Abstract:
A living body testing probe includes a living body contact part, a grip part, a non-mechanical switch part and a notification part. The living body contact part is configured and arranged to contact a living body. The non-mechanical switch part is configured and arranged to receive an operation input for changing test conditions upon being touched or approached. The notification part is configured and arranged to output information indicative of a change in the test conditions based on the operation input received by the non-mechanical switch part.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Japanese Patent Application No. 2011-272131 filed on Dec. 13, 2011. The entire disclosure of Japanese Patent Application No. 2011-272131 is hereby incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a living body testing probe that conducts a test by contacting a living body. 
         [0004]    2. Related Art 
         [0005]    As a living body testing probe for testing the inside of a living body, there are an ultrasonic probe in which a test is conducted by using reflection of ultrasonic waves inside a living body, a probe for testing a pulse wave in which a test of a pulse wave is conducted by using reflection of infrared light inside a living body, and the like. Among these living body testing probes, for example, in the ultrasonic probe, an ultrasonic element, an ultrasonic lens section, or the like is disposed in a living body contact part of the probe main body, and the test conditions in the ultrasonic probe are changed in a main testing device connected to the ultrasonic probe with a wire or wirelessly. For example, conventional living body testing probes are disclosed in Japanese Laid-Open Patent Publication No. 2011-72467 and Japanese Laid-Open Patent Publication No. 2003-164450. 
       SUMMARY 
       [0006]    The conventional living body testing probes described in the above mentioned publications, however, have a disadvantage that the main testing device needs to be operated with one hand to change the test conditions while operating the living body testing probe with the other hand. Accordingly, if a dial switch, a lever switch, or the like for changing the test conditions is provided in the living body testing probe itself, the usability will be improved. However, since the living body testing probe needs to be cleaned frequently due to its nature, providing a mechanical switch such as a dial switch or a lever switch for changing the test conditions causes a problem that a space or opening created in a movable portion of the mechanical switch is difficult to clean, and water and the like used for cleaning enters the inside of the living body testing probe from the space or opening in the movable portion to the mechanical switch, which easily results in occurrence of a defect. 
         [0007]    In terms of the above-described circumstances, an object of the present invention is to provide a living body testing probe suitable for cleaning in which the test conditions are easily changed. 
         [0008]    In order to achieve the above-described object, a living body testing probe according to one aspect of the present invention includes a living body contact part, a grip part, a non-mechanical switch part and a notification part. The living body contact part is configured and arranged to contact a living body. The non-mechanical switch part is configured and arranged to receive an operation input for changing test conditions upon being touched or approached. The notification part is configured and arranged to output information indicative of a change in the test conditions based on the operation input received by the non-mechanical switch part. 
         [0009]    According to the above described aspect of the present invention, since the non-mechanical switch part is provided in the living body testing probe itself, changing the test conditions can easily be conducted in the living body testing probe. Further, since the non-mechanical switch that receives operation input for changing test conditions upon being touched or approached is used as the switch, opening and the like will not be easily formed unlike in the case of using a mechanical switch. Therefore, a portion difficult to clean will not easily occur, and a situation in which water and the like used for cleaning enters the inside of the living body testing probe from the space can be avoided. Consequently, a living body testing probe suitable for cleaning in which the test conditions are easily changed can be achieved. 
         [0010]    The living body testing probe preferably further includes a display part configured and arranged to display at least the test conditions. With this configuration, the usability of the living body testing probe is improved because the operation for changing the test conditions and confirmation of the test conditions can be conducted in the living body testing probe. 
         [0011]    In the living body testing probe, the display part preferably serves as the non-mechanical switch part. Specifically, by using the display part as a touch panel (non-mechanical switch), the size of the living body testing probe can be reduced compared to a case in which the switch is provided separately from the display part. 
         [0012]    In the living body testing probe, the notification part preferably includes a signal output section configured and arranged to output an operation signal via a wire. With this configuration, the living body testing probe may be connected to a main testing device via the wire, and the test conditions may be changed in the main testing device. Accordingly, since the living body testing probe does not need to have a drive circuit and the like necessary for driving in the living body testing probe, the size of the living body testing probe can be reduced. 
