Unconventional Breathing Currents Far beyond the Quantum Tunneling Distances in Large-Gapped Nanoplasmonic Systems.

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles propels the field of plasmo-electronics, holding promise for transformative optoelectronic devices through efficient light-to-current conversion. Plasmonic excitations strongly influence the charge distribution within nanoparticles, giving rise to electromagnetic fields that can significantly impact the macroscopic charge flows within the nanoparticle housing material. In this study, we present evidence of ultralow, unconventional breathing currents resulting from dynamic irradiance interactions between widely separated nanoparticles, extending far beyond conventional electron (quantum) tunneling distances. We develop an electric analogue model and derive an empirical expression to elucidate the generation of these unconventional breathing currents in cascaded nanoplasmonic systems under irradiance modulation. This technique and theoretical model have significant potential for applications requiring a deeper understanding of current dynamics, particularly on large nanostructured surfaces relevant to photocatalysis, energy harvesting, sensing, imaging, and the development of future photonic devices.

Complications in children with ventricular assist devices: systematic review and meta-analyses.

Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients' symptoms, age, and severity of their condition, with heart transplantation required when other treatments are unsuccessful. However, due to lack of fitting donor organs, many patients are left untreated, or their transplant is delayed. In these patients, ventricular assist devices (VADs) are used to bridge to heart transplant. However, VAD support presents various complications in patients. The aim of this study was to compile, review, and analyse the studies reporting risk factors and aetiologies of complications of VAD support in children. Random effect risk ratios (RR) with 95% confidence intervals were calculated to analyse relative risk of thrombosis (RR = 3.53 [1.04, 12.06] I2 = 0% P = 0.04), neurological problems (RR = 0.95 [0.29, 3.15] I2 = 53% P = 0.93), infection (RR = 0.31 [0.05, 2.03] I2 = 86% P = 0.22), bleeding (RR = 2.57 [0.76, 8.66] I2 = 0% P = 0.13), and mortality (RR = 2.20 [1.36, 3.55] I2 = 0% P = 0.001) under pulsatile-flow and continuous-flow VAD support, relative risk of mortality (RR = 0.45 [0.15, 1.37] I2 = 36% P = 0.16) under left VAD and biVAD support, relative risk of thrombosis (RR = 1.72 [0.46, 6.44] I2 = 0% P = 0.42), infection (RR = 1.77 [0.10, 32.24] I2 = 46% P = 0.70) and mortality (RR = 0.92 [0.14, 6.28] I2 = 45% P = 0.93) in children with body surface area < 1.2 m2 and > 1.2 m2 under VAD support, relative risk of mortality in children supported with VAD and diagnosed with cardiomyopathy and congenital heart diseases (RR = 1.31 [0.10, 16.61] I2 = 73% P = 0.84), and cardiomyopathy and myocarditis (RR = 0.91 [0.13, 6.24] I2 = 58% P = 0.92). Meta-analyses results show that further research is necessary to reduce complications under VAD support.

Assessment of cardiac dimensions in children diagnosed with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant heart disease, characterized by increased left ventricular wall thickness and abnormal loading conditions. Imaging modalities are the first choice for diagnosis and risk stratification. Although heart dimensions have been characterized widely in HCM adults from cardiac imaging, there is limited information about children affected by HCM. The aim of this study is to evaluate left ventricular function and left heart dimensions in a small population of children diagnosed with HCM. METHODS: A total of 16 (seven male, nine female) pediatric patients with an average age of 14.0 ± 2.5 years diagnosed with HCM at Great Ormond Street Hospital for Children were included in this study. Cardiac magnetic resonance (CMR) images were used to measure left and right ventricular dimensions, and septal and left ventricular free wall thicknesses in Simpleware ScanIP. The gender groups were compared using student t-test or non-parametric Mann-Whitney U-test depending on the sample distribution. RESULTS: Differences in heart rate, left ventricular end-diastolic volume and end-diastolic volume index, left ventricular stroke volume and stroke volume index, left ventricular end-systolic long axis length, left ventricular end-systolic long axis length index, left ventricular end-diastolic mid-cavity diameter, left ventricular end-diastolic free wall thickness, left ventricular end-diastolic free wall thickness index, right ventricular end-diastolic long axis length were statistically significant in males and females. CONCLUSION: Left ventricular wall and intraventricular septal thickness increase affecting left ventricle cavity dimensions and there may be differences in anatomical and physiological parameters in males and females affected by HCM.

