DETECTING SENTINEL LYMPH NODES DURING SURGERY

A method for detecting sentinel lymph nodes during surgery. The method includes injecting a crystalloid solution into a region, measuring a plurality of electrical parameters utilizing a sensor, and detecting a sentinel lymph node among a plurality of lymph nodes based on the plurality of electrical parameters. The region is associated with a tumor in a patient's body. Measuring the plurality of electrical parameters includes measuring each respective electrical parameter of a respective lymph node of the plurality of lymph nodes. The plurality of lymph nodes are associated with the tumor. The sentinel lymph node is located at a shortest distance from the tumor among the plurality of lymph nodes.

TECHNICAL FIELD

The present disclosure generally relates to medical diagnosis, and particularly, to cancer diagnosis and treatment.

BACKGROUND

Early surgical removal of cancerous tissues, as well as lymph nodes in areas surrounding cancerous tissues is generally carried out to completely arrest cancer progress. However, during a surgical removal of a cancerous tissue, it may be not known if cancer has spread to lymph nodes or not. Therefore, a surgeon may unnecessarily perform a complete lymph node dissection. This procedure may be painful and may impose a heavy burden on patients.

Cancer is not randomly transferred to lymph nodes, but the spread of cancer may follow an orderly pattern, in which cancer may first spread to regional lymph nodes close to a tumor and then, due to directional nature of the flow of a lymph, may spread to other lymph nodes in a predictable fashion. A first draining lymph node or group of lymph nodes may be referred to as sentinel lymph nodes. If a sentinel lymph node corresponding to a primary cancer lesion site is located and found not to have been involved in cancer, a total lymph node dissection may be avoided.

Accordingly, locating a sentinel lymph node before tissue removing surgery may be important. One way to detect a sentinel lymph node is to use a blue colorant method, in which a blue colorant may be injected into a tumor about 20 minutes before tumor removal surgery. The blue colorant may move toward lymph nodes and may reach a sentinel lymph node within 5 to 15 minutes after injection and the surgeon may visually detect the sentinel lymph node. However, fatty tissue surrounding lymph nodes may have to be first peeled away so that visual detection may be possible. This may be time-consuming and an injected blue colorant may have enough time to move forward beyond a sentinel lymph node and reach other lymph nodes and render visual detection of sentinel lymph nodes impossible.

Another method for detecting sentinel lymph nodes is to utilize radioactive materials, radioisotropic materials, or radiopharmaceuticals. In this approach, a radiopharmaceutical such as Technetium 99 m, Indium 111, Iodine 123, or Iodine 125 may be preoperatively injected into a tumor and a gamma probe may be utilized for intraoperative detection of a sentinel lymph node by detecting a gamma radiation emitted by the sentinel lymph node. However, managing of surgical procedure during radiation may be complicated and also utilization of a gamma probe may be time-consuming. As a result, an injected radiopharmaceutical may reach lymph nodes beyond the sentinel lymph node in a short time or an amount of gamma radiation may drop below a detectable level due to the complexity of preparing a patient for surgery. Furthermore, this approach may have a high risk for a patient's health due to utilizing radioactive radiation.

There is, therefore, a need for a method that may provide easier and more accurate intraoperative detection of sentinel lymph nodes while performing sentinel node navigation surgery without a need for injection of hazardous radioactive materials. There is also a need for a system that may be easily utilized for locating sentinel lymph nodes which may allow for avoiding unnecessary lymph node dissection.

SUMMARY

In one general aspect, the present disclosure describes an exemplary method for detecting sentinel lymph nodes during surgery. An exemplary method may include injecting a crystalloid solution into a region, measuring a plurality of electrical parameters utilizing a sensor, and detecting a sentinel lymph node among a plurality of lymph nodes based on the plurality of electrical parameters utilizing one or more processors. An exemplary region may be associated with a tumor in a patient's body. In an exemplary embodiment, measuring the plurality of electrical parameters may include measuring each respective electrical parameter of a respective lymph node of the plurality of lymph nodes. Exemplary plurality of lymph nodes may be associated with the tumor. An exemplary sentinel lymph node may be located at a shortest distance from the tumor among the plurality of lymph nodes.

