16 research outputs found

    The newest clinical version of glass-polyalkenoate restorative biomaterial infused with 3Y-TZP nanocrystals

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    The aim of our study was to preliminarily investigate, in dental practice, the newest commercial formula of bioactive glass-ionomer cement modified with 3% mass of Yttrium Trioxide Partially Stabilized Tetragonal Polycrystalline Zirconia (3YTZP), which should improve restorative survival rate in caries patients’ oral mouth, enhance translucence and match the color of the tooth. Initial laboratory observation has been performed with the use of microscopic structural analysis. By assumption novel dental restorative materials are expected to be indeed bioactive in the meaning of immanent enamel- and dentine-integration/adhesion without demineralization, saliva buffering, hard tissues remineralization and caries microbiome management ability, over a long period of time

    Detection of atrial fibrillation episodes in long-term heart rhythm signals using a support vector machine

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    Atrial fibrillation (AF) is a serious heart arrhythmia leading to a significant increase of the risk for occurrence of ischemic stroke. Clinically, the AF episode is recognized in an electrocardiogram. However, detection of asymptomatic AF, which requires a long-term monitoring, is more efficient when based on irregularity of beat-to-beat intervals estimated by the heart rate (HR) features. Automated classification of heartbeats into AF and non-AF by means of the Lagrangian Support Vector Machine has been proposed. The classifier input vector consisted of sixteen features, including four coefficients very sensitive to beat-to-beat heart changes, taken from the fetal heart rate analysis in perinatal medicine. Effectiveness of the proposed classifier has been verified on the MIT-BIH Atrial Fibrillation Database. Designing of the LSVM classifier using very large number of feature vectors requires extreme computational efforts. Therefore, an original approach has been proposed to determine a training set of the smallest possible size that still would guarantee a high quality of AF detection. It enables to obtain satisfactory results using only 1.39% of all heartbeats as the training data. Post-processing stage based on aggregation of classified heartbeats into AF episodes has been applied to provide more reliable information on patient risk. Results obtained during the testing phase showed the sensitivity of 98.94%, positive predictive value of 98.39%, and classification accuracy of 98.86%.Web of Science203art. no. 76

    Fetal electrocardiograms, direct and abdominal with reference heartbeat annotations

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    Monitoring fetal heart rate (FHR) variability plays a fundamental role in fetal state assessment. Reliable FHR signal can be obtained from an invasive direct fetal electrocardiogram (FECG), but this is limited to labour. Alternative abdominal (indirect) FECG signals can be recorded during pregnancy and labour. Quality, however, is much lower and the maternal heart and uterine contractions provide sources of interference. Here, we present ten twenty-minute pregnancy signals and 12 five-minute labour signals. Abdominal FECG and reference direct FECG were recorded simultaneously during labour. Reference pregnancy signal data came from an automated detector and were corrected by clinical experts. The resulting dataset exhibits a large variety of interferences and clinically significant FHR patterns. We thus provide the scientific community with access to bioelectrical fetal heart activity signals that may enable the development of new methods for FECG signals analysis, and may ultimately advance the use and accuracy of abdominal electrocardiography methods.Web of Science71art. no. 20

