The impact of piezoelectric PVDF on medical ultrasound exposure measurements, standards, and regulations

2000 ◽  
Vol 47 (6) ◽  
pp. 1321-1335 ◽  
Author(s):  
G.R. Harris ◽  
R.C. Preston ◽  
A.S. DeReggi
Author(s):  
Н.Н. Петрищев ◽  
Д.Ю. Семенов ◽  
А.Ю. Цибин ◽  
Г.Ю. Юкина ◽  
А.Е. Беркович ◽  
...  

The purpose. In the study we investigated the impact of the partial blood flow shutdown on structural changes in the rabbit vena cava posterior wall after exposure to high-intensity focused ultrasound (HIFU). Methods. Ultrasound Exposure: frequency of 1.65 MHz, the ultrasound intensity in the focus of 13.6 kW/cm, the area of the focal spot 1 mm, continuous ultrasound, exposure for 3 seconds. Results. Immediately after HIFU exposure all layers of the vein wall showed characteristic signs of thermal damage. A week after exposure structural changes in the intima, media and adventitia was minimal in the part of vessel with preserved blood flow, and after 4 weeks the changes were not revealed. A week after HIFU exposure partial endothelium destruction, destruction of myocytes, disorganization and consolidation of collagen fibers of the adventitia were observed in an isolated segment of the vessel, and in 4 weeks endothelium restored and signs of damage in media and adventitia persisted, but were less obvious than in a week after exposure. Conclusion. The shutdown of blood flow after exposure to HIFU promotes persistent changes in the vein wall. Vein compression appears to be necessary for the obliteration of the vessel, when using HIFU-technology.


2020 ◽  
Vol 69 (6) ◽  
pp. 1301-1319
Author(s):  
Derek E. Crews ◽  
Molly J. Russ

PurposeThe study's purpose was to explore the impact of multitasking on efficiency and accuracy and the relationship between individual differences and multitasking ability.Design/methodology/approachAn experimental study was conducted with individuals that completed an in-box exercise and a personality assessment. Three groups were established as follows: those that completed the in-box exercise without interruption (control group), those that were given a portion of the same initial task but were then interrupted and given an additional task (low multitask group) and those that were given the same initial tasks, then interrupted three times (high multitask group).FindingsThe results show that there were significant effects of gender and age on multitasking efficiency. Females made fewer errors than males. Younger and older participants took more time to complete the experiment, which indicates an inverted U relationship and may mean that people become more effective at multitasking with experience and practice, but then less effective as they get older. The study also found that personality had no significant effect on multitasking efficiency.Research limitations/implicationsThe study was limited in that the sample was 91 percent female, did not include anyone over the age of 51 and did not measure intelligence or experience.Practical implicationsThe findings may have implications for employee training, evaluation and formulation of workplace standards and regulations.Orginality/valueThis study provides empirical research extending the understanding of the nature and impact of multitasking and individual differences based on gender, age and personality.


2021 ◽  
Vol 10 (2) ◽  
pp. 4-16
Author(s):  
Marcelo Carvalho ◽  
Paulo Bandiera-Paiva ◽  
Eduardo Marques ◽  
José Manuel Machado

The personal health information (PHI) that a health information system (HIS) stores and processes requires special caution to ensure authorized manipulation by system users. A diverse set of best practices, standards, and regulations are in place nowadays to achieve that purpose. To the access control element in a HIS, general data protection regulation (GDPR) will require explicit authorization and informed consent prior to this manipulation of patient information by healthcare practitioners in a system. The adaptations to cope this type of previous authorization on HIS requires not only a clear understanding of technicalities and modification to the underlying computational infrastructure but also the impact on players that interact with this type of system during healthcare service provision, namely patients and healthcare professionals. This article is an effort to understand this effect by means of collecting opinion from both players in a multicentric survey that presents different questions establishing scenarios that reflect this new control and its consequences.


