System and method for pressure sensor-based empty reservoir detection for a drug delivery device

Abstract

The drug delivery device includes a microcontroller, a pressure sensor, and / or a reservoir, a pump downstream of the reservoir, and / or a fluid line downstream of the pump, and includes a fluid path. The reservoir may be configured to receive fluid. The pump may be configured to deliver fluid from the reservoir to the fluid line. The pressure sensor may be configured to measure the pressure within the fluid path. The microcontroller may be programmed and / or configured to receive, from the pressure sensor, the pressure measured within the fluid path, determine whether the fluid in the reservoir is empty based on the pressure measured within the fluid path, and / or control an output device to provide output information regarding the determination of whether the fluid in the reservoir is empty.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Patent Application No. 17 / 859,643, filed July 7, 2022, entitled "Systems and Methods for Pressure Sensor - Based Empty Reservoir Detection for a Drug Delivery Device".

[0002] Technical Field The present disclosure relates to devices and methods for pressure - sensor - based empty reservoir detection for a drug delivery device.

Background Art

[0003] Wearable medical devices, such as auto - injectors, have the advantage of providing treatment to a patient at a location outside of a clinical facility and / or while being worn unobtrusively under the patient's clothing. A wearable medical device can be applied to a patient's skin and configured to automatically deliver a dosage of a pharmaceutical composition within a predetermined period after applying the wearable medical device to the patient's skin, for example, after 27 hours. After the device has delivered the pharmaceutical composition to the patient, the patient can then remove and dispose of the device.

[0004] In the context of fluid injection or infusion, some drugs may be prescribed to be administered in a tightly controlled regimen (e.g., an exact dosage may be prescribed to be delivered at a controlled timing, etc.). In injection devices, typically, controlled flow rates and regimens based on volume dosing are possible. In this case, the system displaces a known volume of the fluid to be administered. Exemplary systems that enable volume - based dosing control include syringe pumps, oscillating rotary pumps, systems with moving pistons, peristaltic pumps, as well as membrane pumps and diaphragm pumps.

[0005] Some of these pumps operate based on a "dosing chamber section" that is periodically filled and emptied. These systems are special in that the fluid path upstream of the pump does not have to communicate directly with the path downstream of the pump, and different pressures can be set in each of these fluid paths.

Summary of the Invention

Problems to be Solved by the Invention

[0006] In some cases, it may be desirable for the device to have a function of detecting when the drug reservoir of the device is empty. This makes it possible to notify the patient that the treatment has been successfully completed. It is also possible to detect possible failure modes, or cases where the reservoir empties earlier than expected, i.e., the possibility of underdosing and adverse effects on the treatment of the subject. In a device having a flexible reservoir, it can be particularly difficult to accurately and precisely detect an empty reservoir. On the other hand, in a syringe-type reservoir, the linear movement of the syringe stopper can be more easily utilized.

Means for Solving the Problems

[0007] Accordingly, an improved system, device, product, apparatus, and / or method for detecting an empty reservoir for a drug delivery device is provided.

[0008] According to some non-limiting embodiments or aspects, a fluid path including a reservoir, a pump downstream of the reservoir, and a fluid line downstream of the pump, wherein the reservoir is configured to receive fluid and the pump is configured to deliver fluid from the reservoir to the fluid line; a pressure sensor configured to measure the pressure within the fluid path; and a microcontroller programmed and / or configured to receive the pressure measured within the fluid path from the pressure sensor, determine whether the fluid in the reservoir is empty based on the pressure measured within the fluid path, and control an output device to provide an indication regarding the determination of whether the fluid in the reservoir is empty. A drug delivery device is provided that includes these components.

[0009] In some non-limiting embodiments or aspects, the pressure sensor is within the fluid path downstream of the pump.

[0010] In some non-limiting embodiments or aspects, the pressure sensor is within the fluid path upstream of the pump.

