INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONSAny and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57.
This patent application is a continuation of U.S. application Ser. No. 15/292,697, filed Oct. 13, 2016, entitled, “Cardiac Implantable Electronic Device Pocket Compression Apparatus and Method of Mitigating Localized Bleeding Using Same,” which claims priority from provisional U.S. patent application No. 62/240,967, filed Oct. 13, 2015, entitled, “Implantable Cardiac Device Pocket Compression Apparatus,” and naming Dhanunjaya Lakkireddy and Srijoy Mahapatra as inventors [practitioner's file 4179/1001], the disclosure of which is incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTIONField of the InventionThe invention generally relates to a medical apparatus and, more particularly, the invention relates to a treatment apparatus for use in connection with cardiac device implantations.
Description of the Related ArtSeveral hundred thousands of patients receive subcutaneous cardiac devices (pacemakers, defibrillators, resynchronization therapy devices, loop recorders) throughout the world each year, with many thousands in the United States alone. With increasing advances in medical devices and the advent of life saving implantable cardioverter defibrillators along with cardiac resynchronization therapy, cardiac device therapy placed in the chest through the infraclavicular/subclavian approach has become very common. Usually, after sterile preparation, a small incision is made below the clavicle either on the right or left side. A subcutaneous pocket is created, bleeders are secured, and access to the subclavian vein or cephalic vein is obtained under the guidance of fluoroscopy. Then pacing or defibrillator leads may be placed in the appropriate chambers of the heart. These leads may be secured to the fascia over the pectoralis muscle and the end of which may be usually plugged into the ports in the device generator. The portion of the leads and the generator may be placed in the pocket and closed in two or three layers of suture. Bleeders may be secured before closing the pocket. Sterile strips may be placed over the closed incision and allowed to heal over the next few days.
Based on prior research, pocket bleeding and hematoma formation may be seen in about 4.9% patients and the incidence may be higher in those receiving defibrillators compared to pacemakers. Pocket bleeding can prolong hospital stay in 1.5% of patients who receive these devices up to 2.5 days with about 0.5% requiring repeat hospitalization and close to 1% needing pocket revision and hematoma evacuation. The risk of post device bleeding and hematoma formation may be significantly higher (e.g., up to 12%-20%) in those patients who may be bridged with anticoagulants like heparin and enoxaparin. Even in those cases where warfarin is continued throughout the procedure, the risk of post procedural bleeding may be up to 2-6%. Often, large hematomas and subsequent evacuations lead to increased incidence of infection.
Commonly, small swelling or hematoma left untreated and healing are left to normal body processes. However, hematomas and pocket bleeding can be serious enough in a certain percentage of patients as described above, requiring immediate attention. This can significantly increase the cost of treatment, and the amount of lost wages. This can also add a significant morbidity to the patient's health. Patients with device site hematomas and bleeding are at higher risk for infections which often require hospitalizations, intravenous antibiotic therapy and device extraction that leads to significant procedural risks, costs and patient comfort
SUMMARY OF THE INVENTIONIn accordance with one embodiment of the invention, a medical device for applying pressure to a localized area of patient's body includes a pliable wrap for wrapping around at least a portion of the patient, and a block of solid, non-inflatable material positioned between the wrap and the localized area of the patient. The wrap may be a vest for holding the block against the patient's torso, or a sleeve to hold the block against a patient's arm or a leg, to name but a few examples. In some embodiments, the wrap includes an elastic material, such as neoprene for example, and may also include straps to adjust the pressure applied to a localized area on the patient by the block.
The block is sized and shaped to apply pressure to the localized area of the patient, which pressure is sufficient to hinder but not completely prevent blood flow in the localized area of the patient's body. For example, the block may have a wedge shape with a narrow face positioned to face the patient when the medical device is worn by the patient.
Some embodiments include a sealable pouch in the medical device for securing the block in position, and some embodiments also include an absorbent sheath around the block within the pouch. Moreover, some embodiments include at least one filler member within the pouch to secure the location of the block within the pouch. Other embodiments secure the block with one or more straps, or a hook-and-loop fastener such as Velcro.
