Edgar Herno Sepulveda OviedoLeonardo Enrique Bermeo ClavijoLuis Carlos Mendez Cordoba
19页
查看更多>>摘要：There is a lack of medical simulation tools that can be understood and used, at the same time, by researchers, teachers, clinicians and students. Regarding this issue, in this work we report a virtual simulator (developed in OpenModelica) that allow to experiment with the fundamental variables of the cardiovascular and respiratory system of a neonate. We extended a long-tested lumped parameter model that represents the cardiovascular and respiratory physiology of a neonate. From this model, we implemented a physiological simulator using Modelica. The fidelity and versatility of the reported simulator were evaluated by simulating seven physiological scenarios: two of them representing a healthy infant (newborn and 6-months old) and five representing newborns affected by different heart diseases. The simulator properly and consistently represented the quantitative and qualitative behaviour of the seven physiological scenarios when compared with existing clinical data. Results allow us to consider the simulator reported here as a reliable tool for researching, training and learning. The advanced modelling features of Modelica and the friendly graphical user interface of OpenModelica make the simulator suitable to be used by a broad community of users. Furthermore, it can be easily extended to simulate many clinical scenarios.
查看更多>>摘要：In times of the COVID-19 pandemic, wearing face masks is strongly recommended as a public health measure to stop the spread of the Sars Coronavirus. However, there are still people who ignore using this effective protective tool due to the lack of comfortable face masks on the market. Therefore, in the current study, we assessed commercially available face masks namely N95 masks, surgical masks, and cloth masks in order to find out their weakness. In addition, the identification needs of people from a face mask were collected by an online questionnaire. According to the information obtained; we achieved key factors required to design a new type of face mask using the Computer-Aided Design (CAD) and the final design was printed. Moreover, the long-term use of herbs in Iranian Traditional Medicine persuaded us to add a humidifier containing aromatic plants essential oils such as Eucalyptus globules Labill. and Rosa damascene Mill. with scientifically proven health benefits such as pain reliever, relaxing properties and antimicrobial activities. We are expected that these aromas would be an effective way to eliminate the problems of individuals suffering from air pollutants, respiratory disorders, and COVID which leads to encouraging more people to use face masks during pandemics or air pollution.
查看更多>>摘要：We investigated the effect of the design of bioprosthetic pericardial valves on the downstream fluid flow pattern through four-dimensional flow magnetic resonance imaging (4D Flow). A dedicated in vitro test bench, including a paradigmatic aortic root phantom, was used to compare, under steady flow conditions, three commercially used pericardial bioprostheses (TrifectaTM, Carpentier-Edwards PERIMOUNT Magna, Crown PRTVR), selecting the two smallest and comparable valve sizes. In-house 4D Flow post-processing provided the downstream flow pattern of velocity, the velocity profile at vena contracta, its effective orifice area (EOA) and the corresponding hydraulic diameter (D_H). Trifecta reported the lowest peak of velocity for both the tested sizes, with vena contracta position being the most proximal to the free margin of leaflets. Conversely, in both Crown and Magna, jet flow continued to increase its downstream velocity, resulting in a farther position of vena contracta. EOA shape was trilobal for Magna, triangular for Crown and circular for Trifecta, the last one maximising EOA. The percentage of nominal luminal area effectively exploited by the flow was largely above 80% in Trifecta, below 75% in Crown and below 70% in Magna. Hence, the design of pericardial bioprostheses directly impacts on the downstream flow field pattern and its fluid dynamic performance.
Robert WhitingElizabeth SerClaire ConwayTed J. Vaughan...
11页
查看更多>>摘要：The competing structural and hemodynamic considerations in valve design generally require a large amount of in vitro hydrodynamic and durability testing during development, often resulting in inefficient "trial-and-error" prototyping. While in silico modelling through finite element analysis (FEA) has been widely used to inform valve design by optimising structural performance, few studies have exploited the potential insight FEA could provide into critical hemodynamic performance characteristics of the valve. The objective of this study is to demonstrate the potential of FEA to predict the hydrodynamic performance of tri-leaflet aortic valve implants obtained during development through in vitro testing. Several variations of tri-leaflet aortic valves were designed and manufactured using a synthetic polymer and hydrodynamic testing carried out using a pulsatile flow rig according to ISO 5840, with bulk hydrodynamic parameters measured. In silico models were developed in tandem and suitable surrogate measures were investigated as predictors of the hydrodynamic parameters. Through regression analysis, the in silico parameters of leaflet coaptation area, geometric orifice area and opening pressure were found to be suitable indicators of experimental in vitro hydrodynamic parameters: regurgitant fraction, effective orifice area and transvalvular pressure drop performance, respectively.
Jens KerlAmayu W. GenaHayder AlsaadConrad Voelker...
12页
查看更多>>摘要：Since aerosol inhalation is the most common mechanism for COVID-19 infection, the respiratory protective devices (RPDs) have the highest importance in personal protection. The aim of this study was to assess the efficiency of 10 different RPDs in shortening the travelling distance of exhaled air by range measurement using the schlieren imaging technique. When a RPD is worn by a person resting in a seated position, the expired air does not exceed the human convective boundary layer (CBL). Instead, the CBL lifts the expired aerosols vertically up. Thus, they have a prolonged travelling time in the surrounding air and become less harmful by several mechanisms of virus content decay. Coughing as well as expiration valves can cause far reaching expiration air clouds that cross horizontally the human CBL by opening leakage airway corridors into different directions. Measured by the range of expired air an FFP2 mask provided high security under all conditions tested. A non-vented full-face mask with two viral filters performed even better because of its airtight fit and the excellent filtering capacity of the viral filters during inspiration and expiration, even during cough manoeuvres.
