A method for the acid catalyzed cyclization of an alkenylbenzene feedstock to a dimethyltetralin in a liquid phase reaction wherein the desired dimethyltetralin is removed from the reaction mixture by distillation simultaneously with the addition of the feedstock to the reaction mixture.

Naphthalene dicarboxylic acids are monomers that are known to be useful for the preparation of a variety of polymers. For example, poly(ethylene 2,6-naphthalate) prepared from 2,6-naphthalene dicarboxylic acid and ethylene glycol has better heat resistance and mechanical properties than polyethylene terephthalate and is useful in the manufacture of films and fibers.
Dimethylnaphthalenes are desirable feedstocks for oxidation to the corresponding naphthalene dicarboxylic acids. A known conventional process for producing a naphthalene dicarboxylic acid comprises the oxidation of a dimethylnaphthalene with oxygen in the liquid phase in an acetic acid solvent at an elevated temperature and pressure and in the presence of a catalyst comprising cobalt, manganese and bromine components.
Typically, dimethylnaphthalenes are found in refinery or coal-derived streams as mixtures of all of the ten possible dimethylnaphthalene isomers. However, separation of these isomers is very difficult and expensive. Consequently, methods for producing specific dimethylnaphthalenes or mixtures of two or three specific dimethylnaphthalenes in high purity and quality are highly desirable. One such method is a multistep synthesis involving: (1) the formation of an alkenylbenzene by the reaction of o-, m- or p-xylene or ethylbenzene with butadiene; (2) the cyclization of the resulting alkenylbenzene to form one or more dimethyltetralins belonging to one or two of three groups of isomeric dimethyltetralins--that is, either the group containing the 1,5-, 1,6-, 2,5- and 2,6-dimethyltetralins, the group containing the 1,7-, 1,8- 2,7- and 2,8-dimethyltetralins, or the group containing the 1,3-, 1,4-, 2,3- 5,7- 5,8- and 6,7-dimethyltetralins; (3) the dehydrogenation of the dimethyltetralin(s) to form the corresponding dimethylnaphthalene(s), and (4) the isomerization of the resulting dimethylnaphthalene(s) to the desired specific dimethylnaphthalene. The 1,5-, 1,6-, and 2,6-dimethylnaphthalenes make up the group that is commonly referred to as the Group A triad. The 1,7-, 1,8- and 2,7-dimethylnaphthalenes make up the group that is commonly referred to as the Group B triad. The 1,3-, 1,4- and 2,3-dimethylnaphthalenes make up the group that is commonly referred to as the Group C triad. In this regard, it is known that in the presence of an acid catalyst, the dimethylnaphthalene isomers are isomerizable within each triad of dimethylnaphthalene isomers--that is, within the 1,5- 1,6- and 2,6-dimethylnaphthalenes of triad A, within the 1,7- 1,8-, and 2,7-dimethylnaphthalenes of triad B, and within the 1,3-, 1,4- and 2,3-dimethylnaphthalenes of triad C. It is also known that the interconversion of a dimethylnaphthalene isomer within one of the aforesaid triads to a dimethylnaphthalene isomer within another of the aforesaid triads occurs to a relatively lesser extent.
For example, Sikkenga et al., U.S. Pat. No. 4,950,825 discloses an improved method for preparing one or more dimethyltetralins from 5-(o-, m-, or p-tolyl)-pent-1- or -2-ene or 5-phenyl-hex-1- or -2-ene as the first feedstock which comprises contacting the first feedstock in liquid form with a solid cyclization catalyst comprising an acidic, ultrastable crystalline aluminosilicate molecular sieve Y-zeolite that is substantially free of adsorbed water, and at a temperature in the range of from about 120.degree. C. to about 350.degree. C. and at a pressure that is sufficiently high to maintain the first feedstock substantially in the liquid phase to thereby cyclize the first feedstock to form a first liquid product comprising one or more dimethyltetralins, wherein water is at a concentration in the first feedstock of from 0.0 up to less than about 0.5 weight percent, based on the weight of the feedstock, wherein (a) when the first feedstock comprises 5-(o-tolyl)-pent-1- or -2-ene, at least 80 weight percent of the dimethyltetralin product formed is comprised of 1,5-, 1,6-, 2,5- or 2,6-dimethyltetralin or a mixture thereof, (b) when the first feedstock comprises 5-(m-tolyl)-pent-1- or -2-ene, at least 80 weight percent of the mixture of the dimethyltetralin product formed is comprised of 1,5- 1,6- 1,7-1,8- 2,5-, 2,6-, 2,7- or 2,8-dimethyltetralin or a mixture thereof, (c) when the first feedstock comprises 5-(p-tolyl)-pent-1- or -2-ene, at least 80 weight percent of the dimethyltetralin product formed is comprised of 1,7-, 1,8-, 2,7- or 2,8-dimethyltetralin or a mixture thereof, and (d) when the first feedstock comprises 5-phenyl-1- or -2-hexene, at least 80 weight percent of the dimethyltetralin product formed is comprised of 1,3-, 1,4-, 2,3-, 5,7-, 5,8- or 6,7-dimethyltetralin or a mixture thereof.
Thompson, U.S. Pat. Nos. 3,775,496; 3,775,497; 3,775,498; and 3,775,500 disclose processes for the cyclization of specific alkenylbenzenes to one or more specific dimethyltetralins at 200.degree.-450.degree. C. in the presence of any suitable solid acidic cyclization catalyst such as acidic crystalline zeolites as well as silica-alumina, silica-magnesia, and silica-alumina-zirconia and phosphoric acid, followed by the dehydrogenation of the resulting dimethyltetralin(s) in the vapor state to the corresponding dimethylnaphthalene(s) in a hydrogen atmosphere at 300.degree.-500.degree. C. and in the presence of a solid dehydrogenation catalyst such as noble metals on carriers and chromia-alumina, and thereafter isomerization of each of the aforesaid dimethylnaphthalene(s) to the desired isomer within the triad of dimethylnaphthalenes to which the isomer being isomerized belongs at 275.degree.-500.degree. C. in the presence of a solid acidic isomerization catalyst of the same type as described in respect of the cyclization disclosed therein. In the alternative, both the cyclization and isomerization reactions can be performed in the liquid phase, in which case the cyclization is performed at 200.degree.-275.degree. C. with a solid phosphoric acid catalyst, at 70.degree.-140.degree. C. with an acidic ion exchange resin, an acidic crystalline zeolite, hydrofluoric or sulfuric acid as the catalyst or a siliceous cracking catalyst.
More specifically, Thompson, U.S. Pat. No. 3,775,496, discloses the cyclization of 5-(m-tolyl)-pent-2-ene to 1,6- and 1,8-dimethyltetralins, which are then dehydrogenated to 1,6- and 1,8-dimethylnaphthalenes, which in turn are isomerized to 2,6- and 2,7-dimethylnaphthalenes, respectively. Thompson, U.S. Pat. No. 3,775,497, discloses the cyclization of 5-phenyl-hex-2-ene to 1,4-dimethyltetralin which is then dehydrogenated to 1,4-dimethylnaphthalene, which is in turn isomerized to 2,3-dimethylnaphthalene. Thompson, U.S. Pat. No. 3,775,498, discloses the cyclization of 5-(o-tolyl)pent-2-ene to 1,5-dimethyltetralin, which is then dehydrogenated to 1,5-dimethylnaphthalene, which is in turn isomerized to 2,6-dimethylnaphthalene. Thompson, U.S. Pat. No. 3,775,500 discloses the cyclization of 5-(p-tolyl)pent-2-ene to 1,7-dimethyltetralin, which is then dehydrogenated to 1,7-dimethylnaphthalene, which in turn is isomerized to 2,7-dimethylnaphthalene.
A problem in such prior art methods is the presence of impurities such as unconverted alkenylbenzene as well as by-products, particularly heavy, high-boiling by-products, in the cyclization reaction product. Additionally, because the cyclization reaction is exothermic, prior art processes that utilize a fixed bed of cyclization catalyst are undesirable. The fixed bed reactors can develop hot spots in the catalyst bed because the heat from the reaction cannot be rapidly dissipated. Such hot spots cause catalyst deactivation and increased formation of reaction by-products.
Consequently, it is highly desired to provide for an improved cyclization step in the aforesaid synthesis of dimethyltetralin isomers, which upon dehydrogenation are subsequently converted to dimethylnaphthalene.

Preparation of a dimethyltetralin in a distillation reactor


A data-link processing equipment which reduces the processing delay of the data-link data and performs the data-link processing with a good efficiency and an apparatus for a subscriber terminal office using this equipment. This data-link processing equipment provides a data-link synchronizing unit which establishes the synchronization of the data-link data extracted from frame synchronizing units respectively for a plurality of digital transmission lines; a data-link interface unit which latches the data-link data and outputs a data update flag; and a processor which reads and processes the latched data-link data by using the data update flag as an interrupt signal. The apparatus for a subscriber terminal office is constituted so that a subscriber data cross-connect unit is controlled by this data-link processing equipment; a cross-connection of the subscriber data is performed with phases all adjusted to be the same by a phase adjusting unit; and the subscriber data is distributed to channel units for respective subscribers.

