Patent Publication Number: US-2021162121-A1

Title: Agent administering medical device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority from U.S. Provisional Application No. 62/942,988, filed on Dec. 3, 2019, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to a medical device that administers an agent. More particularly, at least some embodiments of the present disclosure relate to a medical device including a system that can be actuated to administer a dosage of an agent to a lumen. 
     BACKGROUND 
     In certain medical procedures, it may be necessary to stop or minimize bleeding internal to the body. For example, an endoscopic medical procedure may require hemostasis of bleeding tissue within the gastrointestinal tract, for example in the esophagus, stomach, or intestines. 
     During an endoscopic procedure, a user inserts a sheath of an endoscope into a body lumen of a patient. The user utilizes a handle of the endoscope to control the endoscope during the procedure. Tools are passed through a working channel of the endoscope via, for example, a port in the handle, to deliver treatment at the procedure site near a distal end of the endoscope. The procedure site is remote from the operator. 
     To achieve hemostasis at the remote site, a hemostatic agent may be delivered by a device inserted into the working channel of the endoscope. Agent delivery may be achieved through mechanical systems, for example. Such systems, however, may require numerous steps or actuations to achieve delivery, may not achieve a desired rate of agent delivery or a desired dosage of agent, may result in the agent clogging portions of the delivery device, may result in inconsistent dosing of agent, or may not result in the agent reaching the treatment site deep within the GI tract. The current disclosure may solve one or more of these issues or other issues in the art. 
     SUMMARY OF THE DISCLOSURE 
     According to an example, a medical device may comprise an enclosure defining a cavity for containing agent, a lumen for receiving a pressurized gas, and a barrier positioned between the cavity and the lumen, the barrier including at least one opening for storing agent, wherein rotation of the barrier relative to the lumen establishes fluid communication between the at least one opening and the lumen for delivering agent from the at least one opening to the lumen. A bottom end of the cavity may include a wall adjacent to the barrier, wherein the wall includes a wall opening, wherein the wall opening is located on an area of the wall so that the wall opening is aligned with the at least one opening via rotation of the barrier. Alignment of the wall opening with the at least one opening may permit agent from the enclosure to enter the at least one opening. The enclosure may be rotatable relative to the barrier and/or the lumen. The barrier may be rotatable relative to the enclosure. The agent may remain in the at least one opening until fluid communication between the at least one opening and the lumen is established. The enclosure may feed the at least one opening with agent via gravity. The at least one opening for storing agent may feed the lumen with agent via gravity when fluid communication between the at least one opening and the lumen is established. 
     In another example, the at least one opening for storing agent may be a plurality of openings arranged radially about the barrier. The plurality of openings may be symmetrically arranged. Each of the plurality of openings may be different in size. When fluid communication is established between one opening of the plurality of openings and the lumen, the other openings of the plurality of openings and the lumen are not in fluid communication. 
     In another example, the medical device may further comprise an intermediary barrier, wherein the intermediary barrier is positioned between the barrier and the lumen, and wherein the intermediary barrier includes an intermediary opening positioned to be aligned with one of the plurality of openings via rotation of the barrier. The intermediary barrier may be rotatable relative to the barrier. The lumen may be a flexible catheter capable of traversing a tortuous body lumen, and further comprising a source of the pressurized gas. 
     According to an example, a medical device may comprise a cartridge including a plurality of chambers, wherein each of the chambers stores a pre-filled amount of agent, a lumen for receiving a pressurized gas, a channel establishing fluid communication between a first end of the cartridge and the lumen for delivering agent from the cartridge to the lumen, and a plunger coupled to a second end of the cartridge so that the plunger is aligned with one chamber of the plurality of chambers, wherein the plunger advances longitudinally into the one chamber, thereby pushing the pre-filled amount of agent towards the channel, and wherein the cartridge is rotatable relative to the plunger to align the plunger with another of the plurality of chambers. The plunger may be coupled to the cartridge so that the plunger is spring-biased to a position outside of the one chamber and aligned with the one chamber. The medical device may further comprise a trigger including a lever coupled to a linkage via a first articulating joint and a linkage coupled to a plunger via a second articulating joint. 
