Abstract:
This document provides devices and methods for monitoring and maintenance of the temperature of medical reservoirs and boxes in a secure fashion that enables for documentation of a chain of custody and history of temperature while in storage or transit. For example, this document provides devices and methods for monitoring the temperature of blood in phlebotomy tubes or boxes of biological products. In some embodiments of the devices and methods, the temperature of the contents of the medical reservoirs are regulated, modulated, and/or maintained by the devices provided herein.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    This document relates to devices and methods for monitoring and maintaining the temperature of medical reservoirs while maintaining a secure chain of custody and log of sample or product access. For example, this document relates to devices and methods for monitoring and regulating the temperature of blood, cerebrospinal fluid, or bone marrow in tubes or vials, vaccines in ampoules or bottles, and/or biological pharmaceutical products in boxes as well as the presence of it in the device and whether it has been removed. 
         [0003]    2. Background Information 
         [0004]    The Center for Disease Control reports that $300 million dollars was wasted in 2014 due to the improper storage and regulation of temperature for vaccines. If these vaccines and other biomedical samples (such as bone marrow, cerebrospinal fluid, or blood) as well as biomedical products (such as biological or biosimilar pharmaceutical products) freeze or get too warm, they can be ruined or lose potency and efficacy. In addition many samples need to be kept frozen while in storage and in transit. In addition, when phlebotomy tubes are drawn from patients that contain blood, certain clinical diagnostic tests for cryoglobulinemia or complement deficit mandate that the tubes must be kept at body temperature (37 degrees Celsius) or a life threatening diagnosis can be missed. Consequently, rigorous control of biomedical sample and product storage temperatures, and verification of the temperatures to which blood samples have been exposed is advantageous. In addition, having a more reliable and traceable chain of custody for security purposes to prevent tampering and/or the introduction of counterfeit products for these samples and products is advantageous. In addition, it is advantageous if an electronic log can be kept for temperature deviations, changes in location, and whether the sample or product has been accessed. It is also advantageous if all these separate features could be communicated in real-time to the internet and if all these features could be combined into a small, thin, conformable device to favor space constraints. 
       SUMMARY 
       [0005]    This document provides devices and methods for monitoring and maintaining the temperature of biomedical reservoirs which has the capability to maintain a chain of custody and ensure the security of the sample or product through communications in real-time with the internet. For example, this document provides devices and methods for monitoring and maintaining (or regulating) the temperature of vaccines in ampoules, vials, or bottle, while also tracking location and position of the product. In one example of use, the devices provided herein will track and maintain temperatures to prevent excess temperatures above or below 4 degrees Celsius. 
         [0006]    In one implementation, a medical reservoir temperature monitoring and maintenance device includes: a thin and small housing that defines structure for selective coupling to a medical reservoir; a user interface coupled to the housing; and a flexible temperature sensor that can be coupled to the housing. The temperature sensor and pressure sensor is configured and operable to measure temperature of a material within the medical reservoir when the medical reservoir is coupled to the housing, and the pressure sensor to prevent tampering. The user interface includes an alarm functionality for notifying a user that the temperature sensor detected the temperature of the material to be outside of a predetermined range of acceptable temperatures and also if the pressure from stretching of the housing occurs and its contact from the reservoir changes such as when or if the sample or product has been removed from the device. 
