Liquid detection sensor

Abstract

In one aspect, a system for determining a liquid level in a drug delivery device is presented. The system includes a first spring and a second spring positioned adjacent the first spring. The system includes a rod configured to compress at least the first spring and contact the second spring. The system includes a sensing element in communication with the first spring and the second spring. The sensing element is configured to detect a voltage difference of at least the first spring. At least the voltage difference of the first spring corresponds to an amount of liquid drug of the drug delivery device.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and interest in U.S. Provisional Application No. 63 / 612,734, filed December 20, 2023, and U.S. Provisional Application No. 63 / 494,407, filed April 5, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to apparatus, systems, methods, and kits for determining liquid levels in wearable medical devices. More specifically, this disclosure relates to a sensor for detecting liquid levels in wearable drug delivery devices. Background Technology

[0004] Many conventional drug delivery systems, such as handheld autoinjectors, are designed to deliver medications to patients quickly. These conventional drug delivery systems are generally not suitable for delivering medications to users over relatively long periods of time, which is necessary for many medications.

[0005] As an alternative to conventional autoinjectors, there are drug delivery systems designed to be worn (e.g., applied to a patient's skin) and deliver medication to the patient more slowly.

[0006] Wearable medication delivery devices are convenient, portable devices used to deliver medications during a user's daily activities. These devices may include a reservoir or cartridge to hold the medication to be delivered. The reservoir's capacity can be small enough to allow the delivery device to be worn and non-invasive. Importantly, users of wearable medication delivery devices know how much medication is in the device, or when the device is full, empty, or nearly empty, so they can add medication, refill it, or replace the device with another medication-containing device. Many medications delivered by wearable medication delivery devices require multiple injections or continuous delivery to maintain efficacy.

[0007] Traditional wearable medication delivery devices typically indicate that the device is empty when it is actually empty, without providing users with ongoing information about the amount of medication remaining in the device. When a user of a wearable medication delivery device receives a notification that their current device is empty and cannot deliver further medication, they may not be at home or may not have a new device available. Therefore, the user may not be able to immediately replace or refill the device, resulting in an under-treatment level.

[0008] Therefore, there is a need for improved drug delivery devices to have the ability to determine the fluid volume level within wearable drug delivery devices.

[0009] Furthermore, the filling tubes of currently demonstrated wearable medical devices occupy a large space, which limits the potential for device size and reduction in minimum filling requirements. They also present manufacturing challenges. Additionally, the systems and methods used to measure the amount of fluid dispensed by wearable medical devices can be cumbersome. Accordingly, improvements to wearable medical devices are possible. Summary of the Invention

[0010] In one aspect, a system for determining the liquid level in a pharmaceutical delivery device is proposed. The system includes a first spring and a second spring positioned adjacent to the first spring. The system includes a rod configured to compress at least the first spring and contact the second spring. The system includes a sensing element communicating with both the first and second springs. The sensing element is configured to detect a voltage difference in at least the first spring. This voltage difference in at least the first spring corresponds to the amount of liquid pharmaceutical in the pharmaceutical delivery device.

[0011] On the other hand, a device for a fluid meter in a pharmaceutical delivery system is proposed. The device includes a rod extending from a plunger end of the pharmaceutical delivery system, the rod having a first plurality of teeth. The device also includes a gear positioned below the rod and having a second plurality of teeth. The first and second plurality of teeth are configured to interface with each other. The device includes an encoder, wherein the encoder is configured to correlate the rotation angle of the gear with the amount of liquid pharmaceutical product dispensed.

[0012] On the other hand, a method for fuel gauging in a pharmaceutical delivery device is proposed. The method includes: moving a lever of the pharmaceutical delivery device to contact a first spring. The method also includes: contacting a second spring via the lever, wherein contacting the second spring creates a circuit between the first and second springs. The method includes sensing a voltage difference at least in the first spring by a sensing element communicating with the first and second springs. Finally, the method includes calculating the amount of liquid pharmaceutical in the pharmaceutical delivery device based on the voltage difference at least in the first spring by a processor communicating with the sensing element.

[0013] On the other hand, the embodiments described herein relate to a sensor for determining the liquid level in a pharmaceutical delivery device. The sensor for determining the liquid level in the pharmaceutical delivery device includes a first electrical contact, a second electrical contact electrically connected to the first electrical contact, and a conductive strip configured to slide across the first and second electrical contacts. The conductive strip can be configured to relay an electrical signal. The sensor can detect or determine electrical characteristics, such as the resistance between the first and second electrical contacts. This resistance can be used to determine the liquid level of the pharmaceutical product.

[0014] On the other hand, a method for determining the fluid volume in a pharmaceutical delivery device is described. This method may include the step of determining the resistance between a first electrical contact and a second electrical contact. The first electrical contact may be electrically connected to the second electrical contact via a conductive strip of variable length. The determined resistance may be compared with a memory or table of known resistances associated with a known fluid volume. Based on the comparison result, the known fluid volume can be identified.

[0015] On the other hand, a system for detecting the volume of a liquid medicine in a reservoir of a pharmaceutical delivery device is described. The system may include a reservoir, a plunger, a conductive strip, a first contact, and a circuit system. The reservoir may include a first end and a second end opposite to the first end. The plunger may be positioned within the reservoir and operable to move within the reservoir. The conductive strip may be coupled to the plunger and configured to maintain contact with the plunger as the plunger moves within the reservoir. The first contact is operable to contact the conductive strip at a first position and a second position, and a second contact is operable to contact the conductive strip at both positions. The circuit system may be coupled to the first and second contacts of the conductive strip. The circuit system is operable to determine the volume of the liquid medicine based on the length of the conductive strip between the first and second contacts of the conductive strip. Attached Figure Description

[0016] FIGS. 1A-1E An exemplary embodiment of a reservoir with different liquid levels suitable for use in a wearable drug delivery device is illustrated.

[0017] FIG. 2 An exemplary embodiment of a sensor for a reservoir in a wearable drug delivery device is illustrated.

