Methods and apparatus for transmitting documents using the Internet are disclosed. In accordance with a preferred embodiment of the invention, a document (3200) which is to be transmitted to a recipient is fed into a local facsimile machine (3100). The document (3200) includes a cover sheet (3210) containing a destination facsimile number (5100) and number of sheets which contain the message to be transmitted to the destination. The sender then dials the local telephone number of a remote computer system (2000). The document (3200) is then transmitted to the remote computer (2000) via a modem (2400) over a local telephone line (7000). The remote computer (2000) then scans the cover sheet (3210) and extracts the destination facsimile number (5100). The document (3200) is then formatted for transmission via public switched data network, specifically Internet backbone network(s) (6000), and is routed from the remote computer system (2000) to a host network computer system (4000). The document is then routed via the Internet (6000) to a remote computer system (4100) near the destination facsimile, and ultimately is delivered to its destination (5100).

The pace of business, whether domestic or international, is accelerating. At the same time the geography of business has become increasingly global and its morphology more complex and intertwined. Time and information are the most precious commodities of business today. Hence, the tremendous increase in the use of facsimile transmissions, in many cases supplanting postal services.
Pitney Bowes Corporation Facsimile Systems Division commissioned The Gallup Organization for three consecutive years (1992-1994) to conduct market research to determine a measurement of facsimile usage and applications of daily facsimile users at Fortune 500 Corporations and Dun & Bradstreet mid-sized companies in the United States. The Gallup Organization randomly sampled four hundred (400) daily facsimile users at Fortune 500 companies during the first quarter of each of the four going three years. In 1993 Dun & Bradstreet mid-sized companies (100-500 employees) were added to the study.
In 1994 the majority of facsimile users at both Fortune 500 and mid-sized companies stated that their facsimile utilization had increased over the past year and that it would increase in the coming years. The average daily outgoing facsimile volume for a typical facsimile user at a Fortune 500 company averaged 41.4 documents per day from 1992 to 1994, averaging 4.7 pages per facsimile transmission. Thus, a typical user at a Fortune 500 company averaged approximately two hundred (200) pages of facsimile transmission per day during this period. During the same period atypical user at a mid-sized company sent an average of 33.8 documents per day via facsimile averaging 3.5 pages per document. The utilization of facsimile transmissions by typical users at mid-sized companies was approximately one hundred twenty (120) pages per day.
Eleven percent (11%) of Fortune 500 and seven percent (7%) of mid-sized company facsimiles were sent to international destinations outside the United States during the period of the survey. The top five countries were the United Kingdom, Germany, Japan, Canada and Mexico. It is interesting to note that no Asian countries were listed other than Japan. The same survey taken today would undoubtedly show higher facsimile transmission rates to Asia.
Only five percent (5%) of 1994 Fortune 500 and two percent (2%) of mid-sized company users reported sending facsimile transmissions during the evening or night when dialing rates are cheaper.
In the first quarter of 1994 The Gallup Organization undertook a survey Fortune 500 telecommunication managers focused on facsimile costs and management policies. Fortune 500 telecommunications managers reported that thirty-six percent (36%) of their total telephone charges were related to facsimile transmissions, twenty point one percent (20.1%) for long distance and five percent (5%) for international. International long-distance is expected to grow at a compound annual growth rate of over fourteen percent (14%) over the next two to three years. Half of the Fortune 500 companies expected their facsimile charges to increase in the coming years by an average of twelve percent (12%). These managers ranked facsimile as one of the most productive telecommunication systems within their company, second only to voice mail.
Fortune 500 companies spend on average $2.9 million per corporate location for annual telephone services. On this basis approximately one million dollars is spent annually per location for facsimile services of which approximately $600,000 is for long distance facsimile transmission and $150,000 is for international facsimile transmission.
Interestingly, even with the availability of electronic mail ("E-mail" or "e-mail") services and the ability to send facsimile transmissions directly from a personal computer ("PC") with a modem, facsimile transmissions continue to increase and are expected to do so for the coming years. Further, facsimile usage is just as high for companies that use e-mail as for those that do not.
To send a facsimile a person walks to the facsimile machine, inserts the document to be transmitted, dials the destination telephone number and activates the facsimile machine. The sending machine dials the receiving facsimile machine number and when it answers sends the document to the receiving machine. Traditional facsimile transmissions are sent over the Public Switched Telephone Network ("PSTN") just like a voice telephone call. Facsimile machines contain modems (MODulator/DEModulator) which transmit and receive data transmissions over a voice telephone circuit.
The user pays the local and long-distance telephone company charges prevailing at the time he or she sends the facsimile transmission. This can be particularly expensive for international facsimile transmissions.
Advanced-featured facsimile machines, more expensive than basic machines, enable the user to store documents for transmission at a later time. This capability is constrained by the amount of memory in the facsimile machine in which to store documents and requires programming by the user. As is described above, deferred or delayed transmission is not widely utilized. For international transmissions the delay process is further complicated by the need to know or look-up the time periods in which cheaper international dialing rates apply.
The most common modem speed in facsimile machines has been 9600 bits per second ("bps") for quite a long period of time. In many parts of the world, however, facsimile machines are still in use that transmit data at 4800 bps and slower speeds. Newer and more expensive facsimile machines today contain modems capable of operating at speeds up to 14,400 bps (14.4 kbps). However, the ability to use the higher speeds is dependent upon the quality of the telephone line connection between the originating and destination facsimile machines. The slower the speed of the modem, the longer it takes to send a facsimile transmission. In the United States today one page of text takes less than a minute to send; in some parts of the world the same page of text can take up to three minutes to send. The cost implications are obvious.
What is today commonly referred to as the Internet began as a Defense Advanced Research Projects Agency ("DARPA") project in 1969 (at that time "ARPA") entitled Resource Sharing Computer Networks. The object of this project was to develop a robust network across the country that would keep military sites in communication in the event of a nuclear war. Since this project was funded by ARPA, it was generally referred to as ARPANET. The ARPANET, which operated until 1990, consisted entirely of 56 kbps lines linking sixteen cities across the United States. Its use was restricted to the United States Department of Defense ("DOD") and its contractors.
ARPANET was in every sense experimental. From 1969 to 1983 a lot of different packet switching schemes were tried. The term "Internet" was probably first applied to a 1973 research program that culminated in a demonstration system in 1977. It demonstrated networking through various media, including satellite, radio, telephone, ethernet and the like using packet switching. The Transmission Control Protocol and Internet Protocol ("TCP/IP"), a packet switching protocol, is what grew out of ARPANET's experiments.
In 1984 the National Science Foundation ("NSF") established an office for networking with the objective of tying together universities and other research establishments. Their first efforts at a national backbone NSF Network ("NFSNet") was deployed in 1986 as a 56 kbps network. In 1987, NSF contracted with Merit, a non-profit corporation comprised of some eleven Michigan Universities, to build a national backbone network using T-1 1.544 Mbps links to sixteen cities. IBM and MCI joined together to form a subsidiary company entitled Advanced Network Services, Inc. ("ANS") and Merit awarded a subcontract to them to actually build a T-1 network. In the interim, a number of universities and research groups got access to ARPANET. In a very real sense the NFSNet was more of an evolution of ARPANET than an entirely new network.
There was enormous controversy over the switching technology to increase the NSFNet backbone to T-3 speeds of 45 Mbps as late as 1993. In fact, for several years, the packet switches that ANS used did not really switch data packets fast enough to actually achieve 45 Mbps links. But by late 1993, the T-3 network was more or less working. On Apr. 30, 1995, operation of the NSFNet backbone ceased.
Backbone bandwidth refers to the carrying capacity of the top level links connecting various metropolitan areas around the world. Today the Internet consists of as many as eighteen national backbone networks operated by private companies, all interconnected in a few cities. These interconnections take place in several Network Access Points ("NAP's"). The backbones are almost all T-3 links operating at 45 Mbps. Furthermore, these backbones have been extended internationally.
In March 1996, MCI announced that it had increased the speed of its entire backbone to 155 Mbps. Other Internet Service Providers ("ISP's") have made similar announcements.
The problem of providing an easy, reliable and low-cost method for automatically routing and transporting facsimile traffic at high speeds has presented a major challenge to persons skilled in the telecommunications field. The development of methods and apparatus that would overcome this problem would constitute a major technological advance and would satisfy a long felt need within the telephony and electronics industries.

Facsimile transmission via packet switched data networks


A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.

1. Field of the Invention
The present invention relates to a method and apparatus for testing a tunnel magnetoresistive effect (TMR) element such as a TMR read head element using the tunnel magnetoresistive effect or a magnetoresistive random access memory (MRAM) cell, to a manufacturing method of a TMR element, and to a TMR element.
2. Description of the Related Art
An evaluation test is in general performed for determining whether or not a thin-film magnetic head with a TMR read head element is a non-defective product, during or after manufacturing the magnetic head. This evaluation test includes a reliability test for confirming that a breakdown voltage of the MR head element is sufficiently high to withstand an extended period of use.
U.S. Pat. No. 6,473,257 discloses a testing method for confirming a reliability of a TMR read head element without damaging or breaking the TMR read head element. In this testing method, a performance of the TMR read head element such as its electromagnetic conversion performance is measured by using a test current with a predetermined value. The value of the test current value is determined by measuring a resistance of the TMR read head element when a predetermined initial current is flowing there through, or determined by repeatedly measuring a modified current when a reference voltage is applied to the TMR read head element and by measuring a resistance of the TMR read head element when the finally measured modified current is flowing there through.
However, this testing method disclosed in U.S. Pat. No. 6,473,257 requires a performance test of the TMR read head element such as an electromagnetic conversion performance test of the TMR read head element, and thus requires a great deal of expense in manpower and in time for confirming a reliability.

