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Frontiers in Neurorobotics 2022State-of-the-art knee braces use a polycentric mechanism with a predefined locus of the instantaneous center of rotation (centrode) and most exoskeleton devices use a...
State-of-the-art knee braces use a polycentric mechanism with a predefined locus of the instantaneous center of rotation (centrode) and most exoskeleton devices use a knee mechanism with a single axis of rotation. However, human knees do not share a common centrode nor do they have a single axis. This leads to misalignment between the assistive device's joint axis and the user's knee axis, resulting in device migration and interaction forces, which can lead to sores, pain, and abandonment of the device over time. There has been some research into self-aligning knee mechanisms; however, there is a lack of consensus on the benefit of these mechanisms. There is no research that looked purely at the impact of the knee mechanisms, either. In this article, we compare three different knee brace mechanisms: single axis (SA), polycentric with predefined centrode (PPC), and polycentric with a self-aligning center of rotation (PSC). We designed and conducted an experiment to evaluate different joint mechanisms on device migration and interaction forces. Brace material, weight, size, cuff design, fitment location, and tightness were consistent across trials, making the knee joint mechanism the sole variable. The brace mechanisms had no significant effect on walking kinematics or kinetics. However, the PPC brace had greater interaction forces on the top brace strap than the SA and PSC. The PSC and SA had significantly lower interaction forces on the bottom strap compared to the PPC brace. The PSC had significantly less migration than both the SA and PPC braces. These results show that a PPC mechanism may not be beneficial for a wide range of users. This also shows that the PSC mechanisms may improve mechanism alignment and lessen device migration.
PubMed: 35706552
DOI: 10.3389/fnbot.2022.790070 -
Clinical Case Reports Apr 2022An 88-year-old man with history of pacemaker implantation was admitted for septic shock. His first pacemaker in the left subclavian had been removed because of generator...
An 88-year-old man with history of pacemaker implantation was admitted for septic shock. His first pacemaker in the left subclavian had been removed because of generator pocket infection. On presentation, the abandoned lead was fallen out of subclavian and coiled up in the right ventricle, causing moderate tricuspid regurgitation.
PubMed: 35498353
DOI: 10.1002/ccr3.5776 -
Vascular Health and Risk Management 2022Lead-related venous stenosis/obstruction (LRVSO) may be a major challenge in patients with cardiac implantable electronic devices (CIED) when device upgrade, insertion...
BACKGROUND
Lead-related venous stenosis/obstruction (LRVSO) may be a major challenge in patients with cardiac implantable electronic devices (CIED) when device upgrade, insertion of central lines, or creation of an arteriovenous fistula for hemodialysis is indicated. The aim of this study was to evaluate the extent and severity of LRVSO.
METHODS
We performed a retrospective analysis of 3002 venograms from patients awaiting transvenous lead extraction (TLE) to assess the occurrence, severity, and extent of LRVSO.
RESULTS
Mild LRVSO occurred in 19.9%, moderate in 20.7%, severe in 19.9% and total venous occlusion in 22.5% of the patients. Moderate/severe stenosis or total occlusion of the subclavian and brachiocephalic veins was found in 38.2% and 22.5% of the patients, respectively. LRSVO was not detected in 16.9% of the patients. Moderate and severe superior vena cava (SVC) obstruction and total SVC occlusion were rare (0.4%, 0.3%, and 0.3%, respectively). Lead insertion on the left side of the chest contributed to an increased risk of LRVSO compared to right-sided implantation. Major thoracic veins on the opposite side may be narrowed in varying degrees.
CONCLUSION
A total of 60% of the patients with pacemaker or high-voltage leads have an advanced form of LRVSO. Any attempt to insert new pacing leads, central lines, venous ports, or catheters for hemodialysis, or to create dialysis fistula on the same side as the existing lead should be preceded by venography. Furthermore, venography may provide useful information, if it is planned to implant the lead or the catheter on the opposite side of the chest.
