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1.
Pediatr Investig ; 7(4): 297-300, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38050537

RESUMO

Introduction: Hypersalivation has been associated with Rolandic epilepsy and other childhood epilepsy syndromes. However, pure salivatory seizures are a rare type of focal seizure in which ictal hypersalivation is the dominant feature throughout the seizures. Case presentation: We present a case of pure salivatory seizures originating from the right post-central operculum cortex, confirmed by the favorable surgical outcome. We attempt to analyze the symptom from behavioral and neural network perspectives and propose a possible mechanism to generate ictal hypersalivation and pure salivatory seizures. Conclusion: Based on previous reports in the literature and our case, we emphasize the importance of the operculum in patients with ictal hypersalivation, particularly in patients with pure salivatory seizures.

2.
Front Neurosci ; 16: 1042642, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36340784

RESUMO

Epilepsy affects more than 70 million people in the world. It is characterized by recurrent spontaneous seizures, and it is related to many neurological, cognitive, and psychosocial consequences. Glutamate neurotransmitter dysfunction has essential functions in the pathophysiology of epilepsy. In this work, bibliometric analysis was conducted to explore the trends, frontiers, and hotspots of the global scientific output of glutamate in epilepsy research in the past 20 years. The Science Citation Index Expanded of the Web of Science Core Collection (WoSCC) was searched to obtain information on publications and records published between 2002 and 2021. VOSviewer and CiteSpace were used to conduct bibliometric and visual analyses on the overall distribution of annual output, major countries, active institutions, journals, authors, commonly cited literature, and keywords. The impact and quality of the papers were assessed using the global citation score (GCS). Four thousand eight hundred ninety-one publications were retrieved in total. During the past two decades, the number of publications (Np) associated with glutamate in epilepsy has risen yearly. The United States has published the most papers; its H-index and number of citations are also the highest. The League of European Research Universities (LERU) was the most productive institution. In 2016, the total score of the paper written by Zhang Y was 854, ranking first. The keywords that appear most frequently are "epilepsy," "glutamate," "temporal lobe epilepsy (TLE)," "hippocampus," and "seizures." This study showed that although the publications related to epileptic glutamate fluctuated slightly, the Np increased overall. The United States is a great creator and influential country in this field. The first three authors are Eid, T., Aronica, E., and Smolders, I. "spectrum," "animal model," "inflammation," "mutation," "dysfunction," and "prefrontal cortex" are increasing research hotspots. By recognizing the most critical indicators (researchers, countries, research institutes, and journals of glutamate release in epilepsy research), the research hotspot of glutamate in epilepsy could help countries, scholars, and policymakers in this field enhance their understanding of the role of glutamate in epilepsy and make decisions.

3.
Epilepsy Behav ; 135: 108876, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36088785

RESUMO

OBJECTIVE: Although clinical trials have demonstrated that cathodal transcranial direct current stimulation (tDCS) is effective for seizure reduction, its long-term efficacy is unknown. This study aimed to determine the long-term effects of repeated cathodal long tDCS sessions on seizure suppression in patients with refractory epilepsy. METHODS: Patients were recruited to participate in an extended phase of a previous randomized, double-blind, sham-controlled, three-arm, parallel, multicenter study on tDCS. The patients were divided into an active tDCS group (20 min of tDCS per day) and an intensified tDCS group (2 × 20 min of tDCS per day). Each tDCS session lasted 2 weeks and the patients underwent repeated sessions at intervals of 2 to 6 months. The cathode was placed over the epileptogenic focus with the current intensity set as 2 mA. Seizure frequency reduction from baseline was analyzed using the Wilcoxon signed-rank test for two related samples. A generalized estimating equation model was used to estimate group, time, and interaction effects. RESULTS: Among the 19 patients who participated in the extended phase, 11 were in the active tDCS group and underwent 2-16 active tDCS sessions, and eight were in the intensified tDCS group and underwent 3-11 intensified tDCS sessions. Seizure reduction was significant from the first to the seventh follow-up, with a median seizure frequency reduction of 41.7%-83.3% (p < 0.05). Compared to the regular tDCS protocol, each intensified tDCS session substantially decreased seizure frequency by 0.3680 (p < 0.05). One patient experienced an increase of 8.5%-232.8% in the total number of seizures during three treatment sessions and follow-ups. CONCLUSION: Repeated long cathodal tDCS sessions yielded significant and progressive long-term seizure reductions in patients with refractory focal epilepsy.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Estimulação Transcraniana por Corrente Contínua , Método Duplo-Cego , Epilepsia Resistente a Medicamentos/etiologia , Epilepsia Resistente a Medicamentos/terapia , Epilepsias Parciais/etiologia , Epilepsias Parciais/terapia , Humanos , Convulsões/etiologia , Convulsões/terapia , Estimulação Transcraniana por Corrente Contínua/métodos
4.
Front Hum Neurosci ; 16: 836374, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35601902

