A peel-off coupon redemption card includes a plurality of coupons releasably adhered to a base with a release liner. The release liner is composed of a material, such as a dry release adhesive or evaporative adhesive, such that when a coupon is removed from the base substantially no effective adhesive remains on the removed coupon. Each coupon preferably includes promotion indicia and an electronic redemption indicia. The electronic redemption indicia is preferably printed on a face of the coupon facing the base so that each coupon can be electronically redeemed while having sufficient space for the promotion indicia on the opposite face of the coupon.

The present invention generally relates to coupons and coupon redemption cards. More particularly, the present invention relates to a peel-off coupon redemption card having one or more coupons which are beneficially removable with effectively no adhesive remaining on the coupon, as well as redemption means and promotion indicia printed on opposite faces of the coupon.
Cents off coupons and other types of discount coupons are a familiar marketing device, routinely used to promote the sale of various products and services by offering discounts or other types of effective price reduction upon presentation of the coupon to the seller. For example, local newspapers print various grocery item coupons, which will be honored by major supermarket chains. Coupons are also published in magazines, and are frequently mailed to households in mass mailings. Typically, the coupons are torn out or cut out with scissors. Whatever the form of distribution, prior art coupon systems are all somewhat disorganized in bulk, and hard for the consumer to keep track of.
Typically, the cashier accepts the coupons as they are presented to her at the check-out line of the retail establishment. The accepted coupons are typically placed in a special drawer, and later sorted and forwarded to the manufacturer for reimbursement. Although cumbersome, retail establishments are accustomed to this procedure.
As disclosed in U.S. Pat. Nos. 5,308,120 and 5,501,491, peel-off coupon redemption cards and tracking systems have been developed wherein small coupons are removably attached to a redemption card. Oftentimes, such redemption cards are sold as fund raising vehicles. Thus, in order to justify the cost of the redemption card, as many detachable coupons as is possible are typically formed on the back of the redemption card so that the total redemption value far exceeds the cost of the card. The holder of the card peels off a coupon at the retail establishment in order to receive the discount. When the coupon is removed, an adhesive layer remains on the back of the coupon so that it can be adhered onto a tracking sheet to assist the retail establishment in determining the total number of coupons received, etc.
However, some retail establishments find it inconvenient to train their cashiers in handling these coupons and the accompanying tracking sheet. Some cashiers, instead of adhering the coupons onto the tracking sheet, place them in the drawer for the regular coupons. Due to the adhesive layer on the removed coupon, the coupon adheres to other coupons or papers within the drawer, creating a mess. Due to the relatively small size of the removable coupons, the coupons are unable to physically support both the necessary promotion indicia as well as an electronic redemption means, such as a bar code or the like. Thus, the cashier must read the fairly small print on the removed coupon and key in the discount, or scan a bar code or the like on the redemption card itself. Having a magnetic strip or bar code on the redemption card separate from the coupons require that the coupons substantially have the same discount for the same retail establishment. Also, it is difficult to control the number of times the discount is given as the redemption card holder could potentially scan the bar code more times than the number of removable coupons provided on the redemption card itself.
Accordingly, there is a continuing need for a peel-off coupon redemption card in which the removed coupons do not have adhesive thereon, and which can be treated in a more traditional fashion. There is also a continuing need for such a redemption card wherein the removed coupon support both the promotion indicia as well as electronic scanning means for providing the discount. The present invention fulfills these needs and provides other related advantages.


A method for generating spontaneously aligned surface wrinkles utilizes control of local moduli-mismatch and osmotic pressure. The method includes modifying the surface of an elastomeric layer to form a superlayer that is stiffer and/or less absorbent than the elastomeric layer. The elastomeric layer is then swollen with a polymerizable monomer, which causes buckling of the superlayer. The monomer is then polymerized, dimensionally stabilizing the surface buckling. The budded surfaces generated by the method are useful in a wide variety of end-use applications, including microlenses, microlens arrays, compound microlenses, diffraction gratings, photonic crystals, smart adhesives, mechanical strain sensors, microfluidic devices, and cell culture surfaces.

Surface buckling, or wrinkling, can be generated in a variety of systems that include: 1) thermally or mechanically stressed metallic, polymeric and silicate thin films supported on elastomeric substrates, 2) dried thin films prepared by sol-gel method, as well as 3) soft gels placed under geometric confinement that are swollen or dried. See, e.g., N. Bowden, S. Brittain, A. G. Evans, J. W. Hutchinson and G. W. Whitesides, Nature, 1998, vol. 393, pages 146-149; W. T. S. Huck, N. Bowden, P. Onck, T. Pardoen, J. W. Hutchinson and G. W. Whitesides, Langmuir, 2000, vol. 16, pages 3497-3501; C. Harrison, C. M. Stafford, W. Zhang and A. Karim, Applied Physics Letters, 2004, vol. 85, pages 4016-4018; C. M. Stafford, C. M. Harrison, K. L. Beers, A. Karim, E. J. Amis, M. R. Vanlandingham, H.-C. Kim, W. Volksen, R. D. Miller and E. E. Simonyi, Nature Materials, 2004, vol. 3, pages 545-550; D. B. H. Chua, H. T. Ng and S. F. Y. Li, Applied Physics Letters, 2000, vol. 76, pages 721-723; N. Bowden, W. T. S. Huck, K. E. Paul and G. W. Whitesides, Applied Physics Letters, 1999, vol. 75, pages 2557-2559; K. Efimenko, M. Rackaitis, E. Manias, A. Vaziri, L. Mahadevan and J. Genzer, Nature Materials, 2005, vol. 4, pages 293-297; S. J. Kwon, J.-H. Park and J. G. Park, Physical Review E, 2005, vol. 71, pages 11601-11604; R. C. Hayward, B. F. Chmelka and E. J. Kramer, Macromolecules, 2005, vol. 38, pages 7768-7783; T. Tanaka, S.-T. Sun, Y. Hirokawa, S. Katayama, J. Kucera, Y. Hirose and T. Amiya, Nature, 1987, vol. 325, pages 796-798; E. S. Matsuo and T. Tanaka, Nature, 1992, vol. 358, pages 482-484. These surface relief structures are interesting for their pattern complexity as well as ease of formation with a dominant periodicity. Although some mechanisms for global-scale alignment of local wrinkling have been demonstrated, there is a need for surface wrinkling methods that allow global-scale wrinkling alignment with applicability to a range of materials and ease of tuning buckling wavelength and persistence lengths.

Surface buckling method and articles formed thereby


The invention is a system for ferrying at least one aircraft by a ferrying aircraft, the at least one aircraft and ferrying aircraft having vehicle management systems. In detail, the invention includes an attachment device for joining a wing tip of the at least one aircraft to one of the wing tips of the ferrying aircraft. A system is included for controlling the at least one aircraft and the ferrying aircraft such that the at least one aircraft flight characteristics are controlled by the ferrying aircraft. The method of ferrying a at least one aircraft by a ferrying aircraft from a first point to a second point includes the steps of: flying the at least one aircraft and ferrying aircraft; while in flight at the first point, joining a wing tip of the at least one aircraft to one of the wing tips of ferrying aircraft; and controlling the flight characteristics of the joined at least one aircraft such that the at least one aircraft and ferrying aircraft become a single aircraft controlled by the ferrying aircraft as the jointed aircraft fly toward the second point.

