Patent Publication Number: US-2012037571-A1

Title: Method and apparatus for sanitizing water using an ultraviolet light

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to sanitizing water, and, more particularly, to sanitizing water using ultraviolet light. 
     2. Description of the Related Art 
     Water is a vital commodity, necessary for human life. Communities throughout the world are actively engaged in providing water to its residents to use for drinking, bathing, cooking, or other basic needs. Communities typically access a source of raw water, purify the water and then distribute the water throughout the community via a municipal water supply. 
     This raw water may be obtained from a variety of sources in various communities throughout the world. For example, raw water may be obtained from wells in the form of groundwater, or surface water from upland lakes and reservoirs, rivers, canals, low land reservoirs, etc. Typically, the raw water may contain undesirable chemical and biological contaminants that need to be removed via water purification. Most water is purified for human consumption, but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacology, chemical and industrial applications. In general, prior art purification methods include a combination of: physical processes, such as filtration and sedimentation; biological processes, such as slow sand filters or activated sludge; and chemical processes, such as flocculation and chlorination. Purification is intended to reduce the presence of contaminates, such as suspended particles, parasites, bacteria, algae, viruses, fungi, etc. 
     The ramifications of unsanitary water are severe. Various sources report that as many as 1.1 billion people lack access to an improved drinking water supply, 88% of the 4 billion annual cases of diarrheal disease are attributed to unsafe water and inadequate sanitation and hygiene, and 1.8 million people die from diarrheal diseases each year. The World Health Organization estimates that 94% of these diarrheal cases are preventable through modifications to the environment, including access to safe water. 
     Moreover, terrorists and radical groups continue to threaten the safety of the general population. At least one oft-mentioned attack is the purposeful introduction of biological components to contaminate public water supplies, water sources and water treatment facilities. 
     Current chemical purification offers some protection from the various hazards of contaminated water, but chemical disinfectants, such as chlorine, are costly to produce and use and also produce by-products or contaminates that may be harmful to both the individuals dispensing the chemicals as well as those consuming the water. Further, the chemical disinfectants are not earth or environmentally friendly and consume resources. 
     SUMMARY OF THE INVENTION 
     The disclosed subject matter is directed to addressing the effects of one or more of the problems set forth above. The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the disclosed subject matter. This summary is not an exhaustive overview of the disclosed subject matter. It is not intended to identify key or critical elements of the disclosed subject matter or to delineate the scope of the disclosed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later. 
     In one embodiment of the instant invention, a method is provided for sanitizing water. The method comprises directing ultraviolet light into a conduit capable of carrying water therein; measuring an intensity of the ultraviolet light within the conduit; and controlling the intensity of the ultraviolet light introduced into the conduit based on the measured intensity of ultraviolet light within the conduit to provide sanitized water. 
     In another embodiment of the instant invention, a method is provided for sanitizing water. The method comprises directing ultraviolet light into a conduit capable of carrying water therein; measuring a parameter of the water within the conduit associated with sanitization of the water; and controlling the intensity of the ultraviolet light introduced into the conduit based on the measured parameter of the water. 
     In still another embodiment of the instant invention, an apparatus is provided for sanitizing water. The apparatus comprises: a container for housing water; an ultraviolet light; and means for transmitting the ultraviolet light into the container housing the water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosed subject matter may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which: 
         FIG. 1A  conceptually illustrates a block diagram that stylistically depicts one embodiment of the instant invention; 
         FIG. 1B  conceptually illustrates one embodiment of a flowchart that may function to control the operation of the instant invention shown in  FIG. 3A ; 
         FIGS. 2A-2B  conceptually illustrate alternative embodiments of the instant invention with ultraviolet let being directed coaxially with a conduit; 
         FIG. 3A  conceptually illustrates a block diagram that stylistically depicts one embodiment of the instant invention that includes a mechanism for disturbing the flow of water within a conduit; 
         FIG. 3B  conceptually illustrates one embodiment of a flowchart that may function to control the operation of the instant invention shown in  FIG. 3A ; 
         FIGS. 4A-4B  conceptually illustrate alternative embodiments of the instant invention with ultraviolet let being directed coaxially with a conduit; 
         FIG. 5  conceptually illustrates a block diagram that stylistically depicts one embodiment of the instant invention that includes an arrangement for introducing ultraviolet light in a bath; 
         FIGS. 6A-6G  conceptually illustrate alternative embodiments of the instant invention with ultraviolet light being emitted by a vertical cavity surface emitting laser; and 
         FIG. 7  conceptually illustrates one embodiment of a flowchart that may function to control the operation of the instant invention shown in  FIGS. 6A-6G . 