RESUMO

It is a fundamental ability to discriminate incongruent information in daily activity. However, the underlying neural dynamics are still unclear. Using stereoelectroencephalography (SEEG), in this study, we investigated the fine-grained and different states of incongruent information processing in patients with refractory epilepsy who underwent intracranial electrode implantation. All patients performed a delayed match-to-sample paradigm in the sequential pairs of visual stimuli (S1 followed by S2). Participants were asked to discriminate whether the relevant feature of S2 was identical to S1 while ignoring the irrelevant feature. The spatiotemporal cortical responses evoked by different conditions were calculated and compared, respectively, in the context of brain intrinsic functional networks. In total, we obtained SEEG recordings from 241 contacts in gray matter. In the processing of irrelevant incongruent information, the activated brain areas included the superior parietal lobule, supramarginal gyrus, angular gyrus, inferior temporal gyrus, and fusiform gyrus. By comparing the relevant incongruent condition with the congruent condition, the activated brain areas included the middle frontal gyrus, superior temporal gyrus, middle temporal gyrus, posterior superior temporal sulcus, and posterior cingulate cortex. We demonstrated the dynamics of incongruent information processing with high spatiotemporal resolution and suggested that the process of automatic detection of irrelevant incongruent information requires the involvement of local regions and relatively few networks. Meanwhile, controlled discrimination of relevant incongruent information requires the participation of extensive regions and a wide range of nodes in the network. Furthermore, both the frontoparietal control network and default mode network were engaged in the incongruent information processing.

5.
Nurs Open ; 9(2): 1322-1331, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35088576

RESUMO

AIM: To investigate the uncertainty in illness, anxiety, depression and quality of life in patients receiving maintenance haemodialysis and confirm the correlations between these variables. DESIGN: A cross-sectional study was conducted among 396 patients receiving maintenance haemodialysis in four tertiary hospitals in China. METHODS: Uncertainty in illness was measured by Mishel's uncertainty in illness scale. The scores of self-rating anxiety scale, self-rating depression scale and medical outcomes study short form 36 were collected and compared with available norms. The Pearson correlation coefficient was calculated to investigate the correlation between uncertainties in illness with these vital variables. RESULTS: The mean score of uncertainty in illness was 78.16 out of 160. Compared with the norm, patients receiving maintenance haemodialysis had a statistically significantly lower score of depression and higher scores of most domains of quality of life. Uncertainty in illness is corrected with anxiety, depression positively and with quality of life negatively.


