A data retrieval method in a data-string set including a plurality of data strings, each data string having a data identification name storage area, a parent data storage area storing link-information data, wherein when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of a certain data string as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the certain data string is included in none of the parent data storage areas of the traced data strings; the method comprising recursively extracting a data string on the basis of link-information data stored in a parent data storage areas of the data string storing a data identification name to be retrieved and the extracted data string, until the parent data storage area of the extracted data string is empty.

The present invention relates to a data retrieval method in a data structure which can constitute, e.g., database or an artificial intelligence, and a method of adding link-information data to a data string of the data structure.
A variety of databases are practically used at present, and above all, a relational database is the most widely used. A variety of data are stored in a database, and data stored in the database is retrieved by various methods.
With reference to an example in which each of concept names such as DESK, PENCIL, WOOD, GRAPHITE, MICA and BRUSH OF MOTOR consists of element names as shown in the following Table 1, and in a record, the concept name is stored in a concept field and element name(s) is/are stored in element field(s), the outline of a conventional relational database will be explained below. In Table 1, numerals show record numbers, and alphabets show element field numbers.
In the relational database, a new record relationship can made by deriving the relationship of X{Z} on the basis of a combination of two records of X{. . . , Y, . . . } and Y { . . . , Z, . . . }. A capital letter located before the brace "{" stands for a concept name, and capital letters in the braces "{ }" stand for element names. For example, concept name "DESK" and element name "COMBUSTIBILITY" can be combined as
DESK{COMBUSTIBILITY} PA1 DESK{WOOD, . . . } PA1 WOOD {. . . , COMBUSTIBILITY, . . . }. PA1 each data string DS.sub.-- 1 having PA1 each data string DS.sub.-- 1 having PA1 each data string DS.sub.-- 1 having PA1 (a) inputting a data identification name corresponding to data to be retrieved, PA1 (b) extracting a data string on the basis of link-information data stored in an element data storage area of a data string whose data identification name storage area stores the same data identification name as the data identification name to be retrieved, and further extracting a data string on the basis of link-information data stored in an element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, PA1 (c) extracting a data string on the basis of link-information data stored in the parent data storage area of the extracted data string whose element data storage area is empty, from among the data strings extracted in the step (b), and further extracting a data string on the basis of link-information data stored in a parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, and PA1 (d) outputting the extracted data string. PA1 each data string DS.sub.-- 1 having PA1 each data string DS.sub.-- 1 having PA1 each data string DS.sub.-- 1 having PA1 (e') adding no link-information data when the element data storage area of the data string DS.sub.-- P extracted in the step (d) has link-information data about the data string DS.sub.-- I extracted in the step (c), PA1 (f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS.sub.-- I extracted in the step (c) when the element data storage area of the data string DS.sub.-- P extracted in the step (d) has no link-information data about the data string DS.sub.-- I extracted in the step (c), and further extracting a data string on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, PA1 (g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS.sub.-- P extracted in the step (d) and PA1 (h') storing link-information data about the data string DS.sub.-- P extracted in the step (d) in the parent data storage area of the data string DS.sub.-- I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS.sub.-- P extracted in the step (d). PA1 each data string DS.sub.-- 1 having PA1 (e') adding no link-information data when the parent data storage area of the data string DS.sub.-- E extracted in the step (d) has link-information data about the data string DS.sub.-- I extracted in the step (c), PA1 (f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS.sub.-- E extracted in the step (d) when the parent data storage area of the data string DS.sub.-- E extracted in the step (d) has no link-information data about the data string DS.sub.-- I extracted in the step (c), and further extracting a data string on the basis of link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, PA1 (g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS.sub.-- I extracted in the step (c), and PA1 (h') storing link-information data about the data string DS.sub.-- E extracted in the step (d) in the element data storage area of the data string DS.sub.-- I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS.sub.-- I extracted in the step (c).
on the basis of a combination of records of
and
TABLE 1 __________________________________________________________________________ Record Concept Element Field No. Field A B C D E F G H I __________________________________________________________________________ 1 desk wood office furniture supplies 2 pencil wood insulator combusti- conducti- softness black office writing cylindri- bility bility color supplies tools cal form 3 wood insulator combusti- plant specific bility gravity of 1 or less 4 graphite conducti- softness black bility color 5 mica insulator 6 brush of conducti- softness black motor bility color __________________________________________________________________________
For convenience' sake, record "X" refers to a record in which concept name "X" is stored in the concept field.
In the relational database, for obtaining a piece of information that element name of "COMBUSTIBILITY" can be included in concept name "DESK", i.e., for combining record "X" including element name "Y" with record "Y" including element name "Z", it is necessary to know the number of the element field containing element name "Y" in record "X". In the example shown in Table 1, for example, it is necessary to know element name of "WOOD" is stored in element field number A of record number 1. However, the number of the element field containing element name "Y" is not always known. It is therefore necessary to combine all the element fields of record X with the concept fields of other records. However, the above operation requires enormous processing when the records and element fields increase in number. For preventing the above situation, there might be a method in which one record consists of one concept field and one element field, and the element field of the record is combined with the concept field of other records. However, not only a great number of records are required, but also it is required to input one concept name in each concept field of a great number of records.
In the relational database, further, when element name "COMBUSTIBILITY" is retrieved without combining records, record "PENCIL" and record "WOOD" are extracted. That is, a directly related concept name can be extracted. However, since the record "DESK" includes element name "WOOD" but the record "DESK" does not include element name "COMBUSTIBILITY" in its element field, it is impossible to make out a piece of information that record "DESK" can include element name "COMBUSTIBILITY". That is, an indirect related concept name can not be extracted. In the relational database, therefore, it is required to input element name "COMBUSTIBILITY" to the element field of the record "DESK". That is, the problem is that one "element name" is required to be inputted in an element field of each of a plurality of records. Further, it is required to input a number of element names in element fields in records having certain concept names. In another solution, all the element fields can be combined with all concept fields. However, it is required to retrieve huge data made by the above combinations, and it is not known which element field has the element name to be retrieved. It is therefore necessary to retrieve all the element fields.
In the relational database, further, it is impossible to prevent the occurrence of circulating definitions of A{B}, B{C} and C{A}. If the records having a state of the circulating definition are allowed to be present, an endless loop takes place in the retrieval.
In the relational database, further, original data are generally arrayed in the form of a two-dimensional table. Each column corresponds to a concept field and an element field containing fixed data of the same kind, and data are classified in advance and inputted to corresponding fields. The relational database is therefore not suitable for expressing a case where an element of an indefinite number such as concept name "PENCIL" is included and the attributes of data to be inputted in element fields are not classified.
In the above-explained relational database, the concept field is placed in the same table, while the above is also true of a case where one table is made from one concept.

Method for data retrieval in a data-string set by extracting related link-information from a parent node


A marine barrier system comprising first and second barrier sections and a coupler system. The first and second barrier sections comprise first and second main flotation members, respectively, and each main flotation member contains buoyant material. The coupler system is arranged at the juncture of the first and second barrier sections. The coupler system is arranged such that the first and second main flotation members may be placed in a storage configuration and in a deployed configuration. In the storage configuration, the first and second main flotation members are arranged in a parallel, side by side arrangement. In the deployed configuration, the first and second main flotation members are arranged end to end to define a barrier line in a body of water across which movement is limited.

Security concerns make it desirable to limit access to watercraft and/or marine installations. For example, unauthorized persons may be prevented from boarding a docked or moored vessel relatively easily, but preventing an unauthorized person from approaching a vessel from the water can be difficult. The need thus exists for systems and methods for establishing a barrier line in the water to inhibit access over the water by unauthorized personnel to a vessel in or land installation adjacent to the water.

Coupling systems and methods for marine barriers


A biopsy method and apparatus for determining and locating the presence or absence of a neoplastic and other disease condition within a human or animal subject by detecting during a test period the respective electrical potentials of the electromagnetic field present in the subject between each of a plurality of measurement locations in the area of the neoplasm and at least one reference location while a combination biopsy instrument and electrode is inserted into the subject at the location of suspected neoplasm. Electrical potential differences are compared during this period to obtain relationships therebetween which are indicative of either the presence or absence of neoplastic tissue. Once the neoplastic tissue is located and identified, the biopsy instrument is manipulated to remove a tissue sample for further study.

