The present disclosure provides a method for providing an augmented reality, to server and portable terminal for same. Augmented reality providing server provides an augmented reality with information overlaid on captured video and includes server communication unit for inter-working with portable terminal; and server control unit for receiving selected menu information from portable terminal, generating first menu information data attained by extracting data that matches selected menu information by comparing the selected menu information with pre-stored location-associated information, and transmitting first menu information data to portable terminal, wherein the server control unit generates the first menu information data by selecting menus that match the selected menu information among a plurality of menus included in the location-associated information. In an embodiment, fast augmented reality operation can be obtained since portable terminal may receive and output information corresponding to menu selection immediately with a composition onto acquired image information.

Augmented reality (AR) technology is for sensing approximate position of a user and locating a service venue though comparisons between facility information such as nearby building data and real picture image data obtained from a camera in operation to provide related information. More specifically, being a branch of the virtual reality (VR), the augmented reality is a computer graphics technique that visually combines imaginary objects with the real world to provide the viewer with a scene of make-believe that objects appear to exist in the real world. Different from the conventional virtual reality involving only the virtual space and objects, it technically gets the real world reinforced with supplementary information through the synthesis of the virtual objects on the backdrop of the real world. Currently, the technology of augmented reality is in use in various fields such as broadcasting, advertisement, display, game, theme park, military, education, promotion, etc, yet it is not fully distributed to the general public.
The recent trend in the field of the mobile AR technology used in the communication terminal puts the spotlight to such augmented reality technology. Currently, applications based on the mobile AR technology starts to appear, and the early stage of technology is provided by using a marker based mobile AR technology or sensor based mobile AR technology. The marker based mobile AR technology incorporates particular symbols to be photographed and then recognized along with their corresponding building, while the sensor based mobile AR technology uses a GPS, digital compass and the like installed in the terminal to infer the current position of the terminal and its orientation of sight in which associated POI (point of interest) information is overlaid on the photographed image.
Such conventional technologies just presume the current position of the terminal and its orientation of sight by using the GPS, digital compass and the like installed in the terminal yet no technology has been provided for accurately recognizing the images inputted through the terminal.

Method for providing augmented reality, server for same, and portable terminal


Compositing aware digital image search techniques and systems are described that leverage machine learning. In one example, a compositing aware image search system employs a two-stream convolutional neural network (CNN) to jointly learn feature embeddings from foreground digital images that capture a foreground object and background digital images that capture a background scene. In order to train models of the convolutional neural networks, triplets of training digital images are used. Each triplet may include a positive foreground digital image and a positive background digital image taken from the same digital image. The triplet also contains a negative foreground or background digital image that is dissimilar to the positive foreground or background digital image that is also included as part of the triplet.

Digital image compositing is a fundamental task implemented by image processing systems of a computing device as part of digital image editing and graphic design. Digital image compositing involves combining foreground objects and background scenes from different sources to generate a new composite digital image. Conventional techniques used to perform digital image compositing, however, are both computationally inefficient and frustrating to users due to inefficiencies of user interaction supported by these conventional techniques. These inefficiencies and user frustrations are exacerbated by a multitude of diverse digital images that may act as sources for these objects and scenes, which may number in the millions.
Compatibility of a foreground object with a background scene, for instance, may be defined using a wide range of characteristics, the importance of which may differ based on content included in the digital images. In one such example, a viewpoint may have greater importance when inserting a foreground object of a car on a background scene of a road. On the other hand, semantic consistency may have greater importance when composing a skier with a snowy mountain. Conventional techniques, however, focus on a single characteristic or rely on manual extraction of features to define matching criteria. Thus, these conventional techniques are not capable of adapting to different characteristics and the differing relative importance of these characteristics in defining a match for different object categories as described above. Further, these conventional techniques may fail when confronted with "big data" as involved with addressing millions of digital images that may be available as compositing sources, an example of which is a stock digital image system accessible via a network.


A storage container for magnetic tape cassettes adapted to receive cassettes of different design, i.e. standard compact cassettes or digitally recorded cassettes. If a standard compact cassette is inserted tape reel locking members are activated but remain inactive upon insertion of a digitally recorded cassette.

The present invention relates to a container or a storage device for magnetic tape cassettes of the basic design set forth in U.S. Pat. No. 3,899,229 or modifications thereof as disclosed in U.S. Pat. Nos. 4,702,372 or 4,738,361 or 4,828,341 the disclosure of which is incorporated herein by reference.
These conventional devices comprise a housing and a transporter slidably guided in said housing and adapted to carry a cassette. The transporter slider is spring-biassed towards an open or removal position and may be locked or latched within the housing in a storing position. The latch may be manually released.
The known devices are designed to receive the well-known standard compact cassettes which exhibit freely accessible tape reels. When stored and subjected to vibrations, e.g. in a vehicle, there is a risk that the tape reels are inadvertently rotated and the cassette may become destroyed due to so-called "tape salad". Therefore, the known containers are provided with blocking members integrally formed with the slider so as to engage into the tape reels and to lock them.
Recently, a novel type of cassette has appeared under the designation "DCC" or digitally recorded cassette. Such cassettes permit improved reproduction quality over that of conventional compact cassettes with analog recording. Recorders developed for such DCC cassettes are able to reproduce from DCC cassettes but also from conventional cassettes. Consequently, the exterior appearance of the two cassette types is quite similar. There are, however, two significant differences: While the standard compact cassette exhibits protruding head face portions of trapezoid contour such protruding portions are not present with DCC cassettes. Further, DCC cassettes are equipped with shutters shielding the tape reels against intrusion of dust; the reels are locked within the cassette until the reels are exposed upon placing the cassette into the reproducing apparatus whereby the shutters are displaced.
It will be understood that the conventional cassette containers are not suited for storing of DCC cassettes because of their tape reel blocking members, necessitating design of a device specifically adapted to receive DCC cassettes. Since, however, the reproducing apparatus may use both types of cassettes and it is not predictable what cassette type will be the preferred one of a particular person, there is a need to provide a cassette container adapted to receive either type of cassette.

IDN Inventions and Development of Novelties AG


A method enables the positions of inoperable inkjets in printheads to be corrected for positional changes arising from shifts in media, shrinkage of the media, thermal expansion of optical sensors that detect the inoperable inkjets, and other measurement errors. The measurement errors are detected with reference to image data corresponding to a reference pattern printed within a portion of a print job. Thus, reference marks do not need to be printed in areas outside of a print job as previously required.

Imaging devices form images on image receiving members that include paper and other print media. Different imaging or printing techniques, which include laser printing, inkjet printing, offset printing, dye-sublimation printing, thermal printing, and the like, may be used to produce printed documents. In particular, inkjet imaging devices eject liquid ink from printheads to form images on an image receiving member. The printheads include a plurality of inkjets that are arranged in some type of array. Each inkjet has a thermal or piezoelectric actuator that is coupled to a printhead controller. The printhead controller generates firing signals that correspond to digital data for images. The printhead actuators respond to the firing signals by ejecting ink drops onto an image receiving member to form an ink image that corresponds to the digital image used to generate the firing signals. The size of the ink drops and the timing of the ejection of the ink drops are affected by the frequency and amplitude of the firing signals.
Throughout the life cycle of imaging devices, the image generating ability of the device requires evaluation and, if the images contain detectable defects, correction. Various defects in the image generating process affect ink image quality. In an inkjet printing system, one such defect occurs when an individual inkjet becomes inoperable as either a "weak" or "missing" inkjet. A weak inkjet intermittently ejects ink drops or ejects ink drops having a mass that is different than expected for the firing signal used to operate the actuator for the inkjet. A missing inkjet fails to eject ink drops entirely. Inoperable inkjets, including both weak and missing inkjets, negatively impact the quality of printed images.
Some existing printing systems are configured to detect and compensate for weak or missing inkjets. Identifying inoperable inkjets typically requires the printing of reference patterns, which are specially designed and arranged ink lines that are printed on the image receiving member. These reference patterns must be printed separately from the images printed as part of a print job. Consequently, the printing of reference patterns absorbs a portion of the resources to be used for productive printing. Because a printhead often includes hundreds or thousands of individual inkjets, correct identification of a single inoperable inkjet presents challenges. In some imaging devices, an optical sensor is used to generate image data of the reference pattern on an image receiving member and these data are analyzed and correlated to inkjet positions in a printhead to identify a weak or missing inkjet. Errors in the alignment of the photosensors in the optical sensor or in the calibration of the sensor along with distortions that arise from media shifting during operation of the printer affect the accuracy of the analysis of the image data. Consequently, improvements to the identification of weak or missing inkjets in an inkjet printer would be beneficial.

Method and system of in-document detection of weak or missing inkjets in an inkjet printer


A belt or chain tensioner whereby a resonance due to chain or belt vibration is alleviated by means of hysteresis loss obtained by friction between adjacent elements of a reversely and closely wound multiple compression spring which urges a tension rod.

