A system and method for minimizing transmit latency uncertainty in a 100 Mb RMII Ethernet physical layer device is disclosed. A 100 Mb RMII Ethernet transmit physical layer device comprises a divide circuit that selects a phase of a transmit clock signal for transmitting data. The invention comprises a reset circuit that aligns the divide circuit to select an optimal phase of the transmit clock signal for transmitting data. The reset circuit of the invention is capable of reducing the transmit latency uncertainty from approximately twenty nanoseconds to four nanoseconds.

In industrial Ethernet and other real-time networking applications, latency for data transmission is an important issue. Minimizing the total latency is important. But perhaps even more important is minimizing any uncertainty in the latency. In Reduced Media Independent Interface™ (RMII™) based Ethernet systems, one problem is that transmit latency includes an uncertainty based on the relationship between the RMII™ reference clock and the transmit clock that is used to transmit the data on the physical medium.
The Reduced Media Independent Interface™ (RMII™) Specification ("RMII™ Specification") published by the RMII Consortium sets forth an interface protocol for communications between Ethernet physical layer devices and application specific integrated circuit (ASIC) devices. The materials set forth in the RMII™ Specification are hereby incorporated herein by reference. Reduced Media Independent Interface™ is a trademark of the RMII Consortium. For clarity this patent document will not place the trademark designator TM on each reference to the initials RMII. It is understood that the initials RMII represent a trademark.
The RMII Specification defines an interface for transferring Ethernet packet data from a Media Access Controller or Switch to an Ethernet physical layer device. The RMII Specification describes the use of a fifty megahertz (50 MHz) reference clock to transfer data in two-bit increments. The two-bit increments are also referred to as "di-bit" increments.
The operation of a physical layer device is described in an IEEE publication entitled "IEEE Standards for Local and Metropolitan Area Networks: Media Access Control (MAC) Parameters, Physical Layer, Medium Attachment Units, and Repeater for 100 Mb/s Operation, Type 100BASE-T." The short name of this standard is IEEE Standard 802.3. Within a physical layer device, as defined by the IEEE 802.3 specification, the one hundred megabit (100 Mb) data is transmitted as code-group data, which is a 4B5B encoding of four bit ("nibble") data.
Due to the nature of the clock and data generation, there is no known relationship between the phase of the fifty megaHertz (50 MHz) reference clock that is used to initiate each nibble of data transfer and the phase of the one hundred twenty five megaHertz (125 MHz) transmit clock that samples that data for transmission to the Physical Layer. The lack of a known relationship between the phase of the two clocks results in a minimum twenty nanosecond (20 ns) uncertainty in the latency for transmitting the data as measured between the reference clock at the RMII and the actual transmission of the data on the physical medium. The twenty nanosecond (20 ns) time interval represents one clock period of the fifty megahertz (50 MHz) clock.
There is a need in the art for a system and method that is capable of minimizing the transmit latency uncertainty in 100 Mb RMII Ethernet physical layer devices. In particular, there is a need in the art for a system and method that can significantly reduce the transmit latency uncertainty from its present value of approximately twenty nanoseconds (20 ns).
In order to better understand the advance in the art that the present invention provides, a prior art system and method will first be described. FIG. 1 illustrates a system timing diagram for a prior art RMII System 100. FIG. 1 shows the basic components of a single transmit-to-receive Ethernet path from the Transmit Media Access Controller 110 ("Transmit Mac 110") to the Receive Media Access Controller 120 ("Receive Mac 120"). Transmit Mac 100 sends the data to the Transmit physical layer device 130 ("Transmit Phy 130"). The Transmit Mac 110 sends a transmit enable signal ("TX_EN") to the Transmit Phy 130 to enable the transmission of data. The data is sent over the link that is designated TXD[1:0] between the Transmit Mac 110 and the Transmit Phy 130.
The Transmit Phy 130 sends the data over a Category 5 cable 140 ("Cat5 Cable 140"). The data from the Cat5 Cable 140 is received by the Receive physical layer device 150 ("Receive Phy 150"). The Receive Phy 150 sends the data to the Receive Mac 120. The Receive Phy 150 sends a receive enable signal ("RX_DV") to the Receive Mac 120 to enable the receipt of data. The data is sent over the link that is designated RXD[1:0] between the Receive Phy 150 and the Receive Mac 120.
A fifty megaHertz (50 MHz) first reference clock 160 ("REF_CLK1 160") is coupled to the Transmit Mac 110 and to the Transmit Phy 130. A fifty megaHertz (50 MHz) second reference clock 170 ("REF_CLK2 170") is coupled to the Receive Phy 150 and to the Receive Mac 120. The first reference clock 160 and the second reference clock 170 are each accurate to a precision of fifty parts per million (+/−50 ppm). The two reference clocks are independent.
RMII system latency is the delay from the Transmit Mac 110 to the Receive Mac 120 as measured at the RMII interface. Transmit RMII data is generated based on the first reference clock 160 (REF_CLK1 160). Receive RMII data is generated based on the second reference clock 170 (REF_CLK2 170).
The total transit time of the link from measurement at the Transmit RMII interface to the Receive RMII interface is given by the expression:tpTotalPhyRMII=tpPhyTxRMII+tpCable+tpPhyRxRMII
The expression "tpTotalPhyRMII" represents the total transit time of the link. The expression "tpPhyTxRMII" represents the transit time through the Transmit Phy 130. The expression "tpCable" represents the transit time through the Cat5 Cable 140. The expression "tpPhyRxRMII" represents the transit time through the Receive Phy 150. The sum of these three expressions represents the RMII system latency.
We now consider just the RMII Transmit latency. The RMII Transmit latency may be measured from transmit data at the RMII interface to the first bit transmitted on the Cat5 Cable 140. It is understood that while Category 5 cable is the type most often used, other types of cable may be used to connect the Transmit Phy 130 and the Receive Phy 150.
To eliminate system dependencies at the RMII interface (i.e., transmit data setup to REF_CLK1 160), measurement is made from the rising edge of the REF_CLK1 160 clock signal that samples the transmit data. The measurement is made from the assertion of the transmit enable signal TX_EN to the first bit of JK on the cable. The code-group J and the code-group K are the first code-groups in a Start of Stream Delimiter ("SSD").
Because the latency is consistent for all transmit data nibbles, measurements can be made from the Start of Frame Delimiter ("SFD") or any other data in the data packet.
FIG. 2 illustrates how the "tpPhyTxRMII" transit time through the Transmit Phy 130 is measured. FIG. 2 illustrates a diagram showing the transmit delay in a prior art RMII transmit physical layer device. The first waveform 210 in FIG. 2 is the clock signal REF_CLK1 of the first reference clock 160. The second waveform 220 in FIG. 2 is the transmit enable signal TX_EN. The third waveform 230 in FIG. 2 is the data transmission signal TXD[1:0]. The fourth waveform 240 in FIG. 2 is the transmit delay (TD) waveform.
As shown in FIG. 2, the point in time from which the tpPhyTxRMII interval is measured is on the leading edge of the first REF_CLK1 pulse that samples the asserted transmit enable signal TX_EN. The end of the tpPhyTxRMII interval is located at the beginning of the code-group J on the transmit delay (TD) waveform. The tpPhyTxRMII interval is represented in FIG. 2 by an arrow that extends between a first vertical line that marks the beginning of the appropriate REF_CLK1 pulse and a second vertical line that marks the beginning of the code-group J. The tpPhyTxRMII interval represents the RMII Transmit latency.
