A composition and method for generating patient- or person-specific proliferative and substantially pure cardiac myocyte cell lines from pluripotent stem cells (iPSCs) is described herein. The patient-specific cardiac myocyte cell lines of the present invention find applications in research, drug screening and autologous cell-based therapy. The method of the present invention is simple and reproducible and generates cardiac myocyte cells having high purities and proliferating capacities.

Without limiting the scope of the invention, its background is described in connection with generation of cardiac cell lines and tissues for research, drug screening and autologous cell-based therapy by in vitro culturing of differentiable cells and other related methods.
One such method is taught in PCT Patent Application No. PCT/US2011/056329, filed by Singla, et al., entitled, Cardiac Induced Pluripotent Stem Cells And Methods Of Use In Repair And Regeneration Of Myocardium. Briefly, this application is said to disclose iPS cells from cardiac or ventricular specific cell types that are generated having the potential to repair and regenerate infarcted myocardium. The cells were transduced with four sternness factors and reprogrammed them into iPS cells. These cardiac iPS cells were able to differentiate into beating cardiac myocytes, formed cardiac-specific structures, and positively stained for cardiac specific proteins. Transplanted cells also significantly inhibited apoptosis and fibrosis and improved cardiac function.
Another application is U.S. Patent Application No. 2011/097799, filed by Stankewicz, et al., entitled, Cardiomyocyte Production. Briefly, methods and composition for the production of cardiomyocytes from differentiation of pluripotent stem cells are disclosed. For example, in certain aspects methods including differentiating pluripotent stem cells in a large volume of suspension culture in the presence of Rho-associated (ROCK) inhibitors are described. Also, methods for differentiation of stem cells into cardiomyocytes that overcome variability between different stem cell clones and different batch of culture medium are said to be provided.
Another such technique for generating cells predominantly displaying at least one characteristic associated with a cardiac phenotype is disclosed in U.S. Patent Application Publication No. 2005/037489 (Gepstein et al. 2005) (hereinafter Gepstein). The Gepstein invention comprises the steps of (a) partially dispersing a confluent cultured population of human stem cells, thereby generating a cell population including cell aggregates; (b) subjecting said cell aggregates to culturing conditions suitable for generating embryoid bodies; (c) subjecting said embryoid bodies to culturing conditions suitable for inducing cardiac lineage differentiation in at least a portion of the cells of said embryoid bodies, said culturing conditions suitable for inducing cardiac lineage differentiation including adherence of said embryoid bodies to a surface, and culture, medium supplemented with serum, thereby generating cells predominantly displaying at least one characteristic associated with a cardiac phenotype.
U.S. Patent Application Publication No. 2005/0054092 (Xu and Gold, 2005) provides a method of obtaining populations of human cells of the cardiomyocyte lineage. The cells are said to be obtained by causing cultures of pluripotent stem cells to differentiate in vitro, and then harvesting cells with certain phenotypic features. Differentiated cells bear cell surface and morphologic markers characteristic of cardiomyocytes, and a proportion of them undergo spontaneous periodic contraction. Highly enriched populations of cardiomyocytes and their replicating precursors can be obtained, and are suitable for use in a variety of applications, such as drug screening and therapy for cardiac disease.
A procedure for generating cardiomyocyte lineage cells from embryonic stem cells for use in regenerative medicine is described in U.S. Pat. No. 7,452,718 issued to (Gold et al. 2008) (hereinafter the '718 patent). The '718 patent describes a method that does not require differentiating by way of embryoid body formation or in serum. Instead, the stem cells are plated onto a solid substrate, and differentiated in the presence of select factors and morphogens. After enrichment for cells with the appropriate phenotype, the cells are allowed to cluster into cardiac Bodies™, which are remarkably homogeneous and suitable for the treatment of heart disease.
U.S. Patent Application Publication No. 2009/0017465 (Xu, 2009) provides populations human cells of the cardiomyocyte lineage. The cells are obtained by causing cultures of pluripotent stem cells to differentiate in vitro, and then harvesting cells with certain phenotypic features. Differentiated cells bear cell surface and morphologic markers characteristic of cardiomyocytes, and a proportion of them undergo spontaneous periodic contraction. Highly enriched populations of cardiomyocytes and their replicating precursors can be obtained, suitable for use in a variety of applications, such as drug screening and therapy for cardiac disease.
Finally, U.S. Pat. No. 7,611,852 issued to (Thomson et al., 2009) discloses human embryonic stem cells form embryoid bodies in culture, which contain differentiated human cells. Some of the human cells in embryoid bodies differentiate into cardiomyocytes. Here the biological and electrical characteristics of those cardiomyocytes are described with reference to the use of cardiomyocytes derived from human embryonic stem cells in drug screening protocols for mechanisms of cardiac toxicity.

Establishment of patient- or person-specific cardiac myocyte cell lines from human induced pluripotent stem cells (iPSCs)


An electronically-commutated synchronous system and method includes a permanently-excited rotor and a stator which is provided with three phase windings, together with three rotor position sensors in an appropriate arrangement for a first commutation scheme. The rotor position is determined by the read-out of data from the position sensors. The appropriate voltage vector is defined by a second commutation scheme, and the second rotor position thus determined is compared with the first commutation scheme. If the rotor position sensors are operating correctly, the position of the rotor may be determined to an accuracy which is equivalent to the interval between two columns in the commutation table.

