Patent Publication Number: US-2022218907-A1

Title: Medical Delivery Device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 63/135,616, filed Jan. 10, 2021, which is incorporated by reference. 
    
    
     GOVERNMENT SUPPORT STATEMENT 
     This invention was made with government support under Grant Number: R43AI140784 awarded by the National Institutes of Health. The government has certain rights in the invention. 
    
    
     TECHNICAL FIELD 
     The subject matter described generally relates to the field of medical devices, and in particular, to a medical delivery device for delivering a vaccine, medication, treatment, or other biological or non-biological material into the epidermis or mucosal tissue of a subject. 
     BACKGROUND 
     Medical delivery devices, such as gene guns, may be used to deliver biological or non-biological material into a subject by accelerating high-density particles to high speeds that allow for epidermal penetration of the material. The use of these devices enables effective delivery of the material while avoiding shortcomings associated with delivery via needle and syringe or jet injectors, including the risk of cross-contamination, accidental needle stick, bruising, or infection. However, conventional gene guns are limited in the maximum dose of gold particles that can be delivered into a single shot to achieve optimum cell viability and in vivo transfection efficiency. Moreover, these devices typically use an internally vented solenoid valve to control the flow of pressurized gas from the gas source to the barrel, resulting in an increased time from solenoid opening to achieve maximum device pressure than if such valve were externally vented. This increased time for solenoid opening on conventional devices reduces the consistency of delivery and penetration of the material between shots. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a side view of a medical delivery device, according to one embodiment. 
         FIG. 2  illustrates external components of a housing of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 3  illustrates an internal view of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 4  illustrates a dose counter window of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 5  illustrates a first exploded view of the separable housing of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 6  illustrates a second exploded view of the separable housing of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 7  illustrates the medical delivery device of  FIG. 1  connected to a compressed gas source, according to one embodiment. 
         FIG. 8  illustrates example specifications of the supersonic barrel of the medical delivery device of  FIG. 1 , according to one embodiment. 
         FIG. 9  is a flow chart illustrating a method for operating the medical delivery device of  FIG. 1 , according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The Figures (FIGS.) and the following description describe certain embodiments by way of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods may be employed without departing from the principles described. Reference will now be made to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers are used in the figures to indicate similar or like functionality. 
     Overview and Benefits 
     Disclosed by way of embodiment is a medical delivery device with a separable housing comprising a durable component and a disposable component. The durable component (referred to throughout as a “reusable body”) comprises a handle portion of the device that may be connected to a compressed gas source to allow for the input of pressurized gas into the device. The disposable component comprises a cartridge containing a plurality of doses of biological or non-biological material and a supersonic barrel through which the dose is propelled out of the device and into the subject. When all of the doses in the cartridge have been administered, or when material is to be delivered to a different subject, the cartridge is removed, and a new cartridge attached to the reusable body. While the primary embodiment discussed herein contemplates a disposable cartridge, in another embodiment, a cylinder containing the doses of material is inserted into a durable cartridge such that the cartridge, in addition to the body, may be used for material delivery to multiple subjects. 
     The medical delivery device uses a high-velocity stream of gas to accelerate gold particles containing the material from the dose chamber through the supersonic barrel at speeds sufficient to penetrate cells. In one embodiment, the barrel comprises a primary expansion zone beginning at a first distal end of the barrel and an overexpansion zone beginning at an endpoint of a step separating the zones and ending at the second distal end of the barrel in an outlet nozzle that may be placed against the epidermis of a subject (e.g., against the subject&#39;s arm or other skin sites) for delivery of the material. Alternatively, the device may be used for mucosal tissue delivery of material into the subject (e.g., into the subject&#39;s eyelid, inner cheek, or tongue). 
     Example Device 
     Figure (“FIG.”)  1  illustrates a side view of a medical delivery device  100 , according to one embodiment. The medical delivery device  100  of  FIG. 1  may be used to deliver vaccines, such as the COVID-19 vaccine or any other vaccine, medication, treatment, or biological or non-biological therapeutic payload (referred to throughout as “material”) loaded onto gold microparticles into the epidermis or mucosal tissue of a subject. 
