Pressure management method for drug delivery devices

Abstract

This invention provides a pressure management method for drug delivery devices. [Solution] A pressure management method for a drug delivery device including a pump, a fluid line, and a power supply, the method comprising the steps of: delivering a fluid via the fluid line through the pump; determining a parameter indicating the pressure inside the fluid line; determining whether the parameter indicating the pressure inside the fluid line exceeds a pressure threshold level; pausing the delivery of the fluid through the fluid line until a predetermined condition is met; and resuming the delivery of the fluid through the fluid line after the predetermined condition is met.

Description

Technical Field

[0001] Field of the Invention The present disclosure relates to a pressure management method for a drug delivery device.

Background Art

[0002] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Application No. 63 / 114,894, filed on November 17, 2020, entitled "Pressure Management Method for a Drug Delivery Device", the entire disclosure of which is incorporated herein by reference in its entirety.

[0003] Description of Related Art Wearable medical devices, such as auto - injectors, have the advantage of providing treatment to patients while they are individually worn at locations far from clinical facilities and / or under the patient's clothing. Wearable medical devices can be applied to the patient's skin and can be configured to automatically administer a dosage of a pharmaceutical composition within a predetermined period after the wearable medical device has been applied to the patient's skin, for example, after a delay of 27 hours. After the device has administered the pharmaceutical composition to the patient, the patient can subsequently remove and discard the device.

[0004] In certain situations, due to the medium in which the liquid is being injected, the flow of fluid out of the device can become poor, which can lead to an increase in pressure in the fluid line of the device. When the pressure rises above a certain threshold, the integrity of the fluid path can be compromised, causing leakage inside the device and the inability to administer the full dosage of the drug. Fluid leakage inside the device can also cause potential contamination due to contact between the fluid and the device, as well as damage to the device and subsequent system failure.

[0005] Human subcutaneous tissue is composed of various cell types, extracellular matrix (ECM) components, microstructure, and the macroscopic arrangement of cells and ECM. These elements contribute to the mechanical properties of the tissue. The tissue may also contain lymphatic systems and blood vessels, and has inherent fluid absorption and fluid retention properties. These properties vary between individuals and locations within the body, and can cause changes in the resistance to fluid injection at the injection site over time. If the tissue resistance is too high, or if the absorption rate is too low for a given flow rate from the device, the pressure may increase and reach the valve beyond a threshold that can damage the fluid line and other components. [Overview of the project]

[0006] In one aspect or embodiment, a pressure management method for a drug delivery device comprising a pump, a fluid line, and a power supply, the method comprising: administering a fluid through the fluid line via the pump; determining a parameter indicating the pressure inside the fluid line; determining whether the parameter indicating the pressure inside the fluid line exceeds a pressure threshold level; pausing the administration of the fluid through the fluid line until a predetermined condition is met; and resuming the administration of the fluid through the fluid line after the predetermined condition is met.

[0007] The method can be implemented using a microcontroller containing at least one processor.

[0008] The method may include the step of terminating the fluid supply through the fluid line if the fluid supply has been suspended for the duration of the maximum delay period. The maximum delay period may be at least 30 seconds. In another configuration, the maximum delay period may be at least 4 minutes. The given condition may be a predetermined pressure level inside the fluid line. The given condition may be a predetermined period of time.

[0009] The pressure inside the fluid line can be determined by measuring pressure-indicating parameters, such as the current in a drug delivery device, during pump operation. Measuring the current in the drug delivery device may involve determining the stroke power value by subtracting a reference current value from a peak current value during the pump's operating cycle. The given conditions may be inputs from sensors in the drug delivery device or inputs from the user.

[0010] The method comprises the steps of first administering fluid through a fluid line at a first flow rate via a pump, and second administering fluid through a fluid line at a second flow rate via a pump, the first flow rate being lower than the second flow rate, and further comprising a step of administering fluid through a fluid line at a first flow rate via a pump. The first administration of fluid through a fluid line at a first flow rate via a pump may be configured to administer 15–50 μL of fluid. The first administration of fluid through a fluid line at a first flow rate via a pump may include pausing the administration of fluid for a predetermined delay period between bolus administrations. The first flow rate may correspond to the maximum allowable flow rate assuming a completely blocked condition. The first administration of fluid through a fluid line at a first flow rate via a pump may be configured to administer up to 20 μL of fluid.