2012 ◽  
Vol 488-489 ◽  
pp. 1547-1552 ◽  
Author(s):  
Noraini Ahmad ◽  
Sabarinah Sh Ahmad ◽  
Anuar Talib

This paper highlights the results of light levels and light-fastness study conducted in four daylit historical museum galleries in Malaysia. These museums architectural features allow sun radiation into the building, causing light exposure damage to artifacts. This study aims to evaluate the luminous exposures and light-fastness as an initial preventive conservation measure in daylit historical museum galleries under the tropical sky conditions. Light sensors with data-loggers and Light-fastness dosimeters were installed throughout the museums to take cumulative light exposure measurements during museum opening hours. Both instrumentations were tested in the field during different campaigns exposures. After exposures between 90 and 100 days, these dosimeters showed photo-induced colour changes which translated exposures into equivalent luminous exposure and estimated annual exposures (Lux hours) which were used to validate the measured values of illuminance data. Simulated light dosimeters and measured illuminance data show good correlation. Thus, equivalent light dosimeter makes sense to assess the impact of light distributions.


2020 ◽  
Author(s):  
Susanna Haga ◽  
Annika Hagenbjörk ◽  
Anna-Carin Olin ◽  
Bertil Forsberg ◽  
Ingrid Liljelind ◽  
...  

Abstract BackgroundExposure to air pollution is of great concern for public health although studies on the associations between exposure estimates and personal exposure are limited and somewhat inconsistent. We aimed to quantify the associations between personal NOx, ozone and PM10 exposure levels to ambient levels, and the impact of climate and time spent outdoors in two cities in Sweden.MethodsSubjects (n=65) from two Swedish cities participated in the study. The study protocol included personal exposure measurements at three occasions, or waves. Personal exposure measurements of NOx, ozone, and PM10, were performed for 10 days and 24 hours respectively, and the participants kept a diary on activities. Stationary monitoring stations provided hourly data of NOx, ozone, and PM, as well as data on air temperature and relative humidity. Data were analysed using mixed linear models with the subject-id as a random effect and stationary exposure and covariates as fixed effects. ResultsPersonal exposure levels of NOx, ozone, and PM10 were significantly associated with levels measured at air-pollution monitoring stations. The associations persisted after adjusting for temperature, relative humidity, city, and wave, but the modelled estimates were slightly attenuated from 2.4% (95% CI 1.8-2.9) to 2.0% (0.97-2.94%) for NOX, from 3.7% (95% CI 3.1-4.4) to 2.1% (95% CI 1.1-2.9%) for O3 and from 2.6% (95% 0.9-4.2%) to 1.3% (95% CI -1.5-4.0) for PM10. After adding covariates, the degree of explanation offered by the model (coefficient of determination, or R2) did not change for NOX (0.64 to 0.63), but increased from 0.46 to 0.63 for O3, and from 0.38 to 0.43 for PM10. ConclusionsPersonal exposure to NOx, ozone and PM have moderate to good association with levels measured at urban background sites. The results indicate that stationary measurements are valid as measure of exposure in environmental health risk assessments, especially if they can be refined using activity diaries and meteorological data. Approximately 50-70% of the variation of the personal exposure was explained by the stationary measurement, implying occurrence of misclassification in studies using more crude exposure metrics, potentially leading to underestimates of the effects of exposure to ambient air pollution


Author(s):  
Xiwei XU ◽  
Tim Heath ◽  
Qing Xia ◽  
Youtian Zhang

This paper draws upon preliminary research into the insufficiencies of the status quo of the disaster prevention and mitigation in architecture heritage areas in China. It summarizes how the common hazards, which are various threats to the survival and development of the historical architectural heritage, such as fire, geological disasters and meteorological disasters occurs and their characteristics, and also analyses their impact on heritage. The paper also focuses on the disaster-prone parts of architecture heritage, exploring the proposals for evaluations of disaster-risk-factors, and the preliminary strategies that promote historic architecture heritage related to disaster prevention and mitigation, so that people can enhance the security capabilities for architecture heritage. This enables strategies to limit the impact of the disaster,improve historic buildings anti-disaster systems, provide the theory and technical basis to the relevant departments for standards and regulations for architecture heritages’ conservation and security. The ultimate aim is to ensure the long-lasting and safe existence and development of architectural heritage.


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