Method and apparatus for testing tunnel magnetoresistive effect element, manufacturing method of tunnel magnetoresistive effect element and tunnel magnetoresistive effect element


Described herein is a biasing circuit for a magnetic-field sensor; the magnetic-field sensor is provided with a first detection structure, which generates a first electrical detection quantity as a function of a first component of an external magnetic field, and a second detection structure, which generates a second electrical detection quantity as a function of a second component of an external magnetic field. The biasing circuit electrically supplies the first detection structure and the second detection structure in respective biasing time intervals, at least partially distinct from one another, which preferably do not temporally overlap one other.

1. Technical Field
The present disclosure relates to an electrical biasing circuit for a magnetic-field sensor, in particular an anisotropic magnetoresistive (AMR) magnetic sensor, and to a corresponding electrical-biasing method.
2. Description of the Related Art
Magnetic-field sensors, in particular AMR sensors, are used in a plurality of applications and systems, for example in compasses, in systems for detecting ferrous materials, in the detection of currents, and in a wide range of other applications, thanks to their capacity for detecting natural magnetic fields (for example, the Earth's magnetic fields) and magnetic fields generated by electrical components (such as electrical or electronic devices and lines traversed by electric current).
In a known way, the phenomenon of anisotropic magnetoresistivity occurs within particular ferrous materials, which, when subjected to an external magnetic field, undergo a variation of resistivity as a function of the characteristics of the external magnetic field. Usually, these materials are applied in the form of thin strips so as to form magnetoresistive elements, and the magnetoresistive elements thus formed are electrically connected to form a bridge structure (typically a Wheatstone bridge).
Manufacturing of AMR sensors with standard techniques of semiconductor micromachining is also known, as described, for example, in U.S. Pat. No. 4,847,584. In particular, each magnetoresistive element can be formed by a film of magnetoresistive material, such as for example Permalloy (a ferromagnetic alloy containing iron and nickel), deposited to form a thin strip on a substrate of semiconductor material, for example silicon.
When an electric current I is made to flow through a magnetoresistive element (see FIG. 1a), the angle θ between the direction of magnetization M of the magnetoresistive element and the direction of flow of the electric current I affects the effective value of resistivity of the magnetoresistive element, so that, as the value of the angle θ varies, the value of electrical resistance also varies (in detail, this variation follows a law of the cos2θ type). The magnetoresistive elements are generally brought into an initial condition of magnetization, via appropriate biasing means; next, an external magnetic field He causes a variation of the direction of magnetization M of the magnetoresistive elements (and a variation of the value of angle θ), and consequently a variation of resistance. In particular, it is the component of the external magnetic field He perpendicular to the direction of magnetization M, acting along the so-called axis of sensitivity or detection, that affects the value of the angle θ.
The Wheatstone-bridge detection structure of an AMR sensor includes magnetoresistive elements that have ideally the same value of resistance and are such as to form diagonal pairs of equal elements, which react in a way opposite with respect to one another to the external magnetic fields, as shown schematically in FIG. 1b (where I is once again the electric current flowing in the magnetoresistive elements and R is the common resistance value). If a supply (or electrical biasing) voltage Vss is applied at input to the bridge detection structure (in particular to first two terminals of the bridge, operating as input terminals), in the presence of an external magnetic field He, a resistance variation ΔR of the magnetoresistive elements and a corresponding variation of the value of voltage drop on the magnetoresistive elements occur. There follows an unbalancing of the bridge, causing a voltage variation ΔV at output (in particular between the remaining two terminals of the bridge, operating as output terminals). Given that the initial direction of magnetization of the magnetoresistive elements is known beforehand, as a function of this voltage variation ΔV it is possible to determine the component of the external magnetic field acting along the axis of sensitivity of the detection structure.
In particular, in order to detect the unbalancing of the Wheatstone bridge and generate an electrical output signal indicating the characteristics of the external magnetic field to be measured, a reading circuit (or front-end) is normally used, which is coupled to the output of the detection structure of the AMR sensor and includes a signal-conditioning stage, comprising amplification and filtering units, and possibly an analog-to-digital-converter stage, which supplies to the outside the output signals.
A measurement technique proposed and widely used moreover envisages the use of coils or straps, which are integrated in the same AMR sensors, and are designed to generate, when traversed by current, a magnetic field with pre-defined direction and sense; these coils are known as "set/reset straps". For example, the set/reset straps are provided on the same substrate as that on which the magnetoresistive elements of the sensor are provided, being electrically insulated from, and set in the proximity of, the magnetoresistive elements.
During operation, the initial orientation of the magnetization direction is obtained by applying to the magnetoresistive elements, via the set/reset straps, an intense magnetic field for a short period of time, of a value such as to force and align the orientation of the magnetic dipoles of the magnetoresistive element in a first pre-defined direction (in the case of a "set" pulse) of a magnetization axis (the so-called "easy axis"), or else in a second pre-defined direction, opposite to the first direction (in the case of a "reset" pulse) along the same magnetization axis, according to the sense of the magnetic field generated, and hence in a way coherent with the sense of the current that circulates in the same set/reset straps. The aforementioned set and reset operations are known and described in detail, for example, in U.S. Pat. No. 5,247,278.
The reversal of orientation of the magnetic dipoles causes inversion of sign of the signal at output from the Wheatstone bridge, in the presence of an external magnetic field He. Instead, any possible offset signals superimposed on the useful signal in the output signal do not reverse their own polarity, since they are due exclusively to mismatch between the components internal to the sensor and are hence independent of the characteristics of the external magnetic field He.
Consequently, the measuring procedure envisages applying a set pulse and, after waiting an appropriate relaxation time such as to eliminate possible current tails and allow settling of the magnetic dipoles of the ferromagnetic material, acquiring a first sample of the output signal (for example, a voltage signal, Vout) in the presence of the external magnetic field He; the first sample of the output signal, designated by Voutset is given by:Voutset=He·S+Voutoff where S is the sensitivity of the magnetic sensor and Voutoff the offset signal superimposed on the output.
Next, a reset pulse is applied and, after waiting an appropriate relaxation time such as to eliminate possible current tails and allow settling of the magnetic dipoles of the ferromagnetic material, a second sample of the output signal is acquired, to obtain:Voutreset=He·(−S)+Voutoff where −S is the value of sensitivity of the magnetic sensor, having in this case a value equal and opposite to the value of sensitivity S during the set operation, on account of the reversal of sense of the magnetic dipoles of the magnetoresistive elements of the sensor.
A subtraction is then made between the first sample and the second sample that have been acquired, which makes it possible to derive the useful signal, cancelling out the effects of the offset contribution on the output signal, as follows:(Voutset−Voutreset)=He·S+Voutoff−(He·(−S)+Voutoff)=2He·S
Moreover known to the art is the joint use of three Wheatstone-bridge detection structures, each constituted by appropriately oriented magnetoresistive elements, having axes of sensitivity orthogonal to one another, for determining the magnitude and direction of an external magnetic field acting in any direction of space (thus determining the corresponding components along the three axes of sensitivity). This configuration is used, for example, in the manufacturing of compasses or magnetometers, for example in mobile-phone devices or in other mobile devices.
In this kind of applications, the magnetic sensor hence comprises, as a whole, three detection structures, each corresponding to a respective axis of sensitivity, x, y or z, and moreover a biasing and reading circuit, typically provided as application-specific integrated circuit (ASIC), configured so as to detect and process the electrical signals supplied by the various detection structures, and supply an appropriate biasing voltage to the same detection structures, during the entire operation of the magnetic-sensor device (the biasing voltage, see FIG. 1b, is used for supplying the Wheatstone bridge and determining unbalancing thereof in the presence of external fields).
Also due to the low values of electrical resistance of the various magnetoresistive elements constituting the detection structures, the consumption of each Wheatstone-bridge detection structure is rather high (even of the order of some milliamps). In addition, the same reading circuit, which comprises amplifiers and in general active electronic components, has considerable consumption levels, which adds to the consumption associated to the detection structures, determining as a whole a considerable energy expenditure. The energy consumption is still higher in the case where a number of reading circuits, which operate in parallel, are used, each coupled to a respective detection structure; a solution of this sort moreover entails a considerable increase in the area occupation for the integrated implementation.
The problem of electrical consumption of magnetic sensors is hence particularly felt, especially in applications in which a number of detection structures is used for detecting components of magnetic fields oriented along respective axes of sensitivity. This problem, of course, is even more important in applications in which the energy usage represent a determining design constraint, such as, for example, in battery-supplied portable applications.

This patent is subject to a terminal disclaimer.

Biasing circuit for a magnetic field sensor, and corresponding biasing method


Ophthalmic suture materials made from biocompatible and biodegradable polymers with high tensile strength for use in drug delivery, methods of making them, and method of using them for ocular surgery and repair have been developed. The suture materials are made from a combination of a biodegradable, biocompatible polymer and a hydrophilic biocompatible polymer. In a preferred embodiment the suture materials are made from a poly(hydroxyl acid) such as poly(l-lactic acid) and a polyalkylene oxide such as poly(ethylene glycol) or a polyalkylene oxide block copolymer. The sutures entrap (e.g., encapsulate) one or more therapeutic, prophylactic or diagnostic agents and provide prolonged release over a period of at least a week, preferably a month.