    ТЕЛЕСНЫЕ НАКАЗАНИЯ

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    Great expectations are connected with application of indirect fetal electrocardiography (FECG), especially for home telemonitoring of pregnancy. Evaluation of fetal heart rate (FHR) variability, when determined from FECG, uses the same criteria as for FHR signal acquired classically—through ultrasound Doppler method (US). Therefore, the equivalence of those two methods has to be confirmed, both in terms of recognizing classical FHR patterns: baseline, accelerations/decelerations (A/D), long-term variability (LTV), as well as evaluating the FHR variability with beat-to-beat accuracy—short-term variability (STV). The research material consisted of recordings collected from 60 patients in physiological and complicated pregnancy. The FHR signals of at least 30 min duration were acquired dually, using two systems for fetal and maternal monitoring, based on US and FECG methods. Recordings were retrospectively divided into normal (41) and abnormal (19) fetal outcome. The complex process of data synchronization and validation was performed. Obtained low level of the signal loss (4.5% for US and 1.8% for FECG method) enabled to perform both direct comparison of FHR signals, as well as indirect one—by using clinically relevant parameters. Direct comparison showed that there is no measurement bias between the acquisition methods, whereas the mean absolute difference, important for both visual and computer-aided signal analysis, was equal to 1.2 bpm. Such low differences do not affect the visual assessment of the FHR signal. However, in the indirect comparison the inconsistencies of several percent were noted. This mainly affects the acceleration (7.8%) and particularly deceleration (54%) patterns. In the signals acquired using the electrocardiography the obtained STV and LTV indices have shown significant overestimation by 10 and 50% respectively. It also turned out, that ability of clinical parameters to distinguish between normal and abnormal groups do not depend on the acquisition method. The obtained results prove that the abdominal FECG, considered as an alternative to the ultrasound approach, does not change the interpretation of the FHR signal, which was confirmed during both visual assessment and automated analysis

    New Method for Beat-to-Beat Fetal Heart Rate Measurement Using Doppler Ultrasound Signal

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    The most commonly used method of fetal monitoring is based on heart activity analysis. Computer-aided fetal monitoring system enables extraction of clinically important information hidden for visual interpretation—the instantaneous fetal heart rate (FHR) variability. Today’s fetal monitors are based on monitoring of mechanical activity of the fetal heart by means of Doppler ultrasound technique. The FHR is determined using autocorrelation methods, and thus it has a form of evenly spaced—every 250 ms—instantaneous measurements, where some of which are incorrect or duplicate. The parameters describing a beat-to-beat FHR variability calculated from such a signal show significant errors. The aim of our research was to develop new analysis methods that will both improve an accuracy of the FHR determination and provide FHR representation as time series of events. The study was carried out on simultaneously recorded (during labor) Doppler ultrasound signal and the reference direct fetal electrocardiogram Two subranges of Doppler bandwidths were separated to describe heart wall movements and valve motions. After reduction of signal complexity by determining the Doppler ultrasound envelope, the signal was analyzed to determine the FHR. The autocorrelation method supported by a trapezoidal prediction function was used. In the final stage, two different methods were developed to provide signal representation as time series of events: the first using correction of duplicate measurements and the second based on segmentation of instantaneous periodicity measurements. Thus, it ensured the mean heart interval measurement error of only 1.35 ms. In a case of beat-to-beat variability assessment the errors ranged from −1.9% to −10.1%. Comparing the obtained values to other published results clearly confirms that the new methods provides a higher accuracy of an interval measurement and a better reliability of the FHR variability estimation

    Virtual Reality Support for Dental Treatment Premedication

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    The objective is to short review the current state of the art of virtual reality medical application in term of minimal invasive dentistry. An outline of the most important aspects of virtual reality has been created, and a subsequent literature search for articles related was conducted. The current state of the art of virtual reality includes a variety of applications, among others premedication, analgesics, anaesthetics plays an important role in informatics medicine. There is a growing consensus regarding the need to develop knowledge and possible introduce virtual reality as a non-pharmacological support for dental treatment

    Nature-inspired Material – A Step Ahead in Dental Materials

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    Glass-ionomer is first choice widely used biomaterial in caries disease. The evolution of dental material science includes insertion of new components into conventional material. A literature-based review outline of biomaterials for dental restorations development was presented in nature-inspired context. This article is a tribute to the entire research community, for all listed and unlisted, involved throughout the ages in the science of dental materials with the key inventions and milestones for the welfare on Earth. Results. Since the Neolithic, the human mind has been seeking for a matter to replace missing tooth tissue imitating/mimicking natural organ in appearance and function, what we call biomimetic/biomimicry approach. However, this restoring philosophy does not refer to the natural composition of hard tooth tissues. Possibly, there is another one concept of drawing inspiration from nature for the design of future dental materials. Nature-inspired synthesis goes beyond aesthetic/and anatomical similarities, and delves into the mechanistic, physico-chemical features or structure-phase of natural systems. In this context, pure glass-ionomer might be taken into consideration as a starting material. However, the search for synthetic nature-inspired mesomaterial with a structural-phase composition analogous to enamel/dentine/cementum, transforming into the original host hard tissues, should focus on elongated hydroxyapatite dipole control for creating and organizing into enamel prisms, and the interwoven alignment of perpendicular clusters/bunches in a picket-fence resembling three-dimensional order. The results of previous studies confirming the possibility of the formation of apatite-enamel-like tissue in glass-ionomer are promising. The concept of inclusion of calcium phosphate nanocrystals/substitution of glass filler seems to be forward-looking. The future role of polyelectrolyte organic matrix based on synthetic tooth polypeptides crosslinked with modified analogues of natural adhesives is still undiscovered

