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1.
Small ; 20(40): e2402961, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38895971

RESUMO

Reservoir computing (RC) system is based upon the reservoir layer, which non-linearly transforms input signals into high-dimensional states, facilitating simple training in the readout layer-a linear neural network. These layers require different types of devices-the former demonstrated as diffusive memristors and the latter prepared as drift memristors. The integration of these components can increase the structural complexity of RC system. Here, a reconfigurable resistive switching memory (RSM) capable of implementing both diffusive and drift dynamics is demonstrated. This reconfigurability is achieved by preparing a medium with a 3D ion transport channel (ITC), enabling precise control of the metal filament that determines memristor operation. The 3D ITC-RSM operates in a volatile threshold switching (TS) mode under a weak electric field and exhibits short-term dynamics that are confirmed to be applicable as reservoir elements in RC systems. Meanwhile, the 3D ITC-RSM operates in a non-volatile bipolar switching (BS) mode under a strong electric field, and the conductance modulation metrics forming the basis of synaptic weight update are validated, which can be utilized as readout elements in the readout layer. Finally, an RC system is designed for the application of reconfigurable 3D ITC-RSM, and performs real-time recognition on Morse code datasets.

2.
Small ; 20(25): e2307276, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38196162

RESUMO

Graphdiyne (GDY) has garnered significant attention as a cutting-edge 2D material owing to its distinctive electronic, optoelectronic, and mechanical properties, including high mobility, direct bandgap, and remarkable flexibility. One of the key challenges hindering the implementation of this material in flexible applications is its large area and uniform synthesis. The facile growth of centimeter-scale bilayer hydrogen substituted graphdiyne (Bi-HsGDY) on germanium (Ge) substrate is achieved using a low-temperature chemical vapor deposition (CVD) method. This material's field effect transistors (FET) showcase a high carrier mobility of 52.6 cm2 V-1 s-1 and an exceptionally low contact resistance of 10 Ω µm. By transferring the as-grown Bi-HsGDY onto a flexible substrate, a long-distance piezoresistive strain sensor is demonstrated, which exhibits a remarkable gauge factor of 43.34 with a fast response time of ≈275 ms. As a proof of concept, communication by means of Morse code is implemented using a Bi-HsGDY strain sensor. It is believed that these results are anticipated to open new horizons in realizing Bi-HsGDY for innovative flexible device applications.

3.
Bull Math Biol ; 86(11): 129, 2024 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-39306809

RESUMO

Formation of organs and specialized tissues in embryonic development requires migration of cells to specific targets. In some instances, such cells migrate as a robust cluster. We here explore a recent local approximation of non-local continuum models by Falcó et al. (SIAM J Appl Math 84:17-42, 2023). We apply their theoretical results by specifying biologically-based cell-cell interactions, showing how such cell communication results in an effective attraction-repulsion Morse potential. We then explore the clustering instability, the existence and size of the cluster, and its stability. For attractant-repellent chemotaxis, we derive an explicit condition on cell and chemical properties that guarantee the existence of robust clusters. We also extend their work by investigating the accuracy of the local approximation relative to the full non-local model.


Assuntos
Comunicação Celular , Movimento Celular , Quimiotaxia , Conceitos Matemáticos , Modelos Biológicos , Comunicação Celular/fisiologia , Movimento Celular/fisiologia , Animais , Quimiotaxia/fisiologia , Simulação por Computador , Desenvolvimento Embrionário/fisiologia , Humanos , Análise por Conglomerados
4.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34518231

RESUMO

Embryonic development leads to the reproducible and ordered appearance of complexity from egg to adult. The successive differentiation of different cell types that elaborate this complexity results from the activity of gene networks and was likened by Waddington to a flow through a landscape in which valleys represent alternative fates. Geometric methods allow the formal representation of such landscapes and codify the types of behaviors that result from systems of differential equations. Results from Smale and coworkers imply that systems encompassing gene network models can be represented as potential gradients with a Riemann metric, justifying the Waddington metaphor. Here, we extend this representation to include parameter dependence and enumerate all three-way cellular decisions realizable by tuning at most two parameters, which can be generalized to include spatial coordinates in a tissue. All diagrams of cell states vs. model parameters are thereby enumerated. We unify a number of standard models for spatial pattern formation by expressing them in potential form (i.e., as topographic elevation). Turing systems appear nonpotential, yet in suitable variables the dynamics are low dimensional and potential. A time-independent embedding recovers the original variables. Lateral inhibition is described by a saddle point with many unstable directions. A model for the patterning of the Drosophila eye appears as relaxation in a bistable potential. Geometric reasoning provides intuitive dynamic models for development that are well adapted to fit time-lapse data.