1. Field of the Invention
The invention relates to the field of aircraft ferrying aircraft and, in particular, to a system wherein a transport aircraft ferries aircraft by attaching the aircraft to be ferried to its wing tip.
2.Description of Related Art
The concept of ferrying aircraft aboard other aircraft is very old in the art. In the 1920s, dirigibles were designed to ferry aircraft attached to the gondola. The advantage of ferrying and aircraft is that it could serve as a scout for the dirigible or provide protection. In the 1940""s small aircraft were suspended under larger bombers. Here the ferried aircraft was typically a fighter, which could be used for protection against hostile aircraft. The problem with such ferrying systems is that the weight of the ferried aircraft limited the payload carrying capacity and/or the range of the ferrying aircraft.
It has long been known that the aerodynamic efficiency of an aircraft can be increased by the incorporation of wing tip devices that prevent or reduce the wing tip vortexes. Thus wing tip fuel tanks installed on the P-80 improved the aerodynamic efficiency to such a degree that tip tanks were xe2x80x9cflown for freexe2x80x9d, in that the increase in aerodynamic efficiency offset the drag and weight penalty. In the early 1950s an attempt was made to ferry small fighter aircraft on the wing tips of a larger aircraft. F-84 fighter aircraft were successfully flown attached to the wing tips of a B-36 bomber. The F-84 aircraft were again almost flown for xe2x80x9cfreexe2x80x9d. However, there were problems attaching the two aircraft together and in-flight stability was difficult to maintain. The pilots of the F-84 aircraft flew xe2x80x9chands offxe2x80x9d once attached to the B-36. Thus only the B-36 flight control effectors such as ailerons, elevators, rudders, etc., were used. After several crashes, the flight test program was terminated in part because of these problems. Additionally, air-to-air refueling became practical.
However, in flight refueling requires the use of dedicated refueling aircraft. With the advent of unmanned aircraft, there is a new need to ferry such aircraft. Most recently, NASA has flown aircraft in close proximity to take advantage of the reduction in drag that such formation flying offers. Both aircraft remain separated, however and their propulsion systems remain the main source of power for flight.
Thus, it is desirable to provide an efficient system to ferry aircraft.
It is further desirable to provide an efficient system to ferry aircraft without significantly compromising the performance of the ferrying aircraft.
It is still further desirable to provide an efficient system to ferry aircraft wherein the ferried aircraft are attached to the wing rips of the ferrying aircraft and stability and aerodynamic loads of all the aircraft is controlled by the ferrying aircraft.
A system for and method of ferrying a least one aircraft by a ferrying aircraft is provided. In one embodiment, the system includes an attachment device for joining a wing tip of the at least one aircraft to one of the wing tips of the ferrying aircraft and a system for controlling the at least one aircraft and the ferrying aircraft, such that the at least one aircraft flight characteristics are controlled by the ferrying aircraft. Preferably, the ferrying aircraft will have an aircraft joined to each wing tip, which will provide improved efficiency. Movement of the aircraft""s effectors controls the flight characteristics of the ferried and ferrying aircraft.
The system for controlling the flight characteristics includes the ferrying aircraft having a first effector commend system, a first vehicle management system is coupled to the first effector system; a signal transmission system is included to transmit signals from the first vehicle management system to the ferried aircraft. The ferried aircraft include: a second vehicle management system; a system to receive transmitted signals from the ferrying aircraft""s vehicle management system; a second effector command system coupled to the ferried aircraft vehicle management system; and a switch mechanism for disconnecting the ferried vehicle management system from its effector command system and coupling the effector command system to the system to receive transmitted signals from the ferrying aircraft.
The first vehicle management system includes: a first control system program for controlling the first effector command system of a ferried aircraft attached to only the right wing of the ferrying aircraft; a second control system program for controlling the first effector command system of a ferried aircraft attached to only the left wing of the ferrying aircraft; a third control system program for simultaneously controlling the first and second effector command systems of ferried aircraft attached to both wings of the ferrying aircraft; and fourth control system program for controlling the ferrying aircraft when no aircraft are attached. In addition sensors mounted in the attachment means on the wing tips sense whether an aircraft is attached and provide a signal to the first vehicle management system. Such that the proper control system program can be selected.
The method includes the steps of: flying the at least one aircraft to be ferried to the ferrying aircraft; joining a wing tip of the at least one aircraft to be ferried to the wing tip of the ferrying aircraft; and controlling the flight characteristics of the joined aircraft such that the ferried aircraft are controlled by the ferrying aircraft.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which the presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention.

Aircraft ferrying system and method thereof


A device for filling containers with free-flowing products under aseptic conditions comprises a conveyor system for intermittently conveying the containers along a conveyor path past appropriate filling stations in separate compartments inside a housing. The conveyor system comprises a guide assembly for guiding at least two carriers which interact with one another in order to position and retain containers, and a pusher mechanism with a chainless drive for displacing the carriers in the guide assembly each time, a container guide, which is arranged beneath the conveyor path of the containers, for supporting the containers, and a blocking device for temporarily blocking the movement of the carrier which is situated at the outlet of the device during operation.

The present invention relates to a device for filling containers with free-flowing products, in particular liquid foodstuffs with a limited shelf life, under aseptic conditions, comprising a housing with an inlet for containers which are to be filled and with an outlet for filled containers, a plurality of separate compartments, which are arranged inside the housing and comprise at least a sterilization compartment with sterilization station and a filling compartment with filling station, and a conveyor system, which is arranged inside the housing, for intermittently conveying the containers, along a conveyor path past the appropriate filling stations in the compartments, adjacent compartments being separated from one another by a partition with at least one passage opening for the containers to pass through.
A device of this nature, which is also known as a linear filler, to distinguish it from rotary filling devices, is known, for example, from EP-A-0 342 690 as a so-called xe2x80x9cfill-and-pack in a non-germ atmosphere machinexe2x80x9d. In this known device, the conveyor system comprises two separate conveyor devices. In a sterilization zone, the containers are conveyed with the aid of carriers, which carriers are fixedly connected to chains arranged on either side of the conveyor path, while in a subsequent filling zone the containers, which rest by means of an upper flanged edge on parallel guides, are moved onwards with the aid of one or more rod mechanisms which comprise a toothed comb element.
In general, the containers have to be filled under aseptic conditions, on account of the risk of the containers or the product with which the containers are to be filled being affected or contaminated, in whatever form, with all the associated risks to the health of the (end) user. Therefore, it is customary to apply a slight superatmospheric pressure in the filling zone, so that it is impossible for any unpurified air to enter the filling zone from the outside or from the sterilization zone. The conveyor system can generally also be used to guide the carriers together with containers past any other processing stations, for example a container-closing station which adjoins the filling station and in which, for example, containers in the form of bottles are provided with a cap.
One of the drawbacks of using chains as a component of a conveyor system which is used in particular in the foodstuffs industry is that they are difficult to clean and sterilize, and consequently inspection services and other licensing authorities view and consider the use of chains in aseptic environments with considerable suspicion and distrust. Inevitable particles worn off the chains as a result of use exacerbate this problem. In addition, chains have the drawback that if one of the chains is no longer functioning correctly, for example if it breaks, the entire machine comes to a standstill in order to allow repair work to be carried out.