[0011] In further embodiments or designs, the drug delivery device includes a power source, a container configured to contain a fluid, a fluid line communicating with the container, a pump configured to deliver the fluid from the container to the fluid line, and a microcontroller including at least one processor programmed or configured to deliver the fluid via the pump through the fluid line, determine a parameter indicating the pressure inside the fluid line, determine whether the parameter indicating the pressure inside the fluid line exceeds a pressure threshold level, pause the delivery of the fluid through the fluid line until a predetermined condition is met, and resume the delivery of the fluid through the fluid line after the predetermined condition is met.

[0012] In a further aspect or embodiment, a computer program product for a pressure management method for a drug delivery device comprising a microcontroller, a container, a pump, a fluid line, and a power supply, wherein the computer program product comprises at least one non-temporary computer-readable medium containing program instructions, the computer program product causing the microcontroller, when executed by the microcontroller, to operate the drug delivery device via the pump and through the fluid line to deliver fluid, to determine a parameter indicating the pressure inside the fluid line, to determine whether the parameter indicating the pressure inside the fluid line exceeds a pressure threshold level, to suspend the delivery of fluid through the fluid line until a predetermined condition is met, and to resume the delivery of fluid through the fluid line after the predetermined condition is met.

[0013] The pressure threshold level includes the threshold, range, and / or the percentage of pressure increase. [Brief explanation of the drawing]

[0014] The above and other features and advantages of the present disclosure, and the manner in which they are achieved, will become more apparent by referring to the following description of embodiments of the present disclosure, which will be considered in conjunction with the accompanying drawings, and the present disclosure itself will be better understood.

[0015] [Figure 1] This is a perspective view of a drug delivery device according to one aspect or embodiment of this application. [Figure 2] This is a perspective view of the drug delivery device shown in Figure 1, with the top cover removed. [Figure 3] Figure 1 is a schematic diagram of a drug delivery device. [Figure 4] Figure 1 is a pressure-to-time graph for the drug delivery device, illustrating a pressure management method according to one aspect or embodiment of this application. [Figure 5] This is a schematic diagram of a pressure control method according to one aspect or embodiment of the present application. [Figure 6] Figure 5 is a further schematic diagram of the method. [Figure 7] This is a schematic diagram of a pressure control method according to a second aspect or second embodiment of the present application. [Figure 8A] Figure 1 is a current-to-time graph for the drug delivery device, illustrating a method for determining fluid path pressure according to one aspect or embodiment of this application. [Figure 8B] This is an enlarged graph of region 8B shown in Figure 8A. [Figure 8C] This is an enlarged graph of region 8C shown in Figure 8B.

[0016] Corresponding reference numerals indicate corresponding parts across several drawings. The examples set forth herein illustrate exemplary embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure in any way. [Modes for carrying out the invention]

[0017] Spatial or directional terms such as "left," "right," "internal," "external," "higher," and "lower" should not be considered limiting to the present invention, as the invention can envision a variety of alternative directions.

[0018] All numbers used in this specification and the claims are to be understood as being modified by the term "about" in all instances. By "about" is meant a range of plus or minus 10 percent of the recited value. As used in this specification and the claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. The terms "first", "second", etc. are not intended to refer to any particular order or sequence of events, but rather to different states, characteristics, or elements. By "at least" is meant "greater than or equal to".

[0019] Referring to FIGS. 1 through 3, the drug delivery device 10 includes a container 12, a power source 14, an insertion mechanism 16, control electronics 18, a lid 20, and a substrate 22. In one aspect or embodiment, the drug delivery device 10 is a wearable auto-injector such as an insulin or bone marrow stimulant delivery device. The drug delivery device 10 can be attached to a patient's skin and can operate to inject a pharmaceutical composition from the container 12 into the patient. The drug delivery device 10 may be pre-filled with a pharmaceutical composition or the drug delivery device 10 may be filled with a pharmaceutical composition prior to use by the patient or a healthcare professional.