The Phy Transmit process may be broken down into components. The Transmit Phy 130 processes data in the following stages. First, the data is subjected to an RMII to MII translation process that converts di-bits to nibbles. Second, the data then is processed in a 100BASE-X Physical Coding Sublayer ("PCS") unit. Third, the data is then processed in a 100BASE-X Physical Medium Attachment ("PMA") unit. Fourth, the data is then processed in a 100BASE-X Physical Medium Dependent ("PMD") sublayer unit.
The latency uncertainty in the transmitter is contained in the RMII to MII translation process and in the Physical Coding Sublayer ("PCS") unit. The implementations of the Physical Medium Attachment ("PMA") unit and the Physical Medium Dependent ("PMD") sublayer unit depend on the actual medium that is selected (e.g., copper cable or optical fiber) and are not significant to the determination of the transmit latency uncertainty. Therefore, only the RMII to MII translation and the operation of the Physical Coding Sublayer ("PCS") unit are pertinent to the determination of the transmit latency uncertainty.
FIG. 3 illustrates a block diagram 300 of a prior art RMII to MII Translation unit 310 and a prior art Physical Coding Sublayer ("PCS") unit 320. The inputs to the RMII to MII Translation unit 310 from the Transmit Mac 110 are the transmit enable signal TX_EN and the data signal TXD[1:0]. The RMII to MII Translation unit 310 also receives the REF_CLK1 signal from the first reference clock 160. Because the second reference clock 170 is not involved in the determination of the transmit latency uncertainty, the first reference clock signal REF_CLK1 will simply be referred to as the reference clock signal REF_CLK.
As shown in FIG. 3, the 50 MHz REF_CLK signal is provided to a Clock Multiplier unit 330. The Clock Multiplier unit 330 multiplies the clock signal REF_CLK signal to obtain a one hundred twenty five megaHertz (125 MHz) Transmit Clock signal. The Clock Multiplier unit 330 provides the 125 MHz Transmit Clock signal to both the RMII to MII Translation unit 310 and the Physical Coding Sublayer ("PCS") unit 320.
The operation of the Physical Coding Sublayer ("PCS") unit 320 will now be described. The PCS unit 320 comprises a 4B5B Encoder 340, a Serializer 350, a Transmit Bits State Machine 360, and a Transmit State Machine 370. The output of the PCS unit 320 is provided to a Physical Medium Attachment ("PMA") unit (not shown in FIG. 3). The operation of the PCS unit 320 is described in Clause 24 of the IEEE 802.3 Specification.
The PCS unit 320 receives and encodes 4-bit (nibble) packet data in the 4B5B Encoder 340. The Transmit Bits State Machine 360 controls the operation of the 4B5B Encoder 340 and the Transmit State Machine 370. The 4B5B Encoder 340 provides the encoded data in the form of 5-bit code-groups to Serializer 350. Serializer 350 uses the 5-bit code-groups to create code_bit output and provides the code_bit output to the PMA unit (not shown in FIG. 3).
The PCS unit 320 receives the 4-bit (nibble) packet data on line mii_txd[3:0] from the RMII to MII Translation unit 310. The PCS unit 320 also receives an enable signal on line mii_tx_en from the RMII to MII Translation unit 310. The 4-bit (nibble) packet data is encoded in 4B5B Encoder 340 as a constant stream of 5-bit code-groups. The IEEE 802.3 Specification also defines an IDLE code-group as well as specific control code-groups to indicate Start of Packet, End of Packet, and error conditions. The packet encapsulation, using control code-groups, is shown in FIG. 24-5 of the IEEE 802.3 Specification. For convenience, FIG. 4 of this patent document sets forth FIG. 24-5 of the IEEE 802.3 Specification.
In sending a frame, the PCS unit 320 replaces the first byte of Preamble with a Start of Stream Delimiter ("SSD") that consists of the two code-groups /J/ and /K/. At the end of the frame transmission, the PCS unit 320 appends an End of Stream Delimiter ("ESD") that consists of the two code-groups /T/ and /R/ prior to resuming transmission of the IDLE code-groups /I/. Therefore an encapsulated packet will have the form /I/I/J/K/<data code-groups>/T/R/I/I/I/ where IDLE code-groups are sent continuously before and after the frame.
In all cases the IEEE 802.3 Specification defines transmit data to be sent as groups of five data bits including IDLE code-groups. The code-group requirements for transmit data are apparent in the Transmit state diagrams set forth and described in FIG. 24-7 and FIG. 24-8 of the IEEE 802.3 Specification.
One of the consequences of the definition as set forth in the IEEE 802.3 Specification is that the device must generate a constant 125 MHz Transmit Clock, and consistently transmit code-group data using the same phase of that 125 MHz Transmit Clock, as controlled by the Transmit Bits State Diagram (FIG. 24-7 of the IEEE 802.3 Specification). Therefore, the transmitter will consistently begin code-group transmissions on one of the five phases of the 125 MHz Transmit Clock. Because the transmit phase must be selected prior to the first packet transmission (because the IDLE code-groups must be sent for a long period prior to establishing a good link status), there is no fixed alignment of the 50 MHz reference clock to the 125 MHz Transmit Clock phase that is used to transmit the code-group data.
FIG. 5 illustrates the possible relationships between the 50 MHz reference clock and the phase of the 125 MHz Transmit Clock that generates the "sentCodeGroup.indicate" control signal as defined by the Transmit Bits state diagram. FIG. 5 is designed primarily to illustrate the relationships between the clocks and does not attempt to accurately model clock skews or overall data latency.
The first waveform 510 in FIG. 5 is the 50 MHz reference clock signal REF_CLK. The second waveform 520 in FIG. 5 is the 125 MHz Transmit Clock signal TX_CLK. The third through seventh waveforms (530 to 570) represent each of the five successive phases of the 125 MHz Transmit Clock.
For a given phase relationship (e.g., Phase 2) the delay from the reference clock REF_CLK positive edge to the "sentCodeGroup.indicate" signal varies by twenty nanoseconds (20 ns). As shown in FIG. 5, for data generated from the positive edge of the first pulse of REF_CLK ("Edge 1"), the delay to the next Phase 2 pulse is essentially one (1) Transmit Clock cycle or eight nanoseconds (8 ns). For data generated from the positive edge of the second pulse of REF_CLK ("Edge 2"), the delay to the next Phase 2 pulse is essentially three and one half (3.5) Transmit Clock cycles or twenty eight nanosecond (28 ns). Therefore, there is a twenty nanosecond (20 ns) difference in data latency that depends on the REF_CLK edge that is used to transfer the RMII data.
The minimum twenty nanoseconds (20 ns) uncertainty is dependent upon the device providing a consistent phase relationship between the reference clock signal REF_CLK and the "divide-by-five" circuit that creates the sentCodeGroup signal (such that only one of the phases is possible). If there is not a consistent relationship between the two functions, then any phase is possible and the uncertainty could be larger than twenty nanoseconds (20 ns). For example, Edge 1 to the next Phase 1 pulse is zero nanoseconds (0 ns) while Edge 2 to the next Phase 3 pulse is thirty six nanoseconds (36 ns).
As previously mentioned, there is a need in the art for a system and method that can significantly reduce the transmit latency uncertainty in 100 Mb RMII Ethernet physical layer devices from its current minimum value of approximately twenty nanoseconds (20 ns).
Before undertaking the Detailed Description of the Invention below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation; the term "or," is inclusive, meaning and/or; the phrases "associated with" and "associated therewith," as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
The term "controller" means any device, system, or part thereof that controls at least one operation. A controller may be implemented in hardware, software, firmware, or combination thereof. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.
Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior uses, as well as to future uses, of such defined words and phrases.