Topics: Brachiocephalic Veins; Constriction, Pathologic; Humans; Retrospective Studies; Vascular Diseases; Vena Cava, Superior
PubMed: 36003848
DOI: 10.2147/VHRM.S369342 -
Magnetic Resonance in Medicine Oct 2021The risks of RF-induced heating of active implantable medical device (AIMD) leads during MR examinations must be well understood and realistically assessed. In this...
PURPOSE
The risks of RF-induced heating of active implantable medical device (AIMD) leads during MR examinations must be well understood and realistically assessed. In this study, we evaluate the potential additional risks of broken and abandoned (cut) leads.
METHODS
First, we defined a generic AIMD with a metallic implantable pulse generator (IPG) and a 100-cm long lead containing 1 or 2 wires. Next, we numerically estimated the deposited in vitro lead-tip power for an intact lead, as well as with wire breaks placed at 10 cm intervals. We studied the effect of the break size (wire gap width), as well as the presence of an intact wire parallel to the broken wire, and experimentally validated the numeric results for the configurations with maximum deposited in vitro lead-tip power. Finally, we performed a Tier 3 assessment of the deposited in vivo lead-tip power for the intact and broken lead in 4 high resolution virtual population anatomic models for over 54,000 MR examination scenarios.
RESULTS
The enhancement of the deposited lead-tip power for the broken leads, compared to the intact lead, reached 30-fold in isoelectric exposure, and 16-fold in realistic clinical exposures. The presence of a nearby intact wire, or even a nearby broken wire, reduced this enhancement factor to <7-fold over the intact lead.
CONCLUSION
Broken and abandoned leads can pose increased risk of RF-induced lead-tip heating to patients undergoing MR examinations. The potential enhancement of deposited in vivo lead-tip power depends on location and type of the wire break, lead design, and clinical routing of the lead, and should be carefully considered when performing risk assessment for MR examinations and MR conditional labeling.
Topics: Heating; Hot Temperature; Humans; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Phantoms, Imaging; Prostheses and Implants; Radio Waves
PubMed: 34080721
DOI: 10.1002/mrm.28836 -
ACS Applied Materials & Interfaces Mar 2023The inevitable usage of toxic lead impedes the commercialization of lead halide perovskite solar cells, especially considering lead ions potentially unseals from the...
The inevitable usage of toxic lead impedes the commercialization of lead halide perovskite solar cells, especially considering lead ions potentially unseals from the discarded and damaged devices and consequently contaminates the environment. In this work, we proposed a poly(ionic liquid) (PIL) cohered sandwich structure (PCSS) to realize lead sequestration in perovskite solar cells by a water-proof and adhesive poly([1-(3-propionic acid)-3-vinylimidazolium] bis(trifluoromethanesulphonyl)imide (PPVI-TFSI). A transparent ambidextrous protective shield manufactured from PPVI-TFSI was achieved and applied in lead sequestration for perovskite solar cells. PCSS provides robustness and water-resistance, which improves device stability toward water erosion and extreme situations (such as acid, base, salty water, and hot water). PPVI-TFSI exhibited excellent affinity toward lead with adsorption capacity of 516 mg·g, which assisted to prevent lead leakage in abandoned devices as proved in the test of wheat germination vividly. PCSS provides a promising solution for complex lead sequestration and management issues, which contribute to the commercialization of perovskite solar cells.
PubMed: 36877534
DOI: 10.1021/acsami.2c22957 -
Frontiers in Cardiovascular Medicine 2021When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead...
When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead abandonment and subcutaneous ICD (S-ICD) implantation may represent an additional option for patients who do not require pacing. The aim of this study was to investigate the outcomes of a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction. We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and compared their outcomes with those of patients who underwent extraction and subsequent reimplantation of a single-chamber transvenous ICD (T-ICD). Forty-three patients underwent S-ICD implantation after abandonment of malfunctioning leads, while 62 patients underwent extraction and subsequent reimplantation of a new T-ICD. The two groups were comparable. In the extraction group, no major complications occurred during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, 3 major complications or deaths occurred in the S-ICD group and 11 in the T-ICD group (HR 1.07; 95% CI 0.29-3.94; = 0.912). Minor complications were 4 in the S-ICD group and 5 in the T-ICD group (HR 2.13; 95% CI 0.49-9.24; = 0.238). In the event of ICD lead malfunction, extraction avoids the potential long-term risks of abandoned leads. Nonetheless the strategy of lead abandonment and S-ICD implantation was feasible and safe, with no significant increase in adverse outcomes, and may represent an option in selected clinical settings. Further studies are needed to fully understand the potential risks of lead abandonment. URL: ClinicalTrials.gov Identifier: NCT02275637.
