Precise positioning of gamma ray interactions in multiplexed pixelated scintillators using artificial neural networks.

INTRODUCTION: The positioning of γ ray interactions in positron emission tomography (PET) detectors is commonly made through the evaluation of the Anger logic flood histograms. Machine learning techniques, leveraging features extracted from signal waveform, have demonstrated successful applications in addressing various challenges in PET instrumentation. AIM: This paper evaluates the use of artificial neural networks (NN) for γ ray interaction positioning in pixelated scintillators coupled to a multiplexed array of silicon photomultipliers (SiPM). METHODS: An array of 16 Cerium doped Lutetium-based (LYSO) crystal pixels (cross-section 2x2 mm2) coupled to 16 SiPM (S13360-1350) were used for the experimental setup. Data from each of the 16 LYSO pixels was recorded, a total of 160 000 events. The detectors were irradiated by 511 keV annihilation γ rays from a Sodium-22 (22Na) source. Another LYSO crystal was used for electronic collimation. Features extracted from the signal waveform were used to train the model. Two models were tested: i) single multiple-class neural network (mcNN), with 16 possible outputs followed by a softmax and ii) 16 binary classification neural networks (bNN), each one specialized in identifying events occurred in each position. RESULTS: Both NN models showed a mean positioning accuracy above 85% on the evaluation dataset, although the mcNN is faster to train. DISCUSSION: The method's accuracy is affected by the introduction of misclassified events that interacted in the neighbour's crystals and were misclassified during the dataset acquisition. Electronic collimation reduces this effect, however results could be improved using a more complex acquisition setup, such as a light-sharing configuration. CONCLUSIONS: The methods comparison showed that mcNN and bNN can surpass the Anger logic, showing the feasibility of using these models in positioning procedures of future multiplexed detector systems in a linear configuration.

Development of a New Integrated System for Vital Sign Monitoring in Small Animals.

Monitoring the vital signs of mice is an essential practice during imaging procedures to avoid populational losses and improve image quality. For this purpose, a system based on a set of devices (piezoelectric sensor, optical module and thermistor) able to detect the heart rate, respiratory rate, body temperature and arterial blood oxygen saturation (SpO2) in mice anesthetized with sevoflurane was implemented. Results were validated by comparison with the reported literature on similar anesthetics. A new non-invasive electrocardiogram (ECG) module was developed, and its first results reflect the viability of its integration in the system. The sensors were strategically positioned on mice, and the signals were acquired through a custom-made printed circuit board during imaging procedures with a micro-PET (Positron Emission Tomography). For sevoflurane concentration of 1.5%, the average values obtained were: 388 bpm (beats/minute), 124 rpm (respirations/minute) and 88.9% for the heart rate, respiratory rate and SpO2, respectively. From the ECG information, the value obtained for the heart rate was around 352 bpm for injectable anesthesia. The results compare favorably to the ones established in the literature, proving the reliability of the proposed system. The ECG measurements show its potential for mice heart monitoring during imaging acquisitions and thus for integration into the developed system.

Single Low Dose of Cocaine-Structural Brain Injury Without Metabolic and Behavioral Changes.

Chronic cocaine use has been shown to lead to neurotoxicity in rodents and humans, being associated with high morbidity and mortality rates. However, recreational use, which may lead to addictive behavior, is often neglected. This occurs, in part, due to the belief that exposure to low doses of cocaine comes with no brain damage risk. Cocaine addicts have shown glucose metabolism changes related to dopamine brain activity and reduced volume of striatal gray matter. This work aims to evaluate the morphological brain changes underlying metabolic and locomotor behavioral outcome, in response to a single low dose of cocaine in a pre-clinical study. In this context, a Balb-c mouse model has been chosen, and animals were injected with a single dose of cocaine (0.5 mg/kg). Control animals were injected with saline. A behavioral test, positron emission tomography (PET) imaging, and anatomopathological studies were conducted with this low dose of cocaine, to study functional, metabolic, and morphological brain changes, respectively. Animals exposed to this cocaine dose showed similar open field activity and brain metabolic activity as compared with controls. However, histological analysis showed alterations in the prefrontal cortex and hippocampus of mice exposed to cocaine. For the first time, it has been demonstrated that a single low dose of cocaine, which can cause no locomotor behavioral and brain metabolic changes, can induce structural damage. These brain changes must always be considered regardless of the dosage used. It is essential to alert the population even against the consumption of low doses of cocaine.

