This disclosure provides a sidelink power control method and a terminal device. The method is applied to the terminal device, and includes: sending information to a first terminal device in sidelink communication, so that the first terminal device generates power control indication information based on a receiving status of the information; receiving the power control indication information from the first terminal device; and determining an information transmit power of the terminal device in the sidelink communication according to the power control indication information.

In fifth generation (5G) mobile communication and subsequent evolved wireless network communication, sidelink communication usually has a power control mechanism. With the power control mechanism, transmit power of an information sending terminal in the sidelink communication can be adjusted, so that a relatively good reception effect can be always maintained for an information receiving terminal in the sidelink communication.
Generally, the power control mechanism of the sidelink communication is implemented by using an open-loop power control mechanism in the sidelink communication. Currently, open-loop power control for the sidelink communication may be implemented based on an open-loop power control method in Long Term Evolution (LTE). That is, the transmit power of the terminal device in the sidelink communication can be controlled in a centralized manner by using path loss (that is, Pathloss) between the terminal device and a network-side device. Specifically, the information sending terminal may calculate a basic open-loop operation point based on a static parameter or a semi-static parameter delivered by the network-side device, and may determine, based on the obtained basic open-loop operation point, the transmit power of the information sending terminal in the sidelink communication.
Open-loop power control for the sidelink communication can be implemented in the foregoing manner; however, with open-loop power control for the sidelink communication, a relatively good information reception effect cannot be always ensured for the information receiving terminal in the sidelink communication, and power control in the sidelink communication features poor accuracy, resulting in power wastes and deteriorated overall performance of the communication system. Therefore, in 5G and subsequent evolved wireless network communication, a more optimized or reliable power control scheme needs to be provided for the sidelink communication.

Sidelink power control method and terminal device


A power lag compensation device is provided including a housing. A socket assembly is situated within the interior space of the housing for releasably receiving a plug connected to an appliance for being in electrical communication therewith. A plug assembly is mounted on the housing and extended therefrom exterior of the housing. The plug assembly includes a pair of spaced parallel rectangular prongs. The rectangular prongs each have an associated interconnect wire connected to a corresponding socket of the socket assembly. The plug assembly serves to releasably insert within a socket which is connected to an alternating current power source. A triggering mechanism is connected in communication with one of the interconnect wires within the housing. The triggering mechanism is adapted for producing an activation signal upon the detection of a current flow therethrough. A triac is connected between the interconnect wires within the housing with the triac having a gate connected to the triggering mechanism for allowing communication between the interconnect wires only during the receipt of the activation signal. Finally, a capacitor is connected between the interconnect wires in series with the triac means for providing a predetermined amount of power lag compensation when the triac means is in receipt of the activation signal.

1. Field of the Invention
The present invention relates to power lag compensators and more particularly pertains to a new retrofittable energy saving device for lengthening the life of appliances, saving energy and reducing the load on power utilities.
2. Description of the Prior Art
The use of power lag compensators is known in the prior art. More specifically, power lag compensators heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art power lag compensators include U. S. Pat. No. 4,876,497; U.S. Pat. No. 3,932,808; U.S. Pat. No. 4,554,502; U.S. Pat. No. 5,387,821; U.S. Pat. No. 4,356,440; and U.S. Pat. No. Des. 244,095.
In these respects, the retrofittable energy saving device according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of lengthening the life of appliances, saving energy and reducing the load on power utilities.


A racemic compound of the formula (1) ##STR1## and an anti-ferroelectric liquid crystal composition consisting essentially of said racemic compound and one anti-ferroelectric liquid crystal compound of the formula (2) or a mixture of two or more compounds selected from anti-ferroelectric liquid crystal compounds of the formula (2), ##STR2## said composition of the present invention, exhibiting a small spontaneous polarization and a fast response so that a display device having a high display quality can be achieved.

(1) Field of the Invention
The present invention relates to a novel racemic compound, a novel anti-ferroelectric liquid crystal composition containing the compound and a liquid crystal display device for which the composition is used.
(2) Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98.
A liquid crystal display device has been so far applied to a small-sized display device of various types due to its low-voltage operability, low-power consumption and display capability with a thin screen. Further, the liquid crystal display device is recently practically being applied to the fields of information and office automation-related machines and equipment and the field of television sets, and simultaneously, it is being applied to various fields of other use.
Under the circumstances, energetic developments are under way for attaining a large-sized liquid crystal display device of higher performance that has a higher display capacity and a higher display quality than a conventional CRT display device.
Liquid crystals used in currently available liquid crystal display devices are nematic liquid crystals, and they are classified into simple matrix driven liquid crystal devices and active matrix driven liquid crystal devices according to their driving methods.
Simple matrix driven liquid crystal display devices are produced advantageously in view of a cost due to their simple structures. However, these devices have the problems that the contrast is low due to a cross-talk phenomenon, that driving in a large capacity is difficult and that the display of video frames at a high duty ratio is difficult due to a low response speed. It is therefore necessary to break through many technical problems for attaining a large-sized liquid crystal display device capable of displaying video frames at a high duty ratio.
On the other hand, active matrix driven liquid crystal devices use a TFT (thin film transistor) method as a main stream, but it is required to form thin film transistors for each pixel, and a large investment is required for high production technology and the construction of a production line. The active matrix driving method is therefore far disadvantageous in view of a cost as compared with the simple matrix driving method. However, the active matrix driven liquid crystal device has a high contrast since the cross-talk phenomenon which is a problem of the simple matrix driving method is few, and further, its response speed is high. Therefore, there can be attained a liquid crystal display device which has a high image quality and is capable of displaying video frames at a high duty ratio. For this reason, the TFT method among the active matrix driving methods is gaining its position as a main stream.
At present, large-sized liquid crystal devices having a size of 10 to 20 inches are being developed, while the problem of viewing angle dependency, which is inherent to a device using the nematic liquid crystal, is critically serious. Various technical studies have been made for overcoming the viewing angle dependency, and as a result, displaying with a viewing angle of about 140.degree. has been possible without causing a gray scale inversion. However, the contrast is still dependent greatly upon a viewing angle, and at present, there cannot yet be obtained such flat contrast characteristics with regard to the wide viewing angle as achieved in CRT.
Under the above circumstances, a liquid crystal display device using a ferroelectric liquid crystal attracts attention as a fast response liquid crystal display device. A surface stabilized ferroelectric liquid crystal (SSFLC) device disclosed by Clark and Lagerwall attracts attention due to its high response speed and wide viewing angle which have not been available in the past. Its switching characteristics have been studied in detail, and a number of ferroelectric liquid crystal compounds have been synthesized for optimizing various physical property constants.
On the other hand, for accomplishing a practical device, there have been a number of technical barriers to be overcome such as difficulties in achieving a memory effect and controlling a layer structure due to the difficulty in controlling an alignment, the destruction of an alignment caused by a mechanical shock, and the like, and these problems have been overcome to produce a device as a product.
However, the ferroelectric liquid crystal display device still has problems that it cannot display colors since it cannot handle, in principle, a gray scale and that the display of video frames is difficult because high speed response has not been attained yet.
Further, as another high speed response liquid crystal display device, the development of a device having a switching mechanism different from that of SSFLC is also under way. This is a liquid crystal display device which utilizes switching among tri-stable states of a liquid crystal having an anti-ferroelectric phase (to be referred to as "anti-ferroelectric liquid crystal" hereinafter) (Japanese Journal of Applied Physics, Vol. 27, pp. L729, (1988)).
The anti-ferroelectric liquid crystal has the following three stable states.
That is, the above three stable states are two uniform states (Ur, Ul) observed in two ferroelectric crystal states and one third state. Chandani et al report that the above third state is an anti-ferroelectric phase (Japanese Journal of Applied Physics, vol. 28, pp. L1261 (1989) and Japanese Journal of Applied Physics, vol. 28, pp. L1265 (1989)).
The above switching among the tri-stable states is the first characteristic of an anti-ferroelectric liquid crystal.
The second characteristic of the anti-ferroelectric liquid crystal is that a sharp threshold is present with regard to an applied voltage.
Further, it has a memory effect when a proper bias voltage is set, which is the third characteristic of the anti-ferroelectric liquid crystal.
Further, the fourth characteristic of the anti-ferroelectric liquid crystal is that its layer structure can be easily switched when an electric field is applied (Japanese Journal of Applied Physics, Vol. 28, pp. L119, (1989), and vol. 29, pp. L111 (1990)). Owing to this characteristic, a liquid crystal display device almost free of defects and having self-restoring ability of the alignment can be produced.
By utilizing those characteristics described above, a liquid crystal device having a high response speed and an excellent contrast can be achieved.
Further, it has been demonstrated that the gray shade display, which is almost impossible to achieve with a ferroelectric liquid crystal device, is possible to achieve with an anti-ferroelectric liquid crystal device. It has been consequently made possible to shift toward a full-color display, and the importance of an anti-ferroelectric liquid crystal is further increasing (Preprints of No. 4 Ferroelectric Liquid Crystal International Symposium, page 77, (1993)).

