Pressure management method for a drug delivery device

Abstract

A method for pressure management of a drug delivery device comprising a pump, a fluid line, and a power source, the method comprising: delivering fluid through the fluid line via the pump; determining a parameter indicative of pressure within the fluid line; determining whether the parameter indicative of pressure within the fluid line exceeds a pressure threshold level; pausing delivery of fluid through the fluid line until a predetermined condition is met; and resuming delivery of the fluid through the fluid line after the predetermined condition is met.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 114,894, filed November 17, 2020, entitled "Pressure Management Method for a Drug Delivery Device," the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to a method for pressure management in a drug delivery device. Background Technology

[0004] Wearable medical devices, such as autoinjectors, offer the benefit of delivering treatment to patients at locations remote from clinical facilities and / or while being discreetly worn under the patient's clothing. The wearable medical device can be applied to the patient's skin and configured to automatically deliver a dose of a drug composition within a predetermined time period after application (e.g., after a 27-hour delay). After the device has delivered the drug composition to the patient, the patient can subsequently remove and dispose of the device.

[0005] In some cases, the flow of fluid leaving the equipment may be impaired due to the medium in which the liquid is injected, potentially leading to increased pressure in the equipment's fluid lines. When the pressure rises above a certain threshold, the integrity of the fluid path may be compromised, resulting in leaks within the equipment and the inability to deliver the full dose of the agent. Fluid leaks within the equipment can also cause damage to the equipment and subsequent system failures, as well as potential contamination problems due to contact between the fluid and the equipment.

[0006] Human subcutaneous tissue is composed of various cell types, extracellular matrix (ECM) components, microstructures, and the macroscopic arrangement of cells and ECM. These elements contribute to the tissue's mechanical properties. The tissue may also include the lymphatic system and blood vessels, and possesses inherent fluid absorption and retention properties. These properties vary between individuals, at different locations within the body, and over time, potentially leading to varying degrees of resistance to fluid infusion at the injection site. When tissue resistance is too high or the absorption rate is too low for a given delivery rate from the device, pressure may increase and exceed valve thresholds, potentially damaging fluid lines and other components. Summary of the Invention

[0007] In one aspect or embodiment, a method for pressure management of a drug delivery device including a pump, a fluid line, and a power source, the method comprising: delivering fluid via the pump through the fluid line; determining a parameter indicating pressure within the fluid line; determining whether the parameter indicating pressure within the fluid line exceeds a pressure threshold level; suspending the delivery of fluid through the fluid line until the predetermined conditions are met; and resuming the delivery of fluid through the fluid line after the predetermined conditions are met.

[0008] This method can also be executed using a microcontroller that includes at least one processor.

[0009] The method may include terminating the flow of fluid through the fluid pipeline when fluid delivery has been suspended for a 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 predetermined condition may be a predetermined pressure level within the fluid pipeline. The predetermined condition includes a predetermined time period.

[0010] The pressure parameters within the fluid pipeline can be determined by measuring parameters indicating the pressure (such as the current of the drug delivery device) during pump actuation. Measuring the current of the drug delivery device may include subtracting a reference current value from the peak current value during the pump's actuation cycle to determine the stroke current value. The predetermined conditions may be input from sensors of the drug delivery device or from user input.

[0011] The method may further include initially delivering fluid through a fluid line via a pump at a first flow rate, and subsequently delivering fluid through the fluid line via a pump at a second flow rate, wherein the first flow rate is lower than the second flow rate. The initial delivery of fluid through the fluid line via the pump at the first flow rate can be configured to deliver 15-50 μL of fluid. The initial delivery of fluid through the fluid line via the pump at the first flow rate may include pausing fluid delivery between deliveries for a predetermined delay period. The first flow rate may correspond to the maximum acceptable flow rate assuming a complete blockage. The initial delivery of fluid through the fluid line via the pump at the first flow rate can be configured to deliver up to 20 μL of fluid.

