163 results on '"automated pattern recognition"'
Search Results
2. A personalized semi-automatic sleep spindle detection (PSASD) framework
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Kafashan, MohammadMehdi, Gupte, Gaurang, Kang, Paul, Hyche, Orlandrea, Luong, Anhthi H., Prateek, G.V., Ju, Yo-El S., and Palanca, Ben Julian A.
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- 2024
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3. Unveiling the sound of the cognitive status: Machine Learning-based speech analysis in the Alzheimer’s disease spectrum
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García-Gutiérrez, Fernando, Alegret, Montserrat, Marquié, Marta, Muñoz, Nathalia, Ortega, Gemma, Cano, Amanda, De Rojas, Itziar, García-González, Pablo, Olivé, Clàudia, Puerta, Raquel, García-Sanchez, Ainhoa, Capdevila-Bayo, María, Montrreal, Laura, Pytel, Vanesa, Rosende-Roca, Maitee, Zaldua, Carla, Gabirondo, Peru, Tárraga, Lluís, Ruiz, Agustín, Boada, Mercè, and Valero, Sergi
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- 2024
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4. Interaction analytics for automatic assessment of communication quality in primary care
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Albert, Pierre, Luz, Saturnino, and McKinstry, Brian
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health care quality, access, and evaluation ,physician-patient communication ,interaction analytics ,automated pattern recognition ,turn-taking analysis ,prosody - Abstract
Effective doctor-patient communication is a crucial element of health care, influencing patients' personal and medical outcomes following the interview. The set of skills used in interpersonal interaction is complex, involving verbal and non-verbal behaviour. Precise attributes of good non-verbal behaviour are difficult to characterise, but models and studies offer insight on relevant factors. In this PhD, I studied how the attributes of non-verbal behaviour can be automatically extracted and assessed, focusing on turn-taking patterns of and the prosody of patient-clinician dialogues. I described clinician-patient communication and the tools and methods used to train and assess communication during the consultation. I then proceeded to a review of the literature on the existing efforts to automate assessment, depicting an emerging domain focused on the semantic content of the exchange and a lack of investigation on interaction dynamics, notably on the structure of turns and prosody. To undertake the study of these aspects, I initially planned the collection of data. I underlined the need for a system that follows the requirements of sensitive data collection regarding data quality and security. I went on to design a secure system which records participants' speech as well as the body posture of the clinician. I provided an open-source implementation and I supported its use by the scientific community. I investigated the automatic extraction and analysis of some non-verbal components of the clinician-patient communication on an existing corpus of GP consultations. I outlined different patterns in the clinician-patient interaction and I further developed explanations of known consulting behaviours, such as the general imbalance of the doctor-patient interaction and differences in the control of the conversation. I compared behaviours present in face to face, telephone, and video consultations, finding overall similarities alongside noticeable differences in patterns of overlapping speech and switching behaviour. I further studied non-verbal signals by analysing speech prosodic features, investigating differences in participants' behaviour and relations between the assessment of the clinician-patient communication and prosodic features. While limited in their interpretative power on the explored dataset, these signals nonetheless provide additional metrics to identify and characterise variations in the non-verbal behaviour of the participants. Analysing clinician-patient communication is difficult even for human experts. Automating that process in this work has been particularly challenging. I demonstrated the capacity of automated processing of non-verbal behaviours to analyse clinician-patient communication. I outlined the ability to explore new aspects, interaction dynamics, and objectively describe how patients and clinicians interact. I further explained known aspects such as clinician dominance in more detail. I also provided a methodology to characterise participants' turns taking behaviour and speech prosody for the objective appraisal of the quality of non-verbal communication. This methodology is aimed at further use in research and education.
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- 2022
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5. Harnessing acoustic speech parameters to decipher amyloid status in individuals with mild cognitive impairment.
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García-Gutiérrez, Fernando, Marquié, Marta, Muñoz, Nathalia, Alegret, Montserrat, Cano, Amanda, de Rojas, Itziar, García-González, Pablo, Olivé, Clàudia, Puerta, Raquel, Orellana, Adelina, Montrreal, Laura, Pytel, Vanesa, Ricciardi, Mario, Zaldua, Carla, Gabirondo, Peru, Hinzen, Wolfram, Lleonart, Núria, García-Sánchez, Ainhoa, Tárraga, Lluís, and Ruiz, Agustín
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AMYLOID ,MACHINE learning ,SPEECH ,VOICE analysis ,ALZHEIMER'S disease ,MILD cognitive impairment - Abstract
Alzheimer's disease (AD) is a neurodegenerative condition characterized by a gradual decline in cognitive functions. Currently, there are no effective treatments for AD, underscoring the importance of identifying individuals in the preclinical stages of mild cognitive impairment (MCI) to enable early interventions. Among the neuropathological events associated with the onset of the disease is the accumulation of amyloid protein in the brain, which correlates with decreased levels of Aβ42 peptide in the cerebrospinal fluid (CSF). Consequently, the development of non-invasive, low-cost, and easy-to-administer proxies for detecting Aβ42 positivity in CSF becomes particularly valuable. A promising approach to achieve this is spontaneous speech analysis, which combined with machine learning (ML) techniques, has proven highly useful in AD. In this study, we examined the relationship between amyloid status in CSF and acoustic features derived from the description of the Cookie Theft picture in MCI patients from a memory clinic. The cohort consisted of fifty-two patients with MCI (mean age 73 years, 65% female, and 57% positive amyloid status). Eighty-eight acoustic parameters were extracted from voice recordings using the extended Geneva Minimalistic Acoustic Parameter Set (eGeMAPS), and several ML models were used to classify the amyloid status. Furthermore, interpretability techniques were employed to examine the influence of input variables on the determination of amyloid-positive status. The best model, based on acoustic variables, achieved an accuracy of 75% with an area under the curve (AUC) of 0.79 in the prediction of amyloid status evaluated by bootstrapping and Leave-One-Out Cross Validation (LOOCV), outperforming conventional neuropsychological tests (AUC = 0.66). Our results showed that the automated analysis of voice recordings derived from spontaneous speech tests offers valuable insights into AD biomarkers during the preclinical stages. These findings introduce novel possibilities for the use of digital biomarkers to identify subjects at high risk of developing AD. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Ein Vergleich von 4 konvolutionalen neuronalen Netzen in der histopathologischen Diagnostik von Speicheldrüsenkarzinomen.
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Schulz, Tobias, Becker, Christoph, and Kayser, Gian
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Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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7. Machine learning methods for functional recovery prediction and prognosis in post-stroke rehabilitation: a systematic review
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Silvia Campagnini, Chiara Arienti, Michele Patrini, Piergiuseppe Liuzzi, Andrea Mannini, and Maria Chiara Carrozza
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Automated pattern recognition ,Clinical ,Efficacy treatment ,Machine learning ,Prognosis ,Regression analysis ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abstract Background Rehabilitation medicine is facing a new development phase thanks to a recent wave of rigorous clinical trials aimed at improving the scientific evidence of protocols. This phenomenon, combined with new trends in personalised medical therapies, is expected to change clinical practice dramatically. The emerging field of Rehabilomics is only possible if methodologies are based on biomedical data collection and analysis. In this framework, the objective of this work is to develop a systematic review of machine learning algorithms as solutions to predict motor functional recovery of post-stroke patients after treatment. Methods We conducted a comprehensive search of five electronic databases using the Patient, Intervention, Comparison and Outcome (PICO) format. We extracted health conditions, population characteristics, outcome assessed, the method for feature extraction and selection, the algorithm used, and the validation approach. The methodological quality of included studies was assessed using the prediction model risk of bias assessment tool (PROBAST). A qualitative description of the characteristics of the included studies as well as a narrative data synthesis was performed. Results A total of 19 primary studies were included. The predictors most frequently used belonged to the areas of demographic characteristics and stroke assessment through clinical examination. Regarding the methods, linear and logistic regressions were the most frequently used and cross-validation was the preferred validation approach. Conclusions We identified several methodological limitations: small sample sizes, a limited number of external validation approaches, and high heterogeneity among input and output variables. Although these elements prevented a quantitative comparison across models, we defined the most frequently used models given a specific outcome, providing useful indications for the application of more complex machine learning algorithms in rehabilitation medicine.
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- 2022
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8. Künstliche Intelligenz in der modernen Mammadiagnostik.
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Banys-Paluchowski, Maggie, Dussan Molinos, Laura, Rübsamen, Marcus, Töllner, Thilo, Rody, Achim, Fehm, Tanja, Bündgen, Nana, and Krawczyk, Natalia
- Abstract
Copyright of Der Gynäkologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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9. Künstliche Intelligenz und Simulation in der Pränatalmedizin – was wir von Maschinen lernen können.
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Steinhard, J., Freundt, P., Janzing, P., Popov, V., Menkhaus, R., and Ross, L.
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Copyright of Der Gynäkologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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10. Machine learning methods for functional recovery prediction and prognosis in post-stroke rehabilitation: a systematic review.
