The constant evolution of Information and Communication Technologies brings new opportunities wit... more The constant evolution of Information and Communication Technologies brings new opportunities with multiple forms of communication, therefore new ways of sharing knowledge. In healthcare practice, being updated it's extremely important in order to provide a better service. The growth of multiple sources of knowledge, mostly supported by technology, gives more opportunity to achieve it. Another way to be updated is sharing knowledge with partners and communities, which is becoming part of the healthcare organizations culture (i.e. Electronic Health Record systems). Healthcare organizations manage with personal information concerning to patients such as clinical treatment, clinical history, drug administration, diseases casuistic, among others; and from many sources, such as patient's feedback, knowledge from suppliers, knowledge from Internet sources, knowledge from decision support systems and inference knowledge (e.g. knowledge from data mining techniques) that are supported by computerbased systems and therefore, demands cautious when are ethical and legal aspects involved. The Critical Knowledge Monitor System Model, proposed, allows knowledge sharing in a controlled ambient and could be a part of the answer to this paradigm that healthcare organizations face. To implement the Critical Knowledge Monitor System model we'll need, to capture knowledge in multiple forms in healthcare organizations, to accomplish it knowledge engineering techniques such as text mining techniques, Information retrieval, ontology construction, among others, should be applied. Since not all knowledge manage by healthcare organizations could be considered critical (or much critical), it's necessary to use specific clinical constructs, such as sensitivity and, we believe, combining it with information security principles CIA and Privacy we could assess documents and classify them as critical to the healthcare organization.
Anticipated and zero-lag synchronization have been observed in different scientific fields. In th... more Anticipated and zero-lag synchronization have been observed in different scientific fields. In the brain, they might play a fundamental role in information processing, temporal coding and spatial attention. Recent numerical work on anticipated and zero-lag synchronization studied the role of delays. However, an analytical understanding of the conditions for these phenomena remains elusive. In this paper, we study both phenomena in systems with small delays. By performing a phase reduction and studying phase locked solutions, we uncover the functional relation between the delay, excitation and inhibition for the onset of anticipated synchronization in a sender-receiver-interneuron motif. In the case of zero-lag synchronization in a chain motif, we determine the stability conditions. These analytical solutions provide an excellent prediction of the phase-locked regimes of Hodgkin-Huxley models and Roessler oscillators.
We show that, in periodically perturbed chaotic systems, Phase Synchronization appears, associate... more We show that, in periodically perturbed chaotic systems, Phase Synchronization appears, associated to a special type of stroboscopic map, in which not only averages quantities are equal to invariants of the perturbation, the angular frequency, but also it exists a very large number of nontransient transformations, possibly infinity. In cases where there is not phase synchronization there is either only transitive transformations on the attractor, or a finite number of non-transitive transformations. We base our statements in experimental and numerical results from the sinusoidally perturbed Chua's circuit.
Spontaneous explosive is an abrupt transition to collective behavior taking place in heterogeneou... more Spontaneous explosive is an abrupt transition to collective behavior taking place in heterogeneous networks when the frequencies of the nodes are positively correlated to the node degree. This explosive transition was conjectured to be discontinuous. Indeed, numerical investigations reveal a hysteresis behavior associated with the transition. Here, we analyze explosive synchronization in star graphs. We show that in the thermodynamic limit the transition to (and out) collective behavior is indeed discontinuous. The discontinuous nature of the transition is related to the nonlinear behavior of the order parameter, which in the thermodynamic limit exhibits multiple fixed points. Moreover, we unravel the hysteresis behavior in terms of the graph parameters. Our numerical results show that finite size graphs are well described by our predictions.
The traditional voting systems have not evolved with the Communication and Information Technologi... more The traditional voting systems have not evolved with the Communication and Information Technologies, despite their recognized advantages in issues like the increasing abstention (specially in nationwide elections); the non-privacy of people with special needs and, the slowness of counting votes process. Naturally, there is a great political motivation to implement e-voting systems. However, the most recent implementations bring up security faults that can compromise the basics requirements of a voting process. Any kind of e-voting system involves many people, many roles, many technologies to support the required functions and many processes, increasing the complexity and the number and type of security breaches. In order to control the security level and optimize resource allocation; and according to the recent security standards, the definition of a Information Security Management System (ISMS) is essential when leading with this issue, allowing a good performance in risk managemen...