Racemic compound and anti-ferroelectric liquid crystal composition containing the compound


Polymeric derivatives of indoles such as

It has been found that a family of protein kinases, namely cyclin-dependent kinases or CDKs, play a central role in the cell division cycle. Deregulation of CDK activity has been documented in a number of human primary tumors and tumor cell lines, see Kamb, A. Cyclin-dependent kinase inhibitors and human cancer, Curr. Top. Microbiol. Immunol., 227: 139-148, 1998. It stands to reason therefore that preferential inhibition of these kinases would be key in the treatment or prevention of proliferative diseases.
Paullones represent a novel class of small molecule CDK inhibitors. They are a family of benzazepinones with promising antitumoral properties. Recently, paullones have been described as potent ATP-competitive inhibitors of the cell cycle regulating cyclin-dependent kinases. They are also indicated as potent inhibitors of glycogen synthase kinase-3B (GSK-3B) and the neuronal DCK5/p25, see Leost et al., Paullones are potent inhibitors of glycogen synthase kinase-3B and cyclin-dependent kinase 5/p25, Eur. J. Biochem., 267: 5983-5994, 2000.
Several chemical agents that are selective CDK inhibitors are known or have been developed such as lactones (e.g. butyrolactone I), flavonoids (e.g. flavopiridol) and purine derivatives to name a few. Some have shown antiproliferative activity for colon and pancreatic carcinoma cell lines. Flavopiridol has entered clinical trials as an anticancer agent. Paullones have been compared to these known compounds and have been found to be equipotent with respect to CDK inhibition.
One lead stucture alsterpaullone (9-nitro-7,12-dihydroindolo-[3,2-d][1]benzazepin-6(5H)-one, has been derivatized at both the lactam and/or indole portion in an effort to increase anti-tumor activity. Although the CDK inhibition activity remains high, the antiproliferative activity remains poor throughout the paullone family. One explanation could be the insolubility of these compounds.
Over the years, several methods of administering biologically-effective materials to mammals have been proposed. Many medicinal agents are available as water-soluble salts and can be included in pharmaceutical formulations relatively easily. Problems arise when the desired medicinal agent is either insoluble in aqueous fluids or is rapidly degraded in vivo. Paullones are often especially difficult to solubilize.
One way to solubilize medicinal agents is to include them as part of a soluble prodrug. Prodrugs include chemical derivatives of a biologically-active parent compound which, upon administration, eventually liberate the parent compound in vivo. Prodrugs allow the artisan to modify the onset and/or duration of action of an agent in vivo and can modify the transportation, distribution or solubility of a drug in the body. Furthermore, prodrug formulations often reduce the toxicity and/or otherwise overcome difficulties encountered when administering pharmaceutical preparations. Typical examples of prodrugs include organic phosphates or esters of alcohols or thioalcohols. See Remington's Pharmaceutical Sciences, 16th Ed., A. Osol, Ed. (1980), the disclosure of which is incorporated by reference herein.
Prodrugs are biologically inert or substantially inactive forms of the parent or active compound. The rate of release of the active drug, i.e. the rate of hydrolysis, is influenced by several factors but especially by the type of bond joining the parent drug to the modifier. Care must be taken to avoid preparing prodrugs which are eliminated through the kidney or reticular endothelial system, etc. before a sufficient amount of hydrolysis of the parent compound occurs.
Incorporating a polymer as part of a prodrug system has been suggested to increase the circulating life of a drug. However, it has been determined that when only one or two polymers of less than about 10,000 daltons are conjugated to certain biologically active substances such as alkaloid compounds, the resulting conjugates are rapidly eliminated in vivo, especially if a somewhat hydrolysis-resistant linkage is used. In fact, such conjugates can be so rapidly cleared from the body that even if a hydrolysis-prone ester linkage is used, not enough of the parent molecule is regenerated in vivo to be therapeutic.
Paullones are often poorly water soluble and are examples of substances which would benefit from PEG prodrug technology.
Attempts to increase the antiproliferative activity of the paullones has been reported. See Kunick et al., 2-Substituted Paullones. CDK1/Cyclin B-Inhibiting Property and In Vitro Antiproliferative Activity, Bioorganic & Medicinal Chemistry Letters, 10: 567-569, 2000. However, the study concentrates on substitution at the 2 position of 9-trifluoromethyl-paullones specifically with groups such as cyano, and carbon chain esters and ethers of varying length and saturation. The study does not solve the problem of maintaining CDK activity while increasing antiproliferative activity or improving the solubility of paullone analogs.
Thus, there still exists a need for derivatized heteroaromatic amine-containing compounds, for example, indole-containing compounds such as paullones, that exhibit potent preferential CDK inhibition combined with high antiproliferative activity. The present invention addresses this need.

Abstract: are disclosed. Methods of making and using the same as well as related polymeric conjugates are also disclosed.


A liquid polymer-salt solution as a desiccant in an air conditioning system comprised of a heat-pipe having its heat absorber section in an outside air inlet duct following water vapor adsorption into the desiccant by a contacter section of a dehumidifier, and the heat-pipe having its heat rejecter section in an exhaust air duct and preferably preceeding water vapor discharge from the desiccant by a regenerater section of the dehumidifier.

This invention relates to air conditioning wherein the intake of outside air is dehumidified. Heretofore, the desiccants employed have been expensive and because of their corrosive nature the dehumidifying section of air conditioning equipment has been fabricated of exceedingly expensive corrosive resistant materials, for examples calcium chloride or lithium chloride desiccants employing copper-nickel steel equipment is the usual requirement. Accordingly, it is a primary object of this invention to provide a relatively inexpensive and less corrosive desiccant, and a desiccant that is economically effective and which is adapted to use in relatively inexpensive equipment made of commercial grade materials such as steel that is protectively coated as by a paint or sealant, plating, or galvanizing and the like. It is cost effective dehumidification which is an object of this invention, all of which is accomplished without change to the downstream refrigeration and/or heating equipment.
There are a number of materials known to be useful as desiccants and particularly polymers proposed to be used as solids adapted to absorb water and to be regenerated as by drying for repeated use. However, the use of solid desiccant involves equipment implementation that can become bulky and oversized due to the nature of volume increase by the cube of the structural dimensions. With solid polymer the composition of the desiccant in a substrate is fixed. Therefore, the water uptake is dependent only upon temperature. However, with an aqueous polymer solution the liquid concentration can be variable, so that the water uptake is controllable, since the vapor pressure, concentration and temperature are all adjustable so as to maximize their functions. It is therefore an object of this invention to avoid objectionable size increase in the equipment by employing liquid polymers which avoid the same as capacity requirements increase, since they are fluid and are therefore more versatile in their applications. Such polymers which are feasible to be used as packed desiccants are:
Polystyrene sulfonic acids sodium salt PA1 Polyacrylic acid ammonium salt PA1 Poly (methacrylic acid) sodium salt PA1 Poly (n-vinylacetamide vinyl sulfonate) sodium salt PA1 Polyacrylic acid sodium salt PA1 Cellulose sulfonate sodium salt PA1 Methyl cellulose
However, it is a liquid desiccant of polymer material with which this invention is concerned, and to this end it is an object to provide the same in the form of hygroscopic fluids as a desiccant, rather than in the form of solid salts.
Water vapor sorption by polymers is a recognized advantage, however there is criticality involved in the salt to be employed therewith, the water uptake capability being most important. The ion-dipole interaction is therefore to be considered, reference being made to FIGS. 3a, 3b and 3c of the drawings, which illustrate the comparisons between the use of Lithium, Sodium and Potassium. It becomes apparent that the Lithium ion Li+ accommodates a far greater amount of water, of the three, due to its small cationic size as compared with either Sodium Na+ Potassium K+. The atomic weight and corresponding cationic size of various elements are considered, as follows:
______________________________________ Li Lithium 6.9 Na Sodium 23 K Potassium 39 Ca Calcium 40 Ca Cesium 133 ______________________________________
Therefore, it is an object of this invention to employ any one of the known salts in the sulfonation of the aforementioned polymers to be employed in a liquid form as a hygroscopic liquid, especially as a desiccant. Accordingly, Polystyrene Sulfonic Acid Lithium Salt Solution or PSSALS is a preferred embodiment herein (see FIG. 5b).
It is an object of this invention to implement the advantages of a polymer-salt solution in dehumidification equipment, as a low cost unit or section of equipment applicable to existant refrigeration air conditioning equipment, without major change thereto. Air conditioning involves generally, an outside air supply, a supply air discharge into a building interior, return air intake from the building interior, and a relief air discharge. The polymer-salt solution dehumidifier of the present invention is adapted to the outside air intake and to the relief air discharge of the existent air conditioning equipment. It is an object of this invention to advantageously employ the outside supply air intake temperature for desiccant treatment. It is also an object of this invention to advantageously employ a heat-pipe to extract heat after dehumidifier intake section herein disclosed replaces an air intake or power section of usual equipment and is preferably attached to a blower section unit that separates the relief air from the return air, as shown.
An air conditioning system involves the discharge of relief air that is replaced by outside supply air. The volume ratio of these two columns of air varies as a result of variations in leakage from the conditioned air spaced involved, the relief air being stale interior air retrieved at a place or places of higher interior temperature and where stale air exists. Consequently, relief air is substantially warmer than supply air (the conditioned air), it being an object of this invention to advantageously employ warmer relief air before its discharge as exhaust air, by dissipating its usable heat energy through the regenerater section of the dehumidifier. It is still another object of this invention to advantageously employ the heat energy rejected by the heat pipe, or pipes, for this purpose, as disclosed in each of the embodiments of this invention as later described.
In a second embodiment of this invention, FIG. 4, the adsorption element of the dehumidifier is a heat exchanger over which the polymer-salt solution is wetted and through which a coolant is circulated for reduced temperature intake air into the air conditioning equipment. In practice, the coolant is controlled and circulated by a pump, over or through a heat exchanger, and chilled or cooled as by means of an evaporative cooling tower (employing water). The heat-pipe relationship remains the same as in the first embodiment.
In a third embodiment of this invention, FIG. 6, the adsorption element of the dehumidifier is the absorber section or hot end of the heat-pipe and over which the polymer-salt solution is wetted for water vapor sorption and through which the heat-pipe refrigerant recirculates for heat absorption. There is a simultaneous heating effect and cooling effect on the outside supply air, said air being heated as a result of the water vapor sorption by the polymer-salt solution while being cooled as a result of heat adsorption by the hot end of the heat-pipe. It is to be understood that the use of a hygroscopic desiccant liquid involves regeneration through the application of heat, which is shown herein generally as a supplemental heat source, all according to state of the art processes. In accordance with this invention, regeneration is by means in the discharge of relief air over the heat rejector section or cold end of the heat-pipe.
In a fourth embodiment of this invention, FIG. 9, a central regenerater unit services a multiplicity of dehumidifier contactor sections. That is, a multiplicity of dehumidifier means, each serving an independent air conditioning unit, commingles weakened desiccant to be strengthened by a single regenerater section or unit. This combination reduces the complexity of the dehumidifier means operable with each air conditioner unit, and makes possible the use of a larger most efficient regenerater unit for cost efficient operation.
In a fifth embodiment of this invention, FIG. 10, the regenerater section is a self contained and self operable unit wherein heat is the prime mover directly applied to the water saturated desiccant without resort to contact with blower motivated air. Reference is made to the polymer-salt desiccant solution disclosed herein as the preferred hygroscopic liquid for the adsorption of water vapor. This preferred desiccant is known to be more viscous than the usual prior art desiccant such as Lithium Chloride, and through spray bar distribution is practical in the contacter section of a dehumidifier means, regeneration by means of spray bar and interface heat application presents liquid handling problems, because of the higher viscosity. It is an object of this invention, therefore, to directly process the weakened higher viscosity desiccant through a multi effect boiler concentrater, using the direct application of heat in a first high pressure stage followed by at least one or more lower pressure stages and with a counter flow of desiccant from which water vapor is driven out of the weakened water saturated liquid and returned to the contacter section or sections as strengthened desiccant.

