A method and apparatus for activating a remote light source in synchronization with an indication provided from a camera. A transducer is coupled to the external electrical connector of a conventional camera in order to convert the electrical signals that are output from the camera into an alternative form (e.g., optical signals). A different transducer is coupled to the external electrical connector of a remote light source, such as a photographic strobe. The light source transducer receives the signal from the camera transducer and converts the signal back into one or more conventional electrical signals to activate the remote light source. A light source activation signal and a light source modulation signal are multiplexed onto a single communication channel. A first indication is provided on the communication channel to activate the remote light source (i.e., cause the light source to emit light). A second indication is preferably provided on the communication channel in response to signals generated by a photo-detector within the camera. The second indication causes the remote light source to modulate its emission of light. The multiplexing camera transducer and demultiplexing light source transducer may be housed within the camera and remote light source, respectively. A Slave remote light source, coupled to a Slave light source transducer is activated by detecting when either a Master remote light source or a local light source has been activated. An open end of an optical conductor that is coupled to a Slave light source transducer is directed in such a way as to be illuminated by the Master remote light source or local light source.

1. Field of the Invention
This invention relates to external lighting devices for use with still cameras, and more particularly to a method and apparatus for coupling a remote light source to a still camera and for activating and preferably modulating the remote light source.
2. Description of Related Art
Still cameras are frequently used with artificial light sources, such as flash or strobe units, in order to provide more or different light than is naturally available. In most amateur photography, the photographer uses a single strobe that is directly attached to a camera. However, there are many situations in which photographers use one or more strobes that are physically remote from the camera. Studio photographers frequently use several highpowered strobes positioned at remote locations with respect to the camera in order to provide a desired direction, color, and quality of light to the subject. Similar techniques are used by photographers who are photographing large or distant outdoor subjects. Furthermore, because of the light filtering qualities of water, it is customary to use remote strobes in underwater photography. Underwater strobes are almost universally sealed in a watertight enclosure that is separate and apart from the enclosure in which the associated camera is sealed. In all these situations, a communication link must be established between the camera and each associated strobe in order to synchronize the triggering of the strobe to the activation of the shutter of the associated camera.
Communication between a camera and remote strobe is commonly provided by a multi-conductor electrical cable having an electrical connector at each end. Such a cable is commonly referred to as a "SYNC" cord. FIG. 1 is an illustration of a conventional camera 101 and a strobe 102 connected by a conventional SYNC cord 107. One end of the SYNC cord 107 mates with an electrical connector 103 provided on the housing of the camera 101. The other end of the SYNC cord 107 mates with an electrical connector 105 provided on the housing of the strobe 102. Some prior art strobes are provided with a SYNC cord having only one connector at the distal end for connecting to the housing of a camera. The other end is fixed to the strobe (e.g., attached by solder).
In accordance with one prior art scheme for triggering a remote strobe, the SYNC cord 107 has two wires. The first wire conducts a SYNC signal. The second wire serves as a GROUND return path. The SYNC signal is commonly controlled using an "open collector" protocol. The open collector output for the SYNC signal is "pulled-up" by a resistor coupled to a voltage source. The SYNC signal is shorted to ground to trigger the strobe. This simple scheme allows a mechanical switch to trigger a strobe. The mechanical switch may be mechanically coupled to the shutter of the camera. This scheme also allows the low-cost analog signal processing in the strobe. Furthermore, this scheme allows a plurality of strobes to be connected in parallel and triggered at once. Still further, the propagation delay between initiation of the command to trigger the strobe and receipt of the command at the strobe which results from this scheme is very small (on the order of 3 to 4 microseconds).
One problem with the above described system is that while the camera 101 controls the time at which the strobe 102 is triggered, there is no control from the camera over the amount of light the strobe 102 generates. In the mid-1980's, a system was introduced for triggering remote strobes. In accordance with this new system, the strobe is turned off when the film plane has accumulated an appropriate amount of light (as determined by the type of film used and the settings on the camera). Typically, a photo-sensor (photo-integrator) built into the camera is focused on the film plane to determine the amount of light received. When sufficient light has been received on the film plane, a stop signal is sent from the camera to the strobe, causing the strobe to turn off. Such a system is commonly referred to as a TTL ("through the lens") exposure control system. TTL exposure control systems require a STOP wire in addition to the GROUND wire and SYNC wires discussed above. The STOP signal is transmitted by an open collector protocol similar to the protocol used with the SYNC signal. Use of an open collector STOP signal allows multiple strobes to be controlled by the same STOP signal. As noted above; such open collector control has relatively short propagation delay when the STOP wire is shorted to the GROUND wire. Using a third separate wire to communicate the STOP signal provides full backward compatibility with two wire "non-TTL" cameras. In addition, there are significant manufacturing economies which result from isolating the TIL exposure control functionality from the SYNC functionality, since the camera or strobe may easily be made in two versions: one which includes TTL functionality, and the other which does not.
Many cameras currently use a protocol which also includes a READY signal sent from the strobe 102 to the camera 101. The READY signal permits the camera 101 (and the photographer, if the camera has a suitable display in its view finder) to know whether the strobe 102 is ready to be triggered. Unlike the SYNC and STOP signals, which are edge-triggered, the READY signal is a simple active-high logic signal. That is, the strobe 102 pulls the READY line high when it is in the "READY" state (i.e., the strobe is fully charged and ready to be triggered), and leaves it low when it is not ready (i.e., it is either off or is not fully charged).
In situations in which a photographer is using multiple strobes attached to one camera, the READY signal from only one strobe is transmitted to the camera. Accordingly, information regarding the status of the other strobes is not available to the camera. Therefore, the photographer must look at each other strobe to determine whether those strobes are ready to be triggered.
A fifth signal is also commonly used in cameras having TTL exposure control. The fifth (MONITOR) signal is an active-high current signal (as opposed to a voltage signal). The MONITOR signal indicates to the strobe that the camera is "awake" and that a pulse on the SYNC signal may be forthcoming. Typically, a camera begins transmitting the MONITOR signal when the photographer has partially depressed the shutter button. The camera continues transmitting the MONITOR signal for some period of time afterwards (usually between 10 seconds and 1 minute).
One problem that exists with prior art systems is the lack of a mechanical standard for interfacing a SYNC cord with a camera and remote light source. While the connectors on the camera side of a SYNC cord are reasonably standard, each manufacturer uses its own mechanically different connector to attach the SYNC cord to a remote light source. Because each manufacturer has a different mechanical standard, different SYNC cords are required for use with different manufacturers' strobes.
Even on the camera side, the standardization of the mechanical interface is not complete. Some camera manufacturers use a unique SYNC cord mechanical interface. Therefore, different SYNC cords may be required for different cameras as well. This lack of standardization makes it necessary for a photographer who owns strobes from more than one manufacturer to purchase at least one SYNC cord for each type of strobe he owns. This represents a considerable expense, since each SYNC cord is relatively expensive (e.g., approximately $75.00 each for underwater SYNC cords, and as much as $100 to $200 for above-water TTL sync cords). Furthermore, a photographer who owns a camera from a manufacturer that uses a non-standard interface is generally forced to purchase strobes made only by that manufacturer. Still further, above-water TTL SYNC cords are available in relatively short lengths (up to about 10 feet) and are quite bulky due to the heavy shielding necessary to prevent false-triggering of the strobe's STOP circuit by the pulse of electromagnetic noise that is created when a strobe is triggered. Still further, a photographer who wishes to use more than one strobe (particularly in an underwater setting) must purchase a "dual" SYNC cord in order to interface one camera to two strobes. While most underwater strobe manufacturers make "dual" SYNC cords (which are even more expensive than single cords), all manufacturers use their own connectors on the strobe ends of the dual SYNC cords they sell, making it difficult, and in most cases impractical, to combine strobes from different manufacturers in a single system. Using more than two strobes underwater requires additional, specialized hardware, since manufacturers of underwater equipment do not offer triple SYNC cords as a standard product. Above water, similar problems are encountered. Very few, if any, commercial products exist which permit the photographer to use TTL exposure control with multiple remote strobes in an above-water setting. Instead, the photographer is forced to rely on SYNC-only triggering of multiple strobes, either through two-wire electrical connections or by using the strobes in "slave" mode, as described below.
One common way to address the problem of using multiple strobes is to have one strobe attached to a camera via a single SYNC cord and to have a second strobe triggered in "slave" mode. In slave mode, a photo-sensor in the second strobe is used to detect a burst of light emitted from the first strobe. The photo-sensor then triggers the second strobe in response to detection of the burst of light. By operating strobes from different manufacturers in slave mode, the difficulties which result from each manufacturer having a different mechanical interface is eliminated. In addition, this system allows a relatively large number of strobes to be used. However, slave triggering of a strobe is notoriously unreliable, both with regard to false triggering and failure to trigger, since the illumination of a photo-sensor in the second strobe is typically indirect (e.g., both strobes are typically pointing at the subject). In addition, few if any commercially available strobes permit TTL exposure control to be used in slave mode.
Another disadvantage of prior art systems is the reliability of the SYNC cord. That is, the reliability of the system will be compromised by any of a number of mechanical failures, all of which occur relatively frequently. In underwater systems, a common problem is the breach of the watertight seal between the cable and the strobe or camera. Failure of a watertight seal in an underwater camera or strobe will likely result in the destruction of either the camera, the strobe, or both. Well-designed watertight seals typically have a high reliability if the SYNC cord is not removed from the camera and the strobe frequently. Unfortunately, in practice, a photographer frequently disconnects the SYNC cord from the camera and the strobe for ease of transportation, and to change camera and strobe configurations. In the case of both underwater and outdoor photographers, this is often done in a moist environment, thus decreasing the reliability of the electrical connections between the camera and strobe. Each time the connection between the SYNC cord and either the camera or strobe is broken, particularly in a moist environment, there is a chance that the electrical connection between the pins and sockets that make up the individual contacts of the connectors will become corroded, resulting in electrical failure of the SYNC cord. In addition, conventional SYNC cords are susceptible to breakage of the wire inside the cable due to stress of use. Furthermore, flooding of the cable itself (through the insulating jacket) due to wear or misuse is common in underwater applications.
A further disadvantage of prior art systems is inability to reconfigure the system underwater or in harsh environments. Any attempt to disconnect a SYNC cord from either the strobe or camera underwater would breach the integrity of the watertight seals in the system. Furthermore, conventional SYNC cords are relatively bulky and heavy, making transportation and storage inconvenient, particularly in the case in which several SYNC cords are required.
Still further, conventional SYNC cords are of a relatively short and fixed length and cannot be adjusted or made to a specific length in the field without soldering or crimping electrical conductors to pins and/or sockets of the connector.
Still further, conventional SYNC cords are expensive to manufacture and purchase. The connectors at either end of the SYNC cord typically consist of many small pins and/or sockets which must be soldered or crimped to the ends of the individual wires, and then inserted into a metal connector body which is overmolded onto the end of the cable. Particularly for above-water sync cords, the cable used for this purpose must be heavily shielded to ensure proper operation ofthe TTL exposure control in spite of the electromagnetic emissions caused by the discharge of the strobe's capacitors. In addition to the expense of the SYNC cords themselves, the inclusion of the mating connector on the camera and strobe adds to the expense ofthe overall system. In fact, in order to reduce costs, manufacturers sometimes omit the connector on the strobe side, thus sacrificing convenience and reliability to reduce costs.
FIG. 2 is an illustration of one system available today in which the problem of connecting and disconnecting SYNC cords underwater is overcome by providing a SYNC cord 200 having optical linkage modules 201, 203. For example, one product has an optical transmitter unit 201 on one end of a first long cable 205. The other end of the first cable 205 is attached to a camera 101 using the conventional electrical connector 103 provided on the camera 101. A receiver unit 203 is coupled by a long electrical cable 207 to the connector 105 for making electrical connections to a strobe. The first and second cables 205, 207 are coupled together by directly interfacing the optical receiver unit 203 and transmitter unit 201. Alternatively, the optical receiver unit 203 may be coupled to two long cables for connecting to two strobes. These cables 205, 207 are heavy and bulky. The transmitter unit 201 and receiver unit 203 each have two separate optical transmitter/receiver pairs, one dedicated to transmitting the SYNC signal and the other dedicated to transmitting the STOP signal. Each channel consists of an LED (light emitting diode) and a photo-detector. The LED and photo-detector have optically isolated line-of-sight contact through transparent windows in the transmitter unit 201 and receiver unit 203, respectively. This system does not address many of the reliability issues associated with the use of electrical cables underwater. Further, it relies on the surrounding water and physical distance of the optical modules from the strobe to shield the modules from unwanted electromagnetic interference.
Another system for use underwater is disclosed in Japanese Publication No. JP 55036829 filed in the name of Mamiya Koki Kk (the "Mamiya" patent). The Mamiya patent discloses an underwater camera 1 and underwater strobe 2 connected by a light guide 3, as shown in FIG. 3. A watertight light-emitting window 7 integrated into the camera directs light through an optical connector 4 into the light guide 3 when the light guide 3 is coupled to the camera 1. Connectors 4 are fixed at each end of the light guide to allow the light guide 3 to be coupled to the camera 1 and strobe 2. A light-receiving element 10 integrated into the strobe 2 receives the light which traverses the light guide 3. Upon receiving the light emitted by the camera 1 and transmitted through the connectors 4 and light guide 3, the strobe 2 is triggered. Since the connection between the light guide 3 and the camera 1 and between the light guide 3 and the strobe 2 are water tight, the camera 1 and strobe 2 can be disconnected from the light guide 3 while underwater. However, this system can only be used with cameras and strobes that have the watertight optical connectors 4 required to interface with the light guide 3. Furthermore, the use of connectors 4 on either end of the light guide 3 fixes the length of the light guide 3 at the time of manufacture. In addition, this system does not provide any way for multiple strobes to be used. Still further, this system does not permit TTL exposure control.
Accordingly, there is a need for a SYNC cord that can be used to transmit TTL signals between a camera and strobe in a manner which allows the camera and strobe system to be reconfigured (e.g., allows the SYNC cord to be disconnected from the camera and strobe underwater or in harsh environments). Furthermore, there is a need for a small lightweight SYNC cord for coupling TTL signals between a camera and strobe. Still further, there is a need for a more reliable SYNC cord. Still further, there is a need for a SYNC cord which has the above-mentioned features and which does not require any change in the design or manufacture of conventional cameras and strobes. Furthermore, there is a need for a SYNC cord which permits convenient simultaneous use of strobes from different manufacturers. Still further, there is a need for a system which allows a relatively large number of strobes to be reliably triggered by a single camera. Furthermore, there is a need for an inexpensive SYNC cord for transmitting TTL signals between a camera and a strobe. Still further, there is a need for a SYNC cord which can be adjusted in length by the user in the field. Furthermore, there is a need for a TTL sync cord with a greater maximum usable length. The present invention provides a SYNC cord which satisfies these needs.