Assuntos
Redes Reguladoras de Genes/genética , Genes Reguladores/genética , Animais , Diferenciação Celular/genética , Drosophila/genética , Modelos Genéticos
5.
Arch Orthop Trauma Surg ; 144(5): 2391-2401, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38563982

RESUMO

INTRODUCTION: The importance of the assembly procedure on the taper connection strength is evident. However, existent surgical technique guides frequently lack comprehensive and precise instructions in this regard. The aim of our experimental study was to evaluate the influence of the surgical technique guide on the femoral head assembly procedure in surgeons with differing levels of experience in total hip arthroplasty. MATERIALS AND METHODS: Twenty-eight participants, divided into four groups based on their lifetime experience in total hip arthroplasty, conducted a femoral head assembly procedure in a simulated intraoperative environment before and after reviewing the surgical technique guide. Demographic information and the number of hammer blows were documented. Hammer velocity and impaction angle were recorded using an optical motion capturing system, while the impaction force was measured using a dynamic force sensor within the impactor. RESULTS: We observed a high variation in the number of hammer blows, maximum force, and impaction angle. Overall, the number of hammer blows decreased significantly from 3 to 2.2 after reviewing the surgical technique guide. The only significant intragroup difference in the number of hammer blows was observed in the group with no prior experience in total hip arthroplasty. No correlation was found between individual factors (age, weight, height) or experience and the measured parameters (velocity, maximum force and angle). CONCLUSIONS: The present study demonstrated a high variation in the parameters of the femoral head assembly procedure. Consideration of the surgical technique guide was found to be a limited factor among participants with varying levels of experience in total hip arthroplasty. These findings underline the importance of sufficient preoperative training, to standardize the assembly procedure, including impaction force, angle, and use of instruments.


Assuntos
Artroplastia de Quadril , Competência Clínica , Cabeça do Fêmur , Humanos , Artroplastia de Quadril/métodos , Cabeça do Fêmur/cirurgia , Masculino , Feminino , Prótese de Quadril , Adulto , Pessoa de Meia-Idade
6.
Geriatr Nurs ; 56: 94-99, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38340434

RESUMO

This is a cross-sectional study to investigate the efficacy of Morse Fall Scale (MFS) in nursing homes for older adults with cognitive impairment. According to Rasch analysis, the person separation index was 0.95 (person reliability 0.48), and the item separation index was 9.23 (item reliability 0.99). Wright map showed all items can be considered appropriately directed to the older adults, but the items mainly located at both ends with the center missing. Each item was accepted with good infit and outfit statistics with positive PTMEA CORR. values from 0.49 to 0.68. Two items could be significant differential item functioning (DIF) between the two groups of different fall experience in the past year (item 1 and item 3). In conclusion, nursing assistant could adopt MFS to evaluate fall risk of older adults with cognitive impairment, but the risk grades are still not precise enough. In the future, MFS should be explored and refined further.