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Campagnini, Silvia, Arienti, Chiara, Patrini, Michele, Liuzzi, Piergiuseppe, Mannini, Andrea, and Carrozza, Maria Chiara
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MACHINE learning ,FEATURE selection ,REHABILITATION ,MEDICAL rehabilitation ,PROGNOSIS - Abstract
Background: Rehabilitation medicine is facing a new development phase thanks to a recent wave of rigorous clinical trials aimed at improving the scientific evidence of protocols. This phenomenon, combined with new trends in personalised medical therapies, is expected to change clinical practice dramatically. The emerging field of Rehabilomics is only possible if methodologies are based on biomedical data collection and analysis. In this framework, the objective of this work is to develop a systematic review of machine learning algorithms as solutions to predict motor functional recovery of post-stroke patients after treatment.Methods: We conducted a comprehensive search of five electronic databases using the Patient, Intervention, Comparison and Outcome (PICO) format. We extracted health conditions, population characteristics, outcome assessed, the method for feature extraction and selection, the algorithm used, and the validation approach. The methodological quality of included studies was assessed using the prediction model risk of bias assessment tool (PROBAST). A qualitative description of the characteristics of the included studies as well as a narrative data synthesis was performed.Results: A total of 19 primary studies were included. The predictors most frequently used belonged to the areas of demographic characteristics and stroke assessment through clinical examination. Regarding the methods, linear and logistic regressions were the most frequently used and cross-validation was the preferred validation approach.Conclusions: We identified several methodological limitations: small sample sizes, a limited number of external validation approaches, and high heterogeneity among input and output variables. Although these elements prevented a quantitative comparison across models, we defined the most frequently used models given a specific outcome, providing useful indications for the application of more complex machine learning algorithms in rehabilitation medicine. [ABSTRACT FROM AUTHOR]- Published
- 2022
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11. Pattern Recognition, Tracking and Vertex Reconstruction in Particle Detectors
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Frühwirth, Rudolf and Strandlie, Are
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Particle Acceleration and Detection, Beam Physics ,Measurement Science and Instrumentation ,Pattern Recognition ,Numerical and Computational Physics, Simulation ,Accelerator Physics ,Automated Pattern Recognition ,Theoretical, Mathematical and Computational Physics ,Event reconstruction ,Tracking detectors in High Energy Physics ,Vertex reconstruction ,Clustering algorithms ,Experimental High-Energy Physics ,LHC ,Calolimator for pattern recognition ,Vertex of particle collision ,Triggering event and data analysis ,Open access ,Particle & high-energy physics ,Scientific standards, measurement etc ,Mathematical physics ,Particle and high-energy physics ,Pattern recognition - Abstract
This open access book is a comprehensive review of the methods and algorithms that are used in the reconstruction of events recorded by past, running and planned experiments at particle accelerators such as the LHC, SuperKEKB and FAIR. The main topics are pattern recognition for track and vertex finding, solving the equations of motion by analytical or numerical methods, treatment of material effects such as multiple Coulomb scattering and energy loss, and the estimation of track and vertex parameters by statistical algorithms. The material covers both established methods and recent developments in these fields and illustrates them by outlining exemplary solutions developed by selected experiments. The clear presentation enables readers to easily implement the material in a high-level programming language. It also highlights software solutions that are in the public domain whenever possible. It is a valuable resource for PhD students and researchers working on online or offline reconstruction for their experiments.
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- 2021
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12. Künstliche Intelligenz in der orthopädisch-unfallchirurgischen Radiologie
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Rohde, Stefan and Münnich, Nico
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- 2022
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13. Feature Detection and Biomechanical Analysis to Objectively Identify High Exposure Movement Strategies When Performing the EPIC Lift Capacity test.
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Armstrong, Daniel P., Budarick, Aleksandra R., Pegg, Claragh E. E., Graham, Ryan B., and Fischer, Steven L.
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ANALYSIS of variance ,RANGE of motion of joints ,LIFTING & carrying (Human mechanics) ,CROSS-sectional method ,WORK capacity evaluation ,DYNAMICS ,BODY movement ,RESEARCH funding ,FACTOR analysis ,BIOMECHANICS ,STATISTICAL sampling ,DATA analysis software ,KINEMATICS - Abstract
Purpose The Epic Lift Capacity (ELC) test is used to determine a worker's maximum lifting capacity. In the ELC test, maximum lifting capacity is often determined as the maximum weight lifted without exhibiting a visually appraised "high-risk workstyle." However, the criteria for evaluating lifting mechanics have limited justification. This study applies feature detection and biomechanical analysis to motion capture data obtained while participants performed the ELC test to objectively identify aspects of movement that may help define "high-risk workstyle". Method In this cross-sectional study, 24 participants completed the ELC test. We applied Principal Component Analysis, as a feature detection approach, and biomechanical analysis to motion capture data to objectively identify movement features related to biomechanical exposure on the low back and shoulders. Principal component scores were compared between high and low exposure trials (relative to median exposure) to determine if features of movement differed. Features were interpreted using single component reconstructions of principal components. Results Statistical testing showed that low exposure lifts and lowers maintained the body closer to the load, exhibited squat-like movement (greater knee flexion, wider base of support), and remained closer to neutral posture at the low back (less forward flexion and axial twist) and shoulder (less flexion and abduction). Conclusions Use of feature detection and biomechanical analyses revealed movement features related to biomechanical exposure at the low back and shoulders. The objectively identified criteria could augment the existing scoring criteria for ELC test technique assessment. In the future, such features can inform the design of classifiers to objectively identify "high-risk workstyle" in real-time. [ABSTRACT FROM AUTHOR]
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- 2021
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14. Temporal Segmentation for Capturing Snapshots of Patient Histories in Korean Clinical Narrative
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Wangjin Lee and Jinwook Choi
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natural language processing ,electronic health records ,automated pattern recognition ,rheumatic diseases ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
ObjectivesClinical discharge summaries provide valuable information about patients' clinical history, which is helpful for the realization of intelligent healthcare applications. The documents tend to take the form of separate segments based on temporal or topical information. If a patient's clinical history can be seen as a consecutive sequence of clinical events, then each temporal segment can be seen as a snapshot, providing a certain clinical context at a specific moment. This study aimed to demonstrate a temporal segmentation method of Korean clinical narratives for identifying textual snapshots of patient history as a proof-of-a-concept.MethodsOur method uses pattern-based segmentation to approximate human recognition of the temporal or topical shifts in clinical documents. We utilized rheumatic patients' discharge summaries and transformed them into sequences of constituent chunks. We built 97 single pattern functions to denote whether a certain chunk has attributes that indicate that it can be a segment boundary. We manually defined the relationships between the pattern functions to resolve multiple pattern matchings and to make a final decision.ResultsThe algorithm segmented 30 discharge summaries and processed 1,849 decision points. Three human judges were asked whether they agreed with the algorithm's prediction, and the agreement percentage on the judges' majority opinion was 89.61%.ConclusionsAlthough this method is based on manually constructed rules, our findings demonstrate that the proposed algorithm can achieve fairly good segmentation results, and it may be the basis for methodological improvement in the future.
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- 2018
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15. Deep learning-based detection system for multiclass lesions on chest radiographs: comparison with observer readings.
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Park, Sohee, Lee, Sang Min, Lee, Kyung Hee, Jung, Kyu-Hwan, Bae, Woong, Choe, Jooae, and Seo, Joon Beom
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Objective: To investigate the feasibility of a deep learning-based detection (DLD) system for multiclass lesions on chest radiograph, in comparison with observers.Methods: A total of 15,809 chest radiographs were collected from two tertiary hospitals (7204 normal and 8605 abnormal with nodule/mass, interstitial opacity, pleural effusion, or pneumothorax). Except for the test set (100 normal and 100 abnormal (nodule/mass, 70; interstitial opacity, 10; pleural effusion, 10; pneumothorax, 10)), radiographs were used to develop a DLD system for detecting multiclass lesions. The diagnostic performance of the developed model and that of nine observers with varying experiences were evaluated and compared using area under the receiver operating characteristic curve (AUROC), on a per-image basis, and jackknife alternative free-response receiver operating characteristic figure of merit (FOM) on a per-lesion basis. The false-positive fraction was also calculated.Results: Compared with the group-averaged observations, the DLD system demonstrated significantly higher performances on image-wise normal/abnormal classification and lesion-wise detection with pattern classification (AUROC, 0.985 vs. 0.958; p = 0.001; FOM, 0.962 vs. 0.886; p < 0.001). In lesion-wise detection, the DLD system outperformed all nine observers. In the subgroup analysis, the DLD system exhibited consistently better performance for both nodule/mass (FOM, 0.913 vs. 0.847; p < 0.001) and the other three abnormal classes (FOM, 0.995 vs. 0.843; p < 0.001). The false-positive fraction of all abnormalities was 0.11 for the DLD system and 0.19 for the observers.Conclusions: The DLD system showed the potential for detection of lesions and pattern classification on chest radiographs, performing normal/abnormal classifications and achieving high diagnostic performance.Key Points: • The DLD system was feasible for detection with pattern classification of multiclass lesions on chest radiograph. • The DLD system had high performance of image-wise classification as normal or abnormal chest radiographs (AUROC, 0.985) and showed especially high specificity (99.0%). • In lesion-wise detection of multiclass lesions, the DLD system outperformed all 9 observers (FOM, 0.962 vs. 0.886; p < 0.001). [ABSTRACT FROM AUTHOR]- Published
- 2020
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16. Artificial intelligence for right whale photo identification: from data science competition to worldwide collaboration
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Khan, Christin, Blount, Drew, Parham, Jason, Holmberg, Jason, Hamilton, Philip, Charlton, Claire, Christiansen, Fredrik, Johnston, David, Rayment, Will, Dawson, Steve, Vermeulen, Els, Rowntree, Victoria, Groch, Karina, Levenson, J. Jacob, and Bogucki, Robert
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- 2022
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17. Clinical and automated gait analysis in patients with vestibular, cerebellar, and functional gait disorders: perspectives and limitations.
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Schniepp, Roman, Möhwald, Ken, and Wuehr, Max
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GAIT disorders , *NEUROLOGIC examination , *PATTERN recognition systems , *NEUROLOGICAL disorders , *DECISION making , *VESTIBULAR apparatus diseases - Abstract
This article outlines recent developments in the clinical and automated assessment of neurological gait disorders. With a primary focus on vestibular, cerebellar, and functional gait disorders, we discuss how instrumented gait examination may assist clinical decision making in these disorders with respect to the initial differential diagnosis and prognosis as well as the objective monitoring of disease progression and therapeutic interventions. We delineate strategies for data handling and analysis of quantitative gait examinations that can facilitate the clinical characterization and interpretation of walking impairments. These strategies include data normalization and dimensionality reduction procedures. We further emphasize the value of a comprehensive, standardized gait assessment protocol. Accordingly, the examination of walking conditions that challenge patients with respect to their biomechanical, sensory, or cognitive resources are particularly helpful to disclose and characterize the causes underlying their gait impairment. Finally, we provide a perspective on the emerging implementation of pattern recognition approaches within the framework of clinical management of gait disorders and discuss their potential to assist clinical decision making with respect to the differential diagnosis and the prognosis of fall risk in individual patients. [ABSTRACT FROM AUTHOR]
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- 2019
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18. A Convolutional Neural Network-Based Model for Multi-Source and Single-Source Partial Discharge Pattern Classification Using Only Single-Source Training Set
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Sara Mantach, Ahmed Ashraf, Hamed Janani, and Behzad Kordi
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partial discharges ,phase resolved partial discharge ,insulation systems ,automated pattern recognition ,deep Learning ,convolution neural network ,Technology - Abstract
Classification of the sources of partial discharges has been a standard procedure to assess the status of insulation in high voltage systems. One of the challenges while classifying these sources is the decision on the distinct properties of each one, often requiring the skills of trained human experts. Machine learning offers a solution to this problem by allowing to train models based on extracted features. The performance of such algorithms heavily depends on the choice of features. This can be overcome by using deep learning where feature extraction is done automatically by the algorithm, and the input to such an algorithm is the raw input data. In this work, an enhanced convolutional neural network is proposed that is capable of classifying single sources as well as multiple sources of partial discharges without introducing multiple sources in the training phase. The training is done by using only single-source phase-resolved partial discharge (PRPD) patterns, while testing is performed on both single and multi-source PRPD patterns. The proposed model is compared with single-branch CNN architecture. The average percentage improvements of the proposed architecture for single-source PDs and multi-source PDs are 99.6% and 96.7% respectively, compared to 96.2% and 77.3% for that of the traditional single-branch CNN architecture.
