In a class AB amplifier circuit, an input stage circuit includes a first differential pair configured to receive a differential signal and a first current mirror circuit connected with the first differential pair through a first node. A middle stage circuit includes a floating constant current source connected with the first node, a first transistor whose gate is applied with a bias voltage, and a first constant current source connected with the first node through the first transistor. A last stage circuit includes a first output stage transistor whose gate is connected with the first node and which controls a voltage of an output terminal. A first phase compensation capacitance has one end connected with a first connection node between the first constant current source and the first transistor and the other end connected with the output terminal.

1. Field of the Invention
The present invention is related to a class "AB" amplifier circuit and a display apparatus including a display panel which is driven by a class AB amplifier circuit.
2. Description of Related Art
As one of the application fields of a class AB amplifier circuit, there is known TFT_LCD (Thin Film Transistor_Liquid Crystal Display) driver LSI (hereinafter, to be referred to as a liquid crystal driver). The class AB amplifier circuit for a liquid crystal driver drives capacitive loads (pixel capacitances) provided for a liquid crystal panel. Such a class AB amplifier circuit is required to have a low consumption current amount and to be able to charge and discharge the capacitive load at high speed.
In recent years, a large-sized TFT_LCD panel of 42 inches or more for a TV needs to be drive by the class AB amplifier circuit arises. The large-sized TFT_LCD panel is large in load capacitance and high in a drive frequency. Also, because a current consumption amount increases as the drive speed increases, heat generation in a chip sometimes becomes a problem. From the above reasons, the class AB amplifier circuit for the liquid crystal driver needs to be possible to increase the drive speed and to have a low current consumption amount.
Moreover, in recent years, as the price of the TFT_LCD panel falls, the cost reduction of the liquid crystal driver is required. As an effective measure of the reduction in cost of the liquid crystal driver, it could be considered to shrink the chip size of the driver. A plurality of class AB amplifier circuits (e.g. 400 to 700 circuits) connected in a voltage follower configuration are provided for a buffer circuit in the liquid crystal driver. That is, an occupation rate of the class AB amplifier circuits in the liquid crystal driver is high. Therefore, the shrinkage in the chip size of the class AB amplifier circuit is a key of the chip shrinkage of the liquid crystal driver.
In Japanese Patent Application Publication (JP 2005-124120A: first conventional example), a class AB amplifier circuit is described which is used for the liquid crystal driver and which has a low current consumption amount. FIG. 1 is a circuit diagram showing a configuration of the class AB amplifier circuit described in the first conventional example. This class AB amplifier circuit is so-called Rail-to-Rail amplifier.
Referring to FIG. 1, the class AB amplifier circuit includes an input stage circuit 10 which receives signals INP and INM, which are complementary signals, a middle stage circuit 20 which is connected with the input stage circuit 10 through nodes N1 and N2, and a last stage circuit 30 which is connected with the middle stage circuit 20 through nodes N3 and N4 and outputs an output signal OUT.
The input stage circuit 10 includes a differential circuit 101 which outputs an output to the node N1 in accordance to the input signals INP and INM, and a differential circuit 102 which outputs an output to the node N2 in accordance with the input signals INP and INM. The differential circuit 101 includes an N-channel MOS transistor MN11 and an N-channel MOS transistor MN12, which form a differential pair. The differential circuit 102 includes a P-channel MOS transistor MP11 and a P-channel MOS transistor MP12, which form a differential pair. By such configuration, the differential circuit 102 operates in an input voltage range in which the differential circuit 101 does not operate, and the differential circuit 101 operates in an input voltage range in which the differential circuit 102 does not operate. Thus, a differential stage operating in the whole input voltage range can be obtained. That is, the class AB amplifier circuit in the first conventional example realizes the Rail-to-Rail configuration.
Hereinafter, the configuration and operation of the class AB amplifier circuit will be described below. At first, the configuration of the differential circuit 101 will be described. The N-channel MOS transistor MN11 and the N-channel MOS transistor MN12 form a first differential pair to have their sources connected in common. The N-channel MOS transistor MN15 is connected between the first differential pair and a negative power supply (the power supply of a low voltage side) VSS. In detailed, a source of the N-channel MOS transistor MN15 is connected with the negative power supply VSS, a drain thereof is connected with the sources of the N-channel MOS transistor MN11 and the N-channel MOS transistor MN12 in common and a gate thereof is connected with a constant voltage source terminal BN11. A bias voltage (the constant voltage) is supplied to the constant voltage source terminal BN11 and the N-channel MOS transistor MN15 functions as a constant current source. The differential circuit 101 further includes P-channel MOS transistors MP13 and MP14. Sources of the P-channel MOS transistor MP13 and the P-channel MOS transistor MP14 are connected with a positive power supply (the power supply of a high voltage side) VDD in common. A drain and gate of the P-channel MOS transistor MP13, and a gate of the P-channel MOS transistor MP14 are connected with the drain of the N-channel MOS transistor MN11 in common. A drain of the P-channel MOS transistor MP14 and the drain of the N-channel MOS transistor MN12 are connected with node N1 in common.
Next, the configuration of the differential circuit 102 will be described. The P-channel MOS transistor MP11 and the P-channel MOS transistor MP12 form a second differential pair to have their sources connected in common. The P-channel MOS transistor MP15 is connected between a second differential pair and the positive power supply VDD. In detailed, the source of the P-channel MOS transistor MP15 is connected with the positive power supply VDD. A drain thereof is connected with the sources of the P-channel MOS transistor MP11 and the P-channel MOS transistor MP12 in common. A gate thereof is connected with a constant voltage source terminal BP11. A bias voltage (a constant voltage) is supplied to the constant voltage terminal BP11 and the P-channel MOS transistor MP15 functions as the constant current source. The differential circuit 102 further includes the N-channel MOS transistors MN13 and MN14. The differential circuit 102 further includes the P-channel MOS transistors MP11 and MP12 and. Sources of the N-channel MOS transistor MN13 and the N-channel MOS transistor MN14 are connected with the negative power supply VSS in common. A drain and gate of the N-channel MOS transistor MN13 and a gate of the N-channel MOS transistor MN14 are connected to have a drain of the P-channel MOS transistor MP11 in common. A drain of the N-channel MOS transistor MN14 and a drain of the P-channel MOS transistor MP12 are connected with the node N2 in common. A gate of the P-channel MOS transistor MP11 and a gate of the N-channel MOS transistor MN11 are connected with the input terminal INM in common. A gate of the P-channel MOS transistor MP12 and a gate of the N-channel MOS transistor MN12 are connected with the input terminal INP in common.
The middle stage circuit 20 includes an N-channel MOS transistor MN22 and a P-channel MOS transistor MP22 which function as a floating current source 201, a P-channel MOS transistor MP21 connected with the positive power supply VDD and functioning as a constant current source, and an N-channel MOS transistor MN21 connected with the negative power supply VSS and functioning as a constant current source. A gate of the P-channel MOS transistor MP22 is connected with a constant voltage source terminal BP22 to which a bias voltage is supplied. A source of the P-channel MOS transistor MP22 is connected with a drain of the N-channel MOS transistor MN22, a drain of the P-channel MOS transistor MP21, and nodes N1 and N3 in common. A drain of the P-channel MOS transistor MP22 is connected with a source of the N-channel MOS transistor MN22, a drain of the N-channel MOS transistor MN21, and nodes N2 and N4 in common. A gate of the N-channel MOS transistor MN22 is connected with a constant voltage source terminal BN22 to which a bias voltage is supplied. A source of the N-channel MOS transistor MN22 is connected with the drain of the P-channel MOS transistor MP22, the drain of the N-channel MOS transistor MN21, and the nodes N2 and N4 in common. The drain of the N-channel MOS transistor MN22 is connected with the source of the P-channel MOS transistor MP22, the drain of the P-channel MOS transistor MP21, and the nodes N1 and N3 in common.
The last stage circuit 30 is an AB class output stage in which an output OUT is controlled by the floating current source 201 in the middle stage circuit 20. The last stage circuit 30 includes a P-channel MOS transistor MP31 whose gate is connected with the floating current source 201 through the node N3, and an N-channel MOS transistor MN31 whose gate is connected with the floating current source 201 through the node N4. A source of the P-channel MOS transistor MP31 is connected with the positive power supply VDD and a source of the N-channel MOS transistor MN31 is connected with the negative power supply VSS. A drain of the P-channel MOS transistor MP31 and a drain of the N-channel MOS transistor MN31 are connected with an output terminal OUT in common. Also, the output terminal OUT is connected with the floating current source 201 through phase compensation capacitances C1 and C2. In detail, one end of the phase compensation capacitance C1 is connected with the floating current source 201 through the node N3 and the other end thereof is connected with the output terminal OUT. One end of the phase compensation capacitance C2 is connected with the floating current source 201 through the node N4 and the other end thereof is connected with the output terminal OUT.
