical circulatory support and its potential for providing long-term therapy, which may address the limitations of cardiac transplantation. PMID:26583140

  8. Heart Transplant and Mechanical Circulatory Support in Patients With Advanced Heart Failure.

    PubMed

    Sánchez-Enrique, Cristina; Jorde, Ulrich P; González-Costello, José

    2017-02-07

    Patients with advanced heart failure have a poor prognosis and heart transplant is still the best treatment option. However, the scarcity of donors, long waiting times, and an increasing number of unstable patients have favored the development of mechanical circulatory support. This review summarizes the indications for heart transplant, candidate evaluation, current immunosuppression strategies, the evaluation and treatment of rejection, infectious prophylaxis, and short and long-term outcomes. Regarding mechanical circulatory support, we distinguish between short- and long-term support and the distinct strategies that can be used: bridge to decision, recovery, candidacy, transplant, and destination therapy. We then discuss indications, risk assessment, management of complications, especially with long-term support, and outcomes. Finally, we discuss future challenges and how the widespread use of long-term support for patients with advanced heart failure will only be viable if their complications and costs are reduced.

  9. The Human Resource Cycle as Basis of Human Resource Development System.

    ERIC Educational Resources Information Center

    Jereb, Janez

    The primary aim of human-resource-development systems in companies is to improve organizational performance through satisfying the development needs of individual employees. This paper presents findings of a study that looked at how human-resource-development systems worked in practice, in particular, how performance management, selection,…

  10. The Systems Engineering Process for Human Support Technology Development

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2005-01-01

    Systems engineering is designing and optimizing systems. This paper reviews the systems engineering process and indicates how it can be applied in the development of advanced human support systems. Systems engineering develops the performance requirements, subsystem specifications, and detailed designs needed to construct a desired system. Systems design is difficult, requiring both art and science and balancing human and technical considerations. The essential systems engineering activity is trading off and compromising between competing objectives such as performance and cost, schedule and risk. Systems engineering is not a complete independent process. It usually supports a system development project. This review emphasizes the NASA project management process as described in NASA Procedural Requirement (NPR) 7120.5B. The process is a top down phased approach that includes the most fundamental activities of systems engineering - requirements definition, systems analysis, and design. NPR 7120.5B also requires projects to perform the engineering analyses needed to ensure that the system will operate correctly with regard to reliability, safety, risk, cost, and human factors. We review the system development project process, the standard systems engineering design methodology, and some of the specialized systems analysis techniques. We will discuss how they could apply to advanced human support systems development. The purpose of advanced systems development is not directly to supply human space flight hardware, but rather to provide superior candidate systems that will be selected for implementation by future missions. The most direct application of systems engineering is in guiding the development of prototype and flight experiment hardware. However, anticipatory systems engineering of possible future flight systems would be useful in identifying the most promising development projects.

  11. [Medicinal plants useful in the cure of circulatory problems in legs].

    PubMed

    Alonso, Maria José

    2005-03-01

    Once the fundamentals of phyto-therapy in its western use are understood, this article presents concrete a application of medicinal plants: circulatory problems in legs, a problem which affects a growing sector of the population. According to epidemiological studies, close to 80% of adults suffer problems such as tired legs, swellings, edemas, cramps, or varicose veins during their lifetimes; these appear due to an insufficiency when veins can not conveniently transport blood to the heart.

  12. Challenges and advances in optimizing liver allografts from donation after circulatory death donors

    PubMed Central

    Sutherland, Andrew Ian; Oniscu, Gabriel C.

    2016-01-01

    In recent years, there has been a shift in the donor demographics with an increase in donation after circulatory death (DCD). Livers obtained from DCD donors are known to have poorer outcomes when compared to donors after brainstem death and currently only a small proportion of DCD livers are used. This review outlines the recent technological developments in liver DCD donation, including clinical studies using normothermic regional perfusion and extracorporal machine perfusion of livers from DCD donors. PMID:27003962

  13. Use of Short-term Circulatory Support as a Bridge in Pediatric Heart Transplantation

    PubMed Central

    Canêo, Luiz Fernando; Miana, Leonardo Augusto; Tanamati, Carla; Penha, Juliano Gomes; Shimoda, Monica Satsuki; Azeka, Estela; Miura, Nana; Gomes Galas, Filomena Regina Barbosa; Guimarães, Vanessa Alves; Jatene, Marcelo Biscegli

    2015-01-01

    Background Heart transplantation is considered the gold standard therapy for the advanced heart failure, but donor shortage, especially in pediatric patients, is the main limitation for this procedure, so most sick patients die while waiting for the procedure. Objective To evaluate the use of short-term circulatory support as a bridge to transplantation in end-stage cardiomyopathy. Methods Retrospective clinical study. Between January 2011 and December 2013, 40 patients with cardiomyopathy were admitted in our Pediatric Intensive Care Unit, with a mean age of 4.5 years. Twenty patients evolved during hospitalization with clinical deterioration and were classified as Intermacs 1 and 2. One patient died within 24 hours and 19 could be stabilized and were listed. They were divided into 2 groups: A, clinical support alone and B, implantation of short-term circulatory support as bridge to transplantation additionally to clinical therapy. Results We used short-term mechanical circulatory support as a bridge to transplantation in 9. In group A (n=10), eight died waiting and 2 patients (20%) were transplanted, but none was discharged. In group B (n=9), 6 patients (66.7%) were transplanted and three were discharged.The mean support time was 21,8 days (6 to 984h). The mean transplant waiting list time was 33,8 days. Renal failure and sepsis were the main complication and causeof death in group A while neurologic complications were more prevalent en group B. Conclusion Mechanical circulatory support increases survival on the pediatric heart transplantation waiting list in patients classified as Intermacs 1 and 2. PMID:25372474

  14. A radiographic study of circulatory times of the cerebral blood flow.

    PubMed

    Fagulă, J; Sulla, I

    1985-01-01

    The authors studied circulatory times of the cerebral blood flow by means of radiocirculography (RCG). The mean value of the RCG curve was 20 s in 27 examined control persons, 22 s (increase by 2 s) in 24 patients with light brain injury (commotio cerebri), 24 s (increase by 4 s) in 29 patients with severe injury (contusio cerebri et compressio cerebri), and 23 s (increase by 3 s) in 37 patients with brain tumor.

  15. Contrasting patterns of hospital admissions and mortality during heat waves: are deaths from circulatory disease a real excess or an artifact?

    PubMed

    Mastrangelo, Giuseppe; Hajat, Shakoor; Fadda, Emanuela; Buja, Alessandra; Fedeli, Ugo; Spolaore, Paolo

    2006-01-01

    In old subjects exposed to extreme high temperature during a heat wave, studies have consistently reported an excess of death from cardio- or cerebro-vascular disease. By contrast, dehydration, heat stroke, acute renal insufficiency, and respiratory disease were the main causes of hospital admission in the two studies carried out in elderly during short spells of hot weather. The excess of circulatory disease reported by mortality studies, but not by morbidity studies, could be explained by the hypothesis that deaths from circulatory disease occur rapidly in isolated people before they reach a hospital. Since the contrasting patterns of hospital admission and mortality during heat waves could also be due to chance (random variation over time and space in the spectrum of diseases induced by extreme heat), and bias (poor quality of diagnosis on death certificate and other artifacts), it should be confirmed by a concurrent study of mortality and morbidity. Many heat-related diseases may be preventable with adequate warning and an appropriate response to heat emergencies, but preventive efforts are complicated by the short time interval that may elapse between high temperatures and death. Therefore, prevention programs must be based around rapid identification of high-risk conditions and persons. The effectiveness of the intervention measures must be formally evaluated. If cardio- and cerebro-vascular diseases are rapidly fatal health outcomes with a short time interval between exposure to high temperature and death, deaths from circulatory disease might be an useful indicator in evaluating the effectiveness of a heat watch/warning system.

  16. The immune system in human milk and the developing infant.

    PubMed

    Goldman, Armond S

    2007-12-01

    The concept of the immune system in human milk emerged in the 1970s from clinical and laboratory observations made between the late 18th through the mid-20th centuries. The discovery of living leukocytes in human milk in 1970 was the final link to the chain of evidence that culminated in the concept. The concept was later expanded to include not only antimicrobial but also anti-inflammatory and immunoregulatory agents. These agents evolved to compensate for developmental delays in the immune system during infancy. Indeed, that explains the defense by human milk against common infectious diseases in infancy, necrotizing enterocolitis in preterm infants, and immune-mediated disorders such as Crohn's disease in later childhood. These diverse evolutionary outcomes underscore the superiority of human milk for the nutrition of human infants. Finally, other components of the immune system in human milk and their fate and functions in the developing infant may well be discovered in the near future.

  17. Cardiovascular effects of NA+/H+ exchanger inhibition with BIIB513 following hypovolemic circulatory shock.

    PubMed

    Wu, Dongmei; Bassuk, Jorge; Arias, Jaqueline; Doods, Henri; Adams, Jose A

    2005-03-01

    Na(+)/H(+) exchange (NHE) is involved in the myocardial injury that occurs during ischemia and reperfusion. The goal of the present study was to investigate the role of NHE in hypovolemic circulatory shock by using a potent NHE-1 selective inhibitor BIIB513. Acute rapid hemorrhage was induced in 14 pigs by bleeding (30 mL/kg over 30 min). Seven pigs were used as saline control. Seven other pigs received 3 mg/kg BIIB513 at 30 min after hemorrhage. Each experiment consisted of 2 h of hypovolemia followed by 2 h of fluid resuscitation. One control animal died before the experiment was completed. Six other control animals survived the entire experiment. In contrast, all the BIIB513 treated animals survived the entire protocol. Acute rapid blood loss resulted in impaired myocardial performance as well as severe hemodynamic and metabolic alterations. NHE blockade attenuated the hypovolemic hypotension and improved myocardial performance. NHE blockade also attenuated the metabolic acidosis, improved tissue oxygen delivery, and improved cardiac function from resuscitation. The circulating levels of creatine phosphokinase (CPK) and cardiac troponin-I were significantly lower in the BIIB513 treatment group. These results suggest that NHE activation plays an important pathophysiological role in hypovolemic circulatory shock, and NHE-1 blockade is a powerful intervention to improve cardiovascular outcomes of resuscitation from prolonged hypovolemic circulatory shock.

  18. Preimplant Normothermic Liver Perfusion of a Suboptimal Liver Donated After Circulatory Death.

    PubMed

    Watson, C J E; Kosmoliaptsis, V; Randle, L V; Russell, N K; Griffiths, W J H; Davies, S; Mergental, H; Butler, A J

    2016-01-01

    Livers retrieved after circulatory death are associated with an increased incidence of primary nonfunction, early allograft dysfunction, and biliary strictures. The authors report a case of preimplant normothermic perfusion of a suboptimal liver from a 57-year-old donor after circulatory death who had been hospitalized for 9 days; predonation alanine transaminase level was 63 IU/L, and the period from withdrawal of life-supporting treatment to circulatory arrest was 150 minutes. After 5 hours of static cold storage, the liver was subject to normothermic machine perfusion with a plasma-free red cell-based perfusate. Perfusate lactate level fell from 7.2 to 0.3 mmol/L within 74 minutes of ex situ perfusion, at which point perfusate alanine transaminase level was 1152 IU/L and urea concentration was 9.4 mmol/L. After 132 minutes, normothermic perfusion was stopped and implantation begun. After transplantation, the patient made an uneventful recovery and was discharged on day 8; liver biochemistry was normal by day 19 and has remained normal thereafter. Donor common bile duct excised at implantation showed preservation of peribiliary glands, and cholangiography 6 months posttransplantation showed no evidence of cholangiopathy. Preimplant ex situ normothermic perfusion of the liver appears to be a promising way to evaluate a marginal liver before transplantation and may modify the response to ischemia.