Method and apparatus for controlling a remote light source


Embodiments of the invention provide a color filter substrate, a TFT array substrate, a manufacturing method of the color filter substrate, a manufacturing method of the TFT array substrate, and a liquid crystal display (LCD) panel. The color filter substrate comprises color filter substrate units of different sizes. The manufacturing method of the color filter substrate comprises: coating a common electrode layer on a base substrate for forming the color filter substrate; and forming common electrodes of different thicknesses for the color filter substrate units of different sizes by a patterning process.

Display panel of a Thin Film Transistor-Liquid Crystal Display (TFT-LCD) comprises a TFT array substrate and a color filter substrate bonded with each other and a liquid crystal layer filled between the TFT array substrate and the color filter substrate. In practice, display panel units of different sizes may be provided on a same display panel. After the bonding process of the color filter substrate and the TFT array substrate, the display panel will be divided into display panel units of different sizes.
Cell gaps of the different sized display panel units are required to be different from each other. However, when different sized display panel units are manufactured on the same display panel, the cell gaps thereof tend to be the same because the thicknesses of the TFT array substrate and the thickness of the color filter substrate are kept constant, and in this case, the display performance of some display panel units has to be adversely influenced.

Color filter substrate, TFT array substrate, manufacturing method of the same, and liquid crystal display panel

BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD.


An example operation may include one or more of acquiring, by an organization node, a user profile from a blockchain, determining, by the organization node, a role of the user based on the user profile, detecting, by the organization node, user actions directed to graph expansions, and executing, by the organization node, a smart contract to analyze user behavior based on the detected user actions and the role to produce role-based user behavior parameters.

A centralized database stores and maintains data in a single database (e.g., a database server) at one location. This location is often a central computer, for example, a desktop central processing unit (CPU), a server CPU, or a mainframe computer. Information stored on a centralized database is typically accessible from multiple different points. Multiple users or client workstations can work simultaneously on the centralized database, for example, based on a client/server configuration. A centralized database is easy to manage, maintain, and control, especially for purposes of security because of its single location. Within a centralized database, data redundancy is minimized as a single storing place of all data also implies that a given set of data only has one primary record.
However, a centralized database suffers from significant drawbacks. For example, a centralized database has a single point of failure. In particular, if there are no fault-tolerance considerations and a failure occurs (for example, a hardware, firmware, and/or a software failure), all data within the database is lost and work of all users is interrupted. In addition, centralized databases are highly dependent on network connectivity. As a result, the slower the connection, the amount of time needed for each database access is increased. Another drawback is the occurrence of bottlenecks when a centralized database experiences high traffic due to a single location. Furthermore, a centralized database provides limited access to data because only one copy of the data is maintained by the database. As a result, multiple devices cannot access the same piece of data at the same time without creating significant problems or risk overwriting stored data. Furthermore, because a database storage system has minimal to no data redundancy, data that is unexpectedly lost is very difficult to retrieve other than through manual operation from back-up storage.
Blockchain-based data may be represented by a graph. This is particularly useful for displaying food traceability results of blockchain-based supply-chains. In most of the cases the graph needs to be displayed to a user on a user interface (UI). Expansion of each node of the graph requires some computation power and calculation time. For example, the food traceability result may normally be represented by a tree structure, which requires calculation to trace each node. Very often, the UI needs to trim the tree for responsiveness and performance reasons. Intelligence is needed to decide which part of the graph to be expanded and displayed on UI based on user actions in near real time.
Accordingly, a mechanism for behavior driven graph expansion based on a blockchain is desired.

This patent is subject to a terminal disclaimer.

International Business Machines Corporation


A method of applying total liquid ventilation to a patient according to a ventilation cycle including inspiration and expiration profiles, comprises supplying oxygenated liquid to the patient's lungs, withdrawing liquid from the patient's lungs, and controlling independently supply of oxygenated liquid to the patient's lungs and withdrawal of liquid from the patient's lungs. This supply and withdrawal independent control comprises producing a ventilation cycle having independently controlled inspiration and expiration profiles. To carry out the method, a total liquid ventilator system comprises an inspiration pump for supplying oxygenated liquid to the patient's lungs, and an expiration pump for withdrawing liquid from the patient's lungs. A ventilation cycle control comprises first and second pump controllers connected to the inspiration and expiration pumps, respectively, to produce a ventilation cycle having independently controlled inspiration and expiration profiles.

Three to five percent of newborns in intensive care units are afflicted with a respiratory distress that makes them refractory to optimal ventilation by artificial means. Inflammation of the lungs is even aggravated by conventional artificial ventilation. Insufficient oxygenation of arterial blood and internal organs, particularly of the brain, results from such conditions. A promising alternative in the treatment of acute respiratory distress syndrome (ARDS) is liquid ventilation using breathable inert liquids. The advantages of this technique are suggested by theoretical considerations and supported by solid experimental evidence, which have been well known for many years.
Liquid ventilation can be achieved in two ways, either as partial (PLV) or total liquid ventilation (TLV). PLV uses a conventional gas ventilator after the lungs have been partially filled with perfluorocarbon (PFC) liquid. This technique requires no special ventilator and has been the subject of clinical studies for many years. However, it is clear that the benefits of liquid ventilation are best achieved by total liquid ventilation, wherein the lungs are completely filled with breathable inert liquid oxygenated by external means. Furthermore, the idea of re-establishing prenatal conditions in diseased lungs of newborns while healing occurs appears to be intuitively sound [Praud J P. (2000) "Le liquide pulmonaire". In: Dehan M, Micheli J, eds. Le poumon du nouveau-né. Paris: Doin, pp 49-51].
The considerable advantage of liquid ventilation over gaseous ventilation in acute respiratory failure is the possibility, as a result of eliminating the air-liquid interface of the lungs, of recruiting and expanding pathologically non-compliant lung alveoli at much lower pressures. The risk of volo/barotrauma is greatly reduced, alveolar ventilation is more uniform, atelectasis is eliminated, and ventilation/perfusion unevenness is decreased. These benefits have been noted in all studies carried out on animal models of newborn respiratory distress [Hirschl R B, Tooley R, Parent A, Johnson K, Bartlett R H. (1996) "Evaluation of gas exchange, pulmonary compliance, and lung injury during total and partial liquid ventilation in the acute respiratory distress syndrome", Crit Care Med 24:1001-8; Pedneault C, Renolleau S, Gosselin R, Letourneau P, Praud J P. (1999) "Total liquid ventilation using a modified extra-corporeal gas exchange circuit: preliminary results in lambs", Pediatr Pulmonol Suppl 18: A241; Hirschl R B et al. (1995) "Liquid ventilation in adults, children and full-term neonates", Lancet 346:1201-2; Shaffer T H, Douglas P R, Lowe C A, Bhutani V K. (1983) "The effects of liquid ventilation on cardiopulmonary function in preterm lambs". Pediatr Res 17:303-6; Wolfson M R, Greenspan J S, Deoras K S, Rubenstein S D, Shaffer T H. (1992) "Comparison of gas and liquid ventilation: clinical, physiological, and histological correlates", J Appl Physiol 72:1024-31].
Perfluorocarbons are most often selected as breathable inert liquids. They are non-toxic, chemically stable and biocompatible. In addition, they have been identified as "ideal" liquids for this purpose, since they diffuse rapidly into respiratory airways, have very low surface tension and are very good solvents for respiratory gases allowing them to provide both oxygenation and efficient removal of CO2 [Clark C, Gollan F, (1966) "Survival of mammals breathing organic liquids equilibrated with oxygen at atmospheric pressure, J Appl Physiol, 21:1755-6, 1966]. PFCs not only "wash" debris and inflammatory molecules from the patient's airways [Wolfson M R, Greenspan J S, Shaffer, T H. (1998) "Liquid-assisted ventilation: an alternative respiratory modality" Pediatr Pulmonol 26: 42-63] but can also be used for administering locally-applied medicines such as pulmonary artery dilators [Wolfson M R, Greenspan J S, Shaffer T H. (1996) "Pulmonary administration of vasoactive substances by perfluorochemical ventilation", Pediatrics 97:449-55]. A first PFC, perflubron, has been approved for medical use, while others, such as perfluorobutane, are currently being examined by the FDA.
Many types of liquid ventilators have been developed and disclosed in the literature. Generally, clinical studies have been conducted using with systems supplied by gravity, using reservoirs above and below the patients' lungs to bring about inspiration and expiration. A drawback is that this type of system does not enable adequate monitoring and control of all the ventilation parameters.
Research laboratories initially constructed liquid ventilators using costly existing equipments for oxygenation and external circulation. In most of the cases, complex pumping was used, composed of peristaltic pumps, liquid reservoirs and several valves with by-pass systems. A major problem then acknowledged by researchers was to design a user-friendly, simple, efficient, safe and reliable ventilator to bring TLV in an intensive care environment.
In order to decrease the mechanical complexity of liquid ventilators, Hirsch et al. [Hirschl R B, Tooley R, Parent A, Johnson K, Bartlett R H. (1996) "Evaluation of gas exchange, pulmonary compliance, and lung injury during total and partial liquid ventilation in the acute respiratory distress syndrome", Crit Care Med 24:1001-8] developed a connector with a venturi, which allows both inspiration and expiration without using a by-pass circuit and provides continuous liquid flow throughout the system.
Shaffer et al. [Shaffer, Thomas H., Wolfson, Marla R., Heckman, James L., Hoffman, John, (2000), "Liquid Ventilator", U.S. Pat. No. 6,105,572, 14 p] subsequently developed a total liquid ventilator using a roller pump to force PFC liquid through a respiration and regeneration closed-loop circuit. However, this type of pump generates a pulsatile flow, which causes oscillation of pressure measurements. Thus, other recently developed ventilators [Sekins K M, Nugent L, Mazzoni M, Flanagan C, Neer L, Rozenberg A, Hoffman J. (1999) "Recent innovations in total liquid ventilation system and component design" Biomed Instrum Technol 33 :277-84; Larrabe J L., Alvarez F J., Gatiasoro Cuesta E., Valls-i-Solers A., Alfonso L F., Arnaiz A., Fernandez M B., Loureiro B., Publicover N G., Roman L., Casle J A., Gomez M A. (2001), "Development of a time-cycled volume-controlled Pressure-limited respirator and lung mechanics system for total liquid ventilation", IEEE Transactions on Biomedical engineering 48:1134-1144] use a double piston pump, of which one piston is dedicated to inspiration and the other piston to expiration. Both pistons are displaced simultaneously on a single platform.
The gas exchanger is crucial to efficiency of TLV, since it must completely remove CO2 from the PFC liquid and replace it with oxygen before the liquid may be returned to the patient's lungs. And CO2 dissolves more easily than does oxygen in PFC liquid. Therefore, in order to bring about adequate gas exchange, many total liquid ventilators are equipped with a costly external blood oxygenator. This piece of equipment contains a silicone membrane comprised of two walls; the oxygen flows between the two walls of the silicone membrane while the PFC liquid flows on the outside of these walls. A major drawback of this oxygenator is that oils from the silicone are extracted by the PFC liquid, which increases membrane replacement frequency and hence operating cost. In addition, PFC liquid leaks through the silicone membrane to pass into the oxygen stream, resulting in PCF losses and higher operating cost.
In other applications, a combination of an atomizer with a bubbler tube has been developed to replace the membrane oxygenator. The column of this oxygenator consists principally of a long vertical tube into which PFC liquid is sprayed through a nozzle at the top and oxygen is injected at the base through a porous stone. Gas exchange occurs through direct contact between the gas bubbles and the liquid. Efficiency is improved by inserting grids into the column to increase the time of residence of the gas bubbles in the liquid [Sekins K M, Nugent L, Mazzoni M, Flanagan C, Neer L, Rozenberg A, Hoffman J. (1999) "Recent innovations in total liquid ventilation system and component design", Biomed Instrum Technol 33 :277-84.].
However, the performance of the atomizer-bubbler combination is strongly dependent on gas flow rate. When gas flow rate is insufficient, the porous stone does not generate a uniform flow of bubbles. When too high a flow rate is produced, gas bubbles join together to form a cluster of bubbles, which greatly decreases the gas exchange area. In addition, large amounts of liquid are required to fill the column.
As an alternative to oxygenation systems based on membranes or atomizer-bubbler combinations, Lawrence J. NUGENT developed a new type of liquid-breathing gas exchanger described in International Publication WO 99/62626 dated Mar. 16, 2000. This gas exchanger is composed of a fluid-dispersion unit for projecting a thin film of liquid onto a surface exposed to an oxygen gas stream.
The flow of oxygen through the oxygenator is evacuated, carrying with it both CO2 and PFC liquid vapours. During TLV, significant losses of liquid therefore occur. Multifactorial analysis on the efficiency of the exchangers and the conservation of the liquid during TLV has shown that PFC liquid losses are greater in atomizer-bubbler combinations than in membrane-type gas exchangers [Wolfson M R, Miller T F, Peck G, Shaffer T H. (1999) "Multifactorial analysis of exchanger efficiency and liquid conservation during perfluorochemical liquid-assisted ventilation". Biomed Instrum Technol. 33 :260-7]. This can be explained largely by an evacuation of atomized PFC liquid outside the oxygenator under the form of small droplets conveyed by the gaseous stream, in addition to evaporation losses.
Losses of PFC liquid must be minimized, both for economic reasons and for the protection of medical equipments not compatible with PFC vapours. To meet with this requirement, a condenser is generally incorporated into the system in order to recover PFC vapours escaping from the oxygenators, without interfering with gas flow.
An alternative to the use of condensers would be to recirculate the gas stream, which could allow practically complete retention of PFC vapours. Faithfull and Shutt [Faithfull and Shunt (1999), "Methods and Apparatus for Closed-Circuit Ventilation Therapy", U.S. Pat. No. 6,041,777, 26 p] have developed a method and an apparatus for this type of system, which allows prolonged administration of PFC liquid without excessive losses due to evaporation. A drawback is that these method and apparatus require a system for extracting CO2 from the closed-loop circuit.
Health-care personnel are aware that a patient may suffer hyper distension of the lungs or collapse of the respiratory airways as well as incomplete gas diffusion. The ventilator must therefore inform the health-care personnel about the patient's status by means of measurements such as compliance, respiratory airways pressure, lung volume, etc. To meet with this requirement, Shaffer et al. [Shaffer T H, Wolfson M R, Greenspan J S, Rubenstein S D, Stern R G. (1994) "Perfluorochemical liquid as a respiratory medium", Art Cells Blood Subs Immob Biotech 22:315-326] developed a monitoring process for liquid ventilators, based on a comparison of current conditions with a range of desired values, in order to activate alarms or servo-valves on the network of conduits.
Nevertheless, the problem is more complex than simply determining when to activate an alarm. A continuous measurement of the volume of liquid in the lungs is highly desirable, rather than relying on pressure measurement to indicate errors between the volume of liquid injected into and the volume withdrawn from the lungs. Such errors, even small, could result in decreased or increased residual liquid volume in the lungs on the long term. There is currently no efficient method for continuous measurement of such volume of liquid; for example, measurement of a variation in the patient's weight does not constitute a practical method for implementation in the intensive care units.

