PRIORITY APPLICATION DETAILS

[0001] The present application claims the priority from the Indian provisional patent application number 202121058158 dated March 14, 2022 having a title as - Modified Device for Percutaneous Closure of Intracardiac Shunts.

TECHNICAL FIELD

[0002] The present technical invention relates to a medical device for intracardiac shunts. More particularly, the present technical invention relates to a device for percutaneous closure of intracardiac shunts.

DEFINITIONS:

[0003] Proximal disc - The term "proximal disc" refers to a right atrial disc in case of ASD occluders.

[0004] Eccentric waist - The term "eccentric waist" refers to a part that occludes a device which has an eccentric shape.

[0005] Claw structure - The term "claw structure" refers to a claw shaped attachment for fixing the device.

[0006] Occluder - The term "occluder" refers to an implement that is used to cover or stop up a hole in the heart.

[0007] Amplatzer Device - The term "amplatzer device" refers to a percutaneous, transcatheter occlusion device intended for the nonsurgical closure of intracardiac shunts. BACKGROUND

[0008] In general, percutaneous closure of intracardiac shunts is a nonsurgical procedure used to treat patients with an atrial septal defect (ASD), a ventricular septal defect (VSD) and a Patent ductus arteriosus (PDA). Advancements in a device technology and image guidance now permit the safe and effective catheter-based closure of numerous intracardiac defects. An atrial septal defect (ASD) is a hole in the wall between the heart's two upper chambers. ASD is a congenital condition, which means it is present at birth of a child. A ventricular septal defect (VSD) is a hole in the wall between the two lower chambers. In children, the VSD is also congenital. Percutaneous device closure for intracardiac shunts is an effective alternative to surgery.

[0009] Out of three intracardiac shunts (ASD, VSD and PDA), the PDA device closure has excellent results and almost all cases are amenable to it. Surgical closure is hardly required for PDA these days. The prior art is described with reference to the following figures accompanying the specification.

[0010] Figure 1 illustrates a prior art depicting a configuration of an Amplatzer series device (100). Figure la illustrates a prior art depicting an Amplatzer Muscular VSD Occluder. Figure lb illustrates a prior art depicting an Amplatzer Duct Occluder. Figure 1c illustrates a prior art depicting an Amplatzer Vascular Plug III. Figure Id illustrates a prior art depicting an Occlutech PLD (square-shaped design). Figure le illustrates a prior art depicting an Amplatzer Septal Occluder. Figure If illustrates a prior art depicting an Amplatzer Vascular Plug II. Figure 1g illustrates a prior art depicting an Amplatzer Vascular Plug IV. Figure Ih illustrates a prior art depicting an Occlutech PLD (rectangular-shaped design). [0011] Figure 2 illustrates a prior art depicting a typical septal occluder (200). Figure 2.1 illustrates a prior art depicting an Amplatzer septal Occluder. In Figure 2.1 (A) an Amplatzer septal occlude is shown. And in Figure 2.1 (B) an Amplatzer septal occluder supported by septal tissue is shown. Figure 2.2 illustrates a prior art depicting an Amplatzer septal occluder with different parts of septal occluder. In this, the circular device with no central lumen is shown. Figure 2.3 illustrates a prior art depicting a Amplatzer septal occluder with delivery cable attached to connector.

[0012] Figure 3 illustrates prior art depicting a typical septal occluder (300). Figure 3.1 illustrates a prior art depicting an Amplatzer Muscular VSD Occluder. Figure 3.2 illustrates a prior art depicting different types of Amplatzer VSD occluders. A shows a Symmetric Occluder, B shows an Eccentric Occluder, C shows a thin waist Occluder, D shows an Ampltzer Duct Occluder II. L indicates a left disc and R indicates a right disc. Figure 3.3 illustrates a prior art depicting a device with unequal margins.

[0013] Figure 4 illustrates a prior art depicting a typical design of a PDA occluder (400). The typical design of the PDA occlude shows a (A) Left ventricular retention disc diameter, (B) Left ventricular side diameter, (C) Right ventricular side diameter, (D) Device length, (E) Delivery cable, (F) Internal threat, where a cable connects to the device.