Will artificial intelligence be a blessing or concern in assistive robots for play? / A inteligência artificial será uma bênção ou preocupação em robôs assistivos para brincar?

The recent advances and popularity of artificial intelligence (AI) offer exciting possibilities to improve technology but they also raise concerns. In this paper, we use our research to present the potential benefits of using AI in assistive technology for children with disabilities to access play, and examine potential ethical concerns surrounding data required by AI algorithms. Since play is a key factor in child well-being and cognitive development, secondary disabilities may arise as a consequence of motor impairments. Assistive robots for augmentative manipulation can be instrumental in providing children with physical disabilities play opportunities, but we need to take a principled and user-centered approach to technical innovations.

Os avanços recentes e popularidade da Inteligência Artificial (IA) oferecem possibilidades animadoras para melhorar a tecnologia, mas, também, trazem preocupação. Neste artigo, usamos nossa pesquisa para apresentar os benefícios potenciais do uso da IA em tecnologia assistiva para crianças com deficiências brincarem e examinar possíveis preocupações éticas em torno dos dados exigidos pelos algoritmos de IA. Uma vez que o brincar é um fator chave no bem-estar infantil e no desenvolvimento cognitivo, as incapacidades secundárias podem surgir como consequência de deficiências motoras. Robôs assistivos para manipulação aumentativa podem ser fundamentais para proporcionar às crianças com deficiência física oportunidades de brincar, mas precisamos adotar uma abordagem baseada em princípios e centrada no usuário para inovações técnicas.

Introducing LUDI: a research network on play for children with disabilities.

This paper presents LUDI, an interdisciplinary network of research centred on the topic of play for children with disabilities. The primary aim of the network is to ensure the theme is given the widest recognition as an independent field of research and intervention. Currently, the network comprises over 80 researchers and practitioners from 27 European countries. It is funded by the EU COST Programme through the means of an interdisciplinary Action started in May 2014 and lasting four years. The present contribution will discuss the scientific and social background and their implications that lead to the creation of the network, activities carried out during the first year of the Action and introduces the expected results of the ongoing activities.

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus).

An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg(-1)) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg(-1)). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance.

The role of uncertainty regarding the results of screening immunoassays in blood establishments.

The risk of uncertain results in infectious agents' tests is recognized in blood establishments, being particularly evident during the blood donor selection. The current risk-based approaches require risk assessment and "risk-based thinking". Accordingly, the blood establishment should consider the effect of uncertainty in all the technical decisions taken in a screening laboratory. Since the post-transfusion safety is one of the blood establishments' goals, the risk of post-transfusion infection should be evaluated and actions taken to decrease the chance of blood donations validation use false negative results. This article reviews and discusses the sources of uncertainty of infectious agents' reported results in blood establishments. It describes a set of sources of uncertainty that should be considered in screening immunoassay's decisions. The infectious agents' uncertainty concern is critical for reporting reliable results.

Quality management in European screening laboratories in blood establishments: A view of current approaches and trends.