Method and apparatus for conducting total liquid ventilation with control of residual volume and ventilation cycle profile


Improved methods and apparatuses related to laser-assisted intra-coronary transmyocardial revascularization (ITMR), and more particularly, to improved methods and apparatuses for directing an interventional catheter device, via percutaneous or other entry into the vasculature, for example at the femoral artery, over the aortic arch, through the ascending aorta and over the coronary ostia such that the laser delivery means can be positioned inside a coronary artery and laser energy is used to create a plurality of small channels through the coronary artery into the tissue of the myocardium. An proximal hub portion and method of using it are described, the proximal hub portion adapted for attachment to a central, elongated lumen portion, the proximal hub portion optionally having a plurality of branched extending arms, the sheath and associated branched arms having individual blood loss seals and individually capable of receiving a laser delivery means, visualization or marking means, or other tools. The interventional catheter device has a distal end with, optionally, a guide means for directing an advancing laser delivery or other device to an angle with respect to the central axis of the catheter device, the distal end optionally comprising a radio-opaque portion for visualization via a fluoroscope or other means, the distal end of the catheter device further comprising an ultrasound transducer for visualizing the orientation and firing angles of the catheter device. The methods of use also comprise placing channel opening blockers, such as an angioplasty-type inflatable balloon or an axially compressible, radially expandable stainless steel wire mesh or other material stent in place inside the coronary artery, thereby preventing undesired bleeding from the coronary artery.

FIG. 1 is a schematic view of the human heart. The human heart 10 is a muscular dual pump that beats continuously throughout life sending blood to the lungs and the rest of the body. The interior of the heart consists of four distinct chambers. The septum 12, a thick central muscular wall, divides the cavity into right and left halves. On the right side, the upper half is known as the right atrium 14. Deoxygenated blood from the rest of the body arrives in the right atrium via the vena cava 16, the blood is pumped across a one-way valve known as the tricuspid valve 18 into the lower portion known as the right ventricle 20. From there the blood circulates to the lungs through the pulmonary valve 22 via the pulmonary artery 24 where it is oxygenated by circulation through the alveoli of the lungs (not shown). The blood returns via the pulmonary veins to the left atrium 26 and flows through a second valve, the mitral valve 28 into the left ventricle 30 where it is pumped via the aorta 32 to the rest of the body.
Much of the heart consists of a special type of muscle called myocardium. The myocardium requires a constant supply of oxygen and nutrients to allow it to contract and pump blood throughout the vasculature. The inner surfaces of the chambers of the heart are lined with a smooth membrane, the endocardium, and the entire heart is enclosed in a tough, membranous bag known as the pericardial sac.
The pumping action of the heart has three main phases for each heart beat. Diastole is the resting phase during which the heart fills with blood: while deoxygenated blood is entering the right atrium oxygenated blood is returned from the lungs to the left atrium. During the atrial systole, the two atria contract simultaneously, squeezing the blood into the lower ventricles. Finally, during ventricular systole the ventricles contract to pump the deoxygenated blood into the pulmonary arteries and the oxygenated blood into the main aorta. When the heart is empty, diastole begins again. The electrical impulses which stimulate the heart to contract in this manner emanate from the heart's own pacemaker, the sinoatrial node. The heart rate is under the external control of the body's autonomic nervous system.
FIG. 2 is a schematic view of the coronary arteries on the outer surface of the human heart. Though the heart supplies blood to all other parts of the body, the heart itself has relatively little communication with the oxygenated blood supply. Thus, the two coronary arteries, the right coronary artery 40 and the left coronary artery 42 arise from the aorta 44 beneath the aortic arch 46. Starting at the left coronary osteum 48 and the right coronary osteum 50, respectively, the coronary arteries encircle the heart muscle on either side "like a crown" to supply the heart itself with blood.
Heart disorders are a common cause of death in developed countries. They also impair the quality of life of millions of people restricting activity by causing pain, breathlessness, fatigue, fainting spells and anxiety. The major cause of heart disease in developed countries is impaired blood supply. The coronary arteries, which supply blood to the heart, become narrowed due to atherosclerosis and part of the heart muscle are deprive of oxygen an other nutrients. The resulting ischemia or blockage can lead to angina pectoris, a pain in the chest, arms or jaw due to a lack of oxygen to the heart, or infarction, death of an area of the myocardium caused by the ischemia.
Techniques to supplement the flow of oxygenated blood directly from the left ventricle into the myocardial tissue have included needle acupuncture to create transmural channels (see below) and implantation of T-shaped tubes into the myocardium. Efforts to graft the omentum, parietal pericardium, or mediastinal fat to the surface of the heart had limited success. Others attempted to restore arterial flow by implanting the left internal mammary artery into the myocardium.
Modernly, coronary artery blockage can be relieved in a number of ways. Drug therapy, including nitrates, beta-blockers, and peripheral vasodilatator drugs (to dilate the arteries) or thrombolytic drugs (to dissolve the clot) can be very effective. If drug treatment fails transluminal angioplasty is often indicated-the narrowed part of the artery, clogged with atherosclerotic plaque or other deposits, can be stretched apart by passing a balloon to the site and gently inflating it a certain degree. In the event drug therapy is ineffective or angioplasty is too risky (often introduction of a balloon in an occluded artery can cause portions of the atherosclerotic material to become dislodged which may cause a total blockage at a point downstream of the subject occlusion thereby requiring emergency procedures), the procedure known as coronary artery bypass grafting (CABG) may be indicated. CABG is the most common and successful major heart operation performed, in America alone over 500,000 procedures being performed annually. The procedure takes at least two surgeons and can last up to five hours. First, the surgeon makes an incision down the center of the patient's chest and the heart is exposed by opening the pericardium. A length of vein is removed from another part of the body, typically the leg. The patient is connected to a heart-lung machine which takes over the function of the heart and lungs during the operation. The section of vein is first sewn to the aorta and then sewn onto a coronary artery at a place such that oxygenated blood can flow directly into the heart. The patient is then closed. Not only does the procedure require the installation of the heart-lung machine, a very risky procedure, but the sternum must be sawed through and the risk of infection is enhanced during the time the chest cavity is spread open.
Another method of improving myocardial blood supply is called transmyocardial revascularization (TMR), the creation of channels from the epicardial to the endocardial portions of the heart. The procedure using needles in a form of "myocardial acupuncture" has been experimented with at least as early as the 1930s and used clinically since the 1960s. Deckelbaum. L. I., Cardiovascular Applications of Laser technology, Lasers in Surgery and Medicine 15:315-341 (1994). The technique was said to relieve ischemia by allowing blood to pass from the ventricle through the channels either directly into other vessels perforated by the channels or into myocardial sinusoids which connect to the myocardial microcirculation. The procedure has been likened to transforming the human heart into one resembling that of a reptile.
In the reptilian heart, perfusion occurs via communicating channels between the left ventricle and the coronary arteries. Frazier, O. H., Myocardial Revascularization with Laser--Preliminary Findings, Circulation, 1995; 92 suppl II!:II-58-II-65. There is evidence of these communicating channels in the developing human embryo. In the human heart, myocardial microanatomy involves the presence of myocardial sinusoids. These sinusoidal communications vary in size and structure, but represent a network of direct arterial-luminal, arterial-arterial, arterial-venous, and venous-luminal connections. This vascular mesh forms an important source of myocardial blood supply in reptiles but its role in humans is poorly understood.
Numerous studies have been performed on TMR using lasers to bore holes in the myocardium. The exact mechanism by which blood flows into the myocardium is not well understood however. In one study, 20-30 channels per square centimeter were bored into the left ventricular myocardium of dogs prior to occlusion of the arteries. LAD ligation was conducted on both the revascularized animals as well as a set of control animals. Results showed that animals having undergone TMR prior to LAD ligation acutely showed no evidence of ischemia or infarction in contrast to the control animals. After sacrifice of the animals at ages between 4 weeks and 5 months, the laser-created channels could be demonstrated grossly and microscopically to be open and free of debris and scarring.
It is believed that the TMR channels occlude toward the epicardial surface but that their subendocardial section remains patent (unobstructed) and establishes camerosinusoidal connections. It is possible that the creation of laser channels in the myocardium may promote long-term changes that could augment myocardial blood flow such as by inducing angiogenesis in the region of the lased (and thus damaged) myocardium Support of this possibility is reported in histological evidence of probable new vessel formation adjacent to collagen occluded transmyocardial channels. In the case of myocardial acupuncture or boring, which mechanically displaces or removes tissue, acute thrombosis followed by organization and fibrosis of clots is the principal mechanism of channel closure. By contrast, histological evidence of patent, endothelium-lined tracts within the laser-created channels supports the assumption that the lumen of the laser channels is or can become hemocompatible and that it resists occlusion caused by thrombo-activation and/or fibrosis. A thin zone of charring occurs on the periphery of the laser-created transmyocardial channels through the well-known thermal effects of optical radiation on cardiovascular tissue. This type of interface may inhibit the immediate activation of the intrinsic clotting mechanisms because of the inherent hemocompatibility of carbon. In addition, the precise cutting action that results from the high absorption and low scattering of laser energy (CO.sub.2, HO, etc.) may minimize structural damage to collateral tissue, thus limiting the tissue thromboplastin-mediated activation of the extrinsic coagulation.
U.S. Pat. No. 4,658,817 issued Apr. 21, 1987 to Hardy teaches a method and apparatus for TMR using a laser. A surgical CO.sub.2 laser includes a handpiece for directing a laser beam to a desired location. Mounted on the forward end of the handpiece is a hollow needle to be used in surgical applications where the needle perforated a portion of tissue to provide the laser beam direct access to distal tissue.
U.S. Pat. No. 5,125,926 issued Jun. 30, 1992 to Rudko et al. teaches a heart-synchronized pulsed laser system for TMR. The device and method comprises a device for sensing the contraction and expansion of a beating heart. As the heart beat is monitored, the device triggers a pulse of laser energy to be delivered to the heart during a predetermined portion of the heartbeat cycle. This heart-synchronized pulsed laser system is important where the type of laser, the energy and pulse rate are potentially damaging to the beating heart or it's action. Often, application of laser energy to a beating heart can induce fibrillation or arrhythmia. Additionally, as the heart beats, it's spatial relationship between the heart and the tip of the laser delivery probe may change so that the necessary power of the beam and the required position of the handpiece may be unpredictable.
Finally, U.S. Pat. Nos. 5,380,316 issued Jan. 10, 1995 and 5,389,096 issued Feb. 14, 1995 both to Aita et al. teach systems and methods for intra-operative and percutaneous myocardial revascularization, respectively. The former patent is related to TMR performed by inserting a portion of an elongated flexible lasing apparatus into the chest cavity of a patient and lasing channels directly through the outer surface of the epicardium into the myocardium tissue. In the latter, TMR is performed by guiding an enlongated flexible lasing apparatus into a patient's vasculature such that the firing end of the apparatus is adjacent the endocardium and lasing channels directly through the endocardium into the myocardium tissue without perforating the pericardium layer. These patents do not teach any method for controlling the elongated flexible laser delivery apparatus, nor do they teach methods of visualizing the areas of the heart being lased nor do they teach any method or devices for achieving TMR on surfaces or portions of the heart which are not directly accessible via a sternotomy, mini-sternotomy or via a trocar.
TMR is most often used to treat the lower left chamber of the heart. The lower chambers or ventricles are serviced by the more distal branches of the coronary arteries. Distal coronary arteries are more prone to blockage and resulting heart muscle damage. Roughly 50% of the left ventricle is direct line accessible through a thoracotomy or small incision between the ribs. However, roughly 50% is not direct line accessible and requires either rotating the heart or sliding around to the back side of the heart. Access to the heart is achieved by (1) sliding a device between the heart and pericardial sack which encases the heart, the device likely to have a 45-90 degree bend near the tip, (2) lifting the still beating heart, and (3) penetrating through the direct access side of the heart and/or through the septum of the heart. Lifting the still beating heart is less than desirable especially in patients with lowered heart performance. Furthermore, such manipulation can cause tachycardia (rapid beating of the heart absent undue exertion) fibrillation, arrhythmia or other interruptions in the normal beating cycle.
Thus, broadly, it is an object of the present invention to provide an improved method and device for laser-assisted intra-coronary transmyocardial revascularization (ITMR).
It is a further object of the present invention to provide an improved method or performing ITMR in which channels are created by directing a laser source through the coronary arteries into the myocardium.
It is a further object of the present invention to provide an improved catheter device for performing ITMR which consists of a central lumen, a proximal hub portion at the proximal end of the lumen and a laser delivery means at the distal end of the lumen, optionally along with any of a plurality of additional catheter or surgical tools including visualization means, cutting or resection means, balloons, stents, fluoroscopic marker, ultrasound imaging transmitting or receiving means.