[0018] FIG. 3 The illustration shows an exemplary circuit used to explain the operation of a sensor for determining liquid level in the example described herein;

[0019] FIGS. 4A-4E An exemplary embodiment of another sensor suitable for identifying different liquid levels in a reservoir of a pharmaceutical delivery device is illustrated.

[0020] FIGS. 5A-5E Various views illustrating exemplary embodiments of the empty reservoir of the wearable drug delivery device are shown;

[0021] FIGS. 6A-6E Various views of an exemplary embodiment of a filled reservoir for a wearable drug delivery device are illustrated.

[0022] FIG. 7A and FIG. 7B An exemplary embodiment of a reservoir of a wearable drug delivery device is illustrated, which has a sensor for determining the liquid level in the reservoir.

[0023] FIG. 8 The illustration shows a schematic diagram of a drug delivery system according to an embodiment of the present disclosure;

[0024] FIG. 9A The illustration shows a perspective view of a drug delivery system according to an embodiment of the present disclosure;

[0025] FIG. 9B The illustrations depict embodiments according to the present disclosure. FIG. 9A A detailed perspective view of a portion of an example of a drug delivery system;

[0026] FIG. 9C The illustrations depict embodiments according to the present disclosure. FIG. 9A A top view of an example of the drive mechanism of a drug delivery system;

[0027] FIG. 10 An exemplary embodiment of a system for a fluid meter used in a wearable medical device is illustrated;

[0028] FIG. 11 The diagram shows FIG. 10 A perspective view of the system shown;

[0029] FIGS. 12A-12C The diagram shows FIG. 10 Various views of the system;

[0030] FIG. 13 The diagram illustrates the relationship with FIG. 10 A schematic diagram of the overlapping circuits in the system;

[0031] FIG. 14 The diagram shows FIG. 10 A side view of the system;

[0032] FIG. 15 Another side view of an embodiment of a fluid meter system for wearable medical devices is illustrated;

[0033] FIG. 16 Another embodiment of a system for a fluid meter used in a wearable medical device is illustrated in the side view.

[0034] FIG. 17 An embodiment of a plunger end with a flange is illustrated;

[0035] FIGS. 18A-18B An embodiment of a spring used in a fluid gauge system is illustrated;

[0036] FIG. 19 The diagram illustrates a gear system for a fluid meter used in wearable medical devices; and

[0037] FIG. 20 The diagram shows FIG. 19 A side view of the gear system. Detailed Implementation

[0038] This disclosure presents various systems, components, and methods related to sensors for detecting liquid levels in reservoirs of medical devices, such as wearable drug delivery devices. Each of the systems, components, and methods disclosed herein offers one or more advantages over conventional systems, components, and methods. Various embodiments of sensors, wearable drug delivery device systems, components, and methods for detecting liquid levels in reservoirs are disclosed herein.

[0039] Software-related implementations of the techniques described herein may include, but are not limited to, firmware, proprietary software, or any other type of computer-readable instructions that can be executed by one or more processors.

[0040] Hardware-related implementations of the technologies described herein may include, but are not limited to, integrated circuits (ICs), application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), and / or programmable logic devices (PLDs). In some examples, the technologies and / or any systems or components described herein may be implemented by a processor that executes computer-readable instructions stored on one or more memory components.

[0041] As described herein, the term "plunger end" refers to one end of the reservoir located adjacent to the plunger when the reservoir is full. For example, when the reservoir is full of liquid, the plunger end of the reservoir may be adjacent to the plunger seal. In another example, the plunger end is the end of the reservoir through which the plunger shaft passes.

[0042] As described herein, aspects of this disclosure relate to a sensor for determining the liquid level in a reservoir of a wearable medication delivery device. The liquid level can be, for example, the amount of liquid medication remaining in the device's reservoir. A user or the processor of the wearable medication delivery device can use the amount of liquid medication remaining in the reservoir of the wearable medication delivery device to determine when the wearable medication delivery device needs to be replaced or refilled. The sensor can determine the liquid level by determining resistance or other characteristics based on the position of the plunger in the wearable medication delivery device.

[0043] FIGS. 1A-1EExemplary embodiments of a reservoir system and other components of a wearable drug delivery device integrating a liquid level sensor are illustrated. The reservoir system 9 of the wearable drug delivery device may have at least a reservoir 8, a plunger 11, and a liquid level sensor 13. The reservoir 8 may include a plunger end 10 and a leak-proof reservoir base 17. An inlet port 19 may be coupled to and pass through the leak-proof reservoir base 17. The inlet port 19 is operable for filling the reservoir 8 and may include a one-way valve or diaphragm to prevent leakage of liquid drug 3 from the reservoir 8. The plunger 11 may have a plunger shaft 12 and a plunger sealing end 18. The plunger sealing end 18 is configured to be housed within the reservoir 8 to form a leak-proof seal between it and the leak-proof reservoir base 17. The plunger shaft 12 is coupled to the plunger sealing end 18 and a drive mechanism (not shown).

[0044] Sensor 13 may include a first electrical contact 14, a second electrical contact 16, and a conductive strip 20. In some embodiments, the first electrical contact 14 is located at the plunger end 10 of the reservoir 8. In one example, the first electrical contact 14 is positioned outside the plunger end 10 of the reservoir 8, while in another example, the first electrical contact 14 is positioned inside the plunger end 10 of the reservoir 8. In yet another example, the first electrical contact 14 is positioned through the plunger end 10 of the reservoir 8.

[0045] exist FIGS. 1A-1E In this example, the conductive strip 20 contacts a second electrical contact 16 located on the plunger sealing end 18. The plunger shaft 12 extends from the plunger sealing end 18 to a position beyond the plunger end 10 of the reservoir 8. For example, the conductive strip 20 may extend from the second electrical contact 16 at least to the first electrical contact 14. In this example, as the reservoir 8 is filled with and emptied of the liquid medicine 3, the conductive strip 20 is operable to slide back and forth across the first electrical contact 14 as the plunger 13 moves.