Assuntos
Disfunção Cognitiva , Casas de Saúde , Humanos , Idoso , Estudos Transversais , Reprodutibilidade dos Testes , Inquéritos e Questionários , Psicometria
7.
Medicina (Kaunas) ; 60(3)2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38541184

RESUMO

Background and objectives: wear and corrosion can lead to the gross failure of the Morse taper junction with the consequent fracture of the true neck of the prosthetic stem in hip arthroplasty. Materials and Methods: 58-year-old male patient, with a BMI of 38 kg/m2. Because of avascular necrosis, in 2007, a metal-on-metal total hip arthroplasty was implanted in him, with a TMZF stem and a Co-Cr head. In December 2020, he complained of acute left hip pain associated with the deterioration of his left leg and total functional impairment, preceded by the crunching of the hip. X-rays and CT scan showed a fracture of the prosthetic neck that necessitated prosthetic revision surgery. A Scanning Electron Microscope (SEM) analysis of the retrieved prosthetic components was conducted. Results: Macroscopically, the trunnion showed a typical bird beak appearance, due to a massive material loss of about half of its volume. The gross material loss apparently due to abrasion extended beyond the trunnion to the point of failure on the true neck about half a centimeter distal from the taper. SEM analysis demonstrated fatigue rupture modes, and the crack began close to the neck's surface. On the lateral surface, several scratches were found, suggesting an intense wear that could be due to abrasion. Conclusions: The analysis we conducted on the explanted THA showed a ductile rupture, began close to the upper surface of the prosthetic neck where the presence of many scratches had concentrated stresses and led to a fatigue fracture.


Assuntos
Artroplastia de Quadril , Fraturas Ósseas , Prótese de Quadril , Humanos , Masculino , Pessoa de Meia-Idade , Artroplastia de Quadril/efeitos adversos , Prótese de Quadril/efeitos adversos , Microscopia Eletrônica de Varredura , Falha de Prótese , Desenho de Prótese
8.
Aging Clin Exp Res ; 35(5): 1033-1041, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36859749

RESUMO

BACKGROUND: As a result of falls, older patients experience injury and loss of function, and their length of hospital stay and care costs increase. AIM: This study was conducted to determine fall risks and compare the sensitivity and specificity of three fall risk assessment tools. METHODS: Older patients' fall risk levels were determined according to the Itaki, Hendrich-II, and Morse tools within 2 h following their admission to the wards. A methodological design was used in the study, which included 388 hospitalized elderly patients. The mean age of the patients was 72.29 ± 5.6 years, and 57.7% were female. RESULTS: According to the ROC curve values of Sensitivity and 1-Specificity, the cut-off points for the Hendrich-II, Itaki, and Morse fall tools were accepted as 27.5, 8.5, and 6.5, respectively. According to the analysis results, the ratios of the areas under the ROC curve for the Itaki, Morse, and Hendrich-II fall tools were 0.794, 0.773, and 0.724, respectively, which were found to be statistically significant for all three tools (p ≤ 0.001). CONCLUSIONS: The Itaki Fall Risk Tool was found to be the most sensitive one among the three instruments in assessing the fall risk of older hospitalized patients. The Itaki Fall Risk Tool was followed by the Morse and Hendrich-II tools, respectively, in terms of sensitivity.


Assuntos
Pacientes Internados , Humanos , Feminino , Idoso , Masculino , Turquia , Medição de Risco/métodos , Sensibilidade e Especificidade , Curva ROC , Fatores de Risco
9.
BMC Med Inform Decis Mak ; 23(1): 232, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37858107

RESUMO

BACKGROUND: Cardiac arrhythmia is a cardiovascular disorder characterized by disturbances in the heartbeat caused by electrical conduction anomalies in cardiac muscle. Clinically, ECG machines are utilized to diagnose and monitor cardiac arrhythmia noninvasively. Since ECG signals are dynamic in nature and depict various complex information, visual assessment and analysis are time consuming and very difficult. Therefore, an automated system that can assist physicians in the easy detection of arrhythmia is needed. METHOD: The main objective of this study was to create an automated deep learning model capable of accurately classifying ECG signals into three categories: cardiac arrhythmia (ARR), congestive heart failure (CHF), and normal sinus rhythm (NSR). To achieve this, ECG data from the MIT-BIH and BIDMC databases available on PhysioNet were preprocessed and segmented before being utilized for deep learning model training. Pretrained models, ResNet 50 and AlexNet, were fine-tuned and configured to achieve optimal classification results. The main outcome measures for evaluating the performance of the model were F-measure, recall, precision, sensitivity, specificity, and accuracy, obtained from a multi-class confusion matrix. RESULT: The proposed deep learning model showed overall classification accuracy of 99.2%, average sensitivity of 99.2%, average specificity of 99.6%, average recall, precision and F- measure of 99.2% of test data. CONCLUSION: The proposed work introduced a robust approach for the classification of arrhythmias in comparison with the most recent state of the art and will reduce the diagnosis time and error that occurs in the visual investigation of ECG signals.


