The number of heart transplants is constantly increasing. Each year, it grows by around 60% due to the health problems plaguing the world's population. Furthermore, the lack of available transplanted organs and th...
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ISBN:
(数字)9798350349450
ISBN:
(纸本)9798350349467
The number of heart transplants is constantly increasing. Each year, it grows by around 60% due to the health problems plaguing the world's population. Furthermore, the lack of available transplanted organs and the waiting list greatly increases and can last for years. All these reasons make it increasingly difficult to get a heart transplant. Solutions such as artificial organs are gaining more and more prominence and are in great demand. Considering the advancement of science and technology, new research shows great hope in prolonging and improving the quality of life for many patients. Among these researches is the Left Ventricular Assist Device (LVAD), which uses auxiliary pumps along with the natural heart of the person, allowing a longer waiting time in the transplant queue and giving a quality of life. This work aims to implement autonomous electronic control over this device, allowing autonomous speed control over the pump motor. This method gives patients better control and greater freedom to practice their daily lives. Another important reason is the economic factor, which aims to reduce costs and allow greater popular reach. In this work, the tests were carried out on only the Brushless Direct Current Motor (BLDC). The results are demonstrated in numerical and graphic form for better illustration.
A plug-and-play scheme that relies on a deep neural network for image denoising is used to regularize the nonlinear electromagnetic (EM) inversion. It is shown that any state-of-the-art denoiser can be plugged into th...
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ISBN:
(数字)9798350369908
ISBN:
(纸本)9798350369915
A plug-and-play scheme that relies on a deep neural network for image denoising is used to regularize the nonlinear electromagnetic (EM) inversion. It is shown that any state-of-the-art denoiser can be plugged into the conventional inversion framework as an implicit regularization step. Thus, a pretrained Swin-Conv-UNet (SCUNet) is employed in the EM inversion. SCUNet combines the advantages of residual convolutional layers and swin transformer blocks in accounting for different image priors and it is remarkably effective in image denoising. Nu-merical results obtained using this framework clearly shows its benefits over existing inversion algorithms.
A metamaterial-based plasmonic absorber is designed, fabricated, and characterized. The absorber consists of a periodic array of Ti unit-cells at the top, a layer of Al at the bottom, and a thin SiO 2 layer that is s...
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ISBN:
(数字)9798350369908
ISBN:
(纸本)9798350369915
A metamaterial-based plasmonic absorber is designed, fabricated, and characterized. The absorber consists of a periodic array of Ti unit-cells at the top, a layer of Al at the bottom, and a thin SiO
2
layer that is sandwiched between the top and the bottom layers. Simulations and experiments show that the proposed design supports an average absorption of 96% over the wavelength range changing from 280 nm to 1000 nm (frequency range between ultraviolet [UV] and near-infrared [IR]). Furthermore, the absorption spectrum is polarization insensitive and has a large incidence angle tolerance. The proposed absorber has the potential to be used in photovoltaic applications such as solar cells and photo-detectors.
A nonlinear electromagnetic inversion method that promotes the sparsity in the model gradient is proposed for reconstruction of dielectric profiles. For regularization, the method uses the ratio of $l_{1}$ -norm to ...
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ISBN:
(数字)9781733509671
ISBN:
(纸本)9798350362978
A nonlinear electromagnetic inversion method that promotes the sparsity in the model gradient is proposed for reconstruction of dielectric profiles. For regularization, the method uses the ratio of
$l_{1}$
-norm to
$l_{2}$
-norm (
$l_{1}/l_{2}$
-norm) which is a better approximation to
$l_{0}$
-norm than
$l_{1}$
-norm due to its scale-invariant property. To deal with the non-convexity of the resulting optimization problem, the alternating direction method of mul-tipliers is used to split the quotient structure of the
$l_{1}/l_{2}$
-norm. Consequently, the optimization problem is separated into several sub-steps that are executed iteratively in an alternating fashion. Numerical results show that the proposed method produces more accurate reconstructions of spatially sparse dielectric profiles (by preserving edges and reducing artifacts) compared to the methods relying on Tikhonov and total variation regularization.
The integration of technology into the healthcare system is emerging as a tool to support professionals in the treatment of Heart Failure (HF), and is based on an analysis of the scientific and technological progress ...
