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Formal Methods in System Design 2017is an approach to enforce safety properties at runtime. A shield monitors the system and corrects any erroneous output values instantaneously. The shield deviates from...
is an approach to enforce safety properties at runtime. A shield monitors the system and corrects any erroneous output values instantaneously. The shield deviates from the given outputs as little as it can and recovers to hand back control to the system as soon as possible. In the first part of this paper, we consider shield synthesis for reactive hardware systems. First, we define a general framework for solving the shield synthesis problem. Second, we discuss two concrete shield synthesis methods that automatically construct shields from a set of properties: (1) shields, which guarantee recovery in a finite time. (2) shields, which attempt to work with the system to recover as soon as possible. Next, we discuss an extension of -stabilizing and admissible shields, where erroneous output values of the reactive system are corrected while liveness properties of the system are preserved. Finally, we give experimental results for both synthesis methods. In the second part of the paper, we consider shielding a human operator instead of shielding a reactive system: the outputs to be corrected are not initiated by a system but by a human operator who works with an autonomous system. The challenge here lies in giving simple and intuitive explanations to the human for any interferences of the shield. We present results involving mission planning for unmanned aerial vehicles.
PubMed: 32009740
DOI: 10.1007/s10703-017-0276-9 -
Nature Communications Aug 2022Force and strain sensors made of soft materials enable robots to interact intelligently with their surroundings. Capacitive sensing is widely adopted thanks to its low...
Force and strain sensors made of soft materials enable robots to interact intelligently with their surroundings. Capacitive sensing is widely adopted thanks to its low power consumption, fast response, and facile fabrication. Capacitive sensors are, however, susceptible to electromagnetic interference and proximity effects and thus require electrical shielding. Shielding has not been previously implemented in soft capacitive sensors due to the parasitic capacitance between the shield and sensing electrodes, which changes when the sensor is deformed. We address this crucial challenge by patterning the central sensing elastomer layer to control its compressibility. One design uses an ultrasoft silicone foam, and the other includes microchannels filled with liquid metal and air. The force resolution is sub-mN both in normal and shear directions, yet the sensor withstands large forces (>20 N), demonstrating a wide dynamic range. Performance is unaffected by nearby high DC and AC electric fields and even electric sparks.
PubMed: 35945227
DOI: 10.1038/s41467-022-32391-0 -
Frontiers in Public Health 2015A nipple shield is a breastfeeding aid with a nipple-shaped shield that is positioned over the nipple and areola prior to nursing. Nipple shields are usually recommended... (Review)
Review
INTRODUCTION
A nipple shield is a breastfeeding aid with a nipple-shaped shield that is positioned over the nipple and areola prior to nursing. Nipple shields are usually recommended to mothers with flat nipples or in cases in which there is a failure of the baby to effectively latch onto the breast within the first 2 days postpartum. The use of nipple shields is a controversial topic in the field of lactation. Its use has been an issue in the clinical literature since some older studies discovered reduced breast milk transfer when using nipple shields, while more recent studies reported successful breastfeeding outcomes. The purpose of this review was to examine the evidence and outcomes associated with nipple shield use.
METHODS
A literature search was conducted in Ovid MEDLINE, OLDMEDLINE, EMBASE Classic, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL. The primary endpoint was any breastfeeding outcome following nipple shield use. Secondary endpoints included the reasons for nipple shield use and the average/median length of use. For the analysis, we examined the effect of nipple shield use on physiological responses, premature infants, mothers' experiences, and health professionals' experiences.
RESULTS
The literature search yielded 261 articles, 14 of which were included in this review. Of these 14 articles, three reported on physiological responses, two reported on premature infants, eight reported on mothers' experiences, and one reported on health professionals' experiences.
CONCLUSION
Through examining the use of nipple shields, further insight is provided on the advantages and disadvantages of this practice, thus allowing clinicians and researchers to address improvements on areas that will benefit mothers and infants the most.
PubMed: 26528467
DOI: 10.3389/fpubh.2015.00236 -
American Journal of Ophthalmology Oct 2020To evaluate the efficacy of slit lamp breath shields to prevent droplet spray from a simulated sneeze. (Comparative Study)
Comparative Study
PURPOSE
To evaluate the efficacy of slit lamp breath shields to prevent droplet spray from a simulated sneeze.
