Footstep Adjustment for Biped Push Recovery on Slippery Surfaces

Despite extensive studies on motion stabilization of bipeds, they still suffer from the lack of disturbance coping capability on slippery surfaces. In this paper, a novel controller for stabilizing a bipedal motion in its sagittal plane is developed with regard to the surface friction limitations. By taking into account the physical limitation of the surface in the stabilization trend, a more advanced level of reliability is achieved that provides higher functionalities such as push recovery on low-friction surfaces and prevents the stabilizer from overreacting. The discrete event-based strategy consists of modifying the step length and time period at the beginning of each footstep in order to reestablish stability necessary conditions while taking into account the surface friction limitation as a constraint to prevent slippage. Adjusting footsteps to prevent slippage in confronting external disturbances is perceived as a novel strategy for keeping stability, quite similar to human reaction. The developed methodology consists of rough closed-form solutions utilizing elementary math operations for obtaining the control inputs, allowing to reach a balance between convergence and computational cost, which is quite suitable for real-time operations even with modest computational hardware. Several numerical simulations, including push recovery and switching between different gates on low-friction surfaces, are performed to demonstrate the effectiveness of the proposed controller. In correlation with human-gait experience, the results also reveal some physical aspects favoring stability and the fact of switching between gaits to reduce the risk of falling in confronting different conditions.Comment: for associated simulation video, see https://youtu.be/BWzUgHGdl3

A Survey on Environmentally Friendly Vehicle Routing Problem and a Proposal of Its Classification

The growth of environmental awareness and more robust enforcement of numerous regulations to reduce greenhouse gas (GHG) emissions have directed efforts towards addressing current environmental challenges. Considering the Vehicle Routing Problem (VRP), one of the effective strategies to control greenhouse gas emissions is to convert the fossil fuel-powered fleet into Environmentally Friendly Vehicles (EFVs). Given the multitude of constraints and assumptions defined for different types of VRPs, as well as assumptions and operational constraints specific to each type of EFV, many variants of environmentally friendly VRPs (EF-VRP) have been introduced. In this paper, studies conducted on the subject of EF-VRP are reviewed, considering all the road transport EFV types and problem variants, and classifying and discussing with a single holistic vision. The aim of this paper is twofold. First, it determines a classification of EF-VRP studies based on different types of EFVs, i.e., Alternative-Fuel Vehicles (AFVs), Electric Vehicles (EVs) and Hybrid Vehicles (HVs). Second, it presents a comprehensive survey by considering each variant of the classification, technical constraints and solution methods arising in the literature. The results of this paper show that studies on EF-VRP are relatively novel and there is still room for large improvements in several areas. So, to determine future insights, for each classification of EF-VRP studies, the paper provides the literature gaps and future research needs

A machine learning based exploration of COVID-19 mortality risk

Early prediction of patient mortality risks during a pandemic can decrease mortality by assuring efficient resource allocation and treatment planning. This study aimed to develop and compare prognosis prediction machine learning models based on invasive laboratory and noninvasive clinical and demographic data from patients’ day of admission. Three Support Vector Machine (SVM) models were developed and compared using invasive, noninvasive, and both groups. The results suggested that non-invasive features could provide mortality predictions that are similar to the invasive and roughly on par with the joint model. Feature inspection results from SVM-RFE and sparsity analysis displayed that, compared with the invasive model, the non-invasive model can provide better performances with a fewer number of features, pointing to the presence of high predictive information contents in several non-invasive features, including SPO2, age, and cardiovascular disorders. Furthermore, while the invasive model was able to provide better mortality predictions for the imminent future, non-invasive features displayed better performance for more distant expiration intervals. Early mortality prediction using non-invasive models can give us insights as to where and with whom to intervene. Combined with novel technologies, such as wireless wearable devices, these models can create powerful frameworks for various medical assignments and patient triage

Transient lateral rectus palsy associated with acute coronary syndrome treated with percutaneous coronary intervention: a case report

Abstract Background Patients who experience angina and acute myocardial infarction often receive diagnostic coronary angiography and percutaneous coronary intervention. Case presentation A 54-year-old Persian man with acute coronary syndrome was admitted to the hospital and underwent elective percutaneous coronary intervention. Two hours after the procedure, the patient experienced ophthalmoplegia and diplopia. The diagnosis was abducens nerve palsy resulting in transient lateral rectus palsy. The cause is presumed to have been an ischemic event affecting the unilateral abducens nerve. This could have occurred owing to the microembolism during the percutaneous coronary intervention, which resulted in left lateral rectus palsy. Within 1 month, the diplopia was relieved completely, and the physical examination was normal. Conclusion The occurrence of neuro-ophthalmic complications that may arise from percutaneous coronary intervention is extremely rare. To our knowledge, this is the second reported case of unilateral rectus palsy associated with percutaneous coronary intervention