To study the therapeutic effect of three tube-guides with electrical conductivity associated to m... more To study the therapeutic effect of three tube-guides with electrical conductivity associated to mesenchymal stem cells (MSCs) on neuro-muscular regeneration after neurotmesis. Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol (PVA), PVA-carbon nanotubes (CNTs) and MSCs, and PVA-polypyrrole (PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functional index (SSI), and by withdrawal reflex latency (WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility. SSI remained negative throughout and independently from treatment. Differences between treted groups in ...
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015
ABSTRACT Abstract. The Childhood protection is a subject with high value for the society, but, th... more ABSTRACT Abstract. The Childhood protection is a subject with high value for the society, but, the Child Abuse cases are difficult to identify. The process from suspicious to accusation is very difficult to achieve. It must configure very strong evidences. Typically, Health Care services deal with these cases from the beginning where there are evidences based on the diagnosis, but they aren't enough to promote the accusation. Besides that, this subject it's highly sensitive because there are legal aspects to deal with such as: the patient privacy, paternity issues, medical confidentiality, among others. We propose a Child Abuses critical knowledge monitor system model that addresses this problem. This decision support system is implemented with a multiple scientific domains: to capture of tokens from clinical documents from multiple sources; a topic model approach to identify the topics of the documents; knowledge management through the use of ontologies to support the critical knowledge sensibility concepts and relations such as: symptoms, behaviors, among other evidences in order to match with the topics inferred from the clinical documents and then alert and log when clinical evidences are present. Based on these alerts clinical personnel could analyze the situation and take the appropriate procedures.
Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent... more Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. Neonatal tissues are routinely discarded at parturition so little ethical controversy attends the harvest of the Mesenchymal Stem Cells (MSCs) which may play an important therapeutic role through the secretion of soluble trophic factors which enhance and assist in repair by paracrine activation of surrounding cells. The use of cellular systems is a rational approach for delivering neurotrophic factors at the nerve lesion site, and in our recent research work we have been evaluating the therapeutic value of MSCs isolated from the Wharton jelly (WJ) in nerve repair associated to different tube-guides made of biodegradable and biocompatible biomaterials. The WJ MSCs in vitro studies included cell characterization by immunocytochemistry, karyotype analysis, tri-lineage differentiation capacity and flow cytometry and also citocompatibility by measuring the intracellular calcium concentration ([Ca 2+ ]i) in the presence of different tube-guides.
In many real-world networks the ability to synchronize is a key property for their performance. R... more In many real-world networks the ability to synchronize is a key property for their performance. Recent work on undirected networks with diffusive interaction revealed that improvements in the network connectivity such as making the network more connected and homogeneous enhances synchronization. However, real-world networks have directed and weighted connections. In such directed networks, understanding the impact of structural changes on the network performance remains a major challenge. Here, we show that improving the structure of a directed network can lead to a failure in the network function. For instance, introducing new links to reduce the minimum distance between nodes can lead to instabilities in the synchronized motion. This effect only occurs in directed networks. Our results allow to identify the dynamical importance of a link and thereby have a major impact on the design and control of directed networks.
Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online... more Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online under ''Instructions for Authors''.) They should be no more than 4 double-spaced pages with no Abstract or sub-headings, with a maximum of four (4) references. If figures are included, they should be limited to two (2). The cost of printing color figures is the responsibility of the author.
O conceito de envolvimento dos alunos na escola tem vindo a ser colocado no cerne das discussões ... more O conceito de envolvimento dos alunos na escola tem vindo a ser colocado no cerne das discussões relacionadas com o sucesso académico e com o abandono escolar. Este estudo faz uma revisão de literatura acerca deste conceito e das suas relações com o desempenho académico, destacando a sua importância no âmbito da formação de professores. Vários estudos sustentam que a falta de envolvimento dos alunos aparece associada ao baixo desempenho académico, a problemas de comportamento e ao abandono escolar. O envolvimento dos alunos na escola apresenta-se, na literatura revista, como uma resposta eficaz para os problemas que afetam as escolas e os seus alunos, como um aspeto a ter em conta na prevenção de padrões de comportamento problemático em contexto escolar e, portanto, como um conceito transdisciplinar de elevada importância na formação de professores.