In recent years the theory that measurement of the potential level of the electromagnetic field of a living organism can be used as an accurate diagnostic tool is gaining greater acceptance. Many methods and devices have been developed in an attempt to implement this theory. For example, U.S. Pat. No. 4,328,809 to B. H. Hirschowitz et al deals with a device and method for detecting the potential level of the electromagnetic field present between a reference point and a test point of a living organism. Here, a reference electrode provides a first signal indicative of the potential level of the electromagnetic field at the reference point, while a test electrode provides a second signal indicative of the potential level of the electromagnetic field at the test point. These signals are provided to an analog-to-digital converter which generates a digital signal as a function of the potential difference between the two, and a processor provides an output signal indicative of a parameter or parameters of the living organism as a function of this digital signal.
Similar biopotential measuring devices are shown by U.S. Pat. Nos. 4,407,300 to Davis, and 4,557,271 and 4,557,273 to Stroller et al. Davis, in particular, discloses the diagnosis of cancer by measuring the electromotive forces generated between two electrodes applied to a subject.
Often, the measurement of biopotentials has been accomplished using an electrode array, with some type of multiplexing system to switch between electrodes in the array. The aforementioned Hirschowitz et al patent contemplates the use of a plurality of test electrodes, while U.S. Pat. Nos. 4,416,288 to Freeman and 4,486,835 to Bai disclose the use of measuring electrode arrays.
Unfortunately, previous methods for employing biopotentials measured at the surface of a living organism as a diagnostic tool, while basically valid, are predicated upon an overly simplistic hypothesis which does not provide an effective diagnosis for many disease states. Prior methods and devices which implement them operate on the basis that a disease state is indicated by a negatize polarity which occurs relative to a reference voltage obtained from another site on the body of a patient, while normal or nonmalignant states, in the case of cancer, are indicated by a positive polarity. Based upon this hypothesis, it follows that the detection and diagnosis of disease states can be accomplished by using one measuring electrode situated externally on or near the disease site to provide a measurement of the polarity of the signal received from the site relative to that from the reference site. Where multiple measuring electrodes have been used, their outputs have merely been summed and averaged to obtain one average signal from which a polarity determination is made. This approach can be subject to major deficiencies which lead to diagnostic inaccuracy, particularly where only surf ace measurements are taken.
First, the polarity of diseased tissue underlying a recording electrode has been found to change over time. This fact results in a potential change which confounds reliable diagnosis when only one external recording electrode is used. Additionally, the polarity of tissue is measured by skin surface recording is dependent not only upon the placement of the recording electrode, but also upon the placement of the reference electrode. Therefore, a measured negative polarity is not necessarily indicative of diseases such as cancer, since polarity at the disease site depends in part on the placement of the reference electrode.
As disease states such as cancer progress, they produce local effects which include changes in vascularization, water content, and cell division rate. These effects alter ionic concentrations which can be measured at the skin surface and within the neoplastic tissues. Other local effects, such as distortions in biologically closed electrical circuits, may occur. A key point to recognize is that these effects do not occur uniformly around the disease site. For example, as a tumor grows and differentiates, it may show wide variations in its vascularity, water content and cell division rate, depending on whether examination occurs at the core of the tumor (which may be necrotic) or at the margins of the tumor (which may contain the most metabolically active cells). once this fact is recognized, it follows that important electrical indications of disease are going to be seen in the relative voltages recorded from a number of sites at and near a diseased area, and not, as previously assumed, on the direction (positive vs. negative) of polarity.
Once the location of a disease state, such as suspected neoplastic tissue or cancer, has been identified, the conventional diagnostic approach has been to perform a biopsy so that the diseased tissue could be examined to confirm the diagnosis. During this procedure a needle is inserted from outside the patient's body into the suspected neoplasm or other diseased tissue to permit the removal of a sample for a pathology study. To insure the accurate insertion of the needle into the diseased tissue to be biopsied, it has been necessary to employ radiographic techniques which allow the practitioner to see the neoplasm and view the biopsy needle during insertion. Even then, it is not always a certainty that the needle has reached the neoplasm, and a method of confirming this to augment radiographic techniques would be beneficial.
Biopsy procedures are perferably performed in a surgical suite, an operating room or other area that is sterile as possible. If the pathology report indicates the need for immediate surgery, it is diserable for the patient to be near surgical facilities. In many cases patients have had to be moved from the radiology area to the surigical suite with the biopsy needle in place because the necessary radiology equipment for positioning the needle was located only in the radiology area.
There is a need, therefore, for a discriminant analysis method and apparatus which not only externally diagnoses and screens disease sites, but which also internally identifies and locates diseased tissue, particularly neoplastic tissue so that the appropriate further diagnostic and treatment steps may be taken.

Discriminant function analysis method and apparatus for disease diagnosis and screening with biopsy needle sensor


A method (900) of generating an atlas for a universal atlas database (901) is provided. A new medical scan image (905) is provided. A universal auto-contouring operation (920) is performed on the medical scan image, to generate a set of universal contours (930) for the medical scan image. A local auto-contouring customisation operation (940) is performed on the medical scan image, to generate a set of local contours (950) for the medical scan image. The set of local contours is standardised (980) using a trained model to compensate for biases in the set of local contours, thereby creating a set of standardised global contours (985) for the medical scan image. The set of standardised global contours (985) and the medical scan image (905) can be added to the universal atlas database (901) as a new atlas, thereby expanding the set of atlases that are available in the universal atlas database.

