scholarly journals Signal Analysis For Cardiac Electrical Activation Studies

2021 ◽  
Author(s):  
Elnaz Shokrollahi

The aim of this study is to determine if some of the characteristics of reconstructed unipolar electrograms from the noncontact mapping system can be used to detect epicardial and to differentiate it from endocardial electrical activation in a canine heart. This would help the electrophysiologist know where exactly the origin of ventricular tachycardia or the critical point in tissue is located. Following this, arrhythmia can be successfully treated by ablating that part of the tissue of the heart. Virtual electrograms were recorded while pacing the right ventricle of an open-chest dog at multiple endocardial and epicardial sites using the commercially available noncontact mapping system (EnSite Array™ Catheter 3000). The endocardial and epicardial paced virtual electrograms from the juxtaposing sites allow for analyzing systematically the differences in their morphologies. Maximal dV / dt, area under the depolarization curve and latency extracted from unipolar electrograms demonstrated significant difference between epicardial and endocardial pacing sites with a p-value of less than 0.01 in all three cases. The above features were fed to a linear discriminant analysis based classifier and high classification accuracy was achieved. Therefore, reliable criteria can be proposed to allow for discrimination of an endocardial versus epicardial origin of electrical activation. And also the endocardial and epicardial paced virtual electrograms from the juxtaposing sites allows for an estimate of the transfer function of the myocardium in different positions of the right ventricles of a canine heart. The transfer function estimation will aid in better mathematical modeling of myocardium and could be a sensitive measure of myocardial homogeneity and arrhythmic foci localization.Another study was done on a human heart. This study was to evaluate the ability of virtual electrograms to predict abnormal bipolar electrograms. We tested the hypothesis of maxdV/dt, filtering and optimized DSM threshold. This allows better identification of abnormal myocardial substrate traditionally defined by contact bipolar mapping in human RVOT.

2021 ◽  
Author(s):  
Elnaz Shokrollahi

The aim of this study is to determine if some of the characteristics of reconstructed unipolar electrograms from the noncontact mapping system can be used to detect epicardial and to differentiate it from endocardial electrical activation in a canine heart. This would help the electrophysiologist know where exactly the origin of ventricular tachycardia or the critical point in tissue is located. Following this, arrhythmia can be successfully treated by ablating that part of the tissue of the heart. Virtual electrograms were recorded while pacing the right ventricle of an open-chest dog at multiple endocardial and epicardial sites using the commercially available noncontact mapping system (EnSite Array™ Catheter 3000). The endocardial and epicardial paced virtual electrograms from the juxtaposing sites allow for analyzing systematically the differences in their morphologies. Maximal dV / dt, area under the depolarization curve and latency extracted from unipolar electrograms demonstrated significant difference between epicardial and endocardial pacing sites with a p-value of less than 0.01 in all three cases. The above features were fed to a linear discriminant analysis based classifier and high classification accuracy was achieved. Therefore, reliable criteria can be proposed to allow for discrimination of an endocardial versus epicardial origin of electrical activation. And also the endocardial and epicardial paced virtual electrograms from the juxtaposing sites allows for an estimate of the transfer function of the myocardium in different positions of the right ventricles of a canine heart. The transfer function estimation will aid in better mathematical modeling of myocardium and could be a sensitive measure of myocardial homogeneity and arrhythmic foci localization.Another study was done on a human heart. This study was to evaluate the ability of virtual electrograms to predict abnormal bipolar electrograms. We tested the hypothesis of maxdV/dt, filtering and optimized DSM threshold. This allows better identification of abnormal myocardial substrate traditionally defined by contact bipolar mapping in human RVOT.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Saleh Alshaibi ◽  
Tala AlBassri ◽  
Suliman AlQeuflie ◽  
Winnie Philip ◽  
Nesrin Alharthy

