An apparatus and method for handling an interrupt are disclosed. In one embodiment, a processor may receive an interrupt request corresponding to a particular interrupt. The particular interrupt may be one of a group of interrupts. Responsive to receiving the interrupt request, the processor may substitute a vector corresponding to the group of interrupts with a vector corresponding to the particular interrupt. Responsive to the substitution, the processor may then jump to a service routine corresponding to the particular interrupt. Execution of the service routine may resolve the condition which initially caused the interrupt request.

1. Field of the Invention
This invention relates to computer systems, and more particularly, the handling of interrupts by a processor of a computer system.
2. Description of the Related Art
Computer systems typically include a number of devices that perform various functions. A typical computer system includes at least one processor and may have a number of peripheral devices coupled to one or more buses. The one or more buses may be directly coupled to the processor, or may be coupled to the processor through a bus bridge. Examples of peripheral buses include the peripheral component interface (PCI) bus and the universal serial bus (USB). In addition to peripheral devices coupled to the peripheral buses, a computer system may also include various input/output devices (e.g., keyboard, mouse) as well as storage devices (e.g., a hard disk drive). These devices in a computer system may signal a need to communicate with the processor by using an interrupt.
An interrupt signal (often times referred to as an interrupt request) may be conveyed to the processor through an interrupt line. After receiving the interrupt request, the processor may temporarily halt the execution of an instruction stream to deal with the, interrupt by performing a service routine, which may resolve the condition that initially triggered the interrupt request.
As the functionality and complexity of computer systems has increased, the number of sources for interrupts has also increased. Often times, interrupts are arranged into groups. Different service routines may be performed for each interrupt of an interrupt group. A given processor may also have the capability of enabling or disabling specific interrupts, and may also include priority encoding logic to determine which interrupt should be resolved first when more than one interrupt request is pending.
When an interrupt request is received, a processor may be required to perform a number of steps before the request can be resolved. When a large number of interrupts are present and arranged into groups, the processor may first execute instructions to determine which one of the interrupts of the group to which the interrupt request corresponds (i.e. the source of the interrupt). Following this determination, additional instructions may be executed in order to determine if the interrupt corresponding with the interrupt request is enabled or not. If the corresponding interrupt is enabled, the processor may be required to perform an additional step of determining the source of the interrupt and whether or not it is enabled, the processor may be required to resolve the priority of the interrupt with respect to a number of pending interrupt requests. Due to these various factors, it may take a significant amount of time for a processor to resolve each interrupt request. The amount of time required to resolve each interrupt request can have an adverse affect on system performance. Furthermore, the amount of time required to resolve interrupt requests may exceed operating margins for some devices which may generate interrupts, thus preventing their use in the system.

Method and apparatus for handling interrupts


A circuit card assembly (CCA) comprises a printed circuit board (PCB) having first and second opposing major faces with a first pair of elongated edges extending therebetween. Heat management layers are disposed within the CCA and/or PCB, which extend to said edges, and a thermally conductive bar is engaged in a slot provided in each of the elongated edges. Each conductive bar extends over at least the thickness of the PCB, one face preferably being flush with one of the major faces of the PCB and is thermally connected to the heat management layer(s) by thermal connecting means so as to conduct heat from the or each heat management layer to said bar.

It is well known in the electronics industry to provide PCBs with heat management layers. A heat management layer consists of a layer of material having a relatively high thermal conductivity incorporated within a CCA and/or PCB to assist removal of heat from the CCA. In typical multi-layer PCBs and CCAs several heat management layers may be provided.
Heretofore, the usual arrangement for removing heat from heat management layers consisted of providing a multiplicity of vias in one or more edge regions of the PCBs, the vias passing through the or each heat management layer. The vias were through-plated with a metal layer which contacted the or each heat management layer and extended through the full thickness of the PCB. One surface of the PCB was provided with a metal surface layer to which a bar was secured by soldering. During the soldering process solder filled the vias and the space between the bar and the metallic layer on the surface of the PCB. The CCA with attached bar was then connected to a suitable heat removal assembly with the bar providing a means of conducting heat from the heat management layers to the heat removal assembly via the through-plating of the vias, the solder filling the vias, the solder between the bar and the PCB, and the bar itself.

Heat management in circuit card assemblies


A polymer electrolyte membrane, a method of manufacturing the same, and a fuel cell including the polymer electrolyte membrane are provided, wherein the polymer electrolyte forms an interpenetrating polymer network (IPN) of a polymer by simple blending of a hydrophobic polyimide having a reactive terminal group and a hydrophilic aromatic polymer having ion conductivity. The polymer electrolyte membrane has reduced swelling properties due to highly dense crosslinking of polyimide through the reactive terminal group, shows high ion conductivity at low humidity, and has methanol crossover suppressing ability. Accordingly, a fuel cell with improved electric and mechanical properties can be provided.

1. Field of the Invention
The present invention relates to a polymer electrolyte membrane, a method of manufacturing the same, and a fuel cell including the polymer electrolyte membrane.
2. Description of the Related Art
Fuel cells may be classified according to the type of electrolyte used therein. Types of fuel cells include polymer electrolyte membrane fuel cells (PEMFCs), phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and others. The operating temperatures of fuel cells and constituent materials thereof vary depending on the electrolyte type.
According to a method of supplying fuel to an anode, fuel cells can be classified into external reforming type fuel cells in which fuel is supplied to the anode after being converted into hydrogen enrichment gas by a fuel reformer, and internal reforming type fuel cells in which fuel in liquid or gaseous state is directly supplied to the anode.
A representative example of a direct fuel supply type fuel cell is a direct methanol fuel cell (DMFC). In a DMFC, an aqueous methanol solution is used as fuel, and a proton conductive polymer electrolyte membrane is used as an electrolyte. Accordingly, a DMFC is a kind of PEMFC.
PEMFCs are small and light but can realize high output density. Moreover, PEMFCs simplify the structure of a power generating system.
A PEMFC is usually formed of an anode (a fuel cell), a cathode (oxidizer electrode), and a polymer electrolyte membrane disposed between the anode and the cathode. The anode of a PEMFC includes a catalyst layer to facilitate oxidization of fuel, and the cathode of a PEMFC includes a catalyst layer to facilitate reduction of an oxidizer.
The polymer electrolyte membrane of a PEMFC functions as an ion conductor for hydrogen ions to move from the anode to the cathode and as a separator to physically separate the anode and the cathode. Accordingly, the polymer electrolyte membrane needs to have good ion conductivity, electrochemical stability, high mechanical intensity, and thermal stability at operating temperatures, and be easy to be made thin.

Polymer electrolyte membrane, method of manufacturing the same and fuel cell including the polymer electrolyte membrane


Methods and systems according to embodiments of the present disclosure provide intelligent transmission of beacons by a SoftAP-enabled user device for minimizing power consumption. In an embodiment, a method comprises transmitting a first beacon from the SoftAP to a station connected to the SoftAP. The method also comprises determining a beacon interval between the first beacon and a second beacon. The method further comprises dynamically changing the beacon interval. And the method also comprises transmitting the second beacon upon the changed beacon interval passing since the transmitting of the first beacon.

Currently, most user devices (e.g., mobile devices such as smart phones, tablets, cellular phones, laptops, etc.) support searching for and connecting to wireless communication systems such as Wi-Fi networks via hotspots, i.e., Wi-Fi network access points or areas. A Wi-Fi network access point, in general, may work as an Access Point (AP) for network connections.
In contrast, a set of user devices may establish an ad-hoc wireless network where a user device having a Software-enabled Access Point (SoftAP) may be used to provide a wireless client antenna that may act as both an Access Point and a client in the ad-hoc network. That is, SoftAP may act as "virtual" Wi-Fi such that software in a user device may enable the user device to create a hotspot or portable hotspot that other user devices in the vicinity may be able to use.
As such, SoftAP may enable a user device, for example, one having a wireless client antenna and network connection, as an Access Point (AP) to serve other user devices that may not otherwise have a network connection. When user devices, which may not have network (e.g., Internet) access directly, are in the vicinity or neighborhood of a SoftAP user device, those neighboring user devices may connect to a network through the user device having SoftAP functionality. It should be noted that in this disclosure, a SoftAP user device may be referred to as a Service Access Point or "SoftAP". Also, a user device that may connect to a network through a SoftAP may be referred to as a station (STA).
SoftAP user devices generally have capabilities to use the IEEE defined 802.11 groups of protocols (e.g., 802.11a, b, c, g, n, ac, etc.), and may be any fixed, mobile, or portable user device (e.g., smart phones, tablets, cellular phones, laptops, etc.).
Most use cases of SoftAP are generally limited to a small number of stations (STAs), for example, one or two STAs. One particular aspect in which SoftAP differs from a commercial AP is that for SoftAP, there may not be a need to repeat beaconing continuously to advertise its capabilities. For a commercial access point (AP), for example, in a corporate network or a shopping mall, any user device can try to connect to a network via the commercial AP. As such, the commercial AP generally may need to continue beaconing even if there are no STAs connected.
Because user devices may be the source of a Wi-Fi hotspot, it is commonly desirable that power consumption be minimized as much as possible (especially in mobile devices, for example). However, IEEE standards may not specify power save processes for user devices working in AP mode. As such, in cases where a user device is acting as a hotspot or a SoftAP, the user device may not go into power save mode, which may result in quicker draining of the battery.

