A container holder for an injector for injecting a fluid into the human or animal body includes at least one container clamping member for clamping onto a container that is filled with the fluid and a temperature control device for bringing the temperature of the container to a predefined temperature. To be able to clamp containers of different shapes and sizes onto the container holder and to bring the temperature of the containers to a desired temperature without any thermal loss, by means of the temperature control device, and to ensure easy and unimpeded clamping and removal of the container, the temperature control device is connected to a transporting device, by means of which the temperature control device can be brought into and out of thermal contact with the container that is clamped onto the container clamping member.

In imaging procedures performed on the human or animal body for the purpose of medical diagnostics and the visualization of structures and functions of the body tissues and organs, such as magnetic resonance imaging (MM) and computed tomography (CT), contrast media are frequently administered into the body before or during the procedure in order to enhance the contrast of the images acquired. By comparing the images acquired during the imaging procedure with and without the administration of contrast media, the reliability of the images acquired can be improved, and it is possible to more accurately identify foci of inflammation or tumors marked, for example, by a more intense white color.
For the intravenous injection of contrast media, injectors are used, which transfer a contrast medium stored in a storage container into a patient's tube by means of a pump which, for the intravenous administration of the contrast medium into the body of a patient, is connected to a cannula. As a rule, a delivery mechanism with a peristaltic pump is used to transfer the contrast medium from the storage container into the patient's tube. To this end, provision is made for a transfer device in the form of a tubular system or a cartridge comprising fluid channels which transfer the contrast medium from the storage container into a pump tube which is inserted into the peristaltic pump and connected to the patient's tube. The peristaltic pump delivers the contrast medium from the storage container into the patient's tube.
This type of injector for the administration of contrast media for use in X-ray and nuclear spin resonance tomography is known, for example, from DE 20 2015 102 187 U1. This injector comprises a plurality of storage containers, which are filled with a fluid to be injected (for example, a contrast medium or a rinsing solution), and a cartridge which is replaceably disposed on the injector and which is connected to a pump tube and, via connecting tubes, to the storage containers. The cartridge comprises a body with fluid channels formed therein, which are connected via the connecting tubes to the storage containers and to the pump tube. To deliver the fluid to be injected (contrast medium or rinsing solution, for example, NaCl) from the storage containers through the fluid channels of the cartridge and through the pump tube connected thereto into the patient's tube, a peristaltic pump (a roller pump) is provided, which periodically squeezes the pump tube against a counter surface and thereby delivers the fluid contained in the pump tube into the patient's tube.
To avoid hypothermia, trauma or other health impairments, fluids that are to be administered, for example, by infusion or intravenous injection, into the human or animal body should be at least approximately close to the body temperature. To bring the fluid to be injected to body temperature, and to maintain it thereat, the, it is known from the prior art to use injectors with heating devices, by means of which the fluid can be heated to the body temperature and maintained at this temperature during the injection procedure. Thus, for example, EP 1 526 881 B1 discloses an injector for injecting fluids from a syringe into an animal subject, which injector comprises a heatable syringe clamping member for clamping the syringe that is filled with the fluid. A different heating device comprising a heatable fluid tube for heating fluids contained therein and intended for administration into the body of a patient has been disclosed in WO 2014/098675 A1.
The heating devices integrated into injectors for heating or cooling fluids to be injected at body temperature, such as the heatable syringe clamping member known, e.g., from EP 1 526 881 B1, have a disadvantage in that they are shaped to fit the shape and size of the container containing the fluid. Consequently, only containers with a predefined shape and size can be used with the heating device and be heated to and maintained at body temperature. However, fluids to be injected, such as contrast media and rinsing solutions, as a rule, are bottled in storage containers of different shapes and sizes. It is therefore not possible to simply attach different storage containers to a clamping member on the injector, which clamping member is intended for a specific and complementarily shaped container, and to heat it to body temperature and maintain it thereat.
Therefore, there is a need for an injector with a container holder which is suitable for clamping onto containers of different shapes and sizes and which comprises a temperature controlling device, by means of which different containers that are clamped onto the clamping member can be heated and, in particular, maintained at body temperature. At the same time, it should be possible to control the temperature as energy-efficiently as possible without any thermal loss, and access to the container for clamping and removing the container should be easy and unimpeded.

Container holder with a temperature control device for an injector


A tester that generates various data patterns to assure that link receivers and transmitters are functioning properly (i.e., are functioning according to a relevant network specification) across the entire storage area network. In various embodiments, this tester may be used in Fibre Channel type SANs or in fiber connectivity (FICON) type SANs.

1. Field of the Invention
The present invention generally relates to a storage area network ("SAN") employing a plurality of Fibre Channel switches which are connected together to form a fabric. The present invention specifically relates to a storage area network link integrity tester.
2. Description of the Related Art
FIG. 1 illustrates a SAN 110 employing one or more fibre channel switches 20 and a plurality of end devices 30. As known in the art, fibre channel switches 20 are used to establish a fibre channel communication network topology (i.e., fabric) providing direct connections between end devices 30 (e.g., personal computers, workstations, servers and the like). Testing of the fibre channel communication network topology often requires the use of a large quantity of expensive equipment, particularly a large quantity of additional fibre channel switches 20 and end devices 30 for testing purposes.
With known SANs, higher data rates and embedded clocks can often result in greater susceptibility to link issues within the SAN. Link issues can include jitter and degrading bit error rate (BER) performance. Data Patterns that may produce jitter problems can be found discussed in the document T11.2/Project/230/Rev10 entitled Fibre Channel—Methodologies for Jitter Specification. The process to determine whether jitter, signal integrity, or degrading bit error rates exist is very complex and can require a great deal of expertise in the area of electronics and signal analysis. Jitter is an unwanted variation of one or more signal characteristics in electronics and telecommunications. Jitter may be seen in characteristics such as the interval between successive pulses, or the amplitude, frequency, or phase of successive cycles.

Storage area network (SAN) link integrity tester

International Business Machines Corporation


A memory controlling apparatus which receives from an upper module of a system a command to read data from a memory module or write data in the memory module and controls accessing the memory module in response to the command. The memory controlling apparatus includes a first transmitter which transmits an address of read data or write data and the write data to a memory module via an address line; and a second transmitter which transmits data read from a memory module to the upper module of the system via a data line.

1. Field of the Invention
The present invention relates to controlling access to memory, and more particularly, to a memory controller which writes data on memory using an address line.
2. Description of the Related Art
Recently, synchronous dynamic random access memories (SDRAMs), such as double data rate synchronous dynamic random access memories (DDR SDRAMs) or Rambus DRAMs, have been welcomed as next-generation DRAMs and are also expected to dominate the future RAM market due to their high-speed data accessibility.
FIG. 1 is a diagram illustrating a conventional method of controlling the access of a DDR SDRAM when writing data on or reading data from the DDR SDRAM. In particular, FIG. 1 shows a memory controller 100 and a memory module 110.
Referring to FIG. 1, the memory controller 100 includes an address latch (AL) 101, a memory address queue (MAQ) 102, a data latch (DL) 103, a read data queue (RDQ) 104, and a write data queue (WDQ) 105.
The address latch 101 latches address data input into the memory controller 100.
The memory address queue 102 sequentially stores the address data transmitted from the address latch 101 and keeps the address data at a state where the address data is to be output. The address data include column address data and row address data, and the column address data and the row address data are sequentially output via a 12-bit address line.
The data latch 103 latches data input into the memory controller 100 from a system, i.e., written data, or data transmitted to the system, i.e., read data.
The read data queue 104 sequentially stores data read by the memory module 110 and keeps the stored data in a state ready to be output to the data latch 103.
The write data queue 105 sequentially stores the data transmitted from the data latch 103 that is to be stored in the memory module 110 and keeps the stored data in a state ready to be output to the memory module 110.
The memory module 110 includes a column address data register (CA) 111 which interprets the column address data provided by the memory controller 100, a row address data register (RA) 112 which interprets row addresses, a memory cell (MC) 113 which is comprised of a matrix of addresses interpreted by the column address data register 111 and the row address data register 112, a read data buffer (RD) 114 which temporarily stores data read from the memory cell 113, and a write data buffer 115 which temporarily stores data to be written on the memory cell 113.
The operation of the memory controller 100 in a typical memory device is as follows.
Address data and data that are input from a predetermined element 160 of a system 150, such as an interface or a central processing unit (CPU) via a system bus 170 are sequentially latched by the address latch 101 and the data latch 103, respectively. The latched address data are divided into a column address and a row address, and then the column address and the row address are encoded separately. Thereafter, the encoded column address and the encoded row address are sequentially stored in an address queue, i.e., the memory address queue 102. An upper module 180, a lower module 190, and a system element 160 are coupled to system bus 170.
Depending on whether the current mode is a data write mode or a data read mode, different manners for transmitting data can be adopted. In a data read mode, full-byte (8-byte or 16-byte) data is transmitted from the memory module 110 to the memory controller 100. The transmitted data is sequentially stored in the read data queue 104 of the memory controller 100. Thereafter, the stored data is output to a system bus via the data latch 103 and then provided to a micom, thus completing the reading of the corresponding data from the memory module 110. Thereafter, the memory controller 100 returns to an idle state and waits for the next mode shift.
When the memory controller 100 enters into a data write mode, two different manners of writing data on a memory, i.e., a partial-write manner and a full-write manner, can be considered. In most data transmission cases, except for direct memory access (DMA) transmission, the partial-write manner is adopted. In the full-write manner, all the bytes of data are written on the memory together, while in the partial-write manner, data are written on the memory in groups of a predetermined number of bytes.
For example, in the case of correcting 1-byte data using the partial-write manner, the memory controller 100 receives 8-byte or 16-byte data read from a place in a memory module 110 where the 1-byte data to be corrected is written via a data line and corrects the 1-byte data included in the 8-byte or 16-byte data. Thereafter, the memory controller 100 transmits the corrected 8-byte or 16-byte data to the memory module 110. When the writing of data in the memory module 110 is complete, the memory controller 100 returns to an idle state.
FIGS. 2A–2E are timing diagrams of signals generated when controlling the access of memory using the conventional method of controlling the access of a DDR SDRAM when writing data on, or reading data from, the DDR SDRAM, shown in FIG. 1. Referring to FIGS. 2A–2E, according to a predetermined memory access protocol, a row address and a column address of a place from which data will be read and a row address and a column address of a place on which data will be written are transmitted via an address line in response to the clock signal (CLOCK) of FIG. 2A. The column addresses and the row addresses of FIG. 2B are transmitted in response to a column address strobe (CAS) signal of FIG. 2D and a row address strobe (RAS) signal of FIG. 2C, respectively. The clock signal (CLOCK), the CAS signal, and the RAS signal are generated from an upper module of a system and then transmitted to a memory controlling apparatus of a lower module through the memory data bus of FIG. 2E.
When there is not much of a time interval provided between the time when the column and row addresses used to read data from the memory module 110 are generated and the time when the column and row addresses used to write data in the memory module 110 are generated, data (read data) read from the memory module 110 and then transmitted from the memory module 110 to the memory controller 100 via a data line and data (write data) to be written in the memory module 110, transmitted from the memory controller 100 to the memory module 110, may be congested in the data line. In order to prevent such a bottle neck phenomenon from occurring in a single data line, a sufficient interval should be provided between the time when a memory is accessed in order to read data from the memory module 110 and the time when the memory is accessed in order to write data in the memory module 110. In other words, one should wait for a sufficient amount of time until a current memory accessing process in one of a data read mode or a data write mode is completed before launching a following memory accessing process in the other mode. However, the general performance of a system may deteriorate due to the delay in data processing. In addition, in order to correct a predetermined portion of data stored in the memory module 110 in a partial-write manner, data to be modified is read from the memory module 110 in a full-read cycle. However, the process of reading the data to be modified from the memory module 110 in a full-read cycle may cause problems with the control of a read-write cycle, as well as a substantial delay in the entire process, equivalent to the read cycle, that may lengthen other transmission processes' standby time.

