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Recent demand and initiatives in brain research have driven significant interest toward developing chronically implantable neural interface systems with high spatiotemporal resolution and spatial coverage extending to the whole brain. Electroencephalography-based systems are noninvasive and cost efficient in monitoring neural activity across the brain, but suffer from fundamental limitations in spatiotemporal resolution. On the other hand, neural spike and local field potential (LFP) monitoring with penetrating electrodes offer higher resolution, but are highly invasive and inadequate for long-term use in humans due to unreliability in long-term data recording and risk for infection and inflammation. Alternatively, electrocorticography (ECoG) promises a minimally invasive, chronically implantable neural interface with resolution and spatial coverage capabilities that, with future technology scaling, may meet the needs of recently proposed brain initiatives. In this paper, we discuss the challenges and state-of-the-art technologies that are enabling next-generation fully implantable high-density ECoG interfaces, including details on electrodes, data acquisition front-ends, stimulation drivers, and circuits and antennas for wireless communications and power delivery. Along with state-of-the-art implantable ECoG interface systems, we introduce a modular ECoG system concept based on a fully encapsulated neural interfacing acquisition chip (ENIAC). Multiple ENIACs can be placed across the cortical surface, enabling dense coverage over wide area with high spatiotemporal resolution. The circuit and system level details of ENIAC are presented, along with measurement results.

Advances in free-floating miniature medical implants promise to offer greater effectiveness, safety, endurance, and robustness than today's prevailing medical implants. Wireless power transfer (WPT) is key to miniaturized implants by eliminating the need for bulky batteries. This paper reviews design strategies for WPT with mm-sized implants focusing on resonant electromagnetic and ultrasonic transmission. While ultrasonic WPT offers shorter wavelengths for sub-mm implants, electromagnetic WPT above 100 MHz offers superior power transfer and conversion efficiency owing to better impedance matching through inhomogeneous tissue. Electromagnetic WPT also allows for fully integrating the entire wireless power receiver system with an on-chip coil. Attaining high power transfer efficiency requires careful design of the integrated coil geometry for high quality factor as well as loop-free power and signal distribution routing to avoid eddy currents. Regulating rectifiers have improved power and voltage conversion efficiency by combining the two RF to DC conversion steps into a single process. Example designs of regulating rectifiers for fully integrated wireless power receivers are presented.

This paper presents an overview of the fundamentals and state of the-art in noninvasive physiological monitoring instrumentation with a focus on electrode and optrode interfaces to the body, and micropower-integrated circuit design for unobtrusive wearable applications. Since the electrode/optrode-body interface is a performance limiting factor in noninvasive monitoring systems, practical interface configurations are offered for biopotential acquisition, electrode-tissue impedance measurement, and optical biosignal sensing. A systematic approach to instrumentation amplifier (IA) design using CMOS transistors operating in weak inversion is shown to offer high energy and noise efficiency. Practical methodologies to obviate 1/f noise, counteract electrode offset drift, improve common-mode rejection ratio, and obtain subhertz high-pass cutoff are illustrated with a survey of the state-of-the-art IAs. Furthermore, fundamental principles and state-of-the-art technologies for electrode-tissue impedance measurement, photoplethysmography, functional near-infrared spectroscopy, and signal coding and quantization are reviewed, with additional guidelines for overall power management including wireless transmission. Examples are presented of practical dry-contact and noncontact cardiac, respiratory, muscle and brain monitoring systems, and their clinical applications.

An adaptive buck-boost resonant regulating rectifier (B2 R3 ) with an integrated on-chip coil and low-loss H-Tree power/signal distribution is presented for efficient and robust wireless power transfer (WPT) over a wide range of input and load conditions. The B2 R3 integrated on a 9 mm2 chip powers integrated neural interfacing circuits as a load, with a TX-load power conversion efficiency of 2.64 % at 10 mm distance, resulting in a WPT system efficiency FoM of 102.

The Sokhatnyi intrusion is an example of a later Mesozoic deferential massif referred to the gabbro-monzodiorite type in Northeastern Russia; according to geological data, it precedes high-alumina granitoids of the Yano-Kolymskaya folded system. It is shown that formation of the layered series of the massif is caused by the crystallized and gravitational fractioning of the high-alumina olivine basalt with increased potassium alkalinity in shallow water media. The boundary facies of the massif are represented by manzogabbroidnorites and monzodiorites. The U-Pb age determinations of zircon (SHRIMP-II) from the taxitite striped biothite gabbro in the lower boundary facies showed 148 ± 1 million years. Thus, taking into account the geological relations and geochronological data on the Sokhatinyi gabbro-monzodiorite, a differential intrusion was formed within the same age period as granite batholites of the Main belt.