[0046] In some embodiments, a portion of the conductive strip 20 (referred to herein as the overhang portion 22) may extend beyond the first electrical contact 14 as the plunger 13 may move, for example as... FIGS. 1B-1D As shown. For example. FIG. 1C The suspended portion 22 in the reservoir 8, which is filled with more liquid, is more than FIG. 1D The reservoir 8 shown is longer.

[0047] When the reservoir 8 is filled with liquid medicine 3, the overhang portion 22 of the conductive strip 20 can be longer. For example, when the plunger sealing end 18 moves toward the plunger end 10 of the reservoir 8 to accommodate the liquid medicine 3 flowing into the reservoir 8, the conductive strip 20 can slide beyond the first electrical contact 14 to form the overhang portion 22.

[0048] The conductive strip 20 may be made of, for example, a metallic material, graphene, carbon nanotubes, or a combination thereof, and may also be in the form of a wire, etc., as an alternative to the strip. In some embodiments, the conductive strip 20 is a wire. In some embodiments, when the reservoir 8 is filled with liquid medicine 3 through the inlet port 19, the plunger sealing end 18 and the plunger shaft 12 move toward the plunger end 10 of the reservoir to allow the liquid medicine 3 to fill the reservoir 8.

[0049] FIGS. 1A-1C The illustration shows the progress of the liquid drug 3 level in reservoir 8 as the reservoir is filled. FIG. 1C The diagram illustrates the basis FIG. 1A and FIG. 1B The example shown illustrates the response of the level sensor 13 and the final amount of liquid medicine in the reservoir 8. For example, FIG. 1B The diagram shows reservoir 8, which is filled with a specific amount of liquid. FIG. 1A The reservoir 8 shown contains more liquid. FIGS. 1C-1E The diagram illustrates the progression of the liquid reservoir 8 as the amount of liquid medicine gradually decreases, and the corresponding response of the level sensor 13. For example, in response to the plunger 11 being pressed to displace the liquid medicine from the reservoir 8, liquid medicine 3 can be discharged.

[0050] As the liquid medicine level in reservoir 8 (e.g.) FIGS. 1A-1C As the position of the plunger 11 changes (as shown), the length of the overhang portion 22 of the conductive strip 20 can increase. As the liquid level in the reservoir 8 rises, the distance between the first electrical contact 14 and the second electrical contact 16 can decrease because the plunger sealing end 18 moves closer to the plunger end 10. In some embodiments, a tensioner (not shown in this example) is connected to the first electrical contact 14 to maintain tension in the conductive strip 20.

[0051] FIGS. 1A-1E The example illustrates how the conductive strip 20 can be configured to slide across the first electrical contact 14 and the second electrical contact 16, wherein the conductive strip is electrically connected to the first electrical contact 14 and the second electrical contact 16. As shown in the later examples, the first electrical contact 14 and the second electrical contact 16 can also be coupled to a sensor circuit system, as described in more detail with reference to the later examples.

[0052] FIG. 2Another exemplary embodiment of a liquid level sensor arrangement within the reservoir of a wearable drug delivery device is illustrated. The liquid level sensor arrangement 201 may include a first electrical contact 24, a second electrical contact 26, and a conductive strip 28. The second electrical contact 26 may be positioned at a plunger seal end 28. The plunger seal end 28 may move upward toward the first electrical contact 24 or downward away from the first electrical contact 24 in the direction indicated by arrow 25. In this example, the second electrical contact 26 may be fixed to the plunger seal end 28. In some embodiments, the conductive strip 22 may extend from the first electrical contact 24 to the second electrical contact 26. The conductive strip 24 may be similar to... FIGS. 1A-1E The conductive strip 20 in the example is configured. FIG. 2 In this example, the first electrical contact 24 and the second electrical contact 26 may have a loop surrounding the conductive strip 28 or may be filaments within a loop touching the surface of the conductive strip 22. Alternatively, the first electrical contact 24 and the second electrical contact 26 may each have a generally loop-shaped structure. The first electrical contact 24 and the second electrical contact 26 are made of a highly conductive material that minimizes unwanted resistance. In this example, the conductive strip 22 may pass through or be wound around the loop coupled to the first electrical contact 24. For example, one or more wires may be soldered, glued, or otherwise connected to one or more loops to connect the first electrical contact 24 and the second electrical contact 26 to the sensor processing assembly.

[0053] FIG. 3 The illustration shows an exemplary circuit representation suitable for determining the liquid level in a reservoir of a wearable drug delivery device. In some embodiments, sensor 310 detects a change in an electrical characteristic (such as resistance) between a first electrical contact 34 and a second electrical contact 36. Variable electrical characteristics (e.g., current or voltage) can change along a path from the first electrical contact 34 (also referred to as the top ring, such as...) FIG. 2 24) extends through conductive strip 30 to second electrical contact 36 (also known as bottom ring, such as...) FIG. 2 The electrical path (26) is detected. Variable electrical characteristics can be used to determine resistance (e.g., R in Ohm's law R=V / I, where V is voltage and I is current). For example, current (I) can flow from at least the first contact 34 through the conductive strip 30 to the second contact 36. The current flowing from the first contact 34 through the conductive strip 30 to the second contact 36 can be a low current (e.g., one-tenth of a milliamp, microamp, etc.). In some embodiments, the sensor 35 may have a circuit system operable to detect a change in voltage between the first contact 34 and the second contact 36 when the current is known. Using the value of the detected voltage or the detected change in the value of the voltage, the resistance can be determined by the circuit system in the sensor 35 according to Ohm's law.

[0054] In the example, the resistance between the first electrical contact 34 and the second electrical contact 36 may increase as the length of the conductive strip 30 between the first electrical contact 34 and the second electrical contact 36 increases. Alternatively, the resistance between the first electrical contact 34 and the second electrical contact 36 may decrease as the length of the conductive strip 30 between the first electrical contact 34 and the second electrical contact 36 decreases.