An idling current in the class AB amplifier circuit in the first conventional example is determined by the floating current source 201. The power consumption amount of the idling current when the output terminal OUT is directly connected with the input terminal INM to use the class AB amplifier circuit as a voltage follower circuit will be described. The class AB amplifier circuit used as the voltage follower is an amplifier circuit having high input impedance and a low output impedance, and outputs a voltage supplied to the input terminal INP to the output terminal OUT just as it is.
Here, it is supposed that each of the drain currents of the P-channel MOS transistor MP15 and the N-channel MOS transistor MN15 as the constant current source is 2I in the input stage circuit 10. When the voltage of the input terminal INP and that of the output terminal OUT are same, a half I of the drain current flowing through each of the P-channel MOS transistor MP15 and the N-channel MOS transistor MN15 flows through the drains of the P-channel MOS transistor MP11, the P-channel MOS transistor MP12, the N-channel MOS transistor MN11, and the N-channel MOS transistor MN12.
When the voltage at the input terminal INP is shifted to the side of a higher voltage as compared with the voltage at the output terminal OUT, current of the same value as the drain current 2I which flows through the input stage constant current source (the P-channel MOS transistor MP15 or the N-channel MOS transistor MN15) flows through the P-channel MOS transistor MP11 and the N-channel MOS transistor MN12. However, any current does not flow through the P-channel MOS transistor MP12 and the N-channel MOS transistor MN11.
On the other hand, because the P-channel MOS transistor MP13 and the P-channel MOS transistor MP14 form a current mirror circuit, the current which flows through the P-channel MOS transistor MP14 becomes zero. Similarly, because the N-channel MOS transistor MN13 and the N-channel MOS transistor MN14 form a current mirror circuit, the current which flows through the N-channel MOS transistor MN14 becomes 2I.
The gate voltage of the P-channel MOS transistor MP31 in the last stage circuit 30 falls because of a difference "−2I" between the current value "2I" of the N-channel MOS transistor MN12 and the current value "0" of the P-channel MOS transistor MP14. Also, the gate voltage of the N-channel MOS transistor MN31 in the last stage circuit 30 falls because of a difference "−2I" between the current value "2I" of the N-channel MOS transistor MN14 and the current value "0" of the P-channel MOS transistor MP12. Thus, the voltage of the output terminal OUT follows the voltage of the input terminal INP and changes to the side of the higher voltage. At this time, the phase compensation capacitance C2 functions as a coupling capacitance, to increase the gate voltage of the N-channel MOS transistor MN31 with the change of the voltage at the output terminal OUT. When the gate voltage of the N-channel MOS transistor MN31 rises, a penetrating current flows through a route from the positive power supply VDD to the negative power supply VSS through the P-channel MOS transistor MP31 and the N-channel MOS transistor MN31.
When the voltage of the input terminal INP is changed to the side of the lower voltage as compared with the voltage of the output terminal OUT, a current does not flow through the P-channel MOS transistor MP11 and the N-channel MOS transistor MN12. However, a current of the same value as the drain current 2I flows through the P-channel MOS transistor MP12 and the N-channel MOS transistor MN11. On the other hand, because the P-channel MOS transistor MP13 and the P-channel MOS transistor MP14 form the current mirror circuit, the current which flows through the P-channel MOS transistor MP14 becomes 2I. Similarly, because the N-channel MOS transistor MN13 and the N-channel MOS transistor MN14 form the current mirror circuit, the current which flows through the N-channel MOS transistor MN14 becomes zero.
The gate voltage of the P-channel MOS transistor MP31 rises because of a difference "+2I" between the current value "0" of the N-channel MOS transistor MN12 and the current value "2I" of the P-channel MOS transistor MP14. Also, the gate voltage of the N-channel MOS transistor MN31 rises because of a difference "+2I" between the current value "0" of the N-channel MOS transistor MN14 and the current value "2I" of the P-channel MOS transistor MP12. Therefore, the voltage at the output terminal OUT follows the voltage of the input terminal INP and changes to the side of the lower voltage. At this time, the phase compensation capacitance C1 functions as a coupling capacitance, to decrease the gate voltage of the P-channel MOS transistor MP31 with the change of the voltage of the output terminal OUT. When the gate voltage of the P-channel MOS transistor MP31 falls, the penetrating current flows through the course from the positive power supply VDD to the negative power supply VSS through the P-channel MOS transistor MP31 and the N-channel MOS transistor MN31.
As described above, in the class AB amplifier circuit of the first conventional example, the voltage of the output terminal OUT follows the voltage of the input terminal INP.
Also, the class AB amplifier circuit using a folded cascade type differential amplifying circuit is described in Japanese Patent Application Publications (JP-P2006-094533A: second conventional example; JP-A-Heisei 06-326529: third conventional example).
In order to realize a Rail-to-Rail system, the class AB differential amplifying circuit in the second and third conventional examples includes an input stage circuit having two differential pairs to which a differential signal is supplied, a middle stage circuit having two cascode circuits respectively connected with outputs of the two differential pairs, and a last stage circuit connected with the middle stage circuit to output an output signal according to the differential signal.
The middle stage circuit includes a floating current source to which a bias voltage is supplied. The last stage circuit is a class AB output stage circuit in which an idling current is controlled with the floating current source. Also, in the class AB amplifier circuit in the second conventional example, a phase compensation capacitance is provided between the middle stage circuit and the last stage circuit. One end of the phase compensation capacitance is connected with a connection node of the differential pair and the cascode circuit and the other end thereof is connected with the output terminal OUT.
A power consumption amount when the AB class differential amplifying circuit in the first conventional example is used as a voltage follower circuit to drive a liquid crystal panel will be described. When the voltage of the input terminal INP of the class AB differential amplifying circuit is changed to the side of a higher voltage as compared with the voltage of the output terminal OUT, the voltage of the output terminal OUT follows the voltage of the input terminal INP and changes to the side of the higher voltage, as described above. At this time, the phase compensation capacitance C2 functions as the coupling capacitance and the penetrating current flows through the route from the positive power supply VDD to the negative power supply VSS through the P-channel MOS transistor MP31 and the N-channel MOS transistor MN31. Similarly, when the voltage at the input terminal INP is changed to the side of a lower voltage as compared with the voltage of the output terminal OUT, the phase compensation capacitance C1 functions as the coupling capacitance and the penetrating current flows through the route from the positive power supply VDD to the negative power supply VSS through the P-channel MOS transistor MP31 and the N-channel MOS transistor MN31. Such a penetrating current does not contribute to charging and discharging operations to a capacitive load in the liquid crystal panel at all.
Next, a case to use the class AB amplifier circuit in the second or third conventional example as voltage follower circuit will be described. The middle stage circuit in the class AB amplifier circuit adds a current outputted from a differential pair of an input stage circuit. Also, it is necessary for a current which is larger than a current from a constant current source connected with the input stage circuit to flow through a floating current source in the middle stage circuit. For example, supposing that the current of the constant current source in the input stage circuit is 2I, in the class AB amplifier circuit of the first conventional example, it is possible to design the amplifier circuit under the condition that the current is "4I" which flows through the input stage circuit, and the current value is "I" which flows through the middle stage circuit. On the other hand, in the class AB amplifier circuit the second conventional example, it is necessary that the current is "4I" which flows through the input stage circuit, and the current is "6I" which flows through the middle stage circuit. That is, the current consumption amount of the class AB amplifier circuit in the second conventional example is twice the current consumption amount of the class AB amplifier circuit in the second conventional example.
Also, the class AB amplifier circuit of a folded cascade type in the second conventional example uses many elements and does not suit for chip shrinkage. As described above, a plurality of class AB amplifier circuits (400-700 circuits) connected to form voltage follower circuits as buffer circuits are included in the liquid crystal driver. Therefore, it is strongly required to decrease the power consumption amount and the chip area of the class AB amplifier circuit.