Assuntos
Depressão , Qualidade de Vida , Ansiedade , Estudos Transversais , Humanos , Diálise Renal , Incerteza
6.
West J Nurs Res ; 44(4): 367-374, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33666119

RESUMO

Self-management is essential for patients who require regular hemodialysis treatment. This study aimed to explore the relationships between social support, sense of coherence (SOC), and self-management in hemodialysis patients and to examine whether SOC plays a mediating role. In a cross-sectional study, 402 hemodialysis patients from four tertiary hospitals were recruited. Data were analyzed using structural equation modeling. Social support, SOC, and self-management were significantly correlated with each other. The proposed model provided a good fit to the data. Social support had a direct effect on self-management and SOC, partially mediated the effect of social support on self-management (ß = 0.248, p = 0.001). Social support and SOC explained 69% of the variance in self-management. Our findings indicate that health care providers can enhance social support with an emphasis on strengthening SOC strategies to better improve self-management in hemodialysis patients.


Assuntos
Autogestão , Senso de Coerência , Estudos Transversais , Humanos , Diálise Renal , Apoio Social , Inquéritos e Questionários
7.
Front Neurol ; 12: 651592, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995250

RESUMO

Purpose: Delineation of subtle lesions in magnetic resonance imaging (MRI)-negative patients is of great importance in preoperative epilepsy evaluation. The aim of our study was to explore the diagnostic value of the novel fluid and white matter suppression (FLAWS) sequence in comparison with a voxel-based MRI postprocessing morphometric analysis program (MAP) in a consecutive cohort of non-lesional patients. Methods: Surgical candidates with a negative finding on an official neuroradiology report were enrolled. High-resolution FLAWS image and MAP maps generated based on high-resolution three-dimensional (3D) T1 image were visually inspected for each patient. The findings of FLAWS or MAP-positive (FLAWS/MAP+) regions were compared with the surgical resection cavity in correlation with surgical outcome and pathology. Results: Forty-five patients were enrolled; the pathological examination revealed focal cortical dysplasia (FCD) in 32 patients and other findings in 13 patients. The positive rate, sensitivity, and specificity were 48.9%, 0.43, and 0.87, respectively, for FLAWS and 64.4%, 0.57, and 0.8, respectively, for MAP. Concordance between surgical resection and FLAWS+ or MAP+ regions was significantly associated with a seizure-free outcome (FLAWS: p = 0.002; MAP: p = 0.0003). A positive finding in FLAWS and MAP together with abnormalities in the same gyrus (FLAWS-MAP gyral+) was detected in 31.1% of patients. FLAWS+ only and MAP+ only were found in 7 (15.5%) and 14 (31.1%) patients, respectively. Conclusions: FLAWS showed a promising value for identifying subtle epileptogenic lesions and can be used as a complement to current MAP in patients with MRI-negative epilepsy.

9.
Epilepsy Res ; 171: 106568, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33610065

RESUMO

OBJECTIVE: Diagnostic challenges exist in the presurgical evaluation of patients with magnetic resonance imaging (MRI) negative cingulate epilepsy (CE) because of the heterogeneity in clinical semiology and lack of localizing findings on scalp electroencephalographic (EEG) recordings. We aimed to examine the neuroimaging characteristics in a consecutive cohort of patients with MRI-negative CE with a focus on two image post-processing methods, including the MRI post-processing morphometric analysis program (MAP) and 18F-fluorodeoxyglucose-positron emission tomography-MRI (PET/MRI) co-registration. METHODS: Included in this retrospective study were patients with MRI-negative CE who met the following criteria: negative on preoperative MRI, invasive EEG (iEEG) confirmed cingulate gyrus-onset seizures, surgical resection of the cingulate gyrus with/without adjacent cortex, and seizure-free for more than 12 months. MAP and PET/MRI co-registration were performed and investigated by comparison to ictal intracranial EEG findings. Other characteristics obtained from scalp EEG, magnetoencephalography (MEG), iEEG, and pathological study were also reported. RESULTS: Ten patients were included, of which eight were diagnosed with anterior CE, one with middle CE, and one with posterior CE. The semiology included fear, embarrassment, vocalization, ictal pouting, asymmetric tonic posture, hypermotor, and automatism. Scalp EEG revealed unilateral or bilateral frontal-temporal onset. MEG localized the dipoles correctly in one patient (1/10). MAP detected subtle abnormalities in regions concordant with iEEG onset in seven patients (7/10) while PET/MRI co-registration revealed focal concordant hypometabolism in five patients (5/10). Combining MAP with PET/MRI co-registration improved the detection rate to 90 % in this cohort. The pathology was focal cortical dysplasia (FCD), including FCD type IIA in three, type IIB in three, and type I in four. CONCLUSION: MAP and PET/MRI co-registration show promising results in identifying subtle FCD abnormalities in CE with negative results on conventional MRI, which can be otherwise challenging. More importantly, a combination of MRI post-processing and PET/MRI co-registration can greatly improve the identification of epileptic abnormalities, which can be used as surgical target. MAP and PET/MRI co-registration should be incorporated into the routine presurgical evaluation.


