Analysis of Input Impedance and Mutual Coupling of Microstrip Antennas on Multilayered Circular Cylinders Using Closed-Form Green’s Function Representations

Cataloged from PDF version of article.Closed-form Green’s function (CFGF) representations for cylindrically stratified media are developed and used in conjunction with a Galerkinmethod ofmoments (MoM)in the space domain for the analysis of microstrip antennas on multilayered circular cylinders. An attachment mode is used in the MoM solution procedure to accurately model the feeding of probe-fed microstrip antennas. The developed CFGF representations are modified in the source region (where two current modes can partially or fully overlap with each other during the MoM procedure) so that singularities can be treated analytically and hence, the proposed CFGF representations can be safely used in this region. Furthermore, accurate CFGF representations for the probe-related components (necessary for probe type excitations including the attachment mode) are obtained when the radial distance between the source and field points is electrically small or zero. Numerical results in the form of input impedance of various microstrip antennas and the mutual coupling between two antennas are presented showing good agreement when compared to the available published results as well as the results obtained from CST Microwave Studio

Closed-Form Green's Function Representations in Cylindrically Stratified Media for Method of Moments Applications

Cataloged from PDF version of article.Closed-form Green's function (CFGF) representations for cylindrically stratified media, which can be used as the kernel of an electric field integral equation, are developed. The developed CFGF representations can safely be used in a method of moments solution procedure, as they are valid for almost all possible source and field points that lie on the same radial distance from the axis of the cylinder (such as the air-dielectric and dielectric-dielectric interfaces) including the axial line (ρ = ρ′ and φ = φ′), which has not been available before. In the course of obtaining these expressions, the conventional spectral domain Green's function representations are rewritten in a different form so that i) we can attack the axial line problem and ii) the method can handle electrically large cylinders. Available acceleration techniques that exist in the literature are implemented to perform the summation over the cylindrical eigenmodes efficiently. Lastly, the resulting expressions are transformed to the spatial domain using the discrete complex image method with the help of the generalized pencil of function method, where a modified two-level approach is used. Numerical results are presented in the form of mutual coupling between two current modes to assess the accuracy of the final spatial domain CFGF representations. © 2009 IEE

Wavelet Transform-Based Classification of ElectroMyogram Signals Using an ANOVA Technique

Wavelet analysis of surface electromyogram (sEMG) signals has been investigated. Methods to remove noise before processing and further analysis are rather significant for these signals. The sEMG signals were estimated with the following steps, first, the obtained signal was decomposed using wavelet transform; then, decomposed coefficients were analyzed by threshold methods, and, finally, reconstruction was performed. Comparison of the Daubechies wavelet family for effective removing noise from the recorded sEMGs was executed preciously. As was found, wavelet transform db4 performs denoising best among the aforesaid wavelet family. Results inferred that Daubechies wavelet families (db4) were more suitable for the analysis of sEMG signals related to different upper limb motions, and a classification accuracy of 88.90% was achieved. Then, a statistical technique (one-way repeated factorial analysis) for the experimental coefficient was done to investigate the class separability among different motions.Досліджували можливість застосування вейвлет-аналізу щодо сигналів поверхневої електроміограми (пЕМГ). Використання видалення шумів із записів пЕМГ перед обробкою таких сигналів для подальшого аналізу є дуже істотним. Сигнали пЕМГ оцінювалися в наступній послідовності: спочатку отриманий сигнал підлягав декомпозиції з використанням вейвлет-перетворення, потім декомпозовані коефіцієнти аналізувались із застосуванням порогових методик, і, нарешті, виконувалася реконструкція. Попередньо порівнювали ефективність видалення шумів у межах вейвлет-сімейства Daubechies. Було встановлено, що вейвлет-перетворення db4 із цього сімейства виконує знешумлення найкращим чином. Отримані результати вказують на те, що вейвлет-сімейства Daubechies є більш придатними для аналізу пЕМГ сигналів, отриманих в умовах реєстрації різних моторних реакцій м’язів верхніх кінцівок; досягалася точність класифікації 88.9 %. Потім статистична методика (однобічний повторний факторіальний аналіз) застосовувалася щодо експериментальних коефіцієнтів для встановлення якості розділення даних при різних рухах

Comparative evaluation of efficacy of physics forceps versus conventional forceps in therapeutic extractions of premolars: a prospective clinical study