Class AB amplifier circuit and display apparatus


A musical instrument includes a neck, a body and a quick-release neck clamp adjacent the neck and the body. The quick-release neck clamp includes a neck plate attached to the neck, a body assembly with an elongated body assembly pocket attached to the body and at least one releasable fastener adjacent both the neck plate and the body assembly. The body includes a front surface formed on the body that defines a front surface plane, and the elongated body assembly pocket defines an axis that is parallel to the front surface plane.

A conventional stringed instrument is typically constructed in such a manner that the neck of the instrument is permanently attached to the body. For example, some guitars have integral necks and others have necks that are bolted onto the body of the guitar as a single piece. Although such bolt-on necks are theoretically detachable, due to the critical alignment requirements between the neck of a guitar and the body, as well as the time required to loosen both the strings and the bolts, these "bolt-on" guitar necks are for all practical purposes permanently attached.
Thus, due to the fixed presence of the neck, the length of conventional guitars presents a major problem with respect to transportation and storage. Also, the volumetric bulk of a conventional guitar additionally causes great difficulties, particularly with regard to commercial carriers such as airlines. Until now, there have been only two practical ways to transport guitars by commercial transportation. One way was to hand carry the guitar aboard the vehicle and gamble on having sufficient storage space. The alternative has previously been to utilize a massive reinforced shipping case that provides sufficient protection from the rough handling checked baggage typically receives. For the typical traveler neither of the above described options is entirely satisfactory. Moreover, in addition to the bulk and the resulting extra luggage, many travelers object to the "appearance" presented by a traveler carrying a guitar aboard a commercial carrier.
Although there are several commercially produced "travel guitars" currently available, these are merely slightly scaled-down versions of full size guitars. Scaled-down prior art travel guitars are still relatively large and are almost as inconvenient to transport as regular full-size guitars.
It has been proposed in the past to design a guitar so as to be collapsible, to a configuration that is smaller in size, in order to make it easier to transport and more convenient to store. One approach has been to construct the guitar with a foldable neck or fingerboard portion. A major disadvantage with such guitars is that folding in order to collapse the guitar usually requires that the guitar be completely re-tuned when erected. For example, a representative prior art embodiment is disclosed in U.S. Pat. No. 4,073,211, to Jorgensen, hereby expressly incorporated by reference. The Jorgensen design utilizes a hinged arrangement with a shaped recess in the back of the instrument into which the neck swings when it is folded into the collapsed position. Although folding the Jorgensen neck does result in a more compact overall size, the strings of the Jorgensen guitar must be completely disconnected prior to folding. Further, the bridge of the Jorgensen guitar must be detached from the body of the guitar for storage purposes. Furthermore, to maintain the desirable full scale-length fret board (of from 24 to 251/2 inches), the Jorgensen guitar still requires a relatively long storage space even in the folded configuration because the neck is folded and stowed parallel to its deployed axis.
Similarly, U.S. Pat. No. 4,111,093, to Field, hereby expressly incorporated by reference, also attempts to reduce the size of a guitar by folding the neck. The Field guitar employs a complex system of gears and rollers so that the tension of the strings can be relaxed in order to permit the neck to be folded. Additionally, the Field guitar employs a spring-loaded pin for the purpose of locking the neck in an extended position when the instrument is to be played. A significant disadvantage with the Field guitar is that the mechanical complexity of its precision linkages adds to the cost of manufacturing. Thus, the Field guitar is substantially more expensive than a fixed neck guitar of comparable musical quality. Further, the functional reliability of the guitar is lowered by both the complexity of the mechanism itself as well as the resulting weakening of the body caused by mounting the mechanism. Furthermore, the presence of this complicated mechanism adversely affects the tonal characteristics of the instrument. As with the Jorgensen guitar, the Field guitar still requires a relatively long storage space because, although the neck is folded, it is stowed parallel to its deployed axis. Thus, the above discussed prior art folding guitars do not provide the ultimate compact travel guitar greatly desired by guitar owners.
Another type of prior art folding guitar includes radially collapsible body sections. An example of such a prior art guitar is described in U.S. Pat. No. 4,686,882, to Shaw, hereby expressly incorporated by reference. The Shaw guitar has a main body to which laterally moveable wing-like sections are connected. These wing sections are provided with expander mechanisms which include a threaded stem projecting through one wall in order to allow the musician to manually expand the wings into their playing position. In addition, the Shaw guitar also has a neck portion which is folded by means of a hinge on the top of the instrument body. However, although folding the Shaw guitar does reduce its length, the front-to-back thickness of the Shaw guitar is actually increased by folding the neck because the radially collapsing wings preclude the presence of a recess in the back of the guitar into which the neck could swing. As with the Jorgensen and Field guitars, a relatively long storage space is still needed because the Shaw neck is also folded and stowed parallel to its deployed axis, albeit against the front of the body. Again, a major disadvantage with such guitars is that folding the neck in order to collapse the guitar requires that the guitar be re-tuned when erected. Another disadvantage with such laterally collapsible wing section prior art guitars is that they are limited to bodies of a particular shape (i.e., the wings must be generally triangular in form so that the guitar is collapsible). This design constraint severely limits the choice of body styles and designs. In addition, the complex mechanical mechanisms inherent to such radially collapsible wings make the guitar more expensive, tend to adversely affect the tonal characteristics of the instrument and lower the functional reliability of the instrument.
Still other prior art guitars are composed of separate sections or parts which may be joined together in a modular manner to yield a musical instrument in unitary form. An example of such a prior art guitar is disclosed in U.S. Pat. No. 4,254,683, to Nulman, hereby expressly incorporated by reference. The Nulman guitar includes two portions, a neck with minor body portion and a major body section. The major body section has a recess, or socket, which receives the minor body portion to which the neck is connected. When assembled, the upper surfaces of the main body and the fingerboard define substantially parallel planes. However, such prior art guitars provide only a limited degree of reduced dimensional size, are difficult to assemble, requires special tools and a certain amount of manual dexterity. Design flexibility is again severely limited.

Collapsible guitar with quick disconnect neck and submerged string tunnels


Embodiments described herein provide an apparatus comprising a plurality of processing resources including a first processing resource and a second processing resource, a shared local memory communicatively coupled to the first processing resource and the second processing resource, and a processor to receive an instruction to initiate a matrix multiplication operation, write a first set of matrix data into a first set of registers, and share the first set of matrix data between the first processing resource and the second processing resource for use in the matrix multiplication operation. Other embodiments may be described and claimed.

Subject matter described herein relates generally to electronic computing, and in some examples, to graphics processing.
Highly dense computations such a matrix multiplications are common building block operations in many Deep Learning (DL) and High Performance Computing (HPC) workloads. Such building block operations have significant data reuse, both spatially and temporally. Often, the performance of such building block operations is limited by the rate at which the data can be fed into the execution units of a processor, and such data movement is limited by the width and speeds of the buses that connect the execution units and the shared local memory.
Accordingly, techniques to improve data transfer speeds between memory and execution units may find utility, e.g., in computing operations.

Sharing register file usage between fused processing resources


Provided is an adhesive film that enables manufacturing of a high quality semiconductor device with good yield ratio, and related methods of manufacturing a semiconductor device, and semiconductor devices. Provided is an adhesive film for embedding a first semiconductor element fixed to an adherend and fixing a second semiconductor element that is different from the first semiconductor element to the adherend, wherein the adhesive film has a thickness T that is larger than a thickness T1 of the first semiconductor element, and the adherend and the first semiconductor element are connected by wire bonding and a difference between the thickness T and the thickness T1 is 40 μm or more and 260 μm or less, or the adherend and the first semiconductor element are connected by flip-chip bonding and a difference between the thickness T and the thickness T1 is 10 μm or more and 200 μm or less.

1. Field of the Invention
The present invention relates to an adhesive film, a method of manufacturing a semiconductor device, and a semiconductor device.
2. Description of the Related Art
In recent years, higher functionality, thinning, and downsizing of semiconductor devices and packages thereof have been desired increasingly. As one idea, a three-dimensional mounting technique has been developed, in which a plurality of semiconductor elements are laminated in layers in the thickness direction to achieve high-density integration.
As a general three-dimensional mounting method, a procedure has been adopted in which a semiconductor element is fixed to an adherend such as a substrate, and semiconductor elements are laminated one by one on the lowermost semiconductor element. An electrical connection is established between the semiconductor elements and between the semiconductor element and the adherend by a bonding wire (hereinafter, sometimes referred to as a "wire"). A film-like adhesive or a liquid adhesive has been broadly used to fix the semiconductor element.
In such a semiconductor device, a semiconductor element for controlling (hereinafter, sometimes referred to as a "controller") is arranged on the uppermost semiconductor element for controlling the individual operation of a plurality of semiconductor elements and controlling communication between the semiconductor elements, for example (JP-A-2007-096071).

Adhesive film, method of manufacturing semiconductor device, and semiconductor device


A power converter system includes a converter, a DC link, an inverter, a damping circuit, and a control system. The converter includes an input to couple to a power generation unit and an output to provide a direct current (DC) DC power output. The DC link includes a capacitor coupled to the converter output. A voltage across the capacitor defines a DC link voltage. The inverter includes an input coupled to the DC link. The damping circuit is coupled between the converter and the inverter in parallel with the DC link capacitor. The damping circuit includes a normally closed switching device, and a resistor coupled in series with the normally closed switching device. The control system is coupled to the damping circuit and configured to control the normally closed switching device as a function of at least one operating parameter of the power converter system.

The subject matter described herein relates generally to power systems and, more particularly, to a power converter system and methods of operating the power converter system.
In some known solar power systems, a plurality of photovoltaic panels (also known as solar panels) are logically or physically grouped together to form an array of solar panels. The solar panel array converts solar energy into electrical energy and transmits the energy to an electrical grid or other destination.
Solar panels generally output direct current (DC) electrical power. To properly couple such solar panels to an electrical grid, the electrical power received from the solar panels is converted to alternating current (AC). At least some known power systems use a power converter to convert DC power to AC power. In certain situations, such as during startup of the power converter and/or during a fault in electrical grid, less than all of the available energy within the converter may be delivered to the electrical grid. In such situations, voltages within the converter may increase to levels dangerous to the health of the converter.

Power converter systems and methods of operating a power converter system


A combination pipe piercing fitting and valve including a housing formed of a weldable plastic and having a valve casing communicating with a branch nipple. In the valve casing a valve stem and a boring tool are disposed for axial movement so as first to pierce a pipe welded to the housing and to then selectively open or close the branch nipple from the pipe. A sleeve for guiding the boring tool is axially and rotationally secured in the valve casing and extends at least past the area where the branch nipple enters the valve casing. This guide sleeve has a valve seat at its bottom end and an opening adjacent the branch nipple. This combination fitting and valve assures high operating reliability without leakage both during piercing of the pipe and during operation as a valve.