System and method for minimizing transmit latency uncertainty in 100 Mb RMII ethernet physical layer devices


The present invention relates to a photoresist composition comprising a photoacid generator and at least one polymer comprising at least one unit as described by structure 1,

Photoresist compositions are used in microlithography processes for making miniaturized electronic components such as in the fabrication of computer chips and integrated circuits. Generally, in these processes, a thin coating of film of a photoresist composition is first applied to a substrate material, such as silicon wafers used for making integrated circuits. The coated substrate is then baked to evaporate any solvent in the photoresist composition and to fix the coating onto the substrate. The photoresist coated on the substrate is next subjected to an image-wise exposure to radiation.
The radiation exposure causes a chemical transformation in the exposed areas of the coated surface. Visible light, ultraviolet (UV) light, electron beam and X-ray radiant energy are radiation types commonly used today in microlithographic processes. After this image-wise exposure, the coated substrate is treated with a developer solution to dissolve and remove either the radiation exposed or the unexposed areas of the photoresist.
The trend towards the miniaturization of semiconductor devices has led to the use of new photoresists that are sensitive at lower and lower wavelengths of radiation and has also led to the use of sophisticated multilevel systems to overcome difficulties associated with such miniaturization.
The present photoresist compositions are positive-working photoresist, i.e. when they are exposed image-wise to radiation, those areas of the photoresist composition exposed to the radiation become more soluble to the developer solution (e.g. a rearrangement reaction occurs) while those areas not exposed remain relatively insoluble to the developer solution. Thus, treatment of an exposed positive-working photoresist with the developer causes removal of the exposed areas of the coating and the formation of a positive image in the photoresist coating. Again, a desired portion of the underlying surface is uncovered.
Photoresist resolution is defined as the smallest feature which the resist composition can transfer from the photomask to the substrate with a high degree of image edge acuity after exposure and development. In many leading edge manufacturing applications today, photoresist resolution on the order of less than 100 nm are necessary. In addition, it is almost always desirable that the developed photoresist wall profiles be near vertical relative to the substrate. Such demarcations between developed and undeveloped areas of the resist coating translate into accurate pattern transfer of the mask image onto the substrate. This becomes even more critical as the push toward miniaturization reduces the critical dimensions on the devices.
Photoresists sensitive to short wavelengths, between about 100 nm and about 300 nm are often used where subhalfmicron geometries are required. Particularly preferred are photoresists comprising non-aromatic polymers, a photoacid generator, optionally a dissolution inhibitor, and solvent.
High resolution, chemically amplified, deep ultraviolet (100–300 nm) positive and negative tone photoresists are available for patterning images with less than quarter micron geometries. To date, there are three major deep ultraviolet (uv) exposure technologies that have provided significant advancement in miniaturization, and these use lasers that emit radiation at 248 nm, 193 nm and 157 nm. Photoresists for 248 nm have typically been based on substituted polyhydroxystyrene and its copolymers, such as those described in U.S. Pat. No. 4,491,628 and U.S. Pat. No. 5,350,660. On the other hand, photoresists for exposure below 200 nm require non-aromatic polymers since aromatics are opaque at this wavelength. U.S. Pat. No. 5,843,624 and GB 2320718 disclose photoresists useful for 193 nm exposure. Generally, polymers containing alicyclic hydrocarbons are used for photoresists for exposure below 200 nm. Alicyclic hydrocarbons are incorporated into the polymer for many reasons, primarily since they have relatively high carbon hydrogen ratios which improve etch resistance, they also provide transparency at low wavelengths and they have relatively high glass transition temperatures. U.S. Pat. No. 5,843,624 discloses polymers for photoresist that are obtained by free radical polymerization of maleic anhydride and unsaturated cyclic monomers, but the presence of maleic anhydride makes these polymers insufficiently transparent at 157 nm.
Two basic classes of photoresists sensitive at 157 nm, and based on fluorinated polymers with pendant fluoroalcohol groups, are known to be substantially transparent at that wavelength. One class of 157 nm fluoroalcohol photoresists is derived from polymers containing groups such as fluorinated-norbornenes, and are homopolymerized or copolymerized with other transparent monomers such as tetrafluoroethylene (Hoang V. Tran et al Macromolecules 35, 6539, 2002, WO 00/67072, WO 00/17712) using either metal catalyzed or radical polymerization. Generally, these materials give higher absorbencies but have good plasma etch resistance due to their high alicyclic content. More recently, a class of 157 nm fluoroalcohol polymers was described in which the polymer backbone is derived from the cyclopolymerization of an asymmetrical diene such as 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene (Shun-ichi Kodama et al Advances in Resist Technology and Processing XIX, Proceedings of SPIE Vol. 4690 p76 2002; WO 02/065212) or copolymerization of a fluorodiene with an olefin (WO 01/98834-A1). These materials give acceptable absorbance at 157 nm, but due to their lower alicyclic content as compared to the fluoro-norbornene polymer, have lower plasma etch resistance. These two classes of polymers can often be blended to provide a balance between the high etch resistance of the first polymer type and the high transparency at 157 nm of the second polymer type.
However, an important limitation to any of these approaches is the availability of a suitable protecting group for fluoroalcohols. In almost all of these approaches, the acid labile protecting groups for the fluoroalcohol moiety has been mainly limited in scope to either acetal type (e.g. MOM (methoxymethyl), or tertiaryalkoxycarbonyl (eg. t-BOC (tert-butyloxycarbonyl) or tertiary alkyl protecting groups. These protecting groups on the perfluoroalcohol moiety are relatively unstable and often undergo partial or complete deprotection during polymerization.
The difficulty in protecting the fluoroalcohol functionality, and the resultant loss of the unexposed photoresist film, has meant that the acid labile functionality can often only be attached to either a methacrylate, acrylate, or norbornenecarboxylic acid repeat unit (which are deleterious to transparency at 157 nm) or to a dissolution inhibitor additive (WO 00/67072, WO 00/17712 Hoang V. Tran et al Macromolecules 35, 6539, 2002). The objective of this invention is to provide a protecting group which would confer good transparency at 157 nm, and would possess high thermal stability towards both synthetic and photoresist processing conditions.
The inventors of this application have found that, surprisingly, aliphatic cyclic polymers can have their fluoroalcohol moieties easily functionalized with an alkyloxycarbonylalkyl(AOCA) group and that this group provides these types of resins with surprising advantages for photoresist applications.
The AOCA group, particularly the tert-butoxycarbonylmethyl (BOCME) group, has had some prior use as a substituent in pharmaceutical applications (WO9533753, DE 2460537). It has also been employed in resist applications where the BOCME group is attached to a phenolic moiety in a resin or as small molecule dissolution inhibitor, and used with radiation at i-line (JP 09211865), 248 nm (JP 20011312065, U.S. Pat. No. 6,333,436B1, U.S. Pat. No. 6,369,276, JP 08193055) or electron beam and X-ray (JP 2000-376059). In addition, at 248 nm, it has also been employed to protect phenolic resins (JP 08176051). Additionally, the BOCME group has been used to protect some specific monomers for 157 nm photoresists. US 2002/090572 A1 and US2002/0081520 A1 discuss the use of BOCME protected hexafluorobisphenol-A in silsesquioxane based polymers and copolymers, which, however, are very absorbent at 157 nm. Additionally, the use of the BOCME group to protect fluoroalcohol moieties attached to cyclic or alicyclic polymer repeating units are disclosed in WO 02/44811 A2 and EP 1,275,666. In WO 01/74916A1, the abstract discloses a polymer having one segment with an acid decomposable group, one segment derived from a fluoroacrylate and another segment derived from other copolymerizable monomer, and the patent application discloses a large variety of possible polymers. In WO 02/44811 A2, the BOCME group is used to protect a norbornenefluoroalcohol group, however, the polymer is used in a blend with a tetrafluoroethylene copolymer.
Fluorinated analogs of BOCME (e.g. —FC(CH3)CO2t-Bu) have been described as substituents for phenol moieties in applications such as herbicides (EP0044979). US 2002/0061466 discloses the functionalization of the fluorinated analogue of the BOCME group, but on an acrylate monomer.
The present inventors have found that when the AOCA group is used to protect fluoroalcohol moieties it is unexpectedly found to possess higher stability towards thermal cleavage than the t-BOC group or the MOM protecting group. Generally, from a photoresist standpoint, such an increase in thermal stability of the protected fluoroalcohol imparted by use of AOCA, particularly the BOCME group, is desirable as it increases thermal processing latitude and shelf life. Also, from a synthetic standpoint, such a increase in thermal stability is desirable as it helps to increase the yield of protected fluoroalcohol polymers, whether they are made by protection of pre-formed fluoroalcohol polymers or through polymerization of monomers containing a fluoroalcohol bearing polymer protected by AOCA groups. Surprisingly, despite its high thermal stability, the BOCME protecting group, in particular, can be easily removed by photoreleased acid in the exposed resist areas, requiring standard post-exposure bake temperatures to affect cleavage (110° C.–130° C.). It has also been found by the applicants that the functionalization of perfluoroalcohols with AOCA groups results in higher contrast photoresist systems than using tert-butyl carboxylates of photoresist resins containing norbornene-5-carboxylic acid repeat units.
The process of functionalizing the AOCA group to the polymer comprises reacting a polymer containing a hydroxyl group with a reactant that can provide the AOCA group and the reaction proceeds in the presence of a base. Typically, metal bases, especially alkali and alkaline-earth metals, have been used for this reaction, examples of such bases are, sodium hydride, lithium t-butoxide, potassium t-butoxide, etc. U.S. Pat. No. 6,210,859 discloses the reaction of polyhydroxystyrene with t-butyl bromoacetate and morpholino bromoacetate in the presence of 25% tetramethyl ammonium hydroxide aqueous solution.
The inventors of the present application have found that for the synthesis of the aliphatic polymer of the present invention, organic bases, especially ammonium bases, are advantageous over metal bases. Metals from metal bases are harder to remove from the final photoresist than organic bases, and metal bases can leave behind trace amounts of metals which are detrimental to the final product.

Photoresist composition for deep ultraviolet lithography

Abstract: The invention also relates to a process for imaging the photoresist composition of the present invention, and to a process of making the polymer in the presence of an organic base.


A door, particularly for large doorways, which includes a door leaf suspended from an upper edge of the doorway and including at least one of a continuous sheet or a number of sheets arranged in a single or several layers attached to a series of lateral braces at an equal or common distance from each other in a vertical direction of the doorway. The lateral braces extend at respective ends thereof into a generally vertically extending guide profile, and from an upper edge of the doorway, a hoist is provided which includes lines or belts. Each lateral brace includes an attached hoisting device, with the hoisting devices being connected so as to enable movement of the door in an upward and downward direction.

In various connections there is a need for a door that can cover large openings, with the door being lightweight, simple in construction and inexpensive to manufacture.
Norwegian Patent 136,110 describes a door that has a hoisting wire for raising the door which is fed through the separate lateral braces and fastened to a lowermost lateral brace. When this door is raised, the first lateral brace is initially raised while the rest of the door is motionless until the lateral braces below are raised toward the upper lateral brace thereby resulting in the lateral braces being forced together and squeezing the fabric of the door therebetween causing a number of problems. In the closed position the individual lateral braces will load the fabric and thereby stretch the same and there is a general need to improve this existing type of door.


A plurality of targets in a mobile platform's obstructed zone can be cleared from the obstructed zone and engaged in the most time-efficient manner by maneuvering the platform to clear and engage each target having the minimum clearance displacement in turn as measured from the platform's position following each maneuver.

Many armed military vehicles generally have some blind spots or obstructed zones and do not have the ability to engage hostile targets with the onboard weaponry with 360° coverage. For example, on many armed military ships, some on-deck structure such as the ship's superstructure impose obstructions to the on-board weaponry. The area around the ship that can not be reached by the on-board weaponry because of the on-deck obstructions is identified as the ship's obstructed zone. So such a ship does not have 360° clearance for its weaponry and the ship can not engage any hostile targets that are in the ship's obstructed zone. When hostile targets are in the ship's obstructed zone, the ship must maneuver to bring the targets out of the obstructed zone (i.e. clear the targets) in order to engage them. When multiple hostile targets are in the ship's obstructed zone, it would be desirable to know the most time efficient way of maneuvering the ship to clear and engage each of the multiple hostile targets.

System AMD method for maneuvering a mobile platform with an on-board obstruction


A network for category-level 6D pose and size estimation, including a 3D-OCR module for 3D Orientation-Consistent Representation, a GeoReS module for Geometry-constrained Reflection Symmetry, and a MPDE module for Mirror-Paired Dimensional Estimation; wherein the 3D-OCR module and the GeoReS module are incorporated in parallel; the 3D-OCR module receives a canonical template shape including canonical category-specific keypoints; the GeoReS module receives an original input depth observation including pre-processed predicted category labels and potential masks of the target instances; the MPDE module receives the output from the GeoReS module as well as the original input depth observation; and the network outputs the estimation results based on the output of the MPDE module, the output of the 3D-OCR module, as well as the canonical template shape. Also provided are corresponding systems and methods.