         [0007]    Such a medical reservoir temperature monitoring and maintenance device may optionally include one or more of the following features. The structure defined by the housing for selective coupling to the medical reservoir may be included by a stretchable elastic and/or conformable plastic that allows for the tube to slip through, or could wrap around a bottle. The structure defined by the housing for selective coupling to the medical reservoir may comprise thin and small elements that are flexible and can be enclosed by a stretchable plastic that is conformable and may stick to the bottle. The medical reservoir may be a vaccine bottle or therapeutic ampoule. The temperature sensor may comprise a micro thermistor, or STT-MTJ sensor that have previously been described under US Patent Pub. #2012/0181651 A1. The user interface may include a small display. The user interface may include one or more electrical buttons. The medical reservoir temperature monitoring and maintenance device may further comprise an electrical connector coupled to the housing. The medical reservoir temperature monitoring and maintenance device may be configured and operable to wirelessly communicate with a separate computer or other device through cellular or satellite or low energy Bluetooth methods. The medical reservoir temperature monitoring and maintenance device may be configured so that it can be resistant to sterilization procedures for reusability, or it could be disposable. The medical reservoir temperature monitoring and maintenance device may further comprise a heating and cooling device (such as a micro Peltier device, or newer classes of thermoelectric-cooling mechanisms based on the adiabatic spin entropy expansion i ) coupled to the housing. The cooling and heating device may be configured and operable to heat and cool the material within the medical reservoir when the medical reservoir is coupled to the housing. The data from the temperature sensor and pressure or stretch sensor may be periodically stored in memory that is coupled to the housing. That memory may be periodically communicated to the internet through cellular or satellite communications. 
         [0008]    In another implementation, a method for monitoring a temperature of contents of a medical reservoir includes coupling a medical reservoir temperature monitoring device to the medical reservoir; on a periodic time interval basis, storing temperature values from the temperature sensor in memory that is coupled to the housing; and based on the temperature values, providing temperature information via the user interface or wirelessly to a separate unit that records this information on many units. The medical reservoir temperature monitoring device includes: a housing, the housing defining structure for selective coupling to a medical reservoir; a temperature sensor coupled to the housing, pressure and/or stretch sensors coupled to the housing, the temperature sensor being configured and operable to measure temperature of a material within the medical reservoir when the medical reservoir is coupled to the housing; the pressure or stretch sensor being configured and operable to measure the pressure of a material within the housing, when the medical reservoir is coupled to the housing and a user interface coupled to the housing or transmissible to a separate mobile unit, the user interface including an alarm functionality for notifying a user that the temperature sensor detected the temperature of the material to be outside of a predetermined range of acceptable temperatures as well as status of the battery of the device and whether the pressure or stretch sensor has detected a stimulus outside of a predetermined range, or has changed. 
         [0009]    Such a method for monitoring a temperature and pressure of contents of a medical reservoir, or the stretching of the housing may optionally include one or more of the following features. The temperature, and/or pressure, and/or stretch information may be connected to a local or remote alarm. The pressure and or stretch information may comprise a local alarm that is audible and visible, and it may also be communicated through the internet to signal the owner as to its status. The time interval may be within a range between about 10 micro-seconds and about 5 minutes. The method may further comprise transmitting the stored temperature and pressure or stretch values to an external computer or device. The transmitting may be performed wirelessly. The user interface may include a display, and temperature values and pressure and stretch values measured by the temperature sensor may be indicated on the display. The method may further comprise heating or cooling, by the medical reservoir temperature monitoring device, the material within the medical reservoir, wherein the heating or cooling is initiated based on the temperature values. The medical reservoir may be a phlebotomy tube, it could also be a box that contains products within it. 
         [0010]    Particular embodiments of the subject matter described in this document can be implemented to realize one or more of the following advantages. In some embodiments, the medical reservoir temperature monitoring and maintenance devices provided herein detect and store in memory a real-time and time-based record of the temperature and of the contents (e.g., blood) of a phlebotomy tube, and its presence or absence, attempts to remove the reservoir, and may insure that temperature deviations beyond normal body temperature 37 degrees Celsius are minimal if they occur. Using the temperature record, a clinical pathologist or laboratory healthcare worker can verify that the sample has not reached a temperature that could be detrimental to the sample and ultimately the patient if an incorrect diagnosis is made based on this type of pre-analytical error. In conclusion, patient safety and clinical results can be improved. 
         [0011]    In some embodiments, the medical reservoir temperature monitoring and maintenance devices provided herein will provide a visual notification or silent alarm if the sample deviates from an acceptable temperature range. Such notifications or alarms can assist individuals to readily identify samples that may require rejection and an immediate request for a new sample(s) to be drawn, or for additional quarantine or further analysis of that suspect sample if needed or if necessary. In some embodiments, the temperature data will be available for download from the temperature monitoring device to another computing device. Historical data records can thereby be maintained in conjunction with an electronic medical record. In some embodiments, the temperature monitoring devices provided herein are portable and thereby allow portability of the medical reservoirs while continuing to monitor the temperature of the contents. In some embodiments, the medical reservoir temperature monitoring devices provided herein are reusable, and in particular embodiments the devices can be decontaminated by sterilization, and thus reused. 