Various technologies can be used to acquire internal images of human anatomy. Typically, internal images are acquired with a Computed Tomography (CT) scan. However, other imaging modalities, such as Magnetic Resonance (MR), may be used. Lower accuracy applications may rely on ultrasound scans. The raw images acquired using CT and MR scanners can be enhanced and analysed to provide very valuable information, such as accurate measurements of structures in the images.
Measuring and analysing structures in CT or MR images may provide information that serves as one input to a variety of subsequent tasks. One such task may be part of research. In some research projects, there is a need for accurate measurement or delineation of structures in CT or MR images to assess individual organs. Alternatively, research may focus on analyses of differences between organs across a population of different individuals.
In a further alternative, the subsequent tasks may include work by a radiation oncologist. A radiation oncologist may take images, and use them as an input to for example, preparing for treatment of a patient. The delineation of tumours and target volumes in CT or MR images enables a radiation oncologist to better discriminate between organs-at-risk (OARs) and other areas, such as healthy tissue. The radiation oncologist can then develop a 'planning' image, with the aim of sparing healthy tissues in subsequent actions.
When a radiation oncologist reaches the point of planning interventions in radiotherapy, (s)he may use planning software to calculate a treatment plan. That plan typically maximises radiation dose to the target volume and tumour, while minimising dose to the surrounding healthy tissues. Accurate delineation and targeting is very important during treatment planning. This example serves to illustrate the value of any input that can be provided by the enhancement, analysis and interpretation of original CT and MR images.
Contouring
The process of delineating structures within an image is also known as 'contouring'. The term contouring may be used to indicate the process of delineation in either 2D or 3D, to define the boundary of an anatomical structure. Similarly, the term 'auto-contouring' may be used to indicate the process of producing a contour automatically, and this is discussed further in a separate section below.
Medical scan images of anatomical structures are typically approved by trained radiation oncologists, dosimetrists or radiographers for subsequent treatment planning. Approved anatomical structures may be referred to as 'gold-standard contours'. Gold-standard contours are therefore contours that have been curated and approved by expert clinicians as having high quality. Gold-standard contours are sometimes also termed 'ground-truth' contours. An 'atlas' comprises the pairing of an image and the gold-standard contours for that image. Gold-standard contours are often created in accordance with a given set of contouring guidelines. One such set of contouring guidelines is the 'RTOG' guidelines at: http://www.rtog.org/CoreLab/ContouringAtlases.aspx
The atlases, each comprising gold-standard contours and a corresponding image, can be stored in a database, thereby providing a database of atlases. The atlases are then available for various uses with images that are obtained subsequently. Atlases in the database act as an accumulated store of information, which may greatly improve the processing of subsequent, newly acquired images. Atlases are used to facilitate the contouring of newly acquired patient images, which typically are not images of the same patient as the image from which the atlas and its gold standard contours were derived.
Manual contouring of a medical scan image by a human operator is time consuming, and subject to variability in delineating the anatomical structures. Such variability is due to intra- and inter-operator variation, and due to protocol variations between different medical institutions, or different departments in one medical institution. In fact, different institutions, or even different groups within an institution, may have different contouring guidelines for OARs. Differences between contouring guidelines can exist because the different institutions may subsequently use different protocols for research evaluation or at the stage of planning subsequent treatment. For example, a protocol used at institution A may not be usable at institution B. Within the same institution, different protocols may also be employed, depending for example on the stage and location of a structure such as a tumour.
As a consequence, there may be variations in the gold-standard contours that are generated for a single medical scan image. These variations depend on factors such as the institution/department guidelines and protocols, the state of an organ in the image, and individual operators who process the images.
Given the required amount of time and the inherent variability in defining a gold-standard, contouring represents one of the institutional bottlenecks in the processing of CT and MR images. Delays in image processing may lead to delays in publishing research, or in other subsequent work. Very accurate contours may need to be provided, and such accuracy may take time with known systems.
Auto-Contouring
Auto-contouring methods have been developed. Auto-contouring methods aim, at least in part, to overcome the issues described above.
Auto-contouring methods may generate contours using different technologies. One example of such technologies involves the use of previously delineated cases. Another example of such technologies involves developing model-based approaches. The results of auto-contouring may still require manual editing to account for inaccuracies, and to make the results adhere to an institution or department's contouring guidelines, i.e. to provide a suitable input to subsequent protocols that are in use at that institution or department. In this case, the editing time for the results of auto-contouring can be significantly less than the time that would be required to manually delineate the entire image volume.
The term 'auto-contouring' is a collective description for various underlying approaches. The underlying technological approaches may actually differ widely between systems. These variations in underlying technological approaches are as reported in the literature, see for example reference [1] in the list of references at the end of this 'Background' section.
In generating any auto-contouring method, the organs within one or more example medical images, normally CT images, are carefully delineated by a clinical expert to generate gold-standard contours following specific contouring guidelines. This combination of a medical image and gold-standard structures is the 'atlas'.
FIG. 1 illustrates a generic auto-contouring method. Method 100 in FIG. 1 is a generic implementation of a known auto-contouring method. FIG. 1 is partly a high-level flowchart and partly a schematic diagram.
At step 105, a new image is acquired, for example by a CT or MR scan. The aim of method 100 is to contour the new image. At step 120, one of several auto-contouring methods may be applied. Training atlas database 101 provides at least one training atlas as an input to step 120.
Each of subsequent FIGS. 2-4 provides more detailed steps for one way of carrying out the auto-contouring method of step 120. Thus, in FIG. 1, the step 120 should be seen as representing any of the methods of FIGS. 2-4. Regardless of the algorithm used in step 120, step 120 will provide estimated contours 130. The estimated contours 130 will reflect the contouring style described by the training atlas database 101.
In the case of commercial systems, users typically cannot modify the auto-contouring algorithm that is used in step 120. However, the users might be able to access/modify the training atlas database 101. Examples of such modification might be adding new atlases, in atlas-based contouring.
Traditional approaches to auto-contouring simply rely on the image intensity values and image intensity gradient values. More recent approaches incorporate prior-knowledge about the appearance and shape of the structure that is to be contoured.
Three main methodological approaches amongst these prior-knowledge-based methods are described below. These are 'atlas-based' contouring, statistical models of shape and appearance, and machine learning. An example of atlas-based contouring is shown in FIG. 2. An example of shape-model based autocontouring is shown in FIG. 3. An example of machine learning-based auto-contouring is shown in FIG. 4. The methods of FIGS. 2-4 may be used alone, or alternatively may also be used in combination.
Atlases are used to generate any of the auto-contouring methods described in FIGS. 2-4 below. However, atlases are very widely applicable in image interpretation, and are used for other actions than just autocontouring. Thus, in the remainder of this description and the figures, the use of an atlas in any step should not be taken necessarily to imply that atlas-based autocontouring is occurring.
Atlas-Based Auto-Contouring
In the remainder of the present application, an atlas database is considered as storing a pool of atlases that are available for selection. Each atlas in the pool of atlases comprises a medical image dataset and at least one defined structure delineating at least one object (e.g. region or organ) within the medical image. Typically, the pool of candidate atlases comprises a large number of candidate atlases, for example potentially hundreds or even thousands of candidate atlases.
When a new patient image is to be contoured, the atlas image/s is/are aligned to the new patient image using deformable image registration. The structures shown in the atlas are then mapped from the atlas to the new patient image, using the estimated deformation field.
Where multiple atlases are available, multiple estimates for the boundary of each organ can be obtained for the patient image. These would be merged into a consensus structure. If contours from multiple atlases have been warped to one new CT image, then each one represents a different estimate of the required contour. In this case, it is possible to obtain the consensus structure, i.e. a single consensus estimate for the required contour. This can be achieved by averaging the warped contours. Alternative approaches are to take a 'majority vote' of the labels that the contours provide at each location, or to use some more advanced statistical method.
Atlas-based contouring methods are typically limited by the amount of deformation that the registration is able to represent correctly, and by the number and quality of the atlases. Atlas contouring is widely reported in the literature, for example references [2] and [3].
FIG. 2
FIG. 2 shows an example implementation of a generic atlas-based auto-contouring method 200. Method 200 is one example of an implementation of method step 120 of FIG. 1. The aim of method 200 is to contour a new image. At step 210, a new image is acquired, for example by a CT or MR scan, for contouring. At step 220, one or more atlases is selected from training atlas database 201.
At step 230, one or more atlases is brought into registration with the CT image to be contoured. The registration requires a transformation, in order to register the atlas to the CT image that is to be contoured. That transformation is derived, either iteratively or directly, as part of step 230. The transformation is saved and used in step 240.
At step 240, the gold-standard contours are warped from the atlas coordinate system to the coordinate system of the CT image. This warping is done using the transformations estimated at step 230.
At step 250, if more than one atlas was used from step 220, then a consensus contour is generated from the warped contours.
At step 260, the contours can be returned to the user. Thus the CT image that served as the starting point of method 200 at step 210 has been auto-contoured, and is ready for subsequent use. This use may be, for example, to evaluate a medical image for research purposes, or as an input to subsequent preparations for radiotherapy.
At step 220, one or more atlases were selected. However, the selection of the one or more atlases can be undertaken during a training phase, prior to the start of the auto-contouring method 200 on the particular CT image that was acquired at 210.
Statistical Models of Shape and Appearance
Statistical models of shape and appearance aim to capture the statistical variations in shape and appearance of an anatomical structure(s) within a given training dataset of atlases. At training time, gold-standard structures and the corresponding CT images need to be available to develop a statistical model, just as for atlas-based contouring. Therefore, it is necessary to build such a training dataset of atlases following specific contouring guidelines. As these methods model the variation in shape and appearance of the training data, their performance is highly dependent on the size and quality of the training atlas database. For instance, the literature in references [4]-[6] covers some types of statistical shape and appearance models.
FIG. 3
FIG. 3 illustrates a generic statistical shape and appearance auto-contouring method. FIG. 3 shows an implementation of a shape and appearance model-based auto-contouring method 300. Method 300 is another example of an implementation of method step 120 of FIG. 1.
Atlas database 301 provides a source of atlases. The remainder of method 300 is divided into first section 304, which includes the training steps, and second section 306, which includes the testing steps.
Within first section 304, in the training steps, the anatomical variability in shape and size of training ground-truth contours is described using statistical techniques. One example of such a statistical technique is 'Principal Component Analysis'. The image appearance of the training CT images, from atlas database 301, can also be used when generating the statistical model. At the end of training, a statistical shape model will be generated and used for contouring unseen CT images. Within first section 304:
(i) Step 310 comprises retrieving training CT images and corresponding gold-standard contours from atlas database 301.
(ii) Step 320 comprises generating a statistical model correlating image appearance with organ shape.
(iii) Step 330 comprises returning a statistical shape model. The statistical shape model then serves as an input to second section 306, including the testing steps.
Within second section 306, during testing, the statistical shape model will be fitted to an unseen, new CT image. At the end of the testing, the resulting contours are returned to the user. Within second section 306:
(i) Step 340 comprises acquiring a CT image to be contoured. The acquisition may be simply retrieving the CT image from a database, or may involve the steps of operating a CT, MR or other scanner to acquire the image.
(ii) Step 350 comprises fitting the statistical shape model from step 330 to the CT image to be contoured.
(iii) Step 360 comprises returning the contours to a user.
Machine Learning
Machine learning refers to a set of mathematical and statistical techniques for learning underlying patterns in training data. 'Deep learning' is one example of machine learning.
Unlike statistical shape and appearance models, machine learning does not explicitly enforce constraints on shapes, or assume that they have particular statistical distributions. Instead, machine learning approaches seek to learn such distributions automatically. For this reason, machine learning methods tend to model variation better than statistical shape models. However, machine learning methods remain limited by the size and content of the training data. Similarly, such approaches need a carefully curated atlas database. The atlas database must have carefully contoured gold-standard cases, which have been contoured to a consistent set of contouring guidelines. Some examples of machine learning methods for auto-contouring in the literature are shown in references [7]-[9].
FIG. 4
FIG. 4 illustrates a generic machine learning auto-contouring method 400. Atlas database 401 provides a source of atlases. The remainder of method 400 is divided into first section 404, which includes training steps, and second section 406, which includes testing steps.
Within first section 404, a mathematical model with trainable parameters is optimised to correlate image features extracted from training CT images and their gold-standard contours. At the end of the training of first section 404, the mathematical model is optimised to predict contours of CT image that was to be contoured. Within first section 404:
(i) At step 410, training CT images and corresponding gold-standard contours are retrieved from atlas database 401.
(ii) At step 420, imaging features are extracted from the training medical image scan(s).
(iii) At step 430, a mathematical model with trainable parameters is chosen to correlate imaging features to gold standard contours.
(iv) At step 440, the model parameters are optimised. This optimisation continues until convergence of the training objective function has been achieved.
(v) At step 450, the model is ready for use and is returned to the user.
Within second section 406, during testing, the trained model will be run on an unseen, new CT image. At the end of the testing, the resulting contours are returned to user. During testing, the unseen, new CT image is provided as the input to the trained machine learning model, and contours are generated as the output. Within second section 406:
(i) Step 460 comprises acquiring a CT image to be contoured. The acquisition may be simply retrieving the CT image from a database, or may involve the steps of operating a CT, MR or other scanner to acquire the image.
(ii) Step 470 comprises running the trained model on the CT image to be contoured. The result comprises contours.
(iii) Step 480 comprises returning the contours to a user.
Comparing FIGS. 1 and 4, it is clear that steps 460, 470 and 480 of method 400 correspond respectively to steps 105, 120 and 130 respectively of method 100.
The Performance of Auto-Contouring
The performance of auto-contouring methods is currently hampered by the inherent variation in the definition and execution of the gold-standard contours. The gold-standard contours form the data that is used to build the auto-contouring methods. In practice, in known systems, this has limited the accuracy and robustness of auto-contouring methods.
'Accuracy' typically measures the degree of agreement between the automatic contours and the manually defined gold-standard. 'Robustness' ensures that accurate results are achieved regardless of random and systematic biases in the particular medical image case. Examples and sources of these biases are imaging artefacts, imaging scanner manufacturer, and acquisition protocols.
A robust method may generalize well, in that it provides reasonable average accuracy across a range of institutions. However, a robust method may still fail to produce contours that meet the contouring guidelines for OARs of specific clinical departments or operators. Conversely, an auto-contouring method that is carefully tailored to be accurate for a specific set of contouring guidelines, to provide a set of contours that is suitable for a subsequent treatment planning protocol, is likely to fail drastically when applied to a different set of contouring guidelines. A robust model could be generated using a database populated by multiple institutions. However it is paramount that such a database of atlases is coherently and similarly defined.
All the auto-contouring methods mentioned above can model the variation of the population of images in the atlases available at training time, or, in the case of atlas-based auto-contouring, the variation represented with the selected atlas set. However, given an auto-contouring model generated using a specific training dataset developed to just one contouring standard, an operator will be required to adapt the resulting contours to their institutional/departmental guidelines. Once again, this adaptation is a source of delay, and may introduce further inaccuracies.
To overcome this limitation, a local contouring method to correct for systematic errors introduced by a universal auto-contouring method has been proposed in the literature. See reference [10]. In Reference [10], an enhanced approach is provided, which will now be described in detail.
FIG. 5
FIG. 5 illustrates a known local customisation method of auto-contouring a medical scan image. FIG. 5 shows the use of a local contouring method in accordance with [10]. Method 500 shown in FIG. 5 uses a machine learning technique. The method 500 is referred to as a 'local' method.
The technique of method 500 is used to learn to correct for systematic biases introduced by a universal auto-contouring method that uses pre-determined image, contextual and spatial features. In this case, the universal auto-contouring method is not accessible to the operator and cannot be updated or modified. The universal auto-contouring method could be any of the auto-contouring systems described above.
A universal training atlas database 501 holds training atlases. A local atlas database 510 holds local atlases that are appropriate to a local context, such as a particular institution or medical department.
The method 500 starts when there is a CT image 505 to contour. However, method 500 could start with an MR or other image. At step 520, a universal auto-contouring method operates on the CT image acquired at 505. The universal auto-contouring method applies a contouring style from universal training atlas database 501 to CT image 505. The result of step 520 is a set of estimated contours 530.
At step 540, the estimated contours 530 are then fed to a local contouring method at 540. Local contouring method 540 learns from local atlas database 510, to correct the estimated contours 530 for systematic biases introduced by step 520. The result is a set of corrected contours 550. The resulting corrected contours 550 are then available to the local operator. At step 560, the operator edits and finally approves the corrected contours.
The inventors have realised that, potentially, method 500 would allow the incorporation of the approved, corrected contours and the CT image back into the local atlas database 510. However, such incorporation of the approved corrected contours is not shown in reference [10].
Thus method 500 provides edited and approved, corrected contours for the CT image 505 that was the starting input to method 500. Those contours are of particular use for just the CT image 505 itself. However, in addition, method 500 potentially provides a way to expand local atlas database 510. If method 500 were repeated for many different initial images such as CT image 505, then over time the local atlas database 510 could then provide a reservoir of images. From those images it would be possible to learn how to correct the estimated contours of subsequent images 505 for systematic biases introduced by step 520.
Such an approach to expanding the local atlas database 510 shown in FIG. 5 would lead, over time, to the creation of a more useful reservoir of images. Those images could then be used within the institution of their origin.
More generally, all of the types of auto-contouring detailed in FIGS. 1-5 above would benefit from using a larger dataset in the atlas database. This is true, whether the dataset is to be used to train a model, or to be treated as a set of accepted atlases from which to select a particular subset. However, while method 500 would potentially allow expansion of the local atlas database 510, the inventors have realised that there would be significant issues that would prevent the approved local contours and corresponding CT image 505 being added to the universal atlas database 501, as explained in the following.
In general, whenever a larger dataset can be made available, most of the methods used for universal auto-contouring would be improved. This is true whether the data are used to train a model, or are treated as a repository from which to select atlases for a multi-atlas contouring step. As described earlier, the inventors have considered that locally curated contouring results could be used to update the local database in method 500, and this would lead to local benefits. However, the inventors have recognised further advantages that could also be achieved if the different centres could all provide their quality assessed results to expand the universal atlas database 501. An expanded universal atlas database 501 would improve the universal contouring standard for all centres to then use. There are however, issues that would arise when using approved local contours 560, and the corresponding CT images 505, to expand the universal database 501, as explained in the following.
Returning to method 500, reference [10] proposed a local auto-contouring method 540 to correct for systematic contouring errors produced by a universal auto-contouring method 520. The universal method can be any of the auto-contouring algorithms described in FIGS. 2-4. The method 500 extends to the local auto-contouring method learning to adapt the contours generated by the universal auto-contouring method to the local guidelines of the institution/department. This part of the process is achieved in step 540 and is described in further detail in FIG. 6. At training time, method 500 is provided with both universal and local contours. It then optimises the parameters of a machine learning algorithm to adjust the output of each set of estimated contours 530, i.e. each universal contour set, so that it matches the corresponding local set as closely as possible. Reference [10] actually proposed two possible implementations of the algorithm, although the aim of each is the same.
FIG. 6
FIG. 6 illustrates an implementation of a known local customisation method shown in FIG. 5. Method 600 of FIG. 6 illustrates a known training implementation, for a local auto-contouring method.
In order to train a local auto-contouring method, the medical image scans, the associated local gold standard contours and the contours generated by the universal auto-contouring system will be considered. Imaging, spatial and contextual features are extracted from the images and from the generated universal contours. Reference [10] proposed two methods:
(i) Two machine learning classifiers are trained using the extracted features. The first classifier estimates voxels which are mis-labelled by the universal auto-contouring method, while a second classifier then re-labels the voxels identified by the first classifier.
(ii) One machine learning classifier is trained using the extracted features to re-label all voxels in a pre-defined region-of-interest.
With method 600, local atlas database 610 provides local gold standard contours. Universal atlas database 620 provides universal auto-contouring contours.
At step 630, a training medical image scan, the local gold standard contours and the universal auto-contouring contours are retrieved. Step 630 involves the retrieval of the corresponding contours, i.e. local gold-standard and estimated universal contours, from databases 610 and 620 associated to the training CT image.
At step 640, method 600 finds any voxels that had been mis-labelled by the universal auto-contouring method 520, compared to the local gold-standard contours.
At step 650, method 600 extracts imaging and contextual features from the training images and the universal contours. At step 660, an AdaBoost algorithm is trained to correlate imaging and contextual features with correct labels. At step 670, the trained model is returned for subsequent use.
FIG. 7
The problems recognised by the inventors in any attempt to expand the universal atlas database, i.e. dataset of training atlases for the universal auto-contouring method, can be understood more clearly from FIGS. 7 and 8. Datasets need to be consistent to be effective, and this can be difficult to achieve with known approaches.
FIG. 7 illustrates the outcome of applying a known local customisation method of auto-contouring to a medical scan image. FIG. 7 provides a visual example of the contouring style of the universal and local methods.
For example, in FIG. 7 a new medical scan image, 701, is to be contoured. The contouring is to use contours 710 that have been provided to the contouring standard of images in the universal atlas database 501, i.e. the new medical scan image is to be contoured by a method trained on or using an atlas database 501. The contours shown at 710 are an example of the contouring style of the universal auto-contouring method, derived by using the universal training atlas database 101. The universal auto-contouring method can be any of the methods in FIGS. 2-4.
The process results in contours that are schematically illustrated as the image 720. Thus the contours shown at 720 are contours that are generated by the universal auto-contouring method for medical image scan 701.
By comparing the various contours of the image 720 with the original medical scan image 701, it is possible to recognise the effects of the contouring standard using the universal auto-contouring method 520.
The contours shown at 730 are then the results of a local method A trained on a local atlas database from institution/department A. The contours reflect the contouring style of institution/department A. The contours shown at 740 are the results of another local method B trained on a local atlas database from institution/department B. The contours reflect the contouring style of institution/department B
Considering again step 540 of FIG. 5, a local auto-contouring method has been applied to image 720. The local method has corrected the contours for different destination institutions A and B. The result of this correction step is image 730 for institution A, and image 740 for institution B.
As shown at step 560 of FIG. 5, institutions A and B can edit images 730 and 740, respectively, if required, and accept the contours shown in each of images 730 and 740. Each of institutions A and B can choose to contribute its image 730, 740 to their corresponding local atlas databases 510. However, it is clear that one image 720 has been altered very differently at institution A, providing image 730, than at institution B, providing image 740.
FIG. 8
FIG. 8 illustrates problems that the inventors have recognised would occur with known systems, if an attempt were made with known systems to use the contouring results approved at a local level to update the universal atlas database 501. With known systems, any such attempt would lead to difficulties that can be understood with reference to the specific example illustrated in FIG. 8.
In FIG. 8, a further medical scan image 801 is to be contoured. If a locally approved contour and CT image scan 730 were previously added to the universal atlas database and used to update the universal auto-contouring system, the universal contouring standard would be affected as shown in 810. The contouring standard 810 is biased towards image 730 in FIG. 7 that is valid for institution A. This can be seen by comparing image 810 of FIG. 8 with image 730 in FIG. 7.
Medical scan image 801 is then contoured using the updated universal standard 810, which results in the contours shown in image 820. However, the correction system that had earlier been tuned to adjust for the systematic universal errors, based on the local atlas 510, is no longer appropriate, because the universal contouring standard 810 has changed. Therefore, as illustrated in FIG. 8, the system results in images 830 and 840 for institutions A and B. Each of images 830 and 840 would not fulfil the local guidelines and would require yet more correction.
FIG. 8 thus illustrates the outcome of known method, when a universal atlas database is used to contour new data. However, the method 800 shows what would happen if the universal atlas database were to be expanded with examples that were customised for and approved by a specific local centre. The processed images that are shown in FIG. 8 demonstrate that, with known approaches, any attempt to provide additional data by adding more images into the universal atlas database 501 would actually degrade the performance of the system. FIG. 8 thus provides an overview of problem that the present invention seeks to solve.
Reviewing each set of contours in FIG. 8 in more detail, 801 shows a new medical scan image to be contoured. Contours 810 are generated from an atlas, by local auto-contouring method A, and are approved by users of institution/department A. If atlases from institution A are used to update the universal auto-contouring system, a bias towards the contouring style of that institution is introduced.
Contours 820 are generated by the universal auto-contouring method, using the atlases added from institution/department A. The contouring style is different from the original universal method as shown in 710.
Contours 830 are then generated by applying a different local auto-contouring method A on contours 820. The bias introduced by 810 propagates to the local contouring system A. These contours might not comply with the guidelines of institution/department A, due to the introduced bias.
Contours 840 are generated by applying a different local auto-contouring method B on contours 820. The bias introduced by 810 propagates to the local contouring system B. These contours might not comply with the guidelines of institution/department B, due to the introduced bias.
The contours generated by the local contouring methods could be used to update the database of local atlases only. However, with known approaches, the contours generated by the local contouring methods cannot be used to update the universal training database used to generate the universal auto-contouring system, because they introduce biases towards institutional/departmental guidelines.