[0011] In some non-limiting embodiments or aspects, the microcontroller is programmed and / or configured to compare the pressure measured within the fluid path with a threshold pressure and determine that the fluid in the reservoir is empty when the pressure measured within the fluid path meets the threshold pressure, thereby determining whether the fluid in the reservoir is empty.

[0012] In some non-limiting embodiments or aspects, the microcontroller is programmed and / or configured to identify a rate of change of the pressure measured within the fluid path based on the pressure measured within the fluid path, compare the rate of change of the pressure measured within the fluid path with a threshold rate of change, and determine that the fluid in the reservoir is empty when the rate of change of the pressure measured within the fluid path meets the threshold rate of change, thereby determining whether the fluid in the reservoir is empty.

[0013] In some non-limiting embodiments or aspects, the pump includes a dosing chamber and periodically, (i) sucks the fluid from the reservoir while the dosing chamber is in fluid communication with the reservoir and not in fluid communication with the fluid line, and (ii) is configured to fluidly connect the dosing chamber to the fluid line.

[0014] In some non-limiting embodiments or aspects, the microcontroller is programmed and / or configured to determine a reference pressure based on the pressure measured in the fluid path before fluidly connecting the dosing chamber to the fluid line, and the microcontroller is programmed and / or configured to determine whether the reservoir is empty based on the pressure measured in the fluid path and the reference pressure.

[0015] In some non-limiting embodiments or aspects, the pressure sensor includes at least one of an absolute pressure sensor, a differential pressure sensor, or any combination of the absolute pressure sensor and the differential pressure sensor.

[0016] A pressure sensor-based method for detecting an empty reservoir for a drug delivery device, including a fluid path including a reservoir configured to receive fluid, a pump downstream of the reservoir, and a fluid line downstream of the pump, the method comprising delivering fluid with the pump from the reservoir to the fluid line, measuring the pressure in the fluid path with a pressure sensor, receiving the pressure measured in the fluid path with a microcontroller, determining with the microcontroller whether the fluid in the reservoir is empty based on the pressure measured in the fluid path, and controlling an output device with the microcontroller to provide output information regarding the determination of whether the fluid in the reservoir is empty.

[0017] In some non-limiting embodiments or aspects, the pressure sensor measures the pressure in the fluid path downstream of the pump.

[0018] In some non-limiting embodiments or aspects, the pressure sensor measures the fluid within the fluid path upstream of the pump.

[0019] In some non-limiting embodiments or aspects, in determining whether the fluid in the reservoir is empty, the pressure measured within the fluid path is compared with a threshold pressure, and when the pressure measured within the fluid path meets the threshold pressure, it is determined that the fluid in the reservoir is empty.

[0020] In some non-limiting embodiments or aspects, in determining whether the fluid in the reservoir is empty, based on the pressure measured within the fluid path, a rate of change with respect to the pressure measured within the fluid path is identified, the rate of change with respect to the pressure measured within the fluid path is compared with a threshold rate of change, and when the rate of change with respect to the pressure measured within the fluid path meets the threshold rate of change, it is determined that the fluid in the reservoir is empty.

[0021] In some non-limiting embodiments or aspects, the pump includes a dosing chamber, and in delivering fluid from the reservoir to the fluid line, periodically, (i) the dosing chamber draws out the fluid in the reservoir while being in fluid communication with the reservoir and not in fluid communication with the fluid line, and (ii) the dosing chamber is fluid-connected to the fluid line.

[0022] In some non-limiting embodiments or aspects, the method further determines a reference pressure with a microcontroller based on the pressure measured within the fluid path before fluid-connecting the dosing chamber to the fluid line, and whether the reservoir is empty is determined based on the pressure measured within the fluid path and the reference pressure.

[0023] In some non-limiting embodiments or aspects, it includes at least one of an absolute pressure sensor, a differential pressure sensor, or any combination of the absolute pressure sensor and the differential pressure sensor.