         [0012]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
         [0013]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a perspective view of an example medical reservoir temperature monitoring and maintenance device with an expanded orifice in accordance with some embodiments. 
           [0015]      FIG. 2  is an exploded view of the temperature monitoring and maintenance device of  FIG. 1  with a collapsed orifice and a phlebotomy tube. 
           [0016]      FIG. 3  is a perspective view of the temperature monitoring and maintenance device and phlebotomy tube of  FIG. 2  in a coupled arrangement in accordance with some embodiments. 
       
    
    
       [0017]    Like reference numbers represent corresponding parts throughout. 
       DETAILED DESCRIPTION 
       [0018]    This document provides devices and methods for monitoring and maintenance of the temperature of medical reservoirs while maintaining a chain of custody. For example, in one non-limiting example this document provides devices and methods for monitoring the temperature of blood in phlebotomy tubes. The devices can also be used, for example, for measuring and detecting stretch or pressure that may be caused from moving the tube out of or into the device. Further, the device can be used for measuring/detecting every time the sample or product is accessed. Other uses and implementations of the inventive concepts provided herein will be readily apparent to one of skill in the art. 
         [0019]    Referring to  FIG. 1 , an example medical reservoir temperature monitoring and maintenance device  100  includes a housing  110  that defines an opening  116  that is expandable. As described further below, opening  116  is configured to receive a medical reservoir therein. For example, in the depicted embodiment opening  116  is configured to receive a cylindrical sample container such as a phlebotomy tube therein and can stretch to accommodate such an item  FIGS. 2 &amp; 3 . 
         [0020]    While opening  116  of the depicted embodiment defines a circular cross-sectional shape that can be slid onto a cylindrical sample container, in some embodiments opening  116  is configured differently. For example, in some embodiments opening  116  is thicker. In some such embodiments, housing  110  can be take the shape of a ball. In other embodiments, housing  110  can be a thin sheet of plastic that has the thin sensors and microchip within it. In some embodiments, the axial length of housing  110  is longer or shorter than represented in  FIG. 1 . For example, in some embodiments housing  110  is longer so as to cover a majority of the exterior surface areas of a sample container such as a phlebotomy tube. 
         [0021]    While opening  116  of the depicted embodiment defines a circular cross-sectional shape it should be understood that the housing may be a piece of tape or plastic that can stick to the tube and may only take up a small area of the sample or product. 
         [0022]    While in some embodiments, housing  110  substantially surrounds a sample container, it should be understood that some embodiments do not fully surround a container. In fact, contact may only be necessary between housing  110  and a sample container at a single point. However, in some embodiments medical reservoir temperature monitoring and maintenance device  100  is insulated and fits tightly, like a glove might around a finger, around the phlebotomy tube (or other sample or product reservoir). This may save energy, battery life, and prolong the use of the device for more extended periods if needed. 
         [0023]    In some embodiments, temperature monitoring device  100  includes a connector  112  coupled to housing  110 . Connector  112  can be a computer bus and power connector. Connector  112  can be used, as described further below, for functions such as data transmission, on-board battery charging, input of user settings (e.g., using a keyboard, etc.) for configuration of temperature monitoring device  100 , and the like, and combinations thereof. In some embodiments, no such connector  112  is included, and these procedures could be performed wirelessly and/or through an electro-magnet  118  or coils. 
         [0024]    In some embodiments, there may be an additional temperature probe that determines the outside/exterior temperature not directly attached to the tube, so that the device  100  can anticipate if it will need to prepare to heat or cool the sample. 