Method and apparatus for generating a universal atlas database


An optical storage medium can be provided by which illegal usage of the optical storage medium involving an infringement on the copyright can be prevented effectively without impairment of the functions for reproducing physical format information and optical storage medium manufacturing information. The optical storage medium includes a main information region in which encrypted data information is recorded as a pit row that is capable of being read out by means of light and a control data region. In the control data region, key information for decoding the encryption of the data information, the physical format information and the optical storage medium manufacturing information are recorded by wobbling a groove.

1. Field of the Invention
The present invention relates to an optical storage medium and an information recording/reproducing apparatus for recording or reproducing information with respect to the optical storage medium. More particularly, the present invention relates to an optical storage medium in which recording signals of images, sounds and the like are encrypted for protecting works from improper duplication, and relates to an information recording/reproducing apparatus for recording or reproducing information with respect to such an optical storage medium.
2. Related Background Art
Optical discs exemplified by DVDs (Digital Versatile/Video Discs) have become widespread as a medium for recording massive amounts of digital data such as AV (Audio Visual) data, a medium used for computers and the like. For example, DVDs in which high quality moving images are recorded for two hours or longer are now on the market. In order to protect such digital works against improper copying to another recording medium, a method called contents encryption is adopted (See ITE Technical Report Vol. 21, No. 31, pp. 15 to 19, for example).
According to this method, compressed digital works such as a movie are encrypted by means of secret keys with a three-level hierarchy (title key, disc key and master key) and are recorded in a user region to which a user is allowed to access. Then, only the authorized maker having a license is notified of the master key that is the most important key among the secret keys. The disc key and the title key that are necessary for each DVD and each title are encrypted based on the master key and are stored in a control information region to which a user is not allowed access. With this configuration, a restriction is imposed on the user so as not to access the secret keys required for decoding, and therefore improper copy by means of file copying and the like can be prohibited. However, such technology cannot cope with an improper action in which contents of all regions including the control information region for recording the secret keys are improperly copied in their entirety to another optical disc.
To address this, a method for judging whether an optical disc is an authorized one or an improperly copied one is suggested as shown in FIG. 53, where recording marks in the optical disc are displaced in units of a frame (A of FIG. 53) in the radial direction so as to record a singular pit row (B of FIG. 53) (See JP 3061098 B, for example).
The presence of such a singular pit row can be detected by a burst TE signal (D of FIG. 53) that is generated from a tracking error signal (C of FIG. 53). Therefore, by counting the number of frames in which a signal level of a standard signal that is generated internally and that of the burst TE signal agree with each other, the optical disc can be distinguished between the authorized medium and the copied medium based on this counter value.
When this optical disc in which recording marks are displaced in the radial direction is copied by an ordinary method, the singular pits cannot be generated in the copied optical disc. Therefore, it becomes possible to find an improperly copied optical disc.
However, when pit rows are recorded so as to wobble, the tolerance for offtrack will be narrowed correspondingly, thus reducing the reliability of the optical storage medium and an information reproducing apparatus. In order to secure the reliability, a pitch of tracks for recording the pit rows has to be widened by the size of the wobble, thus decreasing the storage capacity.
In addition, according to the above conventional technology, judgment on the authorized disc is conducted depending on the presence of singular pits only, and therefore if a location of the singular pits is determined, improper copying can be conducted by generating any singular pit row at that location. As a result, unauthorized disc makers who do not have a license can manufacture a large amount of copied digital works, which might hinder the appropriate distribution of digital contents.

Optical storage medium, information recording apparatus, and information reproducing apparatus


A disposable diaper has a pair of barrier cuffs. Each of the barrier cuffs includes inner and outer sheet strips provided separately of each other. The first and second sheet strips include bottom side edges fixed to the inner surface of the diaper and top side edges left free from the inner surface. The bottom side edge of the first sheet strip is inwardly spaced from the bottom side edge of the second sheet strip. The first and second sheet strips are locally bonded to each other in a part of the overlapping area of these sheet strips. One of the first and second sheet strips has its top side edge spaced from the top side edge of the other sheet strip and is provided with an elastic member.

The present invention relates to a disposable diaper including a pair of elasticized barrier cuffs.
Disposable diapers including a pair of barrier cuffs elastically biased to be raised from the inner surface of the diaper have conventionally been well known. Specifically, such cuffs are raised from the inner surface of the diaper as elastic members attached in a stretched state to the diaper contract. Rising up in this manner, the cuffs function to prevent body fluid discharged on the inner surface of the diaper from leaking sideways.
For example, a disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1989-162807 (REFERENCE 1) is provided in a crotch region with a pair of floating inner cuffs extending in a longitudinal direction. Each of these floating inner cuffs comprises a cuff layer defined by a part of topsheet, a base layer underlying the cuff layer and an elastic member sandwiched between the cuff layer and the base layer so as to extend in the longitudinal direction in a contractible manner. The elastic member is partially bonded to the base layer and the segment of the elastic member left free from the base layer functions to lift the cuff layer off from the base layer as this segment contracts. The cuff layer is bonded in its region a predetermined dimension spaced from the elastic member in a transverse direction of the diaper to the base layer. When lifted in this manner, the cuff layer describes an inverted V-shaped cross-section and thereby forms a double wall barrier cuff comprising walls lying inwardly and outwardly as viewed in a transverse direction of the diaper.
A disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1989-213402 (REFERENCE 2) comprises a first sheet including side flaps put in close contact with the wearer's skin and a second sheet underlying the first sheet wherein each of the side flaps is provided in the vicinity of its outer side edge with a first elastic member and between the first elastic member and a liquid-absorbent core with a second elastic member. The first sheet is bonded in its two regions spaced from the second elastic member in opposite directions to the second sheet so that the first sheet may protuberate between these two regions as the second elastic member contracts. Consequentially, the first sheet forms a double wall barrier cuff comprising walls lying inwardly and outwardly as viewed in the transverse direction of the diaper.
The elasticized double wall barrier cuffs disclosed in REFERENCES 1 and 2 are respectively constructed in the manner that the elastic members are sandwiched between two sheets defining the inner walls and the outer walls as viewed in the transverse direction of the diaper, respectively, on transversely opposite lateral zones of the diaper so that these elastic members may lift the inner walls from below. According to such construction, a height of these barrier cuffs depends on the transversely opposite lateral zones of the diaper. It is desired to increase a height of the barrier cuffs, the transversely opposite lateral zones, particularly in the crotch region must be widened. However, any intention to widen a dimension of the crotch region is constrained by the essential condition for design. In order to increase a height of the barrier cuffs with the knowledge of such constraint, a width dimension of the body fluid absorbent core laid in the crotch region should be inevitably reduced. With the diaper having such narrow core, a capacity of the body fluid absorption in the crotch region is generally deteriorated. Therefore, it is an object of the present invention to solve the problem left behind unsolved by the prior art concerning the double wall barrier cuffs.