Polymer desiccant and system for dehumidified air conditioning


The construction of a medical device having a disposable element is disclosed. Detachable elements comprising a body having a retention feature, an electrical contactor, and sensors are also disclosed. Further disclosed are detachable elements comprising a body having a hole and a retention pocket, an electrical contactor, and a printed circuit board assembly (PCB) in contact with the innermost surface of the body that forms the retention pocket. Further disclosed are detachable elements comprising a body having an opening and a printed film comprising conductive elements, where the conductive elements comprise a sensor configured to be aligned with the opening to expose the sensor. Further disclosed are reusable components having matching retention features.

A printed circuit board (PCB) is employed in medical devices as a flat base that physically supports and electronically connects electronic components and conductors. PCBs may be single-sided, double-sided, and multilayered. PCBs are currently retained in device frames by either adhesive or provision of a lip in the frame that captures the edge of the PCB.

This patent is subject to a terminal disclaimer.


New negative-acting photoresist compositions are provided that are particularly useful for imaging at short wavelengths, particularly sub-200 nm wavelengths such as 193 nm. Resists of the invention provide contrast between exposed and unexposed coating layer regions through crosslinking or other solubility switching mechanism. Preferred resists of the invention include a resin component that contains repeat units that facilitate aqueous base solubility.

1. Field of the Invention
The present invention relates to new negative-acting photoresist compositions that are particularly useful for imaging at short wavelengths, particularly sub-200 nm wavelengths such as 193 nm. Resists of the invention provide contrast between exposed and unexposed coating layer regions through crosslinking or other solubility switching mechanism. Preferred resists of the invention include a resin component that contains repeat units that facilitate aqueous base solubility.
2. Background
Photoresists are photosensitive films used for transfer of images to a substrate. A coating layer of a photoresist is formed on a substrate and the photoresist layer is then exposed through a photomask to a source of activating radiation. The photomask has areas that are opaque to activating radiation and other areas that are transparent to activating radiation. Exposure to activating radiation provides a photoinduced chemical transformation of the photoresist coating to thereby transfer the pattern of the photomask to the photoresist-coated substrate. Following exposure, the photoresist is developed to provide a relief image that permits selective processing of a substrate.
A photoresist can be either positive-acting or negative-acting. For most negative-acting photoresists, those coating layer portions that are exposed to activating radiation polymerize or crosslink in a reaction between a photoactive compound and polymerizable reagents of the photoresist composition. Consequently, the exposed coating portions are rendered less soluble in a developer solution than unexposed portions. For a positive-acting photoresist, exposed portions are rendered more soluble in a developer solution while areas not exposed remain comparatively less developer soluble. Photoresist compositions are described in Deforest, Photoresist Materials and Processes, McGraw Hill Book Company, New York, ch. 2, 1975 and by Moreau, Semiconductor Lithography, Principles, Practices and Materials, Plenum Press, New York, ch. 2 and 4.
While currently available photoresists are suitable for many applications, current resists also can exhibit significant shortcomings, particularly in high performance applications such as formation of highly resolved sub-half micron and sub-quarter micron features.
Consequently, interest has increased in photoresists that can be photoimaged with short wavelength radiation, including exposure radiation of about 250 nm or less, or even about 200 nm or less, such as wavelengths of about 248 nm (provided by KrF laser) or 193 nm (provided by an ArF exposure tool). See European Published Application EP915382A2. Use of such short exposure wavelengths can enable formation of smaller features. Accordingly, a photoresist that yields well-resolved images upon 248 nm or 193 nm exposure could enable formation of extremely small (e.g. sub-0.25 μm) features that respond to constant industry demands for smaller dimension circuit patterns, e.g. to provide greater circuit density and enhanced device performance.
More specifically, current photoresists can be highly opaque to extremely short exposure wavelengths such as 193 nm, thereby resulting in poorly resolved images.
Most efforts to date for imaging at 193 nm have been directed positive-acting resists. Certain reports have been made of negative resists for imaging at 193 nm. See U.S. Pat. Nos. 6,146,806; 6,140,010; and 6,103,449.
It thus would be desirable to have new photoresist compositions, particularly resist compositions that can be imaged at short wavelengths such as sub-200 nm exposure wavelengths, particularly 193 nm. It would be particularly desirable to have new negative-acting resists that could be imaged at sub-200 nm wavelengths, such as 193 nm.

Negative photoresists for short wavelength imaging


A mutability mechanism is provided for parsing an object at loading time. The mutability mechanism inserts a property into the object that indicates whether or not the object is immutable. The mutability mechanism looks at the code for the object and determines whether any other objects can modify the object. If the object cannot be modified after it is created, then the new property is set to indicate that the object is immutable; otherwise, the property is set to indicate that the object is mutable. This property can be inspected at runtime when a call is made to a program object. If an object passed as an argument is marked mutable, a clone of this object must be passed to the callee. However, if an object passed as an argument is marked immutable, a simple reference to the object may be passed as an argument to the callee.

Java is an object oriented programming language and environment focusing on defining data as objects and the methods that may be applied to those objects. Java supports only a single inheritance, meaning that each class can inherit from only one other class at any given time. Java also allows for the creation of totally abstract classes known as interfaces, which allow the defining of methods that may be shared with several classes without regard for how other classes are handling the methods. Java provides a mechanism to distribute software and extends the capabilities of a Web browser because programmers can write an applet once and the applet can be run on any Java enabled machine on the Web.
Java objects may invoke other Java objects. Enterprise Java Beans (EJB) is a component software architecture that is used to build Java applications (objects) that run in a server. EJB uses a "container" layer that provides common functions such as security and transaction support and delivers a consistent interface to the applications regardless of the type of server.
Currently, the EJB 1.0 and 1.1 specification requires the implementation of a call by value as opposed to a call by reference for the invocation of EJBs. This same requirement may apply to future versions of the EJB or other programming specifications. When the EJB lives in the same container as the caller, it is more efficient to pass a reference to objects used by the EJB rather than making a copy of the object. However, passing a reference exposes the caller to corruption of the passed object.
There are instances, however, when a passed object does not need to be copied because it is immutable, meaning that once the object is created it cannot be modified. In these instances, the object may be referenced because there is no danger of corruption and the semantic of pass by value is maintained.
In the prior art, the solution used by Application Server vendors is to provide an override at runtime allowing the customer to choose to pass by reference rather than by value. Although this provides better performance, it also exposes the customer to a violation of the EJB specification and the object may be corrupted if it is not immutable.
Therefore, it would be advantageous to provide a method, apparatus, and program to determine the mutability of an object at loading time to avoid unnecessarily copying an object when passing the object as an argument when invoking a program object.

Method, apparatus, and program to determine the mutability of an object at loading time

International Business Machines Corporation


The invention relates to a liquid crystal display used in a television receiver or a display section of an electronic apparatus and provides a liquid crystal display having a wide viewing angle and high viewing angle characteristics. The viewing angle characteristics of low gradations are improved by the capacitive coupling HT method. The viewing angle characteristics of high gradations above the intermediate gradation are improved by the driving HT method. A liquid crystal is driven using the capacitive coupling HT method and the driving HT method in combination to combine the effect of improvement of both methods, thereby improving the viewing angle characteristics of a liquid crystal display for a wide range from a low gradation to a high gradation.

