139 research outputs found

    Stereo visual-inertial odometry with an online calibration and its field testing

    Get PDF
    In this paper, we present a visual-inertial odometry (VIO) with an online calibration using a stereo camera in planetary rover localization. We augment the state vector with extrinsic (rigid body transformation) and temporal (time-offset) parameters of a camera-IMU system in a framework of an extended Kalman filter. This is motivated by the fact that when fusing independent systems, it is practically crucial to obtain precise extrinsic and temporal parameters. Unlike the conventional calibration procedures, this method estimates both navigation and calibration states from naturally occurred visual point features during operation. We describe mathematical formulations of the proposed method, and it is evaluated through the author-collected dataset which is recorded by the commercially available visual-inertial sensor installed on the testing rover in the environment lack of vegetation and artificial objects. Our experimental results showed that 3D return position error as 1.54m of total 173m traveled and 10ms of time-offset with the online calibration, while 6.52m of return position error without the online calibration

    Transient Anarthria and Quadriplegia in a Patient with Basilar Artery Hypoplasia and Coincidental Intracranial Lipoma: A Case Report

    Get PDF
    Cerebral ischemia may be rarely associated with a hypoplastic vertebrobasilar system. Intracranial lipoma is also a very rare congenital malformation. We report the case of a 52-year-old woman with vertebrobasilar transient ischemic attack associated with basilar artery hypoplasia and coincidental intracranial lipoma. She presented with sudden-onset dizziness, anarthria, and quadriplegia lasting for about 30 min. The patient’s initial blood pressure was measured at 200/120 mm Hg. The magnetic resonance and computed tomographic images showed the absence of an acute ischemic lesion in the brain but revealed a hypoplasia of the basilar artery and bilateral V4 vertebral arteries. A lipoma of 11 mm in long diameter was also found in the quadrigeminal cistern and at the superior vermis. The electroencephalography, transthoracic echocardiogram, 24-h Holter monitoring, and transcranial Doppler ultrasonography, including patent foramen ovale study, were all noted as negative. The patient was treated with oral aspirin 100 mg, atorvastatin 10 mg, and antihypertensive medication. She had no symptom recurrence after the treatment. Our case suggests that hypoplasia of the vertebrobasilar arteries can be a predisposing factor for posterior circulation ischemia, especially when additional vascular risk factors coexist

    Improved Sugar Production by Optimizing Planetary Mill Pretreatment and Enzyme Hydrolysis Process

    Get PDF
    This paper describes an optimization of planetary mill pretreatment and saccharification processes for improving biosugar production. Pitch pine (Pinus rigida) wood sawdust waste was used as biomass feedstock and the process parameters optimized in this study were the buffering media, the milling time, the enzyme quantity, and the incubation time. Glucose yields were improved when acetate buffer was used rather than citrate buffer. Initially, with each process variable tests, the optimal values were 100 minutes of milling, an enzyme concentration of 16 FPU/g-biomass, and a 12-hour enzymatic hydrolysis. Typically, interactions between these experimental conditions and their effects on glucose production were next investigated using RSM. Glucose yields from the Pinus rigida waste exceeded 80% with several of the conditions tested, demonstrating that milling can be used to obtain high levels of glucose bioconversion from woody biomass for biorefinery purposesopen

    The effects of direct hemoperfusion with polymyxin B-immobilized fiber in patients with acute exacerbation of interstitial lung disease