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- 2021
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19. A novel way to evaluate autoantibody interference in samples with mixed antinuclear antibody patterns in the HEp-2 cell based indirect immunofluorescence assay and comparison of conventional microscopic and computer-aided pattern recognition.
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Nagy, Gábor, Földesi, Róza, Csípő, István, Tarr, Tünde, Szűcs, Gabriella, Szántó, Antónia, Bubán, Tamás, Szekanecz, Zoltán, Papp, Mária, Kappelmayer, János, and Antal-Szalmás, Péter
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ANTINUCLEAR factors , *AUTOANTIBODIES , *IMMUNOFLUORESCENCE , *CELL aggregation , *SPECKLE interference , *TITERS - Abstract
• About one third of positive routine HEp-2 IFA tests show mixed antinuclear patterns. • On these sera correct identification of ANA patterns is challenging. • We established a novel way to analyze the interference between two patterns. • Nuclear homogeneous disturb the recognition of speckled pattern more than vice versa. • Conventional/on-screen evaluation is superior to EUROPattern in pattern analysis. A major challenge of the HEp-2 cell-based indirect immunofluorescence (IIF) assays is the correct identification of the individual anti-nuclear antibodies (ANAs) if more than one is present in a sample. We created artificial mixes by pooling two different samples with a single autoantibody in different titers. Comparison of the expected and observed patterns and titers clarifies the interference between the two tested ANAs. Serum samples with a single homogeneous or speckled ANA pattern were serially diluted and mixed in 16 combinations, providing end-point titers of 1:5,120 to 1:80 for both patterns. These mixes were tested by a HEp-2 IIF assay and were evaluated by conventional evaluation, the EUROPattern (EPa) system and on-screen analysis. Homogeneous pattern can alter the identification of the speckled pattern much more than vice versa, but both has an interfering effect on the other. The effect of the interfering on the tested pattern was higher if the titer of the former one was higher. The pattern recognition efficacy of conventional and the on-screen evaluation was similar and superior compared to the EPa analysis. The application of artificial mixed samples can help the evaluation of the efficacy of manual and computer-aided ANA HEp-2 pattern recognition. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Detection of shockable heart rhythms with convolutional neural networks : Based on ECG spectrograms
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Siegel, Sebastian, Lääketieteen ja terveysteknologian tiedekunta - Faculty of Medicine and Health Technology, and Tampere University
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automated external defibrillator, AED, cardiac arrhythmia, cardiac arrest, convolutional neural network, CNN, defibrillation, ECG data analysis, feature extraction, deep learning, residual neural network, ResNet, shockable, shockable heart rhythms, spectrogram, wavelet transform [Keywords] ,neural networks (information technology) ,automated pattern recognition ,machine learning ,heart diseases ,databases ,ECG ,medicine (science) ,deep learning ,cardiac arrest ,arrhythmias ,Master's Programme in Biomedical Sciences and Engineering - Abstract
Purpose Automated feature extraction combined with deep learning has had and continues to have a strong impact on the improvement and implementation of pattern recognition driven by machine learning. Systems without prior expertise about a problem but with the ability to iteratively learn strategies to solve problems, tend to outperform concepts of manual feature engineering in vari-ous fields. In ECG data analysis as well as in other medical domains, models based on manual feature extraction are tedious to develop, require scientific expertise, and are oftentimes not easily adaptive to variations of the problem to be solved. This work aims to examine automated feature extraction and classification of ECG data, specifically of shockable heart rhythms, with convolu-tional neural networks and residual neural networks. The precise and rapid determination of shockable cardiac conditions is a decisive step to improve the chances of survival for patients having a sudden cardiac arrest. Conventional, commercially available automated external defib-rillators (AEDs) deploy algorithms based on manual feature extraction. Approximately 1 out of 10 shockable conditions is not recognized by the AED. Consequently, strategies for improvement need to be explored. Methods 125 ECG recordings from four annotated cardiac arrhythmia databases (American Heart Association Database, Creighton University Tachyarrhythmia Database, MIT-BIH Arrhythmia Da-tabase, MIT-BIH Malignant Ventricular Arrhythmia Database) with a duration of 30 mins or 8 mins (Creighton University Tachyarrhythmia Database) per recording were processed. Shockable con-ditions are identified as ventricular tachycardia, ventricular fibrillation, and ventricular flutter. The 1 channel ECG recordings (modified limb lead II) were normalized to 250 Hz sampling frequency, high-pass filtered (1 Hz cutoff and 0.85 filter steepness), second order Butterworth low-pass fil-tered (30 Hz cutoff), and notch filtered at 50 Hz. Consistent wavelet transformation with 5 octaves, 20 voices per octave, and a time bandwidth product parameter of 50 was applied to generate greyscale spectrogram representations of the ECG data (pixel value range from 0 to 255). The recordings were segmented into 3 s segments. Data augmentation around the borders of shock-able episodes and along shockable episodes was carried out to create balanced datasets con-sisting of 60340 samples. 45% of samples in the balanced dataset contain shockable rhythms with more than 60% temporal prevalence within each sample. Conventional convolutional neural networks and residual neural networks with varying architectures and hyperparameter settings were trained and evaluated on balanced datasets (train/val/test: 70/15/15). The approach focused on examining a broader range of parameter settings and model architectures rather than optimiz-ing a specific configuration. The best performing model was evaluated in a 5-fold cross-validation. Exemplarily, a leave-one-subject-out cross-validation was deployed with 3 randomly chosen re-cordings, with the constraints that each subject must come from a different database and contain a different shockable condition. Results and Conclusion The best performing model was a residual neural network with 96 residual blocks. The 5-fold cross-validation results on average in an accuracy of 0.987, a sensitivity of 0.992 on shock-able rhythms, and a specificity of 0.984 for non-shockable rhythms on the test sets. The ROC AUC score is 0.998 on average. The 3-fold leave-one-subject-out cross-validation reaches on average an accuracy of 0.984, a sensitivity of 0.984, and a specificity of 0.980. The ROC AUC score reaches 0.997 on average. The analysis of misclassified segments reveals that the classi-fier performs less accurately on border segments containing a shockable and at least one non-shockable rhythm. While the test set contains 4.73% border segments, the set of misclassified samples includes 11.29% border segments. The label distributions of the test set and the set of misclassified samples show that segments annotated as “not defined” (ND) and “ventricular fibril-lation or flutter” (VF-VFL) are significantly more prevalent in the set of misclassified samples. Histogram analysis, referring to the mean pixel intensity of the spectrograms, indicates that the classifier works less accurately on spectrograms with mean pixel values below 2 (practically flat-line signals or signals with very small amplitude). The results indicate that it is possible to improve the analysis of ECG data by deploying automated feature detection combined with artificial neural networks. The methods presented in this work are not restricted to the detection of shockable cardiac arrhythmias, they likewise em-phasize the potential of machine learning in the domain of biosignal analysis and correlated med-ical data. In the next step, the approach needs to be verified on a broader database. The tech-nology can even help create more comprehensive databases of clinical ECG data by supporting automated annotation.
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- 2023
21. Applications of machine learning algorithms to predict therapeutic outcomes in depression: A meta-analysis and systematic review.
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Lee, Yena, Ragguett, Renee-Marie, Mansur, Rodrigo B., Boutilier, Justin J., Rosenblat, Joshua D., Trevizol, Alisson, Brietzke, Elisa, Lin, Kangguang, Pan, Zihang, Subramaniapillai, Mehala, Chan, Timothy C.Y., Fus, Dominika, Park, Caroline, Musial, Natalie, Zuckerman, Hannah, Chen, Vincent Chin-Hung, Ho, Roger, Rong, Carola, and McIntyre, Roger S.
