Device for fluidizing and delivering powdered agent

Abstract

To provide endoscopic medical devices and methods of use, and more specifically, devices and methods for fluidization of materials, e.g., powder or reagents, to a target site in a patient, and for dispensing the materials to the target site in the patient.SOLUTION: A device for fluidizing and delivering a powdered agent comprises: a canister extending from first and second ends and defining a space in which the powdered agent is received; an inlet for supplying gas into the space to fluidize the powdered agent; an outlet through which a gas mixture is delivered; a tube extending from the outlet into an interior space, the tube including a slot extending through a wall thereof so that the gas mixture is passable from the interior space through the outlet via the second end and the slot; and a door movably coupled to the tube so that the door moves over the slot to control a size of the slot open to the interior space of the canister.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to endoscopic medical instruments and methods of use. More particularly, the present invention relates to devices and methods for fluidizing and dispensing a substance, such as a powder or reagent, at a target site in a patient. [Background technology]

[0002] For example, therapeutic agents in the form of dry powders, such as hemostatic agents, may be delivered to target sites in vivo using fluidization and delivery devices. Such devices generally include a chamber into which the powder is received and into which a high flow rate of gas is introduced to create a fluidized bed. This forms a two-phase mixture containing particulate solids suspended in the gas. The suspension retains the properties of a gas-liquid and moves from high pressure to low pressure, effectively delivering particles to the low-pressure region. For example, hemostatic powders can be delivered to a target location (e.g., a bleeding site) through an endoscopic catheter using this method. Studies have shown that when the particle delivery rate of hemostatic powders to a bleeding site falls below a certain threshold level, they may no longer be effective in achieving initial hemostasis in some cases. However, current powder fluidization and delivery devices often exhibit a decline in powder delivery rate over time. Summary of the Invention

[0003] This embodiment relates to an apparatus for fluidizing and delivering a powder agent, and includes a cannister that extends longitudinally from a first end to a second end and defines an internal space for receiving the powder agent, an inlet connectable to a gas source for supplying gas to the internal space to fluidize the powder agent received therein to form a fluidized mixture, an outlet through which the gas mixture passes for delivery to a target site for treatment, a tube that extends from a first end connected to the outlet into the internal space to a second end, and includes slots that extend through the interior of its wall such that the gas mixture can pass from the internal space through the second end and the slots into the outlet, and a door movably coupled to the tube and movable on the slots to control the size of the slots opening into the internal space of the cannister.

[0004] In one embodiment, the door is configured as an overtube movably mounted on the tube. In one embodiment, the apparatus further includes a stabilization ring that extends radially outward from the overtube to the inner surface of the cannister to fix the tube to the cannister.

[0005] In one embodiment, the cannister is rotatable relative to the tube, and the overtube can be moved longitudinally relative to the tube to control the size of the slots opening into the internal space.

[0006] In one embodiment, the apparatus further includes a lid connectable to the cannister to surround the internal space, and the inlet and outlet are configured as openings that extend through the lid. In one embodiment, the apparatus further includes a delivery catheter connectable to the outlet, and the delivery catheter has a size and shape such that it can be inserted through the working channel of an endoscope to a target site.

[0007] This embodiment also relates to an apparatus for fluidizing and delivering a powder agent. The apparatus extends longitudinally from a first end to a second end and has a first internal space in which the powder agent is received, a first inlet connected to a gas source for supplying gas to the first internal space to fluidize the powder agent received therein to generate a fluidized mixture, an outlet through which the gas mixture is delivered from the first internal space to a target site for treatment, and a filler chamber connected to the first internal space through an inlet of the filler and containing a filler that can pass from the filler chamber to the first internal space to maintain the volume of the internal substance substantially constant. The substance includes at least one of the powder agent and the filler.

[0008] In one embodiment, the filler includes one of simulated particles, beads, bounce balls, and foams. In one embodiment, the filler is formed in a size, shape, and configuration such that the filler cannot pass through the outlet.

[0009] In one embodiment, the filler chamber is supplied with gas to drive the filler from the filler chamber to the first internal space. In one embodiment, the filler chamber is configured as a second internal space defined by a canister.

[0010] In one embodiment, the second internal space includes a surface angled to direct the filler towards the filler inlet. In one embodiment, the filler is additional powder agent.

[0011] In one embodiment, the apparatus further includes a door movable relative to the filler inlet between a first configuration in which the door covers the filler inlet and a second configuration in which the door opens the filler inlet to allow the filler to move from the filler chamber to the first internal space by gravity.

[0012] In one embodiment, the device further includes a turbine connected to a paddle housed within an inlet of a packing material, the turbine being driven by a gas flow, and when the gas flow is received within a flow path housing the turbine, the turbine rotates and correspondingly rotates the paddle, and the packing material within the packing material chamber is actively driven from within the packing material chamber into a first internal space.

[0013] This embodiment also relates to a method including supplying a gas into an internal space within a canister in which a powder agent is received to fluidize the powder agent, forming a fluidized mixture, and delivering the fluidized mixture to a target site within a patient's body via a delivery catheter inserted through a working channel of an endoscope to the target site. During delivery of the fluidized mixture, a door movably attached to the tube is moved relative to a slot extending through a wall of the tube extending into the internal space of the canister communicating with the delivery catheter, and controls the size or a portion thereof of the slot exposed to the internal space.

[0014] This embodiment also relates to an apparatus for fluidizing and delivering a powder agent, the apparatus including a canister extending longitudinally from a first end to a second end and defining an internal space in which the powder agent is received, an inlet connectable to a gas source for supplying a gas into the internal space to fluidize the powder agent received therein to generate a fluidized mixture, an outlet through which the gas mixture passes for delivery to a target site for treatment, and a piston pump movably coupled to the canister and moving from an initial configuration coupled to the first end of the canister toward the second end of the canister to reduce the volume of the internal space as the amount of the powder agent decreases during delivery of the fluidized mixture to the target site.

[0015] In one embodiment, the inlet and the outlet each extend through a part of the piston. In one embodiment, the outlet is connectable to a delivery catheter sized and shaped to be inserted through a working channel of an endoscope to the target site.

[0016] In one embodiment, the piston is movable using one of a pneumatic cylinder and a motor. In one embodiment, the apparatus further comprises a chamber connected to a first end of the canister on one side of the piston facing the internal space of the canister, the chamber containing an expandable member configured to receive gas during delivery of the fluidized mixture, the expandable member expanding to move the piston towards a second end of the canister.

[0017] In one embodiment, the expandable member is connected to a gas source by a connecting member including a one-way valve that allows the flow of gas into the expandable member while preventing the flow of gas out of the expandable member.

[0018] In one embodiment, the apparatus further includes a bypass connected to the first end of the canister and coupled to the piston by a threaded rod, the bypass configured to receive the flow of gas passing therethrough and containing a turbine connected to the threaded rod, the turbine and the threaded rod rotating to move the piston towards the second end of the canister when gas flows through the bypass during delivery of the fluidized mixture.

[0019] The present embodiment relates to an apparatus for fluidizing and delivering a powder agent, the apparatus comprising a canister extending longitudinally from a first end to a second end and including a first internal space for receiving the powder agent, an inlet connectable to a gas source for supplying gas to the first internal space to fluidize the powder agent received therein to form a fluidized mixture, an outlet through which the gas mixture passes for delivery to a target site for treatment, and an expandable member movable between an initial biased form and an expanded form, in the expanded form, the expandable member being deformed such that as the amount of powder agent in the first internal space decreases during delivery of the fluidized mixture to the target site, a portion of it extends into the first internal space to reduce its volume.