The present invention relates to a tensioner for tensing belt or chain adequately by using urging tensioning a rod, more particularly to such tensioner having a compression spring for urging tension rod.
This type of tensioner has shown the following problems: when a tension rod is excessively urged and does not return due to the excessive variation of driving torque, the belt or chain becomes excessively tensioned sometimes causing buzzing or until causing excessive wear on itself. Taking this undesirable situation in consideration, a tensioner 100 has been disclosed by the Japanese Utility Model Application Laid-open No. 62-13257 whereby said tension rod has been provided with a restoring capacity.
As shown in the FIG. 4, the tension rod 101 of tensioner 100 for tensioning a chain is mounted in a casing 104 so as to be urged freely by a compression spring 105. The tension rod 101 is formed with a rack on its side and the mating pawls of ratchet 102 are engaged with the rack. A shaft 103 fixed on the ratchet 102 is inserted in the vertical slot 106 so that the ratchet pawls may slip on the rack to change its position. When the chain is slackened, normally the tension rod 101 advances to keep adequate tension on it, the wack or returning stroke of tension rod 101 is controlled by the ratchet pawl 102. On the other hand, when the chain is excessively tensioned due to the excessive advance of tension rod 101, the shaft 103 of the ratchet works to alleviate excessive tension.
Hereinafter the problems to be solved by the invention will be explained. Since the back stroke of tension rod 101 is controlled by the ratchet pawl 102, the shaft 103 and vertical slot 105 as aforementioned, the back stroke of the tension rod 101 excessively urged by the resonant amplitude of belt or chain is reduced and when the shaft 103 of ratchet pawl hits on the bottom of vertical slot 106 after coursing the full stroke of slot, the tension rod 101 does not function to alleviate excessive tension of chain or chain because the tensioner turns only a rigid object against the counterforce of belt or chain.
The present invention has been developed considering the above situations and is to provide a tensioner having a prompt response to slackening, an ability to alleviate excessive tension on belt or chain and a simple and compact construction.

Belt or chain tensioner for power transmitting system


There is disclosed a tool for centering a casing or liner In a borehole. The tool Includes a tubular section Inserted In the casing/liner. A number of pressure cylinders (4) are mounted in the tubular section along the circumference. The pressure cylinders may be expanded by pressure from the Inside of the tubular section. In use, the casing/liner with the tubular section is run into the borehole with the pressure cylinders retracted. Thereafter, the pressure Inside the casing/liner Is Increased pressing the pressure cylinders out and centering the casing/liner.

A well is drilled in several sections (due to formation changes/pressure) of different sizes. There are many types and sizes of casing/liners with associated bits and hole openers. Commonly used casing/liners sizes are: 30″, 20″, 18⅝″, 16″, 13⅜″, 11¾″, 10¾″, 9⅝″, 8⅝″, 7¾″, 7⅝″, 7″, 6⅝″, 5½″, 5″ and 4½″.
Bit sizes go from 30″, 26″, 24″, 22″, 20″, 17½″, 16″, 14¾″, 13½″, 12¼″, 11″, 10¾″, 9⅞″, 9½″, 8¾″, 8⅜″, 8⅜″, 7⅞″, 6¾″, 6½″, 6¼″, 6⅛″, 6″, 5⅞″, 4¼″, 3⅞″ and 3¾″. Different sizes of hole openers in addition to bits are used depending on the formation, they go from 36″ and down to about 7″.
A typical well drilled on the Norwegian continental shelf can be as follows: One starts by drilling a 36″ hole using 30″ bit and a 36″ hole opener in order to insert a 30″ conductor/casing (it can also be rammed into the seabed using a special hammer from the rig).
A 24″ hole is then drilled for 18⅝″ casing/well head assembly (anchoring tube for the next casings).
A 17½″ hole is then drilled for setting a 13⅜″ casing.
A 12½″ hole is then drilled for 9⅝″ casing.
An 8½″ hole is then drilled for 7″ casing.
All casings as mentioned above are cemented either to anchor itself or for making isolation between different zones, or both, but in particular for the 18⅝″, 13⅜″ and 9⅝″ casings it is important to have good zone isolation. The lower part of these sections tends to have a high angle, the angle being more horizontal than vertical.
When a hole is drilled with e.g. a 12½″ bit, the hole normally ranges from 12½″ to maybe in some places up to as much as 14″-15″.
In some cases, the hole will creep after the well has been drilled, i.e. when the hole has been drilled, the drill string must be pulled out of the hole and the casing must run into the hole. This may take up to 1-2 days. The hole can then be significantly smaller in dimension than as originally drilled, sometimes so narrow that it is not possible to run in with the casing to the bottom. The whole length of casing must then be pulled out of the hole (if possible) and go down with the bit again on the drill string to open the hole to the original size and try to run the casing again. Occasionally the casing must be set where it stops due to being stuck, and this section will then be "lost" because it is not fully set, e.g. on top of the reservoir.
When the casing is run into the hole, there will normally be a centralizer on each collar on the lowermost 200 meters (this is a requirement in Norway). Centralizers are designed to center the casing so that, when pumping the cement, the cement will enter inside the casing and exit at the bottom of the casing and up on the outside of the casing, the cement is intended to displace the well fluid between the formation and the casing and fill the volume between the formation and the casing all around the area where there are centralizers, to get a good zone isolation.
One of the biggest challenges of drilling a borehole and completing it in accordance with applicable requirements is precisely zone isolation (the cementing of casings). The challenge is that it is difficult to achieve a good cementing job, cementing jobs are usually of varying quality due to channeling of the cement and/or the lower side of the casing resting against the formation due to gravity.
The consequence of not having a good cementing/isolation job around the casing is that you can get migration of oil/gas reservoir to shallower formations or even all the way to the sea bed and surface.
If the oil/gas reservoir migrates to shallower formations, the pressure from the reservoir at the original depth will be moved to the shallower formation. In some cases this will make it is impossible to drill into the shallower formations because the pressure is too high for the drilling mud to be able to compensate for the abnormally high pressure formed due to the migration.
Only 20% of the cement jobs are satisfactory. The remaining 80% are too poor to be characterized as good zone isolation.
This is one of the reasons that there are leaks between the different zones and in some instances the reservoir migrates into overlying zones and it may lead to being difficult or almost impossible to handle as the pressure becomes too high in the "new" reservoir to balance the formation pressure by work over or new wells (ref. Gullfaks).
Centralizers on the market today are either positive, i.e. they are run into the hole with tensioned steel spring slats centering the casing all the way from the top side to the setting point (bottom of hole), or there are fixed (solid) centralizing tools available, but here the challenge is that they form a resistance/hindrance for the cement to be pumped up the annulus without meeting too much resistance.
Both methods are known to be a resistance/hindrance preventing the casing from entering fully down due to resistance and tearing of the hole wall.
Sometimes it is not possible to run casing as far as planned, then the casing must be pulled again to adjust the length of the casing or the casing must be removed in its entirety and then a new hole section must be drilled before we can run and set the casing again. It is thus a challenge that the centralizing tools may be torn apart and in the worst case cause major problems for completing the well.
Regarding the centralizers on the market today, they are driven into the hole activated, i.e. they are designed to center the casing from the very start to run casing from the rig until they are right on setting depth. They will then tear up the formation and exercise resistance all along the well path length, they will also make "dunes" of formation ahead which will exert great friction when circulating drilling mud before pumping cement.

Tool for centering a casing or liner in a borehole and method of use


A compound represented by general formula (I) below, or a pharmacologically acceptable salt thereof:

In the treatment of disease, morphological and functional changes that are caused by disease within an organism are important for detecting disease at an early stage. In the treatment of cancer, in particular, learning the position, size, and nature of a tumor early on is extremely important for determining a strategy and protocol. Examples of methods that have conventionally been employed for this purpose, in addition to biopsy by puncture and the like, are image diagnosis by X-ray imaging, MRI, PET, and ultrasound imaging. Biopsy is useful for making a diagnosis, but the burden on the patient is great and it is unsuitable for tracking the progression of lesions over time. X-ray imaging, MRI, and PET necessarily expose the patient to radiation and electromagnetic waves. Further, in conventional imaging diagnosis such as that mentioned above, complex operations and long periods are required for measurement. From the perspective of the size and shape of the device, it is difficult to perform surgery while navigating using these methods during surgical operations.
Fluorescence imaging is an imaging diagnostic method that solves these problems. In this method, a substance that generates fluorescence when exposed to stimulating light of a specific wavelength is employed as an imaging agent. Further, this method comprises the steps of irradiating an excitation beam from outside the organism and detecting the fluorescence that is released by the fluorescent material within the organism.
Cyanine compounds are typical compounds that can be used in the fluorescence imaging method. In practice, indocyanine green (abbreviated as "ICG" hereinafter) is currently employed to test liver function and in ophthalmic angiography. However, ICG dissolves readily, and must be employed in formulations to which iodine is added. There is thus a problem in that it cannot be used in patients who are allergic to iodine.
The compound (denoted as "SF-64" hereinafter) that is described in Claim 1 of Japanese Patent No. 3,507,060, the disclosure of which is expressly incorporated by reference herein in its entirety, is an example of a cyanine compound that solves this solubility problem. This dye is characterized by good solubility in water and low toxicity. It is also described in this patent as having the property of outlining tumors.