[0012] In another aspect or embodiment, a drug delivery device includes a power source, a reservoir configured to receive fluid, a fluid line in fluid communication with the reservoir, a pump configured to deliver fluid from the reservoir to the fluid line, and a microcontroller including at least one processor programmed or configured to cause the device to: deliver fluid via the pump through the fluid line; determine a parameter indicating pressure within the fluid line; determine whether the parameter indicating pressure within the fluid line exceeds a pressure threshold level; suspend delivery of fluid through the fluid line until predetermined conditions are met; and resume delivery of fluid through the fluid line after the predetermined conditions are met.

[0013] In another aspect or embodiment, a computer program product for a pressure management method of a drug delivery device, the drug delivery device including a microcontroller, a storage device, a pump, a fluid line, and a power supply, the computer program product including at least one non-transitory computer-readable medium containing program instructions that, when executed by the microcontroller, cause the drug delivery device to: deliver fluid through the fluid line via the pump; determine the pressure within the fluid line; determine whether the pressure within the fluid line exceeds a pressure threshold level; suspend the delivery of fluid through the fluid line until the predetermined conditions are met; and resume the delivery of fluid through the fluid line after the predetermined conditions are met.

[0014] Indicating pressure threshold levels may include a threshold, range, and / or the rate of pressure increase. Attached Figure Description

[0015] The above and other features and advantages of this disclosure, as well as the ways in which they are implemented, will become more apparent from the following description of embodiments of this disclosure taken in conjunction with the accompanying drawings, and the disclosure itself will be better understood, wherein:

[0016] Figure 1 This is a perspective view of a drug delivery device according to one aspect or embodiment of this application.

[0017] Figure 2 yes Figure 1 A perspective view of a drug delivery system, with the top cover removed.

[0018] Figure 3 yes Figure 1 A schematic diagram of a drug delivery system.

[0019] Figure 4 yes Figure 1 The pressure versus time graph of the drug delivery device illustrates a method of pressure management according to one aspect or embodiment of this application.

[0020] Figure 5This is a schematic diagram of a stress management method according to one aspect or embodiment of this application.

[0021] Figure 6 yes Figure 5 Another schematic diagram of the method.

[0022] Figure 7 This is a schematic diagram of a stress management method according to a second aspect or embodiment of this application.

[0023] Figure 8A yes Figure 1 The current versus time curve of the drug delivery device illustrates a method for determining fluid path pressure according to one aspect or embodiment of this application.

[0024] Figure 8B yes Figure 8A An enlarged view of region 8B shown.

[0025] Figure 8C yes Figure 8B An enlarged view of region 8C shown.

[0026] In all the views, corresponding reference numerals denote corresponding parts. The examples illustrated herein illustrate exemplary embodiments of this disclosure, and such examples should not be construed as limiting the scope of this disclosure in any way. Detailed Implementation

[0027] Spatial or directional terms, such as “left,” “right,” “inner,” “outer,” “above,” “below,” etc., should not be considered limiting, as the invention can take various alternative orientations.

[0028] All figures used in the specification and claims shall in all cases be understood to be modified by the term “about.” “About” means a range of plus or minus ten percent of the stated value. As used in the specification and claims, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly indicates otherwise. The terms “first,” “second,” etc., are not intended to refer to any particular order or chronological sequence, but rather to different conditions, properties, or elements. “At least” means “greater than or equal to.”

[0029] refer to Figures 1-3The drug delivery device 10 includes a reservoir 12, a power supply 14, an insertion mechanism 16, control electronics 18, a cap 20, and a base 22. In one aspect or embodiment, the drug delivery device 10 is a wearable autoinjector, such as an insulin or bone marrow stimulant delivery device. The drug delivery device 10 may be attached to a patient's skin and triggered to inject a drug composition from the reservoir 12 into the patient. The drug delivery device 10 may be pre-filled with a drug composition, or it may be filled with a drug composition by a patient or medical professional prior to use.