Invasive ophthalmic surgeries often lead to numerous complications for patients, at least in part because patient compliance with prophylactic drugs after ophthalmic surgery is relatively low and in part because the ocular bioavailability is frequently low for common dosage forms. The vast majority of ophthalmic drug formulations remain the traditional solutions, ointments and suspensions, by one estimate accounting for about 90% of the global market of ophthalmic drug formulations.
Even when patient compliance is high, the ocular bioavailability of drugs applied topically as eye-drops is very poor. The absorption of drugs in the eye is severely limited by some protective mechanisms that ensure the proper functioning of the eye. The contact with the absorbing surfaces (cornea and sclera) is reduced to a maximum of about two minutes. Dosage volumes are limited by drainage via the nasolacrimal system into the nasopharynx and the gastrointestinal tract. Lacrimation and the physiological tear turnover (16% per minute in humans in normal conditions) are often increased by the instillation even of mildly irritating solutions, leading to more rapid clearance of the applied dosage form.
Trabeculectomy is an ophthalmic surgical procedure used in the treatment of glaucoma. Removing part of the eye's trabecular meshwork and adjacent structures allows drainage of aqueous humor from within the eye to underneath the conjunctiva to relieve intraocular pressure. The scleral flap is typically sutured loosely back in place with several sutures. Common complications include blebitis (an isolated bleb infection typically caused by microorganisms such as Staphylococcus epidermidis, Propriobacterium acnes, or Staphylococcus aureus), inflammation, and bleb-associated endophthalmitis.
Endophthalmitis is an inflammation of the ocular cavities and their adjacent structures. It is a possible complication of all intraocular surgeries, particularly cataract surgery, which can result in loss of vision or the eye itself. Endophthalmitis is usually accompanied by severe pain, loss of vision, and redness of the conjunctiva and the underlying episclera. Infectious etiology is the most common and various bacteria and fungi have been isolated as the cause of the endophthalmitis. The patient needs urgent examination by an ophthalmologist and/or vitreo-retina specialist who will usually decide for urgent intervention to provide intravitreal injection of potent antibiotics and also prepare for an urgent pars plana vitrectomy as needed. Enucleation may be required to remove a blind and painful eye.
Ophthalmic sutures are commonly used during ophthalmic surgical procedures, including trabeculectomy as well as pterygium removal, cataract surgery, strabismus correction surgery, penetrating keratoplasty, sclerectomy, and conjunctival closure. The choice of suture material can strongly impact the occurrence of complications related to infection and inflammation post ophthalmic surgery, either causing irritation and local inflammation or providing a substrate for microorganism growth. The suture materials typically employed include nonbiodegradable ophthalmic suture materials such as ETHILON® nylon suture, MERSILENE® polyester fiber suture, PERMA-HAND® silk suture, PROLENE® polypropylene suture, each commercially available from Ethicon, Somerville, N.J.; and VASCUFIL® coated monofilament suture composed of a copolymer of butylene terephthalate and polyteramethylene ether glycol, MONOSOF˜DERMALON® monofilament nylon sutures composed of long-chain aliphatic polymers Nylon 6 and Nylon 6.6, NOVAFIL® monofilament sutures composed of a copolymer of butylene terephthalate and polyteramethylene ether glycol, SOFSILK® braided sutures composed of fibroin, TI-CRON-SURGIDAC® braided polyester sutures composed of polyester terephthalate, SURGILON® braided nylon sutures composed of the long-chain aliphatic polymers Nylon 6 and Nylon 6.6 and SURGIPRO II-SURGIPRO® sutures composed of polypropylene, each commercially available from U.S. Surgical, Norwalk, Conn.
Ideally, ophthalmic suture materials would be biodegradable and biodegradable over the useful suture lifetime, retaining the requisite tensile strength and capable of delivering therapeutic or prophylactic agents to increase patient success. For pterygium removal, cataract surgery and strabismus correction surgery, sutures could be used to close the wound and release antibiotic and anti-inflammatory drugs. For trabeculectomy surgeries, sutures could be placed on sclera flaps providing local chemotherapeutic agents, decreasing production of scar tissue, and also, on conjunctival closure with antibiotic release. In penetrating keratoplasty, the sutures hold the graft, as well as release antibiotic and immunosuppressant agents.
Therefore, it is an object of the invention to provide ophthalmic sutures that are biocompatible and biodegradable and retain the requisite tensile strength over the useful life of the suture.
It is further an object of the invention to provide ophthalmic sutures capable of delivering an effective amount of one or more therapeutic or prophylactic agents to the ocular region over an extended period of time.
It is further an object of the invention to provide ophthalmic sutures having a diameter allowing for use in ophthalmic procedures while causing little to no irritation of the surrounding tissue.
It is further an object of the invention to provide the ophthalmic sutures having a higher tensile strength than commonly employed ophthalmic suture materials of a similar diameter.
It is further an object of the invention to provide methods of making ophthalmic sutures that are biocompatible and biodegradable and capable of delivering one or more therapeutic agents.
It is further an object of the invention to provide method of ophthalmic surgery and repair using the sutures described herein to increase patient comfort and/or success as compared to traditional ophthalmic suture materials.

Drug loaded microfiber sutures for ophthalmic application


A lock arm (12) on a female housing (1) is deformed at an intermediate stage of connecting the female housing (1) with a mating male housing (20). A lock (13) at the leading end of the lock arm (12) contacts an edge (23D) of an engaging portion (23) on the male housing (20) and then parts therefrom by canceling a rubbing state. The lock arm (12) then restores resiliently and the lock (13) engages the engaging portion (23) to lock the housings (1, 20) in a properly connected state. At least one of the lock (13) and the edge (23D) of the engaging portion (23) that rub against each other immediately before the proper connection of the two housings (1, 20) has a resistance alleviating portion (13C) with an apex locally projecting toward the other rubbed part.

1. Field of the Invention
The invention relates to a connector.
2. Description of the Related Art
U.S. Pat. No. 5,336,101 discloses a connector assembly with male and female housings that can be connected together. A lock arm is provided on an upper surface of the female housing and a lock is formed on the leading end of the lock arm. The lock arm can pivot about the base end so that the lock at the leading end of the lock arm displaces. An engaging projection is provided on the upper surface of the male housing. The lock moves onto the engaging projection during the connection of the male and female housings. The lock then contacts the rear edge of engaging projection and parts from the rear edge that have been rubbed against. The lock arm then returns resiliently while following a pivoting path. In this way, the lock engages the engaging projection to lock the male and female housings in their connected state.
The rear edge of the leading end of the above-described lock and the rear edge of the engaging projection are in line contact with each other along the width direction when they part from each other in the connecting process. Thus, the rear edge of the leading end of the above-described lock and the rear edge of the engaging projection cannot part smoothly from each other due to contact resistance therebetween. Accordingly, a connection feeling upon connecting or separating the two housings deteriorates.
The invention was developed in view of the above problem and an object thereof is to improve connection feeling and separation feeling upon connecting and separating two connectors.


A method includes obtaining multiple images of a driver of a vehicle using an imaging sensor associated with the vehicle, where the images of the driver capture the driver's head. The method also includes identifying, in each of at least some of the images, an orientation of the driver's head in the image. The method further includes identifying an average orientation of the driver's head based on at least some of the identified orientations of the driver's head. In addition, the method includes determining whether the driver is inattentive based on the average orientation of the driver's head. Identifying, in each of at least some of the images, the orientation of the driver's head in the image may include identifying a pitch angle and a yaw angle of the driver's head in the image.

Driver inattention is a significant problem in the trucking industry and other vehicle transportation industries. Among other things, drivers who are drowsy, who look at their mobile electronic devices, or who are otherwise inattentive while driving can cause serious accidents that result in significant economic losses, personal injuries, or deaths. Some systems have been developed that use cameras or other imaging sensors to capture images of vehicle drivers and that process the images to identify instances when the drivers appear to be inattentive. However, these systems can suffer from a number of shortcomings.

Highly-accurate and self-adjusting imaging sensor auto-calibration for in-vehicle driver monitoring system or other system


A sodium niobate powder includes sodium niobate particles having a shape of a cuboid and having a side average length of 0.1 μm or more and 100 μm or less, wherein at least one face of each of the sodium niobate particles is a (100) plane in the pseudocubic notation and a moisture content of the sodium niobate powder is 0.15 mass % or less. A method for producing a ceramic using the sodium niobate powder is provided. A method for producing a sodium niobate powder includes a step of holding an aqueous alkali dispersion liquid containing a niobium component and a sodium component at a pressure exceeding 0.1 MPa, a step of isolating a solid matter from the aqueous dispersion liquid after the holding, and a step of heat treating the solid matter at 500° C. to 700° C.

Piezoelectric ceramics are generally composed of an ABO3 perovskite-type metal oxide such as lead zirconate titanate (hereinafter referred to as "PZT"). However, since PZT contains lead as an A-site element, the effect of PZT on environment is regarded as a problem. Therefore, piezoelectric ceramics composed of a lead-free perovskite-type metal oxide have been required.
An example of the piezoelectric ceramics composed of a lead-free perovskite-type metal oxide is an alkali niobate compound (general formula: MNbO3, M is an alkali metal). Perovskite-type metal oxides containing sodium niobate, such as a solid solution of sodium niobate and barium titanate or a solid solution of sodium niobate and potassium niobate, are promising as alternative compounds for PZT. Such an alkali niobate compound has an advantage in that sintering can be performed at a low temperature of, for example, 1300° C. or less.
A metal oxide powder serving as a raw material for obtaining a piezoelectric ceramic from the alkali niobate compound is generally produced by a so-called solid state reaction including a step of mechanically mixing or kneading each metal oxide, a step of molding the mixture into a pellet, and a step of firing the pellet.
In recent years, a synthesis method in a liquid phase has also been considered. For example, PTL 1 discloses a synthesis method that uses a solvothermal process. This synthesis method provides alkali niobate particles that have a shape of a cuboid and a uniform size and are suitable for piezoelectric ceramics.

