550 research outputs found

    Development of a Portable GSM SMS-Based Patient Monitoring System for Healthcare Applications

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    Although health care is a vital problem in recent years mobile communication has become a widespread part and parcel of everyday life even in the rural areas of developing countries This paper proposed a model to include the mobile communication for monitoring vital signs of health such as blood pressure heart rate body temperature blood glucose level and sends result as Short Message Service SMS for the physician so as to monitor their patients continuously Cuffless pressure sensing transducer is taken into consideration to measure pressure pulse and then combined with oscillometric method to measure Blood Pressure BP Availability of different sensors and measurement techniques to determine heart rate is presented Conventional glucometry in low cost electronics and body temperature measurement using electronic thermistor is also described here Sensed parameters are processed and stored into an array in ARM7 processor and sent via GSM SIM300 Modem This portable vital sensing system is useful to analyze daily health condition can be used both in home and hospital to prevent Hypertension Heart Attack and to control Diabete

    Microstructuring of materials with laser technologies for biomedical applications

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    This thesis presents the use of laser technologies for structuring different materials for applications in biomedicine. One of the aims of this work is the fabrication of fluidic chips for their employment as preclinical devices. By direct or indirect laser techniques, materials like soda-lime glass, titanium or tantalum are structured. Dimensions from microns to millimetres are achieved, depending on the final application of the chip. In particular, a device that imitates a coronary bifurcation is fabricated by laser technologies and soft-lithography methods. It is validated by culturing endothelial cells in their inner walls that withstand flow conditions. Other structures, like microchannels, a circulating tumour cells capturing chip or patterns over titanium and tantalum are manufactured

    Bioelectric Effects of Intense Nanosecond Pulses

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    Electrical models for biological cells predict that reducing the duration of applied electrical pulses to values below the charging time of the outer cell membrane (which is on the order of 100 ns for mammalian cells) causes a strong increase in the probability of electric field interactions with intracellular structures due to displacement currents. For electric field amplitudes exceeding MV/m, such pulses are also expected to allow access to the cell interior through conduction currents flowing through the permeabilized plasma membrane. In both cases, limiting the duration of the electrical pulses to nanoseconds ensures only nonthermal interactions of the electric field with subcellular structures. This intracellular access allows the manipulation of cell functions. Experimental studies, in which human cells were exposed to pulsed electric fields of up to 300 kY/cm amplitude with durations as short as 3 ns, have confirmed this hypothesis and have shown that it is possible to selectively alter the behavior and/or survival of cells. Observed nanosecond pulsed effects at moderate electric fields include intracellular release of calcium and enhanced gene expression, which could have long term implications on cell behavior and function. At increased electric fields, the application of nanosecond pulses induces a type of programmed cell death, apoptosis, in biological cells. Cell survival studies with 10 ns pulses have shown that the viability of the cells scales inversely with the electrical energy density, which is similar to the ‘dose’ effect caused by ionizing radiation. On the other hand, there is experimental evidence that, for pulses of varying durations, the onset of a range of observed biological effects is determined by the electrical charge that is transferred to the cell membrane during pulsing. This leads to an empirical similarity law for nanosecond pulse effects, with the product of electric field intensity, pulse duration, and the square root of the number of pulses as the similarity parameter. The similarity law allows one not only to predict cell viability based on pulse parameters, but has also been shown to be applicable for inducing platelet aggregation, an effect which is triggered by internal calcium release. Applications for nanosecond pulse effects cover a wide range: from a rather simple use as preventing biofouling in cooling water systems, to advanced medical applications, such as gene therapy and tumor treatment. Results of this continuing research are leading to the development of wound healing and skin cancer treatments, which are discussed in some detail

    Ablation of Cardiac Tissue with Nanosecond Pulsed Electric Fields: Experiments and Numerical Simulations

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    Cardiac ablation for the treatment of cardiac arrhythmia is usually performed by heating tissue with radio-frequency (RF) electrical currents to create conduction-blocking lesions in order to stop the propagation of electrical waves. Problems associated with RF ablation are recurrence of arrhythmias after successful treatments, tissue loss beyond the targeted tissue, long duration of the ablation procedure, and thermal side effects including thrombus formation that may lead to stroke. Here, we propose a new, non-thermal ablation method using nanosecond pulsed electric fields (nsPEFs) with better-controlled ablation volume, shorter procedure time, and no thermal side effects. We demonstrate that we can create non-conductive transmural lesions using different electrode configurations. We also develop a numerical model of nsPEF ablation, which allows us to estimate the critical electric field which leads in cardiac tissue and helps to provide a guideline for clinical tissue ablation. Our experimental model is a Langendorff-perfused rabbit heart. The heart is placed in a life-support system, and optical mapping is performed to study its electrical activity. We further developed the capability to apply short sequences of nanosecond pulses to tissue through pairs of customized electrodes. In order to characterize the 3D geometry of an ablated volume, we have adopted propidium iodide and TTC staining in conjunction with tissue sectioning. Our results obtained by optical mapping data and PI/TTC stained tissue show that fully transmural lesions can be obtained faster and with better control over the ablated volume than in conventional (RF) ablation, in the absence of thermal side effects. In order to aid nsPEF ablation planning, we used the COMSOL finite element software to create a model of the electric field distribution in cardiac tissue, which has a complex anisotropic architecture, for different electrode configurations. The experimental and numerical results are consistent and suggest a critical electric field strength of 3kV/cm for the death of cardiac tissue. This threshold obtained by the numerical model can function as a guideline for future clinical nsPEF treatment of atrial fibrillation. In summary, we have developed nsPEF ablation for the treatment of cardiac arrhythmia to provide better control over the ablated volume than conventional (RF) ablation, to reduce procedure time, and to avoid thermal side effects. Our ultimate goal is to bring this technology to the clinical practice