Abstract: wherein X represents sulfonic acid group; R1 and R2 represent substituents; R3 to R6 represent optionally substituted alkyl groups; R7 and R8 represent an optionally substituted alkyl groups; L1 to L3 represent optionally substituted methine groups, with at least one of L1 to L3 being a methine group having a substituent with the bulkiness of an ethyl group or greater; r represents an integer of from 0 to 3, and when r is 2 or more, the plural L2 and the plural L3 may be the same or different, respectively; each of m and n independently represents an integer of 0 to 3; and at least one of the substituents is sulfonic acid group or a group comprising sulfonic acid group, which is useful as an imaging component in a near infrared fluorescence imaging agent.


A sample staining device, comprising a staining platform provided with a staining solution and cleaning solution supply part; glass slide support structures located on either side of the staining platform and forming a certain clearance between a glass slide and the staining platform; and a glass slide driving mechanism that enables the glass slide to move while maintaining a certain clearance from the staining platform. When said device works, a staining solution is supplied to the staining platform, and a convex liquid surface is formed due to surface tension; when the glass slide moves to the convex liquid surface of the staining solution, the staining solution infiltrates and diffuses in the clearance formed between the staining platform and the glass slide to cover the glass slide so as to stain a sample; and after the glass slide is stained, a cleaning solution is supplied to clean the residual staining solution.

In the field of medical examination, staining is an experimental method in which tissues and intracellular structures of a sample to be tested are stained with different color(s) by means of one or more dyes, so that the intracellular structures can be clearly observed under a microscope, in order to make a correct judgment for clinical diagnosis.
Conventional sample staining may be classified into manual staining and automatic staining. The automatic staining is accomplished via an automatic staining device. The conventional automatic staining device mainly includes two types of mainstream structures, one of which stains each smear by using a plurality of staining cassettes, resulting in a low working efficiency and a difficulty to meet demands of large quantities of work. The other type of the staining devices simultaneously stain a plurality of smears by using a staining tray, while they have precise and complex structures. The staining device using the staining cassette needs to be provided with various transporting and holding mechanisms to transport the stain cassette and hold the smears, resulting in a complex structure and a high cost. The staining device using the staining tray needs to be provided with a moving mechanism for the stain tray to move the smears to enter and exit the staining tray, resulting in a complex structure and a high cost.
And the manual staining is not suitable for examination of large quantities of samples as it requires a high level of skills for an operator and has a low staining efficiency.
As such, an urgent problem to be solved by those skilled in the art at present is how to effectively solve the technical problem that it is difficult to take into account both the operation efficiency and the equipment cost in the implementation of sample staining.


A wired pipe assembly includes a first wired pipe segment including a first body extending from a first box end to a first pin end and a second wired pipe segment including a second body extending from a second box end to a second pin end. The assembly also includes an electromagnetic directional coupler including an input line disposed in the first wired pipe segment and an output line disposed in the second wired pipe segment.

During subterranean drilling and completion operations, a pipe or other conduit is lowered into a borehole in an earth formation during or after drilling operations. Such pipes are generally configured as multiple pipe segments to form a "string", such as a drill string or production string. As the string is lowered into the borehole, additional pipe segments are coupled to the string by various coupling mechanisms, such as threaded couplings.
Various power and/or communication signals may be transmitted through the pipe segments via a "wired pipe" configuration. Such configurations include electrical, optical or other conductors extending along the length of selected pipe segments. The conductors are operably connected between pipe segments by a variety of coupling configurations.
One such coupling configuration includes a threaded male-female configuration often referred to as a pin box connection. The pin box connection includes a male member, i.e., a "pin" that includes an exterior threaded portion, and a female member, i.e., a "box", that includes an interior threaded portion and is configured to receive the pin in a threaded connection.
Some wired pipe configurations include a transmission device mounted on the tip of the pin as well as in the box end. The transmission device, or "coupler," can transmit power, data or both to an adjacent coupler. The coupler in the pin end is typically connected via a coaxial cable to the coupler in the box end.

Electromagnetic directional coupler wired pipe transmission device


A fluid compressor includes a cylinder and a columnar rotary rod. The rod is arranged in the cylinder so as to extend in the axial direction thereof and be eccentric thereto, and orbitable relative to the cylinder without rotation with respect to the cylinder while part of the rod is in contact with the inner circumferential surface of the cylinder. A spiral groove is formed on the outer circumference of the rod and a spiral blade is fitted in the groove. The space between the outer circumference surface of the rod and the inner circumference surface of the cylinder is divided by the blade into a plurality of operating chambers. The groove has an overall length larger than that of the blade by a predetermined length so that the blade is displaceable relative to the rod in the radial and circumferential directions of the rod without sliding on the inner circumferential of the cylinder.

1. Field of the Invention
The present invention relates to a fluid compressor for compressing, e.g., a refrigerant gas in a refrigeration cycle and, more particularly, to a fluid compressor having a spiral blade.
2. Description of the Related Art
Various conventional compressors such as reciprocating and rotary compressors are known. In these compressors, however, the structures of drive units such as crank shafts for transmitting rotational forces to compression units, as well as the structures of the compression units themselves, are complicated, and a large number of components are required. In addition, in order to obtain high compression efficiency, a check valve must be disposed at the discharge side thereof. However, the pressure difference between the inlet and outlet sides of the check valve is large, with the result that gas tends to leak from the check valve. Thus, any conventional compressor has low compression efficiency. In order to solve this problem, dimensional precision of the respective components as well as assembly precision must be improved and, as a consequence, manufacturing costs become high.
In recent years, in order to solve the above problem, there has been provided a fluid compressor having a spiral blade.
A compressor of this type comprises a cylinder, and a rotary rod eccentrically arranged in the cylinder and orbitable relative thereto. A spiral groove is formed on the outer circumferential surface of the rod, along almost the entire length thereof. A spiral blade is fitted in the spiral groove. The outer circumferential surface of the blade is in tight contact with the inner circumferential surface of the cylinder The spiral blade slides in the spiral groove, in the radial direction of the rod, upon the orbital movement of the rod relative to the cylinder.
The space between the rod and the cylinder is partitioned into a plurality of spaces by the blade. The pitches of the spiral groove are gradually narrowed with a distance from one end of the rod. For this reason, the volumes of the plurality of spaces gradually decrease from one end of the rod to the other. Therefore, a fluid flowing from one end of the rod into the spaces is conveyed to the other end of while being confined in the spaces. During this conveyance, the fluid is gradually compressed and finally delivered from the other end of the rod.
In the fluid compressor having the above structure, the overall length of the spiral groove is equal to that of the blade. Each end of the blade abuts against the corresponding end of the groove. For this reason, during the operation of the compressor, the blade is rotated integral with the rod. Since the rod is located eccentric to the cylinder, the speed at which its outer circumference moves is different from the speed at which the inner circumference of the cylinder moves, except at the start of each rotation of the rod and the cylinder. Therefore, the outer circumferential surface of the blade reciprocally slides on the inner circumferential surface of the cylinder in the circumferential direction.
Sliding movement between the blade and the cylinder occurs along the entire length of the blade. A large friction loss occurs between the blade and the cylinder and, as a result, the operation efficiency of the compressor is degraded.


A method is disclosed for using tubular material to replace a semilunar heart valve (i.e., an aortic or pulmonary valve). To create such a replacement valve, the native valve cusps are removed from inside an aorta or pulmonary artery, and the inlet end of a tubular segment is sutured to the valve annulus. The outlet (distal) end of the tube is either xe2x80x9ctackedxe2x80x9d at three points distally, or sutured longitudinally along three lines; either method will allow the flaps of tissue between the suture lines to function as movable cusps. This approach generates flow patterns that reduce turbulence and closely duplicate the flow patterns of native semilunar valves. An article of manufacture is also disclosed, comprising a sterile biocompatible synthetic material which has been manufactured in tubular form, by methods such as extrusion or coating a cylindrical molding device, to avoid a need for a suture line or other seam to convert a flat sheet of material into a tubular shape. The synthetic tube is packaged within a sealed watertight enclosure that maintains sterility of the tube.