Intelligent beaconing by software-enabled access point


A device for biopsy of body tissue. The device is driven by liquid CO2, and is provided with a control system to control various components to effectuate rotating core biopsies.

Biopsy is an important procedure used for the diagnosis of patients with cancerous tumors, pre-malignant conditions, and other diseases and disorders. Typically, in the case of cancer, when the physician establishes by means of procedures such as palpation, mammography or x-ray, or ultrasound imaging that suspicious circumstances exist, a biopsy is performed. The biopsy will help determine whether the cells are cancerous, the type of cancer, and what treatment should be used to treat the cancer. Biopsy may be done by an open or percutaneous technique. Open biopsy, which is an invasive surgical procedure using a scalpel and involving direct vision of the target area, removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy, on the other hand, is usually done with a needle-like instrument through a relatively small incision, blindly or with the aid of an imaging device, and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment of tissue is obtained for histologic examination which may be done via a frozen section or paraffin section. One important area where biopsies are performed is the diagnosis of breast tumors.
Traditionally, the biopsy technique for breast tumors involves placing a biopsy device multiple times into the breast and taking several samples of tissue from a mass or tumor which is suspected of being cancerous. Several samples are required to be sure that some tissue from the suspect mass has been captured, and enough tissue has been sampled to ensure that, if disperse cancer cells exist in the suspect mass some of those cancer cells will be captured in the samples. Each time the device is placed the physician must locate and direct the device with ultrasound imaging into the correct position near the suspect mass. Some breast tumors and lesions are very well defined, hard spherical masses which grow within the soft, compliant breast tissue. It is difficult to force a needle into these lesions because they are resistant to puncture and fairly mobile. Forcing the biopsy needle into the lesion is like trying to spear an apple floating in water.
Vacuum assisted biopsy system proposed by Biopsys involves sucking a breast lesion into a cannula and shearing off the captured edge of the lesion to obtain a biopsy sample. The device uses a vacuum to collect tissue into the side of an open tubular device, and then uses a rotating corer to cut the tissue collected. The rotating corer is slidable within the tubular section and can be pulled back to remove the tissue collected in the rotating corer. An additional stylet inside the rotating corer can be used to push the tissue out of the corer. The device can be rotated on its axis to remove a sample, 360 degrees around the central placement of the device. Typically, physicians sample six to eight cores. One advantage of this device is that the physician does not have to remove the device for additional biopsy samples. However, the tumor itself must be re-engaged after every coring operation, which entails substantial effort in relocation and confirmation that the target suspect mass has been engaged by the side aperture. Tumors may be too tough to yield to the suction and deform as necessary to enter the side opening of the cannula. Doctors also currently use the device to take a circular sequence of cores by rotating the device about its long axis or by sideways movement of the suction head to take a line of cores.
After biopsy and analysis, the tumor must be treated with a separate device, as Biopsys teaches that their coring device should not be used for resection. Indeed, the device is not designed to perform resection with assurance that complete resection of a suspect mass has been accomplished. Mechanical cutting and disruption of the tissue structure and cancer cell dispersion (that is, tearing of the tissue around the cancer and movement of the cancer cells amongst normal tissue) will result in unintentional delivery of cancer cells into healthy tissue adjacent the lesion.

This patent is subject to a terminal disclaimer.

Rotational core biopsy device with liquid cryogen adhesion probe


A holographic image produced by the impression of a shim onto a metallic ink coating comprising a plurality of metallic particles suspended in a resinous ink binder. A resinous or substantially tactile and nonresilient undercoat can be applied to the substrate also to receive the impression of the shim and to create more distinct holographic imagery. A substantially clear overcoat can also be applied over the metallic ink coating to enhance the reflectivity of the image.

Because holographic images are not readily copied by commercial photocopiers, they are frequently integrated into such sensitive items as stock certificates, travelers checks, identification cards, and credit cards for enhanced security. The cost, expense, and potential for security breaches associated with holographic image processes have, however, inhibited the use of holographic images in a number of applications, including game cards.
Conventional holographic images are produced by a stamping process in which a shim, having the mirror image of a three dimensional holographic image formed thereon, is impressed into a reflective surface. The stamped impression causes light to reflect in varying directions from the reflective surface in the form of the holographic image. In one method the shim is impressed into a metallic foil adhered to a substrate. This method is often cost-prohibitive, however, because the step of adhering the metallic foil to a substrate cannot readily be integrated into conventional printing operations. Boswell, U.S. Pat. No. 5,464,690 (incorporated by reference herein), discloses a holographic imaging process in which a shim is impressed into a reflective surface formed by vapor deposition of metallic particles onto a substrate. Boswell's process also may be cost-prohibitive in some circumstances because of the complexity and expense of the vapor deposition process.
In the foregoing holographic imaging processes, a glossy transparent coating may be applied over the holographic image in order to enhance its iridescence or gloss. In another holographic imaging process a glossy transparent coating is applied over a reflective surface before a holographic image is impressed onto the item. The glossy transparent coating is itself impressed by the shim and, depending upon the depth of the impression and the thickness of the transparent coating, the reflective surface may or may not be impressed in the process. The impression of the transparent coating causes light that is reflected from the reflective surface, and which passes through the transparent coating, to refract and thereby create a holographic image.
Because of the complexity and expense of equipment required to manufacture items incorporating holographic images, holographic imaging traditionally has been performed at separate specialty manufacturing sites. The holographic images often are formed on labels that are transported to a separate manufacturing facility to be applied to sensitive items. Because the holographic imaging is performed at a separate site, however, there is a greater potential for illicit application of holographic labels to counterfeit goods, by theft of the holographic labels, than if the holographic imaging were performed on-site. To overcome this problem Boswell, supra, has developed a label that is manufactured at a separate site, but which is applied to the sensitive item and stamped by a shim at the same site that the sensitive items are manufactured. Boswell's process still requires, however, that labels be manufactured at and transported from a separate site, and that a separate label application step be included in the manufacturing process.


A method is presented for provisioning a communication device. In the method, a call initiated by the communication device to initiate a first form of provisioning of the device is received. In response to the call, capabilities of the communication device are requested. In response to the request, an indication of whether the communication device supports a second form of provisioning different from the first form of provisioning is received. Based on the indication received, provisioning of the communication device using the second form of provisioning is initiated, or the communication device is provisioned using the first form of provisioning.

Oftentimes, a communication device must be provisioned prior to being fully employed within a communication network to facilitate communication with other users. This provisioning is particularly important for wireless communication devices, such as cellular phones or personal digital assistants (PDAs). For example, a wireless communication device is normally programmed with both a mobile identification number (MIN) and a mobile directory number (MDN) to access a wireless communication network to communicate with other communication devices. More specifically, a wireless service provider or carrier assigns a unique MIN and MDN to each phone sold or otherwise provided to a user. If the user subsequently switches to another service provider, the new provider typically assigns the phone a new MIN that is associated with the new carrier. However, the MDN, which represents the actual phone number another party would dial to initiate a connection with the device, may remain the same to facilitate phone number portability, although the user may choose a new MDN to be assigned to the phone. The programmable or provisioning nature of the MDN and the MSN are thus distinguished from the electronic serial number (ESN) or mobile equipment identity (MEID), which the phone manufacturer permanently assigns to allow identification of the phone hardware, and which may be useful in the case of theft or loss of the phone.
In many cases, the wireless service provider may provision a wireless communication device with parameters or values in addition to the MIN and MDN to facilitate the use of a variety of services by the device, such a voice communication, short message service (SMS), Internet access, picture mail, and video mail.
While some provisioning of a wireless communication device may be performed manually by a technician at the time the device is conveyed to the user, most or all of the provisioning may instead be accomplished remotely by way of a server accessible via the wireless communication network. One such method of remote provisioning is termed "over-the-air function" (OTAF), in which an OTAF server is coupled with a wireless communication device requesting provisioning by way of a mobile switching center (MSC). Typically, a user initiates such provisioning by way of a specialized call, such as "*2" on the cellular phone for customer service, which the MSC then routes to the OTAF server.
Another form of remote provisioning is Internet-based over-the-air (IOTA) provisioning, which is accomplished by way of a data session between a wireless communication device requesting provisioning and an OTAF server coupled to the Internet. As with OTAF provisioning, an MSC may provide the connection between the device and the IOTA server. However, to initiate the data session, the IOTA server typically requires a phone number, such as the MIN or MDN described above, to be programmed into the wireless communication device prior to the data session.

System and method for provisioning a communication device based upon device capability


An in-line lapping guide uses a contiguous resistor in a cavity to separate a lithographically-defined sensor from the in-line lapping guide. As lapping proceeds through the cavity toward the sensor, the resistance across the sensor leads increases to a specific target, thereby indicating proximity to the sensor itself. The contiguous resistor is fabricated electrically in parallel to the sensor and the in-line lapping guide. The total resistance across the sensor leads show resistance change even when lapping through the cavity portion. One method to produce the contiguous resistor is to partial mill the cavity between the sensor and the in-line lapping guide so that a film of metal is left. Total resistance across leads is the parallel resistance of the sensor, the contiguous resistor, and the in-line lapping guide.