     As discussed in more detail below, the device  100  has a separable housing comprising a reusable body on a handle side that is connected to an external compressed gas source and a disposable cartridge side that contains one or more doses of the material. In one embodiment, each cartridge may be used with a single subject (e.g., patient) and contain up to four doses of the material. Accordingly, the cartridge side may be removed (e.g., when the doses have all been administered or for a different subject), and the handle side may be re-used with a different cartridge containing the same or a different type of material for the same or a different subject. 
     In one embodiment, the medical delivery device  100  has a height of approximately seven inches from the top of the reusable body to the base of the handle and a width of approximately ten inches from a battery at the base of the reusable body to the end of the exterior of the device housing. The device  100  additionally includes a supersonic barrel for delivering the material into the epidermis or mucosal tissue of the subject. As shown in  FIG. 1 , the terminal end of the barrel extends outwardly from the device housing in a nozzle that may be placed against the subject when the device  100  is to be discharged. However, one of skill in the art will recognize that the device  100  may have a different form factor than in the embodiment described above. For example, in an alternate configuration, the reusable body of the device  100  may be wider and/or have a different shape to accommodate a larger solenoid valve inside the body. 
     Turning now to  FIG. 2 , it illustrates external components of the housing of the medical delivery device  100  of  FIG. 1 , according to one embodiment. In the embodiment illustrated in  FIG. 2 , the medical delivery device  100  includes a reusable body  105  on a handle side of the device  100  and a disposable cartridge  135  on a barrel side of the device  100 . The reusable body  105  includes a cartridge release ring  110 , a battery  115 , a trigger  120 , a safety  125 , and a gas connection  130 . The disposable cartridge  135  includes a supersonic barrel  230  of which a nozzle portion  140  at the terminal end of the barrel  230  extends outwardly from an interior of the disposable cartridge housing. In other embodiments, the medical delivery device  100  contains different and/or additional elements. In addition, the functions may be distributed among the elements in a different manner than described. 
     The reusable body  105  may be coupled to the disposable cartridge  135  via the cartridge release ring  110 . When the cartridge release ring  110  is engaged, it secures the handle side of the device  100  to the barrel side such that the internal components of the device  100  are operably coupled to allow for operation of the device  100  and the delivery of the material. In one embodiment, the cartridge release ring  110  may be turned, e.g., in a clockwise direction, to secure the cartridge  135  to the body  105  and turned in an opposite, e.g., counterclockwise, direction to decouple the cartridge  135  from the body  105 , for example when replacing the disposable cartridge  135 . One of skill in the art will recognize that other coupling means for securing the cartridge  135  to the body  105  may be used in other embodiments. 
     In one embodiment, the body  105  includes a battery  115  that powers the electrical system of the device  100 , enabling the device  100  to be discharged when the trigger  120  is depressed and the safety  125  disengaged. The battery  115  may be removable, for example, to allow the battery to be replaced or charged via a separate charging mechanism. While a majority of the battery length may be positioned in a chamber inside the housing at the base of the body  105 , a portion of the battery  115  may be positioned on an outside of the housing to allow a user (e.g., a clinician) to easily remove the battery  115  from the body  105 . Once charged, the battery  115  may be reinserted into the chamber. In another embodiment, the battery  115  may be charged while engaged with the body  105 , e.g., via a charging cable or other mechanism. While the battery  115  is shown as located at a base of the body  105 , one of skill in the art will recognize that the battery could be positioned elsewhere on the device  100 , such as in the handle. 
     The trigger  120  is located on a handle portion of the body  105  and controls the flow of pressurized gas into the device  100 , causing activation of the pressure delivery system inside the housing when the trigger  120  is depressed. In one embodiment, the trigger is electrical and is driven by the battery  115 , as discussed above. Alternatively, the trigger is mechanical and powered directly from wall power. 