Memory controlling apparatus performing the writing of data using address line


A lens barrel includes a first optical element that is allowed to move along an optical axis, a first driven member connected to the first optical element, a second optical element disposed in the optical axis of the first optical element, which is allowed to move along the optical axis, a second driven member connected to the second optical element, a first drive shaft disposed substantially parallel to the optical axis to drive the first driven member along the optical axis, a second drive shaft disposed substantially parallel to the optical axis to drive the second driven member along the optical axis, a first drive unit connected to an end of the first drive shaft to drive the first drive shaft, and a second drive unit connected to an end of the second drive shaft to drive the second drive shaft and disposed at a position that partially overlaps a position of the first drive unit when viewed from the direction of the optical axis.

1. Field of the Invention
The present invention relates to a lens barrel that includes a plurality of optical elements driven independently of one another along the direction of the optical axis thereof.
2. Description of the Related Art
The lens barrel of a camera that houses the photographic optical system of the camera, known in the related art may include a plurality of movable lens units that move independently of one another along the direction of the optical axis thereof.
At a lens barrel that includes an optical system adopting such a multiple unit structure, lead screws extending parallel to the optical axis and transmission mechanisms that are connected to the movable lens units and each include a threaded portion to engage with the lead screw are disposed so as to drive the movable lens units along the optical axis by rotationally driving the lead screws. One lead screw is disposed in conjunction with each movable lens unit.
Japanese Laid Open Patent Publication No. 2003-241056 discloses a lens barrel that includes two movable lens units. In this lens barrel, two lead screws are disposed adjacent to the optical system, with motors for rotationally driving the individual lead screws disposed side-by-side at the ends of the lead screws on one side.
In the structure described above in which the plurality of lead screws each disposed parallel to the optical axis are driven by motors disposed side-by-side, the distance between the axes of the lead screws is likely to be significant due to the restrictions imposed by the motor size, which makes it difficult to provide a lens barrel as a compact unit, specifically with regard to its measurement along the direction perpendicular to the optical axis of the lens barrel (the direction along which the lead screws are disposed).


The present invention relates to novel cross-linkable or crosslinked photochromic compositions, articles made from or coated with the compositions and method of making the compositions. The compositions contain (i) at least one segmented or non-segmented polyurethane-type or polyurethane-urea-type linear polymer having at least one non-terminal moiety that comprises at least one unsaturated group; and (ii) an effective amount of at least one photochromic organic compound, advantageously selected from spiroxazines, chromenes, spiropyrans fulgides and fulgimides.

Photochromism, which is expressed by various types of photochromic organic molecules, which are accepted into a host organic material, is a known phenomenon which is widely described in the literature.
Within a polymer matrix, the mobility of the polymer chains in the vicinity of the photochromic molecules defines the speed at which the photochromic properties of said molecules are expressed, insofar as the reversible change in colour of said molecules is based upon a reversible process of ring cleavage and isomerisation. Consequently, the process of darkening and fading of a polymer matrix, the host of the photochromic molecules, is dependent upon the free volume left, in said matrix, to said molecules and therefore, upon the flexibility of the polymer chains of said matrix.
From this point of view, the polyurethane or polyurethane-urea matrices are particularly interesting. The free volume within them can in fact easily be adjusted by a careful choice of the blocks assembled during the synthesis. Thus, the colouration and the return to the initial colour of a polyurethane or polyurethane-urea matrix can thus be optimised by an appropriate choice of the blocks incorporated during the synthesis of said matrix.
Furthermore, the use of photochromic coatings on non-photochromic matrices, instead of and in the place of matrices which are rendered photochromic throughout their whole mass, is opportune when said non-photochromic matrices do not offer a flexibility which is sufficient, a free volume which is sufficient, for the expression of the photochromism of molecules accepted within them. Thus, thermoplastic materials, such as polymethylmethacrylate or polycarbonates are not suitable as a host polymer of photochromic molecules insofar as the free volume within them and the flexibility of the chains constituting them are insufficient.
Patent application EP-A-0 294 056 describes the preparation of photochromic polyurethanes. Said polyurethanes are prepared, classically, from diisocyanate reagents and polyol reagents. The photochromic compound is added, prior to the reaction, with one of the reagents or in the mixture of reagents. The isocyanate groups being very reactive groups, the mixture of the reagents made up cannot be preserved. It must be made to react, immediately after its preparation. This constitutes a severe constraint with regard to the implementation of the process.
Additionally, if the isocyanate groups subsist within the polyurethane matrix prepared, they may generate, in the presence of moisture, (during the later use of said matrix), amines. Such amines are capable themselves of destabilising, even of destroying, certain photochromic compounds, which are present in the matrix (chromenes, in particular).
The U.S. Pat. No. 6,187,444 describes photochromic polyurethane coatings which are obtained by a synthesis process, which is exonerated by the constraint set forth above. The reactivity of the mixture of reagents—isocyanate/polyol—is in fact controlled insofar as blocked isocyanates are used. Their NCO functions are, classically, blocked with the aid of suitable organic compounds. When brought to a sufficient temperature—generally between 90 and 200° C.—the blocked isocyanates release the blocking compound and thus are isocyanates which are free to react with the polyols which are present, in order to generate the polyurethane sought after.
Unfortunately, as mentioned in this US patent, it is, in general, not possible to remove all the blocking compounds. Thus, an excess of blocked isocyanates must always be provided in order to ensure the presence of a given amount of free (unblocked) isocyanates. Such an excess of isocyanate is particularly unsuitable in a material which contains photochromic compounds. It has been seen above that the isocyanates can be hydrolysed into amines, and these amines are capable of destabilising, and of destroying, such photochromic compounds (more particular those of the chromene type).
Furthermore, during the synthesis of such coatings, notably of a significant thickness, it is not excluded to trap the blocking compounds. It is even possible, in certain cases, to observe the formation of bubbles on the surface of the coating.
The application WO-A-01 55 269 also describes photochromic polyurethane coatings.
One of the drawbacks of the classical polyurethanes is that they are quasi-biphasic with an ordered structure. Said polyurethanes in fact contain soft segments, which are entirely mobile, and which are present in the form of balls, and rigid oligourethane units, which are known as hard segments. The cohesion of these polyurethanes is mainly due to the hydrogen bonds which exist between the urethane groups, of high polarity, which are present in the hard segments. Consequently, it may be feared that the photochromic compounds which are localised in said hard segments suffer from a lack of mobility and therefore that the rates of darkening and of fading of the material in question be slowed down.
To this day, one has not any photochromic polyurethanes at ones disposal which are very efficient and which are easy to obtain.
The application WO-A-01 02 449 describes a photochromic coating, of poly(meth)acrylic type, which is obtained by copolymerisation of a mixture of (meth)acrylic monomers which contains photochromic molecules. Said mixture of monomers, which is not very viscous, does not enable coatings to be generated which are of a thickness sufficient in order to exhibit good photochromic properties, at a reasonable cost. In fact, in order to compensate for the low thickness of the coating, it is necessary that the photochromic compound be incorporated at a high concentration, and this sometimes poses a problem, in view of the solubility of said compound in said coating.

Photochromic compositions, preparation thereof and articles made therefrom or coated therewith


According to the invention, a system for supporting a floor structure from a central structure is disclosed. The system may include a plurality of receptacles and a plurality of support members. Each of the receptacles may be located within a corner of an exterior perimeter of the central structure. Each of the receptacles may also at least partially define a cavity which may open to two different sides of the central structure. Each of the support members may be configured to pass through the cavity of at least one of the receptacles. Furthermore, each of the support members may be configured to be supported by at least one of the receptacles, and extend outward from two different sides of the central structure. The support members may further be configured to support the floor structure on two different sides of the central structure.

This invention relates generally to building construction. More specifically the invention relates to systems and methods of supporting floors and roofs of buildings.
In some methods of constructing buildings, floors and roofs may be created and/or located in their final position after construction of a central structure. These floors and roofs must be supported in some manner so as to provide stability for activity to occur on the floor or roof during and after construction. Typical construction methods, especially for high-rise buildings, support each floor from the ground upwards.
Often a great number of vertical structural members, columns for example, provide such support, and extend throughout the height of the building. The weight of these vertical structural members must be supported by the vertical structural members below them, compounding design factors at lower levels of the building. Additionally, valuable floor space on each floor may be lost, or at least become unusable, because of the protrusion of each vertical structural member. Embodiments of the present invention provide solutions to this and other problems.


A drum assembly for the collection and disposal of hazardous waste includes an enclosure with an access hole for collecting the waste. After the waste has been collected, the drum is opened and an insert is positioned to cover the access hole. The drum is then closed to form a sealed container.

a. Field of Invention
This invention pertains to a method and a drum for collecting and disposition of hazardous waste materials, and more particularly to method utilizing a drum assembly which includes a cover with an access opening for collection of waste, and an insert for closing the drum, after the collection is completed.
b. Description of the Prior Art
There has been recent, wide-spread concern over the safe, and secure collection and proper disposal of hazardous waste materials in a large number of industries. Failure to safely collect and dispose hazardous materials have led a number of disasters which affected the environment, and the health and welfare of a large number of people. For example, in the health industry, and more specifically in hospitals and clinics, various items including paper towels, syringes, rubber gloves are disposed in large numbers on a daily basis. Frequently these items are hazardous because they may have been infected, or may contain organic material prone to spoilage. As a result, if these items are not collected and disposed properly, they can be the source of infections and may contribute in spreading diseases. This problem has been aggravated by the trend in the industry to use disposable items. Frequently some items (such as syringe needles, and rubber gloves) are disposed after a single use.
Although various methods and containers have been use for the above-mentioned purpose, none of these proved satisfactory. For example, frequently, a plastic bag is disposed in a garbage pail for collection of the waste material. After the bag is full, it is removed from the pail, closed with a bag tie, or other similar means. However sharp objects, such as syringe needles may puncture the bag causing injury and/or infection to the person carrying it, or to any one else coming in contact with the bag. In addition, the bag is then either thrown in a large container for collection with other refuse, or it is disposed in a container for further disposal. The container itself then must be sealed to insure that no one comes in contact with its contents.
Thus, previous methods were unsafe, and labor intensive.

Hazardous waste disposal method and drum assembly


For use with a multiprocessor system employing shared memory, a software controlled method maintains cache coherency and execution synchronization among processors. A processor executing a SEND instruction transfers a cache line to one or more processors executing a RECEIVE instruction in a synchronized manner. The processors also execute the SEND and RECEIVE instructions to synchronize the execution of iterations of a program loop whereby a control processor distributes indices of the iterations to be performed by each worker processor.

Shared memory multiprocessors often use a cache with each processor to reduce memory latency, and to avoid contention on the network between the processors and main memory. In such a system, there must be some mechanism provided to allow programs running in different processors to have a consistent view of the state of the shared memory, even though they may all write to the same location simultaneously. That is, it is necessary to ensure that two processors reading the same address from their caches will see the same value. Most schemes for maintaining this consistency, known as cache coherency, use snoopy caches, directories, or software techniques.
Snoopy cache methods are the most commonly used. In snoopy cache systems, each cache must observe all read and write traffic on the bus which interconnects the processors. A snoopy cache controller listens to transactions between main memory and the other caches, and updates its state based on what it hears. The nature of the update varies from one snoopy cache scheme to another. For example, on hearing that some caches modified the value of a block, the other caches could either invalidate or update their own copy. Because all caches in the system must observe the memory transactions, a shared bus is the typical medium of communication.
Because the caches must also satisfy read requests from other processors for which they have the most recent value, the cache memory must be dual ported. Reads and writes must be permitted both from the processor side of the cache and from the shared bus side. For high performance systems in which the reference rate from the processor is high, either the tag store of the cache must be duplicated, or a significant cycle-stealing penalty must be accepted as bus accesses to the cache interfere with processor accesses.
Snoopy caches provide an illusion of truly shared global memory. This makes the method very difficult to expand to more than a few processors connected by a single shared bus. The fundamental limitation is that when a processor writes a shared datum in a snoopy bus scheme, that data must propagate to all caches in the system in a single cycle. If this were not the case, two processors could succeed in writing different values to the same datum simultaneously, violating the requirement of cache coherence.
Another class of techniques associates a directory entry with each block of main memory; the entry records the current location of each memory block. Memory operations query the directory to determine whether cache coherence actions are necessary.
Both snoopy cache and directory schemes involve increased hardware complexity. However, the caches are invisible at the software level which greatly simplifies machine programming.
As an alternative, cache coherence can be enforced in software, trading software complexity for hardware complexity. Software schemes are attractive not only because they require minimal hardware support, but also because they scale beyond the limits imposed by the bus.

Methods of maintaining cache coherence and processor synchronization in a multiprocessor system using send and receive instructions


An IF amplifier/log detector with a modular architecture includes a plurality of voltage amplifiers, a plurality of rectifiers, a plurality of voltage-to-current converters and a current summing circuit. Each amplifier has a first differential transistor pair driven by a first current proportional to the temperature to fix the gain. Each converter includes a second differential transistor pair driven by a current proportional to the temperature and inversely proportional to a process parameter, and a third differential transistor pair driven by a third current inversely proportional to the process parameter. In this manner a circuit having improved performance with variations in temperature and process parameters is obtained.

The invention relates to an electronic circuit with a logarithmic detector and to an apparatus having such detector, such as a digital cellular telephone.
A logarithmic detector provides an output signal that represents the logarithm of an input signal. Such a circuit is used in equipment that processes an input signal having a wide dynamic range, such as cellular radios, digital cellular telephones, spectrum analyzers, cordless telephones and radar equipment. The logarithmic detector typically functions as a received signal strength indicator (RSSI). In cellular radio, this function is necessary for continuously monitoring the received signal strength by the radio's microcontroller. The RSSI function requires a dc output voltage which is proportional to the logarithm of the input signal level.
Typically, such a detector is composed of a cascade of signal amplifiers. For the sake of clarity, it is assumed that the amplifiers have identical linear-amplification ranges and identical amplification "A". The first amplifier of the cascade receives an input signal "v" that is successively amplified by the subsequent amplifiers in the cascade. The repetitive amplification continues until a particular amplifier runs out of its linear range and into its limiting range. In its limiting range, each amplifier furnishes a clipped version of its amplified input signal. The n-th amplifier along the cascade runs into its limiting range when its output signal A.sup.n v exceeds the limit of the linear amplification range. Consequently, the input signal values at which the respective amplifiers leave their linear amplification ranges are proportional to A.sup.-n. Summing the output signals of all amplifiers approximates a linear function of the logarithm of the input signal.
In practice, the amplifiers are signal voltage amplifiers. The signals-supplied by the cascade have to be rectified in order to generate a dc output quantity representative of the signal's strength. Generally, an interstage filter is inserted into the cascade for reducing noise and preventing regeneration. Such a filter, however, causes undesired losses in amplitude. The output voltages therefore usually are rescaled for loss-compensation before being processed further.
In prior art integrated circuit NE605, manufactured by Signetics Co. (Philips Semiconductors), the output voltages of the amplifiers are routed to a rectifying element via a resistor ladder formed of stacked pairs of resistors. The amplifiers have complementary outputs connected to nodes between particular pairs of resistors. The voltage division attained in this way takes care of the rescaling of the signal. The rescaling, however, also affects the various dc levels of the voltages at the ladder nodes. These rescaled dc levels are to be removed from the rectifier output signal in a subsequent circuit.
The supply voltage required for operating the prior art circuit therefore is determined, among other things, by the resistor ladder. Further, removing the dc levels from the rectified signal requires additional circuitry. As a result, the detector has to be redesigned for each particular combination of rescaling resistors. Also, since various resistor values are used in a ladder, the accuracy of the resistor values should be high in order to reduce the accumulation of signal distortion in the ladder and beyond, due to temperature influences and process parameter spread dependencies.

Temperature-compensated logarithmic detector having a wide dynamic range


The present invention discloses a network communication system that includes a network processing center for receiving and converting an electronic or electro-magnetically transmissible data/content into a physically deliverable object and/or network transmissible content data files for carrying out a hybrid delivery of the data/content by a physical delivery process and/or a network electro-magnetic delivery process to a recipient or an ECRMA.

1. Field of the Invention
This invention relates generally to the systems and methods for applying the network communications to enhance delivery of the electro-magnetically transmissible contents from a sender to the designated recipients. More particularly, this invention is related to methods and network systems that allows a sender to control and direct, and allows a sender to specify among the many options, the delivery of either an article that embodies the Internet-deliverable contents or different functional devices that embodies the contents to designated recipients to achieve delivery speed while reducing the delivery costs.
2. Description of the Related Art
Even through more communications are now carried over the Internet with speed and greatly improved efficiency, however, there are still limitations that the Internet communications cannot satisfy. A most obvious limitation is a communication to a person who has limited or even no access to Internet. This group of people may include some elderly folks or economically disadvantageous people who do not use a computer or devices to have the Internet access at all. As senders of information often initiate a message that is suitable for Internet transmission, e.g., e-mail, the senders are required to apply a different mode of communication, e.g., sending the message as printed copy separately through regular mail services, in order to send the same message to a person who does not communicate over the Internet.
Furthermore, in the field of commercial advertisement, there are still a large amount of printed materials delivered through the regular mail services for promoting commercial products or services. However, such distribution of the printed materials for product or service promotion are limited to certain geographic locations, generally within the territory of a nation through the domestic mail services due to cost considerations. International delivery of printed materials would be too costly for mass mail promotions. Notwithstanding the availability of high-speed data transmission across the globe without national boundaries, an effective solution to overcome the geographic limitations of mail deliveries is still not yet available.
Further limitation of current electronic commerce over the Internet is the lack of control and flexibility of choices for a message or content sender. For example, it is true that a sender of gift or message is provided with options to order gift items from online shops for delivering to a recipient; however, the online shops under most circumstances dictate what and how the messages, and that the messages related with this order, are delivered to the message or gift recipient. A sender does not have much freedom to customize the fashion and ways the messages are delivered.
Another difficulty of the network communications over the Internet is related to the requirements that either a document must be personally delivered or that a returning document must be personally signed, sometimes before a notary public, in order to have certain legal validity. Particularly, when such document must be delivered to an area that require extended delivery processes and time, and the signatures of the senders and/or the recipients be required, the speed of the Internet transmission has not yet been utilized to provide a solution to overcome such difficulties. Current document systems are further limited by speed when technical or trade journals, magazines, or newspapers are delivered over the national boundaries of remote areas.
In order to overcome the above-discussed limitations and difficulties, a prior patent application Ser. No. 12/077,105 was submitted by the Applicant of the present invention to disclose systems and methods to deliver tangible deliverable objects that contain electronic contents including multimedia contents that may be transmitted over the telecommunication networks (TN) with its various sub-networks interconnected by the connections include but not limited to Internet, the wired and wireless telephone networks, cable systems, etc. The sub-networks of TN includes but not limited to Intranet, Wide Area Network (WAN), Metropolitan Area Network (MAN), Campus Area Network (CAN), Local Area Network (LAN), Wireless local area network (WLAN), Personal Area Network (PAN), Virtual Private Network (VPN), Client/Server Network, Peer-to-Peer Network, etc.
However, the delivery of a tangible deliverable object has several limitations. First limitation is a requirement of the involvement of a delivery agent and/or vehicle to accomplish the delivery of the tangible deliverable. It may be difficult where conditions limit the travel of the delivery agent and/or vehicle to reach the delivery destination. A second limitation is the time required for the process to deliver the tangible deliverable. Delivery may take relatively extended time in delivering to destinations due to travel difficulties, and/or other situations, even that the delivery process is much faster than the traditional mail system, especially under the circumstances when the delivery must cross over the state and national boundaries. Furthermore, a sender has only limited choices to select the final delivery form, i.e., in the form of a tangible deliverable.
Therefore, a need exists in the art of telecommunication network to provide improved system configuration to implement a delivery method for delivering contents transmitted over the telecommunication networks in more varieties of embodiments of the electronic contents through more varieties of delivery devices and routes such that the above-discussed difficulties and limitations may be resolved.

This patent is subject to a terminal disclaimer.

User initiated and controlled delivery in hybrid mode of electromagnetically transmissible contents to recipients in designated delivery locations or apparatus


Braid-balls suitable for aneurysm occlusion and/or parent vessel occlusion/sacrifice (e.g., in treating neurovascular defects) are disclosed. Especially for aneurysm treatment, but also for either one of the aforementioned treatments, the form of the ball is very important. In particular, the density of the device is paramount in applications where braid itself is intended to moderate or stop blood flow—allowing thrombosis within a volume formed by the ball.

Especially for aneurysm treatment, but also for either one of the aforementioned treatments, the form of the ball is very important. In particular, the density of the device is paramount in applications where braid itself is intended to moderate or stop blood flow—allowing thrombosis within a volume formed by the ball.
According to the present invention, braid-ball type implants are provided in braid of sufficient density is provided to moderate blood flow within the volume of the implant. Upon thrombosis, flow thereto is stopped. Alternatively, a blood-barrier covering can be applied to the filamentary structure to immediately stop blood flow into the vascular site, in which the implant volume is set.
In either case, to form thrombosis within the volume of the ball, the filaments of the braid matrix permit filling of the implant with blood when emplaced at a vascular treatment site. This blood then thromboses due to the flow-disruption effect(s).
Unlike Nitinol tube-cut cages that may be suitable for (or assist) in coil retention, the ball devices are adapted to work alone—or in combination with each other to effect a complete treatment. As such, high density braid/mesh is typically required. Namely, braid having at least about 48 ends, typically set at about 90 degrees or greater, in diameters from about 4 to about 8 mm may be employed. At larger diameters (e.g., about 6 to 12 or more), more wire ends (e.g., 64, 72 and upwards) may be employed in forming the balls.
Suitable braid for constructing the balls may be obtained from Secant Medical, Inc. Wire diameters may be in the range of about 0.001 to about 0.003 inches, depending on desired delivery profile (which is typically less than about 0.050 inches). The braid forming the balls may incorporate only one size wire, or may be formed with multiple sizes.
The wire is preferably superelastic NiTi alloy. The metal may be a binary alloy or a ternary alloy to provide additional radiopacity. Alternatively, radiopaque platinum fibers may be included in the braid, or the wire may comprise platinum or gold cord Nitinol DFT. Otherwise, wraps or bands (preferably Pt) used to secure the braid wire may serve as the sole radiopaque feature(s).
In any case, the construction approaches described herein enable producing these useful devices. Whether comprising braid alone, or incorporating some further blood-barrier covering (such as a thin urethane film as may be applied by Hantel, Inc. or others) the use of braid presents numerous challenges in managing the termination of multiple wires and in forming the desired structures.
Also included in the invention are detachable implant pushers that utilize a resistance wire heater to thermally sever a suture associated with the implant to effect release. As distinguished from known approaches where an implant is retained by a loop connected back to a delivery system pusher that is withdrawn with the devilry system, the present invention contemplates a leave-behind tether.
Further details, variations, modification and optional features of the invention may be appreciated by review of any of the incorporated patent applications. However, the priority date and subject matter included in the appended claims rely solely on the subject matter filed in U.S. Provisional Patent Application Nos. 61/046,670 and 61/046,594, the earliest patent applications (each filed Apr. 21, 2008) one which U.S. patent application Ser. No. 12/427,620 relies. Selected figures from the '670 and '594 application and all of text from the '594 application—all—incorporated by reference in the parent application hereto is reproduced herein.

Multiple layer filamentary devices for treatment of vascular defects


A method for I/Q imbalance calibration of an OFDM system comprising the steps of initializing parameters Ap, Bp and γp, estimating a loop delay factor L, generating a discrete-time test signal x[n], deriving a signal xcom[n] by compensating the test signal x[n] according to a function with parameters Ap, Bp and γp, converting the signal xcom[n] to an analog signal x(t), applying I/Q modulation to the signal x(t) and outputting a modulated signal xmod(t), obtaining a characteristic signal xc(t) of the modulated signal, obtaining a signal xs[n] by sampling the characteristic signal xc(t) and obtaining statistics U1 and U2 of the signal xs[n], and updating the parameters Ap, Bp and γp respectively by functions of L, U1, U2, and the current values of Ap, Bp and γp.