[0030] The drug delivery device 10 is configured to deliver a dose of a drug composition (e.g., any desired agent) to a patient via subcutaneous injection at a slow, controlled injection rate. Exemplary durations of delivery achieved by the drug delivery device 10 may range from about 5 minutes to about 60 minutes, but are not limited to this exemplary range. Exemplary volumes of the drug composition delivered by the drug delivery device 10 may range from about 0.1 ml to about 10 ml, but are not limited to this exemplary range. The volume of the drug composition delivered to the patient can be adjusted.

[0031] Refer again Figures 1-4 In one aspect or embodiment, the power source 14 is a DC power source comprising 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, which control the actuation of the drug delivery device 10. The drug delivery device 10 includes a fluid subsystem comprising a reservoir 12, a volume sensor 34 for the reservoir 12, a reservoir filling port 36, and a metering system 38 including a pump and valve actuator 40 and a pump and valve mechanism 42. The fluid subsystem may also include a clogging sensor 44, a deployment actuator 46, a cannula 48 for insertion into the patient's skin, and a fluid line 50 in fluid communication with the reservoir 12 and the cannula 48. In an alternative aspect or embodiment, the clogging sensor is a system for measuring motor current. In one aspect or embodiment, the insertion mechanism 16 is configured to move the cannula 48 from a retracted position fully positioned within the device 10 to an extended position where the cannula 48 extends outside the device 10. The drug delivery device 10 can operate in the same manner as discussed in U.S. Patent No. 10,449,292 to Pizzochero et al.

[0032] refer to Figures 4-6In one aspect or embodiment, a method 52 for pressure management of a drug delivery device 10 includes: delivering fluid through a fluid line 50 via a pump and valve mechanism 42; determining a pressure within the fluid line 50; determining whether the pressure within the fluid line 50 exceeds a pressure threshold level; suspending fluid delivery through the fluid line 50 until a predetermined condition is met; and resuming fluid delivery through the fluid line 50 after the predetermined condition is met. The predetermined condition may be a predetermined time period, but it may also be a predetermined pressure level within the fluid line 50, or it may be an input from a sensor in the device or from a user. The pressure level within the fluid line 50 may be continuously monitored using sensors or other devices, but the pressure may also be determined based on the current used during actuation of the device 10, as discussed in further detail below. Figure 4 As shown, when the pressure within the fluid pipeline 50 reaches a pressure threshold level 60, a pause 62 in fluid delivery is initiated to allow the pressure to naturally decay to a level where fluid delivery can resume, if possible. The algorithmic logic of method 52 is as follows: Figure 5 and Figure 6 As shown in the diagram. Method 52 may include one or more iterative processes from the start of fluid delivery to the completion of fluid delivery of the full dose. Method 52 may be executed by the microcontroller 24 or other processor of the drug delivery device 10.

[0033] In one aspect or embodiment, method 52 includes terminating the delivery of fluid through fluid line 50 when fluid delivery has been suspended for a maximum delay period. For example, if fluid delivery is suspended until the pressure within fluid line 50 drops below a predetermined pressure level, and the pressure within fluid line 50 does not drop below the predetermined pressure level after the maximum delay period, the delivery process is terminated, and an error or blockage indication may be provided by drug delivery 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, fluid delivery is provided through a plurality of smaller deliveries, and the maximum delay period includes the total amount of time between these discrete deliveries or the total number of delay periods. For example, if fluid delivery is suspended for a predetermined amount of time due to pressure within fluid line 50 exceeding a pressure threshold level 60, a subsequent bolus may be delivered, and if the pressure continues to exceed the pressure threshold level 60, delivery may be terminated. When delivery has been suspended and has failed to drop below the pressure threshold level 60, delivery may be terminated after one or more subsequent bolus deliveries.