2012 International Conference and Exposition on Electrical and Power Engineering, 2012
In this work, continuous health monitoring for disabled or elderly people is proposed using texti... more In this work, continuous health monitoring for disabled or elderly people is proposed using textile integrated electrodes for ECG measurement. Other applications, such as EMG or skin impedance measurement are also envisaged. The paper specifically describes a shirt integrating electrodes for ECG measurement that has been tested in several conditions. The techniques for integration of ECG electrodes can be directly applied for production of EMG or skin-impedance electrodes. Signal processing techniques for heart rate value extraction and to deal with low-quality signal or motion artefacts are being tested and will also be described. Results show that signals acquired with the shirt are comparable to signals acquired with conventional gel electrodes. The complete integration of the electrodes into clothing may have a very interesting psychological benefit, but some issues related to comfort and daily use have to be further investigated.
2013 2nd Experiment@ International Conference (exp.at'13), 2013
ABSTRACT World Pendulum is a project with the main purpose of studying the behavior of standard g... more ABSTRACT World Pendulum is a project with the main purpose of studying the behavior of standard gravity with latitude. Several automated simple pendulums are distributed across different latitudes. Each of these pendulums can be remotely operated over the Internet, communicating in real time the measured period of the oscillations, which may then be used to calculate the value of g. This article describes the World Pendulum project and it's implementation integrated into e-lab, a software framework that allows remote control of real experiments over the Internet[1]. Preliminary results show that a good agreement with the established spherical harmonics model is obtained, with the absolute overall error being under 0.0002 m/s2.
This paper addresses the problem of decentralized exploration and mapping of unknown environment ... more This paper addresses the problem of decentralized exploration and mapping of unknown environment by a multiple robot team. The exploration methodology relies on individual decision rules and communication of topological maps to achieve efficient and fast mapping, minimizing overlap of explored space. This distributed solution allows scalability of the proposed methods. Each robot broadcasts a graph representing the topological map, with information of exploration status of each region. Therefore, this kind of information can be transmitted to robots that are not in the communication range, through other robots in a multi-hop network. This work has been tested in simulation, and the results demonstrate the performance improvements and robustness that arise from our multirobot approach to exploration.
machine, to the temperature on a conventional vesical bladder thermistor and, for patients underg... more machine, to the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, to oesophageal temperature. Results: Using a linear model for sensor comparison the arterial outlet sensor showed a bias among the other sensor positions between −0.54 • C and −1.12 • C. The 95% confidence interval ranged between 7.06 • C and 8.82 • C for the upper limit and −8.14 • C and −10.62 • C for the lower limit. Due to the hysteretic shape the curvest were fitted into a nonlinear model. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12 • C). Conclusion: We suggest that measured surrogate temperatures, e.g., from the vesical bladder, as an index of cerebral overheating should be interpreted with respect to the direction-dependent behaviour of temperatures during cooling and rewarming phases. In conclusion, with greater deviations from normothermia, the way to interprete the classical temperature measuring sites should be done using a new non-linear, direction dependend model.