[0014] Many types of devices are available in the art, but Amplatzer series is more popular due to its design and easy deployment technique as per Figures 1(a) to 1(h) accompanying the specification. A typical septal occluder has a central waist which fits into the defect and has overhanging margins which takes support from surrounding tissue as per Figure 2.1(A), (B) and Figure 3.1. [0015] The stability of the device is less if the surrounding rims are not adequate and can lead to embolization of the device. In the ASD and VSD, adequate rims all around the defect are preferred for proper placement of device. For PDA, only the left retention disc is present, and stability of the device is provided by selecting a device size, at least 2 millimeters (mm) more than the narrowest diameter of the PDA as shown in Figure 4. For the ASD and VSD not only the size of the device but also the surrounding rims of tissue are important for device stability. Embolization of the device is a known complication of these devices. The device can embolize if the size of the device is smaller than the defect or if enough support is not provided by surrounding tissue. Role of rims of the surrounding tissue is crucial for the ASD and VSD. As adequate rims are not present in sinus venosus ASD and ostium primum ASD, surgery is the only option for such patients whereas devices are used in suitable ostium secundum ASDs with adequate rims.

[0016] Similarly, in inlet and sub-pulmonary VSDs, devices are not recommended. Minor modifications have been done in devices to get good outcome in subaortic VSD, as shown in Figure 3.3, another subset of the VSD with inadequate rims. A muscular VSD is most suitable for device closure due to good rims all around. In spite of all these, the risk of embolization of device is around 1% in intracardiac shunts even in patients with suitable rims all around.

[0017] SHORTCOMINGS OF PRIOR ART (Amplatzer or Amplatzer like devices):

Anatomical and device related limitations: 1. There is a need to have surrounding 'walls' supporting their stability. These devices need more than 5-7 mm of sufficiently stable tissue to support device stability. Enough rims are necessary to avoid disks interference with atrioventricular valves and venous returns. However, isolated absence of aortic rim (in ASD) can be overcome and present generation of device can close such defects effectively. Occasionally, rims are well represented but are too floppy and flimsy. In these cases, the tissue of the rims is too compliant and does not assure stability of device.

2. There is a limited role in ASDs with Atrial septal aneurysms (ASA). The ASA is defined as a localized deformity of the interatrial septum, which protrudes into the right or the left or both and may interfere with device positioning, stability and safety.

3. Size of defect:

(a) ASD closure devices: The available waist diameter of ASD devices is 4 - 40 mm, so larger size of defect cannot be closed with these devices.

(b) PDA closure devices: Maximum available device size is A/ 2. mm, where a first number refers to diameter of the aortic end and a second number refers to the pulmonary end of a conical shaped device.

(c) VSD closure device: Available in sizes ranging from 4-16 mm and higher sizes are available in Post-infarct Muscular VSD Occluder (up to 24 mm).

[0018] In order to increase stability of the device and to reduce the risk of embolization of the device and to extend its application of other subsets of intracardiac shunts, where surgery is the only option right now, the modifications in a present set of devices as per the present invention are proposed.

[0019] Therefore, there is a need for the present invention which overcomes the aforementioned technical problems.

SUMMARY

[0020] This summary is provided to introduce the concept related to a device for percutaneous closure of intra cardiac shunts. The summary is neither intended to identify essential features of the present technical invention nor is it intended for use in determining or limiting the scope of the present technical invention.

[0021] In an embodiment of the present technical invention, a device for percutaneous closure of intra cardiac shunts is disclosed. The device has two semi-circular discs having a joint arrangement at the center of each disc as opposed to single circular disc in the present generation of devices. Semicircular discs can be symmetrical (identical) or asymmetrical with inequal over hanging margins. Waist present on both semicircular discs should be equal or identical. It is the overhanging margins which are different of either disc. One semicircular disc has normal (5-7 mm) or longer overhanging margins and the other disc has little or no overhanging margins. Presence of 2 semicircular disc will create a space in center between these two discs to allow passage of guide wire called as a central lumen that is centrally placed between the two semi-circular discs. A guide wire is placed in the central lumen, the guide wire can help to rotate device on the guidewire to align disc with little or no margins against the part of defect with deficient rims and other disc against adequate rims. The guide wire is configured to rotate the device in one or more directions and align the semi-circular disc with little or no margins to the part of defect with deficient rim. There is a delivery cable which is a hollow tube to accommodate the guide wire and it can be connected or disconnected from a device connector by clockwise or counterclockwise rotation respectively. The delivery cable is configured to accommodate the guide wire inside the structure as well as the delivery cable is configured to help in aligning one of the semi-circular discs to the deficient rim.