Assuntos
Doenças Cardiovasculares , Aprendizado Profundo , Humanos , Processamento de Sinais Assistido por Computador , Arritmias Cardíacas/diagnóstico , Eletrocardiografia/métodos , Algoritmos
10.
J Shoulder Elbow Surg ; 32(1): 201-212, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36202200

RESUMO

BACKGROUND: Morse taper junction tribocorrosion is recognized as an important failure mode in total hip arthroplasty. Although taper junctions are used in almost all shoulder arthroplasty systems currently available in the United States, with large variation in design, limited literature has described comparable analyses of taper damage in these implants. In this study, taper junction damage in retrieved reverse total shoulder arthroplasty (RTSA) implants was assessed and analyzed. METHODS: Fifty-seven retrieved RTSAs with paired baseplate and glenosphere components with Morse taper junctions were identified via database query; 19 of these also included paired humeral stems and trays or spacers with taper junctions. Components were graded for standard damage modes and for fretting and corrosion with a modified Goldberg-Cusick classification system. Medical records and preoperative radiographs were reviewed. Comparative analyses were performed assessing the impact of various implant, radiographic, and patient factors on taper damage. RESULTS: Standard damage modes were commonly found at the evaluated trunnion junctions, with scratching and edge deformation damage on 76% and 46% of all components, respectively. Fretting and corrosion damage was also common, observed on 86% and 72% of baseplates, respectively, and 23% and 40% of glenospheres, respectively. Baseplates showed greater moderate to severe (grade ≥ 3) fretting (43%) and corrosion (27%) damage than matched glenospheres (fretting, 9%; corrosion, 13%). Humeral stems showed moderate to severe fretting and corrosion on 28% and 30% of implants, respectively; matched humeral trays or spacers showed both less fretting (14%) and less corrosion (17%). On subgroup analysis, large-tapered implants had significantly lower summed fretting and corrosion grades than small-tapered implants (P < .001 for both) on glenospheres; paired baseplate corrosion grades were also significantly lower (P = .031) on large-tapered implants. Factorial analysis showed that bolt reinforcement of the taper junction was also associated with less fretting and corrosion damage on both baseplates and glenospheres. Summed fretting and corrosion grades on glenospheres with trunnions (male) were significantly greater than on glenospheres with bores (female) (P < .001 for both). CONCLUSIONS: Damage to the taper junction is commonly found in retrieved RTSAs and can occur after only months of being implanted. In this study, tribocorrosion predominantly occurred on the taper surface of the baseplate (vs. glenosphere) and on the humeral stem (vs. tray or spacer), which may relate to the flexural rigidity difference between the titanium and cobalt-chrome components. Bolt reinforcement and the use of large-diameter trunnions led to less tribocorrosion of the taper junction. The findings of this study provide evidence for the improved design of RTSA prostheses to decrease tribocorrosion.


Assuntos
Artroplastia de Quadril , Artroplastia do Ombro , Prótese de Quadril , Masculino , Feminino , Humanos , Falha de Prótese , Desenho de Prótese , Artroplastia de Quadril/efeitos adversos , Corrosão
11.
Sensors (Basel) ; 23(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36850580

