Guest Editorial Microassembly for Manufacturing at Small Scales.

International audienceMICROELECTRONICS brought an information revolution through integrating a vast number of microscopic transistors. Much progress has beenmade inminiaturization and integration of MEMS or MOEMS (Micro-(Opto-)Electro-Mechanical-Systems to produce accelerometers, inkjet printer heads, micro-mirrors, micro-relays, and pressure sensors. A new generation of MEMS is rapidly moving toward highly integrated, more complex heterogeneous microsystems with increased functionalities. Many limitations remain that are extremelydifficult to overcome, especially concerning processes and materials incompatibilities. microassembly is a natural and powerful approach to overcome these processes incompatibilities and to facilitate complex, heterogeneous, 3D, or out of plane integration. By using basic micro-scale components, microassembly constitutes a new alternative of Microsystems production that may lead to cost savings and shorter development cycle times. Because of the size of the components and of the required precision, automation is needed

Guaranteed manipulator precision via interval analysis of inverse kinematics.

International audienceThe paper presents a new methodology for solving the inverse problem of manipulator precision design. Such design problems are often encountered when the end-effector uncertainty bounds are given, but it is not clear how to allocate precision bounds on individual robot axes. The approach presented in this paper uses interval analysis as a tool for uncertainty modeling and computational analysis. In prior work, the exponential formulation of the forward kinematics map was extended to intervals. Here, we use this result as an inclusion function in the computation of solutions to set-valued inverse kinematic problems. Simulation results are presented in two case studies to illustrate how we can go from an uncertainty interval at the end-effector to a design domain of allowable uncertainties at individual joints and links. The proposed method can be used to determine the level of precision needed in the design of a manipulator such that a predefined end-effector precision can be guaranteed. Also, the approach is general as such it can be easily extended to any degree-of-freedom and kinematic configuration

Explicit force control V.S. impedance control for micromanipulation.

International audienceThis paper presents a study of different force control schemes for controlling contact during manipulation tasks at the microscale. Explicit force control and impedance control are compared in a contact transition scenario consisting of a compliant microforce sensor mounted on a microrobotic positioner, and a compliant microstructure fabricated using Silicon MEMS. A traditional double mass-spring-damper model of the overall robot is employed to develop the closed-loop force controllers. Specific differences between the two control schemes due to the microscale nature of contact are highlighted in this paper from the experimental results obtained. The limitations and tradeoffs of the two control laws at the microscale due to the presence of backlash are discussed. A simple method to deal with the pull-off force effects specific to the microscale is proposed. Future improvements of the impedance control schemes to include adaptation are discussed in order to handle objects with unknown stiffness

Control of a Powered Prosthetic Hand Via a Tracked Glove 1

Although commercially available robotic prosthetic limbs now provide fingers with multiple degrees of freedom (DOFs), closely resembling the human hand, the amount of control channels provided by typical biological signals (electromyography or neural electrodes) Thus, by combining the two technologies, we developed a system to teleoperate the TouchBionics RoboLimb TM device with a custom-built 6DOF glove worn on the sound hand. The RoboLimb hand is a 6DOF prosthetic device which weighs under 500 g and can be controlled via a protocol based on the controller area network (CAN) The purpose of this system is to support on-going work in our laboratory to benefit unilateral amputees who have a sound hand with which they can teleoperate or otherwise interact with a robotic prosthetic device. Specifically, we are investigating the use of this system in (1) The performance of activities of daily living that will benefit from the mirroring of movements between the sound hand and the prosthetic device (e.g., folding a towel, moving a table, picking up a laundry basket, etc.). (2) Allow the user to pose the prosthetic hand in any desired configuration before performing a task. (3) Enable the recording of task specific grasping motions that can be defined and played back by the user in the field. Methods Tracking Glove. We have built a tracking glove using six SparkFun 2.2 00 flexion sensors (SparkFun, Inc.), a glove, an Arduino [4] Uno microcontroller, and Velcro TM to hold the Arduino device on the glove. The flexion sensors were attached to the glove through the use of custom-sewn sleeves which reduce the stress on the sensor attachment point by allowing the sensor to slide during movement. The flexion sensors were soldered to flexible multistrand wires, and the contact areas were encased in moldable thermoplastic (InstaMorph TM ) in order to prevent the soldered connections from failing during use. The resulting glove prototype is shown in The thermoplastic encased ends of the sensors were also molded into sewable buttons by a process involving laser-cut acrylic molds described in Healthy Limb Adaptor. In order to allow nonimpaired volunteers to wear and test the mirrored teleoperation of the system, a healthy limb adapter was created incorporating an Otto Bock QuickConnect ring molded onto the end of a 5 in. diameter polyvinyl chloride pipe using thermoplastic (InstaMorph T

Spike-Timing Precision and Neuronal Synchrony Are Enhanced by an Interaction between Synaptic Inhibition and Membrane Oscillations in the Amygdala

