Abstract:
A retrieval device with a shapeable snare shaft for use in minimally invasive medical procedures. The retrieval device may further comprise a delivery conduit configured to receive both a snare shaft and a guidewire in one or more lumens. The retrieval device may also include a snare loop at both ends of the snare shaft.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/336,832 filed on Jan. 27, 2010, the entire contents of which are hereby incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to devices used to retrieve or manipulate items or structures located in anatomically remote locations, such as items located in body lumens. More specifically, the present disclosure relates to snare devices and methods for their use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    The embodiments disclosed herein will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. These drawings depict only typical embodiments, which will be described with additional specificity and detail through use of the accompanying drawings in which: 
           [0004]      FIG. 1  is a side view of a delivery conduit having a single lumen. 
           [0005]      FIG. 1A  is a cross sectional view taken through lines  1 A- 1 A of the delivery conduit of  FIG. 1 . 
           [0006]      FIG. 2  is a side view of a snare device with two loops. 
           [0007]      FIG. 2A  is a side view of the snare device of  FIG. 2 , with a bend placed in the shaft of the device. 
           [0008]      FIG. 3  is a side view of a snare device having with a loop at each end of the shaft portion and multiple bends in the shaft portion. 
           [0009]      FIG. 3A  is a cross sectional view taken through lines  3 A- 3 A of the snare loop shown in  FIG. 3 . 
           [0010]      FIG. 4  is a side view of a snare device with two loops, each loop having a rectangular profile, and a shaft portion with a single angular bend. 
           [0011]      FIG. 4A  is a cross sectional view taken through lines  4 A- 4 A of the snare loop shown in  FIG. 4 . 
           [0012]      FIG. 5  is a side view of a snare device with a trapezoidal loop at one end of the shaft, a circular loop at another end of the shaft, and a single angular bend in the shaft. 
           [0013]      FIG. 5A  is a cross sectional view taken through lines  5 A- 5 A of the snare loop shown in  FIG. 5 . 
           [0014]      FIG. 6  is a side view of a snare device with an elliptical loop at one end of the shaft, a rectangular loop at another end of the shaft, and a shaft with multiple bends. 
           [0015]      FIG. 6A  is a cross sectional view taken through lines  6 A- 6 A of the snare loop shown in  FIG. 6 . 
           [0016]      FIG. 7A  is a side view of an embodiment of a snare device with a delivery conduit and a guidewire. 
           [0017]      FIG. 7B  is a side view of the snare device of  FIG. 7A  with the snare loop extended from the delivery conduit. 
           [0018]      FIG. 7C  is a side view of the snare device of  FIGS. 7A and 7B  with the snare loop extended from the delivery conduit and surrounding a fragment. 
           [0019]      FIG. 7D  is side view of the snare device of  FIGS. 7A ,  7 B, and  7 C with the snare loop drawn partially into the lumen such that the fragment is trapped between the loop and the delivery conduit. 
           [0020]      FIG. 8A  is a side view of a snare device having a delivery conduit with two lumens. 
           [0021]      FIG. 8B  is a cross sectional view of the delivery conduit taken through lines  8 B- 8 B. 
           [0022]      FIG. 8C  is a cross sectional view of another embodiment of a delivery conduit with two lumens. 
           [0023]      FIG. 8D  is a cross sectional view of yet another embodiment of a delivery conduit with two lumens. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    A snare device may be configured to allow a practitioner to change the shape of the snare device during a therapeutic procedure. Such a device may allow a practitioner to more precisely position the device with respect to the object to be retrieved and the surrounding body lumen. Precise positioning of a snare device may enable a practitioner to more quickly and efficiently perform the needed therapy. Further, precise positioning may lessen trauma at the therapy site, minimizing injury from unwanted contact between the snare and portions of the body lumen. For example, precise positioning of the snare loop may reduce the possibility that the snare loop will rotate (or “whip”) during therapy, which rotation can damage the inner lining of blood vessels. 
         [0025]    It will be readily understood that the components of the embodiments as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the Figures, is not intended to limit the scope of the disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated. 