1. Field of the Invention
The present invention relates to data-link processing equipment connected to a plurality of digital transmission lines and an apparatus for a subscriber terminal office using this processing equipment.
In the apparatus for a subscriber terminal office, it is necessary to expand the scale of the equipment or to install a large capacity equipment in accordance with the demands to increase the number of the subscribers which is to be accommodated. The amount of processing of the data link for transmitting and receiving the control data is also increased along with this. Accordingly, it has become necessary to make the data-link processing more efficient.
2. Description of the Related Art
As will be explained later in detail with reference to the drawings, in the apparatus for a subscriber terminal office of ordinary subscribers, for example, 96 subscribers are regarded as one control unit. At the level of DS1 signal, four transmission lines or two transmission lines are allocated for each above control unit. In this case, the number of the subscribers accommodated in a conventional apparatus for a subscriber terminal office is on the order of 96 or 192. Accordingly, the number of the data links becomes four or two, and it is possible to individually process the data links.
However, if the capacity of the apparatus for the subscriber terminal office is made larger and the number of the accommodated subscribers is increased a few times to 10 times the number of the subscribers mentioned before, the data links to be processed would be greatly increased. Accordingly, if the processing of the data links is achieved individually, it would lead to an enlargement of the scale of the apparatus and thereby a configuration of the apparatus would result in a low efficiency.
Therefore, a configuration for commonly processing a large number of data links can be considered by a person skilled in the art. In this case, consideration may be given to a configuration in which phase adjustment is performed so that the same frame synchronization timing is established with respect to the transmission lines and then the data link data is demultiplexed to process the data-link data by a commonly provided processor. However, the delay times of the transmission lines differ, and so the timing of the frame synchronization at each transmission line is different. For this reason, when matching the timings of the frame synchronizations, there may exist a transmission line which requires very long phase adjustment time. In such a case, the transmission lines must be aligned to the transmission line having the longest delay time, so there arises a problem of an increase of the processing delay of the data-link data.

Data-link processing equipment and apparatus for subscriber terminal office using same


A loading device including a guide frame, a drive mechanism and a lift mechanism. The guide frame includes a pair of spaced apart upright members each having a slot formed therethrough. The drive mechanism is coupled to the guide frame and has a shaft received concurrently through the slots of the guide frame, a sprocket mounted on the shaft, a belt member wrapped about the sprocket and having opposing ends anchored to the guide frame, and a motor coupled to the shaft for reciprocating the shaft vertically within the slots between an upper position and a lower position. Movement of the shaft toward the upper position produces rotation of the shaft in a first direction and a movement of the shaft toward the lower position rotates the shaft in an opposing direction. The lift mechanism is coupled to the drive mechanism and includes a pair of arms each having an end coupled to the shaft and another end coupled to a carriage.

This invention relates to refuse collection.
More particularly, the present invention relates to loading devices for use in refuse collection.
The need to collect refuse is an ever present and growing demand. As populations continue to increase, the need for efficient and inexpensive refuse collection becomes more important. Automatic devices which grasp and dump refuse containers into a refuse collection vehicle are well known and have long been employed. However, many of these devices are expensive, unreliable or not sufficiently robust to handle large refuse receptacles.
Front loading devices are typically very robust for handling large refuse receptacles such as bins. These devices typically include a pair of parallel, forwardly extending forks that are received within slots in the bin. The bin is then lifted and emptied into the vehicle. The drawback to these types of loading devices is that the refuse vehicle must have enough space to directly face the bin. Additionally, the vehicle must back away from the receptacle after loading. This can significantly add to the cycle time of collecting refuse from each receptacle.
Side loaders have been developed to increase the speed and efficiency of refuse collection. Side loaders typically include an articulated arm that reaches out to grasp a refuse container. The container is then lifted and emptied over a hopper of the vehicle. While extremely effective and efficient, current side loaders are less robust than front loaders and are limited to engaging smaller refuse containers. An additional problem with conventional side loader is the requirement of lateral space. Many side loaders move the refuse container in an outward and upward arc. This can prevent the loader from collecting containers substantially up against an obstruction such as a wall, fence, building etc.
Generally stronger side loaders have been developed utilizing linkage arms to raise a larger container along a track adjacent the side of the vehicle. A single cylinder moving an arm can achieve a maximum rotation of 120 degrees. This is insufficient to lift and dump a container. Generally a rotation of approximately 240 degrees is required. This has been achieved by using multiple pivots and multiple links for each arm. While marginally successful, the large number of pivots and links results in a complex, expensive and unreliable device. Each pivot point is a point of wear which greatly reduces the lifetime of the device and increases maintenance and operating costs.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved loading device.
Another object of the invention is to provide a side loading device which will handle large capacity refuse containers.
And another object of the invention is to provide a loading device which is very efficient.
Still another object of the present invention is to provide a loading device that will lift a refuse container along a path parallel to the side of the body of a refuse vehicle.
Yet another object of the invention is to provide a loading device which is robust.
Briefly, to achieve the desired objects of the instant invention in accordance with a preferred embodiment thereof, provided is a loading device including a guide frame, a drive mechanism, and a lift mechanism. The guide frame includes a first upright member having an upper end and a lower end and a slot formed therethrough and a second upright member having an upper end and a lower end and a slot formed therethrough. The second upright member is coupled in spaced apart parallel relation to the first upright member with the slot of the first upright member substantially aligned with the slot of the second upright member. The drive mechanism is coupled to the guide frame and includes a shaft received concurrently through the slot of the first upright member and the slot of the second upright member. A sprocket is mounted on the shaft and a belt member is wrapped about the sprocket. The belt member has opposing ends anchored to the guide frame. A motor is coupled to the shaft for reciprocating the shaft vertically within the slots between an upper position and a lower position, movement of the shaft toward the upper position producing rotation of the shaft in a first direction and a movement of the shaft toward the lower position rotating the shaft in an opposing direction. The lift mechanism is coupled to the drive mechanism and includes a first arm having a first end coupled to the shaft and a second end, a second arm having a first end coupled to the shaft and a second end, and a carriage coupled to the second ends of the first arm and the second arm.
In a further aspect of the invention the belt member includes a first belt portion and a second belt portion. The first belt portion has a first end coupled to an outer periphery of the sprocket and a second end coupled to an upper portion of the guide frame. The second belt portion has a first end coupled to an outer periphery of the sprocket and a second end coupled to a lower portion of the guide frame.
In yet another aspect of the invention, the drive mechanism further includes a second sprocket mounted on the shaft spaced from the sprocket, a second belt member wrapped about the second sprocket with opposing ends anchored to the guide frame, and a second motor coupled to the shaft for reciprocating the shaft vertically within the slots between an upper position and a lower position in concert with the motor.
In additional aspects of the present invention, the loading device includes an extension mechanism and an engagement mechanism.


A lithographic projection apparatus having a masking device for obscuring part of at least one of a patterning device used for patterning a projection beam before imaging the patterned beam onto a substrate. The masking device includes a first masking structure to obscure said part of said patterning device in a first direction and a second masking structure to obscure said part in a second different direction, wherein said first and second masking structure are disposed in the vicinity of said focal plane in a mechanically uncoupled arrangement with respect to each other.