     According to an example, a method of administering an agent via a medical device may comprise positioning the medical device, including an enclosure, a barrier, and a lumen, so that a distal end of the lumen is adjacent to a targeted site, wherein the barrier is positioned between the enclosure and the lumen, the enclosure containing agent, and the barrier including at least one opening for storing the agent, providing a pressurized gas to the lumen, and rotating the barrier relative to the lumen so that fluid communication is established between the at least one opening and the lumen to deliver the agent from the at least one opening to the lumen. The method may further comprise rotating the barrier relative to the lumen so that the at least one opening and the lumen are not in fluid communication after a dose of the agent is delivered from the at least one opening to the lumen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments. 
         FIG. 1A  is a side view of a portion of a shaft of an endoscope including a medical device, according to an embodiment. 
         FIGS. 1B-C  are cross-sectional views of the medical device of  FIG. 1A . 
         FIG. 2A  is a cross-sectional view of a medical device, according to another embodiment. 
         FIG. 2B  is a top view of the barrier of  FIG. 2A . 
         FIG. 3A  is a cross-sectional view of a medical device, according to another embodiment. 
         FIG. 3B  is a top perspective view of the barrier of  FIG. 3A  over the intermediary barrier of  FIG. 3A . 
         FIG. 4A  is a side view of a medical device, according to another embodiment. 
         FIG. 4B  is a top view of the cartridge of  FIG. 4A . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same or similar reference numbers will be used through the drawings to refer to the same or like parts. The term “distal” refers to a portion farthest away from a user when introducing a device into a subject (e.g., patient). By contrast, the term “proximal” refers to a portion closest to the user when placing the device into the subject. 
     Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “having,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. In this disclosure, relative terms, such as, for example, “about,” “substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in a stated value or characteristic. 
     The present disclosure may solve one or more of the limitations in the art. The scope of the disclosure, however, is defined by the attached claims and not the ability to solve a specific problem. The present disclosure is drawn to medical devices configured to administer doses of agents, e.g., therapeutic agents, among other aspects. The agent may be in any suitable form, including a powder form, which may be delivered to a stream of propellant/pressurized gas, e.g., CO 2 , nitrogen, air, etc. Said medical devices allow for the administration of agents in metered doses, which allows for a greater consistency in the quantity of the agent that reaches a target site. 
     Referring to  FIG. 1A , a medical system  5 , e.g., an endoscope, according to an embodiment is shown. Medical system  5  includes a flexible shaft  50  (e.g., a catheter) and a handle  52  connected at a proximal end of flexible shaft  50 . Handle  52 , or some other device for actuating or controlling medical system  5  and any tool or devices associated with medical system  5 , includes first and second actuating devices  42 ,  43 , which control articulation of flexible shaft  50 , and/or an articulation joint at a distal end of flexible shaft  50 , in multiple directions. Devices  42 ,  43 , may be, for example, rotatable knobs that rotate about their axes to push/pull actuating elements (not shown). The actuating elements, such as cables or wires suitable for medical procedures (e.g., medical grade plastic or metal), extend distally from a proximal end of medical system  5  and connect to flexible shaft  50  to control movement thereof. Alternatively, or additionally, a user may operate actuating elements independently of handle  52 . Distal ends of actuating elements may extend through flexible shaft  50  and terminate at an actuating joint and/or a distal tip of flexible shaft  50 . For example, one or more actuating elements may be connected to an articulation joint, and actuation of actuating elements may control the actuating joint or the distal end of flexible shaft  50  to move in multiple directions. 
     In addition, one or more electrical cables (not shown) may extend from the proximal end of endoscope  5  to the distal end of flexible shaft  50  and may provide electrical controls to imaging, lighting, and/or other electrical devices at the distal end of flexible shaft  50 , and may carry imaging signals from the distal end of flexible shaft  50  proximally to be processed and/or displayed on a display. Handle  52  may also include ports  54 ,  46  for introducing and/or removing tools, fluids, or other materials from the patient. Port  54  may be used to introduce tools. Port  46  may be connected to an umbilicus for introducing fluid, suction, and/or wiring for electronic components. For example, as shown in  FIG. 1A , port  54  receives a tube  100 , which extends from the proximal end to the distal end of flexible shaft  50 , via a working channel  50   a  of shaft  50 . 