1. Technical Field
The present invention relates in general to fabricating magnetic sensors and, in particular, to an improved system, method, and apparatus for in-line contiguous resistive lapping of magnetic sensors.
2. Description of the Related Art
Magnetic recording is employed for large memory capacity requirements in high speed data processing systems. For example, in magnetic disc drive systems, data is read from and written to magnetic recording media utilizing magnetic transducers commonly referred to as magnetic heads. Typically, one or more magnetic recording discs are mounted on a spindle such that the disc can rotate to permit the magnetic head mounted on a moveable arm in position closely adjacent to the disc surface to read or write information thereon.
During operation of the disc drive system, an actuator mechanism moves the magnetic transducer to a desired radial position on the surface of the rotating disc where the head electromagnetically reads or writes data. Usually the head is integrally mounted in a carrier or support referred to as a "slider." A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the disc drive system. The slider is aerodynamically shaped to slide over moving air and therefore to maintain a uniform distance from the surface of the rotating disc thereby preventing the head from undesirably contacting the disc.
Typically, a slider is formed with essentially planar areas surrounded by recessed areas etched back from the original surface. The surface of the planar areas that glide over the disc surface during operation is known as the air bearing surface (ABS). Large numbers of sliders are fabricated from a single wafer having rows of the magnetic transducers deposited simultaneously on the wafer surface using semilead-type process methods. After deposition of the heads is complete, single-row bars are sliced from the wafer, each bar comprising a row of units which can be further processed into sliders having one or more magnetic transducers on their end faces. Each row bar is bonded to a fixture or tool where the bar is processed and then further diced, i.e., separated into sliders having one or more magnetic transducers on their end faces. Each row bar is bonded to a fixture or tool where the bar is processed and then further diced, i.e., separated into individual sliders each slider having at least one magnetic head terminating at the slider air bearing surface.
The magnetic head is typically an inductive electromagnetic device including magnetic pole pieces, which read the data from or write the data onto the recording media surface. In other applications the magnetic head may include a magneto resistive read element for separately reading the recorded data with the inductive heads serving only to write the data. In either application, the various elements terminate on the air bearing surface and function to electromagnetically interact with the data contained on the magnetic recording disc.
In order to achieve maximum efficiency from the magnetic heads, the sensing elements must have precision dimensional relationships to each other as well as the application of the slider air bearing surface to the magnetic recording disc. Each head has a polished ABS with flatness parameters, such as crown, camber, and twist. The ABS allows the head to "fly" above the surface of its respective spinning disk. In order to achieve the desired fly height, fly height variance, take-off speed, and other aerodynamic characteristics, the flatness parameters of the ABS need to be tightly controlled. During manufacturing, it is most critical to grind or lap these elements to very close tolerances of desired flatness in order to achieve the unimpaired functionality required of sliders.
Conventional lapping processes utilize either oscillatory or rotary motion of the workpiece across either a rotating or oscillating lapping plate to provide a random motion of the workpiece over the lapping plate and randomize plate imperfections across the head surface in the course of lapping. During the lapping process, the motion of abrasive particles carried on the surface of the lapping plate is typically along, parallel to, or across the magnetic head elements exposed at the slider ABS.
In magnetic head applications, the electrically active components exposed at the ABS are made of relatively softer, ductile materials. These electrically active components during lapping can scratch and smear into the other components causing electrical shorts and degraded head performance. The prior art lapping processes cause different materials exposed at the slider ABS to lap to different depths, resulting in recession or protrusion of the critical head elements relative to the air bearing surface. As a result, poor head performance because of increased space between the critical elements and the recording disc can occur.
Rotating lapping plates having horizontal lapping surfaces in which abrasive particles such as diamond fragments are embedded have been used for lapping and polishing purposes in the high precision lapping of magnetic transducer heads. Generally in these lapping processes, as abrasive slurry utilizing a liquid carrier containing diamond fragments or other abrasive particles is applied to the lapping surface as the lapping plate is rotated relative to the slider or sliders maintained against the lapping surface.
Although a number of processing steps are required to manufacture heads, the ABS flatness parameters are primarily determined during the final lapping process. The final lapping process may be performed on the heads after they have been separated or segmented into individual pieces, or on rows of heads prior to the segmentation step. This process requires the head or row to be restrained while an abrasive plate of specified curvature is rubbed against it. As the plate abrades the surface of the head, the abrasion process causes material removal on the head ABS and, in the optimum case, will cause the ABS to conform to the contour or curvature of the plate. The final lapping process also creates and defines the proper magnetic read sensor element heights needed for magnetic recording.
However, if the components used to lap the heads make contact with the sensors, they will cause lapping-induced stress. Lapping-induced stress causes sensor response to degrade. Traditionally, the potential damage done by lapping-induced stress has been mitigated by offsetting the read element from the ABS surface so that the lapping components do not contact or stress the sensors. In some cases, the read elements are recessed from the ABS surface by a distance in the range of 50 to 125 nm. Unfortunately, such large distances between the sensor and the magnetic surface cause unacceptable signal loss in modern read sensors. Thus, an improved solution for mitigating the damage done by lapping-induced stress is needed.
Controlling the lapping of embedded sensors requires knowledge of the position of the lapping surface relative to the target plane. Such knowledge is typically provided by the resistance of the sensor during lapping. For the embedded sensor, the sensor resistance changes little when lapping in the cavity region. It is desirable to have additional information about the lapping surface position for the cavity region for the lapping of embedded sensors.

In-line contiguous resistive lapping guide for magnetic sensors

Hitachi Global Storage technologies Netherlands BV


An continuous passive lumbar motion (CPLM) device for alleviating lower back stiffness and/or pain. A person seated on a backless seat is subjected to cyclical forward and backward horizontal acceleration, thus imposing a horizontal to-and-fro force to the lower part of the body resulting in flexion and tension of the upper torso relative to the lower torso in the lumbar spinal region.