This invention relates to a pipe piercing fitting and a valve, comprising a housing which can be attached to a pipe, particularly by welding, containing a guide sleeve with a valve stem disposed therein for axial movement, the valve stem carrying a boring tool for piercing the pipe and a valve body for selectively opening or closing a branch connecting nipple communicating with the valve housing.
Published German Patent Application No. DE 2,709,466 discloses a piercing fitting and valve in whose valve casing a nipple is provided for connecting a branch line. The branch can be, for example, a residential connecting line which is connected by the known fitting to a water main. A valve upper part is threaded into the valve casing, and a threaded sleeve and a guide bushing are threaded into the valve upper part so as to be axially displaceable. These two bushings surround the valve stem, and are moved axially with the valve stem toward the pipe when the pipe is pierced and are subsequently fixed axially in the valve upper part by means of a special locking device. The aforementioned component parts are made of metal and contain a number of interengaging threads as well as locking members. This not only results in a correspondingly high manufacturing cost, but also creates a considerable danger of corrosion damage, so that if such valves are placed underground together with underground pipes for an expected long period of use which may be many decades, their operability becomes questionable after only a few years. Between the valve upper part and the valve seat there is a comparatively large free chamber through which the valve stem passes, and from which the branch nipple opens. The valve spindle is guided in the valve upper part, so that overall the valve connection together with the valve upper part and the bushings referred to constitute a considerable length. Due to the comparatively large distance between the valve seat and the valve stem guide sleeve, the valve casing must be made quite stiff in order to prevent damage to the valve seat by the boring tool when the boring is done. Finally, taking into account the large distance between the guide sleeve and the valve seat, a stable configuration must be assured in order to prevent the valve body from lifting off the valve seat and resulting in leakage when external forces act on the valve upper part.
Published German Patent No. DE 3,830,395 discloses a pipe piercing fitting which serves exclusively for piercing a pipe and does not have any valve function. This pipe piercing fitting contains a valve casing into which a branch nipple opens, whereby a cylindrical sleeve is integrated in the casing. The bottom end of the sleeve is positioned in the vicinity of the branch nipple. A boring tool is disposed in the sleeve for axial displacement through a threaded guide. In order to bore into the pipe, a device with a boring spindle is disposed on top of the valve body and is brought into engagement with the boring tool to operate it. After a hole has been bored, the spindle device is removed, and the free end of the casing is closed off with a plug. This pipe piercing fitting cannot readily be used as a valve, inasmuch as neither a valve seat nor a valve head is provided, in order to selectively open or close the flow path between the interior of the pipe and the branch connection.
Further, published German patent application No. DE 3,744,693 discloses a valve piercing clamp comprising a shell with a vertically oriented valve casing integrally formed thereon. This shell is composed, like the pipe, of PVC. The vertical casing contains a stepped bore with a screw thread in which a T-shaped insert of brass is releasably secured. This insert has a lateral branch connection and also, coaxial with the stepped bore, an additional bore at the upper end into which a spindle sleeve can be screwed. A support body for a boring tool is rotatably arranged in an internal thread inside the valve stem sleeve. Also, a spindle extends out the upper end of the spindle sleeve, which when it is rotated moves the boring tool axially via the support body. The valve piercing clamp consists of a number of components, each of which must be sealed against one another, so that a not inconsiderable expense is required for manufacture and assembly. The insert and the spindle sleeve are formed of metal and are thus subject to corrosion, especially when positioned underground, so that there is no assurance of reliable operation of the integrated boring tool and valve over an extended period of service. Finally, this known valve piercing clamp has a substantial height and additional measures are needed in order to prevent damage when the pipe is laid or during subsequent construction operations.


An applicator for applying a paint design along the border of a wall includes a holder having a planar base, a handle extending from one side of the base and a hook-and-loop fastener on an opposite side of the base for attaching in any desired position a sponge or other member for holding paint and applying it to the wall. The hook-and-loop fastener carries a grid so that the paint holding and applying member can be located in a precise position on the base of the holder relative to edges of the base and to other paint holding and applying members.

The present invention relates to a paint applicator and, more particularly, to a hand-held applicator for imprinting paint designs on surfaces, especially along the borders of walls.
One method of enhancing the appearance of a room is to apply a border design along the top of the walls of the room, adjacent the ceiling, and perhaps along the juncture with the adjacent side walls, or in other places. Border designs have been provided on strips of wallpaper for complementing a primary wallpaper design. In addition, stencils are available for applying border designs, especially on painted walls. In both cases, the work involves handling thin, usually long, strips of paper or other material. Furthermore, the designs provided by the paper are fixed so that, at most, a limited variation in the design can be made.


Disclosed is a carbon material for a neurostimulation electrode. The carbon material is composed of a carbon fiber. The carbon fiber has a thickness of 1 to 1000 μm, a linear density of 0.01 to 5.00 g/cm, and an aspect ratio of 100 to 1,000,000. Particularly, the carbon fiber material can be obtained by dry spinning carbon nanotubes, followed by liquid-based densification. The carbon material can be used in the fields of deep brain stimulation, spinal cord stimulation, etc. Also disclosed are an electrode assembly and a neurostimulation device, each including the carbon material.

Nowadays, bio-implantable medical devices are used to treat various diseases. Some of the bio-implantable medical devices are based on neurostimulation as a therapeutic principle and can be used for the treatment and management of diseases, such as pain, constipation, sleep disturbances, Parkinson's disease, epilepsy, hand tremor, and myodystonia. Representative examples of such neurostimulation devices include spinal cord stimulation (SCS) systems and deep brain stimulation (DBS) systems.
FIG. 1 is a schematic diagram of a deep brain stimulation system and shows a state in which a neurostimulation electrode applies a neural stimulus to the thalamus. A neurostimulation-based bio-implantable medical device, such as an SCS or DBS device, essentially includes a neurostimulator adapted to generate pulse signals for electrical neurostimulation and at least one electrode inserted into a nerve site in need of treatment and through which the neurostimulation signals are applied to the nerve site (see FIG. 1). The neurostimulation electrode of the DBS device exemplified in FIG. 1 penetrates the cranium but it is to be understood that the neurostimulation electrode may also be inserted or implanted into any specific nerve site of the spinal cord, the peripheral nervous system or the brain. For example, a bio-implantable electrode of an SCS device may be inserted so as to penetrate the greater pectoral muscle, abdomen or buttock of a patient. In the neurostimulation-based bio-implantable device, the at least one electrode is usually connected to a long lead, as shown in FIG. 1. The lead is responsible for the electrical connection between the electrode and the neurostimulator. The electrode of the device is often inserted into the subcutaneous tissue layer of the patient. In many practical cases, however, the nerve coming into contact with the electrode is positioned deeper in the body. Thus, a connector is provided to connect the neurostimulator to the lead. In many cases, the neurostimulator and the connector are positioned outside the body.
Such an implantable or insertable electrode is used for neurostimulation but should not be reduced in size below a predetermined limit in order to effectively conduct electricity. Accordingly, the electrode cannot be inserted into the body without a relatively extensive surgical incision. For example, DBS treatment requires an extensive incision of the scalp and cranium of a patient. This incision should be made under general anesthesia and causes great inconvenience for the patient.
Highly elastic metals and alloys, such as gold, stainless steel, tungsten, and platinum-iridium alloys, are currently used to produce electrodes for neurostimulation but they are not satisfactory in bioaffinity. When such a highly elastic metal or alloy is used as an electrode material, it tends to react with body fluids. This reaction causes the corrosion of the electrode material in the body, which leads to the limited service life of the electrode. Also, the patient may suffer from pain and inflammation due to the corroded electrode.
Due to its relatively large size, the electrode delivers stimuli to a wide range of sites as well as a target site in the cerebral cortex and should apply strong stimuli to achieve a desired level of stimulation. Further, the production of the electrode requires the construction of a mold and process variations depending on the size and shape of the electrode, which are rather troublesome problems.
Moreover, a combination of neurostimulation therapy and diagnosis by magnetic resonance imaging (MRI) is being increasingly used to observe the therapeutic effect of neurostimulation. MRI is a noninvasive diagnostic tool that provides high resolution 3-dimensional images. However, patients are exposed to a rather strong electromagnetic field during MRI. The intensity of the electromagnetic field increases with increasing resolution of the MRI system. The MRI system emits a static magnetic field, a gradient magnetic field, and a radio-frequency magnetic field, which is generated from the transmitter of the scanner. That is, the MRI system emits a total of three magnetic field components. The static magnetic field has an intensity of about 0.2 to about 3.0 Tesla (T). 3.0 T corresponds to about 60,000 times greater than the earth's magnetic field. The intensity of the gradient magnetic field varies with time. 0 to 5 kHz can produce a gradient magnetic field of 40 mT/m. The radio frequency magnetic field is large in scale and can output a maximum energy of 20,000 W (corresponding to 20 times or more that of a toaster) with 64 MHz at a static magnetic field of 1.5 T. The magnetic fields of the MRI system adversely affect a neurostimulation device. For example, the static magnetic field applies a force to the neurostimulation device placed in the scanner of the MRI system. As a result, the neurostimulation device may be stressed. The radio-frequency magnetic field heats the metal parts of the neurostimulation device. Further, the time-dependent gradient magnetic field gives rise to an induced current, causing damage to the neurostimulation device and imaging disturbances. The most serious negative effect of the magnetic fields is that the lead of the neurostimulation device may be overheated by the radio-frequency magnetic field. Some research results reveal that the temperature of the lead is raised to 25° C. or above. The negative effects of the magnetic field of MRI systems on neurostimulation devices can be found, for example, in Rezai et al., Journal of Magnetic Resonance Imaging, Vol. 15(2002), pp. 241-250.
There is a need in the art for electrode materials that can be safely operated in the magnetic fields of an MRI system, have excellent mechanical properties, are sufficiently thin, and can replace metal materials, but the need is still not met.


Patients having diminished circulation in the cerebral vasculature as a result of cardiac arrest or from other causes are treated by flowing an oxygenated medium through an arterial access site into the cerebral vasculature and collecting the medium through an access site in the venous site of the cerebral vasculature. In addition to oxygenation, the recirculating blood may also be cooled to hypothermically treat and preserve brain tissue. Isolation and cooling of cerebral vasculature in patients undergoing aortic and other procedures is achieved by internally occluding at least the right common carotid artery above the aortic arch. Blood or other oxygenated medium is perfused through the occluded common carotid artery(ies) and into the arterial cerebral vasculature. Usually, oxygen depleted blood or other medium leaving the cerebral vasculature is collected, oxygenated, and cooled in an extracorporeal circuit so that it may be returned to the patient.