1. Field of the Invention
The present invention relates to a liquid crystal display used in a television receiver or a display section of an electronic apparatus.
2. Description of the Related Art
FIGS. 22A and 22B show an example of a configuration of an MVA (Multi-domain Vertical Alignment) type liquid crystal display. FIG. 22A schematically shows a sectional structure of a liquid crystal display panel 101. FIG. 22B shows a structure of one pixel of the MVA type liquid crystal display panel 101 as viewed in a direction normal to the display screen. As shown in FIGS. 22A and 22B, the liquid crystal display panel 101 has a TFT substrate 102 on which thin film transistors (TFTs) 110 are formed and an opposite substrate 103 on which a common electrode and a color filter (CF) layer are formed. The substrates 102 and 103 are combined using a peripheral sealing material 105. A liquid crystal layer 104 is sealed between the substrates 102 and 103. A predetermined gap (cell gap) is maintained by spacers 106 between the TFT substrate 102 and the opposite substrate 103. The call gap may be maintained at the predetermined value by spacers in the form of protrusions instead of the spacers 106. A polarizer 107 is disposed, for example, on a crossed Nicols basis on each of surfaces of the TFT substrate 102 and the opposite substrate 103 opposite to the sides of the substrate facing each other. A mounting terminal 108 for mounting a liquid crystal driving IC (not shown) is formed on the TFT substrate 102.
As shown in FIG. 22B, the TFT substrate 102 includes a gate bus line 112 formed to extend in the horizontal direction in the figure and a drain bus line 111 formed to extend in the vertical direction in the figure across the gate bus line 112 with an insulation film interposed between them. A TFT 110 for driving the pixel is formed in the vicinity of an intersection between the bus lines 111 and 112. A part of the gate bus line 112 serves as a gate electrode of the TFT 110. A drain electrode (D) of the TFT 110 is electrically connected to a drain bus line 111. A source electrode (S) of the TFT 110 is electrically connected to a pixel electrode 109 formed in a pixel region defined by the bus lines 111 and 112. A storage capacitor bus line 117 is formed so as to extend across the pixel region in parallel with the gate bus line 112. A storage capacitor electrode (intermediate electrode) 116 is formed at each pixel above storage capacitor bus line 117 with an insulation film interposed between them. A storage capacitor Cs is formed by the storage capacitor bus line 117, the storage capacitor electrode 116, and the insulation film sandwiched between them.
The pixel electrode 109 is formed with slits 114 which are blanks in the electrode material. Linear protrusions 115 are formed on the opposite substrate 103. The slits 114 and the linear protrusions 115 serve as alignment regulating structures for regulating the direction in which liquid crystal molecules (not shown) in the liquid crystal layer 104 are tilted when a voltage is applied. The pixel region is divided into domains in which liquid crystal molecules are tilted in four respective directions because of the slits 114 and the linear protrusions 115. Since the liquid crystal 103 is tilted in four directions, a bias of the viewing angle of the display panel is leveled when compared to that of a liquid crystal display in which a liquid crystal is tilted only in one direction. A significant improvement in viewing angle characteristics is thus achieved. Such a technique is referred to as a domain division technique.
FIG. 23 schematically shows a sectional structure of an MVA type liquid crystal display employing the domain division technique. FIG. 23A shows a state of the section observed when no voltage is applied to the liquid crystal layer 104. FIGS. 23B and 23C show a state observed when a voltage is applied to the liquid crystal layer 104. Referring to FIGS. 23A and 23B, the linear protrusions 115 serving as alignment regulating structures are formed on both of the opposite substrate 103 on which the pixel electrode 118 and a vertical alignment film 119 are formed in the order listed and the TFT substrate 102 on which the pixel electrode 109 is formed. Referring to FIG. 23C, the slits 114 serving as alignment regulating structures are formed only on the TFT substrate 102. Although not shown, the linear protrusions 115 may be provided on only one of the substrates.
As shown in FIG. 23A, liquid crystal molecules 120 are aligned substantially perpendicularly to a surface of the TFT substrate 102 when no voltage is applied. When a voltage is applied between the substrates 102 and 103, as shown in FIG. 23B, the liquid crystal molecules 120 are tilted in directions which are determined by the shape of the linear protrusions 115. As shown in FIG. 23C, when a voltage is applied between the substrates 102 and 103 in the structure formed with the slits 114, the tilting direction of the liquid crystal molecules 120 is determined by an effect of an electric field generated in the liquid crystal layer 104. Although not shown, some known liquid crystal display panels have a structure in which linear protrusions 115 are formed on either of substrates 102 and 103 and in which slits 114 are formed on the other substrate. Such a structure is most commonly used in existing MVA type liquid crystal displays.
Patent Document 1: JP-A-2-12
Patent Document 2: U.S. Pat. No. 4,840,460
Patent Document 3: Japanese Patent No. 3,076,938
Patent Document 4: JP-A-2002-333,870
FIG. 24 is a graph showing transmittance characteristics relative to applied voltages (T-V characteristics) of a VA (Vertically Aligned) type liquid crystal display. The abscissa axis represents voltages (V) applied to the liquid crystal layer, and the ordinate axis represents light transmittance. The curve A connecting black circles in the figure indicates T-V characteristics in a direction perpendicular to the display screen (hereinafter referred to as a square direction). The curve B connecting asterisks in the figure indicates T-V characteristics in a direction at an azimuth angle of 90° and a polar angle of 60° to the display screen (hereinafter referred to as an oblique direction). An azimuth angle is an angle measured counterclockwise with reference to the direction to the right of the display screen. A polar angle is an angle to a line vertical to the center of the display screen.
As shown in FIG. 24, there is a distortion of transmittance (luminance) in the vicinity of the region enclosed by the circle C. For example, transmittance in the oblique direction is higher than transmittance in the square direction for relatively low gradations appearing a voltage of about 2.5 V is applied, whereas the transmittance in the oblique direction is lower than the transmittance in the square direction for relatively high gradations appearing when a voltage of about 4.5 V is applied. As a result, there are small differences in luminance within the range of effective driving voltages when the screen is viewed in the oblique direction. This phenomenon is most significantly observes as variation of a color.
FIGS. 25A and 25B show variation of a view of an image displayed on a display screen. FIG. 25A shows the image as viewed in a direction square to the screen, and FIG. 25B shows the image as viewed in an oblique direction. As shown in FIGS. 25A and 25B, when the display screen is viewed in the oblique direction, the color of the image appears more whitish than the view in the square direction.
FIGS. 26A, 26B, and 26C show gradation histograms of three primary colors, i.e., red (R), green (G), and blue (B) in a reddish image. FIG. 26A shows a gradation histogram of red. FIG. 26B shows a gradation histogram of green. FIG. 26C shows a gradation histogram of blue. The abscissa axes of FIGS. 26A to 26C represent gradations (256 gradations at levels 0 to 255), and the ordinate axes represent rates of presence (%). As shown in FIGS. 26A to 26C, relatively high gradations of red and relatively low gradations of green and blue are present in this image at high rates of presence. When such an image is displayed on the display screen of a VA type liquid crystal display and viewed in an oblique direction, red which is a light tone turns relatively darker, and green and blue which are dark tones turn relatively lighter. Since differences in luminance between the three primary colors consequently become small, the color of the screen as a whole becomes whitish.
As thus described, an MVA type or VA type liquid crystal display is excellent in viewing angle characteristics in a direction square to the same. However, the liquid crystal display has a problem in that its viewing angle characteristics are not satisfactory because the display screen as a whole appears in a whitish color when it is viewed in a direction oblique to the same. The problem described similarly occurs on a liquid crystal display of the TN (Twisted Nematic) type that is a driving method according to the related art.


Disclosed is an apparatus for assisting driving, including: a stereo camera module mounted in a vehicle, and configured to obtain a first image through a first camera and a second image through a second camera; and a processor configured to stereo-match the first image and the second image to obtain a dense disparity map, estimate a cubic b-spline curved line from the dense disparity map by using a coarse-to-fine method, and perform a road profile for two-dimensionally converting a 3D road, on which the vehicle travels, by using the cubic b-spline curved line.

In general, a vehicle is a transportation means for generating power through an engine thereof, transmitting the generated power to wheels, and transporting passengers or goods on a road. The vehicle may be generally divided into a body forming an exterior appearance, and a chassis in which various devices are organically connected. The chassis includes an engine of the vehicle, which generates driving force for driving, and main devices, such as a power transmission device, a steering device, a suspension device, and a brake device.
In the meantime, research on a stereo camera as a device for convenience of a vehicle has recently been actively conducted. The stereo camera simultaneously provides an image and distance information, so that the stereo camera has been widely researched for the purpose of recognizing a front driving environment.

Driving assistant apparatus of vehicle and operating method thereof

INDUSTRY-UNIVERSITY COOPERATION FOUNDATION HANYANG UNIVERSITY


An operational amplifier frequency self-compensated with respect to closed-loop gain comprises a transconductance input stage and an amplifier output stage connected serially together to receive an input signal on at least one input terminal of the amplifier and generate an amplified signal on an output terminal of the amplifier. Provided between the input and output stages is an intermediate node which is connected to a compensation block to receive a frequency-variable compensation signal therefrom. The compensation block is coupled with its input to the input terminal of the amplifier. The compensation block is connected to receive at least the feedback signal. Preferably, the compensation signal is variable as a function of a gain value which is determined by the feedback circuit, and said variation of the compensation signal occurs in a relationship of inverse proportionality to the gain value.