In accordance with another embodiment of the invention, a method of mitigating pocket bleeding and hematoma formation in a patient locates a localized torso area of the patient that may be subject to bleeding and/or hematoma formation. The localized torso area is at least in part covered by a bandage and/or dressing. Next, the method provides a pliable wrap having a non-inflatable solid block coupled with the wrap, and then secures the pliable wrap around the torso of the patient to align the solid block with the located localized torso area. The solid block is secured between at least a portion of the wrap and the bandage and/or dressing, at least in part covering the localized torso area. The wrap is secured to cause the wrap to apply a force, to the solid block, that produces a corresponding pressure on the localized torso area. The force applied to the solid block is high enough to cause the pressure to hinder blood flow to the localized torso area to promote clotting at the localized torso area. At the same time, the force applied to the solid block is low enough to cause the pressure to permit blood flow to the localized torso area to promote healing.
BRIEF DESCRIPTION OF THE DRAWINGSThose skilled in the art should more fully appreciate advantages of various embodiments from the following description discussed with reference to the drawings summarized immediately below.
FIG. 1 schematically illustrates a front view of the outer surface of a compression vest in a detached configuration in accordance with illustrative embodiments;
FIG. 2 schematically illustrates a rear view of the inner surface of a compression vest in a detached configuration in accordance with illustrative embodiments;
FIG. 3A schematically illustrates details of a fabric for a compression vest in accordance with illustrative embodiments;
FIG. 3B schematically illustrates a compression block urged towards a patient's body by a garment;
FIG. 3C schematically illustrates pressure gradient within a patient;
FIG. 4 schematically illustrates a front view in an attached configuration in accordance with illustrative embodiments;
FIG. 5 schematically shows a rear view in an attached configuration in accordance with illustrative embodiments;
FIGS. 6A-6B schematically illustrate an incision on the chest of a patient;
FIGS. 6C-6D schematically illustrate a front view in an attached configuration on a patient and a rear view in an attached configuration on a patient, respectively, in accordance with illustrative embodiments;
FIGS. 7A-7D schematically illustrate embodiments of compression blocks for use with a compression garment in accordance with illustrative embodiments;
FIGS. 7E-7F schematically illustrate cross sections of embodiments of compression blocks;
FIG. 7G schematically illustrates an embodiment of a compression block in a sheath;
FIG. 8 schematically illustrates an embodiment of a compression sleeve;
FIG. 9 is a flow chart illustrating a method of using a garment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTIllustrative embodiments mitigate pocket bleeding and hematoma formation in a patient by providing constant, adjustable pressure to a localized area of the patient's body. To that end, a mechanical, noninvasive garment has adjustable levels of compression to treat and/or substantially reduce the likelihood of hematomas from cardiac devices, such as pacemakers, defibrillators, loop recorders, and pressure monitoring systems placed underneath the skin in the human chest/torso. Among other configurations, the garment may be formed as a single unit with straps, and includes a compression block in a pouch of the garment. During use, the block applies specific pressure to a targeted area of the patient. The garment may be worn in a similar manner to a jacket, i.e., over the shoulder that is closest to the cardiac device. A first shoulder strap can be adjusted for appropriate contact, while a second strap (e.g., around the chest) may be adjusted to selectively apply pressure to the block, consequently applying pressure to the targeted area. Illustrative embodiments may be used over a device pocket (formed in a patient's body), which may have a hematoma, or may be used in a prophylactic fashion to avoid (or at least substantially reduce the likelihood that) a hematoma when they are expected.
During use, the patient may move around without being limited to a bed or chair. The garment also may enable the patient to carry on activities of daily living with minimal limitation. Accordingly, the garment may decrease the incidence of hematoma formation after cardiac device placement, especially when device implantation was done while the patient was on therapeutic anticoagulation. For patients on anticoagulants (e.g., heparin or enoxaparin), the garment may be used immediately after device implantation until the patient's anticoagulation levels settle to a prescribed therapeutic range. Also, the garment can compress a hematoma of the pocket that has already formed. As a result, the garment may reduce pain and suffering for the patient, decrease duration of hospitalization, decrease recurrent hospitalizations and additional interventions (e.g., reopening the device pocket and hematoma evacuations). Consequently, the garment potentially can reduce significant health care costs. Details of illustrative embodiments are discussed below.