A suite of mainly spinel peridotite and subordinate pyroxenite xenoliths and megacrysts were studied in detail, enabling us to characterize upper mantle conditions and processes beneath the modern North American–Eurasian continental plate boundary. The samples were collected from 37-Ma-old basanites cropping out in the Main Collision Belt of the Chersky Range, Yakutia Republic (Russian Far East). The spinel lherzolites reflect a mantle sequence, equilibrated at temperatures of 890–1,025 °C at pressures of 1.1–2 GPa, with melt extraction estimated to be around 2–6 %. The spinel harzburgites are characterized by lower P–T equilibration conditions and estimated melt extraction up to 12 %. Minor cryptic metasomatic processes are recorded in the clinopyroxene trace elements, revealing that percolating hydrous fluid-rich melts and basaltic melts affected the peridotites. One of the lherzolites preserves a unique melt droplet with primary dolomite in perfect phase contact with Na-rich aluminosilicate glass and sodalite. On the basis of the well-constrained P–T frame of the xenolith suite, as well as the rigorously documented melt extraction and metasomatic history of this upper mantle section, we discuss how a carbonated silicate melt infiltrated the lherzolite at depth and differentiated into an immiscible carbonate and silicate liquid shortly before the xenolith was transported to the surface by the host basalt. Decreasing temperatures triggered crystallization of primary dolomite from the carbonate melt fraction and sodalite as well as quenched glass from the Na-rich aluminosilicate melt fraction. Rapid entrainment and transport to the Earth’s surface prevented decarbonatization processes as well as reaction phenomena with the host lherzolite, preserving this exceptional snapshot of upper mantle carbonatization and liquid immiscibility.

Mantle xenolith bearing olivine melanephelinites from the Okhotsk sector of the Okhotsk–Chukotka Volcanic Belt (OCVB), northeastern Russia, occur as small isolated volcanoes emplaced within massive late Early to Late Cretaceous subduction-related calc-alkaline rocks. The xenoliths are typical mediumto fine-grained anhydrous mainly spinel lherzolites that are strongly to weakly foliated with intensive to minor recrystallization to equigranular texture. The primitive mantle normalized whole-rock REE have flat patterns or patterns with slightly elevated light REE (LREE) ((La/Yb)N 1⁄4 0.48–1.38). The REE in clinopyroxenes have systematically decreasing normalized abundances from Sm to La, implying that the LREE enrichments in the whole-rock REE patterns are attributed to circulation of minor intergranular fluids or melts. Equilibration temperatures and pressures calculated for the Viliga samples are in the range of 1050–1160 8C and 15–21 kbar, respectively. Ca diffusion rates in olivine reveal a rapid transport to the surface (2–6 days) of these peridotites. Model calculations have shown that the fertile lherzolites can be produced by 2–9% batch melting, whereas the depleted peridotites require 15% batch melting of a primitive source. The cessation of the interaction between the palaeo-Pacific plate and the NE Russian margin at c. 87 Ma apparently caused a ‘piecemeal’ collapse of the former followed by intrusion and ascent of olivine melanephelinitic magma, which entrained xenoliths from the asthenospheric mantle of the subducted plate during the Pliocene through the generated window(s). Moreover, clinopyroxenes that have low Sr/Sr and high Nd/Nd and plot in and above the mid-ocean ridge basalt (MORB) field are consistent with an upwelling asthenospheric mantle through the window(s) created by the ‘piecemeal’ collapse of the palaeo-Pacific plate. Mantle xenoliths in alkali basalts emplaced in massive subduction-related calc-alkaline rocks are important rocks, as they could provide information about the nature of the lithospheric mantle wedge and the geochemical and metasomatic processes that occur in such tectonic settings. Fluids released from sediments of a downgoing subduction slab could cause modal metasomatism in the lithospheric mantle wedge, forming hydrous phases such as amphibole and phlogopite (Peacock 1993). Migration of melts produced by melting of a downgoing subduction slab can also affect the lithospheric mantle wedge, causing crypticmetasomatism, as has been demonstrated by Kilian & Stern (2002) for the Cerro Fraile mantle xenoliths in southernmost Patagonia and by Kepezhinskas et al. (1996) for the Valovayam Volcanic Field in the northern segment of Kamchatka arc xenoliths. The mantle xenoliths from the Viliga River volcanic field in the northern Okhotsk region, NE Siberia (Fig. 1), are hosted by olivinemelanephelinites and basanites and occur at two localities (Kananyga River and Aliki River areas) on top of calc-alkaline rocks up to 1550 m above sea level, which are related to the subduction of the palaeo-Pacific slab (Zonenshain et al. 1990). The age of the undersaturated lavas ranges from 10.7 to 7 Ma (Akinin 1997, 2005; Apt et al. 1998). A limited number of mantle xenoliths from the region have been studied by Akinin et al. (1997) and Apt et al. (1998). Here we present a summary of the petrology, mineralogy and geochemistry of the ultramafic xenoliths from both localities and discuss the implications of these data with respect to the subduction slab and mantle wedge processes.