The present invention relates generally to medical devices and methods. More particularly, the present invention relates generally to methods, systems, and kits for perfusing and optionally cooling the cerebral vasculature of a patient with oxygenated blood or other media.
Cerebral ischemia, i.e., reduction or cessation of blood flow to the cerebral tissue, can be characterized as either focal or global. Focal cerebral ischemia refers to reduced perfusion to the cerebral tissue resulting from a partial or complete occlusion in the intracranial or extracranial cerebral arteries, e.g., stroke, subarachnoid hemorrhage spasms, iatrogenic vasospasm. Global cerebral ischemia refers to reduced perfusion to the cerebral tissue resulting from systemic circulatory failure caused by, e.g., cardiac arrest, shock, circulatory arrest, and septicemia.
Cardiac arrest is a major contributor to global cerebral ischemia. Cardiac arrest refers to cessation or significant reduction of a patient""s cardiac output and effective circulation to vital organs, most importantly the brain. Cardiac arrest can result from a number of causes, such as electrical dysfunction, mechanical failure, circulatory shock, or an abnormality in ventilation. Within minutes of blood flow cessation, tissue becomes ischemic (oxygen deprived), particularly in the heart and brain. Brain tissue is perhaps most immediately at risk, with severe, irreversible damage occurring minutes after the initial cardiac arrest. Patients in cardiac or circulatory arrest are usually treated by a combination of forced ventilation of the lungs and forced compression of the heart. Most commonly, cardiopulmonary resuscitation (CPR) is applied to the patient, with manual chest compression and mouth-to-mouth resuscitation. Advanced cardiac support (ACS) may also be provided in the form of drugs, defibrillation, and other techniques. Less commonly, open chest massage of the heart may be performed, particularly in a hospital setting where skilled surgeons may be present. Open chest heart massage is probably the most effective technique at resuscitating a patient and avoiding ischemic brain damage, but the technique is quite invasive and not available in most emergency situations.
CPR and other techniques which are directed at mechanical heart compression and lung ventilation do not usually provide adequate brain oxygenation. In addition, vasoconstrictors, e.g., epinephrine, administered during CPR are often either ineffective or given in dosages too high to produce systemic blood pressure required for cerebral perfusion. In the best cases, conventional cardiac resuscitation techniques will provide no more than 1 l/min of total blood circulation (with only about 200 ml/min passing through the cerebral vasculature) and no more than 5 to 15 mmHg of blood pressure. Normal circulation and blood pressure are 5 l/min and 80 to 100 mmHg, respectively, with about 1 l/min passing through the cerebral vasculature. Such flows are usually not adequate at normothermia. Even when CPR techniques are applied within the first several minutes of a cardiac arrest, the percentage of patients who survive without significant brain damage is very low. Significantly, most patients suffering from cardiac arrest die because of cerebral hypoperfusion.
Recognizing such problems, alternative techniques for treating patients in cardiac arrest have been proposed. Of particular interest to the present invention, the emergency use of cardiopulmonary bypass machines for supporting and cooling systemic circulation has been proposed. Generally, access is provided with a pair of catheters, where one of the catheters may be balloon-tipped to partition the circulation and permit the desired bypass. While such systems are theoretically effective, they do not isolate the cerebral vasculature and do not necessarily provide sufficient oxygenation of the brain. Moreover, the need to deploy intravascular catheters is time consuming and must be performed by a highly skilled and trained personnel.
Surgical procedures on the aorta are required for the treatment of a number of conditions, such as aortic aneurysms, occlusional diseases, aortic dissection, and the like. Exemplary procedures include conventional aortic aneurysm repair and grafting, endarterectomy for the treatment of aortic atheroma, stenting for the treatment of aortic atheroma or dissection, and the like. Such procedures frequently require that the aorta be surgically opened to permit reconstruction or other surgical modification. Surgically accessing and opening the aorta will usually further require that the patient""s circulation be arrested, i.e., blood flow through the aorta cannot be accommodated while the aorta is being surgically accessed. Cessation of systemic circulation places a patient at great risk, particularly in the cerebral vasculature where ischemia can rapidly lead to irreversible brain damage.
A number of techniques have been proposed to at least partially protect a patient having arrested circulation during a variety of aortic procedures. It will be appreciated that conventional cardiopulmonary bypass (CABG) techniques will generally not be useful when the aorta does not remain in tact. Thus, various alternative protective protocols have been proposed.
xe2x80x9cRetrograde aortic perfusion (RAP) can be used when a procedure is being performed on the aorta between the heart and the aortic arch. The aorta is clamped beneath the aortic arch and retrograde aortic perfusion established, typically via femoral access. Advantageously, such retrograde perfusion can continue throughout the procedure since the operative site within the aorta is isolated by the clamp. RAP, however, is disadvantageous in a number of respects. In particular, retrograde perfusion often results in significant cerebral embolization from dislodgment of atheromatous material in the descending aorta and aortic arch. Such risk, as well as the limited region of the aorta that can be operated on, makes RAP less than ideal. Moreover, RAP is not useful for procedures distal or proximal to the isolated region of the aorta and is useful only at the beginning of procedures performed within the isolated aortic regionxe2x80x9d.
Another approach for protecting the brain during aortic arch procedures is referred to as hypothermic circulatory arrest (HCA). HCA relies on inducing marked hypothermia in the entire body prior to stopping blood circulation altogether. Circulation remains stopped during the entire aortic procedure, thus placing the patient at significant risk of ischemia (despite the hypothermia). The patient is at further risk because the whole body has been cooled, thus increasing the duration of the surgery to accommodate the time needed to return to normal body temperature. HCA has also been associated with systemic coagulopathy (impaired coagulation) in a significant number of patients. Coagulopathy can require blood and plasma transfusion, both of which have been associated with the risk of viral infection. Aortic surgery performed with HCA has a very high morbidity, typically about 20%.
In order to retain some cerebral circulation during the time the aortic arch is accessed, HCA may be combined with retrograde cerebral venous perfusion (RCP). A catheter is placed in the superior vena cava and oxygenated blood introduced. Flow is established in a retrograde direction up the vena cava into the brachial and jugular veins. Unfortunately, very little of the oxygenated blood will reach the cerebral vessels for a number of reasons. For example, as much as 85% of the blood will enter the brachial veins and go to the arms with as little as 205 of the blood entering the brain. Moreover, the jugular venous valves may inhibit the blood from reaching the cerebral vessels. Blood that does reach the cerebral veins immediately flows outwardly through the extensive collateral circulation without perfusing the brain tissue. The amount of blood that returns to the aorta from the carotid arteries represents no more than about 5% of the total blood that is initially introduced to the superior vena cava. Additionally, as observed by the inventor herein, such retrograde perfusion results in a build up of the cerebral pressure that further inhibits any blood inflow. For these reasons, HCA, even when combined with RCP, falls far short of providing adequate protection for the patient during procedures performed on the aorta.
Another procedure for perfusing the brain during aortic procedures has recently been proposed. The procedure is referred to as selective antegrade cerebral perfusion (SCP) and relies on introducing a catheter through the aorta into a carotid artery in order to perfuse the cerebral vasculature. Introduction of the catheter can dislodge atheromatous material which will often be present at the take-off from the aorta and which may thus cause cerebral embolization. Furthermore, in order to prevent air from entering the cerebral vessels, the carotid artery and all other cerebral arteries must be externally clamped or snared, which can cause atheromatous embolization. While the procedure can more effectively maintain cerebral perfusion than HCP, alone or combined with RCP, the risk of both air and atheromatous embolization more than outweighs any associated benefits from enhanced perfusion.
It would therefore be desirable to provide improved methods and systems for perfusing the cerebral vasculature of a patient suffering from either focal or global cerebral ischemia with oxygenated blood or other media in patients. Such methods and systems should be suitable for rapid deployment, be capable of use outside of a hospital environment, and should be capable of being performed with less skilled personnel than comparable catheter-based systems. Preferably, such systems may be deployed via direct percutaneous cannulation of the patient vasculature. In addition, the method and systems of the present invention should be suitable for use with patients undergoing cardiac and vascular procedures where it is desirable to perfuse and/or isolate the cerebral vasculature. At least some of these objectives will be met by the invention of the present application.
For these reasons, it would be desirable to provide improved methods, systems, and kits for protecting the brain and cerebral vasculature during the performance of surgical procedures on the aorta. In particular, it would be desirable to provide for cerebral perfusion which is both antegrade and continuous throughout performance of the aortic procedure and which would enable profound cerebral hypothermia without systemic hypothermia. It would be further desirable to provide for improved isolation of the cerebral vasculature, still more preferably with minimum and ideally no external clamping. It would be still further desirable to minimize the risk of air and/or atheromatous embolization in the cerebral vasculature or elsewhere as a result of the aortic procedure. Such methods, systems, and kits should be compatible with reduced and/or localized hypothermia, particularly hypothermia directed specifically at the cerebral vasculature. In addition, cerebral isolation, perfusion and cooling should be compatible with systems and methods for perfusing non-cerebral portions of the patient""s vasculature. At least some of these objectives will be met by the invention described hereinafter.
Selective cerebral perfusion (SCP) procedures are described in Kazui et al. (1992) Ann. Thorac. Surg. 53:109-114; Mohri et al. (1993) Ann. Thorac. Surg. 56:1493-1496; and Tanaka et al. (1995) Ann. Thorac. Surg. 59:651-657. Advanced cardiac life support techniques are discussed and compared in Tucker et al. (1995) Clin. Cardiol. 18:497-504. Emergency cardiopulmonary bypass using access needles introduced via a cut-down procedure is described in Litzie, U.S. Pat. No. 4,540,399. Emergency cardiopulmonary bypass using catheter-based access is described in Safar et al., U.S. Pat. No. 5,383,854; Safar et al., U.S. Pat. No. 5,308,320; Buckberg et al., U.S. Pat. No. 5,011,469; and Safar (1993) Ann. Emerg. Med. 22:58/324-83/349. A cardiopulmonary bypass system with cooling having a balloon tipped cannula for accessing the inferior vena cava and an anastomotically attached catheter for accessing the femoral artery is described in Sausse, U.S. Pat. No. 3,881,483. Cerebral infusion with cooled and/or preservative media is described in Klatz et al., U.S. Pat. Nos. 5,149,321; 5,234,405; 5,395,314; 5,584,804; and 5,653,685. Aortic perfusion with balloon catheters is described in Paradis, U.S. Pat. No. 5,334,142; Manning, U.S. Pat. No. 5,437,633; and Manning et al. (1992) Ann. Emerg. Med. 21:28-35. Coronary and/or cerebral retroperfusion is described in Pizon et al., U.S. Pat. No. 4,459,977; Jackson, U.S. Pat. No. 4,850,969; Jackson, U.S. Pat. No. 4,917,667; and Grady, U.S. Pat. No. 5,084,011. Other relevant patents include Barkalow et al., U.S. Pat. No. 4,198,963; Ward et al., U.S. Pat. No. 5,531,776; and Meyer, III, U.S. Pat. No. 5,626,143.