FIGS. 1 and 2 respectively show front and rear views of illustrative embodiments of a garment orvest100 in a detached configuration. It should be noted that the specific dimensions in the drawing are exemplary only and thus, are not intended to limit various illustrative embodiments.FIGS. 6B and 6C schematically illustrate front and rear views, respectively, of avest100 worn by a patient.
Thevest100 is a single structure configured to anchor over the patient's shoulder and wrap around (e.g., form a loop around) the patient's upper chest in a circumferential fashion.
Thevest100 includes awaist band110 configured to wrap around the patient's torso and secure thevest100 to the patient. To that end, thewaist band110 includes awaist strap220 coupled to aback flap221. Thewaist strap220 includes a hook and loop patch113 (e.g., Velcro) configured to removably and adjustably couple to a counterpart hook andloop patch114 on afront flap222. Thewaist strap220 may be useful in adjusting the top-to-bottom stretch and compression of thevest100.
Thevest100 also includes left andright shoulder portions101 and105 extending from thewaist band110. In use, when worn by a patient, the left andright shoulder portions101 and105 are physically coupled by ashoulder strap120, to secure thevest100 around the patient's shoulder. For example, thestrap120 may go over the ipsilateral shoulder connecting thescapular portion105 to the pectoral101 portion of the vest.
Together, theshoulder strap120 andwaist strap220 provide stretch and compression of thevest100 in four directions (e.g., left and right across the patient's torso, and up and down relative to the patient's shoulders).
Thevest100 also includes at least one structure (e.g.,210;211) for securing a compression block700 (described below) to thevest100. In illustrative embodiments, thestructure210;211 may be a pouch, or sealable pouch, to hold thecompression block700. In some embodiments, thestructure210;211 may include straps, belts, hook and loop fasteners, or other devices.
More specifically, apouch210 holds thecompression block700 adjacent to an area on a patient's body where pressure is desired. In illustrative embodiments, thepouch210,211 is on or in theinner surface202 of thevest100, so that thevest100 presses theblock700 towards the patient.
Chest pads103 and/or104 hold acompression block700 on the incision site (650) on patient's chest. In some embodiments,chest pad103 and/or104 of thevest100 may have a surface that is larger than theirrespective pouches210,211. Moreover, thechest pads103 and104 provide a surface for applying a compressive force to thecompression block700 inside apouch210,211. The amount of compressive force applied bychest pads103 and104 to thecompression block700 may be adjusted using ashoulder strap120 and/or awaist strap220.
Some embodiments may come pre-attached at the shoulder strap and can be worn around the shoulder like a sling. Such embodiments may omit thewaist band110 and itsstrap220.
Thevest100 includes a stretchable body (e.g.,waist strap110 and/orshoulder portions101 and105) made up of stretchy or elastic materials, such as 2 mm thickness SBR Neoprene VELCRO compatible UBL finish, for example. In addition, as schematically illustrated inFIG. 3A, such materials may be waterproof and/or insulated. Moreover, theouter surface102 of the vest may be VELCRO compatible and theinner surface101 may be smooth and impervious to water.
FIG. 3B schematically illustrates acompression block700 urged against a patient'sbody350 by the stretchy material of avest100. In the embodiment ofFIG. 3B, a bandage or dressing355 is positioned between thecompression block700 and thepatient350. When worn by a patient, tension in the material of thevest100 imparts a force to thecompression block700. The amount of the force may be adjusted by adjusting thestraps120 and/or220. In addition, the amount of the force may be a function of the elastic properties and/or tightness of the material of thevest100, in that the more the vest material is stretched, the greater the force it applies to thecompression block700. As discussed below, this force produces a pressure to the patient's body350 (e.g., a portion of the patient's torso).
That force is high enough to cause the pressure to hinder blood flow to the localized torso area. Specifically, in illustrative embodiments, this pressure eventually aids in causing capillaries in the local area under pressure to coagulate, thus reducing and eventually stopping bleeding from the site. In addition, this pressure also preferably is low enough to mitigate the effect of a hematoma in that localized area. While a sufficiently high pressure is desired, such pressure also preferably is low enough to permit blood flow to the localized torso area. Accordingly, while reducing blood to the area to stop bleeding, blood still flows to the area to promote tissue health. As discussed below, a medical professional preferably can select the appropriate pressure to meet these competing demands.