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MENTAL depression , *AFFECTIVE disorders , *MACHINE learning , *TREATMENT effectiveness , *BRAIN imaging , *THERAPEUTICS , *ANTIDEPRESSANTS , *DIAGNOSIS of mental depression , *ALGORITHMS , *META-analysis , *NEURORADIOLOGY , *SYSTEMATIC reviews , *RETROSPECTIVE studies , *COMPUTER-aided diagnosis - Abstract
Background: No previous study has comprehensively reviewed the application of machine learning algorithms in mood disorders populations. Herein, we qualitatively and quantitatively evaluate previous studies of machine learning-devised models that predict therapeutic outcomes in mood disorders populations.Methods: We searched Ovid MEDLINE/PubMed from inception to February 8, 2018 for relevant studies that included adults with bipolar or unipolar depression; assessed therapeutic outcomes with a pharmacological, neuromodulatory, or manual-based psychotherapeutic intervention for depression; applied a machine learning algorithm; and reported predictors of therapeutic response. A random-effects meta-analysis of proportions and meta-regression analyses were conducted.Results: We identified 639 records: 75 full-text publications were assessed for eligibility; 26 studies (n=17,499) and 20 studies (n=6325) were included in qualitative and quantitative review, respectively. Classification algorithms were able to predict therapeutic outcomes with an overall accuracy of 0.82 (95% confidence interval [CI] of [0.77, 0.87]). Pooled estimates of classification accuracy were significantly greater (p < 0.01) in models informed by multiple data types (e.g., composite of phenomenological patient features and neuroimaging or peripheral gene expression data; pooled proportion [95% CI] = 0.93[0.86, 0.97]) when compared to models with lower-dimension data types (pooledproportion=0.68[0.62,0.74]to0.85[0.81,0.88]).Limitations: Most studies were retrospective; differences in machine learning algorithms and their implementation (e.g., cross-validation, hyperparameter tuning); cannot infer importance of individual variables fed into learning algorithm.Conclusions: Machine learning algorithms provide a powerful conceptual and analytic framework capable of integrating multiple data types and sources. An integrative approach may more effectively model neurobiological components as functional modules of pathophysiology embedded within the complex, social dynamics that influence the phenomenology of mental disorders. [ABSTRACT FROM AUTHOR]- Published
- 2018
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22. Challenges and Practical Approaches with Word Sense Disambiguation of Acronyms and Abbreviations in the Clinical Domain
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Sungrim Moon, Bridget McInnes, and Genevieve B. Melton
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abbreviations as topic ,medical records ,natural language processing ,artificial intelligence ,automated pattern recognition ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
ObjectivesAlthough acronyms and abbreviations in clinical text are used widely on a daily basis, relatively little research has focused upon word sense disambiguation (WSD) of acronyms and abbreviations in the healthcare domain. Since clinical notes have distinctive characteristics, it is unclear whether techniques effective for acronym and abbreviation WSD from biomedical literature are sufficient.MethodsThe authors discuss feature selection for automated techniques and challenges with WSD of acronyms and abbreviations in the clinical domain.ResultsThere are significant challenges associated with the informal nature of clinical text, such as typographical errors and incomplete sentences; difficulty with insufficient clinical resources, such as clinical sense inventories; and obstacles with privacy and security for conducting research with clinical text. Although we anticipated that using sophisticated techniques, such as biomedical terminologies, semantic types, part-of-speech, and language modeling, would be needed for feature selection with automated machine learning approaches, we found instead that simple techniques, such as bag-of-words, were quite effective in many cases. Factors, such as majority sense prevalence and the degree of separateness between sense meanings, were also important considerations.ConclusionsThe first lesson is that a comprehensive understanding of the unique characteristics of clinical text is important for automatic acronym and abbreviation WSD. The second lesson learned is that investigators may find that using simple approaches is an effective starting point for these tasks. Finally, similar to other WSD tasks, an understanding of baseline majority sense rates and separateness between senses is important. Further studies and practical solutions are needed to better address these issues.
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- 2015
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23. Machine learning methods for functional recovery prediction and prognosis in post-stroke rehabilitation: a systematic review
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Campagnini, S, Arienti, C, Patrini, M, Liuzzi, P, Mannini, A, Carrozza, M, Campagnini S., Arienti C., Patrini M., Liuzzi P., Mannini A., Carrozza M. C., Campagnini, S, Arienti, C, Patrini, M, Liuzzi, P, Mannini, A, Carrozza, M, Campagnini S., Arienti C., Patrini M., Liuzzi P., Mannini A., and Carrozza M. C.
- Abstract
Background: Rehabilitation medicine is facing a new development phase thanks to a recent wave of rigorous clinical trials aimed at improving the scientific evidence of protocols. This phenomenon, combined with new trends in personalised medical therapies, is expected to change clinical practice dramatically. The emerging field of Rehabilomics is only possible if methodologies are based on biomedical data collection and analysis. In this framework, the objective of this work is to develop a systematic review of machine learning algorithms as solutions to predict motor functional recovery of post-stroke patients after treatment. Methods: We conducted a comprehensive search of five electronic databases using the Patient, Intervention, Comparison and Outcome (PICO) format. We extracted health conditions, population characteristics, outcome assessed, the method for feature extraction and selection, the algorithm used, and the validation approach. The methodological quality of included studies was assessed using the prediction model risk of bias assessment tool (PROBAST). A qualitative description of the characteristics of the included studies as well as a narrative data synthesis was performed. Results: A total of 19 primary studies were included. The predictors most frequently used belonged to the areas of demographic characteristics and stroke assessment through clinical examination. Regarding the methods, linear and logistic regressions were the most frequently used and cross-validation was the preferred validation approach. Conclusions: We identified several methodological limitations: small sample sizes, a limited number of external validation approaches, and high heterogeneity among input and output variables. Although these elements prevented a quantitative comparison across models, we defined the most frequently used models given a specific outcome, providing useful indications for the application of more complex machine learning algorithms in rehabilitation medi
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- 2022
24. Lifelog Agent for Human Activity Pattern Analysis on Health Avatar Platform
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Yongjin Kwon, Kyuchang Kang, Changseok Bae, Hee-Joon Chung, and Ju Han Kim
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activities of daily living ,health behavior ,mobile phone ,automated pattern recognition ,medical records ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
ObjectivesTo provide accurate personalized medical care, it is necessary to gather individual-related data or contextual information regarding the target person. Nowadays a large number of people possess smartphones, which enables sensors in the smartphones to be used for lifelogging. The objective of the study is to analyze human activity pattern by using lifelog agent cooperating with the Health Avatar platform.MethodsUsing the lifelog measured by accelerometer and gyroscope in a smartphone at a 50 Hz rate, the agent reveals how long the user walks, runs, sits, stands, and lies down, and this information is summarized by hours. The summaries are sent to the Health Avatar platform and finally are written in the Continuity of Care Record (CCR) format.ResultsThe lifelog agent is successfully operated with the Health Avatar platform. In addition, we implement an application that displays the user's activity patterns in a graph and calculates the metabolic equivalent of task based calorie burned by hour or by day using the lifelog of the CCR form to show that the lifelog can be used as medical records.ConclusionsThe agent shows how lifelogs are analyzed and summarized to help activity recognition. We believe that our agent demonstrates a way of incorporating lifelogs into medical care and a way of exploiting lifelogs in a medical format.
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- 2014
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25. Nocturnal Oximetry-based Evaluation of Habitually Snoring Children.
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Hornero, Roberto, Kheirandish-Gozal, Leila, Gutiérrez-Tobal, Gonzalo C., Philby, Mona F., Alonso-Álvarez, María Luz, Álvarez, Daniel, Dayyat, Ehab A., Zhifei Xu, Yu-Shu Huang, Kakazu, Maximiliano Tamae, Li, Albert M., Van Eyck, Annelies, Brockmann, Pablo E., Ehsan, Zarmina, Simakajornboon, Narong, Kaditis, Athanasios G., Vaquerizo-Villar, Fernando, Sedano, Andrea Crespo, Capdevila, Oscar Sans, and von Lukowicz, Magnus
- Abstract
Rationale: The vast majority of children around the world undergoing adenotonsillectomy for obstructive sleep apnea-hypopnea syndrome (OSA) are not objectively diagnosed by nocturnal polysomnography because of access availability and cost issues. Automated analysis of nocturnal oximetry (nSpO2), which is readily and globally available, could potentially provide a reliable and convenient diagnostic approach for pediatric OSA.Methods: Deidentified nSpO2 recordings from a total of 4,191 children originating from 13 pediatric sleep laboratories around the world were prospectively evaluated after developing and validating an automated neural network algorithm using an initial set of single-channel nSpO2 recordings from 589 patients referred for suspected OSA.Measurements and Main Results: The automatically estimated apnea-hypopnea index (AHI) showed high agreement with AHI from conventional polysomnography (intraclass correlation coefficient, 0.785) when tested in 3,602 additional subjects. Further assessment on the widely used AHI cutoff points of 1, 5, and 10 events/h revealed an incremental diagnostic ability (75.2, 81.7, and 90.2% accuracy; 0.788, 0.854, and 0.913 area under the receiver operating characteristic curve, respectively).Conclusions: Neural network-based automated analyses of nSpO2 recordings provide accurate identification of OSA severity among habitually snoring children with a high pretest probability of OSA. Thus, nocturnal oximetry may enable a simple and effective diagnostic alternative to nocturnal polysomnography, leading to more timely interventions and potentially improved outcomes. [ABSTRACT FROM AUTHOR]- Published
- 2017
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26. Multiscale Entropy Analysis of Unattended Oximetric Recordings to Assist in the Screening of Paediatric Sleep Apnoea at Home.
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Crespo, Andrea, Álvarez, Daniel, Gutiérrez-Tobal, Gonzalo C., Vaquerizo-Villar, Fernando, Barroso-García, Verónica, Alonso-Álvarez, María L., Terán-Santos, Joaquín, Hornero, Roberto, and Del Campo, Félix
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SLEEP apnea syndromes , *QUALITY of life , *POLYSOMNOGRAPHY , *OXIMETRY , *ENTROPY , *MATHEMATICAL models , *PHYSIOLOGY - Abstract
Untreated paediatric obstructive sleep apnoea syndrome (OSAS) can severely affect the development and quality of life of children. In-hospital polysomnography (PSG) is the gold standard for a definitive diagnosis though it is relatively unavailable and particularly intrusive. Nocturnal portable oximetry has emerged as a reliable technique for OSAS screening. Nevertheless, additional evidences are demanded. Our study is aimed at assessing the usefulness of multiscale entropy (MSE) to characterise oximetric recordings. We hypothesise that MSE could provide relevant information of blood oxygen saturation (SpO2) dynamics in the detection of childhood OSAS. In order to achieve this goal, a dataset composed of unattended SpO2 recordings from 50 children showing clinical suspicion of OSAS was analysed. SpO2 was parameterised by means of MSE and conventional oximetric indices. An optimum feature subset composed of five MSE-derived features and four conventional clinical indices were obtained using automated bidirectional stepwise feature selection. Logistic regression (LR) was used for classification. Our optimum LR model reached 83.5% accuracy (84.5% sensitivity and 83.0% specificity). Our results suggest that MSE provides relevant information from oximetry that is complementary to conventional approaches. Therefore, MSE may be useful to improve the diagnostic ability of unattended oximetry as a simplified screening test for childhood OSAS. [ABSTRACT FROM AUTHOR]
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- 2017
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27. Recognizing Temporal Information in Korean Clinical Narratives through Text Normalization
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Youngho Kim and Jinwook Choi
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medical informatics ,information processing ,multilingualism ,medical record ,automated pattern recognition ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
ObjectivesAcquiring temporal information is important because knowledge in clinical narratives is time-sensitive. In this paper, we describe an approach that can be used to extract the temporal information found in Korean clinical narrative texts.MethodsWe developed a two-stage system, which employs an exhaustive text analysis phase and a temporal expression recognition phase. Since our target document may include tokens that are made up of both Korean and English text joined together, the minimal semantic units are analyzed and then separated from the concatenated phrases and linguistic derivations within a token using a corpus-based approach to decompose complex tokens. A finite state machine is then used on the minimal semantic units in order to find phrases that possess time-related information.ResultsIn the experiment, the temporal expressions within Korean clinical narratives were extracted using our system. The system performance was evaluated through the use of 100 discharge summaries from Seoul National University Hospital containing a total of 805 temporal expressions. Our system scored a phrase-level precision and recall of 0.895 and 0.919, respectively.ConclusionsFinding information in Korean clinical narrative is challenging task, since the text is written in both Korean and English and frequently omits syntactic elements and word spacing, which makes it extremely noisy. This study presents an effective method that can be used to aquire the temporal information found in Korean clinical documents.