Electronically-commutated synchronous machines with a permanently-excited rotor and a stator provided with phase windings, also known as brushless dc motors, enjoy great popularity. They are characterized by low wear, and by their limited electromagnetic or acoustic interference, and show a high degree of efficiency. The influx of current to typically three stator windings generates a magnetic field, in which the permanently-excited rotor in arranged. By the appropriate switchover (commutation) of the currents flowing in the stator windings (or of voltages applied), a rotary motion is generated. Electronically-commutated motors are also used as drive mechanisms for electromechanically-actuated wheel brakes of a motor vehicle, wherein an appropriate linkage mechanism converts the rotary motion of the motor into a translational motion of the brake linings. For the purposes of such application, motors are designed with a high torque rating at rest or at low speeds of rotation.
In order to achieve electronic commutation of the motor, the position of the rotor must be known; for a motor at rest, or a motor rotating at low speed, the rotor position may be appropriately determined by means of sensors. In a widely-applied arrangement, three Hall-effect sensors fixed to the stator are used for the scanning of a rotary encoder associated with the rotor, or for the direct scanning of the stray field of the rotor magnets.
WO 2005/046041 A2 describes a method for the operation of a synchronous machine with a permanently-excited rotor, a stator provided with phase windings and a non-absolute position sensor, whereby the rotor start position is determined. In off-load synchronous machines, for the elimination of angle errors in the determination of the rotor start position, a minimum of one current and/or voltage vector is delivered in the direction of the determined rotor position for a specific time interval, thereby forcing the arrangement of the rotor to the position concerned. Although this method permits the elimination of minor angle errors, it does not permit the reliable detection of a defective sensor.
If the rotor position detected by the sensors is not consistent with the actual rotor position, malfunctions of various types may ensue. In many cases, this may result in damage to the motor, the driven device or the motor control system.
Accordingly, the object of the present invention is to verify the operation of the rotor position sensors and, in case of the correct operation of the sensors, to detect any deviation between the actual rotor position and that indicated by the sensors, and to generate an angular correction for the control of the motor.
This object is fulfilled by the method according to this invention.
A method is therefore provided in accordance with this invention wherein the relative position of the rotor of an electronically-commutated synchronous machine to one or more, specifically three rotor position sensors which are fixed to the stator is determined. After a first rotor position determination process, the off-load rotor is rotated through a predefined angle by the application of an appropriate voltage vector. Thereafter a further rotor position determination process is carried out, and the result of the second rotor position determination process is compared with an anticipated rotor position. After the first position determination process, during rotation through a fixed electrical angle, e.g. 60°, an anticipated rotor position may be determined. In case of the coincidence of the anticipated and measured second rotor position, the positional error lies below the angular resolution defined by the number and position of the rotor position sensors in the rotor position sensor system.
Preferably a first commutation scheme is specified, whereby an association between the voltage vector applied and the anticipated rotor position is established. If a commutation scheme is specified, the anticipated rotor position may be determined by means of a simple read-out from the commutation table.
It is advantageous if the association between the current rotor position and the voltage vector to be applied for the achievement of a desired rotation is determined by means of a specified first commutation scheme. In a specified commutation scheme, rotation through a specific angle may be achieved to an accuracy which is determined by the arrangement and number of sensors, by the application of a voltage vector which differs from the commutation table by an angle-related number of columns.
Preferably, by reference to the comparison between the result of the second rotor position determination process and the anticipated rotor position, all subsequently determined rotor positions and derived variables, including e.g. the instantaneous speed of rotation, are corrected. Should any displacement in the rotor position be detected by the rotor position sensors during the subsequent commutation of the motor, the highest possible mechanical torque will continue to be delivered.
During the determination of the rotor position, the currents flowing in the phase windings are subject to appropriate limitation on the basis of temperature information. Specifically, in case of a higher temperature, a higher limiting current is selected and, in case of a lower temperature, a lower limiting current is selected. At a higher temperature, the reduced magnetization of the permanently-excited rotor is offset by a correspondingly increased current flow in the stator windings. The coil currents may be selected to a sufficiently high rating to permit the execution of the method according to the invention. As a result of the limited torque delivered, the risk of any damage to the motor or the driven device is minimal.
During the determination of the rotor position, it is advantageous if the currents flowing in the phase windings are limited by the alternating cut-in and cut-out of the voltages applied to the phase windings. This permits current limitation, even where the control electronics of the motor include no provision for pulse-width modulation.
In a specifically preferred form of embodiment of the invention, the electronically-commutated synchronous machine is provided with a permanently-excited rotor and a stator which is provided with three phase windings, together with three rotor position sensors in an appropriate arrangement for a first commutation scheme. The rotor position is determined by the read-out of data from the position sensors, the appropriate voltage vector is defined by a second commutation scheme, and the second rotor position thus determined is compared with the first commutation scheme. If the rotor position sensors are operating correctly, the position of the rotor may be determined to an accuracy which is equivalent to the interval between two columns in the commutation table.
In a particularly preferred form of embodiment of the invention, rotor positions are expressed as angles, wherein 360° represents one complete cycle of a commutation scheme and, after the comparison of the second determined rotor position with the first commutation scheme, a voltage vector with an angular displacement of 90° in the first commutation scheme is applied, whereafter a voltage vector in the second commutation scheme at an angle displaced by a further 90° in the same direction is applied, and a third rotor position is determined thereafter, whereby an error is detected if the data from the position sensors for the third rotor position are not inverted in relation to the data for the second rotor position. If these data are inverted, the correct operation of all the rotor position sensors is confirmed.
According to an alternative and particularly preferred form of embodiment of the invention, at least one further voltage vector, adjoining in the opposite direction of rotation, of the second commutation scheme is applied thereafter, and a third rotor position is determined thereafter, whereby an error is detected if the data from the position sensors for the third rotor position do not differ from the data for the second rotor position.
In a particularly preferred arrangement, the electronically-commutated synchronous machine is provided with a permanently-excited rotor and a stator which is provided with three phase windings, together with three rotor position sensors in an appropriate arrangement for a commutation scheme. Prior to the initial determination of a rotor position, a base voltage vector for the commutation scheme is applied, the rotor position is determined by the read-out of data from the position sensors, the appropriate voltage vector is varied in relation to the base voltage vector by specific increments, and the second determination of the rotor position, together with the adjustment of the appropriate voltage vector, are continued progressively until an adjoining rotor position is indicated. This method permits the more accurate determination of the rotor position or of the switchover point of the rotor position sensors.
In a particularly preferred arrangement, the rotor position sensors operate on the basis of the Hall effect; the incremental variation of the voltage vector and the read-out of data from the position sensors are repeated, whereby the desired rotor position is achieved, in both running directions of the motor, by the application of the base voltage vector, the existing voltage vectors at the time of a change to the data from the position sensors are compared with the base voltage vector, and a resulting measure is calculated for the hysteresis of the position sensor operating by the Hall effect, the data read-outs for which have changed.
Specifically, the hysteresis of all position sensors operating by the Hall effect is determined by the application of a base voltage vector which is adjacent to the relevant switchover point, and the repeated incremental variation of the voltage vector with a simultaneous read-out from the position sensor concerned.
In a particularly preferred arrangement, the switchover positions of the rotor position sensor(s) concerned, which are adjusted in relation to the base voltage vector, are considered by the application of appropriate adjustments to the subsequent control of the electronically-commutated synchronous machine whereby, specifically, a positional difference and/or hysteresis is logged and taken into consideration for each rotor position sensor in question.
In a particularly preferred arrangement, the appropriate voltage vectors are set by the use of known vector modulation methods, whereby dead-time effects in particular are compensated by the appropriate adjustment of the relevant pulse duty factor. Dead-time effects are generated by the requisite time delay associated with the connection of a rectifier bridge, in order to prevent any short-circuit. By the adaptation of the pulse duty factor, i.e. the ratio of the pulse width to the pulse interval, the generation of a voltage vector with a defective angle can be avoided.
According to an alternative, particularly preferred form of embodiment of the invention, the appropriate voltage vectors are varied by the adjustment of one of the voltages applied, by means of the pulse duty factor.
In a further particularly preferred form of embodiment of the invention, the appropriate voltage vectors are generated by means of rapid switchover between adjacent base voltage vectors.
It is particularly expedient if a limitation of current is effected by the repeated and short-term input of zero vectors. Under zero vector conditions, all windings are at the same potential, such that no voltage difference is generated.
The invention also relates to a circuit arrangement for the control of an electronically-commutated synchronous machine, which executes a method whereby the position of the rotor of an electronically-commutated synchronous machine relative to one or more, specifically three rotor position sensors which are fixed to the stator is determined and which, specifically, is a constituent element of a circuit arrangement for the control or regulation of the brakes of a motor vehicle.
Appropriately, on-load operation of the motor proceeds only after the error-free execution of a method whereby the position of the rotor of an electronically-commutated synchronous machine relative to one or more rotor position sensors is determined whereby, specifically, the control system considers any difference detected between the actual and notional position of the rotor.
The invention also relates to the use of a circuit arrangement of this type in motor vehicles.
The currents flowing in the stator windings are preferably limited, specifically for the prevention of damage to the motor or the driven device.
In a particularly preferred arrangement, current limitation is achieved by the limitation of the voltage applied, specifically by means of pulse width modulation in the control circuit.
In a further and particularly preferred form of embodiment of the invention, the flow of current is subject to near-total interruption when a temperature threshold is exceeded.

Method and circuit arrangement for checking the rotor position of a synchronous machine


Methods and apparatus for a Wireless Terminal (WT) to convey uplink traffic information, e.g., uplink channel resource requests, to a Base Station (BS) are described. Uplink transmission resources are requested for data corresponding to different priority levels. The WT keeps track of the BS's understanding of WT traffic through the use of a first queue which keeps track of the BS's estimate of WT's uplink queue status for different priority levels by following the same procedure the BS uses to update its estimate of WT queue status. The WT uses this tracked information along with actual traffic information it maintains in a second set of queue information to form uplink traffic channel requests to be transmitted to the BS. Methods used by the BS to interpret uplink traffic channel requests from WTs are also described. The BS maintains its own queue of requests and corresponding priority information for individual WTs.

In a cellular wireless system, a service area is divided into a number of coverage zones generally referred to as cells. Each cell may represent the wireless coverage area for a base station. Wireless terminals, including a wide range of mobile devices such as, e.g., cell phones and other mobile transmitters such as personal data assistants with wireless modems, may communicate with the base station via wireless links while located within the base station's cell. Multiple wireless terminals need to transmit different types of information with different priorities to the base station, e.g. various types of uplink traffic information, over the air link resources. The uplink air link resource may be defined as available bandwidth over time. The bandwidth is centrally controlled by the base station to avoid collisions between multiple wireless terminals who may wish to transmit at the same time. Each wireless terminal has an idea of its own current uplink traffic requirements, e.g., bandwidth over time required, quality of service required, priority level required for the information to be transmitted, time constraints on information to be transmitted, etc. The wireless terminals' uplink traffic requirements need to be conveyed to the base station, so that the base station can make informed decisions to assign uplink air link resources, schedule users, and send assignment messages notifying the wireless terminals of the choice that have been made.
Many known systems use a circuit switch approach to convey this exchange of uplink traffic information. In the circuit switched approach, the wireless terminal and base station typically exchange information over a control channel with a low bandwidth and a low bit rate, the exchange involves conveying requirements and requests from the wireless terminal to the base station, the negotiation of the amount of air link resource that can be allocated, and the assignment of the air link resource to the wireless terminal. Each transaction is generally slow and will require more than a few bits. This circuit switch approach typically will work well where the exchange can take place once at the beginning of a session, and the air link resource can be assigned for long intervals of time (e.g. 10 sec or 1 sec). In this approach you establish a link for an extended period of time and may send a message at the end of a session to relinquish the resource. Intervals of unused transmission time between the establishment of the link and the termination of the link represents wasted air link resources. This circuit switch approach ties up the air link resource for extended periods of time. With packet switch wireless systems, e.g. an OFDM system, this circuit switch approach is inefficient, as the wireless terminal generally do not need the air link resource for long contiguous segments, but rather need short durations, e.g., flash intervals. In addition, it is inefficient, in packet switch systems to be constantly have to renegotiate for a small amount of air link resource, as the overhead signaling becomes significant in relation to the amount of air link resource actually used for traffic.
Other more efficient approaches are possible which are better suited for packet type wireless communications systems, where each wireless terminal has a dedicated uplink channel with a dedicated amount of a air link resources for making uplink traffic requests at pre-determined times coordinated with the base station, and the base station makes assignments. This approach has a delay effect problem. There is a delay between when the wireless terminal transmits a request for uplink air link resources, and the time that a base station receives and processes the request. There is also a delay between the time when the base station generates and transmits the assignment and the wireless terminal receives and recognizes the assignment. These delays create misunderstandings between the base station and the wireless terminal resulting in wasted air link resources, unnecessary additional requests, and unnecessary additional assignments.
This problem of lack of understanding between the base station and wireless terminal becomes more complicated and new problems are created when multiple levels of priorities are considered. Assume that a wireless terminal needs a high levels of resources at a low priority level, e.g. a priority level associated with data, and needs low levels of resources at a high priority level, e.g., a priority level associated with voice. Depending on the timing, it is possible, that the low priority request information will be blocked indefinitely.
Certain information may be timing sensitive, e.g., if the request is not granted with an assignment within a specified time interval, the need for the request may go away. It is inefficient to transmit that requested data units are no longer needed. This dropping of requested data units unbeknown to the base station can result in misunderstanding and unnecessary wasted assignments by the base station. Also, some requests may be lost due to transmission errors, and there are trade-offs between whether to transmit another request immediately or whether to wait, since the wireless terminal does not know whether the base station never received the request or has not transmitted the assignment because of other higher priorities competing for the air link resource.
The needs and priorities within the wireless terminal can change between the request and reception of an assignment message allocating data units. Therefore, the wireless terminal may reallocate to a new priority level received air link resources that were originally intended for different (original) priorities when assigned by the base station. This can also result in misunderstandings between the base station and the wireless terminal.
In view of the above discussion, it should be appreciated that there is a need for improved methods of keeping track of air link resource requests in the case where the requests may correspond to multiple priority levels particularly in the context of signaling delays and potential loss of some transmitted requests and/or assignments. In particular there is a need for an understanding in the base station as to the wireless terminal uplink traffic needs and priorities, a need to maintain an understanding of the base station uplink traffic assignments in the wireless terminals, and/or a need for a methods and apparatus for conveying request information in a fast, efficient and timely manner utilizing a small number of bits so as to keep overhead low. There are also needs for methods that employ flexibility in allocating resources based on requests of various levels of priorities. Such methods should address the different problems presented by different priority users, as well as address concerns presented by lost request and assignment transmissions, and dynamic changes in needs at a wireless terminal. In the case of wireless terminals, there is a need for a method of maintaining an understanding of a base station's perception of a mobile's needs so that the mobile can effectively and efficiently update the base station's understanding in a timely manner.