     When activated, the trigger  120  causes a solenoid valve (shown and discussed below with respect to  FIG. 3 ) to open, allowing input of pressurized gas via the gas connection  130  into the dose chamber. In one embodiment, the trigger  120  must be activated for at least ten milliseconds (ms) to achieve sufficient particle penetration and delivery pressure to release particles from the cartridge  135 . 
     The trigger  120  is functional only when the safety  125  is disengaged. In one embodiment, the safety  125  is a button located at a top of the handle portion and is disengaged when pushed in. Once depressed, the safety  125  activates the trigger  120  for a specified period of time, e.g., ten seconds, thirty seconds, etc. If the device  100  is not discharged (i.e., the trigger  120  not depressed) within the specified time, the safety  125  is reengaged such that the user must press the safety  125  again to reactivate the trigger  120 . In one embodiment, after the device  100  is discharged, there may be a delay (e.g., of N seconds) before the device  100  may be fired again. 
     The gas connection  130  is an inlet at the base of the handle that enables the device  100  to be connected to an external compressed gas source via a hose. As discussed below with respect to  FIG. 3 , activation of the trigger causes the input of pressurized gas obtained via the gas connection  130  through the solenoid valve and gas path connection into the dose chamber to allow the material in the chamber to be propelled through the barrel into the epidermis or mucosal tissue of the subject. In various embodiments, helium, nitrogen, or hydrogen gas may be used, however one of skill in the art will recognize that other pressurized gasses may be used in other embodiments. Additionally, in one embodiment, the gas tank is pressurized to approximately 1500 pounds per square inch (PSI). Alternatively, the gas tank is pressurized to above 500 PSI for 400 PSI delivery of the dose or to above 300 PSI for 200 PSI delivery. 
     The cartridge  135  may be coupled to the reusable body  105  via the cartridge release ring  110  and contain one or more doses of the material. As discussed below with respect to  FIG. 3 , an interior of the cartridge  135  includes a dose cylinder having a plurality of chambers, each configured to carry a dose of material for delivery to a subject. The cylinder is coupled to a first distal end of the elongated barrel  230  that spans the length of the cartridge  135  and protrudes outwardly from an opening in the cartridge. As shown in  FIG. 2 , the second distal end of the barrel comprises a nozzle  140  that may be placed against the subject (e.g., against the subject&#39;s arm or other skin sites) for delivery of the material into the epidermis. Alternatively, the device  100  may be used for mucosal tissue delivery of the material. The configuration of the nozzle  140  provides sufficient surface area to enable material penetration into the epidermis or mucosal tissue of the subject. Additionally, while the nozzle  140  shown in  FIG. 2  is transparent, in other embodiments, the nozzle  140  is opaque. 
       FIG. 3  illustrates an internal view of the medical delivery device  100  of  FIG. 1 , according to one embodiment. In the embodiment shown in  FIG. 3 , the internal components of the medical delivery device  100  include the removable battery  115 , a solenoid valve  205 , a gas path connection  210 , a drive wheel  215 , a dose cylinder  220 , a dose chamber  225 , and a barrel  230 . 
     The solenoid valve  205  opens and closes to control the flow of pressurized gas into the dose chamber. In a default state (i.e., when the trigger  120  is not depressed and/or the safety  125  is engaged), the solenoid valve  205  is closed such that pressurized gas does not enter the chamber  225  containing the dose of material. Activation of the trigger  120  and disengagement of the safety  125  activates the solenoid valve (i.e., causes the solenoid valve  205  to open) and permits the gas to enter the cartridge through the opening in the valve  205 . The solenoid valve  205  remains open when the trigger  120  is depressed. 
     The solenoid valve  205  may be internally vented or externally vented. In one embodiment, use of an externally vented solenoid valve  205  lowers the rise time (i.e., the time from the opening of the solenoid valve  205  to achieve maximum pressure) as compared to a conventional internally vented valve. High-pressure gas flowing through the solenoid valve  205  causes the gold particles in the dose chamber  225  to become dislodged and begin to flow through the barrel  230 . Accordingly, the rapid increase in pressure achieved with an externally vented solenoid valve  205  allows for optimal acceleration of the gold particles. 