    Laser-induced forward transfer (LIFT) of water soluble polyvinyl alcohol (PVA) polymers for use as support material for 3D-printed structures

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    The additive microfabrication method of laser-induced forward transfer (LIFT) permits the creation of functional microstructures with feature sizes down to below a micrometre [1]. Compared to other additive manufacturing techniques, LIFT can be used to deposit a broad range of materials in a contactless fashion. LIFT features the possibility of building out of plane features, but is currently limited to 2D or 2½D structures [2–4]. That is because printing of 3D structures requires sophisticated printing strategies, such as mechanical support structures and post-processing, as the material to be printed is in the liquid phase. Therefore, we propose the use of water-soluble materials as a support (and sacrificial) material, which can be easily removed after printing, by submerging the printed structure in water, without exposing the sample to more aggressive solvents or sintering treatments. Here, we present studies on LIFT printing of polyvinyl alcohol (PVA) polymer thin films via a picosecond pulsed laser source. Glass carriers are coated with a solution of PVA (donor) and brought into proximity to a receiver substrate (glass, silicon) once dried. Focussing of a laser pulse with a beam radius of 2 µm at the interface of carrier and donor leads to the ejection of a small volume of PVA that is being deposited on a receiver substrate. The effect of laser pulse fluence , donor film thickness and receiver material on the morphology (shape and size) of the deposits are studied. Adhesion of the deposits on the receiver is verified via deposition on various receiver materials and via a tape test. The solubility of PVA after laser irradiation is confirmed via dissolution in de-ionised water. In our study, the feasibility of the concept of printing PVA with the help of LIFT is demonstrated. The transfer process maintains the ability of water solubility of the deposits allowing the use as support material in LIFT printing of complex 3D structures. Future studies will investigate the compatibility (i.e. adhesion) of PVA with relevant donor materials, such as metals and functional polymers. References: [1] A. Piqué and P. Serra (2018) Laser Printing of Functional Materials. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA. [2] R. C. Y. Auyeung, H. Kim, A. J. Birnbaum, M. Zalalutdinov, S. A. Mathews, and A. Piqué (2009) Laser decal transfer of freestanding microcantilevers and microbridges, Appl. Phys. A, vol. 97, no. 3, pp. 513–519. [3] C. W. Visser, R. Pohl, C. Sun, G.-W. Römer, B. Huis in ‘t Veld, and D. Lohse (2015) Toward 3D Printing of Pure Metals by Laser-Induced Forward Transfer, Adv. Mater., vol. 27, no. 27, pp. 4087–4092. [4] J. Luo et al. (2017) Printing Functional 3D Microdevices by Laser-Induced Forward Transfer, Small, vol. 13, no. 9, p. 1602553

    Photoacoustic imaging in biomedicine and life sciences

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    Photo-acoustic imaging, also known as opto-acoustic imaging, has become a widely popular modality for biomedical applications. This hybrid technique possesses the advantages of high optical contrast and high ultrasonic resolution. Due to the distinct optical absorption properties of tissue compartments and main chromophores, photo-acoustics is able to non-invasively observe structural and functional variations within biological tissues including oxygenation and deoxygenation, blood vessels and spatial melanin distribution. The detection of acoustic waves produced by a pulsed laser source yields a high scaling range, from organ level photo-acoustic tomography to sub-cellular or even molecular imaging. This review discusses significant novel technical solutions utilising photo-acoustics and their applications in the fields of biomedicine and life sciences

    Biomedical Photoacoustic Imaging and Sensing Using Affordable Resources

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    The overarching goal of this book is to provide a current picture of the latest developments in the capabilities of biomedical photoacoustic imaging and sensing in an affordable setting, such as advances in the technology involving light sources, and delivery, acoustic detection, and image reconstruction and processing algorithms. This book includes 14 chapters from globally prominent researchers , covering a comprehensive spectrum of photoacoustic imaging topics from technology developments and novel imaging methods to preclinical and clinical studies, predominantly in a cost-effective setting. Affordability is undoubtedly an important factor to be considered in the following years to help translate photoacoustic imaging to clinics around the globe. This first-ever book focused on biomedical photoacoustic imaging and sensing using affordable resources is thus timely, especially considering the fact that this technique is facing an exciting transition from benchtop to bedside. Given its scope, the book will appeal to scientists and engineers in academia and industry, as well as medical experts interested in the clinical applications of photoacoustic imaging

    White paper on the future of plasma science and technology in plastics and textiles

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    This is the peer reviewed version of the following article: “Uros, C., Walsh, J., Cernák, M., Labay, C., Canal, J.M., Canal, C. (2019) White paper on the future of plasma science and technology in plastics and textiles. Plasma processes and polymers, 16 1 which has been published in final form at [doi: 10.1002/ppap.201700228]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."This white paper considers the future of plasma science and technology related to the manufacturing and modifications of plastics and textiles, summarizing existing efforts and the current state‐of‐art for major topics related to plasma processing techniques. It draws on the frontier of plasma technologies in order to see beyond and identify the grand challenges which we face in the following 5–10 years. To progress and move the frontier forward, the paper highlights the major enabling technologies and topics related to the design of surfaces, coatings and materials with non‐equilibrium plasmas. The aim is to progress the field of plastics and textile production using advanced plasma processing as the key enabling technology which is environmentally friendly, cost efficient, and offers high‐speed processingPeer ReviewedPostprint (author's final draft
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