RESUMO

This article analyses the possibility of using the Analytic Wavelet Transform (AWT) and the Convolutional Neural Network (CNN) for the purpose of recognizing the intrapulse modulation of radar signals. Firstly, the possibilities of using AWT by the algorithms of automatic signal recognition are discussed. Then, the research focuses on the influence of the parameters of the generalized Morse wavelet on the classification accuracy. The paper's novelty is also related to the use of the generalized Morse wavelet (GMW) as a superfamily of analytical wavelets with a Convolutional Neural Network (CNN) as classifier applied for intrapulse recognition purposes. GWT is used to obtain time-frequency images (TFI), and SqueezeNet was chosen as the CNN classifier. The article takes into account selected types of intrapulse modulation, namely linear frequency modulation (LFM) and the following types of phase-coded waveform (PCW): Frank, Barker, P1, P2, and Px. The authors also consider the possibility of using other time-frequency transformations such as Short-Time Fourier Transform(STFT) or Wigner-Ville Distribution (WVD). Finally, authors present the results of the simulation tests carried out in the Matlab environment, taking into account the signal-to-noise ratio (SNR) in the range from -6 to 0 dB.

12.
J Oral Implantol ; 49(3): 323-329, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36796063

RESUMO

Among the complications that can occur at dental implants, the fracture of any implant component is a relatively infrequent but clinically relevant problem. Because of their mechanical characteristics, small diameter implants are at higher risk of such complication. The aim of this laboratory and finite element method (FEM) study was to compare the mechanical behavior of a 2.9- and 3.3-mm-diameter implant with a conical connection under standard static and dynamic conditions, following the International Organization for Standardization (ISO) 14801:2017. Finite element analysis was performed to compare the stress distribution on the tested implant systems under a 300-N, 30° inclined force. Static tests were performed with a load cell of 2 kN; the force was applied on the experimental samples at 30° with respect to the implant-abutment axis, with an arm of 5.5 mm. Fatigue tests were performed with decreasing loads, at 2-Hz frequency, until 3 specimens survived without any damage after 2 million cycles. The emergence profile of the abutment resulted the most stressed area in finite element analysis, with a maximum stress of 5829 and 5480 MPa for 2.9- and 3.3-mm-diameter implant complex, respectively. The mean maximum load resulted in 360 N for 2.9-mm-diameter and 370 N for 3.3-mm-diameter implants. The fatigue limit was recorded to be 220 and 240 N, respectively. Despite the more favorable results of 3.3-mm-diameter implants, the difference between the tested implants could be considered clinically negligible. This is probably due to the conical design of the implant-abutment connection, which has been reported to present low stress values in the implant neck region, thus increasing the fracture resistance.


Assuntos
Implantes Dentários , Projeto do Implante Dentário-Pivô , Estresse Mecânico , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Dente Suporte , Teste de Materiais
13.
BMC Oral Health ; 23(1): 775, 2023 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-37865734

RESUMO

AIM: The implant-abutment connection is a crucial factor in determining the long-term stability of dental implants. The use of a prosthetic index structure in the Morse taper implant-abutment connection has been proposed as a potential solution to improve the accuracy of this connection. This study aimed to provide a scoping review of the mechanical and clinical effects of the prosthetic index structure in the Morse taper implant-abutment connection. METHODS: A systematic scoping review of articles related to "dental implants," "Morse taper," and "index" was conducted using PubMed/MEDLINE, Web of Science, Cochrane, and Scopus databases, as well as a comprehensive literature search by two independent reviewers. Relevant articles were selected for analysis and discussion, with a specific focus on investigating the impact of prosthetic index structure on the mechanical and clinical aspects of Morse taper implant-abutment connections. RESULTS: Finally, a total of 16 articles that met the inclusion criteria were included for data extraction and review. In vitro studies have demonstrated that the use of a prosthetic index structure in the Morse taper implant-abutment connection can affect stress distribution, biomechanical stability, and reverse torque values, which may reduce stress within cancellous bone and help limit crestal bone resorption. However, retrospective clinical studies have shown that this structure is also associated with a higher risk of mechanical complications, such as abutment fracture and abutment screw loosening. CONCLUSIONS: Therefore, the clinical trade-off between preventing crestal bone resorption and mechanical complications must be carefully considered when selecting appropriate abutments. The findings suggest that this structure can improve the accuracy and stability of the implant-abutment connection, but its use should be carefully evaluated in clinical practice.


