An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.

The present invention relates to an image display device and method, more particularly to a method of digitally processing an image signal to clarify lines, dots, and edges.
Images are displayed physically by a variety of devices, including the cathode-ray tube (CRT), liquid-crystal display (CRT), plasma display panel (PDP), light-emitting diode (LED) display, and electroluminescence (EL) panel. To display color images, these devices have separate light-emitting components for three primary colors, normally red, green, and blue.
In a CRT display, the separate colors are produced by a repeating pattern of red, green, and blue phosphor dots or stripes. FIG. 1 shows how a round white dot having a width of seven phosphor stripes, for example, is displayed. Electron beams illuminate red phosphors Rb, Rc, green phosphors Ga, Gb, Gc, and blue phosphors Ba, Bb in the spatial pattern shown. FIG. 2 maps the luminance distribution of this displayed dot in the horizontal direction. The distribution has separate luminance centroids R′, B′, G′ for the three primary colors, but all three centroids are disposed near the center of the dot, near phosphor Gb in this example.
The other types of display devices mentioned above are flat panel matrix display devices comprising two-dimensional arrays of picture elements (pixels). In a color matrix display, each pixel includes separate cells of the three primary colors. For example, FIG. 3 shows an LCD pixel comprising a red cell R1, a green cell G1, and a blue cell B1. Personal computers often have matrix-type displays of this type.
Although there is a trend toward increasing resolution in matrix-type displays, it is difficult to fabricate a display screen with extremely small pixels, especially when each pixel comprises three separate cells. Since there is also a trend toward the display of increasing amounts of information on the display screen by the use of small fonts, it is not unusual for lines and dots with a width of just one pixel to be displayed.
FIG. 4 maps the luminance distribution in the horizontal direction of a white dot displayed as a single pixel in an LCD matrix. The red and blue luminance centroids R′ and B′ are considerably displaced from the center of the dot. Depending on the size of the pixel, the viewer may perceive a red tinge in the left part of the white dot and a blue tinge in the right part. The same tinged effect may also be visible in vertical white lines, and at the left and right edges of any white objects displayed against a darker background.
Another problem occurs when dark (for example, black) lines or letters are displayed on a bright (for example, white) background, to mimic the appearance of a printed page. It is generally true that bright objects tend to appear larger than dark objects. For example, a white pixel displayed against a black background appears larger than a black pixel displayed against a white background.
FIG. 5 shows the horizontal luminance distribution of a white pixel displayed on a black background. FIG. 6 shows the horizontal luminance distribution of a black pixel displayed on a white background. In both cases the display is a matrix-type display. ST0 to ST9 are pixels comprising respective sets of red, green, and blue cells. R0a to R9a are the luminance levels of the red cells, G0a to G9a are the luminance levels of the green cells, and B0a to B9a are the luminance levels of the blue cells.
The white pixel displayed as in FIG. 5 is perceived by the viewer as being larger than its actual size. Similarly, when fine bright lines are displayed on a dark background, they appear thicker than intended, and when bright text is displayed on a dark background, the letters may appear somewhat thickened. Still, the bright lines can be seen and the bright text can be read.
The black pixel displayed in FIG. 6, however, is perceived as being smaller than its actual size. When fine dark lines formed from dark dots are displayed on a bright background, the lines may become too faint to be seen easily. When dark text is displayed in a small font on a bright background, the letters may become difficult to read. These problems are aggravated in recent personal-computer display devices in which the resolution is increased and the pixel size is correspondingly reduced in order to increase the amount of information that can be displayed on the screen.
A known means of solving these problems is to use smoothing filters to reduce the sharpness of black-white boundaries, so that dark lines and letters do not appear too thin. Referring to FIG. 7, a conventional image display device in which this solution is adopted comprises analog-to-digital converters (ADCs) 1, 2, 3, smoothing units 5, 6, 7, and a display unit 8. The device receives analog input signals SR1, SG1, SB1 representing the red, green, and blue components of the image to be displayed. The analog-to-digital converters 1, 2, 3 convert these signals to corresponding digital signals SR2, SG2, SB2. These signals are filtered by the smoothing units 5, 6, 7 to obtain image data SR3, SG3, SB3 that are supplied to the display unit 8.
The smoothing units 5, 6, 7 operate with the characteristics FR1, FG1, FB1 illustrated in FIG. 8. These characteristics show how the image data SR2, SG2, SB2 for, in this case, three adjacent pixels STn, STn+1, STn+2 are used to calculate the filtered values for the central pixel STn+1, n being an arbitrary non-negative integer. The filtered luminance level SR3 of the red cell Rn+1 includes a large contribution from the original SR2 luminance level of this cell Rn+1 and smaller contributions from the original SR2 luminance levels of the adjacent red cells Rn and Rn+2, these two smaller contributions being mutually equal. Similarly, the filtered luminance level SG3 of green cell Gn+1 includes a large contribution from the SG2 level of cell Gn+1 and smaller, equal contributions from the SG2 levels of the adjacent green cells Gn and Gn+2. Likewise, the filtered luminance level SB3 of blue cell Bn+1 includes a large contribution from the SB2 level of cell Bn+1 and smaller, equal contributions from the SB2 levels of the adjacent blue cells Bn and Bn+2.
FIG. 9 shows the horizontal luminance distribution of a white pixel displayed on a black background after this filtering process. FIG. 10 shows the horizontal luminance distribution of a black pixel displayed on a white background after the same filtering process. These drawings may be compared with FIGS. 5 and 6. ST0 to ST9 are again pixels comprising respective sets of cells. R0b to R9b are the filtered luminance levels of the red cells, G0b to G9b are the filtered luminance levels of the green cells, and B0b to B9b are the filtered luminance levels of the blue cells.
In FIG. 9, the cell outputs in pixel ST2 are reduced by amounts R2c, G2c, B2c and the cell outputs in adjacent pixels ST1, ST3 are increased by amounts R1c, G1c, B1c, R3c, G3c, B3c, as compared with FIG. 5. In FIG. 10, the cell outputs in pixel ST7 are increased by double amounts R7c1+R7c2, G7c1+G7c2, B7c1+B7c2 and the cell outputs in adjacent pixels ST1, ST3 are reduced by amounts R6c, G6c, B6c, R8c, G8c, B8c, as compared with FIG. 6.
While this filtering process prevents the apparent decrease in size of dark dots and lines on bright backgrounds, it also leads to a certain loss of sharpness. In FIG. 9 the white dot in pixel ST2, which has an intrinsic tendency to appear larger than its actual size, is further enlarged by the redistribution of part of its luminance to adjacent pixels ST1 and ST3. In FIG. 10, the double increase in the luminance level of pixel ST7 implies a doubled loss of contrast with the background.
The conventional smoothing units 5, 6, 7 also fail to solve the problem of unwanted tinges of color at the right and left edges of white areas. FIG. 11 shows the locations of the red, green, and blue luminance centroids R′, G′, B′ of a one-pixel white dot after the conventional filtering process described above. Since the three primary colors are filtered with identical characteristics, the luminance centroids are separated just as much as they were in FIG. 4.
A further problem occurs when the input analog signals are transmitted to the image display device through cables with imperfect impedance matching, leading to ringing phenomena. FIG. 12 illustrates the ringing effect in the display of a single white dot of arbitrary width, the horizontal axis indicating horizontal position on the display screen, the vertical axis indicating luminance. The display screen is generally scanned from left to right, so ringing occurs at the right edge of the white dot. FIG. 13 illustrates the effect of the filtering process described above. The ringing is reduced at the right edge E1, but the left edge E2 is needlessly smoothed, reducing the sharpness of the displayed image.
The problems described above are not restricted to flat panel matrix-type displays, but can also be seen on CRT displays.

Image display device employing selective or asymmetrical smoothing


The invention relates to controlling selection of a gateway support node of a packet-switched network. The invention includes defining at least one condition for the gateway support node. When the condition is fulfilled, another gateway support node is more suitable for transmitting packets. When fulfillment of the condition is detected, a first message indicating the other gateway support node is transmitted to the serving support node.