The present invention recovers data utilizing information from previously received data packets to reconstruct a data packet with an ever increasing probability of reconstructing the actually transmitted data packet. With each new reception, the accumulated information brings the receiver closer to obtaining the actually transmitted data packet. This use of information which might otherwise be discarded permits highly efficient and effective bit error correction particularly useful in hostile communications environments by transceivers with limited data processing and/or memory resources.

In digital data systems, it is common for data stored in memory as well as data transmitted over a communications channel to be corrupted by errors. There are numerous techniques typically employed to detect errors and/or correct detected errors. One example of an error detection technique is the well known cyclic redundancy code (CRC) check. Other techniques that use block codes and convolutional codes permit both error detection and error correction. For error detection and correction, additional coding bits are added to the data bits. When the data is received over the communications channel or retrieved from memory, the received/retrieved data are decoded using the additional bits in some fashion to detect if some of the data are in error. One way of thinking of these decoding procedures is to analogize them to a human's ability to correct spelling errors while reading printed text. Because words are sufficiently different from each other, the reader intuitively knows which word is meant.
These error detection and/or correction coding techniques all add, to some degree, redundant information. The more redundancy built into a unit of data, the more likely that errors can be accurately detected, and in some instances, corrected. Unfortunately, as the number of coding/redundant bits increases, the overall data "throughput" decreases. In other words, the actual data content transmitted per unit time is reduced. Additionally, as the number of coding/redundancy bits increases, the complexity of the encoding/decoding algorithms increases which consumes limited data processing resources and slows down data processing time.
In some relatively "clean" environments where data are unlikely to be corrupted, fewer coding/redundancy bits can be used in conjunction with simpler error detection and/or correction procedures. However, in hostile environments where there is considerable noise, interference, etc., such simplification is usually not an option. Consider for example a radio/wireless communications environment. The radio frequency communications channel is subjected to a barrage of corrupting factors including ever present noise, nearly continuously changing communications channel characteristics, multipath fading, time dispersion which causes intersymbol interference (ISI), interference from adjacent channel communications, and a host of other factors.
One communications protocol (i.e., procedure) used to protect against these various corrupting factors is automatic repeat request (ARQ) transaction processing. A pure ARQ system employs only error detection--error correction is not used. More specifically, data packets having some type of error detection bits/coding are transmitted from a sender to a receiver over a communications channel. Each received data packet is processed by the receiver using the error detection bits included in the data packet to determine if the data packet was received correctly. If the packet was safely and accurately received, the receiver transmits an acknowledgment signal (ACK) back to the sender. If errors are detected, the receiver sends a negative acknowledgment (NAK) back to the sender, discards the data packet, and waits for a retransmission of that same data packet from the sender. In addition, a predetermined timing window is set to allow the sender sufficient time to transmit information, the receiver to receive and process the information, and then transmit an ACK or NAK signal to the sender. If the sender does not receive an ACK signal within that predetermined window or if it receives a NAK signal during the window, the sender retransmits the data packet.
In a noisy or otherwise data corrupting environment like wireless communications, a large number of retransmissions may occur before data is correctly received. Significantly, no matter how many times a data packet is transmitted/retransmitted, the receiver does not become any "smarter" about how to decode the correct information from a later retransmitted data packet In other words, the probability of receiving the packet correctly on any given data packet retransmission is no better than the probability of the previous retransmission of that packet.
One possible option for improving this ARQ protocol is to add forward error correction (FEC) bits to the data packet to permit some degree of bit correction. An example of such a "hybrid" technique would be to replace CRC error detection bits with Bose-Chaudhuri-Hocquenghem (BCH) parity check bits. If erroneous bits could be corrected by the receiver, an acknowledgment could be sent to the transmitter without the need for further retransmission. Even using such a hybrid technique where a limited number of error patterns can be corrected, such a hybrid technique (like the pure ARQ protocol) does not make use of the information contained in the previously received packets. Erroneous data packets in the pure ARQ protocol or data packets having errors uncorrectable using the hybrid technique are simply discarded requiring a continuing sequence of retransmissions.
What is needed is a data recovery technique applicable for example to ARQ protocols which makes use of information contained in previously transmitted packets, i.e., using erroneous data packets rather than discarding them, so that the currently received retransmission of the data packet can be corrected using that information from the previously received data packets. Many of the bits of the earlier transmitted packets are likely to be correct, and only one or a few of the bits in most instances are corrupted. A main objective of this invention is to utilize the correct information accumulated from prior transmissions of the packet to generate a correct data packet. Such a technique should not, however, consume too much processing time and should minimize, if possible, the amount of memory required for such processing so that the technique can be used in various environments where memory resources are limited, e.g., portable/mobile radios. It would be desirable therefore to have forward error correction in an ARQ protocol without requiring the addition of forward error correction bits to each data packet.
It is an object of the present invention to provide a data recovery system in which a correct data unit is recovered using information contained in previously received/transmitted but unacceptable data units.
It is an object of the present invention to provide such a data recovery technique in an automatic repeat request (ARQ) transaction environment so that data can be corrected without having to add additional forward error correction bits to the data units.
It is a further object of the invention to provide an error recovery technique which is effective in recovering data in a hostile environment without requiring the addition of forward error correction bits to the data packet, complex forward error data correction decoding procedures, or significant memory resources.
The present invention solves the various problems noted above and meets these and other objectives. In an automatic repeat request data transmission system where data units are received, checked for errors, and retransmitted if errors are detected such that a set of data units is generated, the present invention performs a first reconstruction operation on alternate data units in the sequence and a second reconstruction operation on the other data units in the sequence in order to reconstruct an acceptable data unit. One of the reconstruction operations may include determining a majority voted data unit based on a currently received data unit and previously received data units in the sequence. The other reconstruction operation may perform a direct comparison of the majority voted data to a currently received data unit to identify those bit positions which have different bit values. One or more bit values at those bit positions are changed in the hope of generating a correct data unit. This alternate application of voting and packet comparison reconstruction techniques to a pure automatic repeat request (ARQ) environment (i.e., one without forward error correction) is very significant because a communication unit can significantly improve its performance in high bit error rate environments and increase the probability of correctly receiving a transmitted packet in shorter time periods.
In the preferred example embodiment using alternate majority vote and packet comparison data unit reconstruction techniques, majority voting is less effective when there are an even number of packets in the vote in the sense that it is difficult to resolve "tie" votes. For example, if there are four packets being voted, what value should be assigned to a bit position where two of the packets have "1's" for that bit position and the other two packets have "0's" for that bit position? Rather than arbitrarily selecting a "1" or "0", the preferred example embodiment of the present invention uses a majority vote only for odd numbers of received data packets and direct comparison of the currently received data packet to the majority voted data packet for evenly numbered packets to avoid this tie-breaking dilemma. In both the majority vote and direct comparison techniques, information from previously received data packets is used which increases the likelihood of obtaining a correct packet.
Because the majority vote and direct comparison operations are relatively simple to perform, relatively small amounts of data processing resources and time are consumed. Moreover, the present invention provides a novel technique of making use of information contained in previously received but nonetheless erroneous packets with minimal memory. While the information from previously received erroneous packets is preserved, the packets themselves are not stored. Instead, the present invention accumulates for each corresponding bit position in the reconstructed data packet a sum of bits in that bit position from each received data unit. A threshold is then determined based on the number of retransmitted data units in the sequence, and each accumulated sum is compared to the threshold. If the accumulated sum is less than or equal to the threshold, the bit value for the corresponding bit position of the reconstructed data packet is set to 0. Otherwise, the bit value for the corresponding bit position of the reconstructed data packet is set to 1.