In an exemplary embodiment, injecting the crystalloid solution may include injecting one of a normal saline, a dextrose solution, or a Ringer's solution into the region. In an exemplary embodiment, injecting the crystalloid solution into the region may include injecting the crystalloid solution into the tumor.

In an exemplary embodiment, utilizing the sensor may include inserting a probe of a flexible gigahertz antenna into each of the plurality of lymph nodes, measuring each of the plurality of electrical parameters by the probe, transmitting each of the plurality of electrical parameters from the probe to a signal transmission unit via a detachable cable, and transmitting the plurality of electrical parameters to the one or more processors from the signal transmission unit. An exemplary flexible gigahertz antenna may include a flexible coplanar waveguide (CPW) antenna. In an exemplary embodiment, inserting the probe into each of the plurality of lymph nodes may include wearing a glove by an operator of the sensor, placing a mounting member on one of a fingers of the glove, and attaching the probe onto the mounting member.

In an exemplary embodiment, detecting the sentinel lymph node may include finding a largest electrical parameter of the plurality of electrical parameters and identifying a lymph node of the plurality of lymph nodes that may include the largest electrical parameter as the sentinel lymph node. An exemplary largest electrical parameter may include a highest magnitude among the plurality of electrical parameters.

In an exemplary embodiment, finding the largest electrical parameter may include measuring respective variations of each of the plurality of electrical parameters in a frequency domain utilizing the sensor, obtaining a plurality of maximum values by finding each respective maximum value of respective variations of each of the plurality of electrical parameters in a predetermined frequency range of the frequency domain, and obtaining the largest electrical parameter by finding a largest maximum value among the plurality of maximum values. In an exemplary embodiment, measuring respective variations of each of the plurality of electrical parameters may include measuring respective variations of one of a plurality of scattering parameters, a plurality of electrical conductivities, or a plurality of relative permittivities in the frequency domain for each respective lymph node of the plurality of lymph nodes.

In an exemplary embodiment, finding each respective maximum value of respective variations of each of the plurality of electrical parameters in the predetermined frequency range may include finding each respective maximum value of respective variations of each of the plurality of relative permittivities for each respective lymph node of the plurality of lymph nodes in a frequency range of 2 GHz to 4 GHz in the frequency domain.

An exemplary method may further include detecting metastatic cancer cells inside the sentinel lymph node by inserting a needle of the sensor into the sentinel lymph node, measuring one of an aqueous carbon dioxide (CO2) concentration or a pH concentration of the sentinel lymph node utilizing the needle, and identifying the metastatic cancer cells inside the sentinel lymph node based on the one of the aqueous CO2concentration or the pH concentration. An exemplary the needle may include one of a miniaturized CO2sensor needle or a miniaturized pH sensor needle.

DETAILED DESCRIPTION

The following detailed description is presented to enable a person skilled in the art to make and use the methods and devices disclosed in exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

Herein is disclosed an exemplary method and system for locating sentinel lymph nodes associated with primary cancer lesion sites during surgery, for example, during a breast cancer surgery. An exemplary sentinel lymph node may refer to a nearest lymph node to an exemplary tumor. Therefore, if an exemplary solution is injected into the tumor, a larger amount of the solution may be eventually received by the sentinel lymph node than other lymph nodes. As a result, if an electrically conductive solution is injected into the tumor, electrical properties of an exemplary sentinel lymph node may experience a larger change than other lymph nodes due to presence of a larger amount of injected solution in the sentinel lymph node. Therefore, an exemplary sentinel lymph node may be detected by finding a lymph node with a more considerable change in its electrical properties.

Based on the above, an exemplary method for locating sentinel lymph nodes may be designed and implemented. An exemplary method may include injecting a crystalloid solution (such as saline, which is electrically conductive) into a tumor. Next, an exemplary method may measure changes of electrical properties (such as relative permittivity) of lymph nodes around the tumor caused by a discharge of the injected crystalloid solution into regional lymph nodes. An exemplary method may identify a lymph node with a largest change of its electrical properties as the sentinel lymph node.