1. Field of the Invention
The present invention relates to compensation of physical layer impairments on transmitter systems and particularly to a method and apparatus for I/Q imbalance calibration in transmitter systems.
2. Description of the Prior Art
OFDM is a multi-channel modulation system employing Frequency Division Multiplexing (FDM) of orthogonal sub-carriers, each modulating a low bit-rate digital stream. The simplest way to describe an orthogonal frequency-division multiplexing (OFDM) signal is as a set of closely spaced frequency-division multiplexed carriers. While this is a good starting point for those unfamiliar with the technology, it falls short as a model for analyzing the effects of signal impairment.
The reason it falls short is that the carriers are more than closely spaced; they are heavily overlapped. In a perfect OFDM signal, the orthogonality property prevents interference between overlapping carriers. This is different from the FDM systems. In FDM systems, any overlap in the spectrums of adjacent signals will result in interference. In OFDM systems, the carriers will interfere with each other only if there is a loss of orthogonality. So long as orthogonality can be maintained, the carriers can be heavily overlapped, allowing increased spectral efficiency.
Table 1 lists a variety of common analog signal impairments and their effects on both OFDM signals and the more familiar single-carrier modulations such as quadrature phase-shift keying (QPSK) or 64-QAM (quadrature amplitude modulation). Most of these impairments can occur in either the transmitter or the receiver.
ImpairmentOFDMQPSKI/Q gain balanceState spreadingDistortion of(uniform/carrier)constellationI/Q quadrature skewState spreadingDistortion of(uniform/carrier)constellationI/Q channel mismatchState spreadingState spreading(non-uniform/carrier)UncompensatedState spreadingSpinning constellationfrequency errorPhase noiseState spreadingConstellation phase(uniform/carrier)arcingNonlinear distortionState spreadingState spreadingLinear distortionUsually no effectState spreading if not(equalized)equalizedCarrier leakageOffset constellationOffset constellationfor center carrieronly (if used)Frequency errorState spreadingConstellation phasearcingAmplifier droopRadial constellationRadial constellationdistortiondistortionSpuriousState spreading orState spreading,shifting of affectedgenerally circularsub-carrier
IQ Imperfections
For cost reasons, analog in-phase and quadrature (I/Q) modulators and demodulators are often used in transceivers—especially for wide bandwidth signals. Being analog, these I/Q modulators and demodulators usually have imperfections that result in an imperfect match between the two baseband analog signals, I and Q, which represent the complex carrier. For example, gain mismatch might cause the I signal to be slightly smaller than the Q. In a single-carrier modulation system, this results in a visible distortion in the constellation—the square constellation of a 64-QAM signal would become rectangular.
To better understand how gain imbalance will affect an OFDM signal, look at the equations describing each individual sub-carrier. In the following analysis, it's important to keep in mind that, while an individual sub-carrier is analyzed, the IQ gain imbalance error is on the signal that is the composite of all sub-carriers.
In the equation (1), Ck,m is a complex number representing the location of the symbol within the constellation for the Kth sub-carrier at the mth symbol time. For example, if sub-carrier k is binary-phase-shift-keying (BPSK) modulated, then Ck,m might take on values of ±1+j0. The complex exponential portion of Equation 1 represents the Kth sub-carrier, which is amplitude- and phase-modulated by the symbol Ck,m. Therefore:Ck,m(ej2πkΔft)  (1)
Using Euler's relation, the equation (1) can be rewritten as:Ck,m (cos(2π·kΔft)+j sin(2π·kΔft))  (2)
Now add the term "β" to represent gain imbalance. For a perfect signal, set β=0. As shown, the gain imbalance term will also produce a gain change. This was done to simplify the analysis. Therefore:Ck,m((1+β)cos(2π·kΔft)+j sin(2π·kΔft)  (3)
The equation can be rearranged and this can be rewritten as the sum of a perfect signal and an error signal:Ck,m(cos(2π·kΔft)+j sin(2π·kΔft))+Ck,mβ cos(2π·kΔft)  (4)
Finally, converting back into complex exponential notation, we get:
                                          C                          k              ,              m                                                      ⅇ                          j2π                                                                                k                                                                                Δ                                                                                f                                                                                t                                      +                              (                                          C                                  k                  ,                  m                                                                          β                2                                      )                    ·                      (                                          ⅇ                                  j2π                                                                                k                                                                                Δ                                                                                ft                                            +                              ⅇ                                                      -                    j2π                                                                                k                                                                                Δ                                        ft                                                                        )                                              (        5        )
In words, the equation (5) shows that a gain imbalance produces two error terms. The first error term is at the frequency of the Kth sub-carrier. The second error term is at the frequency of the −Kth sub-carrier. The phase and magnitude of the error terms are proportional to the symbol being transmitted on the Kth sub-carrier. Another way of saying this is that I/Q gain imbalance will result in each sub-carrier being interfered with by its frequency mirror-image sub-carrier. Persons skilled in the art will instantly recognize this as imperfect sideband cancellation.
The equation (5) has several implications. First, it is generally true that for sub-carriers used to carry data (as opposed to pilots), the symbol being transmitted at any given time on the Kth sub-carrier is uncorrelated to the symbol on the −Kth sub-carrier.
For a given sub-carrier, the lack of correlation from the mirror-image sub-carrier implies a certain randomness to the error. This results in a spreading of the sub-carrier's constellation states in a noise-like fashion. This is especially true for higher-order modulations such as 64-QAM. For lower-order modulations, such as BPSK, the error term from the mirror-image carrier has fewer states.
This can result in constellations where the BPSK pilot carriers of an 802.11a signal exhibit spreading that does not appear noise-like. Also, as the BPSK pilots do not have an imaginary component; the error terms associated with the pilot sub-carriers are real—so the spreading is only along the real (I) axis. Note that the phase relationships between the pilot carriers in an 802.11a system are highly correlated, so the errors introduced by quadrature errors are not random.
Quadrature skew produces error terms similar to those produced by gain imbalance. Quadrature skew occurs when the two oscillators used in an I/Q modulator or demodulator do not differ by exactly 90°. For a small angular error, it can be shown that the resulting error is orthogonal to the data. This is indicated by the j in front of the error terms in the equation (6). As with gain imbalance, the error generates energy at the Kth and −Kth sub-carriers. Again, the 802.11a BPSK pilots do not have an imaginary component, so the error term, which is now orthogonal, causes spreading along the Q axis. For the QPSK carriers in this example, the error is also orthogonal. However, unlike BPSK, a QPSK constellation doesn't look any different when rotated by 90°. (See the equation (6).):
                                          C                          k              ,              m                                                      ⅇ                                          j2π                                                                                k                                                                                Δ                                                                                ft                                                                                +                  j                                                                                C                                      k                    ,                    m                                                                  ϕ                            2                        ·                          (                                                ⅇ                                      j2π                                                                                k                                                                                Δ                                            f                                            t                                                                      +                                  ⅇ                                                            -                      j2π                                                                                k                                                                                Δ                                            f                                            t                                                                                )                                                          (        6        )
In both 802.11a and Hiperlan2, a channel estimation sequence is transmitted at the beginning of a burst. This special sequence is used to train the receiver's equalizer. The intended function of the equalizer is to compensate the received signal for multi-path distortion—a linear impairment in the signal that is the result of multiple signal paths between the transmitter and the receiver. As the ideal channel estimation sequence is known by the receiver, the receiver can observe the effects of the channel on the transmitted signal and compute a set of equalizer coefficients.
In the transmitter, the channel estimation sequence is created by BPSK modulating all 52 carriers for a portion of the preamble. Not coincidentally, the equalizer consists of 52 complex coefficients—one for each sub-carrier. It should come as no surprise that each sub-carrier in the channel estimation sequence has the greatest influence on the equalizer coefficient computed for that same sub-carrier.
The channel estimation sequence, and the receiver algorithms that compute the equalizer coefficients, are not immune from signal impairments. Consider, for example, the effect of I/Q gain imbalance on sub-carriers +26 and −26 of the channel estimation sequence. Recall from Equation 5 that each sub-carrier has two error terms: one at the same frequency as the sub-carrier, and one at the mirror image frequency. The I/Q gain imbalance will cause mutual interference between sub-carriers +26 and −26.
From the IEEE 802.11a standard, the sub-carrier modulation for the channel estimation sequence is defined to be C−26=1+j0 and C+26=1+j0. Using these values in Equation 5, one can easily determine that the two sub-carriers, when combined with the resulting error terms, will suffer an increase in amplitude. The equalizer algorithm will be unable to differentiate the error from the actual channel response, and will interpret this as a channel with too much gain at these two sub-carrier frequencies. The equalizer will incorrectly attempt to compensate by reducing the gain on these sub-carriers for subsequent data symbols.
The result will be different for other sub-carrier pairs, depending on the BPSK channel estimation symbols assigned to each.
With QPSK sub-carriers, the equalizer error caused by gain imbalance, or quadrature skew, results in seven groupings in each corner. Each QPSK sub-carrier suffers from QPSK interference from its mirror image. This results in a spreading to four constellation points in each corner. Each QPSK sub-carrier also suffers from a bi-level gain error introduced by the equalizer. This would produce eight groupings, except that the gain error is such that corners of the groupings overlap at the ideal corner state. Only seven groupings are visible.
IQ Channel Mismatch
When the frequency response of the baseband I and Q channel signal paths are different, an I/Q channel mismatch exists. I/Q channel mismatch can be modeled as a sub-carrier-dependent gain imbalance and quadrature skew. I/Q gain imbalance and quadrature skew, as described above, are simply a degenerate form of I/Q channel mismatch in which the mismatch is constant over all sub-carriers. Think of channel mismatch as gain imbalance and quadrature skew as a function of a sub-carrier. It is still generally true that channel mismatch causes interaction between the Kth and −Kth sub-carriers, but that the magnitude of the impairment could differ between the Kth and the (k+n)th carriers.
Delay mismatch is a distinct error. It can occur when the signal path for the I signal differs in electrical length from the Q signal. This can be caused by different cable lengths (or traces), timing skew between D/A converters used to generate the I and Q signals, or group delay differences in filters in the I and Q signal paths.
What makes this error distinctive is that the error is greater for the outer carriers than it is for the inner carriers. In other words, the error increases with distance from the center sub-carrier. With a vector spectrum display, it may be shown that the signal error is a function of the sub-carrier number (frequency). That is to say, the phase arcing may occur as a function of frequency.
Phase Noise
Phase noise results in each sub-carrier interfering with several other sub-carriers—especially those in close proximity. Close-in phase noise that results in the constellation rotation for the data carriers also results in rotation of the pilot carriers. In fact, carrier phase error rotates all sub-carriers by the same amount, regardless of the sub-carrier frequency. Phase-tracking algorithms use the pilot symbols to detect this common rotation and compensate all of the carriers accordingly. This error is often referred to as common pilot, or common phase error (CPE). Phase noise that is not considered to be close-in results in inter-carrier interference. Instead of constellations with visible rotation, phase noise in an OFDM signal generally results in fuzzy constellation displays, similar to what would be expected if noise is added to the signal.
In 802.11a, the symbol rate is 250 kHz. As pilot symbols are present in every OFDM symbol interval, one might think of this as the sample rate at which the phase-tracking algorithms are operating. Sampling theory would suggest that one will have problems with phase noise beyond one-half the sample rate, or 125 kHz (Nyquist).
Unfortunately, there's another error mechanism that occurs at frequencies much lower than one-half the sample rate. The pilot tracking algorithms are post-fast Fourier transform (FFT). As the FFT is a mapping of the time waveform into the frequency domain (Fourier coefficients), any error that results in energy from one sub-carrier leaking into other sub-carriers cannot be compensated for with a simple post-FFT sub-carrier de-rotation.
Phase noise modulates each of the sub-carriers to the point that they no longer look like simple sinusoids within the FFT interval. Consider an FFT of a single tone. If the tone is pure and has a frequency that produces an integral number of cycles within the FFT time buffer, then an FFT will produce a result with only one non-zero value. If the pure tone is now phase modulated, it can no longer be represented as a single Fourier coefficient—even if the signal is periodic with the FFT time buffer. In other words, the sub-carrier will interfere with the other sub-carriers. If the phase-modulating signal is separated into a DC component plus an AC component, the DC component is corrected by the post-FFT pilot-tracking algorithms.
The impact of random phase noise on the sin(x)/x shape of an individual sub-carrier is a gradual roll-off (an artifact mostly caused by the uniform-windowed FFT used in the receiver). Phase noise causes the nulls of the sin(x)/x spectrum to fill in, creating interference between every sub-carrier and its neighbors.
Frequency Error
In any coherent modulation format, it is critical that the receiver accurately track the transmitter frequency. Frequency is defined to be the derivative of the phase with respect to time, so frequency error can be described as a cumulative phase error that linearly increases or decreases with time, depending on the sign of the frequency error. For single-carrier modulation formats such as 64-QAM, a frequency error can be visualized as a spinning constellation diagram.
The effect of frequency error on OFDM signals is different. Under ideal conditions, each of the sub-carriers in an OFDM signal is periodic within the FFT time buffer. This is critical if the sub-carriers are to remain orthogonal and avoid mutual interference.
A frequency error between the transmitter and the receiver will cause all of the sub-carriers to have a non-integral number of cycles in the FFT time interval, causing leakage. A frequency error shifts the sin(x)/x spectrum of each sub-carrier relative to the FFT frequency bins to the point that the spectral nulls are no longer aligned with the FFT bins. The result is that frequency error causes every sub-carrier to interfere with its neighbors.
Nonlinear Distortion
The effects of nonlinear distortion on an OFDM signal are easily understood by those familiar with inter-modulation distortion. Nonlinear distortion is a particularly important topic for OFDM signals because the signal represents the linear summation of a large number of statistically independent sub-carriers. This results in a signal with Gaussian voltage statistics on the I and Q waveforms.
Sometimes people refer to the signal as having Gaussian statistics in the context of peak-to-average power. This can be misleading because the power statistics are not Gaussian. The I and Q voltage waveforms are Gaussian, but the power, which is the sum of the squares of the I and Q signals, has a chi-square distribution. All that aside, a perfect OFDM signal can have peak envelope power that exceeds the average envelope power by more than 10 dB. This presents the power amplifier designer with some difficult challenges.
In the context of nonlinear distortion, it's safe to model the OFDM signal as a multi-tone signal with each of the tones having a random phase component. In fact, that's exactly what an OFDM signal is. Multi-tone analysis and testing is probably better suited to OFDM signals than to the multi-carrier signals for which it was originally developed.
For most single-carrier modulation formats (excluding code-division multiple access (CDMA) signals), the Nyquist filters. create peak power excursions that occur between symbols.
Errors due to saturation will cause adjacent channel power problems, but may not have a large impact on data transmission—depending on the amount of dispersion in the transmission channel and the receiver's matched filter. For OFDM, the peak power excursions may occur at any time within the symbol interval. Because the OFDM time waveform is a summation of all sub-carriers, nonlinear distortion will create inter-carrier interference. Of course, it will also result in increased adjacent channel power.
Spurious Signals
When a spurious signal is added to an OFDM signal, the effect is similar to what happens with single-carrier modulations. If the spurious tone is at the exact frequency of a sub-carrier, then the effect is to shift the constellation of that sub-carrier—just as carrier leakage shifts the constellation of a single-carrier modulation. Otherwise, the spurious signal causes a spreading of the constellation points for sub-carriers near the spurious tone. Carrier leakage in an OFDM signal only affects the center carrier (if used).
In order to eliminate the effects of the previously described impairments on the OFDM systems, various kinds of compensation circuit and method have been proposed.
U.S. Application Publication No. 20020015450 discloses a method and an arrangement for determining correction parameters used for correcting phase and amplitude imbalance of an I/Q modulator in a transmitter. The transmitter includes an I/Q modulator and a corrector for correcting the phase and amplitude imbalance caused by the I/Q modulator. The arrangement has means for sampling the I/Q-modulated test signal to be transmitted, means for A/D-converting the signal samples taken from the test signal, means for I/Q-demodulating the signal samples digitally into I- and Q-feedback signals, means for determining the phase and amplitude imbalance caused by the I/Q modulator on the basis of the I- and Q-feedback signals, and means for determining the correction parameters of phase and amplitude on the basis of the determined phase and amplitude imbalance.
U.S. Pat. No. 6,208,698 discloses a quadrature modulator controlled by an imbalance estimator, as shown in FIG. 1. The estimator is entirely analog and includes two mixers 120, 121 to which are applied two carrier signals P1 and P2 derived from a carrier signal P obtained from a local oscillator and from a 90° phase-shifter 122. A modulating signal X, Y is applied to each of the mixers 120, 121. The output signals of the mixers 120, 121 are applied to a combiner 123 to constitute a modulated signal S. The modulated signal S is either an intermediate frequency signal or a microwave frequency signal. The estimator 124 of the invention includes means 125 for detecting the instantaneous power Pd of the modulated signal S, means 126, 127 for multiplying the detected instantaneous power Pd by each of the modulating signals X, Y, means 128A, 129A for rectifying the signals produced, which rectifier means can be diodes, for example, and means 130, 131 for integrating the rectified signals, the integrator means being followed by subtractors 160, 161 supplying respective signals E1 and E2 proportional to the amplitude of the modulator imbalance. The subtractors 160 and 161 receive respective analog reference signals REF1 and REF2, which are usually identical (REF1=REF2), the output signals of the integrator means 130, 131 being subtracted from REF1 and REF2, respectively. For example, REF1 and REF2 are equal to twice the mean amplitude of the modulated signal S. The subtractors 160 and 161 generally need to be used only for the purposes of correcting imbalance. The signals E1 and E2 are respectively applied to the multipliers 150 and 151 on the input side of the mixers 121 and 120, respectively, to correct the offsets introduced by these mixers.
Although there are already many kinds of compensation circuit and method, it is still a goal for researchers around the world to propose newer and better solutions to the I/Q imbalance issue in the OFDM systems.

