Journals
2019 EN
Sherwan A. Hamawandi · Injam Ibrahim Sulaiman · Ameer Kadhim Al-Humairi.
Background. Lumbar spinal stenosis most often results from a gradual, degenerative ageing process. Open or wide decompressive laminectomy was formerly the standard treatment. However, in recent years, a growing tendency towards less invasive decompressive procedures has emerged. The purpose of this study was to compare the results of microdecompression with those of open wide laminectomy and posterior stabilization for patients with symptomatic multilevel lumbar spinal stenosis who failed to respond to conservative treatment. Methods. This randomized controlled study was conducted between January 2016 and October 2018. One hundred patients were involved in this study. All these patients suffered from radicular leg pain with MRI features of multilevel lumbar spinal stenosis and were treated by conservative treatment of medical treatment and physiotherapy without benefit for 6 months. Those patients were divided into two groups: Group A, 50 microdecompression, and Group B, 50 patients who were treated by open wide laminectomy and posterior stabilization. Both groups of patients were followed up with ODI (Oswestry disability index) and VAS (visual analogue score) for the back and leg pain for one year. Results. The results showed that both groups got significant improvement regarding the Oswestry disability index. Regarding back pain, there was a significant improvement in both groups with better results in group A due to minimal tissue injury as the advantage of the minimal invasive technique. In both groups, there was marked improvement of radicular leg pain postoperatively. Conclusions. Both microdecompression and wide open laminectomy with posterior stabilization were effective in treatment of multilevel lumbar spinal stenosis with superior results of microdecompression regarding less back pain postoperatively with less blood loss and soft tissue dissection. Clinical trial number: NCT04087694.
Journals
2019 EN
Ameer E Hassan · Hafsah Shamim · Haralabos Zacharatos
+6 more
Background: Studies have shown a lack of agreement of computed tomography perfusion (CTP) in the selection of acute ischemic stroke (AIS) patients for endovascular treatment. Purpose: To demonstrate whether non-contrast computed tomography (CT) within 8 h of symptom onset is comparable to CTP imaging. Methods: Prospective study of consecutive anterior circulation AIS patients with a National Institute of Health Stroke Scale (NIHSS) score > 7 presenting within 8 h of symptom onset with endovascular treatment. All patients had non-contrast CT, CT angiography, and CTP. The neuro-interventionalist was blinded to the results of the CTP and based the treatment decision using the Alberta Stroke Program Early CT score (ASPECTS). Baseline demographics, co-morbidities, and baseline NIHSS scores were collected. Outcomes were modified Rankin scale (mRS) score at discharge and in-hospital mortality. Good outcomes were defined as a mRS score of 0–2. Results: 283 AIS patients were screened for the trial, and 119 were enrolled. The remaining patients were excluded for: posterior circulation stroke, no CTP performed, could not obtain consent, and NIHSS score < 7. Mean NIHSS score at admission was 16.8 ± 3, and mean ASPECTS was 8.4 ± 1.4. There was no statistically significant correlation with CTP penumbra and good outcomes: 50 versus 47.8% with no penumbra present (p = 0.85). In patients without evidence of CTP penumbra, there was 22.5% mortality compared to 22.1% mortality in patients with a CTP penumbra. If ASPECTS ≥7, 64.6% had good outcome versus 13.3% if ASPECTS < 7 (p < 0.001). Patients with an ASPECTS ≥7 had 10% mortality versus 51.4% in patients with an ASPECTS < 7 (p < 0.001). Conclusions: CTP penumbra did not identify patients who would benefit from endovascular treatment when patients were selected with non-contrast CT ASPECTS ≥7. There is no correlation of CTP penumbra with good outcomes or mortality. Larger prospective trials are warranted to justify the use of CTP within 6 h of symptom onset.
Journals
2019 EN
K.E. Kaharudin · Z. A. F. M. Napiah · F. Salehuddin
+2 more
The main challenge in MOSFET minituarization is to form an ultra-shallow source/drain (S/D) junction with high doping concentration gradient, which requires an intricate S/D and channel engineering. Junctionless MOSFET configuration is an alternative solution for this issue as the junction and doping gradients is totally eliminated. A process simulation has been developed to investigate the impact of junctionless configuration on the double-gate vertical MOSFET. The result proves that the performance of junctionless double-gate vertical MOSFETs (JLDGVM) are superior to the conventional junctioned double-gate vertical MOSFETs (JDGVM). The results reveal that the drain current (I D ) of the n-JLVDGM and p-JLVDGM could be tremendously enhanced by 57% and 60% respectively as the junctionless configuration was applied to the double-gate vertical MOSFET. In addition, junctionless devices also exhibit larger I ON /I OFF ratio and smaller subthreshold slope compared to the junction devices, implying that the junctionless devices have better power consumption and faster switching capability.