1. Field of the Invention
The present invention relates generally to the field of physical exercise and, in particular, to that of exercise leading to an enhanced range of back motion and concurrent reduction in back discomfort. More particularly, the present invention relates to an exercise device and method for applying continuous passive motion (CPM) to the lumbosacral spine. More particularly yet, the present invention relates to such a device and method that causes the lower body of the person being exercised to move back and forth horizontally in a motion mimicking that experienced by a horseback rider on a horse at the walk, thereby subjecting the lumbosacral spine to repetitious flexion and extension resulting in rotating the pelvis, a movement called pelvic tilting.
2. Description of the Prior Art
Limited back motion may be a normal function of back configuration, varying greatly from individual to individual, or it may be abnormal reflecting some structural change resulting from genetic deformity or some degenerative or traumatic process causing arthritic deformation, either recognized or unrecognized. Nevertheless, most limitations of back motion and, hence, most incidences of back pain, are not associated with an identifiable anatomic deformity. Usually the reported limitations are not investigated beyond a spinal x-ray. Specific soft tissue imaging techniques, such as CAT or MRI studies, are usually reserved for individuals with unremitting and severe back pain and stiffness with or without neurological findings. In contrast, most stiff and painful back complaints are initially placed in a common category and treated empirically. Although the individual may relate the complaint to some specific event such as lifting a heavy object or twisting the back excessively, it is just as common that there is no identifiable causative incident. In other words, in most cases no anatomic abnormality or other identifiable cause is found for the limitation. Patients are frequently told semi-whimsically that the major part of back complaints results from humankind""s xe2x80x9cdecisionxe2x80x9d to walk erect supported in part by a vertical column of vertebrae. If the back limitation is incapacitating and resistant to the usual home remedies, the individual often seeks the help of chiropractor, an osteopath, a physical therapist or an orthopedist, clinicians much involved in relieving individuals with back complaints. In the absence of a clear causation, the limitation is managed by one or several modalities with relief ranging from non-existent to full. This is one of several examples illustrating the maxim that the more intractable a condition is to cure, the greater is the number of xe2x80x9ccuresxe2x80x9d. In other words, management of back stiffness remains far from a mature therapeutic modality.
Regardless of the cause of the back stiffness, its cause relates to some degree of muscle spasm restricting the back""s range of motion, commonly asymmetrically limiting one motion more than another. Pain is a common accompaniment of this stiffness. There commonly is some associated degree of tenderness over the spastic muscle group. Traditionally, these subjects have been advised to stay in bed for several days until the complaint remits or greatly reduces. Then, several years ago, it was found that such prolonged inactivity actually caused a worsening of the disability attributed to further muscle weakness from disuse. Good muscle tone is essential to the erect posture, the full range of motion and freedom from discomfort. This observation was further supported by the quicker return to good function of individuals who resumed walking after only a couple of days of rest. While the precise mechanism of the recovery remains obscure, many investigators suspect that in addition to the resumption of normal muscular activity there may be some additional factor of recovery attributed to the effects of spinal motion.
Animal studies have suggested that one mechanism of recovery may be related to the distribution of nutrients transferring into and out of the intervertebral discs, those cartilaginous plates separating the bodies of the vertebrae. It is well established that, in arthritis of the spine, these discs narrow, causing a constriction of the small passageways between the vertebrae and creating abnormal pressure on the segmental nerves emerging through these spaces. Such pressure commonly causes muscle spasm and accompanying discomfort. If it is that pressure that gives rise to the reported pain, then improved disc-nutrition mediated by spinal motion may be the mechanism by which early return to activity (including spinal motion) following acute back discomfort results in more efficient relief of back pain.
In any event, since the discovery of the beneficial effect produced by back motion in these individuals, new therapies have been designed to enhance the early return to back motion through devices that flex and extend the lumbar vertebrae. The common name for the maneuver is xe2x80x9cpelvic tilt,xe2x80x9d from the fact that the alternating flexion and extension of the lumbar vertebrae results in a tilting back and forth of the pelvis. In the traditional pelvic tilt exercise, the individual is supine (lying on his back) and actively rotates the pelvis forward and backward. The benefit from the pelvic tilt exercises is attributed to the strengthening of the abdominal muscles so essential in maintaining the erect posture. There may be some yet unidentified beneficial factor caused by the motion itself possibly the direct stretching of the muscles and ligaments occasioned by this range of skeletal movement. It then follows that if the active motion of pelvic tilting produces this effect, why may not passive motion through the same range of movement result in the same beneficial result.
At this point it is well to reemphasize that stiffness and discomfort are consistently associated in limited back motion. This affliction is increasingly experienced with advancing age. Past the age of 35, individuals are more susceptible to stiffness when they rise from bed in the morning or when standing after a period of immobilization from sitting. Normally, stretching or moving around brings prompt relief. The back becomes more flexible and the discomfort disappears. It has become a commonplace that the trained athlete stretches before exercise and those of us who learned the discipline of daily exercise are advised to devote a period preceding the exercise to a stretching routine.
Only recently have clinicians started to recognize that patients who complain of back pain may symptomatically benefit from passively induced flexion and extension of the lumbar spine, that is motion occasioned by an external force moving the pelvis forward and backward and, thus, flexing and extending the lumbar spine. This type of motion has been termed Continuous Passive Motion (CPM) and has been described in, among other places, xe2x80x9cThe Power of CPM: Healing Through Motionxe2x80x9d, Continuing Care, vol. 8, No. 10, November 1989.
A typical device applying CPM for back-pain relief is that disclosed by Riddle et al. (U.S. Pat. No. 5,500,002; issued 1996). The device of Riddle et al. provides a three-panel horizontal support on which the patient lies. The central panel supports the buttocks of the patient, and the other panels the upper body and legs, respectively. While the central panel remains static, one or both of the other panels tilt up and down. Thus, tilting the upper panel up and down, for example, will result in a motion that serves to flex the lower back region. Care must be exercised to position the body accurately so that flexion will occur in the intended segment of the spine. Beyond this consideration though is the undesirable and possibly harmful result of bending the trunk forcibly to a degree that causes pain and further spasm in the back muscles. There is no built-in mechanism to monitor the flexion according to the discomfort the device may produce. It may be postulated that the patient""s position, lying instead of upright, by not utilizing the normal supporting musculature of the back may have a consequent limited beneficial effect.
Other devices have been developed that utilize the vertical position of the spine for the application of the therapeutic effect. Such a device is the one taught by Hazard et al. (U.S. Pat. No. 5,637,076; issued 1997). That device creates motion in the upright lumbar spine by means of a bladder-containing cushion placed between the subject""s back and a supporting seat back. The bladder is sequentially inflated, causing a forward excursion of the lumbar spine, and then deflated, allowing the spine to return to its initial position. (The bladder-inflation/deflation cycle is carefully controlled by a pump that periodically forces air into the bladder then allows the air to escape.) This action produces CPLM of a limited yet effective degree so as to prevent the consequences, such as, stiffness and discomfort, of statically sitting in a fixed position for a prolonged period. The device has met with clinical success, particularly for drivers who must sit for long periods of time and for those office workers who are positioned before typewriters or computers for much of the day. The Hazard et al. device has been adopted by major airlines for their first-class passengers. Furthermore, a company that manufactures a chair designed to establish comfortable angles between the spine and the legs of the person seated in it now offers for sale a version of its chair that incorporates the Hazard et al. device. Thus, CPLM is slowly being recognized as a beneficial comfort mechanism to answer one of the assaults of modern civilization on the well-being of working people.
Man has for centuries, unbeknownst to him, benefited from CPM in a pre-mechanical form of transportation, horseback riding. Horses move in three gaits, walk, trot and canter. Let us examine the motion of the walk. While the horse moves forward in an uninterrupted forward progression, the back of the horse is involved in a series of repetitive thrusts as each hind leg exerts its forward motion. There is also a minimal lateral component in the motion which will be disregarded. Awareness of this intermittent acceleration is immediately apparent to the observant rider, although imperceptible to the observer on the ground. The resultant movement of the pelvis to and fro causes the lumbar spine to flex and then extend in the same manner as the active motion of the lumbar vertebrae causes the pelvis to tilt forward and backward in the pelvic tilt exercise. It is a commonplace for riders, particularly old ones, to comment that any back stiffness and discomfort they normally experience is lessened by a period of horseback riding. Pelvic tilting is the mechanism of this relief.
One of the present inventors was particularly struck by his consistent observation that riding his horse in the evening after supper resulted in the disappearance of the intense back pain and stiffness occasioned by the static upright position he necessarily maintained throughout long periods at work. A still more dramatic event occurred one morning when he awoke with extreme pain in the back and intense radiation of the pain down one leg, so-called sciatica. In some desperation, he managed to climb aboard his horse to see if the horse motion would improve his pain. To his amazement, after ten minutes of walking, he dismounted with no pain and no stiffness. Had he visited a chiropractor, instead of his horse, the relief would have been attributed to the professional manipulation. In a very real sense, he had experienced an equine adjustment.
It must be emphasized that not all horseback riding results in pelvic tilting. The tense and unsure rider""s back is held rigid and resists the horse""s motion, while the experienced rider maintains a relaxed and balanced position on the horse and absorbs the horse""s natural motion in his back. It is not the horse but the transmitted motion of the horse that effects the beneficial effect to the rider, the CPLM.
It should be further pointed out that the experienced rider assumes a natural position of balance in which a straight line can be drawn through the point of the shoulder (the head of the humerus), the hip (the greater trochanter of the femur) and the ankle (the external malleolus of the tibia). This position translates into a straight spine, a flexion of the thigh on the trunk at a 135 degree angle and a reciprocal reverse of that 135 degrees at the knee to return the ankle to the straight line referred to above. An added benefit of this position is that it relaxes the psoas muscles, those strong muscles attached anteriorly to the lower spine and the femur which primarily flex the hips. Relaxation of these muscles further relaxes the lower spine so that it can accommodate passively to forces applied to it. Any deviation from that alignment tilts the body forward or backward resulting in increased muscle action occasioning stiffness and a loss of pelvic motion.
Therefore, what is needed is a device and method for exercise and therapy that subjects the lumbar spine to CPLM in the form of reciprocal pelvic tilts. What is also needed is such a device and method that provide this CPLM under conditions where the spine is relaxed, self-supported, and in proper vertical alignment. What is also needed is such a device and method that produce CPLM in the subject in a controlled fashion over a designated period of time in a reproducible way, with minimal instruction from a therapist or trainer. Finally, what is needed is such a device and method that after a period of self-instruction the individual can use properly without supervision.