1. Field of the Invention
The present invention relates to a masking device, a related lithographic projection apparatus, and a device manufacturing method.
2. Description of the Related Art
Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device may be used to generate a desired circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto a target portion (e.g. comprising one or more dies) on a substrate (silicon wafer) that has been coated with a layer of radiation-sensitive material (resist).
The term "patterning device" as here employed should be broadly interpreted as referring to a device that can be used to impart an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate; the term "light valve" can also be used in this context. Generally, the pattern will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit or other device (see below). Examples of such patterning devices include:                a mask: the concept of a mask is well known in lithography, and it includes mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. Placement of such a mask in the radiation beam causes selective transmission (in the case of a transmission mask) or reflection (in the case of a reflective mask) of the radiation impinging on the mask, according to the pattern on the mask. In the case of a mask, the support structure will generally be a mask table/holder, which ensures that the mask can be held at a desired position in the incoming radiation beam, and that it can be moved relative to the beam if so desired;        a programmable mirror array: one example of such a device is a matrix-addressable surface having a visco-elastic control layer and a reflective surface. The basic principle behind such an apparatus is that (for example) addressed areas of the reflective surface reflect incident light as diffracted light, whereas unaddressed areas reflect incident light as non-diffracted light. Using an appropriate filter, the non-diffracted light can be filtered out of the reflected beam, leaving only the diffracted light behind; in this manner, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. An alternative embodiment of a programmable mirror array employs a matrix arrangement of tiny mirrors, each of which can be individually tilted about an axis by applying a suitable localized electric field, or by employing piezoelectric actuation mechanism. Once again, the mirrors are matrix-addressable, such that addressed mirrors will reflect an incoming radiation beam in a different direction to unaddressed mirrors; in this manner, the reflected beam is patterned according to the addressing pattern of the matrix-addressable mirrors. The required matrix addressing can be performed using suitable electronic means. In both of the situations described here above, the patterning device can comprise one or more programmable mirror arrays. More information on mirror arrays as here referred to can be gleaned, for example, from United States Patents U.S. Pat. No. 5,296,891 and U.S. Pat. No. 5,523,193, and PCT patent applications WO 98/38597 and WO 98/33096, which are incorporated herein by reference. In the case of a programmable mirror array, the support structure may be embodied as a frame or table, for example, which may be fixed or movable as required; and        a programmable LCD array: an example of such a construction is given in United States Patent U.S. Pat. No. 5,229,872, which is incorporated herein by reference. As above, the support structure in this case may be embodied as a frame or table, for example, which may be fixed or movable as required.
For purposes of simplicity, the rest of this text may, at certain locations, specifically direct itself to examples involving a mask and mask table/holder; however, the general principles discussed in such instances should be seen in the broader context of the patterning device as set forth here above.
For the sake of simplicity, the projection system may hereinafter be referred to as the "lens"; however, this term should be broadly interpreted as encompassing various types of projection system, including refractive optics, reflective optics, and catadioptric systems, for example. The radiation system may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, and such components may also be referred to below, collectively or singularly, as a "lens". Further, the lithographic apparatus may be of a type having two or more substrate tables (and/or two or more mask table/holders). In such "multiple stage" devices the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposures. Twin stage lithographic apparatus are described, for example, in U.S. Pat. No. 5,969,441 and U.S. Ser. No. 09/180,011, filed 27 February, 1998 (WO 98/40791), incorporated herein by reference.
In general, a single wafer will contain a whole network of adjacent target portions that are successively irradiated via the projection system, one at a time. In current apparatus, employing patterning by a mask on a mask table/holder, a distinction can be made between two different types of machine. In one type of lithographic projection apparatus, each target portion is irradiated by exposing the entire mask pattern onto the target portion in one go; such an apparatus is commonly referred to as a wafer stepper. In an alternative apparatus—commonly referred to as a step-and-scan apparatus—each target portion is irradiated by progressively scanning the mask pattern under the projection beam in a given reference direction (the "scanning" direction) while synchronously scanning the substrate table parallel or anti-parallel to this direction. Since, in general, the projection system will have a magnification factor M (generally <1), the speed V at which the substrate table is scanned will be a factor M times that at which the mask table/holder is scanned. More information with regard to lithographic devices as here described can be gleaned, for example, from U.S. Pat. No. 6,046,792, incorporated herein by reference.
It is often desirable or necessary to ensure that only a certain part of the mask is imaged by the projection beam to the substrate. For example, the mask may contain more than one pattern of which only one is used for a given exposure. It is also often desirable or necessary to stop stray light from impinging on the substrate. In lithographic projection systems using this function, it is typically achieved by providing a mask masking device at an intermediate plane in the illuminator.
In a stepper system, where the mask is fixed with respect to the illuminator, the mask masking device is provided adjacent the mask and is also fixed with respect to the illuminator and the mask.
Conventional masking devices comprise at least one movable blade. In certain conventional devices two sets of moveable blades are provided. Typically, the two sets of blades are mechanically coupled to a support and each support is mounted on a common frame. Thus, conventionally the sets of blades are mechanically coupled to each other.
Generally, the two sets of blades may be disposed in a plane in the illumination unit. Each set of moveable blades comprise a pair of blades arranged to move together and apart in one direction, the Y-direction, hereinafter referred to as the Y-blades, and the other pair of blades is arranged to move together and apart in a direction perpendicular to the Y-blades, in the X-direction, hereinafter referred to as the X-blades. There are currently two types of mask masking schemes: (a) masking for static exposure and (b) masking for scanning exposure. In static exposure, part of the mask is blocked for the duration of an exposure. In scanning exposure, a part of the mask is blocked for a predetermined length of time.
The blades may be set so that there is a predetermined distance between the X-blades and the Y-blades, respectively. Conventionally, the Y-blades are arranged to be moveable during scanning, and the X-blades, although moveable, are generally arranged to be stationary during scanning. If the X-blades are to be moved, this generally takes place in between scans. For static exposures the X-blades may be moved between exposures. For scanning exposure, Y-blades in particular are arranged to perform additional movements to allow scanning of the patterning device by the radiation source to take place. Before a scanning cycle begins, the blades are arranged to prevent any radiation impinging on the patterning device. At the beginning of the scanning cycle the Y-blades open to a scanning distance. At the end of the scanning cycle, the Y-blades, in particular, move into a position in which light is prevented from impinging on the patterning device, so that at the end of the scanning cycle no light impinges on the patterning device.

Masking device, lithographic apparatus, and device manufacturing method


The acoustic properties of so-called instant fit ear tips, which in contrast to otoplastics are not produced individually, should be able to be better taken into consideration when adjusting a hearing aid for an individual wearer. To this end a method is proposed in which an OLG measurement, in other words an open loop gain measurement, is performed on the hearing aid when it is being worn. The OLG measurement curve obtained is compared with an OLG reference curve. A value is ascertained from the comparison which represents the level of closure of the hearing aid or of its otoplastic in the ear of the wearer. On the basis of this value the gain of the hearing aid is finally corrected. Furthermore, a corresponding adjustment device is provided. It is thus possible in a simple manner to take into consideration the individual, current level of closure during the adjustment.

Hearing aids are wearable hearing devices which serve to support the hard of hearing. In order to accommodate the numerous individual requirements, different styles of hearing aids such as behind-the-ear hearing aids (BTE), in-the-ear hearing aids (ITE) and concha hearing aids are made available. The hearing aids listed by way of example are worn on the outer ear or in the auditory canal. Furthermore however, bone conduction hearing aids, implantable or vibrotactile hearing aids are also available on the market. In this situation, stimulation of the damaged hearing is effected either mechanically or electrically.
Hearing aids always have as their essential components an input converter, an amplifier and an output converter. The input converter is as a general rule a receiving transducer, for example a microphone, and/or an electromagnetic receiver, for example an induction coil. The output converter is usually implemented as an electroacoustic converter, for example a miniature loudspeaker, or as an electromechanical converter, for example a bone conduction earpiece. The amplifier is normally integrated into a signal processing unit. This basic structure is illustrated in FIG. 1 by way of example of a behind-the-ear hearing aid. One or more microphones 2 for receiving the ambient sound are built into a hearing-aid housing 1 for wearing behind the ear. A signal processing unit 3, which is likewise integrated into the hearing-aid housing 1, processes the microphone signals and amplifies them. The output signal from the signal processing unit 3 is transferred to a loudspeaker or earpiece 4 which outputs an acoustic signal. The sound is transferred if need be by way of a sound tube, which is fixed in the auditory canal by means of an otoplastic, to the eardrum of the device wearer. The power supply for the hearing aid and in particular that for the signal processing unit 3 is provided by means of a battery 5 similarly integrated into the hearing-aid housing 1.
With regard to open hearing aid fitting, instead of individually produced ear fitting pieces or otoplastics, so-called "instant fit ear tips" are common. These ear tips are not produced individually. They are supplied for open hearing aid fitting, but also for a closed fitting. The choice of the ear tip determines, among other things, the outflow of low frequencies from the auditory canal. This outflow must be taken into consideration with regard to the individual adjustment, particularly the adjustment of the gain, to suit the hearing aid wearer.
The use of such types of instant fit ear tips means that the seating of the ear tip and thus also its acoustic properties depend on the individual physiognomy. In the situation when an open ear tip is used, in the case of a narrow auditory canal it is actually possible for an appreciable closure to be present, so that effectively a far more closed provision results than intended. On the other hand, when a "closed" ear tip is used, in the case of a wide auditory canal or in the event of incorrect seating a significant leakage effect can occur. An individual level of closure or an "effective vent" is thus always produced by the ear tip.
Up to now this problem has only been incompletely resolved. Since a vent results in the signal feeding back and thus leads to whistling if the gain is sufficiently high, the gain can be limited to the extent that no feedback whistling occurs. To this end, measurements of the open loop gain (OLG) are performed in order to ascertain the maximum possible gain and to keep the gain correspondingly small in practice. In addition, the gain prescribed by the adjustment formula is normally modified such that the acoustic effects of the existing vent are compensated for. With regard to the use of instant fit ear tips, it is however assumed that an open ear tip is by definition open and a closed ear tip is by definition closed. The individual, actual seating of the ear tip is not incorporated in the adjustment formula.
A device and a method for measuring the performance, for adjusting and for initializing a hearing aid are known from the publication US 2002/0176584 A1. For the adjustment of a hearing aid whose ear tip has a vent, a check is first made as to whether the target gain lies below a maximum stable gain. If this is not the case, a check is made as to whether the vent in the ear tip is too large and, if necessary, needs to be reduced in size. In addition, it is also possible to check whether the leakiness of the ear tip is too great by measuring the maximum stable gain in the case of a closed vent and of an open vent. If, when the vent is closed, the maximum stable gain is not significantly greater, the ear tip should be better adjusted to the auditory canal.

Method and device for determining an effective vent


The present invention is directed to an apparatus and method for supportably positioning an implantable hearing aid actuator within a patient""s skull. The improved apparatus includes a carry device for carrying an implantable hearing aid actuator at a first end, a swivel device for pivotably supporting the carrier device, and a mounting device for mounting the apparatus to a patient""s skull. To facilitate installation, a swivel device may be provided in a unitary manner so as to provide for selective placement and securement as a single unit to the mounting device. To yield enhanced depth positioning, the carrier device may be selectively advancable relative to the swivel device, and the carrier device may comprise two or more members interconnected for selective advancement of one relative to other. In the later regard, the carrier device may include at least a first member which telescopes coaxially relative to a second member.