Abstract Background Emergency care continues to be a challenge, since patients’ arrival is unscheduled and could occur at the same time which may fill the Emergency Department with non-urgent patients. Triaging is an integral part of every busy ED. The Canadian Triage and Acuity Scale (CTAS) is considered an accurate tool to be used outside Canada. This study aims to identify the chosen triage level and compare the variation between registered nurses, pediatric and adult emergency residents by using CTAS cases. Method This study was conducted at King Abdulaziz Medical City,Saudi Arabia. A cross-sectional self-administered questionnaire was used, and which contains 15 case scenarios with different triage levels. All cases were adopted from a Canadian triage course after receiving permission. Each case provides the patient’s symptoms, clinical signs and mode of arrival to the ED. The participants were instructed to assign a triage level using the following scale. A non-random sampling technique was used for this study. The rates of agreement between residents were calculated using kappa statistics (weighted-kappa) (95%CI). Result A total of 151 participants completed the study questionnaire which include 15 case scenarios. 73 were nurses and 78 were residents. The results showed 51.3, 56.6, and 59.9% mis-triaged the cases among the nurses, emergency residents, and pediatric residents respectively. Triage scores were compared using the Kruskal Wallis test and were statistically significant with a p value of 0.006. The mean ranks for nurses, emergency residents and pediatric residents were 86.41, 73.6 and 59.96, respectively. The Kruskal Wallis Post-Hoc test was performed to see which groups were statistically significant, and it was found that there was a significant difference between nurses and pediatrics residents (P value = 0.005). Moreover, there were no significant differences found between nurses and ER residents (P value> 0.05). Conclusion The triaging system was found to be a very important tool to prioritize patients based on their complaints. The results showed that nurses had the greatest experience in implementing patients on the right triage level. On the other hand, ER and pediatric residents need to develop more knowledge about CTAS and become exposed more to the triaging system during their training.


2020 ◽  
Vol 2 (3) ◽  
pp. 99-107
Author(s):  
Zahra Sativani ◽  
Riza Pahlawi

The activities of children more involve the foot. One of the common problems in the foot is flexible flatfoot. A disturbance in the process of the formation of the arch foot could result in a deformation of the foot and increases the risk of an injury due to postural balance change. Normally, the arch of the foot formed the first five years for the age range of 2-6 years. The right choices of the intrinsic muscle exercises of the foot can prevent deformation and improve postural balance. This study aimed to discuss the effectiveness of foot strengthening exercise to improving postural balance and functional ability of foot on a flexible flatfoot 6-10 years old. This study was pre-experimental research with two groups of pre-post test design. The subjects of this research were 30 students that had been divided into two groups, case, and control. Each group consists of 15 students selected used purposive sampling method based on the criteria of inclusion that had been set. There was a significant difference after foot strengthening exercise between the case and control group, p-value = 0,000. The foot strengthening exercise could improve the postural balance and functional ability of the foot on a flexible flatfoot 6-10 years old.


2019 ◽  
Vol 2 (3) ◽  
pp. 84
Author(s):  
Rina Septiadiningsih ◽  
Euis Rohaety ◽  
Lenny Nuraeni

Sensitive period is the right time to instill the basis of the importance of counting. In addition to counting skills that must be developed also pay attention to the application of learning used. However, in the learning process, teachers often forget the importance of playing methods. If too often with giving assignments the child will feel bored, therefore what is used is the method of playing. Play method is one method that can be used by teachers to teach the ability to count children in the beginning. Based on this background, the purpose of this study was to determine the effect of the use of playing methods on initial numeracy skills. This study used the Quasi Experiment method with the Nonequevalent Control Group Design research design. The results of the pre test showed that there were no significant differences in the experimental group and the control group with p-value> 0.05, which was 0.135> 0.05 which was tested by the two average test results. While the post-test results showed that the initial numeracy ability after the application of the playing method experienced a significant difference with the p-value <0.05, that is with the results of 0.0001 with the Mann-Whitney test. This method of playing can be used as a learning suggestion for educators to improve their ability to have an early start.


Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2902 ◽  
Author(s):  
Mehrdad Davoudi ◽  
Seyyed Mohammadreza Shokouhyan ◽  
Mohsen Abedi ◽  
Narges Meftahi ◽  
Atefeh Rahimi ◽  
...  

The successful clinical application of patient-specific personalized medicine for the management of low back patients remains elusive. This study aimed to classify chronic nonspecific low back pain (NSLBP) patients using our previously developed and validated wearable inertial sensor (SHARIF-HMIS) for the assessment of trunk kinematic parameters. One hundred NSLBP patients consented to perform repetitive flexural movements in five different planes of motion (PLM): 0° in the sagittal plane, as well as 15° and 30° lateral rotation to the right and left, respectively. They were divided into three subgroups based on the STarT Back Screening Tool. The sensor was placed on the trunk of each patient. An ANOVA mixed model was conducted on the maximum and average angular velocity, linear acceleration and maximum jerk, respectively. The effect of the three-way interaction of Subgroup by direction by PLM on the mean trunk acceleration was significant. Subgrouping by STarT had no main effect on the kinematic indices in the sagittal plane, although significant effects were observed in the asymmetric directions. A significant difference was also identified during pre-rotation in the transverse plane, where the velocity and acceleration decreased while the jerk increased with increasing asymmetry. The acceleration during trunk flexion was significantly higher than that during extension, in contrast to the velocity, which was higher in extension. A Linear Discriminant Analysis, utilized for classification purposes, demonstrated that 51% of the total performance classifying the three STarT subgroups (65% for high risk) occurred at a position of 15° of rotation to the right during extension. Greater discrimination (67%) was obtained in the classification of the high risk vs. low-medium risk. This study provided a smart “sensor-based” practical methodology for quantitatively assessing and classifying NSLBP patients in clinical settings. The outcomes may also be utilized by leveraging cost-effective inertial sensors, already available in today’s smartphones, as objective tools for various health applications towards personalized precision medicine.