Sodium niobate powder, method for producing the same, method for producing ceramic, and piezoelectric element


A display device including a display unit having a plurality of pixels is disclosed. In one aspect, at least one first pixel among the pixels includes: a first compensation capacitor including one electrode connected to a data line and the other electrode connected to a first node; a first switching transistor including a gate electrode configured to have a scan signal, one electrode connected to the first node, and the other electrode connected to a second node; a first driving transistor including a gate electrode connected to the second node, one electrode connected to a first power source voltage, and the other electrode connected to a first organic light emitting diode (OLED); and a first link transistor including a gate electrode configured to have a link control signal, one electrode connected to the data line, and the other electrode connected to the first power source voltage. Pixels of the type with four transistors may be alternated with pixels of the type having three transistors (no link transistor) according to a desired aspect ratio.

1. Field
The disclosed technology relates to a pixel, a display device including the same, and a driving method thereof. More particularly, the disclosed technology relates to a pixel that is robust to a coupling or a leakage current caused by an external voltage, a display device including the same, and a driving method thereof.
2. Description of the Related Technology
An organic light emitting diode (OLED) display uses an OLED for controlling luminance by current or voltage. The OLED includes an anode layer and a cathode layer for forming an electric field, and an organic light emitting material electric field for emitting light by the electric field.
Generally, OLED displays are classified into one of two types: a passive matrix OLED (PMOLED) and an active matrix OLED (AMOLED) according to the driving circuitry.
Between them, in view of resolution, contrast, and operational speed, AMOLED drivers that are selectively turned on for every unit pixel find the most widespread commercial applications.
One pixel of an active matrix OLED includes an organic light emitting diode, a driving transistor that controls the amount of current that is supplied to the organic light emitting diode, and a switching transistor that transmits a data voltage that controls the driving transistor to adjust the amount of light that is generated by the OLED. The switching transistor is turned on by a scan signal of a gate-on voltage.
An OLED display may be operated with a simultaneous light emitting method in which all pixels simultaneously emit light after all pixels are programmed with data during one frame. The simultaneous light emitting method has merit in that it is not influenced by a voltage drop of a power source voltage due to wire length when programming the data.
However, this method has a short light emitting period compared with a sequential light emitting method in which a plurality of pixels sequentially emit light. Accordingly, to maintain the same luminance as in the sequential light emitting method, much current must flow to a plurality of pixels in the light emitting period. For this, the power output of a data driving IC (integrated circuit) must not only be expanded, but also a voltage difference between the power source voltage of both terminals of the pixel providing the driving current must be increased. If the voltage difference between the power source voltage of both terminals of the pixel providing the driving current is increased, the voltage drop caused by the wire is increased such that the power source voltage must be designed for the voltage difference between the power source voltage of both terminals of the pixel to have a margin of error.
Resultantly, the voltage difference between the power source voltage of both terminals of the pixel must be designed to meet this criteria, and accordingly power consumption is increased. Also, by considering the voltage drop of the wire length, although the power source voltage is set up or the voltage difference between the power source voltage of both terminals of the pixel is sufficient, uniformity of luminescence across the entire screen of pixels may decrease by the voltage drop of the power source voltage.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Pixel, including a link transistor, display device including the same, and driving method thereof


This invention pertains to hydroformylation catalysts containing a mixture of isomeric forms of halo-phosphorus ligands. This invention also describes a procedure for preparing isomers of certain halophosphite ligands, which contain the phosphorus atom in a macrocyclic ring.

The hydroformylation reaction, also known as the oxo reaction, is used extensively in commercial processes for preparing aldehydes by reacting one mole of an olefin with one mole each of hydrogen and carbon monoxide. The most extensive use of the reaction is in the preparation of normal- and iso-butyraldehyde from propylene.
The ratio of the amount of the normal-aldehyde product to the amount of the iso-aldehyde product typically is referred to as the normal to iso (N:I or N/I) or the normal to branched (N:B or N/B) ratio.
In the case of propylene, the normal- and iso-butyraldehydes obtained from propylene are, in turn, converted into many commercially valuable chemical products, such as, for example, n-butanol, 2-ethyl-hexanol, n-butyric acid, iso-butanol, neo-pentyl glycol, 2,2,4-trimethyl-1,3-pentanediol, and the mono-isobutyrate and di-isobutyrate esters of 2,2,4-trimethyl-1,3-pentanediol. The hydroformylation of higher α-olefins (such as 1-octene, 1-hexene, and 1-tetradecene) yields aldehyde products that are useful feedstocks for preparing detergent alcohols and plasticizer alcohols.
U.S. Pat. No. 5,840,647 and U.S. Pat. No. 6,130,358 introduced a new concept in ligand design with the disclosure of halogen substituents on the phosphorus atom of trivalent phosphorus ligands. These halogenated phosphorus ligands are readily prepared, possess high activity and good stability, and permit a wide N/I range of products to be prepared by simply varying the process parameters.
Many of the halophosphite ligand compositions contain the phosphorus atom in a macrocyclic ring structure. Macrocyclic rings introduce the possibility of many different structural and conformational isomers of the phosphorus ligands. The presence of a plurality of isomeric forms of the phosphorus ligand can be problematic, because each of the different isomers can form complexes with the transition metal catalyst, and the reactivity and selectivity of the catalyst can vary greatly depending on which isomeric form of the phosphorus ligand is attached to the transition metal atom. Frequently, using mixed isomeric forms of the phosphorus ligand results in a complex catalyst composition, which makes it difficult to predict and control the activity and selectivity of the catalyst.
Thus, it is desirable to be capable of creating a catalyst composition from a mixture of phosphorus ligand isomers that behaves in a manner as if it were a single isomer of the phosphorus ligand. In addition or alternatively, it is desirable to have a process by which a single isomer can be isolated from a mixture of isomers.
The present invention addresses these desires as well as others, which will become apparent from the following description and the appended claims.


An optical scanning device includes a laser-beam-phase-modulatable liquid crystal device. The liquid crystal device has stripe-like electrode patterns arranged in one direction, with a provision of a part for changing an effective value of a driving voltage separately for each of stripe-like electrode patterns.