Computational Evaluation of Potential Correction Methods for Unicoronal Craniosynostosis.

Unicoronal craniosynostosis is the second most common type of nonsyndromic craniosynostosis: it is characterized by ipsilateral forehead and fronto-parietal region flattening with contralateral compensatory bossing. It is a complex condition; therefore, which is difficult to treat because of the asymmetry in the orbits, cranium, and face. The aim of this study is to understand optimal osteotomy locations, dimensions, and force requirements for surgical operations of unicoronal craniosynostosis using a patient-specific finite element model and - at the same time - to evaluate the potential application of a new device made from Nitinol which was developed to expand the affected side of a unicoronal craniosynostosis skull without performing osteotomies. The model geometry was reconstructed using Simpleware ScanIP. The bone and sutures were modeled using elastic properties to perform the finite element analyses in MSc Marc software. The simulation results showed that expanding the cranium without osteotomy requires a significant amount of force. Therefore, expansion of the cranium achieved by Nitinol devices may not be sufficient to correct the deformity. Moreover, the size and locations of the osteotomies are crucial for an optimal outcome from surgical operations in unicoronal craniosynostosis.

The Science Behind the Springs: Using Biomechanics and Finite Element Modeling to Predict Outcomes in Spring-Assisted Sagittal Synostosis Surgery.

Spring-assisted surgery for the correction of scaphocephaly has gained popularity over the past 2 decades. Our unit utilizes standardized torsional springs with a central helix for spring-assisted surgery. This design allows a high degree of accuracy and reproducibility of the force vectors and force distance curves. In this manuscript, we expand on the biomechanical testing and properties of these springs. Standardization of design has enabled us to study the springs on bench and in vivo and a comprehensive repository of calvarial remodeling and spring dynamics has been acquired and analyzed.Finite element modeling is a technique utilized to predict the outcomes of spring-assisted surgery. We have found this to be a useful tool, in planning our surgical strategy and improving outcomes. This technique has also contributed significantly to the process of informed consent preoperatively. In this article, we expand on our spring design and dynamics as well as the finite element modeling used to predict and improve outcomes.In our unit, this practice has led to a significant improvement in patient outcomes and parental satisfaction and we hope to make our techniques available to a wider audience.

Effect of Cerebral Flow Autoregulation Function on Cerebral Flow Rate Under Continuous Flow Left Ventricular Assist Device Support.

Neurological complications in continuous flow left ventricular assist device (CF-LVAD) patients are the second-leading risk of death after multi-organ failure. They are associated with altered blood flow in the cardiovascular system because of CF-LVAD support. Moreover, an impaired cerebral autoregulation function may also contribute to complications such as hyperperfusion in the cerebral circulation under mechanical circulatory support. The aim of this study is to evaluate the effect of cerebral autoregulatory function on cerebral blood flow rate under CF-LVAD support. A lumped parameter model was used to simulate the cardiovascular system including the heart chambers, heart valves, systemic and pulmonary circulations and cerebral circulation which includes entire Circle of Willis. A baroreflex model was used to regulate the systemic arteriolar and cerebral vascular resistances and a model of the Micromed CF-LVAD was used to simulate the pump dynamics at different operating speeds. Additionally, preserved and impaired cerebral autoregulatory functions were simulated in heart failure and under CF-LVAD support. Cerebral blood flow rate was restored under CF-LVAD support at 10 500 rpm pump operating speed which generated a similar arterial blood pressure and blood flow as in a healthy condition for the impaired cerebral autoregulatory function while the preserved cerebral autoregulatory function regulated the cerebral flow rate within a relatively low range for the applied pump operating speeds. Relatively low or high pump operating speeds may cause underpefusion or hyperperfusion for a failing cardiovascular system with impaired cerebral autoregulatory function under CF-LVAD support which will contribute to the worsening of cerebral complications.

Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

Ophthalmic findings in acute mercury poisoning in adults: A case series study.