     As shown in  FIG. 1A , tube  100  of medical device  1  is attached to a pressurized gas source  56 , e.g., CO 2 , which may be controlled by a user to turn on/off and to adjust a rate at which gas flows into tube  100 . Source  56  may be a gas canister or tank, a source of gas supplied by a medical facility, or any other suitable source. Medical device  1  further includes an enclosure  10 , and a barrier  11  positioned between enclosure  10  and tube  100 . Enclosure  10  and barrier  11  are coupled to a proximal portion of tube  100 , distal of the connection between tube  100  and source  56 . 
       FIGS. 1B and 1C  illustrate an embodiment of medical device  1 ,  1 ′ in  FIG. 1A  in further detail. As discussed above, medical device  1  includes enclosure  10  defining a cavity for containing an agent  1000 , a tube (e.g., a catheter or a sheath)  100  defining a lumen  100   a  receiving pressurized gas, e.g., CO 2 , from a proximal end, and barrier  11  positioned between the cavity of enclosure  10  and lumen  100   a . The shape or size of enclosure  10  is not particularly limited, and may be any suitable shape or size, including cylindrical. As indicated by the directional arrows in  FIG. 1B , barrier  11  is rotatable relative to tube  100  and lumen  100   a , e.g., about a central axis of barrier  11 . In other embodiments, barrier  11  may be rotatable relative to both tube  100  and enclosure  10 . In some other embodiments, enclosure  10  may be rotatable relative to barrier  11  and/or tube  100 . Rotation of barrier  11  may be by any suitable action, for example, by hand or by mechanical, electrical, or pneumatic action. 
     Barrier  11  may be an annular, disk-like structure with openings and a passage therethrough. For example, barrier  11  includes a first opening  12   a  on the barrier surface (e.g., an upper surface) adjacent to the cavity of enclosure  10 , for receiving agent  1000  in a passage  14  that extends through barrier  11 . Barrier  11  further includes a second opening  12   b  on the opposite barrier surface (e.g., a bottom surface) adjacent to tube  100  and lumen  100   a , from which agent  1000  may be dispensed into lumen  100   a . It is noted that the size and shape of first opening  12   a  and second opening  12   b  are not particularly limited, and may be any suitable size or shape. First opening  12   a  and second opening  12   b  are located on opposite ends of barrier  11 , but are connected via passage  14  extending across the length and thickness of barrier  11 . Tube  100  also includes an opening  101  which may or may not be aligned with second opening  12   b  of barrier  11 , depending on the rotational position of barrier  11  relative to tube  100  and lumen  100   a . Thus, the rotation of barrier  11  relative to tube  100  may establish fluid communication between opening  12   b  and lumen  100   a  for delivering agent  1000  from passage  14  to lumen  100   a . Enclosure  10  feeds opening  12   a  with agent  1000  via gravity, and passage  14  storing agent  1000  feeds lumen  100   a  with agent  1000  via gravity when second opening  12   b  and lumen opening  101  are aligned. In other embodiments, agent  1000  may be delivered to opening  12   a  and/or lumen  100   a  via other suitable mechanisms. Barrier  11  may also be rotated so that second opening  12   b  and opening  101  of lumen  100   a  are not aligned, thereby inhibiting the delivery of agent  1000  from passage  14  to lumen  100   a . In this instance, passage  14  receives and stores agent  10000 , until fluid communication between opening  12   b  of passage  14  and lumen  100   a  is established. It is noted that enclosure  10 , in any rotational position of barrier  11 , is not in fluid communication with lumen  100   a . Furthermore, in embodiments prior to any use, passage  14  may be empty an without agent  1000 . 