In particular, chitosan has recently attracted particular attention because of its biocompatibili... more In particular, chitosan has recently attracted particular attention because of its biocompatibility, biodegradability, low toxicity, low cost, enhancement of wound-healing and antibacterial effects and its potential usefulness in nerve regeneration have been demonstrated both in vitro and in vivo (Amado et al., 2010; Shirosaki et al., 2005; Simoes et al., 2010). Chitosan is a partially deacetylated polymer of acetyl glucosamine obtained after the alkaline deacetylation of chitin (Senel & McClure, 2004). While chitosan matrices have low mechanical strength under physiological conditions and are unable to maintain a predefined shape after transplantation, their mechanical properties can be improved by modification with a silane agent, namely γglycidoxypropyltrimethoxysilane (GPTMS), one of the silane-coupling agents which has epoxy and methoxysilane groups. The epoxy group reacts with the amino groups of chitosan molecules, while the methoxysilane groups are hydrolyzed and form silanol groups, and the silanol groups are subjected to the construction of a siloxane network due to the condensation. Thus, the mechanical strength of chitosan can be improved by the crosslinking between chitosan, GPTMS and siloxane network. We have previously obtained by adding GPTMS, chitosan type III membranes (hybrid chitosan membranes) which have about 110 µm pores and about 90% of porosity, due to the employment of freeze-drying technique, and which were successful in improving sciatic nerve regeneration after axonotmesis (Amado et al., 2008). Wettability of the material surfaces is one of the key factors for protein adsorption, cell attachment and migration (Amado et al., 2008). The addition of GPTMS improves the wettability of chitosan surfaces, and therefore chitosan type III membranes are more hydrophilic than types of chitosan membranes (Shirosaki et al., 2005). In addition, chitosan type III was developed to be more porous, with a larger surface to volume ratio, and to preserve mechanical strength and ability to adapt to different shapes. Significant differences in water uptake between commonly used chitosan and our hybrid chitosan type III were previously reported and it has been shown that they retain about two times as much biological fluid (Tateishi et al., 2002). The Neurolac® and the PLGA90:10 tube-guides guides show several different physical-chemical properties, namely Neurolac® is stiffer than PLGA due to structural reinforcement of the ester bonds and does not degrade so quickly. The biodegradation rate of PLGA tubes is estimated to be around 3 months while that complete resorption of Neurolac® is estimated to be of 16 months approximately (Geuna et al., 2009; Luis et al., 2007b; Luis et al., 2008). The degradation products of Neurolac® are less acidic, which may cause less damage to the surrounding tissue, and they are transparent so that the correct positioning of the nerve stumps may be confirmed after suturing. On the other hand, the biodegradable non woven structure of PLGA tubes may offer some advantages in terms of microporosity which may enhance nerve repair (Luis et al., 2007b; Luis et al., 2008). In vitro studies have shown that the four types of tube-guides, namely, the PLGA, the collagen, the hybrid chitosan and the Neurolac® are biocompatible to nerve cells and can facilitate nerve cell attachment, differentiation and growth (
The constant evolution of Information and Communication Technologies brings new opportunities wit... more The constant evolution of Information and Communication Technologies brings new opportunities with multiple forms of communication, therefore new ways of sharing knowledge. In healthcare practice, being updated it's extremely important in order to provide a better service. The growth of multiple sources of knowledge, mostly supported by technology, gives more opportunity to achieve it. Another way to be updated is sharing knowledge with partners and communities, which is becoming part of the healthcare organizations culture (i.e. Electronic Health Record systems). Healthcare organizations manage with personal information concerning to patients such as clinical treatment, clinical history, drug administration, diseases casuistic, among others; and from many sources, such as patient's feedback, knowledge from suppliers, knowledge from Internet sources, knowledge from decision support systems and inference knowledge (e.g. knowledge from data mining techniques) that are supported by computerbased systems and therefore, demands cautious when are ethical and legal aspects involved. The Critical Knowledge Monitor System Model, proposed, allows knowledge sharing in a controlled ambient and could be a part of the answer to this paradigm that healthcare organizations face. To implement the Critical Knowledge Monitor System model we'll need, to capture knowledge in multiple forms in healthcare organizations, to accomplish it knowledge engineering techniques such as text mining techniques, Information retrieval, ontology construction, among others, should be applied. Since not all knowledge manage by healthcare organizations could be considered critical (or much critical), it's necessary to use specific clinical constructs, such as sensitivity and, we believe, combining it with information security principles CIA and Privacy we could assess documents and classify them as critical to the healthcare organization.
Anticipated and zero-lag synchronization have been observed in different scientific fields. In th... more Anticipated and zero-lag synchronization have been observed in different scientific fields. In the brain, they might play a fundamental role in information processing, temporal coding and spatial attention. Recent numerical work on anticipated and zero-lag synchronization studied the role of delays. However, an analytical understanding of the conditions for these phenomena remains elusive. In this paper, we study both phenomena in systems with small delays. By performing a phase reduction and studying phase locked solutions, we uncover the functional relation between the delay, excitation and inhibition for the onset of anticipated synchronization in a sender-receiver-interneuron motif. In the case of zero-lag synchronization in a chain motif, we determine the stability conditions. These analytical solutions provide an excellent prediction of the phase-locked regimes of Hodgkin-Huxley models and Roessler oscillators.