[0055] Additionally or alternatively, the voltage between the first electrical contact 34 and the second electrical contact 36 can be detected, and this voltage varies based on the length of the conductive strip 30. In this example, the resistance can be determined by multiplying the resistivity of the material forming the conductive strip 30 by the length of the conductive strip 30 and dividing the result by the area of ​​the conductive strip 30, etc. Alternatively, a lookup table can be established with reference values, such as a reference resistance, a reference voltage, a reference current, a reference conductive strip length, some other reference value, or a combination of reference values, corresponding to the amount of liquid medicine remaining in the reservoir or discharged from the reservoir. The lookup table can be stored in a memory coupled to the sensor circuitry 35, to a processor coupled to the sensor circuitry 35, etc.

[0056] FIGS. 4A-4E Another exemplary embodiment of a sensor arrangement for a reservoir in a wearable drug delivery device is illustrated. The reservoir 48 of the wearable drug delivery device may have a plunger end 40 and a leak-proof reservoir base 47. The plunger 41 may include a plunger shaft 42 and a plunger sealing end 43. The plunger sealing end 43 is configured to be housed within the reservoir 48 to form a leak-proof seal between itself and the leak-proof reservoir base 47. The plunger shaft 42 is coupled to the plunger sealing end 43 and to a drive mechanism (not shown). The reservoir 48 may include a first electrical contact 114, a second electrical contact 116, a conductive strip 120, a first alignment member 126, and a second alignment member 128. For example, as... FIG. 4A As shown, the first electrical contact 114 can be fixed to the plunger end 40. The inlet port 49 can be coupled to and pass through the leak-proof reservoir base 47. The inlet port 49 is operable for filling the reservoir 48 and may include a one-way valve or diaphragm to prevent leakage of the liquid medicine 3 from the reservoir 48.

[0057] The sensor arrangement may include a configuration in which the second electrical contact 116 can be secured to the other side of the plunger end 40. For example, a first alignment member 126 may be attached to a first portion of the plunger sealing end 43. A second alignment member 128 may be attached to a second portion of the plunger sealing end 43. When the first alignment member 126 and the second alignment member 128 are present, a conductive strip 120 extends downward from the first electrical contact 114 to the first alignment member 126, across a portion of the plunger sealing end 43 to the second alignment member 128, and extends to the second alignment member 128. Furthermore, the conductive strip 120 may be held in a predetermined tension state between the first electrical contact 114 and the second electrical contact 116 by a tensioner (shown in later examples). Additionally or alternatively, the conductive strip 120 may be held in a predetermined tension state between the first electrical contact 114, the first alignment member 126, the second alignment member 128, and the second electrical contact 116 by one or more tensioners (shown in later examples).

[0058] In another example, the conductive strip 120 may be configured to slide over at least one of the first electrical contact 114 and the second electrical contact 116, or slide over both the first electrical contact 114 and the second electrical contact 116. As the reservoir 48 fills with liquid and the plunger sealing end 43 moves toward the plunger end 40, the conductive strip 120 may have a first loose end 122 and a second loose end 124 extending from the first electrical contact 114 and the second electrical contact 116, respectively, for example as... FIG. 4B As shown in the figure. In some embodiments, the variable electrical characteristics detected between the first electrical contact 114 and the second electrical contact 116 exclude any contribution from the first loose end 122 and the second loose end 124 of the conductive strip 120, since the length of the conductive strip 120 forming the respective first loose end 122 and the second loose end 124 is in an open circuit.

[0059] In another embodiment, an optional first tensioner 125 may be coupled to a first electrical contact 114 and an optional second tensioner 127 may be coupled to a second electrical contact 116. For ease of illustration, the optional first tensioner 125 and the optional second tensioner 127 are only used in conjunction with the first electrical contact 116. FIG. 4A As shown, but it should be understood that optional first tensioner 125 and optional second tensioner 127 may also appear. FIGS. 4B-4E The first and second tensioners 125 and 127 can be configured to maintain the conductive strip 120 at a preset minimum tension. This preset minimum tension is maintained as the plunger sealing end 43 moves up and down within the reservoir 48, thereby allowing the liquid medicine ( FIG. 4A (Not shown) Filling the reservoir 48 and discharging the liquid medicine from the reservoir 48.

[0060] FIGS. 4A-4C The illustration shows the progress of filling the reservoir 48 of a wearable drug delivery device with an increasing level of liquid drug 3. FIGS. 4A-4C In the progress shown, FIG. 4C The liquid with the largest quantity is 3. FIG. 4B The amount of liquid medicine 3 in the reservoir 8 shown can be greater than FIG. 4A The quantity shown, but less than FIG. 4C The quantities shown. As... FIG. 4C As shown, as the liquid level of the liquid medicine 3 in the reservoir 48 increases, the lengths of the first loose end 122 and the second loose end 124 can be increased. FIGS. 4C-4E The illustration shows the progress of liquid medicine 3 as it is discharged from reservoir 48. Liquid can be discharged by pressing plunger 41 into reservoir 48 to discharge liquid medicine 3 from reservoir 48. FIG. 4D and FIG. 4E The amount of liquid medicine 3 in the reservoir 48 shown gradually decreases. FIG. 4C The amount of liquid medicine 3 shown.

[0061] FIGS. 5A-5E Various views of an exemplary embodiment of the sensor arrangement for the reservoir 58 are illustrated.

[0062] like FIG. 5A As shown, reservoir 58 is depicted as substantially empty or with a liquid drug level of zero. Reservoir 58 may have a first conductive strip 520 extending from a first electrical contact to a first alignment member 526, then to a second alignment member 528, and finally to a tension meter 538. In some embodiments, a protrusion 551 extending from reservoir cap 50 is the first electrical contact. Reservoir may have a second conductive strip 521 extending from tension meter 538 to a third alignment member 530, then to a fourth alignment member 532, and upward to a second electrical contact (not shown). In some embodiments, this electrical contact is connected to a tensioner 540. In some embodiments, this electrical contact is located below reservoir cap 50.

[0063] In some embodiments, the first conductive strip 520 and the second conductive strip 521 are a single component. In some embodiments, the first conductive strip 520 and the second conductive strip 521 are separate components. In some embodiments, the resistance between the first electrical contact and the second electrical contact is measured.

[0064] exist FIG. 5AIn the example shown, the first alignment member 526, the second alignment member 528, the third alignment member 530, and the fourth alignment member 532 can all be fixedly deployed on the surface of the plunger sealing end 518. The first alignment member 526 and the fourth alignment member 532 can be deployed on the outer end of the surface of the plunger sealing end 518, while the second alignment member 528 and the third alignment member 530 can be deployed more closely together on the inner end of the surface of the plunger sealing end 518. As shown, the first alignment member 526 and the fourth alignment member 532 can be deployed on either side of the plunger shaft 52. In some embodiments, the second alignment member 528 and the third alignment member 530 are made of a conductive material. In some embodiments, the first alignment member 526 and the fourth alignment member 532 are made of a non-conductive material.

[0065] In some embodiments, the reservoir 58 may include one or more tensioners 540. The tensioners 540 may hold the second conductive strip 521 at a preset minimum tension as it passes through each alignment member. The tensioner 540 may be, for example, a small spring on a wheel configured to apply tension to a portion of the second conductive strip 521 by pressing the wheel against it. Other forms of applying tension to the second conductive strip 521, known to those skilled in the art, are of course conceivable. In some embodiments, the tensioner 540 is located inside the reservoir 58. In some embodiments, the tensioner 540 is located outside the reservoir 58. In some embodiments, the tensioner 540 abuts an inner or outer surface of the reservoir 58.

[0066] In some embodiments, at least one of the first alignment member 526, the second alignment member 528, the third alignment member 530, or the fourth alignment member 532 is a hook configured to hold at least one of the first conductive strip 520 and the second conductive strip 521. In another embodiment, at least one of the first alignment member 526, the second alignment member 528, the third alignment member 530, or the fourth alignment member 532 is a loop configured to hold at least one of the first conductive strip 520 and the second conductive strip 521. Alternatively, at least one of the first alignment member 526, the second alignment member 528, the third alignment member 530, or the fourth alignment member 532 is generally a spring washer, a U-bolt, an eye bolt, a hook, a ring, a washer, a ring clip, a wiring clip, a standoff clamp, a safety hook, a rope loop, a clevis-end plug-lock, an eye-end plug lock, a swivel hook-end plug lock, a feedthrough end fitting, or any other fitting capable of aligning at least one of the first conductive strip 520 and the second conductive strip 521. The corresponding alignment members 526, 528, 530, and 532 may be formed (e.g., molded or welded) into the plunger sealing end 518 as part of the surface of the plunger sealing end 518. FIG. 5A As further shown, alignment members 526 and 532 have open surfaces that open in a direction opposite (or away from) the other alignment members 528 and 530. In the example, the radius of the open surface of alignment member 526 allows the first conductive strip 520 to exit alignment member 526 at an angle to engage with the open surface of the second alignment member 528. In some embodiments, the structure and layout of alignment members 530 and 532 are configured similarly to those of alignment members 526 and 528.

[0067] In some embodiments, the reservoir 58 has a tension meter 538 deployed around the plunger shaft 52. In some embodiments, the tension meter 538 is connected to a first conductive strip 520 and a second conductive strip 521 at the plunger sealing end 518. In some embodiments, the tension meter 538 acts as a potentiometer to provide variable resistance. In an operational example, when the reservoir 58 is empty, at least one of the first conductive strip 520 and the second conductive strip 521 can apply different levels of tension to the tension meter 538 compared to when the reservoir 58 is full or even partially filled.

[0068] like FIG. 5BAs shown, the reservoir 58 is depicted as being substantially full of liquid medicine. When the reservoir 58 is full of liquid, the plunger sealing end 8 is positioned adjacent to the reservoir plunger end 51. For example, when the reservoir 58 is empty, at least one of the first conductive strip 520 and the second conductive strip 521 does not cause rotation or turning of the tension gauge 538. FIG. 5C The illustration shows how the turns of the tension gauge coil or spring are evenly spaced and how the connection between each turn and the first conductive strip 520 is closest to the third alignment member 530.

[0069] FIG. 5D An example of the reservoir is illustrated from a view facing the reservoir cap 50. When the plunger sealing end 518 moves closer to the plunger end 51 or the reservoir cap 50 (such as when the device is being filled with liquid), the spring of the tension gauge 538 is configured to pull a larger portion of the first conductive strip 520 and the second conductive strip 521 around the circumference of the plunger shaft (see [reference]). FIG. 6C (Example shown). As the reservoir 58 is filled, the connection between the first conductive strip 520 and the tension meter 538 rotates about the tension meter spring from a position adjacent to the third alignment member to a position between the second alignment member 528 and the third alignment member 530. Accordingly, the potential of the tension meter 538 (i.e., the resistance of the potentiometer) changes.

[0070] In this example, the measured resistance may be related to or correspond to the liquid level in reservoir 58. Alternatively, or additionally, the measured resistance may be used to calculate the liquid level in reservoir 58.

[0071] exist FIG. 5C In the example, at least a portion of the tension gauge 538 is deployed between the second alignment member 528 and the third alignment member 530. In some embodiments, at least one of the first conductive strip 520 and the second conductive strip 521 at least partially wraps around the plunger shaft 52. Alternatively, at least one of the first conductive strip 520 and the second conductive strip 521 may wrap around the plunger shaft 52 several times. In some embodiments, the increased length of at least one of the first conductive strip 520 and the second conductive strip 521 due to its wrapping around the plunger shaft 52 provides a more accurately determined resistance, a determined liquid level, or a combination thereof.