Assuntos
Reabsorção Óssea , Implantes Dentários , Humanos , Estudos Retrospectivos , Torque , Bases de Dados Factuais , Estresse Mecânico , Análise do Estresse Dentário
14.
Medicina (Kaunas) ; 59(7)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37512062

RESUMO

Objective: The primary objective of the present retrospective clinical study was to evaluate and compare the clinical performance presented by castable abutments developed for the MT system versus intermediate machined abutments, specifically regarding prosthetic or implant fractures/loss; the secondary objective was to verify the looseness of the abutments and the behavior of the peri-implant soft tissues. Methods: This clinical retrospective study was conducted on patients rehabilitated between 2019 and 2020. Inclusion criteria were patients in good general health, with an implants-supporting single crown; with solid machined abutments (control group) or castable UCLA abutments; with a connection portion (base) machined in cobalt-chrome (test group) over Morse taper DuoCone implants in the posterior mandible area; and at least two years in function. Clinical assessment was carried out by the same professional, considering the following parameters: (A) prosthetic: (i) loosening of the fixation screw, (ii) fracture of the screw and (iii) the number of times the patient had some type of complication after the installation of the prostheses were evaluated; (B) biological: (i) without keratinized mucosa (KM), (ii) 1 mm or less, (iii) between 1 and 2 mm and (iv) greater than 2 mm of KM width; and the presence or absence of mucositis. Furthermore, radiographic evaluation was performed in order to assess the marginal bone loss. These evaluations permitted to compare the groups analyzed and patients enrolled. Data were statistically analyzed, with the level of significance set at α = 0.05. Results: 79 patients with 120 MT implants were evaluated (80 castable UCLA abutments and 40 machined solid abutments). The follow-up was from 2 to 4 years. There was a 100% implant survival rate. Therefore, the control group showed two fractured abutments (5%) and no abutment loosening (95% for prosthetic survival rate), whereas the test group showed no abutment fracture but nine loosening screws (11.3%) (100% for prosthetic survival rate). Keratinized mucosa was considered thin or absent in 19 implants in the control group (47.5%) and 42 in the test group (52.5%). Mucositis was found in 11 implants in the control group (27.5%) and 27 in the test group (33.8%). A positive correlation was observed between the width of keratinized mucosa and mucositis (r = 0.521, p = 0.002). The mean marginal bone loss was 2.3 mm, ranging from 1.1 to 5.8 mm. No correlation was observed when considering marginal bone loss versus the three parameters (implant diameter, implant length and time of the prosthesis in function). Conclusions: The results suggest that UCLA-type abutments are a viable option for rehabilitating implants with Morse taper connections, suggesting lower fracture risk. Further research is necessary to confirm these findings and thoroughly evaluate the clinical performance and long-term outcomes.


Assuntos
Mucosite , Humanos , Estudos Retrospectivos , Próteses e Implantes
15.
Bull Math Biol ; 84(8): 74, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35713756

RESUMO

Empirical essays of fitness landscapes suggest that they may be rugged, that is having multiple fitness peaks. Such fitness landscapes, those that have multiple peaks, necessarily have special local structures, called reciprocal sign epistasis (Poelwijk et al. in J Theor Biol 272:141-144, 2011). Here, we investigate the quantitative relationship between the number of fitness peaks and the number of reciprocal sign epistatic interactions. Previously, it has been shown (Poelwijk et al. in J Theor Biol 272:141-144, 2011) that pairwise reciprocal sign epistasis is a necessary but not sufficient condition for the existence of multiple peaks. Applying discrete Morse theory, which to our knowledge has never been used in this context, we extend this result by giving the minimal number of reciprocal sign epistatic interactions required to create a given number of peaks.


Assuntos
Epistasia Genética , Modelos Genéticos , Aptidão Genética , Conceitos Matemáticos , Modelos Biológicos , Mutação
16.
BMC Med Inform Decis Mak ; 22(1): 329, 2022 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-36517791

RESUMO

BACKGROUND: Clinically cardiotocography is a technique which is used to monitor and evaluate the level of fetal distress. Even though, CTG is the most widely used device to monitor determine the fetus health, existence of high false positive result from the visual interpretation has a significant contribution to unnecessary surgical delivery or delayed intervention. OBJECTIVE: In the current study an innovative computer aided fetal distress diagnosing model is developed by using time frequency representation of FHR signal using generalized Morse wavelet and the concept of transfer learning of pre-trained ResNet 50 deep neural network model. METHOD: From the CTG data that is obtained from the only open access CTU-UHB data base only FHR signal is extracted and preprocessed to remove noises and spikes. After preprocessing the time frequency information of FHR signal is extracted by using generalized Morse wavelet and fed to a pre-trained ResNet 50 model which is fine tuned and configured according to the dataset. MAIN OUTCOME MEASURES: Sensitivity (Se), specificity (Sp) and accuracy (Acc) of the model adopted from binary confusion matrix is used as outcome measures. RESULT: After successfully training the model, a comprehensive experimentation of testing is conducted for FHR data for which a recording is made during early stage of labor and last stage of labor. Thus, a promising classification result which is accuracy of 98.7%, sensitivity of 97.0% and specificity 100% are achieved for FHR signal of 1st stage of labor. For FHR recorded in last stage of labor, accuracy of 96.1%, sensitivity of 94.1% and specificity 97.7% are achieved. CONCLUSION: The developed model can be used as a decision-making aid system for obstetrician and gynecologist.


Assuntos
Aprendizado Profundo , Trabalho de Parto , Gravidez , Feminino , Humanos , Cardiotocografia/métodos , Sofrimento Fetal/diagnóstico , Frequência Cardíaca Fetal
17.
Sensors (Basel) ; 22(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35890756

RESUMO

This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack of effective sensors and the associated algorithms specifically designed for fatigue crack monitoring. To fill this gap, this paper proposes a wireless large-area strain sensor (WLASS) to measure large-area strain fatigue cracks and develops an effective algorithm to process the measured large-area strain data into actionable information. The proposed WLASS consists of a soft elastomeric capacitor (SEC) used to measure large-area structural surface strain, a capacitive sensor board to convert the signal from SEC to a measurable change in voltage, and a commercial wireless smart sensor platform for triggered-based wireless data acquisition, remote data retrieval, and cloud storage. Meanwhile, the developed algorithm for fatigue crack monitoring processes the data obtained from the WLASS under traffic loading through three automated steps, including (1) traffic event detection, (2) time-frequency analysis using a generalized Morse wavelet (GM-CWT) and peak identification, and (3) a modified crack growth index (CGI) that tracks potential fatigue crack growth. The developed WLASS and the algorithm present a complete system for long-term fatigue crack monitoring in the field. The effectiveness of the proposed time-frequency analysis algorithm based on GM-CWT to reliably extract the impulsive traffic events is validated using a numerical investigation. Subsequently, the developed WLASS and algorithm are validated through a field deployment on a steel highway bridge in Kansas City, KS, USA.


Assuntos
Tecnologia de Sensoriamento Remoto , Aço , Colapso Estrutural , Humanos
18.
J Clin Nurs ; 31(23-24): 3584-3594, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34964175

RESUMO

AIMS AND OBJECTIVES: To evaluate the measured fall risk score that more accurately reflects the changeable conditions in acute care settings, and to efficiently evaluate the association between falls and fall risk score. BACKGROUND: The Morse Fall Scale (MFS) is a well-known easy-to-use tool, while the Johns Hopkins Fall Risk Assessment Tool (JHFRAT) consists of items with high specificity. Evaluating suitable fall-risk assessment tools to measure these changeable conditions may contribute to preventing falls in acute care settings. DESIGN: Retrospective case-control study using the STROBE checklist. METHODS: In an acute care setting (708-bedded university hospital with a regional emergency medical centre), the non-fall group was adjusted to fall group using propensity score matching. According to the fall rate of 3-5%, non-fall groups for each tool were selected (1386 and 1947) from the before adjusted data, and the fall groups included 42 and 59. The applied covariates were individual characteristics that ordinarily changed such as age, gender, diagnostic department and hospitalisation period. The adjusted data were analysed using generalised estimating equations and mixed effect model. RESULTS: After adjustment, the fall group measured using the JHFRAT had a significantly higher difference between the initial and re-measured total score than the non-fall group. The JHFRAT, especially with the re-measured score, had a higher AUC value for predicting falls than the MFS. MFS's sensitivity was 85.7%, and specificity was 58.8% at 50 points; for JHFRAT, these were 67.8% and 80.2% at 14 points, respectively. These cut-off points were used to evaluate validity during tool development and are commonly used as reference scores. CONCLUSIONS: JHFRAT more accurately reflects acute changeable conditions related to fall risk measurements after admission. RELEVANCE TO CLINICAL PRACTICE: JHFRAT may be useful for effective fall prevention activities in acute care settings.