Apparatus for laser-assisted intra-coronary transmyocardial revascularization and other applications


A heat exchange unit for a heat exchanger which includes a first tube with an outer surface and extended surface members located axially along the outer surface. Each member has a tube engagement surface and are axially Positioned. There is also taught a heat exchange fin block having a heat exchange unit with a second tube interconnected to the first tube by the extended surface members, wherein the extended surface members being tube fins at predetermined axial spacings. A tube finning machine is disclosed which includes a base with clamping means mounted thereon, carrier means movable relative to the base, and drive means for moving the carrier means. The clamping means clamps a portion of the first tube, and the carrier means transports at least one fin to an axially predetermined position adjacent the portion. Also disclosed is a method of finning a tube which includes supporting the tube to include a free end, positioning a carrier means at a start position, presenting a fin to the carrier means with pre-set angular orientation, locating the fin upon the carrier means while the carrier means is at the start position, moving the carrier means to drive the fin over the free end of the tube and thereafter a predetermined distance along the tube, returning the carrier means without the fin to the start position, and repeating the cycle by presenting another fin to the carrier means with the angular orientation but with the carrier means having a smaller predetermined distance.

Often it is necessary to cool a working fluid, and it is known for this purpose to use a heat exchanger. Heat exchangers usually comprise one or more metallic tubes suspended between two tube plates. The working fluid to be cooled, which may for example be water or oil, flows through the tubes, whilst the coolant passes around and between those tubes, the working fluid giving up its latent heat to the tubes and thus to the coolant.
The effective surface area of a tube can be enlarged in order to increase the heat transfer, as by the addition of one or more annular fins in thermal contact with the outer surface of the tube. Such finned tubes are particularly useful if the coolant has a low viscosity, and if the coolant is a gas, such as air.
If the tubes are to withstand the internal pressure of the fluid to be cooled, the addition of the fins should not reduce or significantly reduce the tube bursting strength. If the fins are to increase the heat transfer they should not inhibit the flow of coolant, and preferably should encourage turbulent coolant flow.
The tubes to be used for heat exchangers should meet certain standards (in the UK for instance British Standard 2871 Part 3), these standards being relevant also for those tubes which are formed by extrusion to provide selected internal formations chosen to enhance internal turbulent flow i.e. to avoid laminar or stratified flow of the liquid to be cooled; desirably the tube finning should not reduce those respective standards e.g. of tube wall thickness and thus of strength, or of tube uniformity and fin engagement and thus of heat transfer to the fins.
The fins should be positioned on the tube so as to encourage maximum heat transfer to the coolant, which will not occur if the fin spacing is irregular, or if the fin angles are irregular (with an annular gap of varying axial length between adjacent fins).
If the tube walls need to be thinned to accept the fins, one or more of the tubes may burst in service and need to be plugged; if the fins are irregularly spaced and/or angled the performance of the heat exchanger will be reduced.
It is a known design criterion when constructing a matrix or array of finned tubes for a heat exchanger both to arrange the tubes as close as possible to each other (to reduce the size of the heat exchanger), and to have a maximum area of thermal transfer between the working fluid and the coolant (to maximise the possible heat exchange). When utilising tubes fitted with the known annular fins in such an array, the spacing between the tubes will be limited by the outer diameter of the fin(s); if as is usual the fins have circular outer peripheries there are areas between adjacent tubes which do not contribute to heat transfer, and a finning method and machine permitting fins to be fitted which can utilise these areas is desirable.
The performance of a heat exchanger in part depends upon the number of fins fitted to a tube, and to the total number of fins i.e. to the aggregate extended area available for heat exchange as well as to the positioning and disposition of those fins.

Tube finning machine and method and product


Devices and methods for implementing selective, or asymmetric, attenuation of an x-ray beam. In one example, a filter is provided that is substantially in the form of a wedge where some portions of the filter are thicker, and thus provide greater attenuation, than other, thinner portions of the filter. The filter is situated between the target surface of the anode and the x-ray subject so that x-rays generated by the target pass through the filter before reaching the x-ray subject. Specifically, the filter is oriented so that the thicker portion of the filter receives the higher intensity portion of the x-ray beam, while the thinner portion of the filter receives the relatively lower intensity portion of the x-ray beam. Thus, the gain profile of the x-ray beam is flattened so that the intensity, or flux, of the x-ray beam is relatively uniform throughout a substantial portion of the beam profile.