The screening laboratory has a critical role in the post-transfusion safety. The success of its targets and efficiency depends on the management system used. Even though the European Union directive 2002/98/EC requires a quality management system in blood establishments, its requirements for screening laboratories are generic. Complementary approaches are needed to implement a quality management system focused on screening laboratories. This article briefly discusses the current good manufacturing practices and good laboratory practices, as well as the trends in quality management system standards. ISO 9001 is widely accepted in some European Union blood establishments as the quality management standard, however this is not synonymous of its successful application. The ISO "risk-based thinking" is interrelated with the quality risk-management process of the EuBIS "Standards and criteria for the inspection of blood establishments". ISO 15189 should be the next step on the quality assurance of a screening laboratory, since it is focused on medical laboratory. To standardize the quality management systems in blood establishments' screening laboratories, new national and European claims focused on technical requirements following ISO 15189 is needed.

Evaluation of the measurement uncertainty in screening immunoassays in blood establishments: computation of diagnostic accuracy models.

The European Union regulation for blood establishments does not require the evaluation of measurement uncertainty in virology screening tests, which is required by ISO 15189 guideline following GUM principles. GUM modular approaches have been discussed by medical laboratory researchers but no consensus has been achieved regarding practical application. Meanwhile, the application of empirical approaches fulfilling GUM principles has gained support. Blood establishments' screening tests accredited by ISO 15189 need to select an appropriate model even GUM models are intended uniquely for quantitative examination procedures. Alternative (to GUM) models focused on probability have been proposed in medical laboratories' diagnostic tests. This article reviews, discusses and proposes models for diagnostic accuracy in blood establishments' screening tests. The output of these models is an alternative to VIM's measurement uncertainty concept. Example applications are provided for an anti-HCV test where calculations were performed using a commercial spreadsheet. The results show that these models satisfy ISO 15189 principles and that the estimation of clinical sensitivity, clinical specificity, binary results agreement and area under the ROC curve are alternatives to the measurement uncertainty concept.

Scheme for the selection of measurement uncertainty models in blood establishments' screening immunoassays.

Blood establishments routinely perform screening immunoassays to assess safety of the blood components. As with any other screening test, results have an inherent uncertainty. In blood establishments the major concern is the chance of false negatives, due to its possible impact on patients' health. This article briefly reviews GUM and diagnostic accuracy models for screening immunoassays, recommending a scheme to support the screening laboratories' staffs on the selection of a model considering the intended use of the screening results (i.e., post-transfusion safety). The discussion is grounded on a "risk-based thinking", risk being considered from the blood donor selection to the screening immunoassays. A combination of GUM and diagnostic accuracy models to evaluate measurement uncertainty in blood establishments is recommended.

Effect of dietary incorporation of a multi-strain probiotic on growth performance and health status in rainbow trout (Oncorhynchus mykiss).

Dietary supplementation with a multi-strain probiotic containing Bacillus subtilis, Enterococcus faecium, Pediococcus acidilactici and Lactobacillus reuteri has been examined for its effects on growth performance, intestinal microbiota, non-specific immune response and antioxidant status of rainbow trout. Three groups of sub-adult trout were stocked into experimental tanks. A commercial diet was used as control, while the other two groups received diets supplemented with the multi-strain probiotic at levels of 1 and 5 g kg(-1) diet. The fish were fed to apparent satiation three times daily for 8 weeks. Dietary probiotic at 1 g kg(-1) diet improved (P < 0.05) growth and feed efficiency compared to control diet. Lactic acid bacteria loads were higher in probiotic fed fish at both inclusion levels compared to control; however, Enterobacteriaceae, Coliforms and Aeromonas spp. were similar between groups. Dietary probiotics decreased (P < 0.05) malondialdehyde formation on day 0 compared to control fish but not on day 5 of storage. Probiotics also increased (P < 0.05) the activity of glutathione-based enzymes. Serum lysozyme levels were similar among dietary treatments. Probiotic supplementation at 1 g kg(-1) diet reduced serum nitric oxide levels compared to control. In conclusion, dietary probiotics at the level of 1 g kg(-1) of diet exerted both a growth promoting and antioxidant protective activity.

Analytical model for calculating indeterminate results interval of screening tests, the effect on seroconversion window period: a brief evaluation of the impact of uncertain results on the blood establishment budget.