DESIGN
Experimental study to test the effectiveness of personal protective equipment.
METHODS
The nozzle of a spray gun was adjusted to angularly disperse a mist of colored dye that approximated a patient sneezing on a dimensionally accurate cardboard slit lamp model. The designs of 6 commercially available breath shields and 1 breath shield repurposed from a plastic container lid were tested. Each breath shield was sprayed in a standardized fashion 3 times, and the amount of overspray was compared to spray with no shield and quantified. The surface area that was sprayed was calculated using a commercially available software with color range function. The average percentage of overspray of each breath shield was computed in comparison to the control.
RESULTS
The breath shields ranged in surface area from 116 to 924 cm, and the amount of overspray varied from 54% to virtually none. Larger breath shields offered better protection than smaller ones. Breath shields attached to the objective lens arm were better barriers than those of comparable size hung by the oculars. A repurposed plastic lid breath shield, 513 cm, was slightly curved toward the examiner's face and allowed only 2% overspray. The largest breath shield (924 cm) hung near the oculars and prevented essentially all overspray.
CONCLUSIONS
The performance of different designs of breath shields was variable. Even high-functioning shields should be used in conjunction with personal protective equipment including masks, goggles, and gloves and handwashing. Ideally patients should also wear a face mask during all slit lamp examinations.
Topics: Aerosols; Betacoronavirus; COVID-19; Coronavirus Infections; Equipment Design; Humans; Infectious Disease Transmission, Patient-to-Professional; Inhalation Exposure; Models, Theoretical; Pandemics; Personal Protective Equipment; Pneumonia, Viral; SARS-CoV-2; Slit Lamp Microscopy; Sneezing; Video Recording
PubMed: 32407727
DOI: 10.1016/j.ajo.2020.05.005 -
Ecancermedicalscience 2017Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct... (Review)
Review
Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community. Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise. IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers). This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.
PubMed: 28717396
DOI: 10.3332/ecancer.2017.750 -
Physics of Fluids (Woodbury, N.Y. :... Dec 2020A flow analysis around a face shield was performed to examine the risk of virus infection when a medical worker wearing a face shield is exposed to a patient's sneeze...
A flow analysis around a face shield was performed to examine the risk of virus infection when a medical worker wearing a face shield is exposed to a patient's sneeze from the front. We ensured a space between the shield surface and the face of the human model to imitate the most popularly used face shields. In the present simulation, a large eddy simulation was conducted to simulate the vortex structure generated by the sneezing flow near the face shield. It was confirmed that the airflow in the space between the face shield and the face was observed to vary with human respiration. The high-velocity flow created by sneezing or coughing generates vortex ring structures, which gradually become unstable and deform in three dimensions. Vortex rings reach the top and bottom edges of the shield and form a high-velocity entrainment flow. It is suggested that vortex rings capture small-sized particles, i.e., sneezing droplets and aerosols, and transport them to the top and bottom edges of the face shield because vortex rings have the ability to transport microparticles. It was also confirmed that some particles (in this simulation, 4.4% of the released droplets) entered the inside of the face shield and reached the vicinity of the nose. This indicates that a medical worker wearing a face shield may inhale the transported droplets or aerosol if the time when the vortex rings reach the face shield is synchronized with the inhalation period of breathing.
PubMed: 33362403
DOI: 10.1063/5.0031150 -
Children (Basel, Switzerland) Dec 2022This systematic literature search was performed to determine the clinical effectiveness of vestibular shields (VSs) in children undergoing orthodontic treatment. A... (Review)
Review
This systematic literature search was performed to determine the clinical effectiveness of vestibular shields (VSs) in children undergoing orthodontic treatment. A comprehensive electronic search was performed in May 2022 using three databases (Medline via PubMed, the Cochrane Central Register of Controlled Trials, and Ovid). The initial screening of articles was based on titles and abstracts. Studies meeting the inclusion criteria were retrieved for the final quality assessment and the methodological qualities were assessed according to the Newcastle-Ottawa Scale and Cochrane risk of bias. The initial search identified 262 publications, of which 15 studies were potentially eligible, with excellent intra-examiner reliability (K = 0.88). A total of five studies were selected for the final analysis, including one randomized controlled trial, three clinical trials, and one cohort study. VS may have potential impacts on orthodontic treatment, lips and dental arches, but further high-quality studies are warranted.