Method to convey uplink traffic information


A tube-coated belt suited for heat fixation of color images and the like, downsizing and high-speed operation; and an organopolysiloxane adhesive composition of high adhesion durability suited for the manufacture of tube-coated belt, wherein the tube-coated belt has a resin tube on a silicone-rubber elastic layer through an adhesive layer, wherein the adhesive layer is composed of a cured product of an organopolysiloxane adhesive composition containing a specific organopolysiloxane component.

1. Field of the Invention
The present invention relates to a heat fixing apparatus used in toner-image forming apparatus, such as copying machines, printers and facsimiles; a tube-coated belt; and an adhesive composition that can be used for the manufacture of a tube-coated belt.
2. Related Background Art
In a heat fixing apparatus generally used in an electrophotography, rotating bodies, such as a pair of heated rollers and a roller, a film and a roller, and a belt and a roller, are pressure-contacted; and a recording material holding toner images before fixation is introduced into a pressure-contacted region formed between the rotating bodies, heated and fused, then cooled and solidified to form permanent images on the recording material.
The rotating bodies to which toner images before fixation held on a recording material contact are referred to as fixation members, and called a fixation roller, a fixation film or a fixation belt depending on their configurations. These fixation members are often formed of a single layer or multiple layers of heat resistant elastic bodies laminated on a base layer formed of a metal or a heat-resistant resin. The outermost layer of a fixation member is called a surface layer, and is formed of a silicone rubber, a fluorine rubber, a fluorine resin or the like. Among them, when a fluorine resin is used for the surface layer, an example of coating with a PFA tube is well known. A structure using a PFA tube through an adhesive layer as the surface layer has also been well known in the art, and a large number of the related techniques have been proposed.
For example, aiming at the surface softness and the thermal conductivity in continuous printing, a fixation roller using a core metal coated with a fluorine resin tube of a thickness of 30 to 50 μm through a silicone-based adhesive of a thickness of 50 to 170 μm has been disclosed (e.g., refer to Japanese Patent Application Laid-Open No. H09-127816).
For improving adhesion durability and elevating accuracy, a PFA tube-coated fixation roller having an elastic layer and an adhesive layer has been disclosed. The adhesive layer is composed of a self-adhesive silicone rubber of a thickness of 3 to 100 μm (e.g., refer to Japanese Patent Application Laid-Open No. 2001-312169).
In order to secure the evenness of adhesion and thickness of an elastic roller having a silicone elastic layer/adhesive layer/fluorine resin coated layer structure, a roller having an adhesive layer formed of a cured product of an additive silicone composition containing an organic silicon compound having selected functional groups, of a thickness of 0.1 to 0.3 mm, has been disclosed (e.g., refer to Japanese Patent Application Laid-Open No. H07-53432).
Furthermore, a method wherein a silicone-rubber layer is formed on a core metal, a self-adhesive silicone rubber, to which an acrylic or methacrylic functional silane coupling agent is added, is applied thereto, and a fluorine resin tube is thermally adhered thereon, has also been disclosed (e.g., refer to Japanese Patent No. 3270489).
In addition, there has also been disclosed a method for manufacturing a tube-coated fixation belt, wherein an additive silicone-rubber adhesive is previously intervened between a rubber-layer coated metal-based belt and a PFA tube, and the adhesive is spread from the outer surface of the tube using a squeezing ring to adjust the thickness of the adhesive layer to be thin (e.g., refer to Japanese Patent Applications Laid-Open No. 2002-36361 and No. 2002-36383).
It has been known that a heat fixing apparatus of a belt-fixation system has a belt-shaped fixation member facilitating to constitute a wide nip and to lower the thermal capacity of the fixation members, and is advantageous for speed raising, energy saving and downsizing of the heat-fixing apparatus. In other words, in order to pass a recording material holding toner images before fixation through the nip portion, and to heat and fuse, then cool and solidify the toner to form permanent images on the recording material, a sufficient quantity of heat must be supplied to the recording material and the toner in the nip portion. Therefore, in order to form permanent images, sufficient surface temperature of the fixation member, and retention time in the nip are required; and in order to achieve high speed, the nip width must be widened to secure a sufficient retention time in the nip.
In the case of the heat-roller fixing, although a method to increase the outer diameter of the roller is used to widen the nip width, this results in the enlargement of the apparatus. Whereas in the fixation apparatus of a belt-fixation system, since the fixation member is belt-shaped, a constitution that can easily secure a wide nip due to a high degree of freedom of shapes can be achieved. Specifically, the belt member is characterized in that a wide nip width to the same outer diameter can be secured compared with the roller member, and is advantageous for downsizing.
For methods of adhering a silicone rubber to a surface fluorine resin layer, adhesiveness and durability at high temperatures are required. A convenient method is the addition of a silane coupling agent in the silicone rubber to impart self-adhesiveness to the silicone rubber itself.
For example, there has been disclosed a method for adhering a fluorine resin tube on the silicone-rubber layer of an elastic roller, such as a fixation roller, wherein a self-adhesive silicone rubber containing an acrylic or methacrylic functional silane coupling agent is used (e.g., refer to Japanese Patent No. 2922712).
There has also been disclosed a method for improving the adhesiveness to a plastic material wherein a combination of an unsaturated-group-containing silane coupling agent and an epoxy-group-containing silane coupling agent is added to a silicone rubber, and an aluminum compound or a zirconium compound is further added thereto (e.g., refer to Japanese Patent No. 3270489).
On the other hand, as an additive silicone-rubber adhesive, an adhesive prepared by adding metal particles to an adhesive containing a resinous organopolysiloxane to control conductive properties has been disclosed (e.g., refer to Japanese Patent Application Laid-Open No. 2002-322363).
When an adhesive layer is formed between the elastic layer and the surface layer, since a roller-type fixation member is generally used without significant deformation, the adhesive layer little undergoes fatigue caused by deformation due to bending or the like, and maintains sufficient adhesiveness; however, since a belt-type fixation member is significantly deformed in operation, large stress is generated between the elastic layer and the surface layer due to bending, which cause a problem of adhesive durability.
Since commercially available silicone-rubber-based adhesives generally contain fillers such as reinforcing silica, they have high viscosities, and are difficult to apply to a thin layer, which cause a problem of poor workability.
Furthermore, in a heat fixing apparatus of a belt-fixation system oriented to downsizing and high-speed operation, since the adhesive layer used in a tube-coated fixation belt is subjected to extensive repetitive bending deformation in operation and easily undergoes fatigue, higher adhesive durability is required.
In a belt coated with a tube having a small diameter oriented to the downsizing of the heat fixing apparatus, the heat-supply time is inevitably short, and the manifestation of the heat supplied from the heat source on the surface of the fixation member delays. Therefore, the surface temperature in the second round is lower than in the first round, and the surface temperature in the third round is lower than in the second round. Thereby, the fixation ability at the leading end and the tailing end of a sheet of recording paper is remarkably lowered, and for example, unevenness of gloss on the recording paper occurs resulting in unsatisfied image quality. Therefore, higher thermal response is demanded. This problem becomes more significant at a process speed exceeding 100 mm/sec, which orients to higher speed.

Tube-coated belt, heat fixing apparatus, and organopolysiloxane adhesive composition


There is disclosed an image scanning and video printing apparatus comprising a video printing unit controlled by a video synchronization signal, printing control signal and memory control signal for printing the images corresponding to a first video signal received through a first video signal input terminal and a second video signal produced by an image scanning on a printing paper, and generating a monitoring video signal, an image scanning unit for scanning a given material by an sensing device in response to an image sensing device drive control signal for controlling the driving of the image sensing device and image sensing device transfer control signal for controlling the transferring of the image sensing device so as to produce the second video signal supplied to the video printing unit, and a system control unit for controlling the image scanning and video printing apparatus by providing the image sensing device drive control signal and the image sensing device transfer control signal for the image scanning unit, and the video synchronization signal, memory control signal and printing control signal for the video printing unit.