The amount, location and gradient of the applied force may influence the efficacy of thevest100. For example, as schematically by thecompression gradient line360 illustrated inFIG. 3C, the compression applied by thecompression block700 is high immediately beneath thecompression block700, but dissipates with distance from the block. The relatively high compression beneath the compression block700 (e.g., at point at point361), and relatively lower compression away from the block (e.g., at point362) forces fluids within a hematoma or pocket outward from under thecompression block700. The structure of thecompression block700 directly impacts efficacy. Specifically, the inventors recognized that asolid compression block700 produces a better-defined gradient than, for example, a bladder, which can be inflated. Accordingly, illustrative embodiments of thevest100 and itscompression block700 should be beneficial to a patient with either or both a hematoma, and a high risk for pocket hematoma.
Specifically, various embodiments may be useful, for example, to:
1. Patients undergoing cardiac device implantation (pacemakers, cardioverter defibrillators, cardiac resynchronization therapy pacemakers & defibrillators, loop recorders, cardiac chamber pressure monitors) and chemotherapy ports who develop bleeding into the pocket and hematoma,
2. Patients who may be on antiplatelet and or anticoagulation therapy and may be at high risk for bleeding and hematoma formation,
3. Patients who may be on bridging therapy with heparin or enoxaparin immediately after cardiac device implantation for mechanical prosthetic valves, deep venous thrombosis, high risk atrial fibrillation patients, intracardiac thrombi etc.,
4. Patients who may be high risk for bleeding into pocket—elderly, renal failure, prolonged intervention, prior device extraction, pocket revisions, bleeding disorders etc., and/or
5. Patients who had a cardiac implantable electronic device (“CIED”) placed and developed a hematoma that needs that needs further care.
FIG. 4 andFIG. 5 show that the fabric pad may be folded approximately at its middle.
FIG. 6A,FIG. 6B andFIG. 6C schematically illustrate the patient with anincision650 dressed on the left hand side of the body.FIG. 6B schematically illustrates alocalized area655 defined at least in part by the area where acompression block700 meets a patient's body. For example,FIG. 6B schematically illustrates alocalized area655 near a patient'sincision650 andsuture651.
FIG. 6C schematically shows a front view in an attached configuration on the patient, whileFIG. 6D shows a rear view of thevest100 in an attached configuration on the patient. In some embodiments, from the front of the patient, the apparatus may be dressed on the patient and may approximately look like the front view illustrated inFIG. 6C. From the back of the patient, the dressed apparatus may approximately look like the rear view illustration inFIG. 6D. In other embodiments, the incision may be dressed on the right hand side of the body. In some embodiments, the adjustments described in reference toFIG. 1 may also be made when the vest is on the patient.
FIGS. 7A-7C schematically illustrate acompression block700 in accordance with illustrative embodiments. Theblock700 is solid, and in some embodiments is somewhat compressible. As a somewhat compressible member, the face of theblock700 preferably conforms to some extent with a facing surface of the portion of the patient to which it applies a pressure. Theblock700 is not pneumatic, e.g., it is not an inflatable or deflatable bladder. Moreover, theblock700 is not formed from or include ice, which the inventors believe would be too hard and possibly injure the patient. In some embodiments, thecompression block700 may be made of gel foam, polystyrene foam (e.g., STYROFOAM), or other appropriate material can be placed to enhance the compression/pressure applied to the local area, as described further below.
The inventors have found that a solid compression block provides advantages over a bladder. For example, an inflatable bladder requires additional components, such as a pump mechanism to inflate the bladder, and a release mechanism to deflate the bladder. Such mechanisms increase the cost and complexity of the bladder, while decreasing the bladder's reliability and ease of use. In contrast, asolid block700 is simple, durable, and reliable.
Moreover, the inventors believe that a bladder (whether inflatable or otherwise) deforms with an increase of internal pressure, and/or pressure against the patient, resulting a variable, and less precise pressure gradient and distribution or dispersal of pressure against the patient. Such an undesirable distribution of pressure can cause complications or impede the healing process. In contrast, pressure applied by ablock700 is more readily focused on a desired area, with less distortion and uncertainty.
As compared to a bladder, asolid block700 may provide a more effective pressure suited to patient comfort.
For example, the location of pressure applied to a patient by asolid block700 results in part from the size of the surface of the block that faces the patient. To that end, embodiments ofblock700 may have surfaces of varying shapes and sizes.