[0024] According to some non-limiting embodiments or aspects, a computer program product for pressure sensor-based empty reservoir detection for a drug delivery device comprising a fluid path including a microcontroller, a pressure sensor, a reservoir configured to receive a fluid, a pump downstream of the reservoir, and a fluid line downstream of the pump, the computer program product including at least one non-transitory computer-readable medium including program instructions which, when executed by the microcontroller, cause the microcontroller to control the pump to deliver fluid from the reservoir to the fluid line, control the pressure sensor to measure the pressure within the fluid path, receive the pressure measured within the fluid path, determine whether the fluid in the reservoir is empty based on the pressure measured within the fluid path, and control an output device to provide output information regarding the determination of whether the fluid in the reservoir is empty.

[0025] In some non-limiting embodiments or aspects, the microcontroller controls the pressure sensor to measure the pressure within the fluid path downstream of the pump.

[0026] In some non-limiting embodiments or aspects, the pump includes a dosing chamber and the pump periodically (i) draws fluid from the reservoir with the dosing chamber in fluid communication with the reservoir and not in fluid communication with the fluid line, and (ii) delivers fluid from the reservoir to the fluid line by fluidly connecting the dosing chamber to the fluid line.

[0027] In some non-limiting embodiments or aspects, the microcontroller controls the pressure sensor to measure the pressure within the fluid path upstream of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features and advantages of the present disclosure, and the manner in which these are achieved, will become more apparent and the present disclosure itself will be better understood by reference to the following description of embodiments of the present disclosure in conjunction with the accompanying drawings.

[0029] FIG. 1 is a perspective view of a drug delivery device according to one aspect or embodiment of the present application.

[0030] FIG. 2 is a perspective view of the drug delivery device of FIG. 1 with the upper cover removed.

[0031] FIG. 3 is a schematic diagram of the drug delivery device of FIG. 1.

[0032] FIG. 4 is a schematic diagram of a system for pressure sensor-based empty reservoir detection according to one aspect or embodiment of the present application.

[0033] FIG. 5 is a graph of an example of a pressure signature for the drug delivery device of FIG. 1.

[0034] FIG. 6 is a graph of another example of a pressure signature for the drug delivery device of FIG. 1.

[0035] FIG. 7 is a graph of an example of a pressure signature and a motor current signature for the drug delivery device of FIG. 1.

[0036] FIG. 8 is a flowchart of a pressure sensor-based empty reservoir detection process for a drug delivery device according to one aspect or embodiment of the present application.

[0037] The same reference numerals indicate the same parts throughout the plurality of figures. The examples described herein illustrate exemplary embodiments of the present disclosure and such examples should not be construed as limiting the scope of the present disclosure in any way.

DETAILED DESCRIPTION OF THE INVENTION

[0038] In aspects or embodiments of the present disclosure, various alternative postures are conceivable. Therefore, terms indicating spaces or directions such as "left", "right", "inside", "outside", "up", and "down" should not be regarded as limiting.

[0039] All numbers used in this specification and the claims should be understood to be modified by the term "about" in all cases. "About" means a range of ±10 percent of the stated value. When used in this specification and the claims, the singular forms of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Terms such as "first", "second", etc. are not intended to refer to any particular order or time series, but rather to refer to different conditions, characteristics, or elements. "At least" means "more than".

[0040] Referring to FIGS. 1 - 3, the drug delivery device 10 includes a reservoir 12, a power source 14, an insertion mechanism 16, control electronics 18, a cover 20, and a base 22. In one aspect or embodiment, the drug delivery device 10 is a wearable automatic syringe such as an insulin or bone marrow stimulant delivery device. The drug delivery device 10 can be attached to a patient's skin and is operative to inject a pharmaceutical composition from the reservoir 12 into the patient. The drug delivery device 10 may be pre - filled with a pharmaceutical composition or may be filled by the patient or a medical professional prior to use.

[0041] The drug delivery device 10 is configured to administer a single dose of a pharmaceutical composition (e.g., any desired drug) into the patient's body by subcutaneous injection at a low, controlled injection rate. The administration period achieved by the drug delivery device 10 can be, for example, in the range of about 5 minutes to about 60 minutes, but is not limited to this exemplary range. The volume of the pharmaceutical composition administered by the drug delivery device 10 can be, for example, in the range of 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.

[0042] Referring again to FIGS. 1 - 3, in one aspect or embodiment, power source 14 is a DC power source including one or more batteries. Control electronics 18 includes a microcontroller 24, sensing electronics 26, a pump and valve control 28, sensing electronics 30, and deployment electronics 32 that controls the operation of drug delivery device 10. Drug delivery device 10 includes a reservoir 12, a volume sensor 34 for reservoir 12, a reservoir fill port 36, and a metering system 38 including a pump and valve actuator 40 and a pump and valve mechanism 42, and includes a fluid subsystem. The fluid subsystem may further include an occlusion sensor 44, a placement actuator 46, a cannula 48 for insertion into a patient's skin, and a fluid line 50 fluidly connecting reservoir 12 and cannula 48. In one aspect or embodiment, occlusion sensor 44 includes a pressure sensor, such as pressure sensor 54, described in more detail herein in connection with FIG. 4. In one aspect or embodiment, insertion mechanism 16 is configured to move cannula 48 from a retracted position where cannula 48 is fully contained within drug delivery device 10 to an extended position extending outside drug delivery device 10. Drug delivery device 10 can operate in a manner similar to that described in U.S. Patent No. 10,449,292 to Pizzochero et al., which is incorporated herein by reference.

[0043] In one aspect or embodiment, the fluid path is formed by reservoir 12, a pump and valve mechanism 42 downstream of reservoir 12, and a fluid line 50 downstream of pump and valve mechanism 42. For example, reservoir 12 may be configured to receive fluid, and pump and valve mechanism 42 may be configured to deliver fluid from reservoir 12 to fluid line 50.

[0044] Referring to FIG. 4, in one aspect or embodiment, the pump and valve mechanism 42 includes a dosing chamber 52. The pump and valve mechanism 42 is periodically configured to (i) draw fluid from the reservoir 12 with the dosing chamber 52 in fluid communication with the reservoir 12 and not in fluid communication with the fluid line 50, and (ii) fluidly connect the dosing chamber 52 to the fluid line 50 (e.g., with the dosing chamber 52 not in fluid communication with the reservoir 12). For example, the pump and valve mechanism 42 can draw fluid from the reservoir 12 to fill the dosing chamber 52 with fluid from the reservoir 12 with the dosing chamber 52 in fluid communication with the reservoir 12 and not in fluid communication with the fluid line 50, and the pump and valve mechanism 42 can empty the fluid in the dosing chamber 52 and send the fluid to the fluid line 50 by connecting the dosing chamber 52 to the fluid line 50 (e.g., in a state where the dosing chamber 52 is not in fluid communication with the reservoir 12). In this way, the upstream fluid path of the pump and valve mechanism 42 (e.g., upstream of the dosing chamber 52) may not be in direct fluid communication with the downstream fluid path of the pump and valve mechanism 42, so that different pressures can be established in each of the upstream and downstream fluid paths.

[0045] Referring further to FIG. 4, the drug delivery device 10 can include a pressure sensor 54. The pressure sensor 54 can be configured to measure the pressure within a fluid path constituted by a reservoir 12, a pump and valve mechanism 42 downstream of the reservoir 12, and a fluid line 50 downstream of the pump and valve mechanism 42. The pressure sensor 54 may be provided in the downstream fluid path of the pump and valve mechanism 42 and / or in the upstream fluid path of the pump and valve mechanism 42. For example, the pressure sensor 54 can be configured to measure the pressure within the downstream (e.g., downstream of the dosing chamber 52, etc.) fluid path of the pump and valve mechanism 42 and / or within the upstream (e.g., upstream of the dosing chamber 52, etc.) fluid path of the pump and valve mechanism 42. The pressure sensor 54 can include at least one of an absolute pressure sensor, a differential pressure (e.g., gauge, etc.) sensor, or any combination thereof. The pressure sensor 54 may be miniaturized, may have high resolution, may be cost-effective, and / or may be optimized for low power consumption.