Institute of Advanced Engineering and Science (IAES)
Journals
2019 EN
K.E. Kaharudin · F. Salehuddin · Anis Suhaila Mohd Zain
+1 more
The junctionless MOSFET architectures appear to be attractive in realizing the Moore’s law prediction. In this paper, a comprehensive 2-D simulation on junctionless vertical double-gate MOSFET (JLDGVM) under geometric and process consideration was introduced in order to obtain excellent electrical characteristics. Geometrical designs such as channel length (Lch) and pillar thickness (Tp) were considered and the impact on the electrical performance was analyzed. The influence of doping concentration and metal gate work function (WF) were further investigated for achieving better performance. The results show that the shorter Lch can boost the drain current (ID) of n-JLDGVM and p-JLDGVM by approximately 68% and 70% respectively. The ID of the n-JLVDGM and p-JLVDGM could possibly boost up to 42% and 78% respectively as the Tp is scaled down from 11nm to 8nm. The channel doping (Nch) is also a critical parameter, affecting the electrical performance of both n-JLDGVM and p-JLDGVM in which 15% and 39% improvements are observed in their respective ID as the concentration level is increased from 1E18 to 9E18 atom/cm3. In addition, the adjustment of threshold voltage can be realized by varying the metal WF.
Institute of Advanced Engineering and Science (IAES)
Journals
2019 EN
Ameer F. Roslan · F. Salehuddin · Anis Suhaila Mohd Zain
+5 more
This paper investigates the impact of the high-K material gate spacer on short channel effects (SCEs) for the 16 nm double-gate FinFET (DG-FinFET), where depletion-layer widths of the source-drain corresponds to the channel length. Virtual fabrication process along with design modification throughout the study and its electrical characterization is implemented and significant improvement is shown towards the altered structure design whereby in terms of the ratio of drive current against the leakage current (I ON /I OFF ratio), all three materials tested being S 3 N 4 , HfO 2 and TiO 2 increases from the respective 60.90, 80.70 and 84.77 to 84.77, 91.54 and 92.69. That being said, the incremental in ratio has satisfied the incremental on the drive current as well as decreases the leakage current. Threshold voltage (V TH ) for all dielectric materials have also satisfy the minimum requirement predicted by the International Technology Roadmap Semiconductor (ITRS) 2013 for which is at 0.461±12.7% V. Based on the results obtained, the high-K materials have shown a significant improvement, specifically after the modifications towards the Source/Drain. Compared to the initial design made, TiO 2 has improved by 12.94% after the alteration made in terms of the overall I ON and I OFF performances through the I ON /I OFF ratio value obtained, as well as meeting the required value for V TH obtained at 0.464V. The I ON from high-K materials has proved to meet the minimum requirement by ITRS 2013 for low performance Multi-Gate technology.
Institute of Advanced Engineering and Science (IAES)
Journals
2019 EN
Badriyah Ahmed Obaid · Ameer L. Saleh · Abbas K. Kadhim
This paper exhibits a design procedure for tuning the parameters of Fractional Order Proportional Integral Derivative (FOPID) P controller to optimize the DC motor drive operation. The optimization technique is establishing on Invasive Weed Optimization (IWO). This paper also proposes the use of anti-windup aspect to against the saturation which may occur in the FOPID controller. The objective of this design is to improve the performance of the drive subjected to different transient response and loading conditions. A comparative study is carried out with a classical PID controller. The Matlab simulation results show more improvements in the proposed system.
Institute of Advanced Engineering and Science (IAES)
Journals
2019 EN
Adel A. Obed · Ameer L. Saleh · Abbas K. Kadhim
In this paper, several methods are developed to control the brushless DC (BLDC) motor speed. Since it is difficult to get a good showing by utilizing classical PID controller, the Dynamic Wavelet Neural Network (DWNN) is the proposed work in this paper, with parallel PID controller to obtain an novel controller named DWNN-PID controller. It collects the artificial neural ability of its networks for imparting from motor of BLDC with drive system and the ability of identification for the wavelet decomposition and control of the dynamic system furthermore to have ability for adapting and self-learning. The suggested controller method is utilizing to control the speed of BLDC motor of which supply a better showing than utilizing classical controllers with a wide range of control. The proposed controller parameters are matched continuously using Particle Swarm Optimization (PSO) algorithm. The simulation results based on proposed DWNN-PID controller demonstrate a superior in the stability and performance compared at utilizing classical WNN-PID and conventional PID controllers. The simulation results are accomplished using Matlab/Simulink. It shows that the proposed control scheme has a superior performance.