  19. Power Systems for Human Exploration Missions

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    1998-01-01

    Power system options were reviewed for their appropriateness to meet mission requirements and guidelines. Contending system technologies include: solar, nuclear, isotopic, electro-chemical and chemical. Mission elements can basically be placed into two categories; in-space transportation systems, both cargo and piloted; and surface systems, both stationary and mobile. All transportation and surface element power system requirements were assessed for application synergies that would suggest common hardware (duplicates of the same or similar design) or multi-use (reuse system in a different application/location), wherever prudent.

  20. Failure of glutamate dehydrogenase system to predict oxygenation state of human skeletal muscle.

    PubMed

    Katz, A; Spencer, M K; Sahlin, K

    1990-07-01

    In a recent study, the total tissue contents of glutamate (Glu), ammonium (NH+4), and 2-oxoglutarate (2-OG) were used to estimate changes in the mitochondrial redox state ([NAD+]/[NADH]) of contracting skeletal muscle with intact circulation [Am. J. Physiol. 253 (Cell Physiol. 22): C263-C268, 1987]. These metabolites participate in the glutamate dehydrogenase (GDH) reaction, which, based on a number of assumptions, theoretically enables calculation of the mitochondrial redox state as follows (brackets indicate concentrations): [NAD+]/[NADH] = ([NH+4] [2-OG])/[( Glu]Kapp), where Kapp is the apparent equilibrium constant for GDH. The purpose of this study was to determine whether changes in the total tissue contents of Glu, NH+4, and 2-OG could be used to predict a reduction of the mitochondrial redox state in anoxic skeletal muscle. Anoxia was induced in the quadriceps femoris muscle by 10 min of circulatory occlusion (low metabolic rate) and isometric contraction to fatigue (high metabolic rate). The mean (+/- SE) value for the metabolite ratio ([NH+4][2-OG]/[Glu]) at rest was 6 +/- 3 mmol/kg dry wt (x 10(-4]. No significant change occurred after circulatory occlusion (4 +/- 2 x 10(-4); P greater than 0.05), whereas an almost 60-fold increase was observed after isometric contraction (P less than 0.05). Because the muscle was anoxic under both conditions, a significant decrease in the metabolite ratio should have occurred. These data demonstrate that changes in total tissue contents of Glu, NH+4, and 2-OG cannot be used to estimate changes in the redox and oxygenation state of mitochondria in intact human skeletal muscle.

  1. Human Systems Integration in Practice: Constellation Lessons Learned

    NASA Technical Reports Server (NTRS)

    Zumbado, Jennifer Rochlis

    2012-01-01

    NASA's Constellation program provided a unique testbed for Human Systems Integration (HSI) as a fundamental element of the Systems Engineering process. Constellation was the first major program to have HSI mandated by NASA's Human Rating document. Proper HSI is critical to the success of any project that relies on humans to function as operators, maintainers, or controllers of a system. HSI improves mission, system and human performance, significantly reduces lifecycle costs, lowers risk and minimizes re-design. Successful HSI begins with sufficient project schedule dedicated to the generation of human systems requirements, but is by no means solely a requirements management process. A top-down systems engineering process that recognizes throughout the organization, human factors as a technical discipline equal to traditional engineering disciplines with authority for the overall system. This partners with a bottoms-up mechanism for human-centered design and technical issue resolution. The Constellation Human Systems Integration Group (HSIG) was a part of the Systems Engineering and Integration (SE&I) organization within the program office, and existed alongside similar groups such as Flight Performance, Environments & Constraints, and Integrated Loads, Structures and Mechanisms. While the HSIG successfully managed, via influence leadership, a down-and-in Community of Practice to facilitate technical integration and issue resolution, it lacked parallel top-down authority to drive integrated design. This presentation will discuss how HSI was applied to Constellation, the lessons learned and best practices it revealed, and recommendations to future NASA program and project managers. This presentation will discuss how Human Systems Integration (HSI) was applied to NASA's Constellation program, the lessons learned and best practices it revealed, and recommendations to future NASA program and project managers on how to accomplish this critical function.

  2. Autonomous Systems in Human Behavior and Development

    ERIC Educational Resources Information Center

    Wolff, P.

    1974-01-01

    Reviews research which demonstrates that responses from different behavior systems to a given stimulus situation may be far from perfectly correlated with each other. Discusses the phylogenetic and ontogenetic development of these systems and the roles of both the species and the individual in bringing the systems into mutual correspondence.…

  3. Integrated human-machine intelligence in space systems

    NASA Technical Reports Server (NTRS)

    Boy, Guy A.

    1992-01-01

    The integration of human and machine intelligence in space systems is outlined with respect to the contributions of artificial intelligence. The current state-of-the-art in intelligent assistant systems (IASs) is reviewed, and the requirements of some real-world applications of the technologies are discussed. A concept of integrated human-machine intelligence is examined in the contexts of: (1) interactive systems that tolerate human errors; (2) systems for the relief of workloads; and (3) interactive systems for solving problems in abnormal situations. Key issues in the development of IASs include the compatibility of the systems with astronauts in terms of inputs/outputs, processing, real-time AI, and knowledge-based system validation. Real-world applications are suggested such as the diagnosis, planning, and control of enginnered systems.

  4. Computer Human Interaction for Image Information Systems.

    ERIC Educational Resources Information Center

    Beard, David Volk

    1991-01-01

    Presents an approach to developing viable image computer-human interactions (CHI) involving user metaphors for comprehending image data and methods for locating, accessing, and displaying computer images. A medical-image radiology workstation application is used as an example, and feedback and evaluation methods are discussed. (41 references) (LRW)

  5. A Discourse on Human Systems Integration

    DTIC Science & Technology

    2010-09-01

    effectiveness directorate with several external organizational entities responsible for aerospace medicine education, training, and consultation...research, consultation, and education within a single organizational entity. The HP Wing’s stated primary mission areas are aerospace medicine , science...University Press. 169 Hughes, T. P. (1998). Rescuing Prometheus . New York, NY: Vintage Books. Human Engineering Laboratory (1969 Jan). Manpower

  6. Does human cognition allow Human Factors (HF) certification of advanced aircrew systems?

    NASA Technical Reports Server (NTRS)

    Macleod, Iain S.; Taylor, Robert M.

    1994-01-01

    This paper has examined the requirements of HF specification and certification within advanced or complex aircrew systems. It suggests reasons for current inadequacies in the use of HF in the design process, giving some examples in support, and suggesting an avenue towards the improvement of the HF certification process. The importance of human cognition to the operation and performance of advanced aircrew systems has been stressed. Many of the shortfalls of advanced aircrew systems must be attributed to over automated designs that show little consideration on either the mental limits or the cognitive capabilities of the human system component. Traditional approaches to system design and HF certification are set within an over physicalistic foundation. Also, traditionally it was assumed that physicalistic system functions could be attributed to either the human or the machine on a one to one basis. Moreover, any problems associated with the parallel needs, or promoting human understanding alongside system operation and direction, were generally equated in reality by the natural flexibility and adaptability of human skills. The consideration of the human component of a complex system is seen as being primarily based on manifestations of human behavior to the almost total exclusion of any appreciation of unobservable human mental and cognitive processes. The argument of this paper is that the considered functionality of any complex human-machine system must contain functions that are purely human and purely cognitive. Human-machine system reliability ultimately depends on human reliability and dependability and, therefore, on the form and frequency of cognitive processes that have to be conducted to support system performance. The greater the demand placed by an advanced aircraft system on the human component's basic knowledge processes or cognition, rather than on skill, the more insiduous the effects the human may have on that system. This paper discusses one

  7. NASA Human Research Program Space Radiation Program Element

    NASA Technical Reports Server (NTRS)

    Chappell, Lori; Huff, Janice; Patel, Janapriya; Wang, Minli; Hu, Shaowwen; Kidane, Yared; Myung-Hee, Kim; Li, Yongfeng; Nounu, Hatem; Plante, Ianik; Ponomarev, Artem; Hada, Megumi

    2013-01-01

    The goal of the NASA Human Research Program's Space Radiation Program Element is to ensure that crews can safely live and work in the space radiation environment. Current work is focused on developing the knowledge base and tools required for accurate assessment of health risks resulting from space radiation exposure including cancer and circulatory and central nervous system diseases, as well as acute risks from solar particle events. Division of Space Life Sciences (DSLS) Space Radiation Team scientists work at multiple levels to advance this goal, with major projects in biological risk research; epidemiology; and physical, biophysical, and biological modeling.

  8. Induced Long-Range Attractive Potentials of Human Serum Albumin by Ligand Binding

    SciTech Connect

    Sato, Takaaki; Komatsu, Teruyuki; Nakagawa, Akito; Tsuchida, Eishun

    2007-05-18

    Small-angle x-ray scattering and dielectric spectroscopy investigation on the solutions of recombinant human serum albumin and its heme hybrid revealed that heme incorporation induces a specific long-range attractive potential between protein molecules. This is evidenced by the enhanced forward intensity upon heme binding, despite no hindrance to rotatory Brownian motion, unbiased colloid osmotic pressure, and discontiguous nearest-neighbor distance, confirming monodispersity of the proteins. The heme-induced potential may play a trigger role in recognition of the ligand-filled human serum albumins in the circulatory system.

  9. [Mechanical circulatory assist using a miniaturized Archimedes screw].

    PubMed

    von Segesser, L K; Bisang, B; Leskosek, B; Turina, M

    1991-01-01

    An axial flow blood pump (Archimedes screw) for intraarterial left ventricular assist was evaluated in comparison to standard roller pump left heart bypass (LHBP) in 13 bovine experiments (bodyweight 74 +/- 15 kg). Full systemic heparinization (ACT greater than 500 s) was used for LHBP in comparison to limited systemic heparinization (ACT greater than 180 s) for axial. A standard battery of blood samples was taken before and at regular intervals throughout perfusion: (table; see text) Transarterial access and relatively limited blood trauma appear to be the main advantages of the evaluated axial flow blood pump. However, the impossibility to assess the pump flow may be a major problem for the management of the failing left ventricle.

  10. An implantable centrifugal blood pump for long term circulatory support.

    PubMed

    Yamazaki, K; Litwak, P; Kormos, R L; Mori, T; Tagusari, O; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Umezu, M; Tomioka, J; Koyanagi, H; Griffith, B P

    1997-01-01

    A compact centrifugal blood pump was developed as an implantable left ventricular assist system. The impeller diameter is 40 mm and the pump dimensions are 55 x 64 mm. This first prototype was fabricated from titanium alloy, resulting in a pump weight of 400 g including a brushless DC motor. Weight of the second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon to improve blood compatibility. Flow rates of over 7 L/min against 100 mmHg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system ("Cool-Seal") is used as a shaft seal. In this seal system, seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. The purge fluid is continuously purified and sterilized by an ultrafiltration filter incorporated into the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular apex-descending aorta bypass was performed utilizing a PTFE (Polytetrafluoroethylene) vascular graft, with the pump placed in the left thoracic cavity. In two in vivo experiments, pump flow rate was maintained at 5-8 L/min, and pump power consumption remained stable at 9-10 W. All plasma free hemoglobin levels were measured at < 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (< 0.5 ml/ day). Both animals remain under observation after 162 and 91 days of continuous pump function.