     In some embodiments, a bottom end of the cavity of enclosure  10  may include a wall  105  adjacent to barrier  11 . Wall  105  may include an opening  105   a  that may or may not be aligned with opening  12   a  of barrier  11 , depending on the rotational position of barrier  11  relative to enclosure  10 . Thus, in such embodiments, barrier  11  and/or enclosure  10  may be rotated to align opening  105   a  with opening  12   a  of barrier  11  to deliver agent  1000  from enclosure  10  to passage  14  through opening  12   a . This is illustrated in  FIG. 1B , in which opening  105   a  of wall  105  and opening  12   a  of barrier  11  are aligned, thereby feeding passage  14  with agent  1000  from enclosure  10 .  FIG. 1C  shows barrier  11  rotated by approximately 180° from its position in  FIG. 1B  relative to enclosure  10 , and as a result, opening  105   a  of wall  105  and opening  12   a  are not aligned, being on opposite ends from one another. It is understood that the barrier  11  may be rotatable to any degree for alignment with opening  12   a . Thus, opening  12   a  is sealed by wall  105 , and agent  1000  is no longer fed into opening  12   a . It is noted that opening  105   a  aligns with opening  12   a  when second opening  12   b  does not align with opening  101  of tube  100 , and opening  105   a  does not align with opening  12   a  when second opening  12   b  aligns with opening  101  of tube  100 . Thus, passage  14  may receive agent  1000 , prior to agent  1000  being fed to lumen  100   a . This allows for medical device  1  to administer a metered dose, i.e., the amount of agent  1000  stored in passage  14 , per each degree of rotation, e.g., 180°, of barrier  11  and/or enclosure  10 . Furthermore, in some other embodiments, both wall  105  and tube  100  may respectively include a plurality of openings. It is noted that passage  14  is capable of connecting openings of wall  105  and of tube  100  that are 180° apart. However, this is not desired, and in such embodiments, none of the openings of wall  105  are 180° apart from any of the openings of tube  100 . As a result, there cannot be fluid communication between passage  14  and said openings of wall  105  and tube  100 , at the same time. Instead, fluid communication between passage  14  and the openings of wall  105  and tube  100  is staggered, but not simultaneous. Such embodiments would allow for continuous rotation (both clockwise and counterclockwise) of barrier  11  relative to enclosure  10  to result in passage  14  receiving agent  1000  after a degree of rotation and subsequently dispensing agent  1000  after a further degree of rotation of barrier  11 . 
     Referring to  FIGS. 1A-1C , an example of how medical device  1  may be used is further discussed below. A user may deliver a distal end of tube  100  of medical device  1  into the body of a subject, e.g., via a natural orifice (such as a mouth or anus) and through a tortuous natural body lumen of the subject, such as an esophagus, stomach, colon, etc. Tube  100  may be delivered in any suitable way, for example, through working channel  50   a  of endoscope  5 , by inserting a distal end of tube  100  into port  54  of endoscope  5 . A user may direct/position the distal end of tube  100  to an intended target site for administration of agent  1000 . A user may then fill enclosure  10  with agent  1000 , if not filled already, and rotate barrier  11  and/or enclosure  10  relative to tube  100  and lumen  100   a  so that opening  105   a  aligns with opening  12   a , thereby feeding passage  14  with agent  1000 . As discussed above, when opening  105   a  aligns with opening  12   a , second opening  12   b  does not align with opening  101  of tube  100 . Thus, agent  1000  is received and stored by passage  14 . A user may then rotate barrier  11  to align opening  12   b  with opening  101  of tube  100 , so that all of agent  1000  stored in passage  14  is fed from passage  14  to lumen  100   a , thereby administering a metered dose of agent  1000 . A user may turn on the pressurized gas source at any time prior to the alignment of opening  12   b  with opening  101  and supply pressurized gas until the metered dose of agent  1000  reaches the target tissue site. Alternatively, a user may start supply of pressurized gas after the supply of agent  1000  to lumen  100   a.    
     In  FIG. 2A , another embodiment of medical device  1 ′ is shown. Like the embodiment discussed above, medical device  1 ′ includes an enclosure  10 ′ defining a cavity for containing an agent  1000 , a tube (e.g., a catheter or a sheath)  100  defining a lumen  100   a  receiving pressurized gas, e.g., CO 2 , from a proximal end, and a barrier  21  positioned between the cavity of enclosure  10  and lumen  100   a . The shape or size of enclosure  10 ′ is also not particularly limited, and may be any suitable shape or size. As indicated by the directional arrows in  FIG. 2A , barrier  21  is also rotatable relative to tube  100  and lumen  100   a . In other embodiments, barrier  21  may be rotatable relative to both tube  100  and enclosure  10 ′. In some other embodiments, enclosure  10 ′ may be rotatable relative to barrier  21  and/or tube  100 . Rotation of barrier  21  and enclosure  10 ′ may also be actuated by any suitable action. 