[0046] The microcontroller 24 can receive from the pressure sensor 54 the pressure measured within the fluid path, determine whether the fluid in the reservoir 12 is empty based on the pressure measured within the fluid path, and / or be programmed and / or configured to control an output device (e.g., a display, a light emitting diode (LED), a speaker, etc.) to provide an indication regarding the determination result of whether the fluid in the reservoir 12 is empty. The output device may be included in the drug delivery device 10 and / or may be integrated with the drug delivery device, and / or the output device may be an external device that is external to the drug delivery device 10 and communicates (e.g., wirelessly and / or via wireless communication, etc.) with the drug delivery device 10, such as the remote computing device and / or wireless controller (WC) 500 described in U.S. Patent No. 10,449,292 to Pizzochero et al., which is incorporated herein by reference, and may be included in and / or integrated with the external device.

[0047] In this way, referring also to FIGS. 5 - 7, when the dosing chamber 52 of the pump and valve mechanism 42 pumps out the fluid in the empty reservoir 12 to empty its volume and comes into fluid communication with the downstream fluid path (e.g., fluid line 50, etc.), the drug delivery device 10 can identify the pressure drop as a signature that the reservoir 12 is empty. For example, due to the vacuum pressure generated in the upstream fluid path upstream of the dosing chamber 52, a pressure signature that can be identified may appear in the downstream fluid path downstream of the dosing chamber 52.

[0048] In one aspect or embodiment, the microcontroller 24 is programmed and / or configured to determine whether the fluid in the reservoir 12 is empty by comparing the pressure measured in the fluid path with a threshold pressure and determining that the fluid in the reservoir 12 is empty when the pressure measured in the fluid path meets the threshold pressure. For example, the microcontroller 24 compares the pressure drop that occurs when the dosing chamber 52 of the pump and valve mechanism 42 is connected to the downstream fluid path (e.g., fluid line 50, etc.) with the threshold pressure, and can determine that the fluid in the reservoir 12 is empty when the pressure drop meets the threshold pressure.

[0049] In one aspect or embodiment, the microcontroller 24 is programmed and / or configured to determine whether the fluid in the reservoir 12 is empty by identifying the rate of change of the pressure measured in the fluid path based on the pressure measured in the fluid path, comparing the rate of change of the pressure measured in the fluid path with a threshold rate of change, and determining that the fluid in the reservoir 12 is empty when the rate of change of the pressure measured in the fluid path meets the threshold rate of change. For example, the microcontroller 24 compares the rate of change of the pressure measured in the fluid path during pumping (e.g., the rate of pressure increase, the rate of pressure decrease, the rate of change of the rate of pressure increase, the rate of change of the rate of pressure decrease, etc.) with the threshold rate of change, and can determine that the fluid in the reservoir 12 is empty when the measured rate of change meets the threshold rate of change.

[0050] In one aspect or embodiment, the microcontroller 24 is further programmed and / or configured to determine a reference pressure based on the pressure measured in the fluid path and to determine whether the reservoir 12 is empty based on the pressure measured in the fluid path and the reference pressure, before fluidly connecting the dosing chamber 52 to the fluid line 50. For example, the pressure signature measured in the fluid path can be offset by a reference pressure signature defined by the value of the pressure measured before connecting the dosing chamber 52 to the downstream fluid path.

[0051] In one aspect or embodiment, the output information regarding the determination of whether the fluid in the reservoir 12 is empty includes a notification that the treatment has been successfully completed, or a notification of a fault mode and / or that the reservoir has emptied earlier than expected. For example, the microcontroller 24 can be further programmed and / or configured to compare the time and / or pump cycle at which the reservoir 12 is determined to be empty (e.g., using the clock and / or counter of the microcontroller 24, etc.) with a threshold time and / or threshold pump cycle, and based thereon, to determine that the treatment has been successfully completed, or that there is a fault mode or that the reservoir has emptied earlier than expected, i.e., resulting in an insufficient dosage and / or potentially adversely affecting the treatment of the subject. As an example, when the time and / or pump cycle meets the threshold time and / or threshold pump cycle, the microcontroller 24 can determine that the treatment has been successfully completed. As an example, when the time and / or pump cycle does not meet the threshold time and / or threshold pump cycle, the microcontroller 24 can determine that the drug delivery device 10 is in a fault mode and / or that the reservoir 12 has emptied earlier than expected, i.e., resulting in an insufficient dosage and / or potentially adversely affecting the treatment of the subject.

[0052] Referring to FIG. 8, in one aspect or embodiment, a process 800 for pressure sensor-based empty reservoir detection for the drug delivery device 10 includes receiving fluid into the reservoir 12 (step 802), determining a reference pressure using the microcontroller 24 (e.g., by a pressure sensor 54, etc.) based on the pressure measured within the fluid path (step 804), delivering fluid from the reservoir 12 to the fluid line 50 using the pump and valve mechanism 42 (step 806), measuring the pressure within the fluid path using the pressure sensor 54 (step 808), receiving, by the microcontroller 24, the pressure measured within the fluid path (step 810), determining, by the microcontroller 24, whether the fluid in the reservoir 12 is empty based on the pressure measured within the fluid path (step 812), and controlling an output device using the microcontroller 24 to provide output information regarding the determination of whether the reservoir 12 is empty (step 814).

[0053] Accordingly, each non-limiting embodiment or aspect of the present application can provide a drug delivery device with low manufacturing costs, extremely low power consumption, a compact size, and / or a low computational load. According to this device, potentially existing hardware in the pump system can be utilized, and / or the device can be used with flexible reservoir bags, rigid containers, and / or containers such as syringes.

[0054] Each aspect or embodiment has been described in detail for purposes of illustration based on what is currently considered to be the most practical and preferred embodiments, but such details are for the above purposes only, and each aspect or embodiment of the present disclosure is not limited to the disclosed embodiments. On the contrary, it should be understood that the present disclosure is intended to cover modifications and equivalent configurations within the spirit and scope of the appended claims. For example, it should be understood that the present disclosure assumes that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

1. A fluid path including a reservoir, a pump downstream of the reservoir, and a fluid line downstream of the pump, wherein the reservoir is configured to receive fluid, and the pump is configured to deliver fluid from the reservoir to the fluid line; A pressure sensor configured to measure the pressure within the fluid path; A microcontroller; Comprising; The microcontroller; Receives the pressure measured within the fluid path from the pressure sensor; Based on the pressure measured within the fluid path, determines whether the fluid in the reservoir is empty, and controls an output device to provide output information regarding the determination of whether the fluid in the reservoir is empty; Programmed and / or configured to; Drug delivery device.

2. The drug delivery device according to claim 1, wherein the pressure sensor is within the fluid path downstream of the pump.

3. The drug delivery device according to claim 1, wherein the pressure sensor is within the fluid path upstream of the pump.

4. The microcontroller; Compares the pressure measured within the fluid path with a threshold pressure, and is programmed and / or configured to determine whether the fluid in the reservoir is empty by determining that the fluid in the reservoir is empty when the pressure measured within the fluid path meets the threshold pressure, as claimed in claim 1.

5. The microcontroller; Based on the pressure measured within the fluid path, identifies a rate of change regarding the pressure measured within the fluid path; Compares the rate of change regarding the pressure measured within the fluid path with a threshold rate of change, and determines whether the fluid in the reservoir is empty by determining that the fluid in the reservoir is empty when the rate of change regarding the pressure measured within the fluid path meets the threshold rate of change; Programmed and / or configured to; The drug delivery device according to claim 1.

6. The pump includes a dosing chamber; The pump periodically; (i) Draws out the fluid in the reservoir in a state where the dosing chamber is in fluid communication with the reservoir and not in fluid communication with the fluid line, and (ii) is configured to fluidly connect the dosing chamber to the fluid line; The drug delivery device according to claim 1.

7. The microcontroller is programmed and / or configured to determine a reference pressure based on the pressure measured in the fluid path before fluidly connecting the dosing chamber to the fluid line. The microcontroller is programmed and / or configured to determine whether the reservoir is empty based on the pressure measured in the fluid path and the reference pressure. The drug delivery device according to claim 6.

8. The pressure sensor of the drug delivery device according to claim 1 includes at least one of an absolute pressure sensor, a differential pressure sensor, or any combination of the absolute pressure sensor and the differential pressure sensor.

9. A method for pressure sensor-based empty reservoir detection for a drug delivery device including a fluid path including a reservoir configured to receive fluid, a pump downstream of the reservoir, and a fluid line downstream of the pump, comprising: Pumping fluid with the pump from the reservoir to the fluid line; Measuring the pressure in the fluid path with a pressure sensor; Receiving, by a microcontroller, the pressure measured in the fluid path; Determining, by the microcontroller, whether the fluid in the reservoir is empty based on the pressure measured in the fluid path; Controlling an output device by the microcontroller to provide output information regarding the determination of whether the fluid in the reservoir is empty. Method.

10. The method according to claim 9, wherein the pressure sensor measures the pressure in the fluid path downstream of the pump.

11. The method according to claim 9, wherein the pressure sensor measures the fluid in the fluid path upstream of the pump.

12. In determining whether the fluid in the reservoir is empty, Comparing the pressure measured in the fluid path with a threshold pressure; Determining that the fluid in the reservoir is empty when the pressure measured in the fluid path meets the threshold pressure. The method according to claim 9.

13. In determining whether the fluid in the reservoir is empty, Identifying a rate of change of the pressure measured in the fluid path based on the pressure measured in the fluid path; Comparing the rate of change of the pressure measured in the fluid path with a threshold rate of change; Determining that the fluid in the reservoir is empty when the rate of change of the pressure measured in the fluid path meets the threshold rate of change. The method according to claim 9

14. The pump includes a dosing chamber, In delivering fluid from the reservoir to the fluid line, Periodically, (i) the dosing chamber draws fluid from the reservoir while being in fluid communication with the reservoir and not in fluid communication with the fluid line, (ii) fluidly connecting the dosing chamber to the fluid line, The method according to claim 9.

15. Furthermore, Before fluidly connecting the dosing chamber to the fluid line, based on the pressure measured in the fluid path, a reference pressure is determined by the microcontroller, Whether the reservoir is empty is determined based on the pressure measured in the fluid path and the reference pressure, The method according to claim 14.

16. The pressure sensor includes at least one of an absolute pressure sensor, a differential pressure sensor, or any combination of the absolute pressure sensor and the differential pressure sensor, the method according to claim 9.

17. A microcontroller, A pressure sensor, A fluid path including a reservoir configured to receive fluid, a pump downstream of the reservoir, and a fluid line downstream of the pump, A computer program product for pressure sensor-based empty reservoir detection for a drug delivery device comprising: When executed by the microcontroller, To the microcontroller, Controlling the pump to deliver fluid from the reservoir to the fluid line, Controlling the pressure sensor to measure the pressure in the fluid path, Receiving the pressure measured in the fluid path, Based on the pressure measured in the fluid path, determining whether the fluid in the reservoir is empty and controlling an output device to provide output information regarding the determination of whether the fluid in the reservoir is empty, Including at least one non-transitory computer-readable medium including program instructions, Computer program product.

18. The microcontroller controls the pressure sensor to measure the pressure in the fluid path downstream of the pump, the computer program product according to claim 17.

19. The pump includes a dosing chamber, and the pump, Periodically, (i) With the administration chamber in fluid communication with the reservoir and not in fluid communication with the fluid line, pumping out the fluid in the reservoir, (ii) By fluidly connecting the administration chamber to the fluid line, delivering fluid from the reservoir to the fluid line, The computer program product according to claim 18.

20. The computer program product according to claim 17, wherein the microcontroller controls the pressure sensor to measure the pressure in the fluid path upstream of the pump.

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