  11. Circulatory filling pressures during transient microgravity induced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Latham, Ricky D.; Fanton, John W.; White, C. D.; Vernalis, Mariana N.; Crisman, R. P.; Koenig, S. C.

    1993-01-01

    Theoretical concepts hold that blood in the gravity dependent portion of the body would relocate to more cephalad compartments under microgravity. The result is an increase in blood volume in the thoraic and cardiac chambers. However, experimental data has been somewhat contradictory and nonconclusive. Early studies of peripheral venous pressure and estimates of central venous pressure (CVP) from these data did not show an increase in CVP under microgravity. However, CVP recorded in human volunteers during a parabolic flight revealed an increase in CVP during the microgravity state. On the STS 40 shuttle mission, a payload specialist wore a fluid line that recorded CVP during the first few hours of orbital insertion. These data revealed decreased CVP. When this CVP catheter was tested during parabolic flight in four subjects, two had increased CVP recordings and two had decreased CVP measurements. In 1991, our laboratory performed parabolic flight studies in several chronic-instrumented baboons. It was again noted that centrally recorded right atrial pressure varied with exposure to microgravity, some animals having an increase, and others a decrease.

  12. Circulatory filling pressures during transient microgravity induced by parabolic flight.

    PubMed

    Latham, R D; Fanton, J W; White, C D; Vernalis, M N; Crisman, R P; Koenig, S C

    1993-01-01

    Theoretical concepts hold that blood in the gravity-dependent portion of the body would relocate to more cephalad compartments under microgravity conditions. The result is an increase in blood volume in the thoracic and cardiac chambers. This increase in central volume shift should result in an increase in central atrial filling pressures. However, experimental data has been somewhat contradictory and nonconclusive to date. Early investigations of peripheral venous pressure and estimates of central venous pressure (CVP) from these data did not show an increase in CVP in the microgravity condition. However, CVP recorded in human volunteers during the parabolic flight by Norsk revealed an increase in CVP during the microgravity state. On the June 1991 STS 40 shuttle mission, a payload specialist wore a fluid line that recorded CVP during the first few hours of orbital insertion. These data revealed decreased CVP. When this CVP catheter was tested during parabolic flight in four subjects, two subjects had increased CVP recordings and two other subjects had decreased CVP measurements. In April 1991, our laboratory performed parabolic flight studies in several chronic-instrumented baboon subjects. It was again noted that centrally recorded right atrial pressure varied with exposure to microgravity, some animals having an increase and others having a decrease. Thus, data presently available has demonstrated a variable response in the mechanism not clearly defined. In April 1992, we determined a test hypothesis relating the possible mechanism of these variable pressure responses to venous pressure-volume relationships.

  13. Circulatory bubble dynamics: from physical to biological aspects.

    PubMed

    Papadopoulou, Virginie; Tang, Meng-Xing; Balestra, Costantino; Eckersley, Robert J; Karapantsios, Thodoris D

    2014-04-01

    Bubbles can form in the body during or after decompression from pressure exposures such as those undergone by scuba divers, astronauts, caisson and tunnel workers. Bubble growth and detachment physics then becomes significant in predicting and controlling the probability of these bubbles causing mechanical problems by blocking vessels, displacing tissues, or inducing an inflammatory cascade if they persist for too long in the body before being dissolved. By contrast to decompression induced bubbles whose site of initial formation and exact composition are debated, there are other instances of bubbles in the bloodstream which are well-defined. Gas emboli unwillingly introduced during surgical procedures and ultrasound microbubbles injected for use as contrast or drug delivery agents are therefore also discussed. After presenting the different ways that bubbles can end up in the human bloodstream, the general mathematical formalism related to the physics of bubble growth and detachment from decompression is reviewed. Bubble behavior in the bloodstream is then discussed, including bubble dissolution in blood, bubble rheology and biological interactions for the different cases of bubble and blood composition considered.

  14. Camera systems in human motion analysis for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chin, Lim Chee; Basah, Shafriza Nisha; Yaacob, Sazali; Juan, Yeap Ewe; Kadir, Aida Khairunnisaa Ab.

    2015-05-01

    Human Motion Analysis (HMA) system has been one of the major interests among researchers in the field of computer vision, artificial intelligence and biomedical engineering and sciences. This is due to its wide and promising biomedical applications, namely, bio-instrumentation for human computer interfacing and surveillance system for monitoring human behaviour as well as analysis of biomedical signal and image processing for diagnosis and rehabilitation applications. This paper provides an extensive review of the camera system of HMA, its taxonomy, including camera types, camera calibration and camera configuration. The review focused on evaluating the camera system consideration of the HMA system specifically for biomedical applications. This review is important as it provides guidelines and recommendation for researchers and practitioners in selecting a camera system of the HMA system for biomedical applications.

  15. Patient safety - the role of human factors and systems engineering.

    PubMed

    Carayon, Pascale; Wood, Kenneth E

    2010-01-01

    Patient safety is a global challenge that requires knowledge and skills in multiple areas, including human factors and systems engineering. In this chapter, numerous conceptual approaches and methods for analyzing, preventing and mitigating medical errors are described. Given the complexity of healthcare work systems and processes, we emphasize the need for increasing partnerships between the health sciences and human factors and systems engineering to improve patient safety. Those partnerships will be able to develop and implement the system redesigns that are necessary to improve healthcare work systems and processes for patient safety.

  16. A novel mouse model for stable engraftment of a human immune system and human hepatocytes.

    PubMed

    Strick-Marchand, Helene; Dusséaux, Mathilde; Darche, Sylvie; Huntington, Nicholas D; Legrand, Nicolas; Masse-Ranson, Guillemette; Corcuff, Erwan; Ahodantin, James; Weijer, Kees; Spits, Hergen; Kremsdorf, Dina; Di Santo, James P

    2015-01-01

    Hepatic infections by hepatitis B virus (HBV), hepatitis C virus (HCV) and Plasmodium parasites leading to acute or chronic diseases constitute a global health challenge. The species tropism of these hepatotropic pathogens is restricted to chimpanzees and humans, thus model systems to study their pathological mechanisms are severely limited. Although these pathogens infect hepatocytes, disease pathology is intimately related to the degree and quality of the immune response. As a first step to decipher the immune response to infected hepatocytes, we developed an animal model harboring both a human immune system (HIS) and human hepatocytes (HUHEP) in BALB/c Rag2-/- IL-2Rγc-/- NOD.sirpa uPAtg/tg mice. The extent and kinetics of human hepatocyte engraftment were similar between HUHEP and HIS-HUHEP mice. Transplanted human hepatocytes were polarized and mature in vivo, resulting in 20-50% liver chimerism in these models. Human myeloid and lymphoid cell lineages developed at similar frequencies in HIS and HIS-HUHEP mice, and splenic and hepatic compartments were humanized with mature B cells, NK cells and naïve T cells, as well as monocytes and dendritic cells. Taken together, these results demonstrate that HIS-HUHEP mice can be stably (> 5 months) and robustly engrafted with a humanized immune system and chimeric human liver. This novel HIS-HUHEP model provides a platform to investigate human immune responses against hepatotropic pathogens and to test novel drug strategies or vaccine candidates.

  17. Human Individual Differences in Military Systems

    DTIC Science & Technology

    1983-04-01

    first concept, termed Systems Thinking deals with sets of elements in which the behavior of each element affects the behavior of the whole; the...independent subgroups cannot be formed. The key to systems thinking is synthesis, the putting of elements together and considering their connections and

  18. HRIS: Introduction to Tomorrow's System for Managing Human Resources

    ERIC Educational Resources Information Center

    Hyde, Albert C.; Shafritz, Jay M.

    1977-01-01

    Reports on the U.S. State Department's experiment with a new concept in management information systems for personnel resources--the Human Resources Information Systems (HRIS). Suggests that the HRIS approach may meet public executives' demands for accurate, rapid, responsive, and flexible information systems. (Author/JG)

  19. Context in Models of Human-Machine Systems

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    All human-machine systems models represent context. This paper proposes a theory of context through which models may be usefully related and integrated for design. The paper presents examples of context representation in various models, describes an application to developing models for the Crew Activity Tracking System (CATS), and advances context as a foundation for integrated design of complex dynamic systems.

  20. 21 CFR 862.1370 - Human growth hormone test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Human growth hormone test system. 862.1370 Section 862.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  1. Human Health and Support Systems Capability Roadmap Progress Review

    NASA Technical Reports Server (NTRS)

    Grounds, Dennis; Boehm, Al

    2005-01-01

    The Human Health and Support Systems Capability Roadmap focuses on research and technology development and demonstration required to ensure the health, habitation, safety, and effectiveness of crews in and beyond low Earth orbit. It contains three distinct sub-capabilities: Human Health and Performance. Life Support and Habitats. Extra-Vehicular Activity.

  2. Muscle powered circulatory assist device for diastolic counterpulsator.

    PubMed

    Novoa, R; Jacobs, G; Sakakibara, N; Chen, J F; Davies, C; Cosgrove, D M; Golding, L R; Nosé, Y; Loop, F D

    1989-01-01

    A diastolic counterpulsator that uses either skeletal muscle or pneumatic actuation was developed. The unit is positioned between the latissimus dorsi and the chest wall, without interference with collateral blood supply, and is connected in series with the descending aorta. The system was able to generate stroke volumes between 52 and 16 ccs against pressures of 60 and 140 mmHg, respectively. Stroke work at 200 msec stimulation averaged 2.8 X 10(6) ergs. Power output at an afterload of 100 mmHg, and at a rate of 60 bpm, was 0.51 W. Back-up pneumatic actuation provided by an intraaortic balloon pump resulted in a 46% increase in the endocardial viability ratio (EVR).

  3. Human Factors in Rule-Based Systems.

    DTIC Science & Technology

    1985-10-14

    recommmend, based on the general thoery , design principles for the user engineering of expert systems. A general discussion of the work performed...the level and type of experience and training of users will vary considerably. (4) Finally, the traditional systems were stand alone. The user entered...our hypothesis was supported. Summarizing these two experiments , it appears that a having a good mental model allowed users to be effective operators of

  4. Group & Intergroup Relations in Living Human Systems.

    DTIC Science & Technology

    1980-06-01

    underbounded systems is that they will become totally caught up in their environmental turbulence and lose a consistent sense of their own identity ...intimately tied to the sense of one’s personal identity (Erikson, 1959). Underbounded and overbounded systems differ in their goal structure. Underbounded...lack of self ego identity . This lack of direction may arise either because people genuinely do not know what they are doing or because the conflict

  5. Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS)

    NASA Technical Reports Server (NTRS)

    Alexander, Tiffaney Miller

    2017-01-01

    Research results have shown that more than half of aviation, aerospace and aeronautics mishaps incidents are attributed to human error. As a part of Quality within space exploration ground processing operations, the identification and or classification of underlying contributors and causes of human error must be identified, in order to manage human error.This presentation will provide a framework and methodology using the Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS), as an analysis tool to identify contributing factors, their impact on human error events, and predict the Human Error probabilities (HEPs) of future occurrences. This research methodology was applied (retrospectively) to six (6) NASA ground processing operations scenarios and thirty (30) years of Launch Vehicle related mishap data. This modifiable framework can be used and followed by other space and similar complex operations.