1. Field of the Invention
The present invention relates generally to x-ray systems, devices, and related components. More particularly, exemplary embodiments of the invention concern devices and methods that enhance x-ray flux uniformity and thus contribute to; an improved signal-to-noise ratio and increased dynamic range in the x-ray imaging device.
2. Related Technology
The ability to consistently develop high quality radiographic images is an important element in the usefulness and effectiveness of x-ray imaging devices as diagnostic tools. However, various problems and shortcomings relating to the design, construction and/or operation of the x-ray device often act to materially compromise the quality of radiographic images generated by the device. One problem commonly encountered in x-ray devices is the occurrence of undesirable variation in the intensity, or flux, of x-rays produced by the target. Such variations in x-ray intensity often cause visible differences in the image density of the radiographs, thereby impairing the quality and usefulness of the image. As discussed below, this lack of flux uniformity is due at least in part to anode geometry and other related considerations.
In typical x-ray tubes, x-rays are produced when an electron beam generated by the cathode is directed to a target surface or a target track, composed of a refractory metal such as tungsten, of an associated anode. In many instances, the electron beam penetrates the target surface. Such penetration of the target surface usually occurs when the target surface is worn and/or has other irregularities, but can occur under other circumstances as well.
In general, when x-rays are generated below the target surface, such x-rays typically take a variety of different paths through the target material to the x-ray subject. Because some of such paths are relatively longer than others, the anode material imparts a filtering effect to, or attenuates, the generated x-rays and so that the photon fluence and the spectral distribution are thereby affected. This phenomenon is sometimes referred to as the "heel effect."
One particular consequence of the heel effect with respect to the x-ray beam is that the mean energy of the x-ray spectrum is relatively higher in some areas of the x-ray beam than in others. While this effect is cause for concern in a variety of different type of x-ray tube configurations, the heel effect is particularly acute in rotating anode type tubes since the targets employed in such tubes have relatively small angles, some as low as about 7 degrees. Cone beam computed tomography ("CBCT") devices and processes are particularly susceptible.
As suggested above, the anode geometry, and the geometry of the target track in particular, plays a role in producing the heel effect whereby x-rays that are required to travel relatively further through the target track will experience a relatively greater degree of attenuation than x-rays traveling a relatively shorter distance through the target track. More particularly, the distance traveled by the x-ray through the target track is largely a function of the takeoff angle of the x-ray, or the angle of the travel path of the emitted x-ray with respect to a reference axis, such as an axis parallel to the target surface. Thus, a relatively smaller takeoff angle corresponds to a relatively shorter distance for the x-ray to travel through the target track, while a relatively larger takeoff angle corresponds to a relatively longer distance traveled through the target track material. This relationship, and the relative magnitude of the resulting effects, can be considered in terms of the relation of the takeoff angle of the x-ray to the track angle of the anode.
In particular, as the takeoff angle approaches the track angle, the travel path of the x-ray moves closer to a parallel orientation with respect to the target surface. Consequently, the degree of attenuation experienced by any particular x-ray increases as the takeoff angle of the x-ray approaches the track angle. This is readily illustrated by consideration of the end conditions where an x-ray travels either parallel or perpendicular to the target surface. In particular, an x-ray traveling parallel to the target surface travels a greater distance through the target material than an x-ray traveling perpendicular to the target surface.
Such variations in attenuation imposed on the x-rays by the target track material results in a lack of flux uniformity in the x-ray beam. It is often the case that the flux, or intensity is relatively, higher at the center of the x-ray beam and relatively lower along the edges or peripheral portions of the x-ray beam. While irregularities in flux uniformity are often attributable to considerations such as the anode geometry and the condition of the anode, flux variations may be a function of other variables as well. For example, the distance between the x-ray beam source and the imaging plane may also play a role in the relative uniformity of the flux associated with an x-ray device.
It was noted earlier that a lack of uniform flux in the x-ray beam implicates a variety of different problems. For example, nonuniform flux contributes to unacceptably high signal-to-noise ratios ("SNR"). In particular, the signal, or usable portion, of the x-ray beam is smaller relative to the noise, or unusable portion, of the x-ray beam, than might otherwise be the case. Thus, the portion of the x-ray beam that can be effectively employed in radiographic imaging processes is reduced.
Another concern relates to the impact that nonuniform flux has with respect to a dynamic range of an imager. In particular, to the extent that the flux varies over the imager, the dose available to the edges of the detectors is reduced relative to the dose available elsewhere and, thus, the dynamic range of the imager is correspondingly impaired.
In recognition of these, and other problems, attempts have been made to overcome the problems flowing from the influence of the heel effect. One such attempt involves the calibration of a flat panel imager. Generally, this attempt is a software implemented approach that involves exposing the flat panel imager to an x-ray flux and compensating gains for each pixel based upon a combination of the dose to, and response of, each pixel. If a dose to a particular pixel is reduced, the gain for that pixel is increased. By performing this process repeatedly, the gain of the unattenuated x-ray beam can be flattened somewhat.
This calibration process thus represents somewhat of an after-the-fact approach to nonuniform flux. In particular, this approach concentrates on modifying a response of the imager to the unattenuated x-ray beam, rather than performing any attenuation process on the x-ray beam itself.
The flat panel imager calibration process is largely directed to calibration of imager gain, but does little or nothing to reduce the overall dynamic gain of the x-ray system. Further, the calibration process can be time consuming.
In view of the foregoing, and other, problems in the art, it would be useful to provide methods and devices that, among other things, implement selective attenuation of an x-ray beam so as to aid in overcoming the heel effect, and other phenomena, and thus contribute to a relative improvement in flux uniformity of the x-ray beam.

Asymmetric flattening filter for x-ray device

Varian Medical Systems Technologies, Inc.


A system, method, and computer readable medium that facilitate verbal control of conference call features are provided. Automatic speech recognition functionality is deployed in a conferencing platform. Hot words are configured in the conference platform that may be identified in speech supplied to a conference call. Upon recognition of a hot word, a corresponding feature may be invoked. A speaker may be identified using speaker identification technologies. Identification of the speaker may be utilized to fulfill the speaker's request in response to recognition of a hot word and the speaker. Particular participants may be provided with conference control privileges that are not provided to other participants. Upon recognition of a hot word, the speaker may be identified to determine if the speaker is authorized to invoke the conference feature associated with the hot word.

A conference call is a telephone call in which more than two parties participate in the call. The conference call may be designed to allow a called party to participate during the call, or the call may be set up so that a called party may only listen into the call and is unable to contribute audio to the call. When a plurality of participants are allowed to participate in the call, the conference platform receives a plurality of audio streams from the conference participants, mixes these streams, and transmits the mixed audio streams back to the participants.
Conference calls may be designed so that the calling party, or conference originator, calls other participants and adds them to the call. In other systems, participants are to able call into the conference call themselves, e.g., by dialing into a conference bridge, by using a special telephone number set up for that purpose, or by other mechanisms.
Most companies use a specialized service provider for conference calls. These service providers maintain the conference bridge, and provide the phone numbers used to access the meeting or conference call.
Various conference call features may be activated by one or more conference participants during a conference call. For example, a mute feature may be activated to prohibit transmission of audio into the conference call by the muted participant. A lock control may be activated to prohibit additional participants from joining the conference call. A roll call control may be activated that transmits an audible roll call of the participants included in the conference call.
Contemporary conferencing platforms rely on manual user input, e.g., by dual-tone multi-frequency (DTMF) or keyed input supplied at a conferencing station, to invoke conferencing features or controls. Thus, a user at a rotary phone may not have any mechanism for activating a conference feature. Moreover, contemporary keyed input mechanisms are often cumbersome for participants to supply.
Therefore, what is needed is a mechanism that overcomes the described problems and limitations.

System, method, and computer-readable medium for verbal control of a conference call


An apparatus spreads flowable materials such as adhesives and/or sealants on a surface such as a floor and/or a wall. The apparatus has a pad retainer for a removable spreader pad and a reservoir chamber for flowable material pivotally attached to the pad retainer to permit pivoting of the reservoir chamber frontwards and backwards. The reservoir chamber has an adjustable gate through which the flowable material may exit. The gate is proximal the bottom of the reservoir chamber and complementary to the width of the pad retaining means to permit more uniform spreading of the flowable material. A handle is attached to and extends from the reservoir chamber. The handle may pivot from side to side on the reservoir chamber and may be hollow to house a cable associated with the means for opening the gate.

A number of service industries in which a decorative or protective finish is applied to a surface employ an adhesive and/or sealant for that purpose. The adhesive and/or sealant must be spread uniformly as a thin coating on the surface. A particular industry with such a requirement is the installation of coverings on floors and/or walls. Coverings may be, for example, carpet, sheet plastic (e.g. vinyl), plastic tiles, ceramic tiles, composite strips and wood strips.
Adhesives and sealants are generally supplied in a variety of containers of the type also generally used for paints. Thus, small quantities of a liter or part liter are supplied in metal cans with press-on lids, while larger quantities, e.g. 20 or 40 liters, are supplied in small plastic drums with snap-on lids. Irrespective of the size of the surface that is to be coated, the usual method of application is for a quantity of the material to be poured onto the surface, if it is sufficiently easily flowable, or if too viscous to be poured easily, for small quantities to be scooped from the container and dumped on the surface. It is then spread uniformly by the operator, kneeling when the surface is a floor, employing for the purpose a metal or plastics hand tool of approximately rectangular shape, usually about 20 cm (8 ins) in width, the longer straight edge which engages the floor being toothed or serrated in a regular pattern so as to provide a row of uniform-size, uniformly-spaced gaps whereby corresponding uniform-size, uniformly parallel spaced lines of the adhesive are formed on the surface as the tool is dragged over it, the surplus material being pressed ahead of the tool and escaping around the edges. Such operations are labour-intensive and also tend to be somewhat messy unless the operator is particularly careful, especially as the container is emptied, when it becomes more difficult to extract the remaining material therefrom.
To mitigate against the problems in the art, there have been developed manually operable spreading apparatuses to assist in spreading flowable materials on to a surface. Such apparatuses are disclosed in U.S. Pat. No. 5,937,628 issued Aug. 17, 1999 and U.S. Pat. No. 6,325,563 issued Dec. 4, 2001, both in the name of William Matechuk. While these apparatuses are an improvement over the labour-intensive methods described above, there still remains a need for a spreading apparatus with improved spreading characteristics and improved ease of use.