[0020] In one embodiment, the canister further comprises a second interior space configured to receive gas therein during delivery of the fluidized mixture to the target site. In one embodiment, the first and second internal spaces are separated from one another via an expandable member, and a pressure differential between the first and second internal spaces causes the expandable member to deform into the first internal space.

[0021] In one embodiment, the expandable member is a diaphragm. In one embodiment, the first interior space is defined by an inner wall of the expandable member and the second interior space is defined by an outer wall of the expandable member and an inner surface of the canister.

[0022] In one embodiment, the expandable member is generally cylindrical. In one embodiment, the expandable member may extend from a first end of the canister to a second end of the canister.

[0023] In one embodiment, the expandable member is a balloon contained within the canister and configured to receive gas therein, such that when the balloon is inflated, the balloon fills the first interior space.

[0024] This embodiment includes supplying gas to an interior space of a canister receiving a powder therein, fluidizing the powder, forming a fluidized mixture, and delivering the fluidized mixture to a target site within a patient's body through a delivery catheter inserted through a working channel of an endoscope to the target site, wherein during delivery of the fluidized mixture, the volume of the interior space of the canister is reduced corresponding to the reduction in the volume of the powder, and the delivery rate of the fluidized mixture is maintained approximately constant.

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments and, together with the detailed description, serve to explain the principles of the disclosed embodiments. [Brief explanation of the drawings]

[0026]

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Best Mode for Carrying Out the Invention

[0027] Both the above general description and the following detailed description are exemplary and explanatory, and do not limit the features, as described in the claims. As used herein, terms such as "comprising," "including," "having," "containing," or other variations thereof are intended to non-exclusively encompass, and a process, method, article, or apparatus that includes a listing of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In the present disclosure, relative terms such as, for example, "about," "substantially," "generally," and "approximately" are used to indicate possible variations of ±10% of the recited value or characteristic.

[0028] The present invention can be further understood with reference to the following description and the accompanying drawings, and like elements are referred to by the same reference numerals. The present invention relates to an apparatus and method for delivering fluidized powder at a constant delivery rate in order to increase the duration for which an effective delivery rate of a powder agent is maintained, enabling a user (e.g., a physician) to treat more bleeding sites without the powder delivery rate falling below a threshold rate required to achieve hemostasis. This can reduce the number of devices required per procedure (and / or the number of times the device needs to be reloaded or reset), thereby shortening the treatment time. In one embodiment, the apparatus includes elements for changing the size of a powder outlet opening during delivery of the fluidized powder in order to maintain a desired delivery rate over time. In another embodiment, the apparatus includes a turbulator plate to prevent sedimentation of the powder in the cannister and maintain a desired delivery rate of the powder. In another embodiment, the apparatus includes a plurality of powder outlet slots disposed around the outer periphery of a tube extending into a cannister in which the powder is received to prevent non-uniform powder distribution within the cannister. In yet another embodiment, the apparatus maintains a constant amount of material within the cannister by injecting a packing material and / or additional powder to maintain a substantially constant delivery rate as the fluidized powder is delivered. In another embodiment, a user (e.g., a physician) maintains an effective and optimal delivery zone for a longer period of time. This enables the user to treat more bleeding sites, reducing the number of devices required per procedure, thereby shortening the treatment time. Embodiments describe a powder fluidization chamber and a delivery device that reduce the internal volume of a fluidization cannister over time as the volume of the powder decreases during delivery. The volume of the cannister can be decreased to maintain a constant volume ratio of the powder to the cannister throughout the process and maintain a constant delivery rate during treatment. Those skilled in the art will understand that all of these features maintain a desired delivery rate of the fluidized powder during the course of treatment.For example, the desired delivery rate is maintained substantially constant during the powder application period, or the delivery rate may vary within a desired delivery rate range that does not fall below a critical threshold delivery rate (e.g., a rate at which powder delivery is no longer effective for the intended purpose).

[0029] As shown in FIGS. 1 and 2, an apparatus 100 for fluidizing a powder agent (e.g., a powder therapeutic agent) and delivering it to a site in a living body (e.g., a target site) according to an embodiment of the present invention includes a canister 102 configured to receive a powder agent (e.g., a hemostatic agent) inside its internal space 104. The hemostatic agent may include, for example, a granular chitosan salt, zeolite powder, smectite clay, and a powder agent using polyacrylic acid, or polysaccharide hemospheres derived from potato starch. In the apparatus 100, a gas (e.g., CO2) is introduced from an inlet 106 to fluidize the powder agent and supply it to the canister 102. The fluidized powder mixture passes through an outlet 108 and is discharged from the canister 102, and is delivered to a target site (e.g., a bleeding site) via a delivery device (e.g., an endoscope) inserted into a body lumen from an orifice in the body. A tube 110 (e.g., a hypo tube) extends from the outlet 108 into the internal space 104 of the canister 102, and the fluidized powder mixture is received therein and exits the canister 102. The tube 110 of this embodiment includes slots 112 extending through the wall, and the fluidized powder mixture passes through both the end 114 of the tube 110 and the slots 112 and is discharged from the canister 102. The apparatus 100 according to this embodiment further includes an overtube 116 movably attached onto a part of the tube 110. The overtube 116 moves along the length of the tube 110 and extends over the slots 112 to control the size of the openings of the slots 112. In tests, it was shown that increasing the size of the slots increased the powder delivery rate, and decreasing the size of the slots decreased the powder delivery rate. The overtube 116 is movable relative to the tube 110 from an initial configuration where the overtube 116 at least partially covers the slots 112 towards an opening configuration where the overtube 116 is moved along a certain length of the tube 110 during the treatment process and the size of the slots gradually increases, and the delivery rate of the fluidized powder is maintained above a certain threshold level (e.g., kept substantially constant over time) even as the powder is dispensed and the volume of the powder agent in the canister 102 decreases.The fluidized powder / material includes, but is not limited to, a powder / material that acquires fluid characteristics by passing a propellant fluid (such as a gas) through or within it, a powder / material that follows the propellant fluid, or a stirred powder / material that is pushed by the propellant fluid.

[0030] According to one embodiment, the target delivery rate is 1 gram / 5 seconds or more. The device 100 can provide the best delivery results when the canister 102 is filled with about 45% to 80% of the powder agent. For example, at a filling degree of 80%, the ratio of the target delivery amount / time is maintained for 30 seconds. This delivery rate is also determined by the amount of gas that the device 100 can use for delivery. By gradually increasing the size of the slot 112 through which the fluidized powder mixture can flow out of the canister 102 to the outside, the delivery rate can be maintained even when the amount of the powder agent in the canister 102 decreases (for example, when the delivery time exceeds 30 seconds).

[0031] The canister 102 of this embodiment extends longitudinally from an open first end 118 to a closed second end 120, defining an internal space 104, which is configured to receive a powder agent therein. The lid 122 is connected to the first end 118 to surround the internal space 104 and prevent the powder agent and / or gas from leaking out of the internal space 104. In one embodiment, the lid 122 is connected within the first end 118. The inlet 106 and / or outlet 108 in this embodiment are configured as openings passing through the lid 122. However, those skilled in the art will understand that the inlet 106 and outlet 108 can each have any of a variety of configurations as long as they can be connected to a gas source and a delivery member to supply a high-flow gas to the powder agent to fluidize the powder agent and deliver the fluidized powder mixture to the target site. For example, the inlet 106 is connected to a connecting member 124 connected to a gas source. In one embodiment, the gas is supplied to the canister 102 at a pressure in the range between 5 and 20 psi (34.5 and 137.9 kPa) and / or a flow rate of 8 to 15 standard liters per minute. The outlet 108 of this embodiment is connected to a flexible delivery catheter 126 sized, shaped, and configured to pass through the working channel of a flexible endoscope and be inserted into a target site in the body. In one example, the delivery catheter 126 has an inner diameter between 0.065 inches and 0.11 inches (0.17 and 0.28 centimeters). In another embodiment, the inlet 106 and outlet 108 extend through a portion of the canister 102.