  6. Computer based human-centered display system

    NASA Technical Reports Server (NTRS)

    Still, David L. (Inventor); Temme, Leonard A. (Inventor)

    2002-01-01

    A human centered informational display is disclosed that can be used with vehicles (e.g. aircraft) and in other operational environments where rapid human centered comprehension of an operational environment is required. The informational display integrates all cockpit information into a single display in such a way that the pilot can clearly understand with a glance, his or her spatial orientation, flight performance, engine status and power management issues, radio aids, and the location of other air traffic, runways, weather, and terrain features. With OZ the information is presented as an integrated whole, the pilot instantaneously recognizes flight path deviations, and is instinctively drawn to the corrective maneuvers. Our laboratory studies indicate that OZ transfers to the pilot all of the integrated display information in less than 200 milliseconds. The reacquisition of scan can be accomplished just as quickly. Thus, the time constants for forming a mental model are near instantaneous. The pilot's ability to keep up with rapidly changing and threatening environments is tremendously enhanced. OZ is most easily compatible with aircraft that has flight path information coded electronically. With the correct sensors (which are currently available) OZ can be installed in essentially all current aircraft.

  7. Human Systems Integration (HSI) in Acquisition. Management Guide

    DTIC Science & Technology

    2009-08-01

    Outputs boxes. Tools: ● CATIA ● HSI Requirements Guide ● IMPRINT Activities for Each Output: 1.0 Collect domain requirements inputs 1.1 Ensure...numbers In the Inputs and Outputs boxes. Technology Development Phase (Inputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME...Outputs boxes. Technology Development Phase (Outputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME Activities for Each Output: 1.0

  8. Role of thyroid hormone in postnatal circulatory and metabolic adjustments.

    PubMed Central

    Breall, J A; Rudolph, A M; Heymann, M A

    1984-01-01

    To assess the role of the early postnatal surge in plasma thyroid hormone concentrations on cardiovascular and metabolic adaptations, we measured cardiac output, total oxygen consumption, and plasma triiodothyronine (T3) concentrations in three groups of lambs in the first 6 h after delivery. 15 fetal lambs were prepared at gestational ages of 128-129 d by placing catheters in the brachiocephalic artery, descending aorta, distal inferior vena cava, left atrium, and pulmonary artery so that measurements could be made soon after delivery. They were divided into three groups: Group I comprised five control animals; Group II consisted of five fetuses in which thyroidectomy was performed at surgery at 129 d gestation; and Group III consisted of five animals in which thyroidectomy was performed at term gestation during delivery by caesarian section, prior to severing the umbilical cord. The lambs in Group I exhibited a rapid postnatal rise in T3 concentrations, similar to that described previously, reaching a peak value of about 5 ng/ml. Although the postnatal surge in T3 concentration was arrested in Group II and III animals, Group II had no detectable plasma T3, while the Group III animals had T3 concentrations of about 0.8 ng/ml, which were within the range previously reported for term lamb fetuses. The lambs in group II showed 40-50% lower left ventricular outputs (190 vs. 297 ml/kg per min), systemic blood flows (155 vs. 286 ml/kg per min), and oxygen consumptions (9.8 vs. 20.2 ml/kg per min) as compared with Group I animals over the entire 6-h period. The lambs in Group II also had significantly lower heart rates (131 vs. 192 beats/min) and mean systemic arterial pressures (56 vs. 72 torr). However, there were no significant differences for any of these measurements between the Group III and Group I lambs. The reduction in cardiac output in the Group II animals were reflected in a significantly lower blood flow to the peripheral circulation, but there were no

  9. NASA-STD-3001, Space Flight Human-System Standard and the Human Integration Design Handbook

    NASA Technical Reports Server (NTRS)

    Whitmore, Mihriban; Boyer, Jennifer; Holubec, Keith

    2012-01-01

    NASA-STD-3001 Space Flight Human-System Standard Volume 1, Crew Health, Volume 2, Human Factors, Habitability and Environmental Health, and the Human Integration Design Handbook (HIDH) have replaced the Man-Systems Integration Standards (MSIS), NASA-STD-3000. For decades, NASA-STD-3000 was a significant contribution to human spaceflight programs and to human-systems integration. However, with research program and project results being realized, advances in technology, and the availability of new information in a variety of topic areas, the time had arrived to update this extensive suite of standards and design information. NASA-STD-3001, Volume 2 contains the Agency level standards from the human and environmental factors disciplines that ensure human spaceflight operations are performed safely, efficiently, and effectively. The HIDH is organized in the same sequence and serves as the companion document to NASA-STD-3001, Volume 2, providing a compendium of human spaceflight history and knowledge. The HIDH is intended to aid interpretation of NASA-STD-3001, Volume 2 standards and to provide guidance for requirement writers and vehicle and habitat designers. Keywords Human Factors, Standards, Environmental Factors, NASA

  10. Reprogramming of circulatory cells in sepsis and SIRS.

    PubMed

    Cavaillon, J-M; Adrie, C; Fitting, C; Adib-Conquy, M

    2005-01-01

    Immune status is altered in patients with sepsis or non-infectious systemic inflammatory response syndrome (SIRS). Reduced ex-vivo TNF production by endotoxin-activated monocytes has been regularly reported. This observation is reminiscent of the phenomenon of endotoxin tolerance, and the term 'leukocyte reprogramming' well defines this phenomenon. This review will outline that the hyporesponsiveness of circulating leukocytes is not a generalized phenomenon in sepsis and SIRS. Indeed, the nature of the insult (i.e. infectious versus non-infectious SIRS; under anesthesia [surgery] or not [trauma, burn]), the nature of the activator used to trigger leukocytes (i.e. different Toll-like receptor ligands or whole bacteria), the nature of the cell culture (i.e. isolated monocytes versus peripheral blood mononuclear cells versus whole blood assays), and the nature of the analyzed cytokines (e.g. IL-1beta versus IL-1ra; TNF versus IL-10) have a profound influence on the outcome of the response.

  11. Human Computer Interaction Issues in Clinical Trials Management Systems

    PubMed Central

    Starren, Justin B.; Payne, Philip R.O.; Kaufman, David R.

    2006-01-01

    Clinical trials increasingly rely upon web-based Clinical Trials Management Systems (CTMS). As with clinical care systems, Human Computer Interaction (HCI) issues can greatly affect the usefulness of such systems. Evaluation of the user interface of one web-based CTMS revealed a number of potential human-computer interaction problems, in particular, increased workflow complexity associated with a web application delivery model and potential usability problems resulting from the use of ambiguous icons. Because these design features are shared by a large fraction of current CTMS, the implications extend beyond this individual system. PMID:17238728

  12. UVA system for human cornea irradiation

    NASA Astrophysics Data System (ADS)

    Pereira, Fernando R. A.; Stefani, Mario; Otoboni, José A.; Richter, Eduardo H.; Rossi, Giuliano; Mota, Alessandro D.; Ventura, Liliane

    2009-02-01

    According to recent studies, an increase in corneal stiffness is a promising alternative for avoiding ectasias and for stagnating keratoconus of grades 1 and 2. The clinical treatment consists essentially of instilling Riboflavin (vitamin B2), in the cornea and then irradiating the corneal tissue, with UVA (365nm) radiation at 3mW/cm2 for 30min. This procedure provides collagen cross-linking in the corneal surface, increasing its stiffness. This work presents a system for UVA irradiation of the corneas at a peak wavelength of 365nm with adjustable power up to 5mW. The system has closed loop electronics to control the emitted power with 20% precision from the sated power output. The system is a prototype for performing corneal cross-linking and has been clinically tested. The closed loop electronics is a differential from the equipments available on the market.

  13. Physics of the human cardiovascular system

    NASA Astrophysics Data System (ADS)

    Stefanovska, Aneta

    1999-01-01

    Contemporary measurement techniques permit the non-invasive observation of several cardiovascular functions, both from the central and peripheral points of view. We show that, within one cycle of blood through the cardiovascular system, the same dynamics characterizes heart function as well as blood flow in the capillary bed where cells exchange energy and matter. Analyses of several quite different signals derived from respiration, cardiac function and blood flow, all reveal the existence of five almost periodic frequency components. This result is interpreted as evidence that cardiovascular dynamics is governed by five coupled oscillators. The couplings provide co-ordination among the physiological processes involved, and are essential for efficient cardiovascular function. Understanding the dynamics of a system of five coupled oscillators not only represents a theoretical challenge, but also carries practical implications for diagnosis and for predicting the future behaviour of this life giving system.

  14. Paralysis recovery in humans and model systems

    NASA Technical Reports Server (NTRS)

    Edgerton, V. Reggie; Roy, Roland R.

    2002-01-01

    Considerable evidence now demonstrates that extensive functional and anatomical reorganization following spinal cord injury occurs in centers of the brain that have some input into spinal motor pools. This is very encouraging, given the accumulating evidence that new connections formed across spinal lesions may not be initially functionally useful. The second area of advancement in the field of paralysis recovery is in the development of effective interventions to counter axonal growth inhibition. A third area of significant progress is the development of robotic devices to quantify the performance level of motor tasks following spinal cord injury and to 'teach' the spinal cord to step and stand. Advances are being made with robotic devices for mice, rats and humans.

  15. Human habitat positioning system for NASA's space flight environmental simulator

    NASA Technical Reports Server (NTRS)

    Caldwell, W. F.; Tucker, J.; Keas, P.

    1998-01-01

    Artificial gravity by centrifugation offers an effective countermeasure to the physiologic deconditioning of chronic exposure to microgravity; however, the system requirements of rotational velocity, radius of rotation, and resultant centrifugal acceleration require thorough investigation to ascertain the ideal human-use centrifuge configuration. NASA's Space Flight Environmental Simulator (SFES), a 16-meter (52-foot) diameter, animal-use centrifuge, was recently modified to accommodate human occupancy. This paper describes the SFES Human Habitat Positioning System, the mechanism that facilitates radius of rotation variability and alignment of the centrifuge occupants with the artificial gravity vector.

  16. [Human vital function monitoring as a system with hybrid intelligence].

    PubMed

    Popov, Iu B

    2005-01-01

    Monitoring system is considered in this work as a reanimatologist-monitor-patient-medium system. This work is an upgrade to the previous concept of monitoring systems as systems with hybrid intelligence acting under variable conditions of object and medium. Human cardiorespiratory system was considered within the framework of the P. K. Anokhin theory of functional systems. The problem of resuscitation was formulated for this system and volume of required information was determined. Environment characteristics in resuscitation and surgery departments were considered. The requirements for monitor were formulated on the basis of analysis of these systems. The law of mutual adaptation of reanimatologist and monitor was put forward and safety problems associated with human factor were considered. Implementation of these principles in the MITAR 01-R-D is described.

  17. 1988 workshop on human-machine symbiotic systems proceedings

    SciTech Connect

    Parker, L.E.; Weisbin, C.R.