PubMed: 34395560
DOI: 10.3389/fcvm.2021.692943 -
Factors influencing lead, mercury and other trace element exposure in birds from metal mining areas.Environmental Research Sep 2022Non-ferrous metal mining is considered one of the largest sources of toxic metal released to the environment and may threaten ecosystems, notably biota. We explored how...
Non-ferrous metal mining is considered one of the largest sources of toxic metal released to the environment and may threaten ecosystems, notably biota. We explored how birds that inhabit non-ferrous metal mining sites are exposed to mercury, lead, and other trace elements by analyzing their feathers and verifying which factors may influence element concentrations in feathers. We sampled a total of 168 birds, representing 26 species, with different feeding habits and migration patterns in a non-polluted reference site and two historical metal mining areas: Almadén, which is considered one of the most heavily mercury-contaminated sites worldwide, and the Sierra Madrona mountains where lead has been mined since ancient times. The quantification of aluminum (Al), arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), thorium (Th), thallium (Tl), uranium (U), vanadium (V) and zinc (Zn) was performed by inductively coupled plasma mass spectrometry (ICP-MS). Feather analysis revealed contamination by Hg and Pb, in Almadén and Sierra Madrona, respectively. We found that granivorous birds had the lowest feather Hg levels compared to those found in omnivorous, insectivorous, and piscivorous species, whereas feather Pb was about twice as high in granivores and omnivores, than in insectivorous and piscivorous birds. We also found differences among study sites in 13 elements and confirmed the influence of feather age, migratory patterns of the birds, and external deposition of elements, on metal concentrations in the feathers. Our results highlight that despite the cessation of metal mining in the study areas, local avifauna are being exposed to Hg and Pb from abandoned mines and old tailings sites, indicating that appropriate measures are needed to protect biota from overexposure to these toxic metals.
Topics: Animals; Birds; Ecosystem; Environmental Monitoring; Lead; Mercury; Mining; Trace Elements
PubMed: 35644495
DOI: 10.1016/j.envres.2022.113575 -
Current Opinion in Pulmonary Medicine Nov 2023Biannual clock changes to and from daylight saving time have been pervasive in many societies for over 50 years. Governments are considering abandoning this practice... (Review)
Review
PURPOSE OF REVIEW
Biannual clock changes to and from daylight saving time have been pervasive in many societies for over 50 years. Governments are considering abandoning this practice and choosing a single permanent time.
RECENT FINDINGS
Our endogenous circadian clock follows our photoperiod, which changes over the year. The acute disruption caused by changing our clocks can affect safety (motor vehicle and on the job accidents), health (cardiovascular disease, drug overdoses, suicide), and human behavior (sport performance, generosity, and procrastination). Although abandoning the clock change could help avoid these acute harms, choosing the wrong permanent time could lead to chronic circadian misalignment, which could have even more profound implications for health, safety, and human behavior.
SUMMARY
Ceasing the biannual clock change may be a good choice, but governments need to be mindful of which permanent time to adopt. Many regions of the world already follow the wrong time during standard time, and circadian misalignment would be amplified by moving to permanent daylight saving time. In many regions, Standard Time better aligns with our circadian clock, thus providing a more natural light cycle that minimizes circadian misalignment.
Topics: Humans; Circadian Rhythm; Photoperiod; Circadian Clocks
PubMed: 37578383
DOI: 10.1097/MCP.0000000000001003 -
Environmental Science and Pollution... Jan 2022Interindividual genetic variations determine human's susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of lead (Pb) and cadmium (Cd)...