It is the object of the present invention to provide an exercise method and device that subjects the lumbar spine of the individual to CPM through repetitive reciprocal pelvic tilts performed in a sitting position with the body balanced and postural muscles minimally contracted. This is the position that the experienced horseman has learned through centuries of instruction and experience, and it provides comfort and health. It is also the position taught by gym teachers in hygiene classes, by enlightened parents to their children and by physical therapists. In sitting and standing, this easy balanced position should be maintained as an essential discipline of healthy respect for the body. It is a further object of the present invention to provide such a method and device that can be mastered quickly by the user so that it can then be used without supervision.
As a background to understanding the device, it is well to examine the actual forces that are responsible for the pelvic tilts that are induced by a forward thrust applied to the pelvis with the individual sifting erect. The body position is characterized by inertia. It will maintain this position until some force, either external or internal, moves it. With the horse motion referenced above, the pelvis of the rider is thrust (accelerated) forward as the horse takes a step with one hind leg. The thorax does not move forward to the same degree because of its inherent inertia and the fact that the forward force on it has to be applied through its (flexible) linkage to the rider""s pelvis. The remainder of the pelvic force is taken up by the motion of the lumbar vertebrae. During the relative pauses between thrusts from the alternating hind legs of the horse, the rider experiences a deceleration, causing the pelvic tilt to reverse and the lumbar spine to extend. This then is a description of the motions involved in the horse""s motion and the corresponding motions of the rider. It is further pointed out that the only moving parts of the subject are the lumbar spine and the pelvis, the upper body and the legs remaining essentially immobile. Now to reproduce this action of the spine, that is, tilting the pelvis first forward and then backward, by a mechanical device, the surface on which the body rests must itself first accelerate forward, and then backward. (Unlike in the horse, these accelerations are applied to an object that has no underlying velocity.)
To see what is required to induce the repetitive back-flex motion experienced by the rider, it is useful to reflect on inertial forces which arise within an extended body of interlinked parts because of the acceleration of the body. These inertial forces account for the repetitive pelvic tilts experienced by the horseback rider.
One example of the appearance of inertial forces is provided by a tow-truck coupled to a wagon by a stretchable, compressible spring. Picture the vehicles at rest and assume that there is no friction in the wagon""s wheels. At a particular time the tow truck starts moving at a constant speed V. The wagon will be put in motion only by the force exerted on it by the spring, and that spring will only exert force once it is stretched. Indeed, to a first approximation, the force exerted on the wagon will be directly proportional to the stretch in the spring. As long as the speed of the wagon is not equal to the speed of the tow truck, the spring will continue to lengthen and the force applied to the wagon will continue to increase. Thus, the acceleration of the wagon (which is the applied force divided by the mass of the wagon) will continue to increase as long as the speed of the wagon is less than that of the tow truck. Just as the wagon has a force exerted on it by the spring, so too does the spring have a force exerted on it by the wagon (an example of Newton""s Third Law). The force exerted by the wagon on the spring is an example of an inertial force. Similarly, the force exerted on the tow truck by the spring which can be thought of as the inertial force of the wagon transmitted through the spring, is also an inertial force.
An inertial-force example a bit closer to the present subject matter is provided by a flexible reed, pivotably fixed at one end. If one applies a small force at the free end of the reed and perpendicular to the reed""s axis, the reed will simply rotate around its pivot point. However, if the force applied to the end is great enough the reed will at first bend, as the part to which the force is applied directly accelerates faster than the rest of the reed, which is accelerated only by the intra-reed linkage that couples it to the region that is in direct contact with the force. If the force continues for a sufficiently long period (seconds in the example being discussed), the speed of the lower part of the reed will xe2x80x9ccatch upxe2x80x9d to that in direct contact with the applied force (obviously, the alternative is the reed breaks).
In the case of the horse at a walk, the saddle alternately undergoes positive and is negative acceleration about the average walking speed of the horse. (Negative acceleration is commonly called xe2x80x9cdeceleration.xe2x80x9d During the positive acceleration, the forward speed of the horse increases to a value above the average forward speed; during negative acceleration (deceleration) it falls back below the average speed.) It is the acceleration, rather than the forward speed per se that causes the tilting of the pelvis. The tilting of the pelvis is analogous to the reed example above. The rider""s buttocks and legs, being in direct contact with the horse, accelerate forward and then decelerate. As they accelerate forward, the upper body is initially left behind, as it were. For a few seconds the lower body moves forward with respect to the upper body. Since, with proper riding form, the upper body remains upright during this interval, there must be a displacement between the upper and lower body. This occurs by virtue of the pelvic bone, which bridges the gap, tilting, so that both the angle that it makes with the lower back and the angle that it makes with the thighs change. Once this change has reached a maximum, the upper body follows along. At that point or shortly thereafter, the saddle undergoes deceleration. Since the buttocks and legs are in direct contact with the saddle, this part of the rider""s body follows this deceleration closely. Once again, however, the upper body behaves differently. Since it is not in direct contact with the horse, it continues moving forward at a constant speed until acted upon through its link with the lower body, i.e., through the lower back and pelvic bone. As a result, the pelvic tilt now goes in the other direction.
The present device essentially is a mechanism that provides a seat that alternately accelerates forward and backward at a frequency that roughly approximates that of a horse at a walk. These repetitive cycles occur sixty times a minute. The seat must be readily mountable. It must not only support the weight of the body in the sitting position but be so constructed that the seat itself does not slip forward or backward in response to the movement. Such a displacement of the seat would vitiate the power of the thrust rather than transmit it to the pelvis.
The final form of a device meeting the stated requirements evolved into a platform supporting a pedestal on top of which was mounted a seat resembling a Western-style saddle with a high front prominence (the saddle pommel) and a high back prominence (the saddle cantle), as well as sufficient padding to provide comfort. The propulsive force comes from an electric motor mounted under the platform. It was found that the high torque force required to alter the direction of the motion could only be obtained by a direct current motor rather than the more common indirect current motor. To convert the electric current for this purpose in turn necessitated a transformer. Also incorporated in the power mechanism was a rheostat to control the rate of the cycles. The position of this rheostat must be easily accessible to the operator or the supervising person. There must also be sufficient superstructure to provide a fixed support for the individual during the mounting or dismounting from the apparatus, and in the case the individual loses his or her balance while exercising.
Thus, the present invention is based on a device which allows the subject to sit in the manner described on a support that comes into contact with his or her legs and buttocks, a support that, once the subject has assumed the proper position, can provide back and forth translational motion in a horizontal direction. It can be seen from the above discussion of inertial forces that some experimentation is invited with respect to the nature of the horizontal motion with respect to the acceleration presented as a function of time. This will be in part a function of the total distance of horizontal movement (the xe2x80x9cexcursionxe2x80x9d) and the period of each cycle, that is, the time required for the device to go through a complete cycle and return to the starting point again. However, in addition, it is possible to also vary the shape of the acceleration curve that is applied. For example, one may move the support back and forth in accordance with a sinusoidal function: x=Acosxcfx89t, where t is time, A is the maximum excursion, and xcfx89=2Π/T where T is the period of each cycle. This will result in an acceleration curve of a=xe2x88x92(2Πxcfx89)2Acosxcfx89t, that is, of a=xe2x88x92(2Πxcfx89)2x. Alternatively, one may make the support move at a constant speed through most of the excursion, with acceleration occurring only at the two extremes as the support stops moving in one direction at a particular speed and shifts to moving in the other direction at the same speed.
Although it is not necessary to actually have a simulated saddle on the device of the present invention, the saddle shape is something that encourages the proper posture in the person being treated. For conciseness, therefore, the continuing description of the device and method will refer to the patient support as a saddle. Also, although not essential to the device of the present invention, most embodiments of it will incorporate some kind of platform surrounded by a railing; therefore, for definitiveness, it will be assumed in the description below that the device is so equipped.
Let us now go through a typical exercise of the individual""s use of the device. First, he steps up on the platform and sits down in the saddle. The supervisor may have to make an adjustment in the height of the saddle if the initial estimate of this position was inaccurate. The individual should sit erect with the shoulders, the hip bone and the ankle bone in substantially the same plane. His hips should assume an angle of 135 degrees with the trunk and the knees a reciprocal 135 degrees bringing them back on line with the shoulders and hips. The feet should comfortably rest on the platform, preferably with the soles flat on the surface. After he feels confidently aligned, he, or the supervisor, turns the rheostat knob to a speed that moves the individual""s pelvis forward and backward in continuous even cycles. The movement should not increase any pain the individual may be experiencing. Gradually, if not initially, the individual should experience some motion in the lumbar spine and get a sense of being relaxed rather then stiff in the upper body. The optimal rate of the cycles appears to be about sixty per minute. This optimal rate should be reached by gradually twisting the control knob. If the individual""s back has noticeable stiffness and soreness, he should in a period of minutes begin to notice some increase in the flexibility of the lower back. The natural tendency will be to stiffen the back in a protective reflexive action. But in time, and at an accommodating rate of the device, he should note some benefit in the form of increased flexion and extension of the lumbar vertebrae and accompanying tilting of the pelvis.
In review, the essentials of the exercise consist of the proper leveling of the seat, the easy mounting of the device, the assumption of a relaxed and balanced sitting position, the initiating of the to and fro motion of the machine, adjustment of the optimal rate of the cycles, the experience of the lumbar spine moving in synchrony with the moving platform, performance of the exercise for approximately ten minutes, stopping the motion and dismounting from the device, and realizing increased flexibility of the spine and relief of any accompanying discomfort in the back.
The use of definitive language in the above account was intended to more readily convey the nature of the method and device of the present invention, and not to limit in anyway the scope of the present invention. Rather, the discussion above with specific terms is considered to be merely illustrative of the scope of the present invention and it is to be further understood that numerous changes may be made by those knowledgeable in the field without straying beyond that scope.