     
    
    
     While the disclosed subject matter is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the disclosed subject matter to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims. 
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Illustrative embodiments are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions should be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this Disclosure. 
     The disclosed subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present invention with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the disclosed subject matter. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase. 
       FIG. 1A  conceptually illustrates a first exemplary embodiment of the instant invention. Generally, a system  10  is provided to sanitize raw water  12  while the water is being prepared for distribution to a community. The system  10  includes an ultraviolet (UV) light source, such as a laser  16  operating under the control of a computer control system  18  to dispense UV laser light into the water while the water is contained, such as by a conduit, pipe  20 , tank, or other container. 
     The UV laser  16  may take on any of a variety of forms, but generally, a common wavelength for the UV laser  16 , when used in a sanitizing application, is in the range of about 266 nm to about 355 nm, which those skilled in the art will appreciate includes near UV wavelengths of about 220 nm to about 400 nm, far UV wavelengths of about 190 nm to about 220 nm, and VAC UV wavelengths of about 90 nm to about 190 nm. Depending on the area of coverage and/or size of the container, conduit, pipe or tank, turbidity of the water, and flow rate, the power of the UV laser  16  may range from as little as 2 mW to hundreds or even thousands of watts of UV laser power. In one exemplary embodiment of the instant invention, a UV laser  16  operating at about 355 nm wavelength proved to be highly effective in sanitizing contaminated water to achieve an effective purity rate as high as 99.7% for killing bacteria, viruses, mold, fungi and insect larvae. In one particular embodiment, the UV laser may take the form of Model No. DP-UV-355 available from Han&#39;s Laser and may be comprised of an array of one or more lasers. 
     The UV laser light may be distributed within the pipe  20  using a variety of mechanical and/or optical systems. For example, a rotating or oscillating mirror may be used to reflect the laser light through a port  22  in the pipe  20  to create a pattern of light that effectively exposes the water  12  to the laser light regardless of the location of the water  12  within the pipe  20 .  FIG. 1A  illustrates the laser light being distributed in a circular pattern for illustrative purposes only. Those skilled in the art will appreciate that the laser light could be distributed in a variety of patterns, such as square, rectangular, linear, raster scan or even random patterns in order to effectively expose the water  12  to the UV laser light. 
     It is anticipated that some embodiments of the invention may utilize a plurality of UV lasers  16 . Moreover, when multiple UV lasers  16  are employed, they may be selected to have substantially similar or substantially different wavelengths. In some embodiments, it may be useful to provide two or more UV lasers  16  irradiating the water  12  at substantially the same location with substantially similar wavelengths to achieve higher power levels. Alternatively, in some embodiments, it may be useful to provide two or more UV lasers  16  irradiating the water  12  at different, spaced apart locations to achieve greater coverage. Further, some embodiments of the instant invention may utilize two or more UV lasers  16  that operate at different wavelengths to expose the water  12  to a wider range of UV laser light in cases where the various contaminants are eradicated more effectively by different frequencies of UV laser light. 
     The computer control system  18  may take on any of a variety of forms, including but not limited to conventional desktop computers, laptop computers, servers, minicomputers, controllers, and the like. The computer control system  18  may be comprised of a microprocessor, memory, a display, and input or pointing devices, such mice, keyboards, touch sensitive pads or screens and the like. 