We show that, in periodically perturbed chaotic systems, Phase Synchronization appears, associate... more We show that, in periodically perturbed chaotic systems, Phase Synchronization appears, associated to a special type of stroboscopic map, in which not only averages quantities are equal to invariants of the perturbation, the angular frequency, but also it exists a very large number of nontransient transformations, possibly infinity. In cases where there is not phase synchronization there is either only transitive transformations on the attractor, or a finite number of non-transitive transformations. We base our statements in experimental and numerical results from the sinusoidally perturbed Chua's circuit.
Spontaneous explosive is an abrupt transition to collective behavior taking place in heterogeneou... more Spontaneous explosive is an abrupt transition to collective behavior taking place in heterogeneous networks when the frequencies of the nodes are positively correlated to the node degree. This explosive transition was conjectured to be discontinuous. Indeed, numerical investigations reveal a hysteresis behavior associated with the transition. Here, we analyze explosive synchronization in star graphs. We show that in the thermodynamic limit the transition to (and out) collective behavior is indeed discontinuous. The discontinuous nature of the transition is related to the nonlinear behavior of the order parameter, which in the thermodynamic limit exhibits multiple fixed points. Moreover, we unravel the hysteresis behavior in terms of the graph parameters. Our numerical results show that finite size graphs are well described by our predictions.
The traditional voting systems have not evolved with the Communication and Information Technologi... more The traditional voting systems have not evolved with the Communication and Information Technologies, despite their recognized advantages in issues like the increasing abstention (specially in nationwide elections); the non-privacy of people with special needs and, the slowness of counting votes process. Naturally, there is a great political motivation to implement e-voting systems. However, the most recent implementations bring up security faults that can compromise the basics requirements of a voting process. Any kind of e-voting system involves many people, many roles, many technologies to support the required functions and many processes, increasing the complexity and the number and type of security breaches. In order to control the security level and optimize resource allocation; and according to the recent security standards, the definition of a Information Security Management System (ISMS) is essential when leading with this issue, allowing a good performance in risk managemen...
To study the therapeutic effect of three tube-guides with electrical conductivity associated to m... more To study the therapeutic effect of three tube-guides with electrical conductivity associated to mesenchymal stem cells (MSCs) on neuro-muscular regeneration after neurotmesis. Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol (PVA), PVA-carbon nanotubes (CNTs) and MSCs, and PVA-polypyrrole (PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functional index (SSI), and by withdrawal reflex latency (WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility. SSI remained negative throughout and independently from treatment. Differences between treted groups in ...
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015
ABSTRACT Abstract. The Childhood protection is a subject with high value for the society, but, th... more ABSTRACT Abstract. The Childhood protection is a subject with high value for the society, but, the Child Abuse cases are difficult to identify. The process from suspicious to accusation is very difficult to achieve. It must configure very strong evidences. Typically, Health Care services deal with these cases from the beginning where there are evidences based on the diagnosis, but they aren't enough to promote the accusation. Besides that, this subject it's highly sensitive because there are legal aspects to deal with such as: the patient privacy, paternity issues, medical confidentiality, among others. We propose a Child Abuses critical knowledge monitor system model that addresses this problem. This decision support system is implemented with a multiple scientific domains: to capture of tokens from clinical documents from multiple sources; a topic model approach to identify the topics of the documents; knowledge management through the use of ontologies to support the critical knowledge sensibility concepts and relations such as: symptoms, behaviors, among other evidences in order to match with the topics inferred from the clinical documents and then alert and log when clinical evidences are present. Based on these alerts clinical personnel could analyze the situation and take the appropriate procedures.
Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent... more Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. Neonatal tissues are routinely discarded at parturition so little ethical controversy attends the harvest of the Mesenchymal Stem Cells (MSCs) which may play an important therapeutic role through the secretion of soluble trophic factors which enhance and assist in repair by paracrine activation of surrounding cells. The use of cellular systems is a rational approach for delivering neurotrophic factors at the nerve lesion site, and in our recent research work we have been evaluating the therapeutic value of MSCs isolated from the Wharton jelly (WJ) in nerve repair associated to different tube-guides made of biodegradable and biocompatible biomaterials. The WJ MSCs in vitro studies included cell characterization by immunocytochemistry, karyotype analysis, tri-lineage differentiation capacity and flow cytometry and also citocompatibility by measuring the intracellular calcium concentration ([Ca 2+ ]i) in the presence of different tube-guides.
In many real-world networks the ability to synchronize is a key property for their performance. R... more In many real-world networks the ability to synchronize is a key property for their performance. Recent work on undirected networks with diffusive interaction revealed that improvements in the network connectivity such as making the network more connected and homogeneous enhances synchronization. However, real-world networks have directed and weighted connections. In such directed networks, understanding the impact of structural changes on the network performance remains a major challenge. Here, we show that improving the structure of a directed network can lead to a failure in the network function. For instance, introducing new links to reduce the minimum distance between nodes can lead to instabilities in the synchronized motion. This effect only occurs in directed networks. Our results allow to identify the dynamical importance of a link and thereby have a major impact on the design and control of directed networks.
Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online... more Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online under ''Instructions for Authors''.) They should be no more than 4 double-spaced pages with no Abstract or sub-headings, with a maximum of four (4) references. If figures are included, they should be limited to two (2). The cost of printing color figures is the responsibility of the author.
O conceito de envolvimento dos alunos na escola tem vindo a ser colocado no cerne das discussões ... more O conceito de envolvimento dos alunos na escola tem vindo a ser colocado no cerne das discussões relacionadas com o sucesso académico e com o abandono escolar. Este estudo faz uma revisão de literatura acerca deste conceito e das suas relações com o desempenho académico, destacando a sua importância no âmbito da formação de professores. Vários estudos sustentam que a falta de envolvimento dos alunos aparece associada ao baixo desempenho académico, a problemas de comportamento e ao abandono escolar. O envolvimento dos alunos na escola apresenta-se, na literatura revista, como uma resposta eficaz para os problemas que afetam as escolas e os seus alunos, como um aspeto a ter em conta na prevenção de padrões de comportamento problemático em contexto escolar e, portanto, como um conceito transdisciplinar de elevada importância na formação de professores.
2012 International Conference and Exposition on Electrical and Power Engineering, 2012
In this work, continuous health monitoring for disabled or elderly people is proposed using texti... more In this work, continuous health monitoring for disabled or elderly people is proposed using textile integrated electrodes for ECG measurement. Other applications, such as EMG or skin impedance measurement are also envisaged. The paper specifically describes a shirt integrating electrodes for ECG measurement that has been tested in several conditions. The techniques for integration of ECG electrodes can be directly applied for production of EMG or skin-impedance electrodes. Signal processing techniques for heart rate value extraction and to deal with low-quality signal or motion artefacts are being tested and will also be described. Results show that signals acquired with the shirt are comparable to signals acquired with conventional gel electrodes. The complete integration of the electrodes into clothing may have a very interesting psychological benefit, but some issues related to comfort and daily use have to be further investigated.
2013 2nd Experiment@ International Conference (exp.at'13), 2013
ABSTRACT World Pendulum is a project with the main purpose of studying the behavior of standard g... more ABSTRACT World Pendulum is a project with the main purpose of studying the behavior of standard gravity with latitude. Several automated simple pendulums are distributed across different latitudes. Each of these pendulums can be remotely operated over the Internet, communicating in real time the measured period of the oscillations, which may then be used to calculate the value of g. This article describes the World Pendulum project and it's implementation integrated into e-lab, a software framework that allows remote control of real experiments over the Internet[1]. Preliminary results show that a good agreement with the established spherical harmonics model is obtained, with the absolute overall error being under 0.0002 m/s2.