The Impact of Oral Probiotics on Laboratory Parameters in Patients With Alcohol Toxicity: A Single-blinded Intervention Study

Background: Alcohol toxicity is a significant medical emergency with implications for patient management and outcomes. This single-blinded randomized intervention study investigated the effects of oral probiotics on various laboratory parameters in patients with acute alcohol toxicity. Methods: A total of 30 eligible patients were randomly assigned to either the control (placebo) or intervention (oral probiotics) group. Results: While the study did not reveal a significant impact on the length of hospital stay (LOHS), it did demonstrate notable improvements in laboratory variables, including pH, serum glutathione level, serum vitamin B6 level, and O2 saturation, in the probiotic group. Conclusion: These findings suggest the potential benefits of probiotics in mitigating certain aspects of alcohol toxicity

Multi-mode hybrid electric vehicle routing problem

Hybrid electric vehicles (HEVs) are environmental-friendly vehicles that use a combination of the electric engine and internal combustion engine in their propulsion systems to reduce the fuel consumption and emission. In this paper, we consider a fleet of HEVs in logistics operations and introduce the Hybrid Electric Vehicle Routing Problem (HEVRP). Since we allow HEVs to operate in different drive modes, we refer to this problem as the Multi-Mode HEVRP (MM-HEVRP). We first model the problem as a mixed-integer linear program, where the objective function minimizes the total cost of the distances traveled at different modes. Since the problem is not tractable, we develop a matheuristic approach to solve it. The proposed approach combines Variable Neighborhood Search with mathematical programming. We test the performance of the proposed approach by solving benchmark instances generated for the Hybrid Electric Vehicle-Traveling Salesman Problem (HEV-TSP) and comparing our results with those published in the literature. In addition, we generate new MM-HEVRP data by modifying HEV-TSP benchmark instances. We solve the small-size MM-HEVRP instances using CPLEX and compare our solutions with the optimal solutions. The numerical results show that the proposed matheuristic is able to achieve high-quality solutions with reasonable computation times. Furthermore, we address the large-size instances and present a sensitivity analysis to provide further insights

Unusual Presentation of Renal Cell Carcinoma in Crossed Ectopic Kidney

46 hl

Trivalvular nonbacterial thrombotic endocarditis in a patient with colon adenocarcinoma: a case report

Abstract Background Nonbacterial thrombotic endocarditis is a rare complication of prothrombotic states such as neoplasms that can cause valvular dysfunction and life-threatening complications. Nonbacterial thrombotic endocarditis usually affects the left-sided valves; however, only a minority of cases involving the tricuspid valve have been reported in medical literature. Case presentation The current report describes trivalvular involvement by nonbacterial thrombotic endocarditis in a 54-year-old Azeri female patient with metastatic colorectal carcinoma. This case underlines the necessity of evaluating nonbacterial thrombotic endocarditis as a possible consequence in cancer patients. When thromboembolic events are found in the presence of a hypercoagulable state (such as malignancy) and no growth on blood cultures, nonbacterial thrombotic endocarditis could be suspected as the cause. Conclusion It is critical to achieve early diagnosis in such a setting to initiate treatment plans and prevent further complications rapidly

Unusual presentation of transthyretin (ATTR) cardiac amyloidosis: A case report of pruritus as a possible initial symptom and challenging diagnosis

Key Clinical Message This case emphasizes the significance of cardiac amyloidosis as a potential diagnosis in individuals manifesting with lesion‐free pruritus and normal liver tests. Abstract Amyloidosis is a complex disorder in which misfolded proteins accumulate in various organs of the body. Cardiac amyloidosis (CA) can lead to heart failure, cardiac arrhythmia, sudden cardiac death, and deposition of proteins in coronary arteries. Diagnosing CA can be difficult, as the cardiac manifestations of amyloidosis can be similar to more prevalent etiologies. In addition, the accumulation of proteins in soft tissues, including the skin, can cause pruritus. In this paper, we present a 70‐year‐old man with generalized pruritus and no skin lesions, later diagnosed as CA after detecting ascites fluid. This case underscores the importance of considering amyloidosis in patients presenting with nonspecific symptoms, particularly those affecting the skin, and highlights the need for increased awareness of this disease among clinicians