     In one embodiment of the instant invention, the computer control system  18  operates to control various parameters of the system  10  to insure an effective kill rate. For example, a laser power sensor  24  may be disposed to sense actual laser power being delivered to the water  12  in the pipe  20 . The laser power sensor  24  provides feedback to the computer control system  18 . The computer control system  18  may then vary a signal delivered to the laser  16  to raise or lower the power of the UV laser  16 , as desired. Additionally, the flow rate of the water  12  in the pipe  20  may likewise be adjusted according to the actual laser power detected by the laser power sensor  24 . For example, the computer control system  18  may reduce the flow rate of the water  12  in response to detecting reduced UV laser power, and/or control upstream processes to affect water parameters, such as turbidity. For example, the computer control system may send a signal to an upstream process that is designed to clarify the water. 
     Those skilled in the art will appreciate that clear water will more readily pass the UV laser light than will more turbid water. Those skilled in the art will appreciate that UV laser power may be increased throughout the pipe  20  by increasing water clarity.  FIG. 1B  illustrates an exemplary embodiment of a control sequence that may be implemented, at least partially, within the computer control system  18 . The process begins at block  100  with water flow being provided through the pipe  20 . At block  102 , the computer control system  18  selects or establishes a desired flow rate of the water  12 . At block  104 , the UV laser  16  is enabled, and various parameters of the UV laser  16  are adjusted, either manually, or by the computer control system  18  at block  106 . For example, it may be useful to set the laser and optics focus adjustment, aperture beam alignment, and divergence. At block  108 , the computer control system  18  sets the laser output power based on feedback of digital signals received from the irradiance monitor which detects concentrations of UV laser energy levels and provides continuous feedback of UV energy relayed to the logic control of the computer to maintain stable and effective levels of laser power  16  required for safe purification and sanitization of the water source. Periodically, the computer control system  18  will receive a control signal from the laser power sensor  24 , and use that signal to adjust various parameters of the UV laser  16  to achieve the desired sanitization of the water  12 . For example, at block  110  the computer control system  18  may set or adjust a pulse width, a repetition rate, and/or tune the frequency wavelength of the UV laser  16 . These parameters may be adjusted as necessary to maintain a desired level of UV laser power in the pipe  20 . 
     It may also be useful to periodically test the water  12  to determine the effectiveness of the sanitizing process. Thus, at block  112 , the results of this testing may be input into the computer control system  18  and used to further control the sanitizing process. For example, if the testing indicates an undesirable level of contamination in the sanitized water  12 , then the computer control system  18  may further adjust the parameters of the system to produce a greater level of sanitization, such as by reducing the flow rate of the water  12 , increasing the power of the UV laser  16  and/or increasing the clarity of the water  12 . 
     Additionally or alternatively, it may be useful to route the water  12  through one or more additional sanitizing steps, depending upon the results of the testing. For example, inadequately sanitized water  12  may be passed through the same laser sanitizing process, or alternatively through a second similarly arranged system  10 . 
     It is anticipated that the instant invention may find application in a variety of systems, such as municipal water systems and/or bottled water facilities. Those skilled in the art will appreciate that once the sanitization of the water  12  has been completed to a satisfactory level, and then the water  12  is directed to users of the commercial water system or packaged and shipped to customers, such as is shown in block  114 . 
     In various alternative embodiments of the instant invention, it may be useful to provide a plurality of paths for the laser light to traverse from one or more UV lasers  16  to the water  12 . In this manner, a more complete exposure of the water  12  to the laser light may be accomplished. For example, various laser light paths may be accomplished by routing the laser light through flexible fiber optic links or through other conventional optical devices, such as mirrors, splitters, and the like, to pass through multiple ports  24  distributed at various locations longitudinally along the pipe or at various locations distributed about the periphery of the pipe  20 . 