The present invention relates to an apparatus and method for supportably positioning an implantable hearing aid actuator within a patient""s skull, and more particularly, to a positioning apparatus and method that provides ease-of-installation, range-of-application, actuator loading and depth positioning advantages.
Several types of implantable hearing aid devices have been proposed. Principally, such devices include those which utilize implanted electromechanical transducers for stimulation of the ossicular chain and/or oval window (see e.g., U.S. Pat. No. 5,702,342), and those which utilize implanted excitor coils to electromagnetically stimulate magnets affixed within the middle ear (see e.g., U.S. Pat. No. 5,897,486). For purposes hereof, such electromechanical transducers and excitor coils, as well other implanted devices that stimulate the ossicular chain and/or oval window will be collectively referred to as xe2x80x9cimplantable hearing aid actuatorsxe2x80x9d.
In most instances, hearing aid devices of the above-noted nature entail supportable positioning of the given implantable actuator within a patient""s skull. In many procedures, an opening is surgically defined in a patients skull and the implantable actuator is inserted through the opening for supportable positioning within the mastoid process. In conjunction with such implant procedures, precise placement and orientation of the implantable actuator can be of paramount importance to achieve best results.
To yield precise positioning a number of arrangements have been proposed, wherein implantable actuator(s) may supportably disposed for selective in-site positioning in multiple dimensions relative to a skull mounting device. While such arrangements have represented an advance in the art, they often entailed the positioning of a number of separate, hard-to-handle components, thereby adding to the complexity already associated with implant procedures. Additionally, the present inventors believe that further enhanced positioning of implantable actuators is achievable, particularly with respect to the depth profile which can vary significantly from patient to patient.
In view of the foregoing, a primary objective of the present invention is to provide an apparatus and method for supportably positioning an implantable hearing actuator at a desired location with enhanced ease-of-installation. Additional objectives are to provide an implantation apparatus and method that yields enhanced accuracy in implantable hearing aid actuator positioning and/or range-of-application advantages. Yet a further objective of the present invention is to provide an apparatus and method that facilitates accurate, contact loading of an electromechanical transducer relative to a patient""s ossicle.
One or more of the above-noted objectives as well as additional advantages are provided in the inventive apparatus which includes a carrier device for carrying an implantable hearing aid actuator at a first end, and a swivel device for pivotably supporting the carrier device. Such pivotable support allows the first-end of the carrier device to be laterally pivotable in first and second dimensions relative to the swivel device. The apparatus further includes a mounting device for mounting the apparatus to a patient""s skull, wherein the swivel device may be secured to the mounting device.
In one aspect of the present invention the swivel device is provided in a unitary fashion. That is, the swivel device is selectively positionable relative to and otherwise securable to the mounting device as a single unit. Such an arrangement simplifies installation procedures in conjunction with hearing aid implants. Further, to enhance actuator depth positioning, the carrier device and swivel device are preferably adapted to allow the carrier device to be selectively positioned in a third dimension relative to the swivel device.
Preferably, the unitary swivel device includes interconnected, opposing first and second holder members with a pivot member (e.g., a rotatable ball) captured between the first and second holder members. The pivot member may include an opening for supportably receiving the carrier device, wherein the carrier device is slidably positionable in the opening along a linear continuum of positions in the third dimension. As may be appreciated, pivotable movement of the carrier device will effect corresponding rotation of the pivot member relative to the interconnected first and second holder members.
In the later regard, the first and second holder members may be interconnected to permit a limited range of relative movement therebetween, thereby facilitating selective rotation of the pivot member upon pivotable movement of the carrier device. Relatedly, the inventive apparatus may further comprise a locking member interconnectable to the mounting device to selectively apply a compressive force to and thereby restrict relative movement between the first and second holder members, wherein a selected angular orientation between the carrier device and the mounting device may be maintained by the locking member.
Further, the locking member may also be employable to lock-in a selected linear position of the carrier device relative to the swivel device. More particularly, the pivot member may include a plurality of slits extending through an upper portion thereof to define a plurality of separated, upper portions of the pivot member. Correspondingly, the first holder member may comprise an aperture sized for contact positioning about the slitted portion of the pivot member. Consequently, when the locking member is interconnected to the mounting device to apply a compressive force to the first and second holders, such force will effect inward movement of the plurality of separated, upper portions to restrictably engage the carrier device.
In another aspect of the present invention, the carrier device may be interconnected to the swivel device in a manner that allows for selective advancement of the carrier device relative to the swivel device, wherein a first degree of actuator depth positioning latitude is provided; and, the carrier device may comprise at least a first carrier member and an interconnected second carrier member having a distal end connectable to an actuator, wherein the second carrier member is selectively advancable relative to the first carrier member to yield a second degree of depth positioning latitude. Such multiple depth positioning functionality not only facilitates accurate placement of an implantable hearing aid actuator but also facilitates a greater depth positioning range for an increased range of patient applications. In one arrangement, the first and second carrier members may be disposed coaxially and interconnected for selective, telescoping advancement of the second carrier member relative to the first carrier member.
Preferably, the first and second carrier members may be threadably interconnected, wherein driven rotation of the first carrier member effects a predetermined degree of linear travel by the second carrier member. In this regard, the swivel device may include an opening for supportably receiving the carrier device, wherein a top end of the first carrier member projects from the swivel device to provide ready access for driven rotation by an accessory tool.
In addition to first and second carrier members, the carrier device may further include a third carrier member, rotatably interconnected to the first carrier member, for restricting rotational movement of the second carrier member. In one arrangement, the second carrier member may include a linear slot while the third carrier member includes a projecting retention pin positioned within the slot of the second carrier member. As such, when the third carrier member is rotationally fixes (e.g., via use of a locking member as noted above) and the first carrier member is rotated, the third carrier member restricts rotation of the second carrier member, thereby causing the second carrier member to telescope away from both of the first and third carrier members.
In one embodiment, a mounting device is provided which includes a cylindrical barrel portion for supportably receiving a swivel device and carrier device interconnected thereto. The barrel portion includes a bottom end plate and is internally threaded, wherein the swivel device may be xe2x80x9clocked-inxe2x80x9d between an externally threaded locking member and the bottom end plate. The swivel device may include interconnected, top and bottom plate members with opposing central apertures having beveled edge surfaces for receiving a round pivot member therebetween. The pivot member is provided with a central opening therethrough for slidably receiving an outer support member of the carrier device. The carrier device further includes an internal shaft member rotatably interconnected at a top end to a top end of the outer support member, and interconnected at a bottom end to a telescoping member. In turn, a distal end of the telescoping member is interconnected to an electromechanical transducer actuator.
The entire carrier device may be selectively located at one of a linear continuum of positions relative to the swivel device to provide a first measure of depth positioning control. Further, the carrier device may be pivoted relative to the mounting device to provide for lateral positioning of the electromechanical transducer actuator. When a desired depth and angular orientation of the carrier device is established, such position may be xe2x80x9clocked-inxe2x80x9d by tightening the locking ring down on the swivel assembly. Then, the telescoping member of the carrier device may be selectively advanced to position the electromechanical transducer actuator in a desired contact position with the ossicular chain (e.g., contact with the incus bone) or oval window.
In view of the foregoing, it will apparent that an inventive method for positioning an implantable hearing aid actuator is also provided. The inventive method includes the steps of attaching a mounting device to a patient""s skull and supporting a swivel device on the mounting device, wherein the swivel device pivotably supports a carrier device having an implantable hearing aid actuator interconnected thereto. The method further provides for the positioning of the carrier device so as to locate the implantable hearing aid actuator at a desired location within the patient""s skull.
Preferably, the supporting step is achieved via the placement of the swivel device as a single unit into a support position on the mounting device. In one embodiment, this may be achieved by inserting the swivel device as a unit into a barrel portion of the mounting device and supportably engaging a bottom end plate of the barrel portion.
The positioning step of the inventive method preferably includes the sub-steps of pivoting the carrier device and interconnected implantable hearing aid actuator into a desired angular orientation relative to the mounting device within a patient""s skull, and advancing the carrier device relative to the swivel device. Further, in an arrangement where the carrier device includes at least first and second carrier members, the positioning step may further include the sub-step of advancing the second carrier member relative to the first carrier member.
When an electromechanical transducer actuator is utilized, a desired contact location may be defined on the ossicular chain (e.g., the incus bone) or oval window within a patient""s skull, wherein a probe tip of the electromechanical transducer actuator is brought into gradual contact with the contact location during positioning. In this regard, the inventive method may further provide for advancing the second carrier member relative to the first carrier member so as to provide a predetermined degree of loading by the probe tip on the contact location.
Numerous additional aspects and advantages of the present invention will become apparent to those skilled in the art upon consideration of further description that follows.

Apparatus and method for positioning implantable hearing aid device


A method and apparatus for locating an internal target region during treatment without implanted fiducials is presented. The method comprises producing a plurality of first images that show an internal volume including the internal target region, then producing a live image of the internal volume during treatment and matching this live image to one of the plurality of first images. Since the first images show the internal target region, matching the live image to one of the first images identifies the position of the target region regardless of whether the second image itself shows the position of the target region. The first images may be any three-dimensional images such as CT scans, magnetic resonance imaging, and ultrasound. The live image may be, for example, an x-ray image. The invention may be used in conjunction with a real-time sensor to track the position of the target region on a real-time basis.