The invention relates to controlling selection of a gateway support node in a packet-switched network, and particularly to controlling selection of a packet-switched gateway support node in a mobile communication network.
Mobile communication networks function as effective access networks which provide the users with access to the actual data networks for mobile data transmission. Mobile data transmission is supported particularly well by digital mobile communication systems, such as the pan-European mobile communication system GSM (Global System for Mobile Communication). In this application the term 'data' refers to any information transmitted in a digital telecommunications system. Such information may comprise digitally encoded audio and/or video, inter-computer data traffic, telefax data, short sections of program codes, etc.
General packet radio service GPRS is a new service for the GSM system and one of the issues standardized by ETSI (European Telecommunication Standard Institute) in GSM phase 2+. The GPRS service enables packet data transmission between mobile data terminals and external data networks, while the GSM network functions as an access network. One of the requirements set on the GPRS service is that it should cooperate with different external data networks, such as the Internet or X.25 networks. In other words, the GPRS service and the GSM network should be able to serve all users regardless of the type of the data network they want to attach to via the GPRS service. This means that the GPRS service must support and process different network addresses and data packet forms. Processing of data packets also comprises routing of them in a packet radio network. Furthermore, the users should be able to roam from the home GPRS network to a visiting GPRS network the operator of which may have a backbone network supporting a different protocol (e.g. CLNP) than the home network (e.g. X.25). The logical network architecture of the GPRS service is illustrated in FIG. 1.
FIG. 1 illustrates the network architecture of a GPRS service at a general level because the detailed structure of the network is irrelevant to the invention. The GPRS service comprises an access network which provides radio access and is the base station subsystem BSS of the GSM system in FIG. 1, and support nodes of the GPRS service for packet-switched transmission of packet-switched data between a packet network PDN and a mobile station MS. The support nodes include a serving GPRS support node SGSN and a gateway GPRS support node GGSN. These different support nodes SGSN and GGSN are interconnected by a backbone network. It should be noted that the functionalities of the SGSN and the GGSN can also be physically combined into the same network node. Logically the nodes are, however, separate nodes.
The serving GPRS support node SGSN serves the mobile station MS. Each support node SGSN manages a packet data service within the area of one or more cells in a cellular packet radio network. For this purpose, each support node SGSN is typically connected to a base station subsystem BSS. The mobile station MS in a cell communicates with a base station over the radio interface and further through the base station subsystem with the support node SGSN to the service area of which the cell belongs.
The gateway GPRS support node GGSN connects the GPRS service of an operator to other data networks PDN, such as an IP network (Internet, Intranet) or X.25 network. The GGSN includes the routing information on GPRS subscribers, i.e. SGSN addresses and addresses of the external network related to the PDP contexts. The GGSN functions as a router between the external address and the internal routing information (e.g. SGSN). The GGSN may also transmit packets from one mobile station to another within the network.
A subscriber to the GPRS service has one or more external PDP addresses available. The PDP address is used for identifying a certain user context from the external network. A mobile station attached to the GPRS service may receive and/or transmit data packets with a certain PDP address provided that a corresponding packet data protocol PDP context is activated in the mobile station, serving support node and gateway support node. Activation of the PDP context establishes a tunnel between the support node SGSN serving the mobile station and the gateway support node GGSN. The tunnel is established using a GPRS tunneling protocol GTP between the SGSN and the GGSN. The prior art tunneling protocol is disclosed in ETSI specification GSM 09.60, version 6.2.0 (Digital cellular telecommunications system (Phase 2+); General Packet Radio Service (GPRS); GPRS Tunneling Protocol (GTP) across the Gn and Gp Interface). The tunnel is established in such a manner that the SGSN sends a 'Create PDP Context' request to the GGSN which either accepts or rejects it. If the GGSN accepts the create request, the tunnel is established. If the GGSN rejects the create request, the SGSN either sends the create request to the next GGSN (if it has information on it) or informs the mobile station of the fact that the context cannot be activated. Selection of the next GGSN by the serving support node SGSN is based on static lists which are maintained e.g. in the internal name server of the GPRS service. After the tunnel has been established, the gateway support node GGSN can only either reject or accept any update requests made by the serving support node or request the serving support node to remove the tunnel.
A problem related to the arrangement described above is that the gateway support node GGSN cannot at any stage indicate another gateway support node to the serving support node which would be a more suitable gateway support node.

Control of gateway support node selection


An online system presents content to its users, in which the content includes links that launch a messaging application and initiate conversations via the application. The system receives information indicating that negative experiences occurred during the conversations and may use this information and attributes of entities participating in the conversations to train a model to predict a likelihood of an occurrence of a negative experience. Upon determining an opportunity to present a user with a link that launches the application and initiates a potential conversation with an entity via the application, the system applies the model to predict a likelihood of an occurrence of the negative experience by the user during the potential conversation based on the entity's attributes. Based on the predicted likelihood, the system adjusts a value associated with presenting the link and passes the adjusted value to a process that selects content for presentation to the user.

This disclosure relates generally to online systems, and more specifically to adjusting a value associated with presenting an online system user with a link that initiates a conversation with an entity via a messaging application.
An online system allows its users to connect and communicate with other online system users. Users create profiles in the online system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Because of the popularity of online systems and the significant amount of user-specific information maintained in online systems, an online system provides an ideal forum for allowing users to share content by creating content items for presentation to additional online system users. Content items presented to online system users may include links that launch various types of applications, such as messaging applications. For example, a content item associated with an entity may include a link that launches a messaging application and initiates a conversation with the entity via the messaging application.
Conventionally, to maximize user engagement with online systems, online systems select content for presentation to their users based on values associated with presenting the content to the users, in which the values are determined based on predicted affinities of the users for the content. An affinity of an online system user for content may be predicted based on various types of information maintained in the online system, such as user profile information associated with the user, information describing previous interactions by the user with similar content, information describing previous interactions with the content by similar online system users, etc. For example, an online system may predict that an online system user has a higher affinity for a first content item than for a second content item if the user previously clicked on or performed a conversion in association with being presented with content items similar to the first content item, but did not do so in association with being presented with content items similar to the second content item.
However, it may be difficult for online systems to accurately predict affinities of their users for content if the content includes links that launch messaging applications and initiate conversations via the messaging applications. The reason for this is that while the online systems may be able to determine whether their users interacted with the links included in the content, the online systems may be unable to determine whether negative experiences occurred during conversations initiated by the links. Therefore, online systems may be unable to take this information into account when predicting affinities of their users for the content, making it difficult for the online systems to determine accurate values associated with presenting content including such links to their users.

Adjusting a value associated with presenting an online system user with a link that initiates a conversation with an entity via a messaging application


The invention set forth in this document discloses an optical amplifying circuit which includes a dielectric multilayer interference filter disposed at an output side or an input side of the optical amplifying element that is a part of the optical amplifying circuit. The dielectric multilayer interference filter suppresses off-band spontaneous emission.

The present invention relates generally to an optical signal amplifying circuit. More particularly, the invention is concerned with an optical signal amplifying circuit which exhibits a wide-band amplification characteristic and which can be used advantageously and profitably as an optical transmission device in optical communication systems such as an optical transmitter, optical receiver, optical repeater, branching loss compensating optical amplifier or the like.
The optical amplifier for amplifying simultaneously or en bloc optical signal components contained in a wavelength-multiplexed optical signal resulting from multiplexing of a plurality of optical signals having different wavelengths is generally implemented in such a configuration in which a Mach-Zehnder filter is disposed at an output stage in an attempt to compensate for wavelength dependency of the gain. As the conventional techniques known heretofore concerning this sort of optical signal amplifying circuit, there may be mentioned one disclosed in "IEEE Photonics Technology Letters", Vol. 3, No. 8, 1991, pp. 718-720.
For having better understanding of the present invention, technical background thereof will first be reviewed briefly. FIG. 1 of the accompanying drawings is a block diagram showing, by way of example, a basic circuit structure or configuration of a conventional optical signal amplifying circuit designed for amplifying a wavelength-multiplexed optical signal, which will be described below. In the figure, reference numeral 11 denotes generally an optical signal amplifying circuit, 1 designates an optical amplifier and 22 designates a Mach-Zehnder filter.
Referring to FIG. 1, the optical amplifier 1 destined for amplifying en bloc or collectively optical signal components having respective wavelengths is implemented by using an Er (erbium)-doped optical fiber amplifier for amplifying a wavelength-multiplexed optical signal obtained by multiplexing optical signals of different wavelengths .lambda.1 to .lambda.n. The Mach-Zehnder filter 22 connected to the output of the optical amplifier 1 serves as an optical equalizer circuit. The Mach-Zehnder filter 22 exhibits a characteristic of a gradient opposite to that of gain of the optical amplifier 1 within a relatively narrow wavelength band ranging from about 1548 to 1555 nm (nanometers) and is used for the purpose of compensating for the wavelength dependency of the gain of the optical signal amplifying circuit 11.
The conventional optical signal amplifying circuit 11 described above however suffers a problem that difficulty is encountered in implementing the optical signal amplifying circuit with high reliability because of instability of the Mach-Zehnder filter 22 employed as the optical equalizer circuit with regard to the polarization dependency and temperature characteristic.
Besides, the conventional optical signal amplifying circuit known heretofore suffers another problem in that wide-band characteristic on the order of 30 nm in the bandwidth which can ensure utilization of the wide-band characteristic of the Er-doped optical fiber amplifier to a maximum cannot be realized, because the gain compensating range is limited to a range of several nanometers around the wavelength of 1550 nm for the reason that the compensation for the wavelength dependency of the gain is limited to only a narrow wavelength range due to the intrinsic characteristic of the Mach-Zehnder filter 22.
Additionally, the conventional technique described above suffers a problem that extra-band spontaneous emission light, excitation light, monitoring light, etc., can not adequately be eliminated because of rather gentle cut-off characteristic of the Mach-Zehnder filter 22.


Improved packing density as well as improved performance and manufacturing yield is achieved in an electrically programmable memory by confining floating gate structures between isolation structures covered with a thin nitride layer. The confinement of the floating gate is achieved by planarization, preferably with a self-limiting chemical/mechanical polishing process, to the surface of the nitride layer covering the isolation structures. Gate oxide and control electrode connections can then be formed on a substantially planar surface without compromising the quality of the gate oxide or breakdown voltage the device must withstand for programming. Since severe topology is avoided over which these connections are formed, improved formation of low resistance connections, possibly including metal connections, are possible and allow scaling of transistors of the memory cells to be scaled to sizes not previously possible.

1. Field of the Invention
The present invention generally relates to programmable read only memories (PROMs), and more particularly, to so-called flash memories which are a form of electrically erasable programmable read only memories (EEPROMs) of high integration density.
2. Description of the Prior Art
Digital circuits and data processing systems in particular may use several different types of storage devices for various purposes and to derive various advantages from the respective characteristics thereof. For example, certain types of registers which provide output signals in a sequence which is fixed relative to the input sequence (e.g. first in-first out (FIFO) buffers) may avoid the need to store additional information regarding the identity of the data or how it may be later accessed while it is stored. Other types of memory structures allow data to be retrieved based on an address. Exemplary of the latter types of devices are random access memories and read only memories.
As is known, the former type of memory allows data stored therein to be changed at will at the expense of certain complexities of structure, such as providing for periodic refresh of dynamic RAMs or increased device counts in static RAMs. However, many of those complexities can be avoided in the latter type of memory where stored data is fixed or is only very infrequently changed. Many types of Read only memory are non-volatile and may be used to store commands or data regarding device operation during periods when the device may be disconnected from a power source.
When the application requires that data be changed from time to time, so-called programmable read only memories are often employed. Such memories often require special provisions such as irradiation with ultraviolet light or special purpose circuits to achieve rewriting of memory contents (the latter being referred to as electrically erasable read only memories (EEPROMs)) and often imposing low speed of response when cells must be individually erased and rewritten. To speed this process, so-called flash memories have been developed in which sections of memory are erased in a single operation and writing speed is enhanced.
EEPROMS in general and flash memories in particular operate by formation of a transistor with a so-called floating gate which is separated from a source of charge by a very thin oxide layer, generally referred to as a tunnelling oxide layer or simply tunnelling oxide. A control gate is formed over the floating gate but separated therefrom by a thicker oxide having a thickness similar to the gate oxide of a normal field effect transistor (FET). By applying a voltage to the control gate when charge has been placed below the floating gate by application of a suitable voltage, transfer of electrons through the tunnelling oxide for storage in the floating gate can be achieved. The charge stored in the floating gate can thereafter be detected by the conductance of the channel under the floating gate until the charge is removed by erasure.
One mechanism used in the rewriting of flash memories is channel hot electron (CHE) injection which generally requires an external high voltage power supply. However, a NAND type flash memory using Fowler-Nordheim tunneling has been proposed using only a 5 volt power supply for all operations. The Fowler-Nordheim tunnelling mechanism avoids avalanche breakdown and greatly reduces the chance of hot hole injection into the tunnelling oxide which tends to reduce the amount of stored charge representing data. As a result of the reduction of hot hole injection, a ten-fold increase in data retention time relative to the CHE injection mechanism is achieved.
As in all other types of integrated circuits at the present time, there is much interest in increasing integration density so that more circuits and/or memory cells may be placed on a single chip. Unfortunately, processes currently used for production of all types of EEPROMS and especially flash memories using Fowler-Nordheim tunnelling mechanisms are not amenable to scaling in order to increase packing density. The decrease of size of the floating gate, in particular, reduces capacitive coupling to the floating gate normally employed for programming of the memory and thus reduces writing speed. Increase of word line and bit line resistivity also reduces writing speed and prior art designs have been constrained to the use of doped semiconductor material which has a significant specific resistance for interconnection of circuits contained in the memory.
Additionally, standard designs for EEPROMs of the double poly type which employ a first layer of polysilicon as the floating gate and a second layer of polysilicon as the control or select gate presents a topography problem which compromises quality of an oxide insulating layer used to separate them. Severe topology also restricts the use of metals in connections to elements of the memory since deposition of metals over severe topology is not fully reliable and may cause opens due to metal migration. Thus use of polysilicon for conductors rather than metal tends to increase resistivity. Further, when recessed oxide (ROX) isolation is used, the non-planar surface presents a problem with exposure resolution during lithographic patterning due to limitations on the defocus window (e.g. depth of field). This limitation is especially severe in high numerical aperture tools used for high speed exposure. These limitations can easily cause a reduction of throughput and/or a reduction of manufacturing yield; either of which tends to increase costs of EEPROMs.
Unfortunately, the severe topology actually has advantages in the operation of EEPROMS since it increases the so-called capacitance ratio: the ratio of the control gate capacitance to the capacitance of the floating gate or, more specifically, the ratio of the area of the control gate oxide to the area of the tunnelling oxide since the floating gate between the control gate and the substrate or well forms a capacitive voltage divider. This ratio must generally be kept above a particular value related to the programming voltage for operability and operational reliability increases with increase of this ratio at a given programming voltage. Since the tunnelling oxide is generally planar, the severe topology of the control gate oxide and the control gate, itself, increases the capacitance of the control gate and the capacitance ratio. Accordingly, severe topology has been conventionally tolerated in view of the increase in operational reliability it provides even though manufacturing yield is somewhat compromised.

International Business Machines Corporation


A method for selecting a sleep system comprises positioning a person on a mattress in a lying position. One of the person's arms extends generally perpendicular to the person's torso. A first pillow is positioned underneath the person's head, and a force is applied to the person's arm in a direction generally toward the person's feet. An amount of resistive force supplied by the person's arm is estimated and used to determine whether the proper combination of mattress and pillow is achieved.

This invention relates generally to the field of sleep systems, and in particular to sleep system that comprise both sleep surfaces, such as mattresses, and pillows. More specifically, the invention relates to methods for determining appropriate combinations of mattresses and pillows. In certain aspects, such a determination may be used to enhance the sales of mattresses and pillows, alone or in combination.
Finding the correct mattress can be a difficult task. Within the United States there are literally hundreds of makes and models of mattresses, such as firm mattress, plush mattresses, and the like. Selecting a mattress that will provide an appropriate degree of comfort and/or support to meet a person's needs can be especially challenging.
The use of an appropriate pillow can also be a factor in determining the level of comfort and/or support. For example, if the pillow is too high, too firm, or the like, the user's comfort level and/or the amount of support provided to the user may be seriously compromised.
Importantly, the user's comfort and the amount of support can also be affected by the combination of both the pillow and the mattress. For example, depending on the type of mattress that is selected, a different type of pillow may be needed to provide the appropriate support and/or comfort level. At present, it is believed that no suitable techniques exist for the determining an appropriate sleep system that includes the combination of a pillow and a mattress.


A method for controlling a hybrid drivetrain of a motor vehicle such that, during a thrust operation of the vehicle, a change takes place from a combustion-powered driving mode, in which the combustion engine is in a thrust operation, the separator clutch is engaged and the electric machine contributes no force, or from a combined driving mode in which the engine is in a thrust operation, the clutch is engaged and the electric machine operates as a generator, to an electric driving mode in which the engine is switched off, the clutch is disengaged and the electric machine operates as a generator. To efficiently change driving modes, the clutch is partially disengaged to a slip limit; the clutch is then completely disengaged; and when the clutch reaches the slip limit, the generator torque of the electric machine is increased inversely to the torque that can be transmitted by the clutch.