1. Field of the Invention
The present invention relates to an optical scanning device, an image forming apparatus and a liquid crystal device driving method, and, in particular, to an optical scanning device or a multi-beam optical scanning device used for a laser writing optical system, an image forming apparatus such as a laser writing optical system, or a laser printer, a digital copier, a laser facsimile machine, a laser plotter, or such.
The present invention also relates to an optical scanning device provided with a liquid crystal device which can modulate phase of a laser beam, to an image forming apparatus, such as a laser writing optical system, or a laser printer, a digital copier, a laser facsimile machine, a laser plotter or such, employing the optical scanning device and a liquid crystal device driving method carried out in the optical scanning device.
2. Description of the Related Art
Recently, performance of an image forming apparatus such as a laser printer, a digital copier or such, has been improved, i.e., image quality is improved, processing speed is increased, and color printing or color copy could be practically carried out. Along with such an improvement of the performance, users are requesting a further higher quality.
For the request for processing speed, to apply a multi-beam manner is effective. However, in this manner, pitch adjustment among a plurality of beams is required. For this purpose, a method of rotating a multi-beam light source about an optical axis, a method of using an optical device prepared for pitch adjustment or such may be applied (for example, see Japanese Laid-open Patent Application No. 9-131920).
For the request for image quality improvement, reduction of a beam spot is required. Various methods have been proposed therefor (for example, see Japanese Laid-open Patent Applications Nos. 3-116112, 5-19190 and 2001-166237).
However, technical problems exist in actually achieving reduction of a beam spot diameter. In particular, it is necessary to consider that an image forming apparatus or an optical scanning device has many heat sources such as a fixing unit, a polygon scanner or such. Accordingly, it is necessary to take account of temperature fluctuation in the operation environment in seeking the reduction of a beam spot diameter.
In the above-mentioned related art of rotating a light source unit about an optical axis, since the light source unit itself is moved in this art, a problem may occur in terms of reliability of the electrical components. Further, in the related art of using an optical device for pitch adjustment, since a high accuracy glass optical device is required, a problem in terms of the required cost may occur.
Further, even if a beam spot diameter is adjusted initially at a high accuracy, a positional shift of the beam spot may occur due to influence of aging such as temperature fluctuation or such.
Therefore, a liquid crystal device driven by an electrical signal has been proposed to carry out the above-mentioned pitch adjustment (for example, see Japanese Laid-open Patent Application No. 6-214177). In this method, a beam pitch is detected by means of a detector, and, based on the detection result, the liquid crystal device is driven. Thereby, it is possible to correct for the aging variation of the beam pitch. The liquid crystal device is advantageous when it is used as a beam pitch adjustment device in that it is driven by a low voltage signal, does not generate heat, does not generate vibration, does not generate noise, is small sized, and also, is light weighted.
This liquid crystal device acting as the pitch adjustment device has a cell structure in which a liquid crystal layer on the order of several through tens of μm is sealed by two glass substrates. Therefore, a central part of the liquid crystal layer having a relatively high thermal expansion coefficient expands when an ambient temperature increases. As a result, a positive power lens function may appear. When the liquid crystal device thus has such a lens function due to increase in the ambient temperature, a beam waist position may shift, and thus, the beam spot diameter may degrade (increase).
In an optical scanning device used in an optical writing part of an image forming apparatus, a rotational speed of a polygon mirror acting as a deflection device may be improved for the purpose of improving a recording speed. However, in this case, a problem may occur in terms of durability, noise or vibration of a polygon motor, a problem in a laser modulation speed or such, and thus, there is a limit in the improvement of the recording speed in this manner. Therefore, as an alternative method, a multi-beam scanning device is proposed by which a plurality of laser beams are used to simultaneously carry out scanning and recording a plurality of scan lines simultaneously.
As a type of a multi-beam light source device emitting a plurality of laser beams used in the multi-beam scanning device, there is a type in which a multi-beam semiconductor laser (for example, a semiconductor array) having a plurality of light emitting points (light emitting channels) enclosed by a single package is used. However, it is difficult to increase the number of the channels in terms of manufacturing process. Also, it is difficult to remove influence of thermal/electrical crosstalk. Further, it is difficult to shorten the oscillation wavelength. As a result, the light source device may become expensive.
On the other hand, many proposals have been made for a light source device in which a single beam semiconductor laser is used as a light source, and, with the use of a beam creation device, a plurality of laser beams are created therefrom, and a multi-beam scanning device uses them. However, in this method, a problem in which an arrangement of beam spots (beam pitch, or scan line separation) on a to-be-scanned surface may change due to environmental fluctuation, aging fluctuation or such may occur. Then, many proposals have been made for solving this problem.
The present applicant made one proposal in Japanese Laid-open Patent Application No. 2003-337293, 'Optical Scanning Device, Light Source Device and Image Forming Apparatus'. In the art, a 'liquid crystal device' driven by an electrical signal is used to correct beam spot arrangement on a to-be-scanned surface. In this art, in order to control the beam spot arrangement on the to-be-scanned surface, the liquid crystal device is used as a 'light path deflection device' which is disposed in or immediately subsequent to a light source part, for deflecting a laser beam by a slight angle (several through tens of minutes).
Recently, along with the request for increasing the recording speed of a color image forming apparatus, for example, a so-called 'four drum tandem type image forming apparatus' is practically used in a form of a digital copier, a laser printer or such. In this apparatus, four photosensitive drums are disposed along a direction of conveying a recording member (for example, a recording paper) or a direction of an intermediate transfer body; latent images are formed thereon simultaneously with exposure thereof by means of corresponding plurality of scanning optical systems; these latent images are then visualized with the use of developing agents of respective different colors, such as yellow, magenta, cyan and black, or such, by means of a developing device; these visualized images are transferred onto the common recording member or intermediate transfer body in a superposing manner; and thus, a color image is obtained thereon.
This four drum tandem type image forming apparatus is advantageous for carrying out high-speed printing in comparison to a one drum type image forming apparatus, in that a color image can be output in the same speed as that for a monochrome image. However, since this type of machine has the four scanning optical systems for the respective four photosensitive drums, a problem may occur in that miniaturization of the machine may be difficult. Further, another problem may occur for avoiding color drift which may occur when the toner images of the respective colors developed on the respective photosensitive drums are transferred to the recording member or the intermediate transfer body in the superposing manner.
The following causes of generation of the above-mentioned color drift in particular in a sub-scan direction in the four drum tandem type image forming apparatus may be cited for example:
(1) fluctuation of a feeding speed of the photosensitive drum in a circumferential direction (the sub-scan direction);
(2) fluctuation of the feeding speed of the recording member or the intermediate transfer body in the conveyance direction (the sub-scan direction);
(3) positional error among the photosensitive drums;
(4) positional error of beam spots written among the scanning optical systems;
(5) positional error of the above-mentioned items (1) through (4) due to environmental fluctuation, or temperature fluctuation occurring when continuous printing is carried out for example; and
(6) when writing is carried out simultaneously to the respective photosensitive drums in a multi-beam manner, since rotation of a polygon scanner and the photosensitive drum feeding speed are not in synchronization with one another in general, a positional shift for a number of beams may occur in the sub-scan direction.
As a scheme for avoiding the color drift, the following methods are known for example:
(A) As disclosed in Japanese Laid-open Patent Application No. 2001-133718, in an image forming apparatus using a plurality of scanning devices, a position of each entire scanning device (housing) is adjusted with respect to a photosensitive body, and thus, scan lines can be made coincident on the respective photosensitive bodies. However, in this method, a mechanism may become complicated for the adjustment, and also, a time is required for the adjustment. Furthermore, since the housing having a large weight is adjusted in its position, it may be difficult to respond to an aging fluctuation such as temperature fluctuation, and thus, it may be difficult to carry out color drift correction at high accuracy during printing or for possible fluctuation in the operation environment.
(B) As disclosed in Japanese Laid-open Patent Application No. 2001-100127, a galvano mirror is used to control the sub-scan beam position. However, since the galvano mirror has a sensitivity too high to control the sub-scan position, the control may be easily affected by external vibration, and thus, a high surface accuracy (approximately four times that of a transmission surface) is required for maintaining a further satisfactory beam spot diameter.
(C) As a configuration of solving the problem of positional error among the multiple beams, Japanese Laid-open Patent Application No. 10-239939 discloses a color image forming apparatus having a correction device which switches a laser beam to write an image first from among a plurality of laser beams according to a phase relationship between an intermediate transfer reference signal and a line synchronization signal, whereby an image writing start position can be adjusted for each color in a sub-scan direction, and thus, the color drift can be corrected. However, even by applying this method. it is not possible to achieve a correction in an amount smaller than one line, and, as a result, a color drift more than 42 μm may occur in a case of writing in 600 dpi ('dpi': dots per inch) for example.
Japanese Laid-open Patent Application No. 2002-214579 discloses one example of the prior art for deflecting a laser beam path with the use of a liquid crystal device. In this example relating to an image display apparatus, by applying a voltage to a transparent electrode array formed in an arrangement pitch corresponding to the pixel pitch, an uneven electric field is formed in the liquid crystal layer, and, a light path is deflected by means of refractive index distribution thus generated in the liquid crystal layer.
However, in this case of the deflection device applying the liquid crystal device in the prior art, a voltage is applied between both ends of the transparent electrodes arranged like a stripe with equal separation, and a resistance member is provided such that an electric potential distribution may have a uniform slope (linear characteristic) in the arrangement direction. When the refractive index distribution in the liquid crystal layer is controlled in such a manner that the electric potential distribution in the liquid crystal layer may have a uniform slope, there is a possibility that, even when the electric potential distribution has a uniform slope, the refractive index distribution in the liquid crystal layer may not necessarily have a uniform slope, but may behave to draw a curve which may be approximated by a high-order polynomial. If a laser beam is applied to the liquid crystal layer appearing such a curved refractive index distribution (that is, having a power component), the liquid crystal acts as a lens, and thus, an optical axis direction of an exit beam therefrom changes unexpectedly (that is, the light path is deflected). In addition, also a condition of convergence or divergence of the exit beam may change unexpectedly.

Optical scanning device, image forming apparatus and liquid crystal device driving method


The present invention relates to a class of dihydrophenanthrene which are isolated from Calanthe discolor Lindl. and derivatives thereof.

The alcohol extract from Calanthe discolor Lindl. is known to be useful for promotion of hair growth and restoration. (JP. A 5-294813) However, the components of this extract have not been identified.
Therefore, there is a need to isolate and identify the active components of the alcohol extract of Calanthe discolor Lindl. There also is a need for compounds that are derivatives of these active components which may be more active and possess other physiological activities. ##STR1## wherein X.sub.1, X.sub.2, X.sub.3, X.sub.4, and X.sub.5 are independently H, OR.sub.7, SR.sub.8, or NR.sub.9 R.sub.10 to provided at least 3 of X.sub.1, X.sub.2, X.sub.3, X.sub.4, and X.sub.5 are independently OR.sub.7, SR.sub.8 or NR.sub.9 R.sub.10 ;
R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are independently H, OR.sub.11, SR.sub.12, NR.sub.13 R.sub.14, C.sub.1 -C.sub.4 alkyl, or halogen; and PA1 R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13 and R.sub.14 are independently H or C.sub.1 -C.sub.4 alkyl.
One embodiment of the invention provides a compound 2,4-dimethoxy-3,5,7-trihydroxy-9,10-dihydro-phenanthrene.


An apparatus to target recipients of media content items comprises a camera, a communication interface, and a selector input device. The selector input device is communicatively coupled to the camera and the communication interface and has settings associated with groups of recipients. The groups of recipients include a first group and a second group. In response to receiving a selection of a first setting from the selector input device, the camera captures a first media content item and the communication interface transmits the first media content item to the first group. The selector input device can be a rotary wheel. To select the first setting from the plurality of settings, the user can rotate the rotary wheel to the first setting and press the rotary wheel. Other embodiments are described herein.

Currently, a number of consumer electronic devices are adapted to capture image, audio as well as video content. For example, a user can now use his mobile device to quickly capture a picture or video that he wishes to send to his friends, family and other contacts.
In order to achieve this, the user may first need to unlock his mobile device, locate the camera application, capture the picture or video using the camera, select the people he wishes to share this picture or video with (e.g., selected recipients), and then transmit the picture or video to the selected recipients. While this process is straightforward, there is a growing demand to be able to visually communicate with one another even more quickly.

Selector input device to target recipients of media content items


In a baking oven comprising at least one hearth, a baking conveyor belt, which is guided over a deflection roller, is allocated to each hearth. The deflection roller is extended out of the baking oven through openings where it is lodged for displacement in the direction of the oven. A sealing arrangement is provided for this opening to be sealed, comprising a base plate and a sealing disk resting tightly thereon. The sealing disk is pivotally supported on the deflection roller and simultaneously lodged in a guiding groove in the base plate by means of a guide pin. The edge of the sealing disk is shaped such that on the one hand it covers the opening in all the positions of displacement and on the other hand is displaced in the direction of displacement only by a length which is considerably shorter than the length of displacement of the deflection roller.