Method and apparatus for I/Q imbalance calibration of a transmitter system


Atop the impeller are ancillary vanes, the same provided for pumping cooling liquid to the centrifugal pump motor cooling system. The liquid is conveyed through a narrow slot, vertically, which obtains between an annulus of the pump housing and an impeller extension. Grooves, contiguous with inner tips of the ancillary vanes, and formed in the extension, widen the slot, cyclically, coincident with rotation of the impeller, and hasten deaeration of air bubbles which exist, at start-up, between the impeller and the pump housing.

This invention pertains to centrifugal pump impellers, and to such impellers in combination with centrifugal pump housings, used to pump liquids which contain solid pollutants, and in particular to such impellers which cooperate with the pump housings to supply the pumped liquid to a cooling system which keeps the pump motor from overheating.
A common centrifugal pump is the so-called submersible pump in which the pump and its electric motor comprise a unit which is submersed in the pumped liquid. In this, the motor is normally cooled directly by the surrounding, pumped liquid. If, however, the level of the liquid decreases, so that the motor is surrounded by air, the cooling may be insufficient. Therefore, the motor is provided with an internal cooling system which uses the pumped liquid. An example of such an arrangement is shown in the Swedish Patent No. 367 465 (U.S. Pat. No. 3,371,613).
As the pumped liquid often contains solid pollutants, the aforesaid patent teaches the use of a narrow slot, arranged between the impeller and the pump housing, through which comparatively clean liquid is fed into the cooling liquid area between the pump and the motor. The cooling liquid is circulated by means of vanes arranged on the back of the impeller. The slot prevents pollutants from entering into the cooling liquid area and, thus, diminishes the possibility of clogging the cooling channels disposed about the motor.
Further, according to the aforesaid patent, vanes are arranged within the cooling jacket of the motor to convey the cooling liquid upwardly to effect a cooling of the entire motor.
It has been observed that, at pump start-up, air bubbles can collect within the cooling liquid area at the back of the impeller, i.e., between the pump housing and the impeller. As a consequence, the vanes in the cooling jacket may not be able to ingest the cooling liquid and no circulation of the latter can result.