An exemplary method may utilize a sensor for measuring electrical properties of lymph nodes around a tumor. An exemplary gigahertz antenna may be used as a sensor to achieve an accurate, low-risk and high-reliability diagnosis for detection of sentinel lymph nodes. An exemplary antenna may operate in a wide frequency range and a flexible poly ethylene terephthalate (PET) substrate may be used in design of the antenna. Due to the use of a flexible substrate, a surgeon's maneuverability while touching lymph nodes may be improved and the antenna dimensions may be reduced to make it easier to use the antenna during surgery by a surgeon. By placing an exemplary antenna on all the lymph nodes and comparing their electrical parameters, a lymph node with larger change in electrical properties (for example, a higher relative permittivity) may be identified as a sentinel lymph node.

Utilizing crystalloid solutions may allow for a simple, safe, and accurate detection of sentinel lymph nodes. Since exemplary crystalloid solutions are not harmful to a patient's body, in cases where an amount of an exemplary crystalloid solution within lymph nodes drops below a detectable level, more solution may be injected into a tumor's vicinity to facilitate associated measurements.

An exemplary method may further detect cancerous lymph nodes during surgery. In an exemplary embodiment, metastatic tumor cells within lymph nodes may undergo a metabolic shift toward fatty acid oxidation (FAO) and transcriptional coactivator yes-associated protein (YAP) may be selectively activated in such metastatic tumors. Carbon dioxide (CO2) and water may be two products of FAO, which may lead to formation of carbonic acid (H2CO3) within a cancerous lymph node. An exemplary method may intraoperatively measure concentration of H2CO3or aqueous CO2within a sentinel lymph node and may identify the sentinel lymph node as cancerous if a concentration of H2CO3or aqueous CO2is higher than a predetermined threshold. Since FAO creates an acidic environment within a lymph node, an exemplary method may also measure pH of the lymph node in order to determine if the lymph node is cancerous or not. An exemplary sensor may be inserted within a detected sentinel lymph node and based on concentration and/or pH measurements, lymph node metastasis may be detected. Such configuration of an exemplary sensor may allow for detecting lymph node metastasis without a need for removing the lymph nodes from a patient's body, which may improve the patient's quality of life.

FIG. 1Ashows a flowchart of a method for detecting sentinel lymph nodes during surgery, consistent with one or more exemplary embodiments of the present disclosure. An exemplary method100may include injecting a crystalloid solution into a region associated with a tumor in a patient's body (step102), measuring a plurality of electrical parameters utilizing a sensor (step104), and detecting a sentinel lymph node among a plurality of lymph nodes around the tumor based on the plurality of electrical parameters (step106). In an exemplary embodiment, each respective lymph node of the plurality of lymph nodes may have a respective electrical parameter of the plurality of electrical parameters. Exemplary plurality of lymph nodes may be associated with the tumor and may include lymph nodes in the patient's body that may be candidates for being a sentinel lymph node. An exemplary sentinel lymph node may be located at a shortest distance from the tumor among the plurality of lymph nodes.

FIG. 2shows a schematic of a system for detecting sentinel lymph nodes during surgery, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, different steps of method100may be implemented utilizing an exemplary system200. In an exemplary embodiment, system200may include a sensor202and a processing unit204. In an exemplary embodiment, sensor202may include a probe206, a signal transmission unit208, and a detachable cable210.

FIG. 3shows a schematic of utilizing a system for detecting sentinel lymph nodes during surgery, consistent with one or more exemplary embodiments of the present disclosure. Referring toFIGS. 1A and 3, in an exemplary embodiment, step102may include injecting a crystalloid solution302into a region304. An exemplary crystalloid solution may refer to an isotonic plasma volume expander that may contain an electrolyte. In an exemplary embodiment, crystalloid solution302may increase circulatory volume without altering chemical balance in vascular spaces due to isotonic properties of crystalloid solution302. In an exemplary embodiment, injecting crystalloid solution302may include injecting one of a normal saline, a dextrose solution, or a Ringer's solution into region304. In an exemplary embodiment, region304may include a vicinity surrounding a tumor306. In an exemplary embodiment, a size of region304may be determined such that a majority of crystalloid solution302may be absorbed by tumor306to be eventually discharged into neighboring lymph nodes. Therefore, no exemplary lymph node may be included in region304. In an exemplary embodiment, region304may be twice as large as tumor306. In an exemplary embodiment, crystalloid solution302may be injected anywhere in region304.