Spreading apparatus for flowable materials


Noise estimation circuitry for estimating the noise in a small number of horizontal scanning lines of a video signal includes a lowpass line comb filter responding to said video signal, but not to chrominance-descriptive components thereof. The video signal free from chrominance-descriptive components is repeatedly sampled during the backporch interval of each horizontal scanning line, and the samples are accumulated to generate a revised noise estimate each successive horizontal scanning line.

In television signal processing, various signal processing techniques are preferably changed in accordance with changes in the signal-to-noise conditions. For example, peaking of the higher frequency portions of the luminance signal should be lowered or discontinued for a noisy signal. As a further example, it is desirable to reduce color saturation for a noisy signal, thereby to avoid the kinescope being driven into over-saturation or "blooming" by noise accompanying color-difference signals.
U.S. Pat. No. 5,113,262 issued May 12, 1992 to C. H. Strolle et alii, entitled "VIDEO SIGNAL RECORDING SYSTEM ENABLING LIMITED BANDWIDTH RECORDING AND PLAYBACK" describes a modification of the VHS video cassette recording system, in which a wideband luminance signal has its spectrum folded before being used to frequency-modulate the luminance carrier during the recording of the video tape cassette, and in which the folded-spectrum signal recovered during playback by demodulating the luminance carrier is unfolded to reproduce the wideband luminance signal. During the recording of noisy composite video signals it may be desirable to limit the bandwidth of the luminance signal and avoid spectrum folding procedures. During the playback of the noisy video signals recorded without folding the spectrum of the luminance signal, the unfolding procedures can be dispensed with responsive to sensing the noise being above a prescribed level.
Generally speaking, non-coherent, random noise (such as thermal noise) accompanying a video signal can be detected by monitoring that signal during portions of the vertical blanking interval where no video information is being transmitted. Such a concept is well described in the television literature. In a video cassette recorder, however, monitoring a video signal during vertical blanking intervals in order to measure accompanying noise tends to be impractical, because the nature of video cassette recorder signal processing frequently causes additional noise and distortion during the vertical interval. Alternatively, one may consider monitoring a portion of the television horizontal scanning line. Although monitoring of the noise superposed on horizontal synchronizing pulses is a possibility, synchronization compression is likely to occur in television and video cassette recorders, and as a result monitoring of the peak portions of the horizontal synchronizing pulses is not especially reliable for noise detection.
In U.S. Pat. No. 4,873,574 issued Oct. 10, 1989 and entitled "NOISE MEASUREMENT FOR VIDEO SIGNALS", T. A. Darby describes the monitoring of a video signal during backporch intervals as respectively follow horizontal synchronizing pulses, in order to measure the noise accompanying video signals over a field interval. One noise sample is taken during each backporch interval, and the samples are accumulated over a field interval to provide a measure of the noise content accompanying the field of video information.
However, in a variety of video signal processing environments, noise can vary within the duration of one field of video, giving rise to a need for noise to be detected and measured more frequently than once a field. One noise sample taken during each backporch interval does not provide a noise-signature component that can be relied on to be representative of the noise accompanying a video signal for each horizontal line, since the single sample may be taken during a time noise energy is atypical.

Estimation of noise using burst gate response to video signal


In one embodiment, a method includes: accessing a bite register with a post, upper and lower dental models, and a fixture having upper and lower plates and a clamp; coupling the register post to the fixture, such that the register post has a first orientation; coupling the upper and lower models to the register; coupling the upper and lower models to the upper and lower plates; uncoupling the register; coupling an appliance post to the fixture, such that the appliance post has a second orientation the same as the first orientation; and forming a custom oral appliance coupled to the appliance post and maintaining the second orientation of the appliance post. In one embodiment, a device is configured to couple to an articulator and to position and retain a bite register post. The device includes a lower member, first and second couplers, an upper member, and an adjustor.

Many people experience breathing problems on a recurring basis, which often result in sleep disordered breathing (i.e., difficulty sleeping, snoring, or other more serious conditions such as obstructive sleep apnea). As technology advances, people with such breathing problems demand increased performance and comfort. Previous devices for improving a user's breathing have included oral appliances and clinical gas delivery devices. Examples of clinical gas delivery devices include face masks, nose masks, and nasal inserts that help deliver clinical gases to the user. These devices have been used with various positive air pressure systems to deliver air to the user's nose at a positive pressure to help force open the user's breathing passage and thereby improve the user's breathing. Examples of oral appliances include devices that are inserted into a user's mouth for adjustably extending the user's lower jaw forward. These devices open the breathing passageway more fully to allow easier breathing through the nose and mouth. Previous devices have also included combination systems including both oral appliances and clinical gas delivery devices. These combination systems have been used to obtain the benefits of both oral appliances and clinical gas delivery devices and/or to use the oral appliance to help secure the clinical gas delivery device in position. Previous fitting techniques for these combination systems have involved an iterative approach that has typically required the user to make multiple office visits to obtain satisfactory fit and performance.
Overview
According to one embodiment, a method for forming a custom oral appliance includes accessing a bite register for a particular user, the bite register comprising a post, an upper impression of at least some of the particular user's upper teeth, and a lower impression of at least some of the particular user's lower teeth; accessing an upper dental model of at least some of the particular user's upper teeth and a lower dental model of at least some of the particular user's lower teeth; and accessing a fixture comprising an upper plate, a lower plate, and a clamp and configured to repeatably position and secure a post. The method also includes coupling the bite register post to the fixture using the clamp of the fixture, such that the bite register post has a first orientation relative to the fixture; coupling the upper dental model and the lower dental model to the bite register, such that the upper dental model seats within the upper impression of the bite register and the lower dental model seats within the lower impression of the bite register; while the upper dental model is seated within the upper impression of the bite register and the bite register post is coupled to the fixture, coupling the upper dental model to the upper plate of the fixture; while the lower dental model is seated within the lower impression of the bite register and the bite register post is coupled to the fixture, coupling the lower dental model to the lower plate of the fixture; and while the upper dental model is coupled to the upper plate of the fixture and the lower dental model is coupled to the lower plate of the fixture, uncoupling the bite register from the upper dental model, the lower dental model, and the fixture. The method further includes coupling an oral appliance post to the fixture using the clamp of the fixture, such that the oral appliance post has a second orientation relative to the fixture, the second orientation of the oral appliance post being the same as the first orientation of the bite register post; and while the upper dental model, the lower dental model, and the oral appliance post are coupled to the fixture, forming a custom oral appliance that is custom-fitted to the upper dental model and the lower dental model, such that the custom oral appliance couples to the oral appliance post and maintains the second orientation of the oral appliance post.
According to another embodiment, a method for forming a custom oral appliance includes accessing a bite register for a particular user, the bite register comprising a post, an upper impression of at least some of the particular user's upper teeth, and a lower impression of at least some of the particular user's lower teeth; accessing an upper dental model of at least some of the particular user's upper teeth and a lower dental model of at least some of the particular user's lower teeth; accessing an upper arch custom-fitted to the upper dental model and configured to receive at least some of the particular user's upper teeth, a lower arch custom-fitted to the lower dental model and configured to receive at least some of the particular user's lower teeth, and a connector that couples the upper arch to the lower arch; and accessing a fixture comprising an upper plate, a lower plate, and a clamp and configured to repeatably position and secure a post. The method also includes coupling the bite register post to the fixture using the clamp of the fixture, such that the bite register post has a first orientation relative to the fixture; coupling the upper dental model and the lower dental model to the bite register, such that the upper dental model seats within the upper impression of the bite register and the lower dental model seats within the lower impression of the bite register; while the upper dental model is seated within the upper impression of the bite register and the bite register post is coupled to the fixture, coupling the upper dental model to the upper plate of the fixture; while the lower dental model is seated within the lower impression of the bite register and the bite register post is coupled to the fixture, coupling the lower dental model to the lower plate of the fixture; while the upper dental model is coupled to the upper plate of the fixture and the lower dental model is coupled to the lower plate of the fixture, uncoupling the bite register from the upper dental model, the lower dental model, and the fixture; and coupling an oral appliance post to the fixture using the clamp of the fixture, such that the oral appliance post has a second orientation relative to the fixture, the second orientation of the oral appliance post being the same as the first orientation of the bite register post. The method further includes positioning the upper arch relative to the upper dental model such that at least some of the teeth of the upper dental model seat within the upper arch; positioning the lower arch relative to the lower dental model such that at least some of the teeth of the lower dental model seat within the lower arch; and while the upper dental model, the lower dental model, and the oral appliance post are coupled to the fixture, and while at least some of the teeth of the upper dental model are received within the upper arch and at least some of the teeth of the lower dental model are received within the lower arch, coupling the oral appliance post to the connector coupling the upper arch to the lower arch to form a custom oral appliance that is custom-fitted to the upper dental model and the lower dental model and maintains the second orientation of the oral appliance post.
According to another embodiment, a method for forming a custom oral appliance includes accessing a bite register for a particular user, the bite register comprising an impression of at least some of the particular user's teeth; accessing a dental model of at least some of the particular user's teeth; and accessing a fixture comprising a plate and a clamp and configured to repeatably position and secure a post. The method also includes coupling the bite register post to the fixture using the clamp of the fixture, such that the bite register post has a first orientation relative to the fixture; coupling the dental model to the bite register, such that the dental model seats within the impression of the bite register; while the dental model is seated within the impression of the bite register and the bite register post is coupled to the fixture, coupling the dental model to the plate of the fixture; and while the dental model is coupled to the plate of the fixture, uncoupling the bite register from the dental model and the fixture. The method further includes coupling an oral appliance post to the fixture using the clamp of the fixture, such that the oral appliance post has a second orientation relative to the fixture, the second orientation of the oral appliance post being the same as the first orientation of the bite register post; and while the dental model and the oral appliance post are coupled to the fixture, forming a custom oral appliance that is custom-fitted to the dental model, such that the custom oral appliance couples to the oral appliance post and maintains the second orientation of the oral appliance post.
According to another embodiment, a device for use in forming a custom oral appliance includes a dental articulator and a clamp. The dental articulator is configured to substantially replicate jaw movement and comprises an upper plate configured to position and retain a first dental model, a lower plate configured to position and retain a second dental model, and a hinge configured to rotatably couple the upper plate to the lower plate. The clamp is coupled to the dental articulator and is configured to position and retain a post of a bite register.
According to another embodiment, a device for forming a custom oral appliance is configured to couple to a dental articulator and to position and retain a post of a bite register. The device includes a lower member, first and second couplers, an upper member, and a threaded adjustor. The lower member defines a channel to receive and position a post of a bite register. The first and second couplers couple to the lower member. The upper member includes an opening and a slot, the upper member configured to receive the first coupler through the opening and to engage the second coupler through the slot to position the upper member relative to the lower member. The threaded adjustor couples to the upper member and is configured to apply a force against the post of the bite register when the post of the bite register is received and positioned within the channel and the upper member is positioned relative to the lower member.
Certain embodiments may provide one or more technical advantages. For example, certain embodiments may provide a more accurate or efficient method of forming a custom oral appliance that does not require numerous iterations or repeated visits to the clinician's facilities. Certain embodiments may provide improved systems or methods to orient dental models to a dental fixture. Certain embodiments may provide for the formation of an oral appliance with a precisely oriented post that may be used to precisely and repeatably couple to one or more external devices, such as clinical gas delivery devices. Certain embodiments may provide all, some, or none of these advantages. Certain embodiments may provide one or more other technical advantages, one or more of which may be apparent to those skilled in the art from the figures, descriptions, and claims included herein.