Author(s):  
Iraj Alimohammadi ◽  
Fakhradin Ahmadi Kanrash ◽  
Kazem Rahmani(MSc)

Introduction: Working in noisy environments may cause hearing loss. Studies have shown that some factors along with noise are independently involved in hearing loss, one of which is cigarette smoking. The aim of this study was to evaluate the effects of smoking on hearing loss in workers exposed to occupational noise. Materials and Methods: The workers’ hearing loss was measured through a tonal hearing test (air-conduction). Their demographic information was also recorded and evaluated using some checklists. Results: A total of 250 people were enrolled in this study, of whom 133 were smokers and 117 were non-smokers. The mean age of the participants was 36.07 ± 3.66 years, and there was no significant difference between the two groups in terms of age. The mean sound pressure level in the work environment was 86 dB based on the ISO standard. There was a significant difference between the hearing loss levels in the right ears and the left ears of the two groups of smokers and non-smokers (P value <0.001). Conclusion: In general, smoking plays a significant role in hearing loss along with other factors, such as noise in the workplace, and conducting periodic audiometry tests to identify smokers with hearing impairment can be effective in primary or secondary prevention of occupational hearing impairment. Keywords: Hearing Loss, Smoking, Noise, Occupational  


2020 ◽  
Vol 21 (1) ◽  
pp. 77
Author(s):  
Fabiele Chieregato ◽  
Caroline Nogueira Da Silva ◽  
Tania Maria Carvalho ◽  
Clovis Grecco ◽  
Renata Gomes Moreira ◽  
...  

Introduction: Several technologies have been developed and optimized for the treatment of unaesthetic disorders. Among them is the oscillatory vibration therapy, a novel form of treatment based on the mechanical and physiological fundamentals of the vibration platform. Objective: The present study evaluated the efficacy of the oscillatory vibration therapy in the improvement of body contour remodeling and in the aspect of cellulite in women. Methods: This is a prospective longitudinal comparative study, in which the following evaluation tools are used: anthropometry, perimetry, adipometry, evaluation of skin viscoelasticity with Cutometer®, evaluation of the thickness of the hypodermis with diagnostic ultrasound and analysis of severity of cellulite (CSS). The evaluations occurred at the start and 1 week after the end of ten oscillatory vibration therapy. The results were analyzing using a paired student’s t-test with interval confidence of 95% (P-Value <0.05). Results: Thirty women took part in the research, with age of 33 ± 9 years, weight of 62 ± 11 kg, height of 1.66 ± 0.06 m, BMI of 22 ± 2 kg/m2. The measurements of perimetry, adipometry, analysis of subcutaneous tissue thickness by means of diagnostic ultrasound and analysis of skin viscoelasticity did not present significant alterations. However, the CSS variable of the right gluteus (7.3 ± 1.8 to 5.8 ± 1.6 ≤ 0.0001), left gluteus (7.2 ± 1.9 to 5.8 ± 1.6= 0.0001), right thigh (6.9 ± 1.9 to 5.6 ± 1.4 = 0.0004), left thigh (6.9 ± 1.9 to 5.6 ± 1.3 = 0.0004) and Celluquol® (59 ± 16 to 49 ± 16 = 0.022) presented significant difference. Conclusion: The multi-directional oscillatory vibration therapy is an effective and efficient therapy for the treatment of cellulite; however, for the treatment of body remodeling, it must be further evaluated and studied.Keywords: vibration platform, vibration, cellulite, body contour, aesthetic medicine.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0243024
Author(s):  
Yohannes Kebede ◽  
Zewdie Birhanu ◽  
Diriba Fufa ◽  
Yimenu Yitayih ◽  
Jemal Abafita ◽  
...  