This paper addresses the problem of decentralized exploration and mapping of unknown environment ... more This paper addresses the problem of decentralized exploration and mapping of unknown environment by a multiple robot team. The exploration methodology relies on individual decision rules and communication of topological maps to achieve efficient and fast mapping, minimizing overlap of explored space. This distributed solution allows scalability of the proposed methods. Each robot broadcasts a graph representing the topological map, with information of exploration status of each region. Therefore, this kind of information can be transmitted to robots that are not in the communication range, through other robots in a multi-hop network. This work has been tested in simulation, and the results demonstrate the performance improvements and robustness that arise from our multirobot approach to exploration.
machine, to the temperature on a conventional vesical bladder thermistor and, for patients underg... more machine, to the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, to oesophageal temperature. Results: Using a linear model for sensor comparison the arterial outlet sensor showed a bias among the other sensor positions between −0.54 • C and −1.12 • C. The 95% confidence interval ranged between 7.06 • C and 8.82 • C for the upper limit and −8.14 • C and −10.62 • C for the lower limit. Due to the hysteretic shape the curvest were fitted into a nonlinear model. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12 • C). Conclusion: We suggest that measured surrogate temperatures, e.g., from the vesical bladder, as an index of cerebral overheating should be interpreted with respect to the direction-dependent behaviour of temperatures during cooling and rewarming phases. In conclusion, with greater deviations from normothermia, the way to interprete the classical temperature measuring sites should be done using a new non-linear, direction dependend model.
In particular, chitosan has recently attracted particular attention because of its biocompatibili... more In particular, chitosan has recently attracted particular attention because of its biocompatibility, biodegradability, low toxicity, low cost, enhancement of wound-healing and antibacterial effects and its potential usefulness in nerve regeneration have been demonstrated both in vitro and in vivo (Amado et al., 2010; Shirosaki et al., 2005; Simoes et al., 2010). Chitosan is a partially deacetylated polymer of acetyl glucosamine obtained after the alkaline deacetylation of chitin (Senel & McClure, 2004). While chitosan matrices have low mechanical strength under physiological conditions and are unable to maintain a predefined shape after transplantation, their mechanical properties can be improved by modification with a silane agent, namely γglycidoxypropyltrimethoxysilane (GPTMS), one of the silane-coupling agents which has epoxy and methoxysilane groups. The epoxy group reacts with the amino groups of chitosan molecules, while the methoxysilane groups are hydrolyzed and form silanol groups, and the silanol groups are subjected to the construction of a siloxane network due to the condensation. Thus, the mechanical strength of chitosan can be improved by the crosslinking between chitosan, GPTMS and siloxane network. We have previously obtained by adding GPTMS, chitosan type III membranes (hybrid chitosan membranes) which have about 110 µm pores and about 90% of porosity, due to the employment of freeze-drying technique, and which were successful in improving sciatic nerve regeneration after axonotmesis (Amado et al., 2008). Wettability of the material surfaces is one of the key factors for protein adsorption, cell attachment and migration (Amado et al., 2008). The addition of GPTMS improves the wettability of chitosan surfaces, and therefore chitosan type III membranes are more hydrophilic than types of chitosan membranes (Shirosaki et al., 2005). In addition, chitosan type III was developed to be more porous, with a larger surface to volume ratio, and to preserve mechanical strength and ability to adapt to different shapes. Significant differences in water uptake between commonly used chitosan and our hybrid chitosan type III were previously reported and it has been shown that they retain about two times as much biological fluid (Tateishi et al., 2002). The Neurolac® and the PLGA90:10 tube-guides guides show several different physical-chemical properties, namely Neurolac® is stiffer than PLGA due to structural reinforcement of the ester bonds and does not degrade so quickly. The biodegradation rate of PLGA tubes is estimated to be around 3 months while that complete resorption of Neurolac® is estimated to be of 16 months approximately (Geuna et al., 2009; Luis et al., 2007b; Luis et al., 2008). The degradation products of Neurolac® are less acidic, which may cause less damage to the surrounding tissue, and they are transparent so that the correct positioning of the nerve stumps may be confirmed after suturing. On the other hand, the biodegradable non woven structure of PLGA tubes may offer some advantages in terms of microporosity which may enhance nerve repair (Luis et al., 2007b; Luis et al., 2008). In vitro studies have shown that the four types of tube-guides, namely, the PLGA, the collagen, the hybrid chitosan and the Neurolac® are biocompatible to nerve cells and can facilitate nerve cell attachment, differentiation and growth (
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