According to the present invention, methods, systems, and kits are provided for perfusing an oxygenated medium, usually autologous blood, through the cerebral vasculature of patients suffering from global ischemia caused by, e.g., cardiac arrest, shock, circulatory arrest, and septicemia; focal ischemia caused by stroke, subarachnoid hemorrhage spasms, iatrogenic vasospasm; or, cerebral edema, e.g., head trauma. The method, systems, and kits are useful not only in providing selective isolated cerebral perfusion during all conditions of cerebral ischemia, but also in reducing the dosage of vasoconstrictors required to achieve a desired perfusion pressure.
Optionally, in addition to improving cerebral perfuision, the methods of the present invention may combine or otherwise rely on cooling of the patient""s head and cerebral vasculature in treatment of both global and focal cerebral ischemia to inhibit tissue damage resulting from lack or limitation of cerebral blood circulation. Usually, the oxygenated medium which is circulated as part of the methods of the present invention will be cooled in order to cool the brain tissue and reduce the risk of ischemic damage. Further optionally, the patient""s head may be cooled even prior to initiating perfusion of externally oxygenated, optionally cooled blood. In some instances, the cooled blood can be used to externally cool the patient""s head during the treatment protocol, e.g., by passing the blood through a helmet or other structure which permits the blood to selectively cool the head. This selective isolated cooling of the head and/or cerebral vasculature is desirable and preferred over systemic cooling, since coagulopathy, poor healing, cardiac arrhythmia and cardiac arrest can ensue as a result of systemic cooling.
The methods of the present invention for improving cerebral perfusion comprise accessing at least one extracranial vein, such as the internal jugular vein, the femoral vein, and/or the subelavian vein, and accessing at least one artery which feeds the cerebral vasculature through incisions on any extracranial artery, such as the common carotid artery, the internal carotid artery, the femoral artery, or the subclavian artery. In providing both selective isolated perfusion and cooling of the cerebral tissue, the methods comprise assessing at least one thing at location(s) which drain at least a portion of the cerebral vasculature, such as the internal jugular vein and/or external jugular vein, and assessing at least one artery which feeds the cerebral vasculature through incisions on any extracranial artery, such as the common carotid artery, the internal carotid artery, the femoral artery, or the subdlavian artery. In emergency cases, access will usually be provided by a percutaneous needle stick as described in more detail below. When performed in conjunction with aortic arch or other cardiac surgery, in contrast, the access will usually be provided via surgical exposure of the target vein(s) and artery(ies). An oxygenated medium is flowed from the arterial access location through the cerebral vasculature to the venous access location in order to perfuse the cerebral vasculature with the oxygenated medium. The vein(s) and artery(ies) are chosen to provide access to at least a major portion of the blood circulation through the cerebral vasculature. Preferably, the vein(s) and artery(ies) will also be directly accessible via a percutaneously inserted needle or other cannula for emergency performance of the procedures in the field. Suitable veins include the internal and/or external jugular vein, the superior vena cava, and the like. Suitable arteries include the common carotid arteries, the external and internal carotid artery, and the like. The particular access sites in each of the artery and vein will be selected based primarily on percutaneous accessibility. Preferred venous access sites lie within the internal jugular vein and preferred venous access sites lie within the common carotid artery.
After access is established, typically using percutaneously introduced needles, cannulas, or other conduits, a flow of oxygenated medium is initiated at a rate sufficient to provide oxygen to the brain tissue. The rate will depend on the amount of oxygen being carried by the oxygenated medium, typically being in the range from 0.1 l/min to 1.5 l/min, typically from 0.2 l/min to 1 l/min. For oxygenated autologous blood, the rate will typically be in the range from 0.2 l/min to 1 l/min. In some instances, in order to inhibit possible reperfusion injury, it will be desirable to initiate the flow rate of oxygenated medium at a relatively low rate and subsequently increase the flow rate to a final rate within the ranges set forth above. Usually, the final flow will be maintained at a steady rate, but it will also be possible to initiate a pulsatile or other nonsteady flow rate.
In order to enhance the efficiency of oxygenated medium delivered to the cerebral vasculature, it will usually be desirable to at least partly occlude the access blood vessel(s) near the access sites in order to prevent flow away from the cerebral vasculature. That is, at the venous access site(s), the vein will be occluded in order to inhibit flow caudal to the access location. At the arterial access site(s), the artery will be occluded to inhibit flow into the aorta. As described in more detail in connection with the systems of the present invention, such occlusion will typically be provided by inflatable occluding balloons on the access needles, cannulas, or other conduits.
In the preferred methods of the present invention, the oxygenated medium will consist essentially of blood, usually patient autologous blood, and the blood will be recirculated from the venous access location to the arterial access location using a pump. In addition to the primary antegrade flow, some flow may occur in a retrograde direction to the contralateral hemisphere and/or posterior territories as well. The blood will be extracorporeally oxygenated and optionally cooled, typically to a temperature in the range from 7xc2x0 C. to 35xc2x0 C. External pumping, oxygenation, and cooling can be provided by systems of a type used for cardiopulmonary bypass procedures.
Alternatively, the oxygenated medium may comprise a synthetic oxygen carrier, such as a perfluorocarbon, or other synthetic blood substitute material. In some instances, such synthetic oxygen carriers may be combined with patient or non-autologous blood. The synthetic oxygen carriers may be preoxygenated and flowed through the cerebral vasculature only once. In such cases, a large reservoir of the synthetic oxygen carrier may be provided, passed through the cerebral vasculature, and collected as it passes out of the venous access site. Alternatively, the synthetic oxygen medium, optionally combined with blood, may be extracorporally recirculated and oxygenated as described above for autologous blood.
In all cases, the oxygenated medium may have other biologically active agents combined therewith. For example, drugs and biological agents which inhibit deterioration of brain tissue in cases of limited oxygen supply may be utilized. Such compositions include NMDA receptor-inhibitors, calcium-channel blockers, anticoagulants, glutamate inhibitors, free-radical inhibitors, vasodilators, and the like.
The present invention still further provides improved methods for selective isolated cerebral perfusion in patients with global or focal ischemia. Such improved methods comprise isolating at least a portion of the patient""s cerebral vasculature from the remainder of patient circulation, typically by partitioning using occlusion balloons as described in more detail hereinafter. Patient blood is oxygenated and recirculated through the isolated vasculature in order to inhibit ischemia and resulting damage to brain tissue while steps are taken to treat the cardiac arrest.
In yet another aspect of the method of the present invention, improved antegrade cerebral perfusion with an oxygenated medium comprises introducing the oxygenated medium, typically autologous blood, to a carotid artery to establish antegrade flow into the cerebral vasculature. The oxygenated medium, after it has passed through the cerebral vasculature, is collected through a jugular vein. Such improved methods may be used with both once-through perfusion using a synthetic oxygen carrier and/or heterologous oxygenated blood. More usually, such improved methods will be used with extracorporeal recirculation and oxygenation of autologous blood.
Systems according to the present invention for recirculating and oxygenating blood in the cerebral vasculature of a patient comprise a venous cannula, an arterial cannula, a pump, and an oxygenator. The venous cannula typically has a lumen diameter in the range from 2 mm to 4 mm and includes a distal occlusion balloon, wherein the cannula and balloon are sized to access and occlude a vein which drains the cerebral vasculature, typically a jugular vein. The arterial cannula typically has a lumen diameter in the range from 2 mm to 4 mm and also has a distal occlusion balloon, and the cannula and balloon are sized to access and occlude an artery which feeds the cerebral vascular, typically the common carotid artery. The pump may be connected between the venous cannula and the arterial cannula to circulate blood from the venous cannula to the arterial cannula, typically at a flow rate in the ranges set forth above. The oxygenator processes the externally circulating blood to provide a desired degree of oxygenation, also within the ranges set forth above.
The present invention still further provides kits including a venous cannula sized to access a vein which drains the cerebral vasculature and an arterial cannula sized to access an artery which feeds the cerebral vasculature. Such kits will further include instructions for use according to any of the methods set forth above. Additionally, the kits may comprise a package for holding all or a portion of the kit components, typically in a sterile condition. Typical packages include trays, pouches, boxes, tubes, and the like. Preferably, the cannulas will each have an occlusion balloon sized to occlude the respective blood vessel lumen into which they are placed. Other optional kit components include oxygenated medium, drugs to be delivered via the flowing blood or other oxygenated medium, catheters for connecting the cannulas to an extracorporeal recirculation/oxygenation cooling system, cassettes for use with such extracorporeal recirculation systems, cooling elements, thermometers, pressure transducers, and the like.
In still other embodiments, methods, systems, and kits are provided for isolating and perfusing the cerebral vasculature, usually to facilitate access to a patient""s aorta, during performance of a diagnostic or interventional procedure on the aorta, more usually during performance of an open surgical interventional procedure on the aorta, such as repair of an aortic aneurysm, dissections, reconstruction of the aorta, endarterectomy, or the like. The heart will usually be arrested during open surgical procedures where the aorta is opened and procedure is performed within the lumen of the aorta. In some instances, however, the heart may remain beating while the procedure is performed intravascularly, i.e. through using catheters and other instruments introduced from the peripheral vasculature and into the aorta. The methods of the present invention will serve primarily to isolate the cerebral vasculature and prevent gaseous and atheromatous emboli from entering the cerebral vasculature while the vasculature is perfused with an oxygenated medium.
Methods according to the present invention comprise internally occluding blood flow to the arterial cerebral vasculature at a location(s) above the aortic arch. At a minimum, blood flow to the right cerebral vasculature will be internally occluded. Preferably, blood flow to both the right and left cerebral vasculature is internally occluded. Such internal occlusion is usually accomplished using an expansible occluder or partial occluder with central lumen, such as an inflatable balloon positioned at the distal end of a catheter, cannula, or other access device. The access device further provides for perfusion of an oxygenated medium into the occluded artery distal to the point of occlusion, e.g., the device may have a lumen that delivers the medium at a suitable positive pressure.
Occlusion of blood flow from the aortic arch and perfusion of oxygenated medium to the arterial cerebral vasculature may be accomplished in a number of ways, e.g., by occluding the right common carotid artery or by occluding an upstream portion of the brachiocephalic artery which-feeds the right carotid artery. In both cases, the oxygenated medium can be perfused distally of the balloon or other occluding device so that it flows up through the right common carotid artery into the cerebral vasculature. When occluding the brachiocephalic artery and perfusing the oxygenated medium upstream of the right common carotid artery, it may be desirable to at least partially inhibit blood flow through the right subdlavian artery, e.g. using another occluding balloon or using an externally applied tourniquet on the arm. Inhibiting the loss of oxygenated medium to the arm helps redirect the medium to the cerebral arterial vasculature through both the right common carotid artery as well as the right vertebral artery, assuming that the subdlavian artery is occluded at a point distal to the vertebral arterial branch. Other, more complex occlusion patterns could also be employed, although not necessarily being preferred.