Estimating accurate 6D pose estimation plays a pivotal role in the tasks of augmented reality, scene understanding, and especially robotic applications such as grasping and manipulation. For example, FIG. 1 shows the comparisons between the texture/color and the geometry under the synthetic and real-world image domain (part i), as well as the implementation of DONet deployed in a physical Baxter robot (part ii).
Most prior arts focus on "instance-level" 6D object pose estimation, where the 6D pose of the target instance is recovered given exact 3D models. Given exact 3D models, many traditional tasks focus on feature or template matching. Although they can deal with many scenarios well, the performance will drop sharply when encountering texture-less objects or heavy object occlusion. Recently, the method of directly regressing 6D pose from RGB images by CNN-based architectures has been investigated, e.g., PoseNet (Kendall et al., "A convolutional network for real-time 6-dof camera relocalization", IEEE international conference on computer vision, 2015), PoseCNN (Xiang et al., "A convolutional neural network for 6d object pose estimation in cluttered scenes", arXiv preprint arXiv:1711.00199, 2017). DenseFusion (Wang et al., "Densefusion: 6d object pose estimation by iterative dense fusion", IEEE Conference on Computer Vision and Pattern Recognition, 2019) introduces "densefusion" manner for better aggregating color and depth information from the RGB-D images. Another line of works regress the object coordinates or keypoints in a 2D image with kinds of methods, and then recover pose by Perspective-n-Point (Lepetit et al., "An accurate o (n) solution to the pnp problem", International journal of computer vision, 2009) algorithm. Instead of simply selecting the corners of the model's bounding box, PVNet (Peng, "Pixel-wise voting network for 6dof pose estimation", IEEE Conference on Computer Vision and Pattern Recognition, 2019) utilizes the farthest point sampling (FPS) algorithm to generate keypoints. They also propose a pixelwise voting network to deal with the heavy occlusion and truncated scenes. Heuristically, PVN3D (He et al., "A deep point-wise 3d keypoints voting network for 6dof pose estimation", IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2020) expends key points voting from 2D to 3D space and then recovers the pose by the least-squares fitting. Enlightened by PVNet and PVN3D, our approach searches the potential center in a similar voting manner, available for a more general setting. Unfortunately, these methods have limited generalization to unseen instances of unknown 3D models.
In recent years, there is growing interest in category-level pose estimation approaches, vitally alleviating the premise on available exact 3D models. Sahin et al. ("Category-level 6d object pose recovery in depth images", European Conference on Computer Vision, 2018) first address the category-level 6D object pose estimation problem, by training a part-based random forest with 3D skeleton representations for pose recovery. Wang et al. ("Normalized object coordinate space for category-level 6d object pose and size estimation", IEEE Conference on Computer Vision and Pattern Recognition, 2019) propose a method to learn the pixel-wise correspondence, mapping foreground image pixels to 3D object coordinates in NOCS. Chen et al. ("Learning canonical shape space for category-level 6d object pose and size estimation", IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2020) train a variational auto-encoder (VAE) to learn a pose-independent 3D shape representation for complete model reconstruction in CASS, which is subsequently contrasted with the pose-dependent features to regress pose and size. Tian et al. ("Shape prior deformation for categorical 6d object pose and size estimation", arXiv preprint arXiv:2007.08454, 2020) leverage mean latent embedding to reconstruct the categorical shape prior, and conduct the model deformation for coarse-to-fine shape reconstruction. This approach also learns correspondence for mapping the reconstructed model into NOCS coordinates. 6-PACK ("6-pack: Category-level 6d pose tracker with anchor-based keypoints", IEEE International Conference on Robotics and Automation (ICRA), 2020) is the first category specific pose tracker to achieve real-time tracking given the initial pose.
The intra-category variations make category-level 6D object pose and size estimation extremely challenging. Particularly, to tackle such category-level object variations, most previous works learn the generalized function to map varieties of instances into a unified space, such as Normalized Object Coordinate Space (NOCS) (see also "Normalized object coordinate space for category-level 6d object pose and size estimation") and Canonical Shape Space (CASS) (see Chen et al., "Learning canonical shape space for category-level 6d object pose and size estimation", IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2020). To achieve this, the method like NOCS. utilizes the features extracted from RGB information solely, while other works like CASS exploit the fused RGB-D features, by using "densefusion" manner which has been validated under the "instance-level" setting. However, experimental results of CASS indicate that the primary performance improvement solely relies on the features extracted from the color information, rather than the depth information. Hence, it remains unclear whether such a fusion manner is efficient enough to utilize the depth information under the "category-level" setting.
On the other hand, taking the mug under a certain perspective in FIG. 1 (part i) as an example, different textures cause visual diversity in color space while the shape preserves nearly the same. Intuitively, there should be fewer variations in geometry than that of textures, in term of the 6D object pose and size estimation. Thus it is essential to make the network fully explore the potential of geometry information, and be optimized under geometry-based search space.
The synthetic-real image domain gap is another important challenge in the concerned task. Typically, the gap between the synthetic and real data distributions is caused by multiple factors, like lighting conditions and material textures, etc (see also in "Normalized object coordinate space for category-level 6d object pose and size estimation"). This challenge intrinsically hinders the applications of 6D object pose and size estimation, because a large amount of available synthesized training examples cannot be effectively leveraged to new testing samples in the real image domain. Critically, as one can easily see that such a gap has a larger negative effect to color information of RGB channels than that of depth information in D channel, as illustrated in FIG. 1. Thus, to bridge the domain gap, it is essential to exploit more information from depth channel to improve the generalization ability of the model.
Since most objects are symmetrical or pseudo-symmetrical, the research on estimating object symmetry has been very topical recently. Wu et al. ("Unsupervised learning of probably symmetric deformable 3d objects from images in the wild", IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2020) use latent symmetry properties to disentangle components obtained from a single image. In the field of 6D pose estimation, HybridPose (Song et al., "Hybridpose: 6d object pose estimation under hybrid representations", IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2020) is the first work to leverage reflection symmetry information, which takes the symmetry correspondences as one of the intermediate representations mainly improving the performance of symmetry objects.
It's desired to extend 2D reflection symmetry-correspondence onto 3D point-wise paired points, to fully utilize the geometric constraint conditions which significantly improves the performance of 6D object pose and size inference.
In sum, there is a need to provide a new and different mechanism for category-level 6D object pose and size estimation.

Network and system for pose and size estimation


A method for determining a voice command shortcut includes receiving a first voice command providing instructions for performing a particular task and a second voice command providing additional instructions for performing the same task. The voice command shortcut may be used in place of the first and second voice commands, which are typically submitted in response to system prompts. The availability of a voice command shortcut is determined based on the first and second voice commands. If a voice command shortcut is available, an audible and/or visual notification may be provided to inform the user of the available voice command shortcut.

Automotive vehicles may include hands free communication units allowing an occupant of the vehicle to interact with various vehicle systems and to place and receive cellular telephone calls without having to take a hand off the steering wheel. The hands free communication unit may include microphones or microphone arrays placed within a passenger compartment of the vehicle to receive verbal commands from the occupant. The hands free communication unit may be connected to the vehicle's audio speaker system allowing the occupant to listen to system prompts and notifications and to a person on the other end of a telephone call through the vehicle speakers. The hands free communication unit may be either wired or wirelessly connected to the occupant's cellular telephone, such that the occupant can participate in a telephone conversation through the microphone and audio speakers.
The hands free communication units may utilize a voice recognition system for enabling the occupant to control various vehicle systems and features and connected mobile devices, such as the occupant's cellular telephone, through vocal commands. The voice recognition system may be coupled with a vehicle navigation system integrated into the vehicle, thereby allowing the occupant to input a route destination through vocal commands. Integration of the voice recognition system with the vehicle is a useful feature that allows the vehicle occupant to control various devices without diverting attention from the road.
The voice recognition system may be configured to recognize a predetermined set of verbal commands. Simple voice commands may be used, for example, to initiate phone calls, select radio stations or play music from a vehicle integrated audio system or an interconnected mobile device, such as a smartphone, MP3 player or music-loaded flash drive. The voice recognition system may provide natural-language speech recognition that enables the occupant to use full sentences and common phrases. Multiple discrete verbal commands may be required to commence a particular task, such as initiating a phone call. The verbal commands may be provided in response to prompts from the vehicle's audio system. For example, an occupant may make a verbal request to call a person identified in a contact list. If the selected contact has multiple phone numbers, the audio system may prompt the occupant to select one of the listed phone numbers to call.
To minimize distraction to a vehicle operator, some voice recognition systems may permit combining multiple discrete voice commands into a single continuous command string. The operator, however, may not always be aware of this functionality or understand how to properly format the command string. In those circumstances the operator may benefit from receiving instructions and guidance regarding the availability of alternatively formatted voice command strings.

Providing voice recognition shortcuts based on user verbal input

Toyota Motor Engineering & Manufacturing North America, Inc.


A digital display unit for enabling a user to conveniently select a desired monitor mode to process a display signal. A monitor mode is generally selected by measuring some display signal parameters. If multiple source modes share the same display signal values, all the corresponding monitor modes are stored associated with these common display signal parameter values. The user is provided a convenient interface (such as pushing a button or using a menu provided with an on-screen-display) to cause the display monitor to change the monitor mode. The next monitor mode is again among those associated with the measured display signal parameter values. Accordingly, all the monitor modes associated with the measured display signal parameters can be tried using the interface until a satisfactory display is obtained on the display unit.