This invention relates to an operational amplifier which is frequency self-compensated with respect to closed-loop gain.
The operational amplifier of the preferred embodiment comprises a transconductance input stage and an amplifier output stage connected serially with each other to receive an input signal on at least one input terminal of the amplifier and generate an amplified signal on an output terminal of the amplifier. Also, an intermediate node is provided between the input and output stages which is connected to a compensation block to receive a frequency-variable compensation signal therefrom.
Reference is made, herein, by way of example and not of limitation, to non-predetermined gain systems wherein the integrated operational amplifier is either part of a single monolithically integrated device or, in a preferred embodiment, a separate circuit element.
As is well known, operational amplifiers are circuit elements of fundamental importance to electronic circuits, and are widely used in a variety of applications.
The most common construction of an operational amplifier basically comprises two serially connected stages, namely a transconductance input stage and an amplifier output stage.
Many applications involve the provision of an external feedback circuit which couples at least one output of the amplifier to an input thereof. Diagrams for a feedback operational amplifier, respectively in inverting and non-inverting configurations, are shown in FIG. 1a and 1b. The operational amplifier is schematically indicated at 1 and has an inverting input terminal IN- and a non-inverting input terminal IN+. In both figures, an output terminal OUT is feedback-connected to the inverting input terminal IN- by a feedback network, schematically represented by a resistor Rf. An input resistor Ri is connected to the inverting input IN-. A voltage signal Vs is input between a signal input IN of the fed-back amplifier and a ground line GND. The sign of the input voltage is in both cases inverted such that, in the inverting configuration, the input signal will be applied to the inverting input IN-, whereas in the non-inverting configuration, it will be applied to the other input IN+. The input voltage actually present across the two inputs of the amplifier is denoted by Vi, and the optionally amplified, output voltage present across the output OUT and the ground line GND is denoted by Vo. Also shown are an input current Ii and a feedback current If flowing through the resistor Rf.
A frequency-oriented analysis of the transfer function of the amplifier 1, that is of the mathematical law that governs the relationship between the input and output signals, enables the frequency-wise behavior and stability of the fed-back amplifier to be determined. For the purpose, it is necessary to consider the transfer function G(s), where s is the complex variable. By transfer function, we mean here the modulo of the transfer function, for which the term gain or transfer ratio will be used as being more appropriate. With specific reference to FIGS. 1a and 1b, Vo=-G(s)Vi. Reference will be made hereinafter to open-loop transfer functions, that is having no external feedback, as denoted by G.sub.ol (s), and to closed-loop functions, as denoted by G.sub.cl (s).
In connection with the stability problems of fed-back circuits, it is generally necessary at the designing stage that attention be paid to possible problems of frequency response therefrom. The need for the fed-back amplifier to be a stable one, even at high frequencies and regardless of the external feedback, means in particular that an open-loop transfer function with suitably located poles and zeros must be provided.
It should be considered that the transfer function has a certain number of poles at certain frequencies, mainly due to the presence of capacitances. With an operational amplifier, these are primarily parasitic capacitances internal of the circuit and loads connected to the amplifier output.
The effects of a pole are, on the one side, a lowering circuit gain from its frequency value at a constant rate of decrease, and on the other side, the introduction of a phase shift, that is a phase change in the transfer function. Furthermore, an interaction with following poles enhances the effect on gain from the individual pole.
FIG. 2 shows, in deciBels and on a log scale, the open-loop gain pattern for an ideal operational amplifier as a function of the frequency f. Only the two main poles of the transfer function are shown for the amplifier, namely a first or dominant pole p1 at a low frequency f1 and a second or non-dominant pole p2 at a high frequency f2.
As can be seen, the non-dominant pole p2 locates here at gain values of less than one in modulo. A closed-loop configuration, that is the case of the feedback loop being closed, will be considered. With a closed-loop gain G.sub.cl of unity value, i.e. G.sub.cl =0dB, the corresponding frequency defined by the intersection of the open-loop function G.sub.ol with the frequency axis, the so-called cutoff frequency, precedes the frequency f2 that corresponds to the non-dominant pole p2. If, as in the ideal case illustrated, the frequency f2 is sufficiently higher than the frequency f.sub.t, the phase .phi. of the closed-loop transfer function is amply less than 180.degree.. This ensures the stability of the fed-back system, in conformity with Bode's criterion for phase and gain.
However, open-loop transfer functions usually exhibit the behavior shown in FIG. 3, which is typical of an unstable fed-back system. Notice that the frequency f2, corresponding to the second pole, is in fact lower than the cutoff frequency f.sub.t of the open-loop gain function G.sub.ol. Thus, the combined effects of the two poles resulting, after the second pole, in a doubled rate of gain decrease and combined phase shifts, are felt before the gain value G.sub.ol has dropped down to unity. Accordingly, the fed-back system with gain close to one has a limited phase margin from 180.degree..
The presence of further poles, not shown, at a higher frequency contributes toward making the fed-back amplifier even more unstable because the phase margin is still more restricted.
In the prior art, to obtain a desired pattern for the open-loop transfer function, effective to ensure the amplifier stability in the fed-back configuration, so-called compensation techniques have been used. These allow, in particular, the pole locations to be altered so as to bring the function profile close to that shown in FIG. 2.
A compensation circuit, commonly consisting of a compensation capacitor, is introduced for the purpose, which allows at least one of the main poles to be shifted in frequency so as to re-locate it. The publication "The Monolithic Op Amp: a Tutorial Study", IEEE Solid-State Circuits, Vol. SC-9, December 1974, pages 314-332 provides a detailed description of that technique, and is hereby incorporated by reference.
The compensation circuit may either be provided outside the device or, more frequently, inside the amplifier. Reference will specifically be made hereinafter to the latter option.
In general, a typical arrangement for compensating a fed-back operational amplifier by internal compensation may be that shown in FIG. 4. As previously mentioned, the amplifier comprises two blocks placed serially between an input terminal IN and an output terminal OUT: an input stage 2 and an output stage 3. Notice that, for simplicity, only the actual input and output terminals, respectively for receiving and generating the signal, have been shown in that figure. As shown in the figure, the blocks 2 and 3 provide amplifications -A1(f) and -A2(f), respectively, which are functions of the frequency f.
For the purpose of frequency compensation, the operational amplifier further includes a compensation block 4 connected between the output terminal OUT and a node S which lies intermediate the input stage 2 and the output stage 3. The block 4 is connected functionally to provide internal feedback, as explained herein below.
Assume, as shown in the figure, that the amplifier is fed back, that is that the output terminal OUT and input terminal IN of the operational amplifier are connected via a feedback circuit 5 outside the amplifier.
The amplifier receives an input signal, schematically illustrated by an arrow S.sub.in, which is specifically applied to the input terminal IN, and supplies an output signal S.sub.out at its output terminal OUT. The external feedback circuit 5 receives that same output signal S.sub.out and generates a feedback signal Sf proportional to the output signal S.sub.out, the proportionality factor being equal to the feedback factor .beta..sub.e (f), in turn tied to frequency, and is characteristic to the feedback circuit of choice. For example, where the feedback is simply provided by the resistor Rf, the factor .beta..sub.e (f) is determined by the split between Rf and the input resistor Ri. The feedback signal Sf is applied to the input terminal IN, represented in the figure by a summing node whereon the input signal S.sub.in and the feedback signal merge together. The compensation block also receives the output signal S.sub.out, and generates a compensation signal Sc which is proportional to the former by an internal feedback factor .beta..sub.i (f) characteristic to the compensation block 4. The compensation signal Sc is supplied to the intermediate node S constituting a further summing node for a signal, denoted by S1, from the input stage 2 and for the aforementioned compensation signal Sc.
Thus, the compensation block 4 produces an internal feedback of sort which is only determined by the amplifier output signal and is always present in the standard case.
As previously mentioned, the compensation feature consists in practice of a capacitive element, typically a capacitor having a capacitance in the range: of a few pF to a few tens of pF, when internal, and of about 100 pF when external. This capacitor is adapted to control the value of the dominant pole, and possibly of the following poles in certain circuit configurations of the amplifier. Basically, the compensation capacitor connected to the intermediate node between the input and output stages will vary the actual capacitance as seen from the aforementioned node, which is material to the determination of the main pole locations.
Among the most widely used compensation techniques are the so-called dominant pole one, which provide for a downward shift of one pole to make it dominant, thereby allowing the gain to attain a unity value while the other poles are still ineffective, and the pole splitting techniques which utilize Miller's Effect.
In the examples which follow, the pole splitting technique will be taken into consideration. The effect of this technique on the transfer function is indeed one of splitting, that is of moving the poles, specifically the two main poles, away from each other. This behavior is illustrated diagrammatically by FIG. 5. The poles p1' and p2' of the compensated amplifier, whose frequencies are denoted by f1' and f2', are shifted from the poles p1 and p2 of the uncompensated amplifier which correspond to the frequencies f1 and f2. In particular, the pole p1 is shifted to the pole p1', at a low dominant frequency f1'<f1. The pole p2 is shifted to the pole p2', at a high frequency f2'>f2.
With the compensated dominant pole at a lower frequency than the uncompensated one, the gain begins to drop at an earlier time, so that the gain function will attain unity value more rapidly. This, when added to the fact that the compensated non-dominant pole is shifted in the opposite direction from that of the dominant pole, ensures that the non-dominant pole is at a frequency exceeding the cutoff frequency f.sub.t by a sufficient margin. Thus, upon compensation, the transfer function will be a similar pattern to that shown in FIG. 2.
Known in the art are several embodiments of frequency-compensated operational amplifiers using a variety of technologies of both the MOS type, such as CMOS, NMOS or PMOS, and the bipolar type.
Shown in FIG. 6 is a first embodiment with CMOS technology of an operational amplifier having a traditional compensation wherein a compensation technique known as Miller's Compensation is used.
The operational amplifier comprises a NMOS output transistor, shown at Tg.sub.mo, having drain and source terminals respectively connected to the output terminal OUT of the amplifier and to ground GND. A current flow is forced through the transistor Tg.sub.mo by a current generator I.sub.po being connected to its drain terminal and powered from a supply terminal which is held at a constant voltage Vdd. The transistor Tg.sub.mo forms substantially the output stage 3 of the amplifier.