In some embodiments, theblock700 has a square or rectangular cross section, as schematically illustrated inFIG. 7E andFIG. 7F, respectively, while in other embodiments, theblock700 has a trapezoidal cross section as schematically illustrated inFIG. 7A. For example, the top701 of theblock700 may have the shape of the frustum of a pyramid. The height and length of theblock700 may be selected so as to cover theincision650 and/orsuture651.
Illustrative embodiments of theblock700 have multiple surfaces, such asbase surface711, and narrowertop surface701. The localized area of pressure applied to the patient depends on which of those surfaces faces the patient. For example, a surface of theblock700 to be positioned facing the patent may be determined by a user based on the size of theincision650, thesuture651, and/or the size of the desired localizedarea655.
Further, in some embodiments, the pressure applied to a patient by asolid block700 results in part from the interaction of theblock700 with pliable nature of the material of agarment100. For example, pressure applied to the localized area may be determined at least in part by the elasticity of the garment, the position of straps, and the surface area of the block. In some embodiments, in which the material of the garment is elastic, the pressure delivered to the patent depends in part on the force applied by the fabric, and the compressibility of theblock700.
In some embodiments, the material selected for thecompression block700 may be foamed polystyrene. For example, the block may be an arteriotomy pressure point pad available from Steri-Systems Corp., P.O. Box 909, 1314 Fourth Avenue, Auburn, Ga. 30011 (Mfg. SKU: 100W; National Stock Number (NSN) 6515-01-464-2574). The density of the foamed polystyrene may vary. In preferred embodiments, material with 1 pound per cubic foot may be selected. However, preferred embodiments could vary density, such as from 0.5 to 1.5 pounds per cubic foot.
In some embodiments, theblock700 is non-compressible, or minimally compressible. If the block is too hard (e.g., steel; ice), theblock700 may fail to conform at all to the surface of the patient, and/or it may dig into the patient and distort the application of applied pressure.
To that end, in some embodiments, a minimallycompressible block700 may by a firm polystyrene material, or another material having a Young's modulus of between 2.0×10−10dynes/cm2and 5.0×10−10dynes/cm2, and may be a polystyrene having a Young's modulus of 3.43×10−10dynes/cm2. In some embodiments, theblock700 may have a Young's modulus similar to that of polystyrene at 3 to 3.5 GPa. As another example, theblock700 of some embodiments may have a Young's modulus similar to that of Dow Chemical Company's Styrofoam Highload 60 product has a vertical compressive strength of 60 psi (pounds per square inch), meaning that the product experiences 10% deformation under 60 psi of pressure.
FIG. 7D schematically illustrates an embodiment that includes afiller block730 configured to fit into a garment pouch, e.g.,210, alongside acompression block700. When placed in a garment pouch, e.g.,210, afiller block730 occupies space within thegarment pouch210 and forces thecompression block700 to one side or another of thegarment pouch210, thereby allowing adjustment and fine-tuning of the position of thecompression block700 relative to thegarment100, and relative to the localizedarea655. In some embodiments, two or more filler blocks730 may be used to position acompression block700 within apouch210.
FIG. 8 schematically illustrates an alternative embodiment in which thegarment100 is in the form of acompression sleeve800. Thesleeve800 of this embodiment is configured to wrap around a patient's limb, such as an arm or leg, and to be secured in position by one ormore straps810. Thecompression sleeve800 includes apouch210 on aninner surface801 for securing acompression block700 between theinner surface801 and the patient. In some embodiments, thesleeve800 includes a stretchy material to apply pressure to thecompression block700, as described above in connection with thevest100.
FIG. 9 is a flow chart illustrating a method of using a garment to selectively apply pressure to a localized area of a patient's body. The method may explain, for example, a method of mitigating pocket bleeding and hematoma formation in a patient.
The process begins at step900, in which a medical professional or other user locates alocalized area655 of the patient's body (e.g.,FIGS. 6A-6D). For example, the localizedarea655 may be over a patient'sincision650, or asuture651 closing an incision in the patient's torso. The localized torso area has a topography, and may be at least in part covered by a bandage and/or dressing.
