A robust braille recognition system

Braille is the most effective means of written communication between visually-impaired and sighted people. This paper describes a new system that recognizes Braille characters in scanned Braille document pages. Unlike most other approaches, an inexpensive flatbed scanner is used and the system requires minimal interaction with the user. A unique feature of this system is the use of context at different levels (from the pre-processing of the image through to the post-processing of the recognition results) to enhance robustness and, consequently, recognition results. Braille dots composing characters are identified on both single and double-sided documents of average quality with over 99% accuracy, while Braille characters are also correctly recognised in over 99% of documents of average quality (in both single and double-sided documents)

Predicting perceptual transparency of head-worn devices

| openaire: EC/H2020/812719/EU//VRACEAcoustically transparent head-worn devices are a key component of auditory augmented reality systems, in which both real and virtual sound sources are presented to a listener simultaneously. Head-worn devices can exhibit high transparency simply through their physical design but in practice will always obstruct the sound field to some extent. In this study, a method for predicting the perceptual transparency of head-worn devices is presented using numerical analysis of device measurements, testing both coloration and localization in the horizontal and median plane. Firstly, listening experiments are conducted to assess perceived coloration and localization impairments. Secondly, head-related transfer functions of a dummy head wearing the head-worn devices are measured, and auditory models are used to numerically quantify the introduced perceptual effects. The results show that the tested auditory models are capable of predicting perceptual transparency and are therefore robust in applications that they were not initially designed for.Peer reviewe

Cost-effectiveness of Alzheimer's disease CSF biomarkers and amyloid-PET in early-onset cognitive impairment diagnosis

This study aimed at determining the cost-effectiveness of amyloid-positron emission tomography (PET) compared to Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers (amyloid-?42, total-Tau and phosphorylated-Tau) for the diagnosis of AD in patients with early-onset cognitive impairment. A decision tree model using a national health care perspective was developed to compare the costs and effectiveness associated with Amyloid-PET and AD CSF biomarkers. Available evidence from the literature and primary data from Hospital Clínic de Barcelona were used to inform the model and calculate the efficiency of these diagnostic alternatives. Medical visits and diagnostic procedures were considered and reported in €2020. We calculated the incremental cost-effectiveness ratio to measure the cost per % of correct diagnoses detected and we perform one-way deterministic and probabilistic sensitivity analyses to assess the uncertainty of these results. Compared with AD CSF biomarkers, Amyloid-PET resulted in 7.40% more correctly diagnosed cases of AD, with an incremental total mean cost of €146,854.80 per 100 cases. We found a 50% of probability that Amyloid-PET was cost-effective for a willingness to pay (WTP) of €19,840.39 per correct case detected. Using a WTP of €75,000, the probability that it is cost-effective reached a maximum of 76.9%, thus leading to a conclusion that Amyloid-PET is not a cost-effective technique compared to AD CSF biomarkers, unless the funder is willing to pay a minimum of €19,840.39 to detect one more correct case. Furthermore, obtaining CSF provides simultaneous information on amyloid ? and tau biomarkers and allows other biomarkers to be analyzed at a relatively low cost.© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany

Ultrassonografia cardíaca en individus adietes a l'heroína intravenosa assimptomàtics: evidencia de lesions valvulars induïdes per l'adicció

Echocardiograph

Representativeness in randomised clinical trials supporting acute coronary syndrome guidelines.

This project has received funding to cover the electronic case report form from the Balearic Society of Cardiology (Sociedad Balear Cardiología) through the ‘Bernat Nadal Ginard’ grant. Open access has been partly granted by the LIBERI PROGRAM 2023 of the Health Research Institute of the Balearic Islands (IdISBa).AIMS Clinical practice guidelines (CPGs) are published to guide the management of acute coronary syndrome (ACS). We aimed to critically appraise the representativeness and standard of care of randomised clinical trials (RCTs) supporting CPGs for ACS. METHODS AND RESULTS American and European CPGs for ST- and non-ST-elevation ACS were screened to extract all references (n = 2128) and recommendations (n = 600). Among the 407 primary publications of RCTs (19.1%), there were 52.6% and 73.2% recruiting patients in North America and Europe, respectively, whereas other regions were largely underrepresented (e.g., 25.3% RCTs recruited in Asia). There was 68.6% RCTs enrolling patient with ACS, whereas the remaining 31.4% did not enroll any patient with ACS. There was underrepresentation of some important subgroups, including elderly, female (29.9%) and non-white patients (<20%). The incidence and type of reperfusion reported in these RCTs were not reflective of current clinical practice (the percentage of patients who underwent percutaneous coronary intervention (PCI) among all RCTs was 42.7%; whereas for ST-Elevation Myocardial Infarction patients, the number of participants who underwent fibrinolysis was 3.3-fold higher than those who underwent primary PCI). All-cause mortality in these RCTs was 11.9% in RCTs with a follow-up ≤1 year. CONCLUSION RCTs supporting CPGs for ACS are not fully representative of the diversity of the ACS population and their current standard of care. While some of these issues with representativeness may be explained by how evidence has been accrued over time, efforts should be made by trialists to ensure that the evidence supporting CPGs is representative of the wider ACS population.S

Classifying Alzheimer's disease and frontotemporal dementia using machine learning with cross-sectional and longitudinal magnetic resonance imaging data

