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(N Engl J Med. 2022;386:1121–1131)The diagnosis of bronchopulmonary dysplasia (BPD) in extremely preterm infants portends potentially abnormal growth, neurodevelopment, and respiratory function. This prevalent condition affects half of extreme preterm birth survivors and likely has a multiplicity of causes: prematurity, oxygen exposure, mechanical ventilation, and inflammatory processes. Dexamethasone was previously widely used until adverse neurological effects including cerebral palsy and cognitive impairment became apparent in the patient population later in life. Despite these complications, many extremely premature infants continue to receive dexamethasone therapy for BPD. Hydrocortisone, another steroid, when administered to extremely premature neonates has produced advantageous characteristics and has shown promising test results in neonates who are developing BPD. Administration of hydrocortisone showed mitigating effects on neonatal inflammation and decreased adverse neurodevelopmental effects. This extended trial, beginning in 2011, investigates the efficacy of high-dose hydrocortisone treatment at improving life expectancy without BPD by monitoring for severe neurodevelopmental disorder through 22 to 26 months.

Objective:We examined data from a contemporary cohort of extreme prematurity (EP) infants admitted to an all-referral Children’s Hospital neonatal intensive care unit (NICU) to determine whether prophylactic indomethacin (PI) may continue to benefit these patients.Study Design:An observational study utilizing the small baby ICU data registry that was queried for all EP infants admitted between 2005 and 2014 with documentation of PI use (671 total EP infants; 141 (21%) did not receive PI (control); 530 (79%) received PI (PI). This cohort of EP infants was born at outside hospitals and transferred to our level IV NICU with a mean age on admission of 13 days, well after the PI would have been administered.Results:No difference existed between the control and PI groups in gestational age, birth weight, severity of illness, other in-hospital outcomes or developmental delay. PI infants had a significantly lower mortality rate (P=0.0004), lower relative risk (RR) for mortality 0.52 (95% confidence interval (CI) 0.37 to 0.73, P=0.0001) and lower RR of developing the combined outcome of death or bronchopulmonary dysplasia (RR 0.91, 95% CI 0.85 to 0.98, P=0.012) when compared with the control group. Notably, there was no significant effect of PI on incidence of severe intraventricular hemorrhage or patent ductus arteriosus ligation.Conclusion:PI administration was associated with improved survival in EP infants referred to a level IV Children’s Hospital NICU.

Sensors for autonomous small robotic platforms must be low mass, compact size and low power due to the limited space. For such applications, as the dimensions of the structures shrink, standard machining methods are not suitable because of low fabrication tolerances and high cost in assembly. Commonly, the structures show a high degree of fabrication complexity due to error in alignment, air gaps between conductive parts, poor metal contact, inaccuracy in patterning because of non-contact lithography, complex assemblies of various parts, and high number of steps needed for construction. However, micromachining offers high fabrication precision, provides easy fabrication and integration with active devices and hence is suitable for manufacturing high MMW and submillimeter-wave frequency structures. A radar design compatible with micromachining process is developed to fabricate a Y-band high resolution radar structure with a slot-fed patch array antenna. A multi-step silicon DRIE process is developed for the fabrication of the waveguide structure while the slots are suspended on a thin oxide/nitride/oxide membrane to form the top cover of the waveguide trenches and the patch elements are suspended on a thin Parylene membrane. Gold thermocompression bonding and Parylene bonding are used to assemble different parts of the antenna. These processes result in a compact (4.5 cm × 3.5 cm × 1.5 mm) and light-weight (5 g) radar.

Abstract: In this paper, simultaneous position/force control of a closed-chain planar manipulator with the last link flexible is studied when the manipulator is in contact with an environment. The proposed manipulator consists of a flexible link connected to three rigid linkages whichare optimized for kinematic and force manipulability in the region of interest. The flexible link is modeled as a series of rigid links connected by virtual torsion springs. A hybrid position/force control algorithm is developed and implemented on the manipulator. Experimental results are presented to verify the performance of the controller. [Copyright &y& Elsevier]

Abstract: In this paper, a novel algorithm is developed to achieve efficient and smooth navigation for a differential drive mobile robot in unknown environments. The algorithm takes advantage of the essential characteristics of a differential drive robot and combines fuzzy logic with the ideas of Braitenberg vehicles. We have also proposed and tested a new technique for tuning a membership function referred to as NEAR, representing the closeness of the robot to an obstacle. The tuning scheme is obtained based on the distribution directives of the range sensors on the robot. The resulting navigation algorithm has been implemented on a real mobile robot and tested in various environments. Some problems in the implemented algorithm are identified and effective solutions are proposed. Experimental results are presented which demonstrate the effectiveness and improved performance of the resulting Fuzzy–Braitenberg navigation scheme.