A hybrid drivetrain that acts in parallel with a serial arrangement of the components in the manner described above is possible in various embodiments.
For example, from DE 103 46 640 A1 a hybrid drivetrain of the above type is known, in which the electric machine is arranged coaxially with the input shaft of the drive transmission, the rotor of the electric machine is directly connected with the input shaft of the drive transmission in a rotationally fixed manner, and the drive transmission is made as an automatic planetary transmission.
DE 100 12 221 A1 describes a hybrid drive device with a main drivetrain and an auxiliary drivetrain. In the main drivetrain, which in the present case corresponds to the hybrid drivetrain, the electric machine concerned is arranged axis-parallel to the input shaft of the drive transmission and the rotor of the electric machine is in driving connection with the input shaft of the drive transmission via an input transmission stage EK, which is made as a spur gear pair with a high transmission ratio (iEK>1). The drive transmission is preferably an automatic planetary transmission. In such an arrangement of the electric machine the data presented below concerning the torque and the speed of the electric machine refer analogously to the reduced values at the output element of the input transmission stage or to the input shaft of the drive transmission.
In the present invention the drive transmission is preferably an automated change-under-load transmission such as an automatic planetary transmission, a dual-clutch transmission or a continuously variable transmission. However, the drive transmission can also be an automated change-speed transmission of countershaft design, in which shift processes are associated with a traction force interruption.
Furthermore, a starting element can be positioned immediately upstream from the drive transmission. Thus, in a manner known per se a hydraulic torque converter can be positioned upstream from an automatic transmission, which during normal driving operation, i.e. other than when starting off or maneuvering, is bridged by an engaged bridging clutch. Upstream from a continuously variable transmission and an automated change-speed transmission can, in each case, be positioned a starting clutch or a starting and shifting clutch made as a dry clutch or as a wet clutch, in particular a disk clutch, which is engaged during normal driving operation. The same applies to a dual clutch transmission, which—as is known—comprises two input shafts each respectively associated with a starting and shifting clutch. Alternatively, a starting element can also be integrated in the drive transmission, for example if a starting clutch associated with the input shaft is accommodated inside the transmission housing of the drive transmission, or if a frictional shift element of a drive transmission, made as an automatic transmission, which transmits load during starting, is used as the starting clutch.
A hybrid drivetrain of such type offers the possibility of operating a motor vehicle, as necessary, in a purely combustion-engine-powered driving mode, in a purely electric driving mode or in a combined driving mode. In the combustion-powered mode the separator clutch is engaged, the electric machine is switched to contribute no force and during traction operation the motor vehicle is driven solely by the drive torque produced by the combustion engine, and in thrust operation it is braked by the drag torque of the combustion engine then running in thrust operation, if necessary with further braking devices such as a service brake or a retarder in addition to the braking torque itself.
In the electric mode the separator clutch is disengaged, the combustion engine is switched off and, in traction operation, the motor vehicle is driven solely by the drive torque of the electric machine then being operated as a motor, whereas during thrust operation the vehicle is braked by the drag torque of the electric machine then operating as a generator, if necessary with further braking devices in addition to the braking torque.
In the combined driving mode the separator clutch is engaged. During traction operation the motor vehicle is driven by the sum of the drive torques of the combustion engine and the electric machine, whereas in thrust operation it is braked by the sum of the drag torques of the combustion engine and the electric machine then operating as a generator, if necessary with further braking devices in addition to the braking torque.
Apart from the hybrid driving modes considered above, the combustion engine and the electric machine can if necessary also be operated with different force flow directions, whereby the torques produced partially cancel out. Thus, in certain traction operation phases it can be appropriate to operate the electric machine as a generator in opposition to the action of the drive torque from the combustion engine, for example in order to charge an empty electric energy accumulator, or in order to operate the combustion engine at an optimum operating point. Likewise, in certain thrust operation phases it can be appropriate to operate the electric machine as a motor in opposition to the drag torque of the combustion engine, for example to keep the combustion engine above a critical rotational speed limit.
Owing to the variety and different operating properties of the possible embodiments of such a hybrid drivetrain, known control methods mostly assume at least a certain power of the electric machine and/or a certain structure of the drive transmission. Furthermore, the known control methods are often limited to the solution of partial problems that occur during the control of the specific hybrid drivetrain concerned.
DE 43 24 010 C2 discloses a method for controlling a corresponding hybrid drivetrain which starts with a structure of the drive transmission in the form of an automatic planetary transmission with a hydraulic torque converter immediately upstream from it. In this known method, during pure electric driving operation the electric machine is controlled in such a manner that the torque characteristic of a combustion engine is simulated. Furthermore, the known method provides that when the motor vehicle concerned is operated in thrust mode, the braking torque (drag torque) of the combustion engine is supplemented or replaced by a braking torque produced by operating the electric machine as a generator.
A similar method for controlling a corresponding hybrid drivetrain is described in DE 101 50 990 A1. This known method also starts with a structure of the drive transmission in the form of an automatic planetary transmission, but this time with no hydraulic torque converter upstream from it. In this method too, during pure electric driving operation the electric machine is controlled in such manner that the operating behavior of the combustion engine is imitated. When electric-powered driving (with the combustion engine inactive and the separator clutch disengaged) is changed to combined driving operation or to combustion-engine-powered driving operation, the combustion engine is started by engaging the separator clutch, this being intended to ensure a soft transition, i.e. one with very little jerkiness, to the power of the combustion engine. However, specifically how the separator clutch and the electric machine should be controlled in order to achieve this outcome is not explained in DE 101 50 990 A1.
Another method for controlling a corresponding hybrid drivetrain is known from DE 10 2005 007 966 A1, which starts with a structure of the drive transmission as a change-speed transmission, i.e. an automated change-speed transmission with gearshift-related traction force interruption. In this known method the electric machine, clearly one with relatively low power, is used primarily as a starter motor for the combustion engine, and an electric generator with an auxiliary drive for synchronizing the respective target gear of the drive transmission during gearshift operations. In addition the electric machine is intended for use in other auxiliary functions such as preventing or minimizing rolling downhill, performing a crawling function and for active damping of rotation oscillations. In contrast, no provision is made for using the electric machine as a main drive motor so DE 10 2005 007 966 A1 does not relate to any purpose beyond the auxiliary functions mentioned.
During the operation of a hybrid drivetrain of the structural form considered here, the general problem arises, when changing from the combustion-engine-powered mode or the combined mode to the electric mode, of how to effect the change in the smoothest possible way, i.e. with little or no jerkiness, and thus in a manner that is comfortable for the occupants of the vehicle and which reduces the wear of the hybrid drivetrain's components.
As may be generally appreciated, a smooth change from the combustion-powered driving mode in which the combustion engine is operating in traction, the separator clutch is engaged and the electric machine contributes no force, or from the combined driving mode in which the combustion engine is operating in traction, the separator clutch is engaged and the electric machine is operating as a motor, to the electric driving mode in which the combustion engine is switched off, the separator clutch is disengaged and the electric machine is operating as a motor, is achieved by first reducing the torque of the combustion engine down to zero by means of the engine control system and at the same time correspondingly increasing the torque of the electric machine in its motor operation.
When the torque of the combustion engine has been reduced to zero, the separator clutch is disengaged and the combustion engine is then switched off.
Since the torque of the electric machine is increased to the same extent as the torque of the combustion engine is reduced, and the separator clutch is only disengaged once the torque of the combustion engine has become zero, a change carried out in this way from the combustion-powered or the combined driving mode to the electric-powered mode takes place substantially free from jerkiness and essentially without any change of the resulting drive torque on the input shaft of the drive transmission.
Analogously to this, during thrust operation of the motor vehicle a smooth change from the combustion-powered mode in which the combustion engine is operating in thrust, the separator clutch is engaged and the electric machine contributes no force, and from the combined driving mode in which the combustion engine is operating in thrust, the separator clutch is engaged and the electric machine is operating as a generator, to the electric driving mode in which the combustion engine is switched off, the separator clutch is disengaged and the electric machine is operating as a generator, is achieved by first reducing the drag torque of the combustion engine to zero and at the same time reducing the torque of the electric machine correspondingly, i.e. increasing the drag torque produced by the electric machine when it is operating as a generator to the same extent. When the drag torque of the combustion engine has been reduced to zero, the separator clutch is disengaged and the combustion engine is then switched off.
However, the disadvantage of this last-mentioned procedure during thrust operation of the motor vehicle is that the combustion engine, running in thrust operation and switched appropriately for thrust, has to be ignited in order to reduce its drag torque. This means that the supply of fuel and if needs be the ignition must be switched on in order to bring about the reduction of the drag torque and to be able to control the timing of the drag torque reduction by means of the engine control system in the desired manner. This on the one hand entails relatively large and time-consuming control complexity, and also results in unnecessary fuel consumption and corresponding exhaust gas and noise emissions.

Method for controlling a hybrid drivetrain


A method for enhancing signal-to-noise ratio and resolution of amplitude stable signals wherein underwater acoustic data is first collected with an array of hydrophones, and then the data is digitally sampled. After producing spectra of sequential time snapshots of the digitally-sampled data, the spectra are beamformed for a single frequency. Next the low resolution beamformer response is deconvolved from the data by use of a calculated beam response pattern for the hydrophone array, so that many high-resolution estimates are created for each time snapshot. Finally, the resulting high resolution estimates are reduced to a single estimate for each spatial bin across all of the time snapshots, and the high resolution, high gain results are displayed.

The present invention relates generally to electrical communications, and more particularly to signal processing methods.
High-resolution processing techniques do not always produce significant amounts of gain in the signal-to-noise ratio (SNR) of input underwater acoustic signal and noise data. Further SNR gain improvements normally require an additional technique specifically designed to produce high gain. A signal processing method that simultaneously improves both resolution and SNR gain would be particularly useful for underwater applications that benefit from both resolution and gain improvements.
In the case of underwater acoustics, natural fluctuations in the signal and the noise across time are caused by many factors, including multipath transmission, internal waves, acoustic propagation path interaction with the moving sea surface, and source-receiver relative motion. The advanced WISPR (Wagstaff's Integration Silencing Processor) summation (AWSUM) filter disclosed in Application Ser. No. 08/314,281, filed Sep. 30, 1994, by Wagstaff as sole inventor, and currently pending, the disclosure of which is hereby incorporated by reference, is a signal processing algorithm that has been found to increase the SNR for low-fluctuation amplitude tonal (LOFAT) signals embedded in high-fluctuation amplitude tonal (HIFAT) signals and noise by attenuating the highly fluctuating components more than the LOFAT signals. LOFAT signals are an important class of man-made signals in the ocean, and the AWSUM filter can provide significant gains for automatically detecting and classifying those signals (e.g. projector at the surface or submerged).

Method for enhancing signal-to-noise ratio and resolution of amplitude stable signals


A data normalizer for processing data for use by a CDM system which is capable of dynamically updating user-defined normalization criteria and which is further capable of operating in a multi-tenant environment in which each tenant has distinct data normalization policies.

Businesses and individuals increasingly rely on management of contact data for communication, marketing, monitoring and other basic functions.
Management of data about persons or entities through Contact Data Management (CDM) Systems is a multi-billion dollar market, which experiences double digit growth each year, and which includes, but is not limited to, Contact Resource Management (CRM) systems. Management of contact data is critical to domestic and global productivity, and businesses of all sizes increasingly depend on the effective implementation of all business functions. It is also critical to governments and medical institutions and for security and tracking purposes.
A problem common to all CDM systems is the duplication of data entered into the system. It is estimated that most large scale CDM systems experience fluctuating duplication rates between 10 to 30 percent, and must devote considerable system resources to addressing complications caused by the duplication of data.
Because most CDM systems require periodic repetition of de-duplication processes, CDM systems experience fluctuating duplication rates between the times that the de-duplication process is performed rendering them more error prone.
Errors and redundant resources allocated to duplicated data cause a loss of business productivity, and compromise the overall functionality of CDM systems.
A typical scenario occurs when customer records are recorded in an inconsistent manner. For example, a contact may be shown as salesman Mary Smith in a company, "GRP Transport, Srvcs." A second listing may appear for Bob Jones with "Group Transportation Services." Several types of problems may arise from this hypothetical scenario.
One problem that may arise from this hypothetical may be that the contact entity receives multiple mailings or calls from the end user. Another problem is that the end user of the CDM system may not ever have consistent information about each customer. The customer information may be inconsistent because every time the customer record has to be updated, only one record is updated. There is no assurance that the most recently updated record will be subsequently revised, which results in inconsistent information being accessed. Another problem with duplicated records is that the end user is unable to accurately monitor user activity. Another type of problem may occur when multiple client personnel are contacted by the user's staff and duplicate services are rendered or inconsistent pricing and/or information is offered.
Data entered into a CDM may come from various sources (e.g., list broker services, hand entered data, web crawled data, social networks, association lists, magazine subscriber lists, e-mail signatures). Each of these disparate data sources may obey different rules on how they treat data, or may have no rules. As data is gathered using increasingly sophisticated technology and data mining tools, new types of data duplication errors and data record inconsistencies (e.g., spelling, abbreviation, punctuation, deconstruction, reconstruction anomalies and other differences in records referencing the same contact in disparate data sources) occur more frequently. De-duplication processes in existing CRM and CDM technologies cannot be effective unless data is conformed ("normalized") so that it can be adequately compared. Moreover, decisions on how to normalize data and the conventions to be used for normalizing data can differ greatly depending on the needs of a particular user (tenant) environment.
Most CRM and CDM de-duplication technologies rely on "library-style" retrieval, hash code and character comparisons to detect duplicates. These CRM and CDM components are not effective for screening massive amounts of data from disparate data sources during an updating process. The de-duplication components of CDM and CRM systems known in the art are also not designed to be dynamically updated to anticipate an infinite number of disparate data sources and tenants with unique requirements.
It is desirable to have a data normalization tool which can interface with various CDM systems and process data from infinite disparate data sources.
It is further desirable to have a tool which can normalize data specific to the needs of one or more tenants, and which can be adapted for multi-tenant environments.
It is further desirable to have a tool that can be dynamically updated to normalize data and to address an evolving range of potential data entry variations that can result from changes in data retrieval technology.


A method of estimating torque includes disposing at least one measurement assembly at a downhole component, the at least one measurement assembly including a first set of directional sensors disposed at a first axial location along the downhole component, and a second set of directional sensors disposed at a second axial location along the downhole component. The method also includes collecting directional measurement data from the first set of directional sensors and the second set of directional sensors during rotation of the downhole component, and estimating, by a processing device, an amount of torque on the downhole component based on the directional measurement data.

In downhole operations such as drilling, geosteering and measurement-while-drilling (MWD) operations, sensor devices are included with a borehole string that measure various parameters of a formation, borehole and/or downhole components. For example, some drilling systems include downhole torque sensors (disposed on, e.g., a drill collar, drill pipe or MWD tool) to measure the torque distribution of a downhole component. Knowledge of the torque on downhole components can be used to selected and/or adjust various operational parameters, such as rotational rate, weight on bit and others.

Estimation of downhole torque based on directional measurements


A method and apparatus for easing the use of an optically based noninvasive analyzer is presented. More particularly, a simplified algorithm is used that removes the daily requirement of collecting and using a noninvasive spectrum to update a calibration model. In another embodiment, a guide is used to substantially reduce variation in sample probe placement in relation to a skin tissue sampling site, resulting in the ability to maintain calibration performance with the use of a reference analyte concentration, with or without the use of a reference spectrum collected nearby in time.