A gate terminal of the transistor Tg.sub.mo is connected, through an intermediate node S, to an output of a transconductance block 6 having a transconductance value g.sub.mi. This block also has first and second inputs, designated "+" and "-", which are respectively connected to the input terminals IN- and IN+ of the amplifier. The input stage 2 of the amplifier basically consists of the transconductance block 6 and the resistor ri connected to an output of the block 6 for which it forms the output resistance.
In accordance with prior art techniques, the compensation capacitor, denoted by C.sub.C in the figure, is connected between the gate and the drain of the output transistor Tg.sub.mo, that is between the intermediate node S and the output terminal OUT. This compensation capacitor C.sub.C forms the compensation block 4 of the amplifier.
The voltages Vi and Vo in the figure, which are respectively present across the input terminals IN- and IN+ and across the output terminal OUT and ground, represent the input voltage and the output voltage, respectively.
The compensation capacitor C.sub.C according to that prior art is, therefore, charged from the output. The voltage across it is equal, in fact, to the output voltage Vo, but for the gate-source voltage Vgs of the transistor Tg.sub.mo.
The capacitances C.sub.P, C.sub.L and C.sub.C, where C.sub.L and C.sub.P respectively are the load capacitance connected to the output terminal OUT and the parasitic capacitance present on the gate terminal of Tg.sub.mo, determine the locations of the poles and zeros of the open-loop transfer function of the compensated amplifier.
A calculation based on the equivalent circuit for small signals yields the main poles of the compensated amplifier of FIG. 6. These are identified, with due approximation, by the following relations: EQU p1'(M)=-1/(g.sub.mo r.sub.i r.sub.o C.sub.C) and EQU p2'(M)=-g.sub.mo *K.sub.M /(C.sub.P +C.sub.L) with K.sub.M =C.sub.C / (C.sub.P +C.sub.C)
where, g.sub.mo is the transconductance of the transistor Tg.sub.mo, and r.sub.o is the output resistance of the simplifier. By comparing to the poles of the uncompensated amplifier, a splitting effect of the kind shown in FIG. 5 can be noticed. Lacking compensation, the main poles are expressed, in fact, by p1=-1/r.sub.i C.sub.P and p2=-1/r.sub.o C.sub.L. The shift in the respective frequencies to be obtained from -2.pi./p is readily verified.
The provision of the compensation capacitor C.sub.C also introduces a zero z(M)=g.sub.mo /C.sub.C. This can be eliminated, however, by connecting in series with the compensation capacitor C.sub.C a compensation resistor with a value of 1/g.sub.mo.
A modification of the circuit in FIG. 6 provides, in order to eliminate the zero, for the introduction of a buffer or voltage follower consisting, for example, of a transistor connected in series with a current generator between the compensation capacitor and the output of the operational amplifier. In this way, the capacitor will have no undesired effects on the output voltage. The dominant pole is found from the same relation as in the previous case, whereas the non-dominant pole takes the form p2'(Mb)=-g.sub.mo C.sub.C /(C.sub.P +C.sub.C)C.sub.L.
A further compensation technique has been developed by Bhupendra Ahuja, and is described in detail, for example, in an article entitled "An improved frequency compensation technique for CMOS operational amplifiers", published in IEEE J. Solid-State Circuits, vol. SC-18, No. 6, December 1983, pages 629-633, which is hereby incorporated by reference.
An embodiment based on Ahuja's compensation principle is shown in FIG. 7. This embodiment is similar to that of FIG. 6, except that the compensation block 4 is here a more complicated design. Besides the compensation capacitor C.sub.C, in fact, an additional transistor TB and a pair of current generators I.sub.PI are provided.
The additional transistor TB is of the PMOS type and has a drain terminal connected to the intermediate node S, that is to the gate of Tg.sub.mo, as well as to a generator I.sub.PI, and a source terminal connected to the other generator I.sub.PI. Thus, a constant current is forced through TB. A gate terminal of TB is held at the constant potential VB.
The compensation capacitor C.sub.C has a terminal coupled to the node S through the additional transistor TB, and precisely, directly connected to the source terminal of the transistor TB. The voltage at this terminal of C.sub.C is, in this case, held substantially constant, equal in particular to the value of VB which, as mentioned, is fixed but for the gate-source voltage Vgs of the transistor TB. In a similar way to the circuit based on Miller's principle, the other terminal of C.sub.C is connected to the drain of Tg.sub.mo, that is to the output terminal OUT.
In calculating the characteristic quantities of the transfer function of the open-loop amplifier for this type of compensation, it should be considered that, to determine the non-dominant pole, the actual transconductance as seen from the output end is multiplied by a factor K.sub.A =C.sub.C /C.sub.P given by the particular circuit configuration. The following poles are obtained: EQU p1'(A)=-1/(g.sub.mo r.sub.i r.sub.o C.sub.C) and EQU p2'(A)=-g.sub.mo K.sub.A /(C.sub.C +C.sub.L).
Whereas the dominant pole is left unaltered, the non-dominant pole is shifted toward higher frequencies. Thus, the operational stability range is expanded frequency-wise compared to the previous case, for a compensation capacitor of the same value.
An operational amplifier compensated by conventional techniques of the kind just described has, however, certain drawbacks. Consider applications wherein the amplifier is to operate with different feedbacks, or wherein the closed-loop gain is not predetermined univocally, due to fluctuations in the working parameters during its operation. Take, for example, the instance of electrical systems having discrete elements, wherein the operational amplifier forms a circuit by itself, useful in applications of the audio or telephone type where the feedback can be selected by the user. Also, in a fully integrated device, let us consider the utilization of so-called variable-gain operational amplifiers.
Once the amplifier is designed and fabricated with preset compensation, and therefore, with the open-loop transfer function of the amplifier predetermined, the choice of the fed-back amplifier gain, or closed-loop gain, as determined by the external feedback and essentially by the resistance value applied in the feedback loop as previously explained, is restricted to a relatively narrow range of values.
It should be borne in mind, in this respect, that in the design of fed-back operational amplifiers, special care is taken to maximize the width of the frequency band wherein the amplifier will operate properly and be stable. The selection of certain closed-loop gain values clashes with the requirements for stability and a wide frequency response of the amplifier.
To make this concept more easily understood, two discrete values of closed-loop gain for an amplifier having a predetermined compensation have been shown in FIG. 8a. In FIG. 8b, the same gain values are shown for an amplifier having no compensation or having reduced compensation with respect to the other figure. The numerical gain values are denoted by G1 and G2, with G1>G2 and G2 close to one. The respective frequencies at which the open-loop gain function is cut off are referenced f1a and f2a in FIG. 8a, and f1b and f2b in FIG. 8b. Also shown at f1', f2' and f1, f2 are the frequencies of the main poles.
Where the feedback determines gain values G2 close to one, such as where the fed-back amplifier is configured as a follower, only the compensated amplifier is stable. To have matters better understood, the gain axis should be visualized as shifted to the gain value G2. The frequencies f2a and f2b would then become the cutoff frequencies. Since the frequency f2a precedes the frequency f2' of the non-dominant pole, i.e. f2a=f.sub.t <f2', the compensated amplifier will be stable, as explained hereinabove. The frequency f2b lies instead above the cutoff frequency, i.e. f2b=f.sub.t >f2, with attendant loss of stability for the uncompensated amplifier.
On the other hand, where a particular application requires a high gain, this adversely affects, the width of frequency response. As can be gathered from a comparison of the two figures, for a gain of G1, the width of the response frequency band is too narrow at the higher frequencies, where compensation is used, and is wider for an amplifier with little compensation. It can be seen, in fact, that f1a is significantly less than f1b.
Thus, depending on the particular compensation applied, for a particular choice of gain, one can incur stability problems, on the one side, and excessive constraint on the band and consequent loss of speed, on the other.
This problem is obviated in discrete element systems by using an external compensation capacitor which can be plugged in by the user according to the closed-loop gain value selected.
One underlying technical problem addressed by this application is to provide an operational amplifier which is frequency self-compensated according to the closed-loop gain present in a particular application at a particular time. The compensation value should be controlled automatically, without control from the user, for optimum performance in terms of speed of response and stability of the fed-back amplifier at any gain values.
In particular, an object of this invention is to provide a fed-back operational amplifier which is uniquely versatile, and can be connected in a variety of systems, such as programmable systems, by the user.
The idea underlying the preferred embodiment is that of providing an operational amplifier which includes a compensation capacitor, wherein the voltage across the capacitor is varied according to the feedback applied thereto, and hence to the closed-loop gain. For the purpose, one end of the capacitor is connected to receive a signal generated by the external feedback.
An operational amplifier frequency self-compensated with respect to closed-loop gain, preferably an integrated one, comprises a transconductance input stage and an amplifier output stage connected serially together to receive an input signal on at least one input terminal of the amplifier and generate an amplified signal on an output terminal of the amplifier. Provided between the input and output stages is an intermediate node which is connected to a compensation block to receive a frequency-variable compensation signal therefrom.
According to the preferred embodiment, the compensation block is input coupled to the input terminal of the amplifier. In essence, for frequency compensation, the output terminal is connected to the input terminal of the amplifier by a feedback network including a negative feedback circuit which generates a feedback signal. In the instance of an inverting feedback, the compensation block is downstream connected to the input terminal with respect to the input signal, so as to receive both the input signal and the feedback signal. Where the feedback is non-inverting, the compensation block is connected before the input terminal, toward the feedback network, so as to only receive the feedback signal, not the input signal.
The compensation signal generated by the compensation block is variable according to a gain value which is determined by the feedback circuit, and the compensation signal variation occurs in a relationship of inverse proportionality with the gain value.
In practical embodiments, the compensation block includes at least one storage element, specifically a compensation capacitor having a terminal coupled to the input terminal of the amplifier.
The invention is useful with conventional compensation techniques. In particular, in a preferred embodiment of the invention, the operational amplifier includes a compensation of the Ahuja type, and is preferably connected in a non-inverting configuration.
This invention can be applied to systems wherein gain is neither predetermined nor predeterminable. The disclosed amplifier is also useful where the gain value varies with time. Another example where the load applied to the output of the amplifier is particularly variable in frequency with attendant instability of the operational parameters.
The technical problem is solved by an operational amplifier frequency self-compensated with respect to closed-loop gain, of the type described above and defined in the claims.
This problem is also solved by a method for frequency compensating adaptively an operational amplifier with respect to closed-loop gain, as defined in the claims.
The features and advantages of an operational amplifier according to this invention will be apparent from the description of embodiments thereof given by way of example and not of limitation with reference to the accompanying drawings.

Frequency self-compensated operational amplifier


A portable lighting device according to the present invention includes a battery housing, a light source supported at a first end of the battery housing, and a shroud extending outward from the first end of the battery housing circumferentially around the light source. The shroud is preferably formed of a translucent material having a partially-reflective inner surface for reflecting a portion of incident light emitted from the light source in a forward direction while allowing a portion of the incident light to be transmitted through the shroud and dispersed in peripheral directions. The shroud further preferably includes a diffusing outer surface for diffusing the incident light that is transmitted through the shroud. A shroud is preferably integrally formed with a collar portion as used for threading the integrated head structure onto the battery housing. Additionally, a protective lens cover that may include a collimating lens is also integrally formed in this head structure. Thus, the portable lighting device of the present invention may be constructed with much fewer components and at a much lower cost than conventional flashlights.

The present invention generally relates to a lighting device. More particularly, the present invention relates to a portable battery-powered lighting device.
Portable lighting devices, such as flashlights and lanterns, are known which produce a directional beam of light. FIG. 1 shows the construction of a relatively low-cost flashlight 10 currently marketed by the assignee of the present invention. Conventional flashlight 10 includes a battery housing 12 of a molded plastic construction, which further serves as a handle for holding the flashlight. As shown in FIG. 1, battery housing 12 has a generally cylindrical shape with one end having an integrally-molded end wall 13. The open end of battery housing 12, in which batteries may be inserted or removed, includes external threads 14 for engaging the internal threads 16 of a shroud 18. Battery housing 12 further includes a slot 20 formed in a side thereof in order to enable a raised portion 22 of a sliding electrical contact 24 to be secured to a switch 26 provided on the exterior of battery housing 12.
Flashlight 10 further includes a spring 28 that is inserted within the battery compartment defined by battery housing 12. Spring 28 is provided in contact with the end wall 13 to bias the inserted batteries forward into contact with a positive terminal 30 of a light bulb 32. Spring 28 further provides an electrical contact to the negative terminal of the rearmost battery inserted into battery housing 12. A fixed electrical contact 34 is also provided within the battery compartment of battery housing 12 to provide an electrical connection between spring 28 and a moving electrical contact 24.
Flashlight 10 further includes a bulb holder 36 having internal threads 38 for engaging external threads provided as a negative electrical contact 40 of light bulb 32. Bulb holder 36 also includes either external threads 42 or a welding surface for securing bulb holder 36 within an aperture 44 provided in an electrical contact shell 46. With such an arrangement, the negative contact terminal 40 of light bulb 32 is electrically coupled through holder 36 to contact shell 46. At the same time, with light bulb 32 screwed into bulb holder 36, positive terminal 30 extends beyond the rearward opening of holder 36 so as to come into contact with a positive terminal of the forwardmost inserted battery. To turn light bulb 32 on and off, switch 26 is slid axially along battery housing 12 thereby moving sliding contact 24 forward and rearward into and out of contact with contact shell 46.
Flashlight 10 additionally includes a reflector 48 having a central aperture for receiving light bulb 32 such that light emitted from light bulb 32 is reflected in a generally forward direction. A lens 50 is provided across the forward opening of the flashlight as defined by shroud 18 and reflector 48 to protect the light bulb from damage. The lens 50, reflector 48, contact shell 46, light bulb 32, and bulb holder 36, which together form a head structure of flashlight 10, are secured across the open end of battery housing 12 by shroud 18, which includes a lip at its forward end to prevent lens 50 and the components positioned to its rear from falling out of the forward end of shroud 18.
Although flashlight 10 represents a relatively low-cost flashlight, it nevertheless includes no less than eleven components. Further, due to the number of potential component interfaces through which water could penetrate to reach the interior of battery housing 12, flashlight 10 would not be considered a waterproof flashlight.
Although conventional lanterns and flashlights such as that described above, are well-suited for brightly illuminating a relatively small area, they are not well-suited for providing wide area illumination like that produced by a lighting device designed for area illumination, such as a table lamp or gas lamp. Such area lamps, however, are not well-suited for directing a beam of light to illuminate an area a considerable distance away. Because of the need in the market for lighting devices that may serve as both a directional light and an area light, various devices have been constructed that will perform both of these functions. In some of these lighting devices, separate light sources and lenses are provided that may be independently activated. An example of one such light is disclosed in commonly-assigned U.S. patent application Ser. No. 08/690,287. Because two separate switches or a multi-position switch is required to selectively power the separate light sources, and because separate light chambers and lenses must be integrated within the device, these devices tend to be much more complex, bulky, and expensive.
To provide a less complex and less expensive portable lighting device that may function as both a directional light source and an area light, the assignee of the present invention has previously developed a two-in-one portable lighting device that utilizes a single light source, and hence, a single on/off switch. An example of such a lighting device is disclosed in British Patent No. 2,242,732B. These lighting devices include a two-part housing in which a first part of the housing contains the batteries, the switch, and the light to source, and a second part of the housing includes two separate chambers. The first and forwardmost chamber is a directional lighting chamber and the second chamber is defined by a cylindrically-shaped diffusing lens integrated within the cylindrical body of the second part of the housing. The second part of the housing may thus be slid axially along the first housing to reposition the light source within one of the two light chambers. Thus, a user may use such a lighting device as a directional light by sliding the second part of the housing fully within the first part of the housing such that the light source is pushed through a small opening within a reflector of the directional light chamber. Then, to use the device as an area light, the user may fully extend the first part of the housing such that the light source is removed from the directional light chamber into the area light chamber where the light emitted therefrom is transmitted through the cylindrical diffusing lens. Although these portable lighting devices are less expensive and bulky than the portable lighting devices that utilize two separate light sources, they nevertheless remain relatively complex and expensive compared to a conventional flashlight. Furthermore, because the single light source may only be in one chamber at any one time, the portable lighting device may not be simultaneously used as a directional light source and an area lamp. Therefore, there exists a need for a portable lighting device that may operate simultaneously as an area light and a directional light while being easily manufactured at a significantly lower cost.


A surgical filament snare assembly including an anchor capable of being fixated in bone and having a filament engagement feature. A first filament has a noose on a first portion of at least a first limb and has a second portion connected to the filament engagement feature of the anchor. Preferably, at least one free filament limb, which in some embodiments is a length of the first filament and in other embodiments is a second filament, is capable of being passed through tissue to be repaired and has at least one end passable through the noose to enable incremental tensioning of the tissue after the anchor is fixated in bone. The noose strangulates the free filament limb when tension is applied to at least one of the free filament limb and the noose.

Field of the Invention
The invention relates to filament assemblies for securing tissue to bone and more particularly to adjustable tensioning of tissue independent of anchor fixation.
Description of the Related Art
A common injury, especially among athletes, is the complete or partial detachment of tendons, ligaments or other soft tissues from bone. Tissue detachment may occur during a fall, by overexertion, or for a variety of other reasons. Surgical intervention is often needed, particularly when tissue is completely detached from its associated bone. Currently available devices for tissue attachment include screws, staples, suture anchors and tacks.
Arthroscopic knot tying is commonly practiced in shoulder rotator cuff and instability procedures. Typically, an anchor loaded with suture is attached to bone first. The suture is normally slidably attached to the anchor through an eyelet or around a post, such that a single length of suture has two free limbs. One limb of the suture is passed through soft tissue to be repaired such as a tendon or labrum. The two ends of the suture are then tied to each other, thereby capturing the soft tissue in a loop with the anchor. Upon tightening the loop, the soft tissue is approximated to the bone via the anchor.
Surgeons typically tie the suture ends by first placing a surgical sliding knot such as the Tennessee Slider or Duncan Knot. After tightening the loop, a number of additional half hitches or other knots are tied. The additional knots are needed because a conventional sliding knot does not provide the necessary protection against loosening or slippage, especially when tension is placed primarily on the limbs of the loop. Generally accepted practice is to follow the sliding knot with at least three reversed half hitches on alternating posts of the suture.
Before one or more half hitches or other knots can be added to the sliding knot, however, there exists a potential for the sliding knot to slip, that is, for the loop to enlarge as the tissue places tension on the loop. This has been referred to as "loop security" and can reportedly occur even in the hands of very experienced surgeons. Sometimes, even fully-tied knots may slip. Further, the overall size of a conventional knot can be obstructive or intrusive, especially in tight joints, which may damage cartilage or other tissue by abrasion with the knot.
Suture anchor systems with sliding and locking knots for repairing torn or damaged tissue include U.S. Pat. No. 6,767,037 by Wenstrom, Jr. Other suture anchor systems suited especially for meniscal repair are disclosed in U.S. Pat. No. 7,390,332 by Selvitelli et al. and are utilized in the OmniSpan™ meniscal repair system commercially available from DePuy Mitek Inc., 325 Paramount Drive, Raynham, Mass. 02767.
There are a number of suture implant systems which proclaim to be "knotless", that is, to not require a surgeon to tie a knot during surgery. Many such systems control tension on tissue by the depth to which an anchor is driven into bone. U.S. Pat. Nos. 5,782,864 and 7,381,213 by Lizardi disclose certain types of suture anchors which capture a fixed-length loop of suture. Adjustable loop knotless anchor assemblies utilizing an anchor element inserted into a sleeve are described by Thal in U.S. Pat. Nos. 5,569,306 and 6,045,574 and in U.S. Patent Application Publication No. 2009/0138042. Other systems having clamps or other locking mechanisms include U.S. Pat. No. 5,702,397 by Goble et al. and U.S. Patent Application Publication No. 2008/0091237 by Schwartz et al.
It is therefore desirable to have robust yet adjustable fixation of tissue while minimizing both the number and size of knots to be tied by a surgeon, especially during arthroscopic repair procedures.


