A portable magnetic induction measurement system (PIMS)

Vital parameter monitoring on neonatal intensive care units is essential but very stressful for patients during daily routine care. For contact-less monitoring of breathing and heart activity, magnetic induction measurements are applicable in research scenarios. For monitoring both vital parameters in newborn intensive care wards, we developed a Multi Channel Simultaneous Magnetic Induction Measurement System (MUSIMITOS2+). In this article we now evaluate the technical requirements of a coil array for vital parameter monitoring and finally present a multichannel coil array with 6 excitation and measurement channels combined as axial gradiometers for the specific measurement scenario. This array will be stored underneath the child. As a test case we will present data of a animal trial with the described coil array and the measurement device MUSIMITOS2+.

In this research, measurement of static magnetic induction and magnetic moment induced by HP was carried out. The measurement of static magnetic induction was done for two directions namely horizontal and vertical directions. The static magnetic induction induced by that HP was measured using Pasco Magnetic Probe. The effect of the thickness of material such as cooper (Cu) inserting between magnetic probe and the HP was studied. For the horizontal direction (x direction), Cu and without Cu between magnetic probe and the HP, then the magnetic induction was measured for the distance of 0,7 cm from the HP. Static magnetic induction was also measured in vertical direction (z-direction) with and without Cu. The results showed that the static magnetic induction induced by that HP has a normal distribution with the position of the peak near the top of the HP. The value of magnetic induction was found to be 10 x10 -4 T and 9 x 10 -4 T without and with Cu respectively. For vertical measurement, the static magnetic induction reduced its values with increasing distance from the HP. By plotting B versus distance it was obtained that the magnetic moment of the HP was 1,5 Am 2 . Based on these plots then it was also found that the level of absorption of about 0,02 mm -1 .

Magnetoacoustic tomography with magnetic induction (MAT-MI) is a recently introduced method for imaging tissue electrical impedance properties by integrating magnetic induction and ultrasound measurements. In the present study, we have developed a focused cylindrical scanning mode MAT-MI system and the corresponding reconstruction algorithms. Using this system, we demonstrated 3-dimensional MAT-MI imaging in a physical phantom, with cylindrical scanning combined with ultrasound focusing, and the ability of MAT-MI in imaging electrical conductivity properties of biological tissue.

Effect of Co addition on nanocrystallization and soft magnetic properties of (Fe1−Co )73.5Cu1Nb3Si13.5B9 alloys

An accurate ambulatory breathing monitor is needed to observe acute respiratory changes in patients with medical or psychological disorders outside the clinic (e.g., hyperventilation during panic or apneas during sleep). Significant limitations of existing monitors are size, troublesome operation, and difficulty holding chest and abdomen bands in place during 24-hour recordings. Recently, a garment has been developed with embedded inductive plethysmography sensors for continuous ambulatory monitoring of respiration, heart activity, inductive cardiography, motility, postural changes, and other functions. The signals are displayed and stored on a handheld computer (Visor), and then analyzed offline, extracting more than 40 clinical parameters relating to cardiorespiratory function (e.g., heart rate, respiratory sinus arrhythmia, tidal volume, stroke volume, pre-ejection period, apnea-hypopnea index, thoraco-abdominal coordination, sighing). The device also serves as an electronic diary of symptoms, moods, and activities. This advanced system may open a new era in ambulatory monitoring for clinical practice and scientific research.

Digital medical instruments are essential in today's world to make fast and precise diagnoses. By combining several features into a single device, healthcare can be provided more affordably and with greater patient care and medical efficiency. This project describes the development of a cost-effective digital stethoscope featuring an integrated oximeter sensor and a sound transducer. The stethoscope facilitates the simultaneous monitoring of spO2 (Saturation of Peripheral Oxygen) levels and heart activity. The sound transducer converts cardiac sounds into electrical signals, enabling the detection of anomalies in heart function. Real-time data on these vital signs is transmitted to a web-application that will be deployed on the doctors' phone, providing them with immediate access to patient information. This innovative device offers a two in one solution that is both efficient and affordable for both patients and medical practitioners.

Centrale de mesure ambulatoire biomédicale sur PSoC

Magnetization of large Nd-Fe-B sintered permanent magnets is still challenging. This type of permanent magnet is electrically conductive, so impulse magnetization causes a flow of eddy currents which prevent magnetization of the whole volume of the magnet. The paper deals with the impulse magnetization of sintered Nd-Fe-B permanent magnets and shows a method for the determination of suitable parameters for the supply system. The necessary magnetic field strength for magnetization of the magnet to saturation was determined. The optimal magnetizing fixture supply voltage for magnetization to saturation was determined from simulations in PSpice software, finite element analyses in Maxwell 15 and measurements. Measurements of magnetic induction on the surface of the Nd-Fe-B magnet are also presented to ensure that a magnet with 70 mm diameter and 20 mm in height is fully saturated.