[0022] In one embodiment, the basic structures are same as in the previous embodiment as there are two semi-circular discs with two ends of each disc having a joint arrangement at the ends of each disc. A central lumen is centrally placed between the two semi-circular discs. A guide wire is placed in the central lumen of the device and the guide wire is configured to align device to the part of defect with deficient rim. The guide wire is further configured to rotate the device in one or more directions and align the semi-circular disc with little or no margins to the deficient rim. A delivery cable having a hollow tube structure is configured to accommodate the guide wire inside the structure and is also configured to help in alignment of semi-circular disc to the deficient rim. Further, there is a set of fixation wires that are attached to proximal disc of semicircular disc with normal or longer overhanging margins and help to fix the device to an adjacent septal tissue which is configured to stabilize the device. Fixation wires along with delivery cable can be delivered through delivery sheath. These fixation wires can be screwed on to adjacent tissue to stabilize the device. The delivery cable and these fixation wires on the right disc can be within the delivery sheath to facilitate attachment to septal tissue. Another way to stabilize the device will be to put claw like wires on septal tissue side of proximal disc.

[0023] In another embodiment, a device with two semi-circular discs with two ends of each disc having a joint arrangement at the ends of each disc is shown. A central lumen is present between the two semi-circular discs will facilitate the device to be delivered over the guidewire. The guide wire is also configured to rotate the device in one or more directions and align the semi-circular disc with little or no margins to the deficient rim of the defect. A delivery cable having a hollow tube structure which is configured to accommodate the guide wire inside the structure and to help in aligning the semi-circular disc to the deficient rim is also present. There is also a delivery sheath which is configured to accommodate the guide wire, the delivery cable along with a septal puncture needle, the septal puncture needle is configured to puncture the adjacent septal tissue through the semi-circular disc with normal or longer overhanging margins and enable a passage of a thin wire through the adjacent septal tissue. The septal tissue can be punctured through this needle and a wire can be passed within the lumen of needle. Further, a catheter is used to snare the thin wire left atrium in the central lumen of the delivery cable and the device is fixed to the septal tissue by extreriotating, rotating and cutting the wire from outside to fix the device to the septal tissue.

[0024] The modified device where the discs are symmetrical can be used to occlude defects with sufficient rims all around as they are closed with prior art. The presence of fixation wires, claws or fixation as explained with help of septal puncture needle can be accommodated on one of the symmetrical discs to minimize embolization of device.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[0025] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and modules.

[0026] Figure 1 illustrates a prior art depicting a configuration of an Amplatzer series device. [0027] Figure 2 illustrates a prior art depicting a typical septal occluder.

[0028] Figure 3 illustrates a prior art depicting a typical septal occluder.

[0029] Figure 4 illustrates a prior art depicting a typical design of a PDA occluder.

[0030] Figure 5 illustrates a schematic diagram depicting a device for percutaneous closure of intracardiac shunts, according to an embodiment of the present technical invention.

[0031] Figure 6 illustrates a schematic diagram depicting a device for percutaneous closure of intracardiac shunts having delivery sheath and fixation wires, according to an embodiment of the present technical invention.

[0032] Figure 7 illustrates a schematic diagram depicting a device for percutaneous closure of intracardiac shunts having a septal puncture tool, according to an embodiment of the present technical invention.

[0033] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative methods embodying the principles of the present invention. Similarly, it will be appreciated that any flow charts, flow diagrams, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. DETAILED DESCRIPTION

[0034] The invention will now be described with reference to the accompanying drawings and embodiments which do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.