This invention is in the field of heart surgery and relates to replacement of diseased or injured heart valves.
Anatomy of Normal Heart Valves
There are four valves in the heart that serve to direct the flow of blood through the two sides of the heart in a forward direction. On the left (systemic) side of the heart are: 1) the mitral valve, located between the left atrium and the left ventricle, and 2) the aortic valve, located between the left ventricle and the aorta. These two valves direct oxygenated blood coming from the lungs, through the left side of the heart, into the aorta for distribution to the body. On the right (pulmonary) side of the heart are: 1) the tricuspid valve, located between the right atrium and the right ventricle, and 2) the pulmonary valve, located between the right ventricle and the pulmonary artery. These two valves direct de-oxygenated blood coming from the body, through the right side of the heart, into the pulmonary artery for distribution to the lungs, where it again becomes re-oxygenated to begin the circuit anew.
All four of these heart valves are passive structures in that they do not themselves expend any energy and do not perform any active contractile function. They consist of moveable xe2x80x9cleafletsxe2x80x9d that are designed simply to open and close in response to differential pressures on either side of the valve. The mitral and tricuspid valves are referred to as xe2x80x9catrioventricular valvesxe2x80x9d because of their being situated between an atrium and ventricle on each side of the heart. The mitral valve has two leaflets and the tricuspid valve has three. The aortic and pulmonary valves are referred to as xe2x80x9csemilunar valvesxe2x80x9d because of the unique appearance of their leaflets, which are more aptly termed xe2x80x9ccuspsxe2x80x9d and are shaped somewhat like a half-moon. The aortic and pulmonary valves each have three cusps.
Since the physiological structures of native mitral and tricuspid valves and native aortic and pulmonary valves are important to this invention, they are depicted in FIG. 1, which contains a cross-sectional cutaway depiction of a normal human heart 100 (shown next to heart 100 is a segment of tubular tissue 200 which will be used to replace the mitral valve, as described below). The left side of heart 100 contains left atrium 110, left ventricular chamber 112 positioned between left ventricular wall 114 and septum 116, aortic valve 118, and mitral valve assembly 120. The components of the mitral valve assembly 120 include the mitral valve annulus 121, which will remain as a roughly circular open ring after the leaflets of a diseased or damaged valve have been removed; anterior leaflet 122 (sometimes called the aortic leaflet, since it is adjacent to the aortic region); posterior leaflet 124; two papillary muscles 126 and 128 which are attached at their bases to the interior surface of the left ventricular wall 114; and multiple chordae tendineae 132, which couple the mitral valve leaflets 122 and 124 to the papillary muscles 126 and 128. There is no one-to-one chordal connection between the leaflets and the papillary muscles; instead, numerous chordae are present, and chordae from each papillary muscle 126 and 128 attach to both of the valve leaflets 122 and 124.
The other side of the heart contains the right atrium 150, a right ventricular chamber 152 bounded by right ventricular wall 154 and septum 116, and a tricuspid valve assembly 160. The tricuspid valve assembly 160 comprises a valve annulus 162, three leaflets 164, papillary muscles 170 attached to the interior surface of the right ventricular wall 154, and multiple chordae tendineae 180 which couple the tricuspid valve leaflets 164 to the papillary muscles 170-174.
As mentioned above, the mitral valve leaflets 122 and 124, and tricuspid valve leaflets 164 are all passive structures; they do not themselves expend any energy and do not perform any active contractile function. They are designed to simply open and close in response to differential pressures on either side of the leaflet tissue. When the left ventricular wall 114 relaxes so that the ventricular chamber 112 enlarges and draws in blood, the mitral valve 120 opens (i.e., the leaflets 122 and 124 separate). Oxygenated blood flows in a downward direction through the valve 120, to fill the expanding ventricular cavity. Once the left ventricular cavity has filled, the left ventricle contracts, causing a rapid rise in the left ventricular cavitary pressure. This causes the mitral valve 120 to close (i.e., the leaflets 122 and 124 re-approximate) while the aortic valve 118 opens, allowing the oxygenated blood to be ejected from the left ventricle into the aorta. The chordae tendineae 132 of the mitral valve prevent the mitral leaflets 122 and 124 from prolapsing back into the left atrium 110 when the left ventricular chamber 114 contracts.
The three leaflets, chordae tendineae, and papillary muscles of the tricuspid valve function in a similar manner, in response to the filling of the right ventricle and its subsequent contraction.
The cusps of the aortic valve also respond passively to pressure differentials between the left ventricle and the aorta. When the left ventricle contracts, the aortic valve cusps open to allow the flow of oxygenated blood from the left ventricle into the aorta. When the left ventricle relaxes, the aortic valve cusps reapproximate to prevent the blood which has entered the aorta from leaking (regurgitating) back into the left ventricle. The pulmonary valve cusps respond passively in the same manner in response to relaxation and contraction of the right ventricle in moving de-oxygenated blood into the pulmonary artery and thence to the lungs for re-oxygenation. Neither of these semilunar valves has associated chordae tendineae or papillary muscles.
In summary, with relaxation and expansion of the ventricles (diastole), the mitral and tricuspid valves open, while the aortic and pulmonary valves close. When the ventricles contract (systole), the mitral and tricuspid valves close and the aortic and pulmonary valves open. In this manner, blood is propelled through both sides of the heart.
The anatomy of the heart and the structure and terminology of heart valves are described and illustrated in detail in numerous reference works on anatomy and cardiac surgery, including standard texts such as Surgery of the Chest (Sabiston and Spencer, eds., Saunders Publ., Philadelphia) and Cardiac Surgery by Kirklin and Barrett-Boyes.
Pathology and Abnormalities of Heart Valves
Heart valves may exhibit abnormal anatomy and function as a result of congenital or acquired valve disease. Congenital valve abnormalities may be so severe that emergency surgery is required within the first few hours of life, or they may be well-tolerated for many years only to develop a life-threatening problem in an elderly patient. Acquired valve disease may result from causes such as rheumatic fever, degenerative disorders of the valve tissue, bacterial or fungal infections, and trauma.
Since heart valves are passive structures that simply open and close in response to differential pressures on either side of the particular valve, the problems that can develop with valves can be classified into two categories: 1) stenosis, in which a valve does not open properly, or 2) insufficiency (also called regurgitation), in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve or in different valves. Both of these abnormalities increase the workload placed on the heart, and the severity of this increased stress on the heart and the patient, and the heart""s ability to adapt to it, determine whether the abnormal valve will have to be surgically replaced (or, in some cases, repaired) or not.
In addition to stenosis and insufficiency of heart valves, surgery may also be required for certain types of bacterial or fungal infections in which the valve may continue to function normally, but nevertheless harbors an overgrowth of bacteria (a so-called xe2x80x9cvegetationxe2x80x9d) on the leaflets of the valve that may flake off (xe2x80x9cembolizexe2x80x9d) and lodge downstream in a vital artery. If such vegetations are on the valves of the left side (i.e., the systemic circulation side) of the heart, embolization results in sudden loss of the blood supply to the affected body organ and immediate malfunction of that organ. The organ most commonly affected by such embolization is the brain, in which case the patient suffers a stroke. Thus, surgical replacement of either the mitral or aortic valve (left-sided heart valves) may be necessary for this problem even though neither stenosis nor insufficiency of either valve is present. Likewise, bacterial or fungal vegetations on the tricuspid valve may embolize to the lungs (resulting in a lung abscess) and therefore, may require replacement of the tricuspid valve even though no tricuspid valve stenosis or insufficiency is present. With the exception of congenital pulmonary valve stenosis or insufficiency, it is unusual for a patient to develop an abnormality of the pulmonary valve that is significant enough to require surgical repair or replacement.
Currently, surgical repair of mitral and tricuspid valves is preferred over total valve replacement when possible, although often the valves are too diseased to repair and must be replaced. Most abnormalities of the aortic valve require replacement, although some efforts are now being made to repair insufficient aortic valves in selected patients. Valve repair and valve replacement surgery is described and illustrated in numerous books and articles, including the texts cited herein.
Current Options for Heart Valve Replacement
If a heart valve must be replaced, there are currently several options available, and the choice of a particular type of prosthesis (i.e., artificial valve) depends on factors such as the location of the valve, the age and other specifics of the patient, and the surgeon""s experiences and preferences. Available prostheses include three categories of valves or materials: mechanical valves, tissue valves, and aortic homograft valves. These are briefly discussed below; they are illustrated and described in detail in texts such as Replacement Cardiac Valves, edited by E. Bodnar and R. Frater (Pergamon Press, New York, 1991).
Artificial Mechanical Valves
Mechanical valves include caged-ball valves (such as Starr-Edwards valves), bi-leaflet valves (such as St. Jude valves), and tilting disk valves (such as Medtronic-Hall or Omniscience valves). Caged ball valves usually are made with a ball made of a silicone rubber (Silastic(trademark)) inside a titanium cage, while bi-leaflet and tilting disk valves are made of various combinations of pyrolytic carbon and titanium. All of these valves are attached to a cloth (usually Dacron(trademark)) sewing ring so that the valve prosthesis can be sutured to the patient""s native tissue to hold the artificial valve in place postoperatively. All of these mechanical valves can be used to replace any of the heart""s four valves. No other mechanical valves are currently approved for use by the FDA in the U.S.A.
The main advantage of mechanical valves is their long-term durability. Their main disadvantage is that they require the patient to take systemic anticoagulation drugs for the rest of his or her life, because of the propensity of mechanical valves to cause blood clots to form on them. If such blood clots form on the valve, they may preclude the valve from opening or closing correctly or, more importantly, the blood clots may disengage from the valve and embolize to the brain, causing a stroke. The anticoagulant drugs that are necessary to prevent this are expensive and potentially dangerous in that they may cause abnormal bleeding which, in itself, can cause a stroke if the bleeding occurs within the brain.
In addition to the mechanical valves available for implantation today, a number of other valve designs are described and illustrated in a chapter called xe2x80x9cExtinct Cardiac Valve Prostheses,xe2x80x9d at pages 307-332 of Replacement Cardiac Valves (Bodnar and Frater, cited above). Two of the xe2x80x9cextinctxe2x80x9d valves which deserve attention as prior art in the subject invention are the McGoon valve (pp. 319-320) and the Roe-Moore valve (pp. 320-321). Both of these involve flexible leaflets made of an elastomer or cloth coated with polytetrafluoroethylene (PTFE, widely sold under the trademark TEFLON), mounted inside a cylindrical stent. Although both were tested in humans, they were never commercialized and apparently are not being actively studied or developed today.
Artificial Tissue Valves
Most tissue valves are constructed by sewing the leaflets of pig aortic valves to a stent (to hold the leaflets in proper position), or by constructing valve leaflets from the pericardial sac (which surrounds the heart) of cows or pigs and sewing them to a stent. The stents may be rigid or slightly flexible and are covered with cloth (usually a synthetic material sold under the trademark Dacron(trademark)) and attached to a sewing ring for fixation to the patient""s native tissue. The porcine or bovine tissue is chemically treated to alleviate any antigenicity (i.e., to reduce the risk that the patient""s body will reject the foreign tissue). These tri-leaflet valves may be used to replace any of the heart""s four valves. The only tissue valves currently approved by the FDA for implantation in the U.S.A. are the Carpentier-Edwards Porcine Valve, the Hancock Porcine Valve, and the Carpentier-Edwards Pericardial Valve.
The main advantage of tissue valves is that they do not cause blood clots to form as readily as do the mechanical valves, and therefore, they do not absolutely require systemic anticoagulation. Nevertheless, many surgeons do anticoagulate patients who have any type of artificial mitral valve, including tissue valves. The major disadvantage of tissue valves is that they lack the long-term durability of mechanical valves. Tissue valves have a significant failure rate, usually appearing at approximately 8 years following implantation, although preliminary results with the new commercial pericardial valves suggest that they may last longer. One cause of these failures is believed to be the chemical treatment of the animal tissue that prevents it from being antigenic to the patient. In addition, the presence of the stent and sewing ring prevents the artificial tissue valve from being anatomically accurate in comparison to a normal heart valve, even in the aortic valve position.
Homograft Valves
Homograft valves are harvested from human cadavers. They are most commonly aortic valves but also occasionally include pulmonic valves. These valves are specially prepared and frozen in liquid nitrogen, where they are stored for later use in adults for aortic valve replacement, or in children for pulmonary valve replacement. A variant occasionally employed for aortic valve replacement is to use the patient""s own pulmonary valve (an autograft) to replace a diseased aortic valve, combined with insertion of an aortic (or pulmonary) homograft from a cadaver to replace the excised pulmonary valve (this is commonly called a xe2x80x9cRoss procedurexe2x80x9d).
The advantage of aortic homograft valves is that they appear to be as durable as mechanical valves and yet they do not promote blood clot formation and therefore, do not require anticoagulation. The main disadvantage of these valves is that they are not available in sufficient numbers to satisfy the needs of patients who need new aortic or pulmonary valves. They also cannot be used-to replace either the mitral valve or tricuspid valve. In addition, they are extremely expensive and much more difficult to implant than either mechanical or tissue valves. The difficulty in implantation means that the operative risk with a homograft valve is greater in a given patient than it is with either a mechanical or tissue valve. An additional problem is that in June 1992, the FDA reclassified homograft valves as an experimental device, so they are no longer available on a routine basis.