Glutathione S-transferase gene polymorphisms in association with susceptibility to lead toxicity in lead- and cadmium-exposed children near an abandoned lead-zinc mining area in Kabwe, Zambia.
Interindividual genetic variations determine human's susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of lead (Pb) and cadmium (Cd) in 140 lead-exposed children. Genotyping of the glutathione S-transferase (GST) genes, GSTM1, GSTT1, and GSTP1 genes, was carried out to investigate their possible association with heavy metal concentrations and the risk of susceptibility to Pb toxicity. Exposure to both heavy metals was prevalent among the children. The blood Pb level ranged from 3.30 to 74.0 μg dL with an average value of 26.8 μg dL that is five times above its reference level. The average Cd level (0.22 μg L) was below its reference level. The metal-gene interaction showed positive correlation between GSTT1 null genotype and Pb and Cd levels (β = 0.11; p = 0.02 and β = 0.10; p = 0.01, respectively). More pronounced effects (β = 0.19; p < 0.01 and β = 0.25; p = 0.04) were found for the mixture of the three putative genes with blood Pb concentration. The susceptibility analysis using 10 μg dL as blood Pb cutoff level showed a high risk of Pb toxicity (OR = 2.54; 95% CI: 1.02-6.32, p = 0.04) for children carrying the GSTP1 Ile/Val genotype. Further, the combined effect of GSTP1 Ile/Val with GSTT1 null genotype was more pronounced and showed an increased risk of susceptibility to Pb toxicity (OR = 11.7; 95% CI: 1.36-102.1, p = 0.02). In summary, this study suggests that GSTT1 null and GSTP1 Ile/Val genotypes are the main genetic factors, and individual and specific combinations of GSTP1 Ile/Val with GSTM1 and GSTT1 GST polymorphisms are associated with susceptibility to Pb toxicity.
Topics: Cadmium; Case-Control Studies; Child; Genotype; Glutathione Transferase; Humans; Lead; Mining; Polymorphism, Genetic; Risk Factors; Zambia; Zinc
PubMed: 34453679
DOI: 10.1007/s11356-021-16098-1 -
Reviews in Endocrine & Metabolic... Sep 2020During the last decades, several interventions for the management of overweight and obesity have been proposed. Among diets, the first studies focused on the effect of... (Review)
Review
During the last decades, several interventions for the management of overweight and obesity have been proposed. Among diets, the first studies focused on the effect of water only and total fasting diets with or without proteins. Unfortunately, they were found to be associated with adverse events which lead to the abandon of these strategies. Interestingly, despite the radical approach, total fasting was effective and generally well tolerated. A strict connection between protein-calorie malnutrition and increased in morbidity and mortality in hospitalized patients was found at that time. Then, the seminal works of Blackburn and his collaborators lead to the introduction of the protein-sparing modified fast. Encouraged by the early results using this intervention, diets evolved to the current very-low-calorie ketogenic diets (VLCKD). In the present review, results of studies on the VLCKDs are presented and discussed, with a particular reference to the protocolled VLCKD. Also, a recent proposal on the nomenclature on the ketogenic diets is reported. Available evidence suggests VLCKDs to be effective in achieving a rapid and significant weight loss by means of an easily reversible intervention which could be repeated, if needed. Muscle mass and strength are preserved, resting metabolic rate is not impaired, hunger, appetite and mood are not worsened. Symptoms and abnormal laboratory findings can be there, but they have generally been reported as of mild intensity and transient. Preliminary studies suggest VLCKDs to be a potential game-changer in the management of type 2 diabetes too. Therefore, VLCKDs should be considered as an excellent initial step in properly selected and motivated patients with obesity or type 2 diabetes, to be delivered as a part of a multicomponent strategy and under strict medical supervision.
Topics: Caloric Restriction; Diabetes Mellitus, Type 2; Diet, Ketogenic; Humans; Obesity; Weight Loss
PubMed: 32803691
DOI: 10.1007/s11154-020-09580-7