    1989-01-01

    This report presents the proceedings of the 1988 Workshop on Human-Machine Symbiotic Systems. Held December 5--6, 1988, in Oak Ridge, Tennessee, the workshop served as a forum for the discussion of several critical issues in human-machine symbiosis: human-machine communication, autonomous task planning and execution monitoring for heterogeneous agents, dynamic task allocation, human-machine system architecture, and machine learning via experience and human observation. The presentation of overview papers by invited keynote speakers provided a background for the breakout session discussions in these five areas. The full powers furnished by the speakers are included in the proceedings, along with written summaries of the group discussions that report session conclusions and recommendations for future work.

  18. Energy monitoring system based on human activity in the workplace

    NASA Astrophysics Data System (ADS)

    Mustafa, Nur Hanim; Husain, Mohd Nor; Aziz, Mohamad Zoinol Abidin Abdul; Othman, Mohd Azlishah; Malek, Fareq

    2015-05-01

    Human behaviors always related to day routine activities in a smart house directly give the significant factor to manage energy usage in human life. An Addition that, the factor will contribute to the best efficiency of the system. This paper will focus on the monitoring efficiency based on duration time in office hours around 8am until 5pm which depend on human behavior at working place. Besides that, the correlation coefficient method is used to show the relation between energy consumption and energy saving based on the total hours of time energy spent. In future, the percentages of energy monitoring system usage will be increase to manage energy saving based on human behaviors. This scenario will help to see the human activity in the workplace in order to get the energy saving and support world green environment.

  19. Development of human epithelial cell systems for radiation risk assessment

    NASA Astrophysics Data System (ADS)

    Yang, C. H.; Craise, L. M.

    1994-10-01

    The most important health effect of space radiation for astronauts is cancer induction. For radiation risk assessment, an understanding of carcinogenic effect of heavy ions in human cells is most essential. In our laboratory, we have successfully developed a human mammary epithelial cell system for studying the neoplastic transformation in vitro. Growth variants were obtained from heavy ion irradiated immortal mammary cell line. These cloned growth variants can grow in regular tissue culture media and maintain anchorage dependent growth and density inhibition property. Upon further irradiation with high-LET radiation, transformed foci were found. Experimental results from these studies suggest that multiexposure of radiation is required to induce neoplastic transformation of human epithelial cells. This multihits requirement may be due to high genomic stability of human cells. These growth variants can be useful model systems for space flight experiments to determine the carcinogenic effect of space radiation in human epithelial cells.

  20. Development of human epithelial cell systems for radiation risk assessment

    NASA Technical Reports Server (NTRS)

    Yang, C. H.; Craise, L. M.

    1994-01-01

    The most important health effect of space radiation for astronauts is cancer induction. For radiation risk assessment, an understanding of carcinogenic effect of heavy ions in human cells is most essential. In our laboratory, we have successfully developed a human mammary epithelial cell system for studying the neoplastic transformation in vitro. Growth variants were obtained from heavy ion irradiated immortal mammary cell line. These cloned growth variants can grow in regular tissue culture media and maintain anchorage dependent growth and density inhibition property. Upon further irradiation with high-Linear Energy Transfer (LET) radiation, transformed foci were found. Experimental results from these studies suggest that multiexposure of radiation is required to induce neoplastic tranformation of human epithelial cells. This multihits requirement may be due to high genomic stability of human cells. These growth variants can be useful model systems for space flight experiments to determine the carcinogenic effect of space radiation in human epithelial cells.

  1. A Fully Magnetically Levitated Circulatory Pump for Advanced Heart Failure.

    PubMed

    Mehra, Mandeep R; Naka, Yoshifumi; Uriel, Nir; Goldstein, Daniel J; Cleveland, Joseph C; Colombo, Paolo C; Walsh, Mary N; Milano, Carmelo A; Patel, Chetan B; Jorde, Ulrich P; Pagani, Francis D; Aaronson, Keith D; Dean, David A; McCants, Kelly; Itoh, Akinobu; Ewald, Gregory A; Horstmanshof, Douglas; Long, James W; Salerno, Christopher

    2017-02-02

    Background Continuous-flow left ventricular assist systems increase the rate of survival among patients with advanced heart failure but are associated with the development of pump thrombosis. We investigated the effects of a new magnetically levitated centrifugal continuous-flow pump that was engineered to avert thrombosis. Methods We randomly assigned patients with advanced heart failure to receive either the new centrifugal continuous-flow pump or a commercially available axial continuous-flow pump. Patients could be enrolled irrespective of the intended goal of pump support (bridge to transplantation or destination therapy). The primary end point was a composite of survival free of disabling stroke (with disabling stroke indicated by a modified Rankin score >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove the device at 6 months after implantation. The trial was powered for noninferiority testing of the primary end point (noninferiority margin, -10 percentage points). Results Of 294 patients, 152 were assigned to the centrifugal-flow pump group and 142 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 131 patients (86.2%) in the centrifugal-flow pump group and in 109 (76.8%) in the axial-flow pump group (absolute difference, 9.4 percentage points; 95% lower confidence boundary, -2.1 [P<0.001 for noninferiority]; hazard ratio, 0.55; 95% confidence interval [CI], 0.32 to 0.95 [two-tailed P=0.04 for superiority]). There were no significant between-group differences in the rates of death or disabling stroke, but reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (1 [0.7%] vs. 11 [7.7%]; hazard ratio, 0.08; 95% CI, 0.01 to 0.60; P=0.002). Suspected or confirmed pump thrombosis occurred in no patients in the centrifugal-flow pump group and in 14 patients (10

  2. Human Systems Integration: Requirements and Functional Decomposition

    NASA Technical Reports Server (NTRS)

    Berson, Barry; Gershzohn, Gary; Boltz, Laura; Wolf, Russ; Schultz, Mike

    2005-01-01

    This deliverable was intended as an input to the Access 5 Policy and Simulation Integrated Product Teams. This document contains high-level pilot functionality for operations in the National Airspace System above FL430. Based on the derived pilot functions the associated pilot information and control requirements are given.

  3. The Attention System of the Human Brain

    DTIC Science & Technology

    1989-02-28

    attention deficit disorder, among others. The concept of an attentional system of the brain with specific operations allocated to distinct anatomical... attention deficit disorder to the right hemisphere mechanisms that control sustaining of attention. It seems apparent that a combined cognitive and

  4. Aging of the Human Vestibular System

    PubMed Central

    Zalewski, Christopher K.

    2015-01-01

    Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deterioration, or they are insensitive to the associated physiologic decline and/or central compensatory mechanisms that accompany the vestibular aging process. When compared with healthy younger individuals, a paucity of subtle differences in test results has been reported in the healthy older population, and those differences are often observed only in response to nontraditional and/or more robust stimuli. In addition, the reported differences are often clinically insignificant insomuch that the recorded physiologic responses from the elderly often fall within the wide normative response ranges identified for normal healthy adults. The damaging economic impact of such vestibular sensory decline manifests itself in an exponential increase in geriatric dizziness and a subsequent higher prevalence of injurious falls. An estimated $10 to $20 billion dollar annual cost has been reported to be associated with falls-related injuries and is the sixth leading cause of death in the elderly population, with a 20% mortality rate. With an estimated 115% increase in the geriatric population over 65 years of age by the year 2050, the number of balanced-disordered patients with a declining vestibular system is certain to reach near epidemic proportions. An understanding of the effects of age on the vestibular system is imperative if clinicians are to better manage elderly patients with balance disorders, dizziness, and vestibular disease. PMID:27516717

  5. NASA Space Flight Human-System Standard Human Factors, Habitability, and Environmental Health

    NASA Technical Reports Server (NTRS)

    Holubec, Keith; Connolly, Janis

    2010-01-01

    This slide presentation reviews the history, and development of NASA-STD-3001, NASA Space Flight Human-System Standard Human Factors, Habitability, and Environmental Health, and the related Human Integration Design Handbook. Currently being developed from NASA-STD-3000, this project standard currently in review will be available in two volumes, (i.e., Volume 1 -- VCrew Health and Volume 2 -- Human Factors, Habitability, and Environmental Health) and the handbook will be both available as a pdf file and as a interactive website.

  6. The Development of A Human Systems Simulation Laboratory: Strategic Direction

    SciTech Connect

    Jacques Hugo; Katya le Blanc; David Gertman

    2012-07-01

    The Human System Simulation Laboratory (HSSL) at the Idaho National Laboratory is one of few facilities of its kind that allows human factors researchers to evaluate various aspects of human performance and human system interaction for proposed reactor designs and upgrades. A basic system architecture, physical configuration and simulation capability were established to enable human factors researchers to support multiple, simultaneous simulations and also different power plant technologies. Although still evolving in terms of its technical and functional architecture, the HSSL is already proving its worth in supporting current and future nuclear industry needs for light water reactor sustainability and small modular reactors. The evolution of the HSSL is focused on continual physical and functional refinement to make it a fully equipped, reconfigurable facility where advanced research, testing and validation studies can be conducted on a wider range of reactor technologies. This requires the implementation of additional plant models to produce empirical research data on human performance with emerging human-system interaction technologies. Additional beneficiaries of this information include system designers and HRA practitioners. To ensure that results of control room crew studies will be generalizable to the existing and evolving fleet of US reactors, future expansion of the HSSL may also include other SMR plant models, plant-specific simulators and a generic plant model aligned to the current generation of pressurized water reactors (PWRs) and future advanced reactor designs. Collaboration with industry partners is also proving to be a vital component of the facility as this helps to establish a formal basis for current and future human performance experiments to support nuclear industry objectives. A long-range Program Plan has been developed for the HSSL to ensure that the facility will support not only the Department of Energy’s Light Water Reactor

  7. Simulation of a steady-state integrated human thermal system.

    NASA Technical Reports Server (NTRS)

    Hsu, F. T.; Fan, L. T.; Hwang, C. L.

    1972-01-01

    The mathematical model of an integrated human thermal system is formulated. The system consists of an external thermal regulation device on the human body. The purpose of the device (a network of cooling tubes held in contact with the surface of the skin) is to maintain the human body in a state of thermoneutrality. The device is controlled by varying the inlet coolant temperature and coolant mass flow rate. The differential equations of the model are approximated by a set of algebraic equations which result from the application of the explicit forward finite difference method to the differential equations. The integrated human thermal system is simulated for a variety of combinations of the inlet coolant temperature, coolant mass flow rate, and metabolic rates.

  8. Human Systems Center Products and Progress.

    DTIC Science & Technology

    1993-10-01

    is designed to protect opaque, the lenses shield the eyes from harmful the aircrew member’s eyes from flashblindness light and radiation. Once the... lenses e The TFPD system is small, lightweight, and fits underneath the standard issue helmet. Laser Protection and Personnel Susceptibility Optical...fatiguing. Con- fabric using carbon sphere technology proved tinuous protection must be provided during to be more effective in repelling (and

  9. Dynamic inverse models in human-cyber-physical systems

    NASA Astrophysics Data System (ADS)

    Robinson, Ryan M.; Scobee, Dexter R. R.; Burden, Samuel A.; Sastry, S. Shankar

    2016-05-01

    Human interaction with the physical world is increasingly mediated by automation. This interaction is characterized by dynamic coupling between robotic (i.e. cyber) and neuromechanical (i.e. human) decision-making agents. Guaranteeing performance of such human-cyber-physical systems will require predictive mathematical models of this dynamic coupling. Toward this end, we propose a rapprochement between robotics and neuromechanics premised on the existence of internal forward and inverse models in the human agent. We hypothesize that, in tele-robotic applications of interest, a human operator learns to invert automation dynamics, directly translating from desired task to required control input. By formulating the model inversion problem in the context of a tracking task for a nonlinear control system in control-a_ne form, we derive criteria for exponential tracking and show that the resulting dynamic inverse model generally renders a portion of the physical system state (i.e., the internal dynamics) unobservable from the human operator's perspective. Under stability conditions, we show that the human can achieve exponential tracking without formulating an estimate of the system's state so long as they possess an accurate model of the system's dynamics. These theoretical results are illustrated using a planar quadrotor example. We then demonstrate that the automation can intervene to improve performance of the tracking task by solving an optimal control problem. Performance is guaranteed to improve under the assumption that the human learns and inverts the dynamic model of the altered system. We conclude with a discussion of practical limitations that may hinder exact dynamic model inversion.