Principles of Artificial Heart Valve Construction
All artificial heart valves are designed to optimize three major physiologic characteristics and one practical consideration. The three major physiologic characteristics are (1) hemodynamic performance, (2) thrombogenicity, and (3) durability. The practical consideration involves ease of surgical implantation.
Multiple factors impact on each of these potential problems in the development of artificial valves. As a result, the advantage of artificial valve A over artificial valve B in one area is typically counterbalanced by valve B""s advantage in another area. If one artificial heart valve were clearly superior in all aspects to all other artificial valves in all four of these areas, it would be the only artificial valve used.
Artificial Mechanical Valves
The hemodynamic performance of mechanical heart valves has been satisfactory but not optimal, especially in the smaller sizes. All previously constructed mechanical heart valves have had some type of obstructing structure within the flow orifice of the valve when the valve is in the open position. For example, bi-leaflet valves, such as the St. Jude valve, have two bars across the orifice and in addition, the leaflets themselves are within the orifice when the valve is in the open position. Single-leaflet disc valves, such as the Medtronic-Hall valve, have a central bar and strut mechanism that keep the leaflet in place. The Bjork-Shiley valves have either one or two struts that span the valve orifice in addition to the partially-opened disc itself. The Omniscience valve has the partially opened disk itself in the valve orifice when open, and the Starr-Edwards caged-ball valve has both the ball and the cage within the flow orifice of the valve in the open position. All of these structures decrease the hemodynamic performance of the mechanical valves.
Such obstructions also interfere with the normal flow patterns within and around the mechanical valve and therefore, promote thrombosis. More importantly, all artificial surfaces are thrombogenic (clot-promoting) to a greater or lesser degree. The only completely non-thrombogenic (non-clot-promoting) surface that exists is the layer of viable endothelial cells that line the interior of all the body""s vascular surfaces, including the inside of the heart chambers and the native valve leaflets. Therefore, any metal or plastic material, no matter how highly polished, will have some level of thrombogenicity unless the surface of the artificial material can be covered with endothelial cells. It is for this reason that all patients with artificial mechanical heart valves must be permanently anticoagulated.
The major advantage of mechanical valves over tissue valves is long-term durability. Mechanical valve construction has been based on sophisticated engineering principles that have proven to be sound in terms of providing devices that are extremely resistant to wear and structural failure. Nevertheless, structural failure of mechanical valves does occur and it is the major reason for the recent withdrawal from the market of two commercially available mechanical valves (the Bjork-Shiley Concavo-Convex(trademark) single disc valve and the Duramedics(trademark) bi-leaflet valve).
Artificial Tissue Valves
Under the best of circumstances (i.e., replacement of the aortic valve), the construction of artificial tissue valves has been based on the concept that if the artificial valve can be made to approximate the anatomy (form) of the native valve, then the physiology (function) of the artificial valve will also approximate that of the native valve. This is the concept that xe2x80x9cFunction Follows Form.xe2x80x9d For example, the manufacturers of all artificial porcine valves first re-create the form of a native human aortic valve by: 1) harvesting a porcine aortic valve, 2) fixing it in glutaraldehyde to eliminate antigenicity, and 3) suturing the porcine valve to a stent to hold the three leaflets in place. In other words, the primary goal in the construction of these artificial valves is to reproduce the form of the human aortic valve as closely as possible. The assumption is made that if the artificial valve can be made to look like the human aortic valve, it will function like the human aortic valve (i.e., proper function will follow proper form). The same assumption is also followed for commercially available pericardial valves.
In the case of mitral or tricuspid valve replacement, even the dubious concept of xe2x80x9cfunction follows formxe2x80x9d has been discarded since the same artificial valves that are designed to look like the aortic valve are used to replace the mitral and tricuspid valves. In other words, no attempt at all is made to reproduce even the form of these native valves, much less so their function.
Thus, in the case of artificial valves to be used for aortic valve replacement, the dubious concept of xe2x80x9cfunction follows formxe2x80x9d has dictated the construction of all artificial tissue valves during the 30 years of their development and use. Even worse, no discernable underlying concept at all has. been used in terms of the artificial valves used to replace the mitral and tricuspid valves.
The xe2x80x9cFunction Follows Formxe2x80x9d concept has several limitations and appears to be a fundamental shortcoming which underlies the present construction of all artificial tissue valves. In the first place, it simply is not possible to recreate the exact anatomy (form) of a native heart valve utilizing present techniques. Although homograft (human cadaver) and porcine aortic valves have the gross appearance of native aortic valves, the fixation process (freezing with liquid nitrogen, and chemical treatment, respectively) alters the histologic (microscopic) characteristics of the valve tissue. Porcine and bovine pericardial valves not only require chemical preparation (usually involving fixation with glutaraldehyde), but the leaflets must be sutured to cloth-covered stents in order to hold the leaflets in position for proper opening and closing of the valve. A recent advance has been made in this regard by using xe2x80x9cstentlessxe2x80x9d porcine valves that are sutured directly to the patient""s native tissues for aortic valve replacement, but the problem of chemical fixation remains. In addition, these stentless artificial valves cannot be used for mitral or tricuspid valve replacement.
Perhaps the major limitation of the xe2x80x9cFunction Follows Formxe2x80x9d concept is that no efforts have been made previously to approximate the form of either the mitral valve or the tricuspid valve. If animal tissue valves are used to replace either of these native valves, the tri-leaflet porcine aortic Valve prosthesis or the tri-leaflet bovine pericardial valve prosthesis is normally used. In doing so, even the faulty concept of xe2x80x9cFunction Follows Formxe2x80x9d is ignored, since there are no artificial valves available for human use that approximate the anatomy (form) of the native mitral or tricuspid valves.
The nearest attempt at reproducing the function of he native mitral valve was reported by Mickleborough et al in 1989. These tests involved the use of commercially-prepared sheets of pericardial tissue from cows, which had been treated with glutaraldehyde before storage and shipping. A longitudinal suture line was used to convert the flat sheet of tissue into a cylinder, then two triangular regions were removed from one end of the cylinder, to generate two flaps. The inlet end was sutured to the mitral valve annulus, while the two tissue flaps at the carved outlet end were sutured to the papillary muscles.
The mitral valve disclosed by Mickleborough et al suffers from a drawback which is believed to be important and perhaps even crucial to proper valve functioning. In a properly functioning natural valve, the anterior leaflet does not have its center portion directly attached to the anterior papillary muscle via chordae. Instead, the anterior leaflet is attached to both the anterior and posterior papillary muscles, via chordae that are predominantly attached to the peripheral edges of the leaflet. In the same manner, a native posterior leaflet is attached to both the anterior and posterior papillary muscles, via chordae that are predominantly attached to the peripheral edges of the leaflet. As a result, the line of commissure (closure) between the two mitral leaflets when the valve is closed during systole is oriented in roughly the same direction as an imaginary line that crosses the tips of both papillary muscles. This orientation of the leaflets and papillary muscles is shown in illustrations such as page 11 of Netter 1969. This natural orientation can be achieved in the valve of the subject invention as depicted in FIGS. 2 and 3, discussed below.
By contrast, the replacement valve described by Mickleborough et al alters and distorts the proper orientation of the replacement leaflets. Mickleborough""s approach requires each sculpted leaflet to be trimmed in a way that forms an extended flap, which becomes a relatively narrow strand of tissue near its tip. The tip of each pericardial tissue strand is sutured directly to a papillary muscle, causing the strand to mimic a chordae tendineae. Each strand extends from the center of a leaflet in the Mickleborough et al valve, and each strand is sutured directly to either an anterior and posterior papillary muscle. This requires each leaflet to be positioned directly over a papillary muscle. This effectively rotates the leaflets of the Mickleborough valve about 90xc2x0 compared to the leaflets of a native valve. The line of commissure between the leaflets, when they are pressed together during systole, will bisect (at a perpendicular angle) an imaginary line that crosses the peaks of the two papillary muscles, instead of lying roughly along that line as occurs in a native valve.
There has been no indication since the publication of Mickleborough et al 1989 that their approach is still being studied (either by them, or by any other research team), and there has been no other indication during the intervening years that their approach is likely to lead to a valve replacement technique for actual use in humans.
It should be noted that one of the primary goals of Mickleborough and her associates apparently was to propose a new way to maintain continuity between the valve annulus and the papillary muscles. It was first proposed about 30 years ago (by C. W. Lillehei and perhaps by others as well) that proper muscle tone of the left ventricular wall, and proper postoperative ventricular functioning, required a tensionbearing connection between the mitral valve annulus and the papillary muscles on the inside of the ventricular wall. This suggestion was widely ignored in the design of replacement mitral valves, which required excision of the chordae tendineae without making any effort to provide a substitute that would keep the ventricular wall coupled to the valve annulus. However, various studies (such as Rittenhouse et al 1978, David 1986, Hansen et al 1987, and Miki et al 1988) continued to indicate that the tension-conveying role of the chordae was important to proper ventricular function. Based on those studies, Mickleborough et al apparently were attempting to create and propose a new valve design that could accomplish that goal. They did indeed accomplish that goal, and the apparent lack of any followup or commercialization of their design presumably was due to other problems, such as the altered orientation of the leaflets in their design.
A different approach to creating artificial tissue valves is described in articles such as Love and Love 1991, and in U.S. Pat. No. 5,163,955 (Calvin et al 1992) and U.S. Pat. No. 4,470,157 (Love 1984). In that research, surgeons harvested a piece of pericardial tissue from the same animal that was to receive the artificial valve. Such tissue, if harvested from the same human body that will receive the implant, is referred to as autologous or autogenous (the terms are used interchangeably, by different researchers). Using a cutting die, the pericardial tissue was cut into a carefully defined geometric shape, treated with glutaraldehyde, then clamped in a sandwich-fashion between two stent components. This created a tri-leaflet valve that again resembles an aortic or pulmonary valve, having semilunar-type cusps rather than atrioventricular-type leaflets. These valves were then tested in the mitral (or occasionally tricuspid) valve position, using sheep.
Although those valves were structurally very different from the valves of the subject invention, the Love and Love article is worth attention because it discusses chemical fixation. They used glutaraldehyde treatment even though their tissue source was from the same animal and was therefore non-antigenic, because earlier reports and tests had suggested that some types of untreated autologous tissue suffer from thickening and/or shrinkage over time. Love and Love suggested that glutaraldehyde can help such tissue resist such changes, apparently by forming crosslinking bonds that tend to hold adjacent collagen fibers in a fixed-but-flexible conformation. This use of glutaraldehyde fixation as a treatment to reduce shrinkage or other physical distortion (as distinct from using it as a method of reducing tissue antigenicity) is an old and well-established technique for treating non-autologous tissue, but whether it is also beneficial for treating autologous tissue has not yet been extensively evaluated. The effects of chemical fixation of intestinal or other tubular tissue used to create heart valves as described herein can be evaluated by routine experimentation.
Another report describing the use of autologous tissue to reconstruct mitral valves is Bailey et al 1970. However, Bailey et al focused on repairing rather than replacing mitral valves, usually by cutting an incision into one or both leaflets and then inserting a segment of tissue into the incision to enlarge the leaflet(s).
Physiologic Factor and in Utero Development
The subject invention relates to a method of using tubular starting material to replace any of the four heart is valves during cardiac surgery. This approach is supported by and consistent with a fundamental principle of native heart valve function, which either went unrecognized in previous efforts to develop replacement valves, or which was sacrificed and lost when compromises were required to adapt available materials to surgical requirements.
The basic principle, which deserves repeated emphasis because it has been so widely disregarded by other efforts in this field, is that Form Follows Function. In one manifestation of this principle, if an artificial valve can be created that can truly function like a native valve, its resultant form will be similar to that of the native valve.
A highly important observation by the Applicant that contributed to the recognition of the pervasive and overriding importance of this principle was the following: the entire cardiovascular system, including the heart, begins in utero as a single, relatively straight tube of tissue. Anatomical drawings depicting the in utero development of the heart are available in numerous scientific publications and books, including Netter 1969. As shown in those figures (or similar figures available in other medical reference works), the so-called xe2x80x9cheart tubexe2x80x9d is readily discernible by the 23rd day of gestation. This tube will eventually develop into the entire cardiovascular system of the body. The tissue that exists between the portion of the tube destined to become the ventricles, and the portion that will become the atria, is where the mitral and tricuspid valves will ultimately form. This region of tissue is in a tubular form.