Another problem which occurs in conventional filling devices when switching from one type of container to a different type of container is that the aseptic conditions are lost and consequently, after the device has been reset in order to allow the different type of container to be filled, a relatively long preparation time is still required in order to recreate the aseptic conditions.
The object of the invention is to avoid the abovementioned drawbacks and to provide solutions to the above problems.
In the device according to the invention, for this purpose the conveyor system for intermittently conveying the containers from the inlet to the outlet comprises a guide assembly for guiding at least two carriers for carrying one or more containers, at least one cutout for positioning and retaining a container being provided in mutually facing longitudinal edges of adjacent carriers, and a pusher mechanism with a chainless drive for displacing the carriers in the guide assembly each time, a container guide, which is arranged beneath the conveyor path of the containers, for supporting the containers, and a blocking device for temporarily blocking the movement of a carrier which is situated at the outlet during operation.
The filling device according to the invention comprises a pusher mechanism which is driven without chains for intermittently displacing carriers in a guide assembly. A pusher mechanism of this nature can be arranged outside the usual sterilization zone of the filling device, so that during operation only the carriers and the containers to be filled have to be sterilized. The use of separate carriers which are displaced along or in the guide assembly has the further advantage that if one carrier or a container accommodated therein becomes defective, only that one carrier has to be removed and/or replaced. Therefore, the standstill time and the ease of repair are considerably improved. Furthermore, the use of separate carriers offers the advantage that the device is suitable for filling a plurality of types of container, for example containers of a different shape or different volume. When changing over from one type of container to another type of container with a different cross section, it is merely necessary to replace the carriers, resulting in relatively short changeover times. A set of two carriers which are used in the device according to the invention are provided, on the mutually facing longitudinal edges, with at least one cutout. Two opposite cutouts of adjacent carriers interact with one another in such a way that, when the pusher mechanism at the beginning of the conveyor path and the blocking device at the end of the conveyor path have been activated and the carriers are held between them, they clamp a container in place. The blocking device also has the function of preventing a carrier which is situated at the outlet from being pushed out of the guide assembly, so that it will instead be retained. The device according to the invention will usually employ a large number of carriers, of which both longitudinal edges are provided with one cutout, and preferably a plurality of cutouts. The container guide, which extends from the beginning of the conveyor path to its end, ensures that the containers are engaged of at the correct height and that in the unclamped state the containers do not fall onto the ground. The containers may be bottles, made from glass or plastic, cardboard or metal packages, such as packs and cans. The containers themselves are in no way limited to a specific shape or size. The shape of a cutout in a carrier is adapted to the shape of the container to be filled, which may be round, square, rectangular, oval, etc.
It should be noted that EP-A-0 475 827 has per se disclosed a conveyor device for conveying carriers holding a container, which is guided past a plurality of treatment stations, wherein a drive in the form of a connecting-rod mechanism with a roller (systxc3xa8me bielle-galet) is used.
Furthermore, it should be noted that the carriers used in the invention are already known per se from EP-A-286 514, in which carriers which interact with one another, referred to in the said patent as xe2x80x9cdemi-plaquesxe2x80x9d, are pivotably attached to two independent chain systems.
The pusher mechanism with a chainless drive which is used in the device according to the invention may be a servo-controlled motor with an eccentric arm which executes a reciprocating movement each time. It is advantageous to use a piston/cylinder assembly which is arranged at the beginning of the conveyor path of the conveyor system at the inlet of the device and the piston of which can move to and fro in the machine direction. The piston/cylinder assembly may be of either the pneumatic or the hydraulic type. Preferably, the stroke length of the piston/cylinder assembly is equal to the dimension of the carrier, as seen in the longitudinal direction of the conveyor path (i.e. the machine direction). In this way, during operation a carrier is in each case advanced by one position from the beginning of the conveyor path, past the sterilization station and then the filling station, towards the end of the conveyor path of the conveyor assembly. At each intermediate stopped position, additional treatments or operations can be carried out, as will be explained in more detail below.
The blocking device advantageously comprises two piston/cylinder assemblies which are arranged on either side of the conveyor path. This arrangement leaves sufficient space at the end of the conveyor path to allow the containers and/or carriers to be removed.
The carriers are advantageously made from plastics material, such as polypropylene, which allows simple, repeated sterilization. Stainless steel is another suitable carrier material. In the aseptic zone, which covers at least part of the sterilization zone and the entire filling zone, the carriers advantageously form part of the physical boundary of this zone. In other words, in the relevant section of the conveyor path, the carriers, together with the guides, form a separation between the aseptic zone and the surrounding environment where aseptic conditions do not prevail. Since the carriers and containers are constantly resterilized in the sterilization compartment, the sterility of the aseptic zone is maintained. This also applies when changing over to a different type of container and/or a different product.
To ensure that the carriers can be displaced in a regular and smooth manner without shocks or other irregularities along or in the guides, preferably at least those parts of the guides which come into contact with the carriers are provided with a wear-resistant slip layer, for example a layer of Teflon.
A slip layer of this nature may also be provided on the container guide, the height of which is preferably adjustable. Thus, in the device according to the invention the height can be adapted to the type of containers to be filled.
Advantageously, the device is provided, at a position between the end where the pusher mechanism is arranged and the sterilization station, with a carrier-introduction station for introducing a carrier into the conveyor system and receiving the one or more containers in a carrier. This carrier-introduction station is preferably arranged outside the compartment where the sterilization station is located. Examples of a suitable carrier-introduction station include a lifting platform which is arranged beneath the conveyor path, a sliding mechanism which is arranged next to the conveyor path, for introducing carriers from the side, or a dropping device which is arranged above the conveyor path, for in each case dropping a carrier onto the guides of the conveyor system.
The carriers and containers which are to be filled are sterilized using conventional sterilization means, for example a disinfectant, such as hydrogen peroxide, hot air, UV radiation or a combination of two or more of these techniques.
Adjoining the filling station there will often be a container-closing station where the containers are closed as a function of the type of container and the material from which it is made, for example with a cap or by means of hot-welding of an aluminium closure foil, or another suitable closure method, if appropriate followed by a reclosable cover or cap. These operations are also carried out under aseptic conditions, and consequently the container-closing station will also be accommodated in the aseptic zone.
At the end of the conveyor path, outside the aseptic zone, there will usually be a carrier-removal station where the containers are removed from the carriers and, for example, transferred to other carriers, for example crates or boxes, and then the carriers are removed from the conveyor path and returned to the carrier-introduction station. For this return of the carriers, it is preferable to provide a second conveyor system which is arranged beneath the first conveyor system. This second conveyor system may be suitable for moving the carriers one by one, but also for moving a plurality of carriers stacked on top of one another.