[0020] The drug delivery device 10 is configured to administer a pharmaceutical composition, e.g., a dosage of any desired drug, into a patient's body by subcutaneous injection at a slowly controlled injection rate. An exemplary duration of administration achieved by the drug delivery device 10 can range from about 5 minutes to about 60 minutes, but is not limited to this exemplary range. An exemplary volume of the pharmaceutical composition administered by the drug delivery device 10 can range from about 0.1 milliliters to about 10 milliliters, but is not limited to this exemplary range. The volume of the pharmaceutical composition administered to the patient can be adjusted.

[0021] Referring again to FIGS. 1 through 4, in one aspect or embodiment, power source 14 is a direct current power source including one or more batteries. Control electronics 18 includes a microcontroller 24, sensing electronics 26, a pump and valve controller 28, sensing electronics 30, and deployment electronics 32 that controls the operation of drug delivery device 10. Drug delivery device 10 includes a fluidics subsystem including a container 12, a volume sensor 34 for the container 12, a container fill port 36, a pump and valve actuator 40, and a pump and valve mechanism 42. The fluidics subsystem may further include an occlusion sensor 44, a deployment actuator 46, a cannula 48 for insertion into a patient's skin, and a fluid line 50 in fluid communication with container 12 and cannula 48. In an alternative aspect or embodiment, the occlusion sensor is a system for measuring motor current. In one aspect or embodiment, insertion mechanism 16 is configured to move cannula 48 from a retracted position disposed entirely within device 10 to an extended position where cannula 48 extends outside of device 10. Drug delivery device 10 may operate in a manner similar to that described in U.S. Patent No. 10,449,292 to Pizzochero et al.

[0022] Referring to Figures 4 to 6, in one aspect or embodiment, a method 52 for pressure management of a drug delivery device 10 includes the steps of: administering fluid through a fluid line 50 via a pump and valve mechanism 42; determining the pressure inside the fluid line 50; determining whether the pressure inside the fluid line 50 exceeds a pressure threshold level; pausing the administration of fluid through the fluid line 50 until a predetermined condition is met; and resuming the administration of fluid through the fluid line 50 after the predetermined condition is met. The predetermined condition may be a predetermined period of time, but the predetermined condition may also be a predetermined pressure level inside the fluid line 50, or the predetermined condition may be an input from a sensor in the device or an input from the user. The pressure level inside the fluid line 50 may be continuously monitored using a sensor or other configuration, but the pressure may be determined based on the current used during operation of the device 10, as described in further detail below. As shown in Figure 4, when the pressure inside the fluid line 50 reaches a pressure threshold level 60, a pause in fluid administration 62 is initiated, allowing the pressure to naturally decrease to a level where fluid administration can be resumed if possible. The algorithmic logic of method 52 is shown in Figures 5 and 6. Method 52 may include one or more iterative processes from the start of fluid administration to the completion of administration of the entire fluid dose. Method 52 may be executed by a microcontroller 24 or other processor in the drug delivery device 10.

[0023] In one aspect or embodiment, method 52 includes terminating the administration of a fluid through a fluid line 50 when the fluid administration is paused for a maximum delay period. For example, the fluid administration is paused until the pressure inside the fluid line 50 falls below a predetermined pressure level, and if the pressure inside the fluid line 50 does not fall below the predetermined pressure level after the maximum delay period, the administration process is terminated, and an error or blockage indicator may be provided by the drug administration device 10. In one aspect or embodiment, the maximum delay period is at least 30 seconds. In another aspect or embodiment, the maximum delay period is at least 4 minutes. In one aspect or embodiment, the fluid administration is provided via a plurality of smaller doses, and the maximum delay period includes the total sum of the time between these individual doses or the total number of delay periods. For example, if the fluid administration is paused for a predetermined amount of time because the pressure inside the fluid line 50 exceeds a pressure threshold level 60, a subsequent bolus dose may be administered, and if the pressure continues to exceed the pressure threshold level 60, the administration may be terminated. If administration is paused and the pressure does not fall below the pressure threshold level of 60, administration may be terminated after one or more subsequent bolus doses.