The heart tube undergoes a process of convolution beginning at approximately 25 days gestation. This convolution of the heart tube forms what is called the xe2x80x9cheart loopxe2x80x9d and is responsible for the aortic valve ultimately coming to lie adjacent to the mitral valve. When a mature mitral valve is viewed from the atrial side, the anterior portion of the mitral valve annulus is relatively flat. This distortion of the original roundness of the mitral annulus is caused by the presence of the aorta against the anterior mitral valve. It is also the reason that the anterior leaflet of the mitral valve is contiguous with the aortic valve annulus. Finally, it explains why accessory atrioventricular connections (accessory pathways) that occur in the Wolff-Parkinson-White syndrome never occur in this portion of the mitral valve annulus; this is the only portion of the entire atrioventricular groove on either side of the heart where the atrium and ventricle were never contiguous during fetal development.
By approximately 56 days gestation, the heart tube development reaches a stage that displays a first constricted tube region between the primordial right atrium and the primordial right ventricle (this portion of the tube will become the tricuspid valve) and a second constricted tube region between the primordial left atrium and primordial left ventricle (the future mitral valve).
As the developing heart of a fetus undergoes various convolutions, septations, and compartmentalizations, the tissues that are to eventually become the heart valves maintain their tubular structure. Prior to the onset of fetal heart function, portions of the walls of these tubular structures undergo a process of dissolution, leaving behind only those portions of the original tubes that are necessary for the proper functioning of the heart. This dissolution also affects the ventricular walls as they rapidly enlarge in size; if it did not, the walls would become prohibitively thick as the physical size of the heart increased, and the heart could not function effectively as a pump since it would become simply a large mass of ventricular muscle.
The dissolution process also operates on the tubular constrictions that will become the four heart valves. In the case of the semilunar valves (the aortic and pulmonary valves), the necessary functional remnants are the three cusps, which are the remains of the functioning portion of a simple tube. This principle is strengthened by the fact that although frequent reference is made to the pulmonic or aortic valve xe2x80x9cannulusxe2x80x9d, knowledgeable anatomists are quick to point out that there is no such anatomical structure. The thickened tissue that is commonly referred to as the xe2x80x9cannulusxe2x80x9d of these valves is simply the flexion point of the three cusps, the remnants of a simple tube that is fixed at three points distally and subjected to uniform pressure on its outside, resulting in collapse of the tube on the three sides between the points of distal fixation, which in turn, results in three nearly identical cusps. All tissue other than these moveable and functional cusps has undergone the normal process of dissolution as the aorta and pulmonary artery have enlarged, leaving behind only that tissue recognized as the cusps of these semilunar valves.
At the mitral and tricuspid valves locations, the dissolution process leaves behind the valve leaflets, chordae tendineae, and papillary muscles in both the right ventricle (tricuspid valve) and left ventricle (mitral valve). In other words, that portion of the original tube that is necessary for the development of the native heart valves is spared the dissolution process and the rest of the tube dissolves away. The valve leaflets are tube remnants, which are attached circumferentially to the fibrous annulus of the heart at their base and attached by chordae tendineae additional tube remnants) at their free edges to papillary muscles (still more tube remnants) inside the ventricles. The leaflets, chordae tendineae, and papillary muscles of each the two A-V valves represent the necessary functional remnants of the original in utero tubular structures of the heart.
Using xe2x80x9cForm Follows Functionxe2x80x9d as a basic guiding principle, the present invention is based on the realization that a tubular structure having proper size and suitable material characteristics, if placed inside a mitral or tricuspid valve annulus after excision of the native valve (or inside an aorta or pulmonary artery, as described below) will function exactly like the normal valve in that position, assuming proper fixation of the inlet and outlet ends of the tube. The xe2x80x9cForm Follows Functionxe2x80x9d principle predicts that if the intended function of a replacement valve is to emulate the performance and function of a native mitral or tricuspid valve, then the form of a replacement valvexe2x80x94the structure and appearance of the replacement valvexe2x80x94should resemble the form of a native mitral or tricuspid valve. Since the native valves are generated from tubular starting material during fetal development, this principle further suggests that replacement valves should also be generated from tubular material.
This principle is given added support by the results that were observed in an artificial tissue valve that had been implanted into the mitral valve position in a human heart. The Applicant learned of these results during a presentation by Professor Donald Ross of the National Heart Hospital and Brompton Hospital (London, England), the cardiac surgeon who had performed that surgery. The implanted valve was originally a commercially available trileaflet tissue valve that was implanted into the mitral position in a 35-year-old female. The trileaflet valve had been constructed using fascia lata tissue (a relatively tough and flexible layer of tissue that normally surrounds certain types of muscles) which had been sewn into a circular stent. After 5 years, the artificial valve had to be removed because its leaflets had become calcified and immobile, resulting in both mitral stenosis and mitral insufficiency. Upon exposing the artificial valve during the removal survey, the surgeon was struck by the similarity in shape and appearance of the diseased trileaflet valve to a normal mitral valve. The commissures of the three leaflet artificial tissue valve had fused in a manner so that two leaflets had been formed: one large anterior leaflet, and one smaller posterior leaflet, as seen in a native mitral valve. Furthermore, the commissure between the two leaflets when the patient""s valve was closed by back pressure closely resembled the semi-circular commissure formed by leaflets in a native mitral valve.
During the presentation by Professor Ross, the Applicant witnessed a picture showing how the three-leaflet artificial valve had been converted into a bi-leaflet valve during the course of five years inside a human heart. It became clear to the Applicant that the patient""s heart had been attempting to make the valve conform to the heart""s functional needs.
Prior to witnessing that presentation, the Applicant had already been considering the question of whether tubular tissue might be useful for creating replacement heart valves. After seeing Prof. Ross""s photographs, which provided strong physiological confirmation of the xe2x80x9cForm Follows Functionxe2x80x9d principle, the Applicant began to carry out experiments to assess the possibility of using tubular tissue to replace heart valves. In a simple mechanical test, he obtained some highly flexible rubber tubes by cutting off the fingers of surgical gloves, then he sculpted the finger tubes to resemble the leaflets of mitral or tricuspid valves, then he sutured the sculpted rubber tubes inside of slightly larger tubes made of Dacron(trademark). An internal rubber tube was secured proximally around the entire periphery of a tube, to emulate a valve annulus, and the sculpted rubber flaps at the distal ends were coupled to the tube walls by means of loose suture strands that emulated chordae tendineae. When cyclical pressure was generated by attempting to blow and then suck air through the tube, the interior rubber leaflets opened and closed in a manner that looked identical to natural mitral or tricuspid leaflets opening and closing. This provided additional confirmation of the xe2x80x9cForm Follows Functionxe2x80x9d principle.
The physiologic principle that the functional components of native heart valves are the remnants of simple tissue tubes, and the idea of using tubular structures to replace defective heart valves, has been completely ignored in the design and construction of all replacement valves in use today. Indeed, although xe2x80x9cForm Follows Functionxe2x80x9d is a well-respected principle in fields such as engineering or evolutionary studies, it is often disregarded among medical researchers, some of whom apparently seem to feel that efforts to sever or reverse this relationship represent triumphs of technology over nature. As an example, kidney dialysis machines, which look nothing like normal kidneys, are a purely technological, non-natural solution; they use a completely artificial form to generate and provide a certain needed function. However, as any dialysis patient would attest, they fall far short of being truly optimal.
In a similar manner, all artificial heart valves in use today, whether tissue or mechanical, have been designed based. on the belief that either: 1) function can be forced to follow form (aortic and pulmonary valve replacement), or 2) neither function nor form of the native valve can be reproduced, so a replacement valve (either tissue or mechanical) must merely function as a one-way passive valve (mitral and tricuspid valve replacement). In the case of artificial tissue valves, the form of an artificial valve is established first, in the hope that the valve will function in a manner similar to a native valve. In the case of artificial mechanical valves, the disruption of the interaction between form and function goes even farther, and the caged balls, hinged flappers, and other devices in mechanical valves have even less physical similarity to native valves. However, the problems in both of these approaches are evident in the limitations suffered by every type of replacement valve that is in use today.
There is another way to express the concept of xe2x80x9cForm Follows Functionxe2x80x9d which may help explain it to people who would point to mechanical heart valves, dialysis machines, and other non-natural forms that have been used to mimic the function of body parts. In such examples, function is forced to follow form. In crude and simple terms, the function of a heart valve is merely to allow flow in one direction only. Any type of mechanical check valve with a caged-ball or flapper-and-seat design can provide that level of function.
However, when the long-term aspects of heart valve function are also taken into account (including the functions of providing low hemolysis, low turbulence, avoiding calcification, etc.), it becomes clear that artificial forms cannot fully provide those functions. The best and perhaps only way to provide a replacement valve with the complete, long-term functionality of a natural heart valve is by giving proper deference to the relationship between function and form.
This principle can be stated as, xe2x80x9cForm and function form a cycle.xe2x80x9d Each follows the other, but each also precedes and affects the other. If either half of this cycle is violated or disrupted, it will create problems that will stand in the way of an optimally functional, reliable, durable system with minimal hemolysis, turbulence, and calcification. On a short-term basis, function can be forced to adapt to an unnatural form; however, any such short-term solution will be plagued by problems and limitations over the long run. The problems and shortcomings of current mechanical replacement valves are a clear and direct demonstration of this principle.
The following series can help to illustrate the principle, xe2x80x9cForm and function form a cycle.xe2x80x9d First, a form is created: tubular tissue is used to create a new mitral valve. This form then creates a function: the new valve allows flow in only one direction, from the atrium to the ventricle. This function, in turn, creates another form: the leaflets of the new mitral valve will close in a xe2x80x9csmilexe2x80x9d configuration resembling a native mitral valve during closure. This secondary form then creates a secondary function: the new valve will provide good long-term use and low levels of turbulence, hemolysis, calcification, and leaflet stress. Form and function form a cycle, and this cycle cannot be disrupted by injecting and imposing an artificial, unnatural form in the heart without impeding the ability of proper form and proper function to interact with, support, and enhance each other.
In addition, certain items of evidence suggest that conventional replacement tissue valves, which cause high levels of turbulence, contribute to the important problem of leaflet calcification. The correlation between high turbulence and leaflet calcification is discussed below.
On the basis of the physiological facts, observations, and principles described above, and on the basis of experiments carried out by the Applicant, it appears that if heart valves are damaged or diseased to the point of requiring replacement, they should be replaced by tubular structures which function like native heart valves.
Accordungly, one object of this invention is to provide a replacement heart valve including a tubular segment of material that more closely resembles the construction and function of a native heart valve.
Another object of this invention is to provide a method of surgically replacing heart valves using innately tubular material (i.e., tissue or synthetic material which is harvested or synthesized in tubular form) as the starting material, to increase the long-term durability of replacement heart valves.
Accordungly, one object of this invention is to provide a replacement heart valve including a tubular segment of material that more closely resembles the construction and function of a native heart valve.
Another object of this invention is to provide a method of using tissue from a patient""s own small intestine to create a replacement heart valve.
Another object of this invention is to provide replacement valves which are covered by a layer of epithelial cells, which do not create a risk of blood clot formation, thereby eliminating the need for a patient to take anticoagulant drugs for the rest of his or her life.
These and other objects and advantages of the invention will become clear as the invention and certain preferred embodiments are described below and in the drawings.
This invention comprises a semilunar heart valve (i.e., an aortic or pulmonary valve) having a plurality of thin and flexible wall portions that are formed into a tubular segment by stitching the wall portions longitudinally along the segment. An inlet end is adapted to be circumferentially secured at a valve annulus, and three securement locations adjacent the outlet end are adapted to be attached to a wall of the artery. Three unconstrained regions between the securement locations flex inwardly into and out of engagement with others of the unconstrained regions. At least a portion of the outlet end is adapted to be spaced from the artery wall when the valve is open.