         [0013]    In the living body testing probe, the non-mechanical switch part is preferably an optical switch. With this configuration, liquid-tight properties of the switch can easily be achieved. 
         [0014]    The optical switch is preferably an infrared switch configured and arranged to be operated by light emission and light reception of infrared light. This configuration has an advantage that outside light will not easily affect an operation with the switch. 
         [0015]    In the living body testing probe, the non-mechanical switch part is preferably provided in a protruded area protruding with respect to a region surrounding the non-mechanical switch part, or in a recessed area recessed with respect to the region surrounding the non-mechanical switch part. With this configuration, the position of the non-mechanical switch can easily be sensed by touch. 
         [0016]    The living body testing probe according to the above described aspect of the present invention may be configured as an ultrasonic probe, for example. In such a case, the living body contact part is configured and arranged to generate and receive ultrasonic waves, for example. In the case of the ultrasonic probe, since the living body contact part is caused to contact a surface of a living body with application of gel, the ultrasonic probe is frequently cleaned. Therefore, the effect of the present invention configured to be suitable for cleaning becomes significant. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Referring now to the attached drawings which form a part of this original disclosure: 
           [0018]      FIG. 1  is a simplified perspective view of an ultrasonic probe according to a first embodiment of the present invention. 
           [0019]      FIG. 2  is a simplified perspective view of a testing device provided with an ultrasonic probe according to a second embodiment of the present invention. 
           [0020]      FIGS. 3A and 3B  are simplified top plan view and side elevational view the ultrasonic probe according to the second embodiment of the present invention. 
           [0021]      FIGS. 4A and 4B  are explanatory diagrams of an optical position detection device used as a switch in the ultrasonic probe according to the second embodiment of the present invention. 
           [0022]      FIG. 5  is a simplified perspective view of a switch provided in the ultrasonic probe according to a modification example of the second embodiment of the present invention. 
           [0023]      FIG. 6  is a simplified perspective view of an ultrasonic probe according to a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0024]    Next, embodiments of the present invention will be explained in detail with reference to the attached drawings. In the following explanations, an ultrasonic probe that tests (examines) a state inside a living body with ultrasonic waves will be described as an example of a living body testing probe. 
       First Embodiment 
     Overall Configuration 
       [0025]      FIG. 1  is a simplified perspective view of an ultrasonic probe  1 A according to a first embodiment of the present invention. In the ultrasonic probe  1 A shown in  FIG. 1 , a probe main body  20  has a generally flattened shape. The probe main body  20  has a living body contact part  21  for contacting the living body at the tip end thereof, and the rest of the probe main body  20  is used as a grip part  23 . The tip end of the living body contact part  21  is curved in an arc shape as shown in  FIG. 1 . An ultrasonic transducer  24 , an acoustic lens (not shown in the drawings), and the like are embedded in the living body contact part  21 . The ultrasonic transducer  24  is provided with a plurality of elements configured such that an electrode is formed on both surfaces of a thick film of a piezoelectric body such as PZT (piezoelectric zirconate titanate) or polyvinylidene fluoride. When exciting pulses are applied to both the electrodes of this element, the piezoelectric body is caused to oscillate and generate ultrasonic waves, so that the inside of the living body is irradiated with the ultrasonic waves. When the ultrasonic transducer  24  receives reflected waves from the inside of the living body, the piezoelectric body is caused to oscillate and generate an electric signal, and this electric signal is converted into an ultrasound image. 
         [0026]    In the present embodiment, a drive part  26  and a power supply part  27  are provided in the inside of the probe main body  20 . A monitor  4  (one example of a display part) constructed of a liquid crystal display device is provided in the grip part  23  in a completely liquid-tight state. The drive part  26  drives the ultrasonic transducer  24 . The drive part  26  also converts an electrical signal obtained via the ultrasonic transducer  24  into an ultrasound image (ultrasound image), and outputs it to the monitor  4 . The ultrasound image obtained by the ultrasonic probe  1 A is, therefore, displayed on the monitor  4 . In the present embodiment, the monitor  4  is provided in a recessed region that is recessed slightly with respect to the surrounding regions in the outer circumferential surface of the probe main body  20 . 
         [0027]    In the ultrasonic probe  1 A with the above-described configuration, a power supply switch  29  is provided on a side surface of the probe main body  20 . The power supply switch  29  is a non-mechanical switch that uses a piezoelectric element, and is configured in a completely liquid-tight state. 