In an exemplary embodiment, step104may include measuring a plurality of electrical parameters utilizing sensor202. In an exemplary embodiment, each of the plurality of electrical parameters may be measured by probe206that may be inserted into a respective lymph node of a plurality of lymph nodes308. In an exemplary embodiment, plurality of lymph nodes308may include lymph nodes that may be candidates for being a sentinel lymph node for tumor306, i.e., having a shortest distance from tumor306. Therefore, in an exemplary embodiment, it may be known prior to executing method100that plurality of lymph nodes308may include a nearest lymph node to tumor306among lymph nodes in the patient's body. However, in an exemplary embodiment, a closest lymph node to tumor306among plurality of lymph nodes308may be unknown and method100may be implemented to find the closest lymph node. For each exemplary lymph node of plurality of lymph nodes308a separate parameter may be measured. In an exemplary embodiment, each of the plurality of electrical parameters may be transmitted from probe206to signal transmission unit208via detachable cable210after being measured by probe206. Exemplary plurality of electrical parameters may be sent to processing unit204from signal transmission unit208for further processing through remaining steps of method100.

In an exemplary embodiment, sensor may include a flexible gigahertz antenna.FIG. 4Ashows a schematic of a flexible coplanar waveguide (CPW) antenna, consistent with one or more exemplary embodiments of the present disclosure. An exemplary flexible CPW antenna400A may include a microstrip antenna that may be configured to operate at a specific frequency (that is a single-frequency).

FIG. 4Bshows a schematic of a flexible CPW antenna with a slot, consistent with one or more exemplary embodiments of the present disclosure. An exemplary slot402may be implemented on an exemplary flexible CPW antenna400B to increase the bandwidth of flexible CPW antenna400B. In an exemplary embodiment, corners of flexible CPW antenna400B may be bent to improve a radiation pattern of flexible CPW antenna400B.

Referring again toFIGS. 2 and 3, in an exemplary embodiment, sensor202may further include a glove212. An exemplary mounting member214may be placed on one of a fingers of glove212. In an exemplary embodiment, mounting member214may include a flexible cap similar to a thimble that may be worn on the user's finger. An exemplary flexible cap may be made of a flexible material such as rubber. In an exemplary embodiment, probe206may be attached onto mounting member214. As a result, an exemplary operator may easily use system200by wearing glove212and may insert probe206into each of plurality of lymph nodes308by moving a respective finger on which mounting member214is placed (for example, finger310) to each respective lymph node.

In an exemplary embodiment, probe206and mounting member214may be single serving and after each insertion of probe206in a lymph node, probe206and mounting member214may be disconnected from sensor202to be replaced with new ones to test other lymph nodes to avoid unwanted spread of cancer cells to healthy lymph nodes.

In an exemplary embodiment, step106may include detecting a sentinel lymph node during surgery. An exemplary sentinel lymph node312may refer to a lymph node that may be located at a shortest distance from tumor306among plurality of lymph nodes308. Therefore, in an exemplary embodiment, sentinel lymph node312may absorb a larger portion of injected crystalloid solution302than other lymph nodes of plurality of lymph nodes308. As a result, in an exemplary embodiment, sentinel lymph node312may be affected more by crystalloid solution302than other lymph nodes. Since, in an exemplary embodiment, crystalloid solution302may include an electrolyte which may be electrically conductive, an impact of adding crystalloid solution302to each of plurality of lymph nodes308may be observed by measuring electrical properties of each respective lymph node. Therefore, in an exemplary embodiment, sentinel lymph node312may be recognized from other lymph nodes based on the measured electrical properties.