Centrifugal pump impeller, and in combination with a centrifugal pump housing


On the welding arm of a welding machine is mounted a coaxial application pipe with removable transport means and an application nozzle. Into this application pipe is fed a block-shaped hot-melt mass, in the direction opposite the advance direction of the sheet metal tube, guided in direction (V) of the application tube, melted in the area of a narrowing heater, passed through a supply tube to the application nozzle and applied or sprayed as a hot-melt strip to the inside of the longitudinal weld seam of sheet metal tubes.. The application of a hot-melt strip is suitable in particular for the protection of the longitudinal seam of a tin-plated can shell.

Welding machines are known which have an "in line" application system which applies a protective strip to the inner longitudinal weld seam of sheet metal tubes, in particular longitudinally welded tin and can shells. In principle a distinction is made between the spraying of a paint and the application of a powder which is melted in situ into an adhesive layer.

Weld seam cover on the inside of sheet metal tubes


An insert for an outer package for a thermoformed blister package, wherein the blister package has an outwardly extending flange. The foldable insert is placed within the outer package so that the flange of a blister package is rigidly supported and the outer package has improved stiffness and resistance to flexing. The insert has a pair of hingingly connected members having a rectangular cross-section. A longitudinal based panel having a pair of opposed major and a pair of opposed minor sides is foldably connected to a first end panel along the minor sides of the base panel. A first longitudinal side panel is foldably connected to a first major side of a longitudinal base panel and an opposed second longitudinal side panel is foldably connected to the other major side of the longitudinal base panel. A first longitudinal cover panel is foldably connected to the first longitudinal base panel and an opposed longitudinal side panel is foldably connected to the second longitudinal side panel. An end base panel having a pair of opposed major sides and a pair of opposed minor sides is hingingly connected along one minor side to one minor side of the longitudinal base panel. A first end side panel is foldably connected to a first major side of the end base panel and an opposed second end side panel is foldably connected to the other major side of the end base panel. A first end cover panel is foldably connected to the first end side panel and an opposed second end cover panel is foldably connected to the second end side panel. The ends of each side panel adjacent to the connecting minor ends of the longitudinal base panel and the end base panel are angulated.

Endoscopic surgical instruments have been developed for use in endoscopic surgical procedures. The endoscopic surgical instruments, although rugged, must be properly packaged for sterilization and shipment and handling in order to prevent damage to the instruments. Many endoscopic surgical instruments are packaged in conventional thermoformed formed blister packages. The thermoformed blister packages are typically made to have a number of cavities which conform to the contours of particular surgical instruments. The surgical instruments are placed within these cavities and the cavities serve to both retain and cushion the instruments during sterilization, shipping and handling. Most thermoformed blister packages consist of a relatively rigid thermoformed lower tray and a flexible polymer cover which is typically gas permeable. A flange typically extends about the outer periphery of the blister tray to which the polymer top cover is sealed. The sealing may be accomplished by a number of conventional processes including ultrasonic welding, heat sealing and the use of various adhesives and bonding agents.
For shipment, handling and storage, it is necessary to place the blister packaged instrument into an outer package. The outer package serves several functions. It protects the blister package from inadvertent cuts, punctures and tears thereby preventing compromising of the sterility of the instrument. The package also serves to add a degree of additional protection to the blister package in the event of accidental drops or impacts.
It is especially critical in packaging a sealed, blister packaged, sterile instrument to protect the seal of the blister package. Although the blister tray is relatively rigid, it is still capable of flexing during shipping, handling and storage. This flexing is known to cause the flanges to twist thereby potentially causing the cover seal to delaminate in those areas where the twisting or torsional forces are extreme. In order to prevent this type of flexing, it is necessary to somehow support the flanges of the blister package when it is inserted into an outer package. Present approaches utilize massive amounts of polymeric foams, such as polyurethane foam, to cushion and protect the packages. There are various disadvantages associated with polymeric foam. One disadvantage is that in order for the foam to be effective, a relatively large quantity of the foam is required thereby increasing the size of an outer box into which the blister packed instrument is packaged Another disadvantage of the polymeric foams is the fact that they are difficult to dispose of and recycle. Yet another disadvantage is that the larger boxes required for a foam packed blister package take up additional shelf space in a hospital supply storage area.
Therefore, it is an object of the present invention to provide a package for a thermoformed blister packaged endoscopic instrument which supports the flanges of the blister packages without the need for a polymeric foam outer cushion.
It is a further object of the present invention to provide a package which supports the flange of a blister package thereby minimizing twisting and flexing of the flange of the blister package and additionally minimizing the possibility of a seal delaminating.
It is yet a further object of the present invention to provide a package for a blister package which has improved stiffness.


A system and method for correcting comparator offsets which occur during operating conditions such that static and dynamic offsets are compensated is provided. The comparator may be calibrated for normal operating conditions. The calibration may be accomplished by providing adjustability of the comparators' threshold value and providing a feedback loop for adjusting the threshold value. In one preferred embodiment, the comparator may be utilized within a flash ADC, and in a more preferred embodiment, the comparator may be utilized within a flash ADC of a read/write channel circuit.

1. Field of Invention
This invention relates to calibration of flash analog to digital converters, and more particularly relates to calibration of flash analog to digital converters utilized in data storage systems such as, for example, magnetic disk storage systems having read/write channel circuits.
2. Description of Related Art
In data storage systems data is stored on a storage media such as a CD-ROM, writable CD, DVD or other optical disk, magnetic tape, magnetic hard disk, etc. Typically, when data is read from the storage media, some form of data detection circuitry is utilized to process the signal generated from the storage media. In magnetic disk storage systems for computers, such as hard drives, digital data serves to modulate the current in a read/write head coil so that a sequence of corresponding magnetic flux transitions are written on a magnetic medium in concentric tracks. To read this recorded data, the read/write head passes over the magnetic medium and transduces the recorded magnetic transmissions into a signal of an analog nature that contains pulses that alternate in polarity. These pulses are then decoded by read/write channel circuitry to reproduce the digital data.
Decoding the pulses into a digital sequence can be performed by a simple peak detector in an analog read channel or, as in more recent designs, by using a discrete time sequence detector in a sampled amplitude read channel. Discrete time sequence detectors are preferred over simple analog pulse detectors because they compensate for intersymbol interferences (ISI) and, therefore, can recover pulses recorded at high densities. As a result, discrete time sequence detectors increase the capacity and reliability of the storage system.
There are several well known discrete time sequence detection methods for use in a sampled amplitude read/write channel circuit including discrete time pulse detection (DPD), partial response (PR) with Viterbi detection, partial response maximum likelihood (PRML) sequence detection, decision-feedback equalization (DFE), enhanced decision-feedback equalization (EDFE), and fixed-delay tree-search with decision-feedback (FDTSIDF). When discrete methods are utilized for sampled amplitude read channel systems, an analog to digital converter (ADC) is typically utilized to convert the high frequency data which is contained on disk.
One type of ADC which may be utilized to convert high frequency disk data is a flash ADC. Such an ADC may contain multiple comparators for conversion of the analog data to digital data. In order to accurately convert the high frequency analog data, it is desirable that the comparators exhibit very little electrical variation from ideal operation even in the presence of "offsets". Many sources exists for offsets including mismatch between two devices (for example transistors, resistors, capacitors, etc.) which though intended to be identical, vary to one degree or another due to limitations of fabrication processes.
One approach to compensate for such offsets is to utilize a DC auto-zero operation. FIG. 1 illustrates an example of an auto-zero operation for use with an amplifier of a flash ADC comparator. As shown in FIG. 1, a comparator having input voltages V.sub.in1 and V.sub.in2, differential transistors M.sub.1 and M.sub.2, and outputs V.sub.o1 and V.sub.2 are provided. In normal operation, switches S.sub.1 and S.sub.2 are connected to V.sub.in1 and V.sub.in2 respectively and switches S.sub.3 and S.sub.4 are open. For auto-zero operation, the switches S.sub.1 and S.sub.2 are connected to V.sub.ref1, and V.sub.ref2 respectively and switches S.sub.3 and S.sub.4 are closed. Control of the switches in this manner during auto-zero operation will bias the capacitive nodes V.sub.o1 and V.sub.o2 with the effect that the amplifier stage is biased such the output voltage (V.sub.o1 -V.sub.o2) is substantially zero with an input voltage differential of V.sub.ref1 -V.sub.ref2.
Auto-zero schemes such as described above have disadvantages in that only DC (or static) mismatches are accounted for and dynamic mismatches (from, for example, different parasitic capacitances, differential charge injection from the switches, etc.) are not corrected. Thus, during actual operation of the amplifier (as opposed to a DC auto-zero situation where the inputs are not changing) offsets will still result. Moreover the auto-zero scheme described above does not address the use of comparators having multiple amplifier stages as the DC offset of the first stage may be accounted for, but the offsets of subsequent stages are not corrected.