Method and device for continuous passive lumbar motion (CLMP) for back exercise


Embodiments of the present invention relate to methods and systems that may detect cadences and duplicate fields in a video sequence, and correct the sequence to retrieve the original progressive content. Methods according to the present invention may compare consecutive fields of the same parity for similarity, and consecutive fields of the opposite parity for field and frame activity. By analyzing patterns in the similarity and activity of the fields, the cadence may be determined. The invention also provides methods that may be used to adjust for changes in the cadence, such as can result from scene changes in the video stream.

When a film or other audiovisual recording is transferred from its original format to a compressed format, it is often converted from one frame rate to another. For example, a motion picture is typically recorded at 24 frames per second (fps) in progressive format, but may be converted to 30 fps for distribution on DVD format or for television broadcast, typically using interlaced displays. An original recording may also be made at other frame rates, such as home video recordings which are typically made at 30 fps in interlaced format. Prior to encoding, an original recording may also be preprocessed, for example to perform noise reduction or frame rate conversion, and edited, for example to insert scene changes.
To compensate for the disparity between the original recording's frame rate and the rate at which it may later be displayed, various techniques of repeating and/or dropping portions of frames are used. The most common technique, used to convert from 24 fps progressive to 30 fps interlaced, is the "3-2 pulldown." Each original progressive frame is first converted to a set of two fields. For every other group of two fields one field is repeated, resulting in a group of three fields followed by a group of two fields, i.e., a 3-2 pattern. The resulting video sequence can then be displayed at 30 fps on an interlaced display device without introducing visual artifacts. Various other conversion techniques may be used.
As a specific example, FIG. 1 shows the standard 3-2 pulldown method as it is used in the art. Although the 3-2 pulldown is shown as an example, embodiments of the present invention also may be used with other conversion methods. In FIG. 1, an original audiovisual recording (100) is made of a series of frames 110, 120, 130, . . . 190. To perform a 3-2 pulldown, each frame is first split into a pair of fields (101). For example, frame 110 is split into an even field 110A and an odd field 110B. The fields may be formed, for example, by splitting each frame into many horizontal rows. The even field 110A is then formed of the even-numbered rows; the odd field 110B is similarly formed of only the odd-numbered rows. Each frame is similarly split into a pair of fields: frame 120 is split into 120A and 120B, 130 into 130A and 130B, 140 into 140A and 140B, and so on. Displaying an even "A" field and an odd "B" field in rapid succession or simultaneously causes a complete frame to be displayed. An interlaced display displays the fields in rapid succession; a progressive display displays the fields simultaneously. Each field may be referred to as having an even or odd "parity." Two even fields or two odd fields may be described as having the same parity, while an even field and an odd field may be described as having opposite parity.
To form the video stream using the 3-2 pulldown, the fields are arranged in the order shown at 102. One field from every other frame is repeated, such that the non-repeated field is preceded and followed by a copy of the repeated field. Field 111A is a copy of field 110A; field 131B is a copy of field 130B. In the field order 102 shown in FIG. 1, repeated fields are indicated by bold outlines.
A given conversion technique will result in a "cadence" in the video stream that can be detected during a pre-processing stage prior to encoding, or during a post-processing stage after decoding. When a video stream is encoded it may be desirable for the encoder to identify repeated fields reliably and consistently, to allow the encoder to avoid encoding multiple copies of the same field and accurately identify repeated fields in the encoded stream. Pulldown correction may be done prior to encoding to avoid encoding the repeated fields and optimize processing time and bit rate utilization, resulting in overall higher encoding quality. In such a situation, the repeated fields are marked as such in the compressed stream, instead of being encoded.
However, cadence detection and pulldown correction may be inaccurate due to noise in the original video sequence, which can lead to incorrect processing. In addition, an encoder may be instructed to encode every field, regardless of whether it is a repeated field. In some cases, an encoder may insert flags into the video stream to indicate when a field is repeated, allowing a decoder to avoid decoding the same field twice. Such methods may be error-prone if the encoder incorrectly identifies repeated fields or does not mark fields consistently.
When decoding a stream generated by an encoder that did not perform pulldown correction or performed pulldown correction incorrectly, it may be desirable for a decoder to reliably identify repeated fields regardless of the presence or absence of repeated-field indicators in the stream. A decoder capable of performing pulldown correction may retrieve the original progressive content, thus reducing visual artifacts resulting from improper matching of fields when the video is displayed on a progressive device. By properly identifying and dropping appropriate fields in a video stream, visual artifacts may be reduced.
There are thus several applications where it would be useful to have improved detection of repeated fields and cadences in a video stream.

Pulldown correction for progressive display of audiovisual recordings


A two-stage electrostatic filter includes an ionization section which is arranged in an upstream part of a throughflow passage (28) and includes a wire-like corona electrode (31) which is disposed in an ionization chamber (29) and connected to one pole of an electric high voltage source (16). The filter further includes a target electrode (21;37) which is spaced from the corona electrode (31) and connected to another pole of the high voltage source. A capacitator separator (30) is located in a downstream part of the throughflow passage (28) and includes a first and second group of electrode elements (32,33) which are placed side-by-side in spaced-apart relationship. The electrode elements (32) of the first group are placed alternately with the electrode elements (33) of the second group and are adapted to lie on a potential which is different from the potential on which the electrode elements (33) of the second group lie. The ionization chamber (29) has a target electrode surface (37;21) which is disposed both upstream and downstream of the corona electrode (31). When measured perpendicularly to the upstream-downstream direction of the throughflow passage (28) and to the longitudinal axis of the corona electrode, the distance of the corona electrode (31) from the target electrode surface is at least four times the distance between neighboring electrode elements (32,33). The capacitator separator (30) and the ionization chamber (29) form a disposable unit made of a non-metallic material, preferably a cellulose fibre material.

1. Field of Technology
The present invention relates to a two-stage electrostatic filter (electrostatic precipitator), and more specifically to a two-stage electrostatic filter.
2. Prior Art
Electrostatic filters, also called electrostatic dust separators, are used both in industrial production plants, in which case the electrostatic filters are in the form of large and expensive apparatus, and in apparatus in which air is cleansed for comfort purposes, such as air-conditioning apparatus and other apparatus for use in domestic dwellings, offices and other places of work, schools, hospital care facilities, motor vehicles and other places in which the air can be cleansed with comparatively much smaller apparatus.
In this latter case, in which it is mostly the air present in occupied places or the air entering such places that is to be cleansed, the filters used have hitherto essentially comprised mechanical filters provided with fibre filter cloths, textile or paper-based fibre-filter mats or electrode filter mats.
Electrostatic filters have also been used to a certain extent in this latter case. These electrostatic filters have normally been two-stage electrostatic filters by which is meant electrostatic filters in which the solid or liquid particles, aerosols, which are carried by the airflow and which are to be extracted therefrom are electrically charged in a separate ionization section while the actual separation process takes place in a capacitor separator positioned downstream of the ionization section. The present description is concerned with two-stage electrostatic filters, unless stated otherwise.
Mechanical air filters almost exclusively use disposable or exchangeable filter elements. Thus, those parts of the filter which primarily capture the separated material and which are therefore the filter components that are most subjected to dirt and clogging constitute units which can be readily exchanged. These elements, or units, are used until they can no longer fulfil their intended function in a satisfactory manner and are then replaced with a new unit and scrapped.
Hitherto, disposable units have not been used in electrostatic filters; at most, the capacitor separators typically comprised of aluminium plates and high-grade insulating material have been given the form of cassettes which can be removed readily from the filter apparatus for cleaning purposes. The task of cleaning these cassettes, however, is both time-consuming and expensive and can result in the spreading of unhealthy dust. Electrostatic filters are also expensive to run.
Because of these high running costs, electrostatic filters have not been used to an extent which corresponds to the important advantages that electrostatic filters afford over mechanical filters.
Another contributory cause lies in the fact that present-day electrostatic filters have a complicated and expensive construction due to the use of high voltages and the safety requirements associated therewith, such as the requirement of touch-safe designs and the use of high-grade materials, for instance for the insulators. A further contributory cause lies in the necessity of using high corona current intensities in order to avoid poor separation efficiency, which in turn results in a substantial generation of irritating odourants (ozone) in the chemically highly active plasma layer adjacent the corona electrode, or limits the cleansing capacity of the apparatus.
Furthermore, in conventional electrostatic filters, dust collected on the electrodes of the capacitor separator often causes sparkover between the electrodes, resulting in problems when using the filter in sensitive environments and danger of complete loss of the separating function.
Among the advantages which electrostatic filters afford in comparison with mechanical filters is that despite causing a very small pressure drop in the gas flow to be cleansed, electrostatic filters have the ability to separate extremely small particles from the gas flow; typical respirable particles have a diameter of about 0.3 .mu.m. Mechanical filters always have a considerable pressure drop. In particular, in the case of filters that are constructed to separate respirable particles from the gas flow, the pressure drop across the actual filter part (the filter element) is extremely high. This high pressure drop necessitates the use of noisy and power-demanding fans for transporting the gas through the filter.


An electromechanical transducer element includes a substrate; a first electrode formed on the substrate as a common electrode; an electromechanical transducer membrane formed on the first electrode; a second electrode formed on the electromechanical transducer membrane as an individual electrode; a first insulation protection membrane formed on the first and the second electrode; a third electrode electrically connected to the first electrode; a fourth electrode electrically connected to the second electrode; a second insulation protection membrane including a common electrode pad formed on the third electrode and plural individual electrode pads formed on the fourth electrode; and a fifth electrode formed so as to surround a vicinity of at least one of the individual electrode pads disposed at end parts.