1. Field of the Invention
The present invention relates to computer graphics systems, and more specifically to a method and apparatus implemented in a digital display unit of a computer system for enabling a user to conveniently select a monitor mode corresponding to a received analog display signal.
2. Related Art
Digital display units (e.g., flat panel monitors) are often used to display images encoded in an analog display signal. A signal in SVGA format generated by a graphics controller circuit of a computer system is an example of such an analog display signal. An analog display signal generally includes display data signal and corresponding synchronization signals. The display data signal identifies a color intensity for each point of an image and the synchronization signals provide a time reference such that each portion of the display data signal can be correlated with a corresponding portion of the image.
In general, an analog display signal includes multiple frames, with each frame corresponding to an image. Each frame in turn includes multiple horizontal lines. The synchronization signals typically include horizontal and vertical synchronization signals to indicate transitions to next horizontal line and next frame respectively in the associated display data signal.
A digital display unit typically needs to process a received analog display signal to display the encoded images. Digital display units are usually capable of processing the received signal in one of several modes ("monitor modes"). The display signal parameters (described below) and other user-defined (or manufacturer-defined) parameters generally define a monitor mode. Using pixel data elements generated according to a monitor mode, the digital display unit actuates pixels (points) contained on a digital display screen.
For the sampled values to accurately represent the images encoded in a received display signal, a monitor mode needs to correspond to the `source mode` in which an analog display signal is generated. A source mode characterizes the display signal parameters with which the display signal is generated. For example, each mode may be characterized by the refresh rate (number of frames encoded in the display signal per second), the number of lines in each frame, the number of points forming each horizontal line, among others. As an illustration, the alphanumeric mode of the VGA standard may have a refresh rate of 70 Hertz (i.e., number of frames per second), with each frame including 400 horizontal lines (source image height) and each horizontal line including 720 pixel data element samples (source image width). The need for the monitor mode to correspond to the source mode in a typical digital display unit can be appreciated by considering the manner in which an example analog display signal is generated.
In a typical situation in a computer system, a source image is represented by a plurality of pixel data elements, with each pixel data element representing a point (pixel position) on the image. In the case of the alphanumeric mode of the VGA standard, a source image may be stored as 720 (source image width).times.400 (source image height) pixel data elements. A graphics controller circuit generates an analog display signal with image frames by converting each pixel data element into corresponding display data signal. A digital to analog converter (DAC) and a source clock (dot clock) are typically used for such a conversion.
As the analog display signal is typically designed to operate in conjunction with analog display monitors which need time for horizontal retrace while scanning horizontal lines of the analog display screen, the total number of pixels (HTOTAL) in each line is typically more than the source image width. For example, for the alphanumeric mode of the VGA standard, HTOTAL equals 900 pixels even though the source image width is 720. Similarly, VTOTAL representing the number of vertical lines in each frame is more than the source image height to allow for vertical retrace.
In general, a digital display unit needs to sample a received analog display signal to recover the pixel data elements from which the display signal was generated. For accurate recovery, the number of samples taken in each horizontal line needs to equal HTOTAL. Each horizontal line is usually identified by successive horizontal synchronization pulses. If the number of samples taken is not equal to HTOTAL, the sampling may be inaccurate and display artifacts may results as described with reference to FIG. 1.
FIGS. 1 is a diagram of the amplitude of a display signal as a function of time illustrating typical characteristics of analog display signals. Typically, a display signal portion for each pixel data element has a settling period (shown as 110-A and 110-B) before the steady-state (150-A and 150-B) is reached. The steady-state represents the value (e.g., color intensity) of the pixel data element in the source image. For an accurate reproduction of the source image pixel data values, the monitor mode needs to be designed to sample during steady-state. Hence, a digital display unit may need to sample each horizontal line of a received display signal a number of times equal to HTOTAL.
Therefore, a digital display unit typically needs the HTOTAL for accurate sampling of the received analog display signal. There are other display signal parameters which a digital display unit may need for accurate sampling of a received display signal. The number of colors, the horizontal start position (representing the pixel number in each horizontal line from which the source image data starts) and vertical start position (representing the line number from which the source image data starts) are examples of some of the other display parameters. A monitor mode is defined by monitor parameters which typically include at least some of such display parameters. Monitor modes include other parameters such as gamma correction and intensity (adjusted by user).
Many parameters are often defined by standards (e.g., VGA, SVGA) and a typical digital display unit measures some parameters and determines the others by examining data stored internally. That is, signal parameters such as VTOTAL, synchronization signal polarities, the time for receiving each horizontal line are measured. Data such as tables or arrays to correlate a set of measured parameters to a corresponding source mode is often maintained internally in a non-volatile memory. By determining a source mode according to the measured parameters and the stored data, the display signal parameters (such as HTOTAL) associated with the determined mode are used to process any subsequently received analog display signals.
One problem with the above-described scheme of determining the source mode is that some modes have the same display signal parameters even though the modes represent source images having different characteristics (e.g., size). For example, the alpha-numeric mode of the VGA standard generates display signals at 70 frames/second, with each frame representing 720.times.400 pixels. The graphics APA mode generates display signals at 70 frames/second with 640.times.400 pixels. Besides having the same refresh rate and source image height, the two modes can use the same polarities for the synchronization signals. At least for similar reasons, some source modes may not be distinguishable based purely on the measurement of some display signal parameters.
If a monitor mode is selected based on an incorrect source mode, the sampling can be inaccurate and display artifacts can result. In the above-noted examples, the APA mode display signal is generated with a HTOTAL of 800 with a horizontal start position of 147, and VGA alpha-numeric display signal is generated with a HTOTAL of 900 with a horizontal start position of 160. If a received signal is sampled with the wrong HTOTAL, at least some of the samples will be taken in the unstable settling periods of FIG. 1 and the incorrect sampling values result in display artifacts.
In addition, as the source widths are also different (640 for APA mode versus 720 for VGA alpha-numeric mode), the corresponding correct number of pixel data elements need to be used for display to avoid losing a portion of the image. Further, incorrect assumption of the start positions (horizontal or vertical) typically leads to the image being skewed incorrectly to a direction. Such effects may be undesirable.
Digital display units may use monitor modes with incorrect parameters in other situations as well. For example, given the same standard for a source, different manufacturers can implement the standard with different display signal parameters. As an illustration, manufacturers may maintain the same values for display signal parameters which can be readily measured, but have different values for parameters which cannot be measured. The HTOTAL and start positions can be different. In such situations also a display unit may sample a received analog display signal with incorrect monitor parameters, causing undesirable artifacts or skews in the displayed images.
Therefore, what is needed is a method and apparatus which enables a user to conveniently select a monitor mode which corresponds to the correct source mode when more than one source mode has the same measured display signal parameters.

Digital display unit in a computer system for enabling a user to conveniently select a desired monitor mode for displaying images encoded in a received analog display signal


A microelectromechanical (MEM) apparatus is disclosed which can be used to generate electrical power in response to an external source of vibrations, or to sense the vibrations and generate an electrical output voltage in response thereto. The MEM apparatus utilizes a meandering electrical pickup located near a shuttle which holds a plurality of permanent magnets. Upon movement of the shuttle in response to vibrations coupled thereto, the permanent magnets move in a direction substantially parallel to the meandering electrical pickup, and this generates a voltage across the meandering electrical pickup. The MEM apparatus can be fabricated by LIGA or micromachining.

Microelectromechanical (MEM) fabrication technologies such as surface and bulk micromachining and LIGA (an acronym based on the first letters for the German words for lithography, electroplating and injection molding) have been extensively developed in recent years to form many different types of microsystems and microsensors. For certain uses, these Microsystems and microsensors would benefit considerably from a long-life internal power supply. For example, microsensors or microsystems placed inside medical implantable devices or used for unattended structural monitoring often are not easily accessible so that batteries cannot be replaced without substantial expense or damage. In the case of an implantable medical device, such as a heart pacemaker implanted within a patient, the replacement of a battery generally requires that an operation be performed at some risk to the patient, and that the entire medical device be replaced at a cost of up to several tens of thousands of dollars. What is needed is a miniature power source which harvests ambient energy to generate electrical power on a sustainable basis.
Previous sources of electrical power based on harvesting mechanical energy have met with limited success due to the small amount of electrical power generated, the low voltage produced, the large size of the device, or a combination of these factors. The present invention represents an advance over the prior art in providing a microelectromechanical (MEM) apparatus which can be used as an electrical power generator, or alternately as a vibration sensor, or as an acceleration or impact sensor. The MEM apparatus of the present invention utilizes a plurality of permanent magnets, which are spaced apart and arranged side-by-side to produce a relatively rapid change in magnetic flux over a small range of displacement, in combination with a meandering (i.e. serpentine) electrical pickup which additively senses the magnetic flux from each of the permanent magnets to generate a relatively large voltage and a relatively large amount of electrical power from a small-sized device.
An advantage of the MEM apparatus of the present invention is that it can be sized, as needed, to produce a predetermined level of electrical power of up to a few milliwatts or more.
Another advantage is that the MEM apparatus of the present invention can be fabricated using conventional micromachining technology so that piece-part assembly can be minimized.
A further advantage of the MEM apparatus of the present invention is that it can be integrated directly on a common substrate with various types of microsystems, microsensors or integrated circuitry to provide electrical power to these devices, or to sense vibration, acceleration or impact.
These and other advantages of the present invention will become evident to those skilled in the art.

Microelectromechanical power generator and vibration sensor


An article of footwear includes a sole structure and an upper secured to the sole structure. The upper is configured to receive a foot of a wearer and has a peripheral region. Further, the upper includes a ribbon structure formed of a plurality of ribbon sections, and a plurality of ribbon loops extending from a peripheral region of the upper.