According to one exemplary embodiment, an expandable ring is provided including a continuous ring member having no splits or breaks. According to one exemplary embodiment, the expandable ring is a compliant mechanism configured to expand and contract due to a relative movement of related sections of the continuous ring member.

In the treatment of various spinal conditions, including the treatment of fractures, tumors and degenerative conditions, it is necessary to secure and stabilize the anterior column of the spine following removal of a vertebral body or part. Various devices for internal fixation of bone segments in the human or animal body are known in the art.
Following such removal made using a thoracotomy, thoracoabdominal or retroperitoneal approach, the normal anatomy is reconstructed using tricortical iliac crest or fibular strut grafts. Not only are removals performed on the thoracic spine, as is the case for the above procedures, but also the cervical spine. Once bone matter is removed, it is then common procedure to secure and stabilize the graft, desirably in such a manner as to permit rapid mobilization of the patient. Such objectives can be accomplished by a bone plate. However, to accomplish this service in the optimum manner, it is necessary that the plate be reasonably congruent with the bone to which it is applied, that it have as low a profile as possible, that it be firmly secured to the spinal column so that it is not torn out when the patient places weight and stress upon it and that it be capable of placement and fixation in a manner that is convenient for the surgeon.
In this context it is necessary to secure the plate to the spinal body and also, in some cases, to the graft. Conventionally, such attachment would be by the use of screws driven through screw holes in the plate into the bone. However, when stabilizing the position of cervical vertebrae, the plate is designed to lie near and posterior to the esophagus of the patient. Due to its relative location to the esophagus and other connective tissue, if the screw securing the plate to the cervical spine backs out, the screw could irritate or even pierce the esophagus, resulting in pain, infection, and/or possible death of the patient. Consequently, anti-back out mechanisms are desired in the orthopedic plate industry.

This patent is subject to a terminal disclaimer.

Compliant cervical screw locking mechanism


The present invention teaches a system for the automated palpation testing of a patient, including the use of a robotic device with a actuating element thereto. The system is useful for testing patients at risk of nerve degradation, such as diabetic sufferers. The system includes a controller for programming the robotic device to administer the test in a particular pattern, and a storage medium for storing the results of the test. The system allows a more accurate determination of the stage of nerve degradation, as well as being more standardized because of the inclusion of automation technology.