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ISBN:
(数字)9798350349450
ISBN:
(纸本)9798350349467
The integration of technology into the healthcare system is emerging as a tool to support professionals in the treatment of Heart Failure (HF), and is based on an analysis of the scientific and technological progress of the Internet of Things, applied as an innovative perspective in Health 4.0. This article presents a study that proposes to develop an innovative prototype Left Ventricular Assist Device (artificial heart). The main focus is on advanced sensing, connectivity via mobile network and remote supervision support, aimed at the operation and diagnosis of patients affected by HF. The project incorporates advanced data collection, processing, and analysis tools using Big Data and Data Analytics concepts. The motivation for this work is the search for technological innovation as support for medical science and the contribution to the Unified Health System. The prototype includes a microcontroller, a heartbeat sensor, an accelerometer sensor to collect movement, acceleration and fall detection data, a mobile network module to transmit the data and create an electronic medical record. This article highlights the initial phase, which includes preliminary results such as configuring the module and components, collecting data using heartbeat and movement sensors, storing the data in MongoDB and visualizing it in Jupyter Notebook.
An iterative inversion algorithm to reconstruct the shape of two-dimensional dielectric objects from far-field measurements is formulated and implemented. The proposed method uses an integral operator to map the unkno...
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ISBN:
(数字)9798350369908
ISBN:
(纸本)9798350369915
An iterative inversion algorithm to reconstruct the shape of two-dimensional dielectric objects from far-field measurements is formulated and implemented. The proposed method uses an integral operator to map the unknown boundary of the object onto the far-field pattern of the scattered field. This mapping is inherently ill-posed and nonlinear. Therefore, Newton iterations are used for linearization, and the resulting linear equation at each iteration is regularized using a Tikhonov scheme. Numerical results validate the accuracy and the applicability of the proposed method.
This paper presents an optical coherence tomography (OCT) system in conjunction with a novel image reconstruction technique employed for in vitro imaging of human teeth. The primary goal is to enhance the signal-to-no...
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Thin layers with high conductivity values, such as metal sheets, conductive paint, graphene, and other two-dimensional (2D) materials, are commonly used in various electromagnetic applications. One of the fundamental ...
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ISBN:
(数字)9789463968119
ISBN:
(纸本)9798350359497
Thin layers with high conductivity values, such as metal sheets, conductive paint, graphene, and other two-dimensional (2D) materials, are commonly used in various electromagnetic applications. One of the fundamental challenges in numerical modeling of these thin conductive layers is the requirement for an extremely fine mesh that can accurately capture field variations and account for the intricate geometrical features of the structure (H. Chen, A. J. Taylor and N. Yu, Rep. Prog. Phy., 79,10-35,2016). A dense mesh translates into high computational cost since the number of unknowns is increased and the time step size must be reduced for an explicit time marching scheme (to ensure that the Courant-Friedrichs-Lewy (CFL) condition is satisfied). One can replace the thin conductive layer with an infinitesimally thin sheet on which the resistive boundary condition (RBC) is enforced (T. B. A. Senior and J. L. Volakis, London, UK: IET, 1995). This approach completely avoids the dense mesh and the high computational cost that comes with it. However, RBC has to be incorporated into the electromagnetic solver.
A plasmonic nanostructured metal-dielectric-metal metasurface that supports multiband absorption is fabricated and characterized. Multispectral absorption is observed across the near-IR to telecom frequencies due to t...
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ISBN:
(数字)9798350361957
ISBN:
(纸本)9798350361964
A plasmonic nanostructured metal-dielectric-metal metasurface that supports multiband absorption is fabricated and characterized. Multispectral absorption is observed across the near-IR to telecom frequencies due to the complex excitation of gap-surface plasmon and plasmon polariton modes.
Antenna-on-chip (AoC) is one of the promising solutions in the 6G era. However, it suffers from poor radiation due to the lossy Si substrate. Placing an artificial magnetic conductor (AMC) under the AoC cannot only is...
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ISBN:
(数字)9798350369908
ISBN:
(纸本)9798350369915
Antenna-on-chip (AoC) is one of the promising solutions in the 6G era. However, it suffers from poor radiation due to the lossy Si substrate. Placing an artificial magnetic conductor (AMC) under the AoC cannot only isolate the AoC from the lossy Si substrate but also provide in-phase reflection. Nonetheless, the ultra-thin stack-up of the mainstream semiconductor technology makes the realization of AMC challenging at the millimeter-wave spectrum. To make the AMC electrically thicker, this paper presents four kinds of thickness reduction techniques (TRT): slot, notch, metallic post, and embedded guiding structure. With TRTs, an ultra-thin AMC (
$15\ \mu \mathrm{m}$
thickness) is realized. With the proposed AMC, the AoC demonstrated a gain of 3.2 dB at 72 GHz. Compared to the standalone antenna, the AMC enhances the gain by 7 dB.
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