Assuntos
Epilepsia do Lobo Frontal , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos
10.
West J Nurs Res ; 43(5): 459-467, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32930067

RESUMO

This cross-sectional study assessed the overall symptom burden, including the prevalence, frequency, severity, and distress of symptoms among hemodialysis patients, and explored the relationship between demographic characteristics, clinical variables, self-management, sense of coherence, social support, and symptom burden in these patients. Herein, a regression analysis was performed to determine associations with symptom burden. The mean score of symptom burden among the participants (n = 382) was 74.12, with an average number of 12 symptoms. The analysis revealed that self-management, sense of coherence, and social support were negatively associated with the overall symptom burden. The multiple regression model showed that 48.6% of the variance in symptom burden was explained by meaningfulness, emotional management, daily urine output, subjective support, gender, and manageability. These findings contribute to the knowledge of symptom burden among hemodialysis patients and some new predictors (self-management, sense of coherence, and social support) of their symptom burden.


Assuntos
Diálise Renal , Autogestão , Estudos Transversais , Humanos , Prevalência , Apoio Social , Inquéritos e Questionários
11.
Brain Stimul ; 13(1): 109-116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31606448

RESUMO

BACKGROUND: Transcranial direct current stimulation (tDCS) has been explored in epilepsy with limited samples, varied parameters, and inconclusive results. We aimed to study the efficacy of tDCS for patients with refractory focal epilepsy. METHOD: We conducted a randomized, double-blind, sham-controlled, and three-arm (Group 1 (sham), Group 2 (20-min), and Group 3 (2 × 20-min)) tDCS parallel multicenter study. The primary outcome measurement was seizure frequencies (SFs). The study consisted of 28-days baseline, 14-days treatment, and 56-days follow-up. The cathode was placed over the epileptogenic focus, and the current intensity was 2 mA. The generalized estimating equations model, one-way analysis of variance, chi-square and Kruskal-Wallis test were used for analysis. RESULTS: Of the 82 enrolled patients, 70 patients were included for final analysis (Group 1, n = 21; Group 2, n = 24; and Group 3, n = 25). There was a significant reduction in SFs for both active tDCS groups compared with the sham group. Patients in Group 2 showed a significantly 50.73-21.91% greater reduction in SFs that lasted for 4 weeks (p = 0.008-0.060). Patients in Group 3 showed a significantly 63.19-49.79% greater reduction in SFs compared with the sham group that lasted for 5 weeks (p = 0.011-0.045). Patients in Group 3 had a 64.98-66.32% greater reduction in SFs at W9-W10, when compared with Group 2 (p = 0.021-0.022). CONCLUSION: Fourteen consecutive days tDCS significantly decreased SFs in patients with refractory focal epilepsy, with 2 × 20-min daily stimulation protocol being superior to 20-min daily stimulation protocol.