1. Field of the Invention
The invention relates to a baking oven comprising a housing having side walls; at least one hearth formed in the housing and defined by the side walls thereof; a driving roller provided at one end of each hearth; a deflection roller provided at the other end of each hearth; a baking conveyor belt guided over the driving roller and the deflection roller; two bearings for at least one roller which are provided on the outsides of the housing and displaceable in a horizontal direction of displacement in the lengthwise direction of the respective hearth; a recess formed in each side wall and penetrated by the displaceable roller and adjusted to a maximal length of displacement of the roller; and a sealing arrangement for sealing the recess in each position of displacement of the roller.
2. Background Art
In baking ovens of the generic type, which are regularly multi-deck baking ovens of comparatively great length, the temperature dependent expansions of the housing on the one hand and of the baking conveyor belt on the other vary considerably. For this reason the deflection roller or the driving roller, as a rule the deflection roller, must be displaceable in the lengthwise direction of the respective hearth. Since the bearings of the respective roller are disposed out of the hearth, i.e. on the outside of the side walls of the housing, a recess must be available in the side wall, through which the roller or a corresponding shaft section thereof is extended outwards and in which it is displaceable in the lengthwise direction of the respective hearth. Since the dough pieces must be treated with vapor at the beginning of the baking process, i.e. directly after feed, it is necessary that this vapor is retained for a certain time in the respective baking chamber. Any uncontrolled escape of vapor through the mentioned recesses would lead to drawbacks in baking implementation and must be precluded. Filling up the recesses with a packing of insulating material as tried in practice did not give satisfying results; moreover, the vapor precipitates in this insulating material, leading to thorough moistening. Furthermore, the space available in the direction of displacement of the roller is strongly restricted.

Werner & Pfleiderer Lebensmitteltechnik GmbH


A process for preparing an azetidin-2-one derivative represented by formula (2): ##STR1## wherein R.sup.4 and R.sup.5, which may be the same or different, each represents a hydrogen atom, an alkyl group having from 1 to 8 carbon atoms, or an alkyl group having from 1 to 8 carbon atoms substituted with an alkoxy group, an acyl group, or an alkoxycarbonyl group; R.sup.6 represents a protective group for an amino group; and R.sup.7 represents a vinylidene group of formula ##STR2## or an acetylene group of formula ##STR3## wherein R.sup.2 and R.sup.3, which may be the same or different, each represents a hydrogen atom or an alkyl group having from 1 to 8 carbon atoms; and R.sup.8 represents an alkyl group having from 1 to 8 carbon atoms corresponding to R.sup.2 or R.sup.3, which comprises reacting a propargyl alcohol derivative represented by formula (1): ##STR4## wherein R.sup.1 represents an alkyl group having from 1 to 6 carbon atoms, a phenyl group, or a halogen-substituted phenyl group; R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are as defined above, with carbon monoxide in the presence of a palladium complex. The compound (2), an intermediate of penem antibiotics, can be obtained through one reaction step in good yield.

.beta.-Lactam antibiotics represented by thienamycin have derives weight as medicines from their broad antimicrobial spectra, and various types of .beta.-lactam antibiotics have been studied.
Among the developed .beta.-lactam antibiotics, those having a vinylidene group or an acetylene group at the 3-position of the azetidin-2-one skeleton have recently attracted attention (refer to Tetrahedron Lett., Vol. 29, p. 5053 (1988), J. Chem. Soc., Chem. Commun., p. 294 (1990), and ibid., p. 1066 (1984)). There has been a demand, accordingly, for an industrially advantageous process for preparing an azetidin-2-one derivative having a vinylidene group or an acetylene group at the 3-position which is an intermediate for synthesizing .beta.-lactam antibiotics of this type.
Known processes for preparing azetidin-2-one derivatives having a vinylidene group at the 3-position include a process shown in reaction scheme A below, which comprises alkylating the nitrogen atom of a 3-alkylidene-azetidin-2-one compound, chlorinating the product with t-butyl hypochlorite, and subjecting the resulting compound to desilylation and dechlorination simultaneously to prepare a 3-vinylidene-azetidin-2-one derivative in a percent yield of from 36 to 68% (refer to J. Chem. Soc.. Chem. Commun., p. 735 (1987)). ##STR8## wherein Me represents a methyl group; and R.sup.9 represents a methyl group, a benzyl group, or a substituted benzyl group.
Known processes for preparing azetidin-2-one derivatives having an acetylene group at the 3-position include a process shown in reaction scheme B below, which comprises reacting a di(phenylacetyl)cyclohexadiene derivative with zinc chloride in a carbon tetrachloride solvent to obtain a bicyclo[2.2.2]octadienone derivative in a percent yield of 60%, thermally decomposing the product to obtain an alkenylketene, and reacting the alkenylketene with N-phenylbenzylideneimine to obtain the desired compound in a yield of 72% (refer to Tetrahedron Lett., Vol. 29, p. 2765 (1988)); and a process shown in reaction scheme C below, which comprises reacting a 2,5-dialkynyl-3,6-dichloro-1,4-benzoquinone with an azide ion to obtain a diazidoquinone and reacting the resulting compound in a carbon tetrachloride solvent in the presence of dicyclohexylcarbodiimide (DCC) to obtain a desired compound with the percent yield of the latter reaction being from 42 to 86% (refer to J. Org. Chem., Vol. 52, p. 1315 (1987) and J. Chem. Soc., Chem. Commun., p. 1066 (1984)). ##STR9## wherein R.sup.10 represents a hydrogen atom or a trimethylsilyl group; and Ph represents a phenyl group. ##STR10## wherein R.sup.11 represents an n-butyl group, a phenyl group, a substituted phenyl group, a phenethyl group, etc.
However, any of these known processes involves long reaction steps and is therefore not suitable for industrial production.
It is known, on the other hand, that .beta.-lactam compounds are synthesized through various techniques, such as cyclization of a .beta.-amino acid, cyclization of a halogenated propanamide, reaction between an enol silyl ether and chlorosulfonyl isocyanate, and reaction between an imine and a diketene (refer to Chem. Soc. Rev., Vol. 5, p. 181 (1976), YUKI GOSEI KAGAKU, Vol. 47, p. 606 (1989), etc.). Among these known processes is included a process shown in reaction scheme D, in which a 2-bromo-3-aminopropene derivative is reacted with carbon monoxide to conduct carbonylation and lactamization at the same time (refer to J. Chem. Soc., Chem. Commun., p. 698 (1979)). ##STR11## wherein R.sup.12 a hydrogen atom or a phenyl group; R.sup.13 represents a benzyl group, a phenethyl group, etc.; and Ph represents a phenyl group.

Process for preparing azetidin-2-one derivatives


An advance over the prior art is achieved through an efficient method for an admission control algorithm and a scheduling mechanism that complement each other in providing the following three classes of service. A first class of service is termed Class 1 where users specify a nominal amount of bandwidth desired. A second, lower tier service class is termed Class 2, wherein users specify a nominal and minimum amount of bandwidth desired when entering into a network connection. A third server class is Class 3, where Class 3 users are treated as best effort users. For Class 1 users the methodology of the present invention provides a guaranteed nominal amount of bandwidth. The admission control procedure ensures that Class 1 users are admitted only if resources exist to satisfy the nominal bandwidth requirements of the Class 1 users. Class 2 users are admitted if resources exist to satisfy the minimum bandwidth requirements of the user. Class 2 users are served with a bandwidth of up to their nominal bandwidths if there is capacity left after serving the Class 1 users with their nominal capacities. Class 3 users are served only if the Class 2 users have received their nominal bandwidths.

Wireless service providers need to provide efficient quality of service oriented hotspot services to serve a growing community of users that need wireless Internet access, for example. Hot spots, which are technically wireless fidelity (Wi-Fi) access points have been established in various public and private places to enable individuals having mobile computing devices and the like, such as laptops and PDAs, to be able to access a wireless local area network to enable access, for example, to the internet. Such service providers can increase revenue by providing different grades of service to users. In order to provide the QoS based discrimination, efficient scheduling and admission control algorithms are required.
A wireless broadband access telecommunications system is desired which can provide a QoS capability that is comparable to that delivered by wireline broadband access devices. Conventionally, one of the barriers to the deployment of wireless broadband access systems has been the absence of acceptable QoS characteristics, while at the same time delivering bandwidth sufficient to qualify as broadband. Delivery of raw bandwidth over wireless media without acceptable QoS would not benefit end users. Likewise, the delivery of a high level of QoS at the cost of sufficient bandwidth would also not benefit endusers.

Method and apparatus for adjustable QoS based admission control and scheduling WLANs


A rack structure arranged to accommodate a plurality of plastic type sandwich bags and the like is provided to permit the drying of the bags in an opened configuration to permit the sanitizing and drying thereof for their reuse. The rack structure includes a plurality of semi-circular arcuate support rods arranged for reception within a respective bag to permit the bags to be maintained in an extended opened configuration to enhance their drying.

1. Field of the Invention
The field of invention related to drying apparatus, and more particularly pertains to a new and improved plastic bag drying rack wherein the same is arranged to maintain a plurality of bags in an opened configuration to permit their drying and sanitizing.
2. Description of the Prior Art
Drying apparatus of various types are utilized throughout the prior art to support structure in a drying procedure. Such apparatus has heretofore been typically of a rack structure of generic construction to support a variety of various components thereon. The instant invention attempts to overcome deficiencies of the prior art by providing for a rack structure specifically directed to the support of bag members, and particularly plastic bag members of polyethelene film to support the bags in an opened configuration to permit their drying and in this respect, the present invention substantially fulfills this need.