The aim of this study is to report ophthalmic findings of acute mercury poisoning in 48 adults referred to emergency department. Full ophthalmologic examination including the best corrected visual acuity, external eye examination, reaction to light, a slit-lamp examination, funduscopy, intraocular pressure measurements, and visual field (VF) and color vision (CV) tests were performed at the presentation and repeated after 6 months. The parametric values of VF test, the mean deviation (MD), and pattern standard deviation (PSD) were recorded in order to compare patients and the 30 healthy controls. The mean parameter of color confusion index in patients was found to be statistically different than controls (p < 0.01). The MD and PSD in patients were different from controls statistically significant (p < 0.01 and p < 0.01, respectively). There was no correlation between the ocular findings and the urine and blood mercury levels. Methyl mercury, held in the school laboratory for experimental purpose, may be a source of poisoning. In this case series, we showed that acute exposure to mercury had hazardous effect on the visual system, especially CV and VF. We propose that emphasizing the public education on the potential hazards of mercury is crucial for preventive community health.

Effect of Ramadan fasting on serum concentration of apelin-13 and new obesity indices in healthy adult men.

BACKGROUND: The aim of this study was to determine how Ramadan fasting (RF) affected the recently described new obesity indices [visceral adiposity index (VAI), waist circumference to height ratio (WHtR), body adiposity index (BAI)], and serum concentration of apelin-13 (RF) in healthy adult men. MATERIAL AND METHODS: For this purpose, 42 healthy adult men were selected. Anthropometric parameters were measured and a sample of venous blood was obtained for biochemical assays on the first and last days of Ramadan. When all subjects were evaluated, all anthropometric parameters changed except VAI. Serum apelin-13, triglyceride (TG), HDL-cholesterol (HDL-C), and insulin levels did not change. When patients were divided into 3 groups according to body mass index (BMI), BAI decreased in normal-weight subjects and WHtR decreased in other groups, but VAI and apelin-13 did not change in any groups. RESULTS: We demonstrate for the first time that while some anthropometric parameters changed, VAI and serum apelin-13 levels did not change with RF. BMI, waist circumference (WC), TG, and HDL-C were evaluated together in calculation of VAI. TG, VAI, and HDL-C remained unchanged by RF. Even if body weight (BW) and BMI decreased, apelin-13 was not affected by RF. The data on serum apelin-13 may have been influenced by the small-percentage decrease in BW, as well as insignificant improvements in metabolic parameters such as lipid profiles, glucose, and insulin. CONCLUSIONS: We found that Ramadan fasting in healthy adult men was associated with significant decreases in BW, BMI, WHtR, and BAI, but we found no significant changes in VAI and serum apelin-13 concentrations.

Use of topical anesthetic and non-medical alternatives in welding workers regarding ophthalmic problems.

PURPOSE: Welding workers' ophthalmic problems resulting from their professions are frequently observed in ophthalmic emergencies and can cause severe visual impairment. We aimed to investigate the use of topical anesthetic and non-medical alternatives of this population regarding ophthalmic problems in this study. MATERIALS AND METHODS: The study included 204 welding workers randomly selected from a population of 1852 people who had at least one-year experience as a welding worker and who were members of a chamber of welding workers. Data were collected at face to face interviews with a questionnaire composed of questions about ophthalmic problems caused by their profession and about how they eliminated these problems. Obtained data were analyzed with SPSS. RESULTS: Of 204 workers, 38.7% preferred non-medical alternatives including application of potatoes (22%), dressing with tea (17%), rinsing with cold water (3.4%) and closing eyes (2%). 30.5% of the participants used topical anesthetics (72% commercial and 28% prepared in pharmacies). There was a significant relation between use of non-medical methods and topical anesthetics, and workers' education, duration of work experience and receiving training from their seniors (p < 0.05). CONCLUSION: Use of non-medical methods and topical anesthetics by welding workers was found to be associated with low-education levels and insufficient knowledge about ophthalmologic problems due their professions and their treatment. They should be provided with appropriate training for the issue and precautions should be taken to prevent people from buying drugs without a prescription.

Computational evaluation of heart failure and continuous flow left ventricular assist device support in anaemia.