Institute of Advanced Engineering and Science (IAES)
Journals
2019 EN
Khalid Hadi Aldosari · Yazeed Mohammed Aldhfyan · Mohammed H. Karrar Alsharif
+4 more
Road traffic accidents (RTAs) are the most frequent cause of traumatic spinal injuries (TSIs), which account for up to 33.6% of all spinal fractures. The Kingdom of Saudi Arabia (KSA) is one of the countries which has high rates of SCIs and bears the economic burden of that situation. Methods 120 patients were included in this study, using a stringent set of inclusion and exclusion criteria. The patients were followed-up from the point of triage to admission and discharge. We analysed the clinical notes of the patients to determine the severity of their traumatic spinal injuries, the neurosurgical management carried out, and other prognosticating factors such as blood transfusion and the Glasgow Coma Scale (GCS). The data collected was analysed anonymously, and the confidentiality of all participants was respected. Results Most of the patients were young adults and adolescents under the age of 40 (n = 96). There was a male preponderance of 84.1%. With respect to spinal injury stratification, 55 patients had cervical spine fractures, 10 patients had cervical lacerations, 85 patients had thoracolumbar spinal fractures, and 10 patients had thoracolumbar spinal lacerations. 35 patients had other fractures documented. All 120 patients were followed up to assess the management of their traumatic spinal injuries. 66.6% (n= 80) of all patients were managed conservatively, whereas the remaining 33.3% (n=40) were managed surgically. Conclusion Trauma is an important cause of spinal injuries (TSIs), and untreated TSIs may lead to poor clinical outcome, especially if the cervical region is involved.
African Field Epidemiology Network
Journals
2019 EN
Dean J. Kereiakes · Stephen G. Ellis · D. Christopher Metzger
+12 more
The Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) provides early drug delivery and mechanical support similar to those of metallic drug-eluting stents, followed by complete resorption in ≈3 years with recovery of vascular structure and function. The ABSORB III trial demonstrated noninferior rates of target lesion failure (cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year with BVS compared with cobalt chromium everolimus-eluting stents. Between 1 and 3 years and cumulative to 3 years, adverse event rates (particularly target vessel myocardial infarction and scaffold thrombosis) were increased after BVS. We sought to assess clinical outcomes after BVS through 5 years, including beyond the 3-year time point of complete scaffold resorption.
Lippincott Williams & Wilkins
Journals
2019 EN
Osama O. Zaidat · Nils MuellerKronast · Ameer E Hassan
+61 more
Background and Purpose- Mechanical thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke. However, the impact of balloon guide catheter (BGC) use is not well established. Methods- STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever as first-line therapy. In this study, an independent core laboratory, blinded to the clinical outcomes, reviewed all procedures and angiographic data to classify procedural technique, target clot location, recanalization after each pass, and determine the number of stent retriever passes. The primary clinical end point was functional independence (modified Rankin Scale, 0-2) at 3 months as determined on-site, and the angiographic end point was first-pass effect (FPE) success rate from a single device attempt (modified Thrombolysis in Cerebral Infarction, ≥2c) as determined by a core laboratory. Achieving modified FPE (modified Thrombolysis in Cerebral Infarction, ≥2b) was also assessed. Comparisons of clinical outcomes were made between groups and adjusted for baseline and procedural characteristics. All participating centers received institutional review board approval from their respective institutions. Results- Adjunctive technique groups included BGC (n=445), distal access catheter (n=238), and conventional guide catheter (n=62). The BGC group had a higher rate of FPE following first pass (212/443 [48%]) versus conventional guide catheter (16/62 [26%]; P=0.001) and distal access catheter (83/235 [35%]; P=0.002). Similarly, the BGC group had a higher rate of modified FPE (294/443 [66%]) versus conventional guide catheter (26/62 [42%]; P<0.001) and distal access catheter (129/234 [55%]; P=0.003). The BGC group achieved the highest rate of functional independence (253/415 [61%]) versus conventional guide catheter (23/55 [42%]; P=0.007) and distal access catheter (113/218 [52%]; P=0.027). Final revascularization and mortality rates did not differ across the groups. Conclusions- BGC use was an independent predictor of FPE, modified FPE, and functional independence, suggesting that its routine use may improve the rates of early revascularization success and good clinical outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.
Lippincott Williams & Wilkins