[0034] refer to Figure 7In one aspect or embodiment, method 52 may further include initially delivering fluid through fluid line 50 at a first flow rate via pump and valve mechanism 42, and subsequently delivering fluid through fluid line 50 at a second flow rate via pump and valve mechanism 42, wherein the first flow rate is lower than the second flow rate. After delivering fluid at the second flow rate, the above... Figures 4-6 The method 52 discussed herein can continue until delivery is complete or until a blockage is identified. When biological tissue is permeated by fluid, its mechanical and absorptive properties are altered by the fluid. Permeated tissue typically exhibits lower resistance to further fluid permeation. Therefore, peak infusion pressure typically occurs at the start of delivery and before any fluid enters the target tissue. Thus, by providing a first flow rate at the start of delivery, pressure within the fluid line 50 can be preemptively managed. In one aspect or embodiment, the initial delivery of fluid through the fluid line 50 at the first flow rate is configured to deliver 15-50 μL of fluid. In one aspect or embodiment, the initial delivery of fluid through the fluid line 50 at the first flow rate includes a pause 62 between boluses for a predetermined delay period.

[0035] In one aspect or embodiment, the first flow rate corresponds to the maximum acceptable flow rate under the assumption of a complete blockage. After delivering a known amount of fluid (e.g., 20 μL), delivery is paused for a period of time (e.g., 1 minute) before being resumed at the second flow rate. The delivery of 20 μL of fluid may correspond to four actuation cycles of the pump and valve mechanism 42.

[0036] refer to Figures 8A-8C In one aspect or embodiment, the pressure within the fluid line 50 is determined by measuring parameters indicating pressure, such as directly measuring pressure during actuation of the pump and valve mechanism 42 or measuring the current of the drug delivery device 10. Measuring the current of the drug delivery device 10 involves subtracting a reference or baseline current value 70 from the peak current value 72 during the actuation cycle of the pump and valve mechanism 42 to determine the stroke current value 74; however, other suitable current sensing arrangements may also be utilized. The stroke current value 74 is used to estimate the downstream pressure of the fluid line 50 for a specific actuation cycle of the pump and valve mechanism 42. For example, the stroke current value 74 can be correlated with various downstream pressure levels through testing or performance comparison, allowing the stroke current value 74 to be used to accurately estimate the pressure level of the fluid line 50.

[0037] The device 10 and method 52 provide management of the maximum pressure and total pressure profile during delivery, with low manufacturing cost, low false blockage alarm rate, widening of the effective operating range of the drug delivery device 10, and allowing for optimal delivery time without causing leakage within the device 10.

[0038] Although the invention has been described in detail based on embodiments currently considered to be the most practical and preferred for illustrative purposes, it should be understood that such details are merely for that purpose, and the invention is not limited to the disclosed embodiments, but rather is intended to cover modifications and equivalent arrangements within the spirit and scope of the appended claims. For example, it should be understood that the invention contemplates, to the extent possible, that one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

1. A drug delivery device, comprising: power supply; The storage device is configured to receive fluid; Fluid lines in fluid communication with the storage device; A pump is configured to deliver the fluid from the reservoir to the fluid line; as well as A microcontroller, comprising at least one processor, said at least one processor being programmed or configured to cause the device to: Fluid is delivered via the pump through the fluid pipeline; Determine the parameters that indicate the pressure within the fluid pipeline; Determine whether the parameter indicating the pressure within the fluid line exceeds a pressure threshold level; Suspend the delivery of fluid through the fluid pipeline until predetermined conditions are met; as well as After the predetermined conditions are met, the flow of fluid through the fluid pipeline is resumed. The parameter indicating the pressure within the fluid line is determined by measuring the current of the drug delivery device during pump actuation, wherein the measurement of the current of the drug delivery device includes subtracting a reference current value from a peak current value during the pump actuation cycle to determine a stroke current value used to estimate the downstream pressure of the fluid line.