  10. Stereoscopy and the Human Visual System

    PubMed Central

    Banks, Martin S.; Read, Jenny C. A.; Allison, Robert S.; Watt, Simon J.

    2012-01-01

    Stereoscopic displays have become important for many applications, including operation of remote devices, medical imaging, surgery, scientific visualization, and computer-assisted design. But the most significant and exciting development is the incorporation of stereo technology into entertainment: specifically, cinema, television, and video games. In these applications for stereo, three-dimensional (3D) imagery should create a faithful impression of the 3D structure of the scene being portrayed. In addition, the viewer should be comfortable and not leave the experience with eye fatigue or a headache. Finally, the presentation of the stereo images should not create temporal artifacts like flicker or motion judder. This paper reviews current research on stereo human vision and how it informs us about how best to create and present stereo 3D imagery. The paper is divided into four parts: (1) getting the geometry right, (2) depth cue interactions in stereo 3D media, (3) focusing and fixating on stereo images, and (4) how temporal presentation protocols affect flicker, motion artifacts, and depth distortion. PMID:23144596

  11. The impact of arterial oxygen tension on venous oxygen saturation in circulatory failure.

    PubMed

    Ho, Kwok Ming; Harding, Richard; Chamberlain, Jenny

    2008-01-01

    Central and mixed venous oxygen saturations have been used to guide resuscitation in circulatory failure, but the impact of arterial oxygen tension on venous oxygen saturation has not been thoroughly evaluated. This observational study investigated the impact of arterial oxygen tension on venous oxygen saturation in circulatory failure. Twenty critically ill patients with circulatory failure requiring mechanical ventilation and a pulmonary artery catheter in an intensive care unit in a tertiary hospital in Western Australia were recruited. Samples of arterial blood, central venous blood, and mixed venous blood were simultaneously and slowly drawn from the arterial, central venous, and pulmonary artery catheter, respectively, at baseline and after the patient was ventilated with 100% inspired oxygen for 5 min. The blood samples were redrawn after a significant change in cardiac index (>or =10%) from the baseline, occurring within 24 h of study enrollment while the patient was ventilated with the same baseline inspired oxygen concentration, was detected. An increase in inspired oxygen concentration significantly increased the arterial oxygen tension from 12.5 to 38.4 kPa (93.8-288 mmHg) (mean difference, 25.9 kPa; 95% confidence interval [CI], 7.5-31.9 kPa; P < 0.001) and the venous oxygen saturation from 69.9% to 76.5% (mean difference, 6.6%; 95% CI, 5.3% - 7.9%; P < 0.001). The effect of arterial oxygen tension on venous oxygen saturation was more significant than the effect associated with changes in cardiac index (mean difference, 2.8%; 95% CI, -0.2% to 5.8%; P = 0.063). In conclusion, arterial oxygen tension has a significant effect on venous oxygen saturation, and this effect is more significant and consistent than the effect associated with changes in cardiac index.

  12. Na+/H+ exchange inhibition delays the onset of hypovolemic circulatory shock in pigs.

    PubMed

    Wu, Dongmei; Arias, Jaqueline; Bassuk, Jorge; Doods, Henri; Seidler, Randolph; Adams, Jose A; Abraham, William M

    2008-04-01

    Severe blood loss is a major cause of death occurring within hours of traumatic injury. Na+/H+ exchange (NHE-1) activity is an important determinant of the extent of ischemic myocardial injury. The goal of the present study was to test the hypothesis that NHE-1 inhibition delays the onset of hypovolemic circulatory shock, thereby preventing early death due to severe hemorrhage in pigs. Severe hypovolemia was studied in 16 (25.2 kg) anesthetized male pigs in steps of 10-, 20-, 30-, 40-, and 50-mL kg(-1) blood loss, each in 30-min intervals. Shed blood resuscitation was started 30 min after 50 mL kg(-1) blood loss. The experiment was terminated after 3 h of resuscitation. Eight pigs were used as seline control. Eight pigs received 3 mg kg(-1) benzamide, N-(aminoiminomethyl)-4-[4-(2-furanylcarbonyl)-1-piperazinyl]-3-(methylsulfonyl), methanesulfonate (NHE-1 inhibitor) 15 min before hemorrhage. Seven control pigs died at 40- to 50-mL kg(-1) blood loss. One control pig survived initial resuscitation but died soon after. In contrast, all animals treated with NHE-1 inhibitor survived the entire protocol. In control animals, cardiac output and MAP gradually decreased at each step of blood loss with marked increase in heart rate. Cardiovascular decompensation occurred at 40 mL kg(-1) blood loss. Na+/H+ exchange inhibition increased oxygen delivery, attenuated cardiovascular decompensation, delayed the onset of irreversible hypovolemic circulatory shock, and enabled resuscitation to survival. Echocardiography analysis showed that myocardial hypercontracture gradually developed with each step of blood loss in control animals, but this hypercontracture was attenuated in the animals receiving the NHE-1 inhibitor. We conclude that NHE-1 inhibition attenuates ischemic myocardial hypercontracture, cardiovascular decompensation, delays the onset of hypovolemic circulatory shock, and prevents early death in severe hemorrhage.

  13. Anticoagulation with Bivalirudin during Deep Hypothermic Circulatory Arrest in a Patient with Heparin-Induced Thrombocytopenia

    PubMed Central

    Pericleous, Agamemnon; Fitzmaurice, Mary; Caldwell, Constance; Natividad, Kris; Plestis, Konstadinos A.

    2014-01-01

    Heparin-induced thrombocytopenia is a well-recognized complication of anticoagulation with heparin. We present the case of a patient with recent heparin-induced thrombocytopenia who subsequently needed surgery on an emergency basis for acute type A aortic dissection. This article reports the successful use of bivalirudin, a direct thrombin inhibitor, as an alternative to heparin throughout cardiopulmonary bypass and deep hypothermic circulatory arrest. We contend that bivalirudin is a safe alternative to heparin when performing surgery for aortic dissection and should be considered as an option for use in patients who present with heparin-induced thrombocytopenia. PMID:25593533

  14. Anticoagulation with bivalirudin during deep hypothermic circulatory arrest in a patient with heparin-induced thrombocytopenia.

    PubMed

    Pericleous, Agamemnon; Sadek, Mostafa; Fitzmaurice, Mary; Caldwell, Constance; Natividad, Kris; Plestis, Konstadinos A

    2014-12-01

    Heparin-induced thrombocytopenia is a well-recognized complication of anticoagulation with heparin. We present the case of a patient with recent heparin-induced thrombocytopenia who subsequently needed surgery on an emergency basis for acute type A aortic dissection. This article reports the successful use of bivalirudin, a direct thrombin inhibitor, as an alternative to heparin throughout cardiopulmonary bypass and deep hypothermic circulatory arrest. We contend that bivalirudin is a safe alternative to heparin when performing surgery for aortic dissection and should be considered as an option for use in patients who present with heparin-induced thrombocytopenia.

  15. Circulatory effects of potassium, glucose and insulin following open-heart surgery

    PubMed Central

    Bradley, R. D.; Branthwaite, M. A.

    1970-01-01

    The cardiovascular effects of an acute infusion of potassium, glucose and insulin (PGI) were investigated in 10 subjects following valve replacement surgery. All required circulatory support with isoprenaline and no additional improvement in cardiac function could be demonstrated following PGI. Pressures in both atria rose out of proportion to the volume infused and there were biochemical changes which suggested that haemodilution had occurred. These findings were attributed to the administration of hypertonic dextrose solution and this also resulted in hyperglycaemia, glycosuria and an osmotic diuresis. PMID:5494679

  16. A vicious cycle of acute catecholamine cardiomyopathy and circulatory collapse secondary to pheochromocytoma.

    PubMed

    Otusanya, Olufisayo; Goraya, Harmeen; Iyer, Priyanka; Landi, Kristen; Tibb, Amit; Msaouel, Pavlos

    2015-10-01

    Acute catecholamine cardiomyopathy is an uncommon, life-threatening manifestation of pheochromocytoma. The massive release of catecholamines from the adrenal medulla and their toxic effects on the coronary vessels and the cardiac myocytes play a significant role in the pathogenesis of cardiomyopathy in patients with pheochromocytoma. Severe manifestations, such as acute catecholamine cardiomyopathy, may be the initial presentation, especially in unsuspected and untreated pheochromocytoma cases. The clinical course of catecholamine-induced cardiomyopathy is unpredictable as patients may rapidly deteriorate into circulatory collapse and multisystem crisis. We report a case of a 25-year-old man who presented with catecholamine-induced cardiomyopathy.

  17. Humans vs Hardware: The Unique World of NASA Human System Risk Assessment

    NASA Technical Reports Server (NTRS)

    Anton, W.; Havenhill, M.; Overton, Eric

    2016-01-01

    Understanding spaceflight risks to crew health and performance is a crucial aspect of preparing for exploration missions in the future. The research activities of the Human Research Program (HRP) provide substantial evidence to support most risk reduction work. The Human System Risk Board (HSRB), acting on behalf of the Office of Chief Health and Medical Officer (OCHMO), assesses these risks and assigns likelihood and consequence ratings to track progress. Unfortunately, many traditional approaches in risk assessment such as those used in the engineering aspects of spaceflight are difficult to apply to human system risks. This presentation discusses the unique aspects of risk assessment from the human system risk perspective and how these limitations are accommodated and addressed in order to ensure that reasonable inputs are provided to support the OCHMO's overall risk posture for manned exploration missions.

  18. A new method to evaluate human-robot system performance

    NASA Technical Reports Server (NTRS)

    Rodriguez, G.; Weisbin, C. R.

    2003-01-01

    One of the key issues in space exploration is that of deciding what space tasks are best done with humans, with robots, or a suitable combination of each. In general, human and robot skills are complementary. Humans provide as yet unmatched capabilities to perceive, think, and act when faced with anomalies and unforeseen events, but there can be huge potential risks to human safety in getting these benefits. Robots provide complementary skills in being able to work in extremely risky environments, but their ability to perceive, think, and act by themselves is currently not error-free, although these capabilities are continually improving with the emergence of new technologies. Substantial past experience validates these generally qualitative notions. However, there is a need for more rigorously systematic evaluation of human and robot roles, in order to optimize the design and performance of human-robot system architectures using well-defined performance evaluation metrics. This article summarizes a new analytical method to conduct such quantitative evaluations. While the article focuses on evaluating human-robot systems, the method is generally applicable to a much broader class of systems whose performance needs to be evaluated.

