1,485 research outputs found
A universal six-joint robot controller
A general purpose six-axis robotic manipulator controller was designed and implemented to serve as a research tool for the investigation of the practical and theoretical aspects of various control strategies in robotics. A 80286-based Intel System 310 running the Xenix operating servo software as well as the higher level software (e.g., kinematics and path planning) were employed. A Multibus compatible interface board was designed and constructed to handle I/O signals from the robot manipulator's joint motors. From the design point of view, the universal controller is capable of driving robot manipulators equipped with D.C. joint motors and position optical encoders. To test its functionality, the controller is connected to the joint motor D.C. power amplifier of a PUMA 560 arm bypassing completely the manufacturer-supplied Unimation controller. A controller algorithm consisting of local PD control laws was written and installed into the Xenix operating system. Additional software drivers were implemented to allow application programs access to the interface board. All software was written in the C language
Parallel processing architecture for computing inverse differential kinematic equations of the PUMA arm
In advanced robot control problems, on-line computation of inverse Jacobian solution is frequently required. Parallel processing architecture is an effective way to reduce computation time. A parallel processing architecture is developed for the inverse Jacobian (inverse differential kinematic equation) of the PUMA arm. The proposed pipeline/parallel algorithm can be inplemented on an IC chip using systolic linear arrays. This implementation requires 27 processing cells and 25 time units. Computation time is thus significantly reduced
New modelling technique for aperiodic-sampling linear systems
A general input-output modelling technique for aperiodic-sampling linear
systems has been developed. The procedure describes the dynamics of the system
and includes the sequence of sampling periods among the variables to be
handled. Some restrictive conditions on the sampling sequence are imposed in
order to guarantee the validity of the model. The particularization to the
periodic case represents an alternative to the classic methods of
discretization of continuous systems without using the Z-transform. This kind
of representation can be used largely for identification and control purposes.Comment: 19 pages, 0 figure
Multiscale Modeling of Superior Cavopulmonary Circulation: Hemi-Fontan and Bidirectional Glenn Are Equivalent
Superior cavopulmonary circulation (SCPC) can be achieved by either the Hemi-Fontan (hF) or Bidirectional Glenn (bG) connection. Debate remains as to which results in best hemodynamic results. Adopting patient-specific multiscale computational modeling, we examined both the local dynamics and global physiology to determine if surgical choice can lead to different hemodynamic outcomes. Six patients (age: 3-6 months) underwent cardiac magnetic resonance imaging and catheterization prior to SCPC surgery. For each patient: (1) a finite 3-dimensional (3D) volume model of the preoperative anatomy was constructed to include detailed definition of the distal branch pulmonary arteries, (2) virtual hF and bG operations were performed to create 2 SCPC 3D models, and (3) a specific lumped network representing each patient's entire cardiovascular circulation was developed from clinical data. Using a previously validated multiscale algorithm that couples the 3D models with lumped network, both local flow dynamics, that is, power loss, and global systemic physiology can be quantified. In 2 patients whose preoperative imaging demonstrated significant left pulmonary artery (LPA) stenosis, we performed virtual pulmonary arterioplasty to assess its effect. In one patient, the hF model showed higher power loss (107%) than the bG, while in 3, the power losses were higher in the bG models (18-35%). In the remaining 2 patients, the power loss differences were minor. Despite these variations, for all patients, there were no significant differences between the hF and bG models in hemodynamic or physiological outcomes, including cardiac output, superior vena cava pressure, right-left pulmonary flow distribution, and systemic oxygen delivery. In the 2 patients with LPA stenosis, arterioplasty led to better LPA flow (5-8%) while halving the power loss, but without important improvements in SVC pressure or cardiac output. Despite power loss differences, both hF and bG result in similar SCPC hemodynamics and physiology outcome. This suggests that for SCPC, the pre-existing patient-specific physiology and condition, such as pulmonary vascular resistance, are more deterministic in the hemodynamic performance than the type of surgical palliation. Multiscale modeling can be a decision-assist tool to assess whether an extensive LPA reconstruction is needed at the time of SCPC for LPA stenosis
Golimumab, a human antibody to tumour necrosis factor α given by monthly subcutaneous injections, in active rheumatoid arthritis despite methotrexate therapy: the GO-FORWARD Study
Objective: The phase III GO-FORWARD study examined the efficacy and safety of golimumab in patients with active rheumatoid arthritis (RA) despite methotrexate therapy. Methods: Patients were randomly assigned in a 3 : 3 : 2 : 2 ratio to receive placebo injections plus methotrexate capsules (group 1, n = 133), golimumab 100 mg injections plus placebo capsules (group 2, n = 133), golimumab 50 mg injections plus methotrexate capsules (group 3, n = 89), or golimumab 100 mg injections plus methotrexate capsules (group 4, n = 89). Injections were administered subcutaneously every 4 weeks. The co-primary endpoints were the proportion of patients with 20% or greater improvement in the American College of Rheumatology criteria (ACR20) at week 14 and the change from baseline in the health assessment questionnaire-disability index (HAQ-DI) score at week 24. Results: The proportion of patients who achieved an ACR20 response at week 14 was 33.1% in the placebo plus methotrexate group, 44.4% (p = 0
Machine learning applications on neonatal sepsis treatment: a scoping review.
INTRODUCTION: Neonatal sepsis is a major cause of health loss and mortality worldwide. Without proper treatment, neonatal sepsis can quickly develop into multisystem organ failure. However, the signs of neonatal sepsis are non-specific, and treatment is labour-intensive and expensive. Moreover, antimicrobial resistance is a significant threat globally, and it has been reported that over 70% of neonatal bloodstream infections are resistant to first-line antibiotic treatment. Machine learning is a potential tool to aid clinicians in diagnosing infections and in determining the most appropriate empiric antibiotic treatment, as has been demonstrated for adult populations. This review aimed to present the application of machine learning on neonatal sepsis treatment. METHODS: PubMed, Embase, and Scopus were searched for studies published in English focusing on neonatal sepsis, antibiotics, and machine learning. RESULTS: There were 18 studies included in this scoping review. Three studies focused on using machine learning in antibiotic treatment for bloodstream infections, one focused on predicting in-hospital mortality associated with neonatal sepsis, and the remaining studies focused on developing machine learning prediction models to diagnose possible sepsis cases. Gestational age, C-reactive protein levels, and white blood cell count were important predictors to diagnose neonatal sepsis. Age, weight, and days from hospital admission to blood sample taken were important to predict antibiotic-resistant infections. The best-performing machine learning models were random forest and neural networks. CONCLUSION: Despite the threat antimicrobial resistance poses, there was a lack of studies focusing on the use of machine learning for aiding empirical antibiotic treatment for neonatal sepsis
Golimumab in patients with active rheumatoid arthritis after treatment with tumor necrosis factor inverted question mark inhibitors: findings with up to five years of treatment in the multicenter, randomized, double-blind, placebo-controlled, phase 3 GO-AFTER study
Introduction: The aim of this study was to assess long-term golimumab therapy in rheumatoid arthritis (RA) patients who discontinued previous tumor necrosis factor- inverted question mark (TNF)-inhibitor(s).
Methods:Patients enrolled into this multicenter, randomized, double-blind, placebo-controlled study of active RA ( inverted question mark4 tender, inverted question mark4 swollen joints) received placebo (Group 1) or golimumab 50 mg (Group 2) or 100 mg (Group 3) injections every 4 weeks. Patients in Groups 1 and 2 with inadequate response at week 16 escaped to golimumab 50 and 100 mg, respectively. At week 24, Group 1 patients crossed-over to golimumab 50 mg, Group 2 continued golimumab 50/100 mg per escape status, and Group 3 maintained dosing. During the long-term-extension (LTE), golimumab 50 mg could be increased to 100 mg, and 100 mg could be decreased to 50 mg. Data through 5 years are reported for all patients (safety) and patients using methotrexate (efficacy, intention-to-treat (ITT) analysis with last-observation-carried-forward for missing data and non-responder imputation for unsatisfactory efficacy discontinuations).
Results: In total, 459 of 461 randomized patients received the study agent, 304 of whom were methotrexate-treated and included in efficacy analyses. Through week 256, the proportions of methotrexate-treated patients achieving American-College-of-Rheumatology (ACR) responses were 37.6% to 47.0% for ACR20, 21.4% to 35.0% for ACR50, and 7.8% to 17.0% for ACR70 response across randomized groups. Golimumab safety through week 268 was generally consistent with that at week 24 and week 160 and other anti-TNF agents.
Conclusions:In some patients with active RA discontinuing previous TNF-antagonist therapy, golimumab safety and efficacy, assessed conservatively with ITT analyses, was confirmed through 5 years.
Trial registrationClinicaltrials.gov NCT00299546. Registered 03 March 2006
Efficacy and safety of rociletinib versus chemotherapy in patients with EGFR-mutated NSCLC: the results of TIGER-3, a phase 3 randomized study
Introduction: The TIGER-3 (NCT02322281) study was initiated to compare the efficacy and safety of rociletinib, a third-generation EGFR tyrosine kinase inhibitor (TKI) that targets EGFR T790M and common EGFR-activating mutations, versus chemotherapy in patients with NSCLC who progressed on first- or second-generation EGFR TKIs. Methods: Patients with advanced or metastatic EGFR-mutated NSCLC with disease progression on standard therapy (previous EGFR TKI and platinum-based chemotherapy) were randomized to oral rociletinib (500 or 625 mg twice daily) or single-agent chemotherapy (pemetrexed, gemcitabine, docetaxel, or paclitaxel). Results: Enrollment was halted when rociletinib development was discontinued in 2016. Of 149 enrolled patients, 75 were randomized to rociletinib (n = 53: 500 mg twice daily; n = 22: 625 mg twice daily) and 74 to chemotherapy. The median investigator-assessed progression-free survival (PFS) was 4.1 months (95% confidence interval [CI]: 2.6-5.4) in the rociletinib 500-mg group and 5.5 months (95% CI: 1.8-8.1) in the 625-mg group versus 2.5 months (95% CI: 1.4-2.9) in the chemotherapy group. An improved PFS was observed in patients with T790M-positive NSCLC treated with rociletinib (n = 25; 500 mg and 625 mg twice daily) versus chemotherapy (n = 20; 6.8 versus 2.7 mo; hazard ratio = 0.55, 95% CI: 0.28-1.07, p = 0.074). Grade 3 or higher hyperglycemia (24.0%), corrected QT prolongation (6.7%), diarrhea (2.7%), and vomiting (1.3%) were more frequent with rociletinib than chemotherapy (0%, 0%, 1.4%, and 0%, respectively). Conclusions: Rociletinib had a more favorable median PFS versus chemotherapy but had higher rates of hyperglycemia and corrected QT prolongation in patients with advanced EGFR-mutated NSCLC who progressed on previous EGFR TKI. Incomplete enrollment prevented evaluation of the primary efficacy end point
Polynitroxyl Albumin and Albumin Therapy After Pediatric Asphyxial Cardia Arrest: Effects on Cerebral Blood Flow and Neurologic Outcome
Postresuscitation cerebral blood flow (CBF) disturbances and generation of reactive oxygen species likely contribute to impaired neurologic outcome after pediatric cardiac arrest (CA). Hence, we determined the effects of the antioxidant colloid polynitroxyl albumin (PNA) versus albumin or normal saline (NS) on CBF and neurologic outcome after asphyxial CA in immature rats. We induced asphyxia for 9 minutes in male and female postnatal day 16 to 18 rats randomized to receive PNA, albumin, or NS at resuscitation from CA or sham surgery. Regional CBF was measured serially from 5 to 150 minutes after resuscitation by arterial spin-labeled magnetic resonance imaging. We assessed motor function (beam balance and inclined plane), spatial memory retention (water maze), and hippocampal neuronal survival. Polynitroxyl albumin reduced early hyperemia seen 5 minutes after CA. In contrast, albumin markedly increased and prolonged hyperemia. In the delayed period after resuscitation (90 to 150 minutes), CBF was comparable among groups. Both PNA- and albumin-treated rats performed better in the water maze versus NS after CA. This benefit was observed only in males. Hippocampal neuron survival was similar between injury groups. Treatment of immature rats with PNA or albumin resulted in divergent acute changes in CBF, but both improved spatial memory retention in males after asphyxial CA
Applied Plasma Research
Contains research objectives and reports on three research projects.National Science Foundation (Grant GK-18185)Lincoln Laboratory Purchase Order No. CC-554U. S. Navy (Office of Naval Research) under Contract N00014-67-A-0204-0019Air Force Office of Scientific Researc
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