[0035] One or more embodiments are provided so as to thoroughly and fully convey the scope of the present invention to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present invention. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present invention. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0036] The terminology used, in the present invention, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present invention. As used in the present invention, the forms "a," "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," "including," and "having," are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/ or groups thereof. The particular order of steps disclosed in the method and process of the present invention is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.

[0037] In an embodiment, the present invention provides a device for percutaneous closure of intracardiac shunts.

[0038] In an embodiment, the present invention provides a device for percutaneous closure of intracardiac shunts to close defects with insufficient rims around the defect.

[0039] In an embodiment, the present invention provides a device for percutaneous closure of intracardiac shunts to reduce the embolization of the devices.

[0040] In an embodiment, the present invention provides a device for percutaneous closure of intracardiac shunts to eliminate and / or reduce the shortcomings and defects of the prior art.

[0041] In an embodiment, the present invention provides a device for percutaneous closure of intracardiac shunts that closes defects with inadequate rims for which the present generations of devices are not recommended.

[0042] In ASDs and VSDs, it may be possible to close the defects which are contraindicated right now for device closure e.g., sinus venosus or septum primum ADSs. The device of the present invention reduces the incidence of embolization and it may eliminate this complication seen in current generations of devices. The higher sizes of defect can be closed with the present invention as risk of embolization will be near zero. The incidences of obstruction to atrioventricular valves or venous returns can be reduced with the present invention. [0043] The interference with other intracardiac structures and electrical conduction system can be reduced with the present invention.

[0044] In an embodiment, the present invention makes no change in the nitinol framework of devices. The device according to the present invention is made up of nitinol and has fabric mesh. There is no need to change the material as it is best suited for devices according to the present invention.

[0045] In an embodiment, the present invention provides a modification in overhanging margins of the device. Typically, most of the present set of devices has a 'central' waist with over hanging disc margins on both sides for support and to prevent embolization (Figure 2.1 and Figure 3.1). Typical PDA occluders (ADO I) have a slightly different design (Figure lb and Figure 4). ADO II (Figure 3.2 D) has a central waist and symmetrical margins. In some occluders (for perimembranous and subarterial VSDs), the overhanging margins are unequal to accommodate the deficient rims (Fig 3.2 B and 3.3). In order to close defects with inadequate or deficient rims (applicable for certain ASDs and VSDs), the waist of the device (part that occludes the defect) will remain the same but the overhanging margins should be modified to be eccentric. The margins on one side should be negligible and the side opposite to it should have normal or longer overhanging margins. The side without margins will face a defect with inadequate rims and the opposite side will continue to provide support. As the device must be properly aligned so the side without disc margins must align with the side with inadequate rims, a provision should be there to rotate the device once it is placed across the defect. Therefore, the modifications are required in the present invention: a) Eccentric margins with identical waist b) Rotation facility in device. For PDA occluders, such modifications in margins are not required. [0046] In an embodiment, the device has two semi-circular discs with the two ends of each semi-circular disc having a joint arrangement at the ends of each disc. One disc has normal or longer overhanging margins and the other disc has little or no margins. There is a space between these two discs to allow passage of guide wire called as a central lumen that is centrally placed between the two semi-circular discs. The device can be delivered over the guidewire. The guide wire is configured to rotate the device in one or more directions and help in aligning the semi-circular disc with little or no overhanging margins to the deficient rim. There is a delivery cable which is a hollow tube to accommodate the guide wire and it can be connected or disconnected from a device connector by clockwise or counterclockwise rotation respectively. The delivery cable is configured to accommodate the guide wire inside the structure as well as the delivery cable is configured to help in aligning the semi-circular disc to the deficient rim.

[0047] In an embodiment, a first disc of the two semi-circular discs has longer and over hanging margins.

[0048] In an embodiment, a second disc of the two semi-circular discs has shorter overhanging margins.

[0049] In an embodiment, each disc from the at least two semicircular discs includes an identical waist. The device is eccentric due to unequal overhanging margins but the waist is identical.