The present invention relates to a video color printer, and particularly to a video color printer provided with a device for scanning a material such as photographs, books, magazines, etc.
There has been an increasing need for an apparatus for printing a video signal of a video system on a printing paper. A video color printer is widely used for printing video signals of VTRs (video tape recorders) , camcorders (camera recorders) , TVs, etc. In addition, a color scanner printer is used for printing video signals produced by an image scanner to scan a material such as books, photographs, magazines, etc.
Referring to FIG. 1, there is shown a system for printing a video signal produced by video system or image scanner comprising an image scanner 1, computer 2, scanner printer 3, video system 4 and video printer 5. The video system 4 may be a VTR, camcorder, TV, etc. In this system, the video printer 5 prints the video signal of video system on a printing paper. The image scanner 1 scans a material such as books, photographs, magazines, etc. with an image sensing device, and scanner printer 3 to print video signals produced by the image scanner 1 or processed by the computer 2.
The image sensing device may be generally a line transferring CCD or interline transferring CCD for NTSC. The line transferring CCD scans lines of a material one by one, while the interline transferring CCD scans at once the full extent of a material by using a shutter.
Meanwhile, in order to print a material such a photograph, book, magazine, etc. with a video printer 5, the material should be scanned by the image scanner 1 to generate corresponding video signals processed by the computer 2 for printing with the video printer 5.
As stated above, the conventional system for printing video signals produced by various video systems or obtained by scanning a material such as a photograph, book, magazine, etc. must be simultaneously provided with a video printer and scanner printer, or a video printer, image scanner and computer.

Image scanning and video printing apparatus and method of controlling the same


A device for measuring the preloading of a screw during a screwing operation including a container body in which a support is inserted, inside which there is a leadscrew into which such screw is screwed by a tightening tool, at the bottom of such support and connected thereto a transducer being arranged, capable of measuring the traction generated on itself as a result of the compression created by the screwing of the screw into the leadscrew.

Such screw may be screwed by means of a tightening tool such as for example, an industrial screwdriver, a dynamometric wrench, etc.
The quality of the tool that performed the operation may be determined by measuring the load the screw is subjected to during the screwing.
The assessment of the quality of a tightening tool is a highly felt problem; electronic devices for measuring the characteristics of industrial screwdrivers comprising sensors adapted to measure parameters such as torque, force, angle, length and combinations of the aforesaid parameters, are made for such an object. A field of application of such devices is the one of testing the tightening behaviour of industrial screwdrivers by means of measuring the rotating and/or braking torque of the rotating shaft. Indeed, the test of a screwdriver is a procedure that involves carrying out a tightening sequence for which torque and angle are measured.
Testing the quality of a screwdriver by means of measuring such parameters however at times is not very accurate and is affected by errors, in particular on the uniformity of the behaviour of the brakes that simulate the screw or the bolt that the screwdriver is to tighten.
Therefore, to improve such assessment on the tightening tool, the effects of such tightening on a screw may be assessed by measuring the characteristics thereof. In particular, the tensile force exerted on a transducer in which the screw is inserted during the tightening, is measured on the screw. In particular, such tensile stress is generated on a leadscrew constrained to the transducer as a reaction to the compression created by the screwing of the screw itself.

Device for measuring the preloading of a screw in a particular joint


An apparatus for controlling data exchange with a memory device includes an interface configured to receive an arbitration signal indicating when the apparatus has use of a shared bus and an interface to the memory device configured to provide a clock signal to the memory device that synchronizes data exchange between the apparatus and the memory device. A selection circuit selectively supplies the clock signal to the memory device responsive to the arbitration signal.

The present invention relates to a control apparatus and method, and more particularly, to an apparatus and method for controlling supply of a clock signal to a memory device.
FIG. 1 is a block diagram of a system 10 including a memory device 40 and a conventional controller 20. FIG. 2 is a timing diagram of signals output from a master that interfaces with the memory device 40 illustrated in FIG. 1. Referring to FIGS. 1 and 2, the system 10 includes a controller 20, the memory device 40, a first host 50 and a second host 52.
The controller 20 includes first through fourth masters 22, 24, 26, and 28, an arbiter 30, a first slave 32, a second slave 34, and a bus 36. It is assumed for purposes of this description that the first slave 32 is a data random-access memory (RAM) that stores data exchanged with the third master 26, and the second slave 34 is a data RAM that stores data exchanged with the fourth master 28.
As the first through fourth masters 22, 24, 26, and 28 share the bus 36 in the controller 20, they may access the bus 36 according to a priority protocol controlling use or ownership of the bus 36. The arbiter 30 arbitrates the priority of use of the bus 36 between the first through fourth masters 22, 24, 26, and 28 according to a specified method or protocol, such as a fixed priority method or a round-robin method. Accordingly, while one of the first through fourth masters 22, 24, 26, and 28 uses the bus 36, the other masters must wait for some time period until they obtain priority to use of the bus 36.
If the first host 50 exchanges a large amount of data, e.g., 2 KB of data, with the memory device 40 through the third master 26, the first slave 32, and the second master 24 using the bus 36, the second master 24 may need to use/control the bus 36 for a long period of time. Also, when the second host 52 exchanges a large amount of data with the memory device 40 via the fourth master 28, the second slave 34, and the second master 24 using the bus 36, the second master 24 may also need to use/control the bus 36 for a long period of time.
However, when a master (e.g., the first master 22) having higher priority than the second master 24 requests the arbiter 30 allow it to use/control the bus 36 and uses the bus 36, the second master 24 must wait for a period of time until the first master 22 loses the ownership of the bus 36. That is, when a master (e.g., the first master 22) having higher priority than the second master 24 requests the use of the bus 36, the second master 24 generally stores a predetermined address ADD of currently transmitted data A, B, . . . , C in a predetermined storage device, transfers the ownership of the bus 36 to the first master 22, and waits for a period of time until the higher priority master loses the ownership of the bus 36.
Referring to FIG. 2, when the second master 24 regains the ownership of the bus 36, the second master 24 of the controller 20 and the memory device 40 generally must be reset to transmit the remaining data D, E, . . . , G. Then, the second master 24 may transmit the address following the address of the already transmitted data (e.g., data C) to the memory device 40, and exchange the remaining data D, E, . . . , G with the memory device 40. As a result, the data transmission performance (efficiency) between the second master 24 of the controller 20 having the first through fourth 22, 24, 26, and 28, and the memory device 40 may be significantly lowered.
Also, even if data cannot be exchanged between the second master 24 of the controller 20 and the memory device 40 (for example, when the second master 24 loses the ownership of the bus 36), the second master 24 typically continuously supplies a clock signal CLK to the memory device 40, which may cause unnecessary consumption of power in the second master 24 and the memory device 40.

Apparatus and methods for controlling output of clock signal and systems including the same


A monitoring system for detecting a short circuit condition in a switching subsystem of a bypass input of a power supply. The system may comprise a voltage monitoring subsystem for monitoring a voltage across at least one component of the switching subsystem and generating a first output signal in accordance therewith. A processor, responsive to the first output signal from the voltage monitoring subsystem, may be used to compare the first output signal with a predetermined threshold signal and to generate a second output signal based on the comparison. The processor may also be used to consider a state of a circuit breaker in communication with the switching subsystem and to use the state of the circuit breaker and the second output signal to determine whether at least one of a short circuit condition and an open circuit condition exists with respect to the switching subsystem.

Both Underwriters Laboratories ("UL") and the International Electrotechnical Commission ("IEC") have requirements that state that hazardous voltage shall not appear on the input terminals of an uninterruptible power supply ("UPS") when the UPS is operating in a stored energy mode. The hazardous voltage is presently designated as being any voltage above 30V RMS. Additional requirements are that the hazardous voltage condition shall be cleared within fifteen seconds given a single component failure within the detection/prevention circuit being used (UL 1778 and IEC 62040-1-1).
Ideally, any monitoring/detecting system used to detect open and short circuit conditions in a bypass input of a UPS should be cost effective to implement and not require major modifications to the construction of the UPS itself.

System and method for detecting an electrical short across a static switch of an uninterruptible power supply


There is provided a battery comprising an electrochemical unit comprising at least one electrochemical cell. The at least one electrochemical cell comprises a cell anode, a cell cathode and an electrolyte in contact with said cell anode and cell cathode. The electrochemical unit further comprises a first contact electrode mounted on a surface of the electrochemical unit. The battery further comprises a second contact electrode positioned adjacent to the electrochemical unit, whereby the first and second contact electrodes face each other to allow a contact resistance between the first contact electrode and second contact electrode to be measured.

State of Charge (SOC)/State of Health (SOH) estimation is a fundamental for correct battery use and for ensuring safety use of batteries during their life time. There are many approaches to monitor these parameters including battery voltage measurement and impedance spectroscopy, Coulomb counting method, various adaptive systems introduction or combination of those methods.
U.S. Pat. No. 5,567,541A relates to methods and apparatus for measuring the state of charge in a battery based on volume of battery components. In particular, U.S. Pat. No. 5,567,541A discloses using strain-gauges for determining changes in the length of the outside circumference of a battery.


A signal detector for detecting the presence of a intermittent signal component in a signal. The signal detector receives each of the signal strength samples during a corresponding iteration, and compares a threshold value with the received signal sample. The signal detector sets a counter to a pre-determined number if the sample compared is greater than the threshold value. The signal detector decrements the persistence counter if a corresponding sample is not greater than the threshold value. If the persistence counter is greater than a trigger value, the detector indicates the presence of a intermittent signal component or otherwise declares the absence of a intermittent signal component. The detector may indicate the presence of a intermittent signal component by a logical value of 1 and the absence by a logical value of 0. The threshold value is composed of two components; the intermittent signal component and the background signal component. Each of the components of the threshold is determined separately by using a tracker and a low pass estimator under a control signal obtained from previous decisions as to whether intermittent signal was present or absent.