The evaluation of measurement uncertainty is not required by the European Union regulation or blood establishments' laboratory tests. However, it is required for tests accredited by ISO 15189. Also, the forthcoming ISO 9001 edition requires "risk based thinking" with risk described as "the effect of uncertainty on an expected result". ISO recommends GUM models for determination of measurement uncertainty, but their application is not intended for ordinal value measurements, such as what happens with screening test binary results. This article reviews, discusses and proposes concepts intended for measurement uncertainty of screening test results. The precision model focuses on cutoff level allowing the evaluation of the indeterminate interval using analytical sources of variance. The intervalis considered in the estimation of the seroconversion window period. The delta-value of patients and healthy subjects' samples allows ranking two tests according to the probability of the two classes of indeterminate results: chance of false negative results and chance of false positive results (waste on budget).

Using virtual robot-mediated play activities to assess cognitive skills.

PURPOSE: To evaluate the feasibility of using virtual robot-mediated play activities to assess cognitive skills. METHOD: Children with and without disabilities utilized both a physical robot and a matching virtual robot to perform the same play activities. The activities were designed such that successfully performing them is an indication of understanding of the underlying cognitive skills. RESULTS: Participants' performance with both robots was similar when evaluated by the success rates in each of the activities. Session video analysis encompassing participants' behavioral, interaction and communication aspects revealed differences in sustained attention, visuospatial and temporal perception, and self-regulation, favoring the virtual robot. CONCLUSIONS: The study shows that virtual robots are a viable alternative to the use of physical robots for assessing children's cognitive skills, with the potential of overcoming limitations of physical robots such as cost, reliability and the need for on-site technical support. IMPLICATIONS FOR REHABILITATION: Virtual robots can provide a vehicle for children to demonstrate cognitive understanding. Virtual and physical robots can be used as augmentative manipulation tools allowing children with disabilities to actively participate in play, educational and therapeutic activities. Virtual robots have the potential of overcoming limitations of physical robots such as cost, reliability and the need for on-site technical support.

The role of assisted manipulation in cognitive development.

OBJECTIVE: Motor experience plays a central role in cognitive development. Assistive technologies can thus provide augmentative manipulation for children with motor disabilities. This paper explores the use of robots to this end. METHOD: A revision of studies conducted with typically-developing children and children with disabilities regarding the use of robots is presented. This revision provides a description of the cognitive skills required and revealed by the child when using a robot. Opportunities for participation and exploration were identified and further research is discussed. RESULTS: Robots provide insight into the cognitive skills of children with motor disabilities. Robots also provide means for independent exploration and participation in learning and play activities. Integration of augmentative manipulation and communication increases interest and participation of children with disabilities. CONCLUSION: Children with disabilities can use augmentative manipulation systems to independently explore and interact with their environment. Children can use robots as tools providing them with opportunities to reveal and further develop their cognitive skills. Alternative access methods can increase access for children with severe motor disabilities.

Evaluation of telephone triage and advice services: a systematic review on methods, metrics and results.

UNLABELLED: Telephone triage and advice services (TTAS) have been increasingly used to assess patients' symptoms, provide information and refer patients to appropriate levels of care (attempting to pursue efficiency and quality of care gains while ensuring safety). However, previous reviews have pointed out for the need for adequately evaluating TTAS. AIMS: To review TTAS evaluation studies, compile methodologies and metrics used and compare results. Systematic search in PubMed database; data collection and categorization by TTAS features and context, type of evaluation, methods, metrics and results; critical assessment of studies; discussion on research needs. 395 articles screened, 55 of them included in the analysis. In conclusion, several aspects of TTAS impact on healthcare systems remain unclear either due to a lack of research (e.g. on long term clinical outcomes, clinical pathways, safety, enhanced access) or because of huge disparities in existing studies on the accuracy of advice, patient compliance, system use, satisfaction and economic evaluation. Further research on TTAS impact is required, comprising multiple perspectives and broad range of metrics.