This article consists of three sections. The first discusses how we determine satellite internal structures and what we know about them. The primary probes of internal structure are measurements of magnetic induction, gravity, and topography, as well as rotation state and orientation. Enceladus, Europa, Ganymede, Callisto, Titan, and (perhaps) Pluto all have subsurface oceans; Callisto and Titan may be only incompletely differentiated. The second section describes dynamical processes that affect satellite interiors and surfaces: tidal and radioactive heating, flexure and relaxation, convection, cryovolcanism, true polar wander, non-synchronous rotation, orbital evolution, and impacts. The final section discusses how the satellites formed and evolved. Ancient tidal heating episodes and subsequent refreezing of a subsurface ocean are the likeliest explanation for the deformation observed at Ganymede, Tethys, Dione, Rhea, Miranda, Ariel, and Titania. The high heat output of Enceladus is a consequence of Saturn’s highly dissipative interior, but the dissipation rate is strongly frequency-dependent and does not necessarily imply that Saturn’s moons are young. Major remaining questions include the origins of Titan’s atmosphere and high eccentricity, the regular density progression in the Galilean satellites, and the orbital evolution of the Saturnian and Uranian moons.

Integrated on-line instrumentation for simultaneous automated measurement of magnetic field, induction, Barkhausen effect, magnetoacoustic emission, and magnetostriction: 38835 Jiles, D.C. Journal of Applied Physics, Vol. 63, No. 8, pp. 3946–3948 (15 Apr. 1988)

As part of an electromechanical total artificial heart (TAH) program, an integrated transcutaneous energy and information transmission (TEIT) system has been developed. In vivo performance of the developed system was evaluated through a simplified animal model without implant of a TAH. The design features include the small size of the implanted part, and dual coil structure of the external part. In the transcutaneous energy transmission (TET) system based on magnetic induction, the external primary and implanted secondary coils have the shape of a truncated cone, 7.0 and 3.8 cm in diameter, and 23 and 12 turns of Litz wire, respectively. The external coil is driven by a 350 to 410 kHz tuned class E amplifier that has a minimum switching loss of power transistor. In vitro test results using 1 cm thick dog's skin showed a flat total efficiency (DC to DC) of 75% for 20 to 30 W of delivered mean power. In order to achieve bidirectional communication between implanted and external components, a small circuit board containing four light emitting diodes and a photodiode was incorporated in each TET coil facing each other across the skin. Unmodulated optical pulse transmitted digital data (9600 baud, RS-232 protocol) in error free condition through an up to 15 mm thick dog's skin patch accommodated 18 degrees of misalignment. Three subacute in vivo studies were conducted in dogs to evaluate performance of the developed system. The secondary set was implanted in the mild flank region of the dog, and the output was percutaneously connected to the control system to drive the external TAH on the mock circulatory system.(ABSTRACT TRUNCATED AT 250 WORDS)

Stainless steels are commonly used in hydraulic components where they may be susceptible to cavitation erosion. In this study the cavitation erosion resistance of AISI 420-type stainless steel is examined after quenching and partitioning (Q&P) heat treatment. Q&P-samples were prepared with varying heat treatment parameters, and their initial properties were examined with X-ray diffraction and hardness measurements. Reference samples were also prepared with quenching and tempering and quenching without partitioning. The samples were eroded for 6 h with an ultrasonic cavitation erosion device, and their mass losses were measured. The eroded areas were examined with scanning electron microscopy, optical profilometry, and magnetic induction measurements. The results suggest that the cavitation erosion resistance of the examined stainless steel can be significantly enhanced with Q&P. This enhancement of cavitation erosion resistance results from high initial hardness and retained austenite fraction of the steel. During cavitation erosion the retained austenite can absorb cavitation bubble collapse energy by transforming into strain induced martensite, which increases the hardness of the steel and generates expansion of the lattice. This expansion additionally hinders crack propagation at grain boundaries, which reduces the formation of initial cavitation damage.

Magnetic induction measurement (MIM) is a promising technique for craniocerebral diseases detection with attractive advantages compared with CT and MRI. We propose a convenient method for constructing finite element head model that is applied to perform electromagnetic simulations of MIM. A finite element head model with high mesh quality based on the second Chinese Visible Human dataset is reported for the first time. The head model involves seven tissues, including muscle, bone, brain grey matter, brain white mater, cerebrospinal fluid, cerebellum, and eyeball. It has a good generality and can be imported into various electromagnetic analysis software based on finite element method while only a small amount of computing resources will be consumed.

The isotropic and anisotropic magnetic permeability of Magneto-Rheological Elastomers (MREs) is identified using a simple inverse modelling approach. This involves measuring the magnetic flux density and attractive force occurring between magnets, when MRE specimens are placed in between the magnets. Tests were conducted using isotropic MREs with 10–40% and for anisotropic MREs with 10–30%, particle volume concentration. Magnetic permeabilities were then identified through inverse modelling, by simulating the system using commercially available multi-physics finite element software. As expected, the effective permeability of isotropic MREs was found to be scalar-valued; increasing with increasing particle volume concentration (from about 1.6 at 10% to 3.7 at 30% particle volume concentration). The magnetic permeability of transversely isotropic MRE was itself found to be transversely isotropic, with permeabilities in the direction of particle chain alignment from 1.6 at 10% to 4.45 at 30%, which is up to 1.07–1.25 times higher than in the transverse directions. Results of this investigation are demonstrated to show good agreement with those reported in the literature.

Heart Rate and Activity Monitoring