Medical diagnostic system, apparatus and methods are disclosed. Optical transmitters generate radiation-containing photons having a specific interaction with at least one target chromophore in a target structure, preferably a blood vessel such as the interior jugular vein. The optical transmitters transmit the radiation into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure. Optical receivers detect a portion radiation scattered from at least the first area and the second area. A processor estimates oxygenation, pH or cardiac output based on the scattered radiation detected from the first area, and the scattered radiation from the second area.

Cardiac output is defined as the volume of blood circulated per minute. It is equal to the heart rate multiplied by the stroke volume (the amount ejected by the heart with each contraction). Cardiac output averages approximately 5 liters per minute for an average adult at rest, although it may reach up to 30 liters/minute during extreme exercise.
Cardiac output is of central importance in the monitoring of cardiovascular health, as discussed by Conway "Clinical assessment of cardiac output", Eur. Heart J. 11, 148-150 (1990). Accurate clinical assessment of the circulatory status is particular desirable in critically ill patients in the ICU and patients undergoing cardiac, thoracic, or vascular interventions, and has proven valuable in long term follow-up of outpatient therapies. As the patient's hemodynamic status may change rapidly, continuous monitoring of cardiac output will provide information allowing rapid adjustment of therapy. Measurements of cardiac output and blood pressure can also be used to calculate peripheral resistance.
A recent review of the various techniques for measuring cardiac output is given in Linton and Gilon, "Advances in non-invasive cardiac output monitoring", Annals of Cardiac Anaesthesia, 2002, volume 5, p 141-148. This article lists both non/minimally invasive and invasive methods and compares the advantages and disadvantages of each.
The pulmonary artery catheter (PAC) thermodilution method is generally accepted as the clinical standard for monitoring cardiac output, to which all other methods are compared as discussed by Conway and Lund-Johansen ("Thermodilution method for measuring cardiac output", Europ. Heart J. 11(Suppl 1), 17-20 (1990)). The long history of use has defined the technology, suitable clinical applications, and its inadequacies. Many new methods have attempted to replace the thermodilution technique, but none have so far gained acceptance.
Jansen (J. R. C. Jansen, "Novel methods of invasive/non-invasive cardiac output monitoring", Abstracts of the 7th annual meeting of the European Society for Intravenous Anesthesia, Lisbon 2004) describes eight desirable characteristics for cardiac output monitoring techniques; accuracy, reproducibility or precision, fast response time, operator independency, ease of use, continuous use, cost effectiveness, and no increased mortality and morbidity. A brief description of some of these techniques follows.
Indicator dilution techniques. There are several indicator dilution techniques including transpulmonary thermodilution (also known as PiCCO technology, from Pulsion Medical Technologies of Munich, Germany), transpulmonary lithium dilution method (LiDCO Group plc of London, UK), PAC based thermodilution and other methods (Vigilance, Baxter; Opti-Q, Abbott; and TruCCOMS, AorTech). U.S. Pat. No. 6,757,544 to Rubinstein et al. teaches the technique of optically monitoring indicator dilution in a non-invasive manner for the purpose of computation of cardiac output, cardiac index, and blood volume. Transpulmonary indicator dilution methods with bolus injections are variations on the conventional bolus thermodilution method. CO is calculated with use of the Steward-Hamilton equation (Geddes, "Cardiac output using the saline dilution impedance technique", IEEE Engineering in Medicine and Biology magazine March 1989, 22-26). Application of this equation assumes three major conditions; complete mixing of blood and indicator, no loss of indicator between place of injection and place of detection, and constant blood flow. The errors associated with indicator dilution techniques are primarily related to the violation of these conditions, as discussed by Lund-Johansen ("The dye dilution method for measurement of cardiac output", Europ. Heart J. 11 (Suppl 1), 6-12 (1990)) and de Leeuw and Birkenhager ("Some comments of the usefulness of measuring cardiac output by dye dilution", Europ. Heart J. 11 (Suppl 1), 13-16 (1990)). Of the mentioned methods the transpulmonary indicator dilution methods as well as the so-called 'continuous cardiac output' thermodilution methods have been partially accepted in clinical practice as described in, for example, Rödig et al. "Continuous cardiac output measurement: pulse contour versus thermodilution technique in cardiac surgical patients". Br J Anaesth 1999; 50: 525.
Fick principle. The direct oxygen Fick approach is currently the standard reference technique for cardiac output measurement, as discussed by Keinanen et al., "Continuous measurement of cardiac output by the Fick principle: Clinical validation in intensive care", Crit Care Med 20(3), 360-365 (1992), and Doi et al., "Frequently repeated Fick cardiac output measurements during anesthesia", J. Clin. Monit. 6, 107-112 (1990). It is generally considered the most accurate method currently available, although there are many possibilities of introducing errors, and considerable care is needed. However when using the Fick method to trend cardiac output over a short time interval, i.e. during an operation or in an intensive care unit stay, many of these sources of errors are no longer pertinent. The NICO (Novametrix) system is a non-invasive device that applies Fick's principle on CO2 and relies solely on airway gas measurement as described by Botero et al., "Measurement of cardiac output before and after cardiopulmonary bypass: Comparison among aortic transit-time ultrasound, thermodilution, and noninvasive partial CO2 rebreathing", J. Cardiothoracic. Vasc. Anesth. 18(5) 563-572 (2004). The method calculates effective lung perfusion, i.e. that part of the pulmonary capillary blood flow that has passed through the ventilated parts of the lung. The effects of unknown ventilation/perfusion inequality in patients may explain why the performance of this method shows a lack of agreement between thermodilution and CO2-rebreathing cardiac output as described in Nielsson et al. al "Lack of agreement between thermodilution and CO2-rebreathing cardiac output" Acta Anaesthesiol Scand 2001; 45:680.
Bio-Impedance and conduction techniques. The bio-impedance method was developed as a simple, low-cost method that gives information about the cardiovascular system and/or (de)-hydration status of the body in a non-invasive way. Over the years, a diversity of thoracic impedance measurement systems have also appeared. These systems determine CO on a beat-to-beat time base. Studies have been reported with mostly poor results, but in exceptional cases good correlations compared to a reference method. Many of these studies refer to the poor physical principles of the thoracic impedance method as described in Patterson "Fundamentals of impedance cardiography", IEEE Engineering in Medicine and Biology 1989; 35 to explain the discrepancies. The accuracy of this technique is increased when the electrodes are placed directly in the left ventricle, rather than on the chest, however this also increases its invasiveness.
Echo-Doppler ultrasound. This technique uses ultrasound and the Doppler effect to measure cardiac output. The blood velocity through the aorta causes a 'Doppler shift' in the frequency of the returning ultrasound waves. Echo-Doppler probes positioned inside the esophagus with their echo window on the thoracic aorta may be used for measuring aortic flow velocity, as discussed by Schmidlin et al, "Transoesophageal echocardiography in cardiac and vascular surgery: implications and observer variability", Brit. J. Anaesth. 86(4), 497-505 (2001). Aortic cross sectional area is assumed in devices such as the CardioQ, made by Deltex Medical PLC, Chichester, UK) or measured simultaneously as for example in the HemoSonic device made by Arrow International. With these minimally invasive techniques what is measured is aortic blood flow, not cardiac output. A fixed relationship between aortic blood flow and cardiac output is assumed. CO can therefore be calculated using this relationship. Abrupt changes in cardiac output are better followed with Doppler systems than with the PAC based continuous cardiac output systems as described in Roeck et al. "Change in stroke volume in response to fluid challenge: assessment using esophageal Doppler", Intensive Care Med 2003; 29:1729. This measurement requires an above average level of skill on the part of the operator of the ultrasound machine to get accurate reliable results.
Arterial pulse contour analysis. The estimation of cardiac output based on pulse contour analysis is an indirect method, since cardiac output is not measured directly but is computed from a pressure pulsation on basis of a criterion or model. The origin of the pulse contour method for estimation of beat-to-beat stroke volume goes back to the Windkessel model as described in, for example, Manning et al. "Validity and reliability of diastolic pulse contour analysis (Windkessel model) in humans", Hypertension. 2002 May; 39(5):963-8. Most pulse contour methods are based on this model explicitly or implicitly as described in Rauch et al. "Pulse contour analysis versus thermodilution in cardiac surgery", Acta Anaesthesiol Scand 2002; 46:424, Linton et al. "Estimation of changes in cardiac output from arterial blood pressure waveform in the upper limb", Br J Anaesth 2001; 86:486 and Jansen et al. "A comparison of cardiac output derived from the arterial pressure wave against thermodilution in cardiac surgery patients" Br J Anaesth 2001; 87:212.
Arterial pulse contour analysis techniques relate an arterial pressure or pressure difference to a flow or volume change. Three pulse contour methods are currently available; PiCCO (Pulsion), PulseCO (LiDCO) and Modelflow (TNO/BMI). All three of these pulse contour methods use an invasively measured arterial blood pressure and they need to be calibrated. PiCCO is calibrated by transpulmonary thermodilution, LiDCO by transpulmonary lithium dilution and Modelflow by the mean of 3 or 4 conventional thermodilution measurements equally spread over the ventilatory cycle. Output of these pulse contour systems is calculated on a beat-to-beat basis, but presentation of the data is typically within a 30-second window. A non-invasive pulse contour development is the combination of non-invasively measured arterial finger blood pressure with Modelflow as described in Hirschl et al. "Noninvasive assessment of cardiac output in critically ill patients by analysis of finger blood pressure waveform", Crit Care Med 1997; 25:1909.
None of the above-mentioned CO techniques combines all of the eight "Jansen" criteria mentioned above. With respect to accuracy and precision, a number of methods may approach the thermodilution method with a precision of 15%. None of these new techniques has displaced conventional thermodilution based on the averaged result of 3 or 4 measurements done equally spread over the ventilatory cycle as described in Jansen et al. "An adequate strategy for the thermodilution technique in patients during mechanical ventilation", Intensive Care Med 1990; 16:422. Under research conditions the use of this conventional thermodilution method remains the method of choice. However, in clinical settings, the lower precision of the continuous cardiac output techniques may be outweighed by their advantages of being automatic and continuous.
In addition to measuring cardiac output, it is also desirable in many critical care situations to continuously monitor a patient's blood oxygen level. Currently, hospitals routinely monitor blood oxygenation by pulse oximetry with a monitor attached to the patient's finger or earlobe as described for example in Silva et al., "Near-infrared transmittance pulse oximetry with laser diodes", J. Biomed. Opt. 8(3), 525-533 (2003). Typically the oxygen monitor is a pair of light-emitting diodes (LED) and photodiodes on a probe clipped to a part of the patient's body. Red light from the LED reflects from the blood in a part of the patient's body, such as an ear-lobe or finger-tip. As a patient's oxygenation level drops, the blood becomes more blue, reflecting less red light to the photodiode. Such blood-oxygen monitors customarily measure percent of normal. Reassuring (normal) ranges are from 95 to 100 percent. For a patient breathing room air, at not far above sea level, an estimate of arterial oxygenation can be made from the blood-oxygen monitor reading. Unfortunately, measurements from such oxygen monitors cannot be reliably correlated to oxygenation in the patient's venous blood. Venous oxygen saturation is also a valuable parameter in the diagnosis of septic and cardiogenic shock as described below.
Other methods of measuring oxygenation: Diffuse optical tomography methods as described for example in Boas et al., Method for monitoring venous oxygen saturation", US Patent application 20040122300 are conceptually appealing but are useful only where the vessels in the vicinity of the diffusing photon field are isolated veins. The presence of mixed arterial and venous blood complicates the problem to as described by Wolf et al., "Continuous noninvasive measurement of cerebral arterial and venous oxygen saturation at the bedside in mechanically ventilated neonates", Crit. Care. Med 25(9), 1579-1582 (1997).
Ultrasound-tagged optical spectroscopy involves overlapping an ultrasound wave and a diffusing optical field, and modulating the frequency of the probe photons or their trajectories. A number of different technologies have been developed that utilize some interaction between ultrasound radiation and electromagnetic radiation. U.S. Pat. No. 5,212,667 to Tomlinson et al. and U.S. Pat. No. 5,174,298 to Dolfi et al. teach the technique of ultrasound tagged frequency-modulated imaging. Other patents teaching variations on the theme of frequency-modulated ultrasound tagging techniques include U.S. Pat. No. 6,815,694 to Sfez et al., U.S. Pat. No. 6,738,653 to Sfez et al., U.S. Pat. No. 6,041,248, to Wang, U.S. Pat. No. 6,002,958 to Godik, U.S. Pat. No. 5,951,481 to Evans, U.S. Pat. No. 5,293,873 to Fang. Trajectory modulation is detected by monitoring the speckle pattern of the photons emerging form the target. Image reconstruction techniques are then used to recreate a map of the path the photons followed in the medium. Imaging the speckle resulting from trajectory changes requires significant computation power and post-processing to yield an image. The technique has limited resolution, and is not yet capable of yielding functional (oxygenation) information in a fast flowing vessel.
Some variations of ultrasound-tagged frequency-modulated imaging rely on observing the frequency shift induced by the photoacoustic effect when an electromagnetic wave interacts in a medium with a sound wave. The electromagnetic wave (having a characteristic frequency ωOPT) receives a frequency shift at the ultrasound frequency ωUS to either the + or − side of the carrier wave ωOPT. Frequency modulation is detected by measuring the frequency shifted photons by for example using a Fabry-Perot etalon as described by Sakadzic and Wang, "High resolution ultrasound modulated optical tomography in biological tissues", Opt. Lett. 29(23) 2004, p 2770-2772. Since the Doppler shifts induced by the ultrasound wave are very small compared to the probe photon carrier wave frequency, the detection system must be extremely sensitive to small frequency shifts. In addition, the frequency shift can be to both larger and smaller frequency of the initial carrier wave, and therefore some self-cancellation may result.

Apparatus and method for non-invasive and minimally-invasive sensing of parameters relating to blood


A ski binding reduces a likelihood of injury to the anterior cruciate ligament (ACL) and the tibia is accomplished by absorption in the binding to limit loads transmitted through the boot-binding interface. Release based on an injury threshold includes a binding response tower attached to the ski and adapted for selective engagement with the ski, such that the binding response tower permits biased vertical and lateral horizontal displacement, prior to a release threshold. The binding is in communication with the boot heel and is adapted for slideable engagement in response to vertical and lateral forces exerted from the boot heel. The binding response tower adapted to disengage, or release upon reaching at least one a predetermined lateral displacement or a predetermined vertical displacement, such as when the boot heel is forced sufficiently sideways or upwards due to skier movement that would tend to cause an ACL injury.

Skiing injuries occur when excessive forces beyond human tolerance are transmitted to the skier from the ski. Due to the high-speed nature of the sport, substantial energy is developed by a skier in motion on a steep slope. Ski bindings prevent ski injuries by releasing the skier's leg from rigid communication with the ski when forces deemed to be injurious are applied to the ski, as in a ski fall. Skiers wear specially engageable boots that are adapted to engage a binding attached to the ski, and maintain the boot and thus, the skier's calf and foot, in tight coupling with the ski. Forces transmitted to the legs through the binding system can be injurious, particularly during tight turns, falls, and high-speed maneuvers. Ski bindings are therefore designed to selectively release a skier from the skis by decoupling a ski boot when a predetermined force is achieved. Conventional approaches employ a pivoting toe that pivots the boot from a parallel alignment to the ski to an outward position allowing the boot to freely disengage, such that harmful rotation of the leg relative to the ski is avoided.


A hybrid electric vehicle and method that stores an upper energy storage limit and a lower energy storage limit for an energy storage system for each of a plurality of predetermined driving modes, determines a currently selected driving mode from the plurality of predetermined driving modes, sets the upper energy storage limit and the lower energy storage limit for the energy storage system based on the currently selected driving mode, determines parameters for operation of vehicle components within the currently selected driving mode and generates command signals to the vehicle components for operation within determined parameters.

1. Field of Invention
This invention relates to methods and apparatuses for selectively operating a hybrid electric vehicle in one of a number of driving modes.
2. Description of Related Art
The desire for cleaner air has caused various federal, state, and local governments to adopt or change regulations requiring lower vehicle emissions. Increasing urban traffic congestion has prompted a need for increases in public mass transit services. All mass transit systems utilizes buses, at least in part, to transport people into, out of, and within traffic congested urban areas. Conventional buses use diesel powered internal combustion engines. Diesel engines produce emissions, including carbon monoxide, that contribute to air pollution. It is possible to refine cleaner diesel fuel. However, cleaner diesel fuel is more costly to refine and causes a corresponding increase in the cost of bus service.
Alternative fuels have been used to reduce emissions and conserve oil resources. Compressed natural gas has been used as an alternative fuel. Compressed natural gas does not produce as much power in conventional internal combustion engines as gasoline and diesel and has not been widely developed or accepted as an alternative to gasoline and diesel.
Additives have also been developed for mixing with gasoline to reduce emissions. Ethanol and MTBE have been added to gasoline to oxygenate the combustion of gasoline and reduce emissions of carbon monoxide. These additives, however, are believed to cause decreased gas mileage and, in the case of MTBE, to be a potential public health threat.
Electric vehicles have been developed that produce zero emissions. Electric vehicles are propelled by an electric motor that is powered by a battery array on board the vehicle. The range of electric vehicles is limited as the size of the battery array which can be installed on the vehicle is limited. Recharging of the batteries can only be done by connecting the battery array to a power source. Electric vehicles are not truly zero emitters when the electricity to charge the battery array is produced by a power plant that bums, for example, coal.
Hybrid electric vehicles have also been developed to reduce emissions. Hybrid electric vehicles include an internal combustion engine and at least one electric motor powered by a battery array. In a parallel type hybrid electric vehicle, both the internal combustion engine and the electric motor are coupled to the drive train via mechanical means. The electric motor may be used to propel the vehicle at low speeds and to assist the internal combustion engine at higher speeds. The electric motor may also be driven, in part, by the internal combustion engine and be operated as a generator to recharge the battery array.
In a series type hybrid electric vehicle, the internal combustion engine is used only to run a generator that charges the battery array. There is no mechanical connection of the internal combustion engine to the vehicle drive train. The electric traction drive motor is powered by the battery array and is mechanically connected to the vehicle drive train.
Conventional internal combustion engine vehicles control propulsion by increasing and decreasing the flow of fuel to the cylinders of the engine in response to the position of an accelerator pedal. Electric and hybrid electric vehicles also control propulsion by increasing or decreasing the rotation of the electric motor or motors in response to the position of an accelerator pedal. Electric and series type hybrid electric vehicles may be unable to accelerate properly if the power available from the battery or batteries and/or genset is insufficient.
Conventional internal combustion engine vehicles may also include systems to monitor the slip of a wheel or wheels to thereby control the engine and/or the brakes of the vehicle to reduce the slip of the wheel or wheels. In hybrid electric vehicles, however, it is necessary to control the speed and torque of the electric motor or motors to control the slip of wheels.
Conventional internal combustion engine vehicles may also include systems to modify effects of vehicle braking in certain situations, including loss of traction, wheel slippage, and load shifting. In electric and hybrid electric vehicles, however, regenerative braking operation must interface with these and other propulsion system conditions to prevent unexpected or unsafe operation. Additionally, this system must interface with the energy storage and generation systems because it is electrically based. Furthermore, in electric and hybrid electric vehicles, an operator input may be used to manually indicate the level and types of regenerative braking to be applied.

Method and apparatus for selective operation of a hybrid electric vehicle in various driving modes


A utility tray for use with a substantially upright seat back which includes a seat back connector mechanism and a support tray assembly connected to the seat back connector mechanism. The support tray assembly includes a pair of first and second friction pivot joint assemblies connected to the seat back connector mechanism; a pair of support rails connected to and extending from the friction pivot joint assemblies; a first tray section connected to the pair of support rails for movement between a first retracted position and a second extended position, and a second tray section hingeably connected to the first tray section.

1. Field of the Invention
The present invention relates generally to utility trays for passenger vehicles. More particularly, the invention concerns a foldable food and beverage tray for use in commercial airplanes.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Various types of utility trays for airplanes have been suggested in the past. Typically, such trays are pivotally connected to a seat back of the airplane and can be pivoted downwardly for use. When pivoted downwardly, the top surface of the tray is exposed and when stowed, the top surface faces inwardly toward the seat back. While some prior art utility trays are slidable along guide rails toward and away from the seat back, many lack any adjustability features. Those prior art food trays that are adjustable are often difficult to operate and frequently tend to malfunction. It is this prior art drawback that the present invention seeks to overcome by providing a novel food and beverage tray that is easy to operate and one that provides multiple degrees of easy and trouble free adjustment.


The present disclosure relates to a new catalytic process for the production of methanol from carbon dioxide, comprising: (1) the conversion of carbon dioxide and hydrogen to formic acid or formate salts; (2) converting the formic acid or formate salts to diformate esters of diols; (3) hydrogenating the diformate esters to methanol and diols. The diols produced from the hydrogenation reaction can be recovered and re-used to prepare the diformate esters.

Carbon dioxide is a cheap, safe and renewable source of carbon. However, carbon dioxide is also a greenhouse gas and is of significant environmental concern. Catalytic hydrogenation of carbon dioxide to methanol is regarded as a significant component of a methanol economy, as it is a liquid hydrocarbon that can be easily stored and transported (G. A. Olah et al., Beyond Oil and Gas. The Methanol Economy, Wiley-VCH, 2006). Methanol is valuable industrially, both as a fuel and a chemical feedstock. The direct conversion of carbon dioxide and hydrogen to methanol, using heterogeneous and homogeneous catalysts, has been explored by several groups (C. A. Huff et al., J. Am. Chem. Soc. 2011, 133, 18122-18125; S. Wesselbaum et al., Angew. Chem. Int. Ed. 2012, 51, 7499-7502). However, such procedures are generally expensive and inefficient, and require high temperatures and pressures.
Over the years, several catalytic processes have been developed to produce methanol from a variety of precursors. Milstein and coworkers (E. Balaraman et al., Nature Chemistry 2011, 3, 609-614) reported the use of homogeneous catalysts for the hydrogenation of methyl formate and dimethyl carbonate to methanol. The drawback for this process is that the dimethyl carbonate is derived from, and is more expensive that methanol.
Ding et al. (Z. Han et al., Angew. Chem. Int. Ed. 2012, 51, 13041-13045) reported the hydrogenation of carbonate esters to diols and methanol. However, the carbonate esters are derived from alkene oxides, which are more expensive than methanol, and the diol by-product cannot be readily converted to carbonate esters or alkene oxides.
Hence, there is still a need for an effective and efficient catalytic process to directly or indirectly convert carbon dioxide and hydrogen to methanol. Abdur-Rashid et al. reported the use of ruthenium aminophosphine (PN) catalysts (U.S. Pat. Nos. 7,317,131; 7,579,295; 7,772,445; 8,232,430; 8,658,825; 8,716,508; 9,115,249; K. Abdur-Rashid et al., Adv. Synth. Catal. 2005, 347, 571-579; D. Amoroso et al., Aldrichimica Acta 2008, 41, 15-26; W. Jia et al., Dalton Trans. 2009, 8301-8307; R. Guo et al., J. Org. Chem. 2010, 75, 937-940; C.-W. Tsang et al., Chimica Oggi 2010, 28, 18-22) as well as metal aminodiphosphine (PNP) catalysts (U.S. Pat. Nos. 7,291,753; 7,777,083; 8,518,368; Z. Clarke et al., Organometallics, 2006, 25, 4113-4117; X. Chen et al., Dalton Trans. 2009, 1407-1410; T. W. Graham et al., Angew. Chem. Int. Ed. 2010, 49, 8708-8711; D. Amoroso et al., The Strem Chemiker 2011, 25, 4-12) for the hydrogenation and transfer hydrogenation of carbonyl (C═O), and iminocarbonyl (C═N) and alkene (C═C) bonds. These reports and those of other researchers have demonstrated the applications of these and related catalysts for the broad scope reduction of a variety of carbonyl compounds, including ketones, aldehydes, esters, amides and carbonate esters.

Catalytic conversion of carbon dioxide to methanol using diformate esters as intermediates


An equalizer-combiner for a diversity receiver using at least two receive channels computes equalization coefficients for each channel allowing for a first channel error signal representative of a comparison between the demodulated signal and a channel estimate of the transmitted source signal delivered by a channel estimator fed with the demodulated signal in the channel during an acquisition phase and a second channel error signal representative of a comparison between the demodulated signal and the global estimate of the transmitted source signal during a normal operation phase. The equalizer-combiner computes the weighting coefficients allowing for a first global error signal representative of a comparison between the combined signal and the global estimate of the source signal during the acquisition phase a second global error signal representative of a comparison between local reference information known to the receiver and corresponding received reference information periodically extracted from the global estimate during the normal operation phase.

1. Field of the Invention
The field of the invention is that of diversity signal reception. To be more precise, the invention concerns the equalization and the combination of signals received on the different channels of a diversity receiver. It applies with advantage to all selective and/or scrambled transmission media.
2. Description of the Prior Art
A preferred field of application of the invention is that of tropospheric transmission. A transmission medium of this kind is conventionally subject to Rayleigh fading (deep and fast, up to 15000 dB/s). It is also highly frequency selective, the coherence band of the transmission medium often being less than the transmitted bit rate.
Diversity reception is based on receiving the same source signal on a plurality of separate channels (at least two). Each of these channels is processed (equalized) independently. They are then combined (weighted sum). The combined signal is then conventionally processed to reconstruct the transmitted signal as reliably as possible.
In the case of tropospheric transmission, diversity is assured by simultaneous transmission of the same signal on as many carrier frequencies as there are channels It can also be achieved by spatial arrangement of a plurality of antennas near the receiver.
Diversity equalization-combination is subject to a number of problems, especially in tropospheric transmission.
At low signal/noise ratios, the equalizers tend to become desynchronized or to have difficulties with converging, because of decision errors in estimating the received information, which serves as a criterion for equalization.
It is very difficult to synchronize the equalizers before diversity combination. The differential propagation tire-delays between diversity channels rule out the "fixing" of a coefficient called the central coefficient. The resulting degree of freedom has to be compensated by another constraint for combination in phase.
To be more precise, on a highly selective transmission medium the various channels can have relative time-delays exceeding the transmitted signal period. On summation (combination), the various channels have to be synchronized. The computation is unstable and subject to catastrophic propagation (interaction of equalizers), a problem that it avoided or made less severe by using a slow algorithm.
There are three major classes of combiners, namely:
selection combiners: PA1 equal gain combiners: PA1 optimal combiners: PA1 either by the same information 17. In this case the equalizer itself acts as a weighting device. The desynchronization of the channels, or the poor quality of one channel, then causes the equalizer to diverge from the channel, which unbalances the combiner, which causes decision errors on the combiner channel, which causes the other equalizers to diverge, and so on. PA1 or by external information, such as an AGC voltage 19.sub.1 -19.sub.N, a noise measurement, etc. External information of this kind may be subject to caution primarily in the case of limited equalizer correction capacity or in the presence of a scrambler leading to AGC capture. It does not necessarily represent the quality of the channel. PA1 an equalizer controlled by means for computing equalization coefficients and delivering an equalized signal, PA1 a demodulator fed with the equalized signal and delivering a demodulated signal, and PA1 a weighting device receiving the demodulated signal and delivering a signal weighted in accordance with a weighting coefficient, the weighted signals being then combined by a diversity summing device delivering a combined signal and feeding a global estimator which delivers a global estimate of the transmitted source signal, PA1 a first channel error signal representative of a comparison between the demodulated signal and a channel estimate of the transmitted source signal, delivered by a channel estimator fed with the demodulated signal in the channel during an acquisition phase, and PA1 a second channel error signal representative of a comparison between the demodulated signal and the global estimate of the transmitted source signal during a normal operation phase, PA1 a first global error signal representative of a comparison between the combined signal and the global estimate of the source signal during the acquisition phase, and PA1 a second global error signal representative of a comparison between local reference information known to the receiver and corresponding received reference information periodically extracted from the global estimate during the normal operation phase. PA1 in phase 2 (normal operation): PA1 y.sub.k is the reference information known to the receiver; PA1 Z.sub.k is the reference information as contained in the combined signal, with: PA1 a first channel error signal representative of a comparison between the demodulated signal and a channel estimate of the transmitted source signal during an acquisition phase, and PA1 a second channel error signal representative of a comparison between the demodulated signal and the global estimate of the transmitted source signal during a normal operation phase, and wherein the weighting coefficients are computed in accordance with: PA1 a first global error signal representative of a comparison between the combined signal and the global estimate of the transmitted source signal during the acquisition phase, and PA1 a second global error signal representative of a comparison between local reference information known to the receiver and corresponding received reference information periodically extracted from the global estimate during the normal operation phase. PA1 the equalization coefficients of each channel are computed in accordance with the first channel error signal representative of a comparison between the demodulated signal and a channel estimate of the transmitted source signal, and PA1 the weighting coefficients are computed in accordance with the second global error signal representative of a comparison between local reference information known to the receiver and received reference information extracted periodically from the global estimate.
output=max (p.sub.1 ;p.sub.2 . . . ;p.sub.n) P.sub.i =1: power of signal on channel i S/N.sub.output =max ((S/N).sub.1) PA2 output=p.sub.1 +p.sub.2 + . . . p.sub.n PA2 if S.sub.1 =S.sub.2 =S.sub.n S/N.sub.output =(S/N).sub.i*n PA2 if S.sub.1 =0 for i<>k S/N.sub.output =(S/N).sub.k/n PA2 output=a.sub.1 p.sub.1 +a.sub.2 p.sub.2 + . . . +a.sub.n p.sub.n with a.sub.i =K*(S/N).sub.i S/N.sub.output =(S/N).sub.1 +(S/N).sub.2 + . . . (S/N).sub.n PA2 the equalizers converge from the error computed from the difference between their own decision and their own equalizer signal; PA2 the combiner converges from the combined error computed from its decision (estimate); PA2 the equalizers "track" on the basis of the error computed from the difference between the combined decision (therefore of best quality) and their own equalized signal; PA2 the combiner "tracks" on the basis of the error computed from the difference between the combined received reference signal and the local reference (reliable information). PA2 z.sub.k =a.sub.1 x.sub.k1 + . . . +a.sub.m x.sub.km, where:
where m is the diversity order or number of channels.
The selection combiner does not offer any combination gain. Its output is simply equal to the best input.
The equal gain combiner causes all channels to contribute, whether they enhance or degrade the combined signal.
The optimal combiner maximizes the signal/noise ratio. The problem is to evaluate this ratio on each channel.
FIG. 1 shows an equalizer-combiner of a type known in itself in which the combiner is an optimal combiner.
Each channel 11.sub.1 through 11.sub.n feeds an equalizer 12.sub.1 through 12.sub.n and then a demodulator 13.sub.1 through 13.sub.n and a weighting device 14.sub.1 through 14.sub.n. The weighted signals are combined by a summing device 15 which feeds a decision module 16 supplying an estimate 17 of the received signal for the remainder of the processing.
The equalization coefficients are determined by computation modules 18.sub.1 through 18.sub.n according to the estimate 17 of the received signal.
weighting before combination can be controlled:
When using a measurement of the received power (P=S+N; if N is fixed, then a=K*S), the problem (and the source of error) is to evaluate S in the measurement of P. The system is sensitive to the variation of N, to scrambling and to distortion (non-integrity of S).
In the case of noise measurement after AGC amplification (P=S+N=Constant and a=K/N) the noise measurement is done out of band, leading to errors. Moreover, the system is sensitive to the selectivity of the propagation medium, to scrambling, to distortion and to out-band spectrum pollution.
To overcome these problems so-called "reference directed" equalizers have been developed, relying on the insertion at the transmitter end of a reference sequence which is known at the receiver end. The coefficients of the equalizers and of the combiner are computed using only these reference symbols.
A device of this kind is shown in FIG. 2. The device 21 for analyzing the reference sequence drives the weighting devices 14.sub.1 through 14.sub.n and the modules 18.sub.1 through 18.sub.n for computing the equalization coefficients.
A disadvantage of this technique is that when the channel varies at a fast rate, the overhead due to the reference sequencer can become prohibitive, especially if the convergence algorithm is slow (a gradient algorithm is frequently chosen for reasons of simplicity, robustness and stability).
Moreover, it requires the periodic transmission of a relatively long reference sequence representing a significant loss of usable bit rate.
A particular objective of the invention is to overcome these various drawbacks of the prior art.
To be more precise, one objective of the invention is to provide an equalizer-combiner for diversity receivers offering equalization and combination (weighting) performance better than systems known in themselves.
Accordingly, an objective of the invention is to provide an equalizer-combiner of this kind capable of operating at a very low level. In particular, equalizers of the invention must not be subject to any threshold effect or to any desynchronization.
Another objective of the invention is to provide an equalizer-combiner of this kind which synchronizes the various receive channels in a simple and efficient manner, even on a highly dispersive transmission medium.
Another objective of the invention is to provide an equalizer-combiner of this kind that is capable of eliminating a faulty channel or strongly limiting a channel of poor quality.
Another objective of the invention is to provide an equalizer-combiner of this kind which does not require any significant reduction of usable transmission bit rate.

Equalizer-combiner for diversity receiver, receiver incorporating same and corresponding diversity reception method


A clothes drying rack including a free standing frame that supports a plurality of rods from which articles of clothing can be suspended. Specifically, the clothes drying rack includes a plurality of rods wherein each rod has corrugated exterior to facilitate passage of air between the clothing and the rod.

It is common practice to dry clothes by exposing the recently washed clothes to the atmosphere preferably outdoors. Clothes lines of various types have been proposed from which the garments are suspended, usually by use of clothes pegs. There have also been proposals for portable racks from which the clothes can be suspended. Racks have the advantage that they take up less room than a clothes line and can be used in an indoor environment.
It is considered that there is a need to improve the versatility of a clothing rack by means of increasing its manoeuvrability, rending the rack easy to assemble and disassemble and ensuring good drying efficiency. The rack should be easy to use and durable, capable of resisting damage due to moisture and exposure to sunlight.
It is these issues that have brought about the present invention.


Vapor deposition systems and methods associated with the same are provided. The systems may be designed to include features that can promote high quality deposition; simplify manufacture, modification and use; as well as, reduce the footprint of the system, amongst other advantages.

Atomic layer deposition (ALD) is a technique that allows growth of thin films, atomic layer by layer. The technique can be illustrated with, but is not limited to, the deposition of Al2O3 from water and trimethyl aluminum (TMA) precursors. Recipes for many other materials producing insulators, metals and semiconductors, can be found in the literature. FIG. 1 schematically shows the growth of Al2O3 from water and (TMA). The general steps include: (a) insert an air hydroxilated substrate into the vacuum chamber, (b,c) The TMA precursor is pulsed and the TMA will react with the OH on the surface. TMA does not react with itself and the formed monolayer, thus passivating. (d) The unreacted TMA molecules are removed by evacuation and/or purging with an inert gas such as nitrogen or argon (e,f) Water is pulsed into the reactor. This will remove the CH3 groups, create Al—O—Al bridges and passivates the surface with Al—OH. CH4 (methane) is formed as a gaseous by-product (g) Unreacted H2O and CH4 molecules are removed by evacuation and/or purging with nitrogen. (a-g) is called a cycle and each cycle produces about 1.1 Angstrom of Al2O3. Thus, 100 cycles produces 110 Angstrom of Al2O3.
Design of ALD systems has followed different approaches, some of which are based on deposition systems used for other deposition techniques (e.g., chemical vapor deposition).
One approach is the laminar flow tube furnace, as shown in FIG. 3. In this case, a substrate 28 is inserted into a tube 24 through an access port 36. The substrate is heated using a tube furnace heater 26 and the reaction chamber inside the tube 24 is evacuated using a pump 34. The pressure is measured with a vacuum gauge 30. A continuous inert gas flow (carrier gas) is supplied from a cylinder 10 and injected into the precursor lines using inert gas lines 12. The precursors are heated using an oven 14. Precursor vapor is pulsed from precursor containers 16 and 20, using electronically controlled valves 18 and 22. These types of reactors are often found in research environments and are generally more suitable for small substrates, since large substrates increase the tube furnace size dramatically, both in diameter and length, in order to maintain sufficient temperature uniformity. The design is based on CVD systems, where very high temperatures are typically used and low temperature O-ring access is displaced from the tube furnace heater.
A second ALD system design also derived from the CVD technology is shown in FIG. 4. In this case, a shower head 42 is used to supply the precursors in an effort to uniformly disperse the chemicals over the surface. In such designs, the substrate heater is generally found inside the vacuum space. Although the showerhead vapor injection design may be effective in CVD systems, where gas or vapor is injected that only reacts at the high substrate temperature site, and where uniform gas distribution is essential for uniform film thickness, such a design can lead to clogging in ALD systems where precursor residues can react with each other at showerhead temperature. Moreover, in contrast to certain CVD processes, ALD does not typically require very uniform dispersion of the precursor do to the self-limiting nature of the process. In addition, in order to prevent condensation of precursors, the showerhead and other parts of the system are generally heated to a temperature range of 100-200° C., which can be complicated for complex geometries such as showerheads. Lastly, because of the large surface area and small cavities, the evacuation and purging of precursor in the deposition cycles can be difficult.
For production ALD systems, usually deposition stations are combined in a cluster tool arrangement. Wafers racks are inserted into a load lock, transferred in a transfer chamber through a slit valve arrangement. A robotic arm moves the substrates to the deposition station, where it is stacked vertically with other substrates using a vertical translation robot. After deposition the substrates are removed through unload-lock.
A single unit system is generally characterized by a horizontal precursor gas flow, and horizontal access port (slit valve) in the front. The height of the single unit defines the internal reactor volume and precursor flow speed, and is optimized for fast flow and gas utilization, and for one specific substrate type, thickness and diameter (usually silicon wafers).
Because of the complex nature of the design to achieve large throughput for one particular type of substrate, modification, upgrading, cleaning and repair can be very time consuming, and the systems do not lend themselves for research and development purposes.
Most ALD systems thus far have focused deposition on planar substrates such as silicon wafers, or, in the case of tube furnaces, wafer pieces, even though the ALD technique can be used to coat complex 3D structures, such as capacitor trenches, nanotubes, plastics, inverse opals, catalytic beds, photonic crystals, engine components, tools, optical parts etc. Since the ALD technology is highly scalable to large dimension samples, research of this technique in fields other than the semiconductor industry is desired and a tool that is easily adapted to a variety of samples geometries can be advantageous.


A utility tool configured to be transportable and operable to perform a variety of tasks. The utility tool includes a body that is generally cylindrical in shape and rigid in manner. The body includes a first end and a second end with an aperture formed into the body proximate said first end. Four slots are integrally formed into the body having an interior volume an extending from said second end towards the first end but not completely thereto. The utility tool further includes pivotally mounted arm members having a first position and a second position. The second end is configured to be removable and further functions to bias against a portion of the arm members to hold in their first and/or second positions. A plurality of recesses are integrally formed with the body proximate the second end.

There are on the market today many tools that exist for hikers, campers and military personnel that are designed to perform more than one task. Typically these tools try to combine the ability to perform certain task such as but not limited to digging and chopping. The object of the multipurpose tool is to provide a user the ability to carry one tool as opposed to several and further to provide a multipurpose tool that is compact and lightweight. While a desirable tool is compact and lightweight, it should be constructed with sufficient strength to withstand rugged use. Furthermore a multipurpose tool for users such as military personnel should be manufactured such that it requires little or no assembly and maintenance.
Specific tactical use tools should be designed so as to facilitate speed of use as well as reduce the number of times the tool is used to complete a specific task. A well-designed tactical tool should require relatively little training and increase the success ratio of the user performing the task. By way of example but not limitation, during specialized tactical operations, personnel may explore an area for mines by attempting to discover mine trip wires that may be dispersed in an area that requires entry by tactical personnel. Currently there are many methods and devices that are used in order to facilitate the discovery of mine trip wires. One issue with existing devices is their design lacks in promoting a desired stealth during completion of the task. As will be appreciated, the aforementioned operation is a task in which the user desires to make fewer throws of a device and subsequent drags thereof through an area in order to decrease the opportunity of being detected or for the sake of speed in identifying whether an area is safe.
Another issue with existing multi-purpose tools is their lack of configurability. While many existing multi-purpose tools are configured to adapt to perform two tasks, existing devices are typically not configured to allow a user to enhance the tool with an additional component so as to improve the ability to perform one of its intended tasks. More specifically but not by way of limitation, altering the weight distribution in the field of a tool so as to improve the ability of the tool for a specific purpose.
Accordingly, there is a need for a multipurpose tool that is compact and lightweight that is operable to facilitate the performance of more than one task wherein the tool is further configurable in the field in an efficient manner so as to improve the execution of at least one the intended uses of the multipurpose tool.


A battery tray and a vehicle include a frame structure including a plurality of frames sequentially connected end to end arranged to be connected to the vehicle, and a base plate structure including an inner base plate and a reinforcing beam, wherein the inner base plate is located on an inner side of the reinforcing beam and arranged for mounting a battery module. The battery tray further includes a reinforcing block, wherein the reinforcing block is connected to a corresponding frame and the reinforcing beam in a matching mode, so as to fixedly connect the reinforcing beam to the frame structure through the reinforcing block. In the battery tray, the strength of the battery tray can be enhanced and a total weight can be decreased only by using the reinforcing block to fixedly connect the reinforcing beam to the frame structure.

In the art of electric vehicles, a battery tray is configured to mount and accommodate a battery module and generally includes a frame structure and a reinforcing structure. At present, in order to enhance the strength of the battery tray, the generally-used means is to increase thicknesses of the frame structure and the reinforcing structure of the battery tray, resulting in the increase of a weight, however, the increase of the weight makes the strength enhancement and the weight decrease mutually-constrained factors, and therefore it is difficult to realize the lightweight while the strength of the battery tray is enhanced.

CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED


A method for creating entropy in a virtualized computing environment includes waking one or more samplers, each sampler having a sampling frequency; sampling a sample source with each of the one or more samplers; placing each of the samplers in an inactive state when not sampling; determining a difference between an expected value and a sampled value at each sampler; and providing a function of the difference from each of the one or more samplers to an aggregator.

The present invention relates to random number generators, and more specifically, to utilizing timing jitter in generation of random generator numbers.
Random-number generation generally consists of two stages, short, unpredictable true random numbers (seeds) feeding fast, deterministic random number generators (also called pseudo-random number generators). The deterministic generators contribute no true randomness, but may improve statistical properties of the data stream. All non-predictability is derived from the initial seed. Therefore, the quality and throughput of entropy derived from a particular seed is critical.
A deterministic generator (often simply called an "extractor") is a function which, when applied to a seed (such as radioactive decay, or thermal noise), generates a random output that may be shorter, yet uniformly distributed. In other words, outputting a completely random sample from a semi-random input. The goal of this process is to generate a truly random output stream, which could then be considered as being a true random number generator (TRNG).
In certain popular entropy extractors, raw information content ("entropy") is extracted from measured timing differences. Measured timing differences shall be referred to generally a "jitter" or "clock jitter." Thus, jitter is one seed from which random numbers may be generated.
Jitter is derived from frequent, periodic sampling of an unpredictable event source, typically a clock-derived source. Jitter sampling is usually done at the highest feasible frequency, because the sampling frequency limits the entropy extraction rate.
Jitter-based entropy extraction (i.e., using jitter as a seed) becomes inefficient as the variation in latency decreases because measurements of periodic events, being entirely predictable, contribute no entropy. Indeed, the amount of entropy extractable from a data stream is inversely related to its compressibility, and information related to periodic events may be compressed very efficiently.
In virtualized, timesliced environments, short-term variation of clock (or timer) jitter is generally negligible. Thus, extractable entropy bandwidth is severely limited. Each timesliced process owns its time intervals (timeslices) exclusively, without interference from other active processes. Within an exclusively owned timeslice, the process perceives an environment dedicated to its execution, and periodic sampling results in negligible variation due to the lack of interference. Indeed, in a typical timesliced environment, minimizing cross-process interference is an explicit design goal, which reduces a significant contribution to latency variance as a side effect.
In addition to the lack of inter-process interference, virtualization, especially clock virtualization, may further limit clock jitter. Virtualization separates observable events from their original sources, possibly reducing the entropy during translation. As an example, timer (or clock) virtualization transforms time snapshots of a real time source, remapping into a different time domain. If the virtualized timer is also quantized, which is typical, less entropy remains extractable than in the original source (as described above, quantization reduces entropy because it improves periodicity, therefore compressibility).
The only reliable, periodic interruption in such systems is related to timeslice-switching. Timeslice-switching occurs as a result of administrative operations during timeslicing and are not predictable to arbitrary precision. Essentially, timeslice switches are unpredictable events.
Unfortunately, timeslice switches, also referred to as "context switches" in this context," are relatively infrequent. Indeed, a range of milliseconds is typical, containing tens of millions of (or considerably more) clock cycles within a timeslice. For this reason, it is impractical to use traditional, single-process entropy extractors in such an environment.

High-frequency entropy extraction from timing jitter

International Business Machines Corporation


A computer-assisted diagnostic (CAD) method and apparatus are described for the enhancement, detection, and classification of suspicious regions in digital x-ray images, with particular emphasis on lung nodule detection using chest x-ray images. An objective is to improve the sensitivity and specificity of detection of suspicious areas such as nodules, while maintaining a low false positive detection rate. A modular CAD technique has been developed to be potentially automatic and to be used as a second-opinion method for lung nodule detection. The method consists of using a plurality of CAD modules to preprocess and enhance image features, including image preprocessing, selective enhancement, segmentation, and feature extraction using a multiresolution/multiorientation wavelet transform and a computationally efficient filter, a 1.5 D circular pattern filter.

1. Field of the Invention
The invention relates to the development of computer-assisted diagnostic (CAD) methods for the analysis of digital x-ray images or gray-scale images generated by other digital sensors. More particularly, the invention relates to the use of CAD methods for the analysis of chest x-rays for the detection of lung nodules.
2. Description of Related Art
The use of computer-assisted diagnostic (CAD) methods has been proposed as a second opinion strategy for various medical imaging applications that include breast screening using digital mammography and lung nodule detection. The goals of the CAD methods are to improve sensitivity by increasing the detection of potentially significant suspicious areas and to improve specificity by reducing false-positive interpretations.
Lung nodule detection using conventional planar chest x-ray film typically does not exceed a detection rate of 70%. Typically x-ray CT is used as a follow-up diagnostic procedure. Although x-ray CT has a greater sensitivity of detection, the detection and classification of all LNs within the 3 D volume (stacked 2 D slices) poses a significant logistical and time-consuming research problem (Giger et al., 1994; Buckley et al., 1995). CAD methods are therefore important for both x-ray chest imaging and x-ray CT. However, until now, CAD methods have been found to result in a high rate of false positives (J. S. Lin et al., 1995). The problems associated with CAD methods for lung nodule detection can be attributed to several factors, including that:
1. Lung nodules typically have small structures having very low image contrast and that are spatially distributed in a nonuniform tissue background and image noise; PA1 2. Lung nodules are often adjacent to or hidden by camouflaging structures such as the rib cage, media sternum, or blood vessels, the ribs and vessels being oriented so that they may be viewed in both lateral and cross-section configuration; and PA1 3. Lung nodule features such as circularity, irregularity, and compactness are often similar to blood vessels viewed end on. PA1 1. Segmentation of suspicious areas; and PA1 2. Differentiation of nodules from lung and chest structures (S. B. Lo et al., 1995). PA1 1. CAD modules that are not automatic (operator dependent) and use fixed parameters that are often image dependent as opposed to methods that adapt, for example, to the image noise; PA1 2. Single-scale filtering methods are used for image enhancement or segmentation that do not optimally differentiate LNs from other clinical features with similar pixel intensity characteristics and do not preserve image details, as opposed to multiresolution or multiorientation wavelet transform methods; and PA1 3. Feature extraction is not optimally performed in all domains (grey level, morphological, texture). PA1 1. Unsharp-masking techniques and gradient generation for edge detection using the Sobel or Roberts operator (Tahoces et al., 1991; Daponte et al., 1988); PA1 2. 2 D surface fitting to correct for nonuniform background (Katsuragawa et al., 1988); PA1 3. Morphological operations to selectively enhance circularity of the LNs (Giger et al., 1990 a); and PA1 4. Generalized unsharp-mashing techniques by generating difference images of an enhanced image (2 D profile matching or Fourier transform methods) and a smoothed image (linear or median filters) (Giger et al., 1990 b; Lo et al., 1993). PA1 1. Image noise suppression using a multistage nonlinear tree-structured filter (TSF) using fixed parameters and/or an adaptive multistage nonlinear filter (AMNF); PA1 2. Selective image enhancement or segmentation of clinical features using, for example, multiresolution (M-channel) tree-structured wavelet transforms (TSWTs), which permit improved differentiation of normal anatomical structures from suspicious lung nodule (LN) areas; PA1 3. Multiorientation (N) directional wavelet transforms (DWTs) for additional directional feature enhancement or extraction of specific structures such as the rib cage or blood vessels; PA1 4. A 1.5-dimensional (1.5 D) filter for additional enhancement and segmentation of suspicious lung nodule areas; and PA1 5. Neural networks (NNs) or fuzzy binary decision trees (FBDTs) for classification using features computed in the pixel intensity, morphological, directional texture, and connectivity domains. PA1 1. Fully operator-independent operation to reduce interobserver variation; PA1 2. The preservation of image details for each CAD module using the unique properties of the wavelet transforms; and PA1 3. Improved feature extraction in the grey level, morphological (shape), directional texture, and connectivity domains.
Various CAD lung nodule detection schemes have been realized with two successive steps:
The former can be considered region-of-interest (ROI) localization of suspicious areas, and the latter as a typical pattern recognition problem. Several algorithms proposed in the literature, such as thresholding, 2 D profile matching, and morphological operations, use intensity characteristics on a 2 D matrix and are sensitive to overlapping lung structures, which often appear as stronger signals than nodules in the image (S. B. Lo et al., 1993; M. L. Giger et al., 1990 b). Two-dimensional linear filtering also suffers from high computation cost and a lack of multiscale analysis. A general schematic diagram for the current method of detecting lung nodules is presented in FIG. 1.
Previous methods incorporating CAD modules (Lin et al., 1996; Giger et al., 1994) have limitations that degrade the sensitivity and specificity of LN detection, including:
Previously disclosed image-enhancement methods have included:
Image segmentation methods include global thresholding, adaptive or local thresholding techniques based on pixel intensity histograms and trained classifiers to identify lung fields or asymmetry in chest images (Duryea et al., 1995; McNitt-Gray et al., 1994; Armato et al., 1994).
Feature extraction has proved to be a very difficult task in order to differentiate LNs from end-on vessels or recognize LNs located near rib cage crossings. Methods include region growing to generate various grey-level and morphological features (Matsumoto et al., 1992; Wu et al., 1994). Classification methods used have included discriminant analysis, rule-based schemes, and trained neural networks (Wu et al., 1994; Lo et al., 1993, 1995; Lin et al., 1996). These classification methods aim at reducing the false positive rate in the suspicious area segmentation, the sensitivity of which has been on the order of 70% with a large false positives (FPs) to image ranging from 4 to 12. It is reported that these methods can reduce the false positive rate. Because of the differences and limitation of the databases used, it is difficult to evaluate and compare quantitatively these CAD methods.
Wavelet theory has recently been developed as a unifying framework. Multiresolution signal processing, which is used in computer vision, subband coding developed for image/speech compression, and wavelet series expansion as developed in applied mathematics, has recently been recognized as a different aspect of signal processing theory (Rioul et al., 1991). The application of wavelet theory in mammogram processing includes feature enhancement (Laine et al., 1995), detection of microcalcifications (Qian et al., 1995 b), differentiation of mass from normal tissue (Karssemeijer, 1994). For example, Laine et al. (1995) used linear, exponential, and weighted functions successfully for the modification of the coefficients of dyadic wavelet transform for improving the local feature visibility. This work is focused on image enhancement for improved visual diagnosis, as opposed to improving feature extraction.

Computer-assisted method and apparatus for the detection of lung nodules


A composite material having inherent microbicidal activity is herewith described. The microbicidal composite material comprises of a first layer having a first predefined thickness and a first predefined stitch/thread density; a second layer having a second predefined thickness and a second predefined stitch/thread density; an intermediate layer having a third predefined thickness and a third predefined stitch/thread density, wherein the intermediate layer is sandwiched between the first layer and the second layer, and where the intermediate layer is connected to the first layer and the second layer to form a three dimensional structure, and where each layer in the three dimensional structure has a plurality of apertures. Further, at least one layer in the three dimensional structure comprises at least one of microfibers and nanofibers having augmented surface moieties, wherein the augmented surface moieties allow for binding of a microbicidal agent to impart the inherent microbicidal activity.

The advancement in technology has led to a considerable research being conducted on the application of microbicidal agents on fibres and fabrics, that would effectively retard the growth of various microorganisms. For example, sanitary wipes used for cleaning environmental, food contact surfaces, and personal and health care applications incorporate various microbicidal agents on its fabric to exhibit sanitizing and microbicidal properties. Although several new drugs have now emerged for the treatment of drug resistant infections, the microorganisms that are treated with these new drugs are becoming increasingly drug resistant resulting in the creation of superbugs. There is emerging need to develop a mechanism to kill the microbes commonly referred as pathogens by techniques that do not cause drug resistance in them.


In an arrangement for calibrating a network analyzer for on-wafer measurement, for microwave circuits on a metallic base plate, of a wafer measurement means using calibration standards constructed in coplanar line technology on a calibration substrate. The calibration substrate is spaced above the metallic base plate.

The invention relates to an arrangement for calibrating a network analyzer for on-wafer measurement at integrated microwave circuits on a metallic base plate of a wafer measurement installation using calibration standards constructed in coplanar line technology on a calibration substrate.
In the manufacture of integrated microwave circuits on semiconductor wafers, the circuits must often be electrically measured even before the division of the wafer (on-wafer measurement). For this purpose, special wafer measurement means (wafer samplers) are known, which have a metallic base plate (chuck) having vacuum openings distributed over the surface, which are connected with a partial vacuum means. The wafer is thus held on this flat base plate by a partial vacuum. Above the base plate, mounts are provided for measurement prods, and measurement points on the clamped-on wafer selected in this way can be driven and contacted by means of precise displacement of the base plate in the X, Y and Z direction (see e.g. the data sheet for the wafer samplers PA200HF or PM5HF of the Su.beta. company, or measurement prods according to U.S. Pat. No. 4,871,964).
For on-wafer measurements of this sort at microwave circuits, vectorial network analyzers are used, in which what is known as a system error correction is required before a measurement. Calibration measurements are carried out according to known calibration methods at several calibration standards whose electrical characteristic quantities are known in whole or in part. Correction data is obtained from these measurements via specific computing methods, which data is subsequently taken into account in the actual object measurement for error correction (e.g. see U.S. Pat. No. 4,982,164).
For the calibration of such network analyzers for on-wafer measurement, calibration standards have proven useful that are fashioned in coplanar line technology, e.g. as a coplanar line, a coplanar double-band line or an asymmetrical coplanar lie on a calibration substrate (coplanar striplines e.g. according to Zinke/Brunswick, Hochfrequenztechnik 1, 5.sup.th ed., p. 157 or 169-176). Coplanar striplines have low dispersion and have, over a large bandwidth, a small change in the wave resistance, as well as a low frequency dependence of the electrical length. Such calibration standards in coplanar stripline technology are for example manufactured on a substrate from sapphire or aluminum oxide in thin film technology. A calibration standard particularly suited for such purposes, as offered for example by the Rosenberger company (calibration substrate RCPW-LMR in produce publication TI 020/18.04.96/E1.0) uses two short coplanar stripline segments (LL) formed on a calibration substrate, with a known characteristic impedance and two short-circuit beams (R). Before the actual on-wafer object measurement, this calibration substrate is set on the base plate of the wafer measurement means, and by means of the measurement prods, which are connected with the network analyzer, the mentioned calibration measurements, e.g., according to the LLR method, are carried out successively at the calibration standards L, L and R.
In microwave circuits fashioned on semiconductor substrates (wafers), only a small part of the substrate thickness (about 500 .mu.m) up to a depth of about 10 .mu.m has an influence on the electrical behavior of the circuit. The measurement results in on-wafer measurement are thus not adversely affected by the metallic base plate during the actual object measurement. However, it has turned out that in calibration measurement, considerable measurement errors occur especially at higher frequencies in the GHz range, during measurement of the calibration standard constructed in coplanar line technology. As a consequence correction errors occur during object measurement.

Arrangement for calibrating a network analyzer for on-wafer measurement at integrated microwave circuits

Rosenberger Hochfrequenztechnik GmbH & Co.


In a memory cell array in a hierarchical bit line mode in which sub-arrays in a virtual ground line mode are arranged in a column direction, data is read out at high speed, preventing fluctuation in wiring capacity of a main bit line. In each sub-array, one of a source electrode or a drain electrode in each of the memory cells in the same column is connected to a common first bit line, and the other thereof is connected to a second bit line. The first bit lines of one half of the sub-arrays positioned in the same column are connected to the first main bit line through selection transistors and the second bit lines thereof are connected to the second main bit line through selection transistors, and the first bit lines of the other half of the sub-arrays positioned in the same column are connected to the second main bit line through selection transistors and the second bit lines thereof are connected to the first main bit line through selection transistors.

1. Field of the Invention
The present invention relates to a semiconductor memory device and more particularly, it relates to a semiconductor memory device comprising a memory cell array in a virtual ground line mode which employs a memory cell array structure in a hierarchical bit line mode comprising a main bit line and a sub-bit line.
2. Description of the Related Art
Conventionally, there is a mode in which a memory cell is read out using a bit line and a virtual ground line in a non-volatile semiconductor memory device such as a mask ROM (mask programmable read only memory) and a flush memory (refer to Japanese Unexamined Patent Publication No. 10-11991, and Japanese Unexamined Patent Publication No. 3-179775, for example). Hereinafter, a description will be made using a memory cell of a mask ROM having a simple memory cell structure.
FIG. 5 is a conceptual view showing a reading mode using the virtual ground line. According to the mode, bit lines and virtual ground line are arranged alternately in a column direction, word lines are arranged in a row direction, a memory cell transistor comprising an MOSFET is arranged between the adjacent bit line and the virtual ground line, and a drain electrode and a source electrode of the memory cell transistor are connected to the bit line and the virtual ground line, respectively, in a memory cell array in which memory cells are arranged in the row direction and the column direction in the shape of a matrix. In addition, a gate electrode of the memory cell transistor is connected to the word line. The plurality of memory cell transistors are connected to one word line, so that area efficiency of the memory cell is raised. According to the memory cell transistor, a threshold value is set in a manufacturing stage so that it becomes either a transistor having a high threshold value (OFF transistor which has a threshold value higher than a high-level potential of the word line connected to the gate electrode and which is turned off regardless of a word line potential), or a transistor having a low threshold value (ON transistor which is turned on when the word line potential becomes higher than the threshold value) (binary data is written in each memory cell). At the time of reading out, the word line and the bit line and the virtual ground line connected to the transistor to be read out are selected, the selected bit line is charged to a predetermined potential, the selected virtual ground line is connected to the ground potential, and the selected word line is brought to a high level. A difference in current of the ON transistor and the OFF transistor in this state is detected by the sense circuit and the binary data stored in the memory cell is determined.
In general, as a mode in which the data stored in the memory cell array is read out at high speed in a high-capacity semiconductor memory device, the hierarchical bit line mode is well-known (refer to Japanese Unexamined Patent Publication No. 3-179775, for example). According to the memory cell array in the hierarchical bit line mode, the memory cell array is divided into a plurality of blocks in the column direction, a bit line in each block is set as a sub-bit line (called a local bit line also), and the plurality of sub-bit lines in the blocks are collectively connected to a main bit line (called a global bit line also) through block selection transistors. When the memory cell is selected, the main bit line is selected and then the sub-bit line connected to the selected main bit line is selected by the block selection transistor. Hereinafter, a reading operation in the hierarchical bit line mode will be described with reference the drawings. FIG. 6 shows a constitution example of a memory cell array using the hierarchical bit line mode. In addition, according to the memory cell array illustrated in FIG. 6, a virtual ground line has the same hierarchical structure as that of the bit line.
A memory cell group sandwiched by control signals BLKs 1 and 2 and BLKs 3 and 4 of block selection transistors and having word lines WL0 to WLn connected to gate electrodes is called the block. In order to raise area efficiency of the memory cell, a plurality (two in FIG. 6) of sub-bit lines SBi (i=even number) are connected to a main bit line MBi (i=even number) through a block selection transistor BK-1 or the like in the block. When the memory cell is accessed through the main bit line in the block, a junction capacity induced by a diffusion layer of a source or a drain of the memory cell transistor connected to the main bit line can be considerably reduced, so that readout can be performed at high speed.
As shown in FIG. 6, the block selection transistor BK1-1 or the like is selected by a bank selection line BLK1-1 or the like. The main bit line MB2 or the like is connected to a sub-bit line SB 4 or the like through the block selection transistor BK1-1. The main bit line MBi (i=even number) of the memory arrays is connected to a charging circuit 22, a sense circuit 23 and the like through a block selection circuit 20 which selects the block to be read out and a charging and grounding selection circuit 21. A main virtual ground line MBi (i=odd number) is connected to the charging circuit 22 or the ground line or the like through the block selection circuit 20 and the charging and grounding selection circuit 21. The charging and grounding selection circuit 21, the charging circuit 22, the sense circuit 23 are connected to the plurality of block selection circuits 20 in some cases.
A readout operation of the memory cell array circuit shown in FIG. 6 will be described. Here, it is assumed that a memory cell transistor M4 is selected and read out. The word line WL0 connected to a gate of the transistor M4 is brought to a high level and the other word lines (WLn) are brought to a low level. In order to turn on the block selection transistor BK1-1, a control signal BLK1 of the block selection transistor is brought to the high level and in order to turn on a block selection transistor BK3-2, a control signal BLK3 is brought to the high level and other control signals BLK2 and BLK4 are brought to the low level. Thus, a current path (MB2)-(BK1-1)-(SB4) from the main bit line to the memory cell and a current path (SB5)-(BK3-2)-(MB3) from the memory cell to the main virtual ground line are formed in the transistor M4. In the case the transistor M4 is the ON transistor, when the BSEL2 is brought to the high level, VGSEL1 is brought to the high level, BLOCKSEL1 is brought to the high level, BSEL1 is brought to the low level, and VGSEL2 is brought to the low level, the selected main bit line MB2 becomes a charged potential and the selected main virtual ground line MB3 becomes the ground potential, so that a current flows through a path (MB2)-(BK1-1)-(SB4)-(M4)-(SB5)-(BK3-2)-(MB3). The memory cell transistor M4 is determined to be the ON transistor when the sense circuit 23 connected to the selected main bit line MB2 through the transistor TR1 of the block selection circuit 20 and the transistor TR2 of the charging and grounding selection circuit 21 detects a change and the like in charged potential of the selected main bit line MB2.
However, in a case where the memory cell transistor M4 is the OFF transistor and the transistors M3, M2, M1, M0 and the like of the non-selected memory cells in the same row as the transistor M4 are ON transistors, since the word line WL0 which is a gate line of each transistor is common, even when the transistor M4 is the OFF transistor, a current path passing through the transistors M3, M2 and M1 is formed. That is, when the selected main bit line MB2 becomes the charged potential, a transitional current which charges parasitic capacity of the bit line or the virtual ground line connected to each memory cell flows through (MB2)-(BK1-1)-(SB4)-(M3)-(M2)-(M1) . . . . The current flowing in this current path is tentatively called a detour outflow current. As a result, although the transistor M4 to be read out is the OFF transistor, the current path from the selected main bit line to each bit line and the virtual ground line is formed as if it is the ON transistor, so that error readout is generated or a margin of the readout operation is lowered. In order to prevent such error readout operation, a method in which a non-selected bit line and a non-selected virtual ground line are charged to a predetermined charged potential is conventionally employed.
According to the illustrated circuit in FIG. 6, a non-selected main bit line MB0 and a non-selected main virtual ground line MB1 are brought to the charged potential. The sub-bit line SB0 and the sub-virtual ground line SB 1 become the charged potential through the block selection transistor. Thus, even when the memory cell transistors M3, M2, M1, M0 and the like are the ON transistors, the detour outflow current is not generated when the memory cell transistor M4 is read out, so that a difference in potential change of the selected main bit line MB2 appears when the transistor M4 is the ON transistor and when it is the OFF transistor. As a result, the memory cell can be stably read out.
However, according to the mode in which the non-selected bit line and the non-selected virtual ground line are charged to prevent the detour outflow current, the readout operation margin is lowered when the memory cell transistor to be read out is the ON transistor.
Consequently, as shown in FIG. 7, the applicant of this application separately applies for a patent regarding a semiconductor memory device in which an influence of the detour outflow current is considerably reduced and a readout operation margin is prevented from being lowered by dividing a memory cell array into sub-arrays in columns every four memory cells, so that large capacity can be implemented and an operation can be performed at high speed (U.S. patent Ser. No. 10/769,381). According to a constitution shown in FIG. 7, one sub-array comprises five sub-bit lines LB1 to LB5 in which two of them function as bit lines or virtual ground line and three of them function as bit lines or the virtual ground line. In addition, one sub-array comprises two main bit lines GBA and GBB, odd-numbered sub-bit lines LB1, LB3 and LB5 are connected to the main bit line GBA through bit line selection transistor BK1, BK3 and BK5, respectively, and even-numbered sub-bit lines LB2 and LB4 are connected to the main bit line GBB through bit line selection transistor BK2 and BK4, respectively, and when one of the bit line selection transistors BK1,BK3 and BK5,and one of the bit line selection transistors BK2 and BK4 are turned on, one odd-numbered sub-bit line and one even-numbered sub-bit line are connected to the main bit lines GBA and GBB, respectively, so that memory cells in one column are selected in the sub-array.
According to the above hierarchical bit line mode, since the memory cell array is divided into the plurality of blocks in the column direction, the plurality of sub-arrays (blocks) shown in FIG. 7 are arranged in (even-number normally) columns direction, so that the memory cell array is hierarchically constituted. FIG. 8 simply shows a case where two sub-arrays are arranged in the column direction. In this case, when it is assumed that the number of sub-arrays in the column direction is 2n, the total number of the bit line selection transistor BK1, BK3 and BK5 connected to the main bit line GBA is 6n and the total number of the bit line selection transistor BK2 and BK4 connected to the main bit line GBB is 4n.
Therefore, when the number of the columns of the memory cells in the sub-array is four, a total junction capacity of the bit line selection transistors connected to the main bit line GBA is 1.5 times as much as a total junction capacity of the bit line selection transistors connected to the main bit line GBB, so that there is provided a difference in junction capacity between the main bit lines GBA and GBB as a difference in each wiring capacity. Here, when it is assumed that the number of columns of the memory cells in the sub-array is 2k in general, the number of the bit line selection transistors to select the odd-numbered sub-bit lines is k+1 and the number of the bit line selection transistors to select the even-numbered sub-bit lines is k, so that a ratio of the junction capacity of the main bit line GBA to that of the main bit line GBB is (k+1)/k in the wiring capacities. Thus, when the number of the columns of the memory cells in the sub-array is small, imbalance of the wiring capacities of the main bit lines GBA and GBB becomes noticeable.
Meanwhile, when the memory cell in the sub-array is perfectly symmetric between the source and the drain, since one of the odd-numbered or the even-numbered sub-bit line is allocated to the bit line to read out the data and the other is allotted to the virtual ground line fixedly, one of the main bit lines GBA and GBB becomes the main bit line to read out the data constantly and the other becomes the main bit line as the virtual ground line, so that the unbalance of the wiring capacities does not affect the reading operation. That is, when there is no problem characteristically if either diffusion region of each memory cell becomes the source or the drain electrode, the source electrodes are connected to each other and the drain electrodes are connected to each other in the adjacent memory cells in the row direction, and each drain electrode is connected to the bit line (even-numbered sub-bit line, for example) and each source electrode is connected to the virtual ground line (odd-numbered sub-bit line, for example).
However, when the memory cell transistor has an asymmetric structure in the source and the drain, since it is generally considered that fluctuation in cell characteristics between the memory cells can be prevented by making the asymmetric directionality face the same direction in the memory cell array, one source electrode is connected to the other drain electrode in the adjacent two memory cells in the row direction, and the bit line connected to the memory cell in a certain column becomes the virtual ground line of the adjacent other memory cell in the row direction. Therefore, both main bit lines GBA and GBB can be the main bit line to read out the data depending on the column position of the selected memory cell.
In addition, even when the memory cell transistor is symmetric between the source and the drain, in a case of a memory cell which can store 2-bit data for example, and a multi-level memory cell which can distinctively read each bit depending on the current flow direction, since both sub-bit line connected to the source side of the memory cell transistor and sub-bit line connected to the drain thereof can be the bit line to read out the data, both two main bit lines GBA and GBB can be the main bit lines to read out the data depending on the data stored in the memory cell similar to the above.
As an example of the multi-level memory cell, there is a memory cell comprising a sidewall memory element shown in FIG. 3. The sidewall memory element is described in detail in the international publication pamphlet of the PCT international application by the applicant of this application (International Publication WO03/044868). As shown in FIG. 3(A), a sidewall memory element 100 comprises a gate electrode 104 formed on a semiconductor layer 102 through a gate insulation film 103, a channel region 101 arranged under the gate electrode 104, diffusion regions 105 and 106 arranged on both sides of the channel region 101 and having a conductivity type opposite to that of the channel region 101, and memory functioning bodies 107 and 108 formed on both sidewalls of the gate electrode 104 and having a function to maintain electric charges. FIG. 3(B) shows symbols of the sidewall memory element. Referring to FIG. 3(B), nodes G, S, D are the gate electrode 104, the source electrode 105, the drain electrode 106, respectively, and m1 and m2 are the memory functioning bodies.
In order to write data in the memory functioning body m1, a high voltage is applied to the node G, so that the node S becomes at high voltage and the node D is at the GND level and a current flows from the node S to the node D. Thus, hot electrons are generated and inputted to the memory functioning body m1 to write the data. When data is to be written in the memory functioning body m2, the voltage conditions of the node S and the node D are reversed, so that a current flows from the node D to the node S.
Next, a reading operation of the information written in the memory functioning body will be described. When the information written in the memory functioning body m1 is read out, 3V is applied to the node G, for example, 1.2V is applied to the node D and the node S is brought to the GND level. At this time, when electrons are not stored in the memory functioning body m1, the drain current is easily flow. Meanwhile, when the electrons are stored in the memory functioning body m1, an inversion layer is not easily formed in the vicinity of the memory functioning body m1 and the drain current does not easily flow. Thus, the information stored in the memory functioning body m1 can be read out by detecting levels of the drain current. At this time, since the vicinity of the node D is pinched off, a fact whether the electric charges are stored in the memory functioning body m2 or not does not affect the drain current. In addition, when the information of the memory functioning body m2 is read out, the voltage conditions of the node S and the node D are reversed. Thus, one memory element stores two-bit information, which can be read out.
As described above, in the case of the memory cell array in the hierarchical bit line mode comprising multi-level memory cells which can be read out by discriminating stored bits by the memory cell having the asymmetric structure or the direction of the readout current, when a circuit mode in which data is read out by charging and discharging the main bit line on the data readout side is employed for high-speed reading, the difference (unbalance) in junction capacity in the wiring capacities between the main bit lines GBA and GBB considerably affects the fluctuation in charging and discharging time of the main bit line. That is, a period of data readout is controlled by the memory cell on the side of the main bit line having a large wiring capacity, that it, a long charging and discharging time, which is a cause of a delay in access time for the data readout.
A description will be made of a readout operation when a memory cell comprises the above sidewall memory element and the like and there is provided a memory cell array structure in a conventional hierarchical bit line mode with reference to FIG. 9. Referring to FIG. 9, it is assumed that a current in the transistor A flows from the right to the left. A sub-bit line connected to the right side of the transistor A is set as the bit line B to read out the data, and a sub-bit line connected to the left side thereof is set as the virtual ground line C. The sub-bit line B is connected to a main bit line E through a selection transistor D, and a virtual ground line C is connected to a main bit line G through a selection transistor F.
At the time of readout, the main bit line E is charged to a predetermined voltage, the transistor D connected thereto is turned on to charge the sub-bit line B, the selected main bit line G is brought to the ground potential, the transistor F connected thereto is turned on and the virtual ground line C is brought to the ground potential. Then, a selected word line H is brought to the high level. In this state, a difference in current amount of the transistor A to be read out is detected by a sense circuit to determine the data of the memory cell. While the main bit line E is charged in the reading mode, according to the conventional hierarchical bit line mode, when it is assumed that the number of the sub-arrays (blocks) is 2n, the number of the selection transistors D connected to the main bit line E to read out the data is 4n and the number of the selection transistor F connected to the main bit line G to be grounded is 6n.
Next, a case the readout is performed when the current in the transistor A flows from the left side to the right side is considered. At this time, the main bit line G is charged, which is totally contrary to the above case where the current in the transistor A flows from the right side to the left side. In this case, the number of the selection transistors connected to the main bit line G to read out the data becomes 6n which is 1.5 times as many as the above 4n. This is because the total of the junction capacity is different, which means that the charging and discharging time of the main bit line in the readout operation depends on the direction of the readout current. In addition, a difference between the bit line current of the selected memory cell and a bit line current of a reference cell is detected by the sense circuit, and a time until the difference appears significantly depends on the direction of the readout current. That is, since the totals of the junction capacities of the selection transistors contained in the wiring capacities between two main bit lines are different, the readout time becomes different.


A microfluidic storage device for pre-storing a fluid includes a first substrate, a second substrate, and a membrane. The first substrate has a recess formed in a first surface. The second substrate has a second surface formed to form fit with the first surface at least in subregions outside the recess. The membrane is arranged between the first and second substrates and is in contact with the first and second surfaces in regions outside the recess. In the region of the recess, the membrane is configured to line the recess so that a volume region inside the recess, between the membrane and the second substrate, can be filled with the fluid. The first substrate, the membrane, and the second substrate are configured to be joined together at least in subregions, outside the recess, in which the membrane is in contact with the first and second surfaces.

The disclosure relates to a microfluidic storage device for pre-storing of fluid, to a method for its production and to a use thereof.
Lab-on-a-chip (LOC) systems are used in order to allow laboratory processes, which have previously been carried out by hand, to take place in an automated fashion in an integrated system. To this end, an LOC system comprises channels and cavities which, for example, are formed as mixing cavities or offer the possibility of allowing biochemical reactions to take place in the predetermined miniaturized volume region. The fluids or liquids necessary for this are either supplied from the outside via fluidic interfaces or pre-stored in the LOC system. Pre-storage makes it possible, inter alia, for the entire microfluidic system to remain closed and for a contamination risk to be reduced.
LOC systems often consist of a polymer layer system which is joined together during the construction or production process. For example, laser welding is used as the joining technology. During laser welding, a laser beam passes through a transparent assembly partner onto a light-absorbing assembly partner, the materials at the interface of the assembly partners being liquefied and mixing of the materials and a material-fit connection taking place. During the joining process, a force, or a compression pressure, may be exerted on the layer structure in order to ensure good contact between the assembly partners. To this end, the layer structure to be assembled is conventionally clamped between a base plate and a transparent pressure plate, for example a glass plate, so that the laser radiation can pass through the pressure plate, for example the glass plate, onto a surface region of the light-absorbing assembly partner.
The previously used possibilities for pre-storage of fluids or liquids in polymer layer systems, for instance LOC systems, include blister packages, integrated in the system, for pre-storing the fluids or reagents. A first example relating to this is an LOC system which is described in the article "Automated Closed-Vessel System for in Vitro Diagnostics Based on Polymerase Chain Reaction" by J. B. Findlay et al., Clinical Chemistry, Vol. 39 (9), pages 1927-1933 (1993). This LOC system comprises a multiplicity of storage vessels consisting of bubble-shaped blister containers. These containers are unclosed, however, which greatly restricts the possibilities for practical use. A second example relating to this is mentioned in the article "Clinical applications of a programmable nano-bio-chip" by J. V. Jokerst et al., Clinical Laboratory International, Vol. 33 (6), pages 24-27 (November 2009), relating to an exemplary commercially available nano-bio-chip from the company LabNow. In this case, burst valves are integrated in the system (microfluidic chip) in order to release the reagents from the blister packages, although it is difficult in terms of manufacturing technology to produce these valves with high process reliability.
The known possibilities for pre-storing fluids or liquids in polymer layer systems furthermore include dispensing fluids into previously formed cavities in a polymer layer and subsequently joining together the layer structure, for example by means of laser beam transmission welding, as described for instance in the dissertation (Ph.D. thesis) "Multilayer Pressure Driven Microfluidic Platform—μFLATLab" by J. Rupp, which was submitted to the technical faculty of Albert-Ludwigs University in Freiburg im Breisgau on 24, May 2011 (see http://www.freidok.uni-freiburg.de/volltexte/8374/pdf/111129_Rp_Dissertation_actual.pdf).

Microfluidic storage device for pre-storing of fluid, method for its production and a use thereof