1. Field of the Invention
The present invention generally relates to an electromechanical transducer element, a method of manufacturing the electromechanical transducer element, a liquid droplet discharge head having the electromechanical transducer element, and a liquid droplet discharge device having the liquid droplet discharge head.
2. Description of the Related Art
As a configuration of an inkjet recording device and a liquid droplet discharge head used in an image recording apparatus or an image forming apparatus such as a printer, a facsimile machine, a copier, etc., there is a known configuration as illustrated in FIG. 1. FIG. 1 schematically illustrates an example configuration of a liquid droplet discharge head.
As illustrated in FIG. 1, the liquid droplet discharge head includes a nozzle plate 103 having a nozzle 102 formed (fabricated) therein, so that ink droplets are discharged through the nozzle 102, a compression chamber substrate 104 (Si substrate), and a base 105, so that a compression chamber 101 is defined by the nozzle plate 103 (as the lower surface), the compression chamber substrate 104 (as the side surfaces), and the base 105 (as the upper surface). Further, as a known discharge drive means to drive the discharge of ink droplets, there are, for example, an electromechanical transducer element 106 such as a piezoelectric element, an electro-thermal transducer such as a heater, and a means including a vibration plate forming a wall surface of an ink flow path and an electrode facing the vibration plate. Ink droplets can be discharged from the nozzle 102 by applying pressure to ink in the compression chamber 101 using energy that is generated by such an energy generation means described above. As such an energy generation means in an inkjet recording head, there are two types of practical means. One means is to use a piezoelectric actuator having a longitudinal (axial) vibration mode so as to extend (elongate) and contract (shrink) in the axis direction of the piezoelectric element. The other means is to use a piezoelectric actuator having a flexural oscillation mode.
Various types of inkjet recording heads using such an actuator having the flexural oscillation mode are known. For example, an electromechanical transducer element is formed as if it is independently formed for each of the pressure generation chambers by forming a uniform piezoelectric material layer across the entire surface of the vibration plate using a coating technique and cutting the piezoelectric material in the shapes corresponding to the pressure generation chambers using a lithography technique.
Further, as an example of an electromechanical transducer element used for the actuator having the flexural oscillation mode, there is an electromechanical transducer element formed of a lower electrode 106, which is a common electrode, a PZT film (piezoelectric body layer; electromechanical transducer film 107) formed on the lower electrode 106, and an upper electrode 108 which is an individual electrode formed on the PZT film. Further, an interlayer insulation film is formed on the upper electrode 108 to provide insulation between the lower electrode 106 and the upper electrode 108. Further, a contact hole is formed through the interlayer insulation film as an opening so that a wiring is electrically connected to the upper electrode 108 through the contact hole (see, for example, Japanese Patent Nos. 3365485 and 4218309).
However, as the lower electrode 106, a metal electrode in which Pt is mainly used as the base thereof is widely used. Therefore, there is a concern that it is difficult to provide assurance against the fatigue characteristics of PZT. This is because it is generally thought that the characteristics of PZT are degraded due to diffusion of Pb included in PZT. It is also known that the fatigue characteristics of PZT can be improved when an oxide electrode is used (see, for example, Japanese Patent No. 3019845).
FIGS. 2A and 2B illustrate polarization states of the PZT membrane before and after the polarization process is performed, respectively. As illustrated in FIGS. 2A and 2B, the polarization directions 21 in the piezoelectric body crystal just before voltage application are random (see FIG. 2A before the polarization process is performed). However, when a voltage is repeatedly applied to the piezoelectric body crystal, the polarization directions in most domains 20 are directed in the same direction, so that a set of domains 20 having the same polarization direction can be formed (see FIG. 2B after the polarization process is performed). In this regard, various trials have been conducted to align the directions of the polarizations before the voltage is applied thereto to stabilize a displacement relative to a predetermined drive voltage (see, for example, Japanese Laid-open Patent Publication Nos. 2004-202849 and 2010-34154). This process may be called as an aging process or a poling process (polarization process). Specifically, a method has been conducted of applying a high voltage exceeding a drive pulse voltage to the piezoelectric element.

Electromechanical transducer element, method of manufacturing the same, liquid droplet discharge head, and liquid droplet discharge device

Abstract: Further, the fifth electrode is formed on the first insulation protection membrane and is electrically connected to the first electrode.


An electronic device detects erroneous key selection entries or inaccurate actuation of a keypad. The device has a keypad with aligned keys. Each of the keys is partitioned into two sensor sub regions. A first one of the sub-regions includes at least a first sensor and a second one of the sub-regions includes a second sensor. A processor with a keypad sensor inputs is selectively coupled to the first and second sensors of each of the sub-regions. The second sensor of the first key and a proximal first sensor of an adjacent second key are coupled to a common keypad sensor input to provide indistinguishable sub-regions of adjacent keys. The processor is programmed to detect an erroneous key selection entry when only a key actuation signal is provided from the common keypad sensor.

The present invention relates to touch sensors and, more particularly, to a method for detecting erroneous key selection when, for instance, a user's finger touches two adjacent keys of a key pad.
Touch sensor user interfaces, typically in the form of a designated touch sensitive keypad or touch screen, have been incorporated into a variety of electronic devices such as cellular telephones, portable entertainment devices and computers. Typically, a touch sensor user interface has a plurality of touch actuated sensors associated with a user input region typically comprising input keys. For example, a cellular telephone (touch screen smart phone) may include a touch sensor user interface with an array of input keys, with twenty six of the keys being designated to letters of the alphabet, ten of the keys being designated to each of the numbers from 0 to 9, and further addition keys being designated to punctuations, special symbols and function instructions.
Touch sensor user interfaces such as touch screens have a display area operable to detect the presence and location of a touch within the display area. The term touch generally refers to a contact to the display area by a finger or object such as a stylus or pen. Such touch screens typically work on the effects of a matrix of capacitors or resistors in which the capacitance or resistance variations within the matrix vary at the point of contact. From these variations, row and column coordinates of the matrix are determined and thus a key displayed on the screen at those coordinates can be determined. However, using this approach the identification of an actuated key can be relatively computationally complex especially for high resolution touch screens as many matrix coordinates can be associated with a single key.
One approach that reduces the computational complexity of determining an actuated key of a touch screen or designated touch sensitive keypad is by a firmware coded configuration. With such a configuration, each key is partitioned into two coded sub-regions and each sub-region has one or more detectors directly connected to an input of a processor. When both sub-regions detect concurrent contact from an object, the processor identifies the actuated key from signals sent from two sub regions. This approach is relatively computationally efficient. However, the coding of the sub-regions can result in erroneous keys being identified by the processer when, for instance, a finger touches one sub-region of a first key and another sub-region of an adjacent second key.

Electronic device for detecting erronous key selection entry


In a vehicle provided with a rear wheel toe angle varying device for individually varying toe angles of rear wheels, upon detection of a failure to steer one of the rear wheels, the rear wheel of a healthy side is steered to a zero angle. Whereby, when a straight travel determining unit determines that the vehicle is traveling straight, a toe angle estimating unit estimates a steering angle of the rear wheel which has failed to steer based upon the steering angle of the front wheels of the vehicle as determined by a steering angle sensor.

Each front wheel of a four-wheel vehicle is provided with a certain fixed toe angle with the aim of ensuring a driving stability of the vehicle, in addition to a steering angle which is varied as required for changing the traveling direction of the vehicle. In recent years, there have been proposals to equip a vehicle with a device for varying the toe angles of the rear wheels to the end of improving the driving stability and response.
Japanese patent publication No. 9-030438 discloses a device that includes a pair of electric linear actuators each provided at a junction between a lateral link or a trailing link of a corresponding side a vehicle suspension system and the vehicle body so that the toe angle of the rear wheels may be varied individually.
It was also proposed in Japanese patent publication No. 2008-04981 (by the inventor of the present application and two others, and corresponds to U.S. patent application Ser. No. 11/830,391 and EP patent No. 1892180B) to control the toe angles of the rear wheels to be symmetric to each other or otherwise come to agree with each other if the control of either one of the toe angles becomes faulty or incapacitated for any reason.
However, according to the previous proposal in the aforementioned Japanese patent publication, when a rear wheel of a faulty side is seized or get stuck at a certain angle, it may be possible to keep the vehicle travelling straight ahead but the tires of the rear wheels are subjected to uneven or excessive wears.


A gas turbine engine including air cooling and compressing means configured so that, in one embodiment, cool air from the cooling and compressing means is supplied to the combustor for cooling the combustor and then, after cooling at least a portion of the combustor, for mixing with fuel in the fuel injector, is described. In one form, the combustor includes a flowpath in flow communication with cool air supplied by the cooling and compressing means. The air flows through the flowpath from an aft portion to an outlet located at the fuel injector. The cooling air, after having cooled walls of the combustion chamber, mixes with fuel in the fuel injector. Mixing the high pressure air from the cooling and compressing means with the fuel in the fuel injector facilitates dispersion of fuel from the fuel injector into the combustion chamber, and also aids in increasing the fuel/air energy shear gradients. As a result, the injection velocity is believed to be significantly increased, and NOx emissions are believed to be reduced.

A gas turbine engine includes a core engine having, in serial flow relationship, a high pressure compressor (also called a core compressor) to compress the airflow entering the core engine, a combustor in which a mixture of fuel and the compressed air is burned to generate a propulsive (combustion) gas flow, and a high pressure turbine which is rotated by the propulsive gas flow and which is connected by a larger diameter shaft to drive the high pressure compressor. A typical aircraft bypass turbofan gas turbine engine adds a low pressure turbine (located aft of the high pressure turbine) which is connected by a smaller diameter coaxial shaft to drive a front fan (located forward of the high pressure compressor) which may also drive a low pressure compressor (located between the front fan and the high pressure compressor). The low pressure compressor sometimes is called a booster compressor or simply a booster. It is understood that the term "compressor" includes, without limitation, high pressure compressors and low pressure compressors. A flow splitter, located between the fan and the first (usually the low pressure) compressor, separates the air which exits the fan into a core engine airflow and a surrounding bypass airflow. The bypass airflow from the fan exits the fan bypass duct to provide most of the engine thrust for the aircraft. Some of the engine thrust comes from the core engine airflow after it flows through the low and high pressure compressors to the combustor and is expanded through the high and low pressure turbines and accelerated out of the exhaust nozzle.
Cooling of engine hot section components, such as the combustor, is necessary because of the thermal "redline" limitations of the materials used in the construction of such components. Typically such cooling of the combustor is accomplished by using a significant amount of air which exits the compressor. This cooling air bypasses the combustion chamber and is used to cool the combustor (e.g., the combustor liners) as well as to cool, for example, turbine components. The cooling air, after cooling the combustor (and turbine components), re-enters the gas path downstream of the combustor. Because this cooling air is not available inside the combustion chamber, the combustor has to operate at a higher fuel to air ratio which results in a higher combustor temperature in order to provide a desired turbine inlet temperature which is required for engine power and efficiency. However, the higher combustion chamber temperature generates more undesirable NOx emissions.
Gas turbine engine NOx emissions from operation on liquid fuels is at least partially the result of stoichiometric fuel-air ratio in the vicinity of the liquid fuel droplets. Above the pseudo-critical pressure of jet fuel (approximately 350 psia), liquid droplets absorb heat by convection and radiation. Once the temperature of the droplet reaches the pseudocritical temperature (approximately 750.degree. F.), the droplet loses surface tension and disperses via air shear forces into a fuel-rich concentration of gaseous fuel and air molecules. With additional mixing with air, the gas mixture reaches ignition fuel-air ratio (still fuel rich) and bums. Since the engine overall fuel air ratio is fuel lean, there is a region where the gaseous fuel-air ratio is at or near stoichiometric concentration and the flame temperature is at a maximum (about 4000.degree. F.).
NOx is produced by the reactions N2+O->NO+N followed by O2+N->NO+0. The rate of the second reaction (O2+N) increases NOx by a factor of five over a peak combustor temperature of 3000.degree. F. when the fuel droplets burn at 4000.degree. F. The relative NOx increase is much greater for lower engine power levels.
It would be desirable to lower the NOx emissions of a gas turbine engine without adversely affecting the engine efficiency. It also would be desirable to achieve such reduced NOx emissions without significantly increasing the cost of the engine.