     Alternatively, turning first to  FIG. 2A , the laser  16  projects laser light through one or more optical devices  200 , such as fiber optic cables, beam splitters, mirrors, or the like, to produce one or more beams of laser light  202  extending along a line generally longitudinally aligned with the pipe  20  in either an upstream or downstream direction. These beams of laser light  202  may be configured by the optical devices  200  to diverge and flood the pipe  20  with UV laser light along the length of the pipe  20 . In one embodiment of the instant invention, it may be useful to form at least a portion of the interior of the pipe  20  be coated with or formed from a reflective or refractive material to cause the UV laser light to reflect or bend back toward the interior of the pipe  20  and thereby provide greater coverage of the interior of the pipe  20  with the UV laser light. 
       FIG. 2B  illustrates an alternative embodiments of the instant invention in which multiple laser light paths are presented within the pipe  20 . In the illustrated embodiment of the instant invention, at least a portion of the UV laser light is passed in both an upstream and downstream direction within the pipe  20 . The optical devices  200  may be arranged to produce one or more beams of laser light  202 ,  204  extending along a line generally longitudinally aligned with the pipe  20  in both the upstream and downstream directions. 
     These beams of laser light  202 ,  204  may be configured by the optical devices  200  to diverge or expand and flood the pipe  20  with UV laser light along the length of the pipe  20 . In this manner, water  12  may be more thoroughly exposed to the sanitizing effect of the UV laser as focused coherent UV laser beams provide light energy and power at sufficient concentration and density at great depths to effectively illuminate and sanitize the water and therefore completely eliminates the need for using hazardous chemicals in large volume systems. The UV laser sanitizing systems shown in many flexible designs are easily implemented and adopted to a wide variety of existing water treatment systems or municipal plants to efficiently and effectively irradiate and eradicate ALL impurities without further need or use of chemicals treatments. 
     In various alternative embodiments of the instant invention, it may be useful to disturb the water  12  and any contaminates contained therein to insure that the contaminants within the water  12  are thoroughly exposed to the UV laser light. Turning now to  FIG. 3 , a first embodiment of a system that disturbs the water  12  in the pipe  20  is described. In the illustrated embodiment, the pipe  20  includes a mechanism  300  for creating turbulence in the water within the pipe  20 . In this manner, contaminants within the water  12  become reoriented, exposing previously hidden surfaces to the UV laser light and enhancing the sanitizing effect of the UV laser light. The turbulence creating mechanism  300  may take on any of a variety of forms, such as devices that adjust the flow rate of the water  12 , alter the path of the water  12 , and the like. In one embodiment of the instant invention, a fan or propeller structure  302  may be positioned within the pipe  20 . The propeller  302  may be freewheeling, and thus, it is turned by the force of the water flowing therethrough, or it may be driven to induce a stirring action in the water  12 . In some embodiments of the instant invention, it may be useful to employ a plurality of propellers  302 . In embodiments of the instant invention that employ either single or plural propellers  302  mounted or contained within the pipe  20 , it may be useful to utilize propellers  302  constructed of highly polished stainless steel  303  or other materials having a highly reflective or coated finish. Likewise, the interior surface of the pipe  20  may also be made from or coated with similarly highly reflective materials to provide reflective interior surfaces  304 . In this manner, laser light directed to the propellers  302  may be reflected therefrom, thereby increasing angles of incidence of the UV laser beams within the pipe segment and improving overall pervasiveness of laser light irradiation for more effective water sanitization. 
     Turning now to  FIGS. 4A and 4B , alternative embodiments of the instant invention are shown.  FIGS. 4A and 4B  illustrate alternative embodiments of the instant invention in which water is sanitized by UV laser light that is transmitted substantially along the direction of flow of the water within the pipe  20 . In the illustrated embodiments, the pipe  20  is  15  modified to include a plurality of curved or bent sections  400 ,  402 ,  404 ,  406  to produce a linear region  408  that is offset from the main path  410  of the pipe  20 . This arrangement allows the UV laser light to be readily introduced into the linear region  408  by optically coupling the laser  16  at the curved sections  402 ,  404 . This configuration allows the UV laser beam to be introduced along a line generally longitudinally aligned with the pipe  20  in either  20  the upstream direction (as shown in  FIG. 4A ) or both the upstream and downstream directions (as shown in  FIG. 4B ). These beams of laser light  202  may be configured by the optical devices  200  to diverge and flood the linear region  408  of the pipe  20  with UV laser light along a substantial portion of the length of the pipe  20 . 