[0072] FIG. 5EAn example of a current path 550 passing through at least a portion of the reservoir 58 is illustrated. Current can flow from the tensioner 540 to the second conductive strip 521, to the third alignment member 530, to the second alignment member 528, through the first conductive strip 520, and to the protrusion 551 connected to the reservoir cap 50. In some embodiments, the tension gauge 538 is made of a non-conductive material. In some embodiments, the tension gauge 538 creates a discontinuity between the first conductive strip 520 and the second conductive strip 521.

[0073] FIGS. 6A-6E Various views of an exemplary embodiment of a reservoir 68 at least partially filled with liquid are illustrated. FIG. 6A As shown, the reservoir 68 may include a first alignment member 626, a second alignment member 628, a third alignment member 630, and a fourth alignment member 632. The reservoir may include a tensioner 640. FIG. 6A An example is shown in which the reservoir 68 is more than half-filled with liquid medicine 3. The structure and function of the first alignment member 626, the second alignment member 628, the third alignment member 630, and the fourth alignment member 632 are similar to those of the other alignment members. FIGS. 5A-5E The first alignment member 526, the second alignment member 528, the third alignment member 530, and the fourth alignment member 532 described in the example are similar.

[0074] For example, such as FIG. 6B As shown, because the lower portion of the chamber is filled with liquid, the plunger sealing end 618 can move closer to the plunger end 61. In some embodiments, as the plunger sealing end 618 moves closer to the plunger end 61, the tension in the first conductive strip 620 between the first electrical contact (not shown) and the first alignment member 626 decreases. In some embodiments, the decrease in tension of the first conductive strip 620 is detected by a tension meter 638. In some embodiments, the first conductive strip 620 is at least partially wound around the plunger shaft 62 in the tension meter 638, for example as... FIG. 6C As shown in the diagram. In some embodiments, at least one of the first conductive strip 620 and the second conductive strip 621 is wound around the tension meter 638 such that the tension meter 638 rotates at least partially about the plunger shaft 62. In some embodiments, the rotation of the tension meter 638 produces a defined electrical variable that differs from that defined variable in the reservoir 68 at different liquid levels. In some embodiments, the rotation of the tension meter 638 is used to determine resistance. In some embodiments, the determined resistance is related to or used to determine the liquid level in the reservoir 68. FIG. 6D An example of a reservoir is illustrated from a view facing the reservoir cap 60.

[0075] FIG. 6EAn example of a current path 650 passing through at least a portion of the reservoir 68 is illustrated. Current can flow from the tensioner 640 to the second conductive strip 621, to the third alignment member 630, to the second alignment member 668, through the first conductive strip 620, and to the protrusion 651 connected to the reservoir cap 60. In some embodiments, the tension gauge 638 is made of a non-conductive material. In some embodiments, the tension gauge 638 creates a discontinuity between the first conductive strip 620 and the second conductive strip 621.

[0076] FIG. 7A and FIG. 7B An exemplary embodiment of a liquid reservoir with a wearable drug delivery device is illustrated, the reservoir having a sensor for determining the liquid level in the reservoir. For example, FIG. 7A An embodiment of a reservoir 8 is illustrated, comprising a plunger end 310, a plunger shaft 12, a first electrical contact 314, a second electrical contact 316, a filling rod or conductive strip 320, and an insulating strip 370. In some embodiments, resistance is determined by detecting an electrical change in the first electrical contact 314 through the conductive strip 320 and to the second electrical contact 316. In some embodiments, this electrical change corresponds to or is used to determine the liquid level in the wearable drug delivery device 8. In some embodiments, at least one of the first electrical contact 314 and the second electrical contact 316 is a spring. Both the first electrical contact 314 and the second electrical contact 316 can be springs or flexible conductive members that can bend away when the conductive strip 320 moves between them, while still maintaining contact with the conductive strip 320. In some embodiments, electrical contacts 314 and 316 may be touching or directly electrically connected before the conductive strip 320 is moved between them, such that the resistance between electrical contacts 314 and 316 is practically zero in the initial state. In alternative embodiments, electrical contacts 314 and 316 may not be touching or directly electrically connected before the conductive strip 320 is moved between them, such that the resistance between electrical contacts 314 and 316 is practically infinite in the initial state.

[0077] In some embodiments, the conductive strip 320 is configured to slide through the first electrical contact 314 and the second electrical contact 316, simultaneously touching both the first electrical contact 314 and the second electrical contact 316. For example... FIG. 7B As shown, the conductive strip 320 can be coupled to the plunger sealing end 18. The conductive strip 320 can further slide out of the reservoir 8 as the plunger moves within the reservoir and liquid is added to the wearable drug delivery device 8. The conductive strip 320 can further slide into the reservoir 8 as liquid is discharged from the wearable drug delivery device 8. The conductive strip 320 can be coupled to the plunger sealing end 18 (e.g., see...). FIG. 7BIn some embodiments, the conductive strip 320 is bent into a "U" shape, wherein an optional insulating strip 370 is deployed in the interior or concave surface of the conductive strip 320 to prevent the two sides of the conductive strip 320 from directly contacting each other at a location away from the "U"-shaped end. In some embodiments, the conductive strip 320 is bent into two halves, wherein an insulating strip 370 is deployed between the first half and the second half. The insulating strip 370 prevents the inner surface of the first half of the conductive strip 320 from touching the inner surface of the second half of the conductive strip 320. The insulating strip 370 keeps the first half of the conductive strip 320 electrically insulated from the second half of the conductive strip 320. In some embodiments, the insulating strip 370 may simply be air. Except at the fold at the U-shaped end, the sides of the conductive strip 320 remain electrically insulated from each other, and the resistance or other electrical characteristics between the electrical contacts 314, 316 can be measured along this conductive strip 320. The resistance along the filler bar or conductive strip 320 can be measured at the open end of the folded strip by two fixed contacts (such as electrical contacts 314 and 316), each contacting an alternating side of the conductive strip 320.