Air assist fuel atomization in a gas turbine engine


Systems and methods for determining a distribution map of susceptibility property of an object are provided. The method may include one or more of the following operations. A phase diagram corresponding to a magnetic resonance (MR) signal of the object may be obtained. A preliminary field map may be determined based on the phase diagram. Preliminary error limiting information associated with the preliminary field map may be obtained. A preliminary distribution map of susceptibility property of the object may be determined based on the preliminary field map and the preliminary error limiting information. An iteration process including at least one iteration may be performed to determine a target distribution map of susceptibility property of the object.

Almost all material can become magnetized in a magnetic field and then display magnetic effects similar to magnets (e.g. generating a local magnetic field around the material). Magnetic resonance imaging (MRI) uses externally imposed magnetic fields (including a main magnet and a gradient magnet) and radio frequency waves to generate images of an object. The object is magnetized in the externally imposed magnetic fields and generates local magnetic fields. The local magnetic fields superimpose with the externally imposed magnetic fields, and may affect the signal of MRI.
Susceptibility property (or referred to as magnetic susceptibility or magnetic susceptibility property) is a measure of the extent of a material becomes magnetized in a magnetic field, or in other words, the intensity of a local magnetic field generated by the material (if magnetized). The susceptibility property of an object can be used to derive information such as the content of iron, the degree of calcification, and/or the blood oxygen level in tissue or an organ of the object.
Quantitative Susceptibility Mapping (QSM) is an emerging technique in MRI for determining the susceptibility property of an object. A general process of QSM technology includes obtaining one or more sets of magnetic resonance phase information or phase images, generating a local field map based on the phase information, and determining a distribution map of the magnetic susceptibility based on the local field map and a formulated relationship between the local field map and the distribution map of the magnetic susceptibility. The local field map can be approximated to a convolution of a dipole kernel and the distribution map of the magnetic susceptibility. Accordingly, the distribution map of the magnetic susceptibility can be determined based on the local field map and an inverse dipole kernel. Unlike the dipole kernel, the inverse dipole kernel contains singularity values, thus making the inverse problem mathematically ill-posed and leading to apparent streaking artifacts in the solution results.
The current QSM techniques are facing at least two problems. The first problem is that there may be computational related streaking artifacts in the QSM maps due to the ill-posed nature of the inverse dipole kernel. Superficially, the streaking artifacts occur mainly due to the existence of the singularity values in the inverse dipole kernel. Thus the streaking artifacts can be reduced when the degree of singularity is reduced (which is the basic principle of the truncated k-space QSM methods). However, the truncated k-space QSM method(s) can change the inverse dipole kernel, and may lead to underestimated susceptibility values. And even the artifact is reduced, the remnant streaks usually remains visible in the final distribution maps. The co-localization of a priori information and the susceptibility distribution may reduce the streaking artifacts by adding regularization to the QSM. However, the discrepancy between the a priori information and the actual susceptibility distribution may lead to either over- or under-regularization, affecting the accuracy of the results. Also for tissues or regions with strong susceptibility variance, such as air-tissue boundaries or large bleedings in tissues, relatively strong streaking artifacts may be produced, affecting other regions of interest.
The second problem arises from anatomical a priori information that is involved in solving optimizing QSM as mentioned. The a priori information may provide a reference for the spatial characteristics of the susceptibility distribution (e.g., spatial continuity within tissue, and/or boundaries between different tissues). With such spatial information, one can impose a certain restriction in the form of, e.g., regularization terms (or Bayesian statistics), in solving the ill-posed inverse dipole problem. However, the obtained a priori information may be inaccurate, and the inaccurate a priori information may generate convergence errors in QSM. Usually, the a priori information is estimated by, e.g., the magnitude images of the same scan, or an initial estimate of the susceptibility distribution map. However, there can be non-negligible mismatch between the estimate of the a priori information and the actual spatial continuity of the tissue and/or boundaries between different tissues. Also, the estimate of the a priori information is considered constant during the calculation process of current QSM techniques, hence any mismatch in the a priori information estimation may lead to convergence errors of the calculations.
Therefore, it is desirable to provide a method and system for determining a distribution of susceptibility property of the object with reduced convergence errors and suppressed streaking artifacts.

Method and system for determining magnetic susceptibility distribution

SHANGHAI UNITED IMAGING HEALTHCARE CO., LTD.


A chip package includes a chip, a carrier, and at least a bump connecting structure for connecting the chip to the carrier. The bump connecting structure includes a first metal bump disposed on a chip pad of the chip and has a first height relative to a passivation layer of the chip, a second metal bump disposed on a carrier pad of the carrier and has a second height relative to a solder mask layer of the carrier, and a middle metal part disposed between the first and the second metal bumps. The sum of the minimum distance between the first and the second metal bumps, the first height of the first metal bump, and the second height of the second metal bump is less than 60 micrometers. The melting point of the middle metal part is lower than that of the first and the second metal bumps.

1. Field of Invention
The present invention relates to a semiconductor device and a connecting structure thereof. More particularly, the present invention relates to a chip package and a bump connecting structure thereof.
2. Description of Related Art
In the semiconductor industry, the production of integrated circuits (IC) is mainly divided into three phases: IC design, IC process, and IC package. In IC process, the chip is manufactured through wafer making, integrated circuit making, and wafer dicing etc. procedures. A wafer has an active surface, which refers generally to the surface on which the wafer has an active device. When the integrated circuit on the wafer has been made, the integrated circuit has a plurality of chip pads located on the active surface of the wafer. The chip eventually formed after wafer dicing may be electrically connected externally to a carrier through the chip pads. The carrier is, for example, a leadframe or a package substrate, and the chip may be connected to the carrier through wire bonding or flip chip bonding, so that the chip pads of the chip may be electrically connected to the contacts of the carrier.
In the flip chip bonding technology, after forming chip pads on the active surface of a wafer, bumps are formed on the chip pads respectively for electrically connecting the chip with the package substrate. Since these bumps are generally arranged on the active surface of the chip in area array, the flip chip bonding technology is suitable for chip packages with high contact number and high contact density, such that it has been widely used in the flip chip/ball grid array packages in the semiconductor industry. Moreover, compared with the wire bonding technology, the flip chip bonding technology may improve the electrical performance of the chip package because these bumps may provide shorter transmission paths between the chip and the carrier.
FIG. 1 is a cross-section view of a conventional flip chip package. Referring to FIG. 1, the conventional flip chip package 100 includes a chip 110, a substrate 120, a plurality of solder bumps 130, a plurality of under bump metallurgy (UBM) layers 140, and an underfill 150. The chip 110 has an active surface 112 and a plurality of chip pads 114 disposed on the active surface 112. In addition, the chip 110 further has a passivation layer 116 including a sub-passivation layer 116a and a stress buffer layer (SBL) 116b. The sub-passivation layer 116a and the stress buffer layer 116b overlay the active surface 112 to protect the chip 110 and expose each chip pad 114.
The UBM layers 140 are located between the chip pads 114 and the solder bumps 130 respectively. Each UBM layer 140 may include an adhesion layer, a barrier layer, and a wetting layer formed on the chip pad 114 sequentially. The UBM layers 140 are used for increasing the connecting strength between the solder bumps 130 and the chip pads 114, and for preventing the electro-migration.
The substrate 120 has a substrate surface 122, a plurality of bump pads 124, and a solder mask layer 126. The bump pads 124 are disposed on the substrate surface 122, and the solder mask layer 126 is disposed on the substrate surface 122 and exposes the bump pads 124. Each chip pad 114 is electrically connected to a corresponding bump pad 124 through one of the solder bumps 130. The material of the solder bumps 130 is, for example, lead solder or lead free solder.
The underfill 150 is located between the chip 110 and the substrate 120, and contains the solder bumps 130. The underfill 150 is used for protecting the solder bumps 130, and at the same time may reduce the thermal strain mismatch between the substrate 120 and the chip 110 when they are heated.
However, after the aforementioned flip chip package 100 has been used for a long time, cracks may appear on the side of the solder bumps 130 (especially solder bumps of lead-free solder) close to the chip pads 114, that results in the decrease of the reliability of the flip chip package 100. In addition, cracks may also appear on the side of the solder bumps 130 (especially solder bumps of lead-free solder) close to the bump pads 124, that results in the decrease of the reliability of the flip chip package 100.

Chip package and bump connecting structure thereof