This invention relates generally to an apparatus for improving the accuracy and efficacy of surgical treatments and more particularly to tracking the location of the target region that is displaced during the treatment due to respiratory and other patient motions.
Various treatments require accurate tracking of the location of a target region in order to apply or deliver the treatment to the target region. In radiation therapy and radiosurgery, for example, a tumor may be destroyed by a beam of ionizing radiation that kills the cells in the tumor. As it is desirable to direct the radiation beam only to the tumor and not to the healthy tissues surrounding the tumor, accurate aiming of the beam at the tumor is of paramount importance in radiation treatments. The goal is to focus a high dose of radiation to the tumor while minimizing the exposure of the surrounding healthy tissue to radiation. For adequate distribution of radiation dosage to the tumor, the direction of the radiation beam is typically adjusted during the treatment to track the tumor.
The most advanced modern radiosurgery systems, such as the Cyberknife System of Accuray, Inc., use stereo online x-ray imaging during treatment to enhance the accuracy of radiation treatment. The position of the patient's bony landmarks (e.g., a skull) can be determined with high accuracy by using the Cyberknife stereo x-ray camera system. Thus, this highly accurate x-ray camera system can be used to treat a target region if the position of the target region relative to a bony landmark remains constant. However, this x-ray camera system cannot be used to determine the position of a target region if the position of the target region relative to a bony landmark changes because the target, e.g., a tumor, is generally not visible in x-ray images. For example, a target region in a patient's abdomen or chest cannot be treated with this method alone.
While accurate aiming of the beam is not difficult when the tumor is in a body part that does not move, such as the brain, aiming becomes a challenge when the tumor is in or near a body part that moves, such as the lungs. A tumor located near the lungs moves as the patient inhales and exhales, necessitating continuous adjustment of the radiation beam direction. As the change in the position of the tumor does not necessarily correlate with the change in the position of an external surface of the patient, a tumor cannot be easily tracked based on external measurements alone. For example, placing external sensors on a patient's chest and tracking the movement of the sensors does not provide accurate information about the position of the tumor inside the chest cavity because a certain soft tissue structure may move in one direction while bones move in another direction. Nor can the tumor be located with x-ray systems, because in most cases, neither the target region nor the surrounding soft tissues are visible in the x-ray images. The two-dimensional nature of x-ray images compromises the accuracy with which the radiation is applied to the target region. Moreover, even if x-ray provided accurate enough data, real-time tracking of target region cannot be performed with x-ray imaging alone because of the excess radiation that the patient would be exposed to.
Attempts to improve the tracking accuracy of a target region include use of an internal fiducial. U.S. Pat. No. 6,144,875, for example, discloses a method for tracking a target region by implanting small gold markers that are visible in x-ray images into a patient's abdomen prior to radiation treatment. Once the internal fiducials are implanted, they are periodically imaged with a stereo x-ray camera system so that their positions are accurately determined. Based on the position of the markers, the position of the tumor can be accurately determined.
Unfortunately, use of internal fiducials in the above manner has its disadvantages. First, the x-ray imaging process is too slow and too invasive to track the respiration motion in real-time. The x-ray system allows the location of a tumor to be determined only at certain time intervals, e.g., every 10 seconds, and not continuously. Second, the implanting of the fiducials is an invasive and expensive procedure because the procedure usually takes place under the surveillance of a computer tomography (CT) device and in the presence of a surgeon. The required presence of the surgeon not only drives up the cost of the procedure for the patient but also exposes the surgeon to ionizing radiation. Furthermore, there is a real risk of complications that could result from the fiducial placement.
For the above reasons, it is desirable to provide an apparatus and method for accurately tracking a target region in a patient without the use of internal fiducials, and it is to this end that the present invention is directed.

Method and apparatus for tracking an internal target region without an implanted fiducial


A medical instrument includes an instrument shaft with exit holes near a distal end of the shaft, a tool coupled to the distal end of the shaft, and a backend. The backend may include a mechanism that manipulates a drive element that extends through the shaft and couples to the tool, a fluid inlet, and a fluid channel assembly providing fluid communication between the fluid inlet and the proximal end of the shaft. Cleaning fluid is directed into the fluid inlet, through the fluid channel assembly, and into the shaft. A chassis or other structural piece of the backend may form part of the fluid channel assembly.

Minimally-invasive medical procedures often employ medical instruments having a tool or end effector or other manipulation element at the distal end of an elongated instrument shaft. During such a procedure, the distal end of such a medical instruments may be inserted through small incisions and/or natural lumens to position the distal tools at a work site in a patient, and a surgeon or other medical personnel may control the tools to perform desired clinical functions. The instrument shafts are generally long and thin and may, for example, be over 50 cm in length and less than 1 cm in diameter. Despite the small diameters of some medical instruments, multiple tendons, push-pull elements, and power or signal lines may extend through the length of the instrument shaft.
Complex medical instruments are typically expensive, and users benefit if medical instruments can be reused for multiple procedures. The medical instruments do, however, directly contact patients and must be sterilize for reuse. Before being sterilized, the instrument generally must be cleaned to remove any fluids, particulates, or other contaminants that may have entered the instrument during a previous procedure. Full disassembly of the medical instrument for such cleaning may be impractical, and so systems and methods are needed for cleaning the inside of an instrument shaft that do not require disassembling the instrument.
One cleaning system for a medical instrument includes a flush tube, e.g., a thin walled, flexible, plastic tube that runs the length of the shaft of the medical instrument. The flush tube may particularly extend from a backend (proximal end) of the instrument to a distal end where a tool attaches to the shaft. (In these medical instruments, the ends of structures closest to a robot or other control device are commonly referred to as the "proximal" ends, while the ends closest to the tool are commonly referred to as the "distal" ends.) The proximal end of the flush tube may be connected so that cleaning fluid (e.g., water) may be fed through the flush tube to the distal end of the instrument shaft where the cleaning fluid exits the flush tube. The cleaning fluid from the flush tube hits a seal at the distal end of the instrument shaft and returns back through the instrument shaft, and the returning fluid may flush any contaminants through the inside of the shaft until the cleaning fluid washes contaminants out of the medical instrument through gaps in a backend housing of the medical instrument. For this system, the flush tube must be carefully routed to prevent the flush tube from becoming kinked, because a kink would block the flow of cleaning fluid. Also, the instrument shaft needs to have sufficient internal space for the flush tube, for fluid return, and for any drive cables, drive rods, and electrically energized lines needed for the clinical function of the medical instrument. A medical instrument that provides a high degree of functionality through a small diameter instrument shaft, e.g., an instrument shaft with a diameter less than about 8 mm and particularly having an instrument shaft with articulated joints, may not have space for a flush tube path that can reliably avoid kinking of the flush tube.


A system is described for obtaining goods or services over a networked communication system. Goods and services are provided by a sales related entity or administrator at or through a server system. A client system is configured to obtain goods or services from the provider in a manner that reduces or eliminates the processing burden on the retailer's server system. The invention allows for readily scalable sale related and/or administrator server system(s).

The present invention relates to the use of communication networks such as the Internet for providing online services. In particular, the present invention provides for the transaction of goods and/or services in a network environment in a secure and scalable manner.
With the widespread use of computers, an expanding telecommunication network, and the rising popularity of communication networks such as the Internet, an increasing number of transactions and services are performed online using computer systems coupled to the communication network. Computer systems connected to communication networks such as the Internet can generally be classified as "clients" or "servers" depending on the role the computer systems play with respect to requesting information and services or providing information and services. Computer systems that are used by users to request information or to request a service are classified as "client" computers (or "clients"). Computers systems that store information and provide the information in response to a user request received from a client computer, or computer systems that perform processing to provide the user-requested services are called "server" computers (or "servers"). A particular computer system may function both as a client and as a server.
Accordingly, a user may initiate a request to perform a service (referred to as a "service request") using a client computer coupled to a communication network such as the Internet. In the World Wide Web ("Web") environment, a user may initiate a service request by accessing a web page from a web site hosted by a server coupled to the communication network, and configuring a service request via the web page. The web page provides an interface via which a user can select one or more services to be performed and provide the data for performing the services.
A web page is a form of a hypertext document that may incorporate any combination of text, graphics, audio and video content, software programs, and other data. Web pages may also contain hypertext links to other web pages. Each web page is uniquely identified by an address called a Uniform Resource Locator (URL) that enables users to access the web page. Users typically access web pages using a program called a "web browser" which generally executes on a client user computer coupled to the Internet. A browser enables users to access and interact with web pages. Users generally access web pages by providing URL information to the browser, either directly or indirectly, and the browser responds by retrieving the web page corresponding to the user-provided URL and displaying the web page to the user. Examples of browsers include the Internet Explorer browser program provided by Microsoft Corporation, the Netscape Navigator browser provided by Netscape Corporation, and others.
Servers that store web pages and host web sites are generally referred to as "web servers." Web servers are responsible for receiving web page requests from client systems, and for communicating web pages requested by the clients back to the requesting client systems. In conventional network-based transaction systems, web servers are also configured to perform services requested by clients via service requests. Code modules stored and executed by the web servers generally provide the services. Accordingly, in conventional transaction systems, the web servers not only host web sites storing web pages, but also perform processing to complete/perform the user-requested service.
Since the service is performed by the web servers themselves, conventional transaction and service provider systems comprising one or more web servers require substantial computing and storage resources to be able to operate across high speed network connections and to service multiply connected users (clients) in parallel. Further, to ensure satisfactory performance, the systems are typically designed to handle the worst-case user count scenario. As a result, conventional web server-based service provider systems are very expensive and require constant maintenance to reduce downtime, which further adds to the cost of performing a service.
Conventional web server-based service provider systems are also susceptible to attack by vandals or hackers intent on damaging or disrupting the transaction service provided by the servers. For example, hackers may maliciously "crowd" a particular web server (i.e., swamp the web server with service requests) in order to degrade the performance of the web server. Further, since service request processing is done by the web server itself, the code modules that perform processing related to the service requests and the databases used for the processing are stored by the web servers themselves. Since the web servers can be easily accessed by user clients, these code modules and databases are susceptible to vandals and hackers intent on gaining access to confidential or trade secret information contained in the code modules, the databases, etc.
In light of the above, there is a need for techniques which allow services to be provided in a network-based environment in a secure manner. It is also desirable that the techniques be scalable and economical.

Scalable transaction system for a network environment


It is not uncommon for two or more wireless-enabled devices to spend most of their time in close proximity to one another. For example, a person may routinely carry a personal digital assistant (PDA) and a portable digital audio/video player, or a cellphone and a PDA, or a smartphone and a gaming device. When it is desirable to increase the memory storage capacity of a first such device, it may be possible to use memory on one or more of the other devices to temporarily store data from the first device.