The basolateral complex of the amygdala (BLA) is a critical component of the neural circuit regulating fear learning. During fear learning and recall, the amygdala and other brain regions, including the hippocampus and prefrontal cortex, exhibit phase-locked oscillations in the high delta/low theta frequency band (∼2–6 Hz) that have been shown to contribute to the learning process. Network oscillations are commonly generated by inhibitory synaptic input that coordinates action potentials in groups of neurons. In the rat BLA, principal neurons spontaneously receive synchronized, inhibitory input in the form of compound, rhythmic, inhibitory postsynaptic potentials (IPSPs), likely originating from burst-firing parvalbumin interneurons. Here we investigated the role of compound IPSPs in the rat and rhesus macaque BLA in regulating action potential synchrony and spike-timing precision. Furthermore, because principal neurons exhibit intrinsic oscillatory properties and resonance between 4 and 5 Hz, in the same frequency band observed during fear, we investigated whether compound IPSPs and intrinsic oscillations interact to promote rhythmic activity in the BLA at this frequency. Using whole-cell patch clamp in brain slices, we demonstrate that compound IPSPs, which occur spontaneously and are synchronized across principal neurons in both the rat and primate BLA, significantly improve spike-timing precision in BLA principal neurons for a window of ∼300 ms following each IPSP. We also show that compound IPSPs coordinate the firing of pairs of BLA principal neurons, and significantly improve spike synchrony for a window of ∼130 ms. Compound IPSPs enhance a 5 Hz calcium-dependent membrane potential oscillation (MPO) in these neurons, likely contributing to the improvement in spike-timing precision and synchronization of spiking. Activation of the cAMP-PKA signaling cascade enhanced the MPO, and inhibition of this cascade blocked the MPO. We discuss these results in the context of spike-timing dependent plasticity and modulation by neurotransmitters important for fear learning, such as dopamine

Update of EULAR recommendations for the treatment of systemic sclerosis

The aim was to update the 2009 European League against Rheumatism (EULAR) recommendations for the treatment of systemic sclerosis (SSc), with attention to new therapeutic questions. Update of the previous treatment recommendations was performed according to EULAR standard operating procedures. The task force consisted of 32 SSc clinical experts from Europe and the USA, 2 patients nominated by the pan-European patient association for SSc (Federation of European Scleroderma Associations (FESCA)), a clinical epidemiologist and 2 research fellows. All centres from the EULAR Scleroderma Trials and Research group were invited to submit and select clinical questions concerning SSc treatment using a Delphi approach. Accordingly, 46 clinical questions addressing 26 different interventions were selected for systematic literature review. The new recommendations were based on the available evidence and developed in a consensus meeting with clinical experts and patients. The procedure resulted in 16 recommendations being developed (instead of 14 in 2009) that address treatment of several SSc-related organ complications: Raynaud's phenomenon (RP), digital ulcers (DUs), pulmonary arterial hypertension (PAH), skin and lung disease, scleroderma renal crisis and gastrointestinal involvement. Compared with the 2009 recommendations, the 2016 recommendations include phosphodiesterase type 5 (PDE-5) inhibitors for the treatment of SSc-related RP and DUs, riociguat, new aspects for endothelin receptor antagonists, prostacyclin analogues and PDE-5 inhibitors for SSc-related PAH. New recommendations regarding the use of fluoxetine for SSc-related RP and haematopoietic stem cell transplantation for selected patients with rapidly progressive SSc were also added. In addition, several comments regarding other treatments addressed in clinical questions and suggestions for the SSc research agenda were formulated. These updated data-derived and consensus-derived recommendations will help rheumatologists to manage patients with SSc in an evidence-based way. These recommendations also give directions for future clinical research in SSc

Predictors of disease worsening defined by progression of organ damage in diffuse systemic sclerosis: a European Scleroderma Trials and Research (EUSTAR) analysis.

Objectives Mortality and worsening of organ function are desirable endpoints for clinical trials in systemic sclerosis (SSc). The aim of this study was to identify factors that allow enrichment of patients with these endpoints, in a population of patients from the European Scleroderma Trials and Research group database. Methods Inclusion criteria were diagnosis of diffuse SSc and follow-up over 12\ub13 months. Disease worsening/organ progression was fulfilled if any of the following events occurred: new renal crisis; decrease of lung or heart function; new echocardiography-suspected pulmonary hypertension or death. In total, 42 clinical parameters were chosen as predictors for the analysis by using (1) imputation of missing data on the basis of multivariate imputation and (2) least absolute shrinkage and selection operator regression. Results Of 1451 patients meeting the inclusion criteria, 706 had complete data on outcome parameters and were included in the analysis. Of the 42 outcome predictors, eight remained in the final regression model. There was substantial evidence for a strong association between disease progression and age, active digital ulcer (DU), lung fibrosis, muscle weakness and elevated C-reactive protein (CRP) level. Active DU, CRP elevation, lung fibrosis and muscle weakness were also associated with a significantly shorter time to disease progression. A bootstrap validation step with 10 000 repetitions successfully validated the model. Conclusions The use of the predictive factors presented here could enable cohort enrichment with patients at risk for overall disease worsening in SSc clinical trial

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe