This is a guide catheter assembly. The guide catheter assembly is used to cooperate with a micro-catheter in accessing a tissue target within the body, typically a target which is accessible through the vascular system. Central to the invention is the use of a braided metallic reinforcing member, situated within the catheter body in such a way to create a catheter section having an exceptionally thin wall, controlled stiffness, and high resistance to kinking. The catheter has a terminal segment which is not supported by a braid and the polymer making up that terminal segment is either the same hardness as is the polymer making up the outer covering of next more adjacent section or, preferably, the polymer is harder than is the polymer making up the segment located just proximally of that terminal segment. The braid may have a single pitch or may vary in pitch along the axis of the catheter or catheter section. The braided reinforcing member typically is embedded in a flexible outer tubing member. An inner tubing member is lubricious.

Catheters are increasingly used to access remote regions of the human body and, in doing so, delivering diagnostic or therapeutic agents to those sites. In particular, catheters which use the circulatory system as the pathway to these treatment sites are especially practical. Catheters are also used to access other regions of the body, e.g., genito-urinary regions, for a variety of therapeutic and diagnostic reasons. One such treatment of circulatory system diseases is via angioplasty (PCA). Such a procedure uses catheters having balloons on their distal tips. It is similarly common that those catheters are used to deliver a radio-opaque agent to the site in question prior to the PCA procedure to view the problem prior to treatment.
Often the target which one desires to access by catheter is within a soft tissue such as the liver or the brain. These are difficult sites to reach. The catheter must be introduced through a large artery such as those found in the groin or in the neck and then be passed through ever-narrower regions of the arterial system until the catheter reaches the selected site. Often such pathways will wind back upon themselves in a multi-looped path. These catheters are difficult to design and to utilize in that they must be fairly stiff at their proximal end so to allow the pushing and manipulation of the catheter as it progresses through the body, and yet must be sufficiently flexible at the distal end to allow passage of the catheter tip through the loops and increasingly smaller blood vessels mentioned above and yet at the same time not cause significant trauma to the blood vessel or to the surrounding tissue. Further details on the problems and an early, but yet effective, way of designing a catheter for such a traversal may be found in U.S. Pat. No. 4,739,768, to Engelson. These catheters are designed to be used with a guidewire. A guidewire is simply a wire, typically of very sophisticated design, which is the "scout" for the catheter. The catheter fits over and slides along the guidewire as it passes through the vasculature. Said another way, the guidewire is used to select the proper path through the vasculature with the urging of the attending physician and the catheter slides along behind once the proper path is established.
There are other ways of causing a catheter to proceed through the human vasculature to a selected site, but a guidewire-aided catheter is considered to be both quite quick and somewhat more accurate than the other procedures. One such alternative procedure is the use of a flow-directed catheter. These devices often have a small balloon situated on the distal end of the catheter which may be alternately deflated and inflated as the need to select a route for the catheter is encountered. Flow-directed catheters are rarely used as guide catheters.
This inventive catheter is used to direct a smaller catheter from a body entry site to a site intermediate to the treatment site. The use of this catheter extends the site at which smaller catheter first enters the bloodstream.
This invention is an adaptable one and may be used in a variety of catheter formats. The invention utilizes the concept of combining one or more polymeric tubes with a metallic braid comprising wires or ribbons of a stainless steel or super-elastic alloy. The construction technique has the benefit of producing catheter sections having small overall diameters but with exceptional strength, resistance to kinking, and recovery from kinking (even in vivo) should such kinking occur.
The use of braids in a catheter body is not a novel concept. Typical background patents are discussed below. However, none of these documents have used our concept to produce a catheter which has the physical capabilities of the catheter of this invention.
Multi-Wrap Catheters
There are a number of catheters discussed in the literature which utilize catheter bodies having multiply-wrapped reinforcing material. These catheters include structures having braided bands or ones in which the spirally wound material is simply wound in one direction and the following layer or layers are wound in the other.
Crippendorf, U.S. Pat. No. 2,437,542, describes a "catheter-type instrument" which is typically used as a ureteral or urethral catheter. The physical design is said to be one having a distal section of greater flexibility and a proximal section of lesser flexibility. The device is made of intertwined threads of silk, cotton, or some synthetic fiber. It is made by impregnating a fabric-based tube with a stiffening medium which renders the tube stiff yet flexible. The thus-plasticized tubing is then dipped in some other medium to allow the formation of a flexible varnish-like layer. This latter material may be a tung oil base or a phenolic resin and a suitable plasticizer.
Similarly, U.S. Pat. No. 3,416,531, to Edwards, shows a catheter having braiding-edge walls. The device further has additional layers of other polymers such as TEFLON and the like. The strands found in the braiding in the walls appear to be threads having circular cross-sections. The device is shown to be fairly stiff in that it is designed so that it may be bent using a fairly large handle at its proximal end.
U.S. Pat. No. 3,924,632, to Cook, shows a catheter body utilizing fiberglass bands wrapped spirally for the length of the catheter. As is shown in FIG. 2 and the explanation of the Figure at column 3, lines 12 and following, the catheter uses fiberglass bands which are braided, that is to say, bands which are spiraled in one direction cross over and under bands which are spiraled in the opposite direction. Additionally, it should be observed that FIG. 3 depicts a catheter shaft having both an inner lining or core 30 and an outer tube 35.
U.S. Pat. No. 4,425,919, to Alston, Jr. et al., shows a multilayered catheter assembly using multi-stranded flat wire braid. The braid 14 in FIG. 3 further covers an interior tubing or substrate 12.
U.S. Pat. No. 4,484,586 shows a method for the production of a hollow, conductive medical tubing. The conductive wires are placed in the walls of hollow tubing specifically for implantation in the human body, particularly for pacemaker leads. The tubing is preferably made of an annealed copper wire which has been coated with a body-compatible polymer such as a polyurethane or a silicone. After coating, the copper wire is wound into a tube. The wound substrate is then coated with still another polymer to produce a tubing having spiral conducting wires in its wall.
A document showing the use of a helically wound ribbon of flexible material in a catheter is U.S. Pat. No. 4,516,972, to Samson. This device is a guiding catheter and it may be produced from one or more wound ribbons. The preferred ribbon is a polyaramid material known as Kevlar 49. Again, this device is a device which must be fairly stiff. It is a device which is designed to take a "set" and remain in a particular configuration as another catheter is passed through it. It must be soft enough so as not to cause substantial trauma, but it is certainly not for use with a guidewire.
U.S. Pat. No. 4,806,182, to Rydell et al, shows a device using a stainless steel braid imbedded in its wall and having an inner layer of a polyfluorocarbon. The process also described therein is a way to laminate the polyfluorocarbon to a polyurethane inner layer so as to prevent delamination.
U.S. Pat. No. 4,832,681, to Lenck, shows a method and apparatus useful for artificial fertilization. The device itself is a long portion of tubing which, depending upon its specific materials of construction, may be made somewhat stiffer by the addition of a spiral reinforcement comprising stainless steel wire.
U.S. Pat. No. 4,981,478, to Evard et al., discloses a multi-sectioned or composite vascular catheter. The interior section of the catheter appears to have three sections making up the shaft. The most interior (and distal) section, 47, appears to be a pair of coils 13 and 24 having a polymeric tubing member 21 placed within it. The next, more proximal, section is 41, and FIG. 4 shows it to be "wrapped or braided" about the next inner layer discussed just above. The drawing does not show it to be braided but, instead, a series of spirally wrapped individual strands. Finally, the outermost tubular section of this catheter core is another fiber layer 49, of similar construction to the middle section 26 discussed just above.
Another catheter showing the use of braided wire is shown in U.S. Pat. No. 5,037,404, to Gold et al. Mention is made in Gold et al of the concept of varying the pitch angle between wound strands so to result in a device having differing flexibilities at differing portions of the device. The differing flexibilities are caused by the difference in pitch angle. No mention is made of the particular uses to which the Gold et al. device may be placed.
U.S. Pat. No. 5,057,092, to Webster, Jr., shows a catheter device used to monitor cardiovascular electrical activity or to electrically stimulate the heart. The catheter uses braided helical members having a high modulus of elasticity, e.g., stainless steel. The braid is a fairly complicated, multi-component pattern shown very well in FIG. 2.
U.S. Pat. No. 5,176,660 shows the production of catheters having reinforcing strands in their sheath wall. The metallic strands are wound throughout the tubular sheath in a helical crossing pattern so to produce a substantially stronger sheath. The reinforcing filaments are used to increase the longitudinal stiffness of the catheter for good "pushability". The device appears to be quite strong and is wound at a tension of about 250,000 lb./in..sup.2 or more. The flat strands themselves are said to have a width of between 0.006 and 0.020 inches and a thickness of 0.0015 and 0.004 inches.
Another variation which utilizes a catheter wall having helically placed liquid crystal fibrils is found in U.S. Pat. No. 5,248,305, to Zdrahala. The catheter body is extruded through an annular die, having relatively rotating inner and outer mandrel dies. In this way, the tube containing the liquid crystal polymer plastic-containing material exhibits a bit of circumferential orientation due to the rotating die parts. At column 2, line 40 and following, the patent suggests that the rotation rate of the inner and outer walls of the die may be varied as the tube is extruded, with the result that various sections of the extruded tube exhibit differing stiffnesses.
U.S. Pat. No. 5,217,482 shows a balloon catheter having a stainless steel hypotube catheter shaft and a distal balloon. Certain sections of the device shown in the patent use a spiral ribbon of stainless steel secured to the outer sleeve by a suitable adhesive to act as a transition section from a section of very high stiffness to a section of comparatively low stiffness.
Japanese Kokai 05-220,225, owned by the Terumo Corporation, describes a catheter in which the torsional rigidity of the main body is varied by incorporating onto an inner tubular section 33, a wire layer which is tightly knitted at the proximal section of the catheter and more loosely knitted at a midsection.
Single-Layer Reinforced Catheters
There are a variety of catheters which, unlike the devices discussed above, utilize but a single layer of reinforcing material.
For instance, U.S. Pat. No. 243,396 to Pfarre, patented in June of 1881, shows the use of a surgical tube having a wire helix situated within the tube wall. The wire helix is said to be vulcanized into the cover of the device.
U.S. Pat. No. 2,211,975, to Hendrickson, shows a similar device also comprising a stainless steel wire 15 embedded in the inner wall of a rubber catheter.
U.S. Pat. No. 3,757,768, to de Toledo, shows a "unitary, combined spring guide-catheter that includes an inner wall portion formed as a continuous helical spring with the helices in contact with each other and an outer wall portion formed from an inert plastic material enclosing the spring in such a manner as to become firmly bonded to the spring while having its outer surface smooth". There is no suggestion to separate the windings of the coil in any fashion.
U.S. Pat. No. 4,430,083 describes a catheter used for percutaneous administration of a thrombolytic agent directly to a clot in a coronary artery. The device itself is an elongated, flexible tube supported by helically wound wire having a specific cross-sectional shape. The wire is wound into a series of tight, contiguous coils to allow heat shrinking of tubing onto the outside of the wire of the shape of the outer surface of the wire as wound into the helix provides the heat-shrunk tubing with footing for a tight fit.
U.S. Pat. No. 4,567,024, to Coneys, shows a catheter which employs a set of helical strips within the wall of the catheter. However, the helical strips are of a radio-opaque material, e.g., fluorinated ethylene-propylene. It is not clear that the blended radio-opaque material necessarily provides any physical benefit other than the ability to allow the catheter shaft to be seen when viewed with a fluoroscope.
U.S. Pat. No. 4,737,153, to Shimamura et al., describes a device which is characterized as a "reinforced therapeutic tube" and which uses a spiral reinforcing material embedded within the wall of the device.
U.S. Pat. No. 5,069,674, to Fearnot et al. (and its parent, U.S. Pat. No. 4,985,022), shows a small diameter epidural catheter having a distal tip made up of a stainless steel wire which is helically wound and placed within a tubular sheath or tube.
Similarly, U.S. Pat. No. 5,178,158, to de Toledo, shows what is characterized as a "convertible wire for use as a guidewire or catheter". The patent describes a structure which comprises an interior wire or spring section shown, in the drawings, to be of generally rectangular cross-section. Outer layers of the device include a polyamide sheath placed adjacent to the helical coil at the proximal end of the catheter (see column 4, lines 64 and following). The device also comprises an outer sheath 40 of Teflon that extends from the proximal end 12 to the distal end 14 of the device. The overlying sheath 40 may extend or overhang at the proximal or the distal end of the catheter. The distal tip portion 13 is said to be "flexible, soft, and floppy". The PCT Published Application corresponding to this patent is WO 92/07507.
U.S. Pat. No. 5,184,627 shows a guidewire suitable for infusion of medicaments to various sites along the guidewire. The guidewire is made up of a helically wound coil having a polyamide sheath enclosing its proximal portion and a Teflon sheath tightly covering the entire wire coil. The coil is closed at its distal end.
U.S. Pat. No. 5,313,967, to Lieber et al., shows a medical device, a portion of which is a helical coil which apparently may include an outer plastic sheath in some variations. Apparently, a secondary helix of a somewhat similar design (in that it is formed by rotating a flat wire or the like along its longitudinal axis to form a screw-like configuration) is included within the helical coil to provide axial pushability and torque transmission.
U.S. Pat. No. 5,405,338, to Kranys, describes a helically wound catheter incorporating a shaft component having a helically wound coil with a skin or webbing supported by the coil. The skin or webbing is said to contribute "negligibly to the resistance of the catheter to axially directed compressive forces . . . " The catheter may include an inner, taut skin component.
The PCT application, WO 93/15785, to Sutton et al., describes kink-resistant tubing made up of a thin layer of an encapsulating material and a reinforcing coil. As is shown in the drawings, the supporting material is embedded within the wall of the tubing in each instance.
The PCT application bearing the number WO 93/05842, to Shin et al., shows a ribbon-wrapped catheter. The device is shown as a section of a dilatation catheter. The inner section 34 is a helically wound coil and is preferably a flat wire. See, page 6, lines 25 and following. The coil is then wrapped with a heat-shrunk jacket 34 formed of low-density polyethylene. A lubricious material such as a silicone coating may then be placed on the inner surface of the spring coil to "enhance handling of the guidewire". It is also said, on page 6 of the document, that the "entire spring coil, before it is wound or jacketed, may be coated with other materials such as Teflon to enhance lubricity or provide other advantages. In some embodiments, the spring coil has been plated with gold."
Endoscope Structures
Various endoscopic structures, used primarily in sizes which are larger than endovascular catheters utilize structures including stiffener materials.
U.S. Pat. No. 4,676,229, to Krasnicki et al., describes an endoscopic structure 30 having an ultra-thin walled tubular substrate 31 formed of a lubricious material such as TEFLON. The structure contains a filament supported substrate. The filament is coated with and embedded into a filler material, typically an elastomeric material. A highly lubricious outer coating 35, all as shown in FIG. 2, forms the outer layer of the device. FIG. 3 in Krasnicki et al., describes another variation of the endoscopic device in which a different selection of polymer tubing is utilized but the placement of the filamentary support remains varied in an intermediate material of an elastomer. In some variations of the device, the filament is strongly bonded to the inner tubular substrate using an adhesive 37 "such as an epoxy cement having sufficient bond strength to hold the filament to the substrate as it is deformed into a tight radius." See, column 3, lines 50 and following.
U.S. Pat. No. 4,899,787, to Ouchi et al. (and its foreign relative, German Offenlegungshrifft DE-3242449) describes a flexible tube for use in an endoscope having a flexible, basic tubular core structure made up of three parts. The three parts are an outer meshwork tube, an intermediate thermoplastic resin tube bonded to the outer meshwork tube, and an inner ribbon made of a stainless steel or the like which is adherent to the two polymeric and meshwork tubes such that the resin tube maintains an adherent compressive pressure in the finished flexible tube. The patent also suggests the production of an endoscope tube having "flexibility which varies in step-wise manner from one end of the tube to the other . . . [and is produced] by integrally bonding two or more thermoplastic resin tube sections formed of respective resin materials having different hardnesses to the outer surface of the tubular core structure . . . ". See, column 2, lines 48 and following.
U.S. Pat. No. 5,180,376 describes an introducer sheath utilizing a thin, flat wire metal coil surrounded only on its exterior surface with a plastic tube of coating. The flat wire coil is placed there to lower the "resistance of the sheath to buckling while minimizing the wall thickness of the sheath." A variation using two counter-wound metal ribbons is also described.
European Patent Application 0,098,100 describes a flexible tube for an endoscope which uses a helically wound metallic strip having a braided covering contiguous to the outer surface of the coil and having still further out a polymeric coating 9. Interior to the coil is a pair of slender flexible sheaths which are secured to a "front-end piece 10" by soldering.
Japanese Kokai 2-283,346, describes a flexible endoscope tube. The tubular outer shell is made up of two layers of a high molecular weight laminated material. The tube also has an inner layer of an elastic material and interior to it all is a metallic ribbon providing stiffening.
Japanese Kokai 03-023830, also shows the skin for flexible tube used in an endoscope which is made up of a braid 3 prepared by knitting a fine wire of a metal with a flexible portion 2 which is prepared by spirally winding an elastic belt sheet-like material and a skin 4 with which the whole outer surface of the device is covered. The document appears to emphasize the use of a particular polyester elastomer.
Japanese Kokai 5-56,910, appears to show a multi-layered endoscope tube made up of layers of the spiral wound metallic ribbon covered by a polymeric sheath.
French Patent Document 2,613,231, describes a medical probe used with an endoscope or for some other device used to stimulate the heart. The device appears to be a helix having a spacing between 0 and 0.25mm (See page 4, line 20) preferably rectangular in cross section (See Page 4, Line 1) and of a multiphase alloy such as M35N, SYNTACOBEN, or ELGELOY (See Page 4).
German Offenlegungshrifft DE-3642107 describes an endoscope tube, formed of a spiral tube, a braid formed of fibers interwoven into a net (which braid is fitted on the outer peripheral surface of the spiral tube), and a sheath covering the outer peripheral surface of the braid.
None of the noted devices have the structure required by the claims recited herein.
Other Anti-kinking Configurations
U.S. Pat. No. 5,222,949, to Kaldany, describes a tube in which a number of circumferential bands are placed at regular intervals along a catheter shaft. The bands may be integrated into the wall of the catheter. A variety of methods for producing the bands in the tubular wall are discussed. These methods include periodically irradiating the wall to produce bands of a higher integral of cross-linking.
European Patent Application No. 0,421,650-A1 describes a method for producing a catheter from a roll of polymer film while incorporating other materials such as tinfoil elements or the like.
None of the documents cited above provides a structure required by the disclosure and claims recited below.

Guide catheter with enhanced guidewire tracking


An aircraft landing assist apparatus is designed to be retrofit to existing aircraft having internal constructions that have been modified to support the apparatus. The apparatus is designed so that on rough landings of the aircraft on a ship deck, the apparatus will collapse in a controlled manner to avoid any damage to ammunition and/or fuel storage areas of the aircraft. In one embodiment the apparatus includes a plurality of support struts that each include an eccentric bushing. A locking pin can be used to selectively position the eccentric position to adjust the overall length of its associated strut.

(1) Field
The present disclosure pertains to an aircraft landing assist system. More specifically, the present disclosure pertains to a mounting system for an aircraft landing assist probe, and a method of retrofitting an aircraft with the mounting system to adapt that aircraft for landing on a deck of a ship.
(2) Description of the Related Art
Landing assist systems have been developed that facilitate the landing of an aircraft, for example, a helicopter, on the deck of a ship. An example of one such system is the aircraft/ship integrated secure and traverse (ASIST) deck landing system developed by Indal Technologies, Inc. of Ontario, Canada.
In a typical aircraft landing assist apparatus employed in landing a helicopter on the deck of a ship, the helicopter is provided with a landing probe. The landing probe is positioned on an underside of an aircraft and projects downwardly from the aircraft to a distal end of the probe.
A rapid securing device is provided on the deck of the ship. The rapid securing device includes a track on the ship deck and a cart mounted on the track for sliding movement of the cart along the track. The cart is provided with a securing latch that is removably attachable to the probe distal end.
In landing a helicopter on the deck of a ship using the aircraft landing assist system, the helicopter approaches the ship deck when the pitching motion of the ship is relatively tranquil. As the helicopter descends toward the ship deck, the cart moves along the track, following the movement of the helicopter over the ship deck toward a predetermined landing area. On touchdown of the helicopter landing gear on the deck landing area, the landing probe of the helicopter is received and secured by the latch of the cart, securing the helicopter to the ship deck. With the helicopter secured to the ship deck, the cart can then be moved across the deck to move the helicopter to a hangar.
Helicopters that are designed for ship deck landings are equipped with landing assist probes. When this type of helicopter is constructed, the structural frame of the helicopter is matched to the landing assist probe to provide sufficient structural strength to the probe. This matching of the structural frame of the helicopter with the landing assist probe is necessary because on a pitching and rolling ship deck, there is a great deal of tension on the probe as it holds the helicopter down on the deck. Helicopters by design are top heavy with the rotor assembly and the power unit being positioned in the upper area of the helicopter's structural frame. Thus, known aircraft/ship landing assist systems employ helicopters that have structural frames specifically designed for the landing assist probe that secures the helicopter to the ship deck.
The prior art aircraft/ship landing assist systems are therefore disadvantaged in that the systems are limited to use with helicopters that are dedicated for use with the landing assist system. In the construction of these dedicated helicopters, a primary design consideration is providing the helicopter with a structural frame that is secured to the landing assist probe to facilitate shipboard landings of the helicopter. These specifically designed helicopters may be lacking in other desirable features for helicopters, for example the various different types of weaponry available on modern day military aircraft. What is needed to overcome this disadvantage of aircraft/ship landing assist systems is an aircraft landing assist apparatus that can be retrofit to existing aircraft to adapt these aircraft for shipboard operation.

Landing assist apparatus eccentric bushing


A flexible Galois Field multiplier is provided which implements multiplication of two elements within a finite field defined by a degree and generator polynomial. One preferred embodiment provides a method for multiplying two elements of a finite field. According to the method, two input operands are mapped into a composite finite field, an initial KOA processing is performed upon the two operands in order to prepare the two operands for a multiplication in the ground field, the multiplication in the ground field is performed through the use of a triangular basis multiplier, and final KOA3 processing and optional modulo reduction processing is performed to produce the result. This design allows rapid redefinition of the degree and generator polynomial used for the ground field and the extension field.

1. Field of the Invention
This invention generally relates to the field of algebraic data processors, and more particularly relates to reconfigurable numeric processors that perform multiplication of polynomials over finite fields.
2. Description of Related Art
Galois fields are finite sets of elements on which mathematical operations are specifically defined. The Galois field GF(2n) is a field having N elements, with N=2n. One representation of this field is the polynomial representation. All of the elements are written in the form of an n−1 degree polynomial:an−1Xn−1+an−2Xn−2+ . . . +a2X2+a1X+a0with ai being a coefficient belonging to GF(2) and therefore being equal to either "0" or "1". Consequently, each element can then be likened to a number encoded on n bits. A Galois field of degree n (i.e., GF(2n)), is defined by an irreducible polynomial of degree n. The irreducible polynomial defining a specific Galois Field is referred to as a Generator (or Primitive) Polynomial.
The computations performed on elements in a Galois Field correspond to computations made on polynomials reduced by an irreducible nth degree polynomial. The computations done on the elements of the field therefore operate differently than conventional operations. In particular, addition of two elements within a finite field in the form of GF(2n) is done bit-by-bit using an XOR circuit and subtraction is done identically to addition. Multiplication is defined differently, and may be performed in two steps. In a first step, a multiplication similar to a conventional multiplication is performed, and then in a second step, a reduction is performed on the result of the multiplication using a generator polynomial.
Multiplication of elements contained in larger Galois Fields (e.g., GF(264)), is very computationally expensive. Composite fields are sometimes used to reduce the processing complexity in performing multiplication on elements of such larger Galois Fields. A composite field may be represented as GF((2n)m) and for practical reasons is usually limited to cases where m=2t, where t is an integer. In the example of GF((2n)m), the field GF(2n) is referred to as the ground field. Realization of processing of composite fields includes the use of the "Karatsuba-Ofman Algorithm" (KOA). The KOA is a recursive method for efficient polynomial multiplication and may be used for composite fields of the form GF((2n)m), where m=2t, where t is an integer. The KOA is described in "Multiplication of Multidigit Numbers on Automata," Soviet Physics-Doklady (English translation), Vol. 7, No. 7, pp. 595–596 (1963), which is herein incorporated by reference.
Galois fields have several areas of application, including generation of error correction codes or encryption codes for digital data transmission. Among the encryption codes, there is the encryption known as "elliptic curve encryption." This type of encryption uses binary numbers encoded on a large number of bits (typically, 100 to 200 bits). The effectiveness and efficiency of systems using Galois fields, including encryption and error correction, may be adjusted by the use of different degree Galois fields. Many applications that perform multiplication of Galois fields would benefit if the system design allows changing of the size of the Galois Field, (i.e., the degree of the field) and/or the generator polynomial.
Conventional computation circuits used for performing operations on elements of Galois fields are typically conventional processors that may or may not be coupled to dedicated hardware processing circuits. The use of a conventional processor alone without dedicated hardware circuits requires significant memory resources and computational time to perform Galois Field multiplication. Current Galois Field multiplier designs that employ dedicated hardware are only practical for multiplying Galois Fields with small degree generator polynomials. These multiplier designs are also limited in their efficiency, relative to processing speed and/or circuit complexity, or have been limited in the processing time over which the field definition parameters may be changed. The use of dedicated hardware processing, either alone or in conjunction with a conventional processor, has therefore resulted in far less efficient implementations than fixed realizations that operate on predefined finite fields.


The present invention relates to a mobile system comprising a mobile network having a mobile services switching center (MSC, MSCA) for switching connections in the mobile network, and at least one subscriber database server (CSE) for maintaining data on the subscribers of the mobile network. The mobile services switching center (MSC, MSCA) comprises means for querying for and receiving subscriber data from the subscriber database server (CSE) wherein subscriber data are maintained in www page format, and the subscriber database server (CSE) comprises at least one www page for each subscriber in the mobile network, in which page the subscriber's subscriber data are stored, the search address of the www page being created based on the subscriber's identity.

1 Field of the Invention
The present invention relates to mobile systems and particularly to the management of subscriber data therein.
2 SUMMARY OF THE INVENTION
A solution for maintaining subscriber data in a home location register (HLR) and in a visitor location register (VLR) is previously known in for example the GSM system (Global System for Mobile Communication). In this case, the home location register maintains subscriber data regarding all mobile subscribers in a network. The structure of a home location register is a computer and a data storage associated therewith. As a mobile subscriber moves in the mobile network, necessary subscriber data are copied from the home location register to the visitor location register within whose area the mobile subscriber is located at each particular time. At the same time, information on the visitor location register in whose area the mobile subscriber is located is stored in the home location register. A visitor location register may be located in association with a mobile services switching centre, in which case the area of the visitor register may be the area covered by said mobile services switching centre.
In the above solution, problems are caused by increasing amounts of data in mobile networks and the associated need for a higher processing capacity, and the difficulty of adding supplementary functions. Increasing numbers of subscribers in mobile networks and services that are more versatile are causes of increased amounts of data. Typical functions requiring much capacity include transfer of service profiles associated with subscriber management and monitoring, and maintenance and transfer of location data. The present system, which is based on mobile services switching centre technology, is mainly intended for use with telephone technology, and does not possess the required processing capacity. When a new type of service is added to the present system, the centre always has to adapt a new program. A mobile services switching centre is not either an efficient means for browsing through data.
The object of the invention is to solve the above problems by providing a solution allowing simpler management of large amounts of subscriber data in a mobile system. This object is achieved with a mobile system comprising a mobile network having a mobile services switching centre for switching connections in the mobile network, and at least one subscriber database server for maintaining data on the subscribers of the mobile network. This mobile system is characterized in that the mobile services switching centre comprises means for querying for and receiving subscriber data from the subscriber database server wherein subscriber data are maintained in www (World Wide Web) page format, and the subscriber database server comprises at least one www page for each subscriber in the mobile network, in which page the subscriber's subscriber data are stored, the search address of the www page being created based on the subscriber's identity.
The invention also relates to a mobile services switching centre for switching connections in a mobile network. The mobile services switching centre is characterized in that the mobile services switching centre comprises means for querying for and receiving subscriber data from a subscriber database server wherein subscriber data are maintained in www page format.
The invention further relates to a subscriber data main server for maintaining subscriber data in a mobile network. The main server is characterized in that the main server comprises, for each subscriber in the mobile network, at least one www page wherein the subscriber's subscriber data are stored, the search address of the www page being created based on the subscriber's identity.
The invention still further relates to a subscriber data local server for temporary storage of subscriber data. The local server is characterized in that it comprises means for receiving queries for the subscriber data from a mobile services switching centre, means for retrieving the queried subscriber data from a database in the local server, means for retrieving the queried subscriber data further from a main server if said data are not found in the database of the local server, means for transferring the retrieved subscriber data to the mobile services switching centre, and means for storing the retrieved subscriber data in the local server in www page format.
The idea of the invention is to apply www, http (Hypertext Transfer Protocol), html (Hypertext Markup Language), IP (Internet Protocol) and other Internet technology in the subscriber databases instead of the present HLR/VLR technology. This means that the data of a mobile subscriber in a subscriber database server are used to create at least one www page from which a mobile switching centre queries for information required by different functions. For this reason, the mobile services switching centre has to be provided with an IP interface, via which call control and other programs requiring data are able to query for the information they require, i.e. www pages. The mobile services switching centre uses a www address as the search address, the address indicating the desired subscriber data page and being created based on the subscriber's identity and a control function. It may be said that the mobile services switching centre provides a path for data to be transferred, but the data associated with special services are processed and managed in the IP network. The use of an IP network having higher-capacity hardware facilitates data retrieval and management. As services become more versatile, necessary new functions are increasingly easier to incorporate into IP network servers with different programming tools.
In a first preferred embodiment of the mobile system of the invention, the system comprises a subscriber data main server wherein subscriber-specific www pages are stored, and at least one subscriber data local server between a mobile services switching centre and the main server for temporarily maintaining subscriber data. In this case, the local server is used for buffering subscriber data. Since not all queries have to be transferred all the way to the main server, but the data are found in the local server, access to data does not become unnecessarily slow even in a large network.
In a first preferred embodiment of the subscriber data main server of the invention, the main server comprises at least a subscriber-specific main page wherein the most generally needed subscriber data are stored and whereto said search address points, and at least one subpage wherein the subscriber data needed in special cases are stored and whose search address is created by completing the search address of said main page. This division also aims at faster data retrieval.
In a second preferred embodiment of the subscriber data main server of the invention, the main server comprises means for maintaining a www page specific log regarding subscriber data queries such that the log contains information on the local server that sent a query for a page and the time the query was sent. For example, when an operator or dispatcher changes the subscriber data, the changed data have to be transferred to the local servers that, based on a time stamp, have corresponding usable data. In this case, a check can be made in the log to find out the location of such no-good data and transfer an update there.
In a first preferred embodiment of the subscriber data local server of the invention, the local server comprises means for providing the new or changed subscriber data to be stored in the local server with a time stamp, means for checking the time stamp when the next query or notice of change regarding the same subscriber data is received, means for selecting the stored data if a predetermined term from the storage has not lapsed. This avoids unnecessary data searches. Once certain subscriber data have been queried for, the data may be stored in the local server, provided with a time stamp. If the same data are queried for again soon, the data do not have to be searched for again in the main server, but sufficiently recent stored data can be used directly. This requires that a term be set indicating how long the old data are usable.
The preferred embodiments of the mobile system, mobile services switching centre, main server and local server of the invention are disclosed in the attached dependent claims.
The figures schematically show different data search and management cases. For example, they may describe the invention applied to the TETRA system (Terrestrial Trunked Radio) or some other mobile system.

Management of subscriber data in mobile system


Provided is a managed network service delivery system and method. The managed network service delivery system includes an IOC (Internetworking Operating Center) and a SCA (SAM (Security Activity Manager) Collector Agent) at at least one of a plurality of customer sites of a customer. The customer sites are connected to the IOC through a VPN (Virtual Private Network) or directly from a respective one of the SCAs to the IOC. The SCAs collect log and statistical information from equipment at a respective one of the customer sites and provide summary information to the IOC. The SCAs also perform queries regarding status of equipment and report to the IOC. The customer accesses reports from a web server at the IOC or through a PSTN (Public Switched Telephone Network) connection at the SCAs. A redundant connection, through the PSTN, between a SCA and the IOC provides a robust system for management, monitoring and security of the customer sites.

Remote management and monitoring of networks is becoming more and more common. Furthermore, providing security services to customers is also important in protecting a customer's network against any type of intrusion. Several applications are available to service providers for providing remote network management services, monitoring services and security services to customers. Typically, a service provider runs a network management center that provides a VPN (Virtual Private Network) to a customer. The VPN provides a plurality of connections between the network management center and a number of customer sites. The connections may be established through, for example, a public Internet. Each customer site has a LAN (Local Area Network) and applications at the network management center manage, monitor and provide security for equipment in the LANs. In monitoring several customer sites, the network management center must query the equipment in the LANs at the customer sites. This results in much information being transferred through the VPN and can result in bottlenecks at the network management center when the network management center provides services for many customers. Furthermore, in some cases a connection to a customer site may be unavailable due to, for example, congestion in the public Internet or due to failure of a firewall, or other equipment, at the customer site. In either case the network management center is no longer able to provide management services, monitoring services or security services. The network management center is not able to determine whether a failed connection to the customer site is due to Internet congestion or due to failure of equipment at the customer site. Furthermore, since there is no connection established to the customer site, in the event that the connection is lost due to equipment failure at the customer site the network management center cannot manage the equipment at the customer site to rectify any problems since there is no connection established.

Method and apparatus for secure distributed managed network information services with redundancy


When embodied in a microgyroscope, the invention is comprised of a silicon, four-leaf clover structure with a post attached to the center. The whole structure is suspended by four silicon cantilevers or springs. The device is electrostatically actuated and capacitively detects Coriolis induced motions of the leaves of the leaf clover structure. In the case where the post is not symmetric with the plane of the clover leaves, the device can is usable as an accelerometer. If the post is provided in the shape of a dumb bell or an asymmetric post, the center of gravity is moved out of the plane of clover leaf structure and a hybrid device is provided. When the clover leaf structure is used without a center mass, it performs as a high Q resonator usable as a sensor of any physical phenomena which can be coupled to the resonant performance.

1. Field of the Invention
The invention relates to silicon bulk micromachined transducers and in particular vibratory symmetric transducers usable as gyroscopes, sensors and accelerometers.
2. Description of the Prior Art
The applications for gyroscopes in guidance and control devices is notorious and has been realized in more recent technologies by means of optical gyroscopes such as ring laser gyroscopes, and fiberoptic gyroscopes as well as vibratory gyroscopes such as hemispherical resonator gyroscopes, tuning fork gyroscopes, and silicon micromachined vibratory gyroscopes.
The advantages of optical gyroscopes include high dynamic range, high band width, rapid start up, little acceleration sensitivity at least to the first order, good day-to-day drift stability and a stable linear scale factor. The ring laser gyroscope and fiberoptic gyroscopes in particular have excellent stability over periods of hours, but are noisy during short term intervals of the duration of several seconds, where they act as white noise generators. High performance optical gyroscopes also require complex electronics support, a path link controller, a high voltage power supply, mechanical dithering, optical modulators, thermoelectric coolers, signal processing, high order modeling, precision optical components and complicated and delicate assembly and manufacturing processes. Each of these requirements increases the cost and power requirements of high performance optical gyroscopes. Moreover, the performance of an optical gyroscope depends directly with the area enclosed within its optical path. Apart from various technical difficulties encountered in attempting to reduce fiberoptic gyroscopes and ring laser gyroscopes to millimeter dimensions, this fundamental scaling law makes it effectively impossible to realize small, high performance optical gyroscopes.
In a vibratory gyroscope, the Coriolis effect induces energy transfer from the driver input vibratory mode to another mode which is sensed or output during rotation of the gyroscope. An example of such a high performance vibratory gyroscope is the hemispherical resonator gyroscope. The hemispherical resonator gyroscope is made of quartz and has a shell resonator design. It is immune to external vibration and is capable of standing high g shocks. However, it requires precise machining of the resonator and housing, high vacuum sealing and gettering, and computer support. The hemispherical resonator gyroscope is very large, difficult to manufacture, expensive and consumes a large amount of power.
Another type of vibratory gyroscope is the quartz tuning fork vibratory gyroscope. This type of gyroscope is insensitive to linear vibration, has low mechanical loss, and is capable of standing high g shock. However, the quartz tuning fork microscope has low responsitivity, high temperature sensitivity, and is not integratable with silicon electronics.
Silicon micromachined vibratory gyroscopes are integratable with silicon electronics. These devices are capable of achieving high Q factors, can withstand high g shocks due to their small masses, are insensitive to linear vibration and consume little power. However, most of these micromachined gyroscopes have a very small rotation response, since their input and output vibration modes have different mode shapes and resonant frequencies. The use of different resonant modes also makes these devices very temperature sensitive due to the different temperature dependency of each of the modes. These devices usually have very high resonant frequencies resulting in low responsitivity, since the Coriolis induced response is inversely proportional to the resonant frequency of the structure. Finally, due to the small mass of the structure, thermal noise limits the ultimate performance and use of microgyroscopes. For these reasons, micromachined vibratory gyroscopes have not been used for spacecraft navigation and attitude control applications, but have been employed primarily for automotive applications in which extreme low cost is a major driving factor and performance is set at a lower premium.
Therefore, what is needed is some type of silicon micromachined vibratory gyroscope, accelerometer or sensor which overcomes each of the shortcomings of the prior art. In particular, what is needed is a silicon micromachined vibratory microgyroscope that:
(1) has a much larger mass than other micromachined microgyroscopes therefore providing a much lower mechanical resonance and lower thermal noise limit; PA1 (2) has a design which reduces fabrication complexity, is adaptable for batch production and avoids temperature sensitivity while providing a high rotational response; PA1 (3) has an inherently high Q design; PA1 (4) provides for simple and rugged detection and actuation; PA1 (5) operates to provide increased sensitivity and to reject common mode signals such as environmental vibrations and bias offsets; and PA1 (6) can be fabricated using silicon bulk micromachined techniques to reduce cost of fabrication complexity, to provide high reproducibility in the mechanical characteristics while retaining low cost, overall low mass, and low power.

Silicon bulk micromachined, symmetric, degenerate vibratorygyroscope, accelerometer and sensor and method for using the same


An off-axis Fresnel lens is disclosed that, when combined with a rear projection screen (comprising, e.g., a lenticular lens, a diffuser, or both), enables construction of rear-projection-type screen devices (e.g., projection television systems) that are thinner and have improved contrast and resolution when compared with conventional projection screen devices. The off-axis Fresnel lens comprises a plurality of concentric, outwardly-extending, total internal reflection-type prism facets. Each facet, in turn, comprises top and bottom sides, one or both of which may be flat or outwardly convex. Embodiments of the invention may also include concentric opaque sections that are disposed between successive prisms, between the prism base and the output surface of the Fresnel lens, and/or between the output surface of the Fresnel lens and the input surface of the projection screen in order to improve contrast. Contrast may also be enhanced by laminating the Fresnel lens to the projection screen.

In general, projectors provide images by generating the image in a light source and projecting the same onto a screen. Referring to FIG. 1, a typical rear projection system or projection screen device includes a cabinet 110, a screen 140 installed on the front surface of the cabinet and where an image is formed, a light source 120, installed in the cabinet and generating and projecting an image, and reflection mirrors 100 and 130 reflecting the image input from the light source toward the screen. In the rear projection system having the above structure, an image projected in the rear of the screen and formed on the screen is viewed in front of the screen, that is, outside the cabinet.
Traditional rear projection televisions, as depicted in FIG. 1, generally are bulky, heavy, complicated to use, and expensive. A rear projection television or projection screen device having a flat panel display using projection technology, as shown in FIG. 2, is ultra-thin, lightweight, and has the potential to save cost by using fewer components.
Rear projection screens are made of either a lenticular lens or a diffuser or a combination of a lenticular lens and a diffuser that distributes or spreads the incident light in some angular distribution. FIG. 3 depicts such a rear projection screen without a fresnel lens. Before the screen 310, incident light 320 has a certain incident angle. Beyond the screen, the strongest component of the distributed light 330 is in the incident direction. As such, a viewer sees a varying brightness on the screen, resulting in an uneven image where the light is brightest in the center of the screen and darkest in the corners of the screen. In projection with a refractive-type fresnel lens, depicted in FIG. 4, the fresnel lens 420 redirects the incoming light 410 such that its incident angle, as well as the strongest component of the distributed light 430, are both normal to the projection screen 440. This gives a more even brightness to the screen. Accordingly, even when a viewer moves to the edge of the screen, the level of brightness at different positions decreases more evenly.
FIGS. 5 and 6 illustrate a projection television employing a fresnel lens. Such projection televisions have great depth. FIGS. 7 and 8 show a newer traditional projection television with an off-axis fresnel lens. The depth of such a projection television is considerably thinner due to the off-axis fresnel lens, which permits the light source to be directed from below.
The general fresnel lens structure can be conceptualized as either a collection of grooves between facets, or a collection of facets between grooves. With reference to the cross-sectional view of a fresnel lens shown in FIG. 22, the fresnel lens facets can be described with two angles. The face angle 2220 (also called "facet angle") is defined as the angle between the surfaces adjacent grooves. The groove angle 2210 is the angle formed between the input face (i.e. the bottom side) of one facet and the reflection face (i.e. the top side) of the same facet. The geometry of a facet having a curved side, as in the present invention, is described below.
FIG. 21 shows a conceptual illustration of the sections of a larger fresnel lens. The sections can be used for rear projection screens. The fresnel lens has an axis 2130 at the center of a plurality of concentric facets and grooves having predetermined facet and groove angles. In a rear projection display device in which incoming light enters perpendicularly to the face of the lens, or where the full lens field of the projection lens system is used, a center portion 2120 of fresnel lens 2100 is used as a fresnel lens for the display device. Rectangle 2110 provides an indication of a screen displaced from the center portion of fresnel lens 2100, as used in off-axis fresnel lenses where the incoming light enters at an angle. The size and shape of the portion of the lens to be used corresponds to the size and shape of the screen of the display device, i.e., the projection display. The term "off-axis" is used because the physical center of the fresnel lens 2110 is displaced from the axis 2130 of the larger fresnel lens 2100. In an off-axis lens, only the displaced portion is used. Any remaining portion of a larger fresnel lens from which the off-axis lens may have been derived is not used in the off-axis lens. Alternately, manufacturing techniques exist whereby only the off-axis portion of the fresnel lens is manufactured.
Although only the displaced portion of the lens is used in an off-axis fresnel lens, the off-axis lens is still considered to have an axis. The axis, however, may not appear on the actual lens. However, its position may be extrapolated from the elongated and arcuate concentric facets and grooves of the fresnel lens structure. For example, the off-axis fresnel lens 2110 has an axis 2130, even though the axis 2130 is at the lower edge of the lens. In other embodiments, the axis of an off-axis fresnel lens may even be substantially below or otherwise outside the lens border. Though it may not be visible on the lens itself, the axis of an off-axis fresnel lens can be extrapolated by determining the radius of a circle defined by any one of the concentric arcuate facets.
FIG. 20 shows a side view of a rear projection television with an off-axis fresnel lens. In FIG. 20(a), the light source 2000 is positioned below the screen 2010 having a height H and the incoming light rays strike the input surface of the screen at angles from the lowest ray angle D to the highest ray angle F, with a middle ray angle E. However, an off-axis lens may be used with any projection system where the light source is displaced from the center of the screen. FIG. 20(b) shows a front view of the projection screen with height H and width W. Specific dimensions of screen geometry and light incident angles for one embodiment are shown in FIG. 20(c).
FIG. 9 depicts the limited bending ability of a refractive-type prism, whereby the angle of bending δ is approximately half the prism angle θ. Because the bending angle is limited to only half of the prism angle, the projection angle is limited, which limits the thinness of the projection system. Moreover, when θ is large, reflection loss becomes large. The light angle as well as loss depends on wavelength, thereby resulting in a color shift on the display screen.
FIG. 10 illustrates the greater bending ability of a reflective-type prism, whereby light is more fully reflected at the interface of the prism and air because of "total internal reflection" ("TIR"). While this kind of internal reflection is termed "total," it should not be construed as absolute, as slight reflective loss may occur due to abnormalities or impurities in the prism material, interference of the light with air or other substances, or for other reasons which may be apparent to one skilled in the art. Nonetheless, TIR has a reflection efficiency nearing 100%. The bending angle δ could reach 90°, thereby making the projection system even thinner. A higher output brightness results because of less reflection loss. In addition, there is virtually no color shift because the bending angle and loss have no wavelength dependence.
FIG. 11 shows that a reflective fresnel lens has low resolution and scrambled images. That is, image resolution is limited by the distance Σ between facets, and the image on every pitch is scrambled. Accordingly, the sequence 1-2-3-4 in the input light rays 1100 becomes 2-1-4-3 in the output light rays 1110.
Another problem associated with fresnel lenses and projection screens is the reduced contrast due to ambient light. On the projection screen, dark colors are represented by an absence of light. Thus, any ambient light on the projection surface will decrease contrast by causing dark colors to appear lighter. This ambient light can originate from the input surface or output surface of the fresnel lens.
Thus, there is need for a reflective fresnel lens system that has high resolution, corrects the problem of image scrambling, and which has improved contrast.

Total internal reflection fresnel-lens and devices


According to one aspect of the invention, a magnetorheological fluid (MRF) damping device includes two concentric coils or groups of coils arranged to produce respective magnetic fields that mutually cancel substantially everywhere but within the gap between them. The rheological properties of the MRF are magnetically controlled within this gap. According to a second aspect of the invention, the piston rod of a MRF damper or other viscous fluid damper communicates its motion to a hollow, capped cylinder. Damping fluid within this cylinder communicates via a narrow channel with damping fluid outside of this cylinder. When the piston rod undergoes motions directed so as to expel fluid from the interior of the cylinder, resistance within the narrow channel causes pressure to build up within the cylinder, but prevents any substantial amount of pressure from building up without the cylinder, thus isolating sealing devices from the highest resistive forces generated within the damping fluid. According to a third aspect of the invention, a piston head for a viscous fluid damper is arranged to pass small-amplitude displacements with reduced damping. A floating piston is disposed in a borehole that passes through the piston head. This borehole provides a low-resistance pathway for fluid flow when piston displacements are relatively small, but the floating piston closes this pathway when piston displacements are relatively large.

A magnetorheological fluid (MRF) is a fluid that responds to a magnetic field by changing its rheological behavior. Typically, such a fluid will reversibly change from a free-flowing, linear viscous liquid to a semi-solid when exposed to a magnetic field of sufficient strength. In practice, the time interval over which this change takes place is often limited by the characteristics of the field coil that produces the applied magnetic field, and of the circuitry that drives the field coil. Typical MRFs are particulate suspensions of iron or magnetic alloy in a carrier liquid which may, e.g., be petroleum-based, or water- or glycol-based.
The yield strength of a MRF is magnetically controllable. This property can be utilized in devices that include a magnetic field source, and that contain a MRF. The MRF can be made selectively resistant to flow or shear in portions of the device that are subjected to the magnetic field.
Such devices have been described. For example, U.S. Pat. No. 5,277,281, which issued on Jan. 11, 1994 to J. D. Carlson et al., discloses a fluid damper that utilizes the properties of a MRF. Briefly, a piston moves up and down within a MRF-filled chamber. The piston effectively divides the chamber into upper and lower portions interconnected by a narrow annular channel between the piston and the inner wall of the chamber. When the piston is displaced, MRF is required to flow through this channel. A field coil is included within the piston. When the field coil is energized, a magnetic field permeates the channel and excites a transformation of the MRF to a state that exhibits substantial damping forces.
Devices of this kind have proven to be quite useful. However, they suffer from certain limitations that tend to restrict their range of applications. For example, there is a need for MRF devices that can be switched more rapidly than those that are generally available at present. However, for a given flux density required to control the MRF, the response time of the device tends to go up as the amount of energy stored in the magnetic field is increased. Generally, this quantity tends to increase when steel (or other ferrous metal) components are made part of the magnetic circuit; i.e., when such components are traversed by the magnetic field lines that act upon the MRF. In conventional MRF devices, the magnetic field lines generally traverse a substantial volume of steel. As a consequence, the degree to which the response time of these devices can be shortened is limited.
Furthermore, there is a need for a compact, powerful MRF device such as one that can generate dynamic forces on the order of 50 tons within a package having a maximum dimension on the order of 10 inches or less. Such a device can be achieved only by increasing the magnetic flux density, within the MRF, beyond the levels that are typically encountered in conventional MRF devices. A compact, powerful MRF device will be especially useful if it can be switched between the damping and non-damping states within a relatively short time interval, such as an interval of a few milliseconds or less.
However, there inheres in conventional MRF devices a conflict between the goal of increasing magnetic flux density, and the goal of preserving short response times. As noted, the response time tends to go up as the amount of energy stored in the magnetic field is increased, particularly when there is steel (or other saturable materials) in the magnetic circuit. This effect may become greatly magnified at high values of the flux density. Under such conditions, the required field strength from the coil may be sufficient to cause magnetic saturation of the steel components. As saturation is approached, there is a steep increase in the field strength needed to produce a given flux density and therefore a steep increase in the stored energy. The previous referenced U.S. Pat. No. 5,277,281, discusses the design limitations to which conventional MRF devices are subject.
Another limitation of conventional MRF devices relates to the seal between the high-pressure side of the device and the environment (which is typically the atmosphere). Such a seal is typically a sliding seal that admits, or a deformable seal that seals around, a moveable piston rod. The resistance of the MRF to motions of the piston rod generates high pressures within the device. Unusually high pressures, such as may be caused by unexpectedly severe shock loads, may result in seal failure.
Thus, there has remained a need for MRF devices that can be operated with higher magnetic flux densities, while remaining limited in spatial dimensions and preserving short response times. There has also remained a need for MRF devices that are capable of withstanding exceptionally high resistive forces.

Compact low-inductance magnetorheological damper


The low-field magnetoresistance of a high carrier mobility semiconductor with inhomogeneities which are more conducting than the surrounding semiconductor material matrix is significantly enhanced compared to the magnetoresistance of the homogeneous material. The enhancement results from a magnetic field induced geometric effect in which current is expelled from the conducting inhomogeneity. The enhanced giant magnetoresistance is demonstrated at low field in (near) zero-band-gap material, such as Hg.sub.1-x Cd.sub.x Te(x.about.0.1). The effect is applied to the fabrication of magnetic read head sensors such as Corbino disc, bar magnetoresistance sensors and thin film sensors.

Various types of sensors exhibiting magnetoresistive characteristics are known and implemented in systems, particularly for reading of information signals recorded in magnetic media such as tapes, drums and diskettes. These sensors typically comprise a block made of a ferromagnetic alloy exhibiting high magnetoresistance. A recording medium passing in close proximity to such a sensor causes variations in the magnetic field at the point of the read head, and hence variations of the electrical resistance of the magnetoresistive sensor.
Recently however, magnetoresistive sensors have been described exhibiting a form of magnetoresistance generally known as "spin-valve"(SV) magnetoresistance, in which the change in resistance of the sensor is attributed to the spin-dependent transmission of conduction electrons between the magnetic layers of the sensor and the accompanying spin-dependent scattering at the layer interfaces. In such a sensor, the magnetoresistance is observed to vary as the cosine of the angle between the magnetizations of the layers and is dependent upon the deviation of current flow through the sensor. While such sensors exhibit a magnetoresistance that, for selected combinations of materials, is greater in magnitude than that exhibited by anisotropic magnetoresistors (AMR), they suffer from the relatively small magnitudes of the magnetoresistance at ambient temperatures.
Most recently, magnetoresistance sensors for reading/writing information signals stored on a magnetic medium have been described in issued patents and patent applications Ser. No. 08/396,819, filed Mar. 2, 1995 now abandoned; U.S. Pat. No. 5,646,051, issued Jul. 8, 1997; U.S. Pat. No. 5,696,655, issued Dec. 9, 1997; Ser. No. 08/781,994, filed Jan. 6, 1997 now pending and Ser. No. 08/917,058, filed Aug. 22, 1997 now pending, each assigned to the same assignee as the instant application and incorporated herein by reference.
The prior art also describes non-magnetic giant magnetoresistive sensors constructed from a thin film of non-homogeneous semiconducting magnetoresistive material, e.g. mercury cadmium telluride.
It is often assumed that microscopic inhomogeneities in semiconductors cause a diminution of the carrier mobility due to the additional scattering associated with the inhomogeneity. However, following the seminal work of C. Herring, entitled "Effect of Random Inhomogeneities on Electrical and Galvanomagnetic Measurements", in Journal of Applied Physics, Vol. 31, No. 11, pps. 1939-1953 (1960), C. M. Wolfe et a, in an article entitled "High Apparent Mobility in Inhomogeneous Semiconductors" in Solid State Science and Technology, Vol. 119, No. 2, pps. 250-255 (1972) showed that conducting inhomogeneities in semiconductors could actually result in a huge increase in the "apparent" Hall mobility relative to the actual carrier mobility by as much as a factor of 10.sup.3. The present invention shows that the same physical effect which boosts the Hall mobility also boosts the apparent giant magnetoresistance (GMR), and that this GMR boost may have important consequences for magnetic sensor technology, especially for high mobility semiconductor read-heads in high density magnetic recording.
One such high mobility semiconductor is mercury-cadmium-telluride (MCT) which has the alloy composition Hg.sub.1-x Cd.sub.x Te, 0<x<1. The alloy with composition x.about.0.22 has been extensively employed as a radiation emitter and detector compound in optical devices operating in the 10 .mu.m spectral region. Recently, however, Solin et al., in an article entitled "Self-biasing nonmagnetic giant magnetoresistance sensor", in Applied Physics Letter, 69 (26), pps. 4105-4107 (1996) have shown that the thin film MCT with a composition of x.about.0.1, corresponding to a (near) zero band-gap, exhibited a CGMR (measured using the Corbino disc geometry) which made it competitive with., if not superior to, more conventional metallic GMR detectors such as spin-valves as described by B. Dieny et al, in an article entitled "Magnetotransport properties of magnetically soft spin-valve structures", in Journal Applied Physics, 69 (8), pps. 4774-4776 (1991) and B. Dieny et al, in an article entitled "Giant magnetoresistance in soft ferromagnetic multilayers", Physical Review B, Vol. 43, No. 1, pps. 1297-1300, (1991). This superiority was in part a consequence of the enhancement of the low field GMR (.mu.H<1 where .mu. is the carrier mobility) by a factor of 30 or more over that which was expected on the basis of the high field GMR as noted in Solin et al. Indeed, this low field enhancement had been observed in bulk material many years ago by Korol' et al., in an article entitled "Magnetoresistance of CdHgTe near gapless state", in Sov. Phys. Semicond., Vol. 11, No. 3, pps. 288-289 (1977) and by Korol' et al., in an article entitled "Investigation of Cd.sub.x Hg.sub.1-x Te magnetoresistors in the temperature range 4.2-300.degree. K.", in Sov. Phys. Semicond., 12 (3), pps 275-277 (1978) but was not appreciated or explained. Solin et al supra realized the technological significance of the enhanced GMR and used a phenomenological model to describe it, but acknowledged a lack of understanding of the physics underlying the enhancement.

GMR enhancement in inhomogeneous semiconductors for use in magnetoresistance sensors


The invention provides a device to facilitate precise positioning of a tape head at a particular track on a magnetic tape. Typically, the magnetic tape is adapted to be received in a drive assembly which has a memory and a motor. The device includes a mounting tray for receiving the tape drive assembly, and a laser beam emitted from a laser source. On the tape head of the device, a reflector is positioned and moves with the tape head. Beam directors are provided to ensure that the laser beam passes from the laser source to the reflector. The distance traveled by the tape head from a predetermined point to a position adjacent a track on the magnetic tape is accurately measured, and the extent of movement of the motor required to move the tape head through such a distance is also measured. Thereafter, the measurements are programmed into the tape drive assembly memory.

This invention relates to a method and apparatus for the positioning and setting of a magnetic head in a tape drive assembly for accurate tracking of magnetic tape contained in a cassette, the cassette being adapted to be received in the tape drive assembly.
The use of magnetic tape cassettes is common in the computer industry, where such magnetic tape has a defined width, and a number of tracks, wherein information can be written and subsequently read by appropriately positioned magnetic heads. There is a tendency to provide an increasing number of tracks on a strip of magnetic tape to maximize the amount of information which may be contained therein. As a result of this increasing number of tracks, it has become more and more critical that locating a particular track is carried out with speed and accuracy for precision reading of information contained in that track. By "locating" a particular track is meant that a magnetic read or write head be positioned with respect to the magnetic tape so that the head accurately and precisely corresponds with the track for efficient retrieval of the information thereon.
In order for the magnetic head to read from or write onto a track, it is necessary that the tape drive assembly provide a mechanism whereby the tape head can be displaced in a direction normal to the movement of the tape so that the tape head can move up and down across the width of the tape for the purposes of locating a track. Typically, a head carriage assembly is mounted on a spindle or shaft which may be rotated by a motor, the spindle being threaded and engaging a threaded bore in the head carriage assembly. Rotation of the spindle results in up and down movement of the magnetic head. In order to insure maximum read/write efficiency, the precise orientation and position of the magnetic head should be properly set, and the motor driving the head carriage assembly must be accurately programmed so as to stop the magnetic head in a manner which will cause it to directly register with or correspond to a desired track.
It is the purpose of the present invention to provide a method and apparatus which permit custom setting and programming of a particular tape drive assembly. The invention therefore relates to a method and apparatus which permit accurate setting of the orientation of the magnetic head on the carrier, as well as a method and apparatus designed to measure and program the tape drive assembly to accurately locate a particular track on the magnetic tape, taking into account the particular tolerances of the specific tape drive assembly.

Apparatus for precise positioning of a tape head and programming thereof


This present invention is related to a key ring for keeping a key. The key ring includes a ring body, which has cut planes at both ends thereof. A concave portion (30) is formed at a predetermined place of the key ring (10) and is curved in a direction and in a body with the key ring (10). One of the cut planes is projected toward an inner side of the concave portion (30), and the key (40) is inserted into the ring body (10). With this configuration, it is easy to keep and take out a key by less force by forming a concave portion at a predetermined position of a ring body made of a metallic material and making one cut plane at one end of the concave portion so as to be projected toward an inner side of the concave portion and the other cut plane so as to correspond to the other end of the concave portion.

In general, a key ring is to take charge of various types of keys more conveniently. The key ring is fabricated by winding a metal bar of a small diameter so as to be folded double, with its circumference maintained constantly. Such a key ring will be more fully described with reference to accompanying drawings.
FIG. 1 is a perspective view of a conventional key ring, and FIG. 2 is a front view of the key ring illustrated in FIG. 1.
As illustrated in FIGS. 1 and 2, a ring body 100 of a key ring has a relatively less diameter and is fabricated using a metal rob of a predetermined length.
With the ring body 100, a curved portion 200 is formed at a predetermined place of the ring body 100, and cut planes 110 are formed at both ends of the ring body 100, respectively.
And, if the ring body 100 is wound centering around the curved portion 200 of the ring body 100 so as to be folded double, with its ring shape maintained, the cut planes 110 are close to both upper and lower sides of the curved portion 200, respectively. Thus a key 300 is inserted through a space between the ring body 100 and each cut plane 110.
That is, if the ring body 100 of a predetermined length is wound and double folded without change of its ring shape, the cut planes 110 thereof are placed at upper and lower sides of the curved portion 200, respectively. In order to keep or take out the key 300, a user opens a space between the ring body 100 and one cut plane 110 and then inserts the key 300 through the opened space by force.
According to the above-described key ring, the ring body 100 is formed by a metal rob without increase of its diameter and length, the curved portion 200 is formed at a predetermined place of the ring body 100, and the ring body 100 is wound centering around the curved portion 200 so as to be folded double without change of its ring shape. As a result, the ring body 100 is formed without change of its ring shape. At this time, the cut planes 110 are close to the upper and lower sides of the curved portion 200.
In this state, if a user opens a space between the curved portion 200 and one cut plane 110 by force (e.g., using own fingernail), the cut plane 110 is widened toward an outer side, and the key 300 is inserted through the opened part.
In order to take out the key 300 from the ring body 100 of the key ring, the user widens a space between the curved portion 200 and the cut plane 110 by force (e.g., using own fingernail), and then takes out the key 300 from the ring body 100.
A problem of the conventional key ring, however, is that user's fingernail easily gets hurt when providing a space between the curved portion and the cut plane by force to insert and take out the key.


An integrated circuit comprising a power supply node, a ground node and a gated domain coupled between the power node and the ground node. A Charged Device Model electrostatic discharge protection module is provided for shunting electrical energy of a CDM ESD event away from the gated domain. A gating switch makes an electrical connection in a connected state between the gated domain and at least one of the power node and the ground node. ESD gating control circuitry is coupled to the CDM ESD protection module and controls shunting of energy away from the gated domain by the CDM ESD protection module, thereby avoiding the energy flowing through the gated domain. The ESD gating control circuitry inhibits actuation of the CDM ESD protection module to prevent response to CDM ESD events when the gating domain is powered-up.

Typically, Integrated Circuits (ICs) are provided with ElectroStatic Discharge (ESD) protection circuitry. The ESD protection circuitry protects parts of an integrated circuit by clamping ESD-stressed terminals during an ESD event, and serves to divert an electrostatic discharge current away from protected parts of the integrated circuit, and thus to dissipate the "stress" energy without damage to the integrated circuit.
It is known for integrated circuits provided with power gating capabilities to comprise such ESD protection circuitry. Such integrated circuits typically include one or more so-called "gating switches" on-die, the gating switches being a kind of semiconductor switch that connects a local power supply and/or a ground of one or more circuit blocks, hereinafter referred to as a gated domain, to a main or continuous power supply and/or ground, respectively. The gating switch has a low impedance in a closed (connecting) state, and a high impedance in an open (disconnecting) state. The power supply to the power gated domain can be enabled or disabled by changing the state of the gating switch. Thus, the power supply to a gated domain can be turned off temporarily when not needed, for example to reduce the overall power consumption of the integrated circuit or to reduce noise levels. This temporary shutdown is also referred to as "low power mode" or "inactive mode". When the circuit blocks of the gated domain are required again, they are activated by "closing" the gating switch so as to transition the mode to an "active mode", thereby electrically coupling the power supply or ground to the gated domain.
A number of different types of ESD stress is known. A first category are types related to a transfer of an electrostatic charge into the chip by a charged external body, such as a human body or machine, fixture, or tool, for example so-called "Human Body Model" (HBM) and so-called "Machine Model" (MM) ESD Another category relates to the chip, or an internal part thereof, itself being charged and the subsequent electrostatic discharge thereof, so-called "Charged Device Model" (CDM) ESD. In contrast to HBM and MM ESD stresses that originate from pins of a chip, via the CDM ESD stress is typically generated "internally" in the device, for example when a charged device in the gated domain discharges to a grounded surface through a device pin. Such a charge can build up by, for example, exposing an integrated circuit to an electromagnetic field.
Known circuits to protect gated domains from such CDM ESD stresses demonstrate acceptable performance provided that the power-up time of the gated domain is below a certain threshold. In this respect, CDM ESD stress protection circuits are known to trigger in response to a predetermined voltage level and/or a predetermined slew rate of the voltage level being monitored. The need to consider the slew rate of the power voltage has become increasingly important to be able to detect CDM ESD events in relation to modern circuit technologies, because voltage levels that are slightly higher than the voltage level of the power supply, for example by 10% to 15%, can result in device failure and so a more rapid detection than simply monitoring voltage levels is required. However, it has been discovered by the inventors that triggering of a CDM ESD protection circuit based at least partly upon slew rate as a parameter results in false triggering of the CDM ESD protection circuit when the power-up time of the gated domain conflicts with the slew rate to be detected by the CDM ESD protection circuit. To this end, falsely triggering the CDM ESD protection circuit results, for example, in the power supply terminal or node for the gated domain being short-circuited to ground potential, causing the power system of an integrated circuit to "collapse", which is clearly disadvantageous. The alternative is not to provide gated domains of integrated circuits with CDM ESD stress protection, but this too is clearly disadvantageous.