Disclosed is a mobile communication system whereby, to reduce the connection time, a mobile station closely located to a base wireless station is permitted to continue to use a common channel for exchanging signals, and to suppress an increase in interference, an individual channel is set for a mobile station located near the edge of a cell, and to obtain a stabilized communication quality and to prevent an increase in the connection time, the probability that the transmission power will reach an upper limit is reduced. When communication between a mobile station and a wireless base station is started, the wireless base station measures the transmission power and the communication quality in the communication with the mobile station and the utilization ratio for a common channel, and compares the obtained values with predetermined threshold values. When the obtained values are lower than the threshold values, the wireless base station continues to use the common channel for signal transmission/reception. On the other hand, when the obtained values exceed the threshold values, the wireless base station sets an individual channel and sets a wireless channel so as to be capable of the continued use of the individual channel for the exchange of signals.

1. Field of the Invention
The present invention relates to a wireless channel setting method for a mobile communication system and a mobile communication control apparatus.
2. Related Background Art
A mobile communication system, called "FOMA" (product name) system, that employs CDMA (Code Division Multiple Access) is well known as an IMT-2000 wireless access technique. For this mobile communication system, the following method is employed to set up a wireless channel between a mobile station and a wireless base station.
Since the wireless capacity with the CDMA technology is limited by the level of the interference from other mobile stations located within the same cell, the minimum required power must be employed by all mobile stations in the same cell when communicating with each other in order to reduce interference. As a result with regard to the conventional mobile communication system, the wireless quality between a wireless base station and a mobile station must be measured all the time, and fast transmission power control must be executed in accordance with the measurement results. In this manner, optimization of the transmission power can be achieved, and an improved system capacity and a stable transmission quality can be obtained.
Generally, wireless channels used for a wireless communication system include a "common channel", which is used by all mobile stations for transmission/reception when initiating communication, and an "individual channel", which is allocated for each mobile station as paired uplink and downlink. Consequently, when initiating communication, a mobile station first accesses the common channel, through which control signals are exchanged to set up an individual channel. Thereafter, the wireless channel of the mobile station is shifted to the individual channel to perform voice or data communication.
A "control signal", constituted by an indispensable group of signals transmitted to initiate communication between a mobile station and a network, includes data for identifying the type of mobile station and the requested service for verifying the mobile station, and for setting a confidentiality level. To accomplish all these matters, several signal exchanges are generally required.
Similarly, the FOMA system employs procedures for shifting from a common channel to an individual channel. Since the above described fast transmission power control can be applied only for the individual channel, which is a bi-directional channel, it is preferable that, while taking both the system capacity and the communication quality into account, the shift to the individual channel takes place as early as possible.
Therefore, conventionally, the channel switching process with a sequence in FIG. 4 is performed in the following manner. When a mobile station transmits a control signal over the common channel (sequence Q1), the wireless base station uses the common channel to designate an individual channel for control use (sequence Q2). Thereafter, the transmitting mobile station and the wireless base station switch the common channel to the individual channel for control use and exchange control signals (sequences Q3 and Q4). When the transmission/reception of the control signals has been completed, the wireless base station notifies the transmitting mobile station of an individual channel for communication use (sequence Q5), and in accordance with the communication type, such as voice communication or packet data communication, the two stations switch the current channel to the individual channel for communication use and again exchange wireless signals (sequences Q6 and Q7).
According to a wireless channel switching control method used in the conventional mobile communication system, the transmission/reception of signals over the common channel can be minimized, and individual channels can be employed for the exchange of almost all control signals. Therefore, greater effects can be realized by the fast transmission power control with regard to the individual channels.
However, according to a system such as the conventional mobile communication system, whereby an individual channel for control use and an individual channel for communication use are sequentially set from the common channel, it takes a long time for a user to connect and start transmission and to be capable of voice or data transmission, which has been problem. There are two reasons, the first of which is that, for a mobile station and a network, the layer 1 switching process, such as a change in the transmission rate, is accompanied by the switching of channels, and thus, a period of about 100 milliseconds, and up to seconds in a long case is required for the layer 1 switching process. The second reason is that the transmission rate for an individual channel for control use is lower than that for the common channel, so that, accordingly, an extended time period is required for the transmission of control signals. This second reason is due to the following. Since the common channel is shared by a plurality of mobile stations, the transmission rate provided for it is kept high to a degree. On the other hand, since the individual channel for control use is employed only by a pertinent mobile station, the transmission rate for the individual channel can not be thoroughly increased while taking the wireless and hardware resources into account if these are in proportion to the transmission rate.
As a countermeasure to solve these conventional shortcomings, there is a possible method that uses the common channel for exchanging all the control signals and that directly sets up the individual channel for communication use.
However, according to this countermeasure, regarding the state when the common channel is used, because of the system configuration, fast transmission power control is impossible, and depending on the conditions at the mobile station such as the current location thereof and the utilization thereof, the system capacity and the communication quality obtained may be unsatisfactory, compared with the state wherein an individual channel is used. Further, since the transmission rate for the common channel is higher and the peak transmission power is greater compared with those for an individual channel, the uplink and downlink paths through the common channel tend to act as interference sources for other mobile stations, especially when the pertinent mobile station is located near the edge of a cell. Furthermore, when the transmission power reaches the upper limit, a satisfactory communication quality is apt to not be obtained. And in addition, when multiple mobile stations are connected to the common channel, a delay in the uplink random access and a delay in the downlink transmission waiting may occur due to a contention control, and the connection time may be further extended.

Wireless channel setting method for mobile communication system and mobile communication control apparatus


A surgical wire assembly comprises a first portion comprising a cable including multiple elongated strands of metal, and a second portion comprising an elongated solid strand of metal, the first and second portions being joined end-to-end. The first portion is more flexible than the second portion, and the second portion is provided with a tensile strength exceeding the tensile strength of the first portion. There is further disclosed a method for applying the surgical wire assembly to bone.

Surgical wire is used in many medical procedures for holding together bone.
For example, surgical wire may be used to hold together two or more pieces of the same bone, e.g., in the case of a fractured or surgically separated bone. Alternatively, surgical wire may be used to hold together two or more different bones, e.g., in the case of a surgical repair or reconstruction. Furthermore, surgical wire may also be used to reinforce a bone, e.g., in the case where a bone has been weakened by age or disease or injury.
In these and other situations, a length of surgical wire is generally wrapped around the bone which is to be held together, and then the two free ends of the wire are made fast to one another, e.g., by twisting together the two free ends of the surgical wire.
By way of example, in a so-called "total hip replacement" procedure, the top end of the patient's femur is replaced by a prosthetic device. More particularly, the top end of the patient's femur is surgically removed, and then the lower end of the prosthetic device is secured in the intramedullary canal of the femur, e.g., by tapping and cementing. In many cases, the patient's femur may be weakened, either by age or disease or injury or surgical trauma. Accordingly, in many cases the surgeon may elect to reinforce the top end of the patient's femur by wrapping a length of surgical wire around the outside of the femur and then twisting the two free ends of the wire together so as to secure the wire in place with the desired tension. See, for example, FIG. 1, which shows several lengths of surgical wire 20 secured around the upper end of a femur 22 so as to reinforce the femur about a prosthetic device 24.
By way of another example, in a so-called "open heart" procedure, the patient's sternum is typically cut down its middle so as to permit the patient's rib cage to be spread apart and the patient's heart exposed. In many cases, at the conclusion of the surgery, the surgeon may elect to wire the sternum back together using surgical wire. In particular, the sternum is wired back together by passing a length of surgical wire across the separated sternum and then twisting the two free ends of the wire together so as to secure the wire in place with the desired tension. See, for example, FIG. 2, which shows several lengths of surgical wire 20 holding together a sternum 26.
By way of still another example, and referring now to FIG. 3, surgical wires 20 may also be used to hold a bone graft 28 in place in a spinal column 30.
Conventional surgical wires are generally of two types: (1) a single elongated solid strand of metal, such as stainless steel; and (2) a cable including a multiplicity of elongated thin strands of metal. The former construction is generally of greater tensile strength than the latter construction, and is generally less likely to give way or break down over extended periods of time. However, a surgical wire formed out of a single strand of metal is typically fairly stiff and hence difficult to guide around bone. On the other hand, while the cable construction generally provides the flexibility desired by physicians for guiding around bone, it is generally lacking in strength and more likely to fail in due course.
It is, therefore, desirable to have available surgical wire having the flexibility of the cable type and the strength of the solid strand type.

Surgical wire assembly and method of use