         [0028]    Further, the ultrasonic probe  1 A has a switch  5  (one example of a non-mechanical switch part) for changing test conditions provided in the probe main body  20 . The ultrasonic probe  1 A also has a notification part  28  that outputs information indicative of a change in the test conditions to the drive part  26  based on an operation in the switch  5 . Examples of the test conditions include the intensity of ultrasonic waves, the scan mode (e.g., size of the scanning region, transmission frequency, focus depth, switching between different image modes such as B-mode and Doppler mode), and the like. 
         [0029]    In the present embodiment, the switch  5  is a non-mechanical switch constructed of a resistive touch panel, a capacitance touch panel, or an optical touch panel, that is formed integrally with the monitor  4 . The resistive touch panel, the capacitance touch panel, and the optical touch panel are conventional components that are well known in the art. Since these non-mechanical switches are well known in the art, these structures will not be discussed or illustrated in detail herein. Rather, it will be apparent to those skilled in the art from this disclosure that the components can be any type of structure and/or programming that can be used to carry out the present invention. 
         [0030]    A menu switching button for switching the display into the settings of the test conditions is displayed on the monitor  4  as well as the ultrasound image obtained by the ultrasonic probe  1 A. When a fingertip contacts or approaches the menu switching button, test condition selecting buttons are displayed. When a fingertip contacts or approaches a certain button among the test condition selecting buttons, the notification part  28  converts the results of selecting operation of the test conditions into a signal, and sends the signal to the drive part  26 . As a result, the drive part  26  controls operation of the ultrasonic transducer, such as the output of ultrasonic waves from the ultrasonic transducer  24 , according to the change in the test conditions. Accordingly, the optimum test conditions can be achieved depending on which part of the inside of a living body is tested. After the test conditions are changed in this manner, when a fingertip contacts or approaches the menu switching button, the display on the monitor  4  is switched into the display of an ultrasound image. 
       Effects of Present Embodiment 
       [0031]    As explained above, in the ultrasonic probe  1 A of the present embodiment, since the living body testing probe itself has the switch  5 , the test conditions can easily be changed in the ultrasonic probe  1 A. Also, since a touch panel (non-mechanical switch) in which an operation for changing test conditions is conducted by contact or proximity is used as the switch  5 , a space and the like will not easily occur unlike in the case of using a mechanical switch that has a movable section. Therefore, a portion difficult to clean will not easily occur, and a situation in which water and the like used for cleaning enters the inside of the ultrasonic probe  1 A from the space can be avoided. Consequently, the present embodiment can achieve the ultrasonic probe  1 A suitable for cleaning in which the test conditions are easily changed. 
         [0032]    In the ultrasonic probe  1 A of the present embodiment, the monitor  4  that displays at least the test conditions is provided. Consequently, the usability of the ultrasonic probe  1 A is improved because the operation for changing the test conditions and confirmation of the test conditions can be conducted in the ultrasonic probe  1 A. 
         [0033]    Further, since the monitor  4  also serves as the non-mechanical switch  5  for changing test conditions, the size of the ultrasonic probe  1 A can be reduced compared to a case in which the switch  5  is provided separately from the monitor  4 . 
         [0034]    Further, the monitor  4  (switch  5 ) is configured to be in a recessed region that is recessed slightly with respect to the surrounding regions in the outer circumferential surface of the probe main body  20 . Therefore, the position of the switch  5  can easily be sensed by touch. 
         [0035]    In particular, in the case of the ultrasonic probe  1 A among living body testing probes, since the living body contact part  21  is caused to contact a surface of a living body with application of gel, the ultrasonic probe  1 A is frequently cleaned. Therefore, the effect of the ultrasonic probe  1 A according to the present embodiment configured to be suitable for cleaning becomes significant. 
       Second Embodiment 
       [0036]    Referring now to  FIGS. 2 to 5 , a living body testing probe in accordance with a second embodiment will now be explained. Since the basic configuration of the present embodiment is similar to that of the first embodiment, the components of the present embodiment that are identical or similar to the components of the first embodiment are indicated with a single prime (′). Moreover, in view of the similarity between the first and second embodiments, the descriptions of the parts of the second embodiment that are similar to the parts of the first embodiment may be omitted for the sake of brevity. 