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are common causes of dementia with partly overlapping, symptoms and brain signatures. There is a need to establish an accurate diagnosis and to obtain markers for disease tracking. We combined unsupervised and supervised machine learning to discriminate between AD and FTD using brain magnetic resonance imaging (MRI). We included baseline 3T-T1 MRI data from 339 subjects: 99 healthy controls (CTR), 153 AD and 87 FTD patients; and 2-year follow-up data from 114 subjects. We obtained subcortical gray matter volumes and cortical thickness measures using FreeSurfer. We used dimensionality reduction to obtain a single feature that was later used in a support vector machine for classification. Discrimination patterns were obtained with the contribution of each region to the single feature. Our algorithm differentiated CTR versus AD and CTR versus FTD at the cross-sectional level with 83.3% and 82.1% of accuracy. These increased up to 90.0% and 88.0% with longitudinal data. When we studied the classification between AD versus FTD we obtained an accuracy of 63.3% at the cross-sectional level and 75.0% for longitudinal data. The AD versus FTD versus CTR classification has reached an accuracy of 60.7%, and 71.3% for cross-sectional and longitudinal data respectively. Disease discrimination brain maps are in concordance with previous results obtained with classical approaches. By using a single feature, we were capable to classify CTR, AD, and FTD with good accuracy, considering the inherent overlap between diseases. Importantly, the algorithm can be used with cross-sectional and longitudinal data.© 2023 The Authors. Human Brain Mapping published by Wiley Periodicals LLC

Multifocal Transcranial Direct Current Stimulation in Primary Progressive Aphasia Does Not Provide a Clinical Benefit Over Speech Therapy

Primary progressive aphasia (PPA) is a group of neurodegenerative disorders including Alzheimer's disease and frontotemporal dementia characterized by language deterioration. Transcranial direct current stimulation (tDCS) is a non-invasive intervention for brain dysfunction.To evaluate the tolerability and efficacy of tDCS combined with speech therapy in the three variants of PPA. We evaluate changes in fMRI activity in a subset of patients.Double-blinded, randomized, cross-over, and sham-controlled tDCS study. 15 patients with PPA were included. Each patient underwent two interventions: a) speech therapy + active tDCS and b) speech therapy + sham tDCS stimulation. A multifocal strategy with anodes placed in the left frontal and parietal regions was used to stimulate the entire language network. Efficacy was evaluated by comparing the results of two independent sets of neuropsychological assessments administered at baseline, immediately after the intervention, and at 1 month and 3 months after the intervention. In a subsample, fMRI scanning was performed before and after each intervention.The interventions were well tolerated. Participants in both arms showed clinical improvement, but no differences were found between active and sham tDCS interventions in any of the evaluations. There were trends toward better outcomes in the active tDCS group for semantic association and reading skills. fMRI identified an activity increase in the right frontal medial cortex and the bilateral paracingulate gyrus after the active tDCS intervention.We did not find differences between active and sham tDCS stimulation in clinical scores of language function in PPA patients

Surgical treatment of liver metastases from colorectal carcinoma in elderly patients.

Abstract Background: The elderly are under-represented in series of patients operated on for colorectal liver metastases (LM). Objective: To analyse the influence of age on surgery of colorectal LM, and the identification of factors that could be used as exclusion criteria. Patients and methods: Six hundred and forty-eight patients underwent liver resection between 1990 and 2006. Demographic data, primary tumour related variables, stage of the disease, morbidity, mortality, survival and recurrence were prospectively recorded. Results: One hundred and sixty of 648 patients (25%) were 70 years old or older. Postoperative mortality was significantly higher in elderly patients (8% vs. 3%, p=0.008). Morbidity was also higher (41% vs. 34%, p=0.008). Survival rate at 1, 3 and 5 years was 88%, 62% and 45% respectively in patients younger than 70 years, and 82%, 48% and 36% in the elderly (p=0.007). Excluding the postoperative mortality, the figures were 90%, 64% and 46%. 90%, 53% and 38% (p=0.061). Disease-free survival rates at 1, 3 and 5 years excluding postoperative mortality were 68%, 32% and 25% in younger patients, compared to 68%, 34% and 30% (p=0.71) in the elderly. Major liver resections increased mortality in the elderly. In the multivariate analyses only a tumour size equal to or more than 10 cm significantly increased the postoperative mortality risk in elderly patients. Conclusions: The elderly have a higher mortality. In recent years that difference has been markedly reduced. Excluding the postoperative mortality, the overall survival and diseasefree survival are similar between both groups. The criteria to indicate surgery must be the same in both groups

Cortical thickness modeling and variability in Alzheimer's disease and frontotemporal dementia

Alzheimer's disease (AD) and frontotemporal dementia (FTD) show different patterns of cortical thickness (CTh) loss compared with healthy controls (HC), even though there is relevant heterogeneity between individuals suffering from each of these diseases. Thus, we developed CTh models to study individual variability in AD, FTD, and HC.We used the baseline CTh measures of 379 participants obtained from the structural MRI processed with FreeSurfer. A total of 169 AD patients (63 ± 9 years, 65 men), 88 FTD patients (64 ± 9 years, 43 men), and 122 HC (62 ± 10 years, 47 men) were studied. We fitted region-wise temporal models of CTh using Support Vector Regression. Then, we studied associations of individual deviations from the model with cerebrospinal fluid levels of neurofilament light chain (NfL) and 14-3-3 protein and Mini-Mental State Examination (MMSE). Furthermore, we used real longitudinal data from 144 participants to test model predictivity.We defined CTh spatiotemporal models for each group with a reliable fit. Individual deviation correlated with MMSE for AD and with NfL for FTD. AD patients with higher deviations from the trend presented higher MMSE values. In FTD, lower NfL levels were associated with higher deviations from the CTh prediction. For AD and HC, we could predict longitudinal visits with the presented model trained with baseline data. For FTD, the longitudinal visits had more variability.We highlight the value of CTh models for studying AD and FTD longitudinal changes and variability and their relationships with cognitive features and biomarkers.© 2023. The Author(s)