查看更多>>摘要：Over the last decade, Computer-Aided Diagnosis (CAD) systems have been provided significant research focus by researchers. CAD systems have been developed in order to minimise visual errors, to compensate manual interpretation, and to help medical staff to take decisions swiftly. These systems have been considered as powerful tools for a reliable, automatic, and low-cost monitoring and diagnosis. CAD systems are based on analysis and classification of several physiological signals for detecting and assessing different diseases related to the corresponding organ. The implementation of these systems requires the application of several advanced signal processing techniques. Specifically, in cardiology, CAD systems have achieved promising results in providing an accurate and rapid detection of cardiovascular diseases (CVDs). Particularly, the number of works on signal processing field for impedance cardiography (ICG) signals starts to grow slowly in recent years. This paper presents a review study of signal processing techniques applied to the ICG signal for the denoising, the analysis, the classification and the characterisation purposes. This review is intended to provide researchers with a broad overview of the currently used signal processing techniques for ICG signal analysis, as well as to improve future research by applying other recent advanced methods.
查看更多>>摘要：Manufacturers are invited to send details of new products to be included in this section. All information supplied should be strictly factual. The text may be altered by the editors. There is no charge to the manufacturers of products featured in this section and the journal accepts no responsibility for the accuracy of the information provided. Please send details to Dr J Fenner, Associate Editor (JMET), Medical Physics (Dept. Infection, Immunity and Cardiovascular Disease), Faculty of Medicine Dentistry and Health, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, UK. E-mail: j.w.fenner@sheffield.ac.uk.
查看更多>>摘要：Joint inflammation results from soft-tissue injuries and cartilage damage. PRICE is the standard treatment approach for acute soft tissue injuries like ankle sprain. Electrical stimulation, application of orthotic braces, etc. is also effective for this. In a synergistic device all these components are combined and applied simultaneously. This device was developed for joint inflammation and tested for grade I & II acute ankle joint sprain. To test a synergistic - semirigid device, combining PRICE & electrical stimulation for acute ankle sprains of grades I & II for pain, range of motion and swelling is a case series was the objective. Device was developed using novel concept of synergistic applications of PRICE with electrical stimulation. The joint contour of ankle and specific bio-mechanical bony surface landmarks were considered. Ethical approval was taken from NTCC committee, AIPT. Recordings were taken from eight patients of acute ankle sprain with - in two days of injury, after getting ethical approval. Elevation to the ankle was provided by keeping the part over the pillow and data was recorded with the help of: 1.VAS scale for pain; 2. Measuring tape; 3. Goniometry. t-test was used to find out the significant difference pre and post the application of device. There was a significant reduction in pain (p = 0.006), edema (p = 0.011), dorsi-flex-ion (p = 0.015), and plantar flexion (p=0.008). The synegistic device has been effective for acute ankle inflammation - grade I & II ankle sprains in 5 sessions; sufficient for the return of function.
查看更多>>摘要：Lung auscultation is one of the most common methods for screening of lung diseases. The increasingly high rate of respiratory diseases leads to the need for robust methods to detect the abnormalities in patients' breathing sounds. Lung sounds analysis stands out as a promising approach to automatic screening of lung diseases, serving as a second opinion for doctors as a stand-alone device for preliminary screening of lung diseases in remote areas. In previous research on lung classification using ICBHI Database on Kaggle, lung audios are converted to spectral images and fed into deep neural networks for training. There are a few studies which uses the scalogram, however they focussed on classification among different lung diseases. The use of scalograms in categorising the sound types are rarely used. In this paper, we combined scalograms and neural networks for classification of lung sound types. Padding methods and augmentation are also considered to evaluate the impacts on classification score. An ensemble learning is incorporated to increase classification accuracy by utilising voting of many models. The model trained and evaluated has shown prominent improvement of this method on classification on the benchmark ICBHI database.
查看更多>>摘要：A common but preventable complication of diabetes is diabetic foot ulcer. If appropriate care is not provided such foot lesions progress to the most severe diabetic foot complication, like infection, gangrene, amputation and even death. Diabetic neuropathy results abnormal planter pressure points under the foot and triggers the tendency of foot ulcer. The aim of this paper is to present the development of a low cost, power efficient, soft, lightweight and simple in-shoe planter pressure measurement system. The system is capable to determine the average static pressure under ball and heel of the foot. The insole is comfortable due to the use of textile pressure sensor and its simple data acquisition method makes operation easy for the users. An experiment with 10 participants with and without diabetes was carried out to observe the outcome of the system. The practical implication of this study is to minimise the damage caused by foot ulcer by determining the pressure abnormality at earliest with a fully developed cost effective design. The system is capable to identify the difference in average planter pressure values in different groups of participants. To monitor the foot health proactively, the proposed system is found to be a useful device and can successfully scan the planter pressure under ball and heel of the foot.
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