     In an alternate configuration, a burst membrane is used with an internally vented solenoid valve  205  to control the flow of gas into the dose chamber  225 . The burst membrane may be comprised of gas-impermeable aluminized mylar such that gas cannot pass into the chamber  225  until a pressure threshold is exceeded and the membrane has burst. 
     In various embodiments, the device  100  is operated under conditions ranging from 200-500 PSI. In a configuration in which approximately 400 PSI of supplied pressure is used, the device  100  delivers high-pressure gas flow with an average rise time of 2.30±0.08 ms to an average peak pressure of 309.44±5.98 PSI to enter the dose chamber  225 . Such a pressure delivery profile allows for release of the material from the chamber  225  under high pressure conditions to achieve the required particle acceleration speeds for epidermal or mucosal tissue delivery and penetration. Upon release of the trigger  120 , the solenoid valve  205  closes, and the pressure downstream of the valve  205  drops back down to 0 PSI. In one embodiment, maximum pressure is achieved when the solenoid valve  205  remains open for a time period greater than or equal to the rise time of approximately 2 ms. 
     Additionally, while the device  100  is standardly operated under conditions of an input pressure of 400 PSI, in other embodiments, the device  100  uses an operating pressure of 200 PSI due to enhanced particle acceleration resulting from the supersonic barrel  230 , achieving a full particle release and delivery profile compared to 400 PSI. Operation of the device  100  at an input pressure of 200 PSI reduces the noise generated by the device  100  and provides compatibility with solenoid valves having different sizes and weights as compared to operation at a 400 PSI input pressure. In embodiments in which the input pressure is 200 PSI, the outlet pressure of the solenoid valve  205  is approximately 164.75±4.04 PSI with a rise time of approximately 2.29±0.23 ms. Additionally, in various embodiments, valves having varying opening mechanisms (direct or indirect), flow coefficients, and weights are used. 
     The gas path connection  210  is a chamber connecting the solenoid valve  205  to the dose chamber  225 . When the solenoid valve  205  is open, the pressurized gas flows through the gas path connection  210  into the chamber  225 . 
     The drive wheel  215  is a chamber advancement mechanism on the handle-side of the device  100  that causes the dose cylinder  225  containing the material at the barrel-side to rotate after each dose is administered. In one embodiment, advancement of the cylinder  225  is automatic and not user-dependent. Operation of the drive wheel  215  is discussed below with respect to  FIG. 9 . 
     The dose cylinder  220  is located in the disposable cartridge  135  on the barrel-side of the device  100  adjacent to the drive wheel  215  inside the housing of the reusable body  105  on the handle-side. The dose cylinder  220  comprises a plurality of dose chambers  225  that each contain a single dose of the material. While the embodiment shown in  FIG. 3  and described herein contemplates a four-dose cylinder, one of skill in the art will recognize that the cylinder  220  may contain additional or fewer chambers in other embodiments to enable delivery of different numbers of material doses. As discussed above and below, the drive wheel  215  causes the cylinder  220  to rotate to advance to a first dose chamber  225 , to each subsequent chamber  225  after discharge, and to a hard stop after the final dose has been administered. As shown in  FIG. 3 , each chamber  225  is labeled with a corresponding dose number. 
     The barrel  230  (also referred to as a “supersonic barrel”) is positioned inside the disposable cartridge  135  and has an elongated body that extends from a first distal end where the barrel  230  is coupled to the cylinder  220  to a second distal end at an outlet of the device  100 . The second distal end of the barrel  230  may be placed flush against the epidermis or mucosal tissue of the subject. The barrel  230  is shaped to allow particles from the dose chamber  225  and propelled by the pressurized gas to achieve at least a target velocity at the second distal end (i.e., for penetration into the epidermis or mucosal tissue). In one embodiment, the barrel  230  includes a primary expansion zone beginning at the first distal end and an overexpansion zone having a conical shape beginning at an approximate midpoint of the barrel  230  and expanding in diameter to the second distal end. Example specifications of the supersonic barrel are shown and discussed below with respect to  FIG. 8 . 