A device may detect the presence of a voice component in an input signal including both the voice component and a noise component. The voice component may include, for example, sound generated by a person when a person speaks, music, or other transient sounds (e.g., rustle of paper or other sound). The noise component may be generated, for example, as background noise (e.g., constantly present background sounds such as fan noise, road noise, and the like).
When a device detects that a voice component is present in an input signal, another circuit may process the input signal. Such a detection scheme may have application in several areas such as voice activation recording used in recording devices or in speech recognition where a detection function precedes a recognition function. For example, in a recording device, a detector device may detect the presence of a voice component in an input signal, and a recording circuit may record the input signal on a media when the detector device determines that voice component is present in the input signal.
Envelope-based signal detection is one prior art scheme for determining the presence of a voice component in an input signal as illustrated in FIG. 1. FIG. 1 includes a graph representing input signal 40 (illustrated as a solid line) along amplitude and time axis, and a corresponding envelope signal 20 (illustrated as a dashed line). If envelope signal 20 is at a level greater than a threshold level 10, a detector device may indicate that a voice component is present in input signal 40.
Input signal 40 may be characterized by periods of voice (illustrated during T2, T4, T6, T8, and T10 of FIG. 1), silence (illustrated during T1, T9, and T11), and non-silence gaps (T3, T5, and T7). Voice periods may correspond to a time period during which a voice component is present, as for example, when a person is speaking. Silence periods may be defined as absence of audible sound as experienced by a person or recording instrument, and may correspond to a time period when a speaker may in fact not be speaking.
Non-silence gaps are short duration periods without a voice component, which may be naturally present in between words or even within a word spoken by a person. Non-silence gaps may be of the order of fraction of a millisecond duration to a few milliseconds. In comparison, silence gaps may be much longer in duration. During both silence and non-silence gap periods (T1, T3, T5, T7, T9, and T11), noise component is illustrated in FIG. 1. As will be appreciated, during voice periods, input signal 40 may include a voice component super-imposed over a noise component.
It may be a requirement that envelope signal 20 remain at a high level during non-silence gap periods so as to enable a detector device to indicate that voice is present during non-silence gap periods. By so indicating, input signal 40 may be recorded (or otherwise processed) during non-silence gap periods also, which may result in accurate reproduction of voice captured in input signal 40. Without such recording of non-silence gaps, an audio sound reproduced may be inaccurate and sound unnatural.
To generate envelope signal 20 which remains at a high level during non-silence gap periods, a prior detector device may use components such as analog filters to generate envelope signal 20. As is well known in the art, envelope signal 20 generated by such detector devices may gradually decay in response to sudden reductions in instantaneous level of input signal 40. Thus during periods T3 and T5, envelope signal 20 remains high, and the detector device may indicate that a voice component is present during the corresponding periods.
However, the rate of decay may not be accurately related to the silence and non-silence gaps. Therefore if the decay is made too fast, non-silence gaps are detected as silence as illustrated during time T9. If the decay is made too small, the silence gaps may be missed and mis-identified as voice periods.
Moreover, such a detector device may not quickly respond to changes in input signal 40, envelope signal 20 may not rise to a sufficiently high level immediately when a voice component is present in input signal 40. As illustrated at input samples 70 of FIG. 1, envelope signal 20 may remain at a level lower than threshold level 10 for a short duration, and a detector device may accordingly miss indicating the presence of voice component in input signal 40.
Due to such misses, an audible voice reproduced from input signal 40 may not have acceptable quality as the leading portion of a word or words may be truncated. To avoid or minimize such misses, either the threshold 10 should be lowered or another prior art detector may be designed to respond quicker to changes in input signal 40. However, such changes could lead to falsely detecting background noise as voice.

Persistence and dynamic threshold based intermittent signal detector


A respirator for emergency oxygen supply for passengers in aircraft, with a mounting container (1), which can be closed with a lid (2), is fastened above the row of seats, and accommodates at least one breathing mask and an exothermic chemical oxygen generator (3) connected to the breathing mask in a holder (4, 5). The pivotability of the lid of the mounting container is improved by rigidly arranging the holder on the mounting container (1) such that it permits the oxygen generator (3) to change its place by pivoting in the case of use.

In certain emergency situations in aircraft, it is necessary to enrich the breathing air with oxygen. This may be necessary to raise the oxygen level to a level that permits survival of the user in an atmosphere with reduced oxygen partial pressure, e.g., after a drop in the cabin pressure at high altitude. Therefore, breathing masks connected to chemical oxygen generators are arranged in passenger planes in mounting containers that can be closed with a lid above the passenger seats. The passenger chemical oxygen generators contain, in general, an alkali metal chlorate mixture, which releases oxygen, which can be inhaled via the breathing mask, in an exothermic reaction after activation.
The amount of oxygen to be supplied and consequently the size of the chemical oxygen generator depend on the necessary duration of use. A so-called long-range system, in which the chemical oxygen generators must have a prolonged operating time of up to 22 minutes, is needed especially in the case of prolonged descent time from high altitude.
A considerable amount of heat, which heats the outer wall of the generator housing to about 280.degree. C., is generated in the course of the exothermic reaction in the chemical oxygen generator. Since the mounting container is installed, in general, under the so-called hat racks, the temperature of the mounting container may not exceed a predetermined value even during use, in order not to jeopardize the function of the surrounding components. Moreover, since only a limited space is available for installing the mounting container, the necessary heat insulation cannot, in general, be accommodated within the mounting container.
In an embodiment according to U.S. Pat. No. 4,766,893 (corresponding to DE-A1 36,13,814), the oxygen generator is arranged on the lid of the mounting container, which lid can be opened, and it ensures increased dissipation of heat in the use position. However, the lid attachment of the oxygen generator shows various disadvantages; in particular, because of the considerable weight of the oxygen generator, the lid must be provided with a relatively stable and consequently weight-increasing lid attachment, for which a pivoting range with an angle of 100.degree. is specified to enable the breathing masks to drop freely. In light of these requirements, arranging the oxygen generator on the lid appears to be unsuitable for certain applications.
A mounting container with rigidly installed oxygen generator, in which the heat is dissipated directly onto the mounting container, has been known from, e.g., DE-G 86,11,223.

Respirator for emergency oxygen supply for passengers in aircraft


The present invention is a circuit connecting material used for the mutual connection of a circuit member in which electrodes and insulating layers are formed adjacent to each other on the surface of a board, and a circuit member in which electrodes and insulating layers are formed adjacent to each other on the surface of a board, with the edge parts and of the insulating layers being formed with a greater thickness than the electrodes on the basis of the main surfaces, wherein this circuit connecting material contains a bonding agent composition and conductive particles that have a mean particle size of 1 μm or greater but less than 10 μm and a hardness of 1.961 to 6.865 GPa, and this circuit connecting material exhibits a storage elastic modulus of 0.5 to 3 GPa at 40° C. and a mean coefficient of thermal expansion of 30 to 200 ppm/° C. at from 25° C. to 100° C. when subjected to the curing treatment.

Circuit member connecting structures used for the mutual connection of circuit members such as liquid crystal displays and TCPs (tape carrier packages), FPCs (flexible printed circuits) and TCPs, FPCs and printed wiring boards or the like have been known in the past. Circuit connecting materials in which conductive particles are dispersed in a bonding agent (e.g., anisotropic conductive bonding agents) are used for the connection of such circuit members to each other (for example, see Japanese Patent Application Laid-Open No. 59-120436, Japanese Patent Application Laid-Open No. 60-191228, Japanese Patent Application Laid-Open No. 1-251787, Japanese Patent Application Laid-Open No. 7-90237 and Japanese Patent Application Laid-Open No. 2001-189171).
Meanwhile, circuits have shown progressively higher densities as electronic devices have become smaller and thinner in recent years, so that the spacing between circuit electrodes and the width of circuit electrodes in circuit members have become extremely narrow; consequently, it has become difficult to ensure high insulating properties between circuit electrodes. Accordingly, in order to ensure high insulating properties between the circuit electrodes in circuit members, it is considered necessary to form an insulating layer comprising an organic insulating substance, silicon dioxide, silicon nitride or the like between the circuit electrodes.
FIG. 7 is a sectional view which shows a conventional example of a connecting structure for circuit members. As is shown in FIG. 7, the circuit member connecting structure 100 comprises a first circuit member 131 and a second circuit member 141; this first circuit member 131 and second circuit member 141 are connected by a circuit connecting member 150. The first circuit member 131 is constructed from a circuit board 132, and circuit electrodes 133 and insulating layers 134 that are formed adjacent to each other on one surface 132a of this circuit board 132. Portions of the insulating layers 134 have a shape that rides over the edges of the circuit electrodes 133. Specifically, portions of the insulating layers 134 are formed with a greater thickness than the circuit electrodes 133 on the basis of the surface 132a of the circuit board 132. Furthermore, the second circuit member 141 has a construction similar to that of the first circuit member 131; this second circuit member 141 is constructed from a circuit board 142, and circuit electrodes 143 and insulating layers 144 that are formed adjacent to each other on one surface 142a of this circuit board 142, and portions of the insulating layers 144 have a shape that rides over the edges of the circuit electrodes 143. Meanwhile, the circuit connecting member 150 is a member in which, for example, conductive particles 152 produced by forming a nickel plating layer on the surfaces of benzoguanamine resin particles are disposed in an insulating substance 151. Here, for example, the mean particle size of the conductive particles is 5 μm, and the hardness (K value) is 7490 N/mm2.