Articles of footwear often include two primary elements, an upper and a sole structure, the upper being configured to contain or at least partially surround the foot, and the sole structure being configured to contact the ground. The upper is often formed from a plurality of material elements (for example, textiles, polymer sheets, foam layers, leather, and/or synthetic leather) that are stitched and/or adhesively bonded together to form an interior cavity for receiving a foot of a wearer.
During manufacturing, an article of footwear may be assembled on or around a last. Accordingly, the size and shape of the last determines the size and shape of the interior cavity defined by the upper when the article of footwear is assembled. These footwear components may be assembled together using various methods, including, for example, stitching, adhesives, welding, and other joining techniques. Articles of footwear may be assembled, at least in part, on a structure called a "last." A last is a form having the general shape of a human foot. A last is not typically shaped like any particular type of foot, but rather is formed having a shape with dimensions that are averages of many different foot types. This enables the footwear manufactured using the last to fit a variety of foot types.
When assembling a shoe using a last, one or more pieces of upper material may be assembled, or otherwise placed, on a last. These pieces of upper material are tightened around the last and secured to one another. Then one or more sole structure components may be secured to the upper while the upper is formed around the last.
In some cases, a strobel or sole board may be used to form the bottom of the shoe before the sole structure is attached. The peripheral edges of the upper may be affixed to the strobel during the lasting process to ensure that the upper takes the desired shape around the last. However, it may be desirable to produce a shoe without a strobel, in order to reduce weight and/or to eliminate any restrictions that the properties of the strobel may put on the ability to tune the performance characteristics of the footwear. In such cases, a technique is sometimes used to hold the peripheral edges securely around the last. For example, string lasting is used, which involves using loops at the peripheral edges of the upper, threading a lasting string through the loops and pulling the string tight the draw the edges of the upper toward one another around the periphery of the last bottom. With the edges of the upper drawn firmly in place and held by the lasting string, the sole structure may be attached to the upper.
Lasting loops can be difficult to construct with desired strength. If loops and lasting string are used with sufficient strength, these components can be undesirably thick, such that bumps are formed that are difficult to smooth out using the sole structure and/or insoles. It is desirable to provide a string lasting construction that addresses one or more of these issues discussed above.

Article with ribbon loops for string lasting


A transistor structure is formed to include a substrate and, overlying the substrate, a source; a drain; and a channel disposed vertically between the source and the drain. The channel is coupled to a gate conductor that surrounds the channel via a layer of gate dielectric material that surrounds the channel. The gate conductor is composed of a first electrically conductive material having a first work function that surrounds a first portion of a length of the channel and a second electrically conductive material having a second work function that surrounds a second portion of the length of the channel. A method to fabricate the transistor structure is also disclosed. The transistor structure can be characterized as being a vertical field effect transistor having an asymmetric gate.

An asymmetric transistor device can provide enhanced current handling and increase output resistance. However, it is difficult to fabricate an asymmetric transistor device to have a lateral structure where the gate characteristics vary in a manner that is parallel to the underlying channel.
Various vertical channel transistor devices have been previously proposed. For example, reference can be made to IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 53, NO. 5, May 2006, Asymmetric Gate-Induced Drain Leakage and Body Leakage in Vertical MOSFETs With Reduced Parasitic Capacitance, Enrico Gili, V. Dominik Kunz, Takashi Uchino, Mohammad M. Al Hakim, C. H. de Groot, Peter Ashburn, and Stephen Hall; and to IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 50, NO. 5, May 2003, An Ultrathin Vertical Channel MOSFET for Sub-100-nm Applications, Haitao Liu, Zhibin Xiong, and Johnny K. O. Sin. Reference can also be made to U.S. Pat. No. 6,686,245, Feb. 3, 2004, Vertical MOSFET with Asymmetric Gate Structure, Leo Mathew and Michael Sadd.

Method to fabricate a vertical transistor having an asymmetric gate with two conductive layers having different work functions

International Business Machines Corporation


A system for an object based notification system. The notification system is designed in a flexible manner to support change notification in an object-oriented operating system. The change notification includes a memory for storing connection information including notification routing information and connection registration information. The connection registration information is stored in a connection object of the object-oriented system and the notification system updates the connection object with registration information indicative of enablement or disablement of notification. Then, when a notification event is detected, the object-oriented operating system selectively notifies objects in the system based on the connection registration information stored in the connection object in the memory of the computer system.

Among developers of workstation software, it is increasingly important to provide a flexible software environment while maintaining consistency in the user's interface. An early attempt at providing this type of an operating environment is disclosed in U.S. Pat. No. 4,686,522 to Hernandez et al. This patent discusses a combined graphic and text processing system in which a user can invoke a dynamic object at the location of the cursor and invoke any of a variety of functions from the object. This type of natural interaction with a user improves the user interface and makes the application much more intuitive.
For a system to be intuitive to a user, system changes must be communicated in a consistent manner regardless of what application is currently active. None of the prior art references applicant is aware of provides the innovative hardware and system software features which enable all applications to obtain system changes through a generic framework for notification.

Object-oriented notification framework system


A comprehensive method, and apparatus implementing the method, for providing beam daylighting to a room by one or more reflectors positioned in a window wall of the room. The method involves a mathematical analysis of solar and reflected beam vectors and in determining the optimum orientation of a vector normal to the reflecting surface to provide the best combination of depth of penetration of light into the room while keeping glare to an acceptable level. Arrays of both stationary and moveable reflectors implementing the method are disclosed. In the case of stationary arrays, preferably two are provided in each installation which respectively optimize performance of reflections during periods when the solar beam vector is on the easterly ana westerly sides of a line perpendicular to the window wall. All reflectors are positioned with the vector normal thereto oriented with three nonzero components in a rectangular coordinate system related to the plane of the window wall and taking into consideration the site latitude.

The present invention relates to apparatus for installation in an opening in a building wall or roof for the purpose of enhancing interior illumination by reflected sunlight, and to methods of determining the optimum orientation of reflectors to achieve maximum depth of penetration of reflected light into the area to be illuminated with acceptably low glare. In general terms, the invention relates to improvements in the technology commonly known as "beam daylighting."
Since the invention of the light bulb ana common availability of electrical power, most buildings have been designed under the assumption that electricity will supply interior illumination by way of lighting fixtures, and that it is unnecessary to rely upon natural light for most or all illumination purposes. Over the more recent past, this assumption has been challenged on several grounds. First, artificial lighting doesn't meet the needs of most visual tasks as well as does the broader spectral distribution of natural sunlight. Also, the luminous efficacy of natural light (around 113 lumens/watt) is substantially higher than that of all commonly-used luminaries (over twice that of fluorescents and eight times incandescents). In consequence, using natural light to meet illumination needs in buildings not only supplants electricity that would otherwise be used to power artificial light fixtures, but also lowers air conditioning loads. Thus, given good daylighting designs, the use of natural light is highly advantageous for a number of reasons.
As used herein, and generally in the field of interest, the term "beam daylighting" denotes the use of one or more light-reflecting surfaces which redirect the path of sunlight entering an enclosed area for visual or other illumination purposes. Among the prior art beam daylighting designs are those exemplified by U.S. Pat. Nos. 4,509,825, 4,630,8920, 4,634,222, 4,699,467 and 4,989,952. Some of the previously devised systems employ stationary reflectors, while others include means for moving the reflecting surfaces to track solar position. Planar, parabolic, and other configurations of reflecting surfaces have been used in beam daylighting applications, as have systems involving reflection of incoming light from two or more surfaces in distributing the light at the desired location. In any case, the reflecting surfaces have a longitudinal axis which, in all known prior art systems, is oriented either horizontally or vertically. As will be shown, optimum performance can be achieved only when the longitudinal axis of a single reflecting surface is oriented somewhere between horizontal and vertical. This is true whether the reflectors are fixedly installed, with their orientation providing optimized performance averaged over the period between successive solstices, or are movable to maintain optimized performance over a range of varying solar positions.
While it is generally recognized that orientation of the reflecting surface(s) should provide adequate lighting in all portions of the area to be illuminated (hereafter referred to for convenience as the room), prior art daylighting systems fail to adequately consider both the spatial and the temporal aspects of reflector orientation. That is, reflector performance must take into consideration both the distance of light penetration into the room and the level of glare in the area illuminated. Other design features, such as the relative cost, suitability for incorporation into existing structures, aesthetic appearance of the installed system, maintenance requirements, etc., are also often severely compromised or ignored.
Objects of the present invention are:
to provide a novel and improved beam daylighting system which fully or partially replaces artificial light with natural light at an acceptably low glare level;
to provide a method of determining optimal orientation of reflecting surfaces at a given site location to maximize distance of penetration of reflected light into a room (e.g., up to 30 feet) while eliminating or minimizing glare;
to provide beam daylighting structure wherein stationary reflecting surfaces are oriented to optimize room illumination at a given latitude when positioned in a wall or roof opening facing in a predetermined compass direction;
to provide a daylighting system which is easy to maintain, suitable for installation in both new and existing buildings, and compatible with a variety of residential, commercial, institutional and industrial environments;
to provide a highly effective daylighting system which, in a first embodiment, has no moving parts, is completely passive and functions without user interaction; and
to provide a daylighting system which, in a second embodiment, includes novel structural and operational components which reorient the reflector surfaces during periods when they receive direct sunlight to optimize the effectiveness of the system in terms of sending the reflected light in a desired direction.
Other objects will in part be obvious and will in part appear hereinafter.

Apparatus and method for optimizing useful sunlight reflected into a room


The system and method of the present application can include machining complex part features in a flat metal sheet, and subsequently forming the machined flat metal sheet to have the desired shape and contours. Prior to the step of machining the complex part features, the method can include calculating a scaled location of the complex part features so that the subsequent forming step acts to translate and deform the complex part features into a desired location.

1. Technical Field
The present application relates to a system and method of manufacturing a structure. The system and method of the present application is particularly useful for manufacturing an aerodynamic structure for a rotor blade of an aircraft.
2. Description of Related Art
In general, certain aircraft structures may require a high level of precision, as well as a plurality of complex manufacturing steps configured to achieve the requisite high level of precision. For example, it is well known that chemical milling is a manufacturing process commonly used to manufacture parts having complex contours and tapered surfaces. However, chemically milling has shortcomings, such as surfaces pitting, tolerance variation, labor intensive masking, material limitations, and toxic material risks, to name a few.
Hence, there is a need for an improved manufacturing system and method that improves structure quality and accuracy, while also decreasing labor hours and part rework.