Limited memory resources pose a challenge with some portable electronic devices. Applications installed on a portable electronic device are stored in the device's memory, as are user data items that are used by the applications and system data used by the applications and the operating system of the device. For example, a device having several different applications will store in its memory contact information, e-mail messages, tasks, calendar entries, instant messages, audio files, image files and other forms of user data items.
In order not to waste the limited memory resources, data may be arranged and stored in an efficient manner, and techniques such as compression may be used. A user may also be able to add additional memory to the device, or to replace the existing memory of the device with memory having greater storage capacity. There are also portable memory units that can provide additional storage for the device. For example, if the portable electronic device has a universal serial bus (USB) port and supports the ability to transfer data to an external storage unit, a USB flash drive may be connected to the portable electronic device and the user may transfer data from the device to the drive. In another example, if the portable electronic device is a Bluetooth® (BT) device and supports the ability to transfer data to an external storage unit, then the user may select certain data and transfer the selected data from the device to a dedicated BT hard disk drive.
At some point in time the memory of a portable electronic device may have insufficient capacity to store data in addition to whatever is currently stored therein, or the unused storage capacity of the memory may have fallen below a predetermined threshold. The user of the device may then be prompted to erase some user data items in order to increase the unused storage capacity of the memory. The device may have a memory manager that automatically erases some of the user data items when activated.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity.

This patent is subject to a terminal disclaimer.

Sharing memory resources of wireless portable electronic devices


A device for isolating tissue in the digestive tract including a biocompatible portion having a surface sized to cover the tissue to be isolated and also includes a plurality of micro-anchors attached to the biocompatible portion and extending from the surface, the micro-anchors sized to penetrate the mucosa of the tissue. A method for isolating tissue in the digestive tract in which an isolation element is delivered to a desired location in the digestive system; the isolation element having fixed thereto a plurality of micro-anchors. The method also includes attaching the isolation element to tissue at the desired location by causing the micro-anchors to penetrate the mucosa of the tissue.

The present invention relates to devices and methods for attachment of a device within a patient's digestive tract. In particular, the present invention relates to devices and methods for treatment of obesity and/or its comorbidities, such as diabetes.
According to the Center for Disease Control (CDC), sixty six percent of the United States population is overweight, and thirty two percent are obese, presenting an overwhelming health problem. From an economic standpoint, it is estimated that more than 100 billion dollars are spent on obesity and treating its major co-morbidities. This does not even consider the psychological and social costs of this epidemic problem. In the opinion of many health care experts, obesity is the largest health problem facing westernized societies and is considered an epidemic. From a medical standpoint, obesity is the primary risk factor for type 2 diabetes and obstructive sleep apnea. It increases the chances for heart disease, pulmonary disease, infertility, osteoarthritis, cholecystitis and several major cancers, including breast and colon. Despite these alarming facts, treatment options for obesity remain limited.
Treatment options include dietary modification, very low calorie liquid diet, pharmaceutical agents, counseling, exercise programs and surgery. Diet and exercise plans fail since most individuals do not have the discipline to adhere to such plans. When diet and exercise fail many try dietary supplements and drugs or other ingestible preparations promoted as being capable of suppressing appetite or inducing satiety. In general, these techniques for treating compulsive overeating/obesity have tended to produce only a temporary effect. The individual usually becomes discouraged and/or depressed after the initial rate of weight loss plateaus and further weight loss becomes harder to achieve. The individual then typically reverts to the previous behavior of compulsive overeating.
Surgical procedures that restrict the size of the stomach and/or bypass parts of the intestine are the only remedies that provide lasting weight loss for the majority of morbidly obese individuals. Surgical procedures for morbid obesity are becoming more common based on long-term successful weight loss result.
Bariatric surgery is a treatment for morbid obesity that involves alteration of a patient's digestive tract to encourage weight loss and to help maintain normal weight. Known bariatric surgery procedures include jejuno-ileal bypass, jejuno-colic shunt, biliopancreatic diversion, gastric bypass, Roux-en-Y gastric bypass, gastroplasty, gastric banding, vertical banded gastroplasty, and silastic ring gastroplasty. A more complete history of bariatric surgery can be found in U.S. Patent Application Publication No. 2004/0092892 A1 Apparatus and Methods for Treatment of Morbid Obesity and also on the website of the American Society for Bariatric Surgery at http://www.asbs.org.
The surgeries which create malabsorption, such as the by-pass operation, although effective in weight reduction, involve permanent modification of the GI tract and have a risk of short and long term complication and even death.
The most common weight loss operation in the United States is the Gastric Bypass. These procedures reduce the size of the stomach plus shorten the effective-length of intestine available for nutrient absorption. With gastric bypass many investigators have reported weight loss results that exceed 70% of excess weight. However, this efficacy does not come without complication. The accepted mortality of the procedure is 1 in 200.
Medical sleeve devices for placement in a patient's stomach are described by Rockey in U.S. Pat. Nos. 4,501,264, 4,641,653 and 4,763,653. The medical sleeve described in these patents are said to reduce the surface area available for absorption in the stomach. Other sleeve devices for placement in a patient's intestines are described in U.S. Pat. No. 4,134,405 (Smit), U.S. Pat. No. 4,315,509 (Smit), U.S. Pat. No. 5,306,300 (Berry), and U.S. Pat. No. 5,820,584 (Crabb). The sleeve devices described in these patents are said to be placed at the lower end of the stomach.
Other less invasive techniques for restricting absorption have been suggested. They include bariatric sleeve devices such as those disclosed in US Patent Application Publication Nos. 2004/0092892 to Kagan, et al. and 2004/0107004 to Levine, et al. In these techniques, sleeves are passed through the duodenum so that chyme are passed through the sleeve and do not interact with the absorptive walls of the intestine. The sleeve of the '004 application includes a stent in the pylorus. Another example is Meade et al., U.S. patent application Ser. No. 10/339,786. Other devices to reduce absorption in the small intestines have been proposed (See U.S. Pat. No. 5,820,584 (Crabb), U.S. Pat. No. 5,306,300 (Berry) and U.S. Pat. No. 4,315,509 (Smit)).
In U.S. Patent Application US 2003/0040804, Stack et al. describe a satiation device to aid in weight loss by controlling feelings of hunger. The patent application describes an antral tube that expands into the antrum of the stomach to create a feeling of satiation. In U.S. Patent Application US 2003/0040808, Stack et al. describe a satiation device for inducing weight loss in a patient that includes a tubular prosthesis positionable such that an opening at its proximal end receives masticated food from the esophagus, and such that the masticated food passes through the pouch and into the stomach via an opening in its distal end.

Devices and methods for treatment of obesity


A method of diagnosing a patient with age-related macular degeneration (AMD), by detecting biomarkers in the patient's Bruch's membrane, and diagnosing the patient with AMD. A method of detecting the presence of AMD in a patient, by detecting biomarkers in the patient's Bruch's membrane. A method of detecting inflammation in a patient, by detecting biomarkers in the patient's Bruch's membrane. A method of determining the progression of AMD in a patient. A method of determining efficacy of a treatment for AMD in a patient. A method of determining the presence of AMD in an animal model. A kit for detecting the presence of disease in a patient, including an assay for biomarkers 3-nitrotyrosine and nitro-A2E. An assay of the biomarkers.