A powered threaded rod cutter configured to perform a cutting operation on a threaded rod includes a first cutting die and a second cutting die. At least the first cutting die includes a recess in which a first portion of the threaded rod is at least partly receivable, an electric motor, and a planetary transmission positioned downstream of the electric motor. The powered threaded rod cutter additionally includes a drivetrain for converting a rotational output of the planetary transmission to a pivoting movement of the second cutting die, and a guide against which a second portion of the threaded rod may contact to support the threaded rod to be perpendicular relative to the second cutting die prior to the cutting operation.

Powered threaded rod cutters are used to cut threaded rods. During operation, a rod may be positioned at an angle relative to cutting dies of the cutter, thereby resulting in a slanted cut of the rod. During such instances, various components of the cutter, such as the cutting dies, may be jammed or damaged.


A printed circuit board is disclosed. The printed circuit board includes a first signal transmission layer, a via and a second signal transmission layer. The via connects the first signal transmission layer to the second signal transmission layer. The via includes a first region made of a first dielectric material having a first dielectric constant, and a second region made of a second dielectric material having a second dielectric constant lower than the first dielectric constant. The via allows AC Component of an electromagnetic signal to be transmitted from the first signal transmission layer to the second signal transmission layer while blocking any DC component of the electromagnetic signal.

1. Technical Field
The present invention relates to printed circuit boards in general, and, in particular, to a printed circuit board having dielectric waveguide vias capable of transferring the AC component while blocking the DC component of electrical signals.
2. Description of Related Art
Different types of electronic devices can be mounted on one or both surfaces of a multi-layer printed circuit board (PCB). Transmission lines are typically utilized to route electrical signals among electronic devices. Transmission lines located on various layers of a PCB are interconnected with each other by means of a number of vertical connectors commonly known as vias.
Vias are typically filled with metal, but metallic vias are subject to many side effects that can degrade signal quality. For example, transitions to and from vias may cause an impedance discontinuity that can degrade signal quality. In addition, metallic vias may have stubs that can distort signal waveforms. The above-mentioned side effects become more pronounced when signal frequencies are increased.
In addition, metallic vias generate a DC connection between a trace in one layer of a PCB and a trace in another layer of the PCB. DC-blocking capacitors can be utilized to prevent DC connections; however, the addition of DC-blocking capacitors on the PCB may require more vias and extra board space in case of inner layer traces, which may lead to even more opportunities for signal discontinuity and loss. Capacitor parasitics from DC-blocking capacitors also cause signal degradation when signal frequencies are increased.
Consequently it would be desirable to provide an improved PCB that is free from the above-mentioned shortcomings.

Printed circuit board having DC blocking dielectric waveguide vias

International Business Machines Corporation


Disclosed herein is method for preparing LEV-type zeolites from FAU-type zeolites in fluoride media using an N-methyl quinuclidinium cation as a structure directing agent.

Molecular sieves are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature. According to this classification, framework type zeolites and other crystalline microporous molecular sieves, for which a structure has been established, are assigned a three letter code and are described in the Atlas of Zeolite Framework Types, Sixth Revised Edition, Elsevier (2007).
One known molecular sieve for which a structure has been established is the material designated as LEV, which is a molecular sieve characterized by having 496583 heptadecahedral cavities, to which LEV-type zeolites owe their large micropore volume (about 0.3 cm3/g), although this structure has only small 8-membered ring pore openings (4.8 Å×3.6 Å). Small pore zeolites are of importance because they exhibit zeolite-specific shape selectivity for catalytic applications. In particular, such small pore zeolites having large micropore volumes are attractive due to their large adsorption capacities. Examples of LEV-type zeolites include LZ-132, NU-3, RUB-50, ZK-20 and ZSM-45.
Synthetic zeolites are often prepared from aqueous hydrothermal reaction mixtures (or synthesis mixture(s)/synthesis gel(s)) comprising sources of appropriate oxides. Organic structure directing agents can also be included in the hydrothermal reaction mixture for the purpose of influencing the production of a zeolite having the desired structure. In some cases, the formation of the zeolite requires very long crystallization times.
An alternative approach to conventional zeolite synthesis is interzeolite conversion, i.e., the hydrothermal conversion of one zeolite into another zeolite. In an article entitled "FAU-LEV interzeolite conversion in fluoride media", Microporous Mesoporous Mater. 138 (2011) 32-39, T. Sano et al. describe the interzeolite conversion of FAU-type zeolites into LEV-type zeolites using choline hydroxide and 1-adamantanamine as structure directing agents under hydrothermal reaction conditions. Shortened crystallization time was observed over conventional hydrothermal synthesis. T. Sano et al. report the preparation of pure LEV-type zeolites with SiO2/Al2O3 mole ratios ranging from 10.7 to 28.6. Attempts to produce pure LEV-type zeolites at higher SiO2/Al2O3 mole ratios were not successful.
It has now been found that LEV-type zeolites can be synthesized from FAU-type zeolites using an N-methyl quinuclidinium cation as a structure directing agent. Moreover, high-silica LEV-type zeolites (e.g., SiO2/Al2O3 mole ratio ≧30) can be prepared.

Method for preparing high-silica LEV-type zeolites


A short channel trench MOSFET which has a lower peak concentration of dopants and a substantially uniform concentration of dopants compared to a conventional short channel device.

Referring to FIG. 1, a well known MOS-gated device typically referred to as a trench MOSFET includes a plurality of trenches 10 formed in epitaxial layer 12 which is formed over substrate 14 of a die 8. The vertical sidewalls of trenches 10 are lined with a layer of gate insulation 16 which is typically composed of SiO2. The bottom of each trench also includes a layer of insulation which typically is the same material as the gate insulation material. Each trench 10 is at least partially filled with gate electrode material 18 such as doped polysilicon.
A conventional trench MOSFET also includes base region 20 which is formed in epitaxial layer 12. Base region 20 is doped with dopants of a polarity opposite to those of substrate 14 and those of the rest of epitaxial layer 12. For example, in the device depicted by FIG. 1, base region 20 includes P-type dopants while epitaxial layer 12 and substrate 14 include N-type dopants. A conventional MOSFET also includes source regions 22 formed above base region 20.
Each trench 10 extends to a depth below base region 20 and, therefore, crosses the entire length of base region 20. Upon application of a certain minimum voltage to gate conductive material 18 (threshold voltage) the portion of base region 20 adjacent a layer of gate insulation 16 is inverted to form a channel region which allows a source region 22 adjacent the channel region to be electrically connected to the part of epitaxial layer 12 below base region 20 (the drift region).
A conventional trench MOSFET also includes source contact 24 which is ohmically connected to source regions 22 and highly conductive region 26 formed in base region 20. Source contact 24 is insulated from conductive gate material 18 in each trench by insulation plugs 28. A conventional trench MOSFET such as the one shown by FIG. 1 also includes drain contact 30.
The On-resistance (Rdson) of a trench MOSFET which is the resistance between source contact 24 and drain contact 30 of a trench MOSFET increases with the length of the channel region, which corresponds to the thickness of base region 20.
In order to reduce channel resistance, a shorter channel is desirable. When the channel length is reduced, the trench depth can also be reduced. However, devices having shorter channels tend to be leaky from drain-to-source (Idss). For a device to have the ability to withstand breakdown, it must have sufficient charge in its base regions 20 to support the desired drain-to-source breakdown voltage rating. In devices having shorter channels, therefore, the peak concentration of the dopants in the base region is higher.
The higher peak concentration in the channel leads to a higher threshold voltage, which is undesirable as it increases channel resistance especially at low gate drive conditions. That is, with a conventional short channel device, the peak concentration of the channel has to be made high, which results in a high threshold voltage (Vth).

Short channel trench power MOSFET with low threshold voltage


Automated orientation of an image presented by a display, such as a projector, with the orientation of the display simplifies presentation of images generated by an information handling system. A display orientation sensor detects the orientation of a display so that a display orientation module automatically adjusts the orientation of an image presented by the display to align with the display orientation. For example, display orientation is sensed by an accelerometer associated with the display or by determining the attachment point of the display to a support.

1. Field of the Invention
The present invention relates in general to the field of information handling system displays, and more particularly to a system and method for automated display orientation detection and compensation.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, networking systems, display devices and consumer electronic devices.
As information handling systems grow in capability, they also tend to grow in complexity. Information handling system manufacturers have responded to this increased complexity by attempting to simplify the setup and operation of information handling systems, sometimes referred to as the end user's out-of-box experience. By reducing the number and complexity of setup steps, manufacturers seek to create greater end user satisfaction and to reduce end user reliance on relatively expensive technical assistance provided by telephone representatives.
Information handling system display setup sometimes presents extra challenges for end users. For instance, displays are sometimes setup to present visual information in orientations that differ from an initial expected orientation. As an example, some projector displays are designed to rest on a tabletop and project an image at a screen under normal operating conditions. Instead, the projector may be hung inverted from a ceiling in an installed operating condition. When the projector hangs inverted, the image presented by the projector should also be inverted by the projector image processing system so that the image presented at the screen is upright. Projectors are typically shipped with a default setting to present an upright image in the tabletop configuration. An interface, such as a service menu, accessible through buttons on the projector or through the information handling system allows an end user to selectively invert the image if the projector is installed in a ceiling configuration. The end user may also invert the image back to its original setting if the projector is moved from the ceiling to the tabletop configuration. Unfortunately, the need to invert the projector image is typically not apparent to an end user until the projector is installed and presenting an upside down image of the service menu, which is difficult for the end user to navigate. Similar difficulties arise for other types of displays that present images in various orientations.

