Nowadays, transfer of the health care from ambulance to patient's home needs higher demand on patient's mobility, comfort and acceptance of the system. Therefore, the goal of this study is to proof the concept of a system which is ultra-wearable, less constraining and more suitable for long term measurements than conventional ECG monitoring systems which use conductive electrolytic gels for low impedance electrical contact with skin. The developed system is based on isolated capacitive coupled electrodes without any galvanic contact to patient's body and does not require the common right leg electrode. Measurements performed under real conditions show that it is possible to acquire well known ECG waveforms without the common electrode when the patient is sitting and even during walking. Results of the validation process demonstrate that the system performance is comparable to the conventional ECG system while the wearability is increased.
Purpose: This paper aims to find the optimal deposition conditions for achieving the homogenous structure of the silver layers onto three types of polymeric substrates as well as on the rigid substrates. For this reason, the detailed investigation of the silver-based layers deposited at different technological conditions by microscopic methods is presented in this paper. Design/methodology/approach: The special test pattern has been designed and deposited at different substrate temperatures by using two types of generally available silver-based nano-inks. Cross-sections and 3D profiles of the deposited silver layers have been profoundly analysed by using the optical profiler Sensofar S Neox on the generally used polymeric (PI, PET and PEN) and rigid substrates (951 and 9K7 LTCC, glass and alumina). Findings: The results prove the strong correlation between the substrate temperature during the deposition process and the final shape of the created structure which has the a direct impact on the layers’ homogeneity. The results also prove the theory of the coffee ring effect creation in the inkjet printing technology. Originality/value: The main benefit of this paper lies in the possibility of the homogeneity achievement of the deposited silver-based layers on the several polymeric and rigid substrates by managing the temperature during the deposition. The paper also offers the comparative study of nano-inks’ behaviour on several polymeric and rigid substrates.
1 November 2017 in Journal of Electrical Engineering
The purpose of this paper is to develop convolution implementation of DGHM (Donovan, Geronimo, Harding, Massopust) multiwavelet image transform using a new approach of ordering wavelet coefficients at the second and higher levels. Firstly, the method of implementation of one-dimensional discrete multiwavelet transform (1D DMWT) for DGHM multiwavelet using discrete convolution and scalar filters is presented. Then, convolution implementation of DGHM multiwavelet image transform by application of 1D DMWT for two dimensions (2D) in a separable way is proposed. Next, the second level of 2D DMWT is performed in three possible ways. The novelty of the proposed implementation is in reordering of L subband wavelet coefficients at the first level into one subimage. The results are evaluated as the energy ratios between the transformed images in L subband at the second level and the input original image. According to the experimental results, the developed implementation of 2D DMWT is approximately 5% more effective in energy compression than the ones most commonly mentioned in the literature. This paper shows a possibility of convolution implementation of 2D DMWT with higher energy compression.
Nowadays classification of textures is very actual. Classification means separation of textures into classes. The main task of the classification is to find such a descriptor which is unique for the given class. This article deals with the classification based on energies distributed into DWT subimages. Description vectors are created on the base of subimages energies. The classification is done by comparison of the Euclidian or the Mahalnobis distance between the description vector of the input texture and the description vectors of classes. The efficiency of the classification is evaluated with regard to level of DWT as well. For purposes of experimental verification of this classification method a database is created. This database consist of 21 classes and each class has at least three textures.
26 October 2018 in Journal of Adhesion Science and Technology
This paper presents the improved method of analysis and evaluation of the silver layers’ adhesion printed by inkjet printing technology. The generally known method for adhesion measurement of layers and coatings according to the standards ASTM D3359 and ISO 2409 has been improved by development of the automatic evaluation software of achieved results from cross cut tests. The developed evaluation tool offers the possibilities of calculation the detached area, rotation of the image, setting the threshold and the automatic classification according to the mentioned standards. The inaccuracy caused by samples’ assessment by humans is mainly eliminated by using of this tool. The developed evaluation tool has been applied to experimental works oriented to analysis of the adhesion of two commercially available silver based nano-inks on two polymeric based substrates (PI and PET). For this purpose, different sintering conditions have been applied to analysed samples. The achieved results show the differences between the investigated nano-inks’ adhesion on two types of polymeric substrates. The adhesion of silver layers can be optimized by controlling the sintering conditions. By developing the software tool the simple and inaccurate method of adhesion analysis has been upgraded to the appropriate technique to the silver layers’ adhesion testing. The improved method for adhesion measurements can serve as a tool for fast and relatively simple technique for technologist.
The goal of this paper is to present the method for automatic detection and location of power chip, which is soldered on DBC substrate, and voids in die attach solder joint. The method of chip location is provided by two dimension correlation applied on X-Ray images. When chip location is detected, voids in solder joints can be detected. It is very important to make such analysis, because during soldering process lot of voids and defects in die attach can occur. Basic indicator of joints' quality is quantity and size of voids in die attach. Quality of solder joints depends on homogeneity of solder, which have the crucial effect on it. Automatic detection of chip and voids in die attach is achieved by techniques of image processing like filtering, energetic normalization, thresholding and image enhancement. In the paper, results of analyses of more solder alloy (99.9Sn, SnCu3In0.5, 96Sn4Ag, 99Sn1Ag) are presented. This paper offers the effective and precise method for automatic detection and evaluation of the voids from X-Ray images of solder joint.