       FIG. 4  illustrates a dose counter window  405  of the medical delivery device  100  of  FIG. 1 , according to one embodiment. In one embodiment, the window  405  comprises a cut-out in the housing of the disposable cartridge  135  such that the dose number located on the outside of each dose chamber  225  is viewable to the user (e.g., the clinician administering the dose), indicating a number of remaining doses of material available in the disposable cartridge  135 . After each dose is administered and the cylinder  220  rotated to a subsequent dose chamber  225 , the window  405  displays the updated number of available doses. Once the final dose has been administered, the counter window indicates that no remaining doses are available, such that the cartridge  135  may be discarded and replaced with a new cartridge  135  containing the same or different material. 
       FIG. 5  illustrates a first exploded view of the separable housing of the medical delivery device  100  of  FIG. 1 , according to one embodiment. As shown in  FIG. 5  and discussed above, the housing of the device  100  is separable into two portions for the replacement of the dose cartridge  135 . Components located on the reusable body  105  include the cartridge release ring  105 , battery  115 , trigger  120 , safety  125 , gas connection  130 , and drive wheel  215 , which causes the dose cylinder  220  in the disposable cartridge  135  to turn after each dose is administered. Located below the drive wheel  215  in  FIG. 5  is the outlet of the gas path connection  210 . When the device  110  is assembled (i.e., the disposable cartridge  135  coupled to the reusable body  105  via the cartridge release ring  110 ), the outlet of the gas path connection  210  is positioned flush against a dose chamber  225  in the cylinder  220 . Accordingly, in the embodiment shown in  FIG. 5 , a dose chamber  225  in the discharge position is the chamber  225  located at the bottom of the dose cylinder  220 , and a dose of the material may be discharged from the cylinder  220  when the chamber  225  in which the dose is contained is rotated to the bottom of the cylinder  220 . One of skill in the art will recognize that, in other configurations, the gas path connection  210  may be positioned elsewhere, such as above the drive wheel  215 . 
       FIG. 6  illustrates a second exploded view of the separable housing of the medical delivery device  100  of  FIG. 1 , according to one embodiment. As shown in  FIG. 6  and discussed above, the battery  115  may be removed from the device  100  for charging or replacement. In some embodiments, the trigger  120  is electrical and is driven by the battery  115 . However, in other embodiments, the trigger  120  is mechanical and does not require power. 
       FIG. 7  illustrates the medical delivery device  100  of  FIG. 1  connected to a compressed gas source, according to one embodiment. As shown in  FIG. 7  and discussed above, the device  100  is connected to the gas source via a hose attached at a first end to the gas source and at a second end to the gas connection  130  on the device  100 . In one embodiment, activation of the trigger  120  causes the input of pressurized gas obtained via the gas connection  130  through the solenoid valve  205  and gas path connection  210  into the dose chamber  225  to allow the material to be propelled through the barrel  230  into the epidermis or mucosal tissue of the subject 
       FIG. 8  illustrates example specifications of the supersonic barrel  230  of the medical delivery device  100  of  FIG. 1 , according to one embodiment. A target gas velocity through the barrel  230  is a supersonic velocity. Use of a supersonic barrel, such as the barrel  230 , optimizes the density of gold delivered throughout the target to maximize intracellular delivery of particles into more cells while retaining high cell viability, with higher maximum particle deposition at input pressures of 200-500 PSI. The supersonic barrel  230  also improves gold particle penetration compared to legacy barrels. 