[0078] As the filling rod moves between electrical contacts 314 and 316, the length of the conductive path between the contacts changes. This causes a continuous change in resistance. The resistance can be correlated with the position of the pump plunger, and the filling volume can be determined based on the plunger's position. Since the volume of the reservoir is known, the plunger's position can be used to determine the volume of liquid medicine in the reservoir.

[0079] Furthermore, as the conductive strip 320 moves past and contacts the first electrical contact 314 and the second electrical contact 316, electrical characteristics, such as resistance, can be measured. In some embodiments, the processor compares the determined electrical variable or resistance with a known threshold electrical variable or resistance. In some embodiments, when the determined variable or resistance exceeds the threshold variable or resistance, the reservoir can enter an activation or start-up mode, or a signal can be generated to output data related to the reservoir's fill level to a remote device. For example, the reservoir can enter an activation or start-up mode when the determined variable or resistance is higher or lower than the threshold variable or resistance, and this threshold variable or resistance can correspond to a specific volume of the drug within the reservoir, such as 50 units of liquid drug. Other thresholds and corresponding liquid drug volumes can be used, such as 1 unit, 10 units, 25 units, 50 units, 85 units, 100 units, 200 units, or 300 units. Lower values ​​(such as 1 unit) can correspond to low resistance values ​​and indicate that the liquid medicine has just begun to be injected into the reservoir, and the conductive strip 320 has just begun to make electrical contact with the electrical contacts 314, 316. Higher values ​​(such as 200 units or 300 units) can correspond to high resistance values ​​and indicate that the reservoir is now completely filled with liquid medicine. Any variation between these values ​​is possible, and as explained above, different resistance values ​​between the electrical contacts 314, 316 can correspond to the precise position of the plunger inside the reservoir, and thus to the precise volume of liquid medicine inside the reservoir.

[0080] The sensor can be configured for self-calibration. The sensor can be calibrated to record a fully extended plunger (located inside the reservoir) as an empty or baseline resistance value. In some embodiments, the determined resistance is compared to a lookup table having known resistance values ​​corresponding to a known fluid volume of the wearable drug delivery device 8. The lookup table can be stored in memory on the wearable drug delivery device. In some embodiments, the determined resistance value is used in an equation to calculate the fluid volume of the wearable drug delivery device 8. In some embodiments, the resistance is correlated with the fluid level of the wearable drug delivery device 8 and the position of the plunger. These determinations and calculations can be performed directly on the wearable medical device and output to a user device to indicate whether the user's wearable medical device is activated and how much liquid medicine is inside the reservoir of the wearable medical device. The position of the plunger and / or the amount of liquid medicine inside the reservoir can be output to the user device periodically (e.g., every 5 minutes), or at any time when the volume of liquid medicine inside the reservoir changes, or at any time when the volume of liquid medicine inside the reservoir changes by a threshold amount (e.g., 1 unit). In this way, users can be continuously informed of the status of the wearable medical device and how much liquid medication remains in the reservoir.

[0081] FIG. 8 A simplified block diagram of an example pharmaceutical delivery system is shown. The pharmaceutical delivery system 800 may include a medical device 802, a controller 821, a memory 823, an application application 829 and a delivery control application 899 stored in the memory 823, a drive mechanism 824, a communication device 826, one or more level sensors 822, a user interface 827, and a power supply 828. The memory 823 may be operable to store application and programming code, including the delivery control application 899, the application application 829, data, and a level lookup table 849. The delivery control application 899 and the application application 829 may optionally be stored on other devices. The level lookup table 849 may include different electrical characteristics of one or more level sensors 822, each corresponding to a specific level of the liquid pharmaceutical product in the reservoir 825 (i.e., the volume of the liquid pharmaceutical product, the number of units of the liquid pharmaceutical product, or a decimal or fractional indication of the level (such as 0.6 or 1 / 2, etc.)). Controller 821 may be operable to access level lookup table 849 and compare electrical characteristics received from level sensor(s)(s)822 with data in level lookup table 849 to determine or identify the level of the liquid medicine in reservoir 825. Alternatively, controller 821 may be operable to calculate (e.g., by using logic or software implementing Ohm's law, or a combination of both) the level of the liquid medicine in reservoir 825. Communication device 826 may be operable to transmit the level of the liquid medicine in reservoir 825 to an external device (such as a personal diabetes management device) in response to a command from controller 821 for presentation to a user.

[0082] AP application 829 may be operable to perform various functions related to open-loop operation, such as determining the daily total settings for a drug or combination of drugs, such as the daily total insulin setting. In the example, AP application 829 is configured to provide automated insulin delivery via delivery control application 899 based on analyte sensor inputs, such as signals received from analyte sensors (such as continuous glucose monitors). Delivery control application 899 may, for example, be operable to interpret the signals provided by AP application 829 or apply them to drive mechanism 824 and / or user interface 827.

[0083] Controller 821 may be coupled to drive mechanism 824 and memory 823. Controller 821 may include logic circuitry, clocks, counters or timers, and other processing circuitry systems, and is operable to execute application and programming code, including delivery control application 899, stored in memory 823. Communication device 826 may be communicatively coupled to controller 821 and is operable to communicate wirelessly with external devices, such as personal diabetes management devices, smart devices such as smartphones and / or smartwatches.

[0084] Drive mechanism 824 may be operable to deliver medications, such as insulin, at a fixed or variable rate. For example, an AP application or AID algorithm executing on a personal diabetes management device or smartphone may determine or be informed that a user's total daily insulin (e.g., bolus and / or basal delivery) is 48 units per 24 hours, which may translate to an exemplary physiological basal dose rate of 1 unit per hour (48 / 24 / 2 (assuming a basal / bolus ratio of 1:1)), which may be determined based on a diabetes treatment plan. Of course, drive mechanism 824 may also be operable to deliver insulin at a rate of 8 units per hour, different from the exemplary physiological dose rate. In the example, system 800 may be attached to the body of a user (such as a patient or diabetic) via, for example, an adhesive (e.g., directly to the user's skin) and may deliver any therapeutic agent to the user, including any medication or drug, such as insulin, morphine, etc. In the example, the surface of system 800 may include an adhesive (not shown) to facilitate attachment to the user. For example, the system 800 can be worn on a user's belt or in a pocket, and liquid medications can be delivered to the user's infusion site via tubing.