For further detail with respect to step106,FIG. 1Bshows a flowchart for detecting a sentinel lymph node, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, detecting sentinel lymph node312may include finding a largest electrical parameter of the plurality of electrical parameters (step108) and identifying a lymph node of plurality of lymph nodes308that has the largest electrical parameter as sentinel lymph node312(step110). An exemplary largest electrical parameter may include a highest magnitude among the plurality of electrical parameters.

In further detail with regards to step108,FIG. 1Cshows a flowchart for finding a largest electrical parameter, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, finding the largest electrical parameter in step108may include measuring respective variations of each of the plurality of electrical parameters in a frequency domain utilizing sensor202(step112), obtaining a plurality of maximum values by finding each respective maximum value of respective variations of each of the plurality of electrical parameters in a predetermined frequency range of the frequency domain (step114), and obtaining the largest electrical parameter by finding a largest maximum value among the plurality of maximum values (step116).

For further detail regarding step112, in an exemplary embodiment, measuring respective variations of each of the plurality of electrical parameters may include measuring respective variations of one of a plurality of scattering parameters (or S-parameters), a plurality of electrical conductivities, or a plurality of relative permittivities in the frequency domain for each respective lymph node of plurality of lymph nodes308. In an exemplary embodiment, a flexible gigahertz antenna, such as any of flexible CPW antennas400A and400B may be utilized for measuring variations of each of the plurality of electrical parameters by irradiating gigahertz electromagnetic waves and examining changes in each of the plurality of electrical parameters.

An exemplary S-parameter (i.e., an element of a scattering matrix or S-matrix) may describe the electrical behavior of linear electrical networks when being stimulated by electrical signals.FIG. 5Ashows measured variations of an S-parameter in a lymph node, consistent with one or more exemplary embodiments of the present disclosure. An exemplary curve502illustrates variations of an S11parameter (i.e., a first element of an S-matrix) of an exemplary lymph node before injecting crystalloid solution302. An exemplary curve504illustrates S11variations of an exemplary lymph nodes after crystalloid solution302is injected to region304. An exemplary curve506illustrates S11variations about two minutes after injecting crystalloid solution302. It may be observed in curves504and506that injecting crystalloid solution302may cause changes in S11variations at different frequencies, for example, in a frequency range of about 0.5 to 6 GHz.

Similarly, in an exemplary embodiment, injecting crystalloid solution302may cause changes in electrical conductivity (i.e., ability to conduct electric current) and relative permittivity (i.e., electric polarizability with respect to vacuum) of lymph nodes. In an exemplary embodiment, finding each respective maximum value of respective variations in step114may include finding each respective maximum value of respective variations of each of the plurality of relative permittivities for each respective lymph node of plurality of lymph nodes308in a frequency range of about 2 GHz to about 4 GHz in the frequency domain.

FIG. 5Bshows measured variations of a relative permittivity in an axillary lymph node before and after injecting a dextrose solution, consistent with one or more exemplary embodiments of the present disclosure. An exemplary curve508illustrates relative permittivity variations of an exemplary axillary lymph node before injecting dextrose to region304. An exemplary curve510illustrates relative permittivity variations of the axillary lymph node about five minutes after dextrose is injected. In an exemplary embodiment, curve510may include a local maximum value512in a frequency range of 2 to 4 GHz (at about 3 GHz).

FIG. 5Cshows measured variations of a relative permittivity in an axillary lymph node before and after injecting a Ringer's solution, consistent with one or more exemplary embodiments of the present disclosure. An exemplary curve514illustrates relative permittivity variations of an exemplary axillary lymph node before injecting a Ringer's solution to region304. An exemplary curve516illustrates relative permittivity variations of the axillary lymph node after the Ringer's solution is injected. In an exemplary embodiment, curve516may include a local maximum value518in a frequency range of 2 to 4 GHz (at about 3 GHz).

FIG. 5Dshows measured variations of a relative permittivity in an axillary lymph node before and after injecting a normal saline solution, consistent with one or more exemplary embodiments of the present disclosure. An exemplary curve520illustrates relative permittivity variations of an exemplary axillary lymph node before injecting normal saline to region304. An exemplary curve522illustrates relative permittivity variations of the axillary lymph node after normal saline is injected. In an exemplary embodiment, curve522may include a maximum value524in a frequency range of 2 to 4 GHz (at about 2.8 GHz).