(1) Field of the Invention
The present invention relates to diagnostic biomarkers. In particular, the present invention relates to biomarkers of aging and disease in the retina.
(2) Description of Related Art
Age-related macular degeneration (AMD) is a disease leading to severe visual loss and legal blindness in the elderly population (Klein et al. 1992; Mitchell et al. 1995). The pathophysiology of AMD is complex and can include genetic predispositions, accumulation of lipofuscin and drusen, local inflammation and neovascularization. Recently four independent research groups used different methods to screen the genomes from different groups of AMD patients. All four studies discovered a commonly inherited variant (Y402H) of the complement factor H (CFH) gene that significantly increases the risk of AMD (Edwards et al. 2005; Hageman et al. 2005; Haines et al. 2005; Klein et al. 2005). This finding links genetics and inflammation. Before this finding, the study of the components of drusen had provided compelling evidence that inflammatory and immune-mediated events participate in the development of drusen and progression of AMD. Protein components of drusen include immunoglobulins, components of the complement pathway (e.g., C5 and C5b-9), molecules involved in the acute-phase response to inflammation (e.g., Amyloid P component), and proteins that modulate the immune response (e.g., vitronectin, clusterin, and apolipoprotein E) (Hageman and Muffins 1999; Hageman et al. 1999; Johnson et al. 2000; Mullins et al. 2000). The finding that macrophages are important in choroidal neovascularization (CNV) also supports the involvement of inflammation in AMD (Grossnikiaus et al. 2002). Recent research provided further evidence that inflammation is involved in the development of AMD (Chen et al. 2007; Laine et al. 2007; Schaumberg et al. 2007; Skerka et al. 2007) and the link between inflammation, drusen and oxidative stress (Wu et al. 2007; Hollyfield et al. 2008; Wang et al. 2008).
During inflammation, large fluxes of nitric oxide (NO) are released through the activation of inducible nitric oxide synthase (Marletta et al. 1988; Carreras et al. 1994). Nitrite concentration is reported to be nearly doubled in the diabetic retina (El-Remessy et al. 2003). Cigarette smoking, which has been strongly associated with the development of AMD (Solberg et al. 1998), is also an important chronic contributor to human NO exposure (Council 1986; Borland and Higenbottam 1987). Patients with AMD have significantly higher plasma NO levels than control subjects (Evereklioglu et al. 2003). NO itself is a relatively unreactive radical, however, it is able to form other reactive intermediates including nitrite (NO2−), peroxynitrite (ONOO−), NO2, and N2O3, etc that can modify proteins, lipids and other compounds. Nitrite is one of the major NO metabolic products and has been used as a marker of NO production (Farrell et al. 1992; Gaston et al. 1993). In addition, nonenzymatic nitration of long lived protein such as extracellular matrix proteins is a well known pathway that has been associated with inflammation (Bailey et al. 1998; Paik et al. 2001). The extracellular matrix proteins, such as collagen and elastin have been reported to be nonenzymatically modified by nitrite at physiological pH (Paik et al. 1997; Paik et al. 2001). Applicants have shown that nitrite-modification of basement membrane-like extracellular matrix proteins can impart deleterious effects on adjacent epithelial cell function and viability (Wang et al. 2005) and impair phagocytic capacity (Sun et al. 2007).
Bruch's membrane lies between the choroidal capillary bed and retinal pigment epithelial (RPE) cells. The exchange of various materials between the underlying choriocapillaris and overlying RPE occurs through Bruch's membrane (Lyda et al. 1957; Sellner 1986). Bruch's membrane is permeable to macromolecules up to 300 kD in size in healthy eyes, but there are numerous examples of pathological processes in which larger macromolecules or even cells, including macrophages and leukocytes, can traverse Bruch's membrane in the diseased eye (Crane and Liversidge 2008). In addition to Bruch's membrane, trafficking of material from the RPE to the choriocapillaris is limited in the healthy eye by tight junctions between adjacent cells of the RPE monolayer. This outer blood-retinal barrier is part of the specialized ocular microenvironment that confers protection or immune privilege to mitigate the effect of deleterious immune responses (Streilein 2003). Nevertheless, this barrier is altered in pathological circumstances, and breakdown of the outer blood retinal barrier, including macrophage and leukocyte infiltration of the retina, are implicated in many diseases including AMD (Jha et al. 2007). Several investigators have suggested that age-related damage to Bruch's membrane allows for the accumulation of abnormal extracellular deposits, called drusen, between the basal lamina of the RPE and the inner collagen layer of Bruch's membrane (Newsome et al. 1987; Pauleikhoff et al. 1990; Mullins et al. 2000; Crabb et al. 2002). The accumulation of drusen is thought to elicit a local inflammatory response (Anderson et al. 2002; Yasukawa et al. 2007; Hollyfield et al. 2008).
Recently Applicants have shown that age-related changes in human Bruch's membrane can exert significant deleterious effects on RPE function that are independent of cell aging, including impairing the ability of cultured RPE to phagocytize photoreceptor outer segments (Sun et al. 2007). A similar effect on RPE function is observed after nonenzymatic nitration of RPE basement membrane in tissue culture (Wang et al. 2005). Surprisingly, there have been no studies that have reported nitrite modification occurring in intrinsic Bruch's membrane proteins or extrinsic deposits, although tyrosine nitration has been shown to occur in photoreceptor cells (Miyagi et al. 2002). However, previous studies have demonstrated that numerous structural and molecular alterations occur within human Bruch's membrane as a function of age. These changes, which disrupt the normal molecular architecture of Bruch's membrane, include: (1) structural changes in the main collagen frame work, including cross-linking and deposition of long-spaced collagen (Yamamoto and Yamashita 1989), (2) qualitative and quantitative changes in the native extracellular matrix molecules (Pauleikhoff et al. 2000), (3) deposition of abnormal extrinsic molecules including fluorescent products that accumulate in drusen (Ruberti et al. 2003), (4) macromolecular changes in the structure of Bruch's membrane, such as calcification, cracks or loss of inner layers due to inadequate basal membrane regeneration as in geographic atrophy (Feeney-Burns and Ellersieck 1985), (Grossniklaus et al. 1994), and (5) changes in the physical characteristic of Bruch's membrane, such as an age-dependent increase in trans-membrane hydraulic conductivity (Moore et al. 1995) and age-related linear decline in collagen solubility, an index of deleterious cross-linking (Karwatowski et al. 1995),
3-nitrotyrosine is known as a specific marker for inflammation-induced oxidative damage to proteins. In addition to proteins, Bruch's membrane also contains lipids, lipofuscin and carbohydrates (Hageman et al. 2001; Yasukawa et al. 2007). Lipofuscin is a mixture of autofluorescent material that accumulates in the RPE cells and is reported to photochemically generate a series of reactive oxygen species, including singlet oxygen, hydrogen peroxide, and superoxide anions (Gaillard et al. 1995; Rozanowska et al. 1998) that can enhance oxidative stress in the RPE. One of the major organic soluble chromophores in lipofuscin is A2E (2-[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E, 3E,5E,7E-octatetraenyl]-1-(2-hydroxyethyl)-4-[4-methyl-6-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E-hexatrienyl]-pyridinium).
It would be desirable to be able to identify individuals with a propensity for inflammation so that an effective treatment or preventative measures can be appropriately taken for AMD.

Biomarkers of inflammation in Bruch's membrane of the human retina

Board of Trustees of Northern Illinois University


The present invention is directed to peptide analogues of fragment of parathyroid hormone (PTH) or parathyroid hormone-related protein (PTHrP), a method of using said analogues alone or in combination with a bisphosphonate or calcitonin to treat osteoporosis and pharmaceutical compositions comprising said analogues alone or in combination with a bisphosphonate or calcitonin.

Parathyroid hormone ("PTH") is a polypeptide produced by the parathyroid glands. The mature circulating form of the hormone is comprised of 84 amino acid residues. The biological action of PTH can be reproduced by a peptide fragment of its N-terminus (e.g. amino acid residues 1 through 34). Parathyroid hormone-related protein ("PTHrP") is a 139 to 173 amino acid-protein with N-terminal homology to PTH. PTHrP shares many of the biological effects of PTH including binding to a common PTH/PTHrP receptor. Tregear, et al., Endocrinal., 93:1349 (1983). PTH peptides from many different sources, e.g., human, bovine, rat, chicken, have been characterized. Nissenson, et al., Receptor, 3:193 (1993).
PTH has been shown to both improve bone mass and quality, Dempster, et al., Endocrine Rev., 14:690 (1993); and Riggs, Amer. J. Med., 91 (Suppl. 5B):37S (1991). The anabolic effect of intermittently administered PTH has been observed in osteoporotic men and women either with or without concurrent antiresorptive therapy. Siovik, et al., J. Bone Miner. Res., 1:377 (1986); Reeve, et al., Br. Med. J., 301:314 (1990); and Hesch, R-D., et al., Calcif. Tissue Int'l, 44:176 (1989).

Societe de Conseils de Recherches Et d'Applications Scientifiques, SAS


A method is proposed for controlling a device for distribution of audio, video, data and control signals. The device has a number of inputs and outputs, which can be connected by the switching of takes, and which cover signal paths. Tally signaling signals inputs or outputs as being transmission-relevant. The method comprises the following steps: successful switching operations of takes are locked against further switching operations automatically and without any intervention by an operator. Signal paths are completely locked or unlocked on the basis of tally signaling of an input or output by automatic locking or unlocking of the takes involved. Signal paths are combined to form signal bundles. When signal bundles are locked or unlocked on the basis of tally signaling of the bundle, all of the signal paths involved are automatically locked or unlocked.

Numerous audio, video, data and control signal sources and sinks are available in television studios. These various types of signal sources include recording appliances, such as tape recorders (MAZ), video servers, cameras and satellite or cable links. The various types of signal sinks once again include recorders, video servers, production mixers. By way of example, different image and audio signal sources are combined with one another to form a program in the production of a news program. A speaker in the studio typically provides the lead through the transmission, which is recorded using one or more cameras. The speaker introduces already recorded programs or direct transmissions. In terms of video, audio and data, these come from a source which is controlled via control signals.
Various signal sources can be connected to their destination by means of switching matrices and mixers. This switching matrix, a so-called crossbar, is a matrix which has a fixed defined number of inputs and a fixed defined number of outputs. Each input can be connected to one specific output which, in detail, means that one input can be connected to a plurality of outputs, but one output can be connected to only one input. A production mixer or presentation schedule mixer, has the same characteristics as a switching matrix, that is able to combine a plurality of signal sources to form one transmission signal. Mixing of different video signals with one another, as well as mixing of different audio signals with one another, are desirable from the composition point of view. For further signal distribution, a presentation schedule mixer is also able to combine audio and video signals into one data stream. Mixing devices use control lines to signal which input signals are passed on and are thus transmission-relevant. Recorders signal that recording is taking place. This signal is known by the expressions "On-Air", "Red-Light" or tally signaling.
The selection of which signals are produced at which outputs is carried out by an operator in the studio or control room. Connections are generally switched via a plurality of switching matrices and mixing devices, and cover so-called paths. The search for paths, which is assisted by automatic systems, is normally referred to as "pathfinding". The task of the operator is also made more difficult by paths for different signal types being switched at the same time in the course of production, thus forming a logical unit, a so-called signal bundle. In order to prevent interference with a signal transmission, it is essential to prevent interruption of signal paths and path bundles. The locking of a path, which is assisted by automatic systems, is normally referred to as "path locking", while the locking of a plurality of paths assisted by automatic systems is referred to as "bundle locking".
DE 10 2004 009 265.6 discloses a method by means of which the operator can lock or unlock signal paths or signal bundles in the forward or backward direction by means of an appropriate command. By way of example, this prevents a transmission-relevant signal path from being accidentally interrupted. Since locked resources are normally associated with one user, the attempt to unlock an external resource will fail.
In summary, it can be stated that the activity of the operator also has technical aspects, in addition to the creative aspect of mixing and configuring television pictures from different signal sources. On the one hand, the correct signal sources must be selected for the input side, and must be passed to the correct outputs. Even this is quite difficult when there are more than two hundred inputs and two hundred outputs per switching matrix. On the other hand, the locking and unlocking of the input to output connections must be taken into account at the same time in this case, since a plurality of operators work in one studio or control room. For these reasons, the work of the operators in terms of the use of resources which are or are not jointly used is highly demanding.
There is thus a requirement to provide a method which reduces the load on the operator during his work, and as far as possible takes the stated technical aspects away from him, in order that he can concentrate on the creative aspect of his work.