  19. A new method to evaluate human-robot system performance.

    PubMed

    Rodriguez, G; Weisbin, C R

    2003-01-01

    One of the key issues in space exploration is that of deciding what space tasks are best done with humans, with robots, or a suitable combination of each. In general, human and robot skills are complementary. Humans provide as yet unmatched capabilities to perceive, think, and act when faced with anomalies and unforeseen events, but there can be huge potential risks to human safety in getting these benefits. Robots provide complementary skills in being able to work in extremely risky environments, but their ability to perceive, think, and act by themselves is currently not error-free, although these capabilities are continually improving with the emergence of new technologies. Substantial past experience validates these generally qualitative notions. However, there is a need for more rigorously systematic evaluation of human and robot roles, in order to optimize the design and performance of human-robot system architectures using well-defined performance evaluation metrics. This article summarizes a new analytical method to conduct such quantitative evaluations. While the article focuses on evaluating human-robot systems, the method is generally applicable to a much broader class of systems whose performance needs to be evaluated.

  20. Visualizing failure effects in complex human-machine systems

    NASA Astrophysics Data System (ADS)

    Price, Jana M.; Mathur, Amit; Morley, Rebecca M.; Scalzo, Richard C.

    2001-07-01

    The ability to understand a system's behavior in both normal and failed conditions is fundamental to the design of error-tolerant systems as well as to the development of diagnostics. The System Analysis for Failure and Error Reduction (SAFER) Project seeks to provide designers with tools to visualize potential sources of error and their effects early in the design of human-machine systems. The project is based on an existing technology that provides a failure-space modeling environment, analysis capabilities for troubleshooting, and error diagnostics using design data of machine systems. The SAFER Project extends the functionality of the existing technology in two significant ways. First, by adding a model of human error probability within the tool, designers are able to estimate the probabilities of human errors and the effects that these errors may have on system components and on the entire system. Second, the visual presentation of failure-related measures and metrics has been improved through a process of user-centered design. This paper will describe the process that was used to develop the human error probability model and will present novel metrics for assessing failure within complex systems.

  1. Simplified detection system for neuroreceptor studies in the human brain

    SciTech Connect

    Bice, A.N.; Wagner, H.N. Jr.; Frost, J.J.; Natarajan, T.K.; Lee, M.C.; Wong, D.F.; Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Links, J.M.

    1986-02-01

    A simple, inexpensive dual-detector system has been developed for measurement of positronemitting receptor-binding drugs in the human brain. This high efficiency coincidence counting system requires that only a few hundred microcuries of labeled drug be administered to the subject, thereby allowing for multiple studies without an excessive radiation dose. Measurement of the binding of (11C)carfentanil, a high affinity synthetic opiate, to opiate receptors in the presence and in the absence of a competitive opiate antagonist indicates the potential utility of this system for estimating different degrees of receptor occupation in the human brain.

  2. Calibration Issues of Tekscan Systems for Human Pressure Assessment

    DTIC Science & Technology

    2001-05-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO 11007 TITLE: Calibration Issues of Tekscan Systems for Human Pressure...Calibration Issues of Tekscan Systems For Human Pressure Assessment E.L. Morin Ph.D.’ 2 ., J.T. Bryant, Ph.D.’, S.A. Reid, M.Sc.’, R.A. Whiteside., B. Sc...Ontario, CANADA, K7L 3N6 Summary The Tekscan pressure sensor system has been designed for relatively easy measurement of contact pressures between two

  3. Hemolytic evaluation using polyurethane microcapsule suspensions in circulatory support devices: normalized index of hemolysis comparisons of commercial centrifugal blood pumps.

    PubMed

    Maruyama, Osamu; Yamaguchi, Katsuhiro; Nishida, Masahiro; Onoguchi, Tomio; Tsutsui, Tatsuo; Jikuya, Tomoaki; Yamane, Takashi

    2008-02-01

    We have been developing some types of microcapsule suspensions with polyurethane membranes to evaluate the absolute hemolytic characteristics of the centrifugal blood pumps used in circulatory support devices such as artificial hearts. In order to facilitate/realize hemolysis testing on centrifugal blood pumps that have hemolysis levels as low as those of commercial centrifugal blood pumps, we eliminated capsules with diameters less than 72.2 microm, amounting to 15.4% of all capsules in the conventional suspension (crude suspension [CS]), and adjusted the capsule volume ratio to correspond to a hematocrit of 40%. In this way we succeeded in enhancing the sensitivity of the suspension to microcapsule destruction 61 fold. We used this new suspension (fine suspension [FS]) to perform hemolysis tests on four types of commercial pump with mock circulation systems. Under conditions of 500 mm Hg and 11.2 L/min, we successfully determined the hemolytic characteristics (normalized index of hemolysis [NIH]) of some of the centrifugal blood pumps; the results showed some correlation with those of hemolysis tests on bovine blood and suggest that microcapsule suspensions with polyurethane membranes are useful as standard test solutions for the absolute evaluation of centrifugal blood pumps.

  4. Baylor Gyro Pump: a completely seal-less centrifugal pump aiming for long-term circulatory support.

    PubMed

    Ohara, Y; Sakuma, I; Makinouchi, K; Damm, G; Glueck, J; Mizuguchi, K; Naito, K; Tasai, K; Orime, Y; Takatani, S

    1993-07-01

    A seal-less centrifugal pump aiming for long-term circulatory support has been developed. In this model, shaft seals that cause thrombus formation and blood leakage were eliminated. A brushless direct current motor was incorporated as a driving unit, and pivot bearings were used to support the impeller. With reference to its motor-driven system, this pump was named the M-Gyro Pump. The first model (M1) yielded an index of hemolysis of 0.005 g/100 L using bovine blood and demonstrated satisfactory performance as a right heart assist for 2 days (4 L/min, 60 mm Hg, 1,800 rpm). The second model (M2) has been developed for left heart assist by employing a stronger motor. The pump capacity was improved to 6 L/min against 240 mm Hg at 1,800 rpm, but significant heat generation was observed. By optimization of motor efficiency, the M2 model can be improved to meet the requirements of a pump for left heart assist.

  5. Cultural selection drives the evolution of human communication systems.

    PubMed

    Tamariz, Monica; Ellison, T Mark; Barr, Dale J; Fay, Nicolas

    2014-08-07

    Human communication systems evolve culturally, but the evolutionary mechanisms that drive this evolution are not well understood. Against a baseline that communication variants spread in a population following neutral evolutionary dynamics (also known as drift models), we tested the role of two cultural selection models: coordination- and content-biased. We constructed a parametrized mixed probabilistic model of the spread of communicative variants in four 8-person laboratory micro-societies engaged in a simple communication game. We found that selectionist models, working in combination, explain the majority of the empirical data. The best-fitting parameter setting includes an egocentric bias and a content bias, suggesting that participants retained their own previously used communicative variants unless they encountered a superior (content-biased) variant, in which case it was adopted. This novel pattern of results suggests that (i) a theory of the cultural evolution of human communication systems must integrate selectionist models and (ii) human communication systems are functionally adaptive complex systems.

  6. The sympathetic nervous system alterations in human hypertension.

    PubMed

    Grassi, Guido; Mark, Allyn; Esler, Murray

    2015-03-13

    Several articles have dealt with the importance and mechanisms of the sympathetic nervous system alterations in experimental animal models of hypertension. This review addresses the role of the sympathetic nervous system in the pathophysiology and therapy of human hypertension. We first discuss the strengths and limitations of various techniques for assessing the sympathetic nervous system in humans, with a focus on heart rate, plasma norepinephrine, microneurographic recording of sympathetic nerve traffic, and measurements of radiolabeled norepinephrine spillover. We then examine the evidence supporting the importance of neuroadrenergic factors as promoters and amplifiers of human hypertension. We expand on the role of the sympathetic nervous system in 2 increasingly common forms of secondary hypertension, namely hypertension associated with obesity and with renal disease. With this background, we examine interventions of sympathetic deactivation as a mode of antihypertensive treatment. Particular emphasis is given to the background and results of recent therapeutic approaches based on carotid baroreceptor stimulation and radiofrequency ablation of the renal nerves.

  7. Latitudinal variation in light levels drives human visual system size.

    PubMed

    Pearce, Eiluned; Dunbar, Robin

    2012-02-23

    Ambient light levels influence visual system size in birds and primates. Here, we argue that the same is true for humans. Light levels, in terms of both the amount of light hitting the Earth's surface and day length, decrease with increasing latitude. We demonstrate a significant positive relationship between absolute latitude and human orbital volume, an index of eyeball size. Owing to tight scaling between visual system components, this will translate into enlarged visual cortices at higher latitudes. We also show that visual acuity measured under full-daylight conditions is constant across latitudes, indicating that selection for larger visual systems has mitigated the effect of reduced ambient light levels. This provides, to our knowledge, the first support that light levels drive intraspecific variation in visual system size in the human population.

  8. Human Performance Considerations for Remotely Piloted Aircraft Systems (RPAS)

    NASA Technical Reports Server (NTRS)

    Shively, R. Jay; Hobbs, Alan; Lyall, Beth; Rorie, Conrad

    2015-01-01

    Successful integration of Remotely Piloted Aircraft Systems (RPAS) into civil airspace will not only require solutions to technical challenges, but will also require that the design and operation of RPAS take into account human limitations and capabilities. Human factors can affect overall system performance whenever the system relies on people to interact with another element of the system. Four types of broad interactions can be described. These are (1) interactions between people and hardware, such as controls and displays; (2) human use of procedures and documentation; (3) impact of the task environment, including lighting, noise and monotony; and lastly, (4) interactions between operational personnel, including communication and coordination. In addition to the human factors that have been identified for conventional aviation, RPAS operations introduce a set of unique human challenges. The purpose of document is to raise human factors issues for consideration by workgroups of the ICAO RPAS panel as they work to develop guidance material and additions to ICAO annexes. It is anticipated that the content of this document will be revised and updated as the work of the panel progresses.

  9. Imaging systems of human eye: a review.

    PubMed

    Acharya, Rajendra U; Yun, Wong Li; Ng, E Y K; Yu, Wenwei; Suri, Jasjit S

    2008-08-01

    The eyes are complex sensory organs and are designed to optimize vision under conditions of varying light. There are a number of eye disorders that can influence vision. Eye disorders among the elderly are a major health problem. With advancing age, the normal function of eye tissues decreases and there is an increased incidence of ocular pathology. The most common causes of age related eye disorder and visual impairment in the elderly are cataracts and primary open angle glaucoma. Different imaging systems are available to visualize the different parts of the eye non-invasively with higher accuracy. This paper discusses the various techniques available namely, computed tomography, confocal laser scanning microscopy, magnetic resonance imaging, optical coherence tomography, ultrasound imaging, infrared thermography for the imaging of the different eye abnormalities.