Examination of the feet of diabetic patients is often the most neglected aspect of clinical diabetic examination. Ulcers secondary to neuropathy tend to occur on the plantar aspect of the feet under areas of high plantar pressure, while ischemeic ulcers tend to affect the toes and dorsum of the foot. Due to loss of nerve and sensation from neuropathy, stresses from loading exerted on the soft tissues between the hard bones and callus at the planter of the foot tend to wear out the soft tissues leading to ulcers and possible amputation of the foot of portion thereof under serious situation. Therefore, it is important to detect neuropathy before developing into serious ulcers for diabetic patients. A wide variety of techniques are used to assess neurological integrity on diabetic sufferer's feet, including tuning fork and monofilament testing.
Filament testing has long been used as a sensitive monitoring means for evaluating peripheral nerve function of a patient. In the 1800's, the focus of peripheral nerve testing of the hands was carried out in a study of normal physiology using horse hairs as the filaments. In the late 1950's, it was determined that a broader range of filament forces were needed than those available with horse hairs to refine the filament method for peripheral nerve testing. Thus J. Semmes and S. Weinstein developed and published results of testing cutaneous sensory perception using nylon monofilament rods of varied diameters and consistent tips, and further published methods of using those rods to apply force. The nylon filaments were affixed to plastic rods (or "filaments handles") which were cut to the approximate length of a pencil for ease of handling and comfortable fit in the therapist's hand. The devices were known as "aesthimometers". The advantage of these new filaments, when affixed to a plastic rod, was their ease of handling and their ability to create a range of testing values by varying the diameter of the filament affixed to a rod. These monofilaments attached to plastic rods with glue came to be known as "Semmes-Weinstein monofilaments" and became the standard means for repeatable testing and measurement of the threshold of cutaneous sensory perception. In addition to nylon, monofilaments have also been made of materials such as steel and nitinol.
In the conventional approach of testing diabetic foot, the clinician would contact the foot with different force levels in generally 7 to 10 different places with the monofilaments. The testing is to determine whether the patient has sense in that area. Examination using monofilaments, and testing pinprick sensation in general, has disadvantages as the current methods of testing are prone to inter-investigation variation due to the pressure applied. For example, whereas a general force of 10 grams should be applied to gauge sensation, which can be determined when the monofilament bends, the extent of the bending of the monofilament can vary from clinic to clinic and clinician to clinician. Further, current testing with monofilaments is rather spatial in terms of the points contacted on the foot. Due to human limitations, the clinician often does not have the ability to accurately test more points on the foot. Still more, the clinician likely cannot track a specific nerve on the foot in order to track its degradation. Further, there is no comparison of test results with previous test results conducted at the similar if not at the same location to determine degradation of the nervous system. Also, it is not accurate to determine the palpation force based on the bending of the filament, which at best is qualitative.
It is an object of the present system to overcome the disadvantages and problems in the prior art.
The following description of certain exemplary embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Throughout this description, the term "test" is used interchangeably with the term "diagnostic" in referring to a method of determining the nature of the case of a disease.
The term "automated" refers to the use of electronic systems to replace human operators, however human operators continue to have control over the electronic systems, such as during programming and monitoring.
The term "palpation" refers to the application of an object with pressure to the mammalian body portion for the purpose of diagnoses.
Now, to FIGS. 1-5,
FIG. 1 is an example of the spatial nerve of prior art method of testing diabetic foot. As shown, the prior art generally focused on four points 101 on a patient's foot 103. The drawbacks of such a spatial arrangement include an inability for early detection of nerve degradation, as well as missing particular contact points on the foot.
FIG. 2 is a system 200 of the present invention, comprising a robotic device 205 upon which actuating elements 207 are positioned thereon, a resting portion 209 to accommodate the foot 203 of a patient 201, a controller 211, user interface devices 213, a feedback device 215, and a spatial array 206. The system 200 is useful for performing automated foot testing.
The system 200 is suitable for use by patients 201 afflicted with trauma affecting continuity of nerve fibers such as leprosy, stroke, diabetes, multiple sclerosis, diseases resulting in diminished nerve conductivity, and nerve compression syndromes. In one embodiment, the system 200 is for use by patients 201 in risk of or afflicted with diabetes. In particular, the patients 201 are at risk of developing diabetic neuropathy which metastasizes itself in the foot 203 of the patient 201. The system 200 includes a rest portion 209 by which the patient 201 may relax his foot 203 during testing.
The system 200 also includes a robotic device 205 for providing the means by which the test is administered. The robotic device 205 can be a Cartesian robot system or a Gantry-type robotic system, whereby it operates in the planes of x, y, and/or z. The robotic device 205 can have at least 2 degrees of freedom, including vertical movement, extension and retraction, and rotation traverse in the Y direction. The robotic device 205 can contain one or more sensors 220, including but not limited to some positioning sensors, for example laser distance movement, visual/camera sensors, to position the foot resting on the foot rest, and some force sensors, for example pressure transducers, to sense how much force is being applied by the actuator element. The sensors allow the robotic device 205 to calculate its position in space relative to the patients foot 203, and monitor changing conditions during testing.
The robotic device 205 also contains equipment necessary for operation, including but not limited to gears, servos, power supply, antennas, lubricant, tracks, belts, etc. and electronic devices including fuses, resistors, switches, capacitors, actuator buttons, and the like. The robotic device 205 may further contain communication means 210 allowing it to be programmed and/or controlled by direct link or remote link. Such communication means 210 can include antennas, cables, optical link, radio link, satellite devices, connectors, and the like. The robotic device 205 may also contain on-board operation means, such as on-off switches, display, controller buttons, and safety switches. The robotic device 205 may also contain memory storage, such as RAM or ROM. In one embodiment, the robotic device 205 is a SCARA (Selective Compliant Articulated Robot Arm) capable of operating in planes x, y, and z. In another embodiment, the robotic device 205 is capable of operating in a x plane and a y plane.
Mounted onto the robotic device 205 are actuating elements 207, such as motors, solenoids, or electric pulse devices possessing monofilament, pins or needles. The pins, needles, or monofilaments can range from slightly shift to shift states. The pin, monofilament, or needle is preferable disposable being used a few times and discarded. The elements 207 are attached such that they move in the x, y, and/or z plane in concert with the robotic device 205. The elements 207 are, in essence, electromechanical devices that contain a coil would around a movable core. As will be discusses later, the actuating elements 207 produce a magnetic flux which induces the core to move. As will also be discussed later, the core of the elements 207 can be a pin, monofilament, or needle, said core which contacts the foot of the patient. In one embodiment, the core is a needle. The elements 207 extend from the robotic device in a staggered manner, i.e., the elements 207 positioned on the robotic devices 205 Y-axis is extended more than the elements 207 positioned on the X-axis, or vice versa. In one embodiment, there is at least one element 207 on the robotic devices 205 Y-axis and one element 207 on the X-axis. In another embodiment, multiple elements may be present on the X-Y plane.
The robotic device 205, and correspondingly the actuating elements 207, may be connected to and controlled by a controller 211. As previously mentioned, connection may be through a connection means 210. The controller 211 can contain processors, which include microprocessor, temporary registers, accumulators, holding registers, and logic units, memory, including ROM, RAM, and removable memory, and User Interface Devices (UIDs) 213, including displays, keyboards, mouse', and printers. As a general note, the processor is capable of providing output or control signals in response to input signals from a UID, e.g., displayed on the display 213 which may be a touch sensitive screen, executing instruction stored in the memory, and the like. UIDs 213 allow the clinician to interact with the controller 211.
The memory of the controller 211 may have stored thereon routines, subroutines, and data suitable for programming and controlling the robotic device 205. Algorithms may also be stored on the memory, such as analyzation algorithms, data organization algorithms, and the like. As will be further discussed, the routines also include algorithmic functions that instruct the robotic device 205 to perform in accordance with the instant invention. Subroutines allow the overlying algorithmic functions to be modified, such as by setting a particular pattern for the robotic device 205 to follow during operation. Data can include patient health records, historical data, statistical data, and the like. The data should be able to be drawn upon, i.e., analyzed by the clinician when diagnosing the patient.
The patient can also engage the controller 211, usually by delivering feedback to the controller 211 via a feedback device 215. The feedback device 215 is actuated by the patient in response to sensing stimulation during testing. Suitable feedback devices 215 include actuator device with a button, switching device, auditory-sensing device, and the like. The feedback device 215 can communicate with the controller 211 via direct cable link or wireless communication means such as radio frequency (RF), wifi, satellite, or technologies such as Bluetooth™.
Examples of suitable controllers 211 include personal computers, laptops, PDAs, and control panels. The UIDs 213 may be implemented in the controller 211 or separated therefrom.
The system 200 also includes an array 206. The array 206 is preferably abstract, as opposed to a physical manifestation placed on the foot. The array 206 sets forth the contact points on the foot to be tested by the monofilament solenoid 207. The array 206 may be an unlimited number of contact points, however generally ranging from 4 to 10000 points, preferably from 10 to 1000, more preferably 20 to 500 points. However, the actually number of points may vary depending on the size of the patient's foot, i.e., the larger the foot, the more number of points. In comparison to the prior art, the array of the present invention is much less spatial, allowing for the tracking of nerves and nerve degradation. As will be discussed later, the array 206 can be created by algorithms stored on the controller 211. The element 207 then administers the diagnostic in accordance with the created array 206. The array 206 may also be created using data obtained from the sensing devices of the robotic device 205.