     Those skilled in the art will appreciate that the curved sections  400 ,  402 ,  404 ,  406  may advantageously introduce turbulence into the water  12  within the linear region  408  of the pipe  20 . As discussed previously, this turbulence produces a mixing effect that may further disturb the contaminants so that they are more thoroughly exposed to the UV laser light to produce a greater sanitizing effect. 
       FIG. 5  illustrates an alternative embodiment of the instant invention in which water is sanitized by UV laser light  500  transmitted into a bath  502  rather than the conduit  504 . In this embodiment of the instant invention, the laser light  500  is expanded by optical or mechanical means to encompass a substantial portion of the bath  502 . The flow rate of water into and out of the bath  502  may be controlled by the computer system  18  to insure that the water  12  remains in the bath  502  and exposed to UV laser light for a sufficient period of time to provide a desired level of sanitization. The computer system  18  may adjust the flow rate to compensate for a variety of factors, including turbidity. 
     An alternative embodiment of the instant invention is shown in  FIGS. 6A-6E  and  FIG. 7 . Generally, the embodiment illustrated herein is comprised of a pipe  600  formed from a material that allows UV light to pass therethrough. In some embodiments of the instant invention at least an interior region of the pipe  600  may be formed from translucent, transparent, or otherwise optically neutral material. UV light sources  606  are disposed adjacent or within this interior region and arranged to project UV light into an interior chamber of the pipe  600 , through which water to be sterilized is flowing. In one particular embodiment, the pipe  600  may be formed or cast from acrylic, glass, or other translucent or transparent material with one or more grids or matrices of UV light sources  606  located therein. It is envisioned that hundreds, or even thousands, of the light sources  606  may be disposed therein to provide sufficient UV light to effectively sanitize the water flowing through the pipe  600 . The UV light sources  606  may take on any of a variety of forms, such as UV Vertical Light Emitting Diodes (“VLEDs”), Vertical Cavity Surface Emitting Lasers (“VCSELs”), UV Edge Emitting Lasers (“EELs”), UV plasma devices, or UV phosphor devices. 
     A power source  605  is electrically coupled to the UV light sources  606 . The computer control system  18  is coupled to the power source  605 , and operates to modify or control the amount of power delivered to the UV light sources  606  to provide a desired level of sanitization for the water flowing through the pipe  600 . In some embodiments of the instant invention, it may be useful to provide feedback sensors  610 ,  611  to ensure that a desired level of sanitization is being accomplished. The feedback sensor  610  may take the form of a UV energy sensor, which provides a feedback signal to the computer control system  18  indicating the amount of energy being delivered from the UV light sources  606 . 
     The computer control system  18  uses the feedback signal to controllably adjust the power source  605  to increase or decrease the power delivered to the UV light sources  606  to match the measured (actual) energy with the energy desired by the computer control system  18 . 
     Additionally or alternatively, the feedback sensor  611  may take the form of a water purification sensor. The water purification sensor  611  can provide a feedback signal to the computer control system  18 , which the computer control system  18  may use to adjust the energy being delivered from the UV light sources  606 . In the event that the water purification sensor  611  indicates that the purity of the water falls below a preselected setpoint, then the computer control system  18  may increase the power being delivered from the power source  605  to increase the energy supplied by the UV light sources  606  and provide an additional sanitizing affect. Alternatively, if the water purification sensor  611  indicates that the purity of the water is above a preselected setpoint, then the computer control system  18  may reduce the power being delivered from the power source  605  to provide a reduced sanitizing affect. 
     In some embodiments of the instant invention, it may be useful to have an additional grid of UV light sources  606  positioned downstream of the purification sensor  611 , so that additional sanitizing may be performed in the event that the purification sensor  611  indicates that the purity of the water is below a preselected setpoint. 