Anaemia is common in end-stage heart failure patients supported with continuous flow left ventricular assist device (CF-LVAD) and is associated with adverse outcomes such as heart failure readmission. This study evaluates the haemodynamic effects of anaemia on cardiac function and cerebral blood flow in heart failure patients supported with CF-LVAD using computational simulations. A dynamic model simulating cardiac function, systemic, pulmonary and cerebral circulations, cerebral flow autoregulatory mechanisms and gas contents in blood was used to evaluate the effects of anaemia and iron deficiency in heart failure and during CF-LVAD support. CF-LVAD therapy was simulated by a model describing HeartMate 3. Anaemia and iron deficiency were simulated by reducing the haemoglobin level from 15 to 9 g/dL and modifying scaling coefficients in the models simulating heart chamber volumes. Reduced haemoglobin levels decreased the arterial O2 content, which increased cerebral blood flow rate by more than 50% in heart failure and during CF-LVAD assistance. Reduced haemoglobin levels simulating anaemia had minimal effect on the arterial and atrial blood pressures and ventricular volumes. In contrast, iron deficiency increased end-diastolic left and right ventricular diameters in heart failure from 6.6 cm to 7 cm and 2.9 cm to 3.1 cm and during CF-LVAD support from 6.1 to 6.4 cm and 3.1 to 3.3 cm. The developed numerical model simulates the effects of anaemia in failing heart and during CF-LVAD therapy. It is in good agreement with clinical data and can be utilised to assess CF-LVAD therapy.

Design and Analysis of a Polymeric Left Ventricular Simulator via Computational Modelling.

Preclinical testing of medical devices is an essential step in the product life cycle, whereas testing of cardiovascular implants requires specialised testbeds or numerical simulations using computer software Ansys 2016. Existing test setups used to evaluate physiological scenarios and test cardiac implants such as mock circulatory systems or isolated beating heart platforms are driven by sophisticated hardware which comes at a high cost or raises ethical concerns. On the other hand, computational methods used to simulate blood flow in the cardiovascular system may be simplified or computationally expensive. Therefore, there is a need for low-cost, relatively simple and efficient test beds that can provide realistic conditions to simulate physiological scenarios and evaluate cardiovascular devices. In this study, the concept design of a novel left ventricular simulator made of latex rubber and actuated by pneumatic artificial muscles is presented. The designed left ventricular simulator is geometrically similar to a native left ventricle, whereas the basal diameter and long axis length are within an anatomical range. Finite element simulations evaluating left ventricular twisting and shortening predicted that the designed left ventricular simulator rotates approximately 17 degrees at the apex and the long axis shortens around 11 mm. Experimental results showed that the twist angle is 18 degrees and the left ventricular simulator shortens 5 mm. Twist angles and long axis shortening as in a native left ventricle show it is capable of functioning like a native left ventricle and simulating a variety of scenarios, and therefore has the potential to be used as a test platform.

Plasma exchange as a complementary approach to snake bite treatment: an academic emergency department's experiences.

Snake bites are leading causes of morbidity and mortality worldwide, especially in rural areas. Therapeutic plasma exchange has been used in the treatment of many different conditions such as immunologic diseases, toxicologic disorders, and snake envenomation. The aim of this study is to evaluate the efficacy of plasma exchange treatment on clinical status, outcomes, and discharge of patients who were bitten by venomous snakes. The study was conducted retrospectively in the Emergency Department of Gaziantep University from January 2002 to December 2011. Thirty-seven patients were included in the present study. Routine biochemical and hematologic laboratory parameters were studied before and after plasma exchange. Demographic data, clinical status, and outcomes of patients were recorded. Plasma exchange was performed by using centrifugation technology via an intravenous antecubital or subclavian vein catheter access. Human albumin/fresh frozen plasma was used as replacement fluids. A significant correlation was seen between therapeutic plasma exchange and improvement of laboratory results. None of the study patients lost their limbs. Eight patients were sent to the intensive care unit. The mean length of the hospital stay was 12.2 days (4-28). All patients were discharged with good recovery. No complications were seen during the 3 months following discharge. Plasma exchange appears to be an effective treatment intervention for snake bite envenomations, especially in the management of hematologic problems and in limb preservation/salvage strategies. In addition to traditional treatment methods, plasma exchange should be considered by emergency physicians in cases of snake bite envenomation as a therapeutic approach to facilitate rapid improvement.

Correlation of volume, position of stone, and hydronephrosis with microhematuria in patients with solitary urolithiasis.

