13 research outputs found
Bilevel shared control for teleoperators
A shared system is disclosed for robot control including integration of the human and autonomous input modalities for an improved control. Autonomously planned motion trajectories are modified by a teleoperator to track unmodelled target motions, while nominal teleoperator motions are modified through compliance to accommodate geometric errors autonomously in the latter. A hierarchical shared system intelligently shares control over a remote robot between the autonomous and teleoperative portions of an overall control system. Architecture is hierarchical, and consists of two levels. The top level represents the task level, while the bottom, the execution level. In space applications, the performance of pure teleoperation systems depend significantly on the communication time delays between the local and the remote sites. Selection/mixing matrices are provided with entries which reflect how each input's signals modality is weighted. The shared control minimizes the detrimental effects caused by these time delays between earth and space
Method and apparatus for hybrid position/force control of multi-arm cooperating robots
Two or more robotic arms having end effectors rigidly attached to an object to be moved are disclosed. A hybrid position/force control system is provided for driving each of the robotic arms. The object to be moved is represented as having a total mass that consists of the actual mass of the object to be moved plus the mass of the moveable arms that are rigidly attached to the moveable object. The arms are driven in a positive way by the hybrid control system to assure that each arm shares in the position/force applied to the object. The burden of actuation is shared by each arm in a non-conflicting way as the arm independently control the position of, and force upon, a designated point on the object
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Overview of Mars Technology Program
This viewgraph presentation reviews the development of a technology program leading to Mars missions. The presentation includes: the goals of technology program, elements of technology program, program metrics, major accomplishments, examples and Information about the Mars Technology Program
The Potential Benefits of Nuclear Power on the Surface of Mars: The Robotic Exploration Perspective
This viewgraph presentation reviews the future planning for further exploration of the Martian Surface by robotic vehicles. Particular emphasis is given to the use of nuclear power in the planning process. Advantages of Radioisotope Power Systems and Radioisotope Heating units are reviewed
Mars base technology program overview
In this paper, we present an overview of the current technology portfolio for Mars Base Technology Program. Brief descriptions of the awarded technologies and the high-priority areas in both NRAs are provided to show the current focus of MTP. We also present the approach that MTP uses to evaluate technology maturity for each of the technology tasks
Improving spatial ability using a web-based virtual environment (WbVE)
We examine transfers and tied aid in a model with increasing returns to scale and monopolistic competition. Transfers give rise to an additional (love of variety) welfare effect and affect the utility possibility locus. Generic tied aid may exacerbate or reverse these results. The popularity of aid tied to specific manufactured goods can be explained through rent-seeking behavior since such aid gives rise to profits in the donor country. These profits in turn largely repatriate the transfer such that donors can appear to be more generous than they really are
Initiating the 2002 Mars Science Laboratory (MSL) Technology Program
The Mars Science Laboratory (MSL) Project is an aggressive mission launching in 2009 to investigate the Martian environment and requires new capabilities that are currently are not available. The MSL Technology Program is developing a wide-range of technologies needed for this Mission and potentially other space missions. The MSL Technology Program reports to both the MSL Project and the Mars Technology Program (MTP). The dual reporting process creates a challenging management situation, but ensures the new technology meets both the specific MSL requirements and the broader Mars Program requirements. MTP is a NASA-wide technology development program managed by JPL and is divided into a Focused Program and a Base Program. The MSL Technology Program is under the focused program and is tightly coupled to MSL's mission milestones and deliverables. The technology budget is separate from the flight Project budget, but the technology's requirements and the development process are tightly coordinated with the Project. The MSL Technology Program combines the proven management techniques of flight projects with the commercial technology management strategies of industry and academia, to create a technology management program that meets the short-term requirements of MSL and the long-term requirements of MTP. This paper examines the initiation of 2002 MSL Technology program. Some of the areas discussed in this paper include technology definition, task selection, technology management, and technology assessment. This paper also provides an update of the 2003 MSL technology program and examines some of the drivers that changed the program from its initiation