Background: Dental extraction is the removal of a tooth from the oral cavity and is the most common procedure performed in oral surgery. Conventional exodontia tends to cause unnecessary trauma leading to postoperative pain, loss of tissue and stress for the patient. ‘Atraumatic’ dental extraction techniques have nowadays gained popularity and in such case, physics forceps can be helpful in achieving such results. The aim of the study was to evaluate and compare efficacy of physics forceps versus conventional forceps in therapeutic extraction of premolars.Methods: A total of 35 patients requiring extraction of premolars in maxillary or mandibular arch or both arches for orthodontic treatment purpose were included and divided into groups A and B wherein right sided extractions performed with physics forceps were compared with left sided extractions carried out using conventional forceps in terms of time taken for extraction, bone and soft tissue injury, success score and pain assessment.Results: The present study suggested statistically significant difference between both the groups. Time taken for extraction, trauma to gingival tissue, bone loss, and visual analogue scale (VAS) score was significantly lesser with physics forceps group, when compared to conventional forceps group. Moreover no significant difference in success score was noted between both the groups.Conclusions: Physics forceps are comparatively superior to conventional extraction forceps in terms of lesser time taken for the procedure, lesser tendency to induce trauma to both hard and soft tissue and have been found to induce comparatively lesser pain post extraction

Prevalence of mental nerve injury in facial fractures: a 3 year retrospective study

Background: Mandibular fracture is the most common facial bone fracture. Fractures occurring at the Para symphysis region frequently results in mental nerve injury, due to which anaesthesia or paraesthesia of the skin and mucous membrane within the distribution of mental nerve may be observed and may cause reduced quality of life for patients. Aim of this study was to retrospectively analyse and evaluate the prevalence rate of mental nerve injury in patients that reported to the department of oral and maxillofacial surgery, managed conservatively or open reduction and internal fixation method during the last 3 yearsMethods: Patients with neurosensory deficit following para symphysis fracture were recorded, statistically analyzed and results and observation were prepared from it.Results: The patients with age group 21-30 diagnosed with para symphysis fracture constituted 25% of all operated case and were found to be more associated with midface and angle fracture. Etiology behind the trauma was mostly as a result of RTA. Neurosensory disturbances as a result of mental nerve injury were found to be associated in 20.89% case, out of which in most of the cases, it gradually recovered within a duration of 7-15 days.Conclusions: RTA’s have been a prime cause for para symphysis fracture, which may at times accompany neurosensory deficit following trauma or may occur post-surgery, has been found to cause troublesome sequelae and reduced quality of life. Moreover, further research study needs to be carried out over a larger time span having a larger group of patients

Obesity in pregnancy: maternal and perinatal outcome

Background: The objective of this study was to find out the spectrum of complications during pregnancy due to maternal obesity with incidence and to assess the neonatal outcome.Methods: Retrospective study of antenatal patients was done in Sardar Vallabhbhai Patel Institute of Medical Sciences and Research (SVPIMSR), Ahmedabad from June 2019 to December 2019. Antenatal patients were categorized into 3 classes based on body mass index (BMI): class I=30-34.9 kg/m2, class II=35-39.9 kg/m2, and class III ≥40 kg/m2. The maternal and perinatal outcome of the patients was evaluated in relation to BMI.Results: A total of 61 women were included in the study, with 44 belonging to class I, 15 women to class II and 2 women to class III. In class I, 27% women had pre-eclampsia and its incidence increased with class II (69.2%) and class III (100%). The incidence of gestational diabetes mellitus (GDM) increases with increase in BMI (class I=5.4%, class II=7.6% and class III=50%). Incidence of fetal growth restriction (FGR) (7.6% and 2.7%) and post term pregnancy (38% and 16.2%) more in class II compared to class I respectively. Lower segment caesarean section (LSCS) rates are seen to be highest in class III (100%) as compared to class II (53%) and class I (50%). Class III (50%) women were more likely to have macrosomic babies than class II (40%) and class I (34.1%).Conclusions: Interventions directed towards weight loss and prevention of excessive weight gain must begin in the preconceptional period. Obese mothers must be counselled regarding risk and complications of obesity and importance of weight loss