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- 2011
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28. Shack-Hartmann spot dislocation map determination using an optical flow method
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Universidad EAFIT. Departamento de Ciencias Básicas, Óptica Aplicada, Vargas, J., Restrepo, R., Belenguer, T., Universidad EAFIT. Departamento de Ciencias Básicas, Óptica Aplicada, Vargas, J., Restrepo, R., and Belenguer, T.
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We present a robust, dense, and accurate Shack-Hartmann spot dislocation map determination method based on a regularized optical flow algorithm that does not require obtaining the spot centroids. The method is capable to measure in presence of strong noise, background illumination and spot modulating signals, which are typical limiting factors of traditional centroid detection algorithms. Moreover, the proposed approach is able to face cases where some of the reference beam spots have not a corresponding one in the distorted Hartmann diagram, and it can expand the dynamic range of the Shack-Hartmann sensor unwrapping the obtained dense dislocation maps. We have tested the algorithm with both simulations and experimental data obtaining satisfactory results. A complete MATLAB package that can reproduce all the results can be downloaded from [http://goo.gl/XbZVOr]. © 2014 Optical Society of America.
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- 2021
29. Volume Visual Attention Maps (VVAM) in ray-casting rendering
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Universidad EAFIT. Departamento de Ingeniería Mecánica, Laboratorio CAD/CAM/CAE, Beristain, A., Congote, J., Ruiz, O., Universidad EAFIT. Departamento de Ingeniería Mecánica, Laboratorio CAD/CAM/CAE, Beristain, A., Congote, J., and Ruiz, O.
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This paper presents an extension visual attention maps for volume data visualization, where eye fixation points become rays in the 3D space, and the visual attention map becomes a volume. This Volume Visual Attention Map (VVAM) is used to interactively enhance a ray-casting based direct volume rendering (DVR) visualization. The practical application of this idea into the biomedical image visualization field is explored for interactive visualization. © 2012 The authors and IOS Press. All rights reserved.
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- 2021
30. Detecting Medication-Taking Gestures Using Machine Learning and Accelerometer Data Collected via Smartwatch Technology: Instrument Validation Study.
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Odhiambo CO, Ablonczy L, Wright PJ, Corbett CF, Reichardt S, and Valafar H
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Background: Medication adherence is a global public health challenge, as only approximately 50% of people adhere to their medication regimens. Medication reminders have shown promising results in terms of promoting medication adherence. However, practical mechanisms to determine whether a medication has been taken or not, once people are reminded, remain elusive. Emerging smartwatch technology may more objectively, unobtrusively, and automatically detect medication taking than currently available methods., Objective: This study aimed to examine the feasibility of detecting natural medication-taking gestures using smartwatches., Methods: A convenience sample (N=28) was recruited using the snowball sampling method. During data collection, each participant recorded at least 5 protocol-guided (scripted) medication-taking events and at least 10 natural instances of medication-taking events per day for 5 days. Using a smartwatch, the accelerometer data were recorded for each session at a sampling rate of 25 Hz. The raw recordings were scrutinized by a team member to validate the accuracy of the self-reports. The validated data were used to train an artificial neural network (ANN) to detect a medication-taking event. The training and testing data included previously recorded accelerometer data from smoking, eating, and jogging activities in addition to the medication-taking data recorded in this study. The accuracy of the model to identify medication taking was evaluated by comparing the ANN's output with the actual output., Results: Most (n=20, 71%) of the 28 study participants were college students and aged 20 to 56 years. Most individuals were Asian (n=12, 43%) or White (n=12, 43%), single (n=24, 86%), and right-hand dominant (n=23, 82%). In total, 2800 medication-taking gestures (n=1400, 50% natural plus n=1400, 50% scripted gestures) were used to train the network. During the testing session, 560 natural medication-taking events that were not previously presented to the ANN were used to assess the network. The accuracy, precision, and recall were calculated to confirm the performance of the network. The trained ANN exhibited an average true-positive and true-negative performance of 96.5% and 94.5%, respectively. The network exhibited <5% error in the incorrect classification of medication-taking gestures., Conclusions: Smartwatch technology may provide an accurate, nonintrusive means of monitoring complex human behaviors such as natural medication-taking gestures. Future research is warranted to evaluate the efficacy of using modern sensing devices and machine learning algorithms to monitor medication-taking behavior and improve medication adherence., (©Chrisogonas Odero Odhiambo, Lukacs Ablonczy, Pamela J Wright, Cynthia F Corbett, Sydney Reichardt, Homayoun Valafar. Originally published in JMIR Human Factors (https://humanfactors.jmir.org), 04.05.2023.)
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- 2023
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31. Computer-automated focus lateralization of temporal lobe epilepsy using fMRI.
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Chiang, Sharon, Levin, Harvey S., and Haneef, Zulfi
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Purpose To compare the performance of computer-automated diagnosis using functional magnetic resonance imaging (fMRI) interictal graph theory (CADFIG) to that achieved in standard clinical practice with MRI, for lateralizing the affected hemisphere in temporal lobe epilepsy (TLE). Materials and Methods Interictal resting state fMRI and high-resolution MRI were performed on 14 left and 10 right TLE patients. Functional topology measures were calculated from fMRI using graph theory, and used to lateralize the epileptogenic hemisphere using quadratic discriminant analysis. Leave-one-out cross-validation prediction accuracy of CADFIG was compared to performance based on expert manual analysis (MA) of MRI, using video EEG as the "gold standard" for focus lateralization. Results CADFIG correctly lateralized 95.8% (23/24) of cases, compared to 66.7% (16/24) with expert MA of MRI. Combining MA with CADFIG allowed all cases (24/24) to be correctly lateralized. CADFIG correctly identified the affected hemisphere for all patients (8/8) where MRI failed to lateralize. Conclusion CADFIG based on fMRI lateralized the affected hemisphere in TLE with superior performance compared to expert MA of MRI. These results demonstrate that functional patterns in fMRI can be used with automated machine learning for diagnostic lateralization in TLE. Addition of fMRI-based tests to existing protocols for identifying the affected hemisphere in presurgical assessment can improve diagnostic accuracy and surgical outcome in TLE. J. Magn. Reson. Imaging 2015;41:1689-1694. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]
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- 2015
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32. Self-organized operational neural networks for severe image restoration problems
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Malik J., Kiranyaz, Mustafa Serkan, and Gabbouj M.
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Function approximation ,convolutional neural network ,receptive field ,Pattern Recognition, Automated ,photostimulation ,Linear transformations ,Image Processing, Computer-Assisted ,Humans ,human ,procedures ,Mathematical operators ,Generalization performance ,Neurons ,learning ,Ablation experiments ,Strict equivalence ,article ,Restoration problems ,image reconstruction ,Convolution ,image processing ,drug efficacy ,Discriminative learning ,Image restoration problem ,automated pattern recognition ,Restoration ,physiology ,Convolutional neural networks ,Mathematical transformations ,Neural Networks, Computer ,nerve cell ,Receptive fields ,Photic Stimulation ,Personnel training - Abstract
Discriminative learning based on convolutional neural networks (CNNs) aims to perform image restoration by learning from training examples of noisy-clean image pairs. It has become the go-to methodology for tackling image restoration and has outperformed the traditional non-local class of methods. However, the top-performing networks are generally composed of many convolutional layers and hundreds of neurons, with trainable parameters in excess of several million. We claim that this is due to the inherently linear nature of convolution-based transformation, which is inadequate for handling severe restoration problems. Recently, a non-linear generalization of CNNs, called the operational neural networks (ONN), has been shown to outperform CNN on AWGN denoising. However, its formulation is burdened by a fixed collection of well-known non-linear operators and an exhaustive search to find the best possible configuration for a given architecture, whose efficacy is further limited by a fixed output layer operator assignment. In this study, we leverage the Taylor series-based function approximation to propose a self-organizing variant of ONNs, Self-ONNs, for image restoration, which synthesizes novel nodal transformations on-the-fly as part of the learning process, thus eliminating the need for redundant training runs for operator search. In addition, it enables a finer level of operator heterogeneity by diversifying individual connections of the receptive fields and weights. We perform a series of extensive ablation experiments across three severe image restoration tasks. Even when a strict equivalence of learnable parameters is imposed, Self-ONNs surpass CNNs by a considerable margin across all problems, improving the generalization performance by up to 3 dB in terms of PSNR. Scopus
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- 2021
33. Measuring the Accuracy of Automatic Shoeprint Recognition Methods.
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Luostarinen, Tapio and Lehmussola, Antti
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CRIMINAL investigation , *FORENSIC sciences , *COMPUTER vision , *CRIME scene searches , *ALGORITHMS , *PATTERN perception - Abstract
Shoeprints are an important source of information for criminal investigation. Therefore, an increasing number of automatic shoeprint recognition methods have been proposed for detecting the corresponding shoe models. However, comprehensive comparisons among the methods have not previously been made. In this study, an extensive set of methods proposed in the literature was implemented, and their performance was studied in varying conditions. Three datasets of different quality shoeprints were used, and the methods were evaluated also with partial and rotated prints. The results show clear differences between the algorithms: while the best performing method, based on local image descriptors and RANSAC, provides rather good results with most of the experiments, some methods are almost completely unrobust against any unidealities in the images. Finally, the results demonstrate that there is still a need for extensive research to improve the accuracy of automatic recognition of crime scene prints. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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34. Extracting Salient Brain Patterns for Imaging-Based Classification of Neurodegenerative Diseases.