1. Field of the Invention
The invention relates to noninvasive determination of analytes in the human body. More particularly, the invention relates to methods of analyte calibration and prediction that adjust for state changes not compensated for with a static calibration model.
2. Description of Related Art
Noninvasive
A spectroscopy based noninvasive analyzer delivers external energy in the form of light to a region of the body where the photons interact with the chemical constituents and physiology of the sampled tissue. A portion of the incident photons are scattered or transmitted out of the body where they are detected. Based upon knowledge of the incident photons and detected photons, the chemical and/or structural basis of the sampled site is elucidated. A distinct advantages of a noninvasive system includes the determination of a chemical constituent concentration in the body without the generation of a biohazard in a pain free manner and with the use of limited consumables. Further the technique allows for multiple analyte concentrations to be determined at one time. Some common examples of noninvasive analyzers are magnetic resonance imaging (MRI), X-rays, pulse oximeters, and noninvasive glucose analyzers. With the exception of X-rays, these determinations are performed with relatively harmless wavelengths of radiation. Examples herein focus on noninvasive glucose concentration determination, but the principles apply to the detection of other analytes, such as fats, proteins, water, and blood or tissue constituents.
Diabetes
Diabetes is a chronic disease that results in improper production and utilization of insulin, a hormone that facilitates glucose uptake into cells. While a precise cause of diabetes is unknown, genetic factors, environmental factors, and obesity appear to play roles. Diabetics have increased risk in three broad categories: cardiovascular heart disease, retinopathy, and neuropathy. Diabetics often have one or more of the following complications: heart disease and stroke, high blood pressure, kidney disease, neuropathy (nerve disease and amputations), retinopathy, diabetic ketoacidosis, skin conditions, gum disease, impotence, and fetal complications. Diabetes is a leading cause of death and disability worldwide. Moreover, diabetes is merely one among a group of disorders of glucose metabolism that also include impaired glucose tolerance, and hyperinsulinemia, or hypoglycemia.
Diabetes Prevalence and Trends
Diabetes is an ever more common disease. The World Health Organization (WHO) estimates that diabetes currently afflicts 154 million people worldwide. There are 54 million people with diabetes living in developed countries. The WHO estimates that the number of people with diabetes will grow to 300 million by the year 2025. In the United States, 15.7 million people or 5.9 percent of the population are estimated to have diabetes. Within the United States, the prevalence of adults diagnosed with diabetes increased by six percent in 1999 and rose by 33 percent between 1990 and 1998. This corresponds to approximately eight hundred thousand new cases every year in America. The estimated total cost to the United States economy alone exceeds $90 billion per year. Diabetes Statistics, National Institutes of Health, Publication No. 98-3926, Bethesda, Md. (November 1997).
Long-term clinical studies show that the onset of diabetes related complications is significantly reduced through proper control of blood glucose concentrations. The Diabetes Control and Complications Trial Research Group, The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus, N Eng J of Med , 329:977-86 (1993); U.K. Prospective Diabetes Study (UKPDS) Group, Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes, Lancet, 352:837-853 (1998); and Y. Ohkubo, H. Kishikawa, E. Araki, T. Miyata, S. Isami, S. Motoyoshi, Y. Kojima, N. Furuyoshi, M. Shichizi, Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non-insulin-dependent diabetes mellitus: a randomized prospective 6-year study, Diabetes Res Clin Pract, 28:103-117 (1995).
A vital element of diabetes management is the self-monitoring of blood glucose concentrations by diabetics in the home environment. However, current monitoring techniques discourage regular use due to the inconvenient and painful nature of drawing blood through the skin prior to analysis. The Diabetes Control and Complication Trial Research Group, supra. As a result, noninvasive measurement of glucose concentration is identified as a beneficial development for the management of diabetes. Implantable glucose concentration analyzers coupled to an insulin delivery system providing an artificial pancreas are also being pursued.
Sampling Methodology
A wide range of technologies serve to analyze the chemical make-up of the body. These techniques are broadly categorized into two groups, invasive and noninvasive. For the purposes of this document, a technology that acquires any biosample from the body for analysis or if any part of the measuring apparatus penetrates into the body, the technology is referred to as invasive.                Invasive: Some examples of invasive technologies for glucose concentration determination in the body are those that analyze the biosamples of whole blood, serum, plasma, interstitial fluid, and mixtures or selectively sampled components of the aforementioned. Typically, these samples are analyzed with electrochemical, electroenzymatic, and/or colorimetric approaches. For example, enzymatic and colorimetric approaches are used to determine the glucose concentration in interstitial fluid samples.        Noninvasive: A number of approaches for determining the glucose concentration in biosamples have been developed that utilize spectrophotometric technologies. These techniques include: Raman and fluorescence, as well as techniques using light from the ultraviolet through the infrared [ultraviolet (200 to 400 nm), visible (400 to 700 nm), near-IR (700 to 2500 nm or 14,286 to 4000 cm−1), and infrared (2500 to 14,285 nm or 4000 to 700 cm−1)].Noninvasive Glucose Determination
There exist a number of noninvasive approaches for glucose concentration determination. These approaches vary widely, but have at least two common steps. First, an apparatus is used to acquire a signal from the body without obtaining a biological sample. Second, an algorithm is used to convert this signal into a glucose concentration determination.
One type of noninvasive glucose concentration analyzer is based upon spectra. Typically, a noninvasive apparatus uses some form of spectroscopy to acquire a signal or spectrum of a body part. Utilized spectroscopic techniques include Raman and fluorescence, as well as techniques using light from the ultraviolet through the infrared [ultraviolet (200 to 400 nm), visible (400 to 700 nm), near-IR (700 to 2500 nm or 14,286 to 4000 cm−1), and infrared (2500 to 14,285 nm or 4000 to 700 cm−1)]. A particular range for noninvasive glucose determination in diffuse reflectance mode is about 1100 to 2500 nm or ranges therein. K. Hazen, Glucose Determination in Biological Matrices Using Near-Infrared Spectroscopy, doctoral dissertation, University of Iowa (1995).
Mode
Typically, three modes are used to collect noninvasive spectra: transmittance, transflectance, and/or diffuse reflectance. For example the signal collected, typically being light or a spectrum, is transmitted through a region of the body such as a fingertip, diffusely reflected, or transflected. Transflected here refers to collection of the signal not at the incident point or area (diffuse reflectance), and not at the opposite side of the sample (transmittance), but rather at some point on the body between the transmitted and diffuse reflectance collection areas. For example, transflected light enters the fingertip or forearm in one region and exits in another region typically 0.2 to 5 mm or more away depending on the wavelength used. Thus, light that is strongly absorbed by the body such as light near water absorbance maxima at 1450 or 1950 nm is collected after a small radial divergence and light that is less absorbed such as light near water absorbance minima at 1300, 1600, or 2250 nm is collected at greater radial or transflected distances from the incident photons.
Site
Noninvasive techniques are not limited to using the fingertip as a measurement site. Alternative sites for taking noninvasive measurements include: a hand, finger, palmar region, base of thumb, wrist, dorsal aspect of the wrist, forearm, volar aspect of the forearm, dorsal aspect of the forearm, upper arm, head, earlobe, eye, tongue, chest, torso, abdominal region, thigh, calf, foot, plantar region, and toe.
Instrumentation
While this specification focuses on optical based noninvasive analyzers, it is important to note that noninvasive techniques do not have to be based upon spectroscopy. For example, a bioimpedence meter is considered to be a noninvasive device. Within the context of the invention, any device that reads a signal from the body without penetrating the skin and collecting a biological sample is referred to as a noninvasive glucose analyzer. For example, a bioimpedence meter is a noninvasive device.
Noninvasive glucose concentration determination using a near-infrared analyzer generally involves the illumination with an input element of a small region on the body with near-infrared (NIR) electromagnetic radiation, infrared light in the wavelength range 700 to 2500 nm, or one or more wavelength ranges therein, such as 1100 to 1800 nm. The light is partially absorbed and partially scattered according to its interaction with the constituents of the tissue prior to being reflected back to light collection means optically coupled to a detector or directly to a detector. The detected light contains quantitative information that corresponds to the known interaction of the incident light with components of the body tissue including water, fat, protein, and glucose.
Optical Registration
In an alternate embodiment, the guide provides a means for optical registration. In this embodiment, reflectors or light sensitive elements are placed onto the guide. The optical probe assembly is equipped with light sources and several detectors that allow the position of the guide to be accurately assessed, in either two or three dimensions. In a first configuration, two dimensions (x,y) are assessed and a mechanical stop is used to control the third dimension. In a second configuration, the location of the guide is optically assessed in all three dimensions (x,y,z). Because the position of the guide is constant with respect to the targeted tissue volume, the positional assessment provides accurate information regarding the location of the targeted tissue volume with respect to the optical probe. The registration information provided by such assessment is used to place the tissue site onto the optical probe, or vice versa, through any of the following means:                an operator or user is given a visual or audible signal indicating how to move the tissue site with respect to the optical probe;        a mechanical positioning system is used to position the tissue measurement site with respect to the optical probe; or        a mechanical positioning system is used to position the optical probe onto the tissue measurement site.
One skilled in the art will appreciate that a magnetic sensing system can also be readily applied for assessment of the location of the guide with respect to the tissue measurement site.
While previously described embodiments of the invention employ structural features to control temperature and humidity at the tissue measurement site passively, an alternative embodiment incorporates an airflow device, such as a small blower, to evaporate moisture from the fiber optic probe, the contact surface, and the tissue measurement site.
A noninvasive glucose concentration analyzer has one or more beam paths from a source to a detector. Light source types include a blackbody source, a tungsten-halogen source, one or more LED's, and one or more laser diodes. For multi-wavelength spectrometers a wavelength selection device is used or a series of optical filters are used for wavelength selection. Wavelength selection devices include one or more gratings, prisms, and wavelength selective filters. Variation of the source such as varying which LED or diode is firing is also used for wavelength selection. Detectors are in the form of one or more single element detectors or one or more arrays or bundles of detectors. Detector types include InGaAs, PbS, PbSe, Si, MCT, or the like. Detector arrays include InGaAs, PbS, PbSe, Si, MCT, or the like. Light collection optics such as fiber optics, lenses, and mirrors are commonly used in various configurations as an output element within a spectrometer to direct light from the source to the detector by way of a sample.
Calibration
Glucose concentration analyzers require calibration. This is true for all types of glucose concentration analyzers such as traditional invasive, alternative invasive, noninvasive, and implantable analyzers. One fact associated with noninvasive glucose concentration analyzers is that they are secondary in nature, that is, they do not measure blood glucose concentrations directly. This means that a primary method is required to calibrate these devices in order to measure blood glucose concentrations properly. Many methods of calibration exist.
One noninvasive technology, near-infrared spectroscopy, requires that a mathematical relationship between an in-vivo near-infrared measurement and the actual blood glucose concentration is developed. This is achieved through the collection of in-vivo NIR measurements with corresponding blood glucose concentrations that have been obtained directly through the use of measurement tools such as a YSI (YSI INCORPORATED, Yellow Springs, Ohio) blood glucose concentration analyzer or any appropriate and accurate traditional invasive reference device such as the THERASENSE FREESTYLE (THERASENSE, INC., Alameda Calif.) glucose concentration analyzer.
For spectrophotometric based analyzers, there are several univariate and multivariate methods that are used to develop the mathematical relationship between the measured signal and the actual blood glucose concentration. However, the basic equation being solved is known as the Beer-Lambert Law. This law states that the strength of an absorbance/reflectance measurement is proportional to the concentration of the analyte which is being measured, as in Equation 1,A=εbC  (1)where A is the absorbance/reflectance measurement at a given wavelength of light, ε is the molar absorptivity associated with the molecule of interest at the same given wavelength, b is the distance that the light travels in the sample, and C is the concentration of the molecule of interest (glucose).
Chemometric calibration techniques extract glucose related signal from the measured spectrum through various methods of signal processing and calibration including one or more mathematical models. The models are developed through the process of calibration on the basis of an exemplary set of spectral measurements known as the calibration set and associated set of reference blood glucose concentrations based upon an analysis of capillary blood, venous blood, or interstitial fluid. Common multivariate approaches requiring an exemplary reference glucose concentration vector for each sample spectrum in a calibration include partial least squares (PLS) and principal component regression (PCR). Many additional forms of calibration or optimization are known to those skilled in the art.
An apparatus for measuring infrared throughput typically includes an energy source emitting infrared energy at multiple wavelengths, an input element, an output element, and a spectrum analyzer. Tissue is irradiated with multiple wavelengths from the input element where at least some of the photons are scattered and absorbed by the tissue. A portion of the photons exit the tissue sample, are collected by the output element, are directed toward a detector, and are detected. The resulting signal is utilized in a model for determining the analyte concentration.
Calibration Maintenance
Multivariate models reduce a complex measurement in a space modeled with a reduced number of factors. Data collected for the creation of the original model is done under a set of conditions. Often this set of conditions changes to the extent that the original model no longer functions adequately. For example, the environmental temperature effects the light collection performance of a spectrometer. In addition to instrumentation and environmental impacts, changes in the sample affect the model. For example, commonly interference concentrations vary outside of those tested or new interferences are introduced. In noninvasive determination of glucose concentration in the body, another key issue with sampling is that the sample is alive and dynamic in nature. This results in updates to the calibration being required.
Prediction
A calibration is used in combination with noninvasive spectra of a subject to determine the analyte concentration of that subject.
Dynamic Properties of Skin