Background The endeavor to tackle the spread of COVID-19 effectively remains futile without the right grasp of perceptions and beliefs presiding in the community. Therefore, this study aimed to assess myths, beliefs, perceptions, and information gaps about COVID-19 in Ethiopia. Methods An internet-based survey was conducted in Ethiopia from April 22 to May 04, 2020. The survey link was promoted through emails, social media, and the Jimma University website. Perceptions about COVID-19 have considered the World Health Organization (WHO) resources and local beliefs. The data were analyzed using Statistical Package for Social Science (SPSS) software version 20.0. Classifications and lists of factors for each thematic perception of facilitators, inhibitors, and information needs were generated. Explanatory factor analysis (EFA) was executed to assist categorizations. Standardized mean scores of the categories were compared using analysis of variance (ANOVA) and t-tests. A significant difference was claimed at p-value <0.05. Results A total of 929 responses were gathered during the study period. The EFA generated two main categories of perceived facilitators of COVID-19 spread: behavioral non-adherence (55.9%) and lack of enablers (86.5%). Behavioral non-adherence was illustrated by fear of stigma (62.9%), not seeking care (59.3%), and hugging and shaking (44.8%). Perceived lack of enablers of precautionary measures includes staying home impossible due to economic challenges (92.4%), overcrowding (87.6%), and inaccessible face masks (81.6%) and hand sanitizers (79.1%). Perceived inhibitors were categorized into three factors: two misperceived, myths (31.6%) and false assurances (32.9%), and one correctly identified; engagement in standard precautions (17.1%). Myths about protection from the virus involve perceived religiosity and effectiveness of selected food items, hot weather, traditional medicine, and alcohol drinking, ranging from 15.1% to 54.7%. False assurances include people’s perception that they were living far away from areas where COVID-19 was rampant (36.9%), and no locally reported cases were present (29.5%). There were tremendous information needs reported about COVID-19 concerning protection methods (62.6%), illness behavior and treatment (59.5%), and quality information, including responses to key unanswered questions such as the origin of the virus (2.4%). Health workers were perceived as the most at-risk group (83.3%). The children, adolescents, youths were marked at low to moderate (45.1%-62.2%) risk of COVID-19. Regional, township, and access to communication showed significant variations in myths, false assurances, and information needs (p <0.05). Conclusions Considering young population as being at low risk of COVID-19 would be challenging to the control efforts, and needs special attention. Risk communication and community engagement efforts should consider regional and township variations of myths and false assurances. It should also need to satisfy information needs, design local initiatives that enhance community ownership of the control of the virus, and thereby support engagement in standard precautionary measures. All forms of media should be properly used and regulated to disseminate credible information while filtering out myths and falsehoods.


2021 ◽  
Author(s):  
Saleh Alshaibi ◽  
Tala AlBassri ◽  
Suliman AlQeuflie ◽  
Winnie Philip ◽  
Nesrin Alharthy

Abstract BackgroundEmergency care continues to be a challenge, since patients’ arrival is unscheduled and could occur at the same time which may fill the Emergency Department with non-urgent patients. Triaging is an integral part of every busy ED. The Canadian Triage and Acuity Scale (CTAS) is considered to accurate tool to be used outside Canada. This study aims to identify the chosen triage level and compare the variation between registered nurses, pediatric and adult emergency residents by using CTAS cases.MethodThis study was conducted at King Abdulaziz Medical City, Saudi Arabia. A cross-sectional self-administered questionnaire was used, and which contains 15 case scenarios with different triage levels. All cases were adopted from a Canadian triage course after receiving permission. Each case provides the patient’s symptoms, clinical signs and mode of arrival to the ED. The participants were instructed to assign a triage level using the following scale: 1=resuscitation, 2=emergent, 3=urgent, 4=less urgent, and 5=non-urgent. A non-random sampling technique was used for this study.ResultA total of 151 participants completed the study questionnaire. 73 (48.34%) were nurses and 78 (51.66%) were residents (42 pediatric residents and 36 emergency residents).Each participant was given a score based on the correct answer for the case scenario. A mean score was compared among the nurses, pediatric residents and emergency residents. Since our data were not normally distributed, we used the Kruskal-Wallis test to observe statistical differences between the groups. The Kruskal Wallis Post-Hoc test was performed to see which groups were statistically significant, and it was found that there was a significant difference between nurses and pediatrics residents (P value < 0.001). Moreover, there were no significant differences found between nurses and ER residents (P value > 0.05).ConclusionThe triaging system was found to be a very important tool to prioritize patients based on their complaints. The results showed that nurses had the greatest experience in implementing patients on the right triage level. On the other hand, ER and pediatric residents demonstrated a need to develop more knowledge about CTAS and become exposed more to the triaging system during their training.


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