  10. Human CD8+ T cells mediate protective immunity induced by a human malaria vaccine in human immune system mice.

    PubMed

    Li, Xiangming; Huang, Jing; Zhang, Min; Funakoshi, Ryota; Sheetij, Dutta; Spaccapelo, Roberta; Crisanti, Andrea; Nussenzweig, Victor; Nussenzweig, Ruth S; Tsuji, Moriya

    2016-08-31

    A number of studies have shown that CD8+ T cells mediate protective anti-malaria immunity in a mouse model. However, whether human CD8+ T cells play a role in protection against malaria remains unknown. We recently established human immune system (HIS) mice harboring functional human CD8+ T cells (HIS-CD8 mice) by transduction with HLA-A∗0201 and certain human cytokines using recombinant adeno-associated virus-based gene transfer technologies. These HIS-CD8 mice mount a potent, antigen-specific HLA-A∗0201-restricted human CD8+ T-cell response upon immunization with a recombinant adenovirus expressing a human malaria antigen, the Plasmodium falciparum circumsporozoite protein (PfCSP), termed AdPfCSP. In the present study, we challenged AdPfCSP-immunized HIS-CD8 mice with transgenic Plasmodium berghei sporozoites expressing full-length PfCSP and found that AdPfCSP-immunized (but not naïve) mice were protected against subsequent malaria challenge. The level of the HLA-A∗0201-restricted, PfCSP-specific human CD8+ T-cell response was closely correlated with the level of malaria protection. Furthermore, depletion of human CD8+ T cells from AdPfCSP-immunized HIS-CD8 mice almost completely abolished the anti-malaria immune response. Taken together, our data show that human CD8+ T cells mediate protective anti-malaria immunity in vivo.

  11. Vision Systems with the Human in the Loop

    NASA Astrophysics Data System (ADS)

    Bauckhage, Christian; Hanheide, Marc; Wrede, Sebastian; Käster, Thomas; Pfeiffer, Michael; Sagerer, Gerhard

    2005-12-01

    The emerging cognitive vision paradigm deals with vision systems that apply machine learning and automatic reasoning in order to learn from what they perceive. Cognitive vision systems can rate the relevance and consistency of newly acquired knowledge, they can adapt to their environment and thus will exhibit high robustness. This contribution presents vision systems that aim at flexibility and robustness. One is tailored for content-based image retrieval, the others are cognitive vision systems that constitute prototypes of visual active memories which evaluate, gather, and integrate contextual knowledge for visual analysis. All three systems are designed to interact with human users. After we will have discussed adaptive content-based image retrieval and object and action recognition in an office environment, the issue of assessing cognitive systems will be raised. Experiences from psychologically evaluated human-machine interactions will be reported and the promising potential of psychologically-based usability experiments will be stressed.

  12. Establishment of novel prediction system of intestinal absorption in humans using human intestinal tissues.

    PubMed

    Miyake, Masateru; Toguchi, Hajime; Nishibayashi, Toru; Higaki, Kazutaka; Sugita, Akira; Koganei, Kazutaka; Kamada, Nobuhiko; Kitazume, Mina T; Hisamatsu, Tadakazu; Sato, Toshiro; Okamoto, Susumu; Kanai, Takanori; Hibi, Toshifumi

    2013-08-01

    The objective of this study was to establish a novel prediction system of drug absorption in humans by utilizing human intestinal tissues. Based on the transport index (TI), a newly defined parameter, calculated by taking account of the change in drug concentrations because of precipitation on the apical side and the amounts accumulated in the tissue and transported to the basal side, the absorbability of drugs in rank order as well as the fraction of dose absorbed (Fa) in humans were estimated. Human intestinal tissues taken from ulcerative colitis or Crohn's disease patients were mounted in a mini-Ussing chamber and transport studies were performed to evaluate the permeation of drugs, including FD-4, a very low permeable marker, atenolol, a low permeable marker, and metoprolol, a high permeable marker. Although apparent permeability coefficients calculated by the conventional equation did not reflect human Fa values for FD-4, atenolol, and metoprolol, TI values were well correlated with Fa values, which are described by 100 · [1 - e (- f · (TI - α)) ]. Based on this equation, Fa values in humans for other test drugs were predicted successfully, indicating that our new system utilizing human intestinal tissues would be valuable for predicting oral drug absorption in humans.

  13. NASA's Advanced Life Support Systems Human-Rated Test Facility.

    PubMed

    Henninger, D L; Tri, T O; Packham, N J

    1996-01-01

    Future NASA missions to explore the solar system will be long-duration missions, requiring human life support systems which must operate with very high reliability over long periods of time. Such systems must be highly regenerative, requiring minimum resupply, to enable the crews to be largely self-sufficient. These regenerative life support systems will use a combination of higher plants, microorganisms, and physicochemical processes to recycle air and water, produce food, and process wastes. A key step in the development of these systems is establishment of a human-rated test facility specifically tailored to evaluation of closed, regenerative life supports systems--one in which long-duration, large-scale testing involving human test crews can be performed. Construction of such a facility, the Advanced Life Support Program's (ALS) Human-Rated Test Facility (HRTF), has begun at NASA's Johnson Space Center, and definition of systems and development of initial outfitting concepts for the facility are underway. This paper will provide an overview of the HRTF project plan, an explanation of baseline configurations, and descriptive illustrations of facility outfitting concepts.

  14. Evaluating human performance modeling for system assessment: Promise and problems

    NASA Technical Reports Server (NTRS)

    Patterson, Robert W.; Young, Michael J.

    1992-01-01

    The development and evaluation of computational human performance models is examined. An intention is to develop models which can be used to interact with system prototypes and simulations to perform system assessment. Currently LR is working on a set of models emulating cognitive, psychomotor, auditory, and visual activity for multiple operator positions of a command and control simulation system. These models, developed in conjunction with BBN Systems and Technologies, function within the simulation environment and allow for both unmanned system assessment and manned (human-in-loop) assessment of system interface and team interactions. These are relatively generic models with built-in flexibility which allows modification of some model parameters. These models have great potential for improving the efficiency and effectiveness of system design, test, and evaluation. However, the extent of the practical utility of these models is unclear. Initial verification efforts comparing model performance within the simulation to actual human operators on a similar, independent simulation have been performed and current efforts are directed at comparing human and model performance within the same simulation environment.

  15. Systemic modelling of human bioenergetics and blood circulation.

    PubMed

    Lim, K M; Yang, S-H; Shim, E B

    2012-10-01

    This work reviews the main aspects of human bioenergetics and the dynamics of the cardiovascular system, with emphasis on modelling their physiological characteristics. The methods used to study human bioenergetics and circulation dynamics, including the use of mathematical models, are summarised. The main characteristics of human bioenergetics, including mitochondrial metabolism and global energy balance, are first described, and the systemic aspects of blood circulation and related physiological issues are introduced. The authors also discuss the present status of studies of human bioenergetics and blood circulation. Then, the limitations of the existing studies are described in an effort to identify directions for future research towards integrated and comprehensive modelling. This review emphasises that a multi-scale and multi-physical approach to bioenergetics and blood circulation that considers multiple scales and physiological factors are necessary for the appropriate clinical application of computational models.

  16. Comparing face patch systems in macaques and humans.

    PubMed

    Tsao, Doris Y; Moeller, Sebastian; Freiwald, Winrich A

    2008-12-09

    Face recognition is of central importance for primate social behavior. In both humans and macaques, the visual analysis of faces is supported by a set of specialized face areas. The precise organization of these areas and the correspondence between individual macaque and human face-selective areas are debated. Here, we examined the organization of face-selective regions across the temporal lobe in a large number of macaque and human subjects. Macaques showed 6 regions of face-selective cortex arranged in a stereotypical pattern along the temporal lobe. Human subjects showed, in addition to 3 reported face areas (the occipital, fusiform, and superior temporal sulcus face areas), a face-selective area located anterior to the fusiform face area, in the anterior collateral sulcus. These results suggest a closer anatomical correspondence between macaque and human face-processing systems than previously realized.

  17. NASA UAS Integration into the NAS Project: Human Systems Integration

    NASA Technical Reports Server (NTRS)

    Shively, Jay

    2016-01-01

    This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS (Unmanned Aircraft System) Integration into the NAS project. The most recent simulation on DAA interoperability with Traffic Collision Avoidance System (TCAS) is discussed in the most detail. The relationship of the work to the larger UAS community and next steps are also detailed.

  18. Modeling and simulation of the cardiovascular system: a review of applications, methods, and potentials.

    PubMed

    Brunberg, Anja; Heinke, Stefanie; Spillner, Jan; Autschbach, Rüdiger; Abel, Dirk; Leonhardt, Steffen

    2009-10-01

    Proper function of the cardiovascular system is indispensible to human survival. However, this system is dominated by complex interactions between different physiological processes and control mechanisms. A structured analysis and a mathematical description of this system can provide more insight, and a computer-based simulation of dynamic processes in the cardiovascular system could be applied in numerous tasks. This article gives a review of different approaches to cardio-circulatory modeling and discusses methodological aspects and fields of application for several classes of models.

  19. Sustainability Indicators for Coupled Human-Earth Systems

    NASA Astrophysics Data System (ADS)

    Motesharrei, S.; Rivas, J. R.; Kalnay, E.

    2014-12-01

    Over the last two centuries, the Human System went from having a small impact on the Earth System (including the Climate System) to becoming dominant, because both population and per capita consumption have grown extremely fast, especially since about 1950. We therefore argue that Human System Models must be included into Earth System Models through bidirectional couplings with feedbacks. In particular, population should be modeled endogenously, rather than exogenously as done currently in most Integrated Assessment Models. The growth of the Human System threatens to overwhelm the Carrying Capacity of the Earth System, and may be leading to catastrophic climate change and collapse. We propose a set of Ecological and Economic "Sustainability Indicators" that can employ large data-sets for developing and assessing effective mitigation and adaptation policies. Using the Human and Nature Dynamical Model (HANDY) and Coupled Human-Climate-Water Model (COWA), we carry out experiments with this set of Sustainability Indicators and show that they are applicable to various coupled systems including Population, Climate, Water, Energy, Agriculture, and Economy. Impact of nonrenewable resources and fossil fuels could also be understood using these indicators. We demonstrate interconnections of Ecological and Economic Indicators. Coupled systems often include feedbacks and can thus display counterintuitive dynamics. This makes it difficult for even experts to see coming catastrophes from just the raw data for different variables. Sustainability Indicators boil down the raw data into a set of simple numbers that cross their sustainability thresholds with a large time-lag before variables enter their catastrophic regimes. Therefore, we argue that Sustainability Indicators constitute a powerful but simple set of tools that could be directly used for making policies for sustainability.

  20. Object representation in the human auditory system

    PubMed Central

    Winkler, István; van Zuijen, Titia L.; Sussman, Elyse; Horváth, János; Näätänen, Risto

    2010-01-01

    One important principle of object processing is exclusive allocation. Any part of the sensory input, including the border between two objects, can only belong to one object at a time. We tested whether tones forming a spectro-temporal border between two sound patterns can belong to both patterns at the same time. Sequences were composed of low-, intermediate- and high-pitched tones. Tones were delivered with short onset-to-onset intervals causing the high and low tones to automatically form separate low and high sound streams. The intermediate-pitch tones could be perceived as part of either one or the other stream, but not both streams at the same time. Thus these tones formed a pitch ’border’ between the two streams. The tones were presented in a fixed, cyclically repeating order. Linking the intermediate-pitch tones with the high or the low tones resulted in the perception of two different repeating tonal patterns. Participants were instructed to maintain perception of one of the two tone patterns throughout the stimulus sequences. Occasional changes violated either the selected or the alternative tone pattern, but not both at the same time. We found that only violations of the selected pattern elicited the mismatch negativity event-related potential, indicating that only this pattern was represented in the auditory system. This result suggests that individual sounds are processed as part of only one auditory pattern at a time. Thus tones forming a spectro-temporal border are exclusively assigned to one sound object at any given time, as are spatio-temporal borders in vision. PMID:16836636