       Overall Configuration 
       [0037]      FIG. 2  is a simplified perspective view of a testing device provided with an ultrasonic probe  1 B according to a second embodiment of the present invention.  FIGS. 3A and 3B  are enlarged views of the ultrasonic probe  1 B according to the second embodiment of the present invention. Specifically,  FIG. 3A  is a top plan view of the ultrasonic probe  1 B, and  FIG. 3   b  is a side view of the ultrasonic probe  1 B. 
         [0038]    In the first embodiment explained above, the drive circuit  26  and the monitor  4  are provided in the ultrasonic probe  1 A itself. In the present embodiment, however, an ultrasonic probe  1 B is connected to a main testing device  60  provided with a monitor  61  and the like via a cable  50 , as shown in a testing device  100  of  FIG. 2 . The main testing device  60  is also provided with a drive part  66  and a power supply part  67  for the ultrasonic probe  1 B as well as the monitor  61 . Power feeding to the ultrasonic probe  1 B and driving the ultrasonic probe  1 B are conducted from the main testing device  60  by the cable  50 . Also, an electrical signal obtained in the ultrasonic probe  1 B is output to the main testing device  60  via the cable  50 , and an ultrasound image is displayed on the monitor  61  of the main testing device  60 . 
         [0039]    In the present embodiment, similarly to the first embodiment, the ultrasonic probe  1 B has a switch  10  for easily changing test conditions, and the ultrasonic probe  1 B also has the notification part  28 ′ that output information indicative of a change in the test conditions based on an operation to the switch  10 . 
         [0040]    More specifically, as shown in  FIGS. 3A and 3B , in the ultrasonic probe  1 B of the present embodiment, the probe main body  20 ′ has a generally rod shape as a whole, and the probe main body  20 ′ has the living body contact part  21 ′ at the tip end thereof. The rest of the probe main body  20 ′ other than the living body contact part  21 ′ is used as the grip part  23 ′. The living body contact part  21 ′ is configured to be in a bulging area that bulges in a hemispherical shape as shown in  FIG. 3A , and the ultrasonic transducer  24 ′, an acoustic lens (not shown in the drawings), and the like are embedded in the inside of the living body contact part  21 ′. 
         [0041]    In the probe main body  20 ′, the switch  10  for changing test conditions such as the intensity of ultrasonic waves is provided in the grip part  23 ′, and the notification part  28 ′ that outputs information indicative of a change in the test conditions based on an operation in the switch  10  to the drive part  66  of the main testing device  60  by the cable  50  is provided in an end portion of the grip part  23 ′ on the opposite side of the living body contact part  21 ′. In the present embodiment, the notification part  28 ′ is a signal output section that outputs an operation signal in the switch  10  to the main testing device  60  via the cable  50  (one example of a wire). The notification part  28 ′ also has a function of sending an electrical signal obtained in the ultrasonic transducer  24 ′ to the drive part  66  of the main testing device  60  by the cable  50 . 
         [0042]    Here, the switch  10  is an optical switch for changing test conditions based on a contact position or a proximity position of a fingertip, and such an optical switch is a type of a non-mechanical switch that does not have a movable portion. Various kinds of conventional non-mechanical switches can be used as the switch  10 . In the present embodiment, for example, the optical position detection device disclosed in Japanese Laid-open Patent Publication No. 2011-232191 and the like can be used. 
       Configuration of Switch  10   
       [0043]      FIGS. 4A and 4B  are explanatory diagrams of an optical position detection device used as the switch  10  in the ultrasonic probe  1 B according to the second embodiment of the present invention. Specifically,  FIG. 4A  is an explanatory diagram showing an overall configuration of the optical position detection device, and  FIG. 4B  is an explanatory diagram showing a positional relationship of a light source section and the like. 