System and method of manufacturing a structure


An image forming apparatus which having a plurality of image processing modes, that is capable of accurate density gradation control without performing output of any patch image to a recording medium in all the image processing modes. A first correction parameter corresponding to a first image processing mode is prepared on the basis of a result of detection, by a second density detection unit, of the image formed on a recording medium in a first image processing mode. A second correction parameter corresponding to a second image processing mode is prepared on the basis of the first correction parameter and a correlation, stored in a storage unit in advance, between density of a toner image formed on an image bearing member in the first image processing mode and density of toner image formed on the image bearing member in the second image processing mode.

1. Field of the Invention
The present invention relates to an image forming apparatus which forms an image on a recording medium by using an electrophotographic printing method or the like and to a image density control method therefor.
2. Description of the Related Art
In recent years, there has been an increasing demand for improving the image quality and stability of image forming apparatuses. As a result of an effort to improve the image quality, in image forming apparatuses, a plurality of image forming modes have been provided. In such image forming apparatuses, an image is formed in a mode suitable for characters or in a mode suitable for photographs by changing lines, dots, or the definition (the number of lines per inch) of the image to be formed. Expressions of images are thus enriched to meet various user needs in the market.
One of consideration items to which prime importance is attached in a stability improving scheme is density gradation stability. In particular, output densities of an image forming apparatus vary due to environmental changes, changes with time and the like. There is, therefore, a demand for the provision of a density control sequence for maintaining correct density gradations of the image at all times.
In conventional image forming apparatuses, therefore, correction parameters (e.g., a lookup table: LUT) are set such that proper relationships are maintained between input image densities and output image densities. Input image data is corrected on the basis of a LUT to maintain proper relationships between input image densities and output image densities.
The LUT is obtained, for example, by reading the optical density of an image pattern formed on a recording medium such as recording paper or an image pattern formed on an image bearing member such as a photosensitive drum. In a case where a high-quality output image is required, it is desirable to perform density gradation control using a recording medium. Also, it is desirable to perform density gradation control with respect to each of a plurality of image processing modes in order to obtain high-quality images in the plurality of image processing modes.
An image forming apparatus which performs gradation correction without forming gradation patterns on an image bearing member in all image processing modes (see Japanese Laid-Open Patent Publication (Kokai) No. 08-156330) has been proposed. This image forming apparatus functionizes the correlations between input/output characteristics (γ-characteristics) for the image processing modes or patternizes the correlations. Then, on the basis of a gradation pattern formed on the image bearing member in one of the image processing modes and the functionized or patternized correlations, the image forming apparatus performs density gradation control uniquely in another of the image processing modes.
As described above, the image forming apparatus described in Japanese Laid-Open Patent Publication (Kokai) No. 08-156330 is disclosed with respect to gradation control using an image bearing member. However, a method of comparing the density of a gradation pattern actually printed on a recording medium with the desired density and performing gradation control on the basis of the comparison result enables gradation control with higher accuracy than the method described in Japanese Laid-Open Patent Publication (Kokai) No. 08-156330.
This density gradation control using a recording medium is performed by a user moving the recording medium output from the image forming apparatus to a reader and making the reader read the recording medium at the time of execution of density gradation control. However, a heavy burden would be put on the user if density gradation control using a recording medium needs to be performed with respect to all the plurality of image processing modes that the user may use.

Image forming apparatus and image density control method therefor


A fiber optic monitor that utilizes optical phase interferometry to monitor a patient""s vital signs such as respiration, cardiac activity and body""s physical movement. The monitor, which is non-invasive, comprises an optical fiber interferometer that includes an optical fiber proximately situated to the patient so that acousto-mechanical signals from the patient are coupled into the optical fiber. Responsive thereto, the interferometer generates a time-varying serial train of fringes which is detected by a photo-detector. A signal processor coupled to the optical detector provides one or more processed output signals indicative of the vital functions. The monitor system has broad applicability, from routine monitoring of infants at home to apnea, arrhythmia and trauma situations. The system can be implemented in embodiments ranging from a low cost in-home monitor for infants to a high end product for in hospital use to monitor infants in nenonatalogy laboratories or at home by physician""s prescription. The monitor can be integrated with other sensors such as an EKG, a camera, an oxygen sensor, a carbon-di-oxide sensor, temperature sensor or a microphone to get additional required information depending on the application. When integrated and combined with EKG information, the monitor provides ballisto-mechanical information of the heart for early diagnosis or prediction of cardiac conditions or events. In some embodiments of the monitor, the system can be made portable so that the patient can walk around while still being continuously monitored.