         [0026]    The phrases “connected to,” “coupled to,” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. For example, two components may be coupled to each other through an intermediate component. 
         [0027]    The directional terms “distal” and “proximal” are given their ordinary meaning in the art. That is, the distal end of a medical device means the end of the device furthest from the practitioner during use. The proximal end refers to the opposite end, or the end nearest the practitioner during use. 
         [0028]    “Delivery conduit,” as used herein, refers to an artificial channel capable of establishing communication between a remote location and an external environment. For example, in certain embodiments described herein, the delivery conduit comprises the outer sheath of a snare device, which in some embodiments comprises a catheter. 
         [0029]    A used herein “fragment” means either a foreign object disposed within a body lumen or an anatomical structure within the body which requires ligation or removal. 
         [0030]    Further, as used herein, a “snare device” refers to a medical device with an elongate shape having at least one “snare loop.” Thus, a snare device may or may not include a delivery conduit or outer sheath member. As used herein a “snare loop” refers to a closed shape configuration of an elongate member such as a wire. The term is not limited to “loops” with generally circular shapes, but includes any variety of shapes, including, for example, square loops, rectangular loops, ellipsoidal loops, trapezoidal loops, etc. 
         [0031]    Finally, as used herein, the term “shapeable” refers to a component that retains approximately at least 25% of its shape when it is (1) plastically deformed or shaped, (2) coupled with a second component which tends to deform the first component from its shaped state (such as to its original shape), and (3) removed from the second component. For example, a shaft which is initially substantially straight, deformed with an angular bend, then placed in a sheath which tends to hold the shaft in a straight position is “shapeable” if the shaft retains approximately at least 25% of the angle of the deformation when it is removed from the sheath. Similarly, the term “shaped” refers to components that are pre-shaped, which tend to retain their shape and cannot be readily plastically deformed. For example, a snare loop formed from a memory alloy with a given shape which is placed in a sheath which constrains that shape may be said to be “shaped” if the snare loop returns to its original shape when removed from the sheath. 
         [0032]    Referring now to  FIG. 1  which is a side view of a delivery conduit  12  having a single lumen  13 . In the illustrated embodiment, the lumen  13  extends the length of the delivery conduit  12 , from the proximal end  18  of the delivery conduit  12  to the distal end  16  of the delivery conduit  12 . As also shown in  FIG. 1A , the delivery conduit  12  and the lumen  13  may define a side wall  15  of the delivery conduit. The side wall  15  may be defined as the portion of the delivery conduit  12  surrounding the lumen where the outer surface of the side wall runs generally parallel to the longitudinal axis of the delivery conduit  12 . In some embodiments, the delivery conduit may have a side port  14 , or an opening in the side wall  15  of the delivery conduit  12 . 
         [0033]    In certain embodiments the delivery conduit  12  may also be configured with a connector  19  to couple the delivery conduit  12  to another device. This connector  19  may be any type of connector known in the art, for example a Luer connector. 
         [0034]    In the illustrated embodiment the side port  14  extends through the side wall  15  of the delivery conduit  12  allowing access from the lumen  13  to an area outside the delivery conduit  12 . In one embodiment the side port  14  constitutes a removed area of from about 5% to about 48% of the circumference of the side wall  15  of the delivery conduit. In other embodiments the side port  14  may fall into a smaller range of values, for example from about 25% to about 48% of the circumference of the delivery conduit. 
         [0035]    In some embodiments the distal end  16  of the delivery conduit  12  may be open, creating an end port, or distal opening in the distal tip of the delivery conduit  12 . In such embodiments, the lumen  13  extends through the end of the delivery conduit  12  at the distal end  16 . It other embodiments the lumen  13  may not extend through the distal end  16  of the delivery conduit  12 . It will be appreciated that in some embodiments the delivery conduit  12  will have such an opening at the distal end  16  in addition to a side port  14 , whereas in other embodiments the delivery conduit  12  will only have a side port  14  with no opening at the distal end  16 . In still further embodiments the delivery conduit will only have an opening at the distal end  16  and have no side port  14 . 