Embodiments of the invention generally relate to a grounding kit for a semiconductor processing chamber, and a semiconductor processing chamber having a grounding kit. More specifically, embodiments described herein relate to a grounding kit which creates an asymmetric grounding path selected to significantly reduce the asymmetries caused by an off center RF power delivery.

1. Field of the Invention
Embodiments of the invention generally relate to a grounding kit for a semiconductor processing chamber, and a semiconductor processing chamber having a grounding kit. More specifically, embodiments of the invention relate to a grounding kit capable of producing a uniform plasma in a physical vapor deposition chamber having asymmetrical RF power delivery.
2. Description of the Related Art
Physical vapor deposition (PVD), or sputtering, is one of the most commonly used processes in the fabrication of electronic devices. PVD is a plasma process performed in a vacuum chamber where a negatively biased target is exposed to a plasma of an inert gas having relatively heavy atoms (e.g., argon (Ar)) or a gas mixture comprising such inert gas. Bombardment of the target by ions of the inert gas results in ejection of atoms of the target material. The ejected atoms accumulate as a deposited film on a substrate placed on a substrate support pedestal disposed within the chamber. The support pedestal usually includes an electrostatic chuck (ESC) to support and retain substrates within the processing chamber during processing.
A grounding kit may be disposed in the chamber to create a return path for the RF power, which is used to create the plasma, to travel back to the RF power source. Due to process chamber complexity and size constraints, not all of the chamber components can be coaxially aligned with the substrate support pedestal. This offset of components can cause uniformity issues in the plasma created within the chamber. For instance, it has been found by the inventors that using a conventional grounding kit in a chamber having an offset RF power delivery site can cause the RF power to be distributed asymmetrically, especially at RF power frequencies greater than 13.56 MHz. Thus, the plasma created is distributed asymmetrically across the substrate being processed which can cause the substrate to be processed unevenly.
Although conventional grounding kit designs have a robust processing history at 13.56 MHz of RF power, processes performed using conventional kits at higher frequencies exhibit asymmetries beyond desirable limits. Therefore, there is a need in the art for an improved grounding kit.

Uniformity tuning capable ESC grounding kit for RF PVD chamber


Embodiments of the disclosure include a multi-band radio frequency (RF) circuit. The multi-band RF circuit includes multiple antenna ports coupled to multiple antennas and an antenna swapping circuit coupled to the multiple antenna ports. Control circuitry in the multi-band RF circuit controls the antenna swapping circuit to selectively couple various transmit and/or receive filters with any one or more of the multiple antenna ports to support uplink carrier aggregation (ULCA) and/or multiple-input multiple-output (MIMO) operations with a minimum number of transmit and receive filters. Transmit filters of adjacent RF bands are physically separated, but disposed in proximity, in the multi-band RF circuit to help reduce intermodulation products between the adjacent RF bands during the ULCA operation. As a result, it is possible to improve RF performance of ULCA and MIMO operations, without increasing complexity, cost, and footprint of the multi-band RF circuit.

Mobile communication devices have become increasingly common in current society for providing wireless communication services. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Increased processing capabilities in such devices means that mobile communication devices have evolved from being pure communication tools into sophisticated mobile multimedia centers that enable enhanced user experiences.
The redefined user experience requires higher data rates offered by wireless communication technologies, such as long-term evolution (LTE). Particularly in light of carrier aggregation (CA) schemes supported by modern cellular communications networks, a mobile communication device can be configured to simultaneously transmit an outgoing radio frequency (RF) signal(s) in multiple uplink frequency bands, while receiving an incoming RF signal(s) in multiple downlink frequency bands. The uplink and downlink frequency bands supported by a mobile communication device can be generally categorized based on respective frequency spectrums for easy reference. Some of the most commonly referenced frequency band categories include low-band (LB), mid-low-band (MLB), mid-band (MB), and high-band (HB). The LB, the MLB, the MB, and the HB categories typically refer to frequency spectrums between 450-960 MHz, 1452-1496 MHz, 1710-2200 MHz, and 2300-2700 MHz, respectively.
Support for the multiple frequency bands is provided by multiple radio front-ends, each supporting one or more frequency bands. Each radio front-end may include a multiplexer(s) (e.g., a diplexer for a dual-band scenario, a triplexer for a tri-band scenario, a quadplexer for a quad-band scenario, or a pentaplexer for a penta-band scenario) that can be selectively coupled to an antenna port(s). Furthermore, the mobile communication device may include multiple antennas, each coupled to a respective antenna port, to support multiple-input multiple-output (MIMO) and/or RF beamforming operations. In this regard, it may be desired to optimize configurations between the multiple radio front-ends and the multiple antennas to support flexible band combinations without compromising RF performance of the mobile communication device.


A method and apparatus is provided for recording a program. The method includes storing, in response to a user request, at least one content file that includes first and second program segments that are spliced to form a single program. At least one index file is created and stored. The file index includes program specific information associated with the first and second program segments. The index file also includes an identification of a splice point denoting a transition between the first and second program segments. In addition, a splice index is created and stored. The splice index includes timing information specifying a time at which the splice point occurs.

As is well known, advertising forms an important part of programming that is broadcast or otherwise delivered to viewers. The revenues generated from advertisers subsidize and in some cases pay entirely for the programming. Even in subscriber-based television systems such as cable and satellite television systems, the revenues from advertisements subsidize the cost of the programming, and were it not for advertisements, the monthly subscription rates in such systems could be many times higher than at present. In the past, analog video ads were commonly inserted into analog satellite video feeds by the local cable operators. Most often, analog ads were stored on tape and switched into the network feed by analog video switches, with the switching process being triggered by a cue tone sequence on the associated audio feeds delivered together with the video feed and received by a satellite receiver. As more cable systems have been converted to deliver digitally compressed video to the customer's home, cable operators have developed a variety of new technologies for inserting digital advertising content into the digital bitstream.
In the digital realm, video programs are typically encoded into MPEG video streams that are then multiplexed into a Multi-Program Transport Stream (MPTS). The process of concatenating digitally encoded video segments such as a program and an advertisement is referred to as splicing. Splicing is generally accomplished by defining "in-points" and "out-points" for each video stream, which are indicative of appropriate stream entry and exit points, respectively. The Society of Cable Television Engineers Standard 35 (SCTE 35) is one example of a cable protocol that supports Digital Program Insertion (DPI) in MPEG-2 streams by defining digital cue tone signals that are inserted in the digital video stream at the headend during the network encoding process. These cue tone messages exist as specific data packets with specific header information. Common cue tone signals include a pre-roll signal, which is sent approximately 5 to 8 seconds before splice time to indicate an upcoming available advertisement time slot (frequently referred to as an "avail"); a start signal, which marks the beginning of the avail and is used to trigger switching from the original video stream into the ad stream; and a stop signal, which occurs at the end of the avail for switching back to the original video stream.
In the context of advertising, splicing is sometimes used to deliver targeted ads to viewers. Traditional broadcast television systems broadcast the same television signal to each person viewing a particular station. Thus, each person viewing a particular channel will necessarily view the same programming content as well as the same advertisements embedded in the programming content. However, with modern digital television systems more personalized television service is possible. For instance, a group of subscriber households can be selectively addressed through a cable node serving that group. Similarly, individual subscriber households can be selectively addressed though their set top terminals. In other words, the service provider can send different data to different subscribers or groups of subscribers. As result, different viewers receiving the same program may be presented with different advertisements. This can be accomplished at the time the advertisement is to be presented by forcing the viewer's terminal (e.g., a set top terminal) to transition from one service to another service. In one example, the transition may be accomplished by forcing the viewer terminal to tune from one physical or logical channel on which a program is being received to another physical or logical channel on which an advertisement targeted to that viewer is being received. Once the advertisement has been received the viewer terminal will transition back to the service that is delivering the original program. Alternatively, instead of using different services, both the program and the advertisement may be sent in a common transport packet stream on a single channel. The common transport packet stream will include the individual program transport streams for both the program and the advertisement.
Concurrent with the increase in growth of digital cable systems has been the increasing popularity in the use of Digital Video Recorders (DVRs) by viewers. DVRs store program material onto a storage medium that is easily accessible and reusable, and the recording does not degrade over time as with video tapes. DVRs may be implemented as stand alone devices that are interconnected to other devices. Alternatively, they may be implemented as a subsystem of a set top terminal, media center or television. In this case the DVR can control the channel tuned on the television, provide an interactive electronic program guide, and record programming on a manual or timer controlled basis. Additionally, the DVR can buffer incoming audiovisual programming to enable a viewer to pause or replay a portion of a live television program, so long as the pause or replay does not exceed the capacity of the buffer. In addition to the standard play mode (forward direction, standard speed), DVRs are capable of displaying video in several "trick play" modes. Trick play modes include fast forward play, slow forward play, fast reverse play, slow reverse play, and pause.
When programming content that includes a splice point is recorded and subsequently rendered by a DVR, the DVR will need to identify the splice point defining the transition point between the original program and the advertisement, or, more generally, between any two segments of content that have been spliced together. When the splice point is reached the decoder in the DVR will need to stop rendering the first content segment and then begin rendering the second content segment. This can be problematic in some cases, particularly when the user renders the program using trick play modes, since in many trick play modes of operation (e.g., fast-forward) not all the frames of a program are decoded and presented for viewing, and hence not all the packets associated with the program will be decoded. Moreover, since in other trick play modes of operation (e.g., rewind at the normal presentation rate) the frames of a program are not decoded and presented for viewing in their normal sequential order, the packets associated with those frames are not decoded in their normal sequential order. In either case the data packets identifying the splice points may not be decoded at the appropriate time, thus preventing the DVR from properly transitioning between the different content segments.

Digital video recorder recording and rendering programs formed from spliced segments