Occlusion of blood flow from the aortic arch and perfusion of oxygenated medium to the left arterial cerebral vasculature may be effected within the left common carotid artery, the left subdlavian artery, and/or the left vertebral artery. When blood or other oxygenated medium is introduced into the left subdlavian artery, it may further be desirable to inhibit blood flow into the arm, e.g., by internally or externally occluding the left subdlavian artery at a point that prevents such blood flow.
In a presently preferred procedure, occluding balloons will be positioned within the brachiocephalic artery, the left common carotid artery, and the left subdlavian artery. Both the right subdlavian artery and the left subdlavian artery will be blocked, preferably with external tourniquets on the arms. Blood or other oxygenated medium will then be perfused into the arterial cerebral vasculature to points immediately upstream of each of the occluding balloons, preferably using lumens or other infusion components incorporated within the occluding devices themselves. Inhibition of blood flow down into the arms is beneficial since it redirects the blood or other oxygenated medium back into the cerebral arterial vasculature. While this approach may be optimal in many ways, the present invention can be carried out in other ways as well. Most simply, internal occlusion of the right brachiocephalic artery and perfusion of oxygenated medium distal to the point of occlusion may be sufficient in some cases by itself.
In many cases, it will be desirable to occlude the arteries at a point as close to the aortic arch as possible. In particular, this is true of the brachiocephalic artery, the left carotid artery, and the left subdlavian artery which branch directly from the aortic arch. Occlusion close to the aortic arch (i.e., immediately above the branch or within 3 cm thereof) is of benefit primarily because it enables the surgeon to access the artery and initiate the occlusion with minimal aortic dissection toward the neck. In other cases, of course, it will be possible to access any one of the brachiocephalic artery at a point close to the aortic arch and to intravascularly advance an occluding balloon or other devise to a desired point of occlusion. In some instances, it may even be desirable to deliver and position devices carrying multiple occluding balloons and/or lumens for delivering oxygenated medium to the cerebral arterial vasculature.
Access to the occlusion site and the target artery may be obtained in a variety of ways. For example, the target artery may be surgically exposed when the chest and neck are opened as part of a procedure being performed on the aortic arch. In such cases, small incisions can be made directly into the wall of the target artery to permit introduction of the occluder. Alternatively, in procedures that are performed away from the aortic arch and/or where it is not desired to surgically open the patient above the target sites within the arteries, the target sites can be accessed by conventional cut-down procedure or a needle-based procedure, such as the Seldinger technique. As yet another alternative, the arterial vasculature can be accessed at a LL point remote from the desired point of occlusion, e.g. in the femoral artery or in an artery of the arm, such as the axillary or brachial artery. The balloon or other occluding member on the catheter may then be intravascularly advanced from the access location to the desired point of occlusion in a conventional manner, e.g. over a guidewire under fluoroscopic observation. An approach to a desired occlusion point within the brachiocephalic artery and/or the right common carotid artery from an artery in the arm may be preferred since no catheter would be present in the aortic arch itself.
The oxygenated medium will usually be blood, more usually being autologous blood obtained from the patient being treated. In the most usual cases, patient blood will be recirculated through a conventional blood pump and oxygenator so that the patient may be continuously supplied with oxygen in the perfused cerebral vasculature. The blood or other oxygenated medium will also be cooled in order to induce selective hypothermia within the cerebral vasculature. A preferred hypothermic temperature for the brain will be in the range from 7xc2x0 C. to 35xc2x0 C., more preferably from 9xc2x0 C. to 30xc2x0 C. The actual temperature that is maintained will depend both on the temperature and the flow rate of the oxygenated medium, with higher flow rates generally requiring less cooling to achieve the target hypothermic temperature. Useful flow rates for the oxygenated medium will be in the range from 300 ml/minutes to 1500 ml/minutes, typically from 400 ml/minute to 1000 ml/minute without hypothermia, and from 80 ml/minute to 600 ml/minute, typically from 150 ml/minute to 400 ml/minute with hypothermia induced in the patient. Generally, the patient requires progressively less oxygen with increased hypothermia, allowing the flow rates of oxygenated cooled medium to be decreased. A sufficient flow of the oxygenated medium should be maintained, however, in order to maintain the desired level of hypothermia. Suitable temperatures will be in the range from 8xc2x0 C. to 35xc2x0 C., typically from 14xc2x0 C. to 30xc2x0 C. It will be appreciated, of course, that the values of temperature, flow rate, and degree of oxygenation will be quite interdependent in that particular optimum values might be selected for individual patients and/or for different procedures.
The methods of the present invention will-find their greatest use in open and thoracoscopic surgical procedures where the aorta is exposed and surgically opened to permit performance of the desired procedure. In such cases, the heart will be arrested and the perfusion of the oxygenated medium will be relied on to achieve adequate oxygenation of the brain tissue and to avoid deleterious ischemia. Generally, the flow rates and temperatures set forth above will be sufficient to both achieve adequate perfusion and avoid ischemia. After the open procedure is completed, and the aorta is surgically closed, heart function may be reestablished. In order to avoid the release of emboli from the aorta into the cerebral vasculature, occlusion of carotid artery(ies) will be maintained for a minimum amount of time after heart function has been reestablished, typically for at least about 2 minutes, preferably for at least about 5 minutes, in order to permit atheromatous debris and air to be cleared from the aorta and away from the brain.
Occlusion of the selected arteries with the expansible occluder may be achieved in a variety of ways. Usually, in open surgical procedures, the outside of the target artery(ies) will be surgically exposed, permitting surgical incisions through the arterial wall(s). The expansible occluder may then be introduced through the incision, expanded, and perfusion of oxygenated medium established through the occluder. Alternatively, the expandable occluders may be introduced percutaneously through the patient""s neck and to the selected artery(ies) using conventional access techniques, such as the Seldinger technique. The expansible occluders will typically but not necessarily include catheters, cannulas, or other devices that permit the perfusion of the oxygenated medium through the expansible member and into the carotid artery for perfusion of the cerebral vasculature. It will also be possible to utilize separate devices for occlusion and for the perfusion of oxygenated medium. Fore example, it would be possible to employ an external clamp on the target artery and to utilize a separate needle or other cannula for infusion the oxygenated medium upstream of the clamp. The use of clamps, however, is generally not preferred since they can cause the release of significant amounts of atheromatous debris when released. It would also be possible to employ separate occluder(s) and infusion needles/cannulas, where the points of occlusion and infusion of oxygenated medium could be close together or spaced-apart. Also, as mentioned above, it will be possible to employ devices with more than one occlusion balloons and/or more than one infusion lumens in order to occlude and/or infuse oxygenated medium to different points in the vasculature from a single incision site.
As an alternative to access at points in the arterial vasculature above the aortic arch, the occlusion and perfusion devices may be introduced intravascularly through sites remote from the aortic arch. Most commonly, intravascular catheters may be introduced by conventional techniques through the femoral arteries and advanced to the target cerebral arteries using conventional techniques. Such access routes, will necessarily involve passing the catheters through the aortic arch itself. Thus, in many instances, it will be undesirable to use such intravascular techniques since they will lie within the regions where the procedure is being performed. Intravascular access could also be achieved in a retrograde manner through the axillary and brachial arteries as discussed above.
While it will be possible to perfuse a cold, oxygenated medium without collecting and recycling the medium, it will usually be desirable to establish a continuous extracorporeal flow circuit for filtering, oxygenating, and returning patient blood or other oxygenated medium to the patient. The oxygenated medium perfused into the arterial cerebral vasculature will generally flow through the anterior and posterior regions of the brain and into the venous system of the brain. From the venous system, the oxygenated medium will flow outwardly from the brain, primarily from the jugular veins. Thus, it will be convenient to collect the oxygenated medium from the brain from at least one of the right and left internal jugular veins, preferably from both internal jugular veins, or from the superior vena cava into which the-jugular veins drain. This blood can then be returned to the extracorporeal blood pump, oxygenated, and cooled before return to the patient""s arterial cerebral vasculature. Additionally, a very small portion of the blood or other oxygenated medium perfused into the brain through the cerebral arteries may leak back into the aortic arch through the left vertebral artery if the left subdlavian artery is not occluded. This leakage, typically in an amount from 5 ml/minute to 25 ml/minute, can be suctioned or otherwise collected by the surgeon and returned to the extracorporeal circulation system.
The brain and cerebral vasculature are at greatest risk from embolization and ischemia during the performance of aortic procedures that require arresting of the heart. Other portions and tissues within the body, however, are also at significant risk and in some cases it may be desirable to establish a perfusion of oxygenated medium through the noncerebral vasculature, in particular the vasculature in the lower portion of the patient""s body. For example, oxygenated blood or other medium can be introduced into the aorta below the aortic arch, where the aortic arch is isolated using an expansible occluder or other conventional occlusion device. The oxygenated medium will thus flow to the lower portion of the patient""s body where it will collect in the venous system and be returned towards the patient""s heart through the inferior vena cava. By occluding the inferior vena cava, again typically using an expansible occluder, the blood or other oxygenated medium may be collected and returned to an extracorporeal oxygenation, pumping, and optional cooling circuit.
The present invention still further provides kits including one or more expansible occluders adapted to occlude selected artery(ies) as described above. Such kits will further include instructions for use according to any of the methods set forth above. Additionally, the kit may comprise a package for holding all or a portion of the kit components, typically in a sterile condition. Typical packages include trays, pouches, boxes, tubes, and the like. Preferably, the cannulas will each have an occlusion balloon sized to occlude the respective blood vessel lumen into which they are placed. Other optional kit components include oxygenated medium, drugs to be delivered via the flowing blood or other oxygenated medium, catheters for connecting the cannulas to an extracorporeal recirculation/oxygenation cooling system, cassettes for use with such extracorporeal recirculation systems, cooling elements, thermometers, pressure transducers, and the like.