         [0025]    Coupled to flexible housing  110  is one or more temperature sensors  120 . In the depicted embodiment, temperature sensor  120  is included in a series along the interior of the housing, but in some embodiments only one is needed. Temperature sensor  120  is disposed on housing  110  in a manner to facilitate contact or close proximity between temperature sensor  120  and a medical sample reservoir that is positionable within opening  116 . For example, in the depicted embodiment temperature sensor  120  is disposed on an inner diameter of opening  116 . It is essential that the temperature sensor be flexible so that tubes and reservoirs or containers such as boxes of various sizes are always in contact with the sensor. 
         [0026]    In some embodiments, temperature sensor  120  is a thermistor that is used to detect the surface temperature of a sample reservoir. A thermistor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors. In some embodiments, the thermistor is within a bridge circuit of temperature monitoring device  100 . In some embodiments, other types of temperature detection devices are used for temperature sensor  120 . For example, such temperature detection devices can include, but are not limited to, thermocouples, infrared sensors, bimetallic devices, and the like, and combinations thereof. 
         [0027]    Temperature sensor  120  can periodically measure the temperature of the sample reservoir disposed in opening  116 . The measured temperature values, and/or trends over time of such values, can be stored in an on-board memory of temperature monitoring device  100  may be determined to be below or above a threshold level that is indicative of a potential for adverse effects to the sample. For example, in some implementations temperature sensor  120  may detect and send to memory a temperature reading about every second, about every 5 seconds, about every 10 seconds, about every 30 seconds, about every 1 minute, about every 2 minutes, about every 5 minutes, about every 10 minutes, or less frequently than about every 10 minutes depending on changes in temperature to outside sensor  123 . In some embodiments, the time interval is adjustable and selectable by the user of temperature monitoring device  100 . 
         [0028]    In some embodiments, temperature monitoring device  100  can be configured to initiate an alarm to notify medical personnel when temperature sensor  120  detects that the temperature of a sample material in a reservoir is below a minimum temperature value or above a maximum temperature value for over a threshold period of time. Such an alarm may be audible, visual, and combinations thereof. In some embodiments, an alarm signal is transmitted from temperature monitoring device  100  to another computing device or system. In some such embodiments, transmission of the alarm signal can be performed wirelessly, or over a hardwire connection (e.g., by a cable using connector  112 ), between temperature monitoring device  100  and the other computing device or system. 
         [0029]    Temperature monitoring device  100  can include one or more on-board processors (not visible) within housing  110 . The processor(s) are suitable for the execution of a computer program and can be, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. The processor(s) can execute instructions, including the executable instructions that are stored in memory of temperature monitoring device  100 . The processor(s) may be implemented as a chipset of chips that include separate and multiple analog and digital processors. The processor(s) may provide, for example, for coordination of the other components of temperature monitoring device  100 , such as control of the user interface, applications or configurations run by temperature monitoring device  100 , and communications via temperature monitoring device  100 . 
         [0030]    Temperature monitoring device  100  can include on-board memory (not visible) for storing information within temperature monitoring device  100 , including, but not limited to, the executable instructions. The memory can be implemented as one or more of a computer-readable medium or media, a volatile memory unit or units, or a non-volatile memory unit or units. An expansion memory may also be provided and connected to temperature monitoring device  100 , that may include, for example, a SIMM (Single In-Line Memory Module) card, a micro SD card, and the like, and combinations thereof. In some implementations, such removable memory cards can be used to transfer temperature data collected by temperature monitoring device  100  to another computer or computer system for analysis or archival purposes. Such memory cards may also provide expansion memory for extra storage space for temperature monitoring device  100 , or may also store applications or other information for the memory. The memory may include, for example, flash memory and/or NVRAM memory (non-volatile random access memory). 
         [0031]    The executable instructions can be stored in the memory, the expansion memory, memory on the processor(s), or in a combination thereof. The executable instructions can include instructions that, when executed, perform functions related to the operating systems of temperature monitoring device  100  (e.g., operations of the user interface, coordination of intra-device module communications, coordination and control of applications run by temperature monitoring device  100 , and so on). In addition, in some embodiments the executable instructions include instructions that, when executed, perform one or more of the functions and methods described elsewhere herein in relation to temperature monitoring, analysis of the monitored temperature data, alarming, and communications with other devices and systems. In some implementations, the executable instructions, or portions thereof, can be received in a propagated signal, for example, via an optional wireless interface of temperature monitoring device  100 . 