In further detail with respect to step116, in an exemplary embodiment, each of the plurality of maximum values (for example, maximum value524) may correspond to a respective lymph node of plurality of lymph nodes308. In an exemplary embodiment, finding the largest maximum value among the plurality of maximum values in step116may include finding a maximum value that is larger than the rest of the plurality of maximum values.

Referring again toFIGS. 1B and 3, in an exemplary embodiment, step110may include identifying a lymph node of plurality of lymph nodes308as sentinel lymph node312if said lymph node may have the largest maximum value, i.e., the largest maximum value is obtained from variations of an electrical parameter measured from said lymph node.

Referring again toFIG. 1A, in an exemplary embodiment, method may further include detecting metastatic cancer cells inside sentinel lymph node312by tracking FAO of metastatic cancer cells within sentinel lymph node312(step118). In an exemplary embodiment, metastatic tumor cells within a lymph node may undergo a metabolic shift toward FAO and may produce CO2and water within the lymph node. Therefore, in an exemplary embodiment tracking FAO of metastatic cancer cells within sentinel lymph node312may be carried out by measuring either concentration of aqueous CO2or pH of sentinel lymph node312.

FIG. 1Dshows a flowchart for detecting metastatic cancer cells inside a lymph node, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, step118may include inserting a needle of sensor202into sentinel lymph node312(step120), measuring one of an aqueous CO2concentration or a pH concentration of sentinel lymph node312utilizing the needle (step122), and identifying the metastatic cancer cells inside sentinel lymph node312based on the one of the aqueous CO2concentration or the pH concentration (step124).

For further detail with regards to step120, an exemplary the needle may include one of a miniaturized CO2sensor needle or a miniaturized pH sensor needle. In an exemplary embodiment, a CO2sensor may refer to a sensor that may be configured to measure aqueous CO2concentration in a lymph node. An exemplary pH sensor may refer to a sensor that may be configured to measure pH concentration in a lymph node. Referring again toFIGS. 2 and 3, in an exemplary embodiment, inserting the needle into sentinel lymph node312may include replacing probe206with the needle in sensor202and utilizing sensor202as shown inFIG. 3and described above.

In further detail regarding step122, an exemplary miniaturized CO2sensor needle may be utilized to measure aqueous CO2concentration in sentinel lymph node312. In order to measure pH concentration of sentinel lymph node312, an exemplary miniaturized pH sensor needle may be utilized in sensor202. In an exemplary embodiment, sensor202may measure either of aqueous CO2concentration or pH concentration when the needle is inserted into sentinel lymph node312. Exemplary measured data may be sent to processing unit204for further processing after measurement is done.

In further detail regarding step124, in an exemplary embodiment, processing unit204may compare the measured data with a predetermined cancer threshold. An exemplary cancer threshold may be obtained based on measurements from known cancerous lymph nodes prior to the surgery. In an exemplary embodiment, aqueous CO2concentration and pH concentration may be higher in cancerous lymph nodes than in normal lymph nodes. Therefore, an exemplary predetermined cancer threshold may be set between a lower limit and an upper limit. An exemplary upper limit may be set to a minimum aqueous CO2concentration of a number of aqueous CO2concentrations or a minimum pH concentration of a number of pH concentrations that may be measured from a number of known cancerous lymph nodes. An exemplary lower limit may be set to a maximum aqueous CO2concentration of a number of aqueous CO2concentrations or a maximum pH concentration of a number of pH concentrations that may be measured from a number of known normal lymph nodes. An exemplary predetermined cancer threshold may be utilized to distinguish a cancerous lymph node from a normal lymph node. In an exemplary embodiment, processing unit204may identify sentinel lymph node312as a cancerous tissue if the measured data is larger than the predetermined cancer threshold.