This paper presents a fully-integrated 16-channel wireless neural interfacing SoC that employs an adiabatic stimulator powered directly from a 190-MHz on-chip antenna to eliminate bulky external components while simultaneously avoiding rectifier and regulator losses. Using a charge replenishing architecture, the stimulator outputs up to 145-μA, while achieving a 63.1% charge replenishing ratio and a stimulation efficiency factor of 6.0. Analog front-ends (AFEs) and telemetry circuitry are also included.

This paper presents a CMOS fully-integrated resonant regulating rectifier (IR3) for inductive power telemetry in implantable devices. Employing PWM and PFM feedback, the IR3 achieves 1.87% of ΔV DD /V DD ratio despite a tenfold change in load with a 1nF decoupling capacitor. At 1V regulation of a 100μW load from a 144MHz RF input, the measured voltage conversion efficiency is greater than 92% at under 5.2mV pp ripple and 54% power conversion efficiency. Implemented in 180nm SOI CMOS, the IR3 circuit occupies 0.078mm2 active area.

A CMOS integrated 4-channel capacitive harmonic rejection baseband receiver and 4×4 MIMO analog core spatial filter demonstrate >65dB harmonic folding rejection over 48MHz, and >48.5dB signal separation across 3MHz baseband. The 65nm CMOS IC occupies 3.27mm2 active area and consumes 0.67mW–1.28mW.

This paper presents a fully-integrated 16-channel wireless neural interfacing SoC that employs an adiabatic stimulator powered directly from a 190-MHz on-chip antenna to eliminate bulky external components while simultaneously avoiding rectifier and regulator losses. Using a charge replenishing architecture, the stimulator outputs up to 145-μA, while achieving a 63.1% charge replenishing ratio and a stimulation efficiency factor of 6.0. Analog front-ends (AFEs) and telemetry circuitry are also included.

Test results are presented for a multichannel optoelectronic longitudinal deformometer MOED-1p at the “Oktyabrsky/” mine of the Norilsk deposit with which rock strains and displacements were monitored around an observation working located in the area of a tectonic fault. Basic versions are developed for installing the transducers of the instrument with fixing of the datum-mark support both within the depth of the rock mass and also at the side wall of the working. A relationship is established between the designed technical and actual characteristics of the instrument.

We propose a procedure and results of experimental determination of the dependence of adhesive strength of a ZrO2 plasma-sprayed heat-protective coating with NiCr sublayer on the value of the stationary temperature drop in it. The dependences of the adhesive strength on the temperature of the surface of adhesive contact are compared for homogeneous and inhomogeneous temperature fields. The results obtained enable us to substantiate the choice of temperature drop in heat-protective coatings with regard for the adhesion safety factor.

Nephelinites and basanites of the Enmelen volcanic field, Chukchi Peninsula, Russia, contain upper mantle xenoliths of relatively calcium- and magnesium-rich spinel lherzolites, pyroxenites, and megacrysts. The phase assemblages of the lherzolites require equilibration near 1.5 GPa, and calculated equilibration temperatures for most inclusions are in the range 850–1030 °C. These temperatures are similar to those calculated for lherzolite inclusions from other Bering Sea localities (Nunivak Island and Seward Peninsula) and are higher than temperatures expected for likely conductive geotherms beneath these volcanic fields. The relatively high temperatures may be the result of magma intrusion into the mantle lithosphere and consequent perturbation of the geotherm shortly before entrainment of the xenoliths in basalt. Two Enmelen lherzolites equilibrated at higher temperatures (1230–1240 °C) and provide further evidence for heating due to intrusive magmas. Some spinel lherzolite inclusions have flat rare earth element patterns and major and trace element abundances close to that of the bulk silicate earth. Based on the occurrence of similar fertile peridotites at Nunivak Island and Seward Peninsula, near-primitive mantle compositions appear to be common in the upper mantle beneath the Bering Sea. These peridotites may represent recent additions to the mantle lithosphere from mantle plumes related to the volcanism. Other Enmelen inclusions are relatively light rare earth element-enriched group I lherzolites metasomatized by a silicate melt, group II pyroxenites precipitated from a variety of melts, and augite megacrysts with convex-upward rare earth element patterns consistent with precipitation from the host basalts at high pressures.

Based on laboratory and full-scale (on-site) tests, the developed basic model of the MOED-Ip longitudinal-type multichannel optoelectronic deformometer appears to match its design specifications. Laboratory experiments using acoustic channels have demonstrated the unique possibility of application of individual measuring modules of the MOED-Ip instrument system for diagnosis and monitoring of the state of block media in terms of their loading stages. Based on full-scale (on-site) experiments in the Borok quarry, absolute deformations in rock mass due to blasts of different power under set conditions have been recorded for the first time. We believe that this technical development will find wide application in both mining and civil engineering for monitoring of the effect of blasts, earthquakes, and other factors on the state of natural or engineering structures. In this context, special stress should be laid on integrated application of deformographic and acoustic measurements. The procedure of processing and joint analysis of physical information proposed in this paper is indisputably novel and promising for practical applications.

A prototype of an off-line apparatus is developed to detect deformations, wave processes, parameters, and electromagnetic radiation in block rock masses.

There are proposed methods of film heterostructures deposition by means of a magnetron and an ion source. They make it possible to regulate compositions of film structures and also other parameters, for example refractive indexes, conductivity. It is possible to form a film with preliminary demanded values of parameters in the wide range. Refractive index of films on the base of Ti was varied in the range of values 1.70 . n . 2.45. Conductivity of film structures changed from metal up to high resistance isolator. Diamond . like carbon , SixCy, SixOy, SixOyNz and other kinds of film structures were made by means of an ion source with a cold cathode directly from an ion beam. Refractive index value changed in the range of 1.40 . n . 2.65. It is modified a laser method of end point detection of transparent film deposition process after reaching of a demanded thickness. It has been modified a laser scanning system for wafers and semiconductor structures surfaces investigation. This system can measure parameters at 10000 points on square up to 100 x 100 mm2. It can be used for computer modelling, solar cells and silicon-oninsulator (SOI) structures investigations.

Translated from Probl. Prochnosti; 5: No. 1, l15-118(Jan 1973). The dynamic resonance method was used to determine the temperature dependence of the modulus of elasticity of W, Mo, NiCr, and ZrO₂ coatings applied by the plasma spraying method. An increase in test temperature was found to cause a monotonic decrease in the modulus of elasticity. The absolute value of the modulus of elasticity for plasma-sprayed materials is lower than the corresponding value for the same materials applied by other methods (electron- beam melting, arc melting, and powder metallurgy methods). For W and Mo this difference, for example, was 15 to 20% which may be attributed to a difference in porosity, which also depends on coatmg thickness for plasma-sprayed material. It has been noted that the temperature dependence of the modulus of elasticity has two sections with different temperature coefficients. Thus, investigation results showed that the static adhesion strength of the combination base metal-- coating obtained by the method of continuous plasma spraying, depends on the test temperature and coating thickness. It was shown that the modulus of elasticity of coating materials decreases during the temperature rise to 1200 deg C by 25 to 60% thereby affecting the cohesion strength ofmore » the combination. (auth)« less

1. The strength with which a coating of chromium-nickel spinel adheres to an OT-4 titanium alloy substrate lies in the range 1.15–1.40 kg/mm2. Preheating the surface to be coated to 450°C increases the adhesion of the coating by 25–30%. 2. The adhesion of a coating to its substrate begins to decrease appreciably after 10 thermal cycles. 3. An 80% Ni-20% Cr alloy undercoat has no effect upon the adhesion of a spinel coating and adversely affects its thermal fatigue resistance. 4. The degree of blackness (coefficient of absorption) of a spinel coating is 0.94–0.95.

Clinopyroxene megacrysts from young melanephelinitic lavas were divided into Cr-rich and Cr-poor suites. Sr, Nd, and Pb isotopic ratios of leached megacrysts and host lava are indistinguishable from each other and indicate a depleted source. Host lavas do not display chemical evidence for significant fractional crystallization, which is required to explain the compositional range of the megacrysts. This rules out a simple cognate genetic relationship between the two, and strictly defines megacrysts as xenocrysts. The well-defined correlations of trace elements with the Mg-numbers in the megacrysts are interpreted as the result of extensive fractional/equilibrium crystallization of magma over a large temperature range at near isobaric condition in the upper mantle. Trace element variations in megacrysts are consistent with fractional crystallization of clinopyroxene alone for the Cr-rich suite, and clinopyroxene + garnet for the Cr-poor suite from at least two bathes of related melts. Megacrysts parent magma might represent mantle melts, which were never erupted in their initial composition.