Method and circuit for calibration of flash analog to digital converters


An ovalizer which employs hydraulic cylinders to directly actuate duct forming members for forming round spiral duct to oval. The ovalizer includes a pair of elongated and laterally spaced-apart duct forming members sized to fit within a ductwork section and to bear against opposing interior surfaces of the ductwork section. Spaced longitudinally along and between the duct forming members are a plurality, five in the disclosed embodiment, of double-acting hydraulic cylinder assemblies for selectively forcing the duct forming members apart for forming round duct to oval, and retracting the duct forming members towards each other at the conclusion of a forming operation. A feedback control system ensures that the hydraulic cylinder assemblies extend together at approximately the same rate and stop when a predetermined extended position is reached. The ovalizer includes a plurality of signal-controlled valves, each of which is connected for controlling the application of hydraulic fluid under pressure to a corresponding one of the hydraulic cylinder assemblies for selectively causing the corresponding hydraulic cylinder assembly to extend and to retract. The feedback control system includes a plurality of position transducers connected to corresponding ones of the hydraulic cylinder assemblies. Position signals output by the transducers indicate the positions of the hydraulic cylinder assemblies. A programmed controller receives the individual position signals, and is connected to the valves for individually controlling the valves.

The present invention relates generally to thin-walled spiral duct commonly employed in air conditioning and heating installations, and more particularly, to apparatus for forming round spiral ductwork to oval.
Round, thin-walled spiral seamed metal ducts made from strips of sheet metal are widely employed in heating and air conditioning installations, as well as in other air ducting installations. Such spiral duct is efficiently produced in desired lengths by Tubeformer machines, manufactured for example by Spiral-Helix, Inc. of Buffalo Grove, Ill., and described for example in Castricum U.S. Pat. Nos. 4,567,742; 4,706,481 and 4,711,110. Spiral duct has a number of advantages, in both ease of installation and performance.
There are however installations where limited space prevents the use of round spiral duct, and where, accordingly, flatter ductwork which is rectangular or oval in cross-section is employed. (Oval ductwork is also known in the art as "flat-oval," and the terms "oval" and "flat-oval" are employed interchangeably in the context of the invention.) As the Tubeformer machines produce round and not oval ductwork, a separate machine, known as an ovalizer, is ordinarily employed to form round ductwork to oval.
Very briefly, a typical ovalizer includes a pair of elongated and laterally spaced-apart duct forming members that are sized to fit within a ductwork section and to bear against opposing interior surfaces thereof. The duct forming members are forced apart in some manner to form the round ductwork to oval, slightly stretching the metal, perhaps by one percent, so that the formed oval shape is maintained. Extreme force is required, approximately 34,000 pounds per lineal foot, or approximately 340,000 pounds total force to form a section of ductwork ten feet in length.
One general type of ovalizer which has been proposed employs a plurality of pivoting mechanical linkage or toggle arms spaced longitudinally along the duct forming members and connected to an intermediate actuator rod driven in a longitudinal direction by an hydraulic cylinder. The duct forming members are forced apart as the actuator rod moves longitudinally with reference to the duct forming members. Longitudinal motion of the actuator rod is thus mechanically translated to motion at a right angles as the duct forming members move apart relative to each other.
An inherent beneficial result of this mechanical arrangement, subject to manufacturing tolerances, and subject to bending of the duct forming members, is that the duct forming members move apart in a parallel manner, which is assured by the geometry of the linkage mechanism and actuator rod. In other words, all points along each of the duct forming members inherently move together the same distance. Examples are disclosed in Jones U.S. Pat. No. 3,713,609 and Meserole U.S. Pat. No. 3,996,783. Related mechanisms, for slightly different purposes, are disclosed in Cunningham U.S. Pat. No. 3,747,394 and Haws U.S. Pat. No. 4,862,724.
Such arrangements using mechanical linkage or toggle arms and a longitudinally driven rod for right angle motion translation have several drawbacks. One drawback is that the available force is not constant over the range of motion, since the mechanical advantage increases as the duct forming members move farther apart. Thus, when smaller ductwork sizes are formed from round to oval, relatively less force is available for stretching the metal, compared to when larger ductwork sizes are formed from round to oval and the duct forming members correspondingly are farther apart. Another disadvantage is that the physical size of the linkage arms required to bear the force can limit the range of motion.
A related functional principle is employed in ovalizers manufactured by Spiral-Helix, Inc. such as the commercially available Spiral-Helix, Inc. models known as "The Helix Ovalizer 36/12" and "The Compact Helix Ovalizer 24/6." It is believed that those two machines employ an inclined plane mechanism wherein one of the duct forming members includes a series of inclined plane surfaces, in the form of hardened steel wedges. Corresponding inclined plane surfaces are provided on a actuator rod which is positioned between the two duct forming members and which is driven longitudinally by a hydraulic cylinder. Thus, as the actuator rod and its inclined planes move relative to the duct forming members, which are restrained against longitudinal movement, sliding motion of the inclined plane surfaces against one another forces the duct forming members apart. Again, the mechanism effects right angle motion translation. The stroke of the Spiral-Helix, Inc. ovalizer is six inches.
"The Compact Helix Ovalizer 24/6" and "The Helix Ovalizer 36/12" are equipped with sets of semi-cylindrical heads of different diameters corresponding to the minor axis of different sizes of oval ductwork after forming, as well as a set of spacers that can be selectively installed as required.
Despite the apparently simple principle of the ovalizers manufactured by Spiral-Helix, Inc., the practical implementation is difficult. Relatively high pressure is applied to wearing parts, which accordingly must be maintained. Moreover, as the duct forming members move farther apart, there is less contact area available between the corresponding inclined plane surfaces. Thus, as the duct forming members move apart to the point where the duct metal begins to stretch, less contact area is available, concentrating increasing pressure on decreasing areas of the inclined plane surfaces.
As a result, the list price of a full size "The Helix Ovalizer 36/12" with duct forming members twelve feet in length (known as "mandrels" in the terminology employed by Spiral-Helix, Inc.) is approximately $250,000.00.
One limitation of ovalizers employing a right angle motion translation mechanism is that design compromises must be made among factors such as the length of the duct forming members (and therefore the longest section of ductwork that can be formed), the stroke (the distance of the relative movement of the duct forming members between the fully retracted position and the position where they are farthest apart), the force and stroke of the hydraulic cylinder used to drive the actuator rod, and structural requirements of the actuator rod. The mechanical advantage of the motion translation mechanism (either pivoting linkage arms or inclined planes) determines the relationship of the stroke of the duct forming members to the stroke of the actuator rod. Increasing either the stroke of the duct forming members (greater strokes are desirable) or the length of the duct forming members in general requires a greater force from the hydraulic cylinder.
As an alternative to mechanical linkages for translating longitudinal motion of an actuator rod to uniform motion of duct forming members away from each other, it has also been proposed to force the duct forming members apart by means of directly-attached hydraulic cylinder assemblies, with no motion translation required. One example is disclosed in Goodwin U.S. Pat. No. 4,571,980. The disclosed Goodwin duct-shaping machine employs a pair of duct forming members, reinforced with "I" beams, that are effectively placed inside a ductwork section to be formed. An hydraulic cylinder assembly is connected at each end of the duct forming members to force them apart. The disclosed Goodwin machine in addition has a pair of side compactors which engage exterior surfaces of the ductwork section being formed so as to flatten the sides of the duct along a minor axis, while the interior duct forming members are moving apart along the major axis. A related apparatus for "arching" corrugated steel drainage pipes, related in that hydraulic cylinders are employed to directly force out pipe forming segments, is disclosed in Brinegar U.S. Pat. No. 4,914,939.
Notwithstanding the disclosure of Goodwin U.S. Pat. No. 4,571,980, there are significant practical difficulties in devising an ovalizer which employs direct actuation of the duct forming members by hydraulic cylinders, which perhaps explains in part why the right angle motion translation mechanism approach of the ovalizers manufactured by Spiral-Helix, Inc. are what, heretofore, have primarily been available in the marketplace.
A significant factor is the relatively high force involved to form round ductwork to oval (at least in the absence of the minor axis compaction assemblies of Goodwin), and additionally to stretch the sheet metal approximately one percent, by slightly exceeding the yield strength of the duct metal, so that the oval shape is retained. The force required ranges from approximately 20,000 pounds per lineal foot along the lengths of the duct forming members in the case of 26 gage ductwork to 34,000 pounds per lineal foot along the lengths of the duct forming members of the case of spiral duct made of 16 gage sheet metal. A practical ovalizer has duct forming members that are ten feet in length, requiring a total force of approximately 340,000 pounds. Providing a structural beam to sustain such forces without undue bending if driven from the ends as disclosed in Goodwin U.S. Pat. No. 4,571,980 would be quite difficult.
The pipe arching apparatus of Brinegar U.S. Pat. No. 4,914,939 employs a plurality of cylinders, but still only two per individual forming segment. The requirements of a pipe arching apparatus, as disclosed in Brinegar U.S. Pat. No. 4,914,939, and the requirements of a spiral duct ovalizer differ significantly.