     Barrier  21 , as shown in both  FIGS. 2A and 2B , includes a plurality of openings, i.e., six openings  22   a - 22   f , of equal or approximately equal size, i.e., width or diameter, symmetrically arranged radially about a central axis of rotation of barrier  21 . It is noted that the number of openings, the size of openings, the shape of openings, and the arrangement of openings on barrier  21  is not particularly limited, and may be any suitable configuration. For example, in other embodiments, barrier  21  may have four circular openings, each of which has varying diameters from one another. Each of openings  22   a - 22   f  extends through the thickness of barrier  21 , and is configured to receive and store a pre-determined or selected amount of agent  1000 , depending on the size of the openings. Thus, agent  1000  from enclosure  10  feeds into openings  22   a - 22   f , via gravity in some embodiments, until said openings are filled. Note that  FIG. 2A  shows half of barrier  21  in perspective to show the position of openings  21   a ,  21   b ,  21   c , and  21   d.    
     By rotation of barrier  21  relative to tube  100  and lumen  100   a , one of openings  22   a - 22   f  may align with opening  101 , thereby establishing fluid communication between the one opening and lumen  100   a  for delivering agent  1000  from the one opening to lumen  100   a  via gravity. In some embodiments, enclosure  10 ′ may further include a seal  205 , which is positioned adjacently above barrier  21 , above where one of openings  22   a - 22   f  may be located, and directly above opening  101  of tube  100 . Thus, as one opening of openings  22   a - 22   f  aligns with opening  101  via rotation of barrier  21 , an excess amount of agent  1000  above the one opening is shaved off by seal  205  and the one opening is sealed from receiving further agent  1000  from enclosure  10 ′ when that opening aligns with opening  101  of tube  100 . This allows for medical device  1 ′ to administer a metered dose, i.e., the amount of agent  1000  stored in openings  22   a - 22   f , per each degree of rotation, e.g., 60°, of barrier  21  and/or enclosure  10 ′. It is noted that as a result of such configuration, when fluid communication is established between one of openings  22   a - 22   f  and lumen  100   a , no fluid communication is established between the other remaining openings and lumen  100   a , as the bottom of the remaining openings is sealed by tube  100 . 
     As shown in  FIG. 2B , which shows a top view of barrier  21 , barrier  21  may also be rotated so that none of openings  22   a - 22   f  are aligned with opening  101  of tube  100 , thereby inhibiting the delivery of agent  1000  from any of openings  22   a - 22   f  to lumen  100   a . In this instance, an amount of agent  1000  is stored in openings  22   a - 22   f  until fluid communication between the openings and lumen  100   a  is established. 
     Referring to  FIGS. 2A-2B , an example of how medical device  1 ′ may be used is further discussed below. Similar to medical device  1 , medical device  1 ′ may be delivered into the body of a subject, and directed to an intended target site for agent  1000  administration in the same manner. A user may then fill enclosure  10 ′ with agent  1000 , if not filled already, which will fill openings  22   a - 22   f  with agent  1000 . The user then may rotate barrier  21  relative to tube  100  and lumen  100   a  so that one of openings  22   a - 22   f  aligns with opening  101 . Such alignment results in seal  205  shaving off an excess amount of agent  1000  above the one opening, sealing the one opening from being fed any more of agent  1000  from enclosure  10 ′, and feeding lumen  100   a  with agent  1000  stored in the one opening. As discussed above, when the one opening aligns with opening  101  of tube  100 , the remaining openings  22   a - 22   f  do not align with opening  101  of tube  100 . Thus, agent  1000  is stored within the remaining openings  22   a - 22   f , until each of the remaining openings is aligned with opening  101  via rotation of barrier  21 , in turn. A user may turn on the pressurized gas source at any time prior to or during the alignment of one of the openings  22   a - 22   f  with opening  101 , as in the embodiment described in connection with  FIGS. 1B-1C . 
     In  FIG. 3A , another embodiment of medical device  1 ′″ is shown. Medical device  1 ′″ is similar to medical device  1 ′, and differences between the two devices will be highlighted. Device  1 ′″ may include any of the features of device  1 ′ and operate in the same or substantially the same way. Medical device  1 ′″ includes an enclosure  10 ′″, a barrier  41 , and lumen  100 . Moreover, enclosure  10 ′″ further includes a seal  205 , which is positioned adjacently above barrier  41 , above where one of openings  42   a - 42   c  may be located, and directly above opening  101  of tube  100 . However, unlike medical device  1 ′, lumen  100   a  of medical device  1 ′″ receives pressurized gas from a second lumen  102 , which is connected to tube  100  at a point that is proximal to opening  101 . Alternatively, medical device  1 ′″ may receive pressurized gas from a proximal end of lumen  100   a , and may be without second lumen  102 . Medical device  1 ′″ further includes, in at least some embodiments, an intermediary barrier  15  including an opening  16 , positioned between barrier  41  and tube  100 . As indicated by the directional arrows in  FIG. 3A , barrier  41  is rotatable relative to intermediary barrier  15 , tube  100 , and lumen  100   a . In other embodiments, enclosure  10 ′″ may also be rotatable relative to barrier  41 , intermediary barrier  15 , tube  100 , and lumen  100   a . Rotation of enclosure  10 ′″ and barrier  41  may be actuated by any suitable action. 
     Barrier  41 , as shown in both  FIGS. 3A and 3B , includes three openings, i.e.,  42   a - 42   c , of different sizes, i.e., widths or diameter, arranged radially about a central axis of rotation of barrier  41 , like barrier  21  (referring to  FIG. 2B ). A first opening  42   a  has the smallest width of the three openings, a second opening  42   c  has the largest width of the three openings, and a third opening  42   b  has a width in between that of first opening  42   a  and that of second opening  42   c . Thus, each of openings  42   a - 42   c  receives and stores different amounts or doses of agent  1000 . 
     To help a user differentiate between the different sizes of openings  42   a - 42   c , enclosure  10 ′″ and/or barrier  41  may further include markings on their outer surfaces that indicate the locations of openings  42   a - 42   c  relative to one another, and to openings  16  and  101 . Thus, a user may rotate barrier  41  and/or enclosure  10 ″, relative to intermediary barrier  15 , tube  100 , and lumen  100   a , to select one of openings  42   a - 42   c  based on a desired amount or dose of agent  1000 . 
     Intermediary barrier  15 , as shown in both  FIGS. 3A and 3B , includes opening  16 . Opening  16  may be aligned with lumen opening  101 , and also openings  42   a - 42   c , depending on the rotational position of barrier  41  relative to intermediary barrier  15 . As shown in  FIG. 3B , opening  16  is at least the same width as the largest opening of barrier  41 , i.e., second opening  42   c.    
     Any one of openings  42   a - 42   c  may be aligned with intermediary opening  16  and lumen opening  101  via rotation of barrier  21 . Such alignment establishes fluid communication between one of openings  42   a - 42   c  and lumen  100   a  for delivering agent  1000  from one of openings  42   a - 42   c  to lumen  100   a  via gravity. Similar to that of medical device  1 ′, as one opening of openings  42   a - 42   c  aligns with opening  16  of intermediary barrier  15  and opening  101  via rotation of barrier  41 , an excess amount of agent  1000  above the one opening is shaved off by seal  205  and the one opening is sealed from further receiving agent  1000  from enclosure  10 ′″. This allows for medical device  1 ′″ to administer a metered dose, the amount of agent  1000  stored in openings  42   a - 42   c , per each degree of rotation, e.g., 120°, of barrier  41 . As a result of such configuration, when fluid communication is established between one of openings  42   a - 42   c  and lumen  100   a , no fluid communication is established between the other remaining openings  42   a - 42   c  and lumen  100   a.    
     Barrier  41  may also be rotated so that none of openings  42   a - 42   c  is aligned with intermediary opening  16  and lumen opening  101 , thereby inhibiting the delivery of agent  1000  from enclosure  10 ′″ to lumen  100   a . In this instance, varying amounts of agent  1000  are stored in openings  42   a - 42   c  until fluid communication between openings  42   a - 42   c  and lumen  100   a  is established. 
     It is further noted in some embodiments, intermediary barrier  15  may also be rotatable relative to enclosure  10 ′″, barrier  41 , tube  100 , and lumen  100   a , so that opening  16  does not align with any of the openings of barrier  41 , and/or opening  101  as well. This is applicable in embodiments having barriers with multiple openings. By being able to misalign opening  16  from opening  101 , a user may select another opening  42   a ,  42   b ,  42   c , etc., via rotation of barrier  41 , that is not adjacent to the currently aligned opening, without having to inadvertently dispense agent  1000  stored in openings adjacent to the currently aligned opening, via the necessary degree of rotation to select other non-adjacent openings. 
     Referring to  FIGS. 3A-3B , an example of how medical device  1 ′″ may be used is further discussed below. Similar to medical devices  1  and  1 ′, medical device  1 ′″ may be delivered into the body of a subject, and directed to an intended target site for agent  1000  administration in the same manner. A user may then fill enclosure  10 ′ with agent  1000 , if not filled already, and rotate barrier  41  relative to intermediary barrier  15 , tube  100 , and lumen  100   a , so that one of openings  42   a - 42   c  aligns with openings  16  and  101 . Such alignment results in seal  205  shaving off an excess amount of agent  1000  above the one opening, sealing the one opening from being fed any more of agent  1000  from enclosure  10 ″, and feeding lumen  100   a  with agent  1000  stored in the one opening. As discussed above, when the one opening aligns with opening  16  of intermediary barrier  15  and opening  101  of tube  100 , the remaining openings  42   a - 42   c  do not align with openings  16  and  101 . Thus, agent  1000  is stored within the remaining openings  42   a - 42   c , until each of the remaining openings is aligned with openings  16  and  101  via rotation of barrier  41 . A user may turn on the pressurized gas source at any time prior to or during the alignment of one of the openings  42   a - 42   c  with openings  16  and  101 , as in previously described embodiments. 
     Referring to  FIG. 4A , another embodiment of medical device  1 ″ is shown. Medical device  1 ″ includes a trigger  18 , a rotating cartridge  31  including a plurality of chambers, a lumen  100  receiving pressurized gas from a proximal end, and a channel  14  establishing fluid communication between a distal end of cartridge  31  and lumen  100  for delivering agent  1000  from cartridge  31  to lumen  100 . As shown in  FIG. 4B , cartridge  31  includes a plurality of symmetrically-arranged chambers, i.e., six chambers  32   a - 32   f , of equal or substantially equal size, each of which stores a pre-filled amount of agent  1000 . 
     Trigger  18  includes a lever  18   a  coupled to a linkage  18   c  via an articulating joint  18   b , and linkage  18   c  coupled to a plunger  18   e  via another articulating joint  18   d . A distal portion of plunger  18   e  is housed within a proximal portion of cartridge  31 , and is coupled to cartridge  31  in any suitable manner so that the distal end of plunger  18   e  faces one of chambers  32   a - 32   f  with which plunger  18   e  is aligned. A spring  19  coils around a distal portion of plunger  18   e  outside of cartridge  31  up until a stop  17  fixated on plunger  18   e , thereby spring-biasing plunger  18   e  in its aforementioned position of facing one of chambers  32   a - 32   f . Spring  19  is not particularly limited and may be any suitable spring. Likewise, stop  17  may be of any suitable material, such as rubber. 
     Trigger  18  is configured so that when lever  18   a  is pulled proximally, linkage  18   c  likewise pivots proximally relative to plunger  18   e  via articulating joint  18   d . Such movements of lever  18   a  and linkage  18   c  result in plunger  18   e  longitudinally advancing towards cartridge  31  and into one of chambers  32   a - 32   f , thereby propelling the pre-filled amount of agent  1000  towards and through channel  14 , which extends downward to tube  100 , thereby feeding agent  1000  to tube  100  via gravity. The longitudinal advancement of plunger  18   e  may be actuated by any suitable mechanisms, including, but not limited to, mechanical, electrical, or pneumatic mechanisms. Plunger  18   e  advances within cartridge  31  and one of chambers  32   a - 32   f  up until spring  19  is fully compressed, thereby inhibiting any further advancement of plunger  18   e  towards cartridge  31 . Once lever  18  is released, spring-biased plunger  18   e  automatically reverts back to its initial position of being outside of and facing one of chambers  32   a - 32   f.    
     Cartridge  31  is rotatable relative to plunger  18   e  so that any one of chambers  32   a - 32   f  is aligned with plunger  18   e . In some embodiments, cartridge  31  may be configured to rotate or revolve automatically, after one of chambers  32   a - 32   f  is emptied by plunger  18   e , so that an adjacent chamber  32   a - 32   f  storing a pre-filled amount of agent  1000  is aligned with plunger  18   e.    
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed device without departing from the scope of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.