         [0044]    As shown in  FIGS. 4A and 4B , the optical position detection device used as the switch  10  in the ultrasonic probe  1 B of the present embodiment has a translucent member  40 , a light source device  11 , a light receiving section  30 , and the like. More specifically, the light source device  11  of the switch  10  has a plurality of light source sections  12  that emit detection light L 2  toward a side Z 1  of a Z axis direction, and the light receiving section  30  of the switch  10  detects detection light L 3  reflected on a target object Ob such as a fingertip. In the switch  10 , the light source sections  12  emit the detection light L 2  from a rear surface  42  side of the translucent member  40  to a front surface  41  side of the translucent member  40 , and the light receiving section  30  detects the detection light L 3  reflected on the target object Ob and transmitted toward the rear surface  42  side of the translucent member  40 . For this purpose, a light receiving surface  31  of the light receiving section  30  faces the rear surface  42  of the translucent member  40 . 
         [0045]    The light source device  11  has a first light source section  12 A, a second light source section  12 B, a third light source section  12 C, and a fourth light source section  12 D as the plurality of light source sections  12  on the rear surface  42  side of the translucent member  40 . These light source sections  12  have light emitting sections  120   a - 120   d  directed toward the translucent member  40 , respectively. The detection light L 2  (detection light L 2   a -L 2   d ) emitted from the light source sections  12  is transmitted through the translucent member  40  and exits toward the visible front surface  41  side (detection light exit space of the detection light L 2  from the light source device  11 ). In the present embodiment, this detection light exit space (space on the visible front surface  41  side) forms a detection space in which the position of the target object Ob is detected. 
         [0046]    The first light source section  12 A, the second light source section  12 B, the third light source section  12 C, and the fourth light source section  12 D are arranged in positions that correspond to corners of a rectangle respectively when seen from the detection space (Z axis direction). Each of the light source sections  12  (the first light source section  12 A, the second light source section  12 B, the third light source section  12 C, and the fourth light source section  12 D) is constructed of a light emitting element such as an LED (light emitting diode). In the present embodiment, each of the light source sections  12  emits the detection light L 2  (detection light L 2   a -L 2   d ) composed of infrared light whose peak wavelength is located in 840-1000 nm as diverging light. In the present embodiment, since the target object Ob is often a fingertip, infrared light (near infrared light of around 840-920 nm) having a wavelength range in which reflectivity with respect to the target object Ob (human body) is high is used as the detection light L 2 . 
         [0047]    The light receiving section  30  is a photo diode, a photo transistor, or the like, in which the light receiving surface  31  faces the translucent member  40 . In the present embodiment, the light receiving section  30  is a photo diode that has a sensitivity peak in an infrared region. 
         [0048]    In the switch  10 , the position of the target object Ob (fingertip) in the detection space is detected based on the light receiving results in the light receiving section  30  when the plurality of the light source sections  12  are sequentially lighted up. For example, based on the light receiving results in the light receiving section  30  when two of the light source sections  12  spaced apart in an X direction are sequentially lighted up, the ratio of the distance between one of the two light source sections  12  and the target object Ob and the distance between the other of the two light source sections  12  and the target object Ob is obtained. Also, based on the light receiving results in the light receiving section  30  when two of the light source sections  12  spaced apart in a Y direction are sequentially lighted up, the ratio of the distance between one of the two light source sections  12  and the target object Ob and the distance between the other of the two light source sections  12  and the target object Ob is obtained. Then, the X-Y coordinate position of the target object Ob is detected by combining the above results. Further, if a temporal change in the position of the target object Ob is detected, the movement of the target object Ob (movement of fingertip) as shown by arrows  15  of  FIG. 3A  can be detected. In the present embodiment, therefore, the position or movement of the target object Ob is related to the test conditions, and the test conditions are changed depending on a position of a fingertip in the switch  10  or depending on a movement direction of a fingertip. 
         [0049]    In a case where the light receiving intensity in the light receiving section  30  is equal to or less than a predetermined value, it may be configured to determine that there is no operation for changing test conditions because a fingertip is away from the switch  10 . Consequently, an erroneous operation can be prevented. 
       Effects of Present Embodiment 
       [0050]    As explained above, similarly to the above-described first embodiment, the ultrasonic probe  1 B of the present embodiment has the switch  10  provided in the living body testing probe itself. Thus, the test conditions can easily be changed in the ultrasonic probe  1 B. Also, since an optical position detection device (non-mechanical switch) in which an operation for changing test conditions is conducted by contact or proximity is used as the switch  10 , a space or opening will not easily formed in the ultrasonic probe  1 B unlike in the case of using a mechanical switch that has a movable section. Therefore, a portion difficult to clean will not easily occur, and a situation in which water and the like used for cleaning enters the inside of the ultrasonic probe  1 B from the space can be avoided. Consequently, the present embodiment has a similar effect as the first embodiment, and the ultrasonic probe  113  suitable for cleaning in which the test conditions are easily changed can be achieved, for example. 