2. The device according to claim 1, wherein, The at least one processor is also programmed or configured to: When fluid delivery has been suspended for the maximum delay period, the delivery of fluid through the fluid pipeline shall be terminated.

3. The device according to claim 2, wherein, The maximum delay period is at least 30 seconds.

4. The device according to any one of claims 1 to 3, wherein, The predetermined conditions include a predetermined pressure level within the fluid pipeline.

5. The device according to claim 1, wherein, The predetermined conditions include a predetermined time period.

6. The device according to claim 1, wherein, The at least one processor is also programmed or configured to: Initially, fluid is delivered through the fluid line via the pump at a first flow rate; and The fluid is then delivered via the pump through the fluid line at a second flow rate, wherein the first flow rate is lower than the second flow rate.

7. The device according to claim 6, wherein, The initial fluid delivery via the pump through the fluid line at a first flow rate is configured to deliver 15-50 μL of fluid.

8. The device according to claim 6, wherein, The at least one processor is also programmed or configured to pause the delivery of the fluid between injections for a predetermined delay period.

9. The device according to claim 6, wherein, The first flow rate corresponds to the maximum acceptable flow rate under the assumption of a complete blockage.

10. The device according to claim 9, wherein, The initial delivery of fluid via the pump at a first flow rate through the fluid line is configured to deliver a maximum of 20 μL of fluid.

11. A computer program product for a method of pressure management in a drug delivery device, the drug delivery device including a microcontroller, a storage device, a pump, a fluid line, and a power supply, the computer program product including at least one non-transitory computer-readable medium containing program instructions that, when executed by the microcontroller, cause the drug delivery device to: Fluid is delivered via the pump through the fluid pipeline; Determine the pressure within the fluid pipeline; Determine whether the pressure within the fluid pipeline exceeds a pressure threshold level; Suspend the delivery of fluid through the fluid pipeline until predetermined conditions are met; as well as After the predetermined conditions are met, the flow of fluid through the fluid pipeline is resumed. The parameter indicating the pressure within the fluid line is determined by measuring the current of the drug delivery device during pump actuation, wherein the measurement of the current of the drug delivery device includes subtracting a reference current value from a peak current value during the pump actuation cycle to determine a stroke current value used to estimate the downstream pressure of the fluid line.

12. The computer program product according to claim 11, wherein, The at least one non-transitory computer-readable medium further includes program instructions that, when executed by the microcontroller, cause the microcontroller to: When fluid delivery has been suspended for the maximum delay period, the delivery of fluid through the fluid pipeline shall be terminated.

13. The computer program product according to claim 12, wherein, The maximum delay period is at least 30 seconds.

14. The computer program product according to any one of claims 11 to 13, wherein, The predetermined conditions include a predetermined pressure level within the fluid pipeline.

15. The computer program product according to claim 11, wherein, The predetermined conditions include a predetermined time period.

16. The computer program product according to claim 11, wherein, The at least one non-transitory computer-readable medium further includes program instructions that, when executed by the microcontroller, cause the microcontroller to: Initially, fluid is delivered through the fluid line via the pump at a first flow rate; and The fluid is then delivered via the pump through the fluid line at a second flow rate, wherein the first flow rate is lower than the second flow rate.

17. The computer program product according to claim 16, wherein, The initial fluid delivery via the pump through the fluid line at a first flow rate is configured to deliver 15-50 μL of fluid.

18. The computer program product according to claim 16, wherein, The at least one non-transitory computer-readable medium also includes program instructions that, when executed by the microcontroller, cause the microcontroller to pause the delivery of the fluid between injections for a predetermined delay period.

19. The computer program product according to claim 16, wherein, The first flow rate corresponds to the maximum acceptable flow rate under the assumption of a complete blockage.

20. The computer program product according to claim 19, wherein, The initial delivery of fluid via the pump at a first flow rate through the fluid line is configured to deliver a maximum of 20 μL of fluid.

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