1. Field of the Invention
The present invention generally relates to monitors for detecting cardiac and pulmonary motions such as heartbeat, respiration, physical movement, and other body activities of a patient.
2. Description of Related Art
For detecting vital signs of a patient, there are a number of monitors available with a variety of uses and applications. These vital sign monitors and other advanced monitors range from simple sound monitors such as xe2x80x9cbaby monitorsxe2x80x9d used at home, to sophisticated apnea monitors and electro-cardiograms (EKGs) used by physicians and hospitals.
Off-the-shelf low cost, non-prescription baby monitors are currently in wide use to monitor infants at home to verify an infant""s well-being. These monitors generally employ a microphone sensor that sends a signal to a remote unit with visual and audio displays. For example, the microphone sensor can be placed close to the crib on a table or hooked up to the crib with a bracket while the remote unit is carried around in the house by parent or other caregiver. Although these units are suitable to monitor low risk infants when they are awake and moving around or crying in the crib, they are not reliable for monitoring them during sleep periods. Parents may be concerned that their child is in jeopardy if they can not hear their child""s cries or other normal sounds over the monitor. To address this concern, a parent may make many visits to the room where the infant is asleep to either wait patiently until the infant moves in the crib or attempt to touch the infant in an effort to detect child""s breathing.
An alternative system for monitoring infants on the market today uses a rocker switch or pressure/capacitive sensor placed under a mattress to detect the rocking action of the mattress when the infant or other patient moves. To work, such a system requires a hard surface under the mattress and a rocking mechanism placed between the mattress and the hard surface. When the patient moves, the mattress rocks back and forth across a fulcrum causing the sensor to detect the movement. The presence of the right amount of movement might indicate that the patient is healthy, while the lack of movement or too much movement could suggest that the patient is in trouble; although lack of movement does not always reflect that the patient is in trouble. In the case of a small infant who normally does not move much, the sensor may not detect any movement, and accordingly it may produce a large number of false alarms. A significant number of false alarms will undoubtedly cause the parent or caregiver to stop using the device and render it effectively useless. Additionally, the system is not sensitive enough to accurately detect the small-scale acousto-mechanical signals generated by the heart beating, which may provide a complimentary signal that could be used to reduce false alarms.
Neonatologists use apnea monitors for detecting sleep apneic events in premature or high-risk infants, which if not detected can result in Sudden Infant Death Syndrome (SIDS). Generally the apnea monitors are used to detect and measure respiration rate of an infant. In the absence of respiration for about 20 seconds, the monitor sounds an alarm indicating an urgent need for nurse intervention. These type of monitors typically utilize impedance pneumography techniques, in which the electrical sensors are placed on infant""s body to detect variations in resistance caused by respiration and physiologic changes when a 10-100 kHz electrical current of about 50 micro amperes is passed through the patient. The voltage developed and measured is proportional to the transthoracic impedance, which varies during each breath. These sensors are designed to measure changes in this resistance, on the order of 0.1-1 ohms for shallow breather infants to normal ones. One problem with these sensors is that they do not provide high enough sensitivity to distinguish between shallow breathing and no breathing. As a result, they generate a large number of false alarms, requiring constant attention of nurses and frequent re-setting of the instrument. To better detect the apneic event, a separate heart rate sensor is often added to apnea monitors. Monitoring the heart rate in conjunction with respiration can lower the false alarm rates because prolonged apnea is frequently followed by bradycardia (i.e. slowing of the heart rate), which is an event that can be measured using the heart rate sensor. Further improvements can be made by incorporating a saturated oxygen monitoring sensor to an apnea monitor. Such a sensor is affixed at the finger tip of the patient using separate electrical leads. Monitoring the changes in oxygen level in conjunction with respiration and heartbeat rates is useful because it can more accurately detect the onset of an apenic event so that appropriate decisions can be made to administer the correct treatment.
Even though addition of both a heart rate sensor and an oxygen sensor to an apnea monitor is useful to reduce false alarms, and better detect apneic events, such monitors still have a number of shortcomings. For example, 1) with the addition of these sensors and associated electronics, the system""s cost increases; 2) electrical leads can come loose or break; 3) if the sensors are inadvertently pulled due to body motion or lead tangling, the infant""s skin can peel off; 4) the infant""s skin can develop dermatitis from electrode creams, gels and adhesives 5) because the sensors are electrical in nature, they are susceptible to interference from electromagnetic sources, static discharge, radio frequencies, and shocks; 6) they do not function properly in the presence of conductive liquids; 7) they utilize a number of sensors and leads to pick up signals from the patients, which can impede the development of mother/infant relationship; 8) unless the respiration sensors are appropriately placed and the controls adjusted properly, the monitor can be sensitive to artifacts generated by heartbeat; 9) patients can not sleep well because they are forced to lie in a certain position determined by the sensors, and cannot move around freely once the sensors and leads are hooked up; 10) if X-rays are required, the sensors must be removed; and 11) the output signals are susceptible to body motion artifacts.
Another type of monitor is a motion sensing/non-impedance type, such as an air mattress that is designed and developed for the detection of sleep apnea. The motion-sensing sensors are based on the principle of air displacement from one segment to another through a manifold, which is measured by a heated thermistor in the manifold. The moving within the mattress air cools the heated thermistor in the manifold, and this temperature change is detected as a breath. Unfortunately, these pads are very sensitive to body motion and vibration artifact, and therefore the respiration signals are not easily detected from the artifacts. In addition, these sensor pads are not rugged enough to fold and flex, and therefore, are difficult to use and store. Furthermore, because the sensor includes an electrically active thermistor, it is prone to electromagnetic interference.
Other monitor types, including sensors with capacitive mattresses, and sensors with magnetic, thermistor, and pressure transducer pads have similar disadvantages. Because most devices used to date are electrical in nature, they have similar shortcomings as described for the impedance or air mattress sensors. None are totally suitable for reliably detecting apneic conditions or near-miss SIDS.
U.S. Pat. No. 5,241,300 discloses a fiber optic breathing sensor that monitors the air movement localized at the nasal cavities. By placing this fiber optic sensor at the base of the nasal cavity, it measures the change in temperature due to air flow. This sensor does not provide the cardiac signal necessary in the clinical diagnosis of the apnea. Although this system may be useful as a supplementary sensor in the detection of central apnea in adults, it cannot be used with infants because it requires a relatively large volume of air displacement for proper operation.
U.S. Pat. Nos. 5,291,013 and 5,212,379 disclose a Fiber Optical Monitor For Detecting Motion Based on Changes in Speckle Patterns. This speckle-based monitor is designed to detect breathing and heart beat when generally a coherent, narrow band light source is launched at one end of a multimode optical fiber. The central part of the fiber is formed into a xe2x80x9cblanketxe2x80x9d that senses a patient""s normal breathing and heart beat motion. The system, using a photo-detector at the other end of the fiber that senses the changes in optical intensity of a 2-dimensional (2D) speckle pattern. The photo-detector""s amplitude output signal is related to the integration (averaging) of the number of speckles and its time variation is related to the change or re-distribution in the number of speckles. Using a coherent optical source and a multimode fiber, the speckle-based monitor produces a light cone containing a pattern of varying light intensity at the fiber output generating multiple light and dark grainy spots (a speckle pattern). The speckle-based monitor requires that only a certain fraction of the light cone emitting from the fiber output (i.e. less than all of the emitted light cone) is collected by the photo-detector or two halves of a photo detector. This is necessary because if entire cross-section of the light cone, containing the 2D speckle pattern, is collected by the photo-detector (or two detectors halves), its output will not appreciably change when motion signals such as breathing or heartbeat, are coupled to the fiber.
The 2D speckle pattern is produced primarily due to the multiple intermodal interferences between the propagating spatial modes of the fiber, and interferences caused by the coherent beams mixing on the receiving surface. The pattern produced by the intermodal interference is modulated by the motion signals that are coupled to the fiber, whereas the pattern produced by the receiving surface remains unaffected. The speckle-based fiber monitor thus relies only on the intermodal interferences to detect the motion signals such as breathing and heartbeat.
In the speckle-based monitor, generally a multi-mode fiber is required over a single mode fiber to detect the patient""s motion. Without the multi-mode fiber, it is difficult to produce measurable speckle pattern on the optically polished surface of the detector (or two halves) using even a highly coherent light source. This is because specular surfaces can not produce sufficient optical phase shifts required for the coherent light beams to interfere. Single mode fibers do not show intermodal speckle patterns because the interference of the two orthogonal degenerate mode only produces a single light spot, compared to may spots by multi-mode fibers. Higher modes in a single mode fiber may be generated if the operating wavelength of the light source is brought near or below the cut off wavelength of the fiber. These higher order modes may interfere but the speckle visibility is poor due to the presence of only few modes, resulting in poor signal detection and low sensitivity. In addition, the speckle-based monitor requires a coherent light source because incoherent light sources, such as light emitting diodes (LEDs), can not produce a measurable intermodal speckle pattern even if a multimode fiber is used. Therefore, both a coherent light source and a multi-mode optical fiber are needed in the operation of the speckle-based monitor. If compromises are made, the monitor may not be provide sufficient sensitivity to detect and measure patient""s motion signals, especially the heart signals.
The speckle-based monitor has a number of shortcomings and limitations. Such limitations can become large disadvantages when design trade-offs are made. For example, the requirement that the light source be coherent and narrow band, limits the laser source choices to gas or distributed feedback (DFB) lasers, which results in high power or high costs requirements. Unfortunately, gas lasers such as Helium-Neon (Hexe2x80x94Ne) require high voltages to create the plasma and therefore are not very desirable for use at home or in hospitals where patient safety is paramount. DFB lasers, on the other hand are expensive and therefore less desirable in applications where low cost is important. Less coherent (and less costly) broadband light sources, such as edge light emitting diodes (ELEDs) or laser diodes (LDs) that can be operated at low voltages, are not suitable for speckle-based sensors because they do not generate detectable speckle pattern, with or without a multi-mode optical fiber. Another limitation of the speckle-based monitor is the requirement to place the end of the fiber from the detector at sufficient separation to collect a certain fraction of the speckle cross-sectional area. This requirement affects the detection sensitivity in addition to introducing manufacturing difficulties and correspondingly poor yields. Other limitations of the speckle sensor are: 1) since the fiber is placed as a blanket over the patient, it may not stay over the patient at all times especially when the patient is not attended; 2) in order for the speckle-based monitor to provide adequate sensitivity, it must use multi-mode fibers rather than single mode; and 3) use of simple bandpass or high pass filter designs in the speckle-based monitor are insufficient to reliably extract the heart beat signal from the respiration signal in the presence of body movement. The body""s movement can produce noise with frequency components in either signal bands. Since hand, leg or body movements occur typically during apneic events or otherwise, therefore common mode rejection techniques, band pass filters or split detectors can not easily eliminate these unwanted signals.
To overcome the limitations, shortcomings and disadvantages of prior art, the present invention provides a novel fiber optic monitor that utilizes optical phase interferometry to monitor a patient""s vital signs. A number of advantages are provided by using optical phase interferometry for detecting heartbeat, respiration and physical body movement. For example, because these sensors utilize optical phase as compared optical intensity modulation characteristics, they provide a very high detection sensitivity while advantageously needing only single mode fibers. Single mode fibers are widely available, and are much lower in cost compared to multimode fibers. The monitor can be configured with a single sensor and in some embodiments an array of sensors to simultaneously detect physiological parameters such as pulmonary motion, cardiac activity, physical movement, and other body activities in infants, adults, canines, and any other living creature.
Because the system is non-invasive, passive and free from electrical leads, gels and suction cups, it can reliably monitor heart beat and respiration rates in presence of physical movement while remaining virtually transparent to the patient. It has application for the detection of sleep apnea and cardiac disorders in both infants and adults. In addition, it can quantitatively predict the body""s physical parameters such as fat/weight ratio, temperature, etc. In some embodiments of the monitor, the system can be made portable so that the patient can walk around while still being continuously monitored. Advantageously, some embodiments of the monitor utilize low cost, broadband sources of optical radiation which are typically safer and more compact providing lower cost, smaller size and weight.
A fiber optic, interferometric monitor for detecting vital functions in a patient comprises an optical fiber interferometer that generates an optical signal responsive to acousto-mechanical signals generated by vital functions of the patient. The interferometer includes optical fiber means for defining two optical paths including a first optical path and a second optical path. The first optical path includes an optical fiber proximately situated to the patient so that the acousto-mechanical signals are coupled to the optical fiber, thereby modulating a physical parameter of the optical fiber responsive to the acousto-mechanical signals. The optical fiber also includes an optical source coupled to supply optical radiation into an input end of the first and second optical paths. The interferometer generates a serial train of fringes from the optical radiation emitted from an output end of the two optical paths. A photo-detector is arranged to sense an optical signal provided by time variations in the fringe train, the photo-detector providing a raw electrical signal responsive thereto. A signal processor is coupled to the optical detector to process the raw electrical signal to provide one or more processed output signals indicative of the vital functions. An output system is provided for communicating the one or more processed signals.
The optical fiber sensor (or a plurality of sensors) is situated in close proximity to a patient, for example a length of optical fiber may be configured into a pad, which can be placed on top of a mattress but under the bed sheet. In such a configuration, the optical fiber sensor (or sensors) is non-invasive, it does not need to be hooked up to a patient using gels or suction cups or leads, and therefore it remains virtually unnoticed by the patient, allowing the patient to rest comfortably.
The monitor system has applicability across a broad spectrum of fields, from routine monitoring of infants at home to apnea, and arrhythmia that occur in sleep labs, emergency rooms, operating rooms intensive care units (ICU) and rescue and ambulatory vehicles. The system can be implemented in a wide variety of embodiments ranging from a low cost in-home baby monitor to a high end apnea monitor for in hospital use to monitor infants in nenonatology laboratories or at home by physician""s prescription. The monitor can be used for providing additional and complimentary ballisto-mechanical information to be combined with EKG information for early diagnosis or prediction of cardiac conditions or events. If it is used to monitor respiratory rate, an increase may indicate acidotic condition as might be seen with septic shock or diabetic ketoacidosis. The monitor may also be used for monitoring adults in convalescent homes for the detection of vital signs or in psychiatric wards to detect presence of patients in bed. For military applications, the monitor may be used to monitor physiological and pathological changes in personnel under various combat or training conditions as well as in trauma facilities.

Fiber optic monitor using interferometry for detecting vital signs of a patient