     As discussed above with respect to  FIG. 3 , the barrel  230  has an elongated body that extends from a first distal end where the barrel  230  is coupled to the cylinder  220  to a second distal end at an outlet of the device  100  that is placed against the subject for delivery of the material into the epidermis or mucosal tissue. The barrel  230  includes a primary expansion zone  805  beginning at the first distal end and an overexpansion zone  810  beginning at an approximate midpoint of the barrel  230 . In one embodiment, the primary expansion zone  805  has a first inner diameter of approximately 0.08-0.12 inches at the first distal end, a second inner diameter of approximately 0.16-0.25 inches, and a length of approximately 1.6-3.0 inches. The overexpansion zone  810  has a first inner diameter of approximately 0.16-0.24 inches, a second inner diameter of approximately 0.56-0.84 inches, and a length of approximately 1.6-3.0 inches. In one example configuration, the second inner diameter of the primary expansion zone  805  is 0.25 inches, and the second inner diameter of the overexpansion zone is 0.75 inches. 
     In one embodiment, the overexpansion zone  810  has an inner-diameter expansion-to-length ratio that is higher than the inner-diameter expansion to length ratio of the primary expansion zone  805 . For example, the overexpansion zone  810  inner-diameter expansion-to-length ratio may be twice or at least 1.5 times as high as the inner-diameter expansion to length ratio of the primary expansion zone  805 . 
     The primary expansion zone  805  and the overexpansion zone  810  are separated by a step  815  that breaks the high velocity jet away from the wall of the barrel  230  in a clean fashion. In one embodiment, the step  815  is approximately 0.1 inches in length radially such that, when the final diameter of the primary expansion zone  805  is 0.25 inches, the diameter at the step  815  is 0.35 inches (0.25 inches at the terminal end of the primary expansion zone  805  plus 0.1 inches radial step). In this embodiment, the final diameter at the terminal end of the overexpansion zone  810  is 0.75 inches. The step  815  may have a constant diameter over its length and comprise an orifice that enables the downstream flow of particles to be free of boundary effects or conditions and allow the flow to be supersonic and separated from the inner wall of the barrel  230 . 
     The dimensions of the supersonic barrel  230  discussed above are for example only. In alternate embodiments, the dimensions and ratios may be within 10-100% of the numbers listed above. The dimensions may also be proportionally scaled in various embodiments. 
     Example Method 
       FIG. 9  is a flow chart illustrating a method  900  for operating the medical delivery device  100  of  FIG. 1 , according to one embodiment. In some embodiments, the operations in the method  900  are performed in a different order or can include different or additional steps. 
     In the embodiment shown in  FIG. 9 , the method  900  begins by activating  905  the device  100  (e.g., powering on the device  100  via an “on/off” switch or similar activation mechanism). At  910 , a reed switch is used to detect whether a disposable cartridge  135  containing one or more doses of material is coupled to the reusable body  105 . The device  100  cannot be discharged if no cartridge  135  is detected. 
     At  915 , absolute position detection is used to verify the device position and detect whether a cartridge is “new.” As discussed above, each cartridge  135  is used with a single subject (e.g., patient), such that the cartridge  135  must be replaced if the device  100  is to be used to administer material to a different patient. 
     The trigger  120  is depressed  920  a first time to “purge” the device  100 , causing the drive wheel  215  to advance the dose cylinder  220  to a first chamber  225  containing a dose of material. In embodiments in which the cartridge  135  contains four chambers  225  containing four doses of the material, the trigger  120  is depressed  925  four additional times to discharge the doses into the epidermis or mucosal tissue 
     After each discharge of the device  100 , the drive wheel  215  advances  930  the dose cylinder  220  to a subsequent chamber  225 . After the final dose is administered, the drive wheel  215  advances  935  to a hard stop that prevents the device  100  from firing, and the cartridge  135  is replaced  940 . 
     Additional Considerations 
     As used herein, any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
     Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. It should be understood that these terms are not intended as synonyms for each other. For example, some embodiments may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context. 
     As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 
     In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments. This is done merely for convenience and to give a general sense of the disclosure. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 
     Upon reading this disclosure, those of skill in the art will appreciate still additional alternative structural and functional designs for a medical delivery device. Thus, while particular embodiments and applications have been illustrated and described, it is to be understood that the described subject matter is not limited to the precise construction and components disclosed herein and that various modifications, changes and variations which will be apparent to those skilled in the art may be made in the arrangement, operation and details of the method and apparatus disclosed. The scope of protection should be limited only by the following claims.