Next,step902 secures a pliable wrap (i.e., the garment100) around the torso of the patient as discussed above. To that end, thegarment100 is secured so that the block is aligned with the part of the patient's torso requiring pressure. Among other things, as noted above, the patient may have undergone surgery to receive an implantable device. Accordingly, thegarment100 is oriented so that the block is over at least a part of the patient's torso needing the pressure. At this point in the process, the block is between the patient's body (e.g., the bandage and/or dressing355) and the wrap.
The wrap thus applies a force to the solid block, which produces a corresponding pressure on the localized torso area. This force is due to the cooperation of the material forming the wrap and straps, as well as the material properties of the block. The medical professional ensures that the force is neither too high nor too low. Specifically, the force preferably is high enough to cause the pressure to hinder blood flow to the localized torso area. Accordingly, such a force should minimize or eventually stop bleeding at the local site. Importantly, however, the pressure also preferably is low enough to cause the pressure to permit blood flow to the localized torso area. In some embodiments, the force may be in a sufficient amount to cause the face of the block adjacent to the body to conform to some extent to the topography of at least a portion of the local region. This may further enhance the effect and controllability on hematomas and blood flow.
After the wrap has been secured for some prescribed amount of time (e.g., 30-90 minutes), a medical professional may check the progress of the localized torso area (step903).
To that end, the medical professional may remove the wrap to view the localized torso area after the prescribed time period. If the medical professional recognizes fluid discharge from the localized torso area, then the wrap may not have been secured with a sufficient force. In that case, the process continues to step904, in which the medical professional re-secures the wrap with a greater force than the force applied when initially secured. This greater force preferably is high enough to produce a greater block pressure to hinder blood flow to the localized torso area, but again, low enough to cause the pressure to permit blood flow to the localized torso area. Of course, when re-secured, the medical professional secures the wrap so that the block aligns with the local torso area being treated.
Alternatively, if in his/her professional judgement the local area is not bleeding/discharging fluid too much, then the medical professional will re-secure the wrap in the same manner (i.e., aligning the block with the local area) at approximately the same force.
Although the method illustrated by the flow chart inFIG. 9 is directed to a garment for use on a patient's torso, the method could also be applied to the use of garments on a patient's limb, such assleeve800 for example.
The following is a listing of reference numbers used herein:
100: Compression vest
101: Left shoulder portion, or scapular end, of vest
102: Outer surface of vest
103: Left chest pad portion of vest
104: Right chest pad portion of vest
105: Right shoulder portion, or pectoral portion, of vest
110: Waist strap or main body of vest
112: Right end of waist strap
113: Velcro fastener
114: Opposing Velcro fastener
116: Left end of waist strap
202: Inner surface of vest
210: Left pouch
211: Right pouch
220: Waist strap
221: Back flap
222: Front flap
350: Surface of patient's body
355: Bandage or dressing
360: Gradient graph
361: Pressure point
362: Lesser pressure point
650: Incision site
651: Suture
655: Localized area
700: Compression block
701: Top of compression block
711: Bottom of compression block
730: Filler block
740: Sheath
800: Sleeve
801: Inner surface of sleeve
810: Sleeve straps
Accordingly, unlike a tourniquet, when secured to the patient, the pressure that the garment applies is not sufficient to completely prevent blood flow. Rather, the garment applies a pressure sufficient to hinder but not completely prevent blood flow in the localizedarea655 of the patient's body.
It is expressly understood that many other embodiments and modifications may be contemplated as included within the apparatus although not specifically illustrated. For example, it may be expressly contemplated that VELCRO fasteners may be placed in different positions or switched, namely a felt fastener exchange for hook fastener and vice versa. In a similar manner, although VELCRO may be preferred attachment means, any other appropriate attachment means, including bonded pressure adhesives, now known or later devised, may also be equivalently substituted. Still further, although it may be expressly contemplated that no strap, tape, or other means may be necessary to secure the compression block to thevest100, the inclusion of such elements in some embodiments may be contemplated.
Complementary VELCRO fasteners can also be provided on the outside ends of thewaist band110 so thatwaist band110 can be stretched and overlapped at its opposing ends and thus connected together.
Although the above discussion discloses various exemplary embodiments, it should be apparent that those skilled in the art can make various modifications that may achieve some of the advantages of the embodiments described herein without departing from the true scope of the inventive concepts. All such variations and modifications are intended to be within the scope of the present inventions as defined in any appended claims.