         [0051]    In the present invention, since the notification part  28 ′ is a signal output section that outputs an operation signal via the cable  50 , the test conditions can be changed from the main testing device  60  by the cable  50 . Accordingly, since the ultrasonic probe  1 B does not need to have a circuit and the like necessary for driving in the ultrasonic probe  1 B, the size of the ultrasonic probe  1 B can be reduced. 
         [0052]    Further, since the switch  10  is an optical switch, liquid-tight properties of the switch  10  can easily be achieved. Furthermore, since the optical switch  10  is an infrared switch that uses light emission and light reception of infrared light, it has an advantage that outside light will not easily affect an operation with the switch  10 . 
       Modification Example of Second Embodiment 
       [0053]      FIG. 5  is an explanatory diagram of the switch  10 ′ provided in the ultrasonic probe  1 B according to a modification example of the second embodiment of the present invention. 
         [0054]    The switch  10  explained in the second embodiment may be configured to be in the same plane as an outer circumferential surface of the probe main body  20 . In this modification example, the switch  10 ′ is configured such that the translucent member  40 ′ is protruded with respect to the outer circumferential surface of the probe main body  20 ′ as shown in  FIG. 5 . With this configuration, since the switch  10 ′ can be configured to be a protruded section, the position of the switch  10 ′ can easily be sensed by touch. 
         [0055]    When the planar view shape of the translucent member  40 ′ is a cross shape protruded in an operation direction as shown by arrows  15 ′, it has an advantage that the operation direction can be sensed by touch. Further, a shallow recessed section  49  may be formed in the center of the translucent member  40 ′ such that the recessed section  49  indicates a reference position. 
         [0056]    Alternatively, the translucent member  40  may be formed to be recessed with respect to the outer circumferential surface of the probe main body  20 . With this configuration, since the switch  10  can be configured to be a recessed region, the position of the switch  10  can easily be sensed by touch. 
       Third Embodiment 
       [0057]    Referring now to  FIG. 6 , a living body testing probe in accordance with a third embodiment will now be explained. Since the basic configuration of the present embodiment is similar to that of the first or second embodiment, the components of the present embodiment that are identical or similar to the components of the first or second embodiment will be given the same reference numerals as the parts of the first or second embodiment. Moreover, in view of the similarity between the first, second and third embodiments, the descriptions of the parts of the third embodiment that are similar to the parts of the first or second embodiment may be omitted for the sake of brevity. 
         [0058]      FIG. 6  is a simplified perspective view of an ultrasonic probe according to a third embodiment of the present invention. 
         [0059]    In the second embodiment, the monitor  4  is not provided in the ultrasonic probe  1 B that is connected to the main testing device  60  by the cable  50 . In the present embodiment, however, as shown in  FIG. 6 , an ultrasonic probe  1 C provided with the monitor  4  is connected to the main testing device  60  via the cable  50 . The other configurations are substantially similar to the first embodiment. 
         [0060]    Unlike the first embodiment, the ultrasonic probe  1 C does not have the drive part  26  and the power supply part  67 . Therefore, the monitor  4  displays the test conditions as the monitor  4  is mainly used as the switch  5  (touch panel). 
       Other Embodiment 
       [0061]    In the first embodiment, the ultrasonic probe  1 A itself serves as the testing device. In a case where it is difficult to see test results with the small monitor  4 , however, it may be configured such that test results obtained by the ultrasonic probe  1 A are output to the main testing device  60  shown in  FIG. 2  with a wire or wirelessly. 
         [0062]    Although an ultrasonic probe is described as an example of the living body testing probe in the above described first to third embodiments, the present invention can be applied to other types of a testing probe such as a probe for testing a pulse wave in which a test of a pulse wave is conducted by using reflection of infrared light inside a living body. 
       General Interpretation of Terms 
       [0063]    In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. 
         [0064]    While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.