Circuit connecting material, film-like circuit connecting material using the same, circuit member connecting structure, and method of producing the same


A surgical instrument is provided which is formed of a semiconductor substrate material having at least one anisotropically etched sharpened edge and a heating circuit disposed on the substrate. The heating circuits generate heat by means of resistive elements interposed along the circuit path. The substrate material itself may serve as the resistive elements, or resistive layers may be used in the alternative. The resistive heating may be used to heat the sharpened edge directly, or the heating may be thermally isolated from the sharpened edge. The heating circuit may also include a thermal sensor which may be used to control the generation of heat and/or detect damage to the instrument itself. The conformation of the instrument may include a variety of different shapes, including central recesses and windows. The recesses may further include ribs or support members. The substrate may further a suction mechanism for removing fluid which may build up in the vicinity of the surgery.

1. Field of the Invention
This invention relates to a surgical tool for simultaneously performing precision cutting and cauterizing of targeted tissues, and more specifically to a semiconductor knife constructed by appropriate semiconductor processing methods and techniques, said tool having electrocautery circuits imprinted thereon which are capable of heating at least a portion of the tool to sufficient temperatures to effect precise cauterization of adjacent targeted tissues.
2. Brief Description of the Prior Art
Presently, surgical devices for precision cutting are divided into different classes. Two important classes of such devices are microscalpels and laser scalpels. The former class has traditionally been solely a mechanical device, insofar as its only capacity was to physically separate tissues. This limited capacity, coupled with the unavoidable disruption of blood carrying members, required the use of another surgical tool for stemming the flow of fluids which might be initiated during the cutting. It has long been known that the sufficient application of heat to fluids, such as blood, or the tissue from whence such fluids flow, can cause their coagulation. Electrocautery instruments have been utilized in conjunction with mechanical scalpels to apply the heat necessary to cauterize the targeted tissues. These electrocautery tolos suffer from three substantial drawbacks. The first two of these are related to the surgical use.
First, separate electrocautery and mechanical scalpel devices often requires that the surgeon laboriously changes between using the scalpel and the electrocautery tool during the surgical procedure. Surgeons have found several manual means for overcoming this serious disadvantage, none of which truly reaches the ideal flexibility of the present invention. One such manual solutions is to have two surgeons working in the same surgical field, the first manipulating the cutting instrument, and the second manipulating the cauterizing instrument. For obvious reasons, including wasted expertise and the requirement of unnecessary coordinated activity, this solution is the least economically desirable, and is also the least efficient insofar as it often requires verbal communication between the two surgeons during periods of time when more critical information should be discussed.
A second solution which surgeons have discovered to attempt to overcome the serious drawbacks of separate scalpel and electrocautery instrumentation is to hold both instruments in the same hand, or at least in separate hands. Again, for obvious reasons, requiring a surgeon to hold both instruments in one hand, or at best having the two instruments in opposing hands, dramatically limits the flexibility of the surgeon's manipulative freedom.
The final, and least desirable manual methods of overcoming the drawbacks of separate instrumentation is to leave the tool which is not being utilized in the surgical field when it is not being actively used. Again, for obvious reasons, including impairing the visual field for the surgeon, it was known to be desirable to have a single tool which combines cauterizing and mechanical separation ability.
A substantial advance in the area of mechanical separation of tissues as well as cauterization was provided by the laser scalpel. Laser scapels utilize coherent light, often infrared light generated by a C02 or Yttrium-Aluminum-Garnet (YAG) power source, to ablate tissue away in a highly confined region. While the tremendous heat generated by the laser beam is more than substantial enough to cut through tissue as effectively as a scalpel (at least as efficiently as is necessary for many procedures) and also to cauterize surrounding tissues, the laser scalpel suffers from several important drawbacks as well.
Chief among these drawbacks is the fact that a laser scalpel which cuts by means of a coherent infrared beam is by definition invisible to the naked eye. Therefore, a surgeon must be able to manipulate the beam by watching the tissue surface which is literally burning before truly knowing the position of the "blade".
Second, but equally important is the inability to turn the cauterizing capacity off. More particularly, it is an important drawback of the laser scalpel that the cutting capacity is directly coupled to the heat generation, thus requiring at least some cauterization while cutting.
A related drawback of the laser scalpel, which is also a substantial drawback of present manual electrocautery instruments, is the imprecise nature of the cauterization. Both classes of surgical device cause substantial collateral damage to surrounding tissues. If cauterization is required near vital anatomical structures, great care must be taken to avoid damaging such tissues indirectly through the cauterization of the adjacent material. This problem is most severe in the field of microsurgery wherein many small vessels may be within a restricted field surgery, with only selected ones requiring cauterization.
In a sense, the cauterization instrument must combine the surgical precision of the microscalpel, the immediacy and strength of the laser, and also the selectivity of a separate instrument.
It is, therefore, a principle object of the present invention to provide a surgical instrument which combines precise tissue separation and cauterization ability within a single tool which enhances surgical flexibility.
It is further, an object of the present invention to provide a cauterizing cutting instrument which enhances visibility in the surgical field.
It is also an object of the present invention to provide a surgical instrument which permits greater precision in cauterization and cutting that instruments of the prior art.
It is an additional object of the present invention to provide an instrument which may be disposable, but which requires less wasted resources than present related surgical instruments.


Distributed fiber optic chemical and physical sensors provide a relatively highly uniform response over the length of the fiber by, for example, varying such properties as the core/cladding index of refraction ratio to compensate for the non-linearity in sensitivity due for example to the loss of higher order modes in multi-mode fibers. The variation of the ratio changes the absorption coefficient of the fiber and can be used to compensate for any non-linearity in response. Other techniques for compensation also are disclosed.

U.S. Pat. No. 4,834,496 issues May 30, 1989 discloses distributed fiber optic chemical sensors. Such a sensor comprises an optical fiber with a core and a cladding which is permeable. The cladding, or a coating on the cladding, includes a composition, the optical properties of which are altered in the presence of a material to be detected. The light (i.e. the wavelength of the intensity of the light) transmitted through the core of the fiber is a function of the change in optical properties caused by the interaction of the composition included in the permeable coating with the material to be detected. The change in optical properties may comprise (for example) a change in the index of refraction (or indices of refraction differential), or an increase or decrease in the optical absorbance of fluorescence of the composition.
The above-noted patent discloses materials, compositions, sensing parameters and examples of such sensors, all of which are useful in accordance with the principles of this invention. In addition, distributed fiber optic sensors for physical properties, such as temperature or pressure, can also be fabricated based on similar properties, e.g., temperature-induced or pressure-induced changes in the refractive index, optical absorbance, or fluorescence of a cladding or coating material applied to a light-guiding core.
Unfortunately, such optical fibers are characterized by spatial transients for transmitted light which causes the sensitivity of chemically or physically sensitive fibers to vary from point to point along the fiber. This is particularly true of multi-mode fibers with lossy (e.g. absorber-doped) coatings where light does not reach equilibrium for a considerable distance. Such a varying response is due to a spatial transient, associated with the existence of radiation modes, and strong attenuation of higher order bound modes. Accordingly, sensor response over the length of the fiber is not constant.

This patent is subject to a terminal disclaimer.

Distributed optical fiber sensor with controlled response


According to one exemplary embodiment, a frequency synthesizer module includes a loop filter, where the loop filter includes a capacitor having a first terminal and a second terminal. The frequency synthesizer module further includes a loop filter calibration module coupled to the capacitor in the loop filter. The loop filter calibration module causes an initial capacitance between the first terminal and the second terminal of the capacitor to increase to a target capacitance when the loop filter is in a calibration mode. The target capacitance can causes in increase in control of a bandwidth of the loop filter and a reduction in percent error of a unity gain bandwidth of the loop filter. The loop filter further includes a switched capacitor array configured to cause the initial capacitance to increase to the target capacitance in response to a digital feedback signal provided by the loop filter calibration module.

1. Field of the Invention
The present invention is generally in the field of electrical circuits. More particularly, the invention is in the field of frequency synthesizers.
2. Related Art
Modulated frequency synthesizers, such as analog modulated frequency synthesizers, are utilized in cellular communication systems, such as Global System for Mobility ("GSM") cellular communication systems. In a modulated frequency synthesizer, data is modulated by switching a value of a frequency divider, such as a fractional-N frequency divider, in the feedback path of a phase locked loop. Modulated frequency synthesizers, such as analog modulated synthesizers, often employ a pre-emphasis on the data path to compensate for bandpass filtering caused by the phase locked loop. However, if data pre-emphasis is used, the bandwidth of the loop filter in the modulated frequency synthesizer must be accurately controlled to meet required communication system, such as GSM communication system, specifications.
Modulated frequency synthesizers generally utilize a loop filter that includes passive components, such as resistors and capacitors. These passive components are subject to process and temperature variations, which can cause an undesirable change in the bandwidth of the loop filter. For example, the loop filter typically includes a large capacitor in series with a resistor, where the large capacitor can have a significant undesirable effect on loop filter bandwidth as a result of process and temperature variations.
Thus, there is a need in the art for increased loop filter bandwidth control in a modulated frequency synthesizer, such as an analog modulated synthesizer.