Peak cardiac power output and cardiac reserve in sedentary men and women

Background and Purpose: Cardiac power output (CPO) and cardiac reserve (CR) are novel parameters of overall cardiac function. The purpose of this study was to determine differences in values of the CPO at rest and peak exercise and CR in sedentary men and women. Material and Methods: Thirty healthy men (age 21.2±0.7 years, body mass 63±6.3 kg, height 168.3±5.1 cm) and thirty healthy women (age 21.3±1.9 years, mass 82.5±7.9 kg, height 181.9±4.9 cm) were included in this study. Echocardiography was used to assess cardiac and hemodynamic parameters. CPO was calculated, at rest and after performed maximal bicycle test, as the product of cardiac output and mean arterial pressure, and CR as the difference of CPO value measured at peak exercise and at rest. Results: At rest, the two groups had similar values of cardiac power output (1.04±0.3W versus 1.14±0.25W, p>0.05). CPO after peak exercise was higher in men (5.1±0.72W versus 3.9±0.58W, p<0.05), as was cardiac reserve (3.96±0.64W versus 2.86±0.44W, p<0.05), respectively. After allometric scaling method was used to decrease the effect of body size on peak CPO, men still had significantly higher peak CPO (2.79±0.4 W m-2 versus 2.46±0.32 W m-2, p<0.05). At peak exercise, a significant positive relationship was found between cardiac power output and end diastolic volume (r=0.60), end diastolic left ventricular internal dimension (r=0.58), stroke volume (r=0.86) and cardiac output (r=0.87). Conclusion: The study showed that men had higher CPO after peak exercise and greater cardiac reserve than women, even after decreasing body size effect

Peak cardiac power output and cardiac reserve in sedentary men and women

Background and Purpose: Cardiac power output (CPO) and cardiac reserve (CR) are novel parameters of overall cardiac function. The purpose of this study was to determine differences in values of the CPO at rest and peak exercise and CR in sedentary men and women. Material and Methods: Thirty healthy men (age 21.2±0.7 years, body mass 63±6.3 kg, height 168.3±5.1 cm) and thirty healthy women (age 21.3±1.9 years, mass 82.5±7.9 kg, height 181.9±4.9 cm) were included in this study. Echocardiography was used to assess cardiac and hemodynamic parameters. CPO was calculated, at rest and after performed maximal bicycle test, as the product of cardiac output and mean arterial pressure, and CR as the difference of CPO value measured at peak exercise and at rest. Results: At rest, the two groups had similar values of cardiac power output (1.04±0.3W versus 1.14±0.25W, p>0.05). CPO after peak exercise was higher in men (5.1±0.72W versus 3.9±0.58W, p<0.05), as was cardiac reserve (3.96±0.64W versus 2.86±0.44W, p<0.05), respectively. After allometric scaling method was used to decrease the effect of body size on peak CPO, men still had significantly higher peak CPO (2.79±0.4 W m-2 versus 2.46±0.32 W m-2, p<0.05). At peak exercise, a significant positive relationship was found between cardiac power output and end diastolic volume (r=0.60), end diastolic left ventricular internal dimension (r=0.58), stroke volume (r=0.86) and cardiac output (r=0.87). Conclusion: The study showed that men had higher CPO after peak exercise and greater cardiac reserve than women, even after decreasing body size effect

Evaluation of efficacy of submucosal tramadol after mandibular third molar surgery: a prospective pilot study

Background: Surgical extraction of mandibular third molar is one of the most commonly performed procedure in oral and maxillofacial surgery. Its removal causes swelling, trismus, and moderate to severe pain which can be treated with various NSAID’s drugs, which have numerous side effects and gastric disturbances. In order to bypass such disturbances, Tramadol may be considered as an alternative for such patients. The aim of the study was to evaluate analgesic efficacy of submucosal tramadol and its implication over swelling and mouth opening after mandibular third molar surgery.Methods: This is a prospective study where in after post-surgical extraction of mandibular third molar, efficacy of submucosal injection of tramadol is evaluated in terms of pain and its implication over swelling and mouth opening.Results: The present study suggested there was statistically significant VAS score for pain after submucosally injecting tramadol post-surgical extraction of mandibular third molar in the following visits- 4hourly, 8hourly and 24hourly. In respect to swelling, statistically significant values was noted during 24hr and 72 h our post extraction. Also in case of mouth opening, statistically significant values were found 24 hourly.Conclusions: The present pilot study concluded that submucosal tramadol post mandibular third molar extraction has been effective in reducing pain, limiting post-extraction swelling and less impacting mouth opening by inducing less complications thereby bypassing gastric disturbances