    Get PDF
    Background Acute exacerbation of interstitial lung disease (AE-ILD) causes clinically significant deterioration and has an extremely poor prognosis with high mortality. Recently, several studies reported the effectiveness of direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) in patients with AE-ILD as a potential therapy. This study describes the clinical effectiveness and safety of PMX-DHP in patients with AE-ILD. Methods We retrospectively reviewed the medical records of 10 patients (11 episodes) with AE-ILD treated with PMX-DHP from January 2018 to June 2019. We compared laboratory and physiologic data of the ratio of partial pressure arterial oxygen to fraction of inspired oxygen (P/F ratio) and level of inflammatory markers before and after implementation of PMX-DHP. Results Ten patients were included according to the 2016 revised definition of acute exacerbation of idiopathic pulmonary fibrosis (IPF). Nine patients had IPF and one patient had fibrotic nonspecific interstitial pneumonia. Most patients (90.9%) were treated with a steroid pulse, and four patients (36.4%) were treated with an immunosuppressant. The median number of PMX-DHP cycles was 2, and the median duration of each cycle was 6 hours. After PMX-DHP, the mean P/F ratio improved (86 [range, 63–106] vs. 145 [86–260], P=0.030) and interleukin-6 and c-reactive protein decreased (79 [35–640] vs. 10 [5–25], P=0.018 and 14 [4–21] vs. 5 [2–6], P=0.019, respectively). The 30-day mortality rate was 27.3% and the 90-day mortality rate was 72.7%. Conclusions PMX-DHP treatment improved P/F ratio and reduced inflammatory markers in AE-ILD patients

    Quality of life in patients with diabetic nephropathy: findings from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease) cohort

    Get PDF
    Background Diabetic nephropathy (DN) can affect quality of life (QoL) because it requires arduous lifelong management. This study analyzed QoL differences between DN patients and patients with other chronic kidney diseases (CKDs). Methods The analysis included subjects (n = 1,766) from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease) cohort who completed the Kidney Disease Quality of Life Short Form questionnaire. After implementing propensity score matching (PSM) using factors that affect the QoL of DN patients, QoL differences between DN and non-DN participants were examined. Results Among all DN patients (n = 390), higher QoL scores were found for taller subjects, and lower scores were found for those who were unemployed or unmarried, received Medical Aid, had lower economic status, had higher platelet counts or alkaline phosphatase levels, or used clopidogrel or insulin. After PSM, the 239 matched DN subjects reported significantly lower patient satisfaction (59.9 vs. 64.5, p = 0.02) and general health (35.3 vs. 39.1, p = 0.04) than the 239 non-DN subjects. Scores decreased in both groups during the 5-year follow-up, and the scores in the work status, sexual function, and role-physical domains were lower among DN patients than non-DN patients, though those differences were not statistically significant. Conclusion Socioeconomic factors of DN were strong risk factors for impaired QoL, as were high platelet, alkaline phosphatase, and clopidogrel and insulin use. Clinicians should keep in mind that the QoL of DN patients might decrease in some domains compared with non-DN CKDs

    New prognostic scoring system for mortality in idiopathic pulmonary fibrosis by modifying the gender, age, and physiology model with desaturation during the six-minute walk test

    Get PDF
    BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease (ILD) with variable and heterogeneous clinical course. The GAP (gender, age, and physiology) model had been used to predict mortality in patients with IPF, but does not contain exercise capacity. Therefore, our aim in this study was to develop new prognostic scoring system in the Korea IPF Cohort (KICO) registry.Materials and methodsThis is a retrospective study of Korean patients with IPF in KICO registry from June 2016 to August 2021. We developed new scoring system (the GAP6) based on the GAP model adding nadir saturation of percutaneous oxygen (SpO2) during six-minute walk test (6MWT) in the KICO registry and compared the efficacy of the GAP and the GAP6 model.ResultsAmong 2,412 patients in KICO registry, 966 patients were enrolled. The GAP6 model showed significant prognostic value for mortality between each stage [HR Stage II vs. Stage I = 2.89 (95% CI = 2.38–3.51), HR Stage III vs. Stage II = 2.68 (95% CI = 1.60–4.51)]. In comparison the model performance with area under curve (AUC) using receiver operating characteristic (ROC) curve analysis, the GAP6 model showed a significant improvement for predicting mortality than the GAP model (AUC the GAP vs. the GAP6, 0.646 vs. 0.671, p < 0.0019). Also, the C-index values slightly improved from 0.674 to 0.691 for mortality.ConclusionThe GAP6 model adding nadir SpO2 during 6WMT for an indicator of functional capacity improves prediction ability with C-index and AUC. Additional multinational study is needed to confirm these finding and validate the applicability and accuracy of this risk assessment system
    corecore