         [0036]    In embodiments where the delivery conduit  12  has an opening at the distal end  16 , the opening may be configured to allow a guidewire (not shown) or other elongate medical device to extend through the distal end of the delivery conduit  12 . In one embodiment the delivery conduit  12  may be configured such that the lumen  13  is sized to accommodate both a guidewire and the shaft of a snare device. In one example of such an embodiment, the guidewire may be configured to extend through an opening in the distal end  16  of the delivery conduit  12  and the snare device configured to extend through a side port  14 . In other embodiments, both a guidewire and a snare device may extend through the same opening. 
         [0037]    In certain embodiments the delivery conduit  12  defines an outer sheath through which medical devices (for example guidewires or snare devices) may pass during therapy. It will be appreciated that medical devices disposed within the delivery conduit  12  may be configured to be longitudinally displaceable with respect to the delivery conduit  12  during use. 
         [0038]    The delivery conduit  12  may be made from any extrudable, medical grade plastic such as those commonly used for making catheters. Examples include but are not limited to polyurethane, polyethylene (varying densities), PET (polyethylene terephthalate), PVC, polypropylene, nylon, peba byx, ABS, Hytrel®, Santoprene®, polycarbonate, Kraton®, PES, PVDF, and FEP. The extruded plastic may be cut to length, followed by creation of the side opening  14  by conventional cutting or machining methods known in the art. 
         [0039]      FIGS. 2-6  are side views of snare devices comprising shafts and snare loops. It will be appreciated that the illustrated embodiments have analogous features. The disclosure recited in connection with any embodiment may be applicable to any analogous feature in another embodiment, whether or not the components are numbered in both embodiments. Further, it will be appreciated that any of the snare devices illustrated or described in connection with any of  FIGS. 2-6  may be used in any combination with any of the embodiments of delivery conduits disclosed in connection with  FIGS. 1 and 1A .  FIGS. 2A ,  3 A,  4 A,  5 A, and  6 A are cross sectional views of the corresponding snare devices, but it will be appreciated that any of the disclosure or features recited in connection with any of these embodiments may analogously apply to every other embodiment or combination. 
         [0040]      FIG. 2  is a side view of an embodiment of a snare device  20  comprising a first snare loop  24  attached to one end of a shaft  22  and a second snare loop  26  attached to an opposite end of the shaft  22 . In this embodiment both the first snare loop  24  and the second snare loop  26  are configured to be in a generally circular configuration. In some embodiments the snare loops  24 ,  26  may be shaped. In other words, the circular configuration of the first snare loop  24  and the second snare loop  26  may be retained by constructing the first snare loop  24  and the second snare loop  26  of a superelastic material (such as a nickel titanium alloy, for example, nitinol). Superelastic materials may be able to be deformed to a much greater degree than ordinary materials without taking a permanent kink. It will be appreciated that in some embodiments only one of the two loops may be formed of a superelastic material, both loops may be so formed, or neither loop may be formed of a superelastic material. 
         [0041]    In the embodiment illustrated in  FIG. 2 , the first snare loop  24  and the second snare loop  26  are configured to be of differing sizes. When utilizing such embodiments, a physician may discover during the procedure one size of snare loop  24 ,  26  may be preferred or required. Accordingly, in certain embodiments the physician can insert the snare device into a body lumen in such a manner as to utilize the desired snare loop  24 ,  26 . 
         [0042]      FIG. 2A  is a side view of the snare device  20  shown in  FIG. 2 , wherein the shaft  22  has been configured to have a bend  28  along its length. In certain embodiments, the shaft  22  may be shapeable, that is, made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. 