Providing a surgeon with information regarding contacts made between instruments and tissue during robot-assisted interventions can improve task efficiency and reliability. In this report, different methods for feedback of such information to the surgeon are discussed. It is hypothesized that various methods of contact feedback have the potential to enhance performance in a robot-assisted minimally invasive environment. To verify the hypothesis, novel mechanisms needed for incorporating contact feedback were designed, including a surgeon–robot interface with full force feedback capabilities and a surgical end-effector with full force sensing capabilities, that are suitable for minimally invasive applications. These two mechanisms were used to form a robotic “master–slave” test bed for studying the effect of contact feedback on the system and user performance. Using the master–slave system, experiments for surgical tasks involving soft tissue palpation were conducted. The performance of the master–slave system was validated in terms of criteria that assess the accurate transmission of task-related information to the surgeon, which is critical in the context of soft tissue surgical applications. Moreover, using a set of experiments involving human subjects, the performance of several users in carrying out the task was compared among different methods of contact feedback.Providing a surgeon with information regarding contacts made between instruments and tissue during robot-assisted interventions can improve task efficiency and reliability. In this report, different methods for feedback of such information to the surgeon are discussed. It is hypothesized that various methods of contact feedback have the potential to enhance performance in a robot-assisted minimally invasive environment. To verify the hypothesis, novel mechanisms needed for incorporating contact feedback were designed, including a surgeon–robot interface with full force feedback capabilities and a surgical end-effector with full force sensing capabilities, that are suitable for minimally invasive applications. These two mechanisms were used to form a robotic “master–slave” test bed for studying the effect of contact feedback on the system and user performance. Using the master–slave system, experiments for surgical tasks involving soft tissue palpation were conducted. The performance of the master–slave system was validated in terms of criteria that assess the accurate transmission of task-related information to the surgeon, which is critical in the context of soft tissue surgical applications. Moreover, using a set of experiments involving human subjects, the performance of several users in carrying out the task was compared among different methods of contact feedback.

Structural flexibility is an inherent characteristic of a class of macro-micro manipulators consisting of a rigid micro manipulator mounted on a long-reach (flexible) macro manipulator. Vibrations caused by flexibility make it difficult to achieve accurate control of the end-point of the micro manipulator. In this paper, we develop a control strategy that can be applied to such a system. An experimental test-bed has been developed in which a 6 DOF PUMA 560 manipulator is mounted on a compliant platform. The control strategy consists of a rigid body inverse dynamics controller together with a neural network based strategy for damping out the oscillations due to the flexible base. Experimental results obtained from the test-bed are presented to show the effectiveness of the proposed control scheme.

Implementation of a feedback control scheme and its associated user interface and data acquisition modules in a distributed real time computing environment are described. The distributed system consists of an ethernet network interconnecting real time processor modules to host workstations and other embedded controllers. The goal of the feedback control scheme is to maintain positions of the electron beam in the middle of the vacuum chamber in the presence of electromagnetic interference and noise. Technical details of implementing the data acquisition and control scheme and their integration with the existing control system modules are presented, along with experimental results.

This paper presents an inverse dynamics control strategy to achieve small tracking errors for a class of multi-link structurally flexible manipulators. This is done by defining new outputs near the end points of the arms as well as by augmenting the control inputs by terms which ensure stable operation of the closed-loop system under specific conditions. The controller is designed in a two-step process. First, a new output is defined such that the zero dynamics of the original system are stabilized. Next, to ensure stable asymptotic tracking the control input is modified such that stable asymptotic tracking of the new output or approximate tracking of the actual output may be achieved. This is illustrated for the case of single- and two-link flexible manipulators.

Summary Intracranial mycotic infections requiring neurosurgical intervention are being diagnosed more frequently. This study is a review of 17 cases of intracranial mycotic infections that were treated in a neurosurgical unit in Saudi Arabia over an 8-year period. A primary focus of infection was identified in 41% of patients while 18% of patients had a predisposing factor. Forty-seven per cent of patients presented with a brain abscess (solitary 29%, multiple 18%) while 35% had a granuloma, 18% meningitis and ventriculitis and 12% hydrocephalus. The Aspergillus species and Ramichloridium machenziei were the commonest pathogens. Following the appropriate surgical and antimicrobial treatment, the mortality rate was 41% and there was evidence of residual disease at follow-up in 18%. The reason for a fatal outcome was failure to consider a fungal aetiology and to obtain a tissue diagnosis early-because of late referral (2 cases), as well as failure to respond to antimycotic therapy (4 cases) and rupture of the internal carotid artery due to Aspergillus arteritis (one case). It is concluded that an early tissue diagnosis is crucial in the management of intracranial mycotic infection so that the appropriate surgical and antimycotic treatment can be started early.

Autonomous small robotic platforms require a suite of sensor to navigate and function in complex environment. Due to limited space, onboard power, and processing capability these sensors must be low mass, compact size, low power, and run with minimal processing resources. We are in the process of developing a compact and low-power imaging mm-wave radar system for small autonomous robotic platforms operating at Y-band to allow for navigation and obstacle detection in conditions that make the use of passive optical sensors difficult or impossible. The radar system is being fabricated and assembled using silicon micromachining technique with the overall mass of 5 grams, peak power of 200 mW, and operational power of 6.7 mW for one frame per second update rate, field of view of ± 25°, angular resolution of 2°, range resolution of 37.5cm, and range of 400m. The beam steering is accomplished by frequency scanning and the range resolution is obtained from the standard FMCW technique utilizing a chirped signal waveform with step discontinuities. This paper will present the overall architecture of this radar system in addition to the phenomenological investigation of scattering from obstacle in indoor environment. It is also shown how radar images taken from indoor scenes can be interpreted and utilized to create the interior layout of a building.