The dynamic properties of skin tissue is an important and largely ignored aspect of noninvasive glucose determinations. At a given measurement site, skin tissue is often assumed to remain static, except for changes in the target analyte and other interfering species. However, variations in the physiological state and fluid distribution of tissue profoundly affect the optical properties of tissue layers and compartments over a relatively short period of time.
Many factors impact the physical and chemical state of skin. These include environmental and physiological factors. A list of such factors includes at least body temperature, environmental temperature, food intake, drug or medicine intake, and applied pressure to a sampling site. An impact on one part of the body will affect many other locations in the body. For example, food intake into the digestive track causes movement of water between internal body compartments. Another example is caffeine or stimulant intake that changes blood pressure or results in dilation of capillaries.
Noninvasive Glucose Determination
There exist a number of reports on noninvasive glucose technologies. Some of these relate to general instrumentation configurations required for noninvasive glucose determination. Others refer to sampling technologies. Those most related to the present invention are briefly reviewed here:
General Instrumentation
P. Rolfe, Investigating substances in a patient's bloodstream, UK Patent Application No. 2,033,575 (Aug. 24, 1979) describe an apparatus for directing light into the body, detecting attenuated backscattered light, and utilizing the collected signal to determine glucose concentrations in or near the bloodstream.
C. Dahne, D. Gross, Spectrophotometric method and apparatus for the non-invasive, U.S. Pat. No. 4,655,225 (Apr. 7, 1987) describe a method and apparatus for directing light into a patient's body, collecting transmitted or backscattered light, and determining glucose from selected near-IR wavelength bands. Wavelengths include 1560 to 1590, 1750 to 1780, 2085 to 2115, and 2255 to 2285 nm with at least one additional reference signal from 1000 to 2700 nm.
M. Robinson, K. Ward, R. Eaton, D. Haaland, Method and apparatus for determining the similarity of a biological analyte from a model constructed from known biological fluids, U.S. Pat. No. 4,975,581 (Dec. 4, 1990) describe a method and apparatus for measuring a concentration of a biological analyte such as glucose using infrared spectroscopy in conjunction with a multivariate model. The multivariate model is constructed form plural known biological fluid samples.
J. Hall, T. Cadell, Method and device for measuring concentration levels of blood constituents non-invasively, U.S. Pat. No. 5,361,758 (Nov. 8, 1994) describe a noninvasive device and method for determining analyte concentrations within a living subject utilizing polychromatic light, a wavelength separation device, and an array detector. The apparatus uses a receptor shaped to accept a fingertip with means for blocking extraneous light.
R. Barnes, J. Brasch, D. Purdy, W. Lougheed, Non-invasive determination of analyte concentration in body of mammals, U.S. Pat. No. 5,379,764 (Jan. 10, 1995) describe a noninvasive glucose analyzer that uses data pretreatment in conjunction with a multivariate analysis to determine blood glucose concentrations.
S. Malin, G Khalil, Method and apparatus for multi-spectral analysis of organic blood analytes in noninvasive infrared spectroscopy, U.S. Pat. No. 6,040,578 Mar. 21, 2000) describe a method and apparatus for determination of an organic blood analyte using multi-spectral analysis in the near-IR. A plurality of distinct nonoverlapping regions of wavelengths are incident upon a sample surface, diffusely reflected radiation is collected, and the analyte concentration is determined via chemometric techniques.
Temperature
It is a well-known that many physiological constituents have near-IR absorbance spectra that are sensitive in terms of magnitude and location to localized temperature. This has been reported as impacting noninvasive glucose determinations. [see K. Hazen, Glucose determination in biological matrices using near-infrared spectroscopy, Doctoral Dissertation, University of Iowa (August, 1995)].
Coupling Fluid
T. Blank, G. Acosta, M. Mattu, S. Monfre, Fiber optic probe guide placement guide, U.S. Pat. No. 6,415,167 (Jul. 2, 2002) describe a coupling fluid of one or more perfluoro compounds where a quantity of the coupling fluid is placed at an interface of the optical probe and measurement site. Perfluoro compounds do not have the toxicity associated with chlorofluorocarbons.
Calibration Adjustment
Several methods have been reported to compensate in some part for the dynamic variation of tissue samples.
One reported method of calibration model generation for noninvasive glucose concentration determination is to model an individual over a short period of time [see K. Hazen, Glucose determination in biological matrices using near-infrared spectroscopy, Doctoral Dissertation, University of Iowa (August, 1995); and J. Burmeister, In-vitro model for human noninvasive blood glucose measurements, Doctoral Dissertation, University of Iowa (December 1997)]. This approach avoids modeling the differences between patients and therefore cannot be generalized to more individuals. This approach also fails to address the prevalent short-term problem related to physiologically induced variation and no means of compensating for variation related to the dynamic water shifts of fluid compartments is reported.
Another approach to overcome the effect of tissue variation on a model is to use cross-validation. In one study, meal tolerance tests were used to perturb the glucose concentrations of three subjects and calibration models were constructed specific to each subject on single days and tested through cross-validation [see Robinson M. R.; Eaton R. P.; Haaland D. M.; Keep G. W.; Thomas E. V.; Stalled B. R.; and Robinson P. L. Non-invasive glucose monitoring in diabetic patients: A preliminary evaluation, Clin Chem 1992;38:1618-22]. This approach models the differences between some patients presumably with the intent of modeling variations so that future subjects are predicted by the original model. This approach also fails to address the prevalent short-term problem related to physiologically induced variation and no means of compensating for variation related to the dynamic water shifts of fluid compartments is reported.
Still another approach to overcome the effect of tissue variation on a model is to use extensive calibration of each subject through a series of glucose perturbations often over an extended period of time such as 2 to 12 weeks. Often these calibration periods are followed by an evaluation period during which a subject goes through one or more additional glucose excursions. The intent is to incorporate into the model an extensive set of conditions covering future conditions when predictions are made. When many excursions are used, this incorporation often occurs over a period of weeks. To date, this extensive calibration and testing protocol has met with limited success.
Yet another method to overcome the effect of tissue variation on a model is to compensate for variation related to the structure and state of the tissue through an intelligent pattern recognition system capable of determining calibration models that are most appropriate for the patient at the time of measurement [see Malin, S. F.; et. al. An Intelligent System for Noninvasive Blood Analyte Prediction, U.S. Pat. No. 6,280,381]. The calibration models are developed from the spectral absorbance of a representative population of patients that have been segregated into groups. The groups or classes are defined on the basis of structural and state similarity such that the variation within a class is small compared to the variation between classes. Classification occurs through extracted features of the tissue absorbance spectrum related to the current patient state and structure.
Still an additional group of approaches to overcome the effect of tissue variation on a model is calibration transfer. A number of pretreatment of spectral data techniques have been employed. A general but incomplete list of these pretreatment steps include trimming, wavelength selection, centering, scaling, normalization, taking an nth derivative (n≧1), smoothing, Fourier transforming, principle component selection, finite impulse response filtering, linearization, and transformation. This general class of techniques is found to be limiting in terms of noninvasive glucose concentration analyzer requirements.
Still an additional approach to overcome the effect of tissue variation on a model is a group of techniques based upon local centering using a single spectrum [see Lorber et. al., Local Centering in Multivariate Calibration, Journal of Chemometrics, 1996, 10, 215-220]. In this method, a spectrum is selected for mean centering the calibration data set that is the closest match (with respect to Mahalanobis distance) to that of the unknown sample spectrum. A separate partial least squares model is then constructed for each unknown sample. This technique does not reduce the spectroscopic variation of the calibration set.
Another approach to overcome the effect of tissue variation on a model is related to the technique of mean centering [see E. Thomas, R. Rowe, Methods and apparatus for tailoring spectroscopic calibration models, U.S. Pat. No. 6,528,809 (Mar. 4, 2003) and E. Thomas, R. Rowe, Methods and apparatus for tailoring Spectroscopic Calibration Models, U.S. Pat. No. 6,157,041 (Dec. 5, 2000)]. This method uses spectrographic techniques in conjunction with an improved subject-tailored calibration model. In calibration data, the model data is modified to reduce or eliminate subject-specific attributes, resulting in a calibration data set modeling within-subject physiological variation and instrument variation. In the prediction phase, the prediction process is modified for each target subject utilizing a minimal number of spectral measurements for each subject. However, this method does not address the key problem of short term physiological and chemical changes related to the dynamic nature of the tissue nor the intra-patient variation related to the heterogeneity of the tissue sample.
E. Thomas, U.S. Pat. No. 6,528,809, supra and E. Thomas, U.S. Pat. No. 6,157,041, supra use an infrared based noninvasive glucose concentration analyzer to obtain absorbance spectra of human tissue in combination with a model that is periodically corrected with the use of both a spectrum collected from the tested subject and an invasive reference glucose concentration determination collected from the tested subject. The technique employed is loosely referred to as mean centering, though the subtracted spectrum is not the mean spectrum and the glucose value is used to correct an offset in the predicted value. Collection of the reference spectrum is time consuming, requires some expertise on the part of the user, requires data collection software, and requires a microprocessor or other computing means to implement into the calibration. In addition, the acquired sample spectrum to be used as a reference spectrum contains data collection errors and has spectroscopic attributes not accounted for in the original model. Incorporation of the reference spectrum of the individual into the model thereby results in a significant potential source of error in the resulting calibration that directly translates into errors in subsequent glucose concentration predictions. In a noninvasive glucose determination, this results in an erroneous glucose concentration being reported that is used as an adjunct method for directing insulin therapy. For all of these reasons, elimination of the step of collecting and utilizing a reference sample spectrum is beneficial.
Guide
T. Blank, G. Acosta, M. Mattu, S. Monfre, Fiber optic probe guide placement guide, U.S. Pat. No. 6,415,167 (Jul. 2, 2002) and T. Blank, G. Acosta, M. Mattu, M. Makarewicz, S. Monfre, A. Lorenz, T. Ruchti, Optical Sampling Interface System For In Vivo Measurement of Tissue, U.S. patent application Ser. No. 10/170,921, (filed Jun. 12, 2002), which are both herein incorporated in their entirety by this reference thereto, describe use of a guide in conjunction with a noninvasive glucose analyzer to increase precision of the location of the sampled site resulting in increased accuracy and precision in a noninvasive glucose concentration determination. The guide is used for a period of time to increase precision in sampling throughout a period of sampling, such as a fraction of a day, one day, or a period of multiple days.
Equilibration
A number of reports exist describing the difference (or lack of difference) between traditional glucose determinations and alternative site glucose determinations. Some have recognized the potential difference as having impacts upon noninvasive glucose calibration and maintenance, see U.S. patent application Ser. No. 10/377,916. The use of heat, rubrifractants, or the application of topical pharmacologic or vasodilating agents such as nicotinic acid, methyl nicotinamide, minoxidil, nitroglycerin, histamine, menthol, capsaicin, and mixtures thereof to hasten the equilibration of the glucose concentration in the blood vessels with that of the interstitial fluid has been reported. [see Rohrscheib, Mark; Gardner, Craig; Robinson, Mark R. Method and Apparatus for Non-invasive blood analyte measurement with Fluid Compartment Equilibration, U.S. Pat. No. 6,240,306, May 29, 2001 and Robinson, Mark Ries; Messerschmidt, Robert G. Method for Non-Invasive Blood Analyte Measurement with Improved Optical Interface, U.S. Pat. No. 6,152,876, Nov. 28, 2000].
Release of nitric oxide via photo stimulation is described for use in combination with noninvasive glucose determinations as a method of equilibrating glucose concentrations in poorly perfused regions of the body with glucose concentrations of more well perfused regions of the body. [T. Blank, S. Monfre, M. Makarewicz, M. Mattu, K. Hazen, and R. Henderson, Photostimulation method and apparatus in combination with glucose determination, filed May 6, 2004.
In all of the related technology of this section, no suggestion of the use of mean centering utilizing only a reference glucose value in conjunction with a guide that eliminated the need for a spectral reference is made. Further, no suggestion is made for easing the use of a bioanalyzer such as a near-IR based noninvasive glucose analyzer through the use of a guide to reduce the need for mean centering related techniques based upon spectral references. Further, no minimization of reference glucose concentration differences has been suggested with the use of photo stimulation. Finally, to date no FDA device has been approved for the utilization by an individual or a medical professional for noninvasive glucose concentration determination.
The Problem
Physiological parameters that change the state of skin include: tissue hydration, skin temperature, volume fraction of blood in tissue, skin thickness, magnitude of absorbance features related to fat, hematocrit concentration, and surface reflectance. Many of these parameters change over a period of one or more days or over a much longer period of time such as weeks.
Changes in the state of skin alter a number of properties such as: water concentration, the concentration of other analytes such as protein, fat, keratinocytes and glucose, the scattering of skin, the absorbance of skin, the refractive indices of various layers of skin, the thickness of tissue layers, the emitted radiation from the body, the mechanical properties of tissue, magnitude of absorbance features related to water, magnitude of absorbance features related to protein, and the size and distribution of scattering centers.
Noninvasive spectra, such as a near-IR based diffuse reflectance spectrum, are representative of skin tissue properties. Since a large number of state changes each effect a large number of skin tissue properties, variations through time of noninvasive spectra of a given skin sampling site often vary in a highly nonlinear and profound manner. Further, factor analysis based multivariate models result in abstract features. Therefore, change in state often profoundly effects multivariate model predictions.
Because near-IR based noninvasive glucose analyzers typically use multivariate analysis that is susceptible to sample state changes, the model must be robust or optionally updated. The invention herein focuses on maintenance of one or more calibrations. Calibration maintenance is a costly and time-consuming process that requires some technical skill. Elimination or automation of steps required for maintenance of a noninvasive glucose analyzer is beneficial for at least one of increasing marketability of the analyzer, increasing the number of people who may use the analyzer, reduction in time requirements associated with a glucose concentration determination, and increased precision and/or accuracy of a glucose concentration determination. Specifically, elimination of any data gathering step, such as collection of spectra, is beneficial for the above reasons. This invention provides a simple calibration maintenance method for use with a noninvasive glucose concentration analyzer.