         [0032]    In some embodiments, temperature monitoring device  100  is configured for short-range wireless communication with another computer. For example, in some embodiments such communications may occur via communication modes such as, but not limited to, Bluetooth, WiFi, RFID, ANT+, NFC, or other such technologies. 
         [0033]    In some embodiments, temperature monitoring device  100  includes one or more integral power sources (not visible). The power source(s) can provide the energy to operate temperature monitoring device  100 . In some embodiments, the power source is one or more rechargeable batteries such as a nickel-metal hydride, lithium ion, lithium polymer, Hydrogen cell, Carbon Nanotube, Graphene, or zinc oxide battery. The rechargeable batteries may be recharged by electrically coupling an external power source to the battery, or to a battery charging circuit in temperature monitoring device  100  that is electrically connected to the power source. In some embodiments, the coupling of the external power source to temperature monitoring device  100  is via a wired connection, such as by plugging a cord into connector  112  located on housing  110 . The coupling may also be accomplished in some embodiments by the use of a docking station with which temperature monitoring device  100  can mate to establish an electrical connection. In some such embodiments, the docking station includes an electrical connector that couples with a complementary electrical connector located on temperature monitoring device  100 . For example, the electrical connector of the docking station can be a male connector and a corresponding female connector can be located on temperature monitoring device  100  (or vice versa). The electrical connection between temperature monitoring device  100  and the docking station can be used to transmit electrical energy to temperature monitoring device  100 . The electrical energy can power the operations of temperature monitoring device  100 , can recharge the on-board battery or batteries of temperature monitoring device  100 , or a combination thereof. 
         [0034]    In some embodiments, a docking station (or the like) can charge the on-board battery or batteries of temperature monitoring device  100  inductively (wirelessly). A primary coil that located within the docking station can receive AC from an on-board battery charging system. When temperature monitoring device  100  is physically close to the docking station a secondary electrical coil within temperature monitoring device  100  can receive inductive energy via an alternating magnetic field emanating from primary coil of the docking station. Alternating current is thereby induced in and transmitted from the internal coil of temperature monitoring device  100  to a battery charging circuit in temperature monitoring device  100 . The battery charging circuit can rectify the alternating current to produce direct current that can be used to charge the battery or batteries of temperature monitoring device  100 . 
         [0035]    In the depicted embodiment, a display  130  is integral with housing  110 . However, in some embodiments no such display  130  is included (but other user interface elements such as indicator lights, audible elements  124 , and the like may be included alternately, or additionally when a display  130  is included). Display  130  provides visual information to a user. For example, in the depicted embodiment a current temperature  132  is prominently displayed. In some embodiments, current temperature  132  is updated (refreshed) each time temperature sensor  120  detects a new temperature value. In some embodiments, an averaging functionality (or other algorithm) may be used to determine current temperature  132  for display. In some such embodiments, the mode used to determine current temperature  132  for display is user selectable. 
         [0036]    In the depicted example embodiment, display  130  also includes min/max temperature values  134 . Min/max temperature values  134  can be the minimum temperature and the maximum temperature that temperature monitoring device  100  has detected since being reset. The display of min/max temperature values  134  can provide a clinician with an advantageous at-a-glance verification means for determining whether the sample has had a potentially detrimental temperature excursion. In addition, current time and date can be displayed  136  as well as a date of origin from when the sample was originally placed in the device  138 . 
         [0037]    In some embodiments, other information can be provided via display  130 . For example, alarms or alert messages can be provided via display  130 . User settings can be displayed in conjunction with a configuration mode of temperature monitoring device  100 . Other information provided via display  130  can include, but is not limited to, historical temperature readings, a time duration of a temperature excursion, a battery charge level indication, a wireless signal strength indication, data transmission indication, an alphanumeric sample ID, a status indicator, a warming indicator, and the like, and combinations thereof. 