Device and method for forming a custom oral appliance


An atmospheric water generation system comprises water vapor consolidation systems configured to increase the relative humidity of a controlled air stream prior to condensing water from the controlled air stream. The water vapor consolidation system comprises a fluid-desiccant flow system configured to decrease the temperature of the desiccant to encourage water vapor to be absorbed by the desiccant from an atmospheric air flow. The desiccant flow is then heated to encourage water vapor evaporation from the desiccant flow into a controlled air stream that circulates within the system. The humidity of the controlled air stream is thereby increased above the relative humidity of the atmospheric air to facilitate condensation of the water vapor into usable liquid water.

The amount of freshwater available for human consumption, plant irrigation, livestock and herd sustenance, commercial and/or industrial usage, and other purposes has generally been overtaken by the amount of freshwater needed for such purposes. Particularly in arid climates characterized by minimal annual rainfall and without access to other freshwater sources, maintaining an adequate amount of water for human and/or animal consumption and usage has become increasingly expensive in recent years. Processes such as desalination, water filtration and/or purification, groundwater (e.g., aquifer) exploitation, and other processes are often used in combination to supply freshwater to various geographical regions, depending on the relative availability and expense of each water sourcing process.
Water shortages in certain geographical regions are also at least partially responsible for food shortages in certain areas of the globe as well. Where water is not readily available for crop irrigation and for hydrating livestock, basic nutritional foods may be difficult to cultivate, and may be difficult or expensive to procure in an open market.
Accordingly, a need generally exists for processes that expand the availability of freshwater, particularly in arid geographical areas and/or areas with no access to standing water or sub-surface water or in areas where such have become contaminated

Atmospheric water generation systems and methods


A disk drive mechanism includes a disk clamping apparatus which has an improved structure and which is easily fabricated, thereby to reduce costs. The disk clamping apparatus includes a clamp having a plurality of clamp jaws movable horizontally, such that the apparatus is compact. The clamp also includes first and second grooves formed according to central hole sizes of the disks to be accommodated on the turntable so that the clamp can be used for both a compact disk and a laser disk.

1. Field of the Invention
The present invention relates to a disk drive mechanism for reading data recorded on a disk, such as a compact disk or a laser disk, and, more particularly, to a disk clamping apparatus arranged in a disk drive mechanism, which fixedly sets a disk onto a turntable by the centrifugal force resulting from the rotation of a motor rotating the disk so as to read out data from the disk.
2. Description of the Prior Art
Generally, a disk drive mechanism has a turntable having an upper surface on which a disk is stably set, a motor for rotating the turntable, a clamping device for clamping the disk onto the turntable and a pickup for reading data recorded on the disk.
In the disk drive mechanism, the clamping device includes a rack slidably arranged on a slider member, a cam rotated by the movement of the rack, a clamping arm upwardly and downwardly rotated to be centered with a hinge according to the cam rotation, and a clamp driven according to the upward and downward rotation of the clamping arm for clamping the disk onto the turntable.
The clamping device thus constructed serves to stably set the disk on the turntable to prevent undesirable effects, for example, noise, short-signal and jitter, resulting from the disk being eccentrically set on the table or the disk being vibrated due to an external shock.
FIG. is a front view of a conventional disk drive mechanism, in which a partial cross-section of the mechanism is shown to illustrate the operation of the disk clamping apparatus. In FIG. 1, 1 denotes the disk on which data is recorded or read out, 2 denotes the turntable on which the turntable is stably set, and 3 denotes a motor for rotating the turntable 2.
Further, 4 denotes a rotational shaft transferring the force of the motor 3 to the turntable 2. 5 denotes a pickup for recording or reading data on or from the disk 1. The pickup 5 records or reads data on or from the disk while maintaining a predetermined distance from the disk 1. 6 denotes a slider for moving the pickup 5. The slider 6 has the pickup 5 mounted at one side thereof and a rack 6a is arranged at the other side of the slider 6.
7 denotes a guide bar for guiding the movement of the slider 6, and 8 denotes a cam rotated by the rack 6a engaged with the slider 6. The cam 8 has a gear 8a formed at a portion of its outer periphery, so that the cam 8 is rotatably driven by the rack 6a and gear 8a being engaged together when the rack 6a, disposed on the slider 6, is moved rightwardly and leftwardly. 9 denotes a clamp arm upwardly and downwardly rotated to be centered with a hinge 9a formed at an end of the clamp arm 9 in response to the rotation of the cam 8. 10 denotes a clamp disposed at the other end of the clamp arm 9 for stably fixing the disk 1 onto the turntable 2, and 11 denotes a spring for downwardly biasing the clamp arm 9 to control the pressure applied to the disk 1, set on the turntable 2, from the clamp 10.
With the above-described construction and looking at FIG. 1, when the slider 6 is rightwardly moved along the guide bar 7 by a slider moving means (not shown), the rack 6a arranged on the slider 6 is engaged with the gear 8a formed on the outer periphery of the cam 8. Consequently, the cam 8 is rotated leftwardly (i.e., in the counterclockwise direction).
When the cam 8 is leftwardly rotated, the clamp arm 9 is upwardly rotated and moved centering with the hinge 9a. Upon being rotated, the clamp arm 9 is centered with the hinge 9a, and the clamp 10 is upwardly lifted. Therefore, the disk 1 is removably set on the turntable 2.
When the disk 1 is set on the turntable 2 by an operator, the slider 6 is leftwardly moved along the guide bar 7 by the slider moving means, and then the cam 8 is rightwardly rotated (i.e., in the clockwise direction) according to the movement of the slider 6. By the cam rotation, the clamp arm 9 downwardly descends and centers itself with the hinge 9a by its own weight or by the weight of the clamp 10. Accordingly, the clamp 10 stably fixes the disk set on the turntable 2. Herein, the spring 11 serves to downwardly rotate the clamp arm 9 and to control the pressure of the clamp 10 provided on the disk 1.
Under this condition, when the disk drive mechanism is operated, the motor 3 rotates, so that the rotational force is transferred to the turntable 2 through the rotational shaft 4. As a result, the turntable 2 is rotated and the disk 1 fixed on the turntable 2 by the clamp 10 also is rotated.
Simultaneously with the rotation of the disk 1, the slider 6 is moved leftwardly and the pickup 5 records or reads data onto or from the disk 1.
Hence, the conventional disk clamping apparatus includes the rack being movable on the slider, the cam rotatable according to the movement of the rack, the clamp arm upwardly and downwardly rotatable to be centered with the hinge depending upon the cam rotation, and the clamp for clamping the disk set on the turntable by the upward and downward rotation of the clamp arm. Thus, the structure of this conventional apparatus is extremely complicated.
Accordingly, in such a conventional disk drive mechanism, it is difficult to manufacture the disk clamping apparatus and manufacturing costs are relatively high. Further, the clamp is located on the upper side of the disk 1 and operated upwardly and downwardly. Hence, the disk drive mechanism must be designed so that the entire height of the apparatus, to include the range of motion of the clamp, can be accommodated. Therefore, the mechanism is not compact. Further, the turntable and the clamp for stably supporting the disk are previously limited in structure (e.g., independently designed and manufactured), so that a compact disk and a laser disk, each having a differently sized hole formed at their interiors for stably setting the respective disk on the turntable, are not compatibly used in the mechanism.

Disk clamping apparatus including a clamp having a plurality of clamp jaws movable horizontally