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Rueda, Andrea, Gonzalez, Fabio A., and Romero, Eduardo
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ALZHEIMER'S disease diagnosis , *MAGNETIC resonance imaging of the brain , *COMPUTED tomography , *SUPPORT vector machines , *NEURODEGENERATION , *SYMPTOMS - Abstract
Neurodegenerative diseases comprise a wide variety of mental symptoms whose evolution is not directly related to the visual analysis made by radiologists, who can hardly quantify systematic differences. Moreover, automatic brain morphometric analyses, that do perform this quantification, contribute very little to the comprehension of the disease, i.e., many of these methods classify but they do not produce useful anatomo-functional correlations. This paper presents a new fully automatic image analysis method that reveals discriminative brain patterns associated to the presence of neurodegenerative diseases, mining systematic differences and therefore grading objectively any neurological disorder. This is accomplished by a fusion strategy that mixes together bottom-up and top-down information flows. Bottom-up information comes from a multiscale analysis of different image features, while the top-down stage includes learning and fusion strategies formulated as a max-margin multiple-kernel optimization problem. The capacity of finding discriminative anatomic patterns was evaluated using the Alzheimer's disease (AD) as the use case. The classification performance was assessed under different configurations of the proposed approach in two public brain magnetic resonance datasets (OASIS-MIRIAD) with patients diagnosed with AD, showing an improvement varying from 6.2% to 13% in the equal error rate measure, with respect to what has been reported by the feature-based morphometry strategy. In terms of the anatomical analysis, discriminant regions found by the proposed approach highly correlates to what has been reported in clinical studies of AD. [ABSTRACT FROM PUBLISHER]
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- 2014
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35. Neural network versus activity-specific prediction equations for energy expenditure estimation in children.
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Ruch, Nicole, Joss, Franziska, Jimmy, Gerda, Melzer, Katarina, Hänggi, Johanna, and Mäder, Urs
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CALORIC expenditure ,NEURAL circuitry ,ACCELEROMETERS - Abstract
The aim of this study was to compare the energy expenditure (EE) estimations of activity-specific prediction equations (ASPE) and of an artificial neural network (ANN
EE ) based on accelerometry with measured EE. Forty-three children (age: 9.8 ± 2.4 yr) performed eight different activities. They were equipped with one tri-axial accelerometer that collected data in 1-s epochs and a portable gas analyzer. The ASPE and the ANNEE were trained to estimate the EE by including accelerometry, age, gender, and weight of the participants. To provide the activity-specific information, a decision tree was trained to recognize the type of activity through accelerometer data. The ASPE were applied to the activity-type-specific data recognized by the tree (Tree-ASPE). The Tree-ASPE precisely estimated the EE of all activities except cycling [bias: -1.13 ± 1.33 metabolic equivalent (MET)] and walking (bias: 0.29 ± 0.64 MET; P < 0.05). The ANNEE overestimated the EE of stationary activities (bias: 0.31 ± 0.47 MET) and walking (bias: 0.61 ± 0.72 MET) and underestimated the EE of cycling (bias: -0.90 ± 1.18 MET; P < 0.05). Biases of EE in stationary activities (ANNEE : 0.31 ± 0.47 MET, Tree-ASPE: 0.08 ± 0.21 MET) and walking (ANNEE 0.61 ± 0.72 MET, Tree-ASPE: 0.29 ± 0.64 MET) were significantly smaller in the Tree-ASPE than in the ANNEE (P < 0.05). The Tree-ASPE was more precise in estimating the EE than the ANNEE . The use of activity-type-specific information for subsequent EE prediction equations might be a promising approach for future studies. [ABSTRACT FROM AUTHOR]- Published
- 2013
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36. Early Illness Recognition Using In-home Monitoring Sensors and Multiple Instance Learning.
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Popescu, M. and Mahnot, A.
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NURSING ,DETECTORS ,OLDER people ,ALGORITHMS ,NURSING care facilities - Abstract
The article presents a study that predicts early signs of illness in older adults by using the data generated by continuous, unobtrusive nursing home monitoring system. It describes he possibility of employing a multiple instance learning (MIL) framework for early illness detection. It is given that the use of simulated sensor data is very useful for algorithm development and testing.
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- 2012
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37. GPU-based real-time detection and analysis of biological targets using solid-state nanopores.
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Hafeez, Abdul, Asghar, Waseem, Rafique, M., Iqbal, Samir, and Butt, Ali
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COMPUTER-aided diagnosis , *GRAPHICS processing units , *REAL-time control , *SOLID state chemistry , *NANOPORES , *DNA , *CHROMOSOMAL translocation - Abstract
The emergence of nanoscale devices has provided robust interfaces to biomolecules that faithfully transduce and define fundamental interactions of living systems. Measuring single-event behavior of important targets like DNA, and diseased cells has been achieved with a number of devices and systems. An important dimension to these systems, often discounted, is real-time computational decision-making from measured data. This paper describes an adaptive approach that can record single-molecule or single-cell events in real-time and automatically analyze patterns from the measured data. The automated analysis of measured data is done using a static threshold technique and two variations of a dynamic threshold technique: baseline-tracker and moving average filtering. Dynamic techniques for threshold detection enable noise suppression in the measured data and precise detection of patterns, but at the cost of more complex software as compared to static technique. To mitigate the computational overhead, a real-time system is implemented that uses advanced I/O techniques to minimize the execution stalls, thus enabling the system to process data significantly faster than the electrical measurement setup. Furthermore, the algorithms are implemented on programmable graphics processing units for parallel pattern detection. Our implementation provides five times faster data acquisition and pattern detection than the maximum sampling rate of the electrical measurement setup. [ABSTRACT FROM AUTHOR]
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- 2012
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38. TADAA: Towards Automated Detection of Anaesthetic Activity.
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Houliston, B. R., Parry, D. T., and Merry, A. F.
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MEDICAL informatics ,ANESTHESIOLOGISTS ,RADIO frequency identification systems ,NEAR field communication ,TELEMEDICINE - Abstract
The article presents as study aimed at developing an automatic detection system in detecting the activities of anesthetist in the operating room . The study uses a radio frequency identification device (RFID) technology to capture the location, orientation and stance (LOC) of the anesthetist, The study suggests that active RFID tags can provide useful information on LOS at a low cost and minimal impact on the work environment.
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- 2011
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39. TADAA: Towards Automated Detection of Anaesthetic Activity.
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Safran, C., Reti, S., Marin, H.F., Houliston, Bryan, Parry, Dave, and Merry, Alan
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Task analysis is a valuable research method for better understanding the activity of anaesthetists in the operating room (OR), providing evidence for designing and evaluating improvements to systems and processes. It may also assist in identifying potential error paths to adverse events, ultimately improving patient safety. Human observers are the current ‘gold standard’ for capturing task data, but they are expensive and have cognitive limitations. Our current research – Towards Automated Detection of Anaesthetic Activity (TADAA) - aims to produce an automated task analysis system, employing Radio Frequency Identification (RFID) technology to capture anaesthetists' location, orientation and stance (LOS), and machine learning techniques to translate that data into low-level and high-level activity labels. In this paper we present details of the system design and promising results from LOS sensing testing in laboratory and highfidelity OR simulator settings. [ABSTRACT FROM AUTHOR]
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- 2010
40. The individual adjustment method of sleep spindle analysis: Methodological improvements and roots in the fingerprint paradigm
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Bódizs, Róbert, Körmendi, János, Rigó, Péter, and Lázár, Alpár Sándor
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ELECTROENCEPHALOGRAPHY , *EYE movement disorders , *POLYSOMNOGRAPHY , *PATTERN perception , *DIGITAL signal processing , *SYNCHRONIZATION , *HUMAN fingerprints - Abstract
Abstract: Evidence supports the robustness and stability of individual differences in non-rapid eye movement (NREM) sleep electroencephalogram (EEG) spectra with a special emphasis on the 9–16Hz range corresponding to sleep spindle activity. These differences cast doubt on the universal validity of sleep spindle analysis methods based on strict amplitude and frequency criteria or a set of templates of natural spindles. We aim to improve sleep spindle analysis by the individual adjustments of frequency and amplitude criteria, the use of a minimum set of a priori knowledge, and by clear dissections of slow- and fast sleep spindles as well as to transcend the concept of visual inspection as being the ultimate test of the method''s validity. We defined spindles as those segments of the NREM sleep EEG which contribute to the two peak regions within the 9–16Hz EEG spectra. These segments behaved as slow- and fast sleep spindles in terms of topography and sleep cycle effects, while age correlated negatively with the occurrence of fast type events only. Automatic detections covered 92.9% of visual spindle detections (A&VD). More than half of the automatic detections (58.41%) were exclusively automatic detections (EADs). The spectra of EAD correlated significantly and positively with the spectra of A&VD as well as with the average (AVG) spectra. However, both EAD and A&VD had higher individual-specific spindle spectra than AVG had. Results suggest that the individual adjustment method (IAM) detects EEG segments possessing the individual-specific spindle spectra with higher sensitivity than visual scoring does. [Copyright &y& Elsevier]
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- 2009
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41. Automatisierung des Postlaryngektomie-Telefontests.
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Haderlein, T., Riedhammer, K., Maier, A., Nöth, E., Eysholdt, U., and Rosanowski, F.
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- 2009
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42. Reducing the semantic gap in content-based image retrieval in mammography with relevance feedback and inclusion of expert knowledge.