[0024] Referring to Figure 7, in one aspect or embodiment, method 52 may further include the steps of first administering fluid through a fluid line 50 at a first flow rate via a pump and valve mechanism 42, and second administering fluid through a fluid line 50 at a second flow rate via a pump and valve mechanism 42, wherein the first flow rate is lower than the second flow rate. After administering the fluid at the second flow rate, method 52 as described above in Figures 4 to 6 may continue until administration is complete or until an occlusion is determined. When fluid penetrates biological tissue, the mechanical and absorptive properties of the biological tissue are altered by the fluid. The penetrated tissue typically exhibits lower resistance to further penetration of the fluid. Therefore, peak injection pressure typically occurs at the start of administration and before any fluid enters the target tissue. Thus, by providing a first flow rate at the start of administration, the pressure in the fluid line 50 can be proactively controlled. In one aspect or embodiment, the initial dosing of fluid through the fluid line 50 at a first flow rate is configured to dosing 15-50 μL of fluid. In one aspect or embodiment, the initial dosing of fluid through the fluid line 50 at a first flow rate includes pausing the dosing of fluid for a predetermined delay period between bolus dosings 62.

[0025] In one aspect or embodiment, the first flow rate corresponds to the maximum allowable flow rate assuming a completely blocked state. After administering a known amount of fluid, such as 20 μL, administration is paused for a period of time, such as 1 minute, before resuming administration at the second flow rate 62. The administration of 20 μL of fluid may correspond to four operating cycles of the pump and valve mechanism 42.

[0026] Referring to Figures 8A to 8C, in one aspect or embodiment, the pressure in the fluid line 50 is determined by measuring pressure-indicating parameters, such as directly measuring the pressure during operation of the pump and valve mechanism 42, or by measuring the current of the drug delivery device 10. Measuring the current of the drug delivery device 10 involves determining a stroke current value 74 by subtracting a reference current value or baseline current value 70 from a peak current value 72 during the operating cycle of the pump and valve mechanism 42, although other suitable current sensing configurations may be utilized. The stroke current value 74 is used to estimate the downstream pressure in the fluid line 50 for a particular operating cycle of the pump and valve mechanism 42. For example, the stroke current value 74 can be adapted to various downstream pressure levels by testing or benchmarking so that the stroke current value 74 can be used to accurately estimate the pressure level in the fluid line 50.

[0027] Device 10 and method 52 provide control over the maximum pressure and overall pressure profile during the administration process, with low manufacturing costs and fewer false blockage alarms, extending the effective operating range of the drug delivery device 10 and enabling optimal administration time without causing leakage inside the device 10.

[0028] While the present invention has been described in detail for illustrative purposes based on what is currently considered to be the most practical and preferred embodiment, it should be understood that such details are for that purpose only, and the present invention is not limited to the disclosed embodiments, but rather intended to encompass modifications and equivalent configurations that fall within the spirit and scope of the appended claims. For example, it should be understood that the present invention anticipates that one or more features of any embodiment may be combined with one or more features of any other embodiment.

Claims

1. A pressure control method for a drug delivery device comprising a pump, a fluid line, and a power supply, wherein the method is: a) A step of administering fluid via the fluid line through a pump, b) A step of determining a parameter indicating the pressure inside the fluid line, c) A step of determining whether the parameter indicating the pressure inside the fluid line has exceeded a pressure threshold level, d) The step of temporarily suspending the administration of the fluid via the fluid line until predetermined conditions are met, e) After the predetermined conditions are met, the step of resuming the administration of the fluid via the fluid line, Includes, The parameter indicating the pressure inside the fluid line is determined by measuring the current of the drug delivery device while the pump is operating. A method for measuring the current of the drug delivery device, comprising determining a stroke current value by subtracting a reference current value from a peak current value during the operating cycle of the pump.

2. If the administration of the fluid is paused during the maximum delay period, the further step includes terminating the administration of the fluid through the fluid line. The method according to claim 1.

3. The aforementioned maximum delay period is at least 30 seconds. The method according to claim 2.

4. The aforementioned predetermined conditions include a predetermined pressure level inside the fluid line. The method according to any one of claims 1 to 3.

5. The aforementioned predetermined conditions include a predetermined period, The method according to claim 1.

6. The steps include: initially administering the fluid through the fluid line at a first flow rate via the pump; A step of then administering the fluid through the fluid line at a second flow rate via the pump, wherein the first flow rate is lower than the second flow rate, Further including, The method according to any one of claims 1 to 5.

7. The step of initially administering the fluid through the fluid line at the first flow rate via the pump is configured to administer 15-50 μL of the fluid. The method according to claim 6.

8. The step of initially administering the fluid through the fluid line at a first flow rate via the pump includes pausing the administration of the fluid for a predetermined delay period between bolus doses. The method according to claim 6.

9. The first flow rate mentioned above corresponds to the maximum allowable flow rate assuming a completely blocked state. The method according to claim 6.

10. The step of initially administering the fluid through the fluid line at the first flow rate via the pump is configured to administer a maximum of 20 μL of the fluid. The method according to claim 9.

11. At least one of steps b) through e) is performed using a microcontroller including at least one processor. The method according to any one of claims 1 to 10.

12. A drug delivery device, Power supply and A container configured to contain a fluid, A fluid line that is in fluid communication with the aforementioned container, A pump configured to dispense the fluid from the container to the fluid line, A microcontroller, wherein the device has The fluid is administered via the fluid line through the pump, Determining the parameters that indicate the pressure inside the fluid line, The parameter indicating the pressure inside the fluid line is determined to be above a pressure threshold level. The administration of the fluid via the fluid line is temporarily suspended until the predetermined conditions are met, After the predetermined conditions are met, the administration of the fluid via the fluid line is resumed, A microcontroller including at least one processor programmed or configured to perform the following: Includes, The parameter indicating the pressure inside the fluid line is determined by measuring the current of the drug delivery device while the pump is operating. Measuring the current of the drug delivery device includes determining the stroke current value by subtracting a reference current value from the peak current value during the operating cycle of the pump. Drug administration device.

13. The aforementioned at least one processor is The fluid is initially administered via the fluid line at a first flow rate through the pump, The fluid is then administered via the fluid line at a second flow rate through the pump, wherein the first flow rate is lower than the second flow rate. Further programmed or configured to do, The device according to claim 12.

14. The at least one processor is further programmed or configured to pause the administration of the fluid for a predetermined delay period between bolus doses. The device according to claim 13.

15. The first flow rate mentioned above corresponds to the maximum allowable flow rate assuming a completely blocked state. The device according to claim 13.

16. At least one non-temporary computer-readable medium containing program instructions, wherein the program instructions, when executed by a microcontroller, are transmitted to a drug delivery device. The process involves administering fluid via a pump and through a fluid line. Determining the parameters that indicate the pressure inside the fluid line, The parameter indicating the pressure inside the fluid line is determined to be above a pressure threshold level. The administration of the fluid via the fluid line is temporarily suspended until the predetermined conditions are met, After the predetermined conditions are met, the administration of the fluid via the fluid line is resumed, Have them do it, The parameter indicating the pressure inside the fluid line is determined by measuring the current of the drug delivery device while the pump is operating. Measuring the current of the drug delivery device includes determining the stroke current value by subtracting a reference current value from the peak current value during the operating cycle of the pump. At least one non-temporary computer-readable medium.

17. The at least one non-temporary computer-readable medium, when executed by the microcontroller, The fluid is initially administered via the fluid line at a first flow rate through the pump, The fluid is then administered via the fluid line at a second flow rate through the pump, wherein the first flow rate is lower than the second flow rate. Further including program instructions that cause the following: The at least one non-temporary computer-readable medium according to claim 16.

18. The at least one non-transient computer-readable medium further includes a program instruction, when executed by the microcontroller, that causes the microcontroller to pause the administration of the fluid for a predetermined delay period between bolus doses. The at least one non-temporary computer-readable medium according to claim 17.

19. The first flow rate mentioned above corresponds to the maximum allowable flow rate assuming a completely blocked state. The at least one non-temporary computer-readable medium according to claim 17.

20. The parameters indicating the pressure threshold level include the threshold, range, and / or the rate of pressure increase. At least one non-temporary computer-readable medium according to any one of claims 16 to 19.

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