An incoming laser beam is relayed to a steering mirror and a phase correction device. The beam is relayed from the phase correction device to a focal plane array and to a wavefront sensor (WFS). Low order steering mirror tilt corrections can be based on data from the focal plane array. The WFS outputs data on multiple channels to a field programmable gate array (FPGA), with each of the WFS channels corresponding to a subaperture of the beam wavefront. The FPGA calculates phase corrections for each of the subapertures and forwards those corrections to the phase correction device. The FPGA also calculates tilts for the steering mirror based on the WFS output data, which tilts can be used instead of tilts based on focal plane array data. The phase corrections may be based on modulo 2π phase error calculations and/or modal phase error calculations.

There are numerous applications (or potential applications) in which it would be useful to transmit a laser beam over relatively long distances. For example, a laser beam transmitted through free space could be used for communication purposes. Such communications could potentially be horizontal (e.g., entirely within the atmosphere) or vertical (e.g., from ground to an orbiting satellite). As another example, laser detection and ranging (LADAR) could be used for three-dimensional imaging and mapping at long ranges. As yet another example, laser Doppler velocimetry could be useful for tracking objects over long distances.
When transmitting a laser over long distances through the atmosphere, atmospheric turbulence causes significant problems. Atmospheric turbulence leads to random fluctuations in the air density which leads to random fluctuations in refractive index. The random fluctuations in the refractive index in turn induce phase fluctuations on a laser beam propagating through turbulent air. Phase fluctuations lead to two categories of effects. The first category of effects is phase fluctuations. Over any distance, phase fluctuations degrade image quality, reducing the ability of an optical system to image through turbulence. Phase fluctuations can also degrade the ability of a communication system because the received beam must be focused onto a detector or into a single mode fiber. The second category of effects is optical scintillation. Over long propagation distances, phase aberrations lead to intensity fluctuations—referred to as scintillation. One example of scintillation is the "twinkling" of stars in the night sky. A second example is that for a laser beam propagating through turbulence, the phase aberrations along the path lead to a random de-focusing and break-up of the beam, making the beam focus poorly at the desired location. One of the phenomena associated with optical scintillation is the appearance of branch points in the phase function, which occur when the optical field has a null value due to optical scintillation. Branch points in the phase function can degrade the performance of methods that have been developed to correct for the impact of phase aberrations on systems designed for imaging and propagation through turbulence.
Various efforts have been made to develop adaptive optical (AO) systems that compensate for the effects of atmospheric turbulence on laser propagation. In general "adaptive optics" is a blanket name for technologies to improve quality of images obtained through a turbulent optical path and/or pre-compensate a laser beam for propagation through a turbulence optical path. Known AO systems have various limitations. Most known AO systems employ a Hartmann sensor to measure phase variations in a laser beam wavefront to develop commands to be applied to a deformable mirror to correct and cancel the phase aberrations. Hartmann sensor systems are incapable of correcting the branch point contribution to the phase function that is caused by strong scintillation. Other proposed systems employ a self-referencing interferometer (SRI) as a wavefront sensor. These systems generally require full "unwrapping" of the phase (i.e., calculating a phase change through numerous multiples of 2π). Moreover, the best known control system to work with SRI wavefront sensor technology requires four wavefront sensor apertures for each channel of a phase correcting device such as a deformable mirror. This results in a computational complexity on the order N2, where N is the number of phase correcting device control channels.

System and method for correction of turbulence effects on laser or other transmission

Science Applications International Corporation


A method for locating phase to ground faults in DC distribution systems. The method includes utilizing wavelet analysis using Multi-Resolution Analysis (MRA) as a signal processing tool for recognition of characteristic features in the voltage signal. The voltage signal contains characteristic information in the high frequency range above the switching frequencies of the PE converters which allows for localization of the fault.

1. Field of the Invention
This invention relates to the field of electrical direct current distribution systems. More specifically, this invention comprises a method for locating phase to ground faults in DC distribution systems.
2. Description of the Related Art
Ungrounded or high-resistance grounded power systems have many advantages, including continuous operation after a single line to ground fault. While theoretically such an ungrounded DC system can be operated with one phase grounded through a fault, a secondary phase to ground fault on the other phase may occur causing a disruptive fault between the two phases. To reduce the probability of a second ground fault on the other phase, which results in the phase-phase fault condition with high current magnitudes and a consequential sag in supply voltage, it is of great importance to derive methods for fast and robust ground fault location in high-resistance grounded system.
The DC Zonal Electric Distribution System ("DCZEDS") discussed hereafter is part of a notional all-electric ship integrated power system (IPS) for a destroyer class ship, which includes a 80 MW power generation system, a ship hydrodynamic propulsion system, and models of various ship service loads powered through the DCZEDS.
FIG. 1 shows a simplified schematic representation of a DCZEDS (10). Bus 1 (reference numeral (12)) includes a positive and negative line (or "rail"), as does bus 2 (14). The system is divided into zones. Zone 2 (16) and zone 3 (20) are shown. Zone 2 (16) includes a pair of DC/DC converters (26) which feed power from the two buses to the loads within zone 2, which are labeled collectively as zone 2 load (18). Zone 3 likewise has a group of loads denoted as zone 3 load (22). The loads in zone 3 are also fed by a pair of DC/DC converters (26). High-resistance grounding of the buses in the DCZEDS is implemented to permit continuity of service during a ground fault (The high-resistance grounding is not shown in FIG. 1).
A method for detecting and locating a ground fault in such a system should be fast. However, the method must also be tolerant of the different possible operation modes of the DCZEDS, different system parameters causing unbalances, effects from the inherent noise due to switched converter systems, EMI noise, and other random variables (temperature, humidity, etc.). In addition, faults can be continuous or intermittent with either a constant or a random behavior of the fault resistance (which includes the arc resistance, the contact resistance, and the path resistance) as the characteristic features. The fault resistance in low or medium voltage distribution systems may vary in a wide range from a few milliohms (bolted faults) to several tens of kilo ohms (high impedance faults). It is important to remark that in high resistance grounded systems the fault current is practically independent of the fault resistance.
Previously, the ground fault locating method for an ungrounded system injects an AC signal into the faulted network and traces the signal using hand-held detectors or permanently mounted-in sensors to locate the fault. This method can be introduced into DCZEDS for locating ground faults as illustrated in FIG. 2. AC signal generator (30) is applied to center tap (32) in rectifier (24) (which feeds bus 2 (14)).
The onset of a phase-to-ground fault is detected by monitoring the line-to-ground voltages, since the fault creates a distinct voltage unbalance with respect to ground. After detecting the fault, the AC signal generator is applied for a short time and the resulting AC current is traced throughout the system in order to locate the fault. AC current measurement devices are needed in this method. However, the application of handheld AC current sensors is time consuming and subject to human error. Moreover, using a large number of fixed mounted sensors, necessary for an automated approach, requires sophisticated data communication links and also may reduce the overall reliability. Furthermore, applying this pilot signal approach of fault location to DCZEDS is expected to yield additional problems with locating common rail faults in systems with DC/DC converters which create one common bus and one "switched" bus.
Another possible method may utilize the system impedance over a wide frequency band. A signal source is momentarily applied to the DCZEDS between ground and a central point, such as a rectifier mid-point. The source can either be an adjustable, single frequency AC source or a pulse source. For the frequency domain analysis, the system impedance for a wide range of frequency is monitored by applying Fast Fourier Transforms ("FFT's") to the voltages and the resulting currents. However obtaining the accurate system impedance from measurements in a short time during system operation is a challenge. The high frequency noise caused by the interaction between Power Electronic ("PE") switching converters and cables may prohibit a good reading of the system impedance signal which is supposed to provide information regarding the fault location. An extra signal generator is needed for this approach.
Accordingly, it would be desirable to provide a new method for fault location in ungrounded or high-resistance grounded DC distribution systems which neither requires an additional signal source nor requires sensors throughout the system but can still locate the fault quickly and accurately.

Method for locating phase to ground faults in DC distribution systems


A method and a system for transporting a flow of fluid hydrocarbons containing wax and/or asphaltenes or any other precipitating solids through a treatment and transportation system including a pipeline are disclosed. The flow of fluid hydrocarbons is introduced into a reactor (4), where it is mixed with another fluid flow having a temperature below a crystallization temperature for the wax and/or asphaltenes or other solids and containing particles or crystals acting as nucleating and/or growth cores for the wax and/or asphaltenes or other solids, the mixing temperature providing precipitation of the wax and/or asphaltenes or other solids from the flow of fluid hydrocarbons, and the effluent flow of hydrocarbons and particles is conveyed from the reactor (4) to a pipeline (6) for transportation.