Assuntos
Estudos de Casos e Controles , Humanos , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
19.
BMC Oral Health ; 22(1): 431, 2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-36180871

RESUMO

BACKGROUND: The combination of a prosthetic index with Morse taper connection was developed, with the purpose of making prosthetic procedures more precise. However, the presence of the index may compromise the mechanical performance of the abutment. The aim of this study is to evaluate the effect of prosthetic index on stress distribution in implant-abutment-screw system and peri-implant bone by using the 3D finite element methodology. METHODS: Two commercial dental implant systems with different implant-abutment connections were used: the Morse taper connection with platform switching (MT-PS) implant system and the internal hex connection with platform matching (IH-PM) implant system. Meanwhile, there are two different designs of Morse taper connection abutment, namely, abutments with or without index. Consequently, three different models were developed and evaluated: (1) MT-PS indexed, (2) MT-PS non-indexed, and (3) IH-PM. These models were inserted into a bone block. Vertical and oblique forces of 100 N were applied to each abutment to simulate occlusal loadings. RESULTS: For the MT-PS implant system, the maximum stress was always concentrated in the abutment neck under both vertical and oblique loading. Moreover, the maximum von Mises stress in the neck of the MT-PS abutment with index even exceed the yield strength of titanium alloy under the oblique loading. For the IH-PM implant system, however, the maximum stress was always located at the implant. Additionally, the MT-PS implant system has a significantly higher stress level in the abutment neck and a lower stress level around the peri-implant bone compared to the IH-PM implant system. The combined average maximum stress from vertical and oblique loads is 2.04 times higher in the MT-PS indexed model, and 1.82 times for the MT-PS non-indexed model than that of the IH-PM model. CONCLUSIONS: MT-PS with index will cause higher stress concentration on the abutment neck than that of without index, which is more prone to mechanical complications. Nevertheless, MT-PS decreases stress within cancellous bone and may contribute to limiting crestal bone resorption.


Assuntos
Implantes Dentários , Ligas , Fenômenos Biomecânicos , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Humanos , Estresse Mecânico , Titânio
20.
Cas Lek Cesk ; 161(1): 17-23, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35354290

RESUMO

Clinical pharmacists are encouraged to participate in falls prevention programs in many healthcare facilities. A uniform methodology for the work of clinical pharmacist in fall prevention has not yet been established in the Czech Republic. The aim of this work is to offer the methodology based on our own data analysis. Retrospective clinical pharmacist's output analysis was performed in two areas: fall's pharmacoprevention and post-fall drug audits. In the results 78 % of patients who fell during hospitalization were over 65 years of age. Age was subsequently taken as the basic criterion for the patient's medication evaluation with regard to the risk of falling. Thanks to the widespread expansion of clinical pharmaceutical care and the newly introduced fall prevention and monitoring system at ÚVN Prague, there was a positive trend in the incidence of medication's adverse effects on patient's falls: in 2017 it was 34 % of cases, in 2020 only 13 %. Based on our data and experience, we offer a methodology for the clinical pharmacist's activity in fall prevention: 1. performing revision of medication also with regard to the risk of falls in patients over 65 years of age, 2. ensuring the automatic requests sending to the clinical pharmacy department in the case of a patient's fall in a medical facility.


Assuntos
Acidentes por Quedas , Farmacêuticos , Acidentes por Quedas/prevenção & controle , Pré-Escolar , República Tcheca , Atenção à Saúde , Humanos , Estudos Retrospectivos
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