System and method for automated display orientation detection and compensation


A method for forming an SRAM cell, on a semiconductor substrate, comprised of MOSFET devices, and polysilicon load resistors, has been developed. The process for forming the SRAM cell features the use of two, self-aligned contact, (SAC), structures, a polycide SAC structure, used for contact to a source region of a MOSFET pull down transistor, and a tungsten SAC structure, used for contact to a source region of a MOSFET pass gate transistor. A buried contact region is also featured in this SRAM design and fabrication procedure, used to connect underlying active device regions, of MOSFET pull down transistors, and MOSFET pass gate transistors.

(1) Field of the Invention
The present invention relates to processes used to fabricate semiconductor devices, and more specifically to a process used to create a design for a static random access memory, (SRAM), cell, featuring two self-aligned contact, (SAC), structures, and featuring a buried contact region, and a butt contact structure, used to connect a load resistor to an active device region.
(2) Description of Prior Art
Static random access memory, (SRAM), cells are usually designed to include six, metal oxide semiconductor field effect transistors, (MOSFET), usually four N channel, and two P channel, MOSFETs, or four N channel MOSFET devices, and two load resistors. The SRAM performance and cost objectives have been successfully addressed by the ability of the semiconductor industry to fabricate SRAM devices, using sub-micron features. The smaller features result in a decrease in performance degrading capacitances and resistances, while also allowing a greater number of smaller SRAM chips, to be obtained from a specific size starting substrate, thus reducing the manufacturing cost of a specific SRAM chip.
In addition to the advent of micro-miniaturization, or the use of sub-micron features, specific processes and structures, used for advanced SRAM devices, have been developed. For example self-aligned contact (SAC), structures have been used for metal or polysilicon contact, to source/drain regions, located in the semiconductor substrate, used for the SRAM device. The SAC structure is designed to overlap gate structures, encapsulated with silicon nitride, thus allowing a minimum space to be allotted for the source/drain region, located between gate structures, thus allowing smaller, higher performing SRAM devices to be realized.
This invention will describe a design of, and a process for, a SRAM cell, featuring four MOSFET devices and two polysilicon load resistors. Featured in this invention will be the use of two, SAC structures, one SAC structure, comprised of a polycide, (metal silicide--polysilicon, used to contact a source region of a pull down transistor, while a second SAC structure, comprised of a metal, is used to contact a source region of a pass gate transistor. The use of two SAC structures, results in an increase in performance, as well as a decrease in area, when compared to counterparts fabricated using only one SAC structure. In addition this invention will also feature the use of a buried contact region, under a polysilicon gate structure, and a butted contact structure, to the polysilicon gate structure, allowing contact of a polysilicon load resistor to the underlying active device region. Prior art, such as Yoo, in U.S. Pat. No. 5,573,980, Wuu, et al, in U.S. Pat. No. 5,545,584, Wuu, et al, in U.S. Pat. No. 5,652,174, and Wuu, et al, in U.S. Pat. No. 5,607,879, show a SAC structure, polysilicon load resistors, and buried contact regions. However none of the prior art, or a combination of the prior art, describe the unique combination of features described in this invention, including one polysilicon SAC structure, one metal SAC structure, and the combination of a buried contact region, and a butted contact, used for communication between a polysilicon load resistor and an underlying active device region.

Static random access memory design and fabrication process featuring dual self-aligned contact structures

Taiwan Semiconductor Manufacturing Company Ltd.


A storage compartment comprising a housing, a lid, a lid damper, a storage tray, and a tray damper. The lid damper pivotally couples the lid to the housing about a pivot axis such that the lid is moveable between an open position and closed position. The tray damper pivotally couples the storage tray to housing about the pivot axis such that the storage tray is moveable between a lowered position and a raised position independent of the lid.

It has been known to provide passenger compartments of vehicles with console assemblies having storage compartments that include both a lid and an internal tray that are pivotally supported by the storage compartment. However, the previously known storage compartments do not provide both the lids and the trays with dampers due to packaging constraints of the storage compartment. As such, the previously known lids and trays were prone to slam shut when left unsupported in an open position. Further, as the previously known lids and trays were freely pivotal a perceived quality felt by users was decreased to a lack of a perceived weight of the lid and the tray.
Accordingly, there is a need for storage compart assemblies, console assemblies, and vehicles that provide a lid and a tray of a storage compartment with dampers within the packaging constraints of the storage compartment and which increases a perceived quality felt by a user due to an increase in the perceived weight of the lid and the tray.

Storage compartments having lid dampers and tray dampers on a common axis, console assemblies, and vehicles incorporating the same


A triazine-based mixture, used as a multichip module device dielectric (14), is made more robust and more resistant to temperature extremes by making it to be of from twenty to sixty percent by weight of triazine and of one to ten percent by weight of siloxane-caprolactone copolymer. The foregoing mixture can be made to have a higher resolution by including zero to twenty percent by weight of novolak epoxy acrylate. The entire mixture preferably additionally comprises two to eight percent by weight of bisphenol-A diglycidyl ether monoepoxyacrylate, zero to twenty percent by weight of carboxyl-terminated butadiene nitrile rubber, two to six percent of N-vinylpyrrolidone, one to ten percent of trimethylolpropanetriacrylate, zero to five weight percent glycidoxypropyltrimethoxysilane, 0.05 to five weight percent photoinitiator, zero to two percent pigment, 0.1 to one percent surfactant, zero to 0.3 percent copper benzoylacetonate, and thirty to fifty percent solvent.

The U.S. patent of Small, U.S. Pat. No. 4,554,229, granted Nov. 19, 1985, describes a multilayer hybrid integrated circuit comprising photodefinable polymer dielectric layers. Such layers can be formed over a conductor pattern and then patterned by selective exposure to actinic light and development. Microvia holes in the dielectric may, for example, be formed, which are then used to permit interconnection of a conductor pattern on the upper surface of the dielectric layer with the conductor pattern it overlies. Multiple layers can be successively formed in this manner with each interconnection pattern being used to interconnect a number of semiconductor chips. The overall structure may constitute, for example, a multilayer hybrid integrated circuit, multichip module (MCM), or other packages which can provide high density interconnection of a number of complex chips with relatively low loss.
One problem with the dielectric of the Small patent is that it is susceptible to cracking when subjected to temperature extremes. This problem becomes more severe as density requirements dictate an increase in the number of layers. For example, a four layer test circuit may show signs of cracks after fifty temperature cycles of from -40.degree. C. to 150.degree. C. It would also be desirable to increase the resolution with which the photodefinable dielectric film responds to actinic light.

Method of making circuit devices comprising a dielectric layer of siloxane-caprolactone


An apparatus for a direct down-conversion of modulated RF signals, the device including: a first power detector connected between an input port for the modulated RF signal and ground, which outputs a first DC signal, a second power detector connected between an input port for a local oscillator signal and ground, which outputs a second DC signal, the local oscillator signal having the same center frequency as the modulated RF signal, and a third power detector connected between the input port for the modulated RF signal and the input port for the local oscillator signal, which outputs a third DC signal.

The underlying invention generally relates to the field of five-port receivers, especially to a new topology for a five-port junction device with three power sensors to be applied to the processing and direct down-conversion of broadband RF signals i.e. within an operation bandwidth between 1 and 7 GHz. Thereby, said receiver does not need additional passive (resistive) network, which leads to a significant increase in the overall signal-to-noise (S/N) performance. Compared to receivers with a resistive five-port topology according to the state of the art, a non-optimized structure sensitivity enhancement (system gain) of 8–9 dB can be observed. Since a simpler technology is employed, a significant decrease in microchip size (of more than 50%) can be achieved.
Six-port technology can be used for the processing of RF signals, thereby allowing a direct down-conversion from millimeter-wave range and microwave range to the base band without needing any I/Q demodulation microchip (digital or analog). By using suitable calibration procedures, the influences of the non-ideal passive RF components—including manufacturing tolerances—can be minimized. A six-port receiver detects the relative phase and relative magnitude of two incoming RF signals. Its circuitry can be realized by passive components in combination with diodes for the detection of the relative phase and the relative amplitude of the RF signals. In this context, it should be mentioned that an important feature of six-port receivers consists in the possibility of calibrating fabrication tolerances, which inherently allows low-cost production.

Five-port topology for direct down-conversion