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de Azevedo-Marques, Paulo, Rosa, Natália, Traina, Agma, Traina, Caetano, Kinoshita, Sérgio, and Rangayyan, Rangaraj
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We investigate the use of relevance feedback (RFb) and the inclusion of expert knowledge to reduce the semantic gap in content-based image retrieval (CBIR) of mammograms. Tests were conducted with radiologists, in which their judgment of the relevance of the retrieved images was used with techniques of query-point movement to incorporate RFb. The measures of similarity of images used for CBIR were based upon textural characteristics and the distribution of density of fibroglandular tissue in the breast. The features used include statistics of the gray-level histogram, texture features based upon the gray-level co-occurrence matrix, moment-based features, measures computed in the Radon domain, and granulometric measures. Queries for CBIR with RFb were executed by three radiologists. The performance of CBIR was measured in terms of precision of retrieval and a measure of relevance-weighted precision (RWP) of retrieval. The results indicate improvement due to RFb of up to 62% in precision and 39% in RWP. The gain in performance of CBIR with RFb depended upon the BI-RADS breast density index of the query mammographic image, with greater improvement in cases of mammograms with higher density. [ABSTRACT FROM AUTHOR]
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- 2008
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43. Impact of geometry and viewing angle on classification accuracy of 2D based analysis of dysmorphic faces
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Vollmar, Tobias, Maus, Baerbel, Wurtz, Rolf P., Gillessen-Kaesbach, Gabriele, Horsthemke, Bernhard, Wieczorek, Dagmar, and Boehringer, Stefan
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SYNDROMES , *PATHOLOGY , *IMAGING systems , *DISEASES - Abstract
Abstract: Digital image analysis of faces has been demonstrated to be effective in a small number of syndromes. In this paper we investigate several aspects that help bringing these methods closer to clinical application. First, we investigate the impact of increasing the number of syndromes from 10 to 14 as compared to an earlier study. Second, we include a side-view pose into the analysis and third, we scrutinize the effect of geometry information. Picture analysis uses a Gabor wavelet transform, standardization of landmark coordinates and subsequent statistical analysis. We can demonstrate that classification accuracy drops from 76% for 10 syndromes to 70% for 14 syndromes for frontal images. Including side-views achieves an accuracy of 76% again. Geometry performs excellently with 85% for combined poses. Combination of wavelets and geometry for both poses increases accuracy to 93%. In conclusion, a larger number of syndromes can be handled effectively by means of image analysis. [Copyright &y& Elsevier]
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- 2008
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44. Iterative h-minima-based marker-controlled watershed for cell nucleus segmentation
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Tulin Ersahin, Ece Akhan, Rengul Cetin-Atalay, Cigdem Gunduz-Demir, Can Fahrettin Koyuncu, Koyuncu, Can Fahrettin, Akhan, Ece, and Gunduz Demir, Çiğdem
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Automated ,Histology ,Iterative method ,Computer science ,0206 medical engineering ,02 engineering and technology ,Procedures ,Bioinformatics ,Cell Line ,Pattern Recognition, Automated ,Pathology and Forensic Medicine ,Image (mathematics) ,Set (abstract data type) ,Image processing ,Pattern recognition ,Image Processing, Computer-Assisted ,Nucleus segmentation ,0202 electrical engineering, electronic engineering, information engineering ,Humans ,Computer-assisted ,Segmentation ,H-minima transform ,Cell Nucleus ,Pixel ,business.industry ,Cell Biology ,Fluorescence microscopy imaging ,Image Enhancement ,Watershed ,Automated pattern recognition ,020601 biomedical engineering ,Algorithm ,Maxima and minima ,Biological marker ,Image enhancement ,020201 artificial intelligence & image processing ,Noise (video) ,Artificial intelligence ,Cell nucleus ,Cell line ,business ,Distance transform ,Algorithms ,Biomarkers ,Human - Abstract
Automated microscopy imaging systems facilitate high-throughput screening in molecular cellular biology research. The first step of these systems is cell nucleus segmentation, which has a great impact on the success of the overall system. The marker-controlled watershed is a technique commonly used by the previous studies for nucleus segmentation. These studies define their markers finding regional minima on the intensity/gradient and/or distance transform maps. They typically use the h-minima transform beforehand to suppress noise on these maps. The selection of the h value is critical; unnecessarily small values do not sufficiently suppress the noise, resulting in false and oversegmented markers, and unnecessarily large ones suppress too many pixels, causing missing and undersegmented markers. Because cell nuclei show different characteristics within an image, the same h value may not work to define correct markers for all the nuclei. To address this issue, in this work, we propose a new watershed algorithm that iteratively identifies its markers, considering a set of different h values. In each iteration, the proposed algorithm defines a set of candidates using a particular h value and selects the markers from those candidates provided that they fulfill the size requirement. Working with widefield fluorescence microscopy images, our experiments reveal that the use of multiple h values in our iterative algorithm leads to better segmentation results, compared to its counterparts. © 2016 International Society for Advancement of Cytometry.
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- 2016
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45. Differential convolutional neural network
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Mehmet Sarigul, Buse Melis Ozyildirim, Mutlu Avci, Mühendislik ve Doğa Bilimleri Fakültesi -- Bilgisayar Mühendisliği Bölümü, Sarıgül, Mehmet, and Çukurova Üniversitesi
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0209 industrial biotechnology ,Computer science ,Performance ,Mathematical parameters ,02 engineering and technology ,Procedures ,Convolutional neural network ,Pattern Recognition, Automated ,Convolution techniques ,020901 industrial engineering & automation ,Statistical tests ,Convolutional model ,0202 electrical engineering, electronic engineering, information engineering ,Its efficiencies ,Differential (infinitesimal) ,Priority journal ,Artificial neural network ,Backpropagation algorithms ,Measurement accuracy ,Chemical activation ,Classification ,Back propagation ,Automated pattern recognition ,Algorithm ,Analytical error ,Feature (computer vision) ,Pattern recognition (psychology) ,020201 artificial intelligence & image processing ,Convolutional neural networks ,Neural networks ,Human ,Classification performance ,Image classification ,Cognitive Neuroscience ,Neighborhood activation error ,Data analysis ,Set (abstract data type) ,Deep Learning ,Artificial Intelligence ,Pattern recognition ,Machine learning ,Humans ,Error back propagation algorithm ,Adaptation ,Improved back propagation algorithm ,Learning systems ,business.industry ,Intermethod comparison ,Deep learning ,Neurosciences ,Neural Networks (Computer) ,Convolution ,Computer Science ,Experiment sets ,Neural Networks, Computer ,Artificial intelligence ,Trends ,business ,Controlled study - Abstract
WOS: 000471669900024, 31125914, Convolutional neural networks with strong representation ability of deep structures have ever increasing popularity in many research areas. The main difference of Convolutional Neural Networks with respect to existing similar artificial neural networks is the inclusion of the convolutional part. This inclusion directly increases the performance of artificial neural networks. This fact has led to the development of many different convolutional models and techniques. In this work, a novel convolution technique named as Differential Convolution and updated error back-propagation algorithm is proposed. The proposed technique aims to transfer feature maps containing directional activation differences to the next layer. This implementation takes the idea of how convolved features change on the feature map into consideration. In a sense, this process adapts the mathematical differentiation operation into the convolutional process. Proposed improved back propagation algorithm also considers neighborhood activation errors. This property increases the classification performance without changing the number of filters. Four different experiment sets were performed to observe the performance and the adaptability of the differential convolution technique. In the first experiment set utilization of the differential convolution on a traditional convolutional neural network structure made a performance boost up to 55.29% for the test accuracy. In the second experiment set differential convolution adaptation raised the top1 and top5 test accuracies of AlexNet by 5.3% and 4.75% on ImageNet dataset. In the third experiment set differential convolution utilized model outperformed all compared convolutional structures. In the fourth experiment set, the Differential VGGNet model obtained by adapting proposed differential convolution technique performed 93.58% and 75.06% accuracy values for CIFAR10 and CI-FAR100 datasets, respectively. The accuracy values of the Differential NIN model containing differential convolution operation were 92.44% and 72.65% for the same datasets. In these experiment sets, it was observed that the differential convolution technique outperformed both traditional convolution and other compared convolution techniques. In addition, easy adaptation of the proposed technique to different convolutional structures and its efficiency demonstrate that popular deep learning models may be improved with differential convolution. (C) 2019 Elsevier Ltd. All rights reserved.
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- 2019
46. Temporal Pattern Detection to Predict Adverse Events in Critical Care: Case Study With Acute Kidney Injury
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Samir E. AbdelRahman, Del Fiol G, Mohammad Amin Morid, Sheng Orl, Julio C. Facelli, and Bruce E. Bray
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Multivariate statistics ,Computer science ,Feature extraction ,Vital signs ,Health Informatics ,02 engineering and technology ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Health Information Management ,law ,020204 information systems ,Intensive care ,0202 electrical engineering, electronic engineering, information engineering ,supervised machine learning ,030212 general & internal medicine ,Original Paper ,business.industry ,Pattern recognition ,Intensive care unit ,Random forest ,Temporal database ,automated pattern recognition ,acute kidney injury ,adverse effects ,Artificial intelligence ,business ,Classifier (UML) - Abstract
Background More than 20% of patients admitted to the intensive care unit (ICU) develop an adverse event (AE). No previous study has leveraged patients’ data to extract the temporal features using their structural temporal patterns, that is, trends. Objective This study aimed to improve AE prediction methods by using structural temporal pattern detection that captures global and local temporal trends and to demonstrate these improvements in the detection of acute kidney injury (AKI). Methods Using the Medical Information Mart for Intensive Care dataset, containing 22,542 patients, we extracted both global and local trends using structural pattern detection methods to predict AKI (ie, binary prediction). Classifiers were built on 17 input features consisting of vital signs and laboratory test results using state-of-the-art models; the optimal classifier was selected for comparisons with previous approaches. The classifier with structural pattern detection features was compared with two baseline classifiers that used different temporal feature extraction approaches commonly used in the literature: (1) symbolic temporal pattern detection, which is the most common approach for multivariate time series classification; and (2) the last recorded value before the prediction point, which is the most common approach to extract temporal data in the AKI prediction literature. Moreover, we assessed the individual contribution of global and local trends. Classifier performance was measured in terms of accuracy (primary outcome), area under the curve, and F-measure. For all experiments, we employed 20-fold cross-validation. Results Random forest was the best classifier using structural temporal pattern detection. The accuracy of the classifier with local and global trend features was significantly higher than that while using symbolic temporal pattern detection and the last recorded value (81.3% vs 70.6% vs 58.1%; P Conclusions Classifiers using features obtained from structural temporal pattern detection significantly improved the prediction of AKI onset in ICU patients over two baselines based on common previous approaches. The proposed method is a generalizable approach to predict AEs in critical care that may be used to help clinicians intervene in a timely manner to prevent or mitigate AEs.