FIG. 3 is an actuating element 300 used in accordance with the present invention, comprising a case 301 with a core 303. The actuating element can be a motor associated with a mechanical system, solenoid, or an electric pulse device. In the case where the core 300 is a solenoid, the solenoid can be a tubular solenoid, linear solenoid, push-pull solenoid, push solenoid, rotary solenoid, plunger-type solenoid, or soft shift solenoid. In one embodiment, the element is a push-type solenoid. The element 300 may operate under DC power or AC power. In the event the element 300 operates under AC power, a rectifier can be connected therewith for smooth performance. In one embodiment, the core 303 is a needle. In one embodiment, the actuating element 300 is an electromechanical actuator where by the force can be controlled during palpation, in such an embodiment, palpation is performed with a force/pressure transducer, whereby the palpation is controlled by the measured force so that one contact point may have 10 gm (gram-force) of pressure applied and another contact point may have 20 gm of pressure applied. In the case of an electromechanical actuator, one contact point may have several different pressures applied, for example 10 gm, 20 gm, 25 gm, or 30 gm applied in progression until the patient feels sensation.
The case 301 can include a coil, flux path, bore hole (for allowing movement of the core 303), and stop. The case 301 may be sized to allow proper fitting on the robotic device, as previously discussed.
The core 303 is positioned within the case 301. The core 303 can be a strand of material, such strand of material being of a thickness to allow deliverance of a desired force to the foot of the patient before failure of the strand. The core 303 can be designed to deliver a force in the range of from about 2 gm to 40 gm. The diameter size can be dependent on the force as, if it is desired to deliver a particular force, the diameter size should increase to deliver the desired force. This will ensure the desired force is administered in full to the patient's foot before failure of the core, i.e., the core bends before the full force is administered.
The core 303 can be made of a material suitable for use in the solenoid following powering the solenoid (such powering creating an electromagnetic field). Suitable materials include metal-metallic alloys made of from about 80% transition metals selected from the group consisting of Fe, Co, or Ni, and a metallic component selected from B, C, Si, P, or Al. Examples of materials include FeOFe2O3, NiOFe2O3, CuOFe2O3, MgOFe2O3, MnBi, MnSb, MnOFe2O3, Y3Fe2O12, CrO2, MnAs, Gd, Dy, and EuO.
In operation, the core 303 is positioned within the case 301 to create the actuating element 300. When the element 300 is energized, the core 303 will be extended. The element 300 should be energized to the extent that the core 303 will provide a certain force to a contact point on the patient's foot. After the full desired force has been administered, the power to the element 300 will be reduced or decreased, as in through the use of an adjustable power means such as an adjustable resistor, thus withdrawing the core 303 back into the bore hole. Concomitant with the application of full force, the patient will provide feedback to the controller as to whether or not he felt contact from the element 300. When a needle is used as the core, it is not required that the needle bend upon compression.
The core 303 can be removed and replaced with cores of different materials and strengths, allowing for higher or lower forces.
FIG. 4 is an example of an operation algorithm 400 that may be used to control the robotic device and hence the application of the actuating elements of the present invention. The algorithm 400 may be stored on the memory of the controller. Through the programming and control of the robotic device, contact from the solenoids can be made in specific locations on the patient's foot, each contact adhering to an array designed through the controller. This algorithm 400 thus allows for the automated foot testing in a detailed manner. The algorithm 400 can be modified from this example without deviating from the general purpose, which is the automation of foot testing in a palpation patterned method.
The algorithm 400 may first be started 401 by logging onto the controller or turning on the controller. The algorithm 400 can first determine whether the patient is new 403 by requesting this information from the clinician. In the event the patient is new, i.e., first time having the test administered in that hospital or clinic, a new record can be created 405. Creating a new record 405 can consist of asking general patient questions, such as name, age, sex, race, history of health, and more specific questions to the current state of the patient's foot, including but not limited to current foot ulcers, claw toe uniformity, foot shape, elevated skin temperature, ankle dorsiflexion, toenail health, callous build-up, ankle muscle weakness, pedal pulse, and shoe shape. In the event the patient is not new, the patient's record can be located 407 on the memory of the controller on a removable memory source.
Following, the creation 405 or location 407 of a patient's record, the positioning of the robotic device 409 for performing the diagnostic may be performed. Positioning the robotic device 409 can include the steps of changing core of the actuating element readjustment of the actuating element on the robotic device, moving the robotic device, placing the patient's foot on the foot rest, positioning the monofilament actuating element directly in front of the patient's foot, and the like. As different patient's feet are of a different size, positioning can include the robotic device moving within the x, y, and/or z planes to ensure it is at an appropriate height and distance to administer the test. Determining the appropriate height and distance involves being at a height and distance where the core can exert full force at full extension upon a contact point on the patient's foot, and at the same time ensuring that the actuating element is not so close that it punctures or wounds the patient's foot. Further, the puncture point should avoid ulcers, calluses, and scars. As discussed earlier, the robotic device can contain sensors. The sensors can be used to assist in appropriately positioning the robotic device 409, for example a laser sensor can allow the robotic device to determine its distance from the patient's foot, the size of the patient's foot, etc. The information from the sensors may be passed to the controller for further uses.
Following positioning the robotic device 409, a palpation pattern may then be programmed 411 into the controller. The palpation pattern will be used to control the movement of the robotic device, and hence the actuating element, during the diagnostic administration. The palpation pattern will be designed in the X-Y plane. In a preferred embodiment, the palpation pattern will consist of two contact points or more to be tested in succession, without intervention from the clinician. Thus, the diagnostic will operate in an automated manner. The palpation pattern is preferably less spatial, in comparison to the prior art, wherein at least 7 to 10 points on the patient's foot will be contracted with the core. In a preferred embodiment, a minimum of 15 contact points will be created by the array. The palpation pattern can also include force variables for specific contact points, therefore allowing different contacts on the patient's foot to be tested with different forces. Programming the palpation pattern 411 may occur by the clinician accepting a preprogrammed pattern stored on the controller, the clinician designing a palpation pattern based upon contact points he believes should be tested, or the controller designing a pattern based upon information entered into the controller and/or based upon previous diagnostic performed on the patient, such diagnostic results being stored on the controller. The palpation pattern may also be programmed to allow two or more contact points to be tested simultaneously.
During testing the patient can provide feedback 419 to the controller and/or clinician as to the sensations felt during the diagnostic. As discussed previously, feedback 419 can occur via feedback devices such as actuator buttons, auditory feedback, visual feedback including hand signs, and the like. If, following contact with the core, feedback is not received, this lack of response will be recorded 417. If feedback is received, this response is recorded 419. The feedback is delivered to the controller and stored on the memory of the controller.
The palpation pattern will continue 421 to run until its termination, i.e., the pattern has been gone through in its entirety. Of course, the pattern may be ceased prior to it completion by the clinician or controller if desired or an emergency presents itself.
The feedback received can then be stored on the memory of the controller 423 for association with the palpation pattern and with the patient's record. The feedback may also be stored on a removable memory, such as flashdisk, to allow the patient to transport the data to another clinic. The feedback may also be fed into analyzing algorithms 425 to allow comparison the data to the patient's previous diagnostics and against historical medical data. The feedback may also be printed in hardcopy, allowing the clinician to discuss results of the diagnostic with the patient.
FIG. 5 is a method of automated palpation testing performed in accordance with the present invention, including the steps of programming a palpation pattern on a controller 501, performing palpation of a patient's distal portion, such as a hand or foot, 503, having the user provide feedback to the controller 505, and storing the feedback on the controller for future use 507.
As stated previously, programming a palpation pattern consists of directing the future movements of the robotic device, and hence the attached actuating element, in an X-Y plane. Programming can be performed by the clinician, interacting with the controller through the UIDs, or the controller designing a palpation pattern that can be based upon previous test results. In an example, the clinician can interact with the controller by using a joystick to pinpoint contact points on a graphical picture of the patient's foot. Programming can include multi-variables, including using multiple forces applied during the tests, using two or more cores to contact the foot at the same time, setting a high number of contact points on the array which would allow the tracking and monitoring of specific nerves, using a combination of x and y coordinates to vary the contact points, and the like.
Performing palpation on a patient's distal portion 503 is performed in an automated manner, i.e., points on the patient's foot are contact one after the other without input or direction from the clinician. Through the various sensors, the controller will ensure the robotic device is at a sufficient distance to effectuate the proper force while not harming the patient's distal portion.
Concomitant with performance of the palpation test 503, the patient provides feedback to the controller 505. The feedback is used to gauge whether sensation was felt by the patient following contact at a specific point. The feedback can be delivered through a feedback device to the controller. Feedback not only determines whether there is sensation in a specific location, but also the progression of the degradation of a particular nerve. The feedback can be stored 507 on the controller and associated with the patient's record. The feedback can also be accessed by the controller for incorporation into future palpation patterns. Further, the feedback can be analyzed and used for discussion with the patient.
Having described embodiments of the present system with reference to the accompanying drawings, it is to be understood that the present system is not limited to the precise embodiments, and that various changes and modifications may be effected therein by one having ordinary skill in the art without departing from the scope or spirit as defined in the appended claims.
In interpreting the appended claims, it should be understood that:
a) the word "comprising" does not exclude the presence of other elements or acts than those listed in the given claim;
b) the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements;
c) any reference signs in the claims do not limit their scope;
d) any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise; and
e) no specific sequence of acts or steps is intended to be required unless specifically indicated.