PubMed: 36670567
DOI: 10.3390/children10010016 -
Nature Communications Jan 2018Most systemic viral gene therapies have been limited by sequestration and degradation of virions, innate and adaptive immunity, and silencing of therapeutic genes within...
Most systemic viral gene therapies have been limited by sequestration and degradation of virions, innate and adaptive immunity, and silencing of therapeutic genes within the target cells. Here we engineer a high-affinity protein coat, shielding the most commonly used vector in clinical gene therapy, human adenovirus type 5. Using electron microscopy and crystallography we demonstrate a massive coverage of the virion surface through the hexon-shielding scFv fragment, trimerized to exploit the hexon symmetry and gain avidity. The shield reduces virion clearance in the liver. When the shielded particles are equipped with adaptor proteins, the virions deliver their payload genes into human cancer cells expressing HER2 or EGFR. The combination of shield and adapter also increases viral gene delivery to xenografted tumors in vivo, reduces liver off-targeting and immune neutralization. Our study highlights the power of protein engineering for viral vectors overcoming the challenges of local and systemic viral gene therapies.
Topics: Adenoviruses, Human; Animals; Capsid Proteins; Cell Line, Tumor; Crystallography, X-Ray; ErbB Receptors; Female; Gene Transfer Techniques; Genetic Vectors; Humans; Liver; Mice, Transgenic; Molecular Targeted Therapy; Receptor, ErbB-2; Single-Chain Antibodies; Spleen; Virion; Xenograft Model Antitumor Assays
PubMed: 29386504
DOI: 10.1038/s41467-017-02707-6 -
Graefe's Archive For Clinical and... Oct 2020Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic...
PURPOSE
Microscale droplets act as coronaviruses (CoV) carriers in the air when released from an infected person and may infect others during close contact such as ophthalmic examination. The main objective of the present work is to demonstrate how CoV deposited droplets are projected during biomicroscopy and to discuss what kind of precautions should be taken in ophthalmic practice.
METHODS
A coupled fluid-structure system comprising smoothed particle hydrodynamics and the finite element method has been built to assess the projection of droplets spreading from an infected person. Different conditions based on the maximum exit flow velocity from the infector's mouth during the ophthalmic examination were modeled.
RESULTS
During exhalation, for which the exit flow is ~ 1000 mm/s, the average horizontal distance of the flow front was ~ 200 mm while individual particles can reach up to ~ 500 mm. In case of coughing or sneezing (corresponding to an exit flow of ~ 12,000 mm/s), the average horizontal distance of the flow front was ~ 1300 mm.
CONCLUSION
During the ophthalmic examination, the proximity to the patient's nose and mouth was observed to be less than the horizontal distance of flow front particles. Even though mounted breath shields are used, particles flew beyond the shield and contaminate the ophthalmologist. Compared with the current protective breath shields, the use of a larger shield with a minimum radius of 18 cm is needed to decrease viral transmission.
Topics: Aerosols; Air Microbiology; Betacoronavirus; COVID-19; Coronavirus Infections; Eye Diseases; Humans; Infection Control; Inhalation Exposure; Pandemics; Particle Size; Particulate Matter; Physical Examination; Pneumonia, Viral; Rheology; SARS-CoV-2; Slit Lamp; Slit Lamp Microscopy
PubMed: 32588166
DOI: 10.1007/s00417-020-04815-4 -
Interventional Radiology... Jul 2022The medical staff involved in fluoroscopy-guided procedures are at potential risks of radiation-induced cataract. Therefore, proper monitoring of the lens doses is... (Review)
Review
The medical staff involved in fluoroscopy-guided procedures are at potential risks of radiation-induced cataract. Therefore, proper monitoring of the lens doses is critical, and radiation protection should be provided to the maximum extent that is reasonably achievable. The collar dosimeter is necessary to avoid underestimation of the lens dose, and the third dosimeter behind the protective eyewear would be helpful for those who are likely to exceed the dose limit. The reduction of the patient doses will correspondingly reduce the staff doses. Proper placement of the ceiling-mounted shields and minimization of the face-to-glass gap are the keys to effective shielding. The optimization of procedures and devices that help maintain a distance from the irradiated area and to prevent the looking-up posture will substantially reduce the lens dose.
PubMed: 36196387
DOI: 10.22575/interventionalradiology.2022-0006