Method for controlling a device for distribution of signals


A synthetic grass tile system and method are disclosed. An artificial turf tile system has a plurality of connectable tile members and a synthetic turf arrangement adhered to the tile members. The interconnected tile members, having the turf attached thereto, are cut into sections. The sections are then secured on a pallet for sale at a retail establishment. A method for producing a modular synthetic grass tile system follows the following steps: (a) providing a plurality of tile members; (b) snapping the tile members together at their edges to form a grid; and (c) adhering a sheet of synthetic turf to the top surface of the tile members.

The use of artificial turf as an alternative to real grass has been known for some time. Artificial turf is typically provided for installation in rolls. In some applications, artisans use tiles or other sub-turf supporting mechanisms deployed above a ground or concrete surface. The artificial turf is then unrolled and secured atop the supporting mechanism. In other applications, the turf may be directly secured onto a prepared surface, such as concrete.
These conventional installation methods and systems often require professional installation teams to work considerable hours per project. This substantially increases the cost and results in scheduling difficulties. Furthermore, should the turf ever need to be replaced, additional time and money would be lost, as the installers would have to remove the old turf and re-apply the new turf.


Systems and methods for scanning antennas with plasma gratings are described. An apparatus includes a semiconductor slab and an electrode set or illuminating system to inject a plasma grating. The systems and methods provide advantages in the compactness and higher efficiency in comparison with existing antennas.

1. Field of the Invention
The present invention relates generally to the field of antennas. More particularly, the present invention relates to scanning antennas that operate based on diffraction of an electromagnetic signal by a modulated non-equilibrium plasma grating. Specifically, a preferred implementation of the present invention relates to a millimeter wavelength (MMW) scanning antenna that operates based on diffraction of a primary beam by a modulated current-injected non-equilibrium plasma grating.
2. Discussion of the Related Art
Historically, the phased array antenna approach (quasi-optical approach) has generally been considered to be the most promising candidate for electronically controlled scanning antennas. The key components of a phased array antenna are the tunable phase-shifters (i.e., true time delay elements). However, these components are costly and often bulky.
In the past, an optical control has been used to improve the performance of phased array antennas. In this approach, infrared or visible light is used to control the electronic devices (e.g. phase-shifters) in the phased array. However, this photonics approach requires expensive photo-electronic (photonic) elements for conversion of the control signals being routed to each of the electronic devices in the array. The large number of photonic elements required for even a modest size array makes the resulting system unaffordable for most applications. This is particularly true for high frequencies (i.e., millimeter wavelength) where the manufacture of the electronic phase shifters themselves is still a challenging problem from a device fabrication perspective.
Nevertheless, the use of fiber optics technology to control an electronically scanned antenna provides a number of advantages in antenna performance. These advantages include: low interference, remote control operation, light weight, low power consumption, and high flexibility.
More recently, an optical approach rather than quasi-optical (phased array) approach was used to design photonically controlled antennas. In the optical approach, no discrete elements, phase-shifters, photo-detectors, etc., are needed. Instead of directing a millimeter wavelength beam through a photonically controlled array of discrete electronic elements, a reconfigurable plasma-grating is used to steer the antenna beam. A photo-induced plasma is excited in a semiconductor medium so as to form a periodic structure that functions as the diffraction grating. This direct approach eliminates the need for conventional phase-shifters and is a promising solution to the need to provide inexpensive beam steering in the millimeter wavelength band. The direct approach holds particular promise for such price sensitive applications as automobile collision warning systems.
Thus, a wholly optical approach, rather than quasi-optical, has been developed where a semiconductor slab containing a non-equilibrium electron-hole plasma is used as a holographic medium for diffraction of millimeter waves, thereby steering the antenna beam. Plasma patterning within the semiconductor slab defines the diffraction grating and allows the shaping of a passing millimeter wavelength beam so as to send it in a required direction. The main advantage of this direct approach is the avoidance of any need for tunable phase-shifters or other true time delay elements, thereby providing a dramatic cost reduction.
Referring to FIGS. 1A-1B, an antenna design utilizing this direct approach has been fabricated and tested in the past. Referring to FIG. 1A, a millimeter wavelength signal 10 propagates along a semiconductor waveguide 20. Alternatively, the propagation can be through a compound dielectric waveguide containing a photosensitive layer. By patterned illumination, a photo-induced plasma grating 30 (PIPG) is excited in the semiconductor waveguide 20, near its surface. The plasma grating 30 has a grating period .LAMBDA.. As in a leaky-wave antenna loaded with a metal grating, the millimeter wavelength signal 10 propagating along the semiconductor waveguide 20 interacts with the plasma grating 30 and couples out in a specific direction (i.e., at an angle .phi.) that is a function of the grating period .LAMBDA..
Referring now to FIG. 1B, the main disadvantage of this previous design is that the plasma grating 30 also significantly attenuates the millimeter wavelength signal 10 and prevents the millimeter wavelength signal 10 from propagating effectively along the entire length of the semiconductor waveguide 20. The amplitude of the transmitted millimeter wavelength signal (represented in FIG. 1B by the three parallel arrows of diminishing length) decreases as a function of the length of waveguide 20 through which the millimeter wavelength signal 10 has passed before being diffracted by grating 30. Therefore, it is very difficult to produce a radiating aperture of reasonable size with this design.


An improved filtering device for an aquarium tank, particularly a filtering device in which a plurality of "U" notches are formed at equal distance in the rim of the cup, the arc section formed by two notches has a lateral rib and the circular connecting rings in the lower portion of the cup allow the cups of the filtering device to be connected easily, the cup can also be rotated freely after connecting. In addition, the suction tube with the impeller, the filtering cotton and the carbon dioxide guide tube as well as the submerged motor combine to function so that carbon dioxide can be dissolved completely in water. Moreover, more oxygen can be generated inside the aquarium tank for healthier fish and plants, the filtered water through the filtering device according to the present invention becomes pure, crystal clear with a whirling and bubbling action.

(a) Field of the Invention
The present invention relates to a filtering device for an aquarium tank. More specifically, the present invention relates to the structure of an improved filtering device in which the cup body can be connected easily and carbon dioxide can be fully dissolved to give a pure, crystal clear conditioned water in the aquarium tank.
(b) Description of the Prior Art
The assembly of a conventional filtering cup for an aquarium is shown in FIG. 1. The upper cup A1 has a tapered bottom edge A11 the diameter of which is smaller than the upper cup A1. A plurality of equidistant notches A12 is located on the bottom edge A11 of the upper cup A1. Each notch A12 has a rib A121 which is used to fit into a corresponding flange A21 of the lower cup A2. The connecting of the upper cup A1 and the lower cup A2 can be accomplished by aligning the flange A21 with the notch A12 together. Either one of the cups can be twisted to allow the flange A21 to fit with the corresponding rib A121. However, the cup body with this kind of connection has the following disadvantages:
(1) The upper cup and the lower cup have to be aligned first, then twisted to connect together. Therefore, the connection can not be accomplished quickly.
(2) The assembly of the upper cup and the lower cup is complex, as can be seen from the aforesaid description.
(3) The cup assembly can nor be rotated freely to change the flow direction of water. Hence, the filtering device in the aquarium can not be operated efficiently.
The structure of a conventional carbon dioxide diffusing tube is shown in FIGS. 2a and 2b. It is made up of two semi-shell bodies 1 and 2 which are clamped together in slots 31 of plastic strips 3 and 4. A carbon dioxide guide tube 7 is coiled inside the tube body, a top cover 5 and a bottom cover 6 are then used to enclose and form the completed carbon dioxide diffusing tube. The inside surfaces of the semi-shell bodies 1 and 2 have a plurality of protruding plates, each of which has an appropriate width and is projected inward. On the exterior surface of the diffusing tube body are the water inlet and outlet connections 16 and 26 with projected rings 12, 13 and 22, 23. The centers of the top cover 5 and bottom cover 6 have punched holes 51 and 61, from which a plastic ring 52 and a plastic gasket 62 are attached to respectively.
Next to the central punched holes 51 and 61 are openings 53 and 63, which are plugged up by pressure relief plugs 54 and 64 respectively.
The carbon dioxide diffusing tube has the following disadvantages:
(1) The tube is made up of two pieces of shell. Therefore, the sealing can never be tight enough to be leak proof.
(2) It is complex and inconvenient to assemble the tube together.
(3) The tube has a simple carbon dioxide guide tube which is coiled inside the diffusing tube body. It does not delay the release of carbon dioxide into water.
(4) The tube can only provide carbon dioxide which will be mixed in water. The tube can not generate oxygen to the aquarium tank. Therefore, its usage is limited.