This patent is subject to a terminal disclaimer.

Method of sample control and calibration adjustment for use with a noninvasive analyzer


A sending trunk on the input side of an ATM switch is equipped with a test cell generating section, and a receiving trunk on the output side of the ATM switch is equipped with a test cell detecting section. The test cell generating section includes a unit for setting a test cell identifier in the header of a test cell and a unit for generating pieces of data with regularity in the information field of the test cell. The test cell detecting section includes a unit for detecting the test cell identifier from the header of a cell received and a unit for detecting regularity from data in the information field of the cell received. When a test cell is transmitted, the test cell detecting section evaluates the result of a test on the basis of the result of detection of the test cell identifier from the header of the test cell and the result of detection of the regularity from data in the information field of the test cell.

The present invention relates to a path test system for an ATM switch.
Of recent years ATM (Asynchronous Transfer Mode) has been studied actively as a technique for a switching unit for a broadband integrated services digital network (BISDN) that is the next generation of ISDN.
The switch facilities of an ATM switching unit are equipped with a hardware configuration for high-speed operation. Thus, it is difficult to monitor directly the internal operation of the ATM switch. For this reason, the development of a method of performing a test to determine if the switch functions properly has been expected.
FIG. 1 illustrates a prior art. In this figure, 1 denotes a test cell inserting section, 2 denotes a test cell generating section, 3 denotes an ATM switch (ATMSW), 4 denotes a test cell extracting section, and 5 denotes a test cell decision section.
The ATM switch 3 in an ATM exchange has a function of switching a cell comprised of a 5-byte header and a 48-byte information field in accordance with header information (VPI/VCI: virtual path identifier /virtual channel identifier) and transferring it to an output (transmission line) determined by the header. In this case, knowing whether the ATM switch performs a switching operation properly in accordance with the header information is very important for maintaining the quality (performance) of the switching unit and moreover it is essential for maintenance thereof.
Here, a conventional method of checking the ATM switch will be described with reference to FIG. 1. The test cell generating section 2 is associated with the cell inserting section 1 provided on a cell transmission line input to the ATM switch. In testing the ATM switch the test cell generating section 2 generates a cell having a specific value (for example, all zeros) as its VCI and predetermined contents as the contents of its information field. This cell is inserted between usual cells for communication in the cell inserting section 1, and entered into the ATM switch 3 over the transmission line.
The ATM switch 3 establishes a path corresponding to the VCI having the specific value allocated to the test cell so as to transfer the test cell to a predetermined outgoing transmission line. If, therefore, the ATM switch 3 operates properly, the test cell will be output onto a predetermined transmission line. The test cell extracting section 4, provided on a transmission line onto which the test cell is output, extracts the test cell having the specific VCI value and outputs it to the test cell decision section 5.
The test cell decision section 5 checks the test cell extracted by the test cell extracting section 4 with the test cell generated by the test cell generating section 2. If the test cell extracted is identified as the test cell generated, then the decision section 5 outputs the test result representing the normality of the ATM switch 3.
A problem with the prior art system is that when, in the test cell decision section 5, by receiving data of a specific information field set in advance as a test cell from the test cell generating section 2 which does not agree with a cell extracted by the extracting section 4, it becomes impossible to detect whether or not the ATM switch 3 can switch all cells properly. That is, a test of the ATM switch (ATMSW) 3 has required an advance transmission of data in the information field of a test cell from the test cell generating section 2 on the input side of the switch to the test cell decision section 5 on the output side, which takes additional test time.
In addition, since the contents of the information field contained in a test cell are fixed, a problem arises in that variations in a bit pattern caused by a hardware fault occurring on a switch path cannot necessarily be detected. That is, if the contents of the information field in a test cell are fixed, it is impossible to detect the occurrence of a fault which causes a variation in a bit pattern corresponding to the information field pattern of the test cell. For example, when the content of the information field in the test cell is fixed to all zeros, the occurrence of a fault in which a line is stuck to "O" can not be detected.


An adjustable support stand for an article such as a camera employs a plurality of elongated links connected to one another at their ends by lockable universal joints. Each joint consists of a pair of complementary knuckles, each joined to a link end by a splined connection, which connections provide two axes of rotation to the joint. The knuckles are joined to one another about a third axis of rotation, perpendicular to the first two axes by means of a splined pin which passes through splined holes in the two knuckles. The splined connections employ splines of different count to achieve a high resolution of possible positions.

A wide variety of mechanical devices employ universally adjustable joints for connecting two elements at a variety of positional relationships. For example, in optical apparatus it is often necessary to support an element, such as a camera or a laser, in a unique position relative to other elements and to be able to lock the joints which support the element to ensure maintenance of a chosen positional relationship. Similar jointed stands are often used in supporting medical apparatus, vehicle components, etc.
Often these supports include two or more elongated links or arms joined by universal joints so that the arms may be arrayed in any chosen relation with respect to one another. By way of example, U.S. Pat. No. 6,168,126 discloses a multi-adjustable stand for vehicle electronic components including a pair of arms and adjustable, lockable joints for securing the arms in any variety of positions relative to one another. U.S. Pat. No. 6,220,556 discloses a similar system for supporting switches above a base.

Mechanically lockable universal joint and structures employing such joint