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- 2020
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47. A Convolutional Neural Network-Based Model for Multi-Source and Single-Source Partial Discharge Pattern Classification Using Only Single-Source Training Set.
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Mantach, Sara, Ashraf, Ahmed, Janani, Hamed, Kordi, Behzad, and El-Hag, Ayman
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PARTIAL discharges ,DEEP learning ,SIGNAL convolution ,CONVOLUTIONAL neural networks ,MACHINE learning ,FEATURE extraction ,BRAIN stimulation - Abstract
Classification of the sources of partial discharges has been a standard procedure to assess the status of insulation in high voltage systems. One of the challenges while classifying these sources is the decision on the distinct properties of each one, often requiring the skills of trained human experts. Machine learning offers a solution to this problem by allowing to train models based on extracted features. The performance of such algorithms heavily depends on the choice of features. This can be overcome by using deep learning where feature extraction is done automatically by the algorithm, and the input to such an algorithm is the raw input data. In this work, an enhanced convolutional neural network is proposed that is capable of classifying single sources as well as multiple sources of partial discharges without introducing multiple sources in the training phase. The training is done by using only single-source phase-resolved partial discharge (PRPD) patterns, while testing is performed on both single and multi-source PRPD patterns. The proposed model is compared with single-branch CNN architecture. The average percentage improvements of the proposed architecture for single-source PDs and multi-source PDs are 99.6% and 96.7% respectively, compared to 96.2% and 77.3% for that of the traditional single-branch CNN architecture. [ABSTRACT FROM AUTHOR]
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- 2021
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48. Detecting Smoking Events Using Accelerometer Data Collected Via Smartwatch Technology: Validation Study
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Dien Anshari, Casey A. Cole, James F. Thrasher, Homayoun Valafar, and Victoria Lambert
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medicine.medical_specialty ,Activities of daily living ,medicine.medical_treatment ,digital signal processing ,030508 substance abuse ,Health Informatics ,Context (language use) ,Information technology ,02 engineering and technology ,Session (web analytics) ,Smartwatch ,03 medical and health sciences ,Physical medicine and rehabilitation ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,mHealth ,Original Paper ,Data collection ,business.industry ,ecological momentary assessment ,020206 networking & telecommunications ,data mining ,T58.5-58.64 ,neural networks ,3. Good health ,smoking cessation ,automated pattern recognition ,machine learning ,Smoking cessation ,False positive rate ,Public aspects of medicine ,RA1-1270 ,0305 other medical science ,business - Abstract
Background: Smoking is the leading cause of preventable death in the world today. Ecological research on smoking in context currently relies on self-reported smoking behavior. Emerging smartwatch technology may more objectively measure smoking behavior by automatically detecting smoking sessions using robust machine learning models. Objective: This study aimed to examine the feasibility of detecting smoking behavior using smartwatches. The second aim of this study was to compare the success of observing smoking behavior with smartwatches to that of conventional self-reporting. Methods: A convenience sample of smokers was recruited for this study. Participants (N=10) recorded 12 hours of accelerometer data using a mobile phone and smartwatch. During these 12 hours, they engaged in various daily activities, including smoking, for which they logged the beginning and end of each smoking session. Raw data were classified as either smoking or nonsmoking using a machine learning model for pattern recognition. The accuracy of the model was evaluated by comparing the output with a detailed description of a modeled smoking session. Results: In total, 120 hours of data were collected from participants and analyzed. The accuracy of self-reported smoking was approximately 78% (96/123). Our model was successful in detecting 100 of 123 (81%) smoking sessions recorded by participants. After eliminating sessions from the participants that did not adhere to study protocols, the true positive detection rate of the smartwatch based-detection increased to more than 90%. During the 120 hours of combined observation time, only 22 false positive smoking sessions were detected resulting in a 2.8% false positive rate. Conclusions: Smartwatch technology can provide an accurate, nonintrusive means of monitoring smoking behavior in natural contexts. The use of machine learning algorithms for passively detecting smoking sessions may enrich ecological momentary assessment protocols and cessation intervention studies that often rely on self-reported behaviors and may not allow for targeted data collection and communications around smoking events. [JMIR Mhealth Uhealth 2017;5(12):e189]
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- 2017
49. Nocturnal oximetry-based evaluation of habitually snoring children
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Gonzalo C. Gutiérrez-Tobal, Christian F. Poets, Yamei Zhang, John Schuen, Roberto Hornero, Athanasios G. Kaditis, Annelies Van Eyck, Oscar Sans Capdevila, Daniel Álvarez, Rosario Ferreira, Ehab Dayyat, Félix del Campo, Zhifei Xu, Andrea Crespo Sedano, Katalina Bertran, Joaquín Terán-Santos, Leila Kheirandish-Gozal, Narong Simakajornboon, Yu-Shu Huang, Mona F. Philby, Magnus von Lukowicz, Pablo E. Brockmann, David Gozal, María Luz Alonso-Álvarez, Maximiliano Tamae Kakazu, Fernando Vaquerizo-Villar, Albert M. Li, Zarmina Ehsan, Stijn Verhulst, and Repositório da Universidade de Lisboa
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Pulmonary and Respiratory Medicine ,Male ,medicine.medical_specialty ,childhood obstructive sleep apnea–hypopnea syndrome ,Adolescent ,Intraclass correlation ,automated pattern recognition ,blood oxygen saturation ,Polysomnography ,Nocturnal ,Critical Care and Intensive Care Medicine ,Severity of Illness Index ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,Surveys and Questionnaires ,medicine ,Humans ,Blood oxygen saturation ,Oximetry ,Prospective Studies ,nocturnal oximetry ,Child ,neural network ,Sleep Apnea, Obstructive ,medicine.diagnostic_test ,Nocturnal polysomnography ,business.industry ,Snoring ,Editorials ,Reproducibility of Results ,Automated pattern recognition ,Neural network ,nervous system diseases ,respiratory tract diseases ,030228 respiratory system ,Nocturnal oximetry ,Childhood obstructive sleep apnea-hypopnea syndrome ,Child, Preschool ,Physical therapy ,Female ,Human medicine ,business ,030217 neurology & neurosurgery ,Algorithms - Abstract
Copyright © 2017 by the American Thoracic Society, Rationale: The vast majority of children around the world undergoing adenotonsillectomy for obstructive sleep apnea-hypopnea syndrome (OSA) are not objectively diagnosed by nocturnal polysomnography because of access availability and cost issues. Automated analysis of nocturnal oximetry (nSpO2), which is readily and globally available, could potentially provide a reliable and convenient diagnostic approach for pediatric OSA. Methods: Deidentified nSpO2 recordings from a total of 4,191 children originating from 13 pediatric sleep laboratories around the world were prospectively evaluated after developing and validating an automated neural network algorithm using an initial set of single-channel nSpO2 recordings from 589 patients referred for suspected OSA. Measurements and main results: The automatically estimated apnea-hypopnea index (AHI) showed high agreement with AHI from conventional polysomnography (intraclass correlation coefficient, 0.785) when tested in 3,602 additional subjects. Further assessment on the widely used AHI cutoff points of 1, 5, and 10 events/h revealed an incremental diagnostic ability (75.2, 81.7, and 90.2% accuracy; 0.788, 0.854, and 0.913 area under the receiver operating characteristic curve, respectively). Conclusions: Neural network-based automated analyses of nSpO2 recordings provide accurate identification of OSA severity among habitually snoring children with a high pretest probability of OSA. Thus, nocturnal oximetry may enable a simple and effective diagnostic alternative to nocturnal polysomnography, leading to more timely interventions and potentially improved outcomes.
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- 2017
50. Multiscale entropy analysis of unattended oximetric recordings to assist in the screening of paediatric sleep apnoea at home
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Crespo Sedano, Andrea and Crespo Sedano, Andrea
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Producción Científica, Untreated paediatric obstructive sleep apnoea syndrome (OSAS) can severely affect the development and quality of life of children. In-hospital polysomnography (PSG) is the gold standard for a definitive diagnosis though it is relatively unavailable and particularly intrusive. Nocturnal portable oximetry has emerged as a reliable technique for OSAS screening. Nevertheless, additional evidences are demanded. Our study is aimed at assessing the usefulness of multiscale entropy (MSE) to characterise oximetric recordings. We hypothesise that MSE could provide relevant information of blood oxygen saturation (SpO2) dynamics in the detection of childhood OSAS. In order to achieve this goal, a dataset composed of unattended SpO2 recordings from 50 children showing clinical suspicion of OSAS was analysed. SpO2 was parameterised by means of MSE and conventional oximetric indices. An optimum feature subset composed of five MSE-derived features and four conventional clinical indices were obtained using automated bidirectional stepwise feature selection. Logistic regression (LR) was used for classification. Our optimum LR model reached 83.5% accuracy (84.5% sensitivity and 83.0% specificity). Our results suggest that MSE provides relevant information from oximetry that is complementary to conventional approaches. Therefore, MSE may be useful to improve the diagnostic ability of unattended oximetry as a simplified screening test for childhood OSAS., Sociedad Española de Neumología y Cirugía Torácica (SEPAR) project 153/2015, Junta de Castilla y León (Consejería de Educación) y el Fondo Europeo de Desarrollo Regional (FEDER), projects (RTC-2015-3446-1) y (TEC2014-53196-R), Ministerio de Economía y Competitividad (MINECO) y FEDER, y el proyecto POCTEP 0378_AD_EEGWA_2_P de la Comisión Europea. L., National Institutes of Health (NIH) grant 1R01HL130984-01, Ministerio de Asuntos Económicos y Transformación Digital, grant IJCI-2014-22664
- Published
- 2017
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