[0032] The tube 110 extends from a first end 128 connected to the outlet 108 to a second end 114 extending into the internal space 104. As described above, the tube 110 in FIGS. 1 and 2 also includes slots 112 extending through the wall of the tube 110. The slots 112 of this embodiment are disposed proximate the first end 128, and the fluidized powder mixture can flow out of the internal space 104 of the canister 102 through one of the slots 112 proximate the second end 114 and the first end 128 of the tube 110.

[0033] The overtube 116 is movably attached to cover a portion of the length of the tube 110. The overtube 116 is movable relative to the tube 110. When the overtube 116 moves over the tube 110, the area of the slot 112 covered by the overtube 116 changes, exposing the internal space 102 and controlling the size of the portion of the slot 112 through which the fluidized powder mixture can flow out from the internal space 104 of the cannister 102. For example, in an initial configuration, the overtube 116 extends across the entire slot 112 to completely cover the slot 112 and prevent the fluidized powder mixture from flowing out of the slot. However, during the treatment of the target site, the overtube 116 is moved relative to the tube 110 to increase the exposed amount of the outflow portion of the slot 112 and increase the outflow amount of the fluidized powder, thereby maintaining the delivery rate of the fluidized powder mixture at a desired level (e.g., a level exceeding the threshold delivery rate). For example, FIG. 2 shows the slot 112 when partially covered by a portion of the overtube 116, and FIG. 3 shows the slot 112 when fully exposed. This embodiment shows that the entire slot 112 is covered in the initial configuration. The overtube 116 can have any of a variety of initial configurations relative to the slot 112 as long as the size of the slot 112 through which the fluidized powder exits increases as the powder in the cannister 102 is dispensed.

[0034] One skilled in the art can also understand that the overtube 116 can be moved relative to the tube 110 using any of a variety of mechanisms. In one embodiment, the overtube 116 is connected, for example, to a stabilization ring 130 that extends radially outward from the overtube 116 to the inner surface of the canister 102 to fix the position of the overtube 116 relative to the canister 102. In this example, since the canister 102 and the tube 110 are rotatably connected to each other, when the canister 102 is rotated relative to the tube 110, the overtube 116 correspondingly moves longitudinally relative to the tube 110 while rotating about the tube 110, increasing (or decreasing depending on the direction of rotation) the size of the slot 112 through which the fluidized powder mixture can pass through the interior. In one example, the tube 110 extends from the lid 122. The lid 122 has a cam path 123 that extends along a partially helical path. Since an engagement element (e.g., a protrusion) of the canister 102 is placed in the cam path 123, when the canister 102 and the overtube 116 are rotated relative to the lid 122 and the tube 110, the overtube 116 moves longitudinally relative to the tube 110. As will be understood by one skilled in the art, the cam path 123 and the corresponding engagement element of the canister 102 function similarly to a threaded engagement between the canister 102 and the lid 122 to achieve the desired relative movement between the overtube 116 and the tube 110.

[0035] In an embodiment, the size of a portion of the slot 112 used for the fluidized powder mixture to flow out is controlled by the overtube 116. However, the size of the slot 112 may be controlled by a "door" having any structure and shape as long as the "door" can be gradually opened during the treatment process to maintain the desired flow rate of the therapeutic agent exiting the cannister 102. The movement of the overtube 116 or any other arbitrary "door" can be mechanically driven, for example, by physically turning the overtube 116, or can be pneumatically driven by the flow of gas. Further, although the embodiment shows and describes a single slot 112, the tube 110 may include two or more slots 112 that are covered or exposed as needed by any number of the door mechanisms as described above.

[0036] According to an exemplary method of using apparatus 100, prior to assembly of the apparatus 100, the cannister 102 is filled with a powder agent such as, for example, a hemostatic agent. When the cannister 102 is filled with a desired amount of the powder therapeutic agent, a lid 122 is assembled to the cannister 102 to seal the internal powder agent. Next, the inlet 106 is connected to a gas source, for example, via a connecting member 124, and the outlet 108 is connected to a delivery catheter 126. Next, the delivery catheter 126 is inserted into a target site in a living body (e.g., through the working channel of a delivery device such as an endoscope). High flow gas is introduced into the internal space 104 of the cannister 102 to form a fluidized powder mixture. The user can press a trigger or another control member to spray the fluidized mixture and deliver the fluidized mixture to the target site (e.g., a bleeding site) to perform treatment on the target site. When the fluidized powder mixture is delivered to the target site, the user can rotate the cannister 102 relative to the tube 110 to increase the size of the slot 112 through which the fluidized mixture flows out of the internal space 104 to maintain a desired flow rate. Alternatively, if a trigger is used to control the delivery of the fluidized powder mixture, when the trigger is pressed, a pneumatic cylinder or a motor is actuated to rotate and move the lid 122 relative to the cannister 102, so that a larger cross-sectional area of the slot 122 is exposed, and thus the size of the slot 112 through which the fluidized mixture flows out of the internal space increases. Thus, as the volume of the powder agent in the cannister 102 decreases, the cross-sectional area of the exposed slot 112 is increased to substantially maintain the delivery rate of the fluidized powder mixture. Alternatively, a sensor can detect the flow rate and automatically control the opening of the slot 112 to ensure that a desired flow rate is maintained.

[0037] Apparatus 200 according to another embodiment of the present invention shown in FIG. 3 is substantially similar to the above apparatus 100, except where otherwise explicitly described. Apparatus 200 includes a canister 202 that defines an internal space 204 within which a powder agent is received. Similar to apparatus 100, the internal space 204 is enclosed by a lid 222 coupled thereto, and when a high-flow gas is supplied to the internal space 204 through an inlet 206, the powder agent contained within the internal space 204 forms a fluidized powder mixture. The fluidized powder mixture exits the internal space 204 through an outlet 208 and is delivered to a target site within a patient's body during treatment. To maintain a desired delivery rate as the volume of the powder agent within the internal space 204 decreases during the course of treatment, lid 122 includes a turbulator plate 230. When gas passes through the turbulator plate 230, the turbulator plate 230 vibrates or rattles to prevent or at least reduce the settling of the powder agent contained within the canister 202. If the configuration lacks the turbulator plate 230, during the course of treatment, some of the powder agent will settle into an equilibrium state, resist fluidization, and it will be difficult to maintain the desired delivery rate of the therapeutic agent.

[0038] Similar to canister 102, canister 202 extends longitudinally from an open first end 218 to a closed second end 220 and defines an internal space 204. Lid 222 is coupled to the first end 218 to enclose the internal space 204 and contain the powder agent therein. Inlet 206 and outlet 208 are configured as openings that extend through lid 222 and communicate with the internal space 204. Although not shown, similar to apparatus 100, outlet 208 includes a tube that extends into the internal space 204 from the outlet to enable the fluidized powder mixture to exit through the tube and outlet 208.

[0039] In this embodiment, the turbulator plate 230 extends along a portion of the lid 222 facing away from the internal space 204. In this embodiment, the turbulator plate 230 includes an opening 232 that extends through its wall 234, and the opening 232 is connected to a gas source, for example, by a connecting element 224. The turbulator plate 230 extends along the lid 222 such that the opening 232 communicates with the inlet 206. Thus, the gas passes through the turbulator plate 230 and enters the internal space 204 from the inlet 206. The interior 236 of the turbulator plate 230 includes a plurality of structures 238, such as ribs, bumps, or bosses, which cause the flow of gas passing through it to be turbulent and impart a vibration response to the turbulator plate 230. Next, the vibration prevents the powder from settling on the lid 222. Thus, the gas flow through the turbulator plate 230 and into the internal space 204 causes both the vibration of the turbulator plate 230 and the fluidization of the powered agent within the canister 202. As will be understood by those skilled in the art, the magnitude of the vibration can be controlled by controlling the speed at which the gas passes through the turbulator plate 230. In this embodiment, the magnitude of the vibration of the turbulator plate 230 is kept constant over time as long as the user is pressing a trigger for supplying gas to the canister 202. The fluidized powder agent exits the canister 202 through an outlet 208 that does not communicate with the interior 236 of the turbulator plate 230. The outlet 208 of this embodiment is connected to a delivery catheter 226 for delivering the fluidized powder mixture to a target site.

[0040] In an alternative embodiment, as shown in FIG. 4 , apparatus 200′ is substantially similar to apparatus 200 described above, except where expressly noted. In this embodiment, turbulator plate 230′ extends along a portion of lid 222′, which encloses interior space 204′ defined by canister 202′ and includes first and second openings 232′ and 240′ extending through wall 234′ thereof. Neither first opening 232′ nor second opening 240′ communicates with inlet 206′ or outlet 208′ of apparatus 200′. Inlet 206′ and first opening 232′ are configured to be connected to a gas source for supplying gas to interior space 204′ and turbulator plate 230′, respectively. Inlet 206′ and first opening 232′ may be connected to the same or different gas sources.

[0041] Gas supplied to turbulator plate 230' through first opening 232' passes through turbulator plate 230' and exits turbulator plate 230' through second opening 240'. Gas may be supplied to turbulator plate 230' at a constant rate while the powder is fluidized and delivered to the target site, for example, to maintain a constant magnitude of vibration. Alternatively, the flow of gas supplied to turbulator plate 230' can be varied over time or intermittently to change the magnitude of vibration as needed to optimize the delivery rate of the fluidized powder mixture. However, one skilled in the art will appreciate that the function of turbulator plate 230' is otherwise the same as in device 200, namely, to prevent powder from settling on lid 222'.

[0042] As shown in FIGS. 5 and 6, an apparatus 300 according to another embodiment of the present invention is substantially similar to apparatuses 100 and 200, except where otherwise explicitly stated. The apparatus 300 includes a cannister 302 that defines an internal space 304 within which a powder (e.g., a hemostatic agent) is received and fluidized by a high-flow gas for delivery to a target site (e.g., a bleeding site) for treatment. The internal space 304 is surrounded by a lid 322 attached to the open end of the cannister 302, and gas is supplied to the internal space 304 through an inlet 306 that extends through the lid 322. The resulting fluidized powder mixture exits the internal space 304 through an outlet 308 that extends through the lid 322 and is delivered to the target site. The apparatus 300 also includes a tube 310 that extends from a first end 328 connected to the outlet 308 to a second end 314 that extends into the internal space 304. However, instead of a single slot that extends through the wall of the tube 310, the tube 310 includes a plurality of slots 210 disposed around the outer perimeter of the tube 310 to prevent non-uniform distribution of the powder within the cannister 302 and to prevent powder from accumulating on either side of the tube 310, which can reduce the delivery rate of the fluidized powder mixture.

[0043] In one embodiment, as shown in FIG. 6, the tube 310 includes four slots 312 that are provided around the outer perimeter of the tube 310 and are equally spaced from each other. The slots 312 of this embodiment are disposed near the first end 328. However, it will be understood by those skilled in the art that the number, location, and configuration of the slots 312 can be varied.

[0044] As shown in FIG. 7, an apparatus 400 according to another embodiment of the present invention is substantially similar to the above-described apparatuses 100, 200, and 300, unless otherwise explicitly stated. The apparatus 400 includes a cannister 402 that defines an internal space 404 in which a powder agent 405 is received and fluidized to form a fluidized powder mixture for delivery to a target site in a living body. Similarly, the apparatus 400 includes a lid 422 that surrounds the internal space 404, an inlet 406 through which a gas passes to supply the internal space 404 to fluidize the powder agent 405, and an outlet 408 through which the fluidized powder agent passes out of the cannister 402 and is delivered to the target site. The apparatus 400 includes a tube 410 that communicates with the outlet 408 and extends into the internal space 404. The apparatus 400 further includes a filler chamber 450 that is connected to the cannister 402 and communicates with the internal space 404 of the cannister 402. The filler chamber 450 contains a filler 452, such as, for example, simulated particles, beads, small "bounce balls" or foamed material, and is injected as the fluidized powder mixture exits the cannister 402 to compensate for the loss of the amount of the powder mixture as the fluidized powder mixture is delivered to the target site. The filler 452 is injected into the cannister 402 to maintain a constant ratio of the volume of the material (e.g., the powder agent and the filler) to the volume of the gas in the cannister 402, and to maintain a desired delivery rate of the fluidized powder mixture to the target site.

[0045] The filler chamber 450 is connected to the cannister 402 such that the filler 452 passes from the filler chamber 450 through the filler inlet 454 into the cannister 402. In one embodiment, the filler chamber 450 includes a gas inlet 4�6 so that when the user drives the delivery of the fluidized powder mixture to the target site, for example, by pressing a trigger, gas is supplied to both the cannister 402 and the filler chamber 450. The gas supplied to the filler chamber 450 drives the filler 452 from the filler chamber 450 into the cannister 402. The filler chamber 450 may include a pressure regulator that controls the gas inlet pressure to control the volume of the filler 452 supplied to the cannister 402 as needed to correspond to the volume of the powder agent 405 exiting the cannister 402. In one embodiment, the filler inlet 454 is formed in a size, shape, and / or configuration configured to facilitate a single flow of the filler 452 (e.g., beads) therethrough into the cannister 402.

[0046] The filler 452 is configured to be able to enter the internal space 404 of the cannister 402 but is prevented from exiting the cannister 402 during the delivery of the fluidized powder mixture. In one embodiment, this is achieved through sizing of the individual particles of the filler 452. For example, the filler 452 is formed in a size and / or shape such that it prevents it from entering the tube 410 and / or the outlet 408. In other words, each bead or particle of the filler 452 is selected to be larger than the opening of the tube 410 and / or the opening of the outlet 408. The filler 452 is large enough to prevent the filler from exiting the cannister 402 while at the same time being configured to bounce off the walls of the cannister 402 when the powder agent is moved and fluidized within the internal space 404 to prevent clogging of the device 400.

[0047] Accordingly, during use, the cannister 402 of the device 400 loses powder during the delivery of the fluidized powder, but compensates for the loss by simultaneously supplying a corresponding amount of filler 452 to the cannister 402. The delivery rate of the filler 452 to the cannister 402 can be determined by calculating the volume of the lost powder and adjusting based on the difference in the volume of the filler 452 to the powder agent 405 and their flow rates when a given delivery rate of a constant fluidized powder mixture is provided. The delivery rate of the filler 452 into the cannister 402 is selected to compensate for the loss of volume of the powder 405 and maintain the delivery rate of the fluidized powder mixture substantially constant. The inlet 406 of the cannister 402 and the gas inlet 456 of the filling chamber 450 are shown and described as being connected to a single gas source, but one of ordinary skill in the art will understand that the inlet 406 and the gas inlet 456 can each be connected to separate gas sources, and when the delivery of the fluidized powder mixture to the target site is driven and / or triggered, each gas source supplies gas to the inlet 406 and the gas inlet 456.

[0048] As shown in FIGS. 8 and 9, the apparatus 500 is substantially similar to the apparatus 400, except where otherwise explicitly stated. The apparatus 500 includes a cannister 502 that defines a first internal space 504 within which a powder agent is received and fluidized, and through which the fluidized powder mixture is delivered to a target site of a patient for treatment. However, rather than a separate filling chamber, the cannister 502 defines both the first internal space 504 and a second internal space 550 that extends above the first internal space 504 when the apparatus 500 is in the operating position. In addition, rather than filling the first internal space 504 with a filler to maintain a constant volume of the material (powder and / or filler) therein, the second internal space 550 contains additional powder agent, and the additional powder agent is supplied by gravity to the first internal space 504 as the fluidized powder mixture exits the first internal space 504 and is delivered to the target site. Since the inlet and outlet (not shown) communicate with the first internal space 504, only the powder agent contained within the first internal space 504 is fluidized to form a fluidized powder mixture, and only the powder agent within the first internal space 504 is permitted to exit the apparatus 500 and travel towards the target site.

[0049] The second internal space 550 may communicate with the first internal space 504 through an opening 554 that extends therebetween. The apparatus 500 further includes a door 558 that is movable between a first configuration prior to the start of a treatment procedure as shown in FIG. 8 and a second configuration during the treatment process as shown in FIG. 9. In the first configuration, when the fluidized powder mixture is not being delivered, the door 558 extends across the entire opening 554 to prevent the powder agent from entering the first internal space 504 from the second internal space 550. As shown by the dashed line in FIG. 8, the first internal space 504 contains a given amount of powder agent therein.

[0050] As shown in FIG. 9, when the user drives and / or triggers the delivery of the fluidized powder mixture, the movement of door 558 is also initiated, causing door 558 to open and expose opening 554, allowing the powder agent to pass from the second internal space 550 to the first internal space 504. The driving of door 558 can be triggered in any of several different ways. For example, door 558 includes a motor that operates when the device 500 is driven, a magnetic mechanism that uses magnetism to open door 558 when activated, and / or a pressure differential caused by a pressure increase during device operation. Since the second internal space 550 includes an angled surface 560 that directs the powder agent towards the opening 554, when door 558 opens, the powder agent in the second internal space 550 is allowed to fall into the first internal space 504. Thus, the first internal space 504 is passively supplied with additional powder agent by gravity. As shown by the dashed line in FIG. 9, as the fluidized powder mixture is delivered, the first internal space 504 is filled, so the volume of powder in the first internal space 504 should be maintained constant during the course of treatment. The opening 554 can be formed and / or configured to a size that allows the powder agent to fall through it at a controlled rate selected to keep the volume of the powder agent in the first internal space 504 substantially constant.

[0051] The additional powder in the second internal space 550 is described as being passively supplied to the first internal space 504 by gravity. However, in another embodiment, as shown in FIGS. 10 and 11, the powder in the second internal space 550' of the cannister 502' of the device 500' may be actively supplied into the first internal space 504' of the cannister 502' by, for example, a turbine 562' powered by a gas flow. In this embodiment, a rotatable paddle 564' is mounted within an opening 554' extending between the first internal space 504' and the second internal space 550'. The rotatable paddle 564' is connected to the turbine 562', which is disposed along the outside of the cannister 502' and housed within a gas flow path 566'. The gas flow path 566' is configured as a connection element 524' that connects a gas source to an inlet (not shown) and permits gas to pass therethrough and enter the first internal space 504. Thus, in this embodiment, the connection element 524' extends along the outside of the cannister 502' and houses the turbine 562'.

[0052] As shown in FIG. 10, in a first form of the device 500' where the delivery of the fluidized powder mixture is not driven and thus gas does not flow through the flow path 566', the turbine 562' does not rotate, and thus the powder agent is not permitted to enter from the second internal space 550' into the first internal space 504'. As shown in FIG. 11, when the delivery of the fluidized powder mixture is driven, in a second form, the turbine 562' is rotated by the flow of gas passing through the gas flow path 566'. The rotation of the turbine 562' correspondingly rotates the paddle 564' to actively drive the powder agent in the second internal space 550' through the opening 554' into the first internal space 504'. Since the gas flow is initiated when the user drives or triggers the delivery of the fluidized powder mixture to the target site, the supply of the powder agent from the second internal space 550' to the first internal space 504' occurs almost simultaneously with the powder agent (e.g., the fluidized powder mixture) exiting from the first internal space 504', maintaining the volume of the powder agent in the first internal space 504' substantially constant. By maintaining the volume of the powder agent in the first internal space 504', the delivery rate of the correspondingly fluidized powder mixture is maintained substantially constant.

[0053] The above embodiments describe one gas source / supply, but those skilled in the art will understand that as long as the volume of the powder agent supplied from the second internal space 550' to the first internal space 504' corresponds to the volume of the powder agent exiting the first internal space 504', the turbine 562' may be driven via a gas source separate from the gas source connected to the inlet of the device 500'. Further, although the embodiments describe the active movement of the powder agent by a gas-driven turbine, the active movement from the second internal space 550' to the first internal space 504' can also occur by another mechanism.

[0054] As shown in FIG. 12, an apparatus 1200 for fluidizing and delivering a powder agent (e.g., a hemostatic agent) according to an embodiment of the present invention includes a canister 1202 and a piston 1204 movably coupled to the canister 1202. The canister 1202 is configured to receive the powder agent within its internal space 1206. Subsequently, the canister 1202 is filled with gas through an inlet 1208 that is connected to a gas source, for example, via a tubular member 1212. The powder is fluidized using the gas to form a two-phase mixture that is sprayed through a catheter 1214 connected to an outlet 1210 to a target site (e.g., a bleeding site). The catheter 1214 has a size and shape sufficient to be endoscopically inserted into the patient's body to the target site (e.g., along a tortuous path traversed by a flexible endoscope through a body lumen accessed through a natural body opening) and is sufficiently flexible. To maintain the delivery rate of the mixture to the target site substantially constant, the piston 1204 is movable relative to the canister 1202 to reduce the volume of the internal space 1206 during the treatment of the target site. Thus, as the volume of the powder in the canister 1202 is reduced, the volume of the internal space 1206 is also reduced to maintain the ratio of the volume of the powder agent to the volume of the canister substantially constant. The piston 1204 is moved relative to the canister 1202 in any of several different ways. In this embodiment, the piston 1204 is moved by a pneumatic cylinder or a motor 1220.

[0055] The cannister 1202 of this embodiment is formed of a rigid material and defines an internal space 1206, which is configured to receive a powder agent together with a gas and form a gaseous fluid mixture that is sprayed onto a target site for treatment of the target site. The cannister 1202 extends longitudinally from an open first end 1216 to a closed second end 1218. The piston 1204 is movably coupled to the cannister 1202 at the first end 1216 and is movable toward the second end 1218 to reduce the volume of the internal space 1206. The piston 1204 surrounds the internal space 1206, and the powder, gas, and / or gas mixture exits the cannister 1202 through the outlet 1210 without leaking from the cannister 1202 and enters the catheter 1214 therefrom and exits toward the target site. Thus, the piston 1204 of this embodiment is received within the open first end 1216 and is substantially sized and shaped to correspond to the size and shape of the opening of the first end 1216. In one example, the cannister 1202 is generally cylindrical, but the piston 1204 is generally disc-shaped and is received within the open first end 1216 of the cannister 1202. The cannister 1202 is sized and shaped such that the piston 1204 is movable toward the second end 1218 along at least a portion of its length, reducing the volume of the internal space 1206 while preventing leakage of the fluid / substance received within the internal space 1206. In one example, the piston 1204 includes a seal ring extending around its outer periphery to prevent leakage of powder, gas, and / or fluid therethrough.

[0056] As described above, device 1200 includes inlet 1208 through which gas is introduced into interior space 1206 and outlet 1210 through which the fluidized powder is delivered to catheter 1214 for reaching the target site. In one embodiment, inlet 1208 and outlet 1210 are each configured as openings that extend through a portion of piston 1204 and are connected to tubular member 1212 and catheter 1214, respectively. However, one skilled in the art will appreciate that inlet 1208 and outlet 1210 may be located on or along any portion of canister 1202 and / or piston 1204, provided inlet 1208 is configured to receive pressurized gas therethrough and into interior space 1206, and outlet 1210 may be connected to a delivery element, such as catheter 1214, that delivers the fluidized mixture from interior space 1206 to the target site. Those skilled in the art will also appreciate that while inlet 1208 is described as being connected to a gas source via tubular member 1212, inlet 1208 may be connected to a gas source via any number of connections capable of providing a sufficient flow of gas therethrough. Additionally, while outlet 1210 is shown and described as an opening extending through piston 1204, those skilled in the art will appreciate that outlet 1210 may be configured to include a hypotube extending into interior space 1206 such that the fluidized mixture formed within interior space 1206 is received within the hypotube and delivered through catheter 1214 to the target site.

[0057] In this embodiment, the piston 1204 is movable relative to the canister 1202 by a pneumatic cylinder or motor 1220. The device 1200 may be programmed to include one or more inputs such as, for example, time. If it is desired to deliver the fluidized mixture to the target site, the user may initiate the delivery using a controller such as a trigger. For example, when the user presses the trigger to deliver the fluidized mixture, the piston 1204 moves towards the second end 1218 at a preset speed. When the user releases the trigger, the piston 1204 stops and can maintain its position relative to the canister 1202 until the user presses the trigger again. Alternatively or additionally, the device 1200 may use another input such as, for example, an input based on the flow or pressure sensors inside the internal space 1206, the inlet 1208, and / or the outlet 1210 of the canister 1202.

[0058] The piston 1204 of the device 1200 is described and shown as being driven via a pneumatic cylinder or motor 1220, but those skilled in the art will understand that the piston 1204 can be moved from an initial position near the first end 1216 to the second end 1218 by any of a variety of different drive mechanisms, examples of which are described in more detail below. Further, the piston 1204 is shown as forming the base (e.g., bottom) of the canister 1202, but those skilled in the art will understand that the piston 1204 may be connected to the canister 1202 in any configuration. In particular, the piston 1204 may be configured as the lid (e.g., top) of the canister 1202. In further embodiments, the device 1200 includes one or more pistons 1204, each of which is movable relative to the canister 1202 to reduce the volume of its internal space 1206.

[0059] According to an exemplary method of using apparatus 1200, cannister 1202 may be filled with a powder, such as a hemostatic agent, prior to assembly of the apparatus 1200. After filling cannister 1202 with a desired amount of powder, cannister 1202 and piston 1204 are assembled, inlet 1208 is connected to a gas source, e.g., via a tubular member 1212, and outlet 1210 is connected to a catheter 1214. Next, catheter 1214 is inserted through the working channel of a delivery device, such as an endoscope, to a target site within the body. The user depresses a trigger or other controller to introduce a high flow of gas into internal space 1206 of cannister 1202 to form a fluidized mixture and deliver the fluidized mixture to the target site (e.g., a bleeding site) to effect treatment on the target site. When the trigger is depressed, a pneumatic cylinder or motor 1220 is actuated to move piston 1204 towards a second end 1218, reducing the volume of internal space 1206 by an amount corresponding to the decrease in the volume of powder remaining within internal space 1206 as the powder exits cannister 1202 through outlet 1210. When the user releases the trigger, both delivery of the fluidized mixture and movement of piston 1204 cease. Thus, since piston 1204 moves only while the fluidized mixture is being delivered, the decrease in the volume of internal space 1206 corresponds to the decrease in the volume of powder contained within internal space 1206. As described above, the rate of movement of piston 1204 can be based on inputs such as time, flow, and / or pressure within cannister 1202, inlet 1208, and outlet 1210. In one embodiment, piston 1204 is configured to move at a rate that maintains a substantially constant ratio of the volume of internal space 1206 available within cannister 1202 to the volume of powder remaining, to maintain a substantially constant delivery rate of the fluidized mixture.

[0060] As shown in FIG. 13, an apparatus 1300 according to another embodiment is substantially similar to apparatus 1200 and includes a cannister 1302 and a piston 1304 movably coupled to the cannister and configured to move from an initial position proximate a first end 1316 of the cannister 1302 toward a second end 1318 to decrease the volume of the internal space 1306 of the cannister 1302 as the fluidized powder mixture is delivered to the target site. Similar to apparatus 1200, a high flow gas is delivered to the internal space 1306 to fluidize the powder agent received within the cannister 1302 to form a fluidized mixture for delivery to a target site within the body. The gas is received within the cannister 1302, for example, through an inlet 1308 connected to a gas source by a tubular member 1312. The fluidized mixture is delivered to the target site through a delivery catheter 1314 connected to an outlet 1310 of the apparatus 1300. However, in this embodiment, the piston 1304 is moved by a chamber 1320 that includes an expandable member 1322 that expands when gas is received therein. In particular, when the user triggers (e.g., presses) a controller to deliver the fluidized mixture to the target site, a portion of the gas is directed to the expandable member 1322 and the gas expands the expandable member 1322 and moves the piston 1304 toward the second end 1318 as shown by the dashed line in FIG. 13.

[0061] In this embodiment, the chamber 1320 that houses the expandable member 1322 is connected to the first end 1316 of the cannister 1302 on the side of the piston 1304 that is opposite the internal space 1306. Therefore, when the expandable member 1322 expands, the piston 1304 is moved toward the second end 1318 of the cannister 1302. The expandable member 1322 is connected to a gas source via a connecting member 1324 that includes a one-way valve, and gas can pass through it and enter the expandable chamber 1322 in a first direction, but is prevented from flowing out of the expandable chamber 1322 in a second direction. As described above, the gas is directed toward the chamber 1320 only while the fluidized mixture is being delivered to the target site, and the decrease in the volume of the internal space 1306 corresponds to the decrease in the volume of the powder agent within the cannister 1302. Similar to the device 1200, the device 1300 can receive inputs corresponding to flow, pressure, and / or time, and can control the speed at which the piston 1304 is moved toward the second end 1318. Those skilled in the art will understand that the device 1300 can be used in a manner that is substantially similar to the device 1200.

[0062] As shown in FIGS. 14 and 15, an apparatus 1400 according to another embodiment is substantially similar to the apparatuses 1200 and 1300, and includes a cannister 1402 for receiving a powder agent within its internal space 1406 and a piston 1404 movably attached to the cannister 1402. High-flow gas is delivered into the internal space 1406 through an inlet 1408 connected to a gas source to form a fluidized powder mixture for delivery to a target treatment area through a delivery catheter 1414 connected to an outlet 1410 of the apparatus 1400. The piston 1404 is movable from an initial position proximate to a first end 1416 of the cannister 1402 toward a second end 1418, reducing the volume of the internal space 1406 as the volume of the powder agent within the internal space 1406 decreases. However, the apparatus 1400 further includes a turbine 1426 connected to a threaded rod 1428 to which the piston 1404 is threadedly coupled. In the case of the cannister 1402, the turbine 1426 is housed within a bypass 1424 connected to the first end 1416. A portion of the gas is diverted into the bypass 1424 when the user triggers the controller to deliver the fluidized mixture. The gas flow through the bypass 1424 rotates the turbine 1426, whereby the threaded rod 1428 is rotated about its longitudinal axis. As the threaded rod 1428 is rotated, the piston 1404 moves longitudinally along toward the second end 1418.

[0063] As shown in FIG. 15, bypass 1424 includes a first opening 1430 through which gas is received and a second opening 1432 through which gas exits, and the gas flows through bypass 1424 from the first opening 1430 to the second opening 1432 to rotate turbine 1426 housed therein. Threaded rod 1428 is connected to turbine 1426 such that rotation of turbine 1426 results in rotation of threaded rod 1428. Since piston 1404 is threaded onto rod 1428, rotation of threaded rod 1428 moves piston 1404 longitudinally. Piston 1404 is threaded onto rod 1428 such that when threaded rod 1428 is rotated via the gas flow through bypass 1424, piston 1404 moves longitudinally towards the second end 1418. Similar to apparatus 1300, a portion of the gas is diverted only through bypass 1424 during delivery of the fluidized mixture, and the reduction in the volume of the internal space corresponds to the volume of powder remaining in internal space 1406. One of ordinary skill in the art will appreciate that apparatus 1400 can be used in a manner substantially similar to apparatuses 1200 and 1300 as described above.

[0064] As shown in FIG. 16, an apparatus 1600 according to another embodiment of the present invention is substantially similar to apparatuses 1200, 1300, and 1400 described above and includes a canister 1602 configured to receive a powder agent therein for fluidization by gas. Similar to apparatuses 1200, 1300, and 1400, the volume of the internal space 1606 of canister 1602 is reduced as the fluidized mixture is delivered to the target site for treatment. However, instead of reducing the volume of the internal space 1606 via a movable piston, apparatus 1600 includes an expandable member 1604 that expands within the internal space 1606 of canister 1602 to reduce its volume, as shown by the dashed line in FIG. 16.

[0065] Similar to devices 1200, 1300, and 1400, gas is supplied to the cannister 1602 through the inlet 1608, and the inlet is connected to a gas source by a connecting member 1612. The fluidized mixture is delivered to the target site through a delivery catheter 1614 connected to the outlet 1610. The device 1600 further includes a secondary chamber 1620 connected to the cannister 1602. Similar to the device 1300 above, a portion of the gas from the gas source can be directed to the secondary chamber 1620 during the delivery of the fluidized mixture. The internal space of the secondary chamber 1620 is separated from the internal space of the cannister 1602 by an expandable member 1604. In this embodiment, the expandable member 1604 is configured as an expandable diaphragm extending between the cannister 1602 and the secondary chamber 1620. Thus, when gas is received into the internal space of the secondary chamber 1620 through the supply pipe 1624, the internal space of the secondary chamber 1620 and the internal space of the cannister 1602 deflect the expandable member into the cannister 1602, reducing the volume of the internal space, as shown by the dashed line in FIG. 16.

[0066] As described above with respect to devices 1300 and 1400, gas is directed to the secondary chamber 1620 only during the delivery of the fluidized mixture. When delivery is triggered, gas is directed to the secondary chamber 1620. When the user releases the trigger for delivery, the delivery of gas to the secondary chamber 1620 is stopped. Also as described above, the amount of flow directed to the secondary chamber 1620 can be determined by the time, pressure, and / or flow detected within the device 1600. As more gas flows into the secondary chamber 1620, its pressure increases, further deflecting the diaphragm into the internal space of the cannister 1602. Thus, the device 1600 can be utilized in a manner substantially similar to the above-described devices.

[0067] Device 1600 is shown and described with respect to one expandable diaphragm, but one of ordinary skill in the art will understand that device 1600 may include multiple expandable diaphragms and that the expandable member may have any of a variety of shapes.

[0068] As shown in FIG. 17, a device 1700 according to another embodiment is substantially similar to device 1600 above and includes a cannister 1702 having an expandable member 1704 that expands to reduce the volume of a first internal space 1706 of the cannister 1702 as a powder received therein is fluidized and delivered to a target site for treatment. However, in this embodiment, the expandable member 1704 is housed within the cannister 1702 and defines both a first internal space 1706 in which the powder is fluidized and a second internal space 1720 into which a portion of the gas is directed to deflect the expandable member 1704 into the first internal space 1702 to reduce its volume. A first end 1716 of the cannister 1702 is substantially closed by a base 1740. An inlet 1708 for supplying gas to the first internal space 1706 and an outlet 1710 through which the fluidized mixture passes for delivery to the target site extend through the base 1740 that communicates with the first internal space 1706.

[0069] The expandable member 1704, in one example, has a generally cylindrical configuration. The cylindrical expandable member 1704 is housed within a canister 1702, and the interior of the expandable member 1704 defines a first interior space 1706 into which a powdered agent is contained and then fluidized by a high flow rate of gas supplied from a gas source through an inlet 1708. A second interior space 1720 is defined by an outer surface 1736 of the expandable member 1704 and an inner surface 1738 of the canister 1702, and the fluidized mixture is delivered from the first interior space 1706 to a target site through a delivery catheter 1714 connected to an outlet 1710, with a portion of the gas from the gas source being directed into the second interior space 1729 by a connecting member 1724. The pressure differential between the first and second interior spaces 1706, 1720 causes the expandable member 1704 to deflect into the first interior space 1706 toward an expanded configuration, as shown by the dashed lines in FIG. 17 , decreasing the volume of the first interior space 1706 as the volume of powder in the first interior space 1706 decreases, as shown by the dashed lines in FIG. 17 . In one embodiment, in the expanded configuration, the expandable member 1704 forms a generally hourglass shape. However, one skilled in the art will appreciate that the expandable member 1704 can have any of a variety of shapes and configurations, so long as the expandable member 1704 decreases the volume of the first interior space 1706 when expanded. As with the above devices, gas is directed only to the second interior space 1720 during delivery of the fluidized mixture and may be controlled by inputs such as time and / or flow and / or pressure within the device 1700.

[0070] Although the device 1700 is shown and described as including an expandable member 1704 having a generally cylindrical shape, those skilled in the art will understand that the expandable member 1704 may have any of a variety of shapes, so long as the expandable member defines first and second interior spaces 1706, 1720, as described above.

[0071] As shown in FIG. 18, an apparatus 1800 according to another embodiment is substantially similar to the apparatus 1700, and includes a canister 1802, an expandable member 1804 that defines a first internal space 1806 in which a powder is fluidized through a gas from a gas source to form a fluidized mixture, and a second internal space 1820 that receives a portion of the gas diverted from the gas source during delivery of the fluidized mixture to a target site. The first internal space 1806 is defined by an inner wall 1805 of the expandable member 1804. The second external space 1820 is defined by an outer wall 1836 of the expandable member 1806 and an inner surface 1838 of the canister 1802. However, in this embodiment, since the expandable member 1804 extends from a first end 1816 of the canister 1802 to a second end 1818 of the canister 1802, in an initial biased configuration, the expandable member 1804 has a shape that substantially corresponds to the canister 1802. However, as the second internal space 1820 is filled with the diverted gas, the expandable member 1804 deflects into the first internal space 1806, increasing the volume of the second internal space 1820 and decreasing the volume of the second internal space 1820, as shown by the dashed line in FIG. 18.

[0072] Similar to the apparatus 1700, the apparatus 1800 includes a base 1840 at a first end 1816 of the canister 1802 to surround the first and second internal spaces 1806, 1820. An inlet 1808 and an outlet 1810 extend through the base 1840 and communicate with the first internal space 1806, and gas is supplied therethrough the inlet 1808 to fluidize the powder therein, and the fluidized mixture is delivered to a target site through the outlet 1810. A portion of the gas from the gas source is diverted to the second internal space 1820 by a connection element 1824, and the connection element 1824 is disposed along the base 1840 and communicates with the second internal space 1820.

[0073] As described above, during delivery of the fluidized mixture to the target site, a portion of the gas is diverted into the second interior space 1820, and the pressure differential between the first and second interior spaces 1806, 1820 causes the expandable member to deflect radially inward, as shown by the dashed lines in FIG. 18 , decreasing the volume of the first interior space 1806. Thus, as the volume of powder within the first interior space 1806 decreases, the volume of the first interior space 1806 is correspondingly decreased to maintain a substantially constant delivery rate of the fluidized mixture. In the deflected configuration, the expandable member 1804 may be substantially conical in shape. However, one skilled in the art will appreciate that the expandable member 1804 may have any configuration, shape, and size, so long as the expandable member 1804 is formed of a flexible, i.e., deflectable, material that defines both a first interior space 1806 within the walls of the first interior space and a second interior space 1802 between the expandable member 1804 and the walls of the canister 1802.

[0074] 19, another embodiment of device 1900 is generally similar to devices 1600, 1700, and 1800 described above and includes a canister 1902 and an expandable member 1904 that expands to reduce the volume of an interior space 1906 of canister 1902 as the powder is fluidized and delivered to the target site of treatment. The volume of interior space 1906 is reduced to correspond with the reduction in the volume of the powder within interior space 1906. However, in this embodiment, expandable member 1904 is configured as an expandable balloon housed within interior space 1906. Thus, as balloon 1904 expands and the volume of balloon 1904 increases, the volume of interior space 1906 is reduced.

[0075] Similar to devices 1600, 1700, and 1800, device 1900 includes an inlet 1908 for supplying gas to an internal space 1906 to fluidize the powder agent, and an outlet 1910 through which the fluidized mixture passes and is delivered to the target site. The inlet 1908 and the outlet 1910 are each connected to an end of the cannister 1902 and extend through a base 1940 of the device 1900 that defines the internal space 1906. A portion of the gas supplied to the device 1900 is directed through a connection element 1924 to the expandable member 1904 to inflate the balloon and fill the internal space 1906. As described above, the inlet 1908 can have any of a variety of configurations and, in one embodiment, can include a hypo tube 1911 that extends into the internal space 1906. The hypo tube 1911 includes slots 1944 that extend through its wall and along a portion thereof. The inflated expandable member 1904 can fill the space surrounding the hypo tube 1911 without restricting the flow of gas and powder through the slots 1944. Although the hypo tube 1911 is described as including slots 1944, those skilled in the art will understand that the term "slot" can refer to any opening or hole that extends through its wall.

[0076] The connection element 1924 can be connected to the base 1940, as shown, to deliver gas to the expandable member 1904. Those skilled in the art of this embodiment will understand that the connection element 1920 can extend through the internal space 1906 and be connected to the expandable member 1904. Alternatively, as shown in FIG. 20, the device 1900' can have a separate supply line 1924' that extends through a portion of the cannister 1902' and supplies gas to the expandable member 1904' housed therein. Those skilled in the art will understand that the expandable members 1904, 1904' having a balloon configuration can be supplied with gas to inflate the expandable member by any of a variety of mechanisms.

[0077] The above-described embodiments have been described as diverting a portion of the gas from the gas source / supply to drive the movement of the piston or the expansion of the expandable member. However, those skilled in the art will understand that the above device may include one or more gas sources for supplying gas to both internal spaces, for driving the piston, and / or for expanding the expandable member. [[ID=##]] [[ID=##]]

[0078] [[ID=##]] It is obvious 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 present invention. For example, various other structures and techniques can be achieved to maintain a consistent output of the material from the dispensing device to the target site. Other embodiments of the present invention will be obvious to those skilled in the art who practice the invention disclosed herein in view of this specification. This specification and the examples are intended to be considered merely as illustrative, and the true scope and spirit of the present invention are indicated by the following claims.

Claims

1. A cannister extending longitudinally from a first end to a second end and defining an internal space for receiving a powder agent, An inlet connectable to a gas source for supplying gas to the internal space to fluidize the received powder agent to produce a fluidized mixture, An outlet through which the gas mixture is delivered to a target site for treatment, A tube extending from a first end communicating with the outlet into the internal space to a second end, the tube including slots extending through the wall of the tube, and the gas mixture passing through the second end and the slots to pass from the internal space to the outlet, A door movably attached to the tube to move over the slots to control the size of the slots opening into the internal space of the cannister An apparatus for fluidizing and delivering a powder agent comprising the same.

2. The apparatus according to claim 1, wherein the door is an overtube movably attached onto the tube.

3. The apparatus according to claim 2, further comprising a stabilizing ring extending radially outward from the overtube to the inner surface of the cannister to fix the tube to the cannister.

4. The apparatus according to any one of claims 2 and 3, wherein the cannister is rotatable relative to the tube, and the overtube is moved longitudinally relative to the tube to control the size of the slots facing the internal space.

5. The apparatus according to any one of claims 1 to 4, further comprising a lid connectable to the cannister to surround the internal space, and the inlet and the outlet are configured as openings extending through the lid.

6. The apparatus according to any one of claims 1 to 5, further including a delivery catheter connectable to the outlet, the delivery catheter being sized and shaped to be inserted through a working channel of an endoscope to a target site.

7. A cannister extending longitudinally from a first end to a second end and including a first internal space for receiving a powder agent therein, A first inlet connectable to a gas source for supplying gas to the first internal space to fluidize the received powder agent therein to produce a fluidized mixture, An outlet for delivering the gas mixture from the first internal space to a target site for treatment A device for fluidizing and delivering a powder agent, comprising a filler chamber that communicates with the first internal space through an inlet of the filler and that accommodates a filler that can pass from the filler chamber to the first internal space in order to maintain a constant amount of the internal material, the filler including at least one of the powder agent and the filler.

8. The device according to claim 7, wherein the filler includes one of simulated particles, beads, bounce balls, and foaming materials.

9. The device according to claim 7 or 8, wherein the filler is formed in a size, shape, and configuration such that the filler cannot pass through the outlet.

10. The device according to any one of claims 7 to 9, wherein a gas for driving the filler from the filler chamber to the first internal space is supplied to the filler chamber.

11. The device according to any one of claims 7 to 10, wherein the filler chamber is configured as a second internal space defined by the canister.

12. The device according to claim 11, wherein the second internal space includes a surface angled to direct the filler toward the inlet of the filler.

13. The device according to any one of claims 7 and 10 to 12, wherein the filler is an additional powder agent.

14. The device according to any one of claims 7 to 13, further comprising a door movable relative to the inlet of the filler between a first configuration that covers the inlet of the filler and a second configuration that opens the inlet of the filler to allow the filler to pass by gravity from the filler chamber to the first internal space.

15. The device according to any one of claims 7 to 13, further comprising a turbine connected to a paddle housed in the inlet of the filler, the turbine being driven by a gas flow and rotating when the gas flow is received in a flow path housing the turbine, and correspondingly rotating the paddle, and the filler in the filler chamber being actively driven from the filler chamber into the first internal space.

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