The current direction of the oil and gas industry is to develop new offshore fields with multiple subsea tiebacks to host hubs, field centres or onshore facilities for final processing. This is often based on the requirement to make more effective use of existing infrastructure. One of the present key project stoppers for long distance tiebacks is incomplete and very expensive technology for avoiding problems with phase changes in the fluids, and possible deposition in pipelines. Cold flow, with slurry transport of solidified components, is an attractive solution, but it entails substantial challenges due to the phenomena associated with low-temperature fluid flow. Cold flow solutions may also be of high importance for many onshore field developments, as well as for long-distance transport of fully or partly processed liquid hydrocarbons.
Multiphase hydrocarbon wellstream transport exceeding the present-day transfer distances is of strategic importance for future deepwater field developments as well as being an enabler for economical exploitation of many marginal satellite fields and prospects at moderate water depths. Current technology for avoiding problems with e.g. wax or asphaltene deposition, or other solids, often entails adding significant amounts of inhibiting chemicals. This has a great impact on system economy, and is often also detrimental to local and/or global environmental aspects. Alternatively, pipelines for hydrocarbon transport may have to be thoroughly insulated or actively heated (both options are prohibitively expensive), regular scraping operations (pigging) may have to be conducted, or a large amount of fluid processing will have to take place close to the place of production, entailing e.g. complex offshore platform systems or large process facilities for onshore situations.
One challenging problem for cold flow is the presence of paraffinic wax and/or asphaltenes and/or other precipitating solids (i.e. "precipitors") in many oil or condensate systems. When warm oil or condensate from e.g. a reservoir or from any other source of warm hydrocarbons is cooled down and/or the pressure is reduced, precipitors in the oil or condensate may become supersaturated and precipitate out as deposits on for example a pipe wall, or as solid particles/crystals suspended in the oil or condensate fluid. In some situations they may form a gel in the oil or condensate phase. Deposits of precipitors in pipelines can reduce production (by e.g. blocking conduits completely), reduce system regularity, and may increase costs through lost revenue and workovers by e.g. regular pigging of the pipeline.
When precipitors precipitate in an oil or condensate phase as small crystals or particles, they may be carried along with the hydrocarbon fluid without causing deposits or plugging. This is usually promoted by adding chemicals to the oil or condensate fluid before it is cooled to the crystallization temperature of the precipitors, or by mechanically dislodging deposits from surfaces after formation. From laboratory experiments, it is also well known that an increased supersaturation promotes crystallization of smaller precipitor particles inside the bulk of the oil or condensate phase.
U.S. Pat. No. 3,846,279 describes a method for producing wax slurries by using a fractionation tower and a water-filled reactor to produce wax particle slurries which can transport up to about 50% by weight of wax solids in the carrying oil. U.S. Pat. No. 3,910,299 makes use of essentially the same procedure, but with jacket circulation cooling instead of a water bath. A claimed wax fraction of up to 80% by weight is supposed to be transportable as a slurry after the process. Both these patents depend on a fractionation column being present upstream of the wax particle production equipment. U.S. Pat. Nos. 4,697,426 and 4,702,758 use shock cooling by choke expansion of gas or expansion turbines, respectively, to achieve quick formation of wax crystals, which are said to be transportable as a slurry thereafter. In U.S. Pat. No. 6,070,417 a process is described in which a fluid which may form solid deposits is circulated through a heat exchanger where large temperature gradients at the exchanger walls provide a tendency for solids formation to take place there. A runner designed to continuously circulate around in the heat exchanger, dislodges the solid depositions, ensuring that they are carried away into e.g. a pipeline at the outflow end of the heat exchanger. The same principle is explicitly proposed for wax deposition by Amin et al. (SPE paper 62947, ATCE Dallas, Tex., 1-4 Oct. 2000, 9 pp).
In Canadian patent no. 1,289,497, a method is given where a small amount of a cooled oil or condensate containing a large number of small wax particles or crystals suspended therein is added to a waxy oil or condensate at a temperature above the crystallization point of wax. Due to a higher melting point of formed wax the suspended wax particles will act as nuclei or centers of wax precipitation as the oil or condensate is thereafter cooled slowly below the crystallization point of wax. The cooled oil containing small wax particles or crystals may be obtained by withdrawing and cooling a small portion of the warm waxy oil or condensate before it is recycled into the warm waxy oil or condensate. To control wax formation by controlling the rate or degree of cooling of the main oil or condensate fluid is in Canadian patent no. 1,289,497 stated to be impractical or uneconomic.
British patent no. GB 2,358,640 described a method and system for transporting a flow of fluid hydrocarbons containing water, at elevated pressure. In the method, a flow of fluid hydrocarbons containing water at a temperature above the hydrate crystallization temperature is mixed with a cooled flow of fluid hydrocarbons containing gas hydrate particles. At the mixing point, the water from the warm fluid flow will moisten the dry hydrate particles from the cooled fluid flow. The temperature in the fluid flow after the mixing point is below the crystallization temperature of gas hydrates. The water-moistened dry hydrate particles in the fluid flow will—due to the supersaturation—quickly convert to dry hydrate without forming hydrate deposits on e.g. the pipe wall. The cooled fluid flow containing dry hydrate particles is obtained by recycling a sufficient part of the cooled mixed fluid flow. The amount of cooled fluid to be recycled is determined by the cooling required in order to obtain a mixing temperature close to the hydrate crystallization temperature.

Method and system for transporting flows of fluid hydrocarbons containing wax, asphaltenes, and/or other precipitating solids

BP Exploration Operating Company Limited


The utility model discloses a urinary catheter for women and peristaltic pump, which comprises a body tube with an inner surface and an outer surface, and further comprises an external urethral orifice fixing part which can at least sleeve the catheter tip end inside when applied, a flexible urethral guide part, a urinary catheter driving part sleeved with the cylindrical body of the external urethral orifice fixing part, a hydrophobic part for leakage stop at the urinary outlet of the urinary catheter, a thin segment, a pump tube, a tube bed and other special structures for dilating the narrowed part of the urethra, which not only eliminate the defect of the traditional “non-guided suspended placement” in a safe mode of “US-guided adjacent placement” and completely avoid contamination of the urinary catheter by the periurethral tissue, but also avoid the injury of urethral intima caused by urethral stricture in the placement procedure to the greatest extent; avoid contamination of the urinary catheter outlet by urine outflow; effectively clear the blockage of urine inlet due to blood clots and tissue masses in bladder during indwelling, and can also minimize the residual urine volume when used in conjunction with a special peristaltic pump.

Urinary catheter is the most common medical device in clinic, which can drain urine from the bladder to the outside after it is inserted into the body via the urethra, and can be removed after one urine drainage, or can be retained for multiple drainage for prolonged period.
However, the urinary catheterization and its retention will lead to lower urinary tract injury to varying degrees, while lower urinary tract injury is more likely to cause or aggravate lower urinary tract infection and further affect lower urinary tract or even systemic organ function.
The female urethra is much shorter than the male urethra and is only 4 cm long, and the structure around the external urethral orifice is complicated, so even if the urinary catheter is not inserted, females are more susceptible to urinary tract infections. In the existing clinical procedure of female urethral catheterization, after the sterilization of the external urethral orifice and its surrounding tissues, usually use two fingers of one hand to press the periurethral tissue to make it relatively fixed, enlarge and expose the external urethral orifice, while use the other hand to hold the sterile urinary catheter directly or with tweezers, hemostatic forceps, etc., and slowly insert it from the external urethral orifice. When the urethra is bent or accompanied by stricture, it often needs to be inserted with force, which may lead to more serious injury to the urethra. When the urine inlet at the urinary catheter tip enters the bladder, the urine slowly flows out of the urine outlet of the urinary catheter outside the body into a container such as a kidney basin due to the pressure in the bladder, and then a successful catheterization can be expected. When indwelling is needed, immediately insert the urinary drainage bag connector into the urine outlet of the urinary catheter to form a closed system.
Existing female patients have the following problems in urethral catheterization:
1. It is difficult for an operator to use his/her two fingers to fix and expose the external urethral orifice, especially in the case of ectopic urethral orifice caused by urinary tract infections or scar pulling at the lateral incision, atrophy of the external urethral orifice and even entrapment in the anterior wall of the vagina in older women. Poor fixation and exposure of the external urethral orifice not only reduces the success rate of catheterization, but also greatly increases the urethral injury during the procedure.
2. Microorganisms near the female external urethral orifice, such as on the surface of labia majora and labia minora can easily contact and contaminate the urinary catheter outer surface that meanders into the urethra, thus bringing microorganisms into the urethra and bladder. Such extraluminal infection, i.e., the infection caused by a route outside the urinary catheter inner cavity, is the main cause of early urinary tract infection in patients with indwelling catheters.
3. The way of holding the urinary catheter with fingers or tweezers and hemostatic forceps to exert force unsupported results in the direction of force applied difficult to be the same as the urethral centerline due to the flexibility and meandering of the urinary catheter, and the operating force parallel to the urethral centerline is only a component of the force applied because of the direction of meandering at an angle to the direction of force applied, so a larger force is required to insert the urinary catheter, thus causing greater urethral injury and it would be more difficult to operate accurately when there is a bend in the external urethral orifice.
4. When the urinary catheter tip end travels to the stricture of the urethra, it usually needs to increase the force to push it forward and shear with the urethral intima in the stricture. Even if it passes through the stricture, the urethral intima will suffer severe contusion and create conditions for microbial infection.
5. Before the urinary catheter is judged to be inserted in the bladder, it is necessary to drain urine out of the urine outlet of the urinary catheter, then flow to containers such as a kidney basin and connect the drainage urine bag connector. Urine usually pollutes the connection between the urine outlet of the urinary catheter and the drainage urine bag connector. Microorganisms in the air or on the surface of surrounding objects may propagate in this part of the urine at the connection, and intraluminal contamination in the urinary catheter is easily caused when the drainage urine bag connector is removed and inserted again.
6. During the indwelling of the urinary catheter, insoluble blood clots and falling tissue lumps in the bladder due to changes in the state of illness will block the urine inlet of the catheter. The existing solution usually uses a guide wire to enter the urinary catheter inner cavity to dredge or a syringe to aspirate urine. If the effect is not desirable, a thicker catheter may be used instead and the patient may suffer from the pain of secondary catheterization.
7. Some patients have much urine left in the bladder due to bladder detrusor muscle weakness or decreased bladder compliance, which will make them more susceptible to infection. This situation requires nursing staff to use syringes to suck urine from the urinary outlet of the urinary catheter for many times, along with multiple removal and insertion of the drainage urine bag connector, which increases the risk of infection and makes the procedure cumbersome.

Urinary catheter for women and peristaltic pump