Assuntos
Epilepsia Resistente a Medicamentos/terapia , Epilepsias Parciais/terapia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Transcraniana por Corrente Contínua/efeitos adversos , Resultado do Tratamento
12.
Front Neurol ; 10: 50, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30804872

RESUMO

Background: Epileptic spasms (ES) is a severe seizure type and lack of adequate methods for controlling of clinical attacks. Previous studies have indicated that cathodal transcranial direct current stimulation (tDCS) reduces seizure frequency for patients with epilepsy. ES are proposed to have a focal cortical origin. We hypothesized that patients with ES exhibit hyperactive network hubs in the parietal lobe, and that cathodal tDCS targeting the bilateral parietal region can reduce seizure frequency in patients with pharmacoresistant ES. Materials and Methods: The present study consisted of three basic phases: (a) a pre-treatment monitoring period for 14 days; (b) a consecutive 14-day treatment period during which patients were treated with 1 or 2 mA cathode tDCS for 40 min once per day; (c) and a follow-up period for at least 28 days. During the first 20 min of treatment, the cathode was placed over the right parietal lobe (P4) with the reference electrode over the contralateral supra-orbital area. In the second 20 min, the cathode was placed over the left parietal lobe (P3), with the reference electrode over the contralateral supra-orbital area. All patients received active tDCS treatment, and some patients underwent more than one treatment block. Patients maintained a seizure diary throughout the study. Antiepileptic drug therapy remained unchanged throughout the study. K-related samples Friedman tests and two-related samples tests were used to analyze data from all patients. Results: Seven patients with pharmacoresistant ES were included, receiving a total of eighteen 14-day blocks of tDCS treatment. We observed a significant difference in seizure frequency at the second month (p = 0.028, unadjusted), as well as a trend toward decreased seizure frequency at the fourth month (p = 0.068, unadjusted) of the first follow-up, relative to baseline. Three of seven patients (42.9%) exhibited sustained seizure reduction, while one (14.3%) experienced a short-term reduction in seizure frequency following cathodal tDCS treatment. Treatment was well tolerated in all patients. Conclusions: Repeated tDCS with the cathode placed over the bilateral parietal region is safe and may be effective for reducing seizure frequency in a subgroup of patients with pharmacoresistant ES.

13.
Korean Circ J ; 46(1): 33-40, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26798383

RESUMO

BACKGROUND AND OBJECTIVES: Success rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS). SUBJECTS AND METHODS: The study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old). RESULTS: A significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm(3) vs. 143±86 mm(3), p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group. CONCLUSION: CTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA.

14.
Korean Circ J ; 45(1): 28-37, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25653701

RESUMO

BACKGROUND AND OBJECTIVES: Both carotid intima-media thickness (CIMT) and carotid plaque are important factors in the primary prevention of cardiac disease. However, it is unclear which one is more important for prognosis, especially in patients with coronary artery disease (CAD). SUBJECTS AND METHODS: In total, 1426 consecutive CAD patients, proven by angiography, were followed-up for a mean of 85 months. The study population was divided into four groups depending on the CIMT (≥0.83 mm, >95 percentile in Korea) and the presence or absence of carotid plaque. RESULTS: Patients with carotid plaque and thick CIMT (n=237, 16.6%) had a higher prevalence of hypertension, diabetes mellitus, and dyslipidemia than those had plaque and thin CIMT (n=213, 14.9%), those without plaque and thick CIMT (n=265, 18.6%) and those without plaque and thin CIMT (n=711, 49.9%). The patients with carotid plaque and thick CIMT group had a higher cardiac mortality rate (20.7% vs. 13.1%, 9.4% and 3.9%, respectively, p<0.001) and higher major adverse cardiovascular events (MACE) including death, acute myocardial infarction, and stroke (27.8% vs. 18.8%, 15.5% and 9.3%, respectively, p<0.001) than any other groups. Multivariate Cox regression analysis showed that the presence of carotid plaque with thick CIMT had the highest hazard ratio (HR) compared to other groups (HR 2.23 vs. 1.81, 2.01) for cardiac mortality. Also, carotid plaque had a higher HR than CIMT for mortality (HR 1.56 vs. 1.37) and MACE (HR 1.54 vs. 1.36) in the total study population. CONCLUSION: Carotid plaque is a more important prognostic factor than CIMT in patients with CAD, and adding a thick CIMT to carotid plaque increases the prognostic power for cardiac events.