[0050] In an embodiment, a device cable connector is configured to connect the one end of the delivery cable to the device.

[0051] In an embodiment, the delivery cable is attached to the device by using a clockwise rotation of the device cable and detached the delivery cable by using a counterclockwise rotation of the device cable. This rotation is done from the end of delivery cable which is outside and under control of operator.

[0052] In an embodiment, the first disc of the two semi-circular discs provides extra support to reduce embolization of device.

[0053] In an embodiment, the second disc of the two semi-circular discs aligns with part of defect with deficient rims.

[0054] In an embodiment, the device is made up of nitinol material having fabric mesh.

[0055] In an embodiment, a device with two semi-circular discs with two ends of each disc having a joint arrangement at the ends of each disc. A central lumen is centrally placed between the two semi-circular discs. A guide wire is placed in the central lumen of the device and the guide wire is configured to rotate the device in one or more directions and align the one semi-circular disc with little or no margins to the part of defect with deficient rim. A delivery cable having a hollow tube structure is configured to accommodate the guide wire inside the structure and is also configured to help in aligning the semi-circular disc to the deficient rim. Further, there is a set of fixation wires that are attached to proximal disc of semi-circular disc with normal or overhanging margins to fix the device on adjacent septal tissue which is configured to stabilize the device. There is also a delivery sheath which has the delivery cable, and the fixation wires which are further configured to facilitate an attachment to the adjacent septal tissue. These fixation wires can be screwed on to adjacent tissue to stabilize the device. The delivery cable and these fixation wires on the proximal disc can be within the delivery sheath to facilitate attachment to septal tissue. Another way to stabilize the device will be to put claw like wires on septal tissue side of proximal disc.

[0056] In an embodiment, the fixation wires are being fixed on to an adjacent septal tissue and are being screwed in or hooked up with an extension.

[0057] In an embodiment, the semi-circular disc with normal or overhanging margins is having a screw in arrangement to actively fix the device to adjacent tissue.

[0058] In an embodiment, the semi-circular disc with normal or overhanging margins is having a screw in arrangement to actively fix the device to adjacent tissue.

[0059] In an embodiment, a device with two semi-circular discs with two ends of each disc having a joint arrangement at the ends of each disc is shown. A central lumen is centrally placed between the two semi-circular discs with a guide wire placed in the central lumen, the guide wire is configured to rotate the device in one or more directions and align semicircular disc with little or no margins to the deficient rim of the defect. A delivery cable has a hollow tube structure which is configured to accommodate the guide wire inside the structure and to help in aligning the semi-circular disc with little or no margins to the deficient rim is also present. There is also a delivery sheath which is configured to accommodate the guide wire, a delivery cable inside along with a septal puncture needle, the puncture needle is configured to puncture the adjacent septal tissue through the semi-circular disc with normal or over hanging margins and to enable passage of a thin wire through the adjacent septal tissue. The septal tissue can be punctured through this needle and a wire can be passed within the lumen of needle. Further, a catheter is used to snare the thin wire from left atrium in the central lumen of the device and the device is fixed to the septal tissue by extreriotating, rotating and cutting the wire from outside.

[0060] In an embodiment, a thin wire consists of rotating two ends of the thin wire thereby making a knot and cutting the thin wire to fix the device.

[0061] A device for percutaneous closure of intracardiac shunts (hereinafter referred to as "device") (500) includes two semi-circular discs (510,520), a central lumen (550), a guide wire (540), and a delivery cable (530).

[0062] Two semi-circular discs (510,520) with two ends of each disc having a joint arrangement at the ends of each disc. In an embodiment, a first disc (510) of the two semi-circular discs (510,520) is having longer over hanging margin. In another embodiment, a second disc (520) of the two semi-circular discs (510,520) has shorter overhanging margins. In another embodiment, each disc includes an identical waist.

[0063] The central lumen (550) is centrally placed between the two semi-circular discs (510,520).

[0064] The guide wire (540) is placed in the central lumen. The guide wire (540) is configured to rotate the device (500) in one or more directions and align the semi-circular disc with little or no over hanging margins to the deficient rim.