Frequency synthesizer with loop filter calibration for bandwidth control


This invention is selected novel chiral (essentially pure) alpha-amino phosphonates, process for the preparation which is a catalytic asymmetric hydrogenation of olefins and novel intermediates therefor. The alpha-amino phosphonates are useful as antibiotics and/or as intermediates in the preparation of phosphorus-containing analogs of peptides, i.e., phosphonopeptides or pseudopeptides having known uses, such as in antibiotics, antibiotic enhancers, or enzyme inhibitors.

The present invention relates to catalytic asymmetric hydrogenation of olefins to synthesize chiral alpha-amino phosphonates and selected novel chiral alpha-amino phosphonates. The chiral alpha-amino phosphonates are either useful as biocides, antibiotics and/or useful in the preparation of phosphorus-containing analogs of peptides, i.e., phosphono peptides or pseudopeptides having known uses. For example, such phosphorus-type compounds have been shown to be effective as antibiotics, antibiotic enhancers, or enzyme inhibitors.
In the past desired stereoisomers have been difficult to obtain. Laborious and expensive processes such as those using fractional crystallization and recycle loops have been common in procedures involving a resolution step to obtain a desired stereoisomer. More recently some olefins have been subjected to asymmetric hydrogenation over rhodium and other metal coordination catalysts having optically active ligands.
Such asymmetric hydrogenation for the preparation of selected enantiomers is shown by the following references:
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Chem., 1989, 54(9), pp. 2251-2; PA1 Sauveur et al, Phosphorus Sulfur. 1983, 14(3), pp.341-6; PA1 Growiak and Sawka-Dobrowolska, Tetrahedron Letters, 1977, No. 45, pp. 3965-8; and PA1 Parsons et al, J. Med. Chem. 1988, No. 31, pp. 1772-8. PA1 Baylis et al, J. Chem. Soc. Perkin Trans I 1984, 1984,2845-53; PA1 Yuan and Qi, Synthesis, 1988, June, 472-4 disclose 1-amino-substituted benzyl phosphonic acids where the benzyl includes various substituents. PA1 Kukhar and Solodenko, Russ. Chem. Rev. 1987, pp. 1504-32; and PA1 Dhawan and Redmore, Phosphorus and Sulfur, 1987, 32, pp. 119-44. PA1 Sawamura et al, Tetrahedron Letters. 1989, Vol. 30, No. 17, pp 2247-50; PA1 Sting and Steglich, Synthesis, 1990, February, pp. 132-4; PA1 Solodenko et al, Tetrahedron. 1991, Vol 47, No. 24, pp. 3989-98; PA1 Kafarski and Lejczak, Can. J. Chem. 1983, 61, pp. 2425-30; PA1 Atherton et al, Antimicrobial Agents and Chemotherapy, 1979, May, pp. 677-83; PA1 Atherton et al, J. Med. Chem., 1986, 29 pp. 29-40; PA1 Scholkoph and Schutze, Liebigs Ann. Chem., 1987, pp. 45-9; PA1 Bartlett and Lamden, Bioorganic chemistry, 1986, 14, pp. 45-9; PA1 Huber and Vasella, Helvetica Chimica Acta, 1987, 70, pp. 1461-76. PA1 (2) alkyl of from one to six carbons substituted by one or two hydroxyl, chloro, or fluoro; PA1 (3) phenyl substituted by one to three substituent(s) consisting of PA1 (4) tolyl; PA1 (5) tolyl substituted by one to three substituents consisting of PA1 (6) naphthyl optionally attached through a CH.sub.2 group and optionally substituted by one to three substituents consisting of PA1 (7) indol-3-yl, indol-2-yl, or imidazol-4-yl, or indol-3-ylmethyl, indol-2-ylmethyl or imidazol-4-ylmethyl; PA1 (8) NHA wherein A is PA1 (9) R.sub.12 (R.sub.13 R.sub.14 C).sub.m V wherein V is O or NH and R.sub.12, R.sub.13 and R.sub.14 are independently as defined above; PA1 (10) N(R.sub.11).sub.2 wherein R.sub.11 is independently as defined above; PA1 (11) NR.sub.15 NR.sub.16 wherein R.sub.15 and R.sub.16 are joined to form a 4 to 6 membered saturated nitrogen containing heterocycle which is (i) azetidinyl, (ii) pyrrolidinyl, (iii) piperidinyl, or (iv) morpholinyl; PA1 (12) R.sub.17 OCH.sub.2 O wherein R.sub.17 is PA1 (13) R.sub.17 OCH.sub.2 CH.sub.2 OCH.sub.2 wherein R.sub.17 is independently as defined above; PA1 (14) alkynyl of from two to six carbons optionally substituted with R.sub.21 where in R.sub.21 is independently as defined above; PA1 (15) alkenyl of from two to six carbons optionally substituted with R.sub.21 where in R.sub.21 is independently as defined above; PA1 (2) alkyl of from 1 to 6 carbons optionally substituted by one or two hydroxyl, chloro or fluoro; PA1 (3) cycloalkyl of from 3 to 7 ring carbons; PA1 (4) ar.sub.4 which is a group such as phenyl, or phenyl substituted by one to three substituent(s) consisting of PA1 (5) ar.sub.5 which is a group such as tolyl; PA1 (6) ar.sub.6 which is a group such as tolyl substituted by one to three substituents consisting of PA1 (7) ar.sub.7 which is a group optionally attached through a CH.sub.2 and is naphthyl or naphthyl substituted by one to three substituents consisting of PA1 (8) ar.sub.8 which is a group such as indol-3-yl, indol-2-yl, or imidazoly-4-yl or indol-3-ylmethyl, indol-2-ylmethyl or imidazol-4-ylmethyl (preferably unsubstituted or substituted phenyl or indol-3-yl); PA1 (9) NHA wherein A is PA1 (10) R.sub.12 (R.sub.13 R.sub.14 C).sub.m V wherein V is O or NH and R.sub.12, R.sub.13 and R.sub.14 are independently as defined above; PA1 (11) N(R.sub.11).sub.2 wherein R.sub.11 is independently as defined above; PA1 (12) NR.sub.15 NR.sub.16 wherein R.sub.15 and R.sub.16 are joined to form a 4 to 6 membered saturated nitrogen containing heterocycle which is (i) azetidinyl, (ii) pyrrolidinyl, (iii) piperidinyl, or (iv) morpholinyl; PA1 (13) R.sub.17 OCH.sub.2 O wherein R.sub.17 is PA1 (14) R.sub.17 OCH.sub.2 CH.sub.2 OCH.sub.2 wherein R.sub.17 is independently as defined above; PA1 (15) alkynyl of from two to six carbons optionally substituted with R.sub.21 where in R.sub.21 is independently as defined above; PA1 (16) alkenyl of from two to six carbons optionally substituted with R.sub.21 where in R.sub.21 is independently as defined above; PA1 with hydrogen in the presence of rhodium (R,R)(1,2-ethanediyl bis[(orthomethoxyphenyl) phenylphosphine] (H.sub.2 RhDiPAMP) in a deoxygenated solvent; optionally (1) deprotecting the nitrogen or (2) deprotecting the nitrogen and further treating to add an amino acid radical to the nitrogen, to obtain a compound of the formula (I) ##STR4## wherein R.sub.1, R.sub.2, R.sub.4 and R.sub.5 is as defined above; and R.sub.3 ' is hydrogen, amino acid radical or a protecting group.
Some (1-Aminoalkyl)phosphonic acids, the phosphonic acid analogs of amino acids, and particularly the selected enantioselective synthesis of optically pure aminophosphonic acids and phosphonopeptides have been prepared by resolution and by asymmetric synthesis using chiral auxiliaries. This is exemplified by the following references:
Schollkoph et al report that "attempts to hydrogenate 3a" (which is N-[1-(dimethoxyphosphoryl)ethenyl]formamide) at room temperature, normal pressure) in the presence of (R,R)-DIPAMP failed." Schollkoph et al disclose the reduction of certain dehydro alpha-amino phosphonates by catalytic asymmetric hydrogenation in the presence of rhodium (+) DIOP catalyst. Thus, surprisingly, both the chemical yield and the asymmetric induction providing enantiomeric enhancements (ee) of the present invention process provide essentially pure compounds of a particular stereoisomeric form including selected chiral compounds now essentially pure not previously known. Further, Genet et al, Tetrahedron letters. 1986, Vol. 27, No. 38, pp 4573-76, provide comparisons of DIOP and DIPAMP in a different asymmetric allylation consistent with Schollkoph.
Reported diastereomeric mixtures of 1-aminoalkylphosphono type compounds are found in numerous references of which the following are examples:
U.S. Pat. No. 4,016,148 discloses peptide derivatives having a moiety characterized by the replacement of the carboxyl group of a naturally occurring L alpha-amino acid by a phosphorus group including a --P(O)(OH).sub.2 group.
Recent reviews disclosing the preparation of selected diastereomeric and chiral alpha-amino phosphonates are found in the following references respectively:
The following additional references disclose various specific chiral alpha-amino phosphonates:
The interesting biological properties of .alpha.-aminophosphonates make them attractive analogues of .alpha.-amino acids, [(a) Redmore, D. Top. Phosphorus Chem., 1976, 8, 515; (b) Petrov, K. A.; Chauzov, V. A.; Erokhina, T. S. Russ. Chem. Rev. 1974, 43, 984; (c) Kafarski, P.; Mastarlerz, P. Aminophosphonates: Natural Occurance, Biochemistry and Biological Properties, Bertrage zur Wirkstofforschung, Ak. Ind. Kompl. DDR. 1984, 21.] While they resemble their carbon counterparts, the tetrahedral phosphorus also allows them to function as transition state analogues. These pharmaceutically-interesting compounds [Certain phosphorus analogues of .alpha.-amino phosphonates are being investigated by the pharmaceutical industry as antibiotics, see; (a) Atherton, F. R.; Hall, M. J.; Hassall, C. H.; Lambert, R. W.; Llod, W. J.; Ringrose, P. S. Antimicrob. Agents Chemother., 1979, 15, 696; (b) Chakravarty, P. K.; Greenlee, W. J.; Parsons, W. H.; Patchett, A. A.; Combs, P.; Roth, A.; Busch, R. D.; Mellin, T. N. J. Med. Chem., 1989, 32, 1886 and references therein.] have been synthesized by various racemic routes, but the need to develop a practical asymmetric method still exists. The 35 present invention now successfully fulfills this need.
.alpha.-Amino phosphonates have recently been reported to serve as starting materials for the preparation of potent inhibitors of HIV-1 protease. (Dreyer, G. B. New diamino phosphinic acid derivatives are aspartic protease inhibitors used to treat viral infections especially HIV type 1. Patent Application W09200954-A1, Jan. 23, 1992, assigned to SmithKline Beecham Corp.) This application is incorporated herein by reference to provide the basis for utility for the present invention process and its intermediates. Since the .alpha.-amino phosphonate employed by Dreyer et al was racemic (Dreyer, G. B.; Choi, J. K.; Meek, T. D.; Tomaszek, T. A.; Jr. 203rd American Chemical Society Meeting, San Francisco, Calif. Apr. 5-10, 1992, Medicinal Chemistry #179), the inhibitor was made as a mixture of isomers necessitating a tedious chromatographic separation in order to isolate the most active constituent. The most active isomer was derived from the phosphorus analogue of phenylalanine with the L(R) absolute configuration. Not only would the methodology described herein be adaptable to the preparation of the most active isomer of the SKB HIV-protease inhibitor, but to a wide variety of analogues as well, Intermediates of U.S. Pat. No. 4,946,833 and each of European Application Nos. 89401595.7 and 90402226.6 are related to the novel compound I of the present invention. German Application 4029444A abstracted in Derwent Abstract No. 91-095191/14 discloses compounds for regulating plant growth related to the novel compounds of Formula II of the present invention. Further, EP 207,890A disclosed in Derwent Abstract No. 87-001565/01 includes 1-amino-2-phenylethylophosphorus acid derivatives as microbiocidal and biocidal agents.
The flexibility of the present synthesis permits the synthesis of very unique analogues of .alpha.-amino phosphonates that are related to known compounds having biological properties relative to molecules available by more demanding syntheses. The literature is replete with examples of novel amino acid side chains designed to impart improved biological properties to analogous molecules.