         [0043]      FIG. 3  is a side view of another embodiment of a snare device  30  which has a shaft  34  configured with an angular bend  36  and an additional composite bend  38 . In some embodiments bends  36 ,  38  will be formed during therapy and shaped according to an individual physician&#39;s preference. The shaft  34  may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. As illustrated in  FIG. 3 , a first snare loop  32  having an elliptical configuration may be attached to one end of the shaft  34  and a second snare loop  33  having a circular configuration may be attached to an opposite end of the shaft  34 . The elliptical configuration of the first snare loop  32  and the second snare loop  33  may be retained by constructing the first snare loop  32  and the second snare loop  33  of a of a superelastic material (such as a nickel titanium alloy, for example, nitinol). 
         [0044]      FIG. 4  is a side view of an embodiment of a snare device  40  which has a shaft  44  configured with an angular bend  46 . The shaft  44  may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. In the illustrated embodiment, a first snare loop  42  having a rectangular configuration is attached to one end of the shaft  44  and a second snare loop  43  having a smaller rectangular configuration is attached to an opposite end of the shaft  44 . The rectangular configuration of the first snare loop  42  and the second snare loop  43  may be retained by constructing the first snare loop  42  and the second snare loop  43  of a superelastic material. 
         [0045]      FIG. 5  is a side view of yet another embodiment of a snare device  50  having a first snare loop  52  shaped into a trapezoidal configuration and a shaft  54  shaped to have a single, angular, bend  56 . A second snare loop  53  in a circular configuration is attached to an opposite end of the shaft  54 . The trapezoidal configuration of the first snare loop  52  and the circular configuration of the second snare loop  53  may be retained by constructing the first snare loop  52  and the second snare loop  53  of a superelastic material. The shaft  54  may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. 
         [0046]      FIG. 6  is a side view of an embodiment of a snare device  60  having a first snare loop  62  shaped into an elliptical configuration and a shaft  64  shaped to have a first angular bend  66 , second angular bend  68  and a second snare loop  63  having a rectangular configuration. It is noted that, in this embodiment, the second snare loop  63  is smaller in dimension than the first snare loop  62 . The elliptical configuration of the first snare loop  62  and the rectangular configuration of the second snare loop  63  may be retained by constructing the first snare loop  62  and the second snare loop  63  of a superelastic material. The shaft  64  may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. 
         [0047]    It will be understood that the specific configurations shown in  FIGS. 2-6  are illustrative only and that many possible shapes and configurations are possible. For example, any size or shape of snare loop described above may be used in any combination with any other size or shape of snare loop disclosed or any shape or configuration of shaft disclosed. Further, the particular shapes, sizes, and configurations are illustrative only; it is within the scope of the current disclosure to modify these shapes and sizes in a manner known in the art. 
         [0048]    In some embodiments, the shafts  22 ,  34 ,  44 ,  54 ,  64  as seen in  FIGS. 2-6  are shipped in an unshaped configuration and may also be used without a physician shaping the shaft during the procedure. 
         [0049]    As depicted in  FIGS. 3A ,  4 A,  5 A, and  6 A, the snare loops  24 ,  26 ,  32 ,  33 ,  42 ,  43 ,  52 ,  53 ,  62 ,  63  may be radiopaque in nature.  FIGS. 3A ,  4 A,  5 A,  6 A are cross sectional views taken through the snare loops  32 ,  42 ,  52 ,  62  and show a radiopaque coating  95  which surrounds the core wire  97 . Though not shown in the figures, it will be understood that the snare loops  24 ,  26 ,  32 ,  33 ,  42 ,  43 ,  52 ,  53 ,  62 ,  63  may also be radiopaque in some embodiments. Radiopacity may be imparted to the snare loops by processes known to those having skill in the art, including but not limited to dipping, coating, plating, vapor deposition, coils, coverings, and sleeves. Exemplary radiopaque materials include platinum, and gold plated tungsten. In one embodiment only the snare loops  24 ,  26 ,  32 ,  33 ,  42 ,  43 ,  52 ,  53 ,  62 ,  63  are radiopaque, while in other embodiments (not shown) the radiopaque coating  95  may extend proximally further down the shafts  22 ,  34 ,  44 ,  54 ,  64 . 