In an exemplary embodiment, a cancerous lymph node regardless of being a sentinel lymph node or not may be detected by steps122-124. In other words, an exemplary cancerous lymph node, sentinel or not, may be detected by inserting a miniaturized CO2sensor needle or a miniaturized pH sensor needle into the lymph node and measuring either concentration of aqueous CO2or pH of the lymph node, and determining if the lymph node is cancerous or not by comparing CO2or pH levels of the lymph node with those of a healthy lymph node.

FIG. 6shows an example computer system600in which an embodiment of the present invention, or portions thereof, may be implemented as computer-readable code, consistent with exemplary embodiments of the present disclosure. For example, method100may be implemented in computer system600using hardware, software, firmware, tangible computer readable media having instructions stored thereon, or a combination thereof and may be implemented in one or more computer systems or other processing systems. In an exemplary embodiment, system600may be analogous to processing unit204. Hardware, software, or any combination of such may embody any of the modules and components inFIGS. 1A-3.

If programmable logic is used, such logic may execute on a commercially available processing platform or a special purpose device. One ordinary skill in the art may appreciate that an embodiment of the disclosed subject matter can be practiced with various computer system configurations, including multi-core multiprocessor systems, minicomputers, mainframe computers, computers linked or clustered with distributed functions, as well as pervasive or miniature computers that may be embedded into virtually any device.

For instance, a computing device having at least one processor device and a memory may be used to implement the above-described embodiments. A processor device may be a single processor, a plurality of processors, or combinations thereof. Processor devices may have one or more processor “cores.”

Processor device604may be a special purpose or a general-purpose processor device. As will be appreciated by persons skilled in the relevant art, processor device604may also be a single processor in a multi-core/multiprocessor system, such system operating alone, or in a cluster of computing devices operating in a cluster or server farm. Processor device604may be connected to a communication infrastructure606, for example, a bus, message queue, network, or multi-core message-passing scheme.

In an exemplary embodiment, computer system600may include a display interface602, for example a video connector, to transfer data to a display unit630, for example, a monitor. Computer system600may also include a main memory608, for example, random access memory (RAM), and may also include a secondary memory610. Secondary memory610may include, for example, a hard disk drive612, and a removable storage drive614. Removable storage drive614may include a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. Removable storage drive614may read from and/or write to a removable storage unit618in a well-known manner. Removable storage unit618may include a floppy disk, a magnetic tape, an optical disk, etc., which may be read by and written to by removable storage drive614. As will be appreciated by persons skilled in the relevant art, removable storage unit618may include a computer usable storage medium having stored therein computer software and/or data.

In alternative implementations, secondary memory610may include other similar means for allowing computer programs or other instructions to be loaded into computer system600. Such means may include, for example, a removable storage unit622and an interface620. Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units622and interfaces620which allow software and data to be transferred from removable storage unit622to computer system600.

Computer system600may also include a communications interface624. Communications interface624allows software and data to be transferred between computer system600and external devices. Communications interface624may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, or the like. Software and data transferred via communications interface624may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface624. These signals may be provided to communications interface624via a communications path626. Communications path626carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link or other communications channels.

In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit618, removable storage unit622, and a hard disk installed in hard disk drive612. Computer program medium and computer usable medium may also refer to memories, such as main memory608and secondary memory610, which may be memory semiconductors (e.g. DRAMs, etc.).

Computer programs (also called computer control logic) are stored in main memory608and/or secondary memory610. Computer programs may also be received via communications interface624. Such computer programs, when executed, enable computer system600to implement different embodiments of the present disclosure as discussed herein. In particular, the computer programs, when executed, enable processor device604to implement the processes of the present disclosure, such as the operations in method100illustrated by flowcharts ofFIG. 1A-FIG. 1Ddiscussed above. Accordingly, such computer programs represent controllers of computer system600. Where an exemplary embodiment of method100is implemented using software, the software may be stored in a computer program product and loaded into computer system600using removable storage drive614, interface620, and hard disk drive612, or communications interface624.

Embodiments of the present disclosure also may be directed to computer program products including software stored on any computer useable medium. Such software, when executed in one or more data processing device, causes a data processing device to operate as described herein. An embodiment of the present disclosure may employ any computer useable or readable medium. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, and optical storage devices, MEMS, nanotechnological storage device, etc.).