15.
J Phys Ther Sci ; 27(1): 155-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25642062

RESUMO

[Purpose] The purpose of this study was to examine the correlation of age, work experience, cognition, and work ability in older employees working in heavy industry. [Subjects and Methods] The study was conducted using 100 subjects who were over 55 years old and worked in heavy industry. To obtain data, we first had the subjects complete the MoCA-K test and Work Ability Index (WAI). The data were then analyzed by frequency and correlation using statistical software (SPSS 21.0). [Results] Through this study, we discovered a significant positive correlation between WAI and MoCA-K, age, and work experience. [Conclusion] This study revealed that work ability in older employees increases not with the number of years worked but with the enhancement of cognitive ability. Special management that focuses on cognition is therefore required for senior employees working in the field of heavy industry.

16.
Int J Cardiol ; 167(6): 2611-6, 2013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22819606

RESUMO

BACKGROUND: We evaluated discrepancy of calcium detection between gray scale intravascular ultrasound (IVUS) and virtual histology (VH)-IVUS and the association between coronary calcium and plaque composition. METHODS: Study population consisted of 162 consecutive patients who underwent percutaneous coronary intervention with VH-IVUS study. Subjects were divided into 3 groups based on gray scale IVUS findings; No calcification group (n=50), spotty group (n=56) who had a lesion containing only small calcium deposits within an arc <90° and diffuse group (n=56) who had a diffuse calcified lesion with an arc ≥ 90° in ≥ 1 cross-sectional image of the lesion. RESULTS: No calcification group was younger than spotty and diffuse groups (54.4 ± 13.0 years vs. 61.1 ± 10.7 years and 64.2 ± 9.9 years, p=0.011 and p<0.001, respectively). No calcification group had some degree of dense calcium (5. 7 ± 6.9 mm(3)) by VH-IVUS analysis. Furthermore, calcified volume by VH-IVUS in no calcification group was similar to those in spotty group (5.7 ± 6.9 mm(3) vs. 5.4 ± 4.4mm(3)). Dense calcium volume was correlated directly with plaque volume (r=0.65, p<0.001), fibrous volume (r=0.54, p<0.001), fibro-fatty volume (r=0.29, p<0.001) and lipid core volume (r=0.77, p<0.001). In multiple regression analysis, lipid core volume (ß=0.287, 95% confidence interval (CI) 0.187-0.388, p<0.001) was an independent predictor of dense calcium volume. CONCLUSIONS: This study showed that coronary calcium can be present even if invisible in gray scale IVUS and associated with lipid core volume, which is a characteristic of plaque vulnerability.


Assuntos
Cálcio , Doença da Artéria Coronariana/diagnóstico por imagem , Intervenção Coronária Percutânea , Ultrassonografia de Intervenção/métodos , Calcificação Vascular/diagnóstico por imagem , Adulto , Idoso , Cálcio/análise , Doença da Artéria Coronariana/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/métodos , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/cirurgia , Calcificação Vascular/cirurgia
17.
Ultrasonics ; 44 Suppl 1: e1365-9, 2006 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-16806379

RESUMO

In the present study, the possibility of using leaky Rayleigh waves as a nondestructive tool for the evaluation of CVD diamond coating layer is explored experimentally. For this purpose, a set of CVD diamond coated specimens are prepared and the leaky Rayleigh waves are measured in an immersion, pulse-echo setup. For the proper analysis of the acquired signals we propose a novel signal analysis approach, namely the "time trace angular scan (TTAS)" image. Then, the proposed approach together with the backward radiation profiles are applied for the analysis of signals acquired in the initial experiments. The TTAS image shows the entire information on both time-of-arrival and angle of incidence of the signals for the proper "time-angle windowing." Then, the backward radiation profile of the windowed signals provides adequate parameters from which nondestructive evaluation of the coated specimens is carried out.

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