Automated testing for palpating diabetic foot patient


Described is an NCO-group-containing polyurethane prepolymer madefrom polyisocanyates and polyols derived from natural oils. The invention is characterized in that the polyol is obtained by transesterification in the presence of basic lithium compounds. Together with a tertiary amine used to accelerate the moisture curing, the storage stability is thus increased considerably. Up to 4.0 mmol of the lithium compound is used per kilogram of polyol, and 0.1 to 2.0% by wt. of the amine, relative to the total weight of the composition, is used as the accelerator. The polyurethane prepolymer is suitable not only for the production of adhesives but also for the production of foamed materials, in particular those dispensed from throw-away pressure vessels.

This invention relates to a moisture-curing polyurethane prepolymer of oleochemical polyols and polyisocyanates. The invention also relates to the use of this prepolymer in moisture-curing adhesives and foams, more particularly in foams produced from non-reusable pressurized containers using blowing gases liquefied under pressure.
Polyurethane prepolymers of the type in question are known. Thus, in EP 125 579, the oleochemical polyols are obtained from epoxidized triglycerides by reaction with low molecular weight monoalcohols, for example by reaction of epoxidized soybean oil with methanol or ethanol. This ring-opening reaction is accelerated by acidic catalysts which, on completion of the reaction, are neutralized with a basic substance, preferably with an amine. Together with polyisocyanates, these oleochemical polyols form NCO prepolymers with a considerable, but not always adequate storage stability when known tertiary amines are added as accelerators for the reaction of the NCO groups with water.
Corresponding polyurethane prepolymers are described in DE 36 26 223. The polyols used in this document are preferably ring opening products of epoxidized oils with monoalcohols. In this case, however, the epoxide groups are completely reacted. In addition, the triglyceride obtained, which contains secondary OH groups and OR groups, is additionally reacted with excess monoalcohol. A mixture of partial glycerides with unreacted triglyceride is formed in this transesterification reaction. These polyols are also produced in the presence of acid catalysts. Finally, the catalyst is again neutralized with an amine. These oleochemical polyols also form polyurethane prepolymers with inadequate stability in storage, particularly when the usual catalysts are present in relatively high concentrations for the moisture curing process.
Polyether polyols obtained by addition of alkylene oxides to low molecular weight diols or triols in the presence of alkaline compounds also form moisture-curing polyurethane prepolymers with limited stability in storage after reaction with polyisocyanates. This applies, for example, to polyols of propylene oxide and/or ethylene oxide and glycerol or trimethylol propane in the presence of NaOH, KOH, MeONa and MeOK in concentrations of more than 10 ppm metal content. Accordingly, to obtain satisfactory storage stability with polyols such as these, the alkali metal content of the polyols is reduced by additional purification measures to concentrations of about 5 ppm Na or K.
Accordingly, there is a need for polyurethane polymers having improved stability in storage for otherwise the same production and performance properties.
The solution provided by the invention is defined in the claims and consists essentially in the use of basic lithium compounds in the production of polyols, more particularly oleochemical polyester polyols.
Accordingly, the polyurethane prepolymer containing NCO groups according to the invention of oleochemical polyols and polyisocyanates is characterized in that it contains up to 14 ppm of lithium and 0.1 to 2.0% by weight of a tertiary amine to accelerate the moisture curing process and is free from Na, K and other amines, particularly salts thereof with strong acids.
N-substituted morpholines above all are suitable for accelerating the reaction of water with NCO groups. Specific examples include 2,2xe2x80x2-dimorpholinodiethyl ether, N-ethyl morpholine, 2,2-bis-(dimethylaminodiethyl)-ether or mixtures of the compounds mentioned. 2,2xe2x80x2-dimorpholinodiethyl ether (DMDEE) is preferably used. These catalysts are particularly suitable because they catalyze above all the curing reaction and, to a lesser extent, the polymerization of the NCO groups (trimerization) or the urethanization reaction. The catalysts are used in a concentration of 0.1 to 2.0% by weight, preferably in a concentration of 0.2 to 1.2% by weight and more preferably in a concentration of 0.5 to 1.0% by weight, based on the prepolymer as a whole. They are generally added to the polyol or to the polyisocyanate before the prepolymerization.
The lithium is used as a basic lithium compound. Basic lithium compounds in the context of the invention are understood to be the hydroxides and alcoholates. However, compounds, such as lithium acetate, lithium oxides and Li metal, may also be used. They are employed in a concentration of 0.1 to 4.0 and preferably 0.5 to 2.0 mmole/kg polyol. This corresponds to a concentration of 0.35 to 14 and preferably 1.75 to 7.0 ppm of lithium in the polyurethane prepolymer. The lithium compound may be added to the reaction mixture as a basic transesterification catalyst either before or during the transesterification reaction. However, where the transesterification is acid-catalyzed, the acid may be neutralized with the lithium compound.
The oleochemical polyols preferably used are polyols containing ester groups which are derived from natural fats and oils. Accordingly, they contain structural elements of fatty acids and fatty alcohols. Starting materials for the oleochemical polyols of the polyurethane prepolymers according to the invention are fats and/or oils of vegetable and/or animal origin with preferably unsaturated fatty acid residues. Specific examples are castor oil, rapeseed oil and soybean oil. However, beef tallow, palm oil, peanut oil, sunflower oil and fish oil may also be used. These starting fats are preferably epoxidized and transesterified. Of the epoxidized triglycerides, epoxidized soybean oil is preferably used. The epoxidation and the reaction with alcohols or carboxylic acids is known (see, for example, EP 125 579 and DE 36 26 223). The polyols formed contain ether groups besides the ester groups.
To produce the polyester polyols according to the invention, polyhydric alcohols with a functionality of 2 to 4 are required in addition to the fats and oils. They have a molecular weight below 400. Suitable polyhydric alcohols are, for example, glycol, glycerol, pentaerythritol and trimethylol propane. Besides these polyhydric alcohols, dicarboxylic acids may also be used in small amounts. Specific examples are adipic acid, phthalic acid, isophthalic acid, terephthalic acid, glutaric acid, succinic acid, azelaic acid, dimer fatty acid and mixtures thereof.
The esterification is carried out under conditions known per se.
After the transesterification, the oleochemical polyols to be used in accordance with the invention have an OH value of 100 to 400 and preferably in the range from 150 to 350.
Besides these oleochemical polyols, the polyisocyanates are the second important structural element for the polyurethane prepolymers according to the invention.
Particularly suitable isocyanates are aromatic polyisocyanates based on MDI (methylene-bis-diphenyl isocyanate or diphenylmethane-4,4xe2x80x2-diisocyanate). Mixtures of MDI with relatively high molecular weight homologs having an average isocyanate functionality of 2.3 to 2.8 are particularly suitable. Other aromatic isocyanates include NDI and TDI. Cycloaliphatic isocyanates, such as IPDI, H12-MDI, and aliphatic diisocyanates, such as tetramethylene diisocyanate and hexamethylene diisocyanate, are also suitable.
The oleochemical polyol and the polyisocyanate are used in a quantity ratio which corresponds to a molar ratio of OH to isocyanate groups of 1:3 to 1:11 and, more particularly, 1:4 to 1:6.
The reaction between the oleochemical polyol and the polyisocyanate is normally carried out at a temperature of 0 to 100xc2x0 C. and preferably at a temperature of 15 to 50xc2x0 C. Catalysts for the reaction of the isocyanate groups with the OH groups are generally not necessary. However, catalysts may be added in small quantities to control the reaction, accelerating the reaction of the isocyanate group with the OH group, but not the trimerization thereof. Specific examples are dimorpholinodiethyl ether, bis-(dimethyl-aminoethyl)-ether, Dabco X-DM (Air Products) and N-ethyl morpholine. However, other catalysts may also be used providing they do not trimerize the isocyanate groups in storage, for example N-substituted morpholines and mixtures thereof with propylene oxide adducts of triethanolamine and the known metal catalysts, particularly tin.
The polyurethane prepolymer has an NCO functionality of 2 to 5 and more particularly 2.5 to 4.2, and an NCO content of 8 to 30% by weight and, more particularly, 10 to 23% by weight, based on the prepolymer, and a viscosity of 5 to 200 and, more particularly, 10 to 100 Pas at 25xc2x0 C. (as measured in accordance with DIN 53015).
To produce polyurethane foams, at least one amine catalyst for the reaction of the isocyanate group with the OH groups (including water), at least one blowing agent and at least one foam stabilizer are required in addition to the polyurethane prepolymer. In addition, other additives may be incorporated, including for example solvents, flameproofing agents, plasticizers, cell regulators, emulsifiers, fungicides, fillers, pigments and antiagers. The composition is a solution or emulsion.
1,1,1,2-Tetrafluoroethane, 1,1-difluoroethane and dimethyl ether is preferably used as the blowing agent. However, carbon dioxide, dinitrogen oxide, n-propane, n-butane and isobutane may also be used. Preferred blowing agents and solvents are chlorine-free fluorocarbons with boiling points of xe2x88x9240 to +60xc2x0 C., propane/butane mixtures and dimethyl ether or mixtures thereof.
The foam-forming composition additionally contains stabilizers. xe2x80x9cStabilizersxe2x80x9d in the context of the present invention are understood to be on the one hand stabilizers which stabilize the viscosity of the composition during production, storage and application. Suitable stabilizers of this type are, for example, monofunctional carboxylic acid chlorides, monofunctional highly reactive isocyanates and non-corrosive inorganic acids. Examples include benzoyl chloride, toluene sulfonyl isocyanate, phosphoric acid or phosphorous acid.
On the other hand, stabilizers in the context of the present invention are also antioxidants, UV stabilizers or hydrolysis stabilizers. The choice of these stabilizers is determined on the one hand by the principal components of the composition and, on the other hand, by the application conditions and by the loads which the foam plastic is expected to withstand. If the main chain of the polyurethane prepolymer is made up of polyether units, antioxidantsxe2x80x94optionally in combination with UV stabilizersxe2x80x94are mainly necessary. Examples of suitable antioxidants are the commercially available sterically hindered phenols and/or thioethers and/or substituted benzotriazoles and sterically hindered amines of the HALS (hindered amine light stabilizer) type.
If the main chain of the polyurethane prepolymer consists mainly of polyester units, hydrolysis stabilizers, for example of the carbodiimide type, are preferably used.
Preferred foam stabilizers are siloxane/oxyalkylene copolymers, for example Tegostab B 8404 (Goldschmidt), Dabco DC-190 or Dabco DC-193 (Air Products).
Quantitatively, the foam-forming composition preferably has the following composition:
50 to 90 and preferably 60 to 85% by weight of isocyanate prepolymers,
0.1 to 2.0 and preferably 0.2 to 1.2 of catalysts,
5 to 35 and preferably 10 to 25 of blowing agents and
0.1 to 5.0 and preferably 0.5 to 3.0 of foam stabilizer.
Of the optional additives, the flameproofing agent may be added in a quantity of 5 to 50 and preferably 10 to 30. The other optional additives may be added in a quantity of 0.1 to 3.0 and, more particularly, 0.2 to 1.5. These figures represent percentages by weight, based on the composition as a whole.
The foam-forming compositions enable a one-component foam plastic to be produced from a pressurized container, the foam thus produced curing in the usual way on contact with atmospheric moisture. However, two-component foam plastics may also readily be produced where a polyol is added to the composition in equivalent quantities or slightly less than the equivalent quantity. The polyol used is any of the polyols normally used containing 2 to 6 carbon atoms and 2 or 3 preferably primary OH groups.
The foam plastic thus produced is particularly suitable for insulation, assembly and sealing in the building industry, particularly in situ.
The polyurethane prepolymer according to the invention is also suitable for the production of adhesives. They consist essentially of the polyurethane prepolymer and the amine catalyst. There is no need for blowing agents or foam stabilizers.
The polyurethane prepolymer according to the invention is distinguished by high stability in storage. By stability in storage is meant in particular a stable viscosity at storage temperatures of 20 to 50xc2x0 C. In order to be able to compare the storage stabilities of various systems, the viscosity of the polymers is measured after prepolymerization and after various periods of storage at 20xc2x0 C. (room temperature) and 50xc2x0 C. The viscosity measurement itself is carried out at 25xc2x0 C. with a Brookfield viscosimeter of the RVT type. On account of the different initial viscosities, the percentage increase in the initial viscosity per month of storage (=30 days) rather than the absolute increase in viscosity is used as the characteristic quantity for storage stability. This calculated quantity is referred to as the rise in viscosity. In the case of the described polyurethane prepolymers, it is determined solely in the presence of solvents because the preferred application of such prepolymers is in high-solids systems with solvent contents of 5 to 30%. xe2x80x9cFCKW-113xe2x80x9d is used as the solvent. However, other solvents may also be used providing they contain no NCO-reactive groups, for example dimethoxymethane, methyl acetate, pentane, dimethyl carbonate, etc.
The storage stability of the polyurethane prepolymer is determined not only by the type and production of the oleochemical polyol, but also by other factors, namely the type, reactivity and impurities of the di- or polyisocyanate, the type and concentration of the catalysts added to accelerate the NCO/OH reaction in the polyol/isocyanate addition, the type and concentration of the accelerator added for the NCO/H2O reaction and also by the control of temperature during the prepolymerization. The additions of solvents, flameproofing agents and plasticizers also have an additional, but lesser effect on storage stability.