     Over time, the effectiveness of the UV light sources  606  may be reduced. Accordingly, it may be useful to employ two or more grids of UV light sources  606  so that the additional grids may be energized as the original grid of UV light sources  606  become less effective. In this manner, the useful life of the water sanitizing system may be extended. 
     In some embodiments of the instant invention, the effectiveness of the UV light sources  606  may be enhanced by placing a reflective coating or layer  623  around the transparent or translucent section of the pipe  600 . In this manner, light emitted from the UV light sources  606  may be reflected back into the interior chamber of the pipe  600  to further enhance the sanitizing effect of the UV light. 
     Likewise, as can be seen in  FIGS. 6B and 6C , the effectiveness of the UV light sources  606  may be enhanced by the use of optics to expand and/or focus the UV light. For example, as shown in  FIG. 6C , a microlens array  630  may be positioned adjacent a VCSEL array  632  to focus the UV light emitted by each of the individual VCSELs. Thereafter, an expander  634  and focus lens  636  may be used to create the desired optical pattern of UV light. Additionally, Fresnel lenses may be used in conjunction with the UV light sources  606  to focus the UV light and create greater energy density, and thus, a greater sanitizing effect. 
     One embodiment of a method that may be employed to manufacture the pipe  600  and the grid of UV light sources  606  is shown in  FIGS. 6D-6G . As shown in  FIG. 6D , the process begins by forming a generally flat grid  626  of UV light sources  606 . In  FIG. 6E , the flat grid  626  is rolled into a tube shape, placed in a mold, and cast in a transparent or translucent material, such as an acrylic, to form a sleeve  631 . One or more of the sleeves  631  are then slid into a pipe section  640  to form a pipe  600  that is capable of using UV light to sanitize water passing therethrough.  FIG. 6F  illustrates a pipe  600  in which a single sleeve  631  is disposed therein.  FIG. 6G  illustrates a pipe in which two sleeves  631  are serially disposed therein. 
     One process for sanitizing water using the embodiments described in  FIGS. 6A-6G  is set forth in a flow chart in  FIG. 7 . The process begins at block  700  with the UV sanitizing system being turned on. At block  705 , a valve is opened and water begins flowing through the pipe  600 . Signals from the feedback sensors  610 ,  611  are evaluated by the computer control system  18  at block  710 . The computer control system  18  determines whether the UV light energy is at the desired level, and, if not, adjusts the power level supplied by the power supply  605  to the UV light sources  606 . At block  715 , the computer control system  18  receives signals indicative of the actual flow rate of the water in the pipe  600 , and adjusts the setting of a control valve to maintain a desired flow rate. After any adjustment to the parameters of the system, such as power settings or flow rate, the computer control system  18  monitors the energy density and purity to determine if the adjustments have had the desired effect at blocks  720 ,  725 . If not, and the water purity drops below a desired level, an alarm is sounded at block  730  to alert personnel of a problem that requires attention. At block  735 , in the event that the system employs two UV grids  631 , then the secondary grid may be energized to assist in the sanitizing process. 
     Portions of the disclosed subject matter and corresponding detailed description are presented in terms of software, or algorithms and symbolic representations of operations on data bits within a computer memory. These descriptions and representations are the ones by which those of ordinary skill in the art effectively convey the substance of their work to others of ordinary skill in the art. An algorithm, as the term is used here, and as it is used generally, is conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of optical, electrical, or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, or as is apparent from the discussion, terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical, electronic quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Note also that the software implemented aspects of the disclosed subject matter are typically encoded on some form of program storage medium or implemented over some type of transmission medium. The program storage medium may be magnetic (e.g., a floppy disk or a hard drive) or optical (e.g., a compact disk read only memory, or “CD ROM”), and may be read only or random access. Similarly, the transmission medium may be twisted wire pairs, coaxial cable, optical fiber, or some other suitable transmission medium known to the art. The disclosed subject matter is not limited by these aspects of any given implementation. 
     The particular embodiments disclosed above are illustrative only, as the disclosed subject matter may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the claims below.