Method and system for selective or isolated integrate cerebral perfusion and cooling


A second-harmonic generation nonlinear frequency converter includes a nonlinear optical crystal. The nonlinear optical crystal includes a plurality of sections. The sections connect to each other in sequence, and each section has a phase different from others. Each of the phases includes a positive domain and a negative domain. Each of the sections includes a plurality of quasi-phase-matching structures. The quasi-phase-matching structures connect to each other in sequence and have the same phase in one section.

1. Field of Invention
The embodiment of the present invention relates generally to a converter and, more particularly, to a second-harmonic generation nonlinear frequency converter.
2. Description of Related Art
Recent years, demands for more convenient, robust and economical goods continue to rise with the advancement and progress of industry and social-economic. As such, products with more economic values are being developed to meet these and other needs.
In the mini-laser projection technology developed by CORININ and Microvision, the green laser is a wave-guide type and an x-cut PPMgLN with a length of 12 mm. In view of its technical indicator, a 10 ns, 1060 nm DBR-LD is used as a pump of the microminiaturization module to provide a narrow-band fundamental wave source (Δλ=0.16 nm) for second-harmonic conversion.
In this pump structure, the operation temperature of the PPMgLN is strictly limited to 25±1° C. so that three groups of temperature control devices are provided to keep the temperature of the 1060 nm laser source and the optical lens in a constant value. The consumption of the power source of the laser module and the stability of the system are the main concerns for the latter. The solution to the foregoing problem is to remove the limitation of the operation temperature and the temperature environment of the pump of the PPMgLN green light second-harmonic crystal.
One of the solutions is the limitation of the length of the crystal, PPMgLN having the quasi-phase-matching structure is adopted, and the product value of the green light conversion temperature-crystal length of the PPMgLN is T·L=2.1° C.-cm. The crystal length needs to be limited to 0.5 mm to make the PPMgLN crystal have a 40° C. operation temperature bandwidth.
However, the one-way transmission conversion efficiency of the second-harmonic crystal is low when operating with short length crystal. The problem of low conversion efficiency can be solved by using the optical cavity and adopting a 1064 nm infrared light source with short pulse in the optical cavity to increase the second-harmonic conversion efficiency. Additional optical components are needed in the foregoing solution such as a space holographic grating VBG to limit the 808 nm pump source bandwidth and increase the generation efficiency of the 1064 nm laser of the Nd:VYO4. Because the optical cavity is needed, the cost enhances relatively.
In view of the above, the existing apparatus still has obvious inconvenience and defects and needs further improvement. In order to solve the above problems, those skilled in the art are trying hard to find a solution, but no applicable method is put forward. Therefore, it is an important subject and also a purpose in need of improvement that how to improve the low bandwidth of the operation temperature of the nonlinear optical crystal and keep the conversion efficiency of the nonlinear optical crystal without increasing of the cost.

Second-harmonic generation nonliner frenquency converter


Fluid processing apparatus comprising a vessel containing a hydrocyclone and defining an inlet chamber, the vessel having a vessel inlet arranged to feed fluid into the inlet chamber, being arranged to receive fluid from the vessel inlet and to pass the fluid to an inlet of the hydrocyclone. The inlet chamber includes coalescing means arranged to coalesce relatively small droplets contained in the fluid received at the vessel inlet into larger droplets before passing the fluid to the hydrocyclone inlet. The coalescing means having a substantially predetermined external shape which defines at least one elongate liner hole for receiving a respective hydrocyclone liner.

This invention relates to fluid processing apparatus comprising a vessel containing a hydrocyclone.
EP-A-0734751 discloses a cylonic separator having coalescing media placed around the cyclone liners and through which fluid to be separated is forced to flow prior to entering the cyclone liners. In one embodiment the coalescing means is mounted on sleeves which are directly mounted on the cyclone liners. The configuration of the coalescing means and cyclone liners in this sleeved embodiment removal or insertion of the cyclone liners independently of the coalescing means.
According to a first aspect of the invention, there is provided fluid processing apparatus comprising, a vessel containing a hydrocyclone and defining an inlet chamber, the vessel having a vessel inlet arranged to fluid into the inlet chamber, and the inlet chamber being arranged to receive fluid firm the vessel inlet and to pass the fluid to an inlet of the hydrocyclone, the inlet chamber including coalescing means arranged to coalesce relatively small droplets contained in fluid received at the vessel inlet into larger droplets before passing the fluid to the hydrocyclone inlet, the coalescing means having a substantially predetermined external shape which defines at least one elongate liner hole for receiving a respective hydrocyclone liner and which permits removal of the hydrocyclone liner without removing the coalescing means.
By arranging for the coalescing mean to have a substantially predetermined external shape, it is possible to fit the coalescing means to existing fluid processing apparatus. Futhermore by defining at least one elongate liner hole for receiving a respective hydrocyclone liner, the difficulties of the hydrocyclone liner becoming entangled with the coalescing media or causing disruption of the coalescing media when the liner is removed, are avoided. For example, in the preferred embodiment which includes a region of generally parallel fibres which extend generally parallel to the direction of fluid flow, without ensuring that the coalescing media defines an elongate liner hole, it has been found that the parallel fibres restrict entry of the hydrocyclone liners and also become disrupted when hydrocyclone liners are removed because they tend to stick to or snag on the external surface of the liners.
In one embodiment, the substantially predetermined external shape of the coalescing means is produced by the coalescing means including a cage assembly dimensioned to allow it to fit inside the hydrocyclone vessel inlet chamber. Grids may be provided at various points along the cage to allow different stages of coalescing media to be supported. Means may also be provided to segregate the coalescing media from the hydrocyclones to allow passage of the hydrocyclone through the media for ease of installation and removal. The cage assembly may also provide a baffle to divert incoming flow to one end of the hydrocyclone vessel inlet chamber causing a plug flow regime through the media prior to fluid entering the hydrocyclone.
In a second aspect, the invention provides a method of manufacturing fluid processing apparatus having a vessel containing a plurality of hydrocyclones and defining an inlet chamber, the vessel having a vessel inlet arranged to feed fluid into the inlet chamber, and the inlet chamber being arranged to receive fluid from the vessel inlet and to pass the fluid to the respective inlets of the hydrocyclones, comprising the steps of inserting a mass of coalescing media into the inlet chamber, the media having a substantially predetermined external shape defining at least one elongate liner hole for receiving a respective hydrocyclone liners and being arranged to coalesce relatively contained in fluid received at the vessel inlet into larger droplets before passing the fluid to the respect hydocyclone inlets and subsequently inserting at least one hydrocyclone liner into a respective liner hole.
In a third aspect, the invention provides a method of manufacturing fluid processing apparatus having a vessel containing a plurality of hydrocyclones and defining an inlet chamber, the vessel having a vessel inlet arranged to feed fluid into the inlet chamber, and the inlet chamber being arranged to receive fluid from the vessel inlet and to pass the fluid to the respective inlets of the hydrocyclones, the inlet chamber including coalescing means arranged to coalesce relatively small droplets contained in fluid received at the vessel inlet into larger drop before passing the fluid to the respective hydrocyclone inlets, comprising the step of locating an inlet arrangement in the inlet chamber, the inlet arrangement having an inlet baffle which divides the inlet chamber into an inner region which contains the hydroyclones and an outer region adjacent the interior surface of the vessel wall the vessel inlet being arranged to feed fluid into the outer region and the inner region containing a mass of fibrous coalescing medium whose fibres are attached at one end and which at least in use, are arranged generally parallel to the flow direction of fluid in the inner region.

Fluid processing for separating emulsions