         [0038]    In some embodiments, one or more electrical button(s)  114  are coupled to housing  110 . While in the depicted embodiment, a single electrical button  114  is included, in some embodiments two or more electrical buttons  114  are included. Electrical button(s)  114  can be used to facilitate user input to temperature monitoring device  100 . In some embodiments, one or more menus can be accessed by interactions with electrical button(s)  114 . In that manner, operations such as user configuration, data communications, resetting, restarting, and the like, can be initiated by a user of temperature monitoring device  100 . In some embodiments, electrical button(s)  114  (as well as other elements of temperature monitoring device  100 ) are water-proof or water-resistant and configured for decontamination (and sterilization in some embodiments). 
         [0039]    In some embodiments, temperature monitoring device  100  is equipped with a heating and cooling capability. That is, in some embodiments heat can be generated by temperature monitoring device  100  and transferred to a sample container within opening  116 . In some such embodiments, the heating capability functions in concert with the temperature monitoring capability of temperature monitoring device  100  to modulate the temperature of the sample and to thereby maintain a target range of temperature of the sample. For example, in some cases a target temperature range for the storage of blood is about 36° C. to about 38° C. In such a case, when the temperature of the blood is detected by temperature sensor  120  as becoming close to the lower limit of 36° C., temperature monitoring device  100  may automatically delivery heat to the blood to maintain the blood&#39;s temperature above 36° C. Such heating and cooling capability may be facilitated by an integral heating device such as, but not limited to, electrical resistance heater(s), MEMS micro-heater(s), Peltier effect device(s), an infrared heater, an ultrasonic heater, or technology such as magnetic cooling or adiabatic spin entropy expansion, and the like. In some embodiments, temperature monitoring device  100  is equipped with a cooling capability  122 . 
         [0040]    Referring to  FIGS. 2 and 3 , the installation of temperature monitoring device  100  onto an example medical reservoir  200  is depicted. In the depicted embodiment, medical reservoir  200  is illustrated as a phlebotomy tube, but other types/forms/configurations or medical reservoirs may also be used for medical reservoir  200  (e.g., vials, test tubes, syringes, specimen containers, jars, bottles, collectors, a custom container, a standard container, and the like). Medical reservoir  200  may be made of various materials such as, but not limited to, plastic, metal, glass, composites, and the like. In some implementations, medical reservoir  200  may contain a blood sample. However, other fluids may be contained in medical reservoir  200 . Such fluids can include other bodily fluids or other liquids such as medications, and the like. 
         [0041]    In the depicted implementation, temperature monitoring device  100  is slid onto medical reservoir  200 . In some embodiments, a light friction fit exists between medical reservoir  200  and temperature monitoring device  100 . In some embodiments, a pliable element (e.g., an O-ring, leaf spring, barb, and the like) in opening  116  maintains a friction fit between medical reservoir  200  and temperature monitoring device  100 . While in the depicted implementation, temperature monitoring device  100  is slid onto the mid-body portion of medical reservoir  200 , temperature monitoring device  100  can be slidably disposed on any portion of medical reservoir  200 . Using that feature, temperature monitoring device  100  can be located along the length of medical reservoir  200  in a location that is most effective for detecting the temperature of the contents of medical reservoir  200 . 
         [0042]    In some implementations, after use, temperature monitoring device  100  can be removed from medical reservoir  200  and temperature monitoring device  100  can be sanitized (and sterilized, e.g., in an autoclave, in some embodiments). Thereafter, temperature monitoring device  100  can be reset and reused in another implementation. 
         [0043]    In an alternative embodiment, the functionality of temperature monitoring device  100  can be incorporated into a sample rack. That is, one or more temperature monitoring devices  100  (or adaptations thereof) can be installed into a sample rack that can receive medical reservoirs (e.g., phlebotomy tubes, test tubes, and the like). In some embodiments, this rack may replenish individual battery life for each individual unit. In some embodiments the rack has the ability to download data from all the vials or bottles and transmit it to a computer. 
         [0044]    While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
         [0045]    Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system modules and components in the embodiments described herein should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single product or packaged into multiple products. 
         [0046]    Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.