         [0050]    The snare devices  20 ,  30 ,  40 ,  50 ,  60  may be made by obtaining a shapeable wire of a thickness (in some embodiments between about 0.014-0.018 inches) suitable to maintain a bend, for the shaft portions  22 ,  34 ,  44 ,  54 ,  64 , followed by cutting the wire to length. Suitable shaft materials include but are not limited to 304 stainless steel and 316 stainless steel, and could also include any non-superelastic material able to be quickly and easily shaped. In one embodiment, the snare loop  24 ,  26 ,  32 ,  33 ,  42 ,  43 ,  52 ,  53 ,  62 ,  63  is attached to a more proximal point of the shaft wire and attached by conventional attachment methods known in the art, including but not limited to welding, adhesives, ball-and-socket techniques, cinching mechanisms, and mechanical fasteners. When completed, the joined area (not shown) may be substantially flush with the wire so as to minimize the occurrence of rough or inequitable areas that could cause tissue damage upon deployment. 
         [0051]    Radiopacity may be imparted to the snare loops  24 ,  26 ,  32 ,  33 ,  42 ,  43 ,  52 ,  53 ,  62 ,  63  by applying a radiopaque coating  95  by conventional methods as discussed above. Following curing of the radiopaque coating  95  the snare wire  20 ,  30 ,  40 ,  50 ,  60  may be sterilized and loaded into a delivery conduit  12  with the proximal end being inserted through the proximal opening  18 . 
         [0052]      FIGS. 7A-8D  illustrate embodiments of snare devices where shaft members such as those disclosed in connection with  FIGS. 2-6  and  2 A- 6 A are coupled to a delivery conduit such as that described in connection with  FIGS. 1 and 1A . 
         [0053]      FIGS. 7A-7D  illustrate a snare device  10  comprising a single lumen  13  with a snare shaft  22  and a guidewire  90  disposed within the lumen  13 . In the illustrated embodiment the delivery conduit  12  is configured with a side port  14  and an opening at the distal end of the delivery conduit. The guidewire is configured to extend through the opening in the distal end of the delivery conduit  12  and the snare loop and shaft configured to extend through the side port  14 .  FIGS. 7A-7D  illustrate a single lumen delivery conduit  12  in multiple stages of deployment, including trapping a fragment F. 
         [0054]      FIGS. 8A-8D  illustrate embodiments of a snare device  10  with two lumens  13 A,  13 B.  FIG. 8A  illustrates a snare device  10  comprising a delivery conduit  12  with two lumens  13 A,  13 B, a snare shaft  22  and loop  24 , and a guidewire  90 . In the illustrated embodiment, the snare shaft  22  is disposed within lumen  13 A and the guidewire within lumen  13 B. As illustrated, lumen  13 A may have a side port  14  configured to allow communication between lumen  13 A and an area outside the delivery conduit  12 . In addition to side port  14 , lumen  13 A may also be configured with an opening at the distal end of the delivery conduit  12 . Similarly, lumen  13 A could include an opening at the distal end of the delivery conduit without a side port  14 . In the illustrated embodiment, lumen  13 B is configured with an opening at the distal end of the delivery conduit  12 . Similar to lumen  13 A, lumen  13 B could also be configured only with a side port, only with an opening at the distal end of the delivery conduit, or both. Furthermore, though the illustrated embodiment shows guidewire  90  disposed within lumen  13 B and snare shaft  22  disposed within lumen  13 A, in other embodiments, lumen  13 A may be configured to receive a guidewire and lumen  13 B configured to receive a snare shaft. 
         [0055]      FIGS. 8B-8D  illustrate cross sectional views of certain embodiments of a two lumen delivery conduit. The delivery conduit may have a substantially circular cross section with semicircular lumens at in  FIG. 8B , a “FIG.  8 ” cross section with circular lumens as in  FIG. 8C , a circular cross section with one semicircular lumen and one rounded (either circular or elliptical) lumen as in  FIG. 8D , or any combination of delivery conduit and lumen cross sectional shapes. For example, a delivery conduit may also have a circular cross section with two circular or elliptical lumens disposed within it. In  FIG. 8D  a guidewire  90  is disposed within the elliptical lumen  13 B and the snare shaft  22  within the semicircular lumen  13 A. It will be appreciated that in other embodiments the lumen configured to receive the guidewire  90  may be semicircular in shape while the lumen configured to receive the snare shaft  22  may be ellipsoidal. 
