A Parametric Analysis of Endovascular Stent Geometry Manipulation On Radial Force Performance

2020 ◽  
Author(s):  
Joel C. R. Scott ◽  
Darrel A. Doman ◽  
Clifton R. Johnston
Keyword(s):  
Radial Force ◽  
Wire Diameter ◽  
Force Generation ◽  
Patient Specific ◽  
Bend Angle ◽  
Parameter Study ◽  
Stent Design ◽  
Leg Length ◽  
Bend Radius ◽  
The Impact

Abstract Stents were manufactured to investigate the impact of altering stent design characteristics (leg length, bend angle, bend radius, wire diameter) on radial force generation. Results from this design parameter study showed that leg length, bend angle and wire diameter have a statistically significant impact on radial force generation, while lesser changes in bend radius did not (1.00mm vs. the original 0.794mm [1/32in]). However a larger variation of this parameter (1.588mm [1/16in]) was statistically significant. Results gathered for all parameters were used in the creation of a prototypal software. Using input values of patient specific arterial diameter and compliance, as well as stent design characteristic dimensions, this program has been developed to predict stent radial force at varying levels of expansion.

The Role of Stent Design and Polymers in Safety Outcomes – A Review

2012 ◽  
Vol 8 (1) ◽  
pp. 63
Author(s):  
Carlo Zivelonghi ◽  
Giulia Geremia ◽  
Michele Pighi ◽  
Flavio Ribichini ◽  
◽  
...  
Keyword(s):  
Clinical Performance ◽  
Drug Carrier ◽  
Chemical Properties ◽  
Vascular Wall ◽  
Radial Force ◽  
Vascular Trauma ◽  
Polymer Composition ◽  
Drug Eluting Stent ◽  
Stent Design ◽  
Drug Elution

Each component of a drug-eluting stent (DES) contributes to the safety of the device. Continuous efforts are being dedicated to the search of the optimal compromise between facility of use, safety and long-term efficacy. Shorter balloons reduce the vascular trauma beyond the stent struts; the metallic composition of the stent platform and the platform itself interact with the vascular wall in a long-lasting equilibrium between radial force, vessel patency and reparative cellular regrowth. The modality of drug elution is largely regulated by the chosen drug carrier, rather than by the chemical properties of the drug itself. Drug elution can be accomplished by permanent polymers that remain in the vessel wall forever, by biodegradable polymers that leave the naked metallic structure behind after their complete absorption, or even by direct release of the drug from stent reservoirs. The clinical performance of DESs has been exhaustively assessed in a large number of studies that have showed rapid and continuous improvements, from the first-generation DESs to the latest devices, based on substantial changes in stent design and polymer composition.

Uncovering the Diversification of Tissue Engineering on the Emergent Areas of Stem Cells, Nanotechnology and Biomaterials

2020 ◽  
Vol 15 (3) ◽  
pp. 187-201 ◽  
Author(s):  
Sunil K. Dubey ◽  
Amit Alexander ◽  
Munnangi Sivaram ◽  
Mukta Agrawal ◽  
Gautam Singhvi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Immune System ◽  
Clinical Application ◽  
Cell Types ◽  
Patient Specific ◽  
Potential Strategy ◽  
Induced Pluripotent ◽  
Treat All ◽  
The Impact

Damaged or disabled tissue is life-threatening due to the lack of proper treatment. Many conventional transplantation methods like autograft, iso-graft and allograft are in existence for ages, but they are not sufficient to treat all types of tissue or organ damages. Stem cells, with their unique capabilities like self-renewal and differentiate into various cell types, can be a potential strategy for tissue regeneration. However, the challenges like reproducibility, uncontrolled propagation and differentiation, isolation of specific kinds of cell and tumorigenic nature made these stem cells away from clinical application. Today, various types of stem cells like embryonic, fetal or gestational tissue, mesenchymal and induced-pluripotent stem cells are under investigation for their clinical application. Tissue engineering helps in configuring the stem cells to develop into a desired viable tissue, to use them clinically as a substitute for the conventional method. The use of stem cell-derived Extracellular Vesicles (EVs) is being studied to replace the stem cells, which decreases the immunological complications associated with the direct administration of stem cells. Tissue engineering also investigates various biomaterials to use clinically, either to replace the bones or as a scaffold to support the growth of stemcells/ tissue. Depending upon the need, there are various biomaterials like bio-ceramics, natural and synthetic biodegradable polymers to support replacement or regeneration of tissue. Like the other fields of science, tissue engineering is also incorporating the nanotechnology to develop nano-scaffolds to provide and support the growth of stem cells with an environment mimicking the Extracellular matrix (ECM) of the desired tissue. Tissue engineering is also used in the modulation of the immune system by using patient-specific Mesenchymal Stem Cells (MSCs) and by modifying the physical features of scaffolds that may provoke the immune system. This review describes the use of various stem cells, biomaterials and the impact of nanotechnology in regenerative medicine.

scholarly journals Impact of a patient-specific national programme aimed at increasing the use of emollient moisturisers to reduce the risk of skin tears: a longitudinal cohort study

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e039579
Author(s):  
Anna K Moffat ◽  
Kerrie P Westaway ◽  
Jemisha Apajee ◽  
Oliver Frank ◽  
Russell Shute ◽  
...  
Keyword(s):  
Interrupted Time Series ◽  
Self Report ◽  
Additional Patient ◽  
Patient Specific ◽  
Department Of Veterans Affairs ◽  
National Programme ◽  
Sustained Effect ◽  
Skin Tears ◽  
Comparison Groups ◽  
The Impact

ObjectivesTo evaluate the impact of a patient-specific national programme targeting older Australians and health professionals that aimed to increase use of emollient moisturisers to reduce to the risk of skin tears.DesignA prospective cohort intervention.ParticipantsThe intervention targeted 52 778 Australian Government’s Department of Veterans’ Affairs patients aged over 64 years who had risk factors for wound development, and their general practitioners (GPs) (n=14 178).Outcome measuresAn interrupted time series model compared the rate of dispensing of emollients in the targeted cohort before and up to 23 months after the intervention. Commitment questions were included in self-report forms.ResultsIn the first month after the intervention, the rate of claims increased 6.3-fold (95% CI: 5.2 to 7.6, p<0.001) to 10 emollient dispensings per 1000 patients in the first month after the intervention. Overall, the intervention resulted in 10 905 additional patient-months of treatment. The increased rate of dispensing among patients who committed to talking to their GP about using an emollient was six times higher (rate ratio: 6.2, 95% CI: 4.4 to 8.7) than comparison groups.ConclusionsThe intervention had a sustained effect over 23 months. Veterans who responded positively to commitment questions had higher uptake of emollients than those who did not.

scholarly journals Shooting from the ‘Scrip: Scope of Practice Laws and Access to Immunizations in the Pharmacy Setting

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 444
Author(s):  
Charles Stoecker
Keyword(s):  
Positive Impact ◽  
National Level ◽  
State Level ◽  
The United States ◽  
Scope Of Practice ◽  
Patient Specific ◽  
Behavioral Risk ◽  
Influenza Immunization ◽  
Immunization Rates ◽  
The Impact

In the past two decades, most states in the United States have added authorization for pharmacists to administer some vaccinations. Expansions of this authority have also come with prescription requirements or other regulatory burdens. The objective of this study was to evaluate the impact of these expansions on influenza immunization rates in adults age 65 and over. A panel data, differences-in-differences regression framework to control for state-level unobserved confounders and shocks at the national level was used on a combination of a dataset of state-level statute and regulatory changes and influenza immunization data from the Behavioral Risk Factor Surveillance System. Giving pharmacists permission to vaccinate had a positive impact on adult influenza immunization rates of 1.4 percentage points for adults age 65 and over. This effect was diminished by the presence of laws requiring pharmacists to obtain patient-specific prescriptions. There was no evidence that allowing pharmacists to administer vaccinations led patients to have fewer annual check-ups with physicians or not have a usual source of health care. Expanding pharmacists’ scope of practice laws to include administering the influenza vaccine had a positive impact on influenza shot uptake. This may have implications for relaxing restrictions on other forms of care that could be provided by pharmacists.

Creating a Safer Patient Room Environment: The Contribution of Patient Bed Height

2021 ◽  
Vol 10 (1) ◽  
pp. 180-184
Author(s):  
Dorothy Taylor ◽  
Janice Morse ◽  
Andrew Merryweather
Keyword(s):  
Elderly Patient ◽  
Fall Risk ◽  
The Elderly ◽  
Lower Leg ◽  
Patient Specific ◽  
Leg Length ◽  
Patient Room ◽  
Patient Falls ◽  
Sit To Stand ◽  
Bed Height

Elderly patient falls are expensive and may cause serious harm. Studies have identified the sit-to-stand-and-walk (STSW) task as the task where the greatest number of elderly patient falls occur. There is a great need to identify the particular movement and environmental conditions that lead to these elderly patient falls. This study begins to address this gap by evaluating the elderly patient during self-selected hospital bed egress. Using an observed fall risk episode (FRE) as a fall proxy, statistically significant parameters were identified which include bed height, pausing prior to initiating gait, level of fall risk, and Stand phase. Low bed height was identified as the least safe bed height. Patient-specific bed height (PSBH) using the patient’s lower leg length (LLL) is recommended. In addition, suggested guidelines are presented for clinical application in setting PSBH without measuring the patient’s LLL.

scholarly journals Demographics associated with US healthcare disparities are exacerbated by the telemedicine surge during the COVID-19 pandemic

2021 ◽  
pp. 1357633X2110259
Author(s):  
Kristin N Gmunder ◽  
Jose W Ruiz ◽  
Dido Franceschi ◽  
Maritza M Suarez
Keyword(s):  
Income Tax ◽  
Healthcare Disparities ◽  
Descriptive Statistics ◽  
Internal Revenue Service ◽  
Patient Specific ◽  
Postal Code ◽  
The Us ◽  
Hispanic Patients ◽  
The Impact ◽  
Racial Ethnic

Introduction As coronavirus disease 2019 (COVID-19) hit the US, there was widespread and urgent implementation of telemedicine programs nationwide without much focus on the impact on patient populations with known existing healthcare disparities. To better understand which populations cannot access telemedicine during the coronavirus disease 2019 pandemic, this study aims to demographically describe and identify the most important demographic predictors of telemedicine visit completion in an urban health system. Methods Patient de-identified demographics and telemedicine visit data ( N = 362,764) between March 1, 2020 and October 31, 2020 were combined with Internal Revenue Service 2018 individual income tax data by postal code. Descriptive statistics and mixed effects logistic regression were used to determine impactful patient predictors of telemedicine completion, while adjusting for clustering at the clinical site level. Results Many patient-specific demographics were found to be significant. Descriptive statistics showed older patients had lower rates of completion ( p < 0.001). Also, Hispanic patients had statistically significant lower rates ( p < 0.001). Overall, minorities (racial, ethnic, and language) had decreased odds ratios of successful telemedicine completion compared to the reference. Discussion While telemedicine use continues to be critical during the coronavirus disease 2019 pandemic, entire populations struggle with access—possibly widening existing disparities. These results contribute large datasets with significant findings to the limited research on telemedicine access and can help guide us in improving telemedicine disparities across our health systems and on a wider scale.

scholarly journals Braided composite stent for peripheral vascular applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1137-1146
Author(s):  
Qingli Zheng ◽  
Pengfei Dong ◽  
Zhiqiang Li ◽  
Ying Lv ◽  
Meiwen An ◽  
...  
Keyword(s):  
Computational Models ◽  
Surface Coverage ◽  
Mechanical Performance ◽  
Wire Diameter ◽  
Orthogonal Experimental Design ◽  
Braided Composite ◽  
Nitinol Wire ◽  
Radial Strength ◽  
Braiding Angle ◽  
The Impact

AbstractBraided composite stent (BCS), woven with nitinol wires and polyethylene terephthalate (PET) strips, provides a hybrid design of stent. The mechanical performance of this novel stent has not been fully investigated yet. In this work, the influence of five main design factors (number of nitinol wires, braiding angle, diameter of nitinol wire, thickness and stiffness of the PET strip) on the surface coverage, radial strength, and flexibility of the BCS were systematically studied using computational models. The orthogonal experimental design was adopted to quantitatively analyze the sensitivity of multiple factors using the minimal number of study cases. Results have shown that the nitinol wire diameter and the braiding angle are two most important factors determining the mechanical performance of the BCS. A larger nitinol wire diameter led to a larger radial strength and less flexibility of the BCS. A larger braiding angle could provide a larger radial strength and better flexibility. In addition, the impact of the braiding angle decreased when the stent underwent a large deformation. At the same time, the impact of the PET strips increased due to the interaction with nitinol wires. Moreover, the number of PET strips played an important role in the surface coverage. This study could help understand the mechanical performance of BCS stent and provides guidance on the optimal design of the stent targeting less complications.

scholarly journals Effect of Patient-Specific Preanalytic Variables on CSF Aβ1–42 Concentrations Measured on an Automated Chemiluminescent Platform

2020 ◽  
Author(s):  
Jacqueline A Darrow ◽  
Amanda Calabro ◽  
Sara Gannon ◽  
Amanze Orusakwe ◽  
Rianne Esquivel ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Cognitive Impairment ◽  
Patient Specific ◽  
Csf Biomarkers ◽  
Clinical Settings ◽  
Blood Contamination ◽  
Gradient Effect ◽  
Β Amyloid ◽  
The Impact ◽  
Gradient Effects

Abstract Background Cerebrospinal fluid (CSF) biomarkers are increasingly used to confirm the accuracy of a clinical diagnosis of mild cognitive impairment or dementia due to Alzheimer disease (AD). Recent evidence suggests that fully automated assays reduce the impact of some preanalytical factors on the variability of these measures. This study evaluated the effect of several preanalytical variables common in clinical settings on the variability of CSF β-amyloid 1–42 (Aβ1–42) concentrations. Methods Aβ1–42 concentrations were measured using the LUMIPULSE G1200 from both freshly collected and frozen CSF samples. Preanalytic variables examined were: (1) patient fasting prior to CSF collection, (2) blood contamination of specimens, and (3) aliquoting specimens sequentially over the course of collection (i.e., CSF gradients). Results Patient fasting did not significantly affect CSF Aβ1–42 levels. While assessing gradient effects, Aβ1–42 concentrations remained stable within the first 5 1-mL aliquots. However, there is evidence of a gradient effect toward higher concentrations over successive aliquots. Aβ1–42 levels were stable when fresh CSF samples were spiked with up to 2.5% of blood. However, in frozen CSF samples, even 0.25% blood contamination significantly decreased Aβ1–42 concentrations. Conclusions The preanalytical variables examined here do not have significant effects on Aβ1–42 concentrations if fresh samples are processed within 2 h. However, a gradient effect can be observed on Aβ1–42 concentrations after the first 5 mL of collection and blood contamination has a significant impact on Aβ1–42 concentrations once specimens have been frozen.

Energy absorbed ability and damage analysis for honeycomb sandwich material of bio-inspired micro aerial vehicle under low velocity impact

2020 ◽  
pp. 095440622097542
Author(s):  
Jianxun Du ◽  
Peng Hao ◽  
Mabao Liu ◽  
Rui Xue ◽  
Lin’an Li
Keyword(s):  
Honeycomb Structure ◽  
Low Velocity Impact ◽  
Parameter Study ◽  
Low Velocity ◽  
Micro Aerial Vehicle ◽  
Thin Walled Structures ◽  
Wide Range ◽  
Aerial Vehicle ◽  
Thin Walled ◽  
The Impact

Because of the advantages of light weight, small size, and good maneuverability, the bio-inspired micro aerial vehicle has a wide range of application prospects and development potential in military and civil areas, and has become one of the research hotspots in the future aviation field. The beetle’s elytra possess high strength and provide the protection of the abdomen while being functional to guarantee its flight performance. In this study, the internal microstructure of beetle’s elytra was observed by scanning electron microscope (SEM), and a variety of bionic thin-walled structures were proposed and modelled. The energy absorption characteristics and protective performance of different configurations of thin-walled structures with hollow columns under impact loading was analyzed by finite element method. The parameter study was carried out to show the influence of the velocity of impactor, the impact angle of the impactor and the wall thickness of honeycomb structure. This study provides an important inspiration for the design of the protective structure of the micro aerial vehicle.

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