BACKGROUND: The aim of this study was to determine the relationship between hematuria and volume, position of stone, and hydronephrosis in patients with a solitary stone, using unenhanced multidetector computed tomography (MDCT). MATERIAL AND METHODS: This retrospective study evaluated the clinical and radiological records of 83 patients undergoing MDCT for the evaluation of acute flank pain and suspected renal colic, who also underwent a microscopic urinalysis at the emergency department of our hospital during a 1-year period. Inclusion criteria of the MDCT study were solitary urolithiasis and cumulative stone diameter under 1 cm. RESULTS: A total of 83 patients were included in the study, with a mean age of 42.1±14.4 years; 48 (57.8%) were females and 35 (42.2%) were males. Detection of 5 or more red cells on urinalysis was regarded as microscopic hematuria, and was positive in 46 patients (55.4%). There was a positive correlation between the position of the stone (especially upper two-thirds ureteral stones) and microhematuria rate (r: 0.28, p=0.009). There was a statistically significant difference in presence of hydronephrosis between the microhematuria (36 patients, 78%) and non-microhematuria (12 patients, 32%) groups (p<0.001). The median stone volume between the microhematuria and non-microhematuria groups were not statistically different, 37.5 mm3 (range 5-425) and 28 mm3 (range 4-412), respectively (p=0.39). CONCLUSIONS: Although stone volume is one of the best indicators of stone burden, it was not correlated with microhematuria. However, in patients with renal colic, microhematuria requires ultrasound examination whether hydronephrosis and ureteral stones are present or not. Further studies with larger sample sizes are warranted.

Elevated red blood cell distribution width and inflammation in printing workers.

BACKGROUND: The aim of this study was to estimate the effects of exposure to chemical compounds on systemic biochemical inflammatory markers in printing industry workers. MATERIAL/METHODS: Fifty-eight printing workers from 19 different small- and medium-sized enterprises in the printing sector were investigated. For comparison, 80 healthy workers not subjected to workplace chemicals served as control subjects. RESULTS: No significant differences were observed between the printing workers and control subjects with respect to age, BMI, waist circumference/hip circumference ratio, smoking, and alcohol consumption. Printing workers had significantly higher serum TNF-alpha levels (11.02 ± 5.34 vs. 9.26 ± 3.87 pg/ml, p=0.039), plasma fibrinogen levels (1.74 ± 0.49 vs. 1.38 ± 0.5 mg/dl, p=0.012), and red blood cell distribution width (RDW-SD) (49.77 ± 3.09 vs. 47.3 ± 2.88 p<0.01) compared to control subjects. CONCLUSIONS: Elevation of RDW, serum TNF-alpha, and plasma fibrinogen levels in printing workers may be due to systemic toxic effects of chemical compounds used in this sector. TNF-alpha is an inflammatory cytokine that has a wide spectrum of biological activities, and fibrinogen plays an important role in pathological processes. Some compounds may be carcinogenic or mutagenic. Better designed workplaces and working conditions will help to reduce the hazardous effects of chemical compounds.

Bilateral thalamic infarct as a diagnosed conversion disorder.

Bilateral thalamic infarcts are an uncommon type of cerebral infarct. Bilateral paramedian thalamic infarctions may lead to a severe impairment of consciousness. The sudden onset of a lethargy or comatose state, in the absence of motor deficits, easily evokes the idea of a subarachnoid hemorrhage. Other patients present with behavior changes, disorientation in space and time, memory loss, or thought disorders. We believe that bilateral thalamic infarction is often missed in emergency department (ED) in relatively young patients, especially when magnetic resonance imaging is not performed. In these cases, the patient can be discharged with various psychiatric diagnoses. We suggest that bilateral thalamic infarct should be considered in patients in the ED with new diagnoses of conversion disorder.

Computational Modelling of Cerebral Blood Flow Rate at Different Stages of Moyamoya Disease in Adults and Children.

Moyamoya disease is a cerebrovascular disorder which causes a decrease in the cerebral blood flow rate. In this study, a lumped parameter model describing the pressures and flow rates in the heart chambers, circulatory system, and cerebral circulation with the main arteries in the circle of Willis, pial circulation, cerebral capillaries, and veins was used to simulate Moyamoya disease with and without coarctation of the aorta in adults and children. Cerebral blood flow rates were 724 mL/min and 1072 mL/min in the healthy adult and child cardiovascular system models. The cerebral blood flow rates in the adult and child cardiovascular system models simulating Moyamoya disease were 676 mL/min and 1007 mL/min in stage 1, 627 mL/min and 892 mL/min in stage 2, 571 mL/min and 831 in stage 3, and 444 and 537 mL/min in stage 4. The cerebral blood flow rates were 926 mL/min and 1421 mL/min in the adult and child cardiovascular system models simulating coarctation of the aorta. Furthermore, the cerebral blood flow rates in the adult and child cardiovascular system model simulating Moyamoya disease with coarctation of the aorta were 867 mL/min and 1341 mL/min in stage 1, 806 mL/min and 1197 mL/min in stage 2, 735 mL/min and 1121 in stage 3, and 576 and 741 mL/min in stage 4. The numerical model utilised in this study can simulate the advancing stages of Moyamoya disease and evaluate the associated risks with Moyamoya disease.