Polyurethane prepolymer containing NCO groups


A power plant for burning a fuel in a low pressure combustion chamber to produce electrical power. A first compressor supplies compressed air through a first heat exchanger to add heat to the compressed air. The heated compressed air is passed through a first turbine to drive a first electric generator. The first turbine outlet is passed through a second heat exchanger in series with the first heat exchanger to further heat the compressed air. The compressed air is then passed through a second turbine to drive a second electric generator and produce electric power. The outlet from the second turbine is passed through a first combustor to produce the hot gas flow through the second heat exchanger. The outlet from the second heat exchanger is passed through a second combustor before passing through the first heat exchanger. The outlet from the first heat exchanger is passed through a heat recovery steam generator to generate steam to drive another turbine and another generator. An additional compressor and intercooler can be used to supply the compressed air to the first heat exchanger. With this system, one or more fuels can be burned under low pressure and without passing the contaminants from combustion through the turbines.

1. Field of the Invention
The present invention relates to a gas turbine power plant in which two distinct fuels are used to produce steam delivered to the turbines.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Coal has been used as a fuel source in power plants that produce steam, the steam being used to drive a turbine and produce electrical power. The efficiency of a gas turbine engine is related to the temperature of the gas flow into the turbine. Higher gas temperatures result in higher efficiencies. Coal can produce very high temperatures in the resulting gas stream. However, the coal exhaust contains fine particulate matter and corrosive residue that can damage turbines. One theoretical solution to this problem is to use a heat exchanger to transfer heat from the coal gas stream to a gas turbine stream. However, modern metal heat exchangers cannot operate at high enough temperatures to makes this practical.
The use of ceramic heat exchangers has been considered, since ceramic materials can withstand higher temperatures than modern metallic materials. However, ceramic heat exchangers do not have high heat transfer rates (as compared to metal material heat exchangers) to make this practical, or the cost of the ceramic material heat exchangers are very high and therefore prohibitive for use as a cost effective alternative to metal heat exchangers. With the price of petroleum relate fuels rising, there is a continuing need to use coal as a fuel source to drive a gas turbine engine.
The present invention attempts to solve the problem of using a metallic material heat exchanger and a coal fired near atmospheric pressure combustor to produce a gas stream for a gas turbine engine in order to produce electrical power. In the present invention, the combustor is at near atmospheric pressure and therefore can be used to combust any fuel such as coal or biomass that requires low pressure to burn. Also, the present invention delivers no contaminants from the combustion process into the turbine. Also, more than one type of fuel can be burned in the twin combustor arrangement of the present invention.
U.S. Pat. No. 2,401,285 issued to Woodward et al on May 28, 1946 shows a gas turbine system which uses two distinct fuels and a heat exchanger to transfer heat from one of the burners to a gas flow leading into a turbine, but unlike the present invention the Woodward invention does not produce power from the gas flow out of the main furnace. In the Woodward invention, the main furnace is used to provide heat to dry the fuel (garbage with high moisture content) fed to this main furnace.
U.S. Pat. No. 2,691,271 issued to McDevitt on Oct. 12, 1954 shows a waste heat power plant including an air turbine cycle that burns a high moisture content fuel and an oil or gas based fuel is burned in the same boiler to produce a continuous and substantially uniform stream of high temperature gaseous products of combustion which are utilized for the preheating to a high temperature of compressed air subsequently expanded through an air turbine for the generation of electric power, the high temperature exhaust air from the turbine being utilized for the rapid drying and burning of the primary solid fuel and burning of the supplementary fuel.
U.S. Pat. No. 5,704,206 issued to Kaneko et al on Jan. 6, 1998 shows a coal burner combined power plant includes a gas turbine for burning coal in a furnace under the pressure and uses produced gas. A steam turbine is combined with an exhaust gas boiler using exhaust gas from the gas turbine. Another fuel is burned at an inlet of the gas turbine for allowing the temperature at the inlet of the gas turbine to rise. A fuel reformer reforms the other fuel and is located within the furnace. In the Kaneko patent, the non-coal combustion product is not delivered from a turbine into the coal burning combustor, and two heat exchangers are used.
U.S. Pat. No. 6,640,548 issued to Brushwood et al on November 2003 shows a gas turbine (12) capable of combusting a low quality gaseous fuel having a ratio of flammability limits less than 2, or a heat value below 100 BTU/SCF. A high quality fuel is burned simultaneously with the low quality fuel to eliminate instability in the combustion flame. A sensor (46) is used to monitor at least one parameter of the flame indicative of instability. A controller (50) having the sensor signal (48) as input is programmed to control the relative flow rates of the low quality and high quality fuels. When instability is detected, the flow rate of high quality fuel is automatically increased in relation to the flow rate of low quality fuel to restore stability.
U.S. Pat. No. 4,326,382 issued to Baardson on Apr. 27, 1982 shows an indirect gas turbine power plant is provided which includes primary and secondary combustors wherein fuel is burned and heat is conveyed to a turbine working medium which is subsequently passed through the turbine section of a gas turbine. The gas turbine includes both a compressor section and a turbine section. The primary combustor has a first inlet for receiving exhaust air from the turbine section, a second inlet for receiving fuel and an outlet for the discharge of products of combustion. The secondary combustor includes a first inlet for receiving at least a portion of the products of combustion from the primary combustor, a second inlet for receiving a portion of the products of combustion of the secondary combustor, and an outlet for the discharge of the products of combustion of the secondary combustor. An air heat exchanger for conveying heat from the products of combustion to the compressed air is positioned within the secondary combustor. This heat exchanger includes an inlet for receiving compressed air from the compressor section of the gas turbine, and an outlet to direct the compressed, hot air out of the secondary combustor for passage to the turbine section.
U.S. Pat. No. 5,934,065 issued to Bronicki et al on Aug. 10, 1999 shows an apparatus for generating power includes a gas turbine unit having a compressor for compressing ambient air and producing compressed air, a combustion chamber to which the compressed air is supplied, a source of relatively high grade fuel for burning in the combustion chamber and producing combustion gases, and a gas turbine connected to generator and to the compressor for expanding the combustion gases and producing exhaust gases. The apparatus further includes a combustor that burns relatively low grade fuel, and produces combustion products, and an indirect contact heat exchanger responsive to the combustion products for heating the compressed air before the latter is applied to the combustion chamber, and for producing cooled combustion products. In addition, an energy converter is provided having an organic working fluid responsive to the exhaust gases for converting heat in the exhaust gases to electricity. Finally, the apparatus of the invention serves to minimize the consumption of high grade fuel in the presence of changes in the heating value of the low grade fuel.
U.S. Pat. No. 4,896,499 issued to Rice on Jan. 30, 1990 show a compression inter-cooled gas turbine and vapor bottoming combined cycle system with the gas turbine operating at 30 to 65 atmospheres is disclosed. A twin spool hot gas generator incorporates compression inter-cooling at the optimum intercooler pressure ratio to (a) minimize intercooler heat rejection degradation, (b) raise the overall cycle pressure ratio, (c) increase gas generator core mass flow and (d) to increase the gas turbine power output. The gas turbine can operate in either the simple cycle or the reheat cycle mode for optimum combined cycle efficiency.
U.S. Pat. No. 5,647,199 issued to Smith on Jul. 15, 1997 shows a combined-cycle multi-pressure reheat system employs a plurality of power generation units each having a gas turbine, a high-pressure steam turbine, a generator, a compressor and a heat recovery steam generator with a re-heater. In its simplest single-shaft form, high-pressure steam is supplied to the high-pressure steam turbine and exhaust steam there from is supplied to a re-heater of the HRSG. Intermediate-pressure steam from the intermediate section of the HRSG combines with the cold reheat steam for heating in the re-heater section. The hot reheat steam is supplied from each power generation unit to the inlet of an intermediate pressure steam turbine. Low-pressure steam from a low-pressure section of the HRSG is supplied to a header where it combines with exhaust steam from the intermediate-pressure turbine to drive a low-pressure turbine. The intermediate and low-pressure turbines may be coupled to a common generator. The gas turbine may be steam cooled by routing exhaust steam from the high pressure steam turbine to the gas turbine and exhausting spent cooling steam to the intermediate pressure steam turbine.
U.S. Pat. No. 6,269,626 issued to Kim on Aug. 7, 2001 shows a combined cycle cogeneration power plant includes a combustion turbine formed by an inlet for receiving fuel, an inlet for receiving air, a combustor for burning the combustion fuel and the air, and an outlet through which hot gaseous combustion product is released; a regenerative fuel heating system formed by a plurality of heat exchangers for transferring heat to combustion fuel for heating the combustion fuel, and modulating control valves for controlling temperature of the combustion fuel; a heat recovery steam generator (HRSG) connected to the outlet of the combustion turbine for receiving the gaseous combustion product. The HRSG is formed by a plurality of heat exchangers including steam/water drums, each having a surface blow down connection, and evaporators connected to the steam/water drums, a water inlet connected with the heat exchangers of the HRSG, a steam outlet, and a stack for releasing the exhausted gaseous combustion product. A steam turbine is provided, and has a steam inlet for receiving steam from the steam outlet of the HRSG, and an exhaust steam outlet; a condenser is connected to the exhaust steam outlet of the steam turbine for condensing steam to a liquid condensate; at least one pump is provided for supplying the liquid condensate from the condenser to the HRSG; and at least one pump is provided for supplying feed water from at least one drum to the HRSG. A conventional-type power plant with a regenerative fuel heating system is also disclosed.
U.S. Pat. No. 6,050,080 issued to Horner on Apr. 18, 200 shows a system for cooling hot section components of a gas turbine engine. The cooling system includes a plurality of compressors, or compression train, and an intercooler disposed between each adjacent pair of compressors so as to achieve the desired pressure and temperature of the cooling air at reduced shaft power requirements. The first stage of compression may be provided by the booster, or low pressure compressor, of the engine, with the first intercooler receiving all of the air discharging from the booster. After exiting the first intercooler, a first portion of the booster discharge air is routed to the engine high pressure compressor and a second portion is routed to an inlet of the second compressor of the cooling air compression train. The compressed, cooled air exiting the last, downstream one of the compressors is used for cooling at least a first hot section component of the engine.
U.S. Pat. No. 5,313,782 issued to Frutschi et al on May 24, 1994 shows a combined gas/steam power station plant which consists essentially of a fossil-fired gas turbine group and a steam circuit, with an exhaust heat boiler (11) in between, inter-cooling and reheat are provided to maximize the efficiency. The gas turbine group consists of two compressors (1, 2), of two combustion chambers (7, 9) and of two turbines (8, 10). Downstream of the first compressor (1), there is an intercooler (3) and on the cool side of this is placed an evaporator (4) which is in effective connection with the intercooler. The steam quantity formed in the evaporator (4) is introduced into a turbine (6) of the steam circuit, the result of this being a first improvement in efficiency. Downstream of the first turbine (8), there is a second combustion chamber (9) in which the exhaust gases from the first turbine (8) are processed to produce hot gases for the second turbine (10). The large calorific potential still present in the exhaust gases from this second turbine (10) flows through the exhaust heat boiler (11) in which a maximized steam power is produced, the result of which is the second improvement in efficiency.
U.S. Pat. No. 5,664,414 issued to Bronicki et al on September 1997 shows an apparatus for generating power includes a gas turbine unit having a compressor for compressing ambient air and producing compressed air, a combustion chamber to which the compressed air is supplied, a source of relatively high grade fuel for burning in the combustion chamber and producing combustion gases, and a gas turbine connected to generator and to the compressor for expanding the combustion gases and producing exhaust gases. The apparatus further includes a combustor that burns relatively low grade fuel, and produces combustion products, and an indirect contact heat exchanger responsive to the combustion products for heating the compressed air before the latter is applied to the combustion chamber, and for producing cooled combustion products. In addition, an energy converter is provided having an organic working fluid responsive to the exhaust gases for converting heat in the exhaust gases to electricity. Finally, the apparatus of the invention serves to minimize the consumption of high grade fuel in the presence of changes in the heating value of the low grade fuel.