[0065] The delivery cable (530) has a hollow tube structure. The delivery cable (530) is configured to accommodate the guide wire (540) inside the structure and further help in aligning the semi-circular disc to the deficient rim.

[0066] In an embodiment, the device (500) includes a device cable connector (560) which is configured to connect the one end of the delivery cable (530) to the device (500).

[0067] In an exemplary embodiment, the device (500) has two semicircular discs (510,520) as opposed to a single circular disc. One disc (510) has normal or longer overhanging margins and the other disc (520) has little or no margins. There is a central lumen (550) between these 2 discs to allow passage of guide wire (540). The delivery cable (530) is a hollow tube to accommodate the guide wire (540) and it can be connected or disconnected from the device cable connector (560) by clockwise or counterclockwise rotation respectively. Due to this facility, the device (500) can be delivered over the guide wire (540). As the hollow delivery cable is not present in existing systems/ devices, the present invention facilitates help to rotate the device (500) in order to align the semi-circular disc (520) with little or no margins along the deficient rims.

[0068] Figure 6 illustrates a schematic diagram (600) depicting a device (500) for percutaneous closure of intracardiac shunts having delivery sheath and fixation wires, according to an embodiment of the present technical invention.

[0069] In Figure 6, a set of fixation wires and a delivery sheath are disclosed. In an embodiment, the device (500) also includes a set of fixation wires (610). The set of the fixation wires (610) is attached to a proximal disc of semi-circular disc with normal or longer overhanging margins (510,520). In an embodiment, the fixation wires (610) are fixed to an adjacent septal tissue and configured to stabilize the device (500).

[0070] The delivery sheath (620) has the delivery cable (530) and the fixation wires (610), which is further configured to facilitate an attachment to the adjacent septal tissue.

[0071] In an embodiment, a screw in or claw like extension to hook up the device (500) to underlying tissue is disclosed. This mechanism can be understood with an active fixation method used in pacemaker leads. Generally, the present generations of pacemaker leads have screw in facility to actively fix pacemaker lead to cardiac tissue. Similarly, a screw in mechanism can be added in the semi-circular disc with normal or longer over hanging margins (520) so that some of its struts can actively fix to adjacent septal tissue. It can be done by some separate fixation wires (610) on the device and wires can be fixed to underlying septal tissue by screw in mechanism. These wires may remain within the delivery sheath (620) of the device. Even a claw like extension on the side of the disc in contact with septal tissue, can fix it to underlying tissue. This modification will help to stabilize all devices including the PDA occluders. For the PDA occluders, this mechanism is to be added on a left retention disc. For ASD occluders, it should be on the right atrial disc of the occluder. For the VSD, this arrangement can be on either disc. If the VSD occluder is deployed from the right ventricular side, it should be on the right disc (i.e., the proximal disc or the disc to which delivery cable is attached) and the device is deployed from the left ventricular side, then it can be on either disc.

[0072] Figure 7 illustrates a schematic diagram (700) depicting a device (500) for percutaneous closure of intracardiac shunts having a puncture tool, according to an embodiment of the present technical invention.

[0073] In Figure 7, a puncture needle and catheter from the septal puncture tool (710) have been disclosed. In an embodiment, the puncture needle (710) passes through the delivery sheath (620) to puncture an adjacent septal tissue through semi-circular disc with normal or longer overhanging margins and enable passage of a thin wire through the adjacent septal tissue. The catheter (710) is configured to snare the thin wire from left atrium in the central lumen of the device (500) and to fix the device (500) to the septal tissue by extreriotating, rotating and cutting the wire from outside.

[0074] In an exemplary embodiment, the puncture needle (710) can be passed within the delivery sheath (620) after device deployment. The septal tissue can be punctured through the semi-circular disc with normal or longer over hanging margins (520) and a thin wire can be passed through it and snared through the central lumen of the device (500). The two ends of the thin wire can be rotated to make a knot and cut so that the device (500) can remain fixed at its position. With this technique, there will be no chance of embolization of device. This modification is suitable for the ASD and VSD occluders.

[0075] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the invention.