Integrated circuit, integrated circuit package and method of providing protection against an electrostatic discharge event


In a plan view seen from above a vehicle, a cover (20), which closes an airbag deployment opening (14) formed in a hood outer panel (12), is elongate, and has an arc shape. The center portion of the cover (20) in a vehicle-width direction protrudes toward the front of the vehicle. Hinge portions (20E) of the cover (20) are formed in the vehicle rear-side edge of the cover (20) at positions near both end portions in the vehicle-width direction. Each clip (28), which fixes the cover (20), is disposed in a vehicle front-side edge (20J) at a position offset outward from a center portion (20K) in the vehicle-width direction. Thus, the clips (28) are prevented from interfering with an airbag that has passed through the airbag deployment opening (14) and has been deployed.

1. Field of the Invention
The invention relates to an airbag device for a vehicle in which an airbag passes through an opening formed in a vehicle-body panel of an engine hood or the like, and is deployed.
2. Description of the Related Art
Japanese Patent Application Publication No. JP-A-7-125609 describes a structure in which an airbag is deployed on the upper surface of an engine hood to protect an impactor at the time of collision. In this structure, an airbag deployment opening is formed in the engine hood that serves as a cover above an engine room provided in the front of a vehicle. A lid covers the opening, and opens/closes the opening.
In the structure described in Japanese Patent Application Publication No. JP-A-7-125609, right and left extended portions are formed near both end portions of a flange that is disposed along the longitudinal direction of the lid. The right and left extended portions are fixed to the side wall of a backup plate. The extended portions serve as hinges when the lid is opened. Thus, when the lid pivots around the left and right hinge axes and is opened, the center portion of the lid in the longitudinal direction may approach the deployed airbag and may interfere with the deployed airbag.


Interactive data input can include determining a plurality of character subgroups that each comprise at least one follow-on character that, based on a predetermined rule, can follow a preceding character from a predetermined set of characters that form character strings corresponding to a word within a predefined vocabulary. Two or more of the plurality of character subgroups, each of which correspond to a character selected by a user from among the predetermined set of characters, can be presented concurrently to the user in response to an electronically sensed user movement. A character string can be generated based on the user-selected character and at least one follow-on character associated with the user-selected character.

This disclosure relates to human-computer system interaction, and more particularly, to interactive data input to computer systems for creating virtual reality and augmented reality environments and to other computer systems.
Myriad devices enable a human to input data to a computer system, and the computer system to output data in response to the input data. This two-way communication, often referred to as human-computer interaction, can occur over different modalities. As the array of different types of computer systems has expanded, so, too, has the array of different modalities. The expansion is seen, for example, in the context of computer systems for creating virtual reality and augmented reality environments, whereby data entry can involve electronically tracking physical movements of a system user.
Virtual reality is the computer-generated simulation of a three-dimensional image or environment that a computer user can interact with in a seemingly real or physical way by using specialized electronic equipment, such as a helmet with a screen inside or gloves fitted with sensors. Augmented reality creates an enhanced version of reality using computer-based technology to overlay digital information on real-world images of something viewed through a device such as a smartphone camera or similar type device. Although often considered primarily in the context of entertainment, virtual reality and augmented reality find wide application in various other fields as well, including commerce, engineering, education, and medicine. Many observers predict continued increases in the number of users and the range of applications of virtual and augmented realities.

INTERNATIONAL BUSINESS MACHINES CORPORATION


Aryl substituted benzimidazole and imidazo[4,5]pyridine ethers are described as inhibitors of Cds1 and useful as adjuvants to chemotherapy or radiation therapy in the treatment of cancer.

The maintenance of an intact genome is of crucial importance to every organism. The individual cell in a multicellular eukaryotic organism possesses sophisticated and intricate mechanisms to properly respond to DNA damage. Such mechanisms repair damaged DNA or trigger programmed cell death (apoptosis). In response to DNA damage, checkpoint kinases are thought to be intimately involved in these processes. These kinases are activated by upstream proteins, such as ATM (ataxia-telangiectasia mutated) and ATR (ataxia-telangiectasia mutated and rad3-related), and in turn trigger cell cycle arrest by inhibition of proteins such as Cdc25A or Cdc25C. The checkpoint kinases may also modulate the activity of other proteins that are thought to be involved in DNA repair and programmed cell death. Examples of such proteins are BRCA1 and p53.
The checkpoint kinase Cds1 (in man also known as Chk2) is conserved from yeast to man. A human homolog of the Schizosaccharomyces pombe Cds1 gene has been described (Tominaga, K. et al. J. Biol. Chem. 1999, 274(44), 31463-31467; Matsouka, S. et al. Science 1998, 282, 1893-1897; Blasina, A. et al. Curr. Biol. 1999, 9(1), 1-10). Human Cds1 was rapidly activated by phosphorylation in response to DNA damage in both normal cells and in p53-deficient cancer cells. High levels of hCds1 were observed in p53-deficient cells. In human cells Cds1 has been implicated in the regulation by phosphorylation of proteins such as p53, BRCA1, Cdc25A, and Cdc25C (See: Lee, J.-S. et al. Nature 2000, 404, 201-204; Falck, J. et al. Nature 2001, 410, 842-847; and Buscemi, G. et al. Mol. Cell. Biol. 2001, 21(15), 5214-5221). As described below, inhibition of Cds1 offers two strategies for improving the effectiveness of DNA-damaging cancer treatments.
Cancer cells are often deficient in the mechanisms responsible for maintaining an intact genome. In particular, they have often lost proper p53 function, which generally correlates with the progression of a tumor to a more aggressive state, such as the progression from a pre-invasive to invasive stage of colon cancer, or from a low grade to a high grade astrocytoma. Between 30% and 70% of all subtypes of tumors have a point mutation in one of the two p53 gene copies and have lost the other allele. P53-deficient cells are generally more resistant to radiation. It is thought that the lack of initiation of programmed cell death in cancer cells may render such cells less sensitive to DNA-damaging cancer treatments. The transcription factor p53 is of importance not only for the initiation of programmed cell death, but also in cell cycle arrest. Loss of p53 function may therefore leave cancer cells with limited protection against insult to the genome. Further disruption of DNA damage repair and cell cycle arrest by inhibition of kinases such as Cds1 could then render cancer cells unable to survive after DNA damage. Therefore, inhibition of Cds1 could, by removing the remaining components of DNA damage repair, render the cancer cells more susceptible to treatments such as chemical DNA-damaging agents or ionizing radiation.
Normal cells, on the other hand, have an intact p53 system, and will often undergo apoptosis in response to DNA-damaging treatments at a much lower dose than that required to kill cancer cells. Therefore, in such situations, normal cells will be at a disadvantage compared to cancer cells, and cancer treatments often have to be discontinued due to serious side effects caused by loss of normal cells before the cancer has been eradicated. Inhibition of Cds1, which would prevent this kinase from phosphorylating and thereby stabilizing p53, could therefore protect normal cells from the effects of ionizing radiation or DNA-damaging chemotherapeutics while still allowing these agents to be effective against p53-deficient cancer cells. This would have the effect of increasing the therapeutic potential of these agents. This view is supported by studies of mice deficient in Cds1 (See: Hirao, A. et al. Mol. Cell. Biol. 2002, 22(18), 6521-6532; Takai, H. et al. EMBO J. 2002, 21(19), 5195-5205; WO 01/98465 A1 Chugai Seiyaku Kabushiki Kaisha, Dec. 27, 2001). These animals showed increased resistance to the apoptosis caused by ionizing radiation over their wild-type counterparts. For example, it was shown that these animals were protected from apoptosis of intestinal cells, hair follicle cells, cells of the CNS, and thymus cells relative to their wild-type counterparts when treated with ionizing radiation. Cds1 knockout animals also showed increased survival when exposed to ionizing radiation. It is therefore logical to assume that chemical inhibitors of Cds1 would have therapeutic potential in the protection of patients from the deleterious side effects of radiation or DNA-damaging chemotherapeutics.
A p53 deficient tumor is a tumor wherein the functions mediated by p53 are lacking or suppressed due to genetic mutations in the gene encoding p53 or through deficiencies or disregulation of proteins that modulate p53 expression levels and function. Examples of such proteins are MDM2 and p14(ARF).
Additional examples of cell cycle checkpoint modulators in development include UCN-01 (CAS 112953-11-4), UCN-02, KW-2401, NSC-638850 (Kyowa Hakko/National Cancer Institute) and SB-218078 (CAS 135897-06-2) (SmithKline Beecham).
Additional relevant publications include DE 0148431 (T 7570), WO 01/21771 A2, WO 02/072090 A1, WO 03/011219 A2, and White, A. W. et al. J. Med. Chem. 2000, 43(22), 4084-4097.
The features and advantages of the invention are apparent to one of ordinary skill in the art. Based on this disclosure, including the summary, detailed description, background, examples, and claims, one of ordinary skill in the art will be able to make modifications and adaptations to various conditions and usages. Publications described herein are incorporated by reference in their entirety.

Aryl-substituted benzimidazole and imidazopyridine ethers