    Nature-inspired Material – A Step Ahead in Dental Materials

    No full text
    Glass-ionomer is first choice widely used biomaterial in caries disease. The evolution of dental material science includes insertion of new components into conventional material. A literature-based review outline of biomaterials for dental restorations development was presented in nature-inspired context. This article is a tribute to the entire research community, for all listed and unlisted, involved throughout the ages in the science of dental materials with the key inventions and milestones for the welfare on Earth. Results. Since the Neolithic, the human mind has been seeking for a matter to replace missing tooth tissue imitating/mimicking natural organ in appearance and function, what we call biomimetic/biomimicry approach. However, this restoring philosophy does not refer to the natural composition of hard tooth tissues. Possibly, there is another one concept of drawing inspiration from nature for the design of future dental materials. Nature-inspired synthesis goes beyond aesthetic/and anatomical similarities, and delves into the mechanistic, physico-chemical features or structure-phase of natural systems. In this context, pure glass-ionomer might be taken into consideration as a starting material. However, the search for synthetic nature-inspired mesomaterial with a structural-phase composition analogous to enamel/dentine/cementum, transforming into the original host hard tissues, should focus on elongated hydroxyapatite dipole control for creating and organizing into enamel prisms, and the interwoven alignment of perpendicular clusters/bunches in a picket-fence resembling three-dimensional order. The results of previous studies confirming the possibility of the formation of apatite-enamel-like tissue in glass-ionomer are promising. The concept of inclusion of calcium phosphate nanocrystals/substitution of glass filler seems to be forward-looking. The future role of polyelectrolyte organic matrix based on synthetic tooth polypeptides crosslinked with modified analogues of natural adhesives is still undiscovered

    Nature-inspired Material – A Step Ahead in Dental Materials

    No full text
    Glass-ionomer is first choice widely used biomaterial in caries disease. The evolution of dental material science includes insertion of new components into conventional material. A literature-based review outline of biomaterials for dental restorations development was presented in nature-inspired context. This article is a tribute to the entire research community, for all listed and unlisted, involved throughout the ages in the science of dental materials with the key inventions and milestones for the welfare on Earth. Results. Since the Neolithic, the human mind has been seeking for a matter to replace missing tooth tissue imitating/mimicking natural organ in appearance and function, what we call biomimetic/biomimicry approach. However, this restoring philosophy does not refer to the natural composition of hard tooth tissues. Possibly, there is another one concept of drawing inspiration from nature for the design of future dental materials. Nature-inspired synthesis goes beyond aesthetic/and anatomical similarities, and delves into the mechanistic, physico-chemical features or structure-phase of natural systems. In this context, pure glass-ionomer might be taken into consideration as a starting material. However, the search for synthetic nature-inspired mesomaterial with a structural-phase composition analogous to enamel/dentine/cementum, transforming into the original host hard tissues, should focus on elongated hydroxyapatite dipole control for creating and organizing into enamel prisms, and the interwoven alignment of perpendicular clusters/bunches in a picket-fence resembling three-dimensional order. The results of previous studies confirming the possibility of the formation of apatite-enamel-like tissue in glass-ionomer are promising. The concept of inclusion of calcium phosphate nanocrystals/substitution of glass filler seems to be forward-looking. The future role of polyelectrolyte organic matrix based on synthetic tooth polypeptides crosslinked with modified analogues of natural adhesives is still undiscovered
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