         [0056]    In certain embodiments the delivery conduit may further include three or more lumens. For example, in one embodiment the snare device may have a first lumen configured to receive a snare shaft, a second lumen configured to receive a guidewire, and a third lumen configured to receive a balloon device. 
         [0057]      FIGS. 7A-7D  generally may be understood as illustrating potential relative positions of the components of the snare device  10  during therapy. The therapeutic procedure may involve any therapy in which snares or snare devices may be utilized such as removing a fragment (either a foreign object or body matter) from a lumen of the central venous system, for example. To use the device, the physician may first remove the snare device from a sterile package (not shown). A snare shaft  22  may be disposed within the delivery conduit  12  in the packaged configuration. A physician may remove the snare shaft  22  from the delivery conduit  12  by displacing the snare shaft  22  with respect to the delivery conduit  12  in a proximal direction. In embodiments where the snare shaft has a snare loop coupled to each end, the physician will determine which snare loop is desirable to perform the therapy. 
         [0058]    Once the snare shaft  22  is removed from the delivery conduit, the physician may deform the snare shaft into a desired configuration. The desired configuration may include multiple bends (including compound bends), a single bend, or no bend at all. The physician may deform the shaft by use of human hands, by placement of the unshaped shaft over a mandrel, or any other means known in the art. 
         [0059]    During therapy the delivery conduit  12  may be introduced into a body lumen of a patient. In some embodiments a guidewire  90  may be utilized to position the delivery conduit  12  and navigate the delivery conduit  12  through the body lumen. It will also be appreciated that the snare shaft  22  may be disposed within the delivery conduit  12  when the delivery conduit is initially introduced into the body lumen, or the snare shaft may be inserted into a lumen of the delivery conduit  12  after the delivery conduit is disposed within a body lumen of the patent. Further, the physician may: (A) remove the snare shaft  22  from the delivery conduit before the delivery conduit  12  is introduced into the body, shape the snare shaft  22 , and reinsert the snare shaft  22  into the delivery conduit  12  before the delivery conduit is first introduced into the body; (B) the physician may first introduce the delivery conduit  12  (with the snare shaft  22  disposed inside) into the body, then remove the snare shaft  22  for shaping and reinsertion; (C) the physician may insert the delivery conduit  12  into the body lumen without the snare shaft  22  disposed inside, shape the snare shaft  22 , then insert the snare shaft  22  into the delivery conduit  12 ; (D) or any other combination of these sequences. Furthermore, the physician may remove the snare shaft  22  from the delivery conduit  12  at any point during therapy for shaping or reshaping, regardless of whether the snare shaft  22  has already been shaped. 
         [0060]    Once the delivery conduit  12  and snare shaft  22  are positioned and shaped for therapy, the physician may deploy the snare loop  24  by displacing the snare shaft  22  in a distal direction relative to the delivery conduit  12 . As illustrated in  FIG. 7A-7D , the snare loop  24  may then be manipulated to surround the fragment F. Once the snare loop  24  is in place, the physician may then displace the snare shaft  22  in a proximal direction with respect to the delivery conduit  12  such that the fragment F is trapped between the snare loop  24  and the delivery conduit  12 , as shown in  FIG. 7D . The snare device  10  may then be removed from the body lumen, thus removing the fragment F from the body. 
         [0061]    In some embodiments it will be desirable to extend the guidewire  90  beyond the delivery conduit  12  (either through a distal opening or through a side port) prior to deploying the snare loop  24  beyond the delivery conduit  12 . This sequence may reduce the frequency of instances wherein the snare loop  22  inadvertently captures or becomes entangled with the guidewire  90 . 
         [0062]    Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and exemplary and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein.