Delivery devices and methods for surgical substances

Abstract

To provide systems and methods for delivering substances, such as clotting agents, to a surgical site.SOLUTION: A clotting agent delivery system comprises a frame, a passageway extending along the frame, a discharge opening connected to the passageway, a clotting agent reservoir fluidly connected to the passageway to hold a clotting agent substance, a valve in the passageway to control flow of the substance through the passageway, and an actuator to allow a propellant to flow into the passageway. The valve and the clotting agent reservoir cooperate to provide clotting agent substance to the discharge opening at a constant pressure using the propellant. A method for delivering a clotting agent comprises the steps of: inserting a delivery catheter into an anatomic area; coupling a clotting agent delivery system to the delivery catheter, the clotting agent delivery system having a reservoir of a clotting agent; operating a valve to release the propellant for propelling the clotting agent; and conveying the propellant and the clotting agent to the delivery catheter at the constant pressure.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 269,069, filed March 9, 2022, and U.S. Provisional Patent Application No. 63 / 262,850, filed October 21, 2021, the contents of which are incorporated herein in their entireties.

[0002] FIELD OF THE DISCLOSURE This disclosure relates generally, but not by way of limitation, to surgical systems and methods for preparing an anatomical site for surgery. More particularly, but not by way of limitation, the present application relates to systems and methods for delivering drugs, such as clotting agents, to a surgical site. [Background technology]

[0003] Many surgical procedures involve the treatment or removal of target tissues located inside a patient, such as diseased, potentially diseased, or possibly undesirable tissues. Some of these procedures therefore require access to the patient's internal anatomy, either through open surgery or through smaller incisions in minimally invasive (e.g., laparoscopic) procedures. In some endoscopic procedures, the patient's anatomy is accessed through the mouth or anus. In some urological, gynecological, and ear, nose, and throat (ENT) procedures, for example, any other natural orifice may be used to reach internal cavities or ducts within the patient, such as the gastrointestinal (GI) tract, without opening or incising the patient. These endoscopic procedures can be called endolumenal procedures, because they are performed inside tubes, ducts, or hollow organs in the body. Some endoscopic procedures involve removing tissue from tissue walls that form ducts or cavities. As such, it may be desirable in these and other applications to administer a clotting agent, such as a hemostatic powder, to improve the surgeon's visibility within the surgical site and to limit or stop bleeding to promote healing of the patient. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 5,284,299 [Patent Document 2] U.S. Pat. No. 3,633,828 [Patent Document 3] U.S. Pat. No. 4,546,905 [Non-patent literature]

[0005] [Non-Patent Document 1] Khoshmohabat, Hadi et al., “Overview of Agents Used for Emergency Hemostasis,” Trauma monthly vol. 21,1 e26023. 6, February 2016, doi:10.5812 / traumamon.26023 Summary of the Invention [Means for solving the problem]

[0006] The inventors have recognized that, among other things, problems to be solved in hemostatic agent delivery devices include the difficulty in providing an easy-to-use system that provides a user-friendly experience. For example, some hemostatic agent materials include liquids that are delivered using a difficult to use, manually operated syringe. Some hemostatic agent powder delivery systems operate using a pump that is installed in the hospital or facility where the surgery is performed. However, such pumps require a large upfront cost by the surgery provider. Some hemostatic agent delivery systems require the use of pressurized air or CO2 provided by the facility. 2The hemostat powder delivery devices operate using a pressure limiting valve. However, the pressures at which these gases operate can vary based on building conditions, such as how much gas other functions of the facility are using at the time of surgery. In addition, other handheld hemostat powder delivery devices utilize compressed gas cartridges that provide pressurized gas over a wide range of pressures. For example, the cartridge may be initially supplied with a high pressure that gradually decays as the propellant in the cartridge is depleted. The initial high pressure can often be too high, resulting in excessive spraying of the hemostat powder into areas not intended to be reached, such as bleeding or anatomy away from the area being used in the surgery, thereby potentially obstructing the lens and the lumen of the area. In addition, the inventors have recognized that even with the use of a pressure limiting valve, the performance of compressed gas canisters still decreases over time, resulting in an inconsistent user experience.

[0007] In summary, there are two major problems with using pressurized gas cartridges for delivery of coagulants such as hemostatic powder: 1) the initial pressure can be too high, causing the powder to fill the lumen of the anatomy and disperse into the air, obstructing the lens and resulting in loss of vision (what physicians call "whiteout"); and 2) the powder can land in places it is not intended to land, such as the endoscope or areas of the intestine that do not require treatment. The inventors have recognized that as the pressure in the propellant cartridge decreases, the physician has better control and can direct the hemostatic agent to the proper areas, but that a continually decreasing pressure can adversely affect a consistent user experience. Thus, the inventors have recognized that it is desirable for a hemostatic agent delivery device to provide consistent pressure over time to enable delivery at the proper level in a predictable manner.

[0008] The present subject matter can provide solutions to these and other problems, such as by providing a surgical drug delivery device, such as a hemostatic agent powder delivery device, that provides a cost-effective, user-friendly experience. In particular, the present subject matter provides a hemostatic agent delivery system that can deliver hemostatic agent material, such as a powder, via pressurized gas at a constant or near-constant pressure, thereby eliminating or reducing the "white-out" effect and reducing instances of powder depositing in unintended or undesirable locations. The delivery pressure can be set at a level that is lower than where white-out conditions would occur and that allows the propellant cartridge to deliver a consistent dispense over the extended period of time that the user intends the drug to be delivered.

[0009] An exemplary solution of the present disclosure includes a disposable, one-piece package that delivers hemostatic powder at a constant or near-constant flow rate. The present disclosure provides a low-cost method to automatically maintain gas pressure within the handle. For example, a constant flow valve may be used. The constant flow valve may include a spring-loaded diaphragm that allows for a constant outlet volume regardless of the pressure of the incoming flow. An optional adjustment screw may be added to allow the user to adjust the outlet pressure.

[0010] In one example, the coagulant delivery system can include a frame, a passage extending at least partially along the frame, a discharge opening connected to the passage, a coagulant reservoir fluidly connected to the passage for holding a volume of the coagulant drug, a valve disposed within the passage for controlling the flow of the coagulant drug through the passage, and an actuator for selectively allowing propellant to flow into the passage, wherein the valve and the coagulant reservoir cooperate to supply the coagulant drug to the discharge opening at a constant pressure using the propellant.

[0011] In an additional example, a method for delivering a coagulant may include inserting a delivery catheter into a tissue region; coupling a coagulant delivery system to the delivery catheter, the coagulant delivery system having a reservoir of coagulant; operating a valve to release a propellant to push the coagulant; and delivering the propellant and coagulant to the delivery catheter at a constant pressure.

[0012] This Abstract is intended to provide a summary of the subject matter of this patent application. It is not intended to provide an exclusive or comprehensive description of the invention. The Detailed Description is included to provide further information about this patent application. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of a drug delivery device configured to deliver hemostat powder with consistent pressure. [Diagram 2] FIG. 2 is a schematic diagram of a container for storing a drug to be dispensed by the drug delivery device of FIG. 1. [Diagram 3] 2 is a cross-sectional view of a constant flow valve suitable for use with the drug delivery device of FIG. 1. [Figure 4A] 2 is a cross-sectional view of an ejection nozzle mechanism and a trigger mechanism suitable for use with the drug delivery device of FIG. 1. [Figure 4B] FIG. 4B is an enlarged cross-sectional view of the valve needle and valve seat of the exhaust nozzle mechanism of FIG. 4A. [Diagram 5] FIG. 2 is a schematic diagram of a pressurized material container suitable for use with the drug delivery device of FIG. 1. [Figure 6A] 1 is a cross-sectional view of a constant pressure flow control device of the present application including an inflatable bladder shown in an inflated state. [Figure 6B] 6B is a cross-sectional view of the constant pressure flow control device of FIG. 6A with an inflatable bladder shown in a deflated state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In the figures, which are not necessarily drawn to scale, like numerals may describe like components in different figures. Like numerals with different letter suffixes may represent different instances of the like components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0015] 1 is a schematic diagram of a drug delivery device 10 configured to deliver a hemostatic agent powder at a consistent pressure. Drug delivery device 10 can include a frame 12, a pressure control valve 14, a flow valve 15, an actuator 16, a propellant cartridge 18, a drug reservoir 20, a fluid passageway 22, a cartridge socket 24, and an operator control 26. Frame 12 can include a dispensing portion 28, a handle 30, a guard 32, a cartridge reservoir 34, a reservoir socket 36, and an injection coupler 38.

[0016] The drug delivery device 10 can be configured to deliver a clotting agent, such as a hemostat powder, as well as other drugs, at a controlled and consistent pressure. The clotting agent can include one or more granules of materials such as zeolite, chitosan, and starch-based materials. Commercially available clotting agent powders can be utilized with the drug delivery device 10. In an example, the drug delivery device 10 can deliver the hemostat powder at a constant pressure. In an example, the drug delivery device 10 can include a disposable device contained as a single handheld unit.

[0017] The drug delivery device 10 may include a frame 12 having a handle 30 and a dispensing portion 28. From an ergonomic standpoint, the handle 30 and the dispensing portion 28 may be arranged in a pistol-like configuration. The actuator 16 may be configured as a trigger and may extend from the dispensing portion 28 proximate the handle 30. The actuator 16 may be bounded in part by a guard 32 extending from the dispensing portion 28 to the handle 30 to prevent accidental or unintended activation of the actuator 16.

[0018] The passageway 22 may extend through or be attached to one or both portions of the dispensing portion 28 and the handle 30 to fluidly connect the propellant cartridge 18 with the injection coupler 38. In examples, the passageway 22 may include one or more lengths of tubing, conduit, piping, etc. In examples, the passageway 22 may include a tunnel or hole extending through the material of the dispensing portion 28 and the handle 30.

[0019] The first portion 22A of the passage 22 may extend from a socket 24 for the cartridge 18 to the valve 15. The first portion 22A, such as a first end of the passage 22, may include a socket 24 that allows for fluid coupling between the propellant cartridge 18 and the passage 22. The socket 24 may sealably engage the propellant cartridge 18 such that propellant within the propellant cartridge 18 may enter the passage 22 without leakage. In an example, the socket 24 may include a threaded coupler.

[0020] A second portion 22B of the passageway 22 may extend from valve 15 to valve 14. The second portion 22B of the passageway 22 may fluidly connect valve 15 and valve 14 in any suitable manner.

[0021] A third portion 22C of the passageway 22 may extend from the valve 14 to the drug reservoir 20. The third portion 22C of the passageway 22 may fluidly connect the valve 14 and the drug reservoir 20 in any suitable manner.

[0022] The fourth portion 22D, such as the second end of the passageway 22, can include a coupler 38 that allows for a fluid connection between the passageway 22 and a delivery device 40. In an example, the coupler 38 can include a threaded coupler or a barbed hose fitting. The fourth portion 22D of the passageway 22 can extend from the drug reservoir 20 to an infusion coupler 38 for a delivery device 40, such as a catheter, a tube, or another instrument or component, for guiding the drug in the drug reservoir 20 to the patient's anatomy. In an example, the delivery device 40 can be configured for use in an endoluminal procedure. In an endoluminal procedure and otherwise, the delivery device 40 can include a catheter that can be inserted into a working channel of an endoscope having one or more of imaging, illumination, irrigating, steering, and navigation capabilities, as well as other features known in the art. Endoluminal procedures can involve accessing a patient's anatomy through the mouth or anus, as well as any natural orifice such as may be used in urological, gynecological, and ear, nose and throat (ENT) procedures, without creating an open abdomen or incision in the patient to reach an internal cavity or duct within the patient, such as the gastrointestinal (GI) tract. These endoscopic procedures can be referred to as luminal endoscopic procedures because they are performed inside a tube, duct, or hollow organ in the body. Some endoluminal procedures can involve removing tissue from tissue walls that form a duct or cavity and can benefit from the application of a coagulant. Examples of procedures that can be performed using the present disclosure include polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD), used to remove tissue in the gastrointestinal (GI) tract, as well as full thickness rectal resection (FTR) and endoscopic ultrasound (EUS) drainage using a stent.

[0023] The valve 15 may be located in or connect different portions of the passageway 22. As described herein, the valve 15 may be operated to allow the propellant in the propellant cartridge 18 to flow to the valve 14 and ultimately to the drug reservoir 20. The valve 15 may supply propellant from the propellant cartridge 18 to the valve 14, for example, at the pressure at which the propellant cartridge 18 supplies the propellant. The valve 15 may include an on-off valve that operates in two states, open and closed. The valve 15 may be operated via an actuator 16, which may include a trigger or button. In an example, the actuator 16 may simply actuate the valve 15 between an open position and a closed position. The valve 15 may act as a port for propellant from the propellant cartridge 18 that may be opened by a user when desired. The actuator 16 may be connected to the valve 15 via a suitable linkage to allow a user to selectively open and close the valve 15 to dispense a drug from the drug reservoir 20 using the propellant. In an example, additionally or alternatively, the actuator 16 may operate an injection nozzle for the drug delivery device 10, for example as described with respect to Figures 4A and 4B, to allow a user to control the volumetric flow rate of the drug.

[0024] The valve 14 may include a pressure control valve or another device capable of both 1) limiting the maximum pressure delivered to the drug reservoir and 2) maintaining the pressure delivered from the propellant cartridge 18 at a steady level. In an example, the valve 14 may include a constant pressure device, where the variable pressure propellant entering the valve 14 may be discharged at a constant or near constant pressure. The valve 14 may include a gas regulator constructed as described with respect to FIG. 3. In an example, the valve 14 does not impede, e.g., block, the flow of propellant from the valve 15, but allows the propellant to proceed from the valve 14 at a regulated pressure. In an additional example, the valve 14 may include an electronically controlled valve, as described in more detail with respect to FIG. 2. In an example, the valve 14 may include an inflatable balloon or bladder, as described with respect to FIGS. 6A and 6B. Actively or electronically controlled valves and inflatable balloons and bladders may act as a variable constriction to control the back pressure in the passageway 22. An operator control 26 may be connected to the valve 14 and adjusted to control the volume or pressure of propellant entering the drug reservoir 20. In an example, the operator control 26 may be omitted and the valve 14 may be set to provide a single pressure output.

[0025] The drug reservoir 20 may be connected to the fluid passageway 22 at the container socket 36 via the inlet 42. The drug reservoir 20 may include a canister or container configured to hold a drug or material to be dispensed by the drug delivery device 10. In an example, the drug or material may include solid granules or liquid, or solid granules suspended in a liquid. In an example, the drug reservoir 20 may hold a hemostatic powder or another clotting agent. The container socket 36 may provide a connection point for the drug reservoir 20 that allows the propellant to enter the drug reservoir 20 and the drug in the drug reservoir 20 to enter the passageway 22. In an example, the inlet 42 may be configured to receive propellant from the propellant cartridge 18 at the third portion 22C and to supply the drug in the drug reservoir 20 to the fourth portion 22D, as described herein. In an example, the propellant may be used to move or push the drug in the drug reservoir 20 forward. In an example, the propellant in the passageway 22 can collect the drug from the drug reservoir 20 via Bernoulli's action. In an example, the drug reservoir 20 can be directly pressurized with a pressurized propellant, such as an aerosol, as described in more detail with respect to FIG.

[0026] In an example, the propellant cartridge 18 may include a compressed gas cartridge. The propellant cartridge 18 may be removable from the frame 12 to allow a user to replace the propellant cartridge 18 with another propellant cartridge after the propellant is depleted. In an example of the drug delivery device 10 configured to be disposable, the propellant cartridge 18 may be hidden and locked in the frame 12 to prevent a user from easily accessing the propellant cartridge 18. However, the propellant cartridge 18 may be accessible in the handle 30 via a removable panel or the like to allow a user to easily replace the propellant cartridge 18. The passage 22 may fluidly couple the propellant cartridge 18 to the valve 14. In an example, the flow of propellant from the cartridge 18 is not regulated by the propellant cartridge 18, such that the flow of propellant from the cartridge 18 at an initially high, maximum pressure gradually decreases to a low or minimum pressure while the valve 15 is open, and eventually drops to zero pressure or atmospheric pressure as the propellant is depleted. As described herein, the drug delivery device 10 can be configured to control the pressure from the propellant cartridge 18 to deliver a constant volume or pressure of propellant to the drug reservoir 20, thereby delivering the drug at a suitable pressure level that avoids white-out conditions and at one or more levels of constant pressure that allows the user to direct pressure to the target anatomy in a predictable manner.

[0027] The valve 14 can control the transfer of propellant from the propellant cartridge 18 to the drug reservoir 20 when the valve 15 is open. An operator control 26 can be connected to the valve 14 to allow a user to control the discharge pressure of the valve 14. In an example, the valve 14 can be automatically actuated by the pressure in the drug delivery device 10 relative to the ambient pressure. The valve 14 can be configured to maintain the pressure of the propellant supplied to the drug reservoir 20 at a constant or near constant pressure. A pressure regulating valve suitable for use in the drug delivery device 10 of FIG. 1 can include any known valve capable of receiving gas at different inlet pressures and discharging gas at a constant pressure. The pressure control valve 14 can include a gas pressure regulator. An example of a gas pressure regulator is used to regulate gas or propane in the plumbing of a residence, taking varying pressures from a tank or plumbing entering the house and providing a constant pressure to the household appliance to which the gas pressure regulator is directed. Thus, the valve 14 can be configured to receive varying pressures of gas from the propellant cartridge 18 and discharging a constant pressure of propellant.

[0028] In an example, unregulated pressurized gas or propellant may enter the valve 14 at a variable supply pressure, provided by a propellant cartridge 18. As described in more detail with respect to FIG. 3, the supply pressure may be contained in a first chamber (e.g., at surface 104 in FIG. 3) having an outlet flow controlled by a pressure control valve 14 that may be connected to a spring (e.g., spring 122 in FIG. 3) that may adjust the outlet pressure. The pressurized gas may leave the first chamber and pass through the pressure control valve 14 to a second chamber (e.g., chamber 98 in FIG. 3). The second chamber may have a gas outlet for flowing into the drug reservoir 20. The pressure of the gas in the second chamber may be adjusted by the spring to a desired constant outlet pressure. In an example, a user may adjust the tension of the spring to adjust the constant outlet pressure, for example, by adjusting the operator control 26.

[0029] 2 is a schematic diagram of a drug reservoir 20 for storing a material to be dispensed by the drug delivery device 10 of FIG. 1. The drug reservoir 20 may include an inlet 42, a canister 44, a pressure sensor 46, and a valve 48. The inlet 42 may include a propellant outlet port 50 and a drug outlet port 52. The propellant outlet port 50 may be connected to a third portion 22C of the passageway 22. The drug outlet port 52 may be connected to a fourth portion 22D of the passageway 22. The drug outlet port 52 may include an inlet 54 for receiving the drug 56 into the canister 44. The pressure sensor 46 may be connected to a controller 58. The valve 48 may include an outlet 60. In an example, a coagulant suitable for use as the drug 56 is described in "Cellular Drug Delivery Devices for Hemostatic Agents," Journal of Hemostatics, vol. 14, no. 1, 2003, pp. 1171-1175. In an example, the drug 56 may include a commercially available hemostatic agent.

[0030] The canister 44 may include any suitable container for holding the hemostatic powder and other medications. The canister 44 may be manufactured from glass, plastic, or metal. The canister 44 may be clear or transparent so that the amount of medication in the canister 44 can be viewed. The canister may include hash marks, graduations, or graduated markings to provide an indication of the level of medication in the canister 44. The canister 44 may be attached to the frame 12 (FIG. 1) in any suitable manner. In an example, the canister 44 may be threaded to engage the frame 12. In an example, the top end of the canister 44 may be open to allow medication to be filled or added to the canister 44, and the opening is sealed closed when engaged with the frame 12. In an additional example, the canister 44 may be enclosed except for a sealed container into which the inlet 42 may be inserted.

[0031] The inlet 42 can connect the interior of the canister 44 to the passageway 22. In the illustrated example, the inlet 42 can include an exhaust port 50 that connects to the third portion 22C and an exhaust port 52 that connects to the fourth portion 22D. Thus, in the example, the third portion 22C and the fourth portion 22D can be fluidly separated by the canister 44. The third portion 22C can supply pressurized propellant to the exhaust port 50 at a pressure level determined by the valve 14. The exhaust port 50 can supply propellant to a head space in the canister 44 above the drug 56, thereby pushing the drug 56 downward (relative to the orientation of FIG. 2). The pressurized drug 56 can be pressurized to the same pressure as the propellant. The pressurized drug 56 can be forced into the inlet 54 of the exhaust port 52. The inlet 54 can be bent or oriented to facilitate the pressurized drug 56 being forced into the exhaust port 52. Pressurized drug 56 may enter exit port 56, pass into fourth portion 22D of passageway 22, and exit drug delivery device 10 into catheter 40 (FIG. 1).

[0032] In the example of drug reservoir 20, exit ports 50 and 52 may be replaced with openings and third portion 22C may be directly linked to fourth portion 22D. Thus, drug 56 may be configured to be drawn into the propellant flow in passageway 22 via the Bernoulli effect.

[0033] The pressure within the canister 44 may be controlled by the pressure of the propellant flowing into the canister 44, as described, at a pressure determined by the valve 14, for example. Additionally or alternatively, the pressure within the canister 44 may be controlled using one or both of the pressure sensor 46 and the valve 48. The pressure sensor 46 may be configured to sense the pressure within the canister 44. The pressure sensor 46 may be located toward the bottom end of the canister 44, such as within the drug 56, as shown. Alternatively, the pressure sensor 46 may be provided in the headspace of the canister 44 above the drug 56. In additional examples, multiple pressure sensors may be used, for example, in and above the drug 56. In various configurations, the pressure sensor 46 may obtain a pressure measurement indication of the pressure within the canister 44 and provide the indication to the controller 58. The controller 58 may be electronically connected to the valve 14 and the pressure sensor 46 of FIG. 1. In such examples, the valve 14 may include an electronically operated valve that may be opened or closed based on the output of the sensor 46. In an example, the valve 14 can include an on-off valve that can be pulse width modulated, e.g., the amount of time the valve 14 is open can be controlled in short bursts to control the pressure in the third portion 22C. In an example, the valve 14 can include a variable valve that can be opened differently (e.g., the flow area can be variable) in different portions to control the pressure in the third portion 22C. The length of time the valve 14 remains open or the amount the valve 14 is opened can be correlated with the pressure reading of the sensor 46 to maintain the pressure in the canister 44 at a desired pressure. The desired pressure can be set by the controller 58 below a level at which a whiteout condition occurs and at a level that allows the user to apply the hemostatic agent powder at a preferred rate or volume.

[0034] The valve 48 may include a relief or vent valve configured to vent the canister 44 at elevated pressure. In an example, the valve 48 may open at a pressure just before a whiteout condition occurs, before a whiteout condition may occur. In an example, the valve 48 may simply vent to the outside environment. The valve 48 may be automatically operated via spring pressure or may be electronically connected to the controller 58 to be actuated based on the output of the pressure sensor 46. In an example, the valve 48 may be connected to an outlet 60. The outlet 60 may include a conduit, such as tubing, that connects back to the portion 22C of the passage 22, thereby storing the propellant. In an example, the valve 48 may operate without the valve 14 or the sensor 46. Thus, the valve 48 may provide a simple method for avoiding a whiteout condition without actively controlling the pressure in the canister 44, such as with a control valve or an electronically regulated valve. However, the valve 48 may be used with any of the pressure controlling or regulating components described herein as a backup.

[0035] In various examples described herein, the drug delivery device 10 may be powered via an internal power source, including, for example, a battery, to power the controller 58, the pressure sensor 46, and the valve 48.

[0036] Figure 3 is a cross-sectional view of a valve 70 suitable for use with the drug delivery device 10 of Figure 1. Valve 70 may include an example of valve 14 (Figure 1). Valve 70 may be located in a housing 71 between passages 72 and 74. Housing 71 may include frame 12 (Figure 1), and passages 72 and 74 may include portions 22B and 22C, respectively, of passage 22 (Figure 1).

[0037] The valve 70 may include a controlled variable orifice that drops the high pressure of propellant received from the passage 72 to a predetermined constant pressure not exceeding a preset limit for delivery through the passage 74 to the coupler 38 (FIG. 1). A screw 76 on the valve 70 may allow a user of the drug delivery device 10 to adjust the preset pressure delivered to the passage 74. The screw 76 may include an example of an operator control 26. Once the adjustment screw 76 is set, a jam nut 78 may be tightened to prevent accidental changes in the set pressure. If desired, graduations may be marked on the screw 76 to indicate air pressures established by different settings of the screw 76. The valve 70 may maintain a set air pressure delivered to the passage 74 while the pressure in the passage 72 changes due to, for example, a fluctuating fill level in the propellant cartridge 18. In an example, the pressure provided by the propellant cartridge 18 (FIG. 1) may begin at about 800 pounds per square inch (psi) (-5.5 megapascals [MPa]) and the valve 70 may be adjusted to limit the pressure to within a range of about 600.0 psi (-4.1 MPa) and about 200.0 psi (-1.4 MPa).

[0038] The valve 70 may have a body 80 having external threads 82 for engaging threads on the opening 84 in the housing 71. O-rings 86A and 86B may form an airtight seal between the housing 71 and the valve body 80. A tapered valve seat 88 may be formed in a lower surface 90 of the valve body 80. The valve seat 88 is tapered to open toward the passageway 72. The valve needle 92 may have a conical portion 94 that seats on the valve seat 88. The valve needle 92 may have an end 96 that projects through the valve seat 88 into a chamber 98 in the valve body 80. The chamber 98 may connect through the valve body 80 to the passageway 74. A head 100 may be formed on an end of the valve needle 92 opposite the end 96. A biasing spring 102 may be compressed between the head 100 and a surface 104 in the housing 71. Both the spring 102 and the pressure of the propellant within the passage 72 may act on the valve needle 92 urging the valve needle 92 against the valve seat 88 to close the valve 70 .

[0039] The valve body 80 can have a female threaded opening 106. The cap 108 can have male threads configured to connect with the threads on the opening 106 to form a chamber 110. A vent 112 can be provided through the cap 108 to maintain the chamber 110 at atmospheric pressure. The screw 76 can be threaded through the cap 108 and extend into the chamber 110 where it terminates in an enlarged diameter head 114. A resilient diaphragm 116 can be clamped between the cap 108 and the valve body 80 to separate the chambers 110 and 98. At the center of the diaphragm 116, a diaphragm retainer 118 can be installed within the chamber 98. A fastener 120 can be installed within the chamber 110 and extend through the center of the diaphragm 116 to engage the retainer 118 and secure the retainer 118 to the diaphragm 116. The retainer 118 can have a central projection 123 that can abut against the end 96 of the valve needle. A pressure control spring 122 can be mounted in the chamber 110 and compressed between the head 114 on the adjustment screw 76 and the diaphragm 116 to urge the central projection 123 against the end 96 of the valve needle.

[0040] In operation, the pressure control spring 122 can exert a pressure on the valve needle 92 that is greater than the combined force of the needle bias spring 102 and the gas pressure in the passageway 72. As a result, the valve needle 92 can be moved away from the seat 88 to create a relatively large annular orifice. Gas can flow from the passageway 72 through the open orifice into the chamber 98. Gas entering the chamber 98 can flow through the passageway 74 to the drug reservoir 20. Initially, the valve needle 92 can be moved away from the seat 88 to create a relatively large annular orifice. As a result, gas pressure can increase in the chamber 98 and at the drug reservoir 20. As the gas pressure increases in the chamber 98, the gas pressure can act against the diaphragm 116. When the pressure on the diaphragm 116 is sufficient, the diaphragm 116 moves and, in response, the valve needle 92 can be moved by the spring 102 to reduce the size of the annular orifice. In response, the position of the valve needle 92 is automatically adjusted to maintain a constant pressure in the chamber 98, and therefore in the drug reservoir 20. Due to the pressure drop caused by the restricted size of the annular orifice, there may be a corresponding increase in volume for the lower pressure gas entering the chamber 98. As flow requirements in the drug reservoir 20 change, or as the supply pressure changes, the position of the valve needle 92 may be altered by the diaphragm 116 to maintain the pressure in the drug reservoir 20. Adjustment of the screw 76 may vary the force exerted on the diaphragm 116 by the spring 122, thereby adjusting the gas pressure in the chamber 98. The spring 122 may be selected to provide a maximum air pressure of about 600 psi (~4.1 MPa) in the chamber 98 when the screw 76 is set in the position shown, and a minimum air pressure, for example 200.0 psi (~1.4 MPa), in the chamber 98 when the screw 76 is set in the position shown in dashed lines 124. The spring 122 may be configured to maintain a selected pressure within + / - 5% to maintain a constant or near constant, but still consistent, pressure.

[0041] It will be noted that the design of the conical valve needle portion 94 and tapered valve seat 88 presents a relatively large diameter annular orifice when the valve needle 92 is displaced from the seat 88. This configuration may have at least two benefits. First, the annular orifice may be less susceptible to clogging by any debris within the passageway 22. Second, the large diameter allows for a relatively large gas flow through the valve 70 to provide a high volume of gas that is desirable for supplying a relatively large amount of nebulizing air to the medication reservoir 20.

[0042] In an example, the valve 70 may be constructed similarly to the valve described in US Pat. No. 6,399,323, the entirety of which is incorporated herein by reference.

[0043] Therefore, the valve 70 can be configured to limit the pressure at which the propellant can enter the drug reservoir 20 (FIG. 1) to avoid whiteout conditions. Furthermore, the propellant pressure can be maintained at a constant pressure throughout a significant portion of the life of the propellant cartridge 18 so that a user of the drug delivery device can have a consistent user experience. In other words, the total amount of propellant available by the propellant cartridge 18 is reduced and spread out, so that the propellant can be evenly distributed over a period of time before eventually decreasing as the propellant decreases, as opposed to immediately decreasing gradually from a very high initial pressure in the scenario of an unregulated propellant cartridge. Furthermore, a propellant cartridge that is controlled only to limit the maximum pressure, such as a pressure reducing valve, simply reduces the maximum pressure, but still results in an immediate and gradually decreasing pressure from the reduced pressure.

[0044] Figure 4A is a cross-sectional view of an ejection nozzle mechanism 130 suitable for use with the drug delivery device 10 of Figure 1, which may include a valve needle member 132 and a valve seat 134. The ejection nozzle mechanism 130 may further include a spray tip 161 that may be used to shape the drug exiting the valve seat 134. Figure 4B is an enlarged cross-sectional view of the valve needle member 132 and valve seat 134 of Figure 4A. Figures 4A and 4B will be described simultaneously.

[0045] The discharge nozzle mechanism 130 may be mounted at the front end of the frame 12 at the distal-most end of the dispensing portion 28. The spray tip 161, the seat member 166, the cylindrical member 168, and the tip body 169 may be attached to the dispensing portion 28 by an annular cap 175. Discharge of the pressurized drug in the fourth portion 22D of the passage 22 may be controlled by engagement of the valve needle member 132 and the valve seat 134 via the operation of the trigger 140. The valve needle member 132 and the valve seat 134 may operate together as a discharge valve that may control the flow rate of the propellant and the coagulant drug from the coagulant delivery system. The trigger 140 may be mounted to the dispensing portion 28 at a pivot point 142 and may be pivotally connected to a valve stem 179 at a pivot point 144. The valve stem 179 may be biased via a biasing element 146 to engage the valve seat 134. The discharge of the pressurized drug from the fourth portion 22D of the passageway 22 may be influenced by a spray tip 161, which may have a nozzle opening 160 that controls the shape of the drug as it leaves the drug delivery device 10. The trigger 140 may be actuated by a user. The trigger 140 may be connected to the flow valve 15 to control both the flow valve 15 and the discharge nozzle mechanism 130 simultaneously. A further trigger 140 may be stored in an open position and a larger volume of drug may be dispensed at a pressure determined by the valve 14. In other examples, the trigger 140 may be used to control only the discharge nozzle mechanism 130 and a separate user control may be provided for the valve 15.

[0046] The spray tip 161 may include a nozzle opening 160 and a pre-nozzle chamber 162. The nozzle opening 160 may be elongated in the direction of the axis CA and may penetrate the surface of the front or distal end of the spray tip 161. The spray tip 161 may communicate with the pre-nozzle chamber 162. The chamber 162 may have a proximal end with a cross-sectional area significantly larger than the nozzle opening 160 and a tapered side surface 164 that converges toward the nozzle opening 160 to funnel the drug and propellant flowing through the valve assembly 165 to the nozzle opening 160 through a constriction. The rear or proximal end of the spray tip 161 may abut a seat member 166 and a portion of a cylindrical member 168 with a seal gasket 170 located therebetween, all of which may be tightly secured by a tip body 169. The tip body 169 may be held securely by an annular cap 175 having internal threads that cooperate with the external threads of the dispensing portion 28, and a flange portion 189 engages a shoulder portion 171 of the tip body 169. The annular cap 175, and thus the spray tip 161, may be easily removed when it is desired to change to a spray tip having a different size nozzle opening 160 than the spray tip 161, for example to change the discharge pattern. In general, the cylindrical member 168 may be located immediately behind the spray tip 161 and may have its front end abutting the spray tip 161, with a gasket 170 located therebetween. The rear end of the external threads of the cylindrical member 168 may be received in the dispensing portion 28. The inner surface of the cylindrical member 168 may form an axial cavity 176 that may form an extension of the fourth portion 22D.

[0047] The valve assembly 165 may include a seat member 166 that is held about its periphery in coaxial relationship with the nozzle opening 160 by a portion of the inner surface of a cylindrical member 168. A tapered coaxial valve port 194 may be contained within the seat member 166, and a needle or cone member 178 may be carried by the forward end of an axially extending valve stem 179. The member 178 may have tapered sides 196 that converge toward the nozzle opening 160 and terminate at the front end 199 in one direction and at a point where the tapered sides 196 (FIG. 4B) intersect the outer surface of the valve stem 179 in the other direction. The front end 199 of the needle member 132 is terminated to form a substantially flat surface rather than converging to a point. As can be seen in FIG. 4B, the front end 199 can extend slightly past the front end 167 of the seat member 166 when the needle member 132 is in the closed position and can extend behind the front end 167 when the needle member 132 is in the open position. The length of the needle member 132 from the blocking point 195 to the front end 199 can vary, but it can be long enough to form the drug being discharged into an annular cone-shaped seat. The valve stem 179 can be guided by engaging with the actuator 16, which in the illustrated example of FIG. 4A includes a trigger 140. The trigger 140 can control the movement of the valve stem 179 as described herein.

[0048] The valve assembly 165 may be positioned such that when the trigger 140 is in the forward position (to the left in FIG. 4A ), the needle member 132 may contact a blocking point 195 of the seat member 166. This may create a closed position for the needle member 132, thereby preventing the drug in the axial cavity 176 from flowing under pressure through the valve port 194. When the trigger 140 is moved rearward (to the right in FIG. 4A ) to the retracted position, the valve stem 179 and needle member 132 are likewise moved rearward to create an open position, shown by dotted lines 172 in FIG. 4B , thereby allowing the drug to flow at high velocity under high pressure from the axial cavity 176 through the conical passage 150 between the seat member 166 and the needle member 132 and through the nozzle opening 160, causing the drug to be atomized and sprayed onto the surface to be coated.

[0049] The valve port 194 shown in FIG. 4B includes a tapered seating surface 190, a tapered inlet surface 192, and a blocking point 195 located at the intersection of the surfaces 190 and 192. The surfaces 190 and 192 may further form two valve port portions, each having a shape similar to a truncated cone. As shown, the seating surface 190 may converge toward the nozzle opening 160 with a protruding extension that converges to a point that may form a seating angle 191. In an example, the seating angle 191 may facilitate generating a desired spray pattern and may have a value in the range of about 9° to about 20°. Similarly, in an example, the protruding extension of the inlet surface 192 may converge to form an inlet angle that may be significantly greater than the seating angle 191. The drug delivery device 10 may operate without the inlet surface 192. However, the presence of surface 192 can improve the efficiency of drug delivery device 10 by directing the high pressure drug in axial cavity 176 (FIG. 4A) to annular conical passage 150 (FIG. 4B) and by allowing better flow control at cut-off point 195.

[0050] As shown in FIG. 4B, the tapered side 196 of the needle member 132, when extended, can converge in the direction of the nozzle opening 160 to form a needle angle 198, which can be in the range of about 10° to about 30°, by way of example. The value of the needle angle 198 in FIG. 4B, as compared to the seat angle 191, is important in that the two angles are generally not equal to allow shaping of the drug flow between the axial cavity 176 (FIG. 4A) and the pre-nozzle chamber 162, and to prevent sticking of the needle member 132 when the needle member 132 is in a closed position. In addition, a larger needle angle allows the cross-sectional area of ​​the annular conical passage 150, located between the sealing surface 190 and the tapered side 196, to remain relatively constant along its length when the valve assembly 165 is in a selected open position. Thus, the drug flowing through the passage 150 can be maintained at a relatively constant rate even though the outer diameter of the annular conical passage 150 is decreasing in the direction of the nozzle opening 160.

[0051] In FIG. 4B, the distance D is shown to be the distance between the nozzle opening 160 and the blocking point 195. The relationship between the distance D and the needle angle 198 facilitates the creation of a spray pattern for spraying the drug. The protruding extension of the tapered side 196 can converge to or near a point at the nozzle opening 160 when the needle member 132 is in its closed position as shown in FIG. 4B. This relationship can allow the drug under high pressure in the axial cavity 176 to be accelerated through the annular opening 163 between the tapered side 196 and the blocking point 195 and pass through the annular conical passage 150 so that the drug is formed into a thin annular conical sheet that impinges on the nozzle opening 160. This impingement, in combination with the increased surface area of ​​the annular conical passage 150, can create a desired phenomenon at the nozzle opening 160 to generate a spray with a uniform spray pattern. In addition, the adjustable valve assembly 165 can allow the drug to pass through the annular opening 163 and be accelerated to a velocity where it passes through the nozzle opening 160. The length of the annular conical passage 150 between the blocking point 195 and the front end of the seat member 166 can also be long enough to form the drug into a thin hollow conical seat. A length of at least twice the diameter of the orifice opening can be sufficient.

[0052] The annular opening 163 can extend completely around the needle member 132. As the drug flows through the opening 163, some portions of the drug can intersect with other portions such that the impact force of each portion is evenly balanced by the impact force of one or more other portions. In an example, at least two portions of the drug can converge to intersect at the nozzle opening 160.

[0053] In an example, the exhaust nozzle mechanism 130 may be constructed similarly to the valve assembly and injection tip described in US Pat. No. 6,399,323, which is incorporated herein by reference in its entirety.

[0054] The ejection nozzle mechanism 130 of the present disclosure may be configured to allow a user to selectively control the volume of drug ejected from the drug delivery device 10. Thus, the valve 15 may be used to control the on-off flow of drug, the valve 14 may be used to control the pressure of the flowing drug, and the ejection nozzle mechanism 130 may be used to control the volume of the flowing drug. The valve 14 may control the pressure as described herein, such that the user has a consistent and repeatable trigger 16 pull experience where 1) the same volume of drug ejects at the start of the trigger pull each time the trigger 16 is pulled, and 2) the same volume of drug ejects at the end of the trigger pull each time the trigger 16 is pulled, with steadily increasing amounts ejecting at the start all the way through to the end of the trigger pull.

[0055] 5 is a schematic diagram of a pressurized material container 200 suitable for use with the drug delivery device 10 of FIG. 1, as well as other drug delivery devices described herein. The pressurized material container 200 may include a self-pressurized container, in which the propellant and drug to be ejected are contained within a single container. Thus, the pressurized material container 200 may replace both the propellant cartridge 18 and the drug reservoir 20 of FIG. 1.

[0056] The pressurized material container 200 may include a two-phase aerosol system including a container 202, a bottom 204, a collar 206, and a top 208. A valve member 210 may fit into the top 208. The contents of the container 202 may be divided into two phases, an upper phase I and a lower phase II. Phase II may consist of a liquid phase containing the drug to be dispensed. Phase II may be a propellant that is a vapor under super-atmospheric pressure, in which the drug to be dispensed is dissolved or mixed. Phase I may then be vaporized by the propellant. Meanwhile, phase I may be a CO 2and phase II may be a liquid with a liquid drug or product dissolved therein. The valve member 210 may typically include a hollow shaft 212 that seats in a gasket 214 via a spring 216. The hollow shaft 212 and gasket 214 may engage to form a valve 217. The valve body 218 may surround the valve stem 212 having a tail 215 to which a dip tube 220 may be attached. The dip tube 220 may be open at a lower end 221.

[0057] The valve stem 212 can have an actuator or head 222 mounted thereon with a passageway 224 passing through the head. The head 222 can be pressed by an actuator 226, which can move the hollow shaft 212 downward and open into the interior cavity 228 of the valve body 218. Because the vapor phase I is under superatmospheric pressure, the phase II drug can be forced into the end 221 of the dip tube 220 and into the passageway 224 as the expanding vapor of phase I attempts to escape the container 202 when the valve 217 is opened to atmospheric pressure. The phase II liquid can vaporize and leave the head orifice 230 as a spray. The volume of phase I vapor can be sufficient to dispense all or substantially all of the phase II liquid at the same or similar pressure, such that the user receives a consistent output each time the head 222 is pressed by the actuator 226. Thus, the pressurized material container 200 can be configured to reduce or eliminate whiteout conditions. Actuator 226 may be directly coupled to a user control, such as actuator 16 (FIG. 1), or may be connected to an electronically controlled actuator that may be operated by a controller, such as controller 58 (FIG. 2).

[0058] In an example, the pressurized material vessel 200 may be constructed similarly to the pressurized container described in US Pat. No. 6,399,323, which is incorporated herein by reference in its entirety.

[0059] 6A is a cross-sectional view of the constant pressure flow controller 300 of the present application including an inflatable bladder 302 in an inflated state. FIG. 6B is a cross-sectional view of the constant pressure flow controller 300 of the present application with an inflatable bladder 302 in a deflated state.

[0060] The constant pressure flow controller 300 may be used with a drug delivery device 304, which may include a frame 306, a passageway 308, a propellant cartridge 310, a drug reservoir 312, a valve 314, an actuator 316, an inflation conduit 318, a coupler 320, and a delivery device 322. The constant pressure flow controller 300 may include similar components to the drug delivery device 10 of FIG. 1. For example, the frame 306 may be configured similar to the frame 12, the passageway 308 may extend through the frame 306 similar to the passageway 222, the coupler 320 may connect to a delivery device similar to the coupler 38 and device 40, the drug reservoir 312 may be similar to the drug reservoir 20, and the propellant cartridge 310 may connect to the frame 306 similar to the propellant cartridge 18.

[0061] The propellant cartridge 310 may be attached to the frame 306 in any suitable manner. The propellant cartridge 310 may supply pressurized gas or another propellant to a manifold 324. The manifold 324 may be a chamber created within the frame 306. The manifold 324 may supply propellant to the passage 308 and the expansion conduit 318. A valve 314 may be installed on the passage 308 to selectively impede the flow of propellant through the passage 308 via the operation of an actuator 316. The manifold 324 may supply propellant to the passage 308 and the conduit 318 at the same pressure. The passage 308 may be aligned with tubing 326 that may extend into a chamber 328 within the frame 306. The chamber 328 may be aligned with a flexible tubing 330. The coupler 320 may include a tube fluidly coupled to the flexible tubing 330. The tubing 326, the flexible tubing 330, and the coupler 320 may be fluidly connected to supply the propellant from the manifold 324 to the delivery device 322 with zero or minimal leakage.

[0062] The flexible tubing 330 and the bladder 302 may be made of a material, such as rubber, that is stretchable and capable of preventing the penetration of gas. Propellant from the propellant cartridge 310 may be supplied to the bladder 302 via the inflation conduit 318. When the bladder 302 is deflated or minimally inflated, it does not intrude into the chamber 328 and the flexible tubing 330 is at its maximum diameter at the restriction 332, allowing maximum flow rate through the flexible tubing 330. As the bladder 302 gradually expands, a greater portion of the bladder 302 extends into the chamber 328 and the flexible tubing 330 gradually compresses at the restriction 332 to a smaller diameter or size, decreasing the amount of flow through the flexible tubing 330.

[0063] The propellant from the flexible tubing 330 can be supplied to the drug reservoir 312. The drug reservoir 312 can be configured to operate similarly to the drug reservoir 20 of FIG. 2 and thus can operate to displace the drug in the drug reservoir 312 with the propellant or to be drawn into the propellant stream via the Bernoulli effect.

[0064] The bladder 302 may be inflated at the same pressure as the propellant cartridge 310, thereby mimicking the pressure curve of the propellant cartridge 310 over the life of the propellant. For example, the bladder 302 may be initially inflated at a high pressure, which gradually decays as the propellant in the propellant cartridge 310 is consumed or expelled. When a pressurized propellant cartridge 310 is connected to the frame 306, the bladder 302 may be immediately pressurized. However, an additional valve may be provided on the inflation conduit 318 to inflate the bladder 302 alone. Such a valve may be operated independently from the valve 314.

[0065] In operation, the actuator 316 can be moved by a user to open the valve 314. The valve 314 can include an on-off valve to allow unregulated pressure from the propellant cartridge 310 to enter the flexible tubing 330, as described herein. As described, the propellant from the propellant cartridge 310 can be supplied to the bladder 302 via the expansion conduit 318. When the propellant cartridge 310 is initially filled to the maximum, the bladder 302 can be expanded to the maximum, allowing the maximum amount for a given filling of the propellant cartridge 310 to enter into the chamber 328. Thus, as a large amount of propellant tries to leak out of the propellant cartridge, the flexible tubing 330 restricts the flow of the propellant, thereby avoiding a large amount of drug being dispensed from the drug reservoir 312 and reducing the possibility of a whiteout condition. However, as the pressure in the propellant cartridge 310 decreases, the flexible tubing 330 can expand, allowing more propellant to pass through. The ratio of the propellant pressure in the propellant cartridge 310 to the cross-sectional opening of the flexible tubing 330 may be inversely proportional. The ratio of the propellant pressure in the propellant cartridge 310 to the cross-sectional opening of the flexible tubing 330 may be configured to be maintained constant or nearly constant to provide a consistent output of drug from the drug reservoir 312.

[0066] The constant pressure flow controller 300 may be configured to provide a regulated balance between the bladder 302 causing a reduction in the restriction 332 while the pressure from the propellant cartridge 310 is reduced to maintain a constant pressure flow. The constant pressure flow controller 300 may be configured to provide a consistent user experience while avoiding whiteout conditions without the use of complex valves or electronic controls. The constant pressure flow controller 300 may provide an easy to manufacture, low cost system that may be easily incorporated into a disposable device.

[0067] [Example] Example 1 is a coagulant delivery system that includes a frame, a passage extending at least partially along the frame, a discharge opening connected to the passage, a coagulant reservoir fluidly connected to the passage for holding a volume of coagulant drug, a valve disposed within the passage for controlling the flow of the coagulant drug through the passage, and an actuator for selectively allowing propellant to flow into the passage, wherein the valve and the coagulant reservoir cooperate to supply the coagulant drug to the discharge opening at a constant pressure using the propellant.

[0068] In Example 2, the subject matter of Example 1 optionally includes a socket mounted to the frame for receiving a propellant source having a propellant, the valve including a constant pressure device in communication with a passage between the socket and the discharge opening.

[0069] In Example 3, the subject matter of Example 2 optionally includes where the constant pressure device is adjustable by a user to adjust the level of the constant pressure.

[0070] In Example 4, the subject matter of any one or more of Examples 2-3 optionally includes, wherein the constant pressure device is set to a constant pressure.

[0071] In Example 5, the subject matter of any one or more of Examples 2-4 optionally includes, wherein the constant pressure device is actuated by a spring.

[0072] In Example 6, the subject matter of Example 5 optionally includes the constant pressure device including a constant pressure valve including a housing, a diaphragm mounted to the housing to form a chamber, a vent to open the chamber to an external environment, a first biasing element disposed in the chamber to push against the diaphragm, a valve stem connected to the diaphragm opposite the first biasing element and disposed in the passage, a valve seat mounted to the frame and disposed in the passage to receive the valve stem, and a second biasing element configured to push the valve stem into engagement with the valve seat.

[0073] In Example 7, the subject matter of any one or more of Examples 2-6 optionally includes where the constant pressure device is electronically controlled.

[0074] In Example 8, the subject matter of Example 7 optionally includes a pressure sensor in the coagulant reservoir, an electronically actuated valve including a constant pressure device, and a controller electronically coupled to the pressure sensor and the electronically actuated valve for selectively opening the electronically actuated valve to maintain the pressure in the coagulant reservoir at a constant pressure.

[0075] In Example 9, the subject matter of any one or more of Examples 2-8 optionally includes, wherein the constant pressure device includes a variable restriction device.

[0076] In Example 10, the subject matter of Example 9 optionally includes where the variable restriction device includes an inflatable balloon.

[0077] In Example 11, the subject matter of Example 10 optionally includes wherein the variable restriction device further comprises a flexible tube against which the inflatable balloon pushes.

[0078] In Example 12, the subject matter of any one or more of Examples 10-11 optionally includes, wherein the constant pressure device further includes an inflation conduit connecting a propellant source to the inflatable balloon outside the passageway.

[0079] In Example 13, the subject matter of any one or more of Examples 2-12 optionally includes, wherein the constant pressure device is fluidly coupled to an interior of the coagulant reservoir outside the passageway.

[0080] In Example 14, the subject matter of Example 13 optionally includes, wherein the constant pressure device includes a relief valve.

[0081] In Example 15, the subject matter of any one or more of Examples 2 to 14 optionally includes a cartridge.

[0082] In Example 16, the subject matter of any one or more of Examples 2-15 optionally includes a propellant valve connected to the actuator to control a flow of propellant from the propellant source.

[0083] In Example 17, the subject matter of Example 16 optionally includes a discharge valve for controlling flow of the propellant and the coagulant drug from the coagulant delivery system, the discharge valve including an orifice fluidly coupled to the discharge opening and a needle connected to an actuator for selectively opening the discharge orifice.

[0084] Example 18 is the subject matter of any one or more of Examples 1 to 17, optionally including: the coagulant reservoir including a volume of coagulant and a volume of propellant; and the valve configured to simultaneously release the coagulant and the propellant directly from the coagulant reservoir into the passageway.

[0085] In Example 19, the subject matter of Example 18 optionally includes wherein the clotting agent and propellant form an aerosol.

[0086] In Example 20, the subject matter of any one or more of Examples 1 to 19 optionally includes a catheter coupleable to the drainage opening for delivering a clotting agent to the tissue region.

[0087] Example 21 is a method for delivering a coagulant, the method including the steps of inserting a delivery catheter into a tissue region; coupling a coagulant delivery system to the delivery catheter, the coagulant delivery system having a reservoir of coagulant; operating a valve to release a propellant to push the coagulant; and delivering the propellant and coagulant to the delivery catheter at a constant pressure.

[0088] In Example 22, the subject matter of Example 21 optionally includes wherein the valve includes a constant pressure valve and wherein delivering the propellant and coagulant to the delivery catheter at constant pressure includes regulating the flow of the propellant through a valve having a spring-activated diaphragm.

[0089] In Example 23, any one or more of the subject matter of Examples 21 to 22 optionally include, wherein the valve comprises an electronically actuated valve, and wherein delivering the propellant and coagulant to the delivery catheter at constant pressure comprises adjusting the opening of the valve using a controller.

[0090] In Example 24, the subject matter of any one or more of Examples 21 to 23 optionally includes, wherein the valve includes a vent valve in the coagulant reservoir, and wherein delivering the propellant and coagulant to the delivery catheter at constant pressure includes releasing the propellant within the coagulant reservoir at a threshold pressure at which a whiteout condition occurs.

[0091] In Example 25, the subject matter of any one or more of Examples 21 to 24 optionally includes, wherein the valve includes a variable restriction valve and wherein delivering the propellant and coagulant to the delivery catheter at constant pressure includes varying the size of a restriction within the valve.

[0092] In Example 26, the subject matter of Example 25 optionally includes, wherein the variable restriction valve includes a flexible tube through which the propellant flows and an inflatable bladder connected to a propellant source to selectively collapse the flexible tube.

[0093] In Example 27, the subject matter of any one or more of Examples 25-26 optionally includes, wherein the variable restrictor valve includes an electronically controlled valve and a controller for selectively regulating a flow path through the electronically controlled valve.

[0094] In Example 28, the subject matter of any one or more of Examples 21 to 27 optionally includes, wherein the valve includes an injection valve, and wherein delivering the propellant and coagulant to the delivery catheter at constant pressure includes opening the injection valve to simultaneously release the propellant and coagulant from a pressurized canister forming the coagulant reservoir.

[0095] In Example 29, the subject matter of Example 28 optionally includes wherein the propellant and coagulant are aerosolized by an injector.

[0096] In Example 30, the subject matter of any one or more of Examples 21-29 optionally includes using a needle valve to control the volume of coagulant entering the delivery catheter.

[0097] Each of these non-limiting examples may exist alone or may be combined in various rearrangements and in combination with one or more of the other examples.

[0098] [Miscellaneous notes] The above detailed description includes reference to the accompanying figures, which form a part of the detailed description. The figures show, by way of example, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the inventors also contemplate examples that use any combination or rearrangement of those elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0099] In the event of a conflict in usage between this specification and any document so incorporated by reference, the usage in this specification will control.

[0100] As used herein, the terms "a" or "an" are used to include one or more, regardless of any other instances or usages of "at least one" or "one or more," as is commonly found in patent documents. As used herein, the term "or" is used to refer to a non-exclusive or, whereby "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. As used herein, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Similarly, in the following claims, the terms "including" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include elements in addition to the elements listed following such terms in the claim are still considered to be within the scope of the claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used as labels only and are not intended to impose numerical requirements on their objects.

[0101] The example methods described herein may be at least partially machine or computer implemented. Some examples may include computer readable or machine readable media encoded with instructions operable to configure an electronic device to perform the methods described in the examples above. Such method implementations may include code, such as microcode, assembly language code, high level language code, etc. Such code may include computer readable instructions for performing various methods. The code may form part of a computer program product. Further, in one example, the code may be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer readable media, for example during execution or at other times. Examples of these tangible computer readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memory (RAM), read only memory (ROM), etc.

[0102] The above description is intended to aid in understanding, not to be limiting. For example, the examples described above (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, for example, by one of ordinary skill in the art upon review of the above description. The Summary is provided to comply with 37 CFR §1.72(b) to enable the reader to quickly ascertain the nature of the technical disclosure. The Summary is submitted with the understanding that it will not be used to describe or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to simplify the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to the scope of any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, it is intended that the following claims be incorporated into the Detailed Description as an example or embodiment, with each claim standing alone as a separate embodiment, and that such embodiments may be combined with each other in various combinations or rearrangements. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. [Explanation of symbols]

[0103] 10 Drug delivery devices 12 Frames 14 Pressure Control Valve 15 Flow valve 16 Actuators 18 Propellant Cartridge 20 Drug Reservoir 22 Fluid passage 22A First part of the passage 22B Second part of the passage 22C Third Section of Passage 22D Fourth Section of Passage 24 Cartridge Socket 26 Operator Control 28 Dispensing section 30 Handle 32 Guard 34 Cartridge container 36 Container Socket 38 Injection Coupler 40 Transport Device 42 Entrance 44 Canister 46 Pressure Sensor 48 valves 50 Propellant Exhaust Port 52 Drug Evacuation Port 54 Entrance 56 Drugs 58 Controller 60 exit 70 Valves 71 Housing Aisle 72 74 Passage 76 Adjustment screw 78 Thin Nut 80 Main unit 84 Opening 86A O-ring 86B O-ring 88 Valve seat 90 Bottom side 92 Valve needle 94 Cone 96 End 98 Chamber 100 Head 102 Spring 104 Surface 106 Female thread opening 108 Cap 110 Chamber 112 Vent 114 Enlarged diameter head 116 Elastic Diaphragm 118 Diaphragm retainer 120 Fasteners 122 Pressure control spring 123 Central projection 124 positions 130 Discharge nozzle mechanism 132 Valve needle member 134 Valve seat 140 Trigger 142 Pivot point 144 Pivot point 146 Actuating element 150 Cone-shaped passage 160 Nozzle opening 161 Spray Tip 162 Pre-nozzle chamber 163 Annular opening 164 Tapered Side 165 Valve Assembly 166 Seat member 167 Front end 168 Cylindrical member 169 Chip body 170 Seal gasket 171 Shoulder 172 Dotted Line 175 Circular Cap 176 Axial Cavity 178 Needle or cone members 179 Valve stem 189 Flange 190 Tapered seat 191 Seat angle 192 Tapered inlet surface 194 Tapered coaxial valve port 195 Interruption Point 196 Tapered Side 198 Needle angle 199 Front end 200 Pressurized material container 202 Container 204 Bottom 206 Color 208 Top 210 Valve member 212 Hollow shaft 214 Gasket 215 Tail 216 Spring 217 Valve 218 Valve body 220 Dip tube 221 Bottom end 222 Head 224 Aisle 226 Actuator 228 Internal cavity 230 Head Orifice 300 Constant pressure flow control device 302 Inflatable Bag 304 Drug Delivery Devices 306 Frames Aisle 308 310 Propellant Cartridge 312 Drug Reservoir 314 Valve 316 Actuator 318 Expansion duct 320 Coupler 322 Transport Device 324 Manifold 326 Tubing 328 Chamber 330 Flexible Tubing 332 Constraint part

Claims

[Claim 1] A frame, a passageway extending at least partially along the frame; a discharge opening connected to the passage; a clotting agent reservoir fluidly connected to the passageway for holding a volume of a clotting agent drug; a valve positioned in the passageway to control the flow of clotting agent through the passageway; an actuator for selectively flowing propellant into said passage; A coagulant delivery system comprising: The valve and the coagulant reservoir cooperate to supply a coagulant drug to the discharge opening at a constant pressure using the propellant.

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