Process for making chiral alpha-amino phosphonates selected novel chiral alpha-amino phosphonates


A system for connecting a circuit network with a packet network. The system includes a packet switch fabric, a circuit network server, and a packet network server. The circuit network server has a first and second port. The first port of the circuit network server sends and receives circuit-based signals with the circuit network. The second port of the circuit network server sends and receives packet-based signals having packets with the packet switch fabric. The circuit network server also includes a plurality of digital signal processors. A digital signal processor performs packet adaptation and subsequent to the packet adaption a second at least one digital signal processor performs signal processing. The packet network server has a first port for sending and receiving packet-based signals with the packet switch fabric and a second port for sending and receiving packet-based signals with the packet network. The packet switch fabric is capable of transferring packet-based signals among the packet network server and the circuit network server, and among the circuit network server and a second circuit network server.

Currently, circuit switching technology forms the basis for the world-wide telecommunications network infrastructure and is used extensively in telephone systems, however the recent expansion of the Internet has fueled the use of packet-based technologies. Packet-based technologies can be used as an alternative or in combination with circuit switching technologies in these telecommunications networks and telephone systems. When packet-based and circuit-based communication technologies are used together, a bridge, known as a gateway, is necessary to transform and route signals between a circuit network and a packet network. Telephony gateways interconnecting to the circuit network may use standards-based time division multiplexed (TDM) trunks (T1, T3, E1, etc) and standards-based signaling mechanisms (e.g., Signaling System 7 or channel associated signaling). An example of a circuit network is the telephone system that provides subscribers with plain old telephone service (POTS). The gateway may interconnect to the packet network through standards-based packet interfaces such as Internet Protocol (IP), Frame Relay and Asynchronous Transfer Mode (ATM) over a variety of physical interfaces (e.g., 100 BaseT, T3, OC3c, OC12c). An example of a packet network is the Internet.
FIG. 1 illustrates the architecture of a prior art telephony gateway 10. This gateway architecture uses a circuit switch fabric 12 such as a TDM bus or a Time-Slot-Interchange to provide the internal switching between the circuit network 14 and the packet network 16. Circuit-to-circuit calls, as indicated by line 15, are switched between circuit network servers 18 using the circuit switch fabric 12. Circuit-to-packet calls, as indicated by line 17, are switched between circuit network servers 18 and packet network servers 19 using this same circuit switch fabric 12. The conversion of the circuit data to packet data, which is known as packet adaptation, is performed in the packet network servers 19, which incorporate digital signal processors (not shown) for echo cancellation and transcoding. The circuit switch fabric 12, however, limits the overall flexibility of the gateway to move packets among server cards.
FIG. 2 illustrates the architecture of another prior art telephony gateway 20. For greater flexibility, this gateway architecture separates the signal processing functions from the packet network servers 22 and places these functions on signal processing servers 21. In addition, a packet switch fabric 23 allows connectivity from any signal processing server 21 to any packet network server 22. It is well known that a packet switch fabric 23 can be implemented with a variety of technologies, such as an arbitrated packet bus or a centralized switching module. As in the gateway architecture of FIG. 1, circuit-to-circuit calls are switched via the circuit switch fabric 12 as indicated by line 24. Circuit-to-packet calls, as indicated by line 25, are first switched by the circuit switch fabric 26 to a signal processing server 21 that contains an available digital signal processor (DSP) for performing signal processing. The signal processing server 21 uses the packet switch fabric 23 to move the processed information to a packet network server 22 and the associated packet network interface selected during call establishment. The separation of the signal processing function on separate servers allows a call-by-call selection of different DSP-based functions. For example, different calls can use different compression algorithms, with differing processing complexity, residing on different signal processing servers 22. While the flexibility of the packet switch fabric 23 represents an improvement over the architecture of FIG. 1, the architecture of FIG. 2 carries the cost and complexity burden of two separate and independent switch fabrics: one circuit and one packet.

Apparatus and method for a telephony gateway


A system and method to control congestion in a multihopping wireless communication network (100). The system and method distribute the congestion information back to the ingress points (106) and traffic source nodes (102, 106, 107) in the network (100) through the actual route of the data flow that contributes to the congestion. The system and method therefore avoid bottleneck points (102-5) in the network (100) to reduce congestion. The system and method can be used for packet-based, route-based or flow-based traffic shaping in a multihop wireless network (100) employing different media access control (MAC) and routing layer protocols. Moreover, the system and method is capable of distributing congestion and service differentiation information between different interfaces in the network (100).

In recent years, a type of mobile communications network known as an "ad-hoc" network has been developed. In this type of network, each mobile node is capable of operating as a base station or router for the other mobile nodes, thus eliminating the need for a fixed infrastructure of base stations. As can be appreciated by one skilled in the art, network nodes transmit and receive data packet communications in a multiplexed format, such as time-division multiple access (TDMA) format, code-division multiple access (CDMA) format, or frequency-division multiple access (FDMA) format.
More sophisticated ad-hoc networks are also being developed which, in addition to enabling mobile nodes to communicate with each other as in a conventional ad-hoc network, further enable the mobile nodes to access a fixed network and thus communicate with other mobile nodes, such as those on the public switched telephone network (PSTN), and on other networks such as the Internet. Details of these advanced types of ad-hoc networks are described in U.S. Pat. No. 7,072,650 entitled "Ad Hoc Peer-to-Peer Mobile Radio Access System Interfaced to the PSTN and Cellular Networks", granted on Jul. 4, 2006, in U.S. Pat. No. 6,807,165 entitled "Time Division Protocol for an Ad-Hoc, Peer-to-Peer Radio Network Having Coordinating Channel Access to Shared Parallel Data Channels with Separate Reservation Channel", granted Oct. 19, 2004, and in U.S. Pat. No. 6,873,839 entitled "Prioritized-Routing for an Ad-Hoc, Peer-to-Peer, Mobile Radio Access System", granted Mar. 29, 2005, the entire content of each being incorporated herein by reference.
As can be appreciated by one skilled in the art, certain nodes in multihopping wireless networks may receive more traffic than others, and therefore become congested. Accordingly, it is desirable to attempt to avoid congested nodes when routing packets in the network. A publication by C. Y. Wan, S. B. Eisenman, and A. T. Campbell entitled "CODA: Congestion Detection and Avoidance in Sensor Networks", SenSys 2003, describes a congestion control algorithm for networks. In accordance with this algorithm, a suppression message for reducing traffic is broadcasted by devices in the network. However, the reliability of receiving this message is based on the channel quality and can require broadcasting of the message multiple times during the congested period. Hence, although these messages are propagated upstream through the network toward the sources of the traffic, these messages may not always be received by the sources. Furthermore, a node that receives the suppression message may choose to not propagate the message if its local network conditions are acceptable. Therefore, this technique for attempting to avoid congestion is not reliable.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.

System and method for controlling congestion in multihopping wireless networks