Non-invasive electrical measurements for the evaluation of the hydration state of the skin: comparison between three conventional instruments - the Comeometer®, the Skicon® and the Nova DPM®

1999 ◽  
Vol 5 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Peter Clarys ◽  
André O. Barel ◽  
B. Gabard
2019 ◽  
Vol 10 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Jan-Hugo Andersen ◽  
Olav Bjerke ◽  
Fatos Blakaj ◽  
Vilde Moe Flugsrud ◽  
Fredrik Alstad Jacobsen ◽  
...  

Abstract Sixteen volunteers each drank 700 ml sugar-containing soft drink during two successive periods and the blood sugar was measured at 10 min intervals together with electrical impedance spectroscopy and near infrared spectroscopy (NIR). A maximum correlation of 0.46 was found for the electrical measurements but no clear separation between low and high blood glucose levels were found in the NIR measurements. The latter was attributed to the experimental design where the NIR probe was removed from the skin between each measurement.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4435
Author(s):  
Eugenio Camargo ◽  
Nancy Visairo ◽  
Ciro Núñez ◽  
Juan Segundo ◽  
Juan Cuevas ◽  
...  

It is well known that a low level of electrolytes in batteries produces a malfunction or even failure and irreversible damage. There are several kinds of sensors to detect the electrolyte level. Some of them are non-invasive, such as optical sensors of level, while some others are invasive; but both require one sensor per battery. This paper proposes a different approach to detect the low electrolyte level, which neither requires invasive sensors nor one sensor for each battery. The approach is based on the estimation of the internal resistance of an equivalent electrical circuit (EEC) model of the battery. To establish the detection criterion of the low level of electrolytes, a statistical analysis is proposed. To demonstrate the feasibility of this approach to be considered a valid method, multiple experiments were performed. The experiments consisted of determining how the internal resistance is affected at eight different levels of electrolyte at different aging levels of vented lead–acid (VLA) batteries. The results have demonstrated the feasibility of this approach. Hence, this approach has the potential to be used for the reducing of sensors and avoiding invasive methods to determine the low level of electrolytes.


2015 ◽  
Vol 1 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Christian Wilde ◽  
Ralf Bruder ◽  
Sonja Binder ◽  
Lisa Marshall ◽  
Achim Schweikard

AbstractTranscranial alternating current stimulation (tACS) is an emerging non-invasive tool for modulating brain oscillations. There is evidence that weak oscillatory electrical stimulation during sleep can entrain cortical slow oscillations to improve the memory consolidation in rodents and humans. Using a novel method and a custom built stimulation device, automatic stimulation of slow oscillations in-phase with the endogenous activity in a real-time closed-loop setup is possible. Preliminary data from neuroplasticity experiments show a high detection performance of the proposed method, electrical measurements demonstrate the outstanding quality of the presented stimulation device.


Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2060 ◽  
Author(s):  
Yu Wang ◽  
Shangjie Ren ◽  
Feng Dong

Electrical Impedance Tomography (EIT) is a non-invasive detection method to image the conductivity changes inside an observation region by using the electrical measurements at the boundary of this region. In some applications of EIT, the observation domain is infinite and is only accessible from one side, which leads to the so-called open EIT (OEIT) problem. Compared with conventional EIT problems, the observation region in OEIT can only be measured from limited projection directions, which makes high resolution imaging much more challenging. To improve the imaging quality of OEIT, a focusing sensor design strategy is proposed based on shape conformal theory. The conformal bijection is used to map a standard EIT sensor defined at a unit circle to a focusing OEIT sensor defined at an upper half plane. A series of numerical and experimental testes are conducted. Compared with the traditional sensor structure, the proposed focusing sensor has higher spatial resolution at the near-electrode region and is good at distinguishing multi-inclusions which are close to each other.


2011 ◽  
Vol 227 ◽  
pp. 181-184
Author(s):  
Rabah Tadjine ◽  
Hadj Lahmar ◽  
Mohamed Mounis Alim

A non invasive ex-situ harmonic probe technique was used to characterize the plasma-generated harmonics of Ar/O2 plasma. To extract the harmonics, we used an iterative least-squares curve fitting algorithm and taking into account the presence of parasitic electrical elements. This study reports the influence of the process parameters on the harmonic response (from 2nd to 7th) to reveal the most sensitive electrical measurements that represent faithfully the evolution of the plasma. The electrical response of the matching network and the electrical model circuit chamber was taken into account.


Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.


Author(s):  
R. Rajesh ◽  
M.J. Kim ◽  
J.S. Bow ◽  
R.W. Carpenter ◽  
G.N. Maracas

In our previous work on MBE grown low temperature (LT) InP, attempts had been made to understand the relationships between the structural and electrical properties of this material system. Electrical measurements had established an enhancement of the resistivity of the phosphorus-rich LT InP layers with annealing under a P2 flux, which was directly correlated with the presence of second-phase particles. Further investigations, however, have revealed the presence of two fundamentally different types of precipitates. The first type are the surface particles, essentially an artefact of argon ion milling and containing mostly pure indium. The second type and the one more important to the study are the dense precipitates in the bulk of the annealed layers. These are phosphorus-rich and are believed to contribute to the improvement in the resistivity of the material.The observation of metallic indium islands solely in the annealed LT layers warranted further study in order to better understand the exact reasons for their formation.


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