Evaluation of Potential Effects of Increased Outdoor Temperatures Due to Global Warming on Cerebral Blood Flow Rate and Respiratory Function in Chronic Obstructive Disease and Anemia.

Global warming due to increased outdoor carbon dioxide (CO2) levels may cause several health problems such as headaches, cognitive impairment, or kidney dysfunction. It is predicted that further increases in CO2 levels will increase the morbidity and mortality of patients affected by a variety of diseases. For instance, patients with Chronic Obstructive Pulmonary Disease (COPD) may suffer cognitive impairments or intracranial bleeding due to an increased cerebral blood flow rate. Predicting the harmful effects of global warming on human health will help to take measures for potential problems. Therefore, the quantification of physiological parameters is an essential step to investigate the effects of global warming on human health. In this study, the effects of increased outdoor temperatures due to climate change on cerebral blood flow rate and respiratory function in healthy subjects and COPD patients with anemia and respiratory acidosis are evaluated utilizing numerical simulations. The numerical model simulates cardiac function and blood circulation in systemic, pulmonary and cerebral circulations, cerebral autoregulatory functions, respiratory function, alveolar gas exchange, oxygen (O2) and CO2 contents, and hemoglobin levels in the blood. The simulation results show that although the cardiovascular function is not significantly altered, the respiratory function and cerebral blood flow rates are altered remarkably.

Automated surgical planning in spring-assisted sagittal craniosynostosis correction using finite element analysis and machine learning.

Sagittal synostosis is a condition caused by the fused sagittal suture and results in a narrowed skull in infants. Spring-assisted cranioplasty is a correction technique used to expand skulls with sagittal craniosynostosis by placing compressed springs on the skull before six months of age. Proposed methods for surgical planning in spring-assisted sagittal craniosynostosis correction provide information only about the skull anatomy or require iterative finite element simulations. Therefore, the selection of surgical parameters such as spring dimensions and osteotomy sizes may remain unclear and spring-assisted cranioplasty may yield sub-optimal surgical results. The aim of this study is to develop the architectural structure of an automated tool to predict post-operative surgical outcomes in sagittal craniosynostosis correction with spring-assisted cranioplasty using machine learning and finite element analyses. Six different machine learning algorithms were tested using a finite element model which simulated a combination of various mechanical and geometric properties of the calvarium, osteotomy sizes, spring characteristics, and spring implantation positions. Also, a statistical shape model representing an average sagittal craniosynostosis calvarium in 5-month-old patients was used to assess the machine learning algorithms. XGBoost algorithm predicted post-operative cephalic index in spring-assisted sagittal craniosynostosis correction with high accuracy. Finite element simulations confirmed the prediction of the XGBoost algorithm. The presented architectural structure can be used to develop a tool to predict the post-operative cephalic index in spring-assisted cranioplasty in patients with sagittal craniosynostosis can be used to automate surgical planning and improve post-operative surgical outcomes in spring-assisted cranioplasty.

Parametric Design and Prototyping of a Low-Power Planar Biped Robot.

This study proposes a design approach and the development of a low-power planar biped robot named YU-Bibot. The kinematic structure of the robot consists of six independently driven axes, and it weighs approximately 20 kg. Based on biomimetics, the robot dimensions were selected as the average anthropomorphic dimensions of the human lower extremities. The optimization of the mechanical design and actuator selection of the robot was based on the results of parametric simulations. The natural human walking gait was mimicked as a walking pattern in these simulations. As a result of the optimization, a low power-to-weight ratio of 30 W/kg was obtained. The drive system of the robot joints consists of servo-controlled brushless DC motors with reduction gears and additional bevel gears at the knee and ankle joints. The robot features spring-supported knee and ankle joints that counteract the robot's weight and compensate for the backlash present in these joints. The robot is constrained to move only in the sagittal plane by using a lateral support structure. The robot's feet are equipped with low-cost, force-sensitive resistor (FSR)-type sensors for monitoring ground contact and zero-moment point (ZMP) criterion. The experimental results indicate that the proposed robot mechanism can follow the posture commands accurately and demonstrate locomotion at moderate stability. The proposed parametric natural gait simulation-based design approach and the resulting biped robot design with a low power/weight ratio are the main contributions of this study.