[0085] In various examples, system 800 may be an automated, wearable drug delivery device. For example, system 800 may include a reservoir 825 configured to hold a liquid drug (such as insulin), a needle and / or cannula 833 for delivering the drug into the user's body (which may be subcutaneous, intraperitoneal, or intravenous), and a drive mechanism 824 or other drive mechanism for delivering the drug from the reservoir 825 through the needle or cannula 833 into the user.

[0086] A drive mechanism 824 may be fluidly coupled to a reservoir 825 and communicatively coupled to a medical device controller 821. The drive mechanism 824 may be coupled to the reservoir 825 and operable to discharge liquid medication from the reservoir 825 via a fluid delivery path to the outside of a cannula 833. The drive mechanism 824 may have mechanical parameters and specifications indicating the mechanical capabilities of the drive mechanism, such as pump resolution. The drive mechanism 824 may also have an electrical connection to a control circuitry (not shown) operable to control the operation of the drive mechanism 824. Pump resolution is a fixed amount of insulin delivered by the drive mechanism 824 in a drive mechanism pulse, which is the actuation of the drive mechanism within a preset time period. Actuation may occur when power from a power source 828 is applied to the control circuitry coupled to the drive mechanism 824 and the drive mechanism 824 operates to pump a fixed amount of insulin from the reservoir 825 within a preset time period. Alternatively, the drive mechanism 824 can be substantially mechanical in structure and operation, and can be operated using a mechanical energy storage device (such as a spring or other biasing member). One or more level sensors 822 can be coupled to elements of the reservoir 825, such as those described with reference to Figures 1-7. One or more level sensors 122 can be circuits having a high potential or ground potential, or circuits having other electrical characteristics monitored by the controller 821.

[0087] FIG. 8 The sleeve 833 can be coupled to the reservoir 825 via the fluid delivery path 834. When the sleeve 833 is inserted into the user, the sleeve 833 can be operated to discharge liquid medicine to the user.

[0088] System 800 may also include a power supply 828, such as a battery, supercapacitor, piezoelectric device, etc., operable to provide power to drive mechanism 824 and / or other components of system 800, such as controller 821, memory 823 and communication device 826.

[0089] Controller 821 can be implemented in hardware, software, or any combination thereof. In various examples, controller 821 can be implemented as dedicated hardware (e.g., as an application-specific integrated circuit (ASIC)). Controller 821 can be a component of system 800, can be implemented in software as a computational model, or can be implemented externally to system 800 (i.e., remotely). Controller 821 can be configured to communicate with one or more other sensors (not shown).

[0090] A reservoir 825 may be included in a drug delivery device to store liquid medications (such as insulin). For example, the reservoir 825 may be filled or partially filled with a liquid medication or a liquid medication solution. In one example, the liquid medication solution is a mixture of the liquid medication and added preservatives. The reservoir may store the liquid medication until all the liquid medication has been dispensed (e.g., via a cannula into the patient). Therefore, the liquid medication (or solution) may be retained in the reservoir for a period of time (e.g., 1 day, 3 days, 1 week, 2 weeks, etc.).

[0091] Medical device 802 can be a wearable drug delivery device worn on a user's body. For example, an adhesive can couple medical device 802 to the user's skin. Medical device 802 can be a multi-part device. For example, medical device 802 as a wearable drug delivery device can have a first part and a second part coupled or connected together. The first part and / or the second part can be inserted into or slid into a tray or support that adheres to the user's body, and the first part and / or the second part can be removed from the tray. If the first part and the second part are used, the first part can include reusable components (e.g., electronic circuitry, processor, memory, drive mechanism, and possibly a rechargeable battery), while the second part can include disposable components (e.g., a reservoir, needle and / or cannula, disposable battery, and other parts or components that come into contact with liquid drugs or medications). Moreover, the first part and the second part can contain their own housing, or can be combined together to form a single housing. Wearable drug delivery device 802 can be directly coupled to the user (e.g., directly attached to the user's body parts and / or skin via adhesive, directly, via a tray, etc.). In the example, the surface of the wearable drug delivery device 802 or the tray to which the wearable drug delivery device 802 is coupled may include an adhesive to facilitate attachment to the user's skin.

[0092] While medical device 802 is described with reference to insulin delivery and the use of the AID algorithm, medical device 802 may be operable to implement drug delivery protocols using a variety of different liquids or therapeutic drugs via a drug delivery algorithm. Liquid drugs may be or include any drug in liquid form that can be administered via a subcutaneous cannula through a drug delivery device, including, for example, combination preparations of two or more of insulin, glucagon-like peptide-1 (GLP-1), pramlintide, glucagon, GLP-1, pramlintide, and insulin; as well as analgesics such as opioids or anesthetics (e.g., morphine), methadone, arthritis drugs, hormones (such as estrogen and testosterone), antihypertensive drugs, chemotherapy drugs, fertility drugs, etc.

[0093] likeFIG. 9A As shown, system 200 may include a plunger 202 positioned within reservoir 225. An end portion or main body of plunger 202 may extend outside reservoir 225. Pump mechanism 224 may be operable under the control of controller 221 to displace fluid from plunger 202, such as operable to displace liquid medicine (not shown) from reservoir 225 and into fluid assembly 204 and sleeve 233 by advancing plunger 202 into reservoir 225. In various examples, pressure sensors (such as the sensor shown at 222) may be integrated anywhere along the entire fluid delivery path of system 200, which includes reservoir 225, fluid delivery path assembly 204, and sleeve 233.

[0094] Controller 221 can be implemented in hardware, software, or any combination thereof. In various examples, controller 221 can be implemented as dedicated hardware (e.g., as an application-specific integrated circuit (ASIC)). Controller 221 can be a component of system 200, can be implemented in software as a computational model, or can be implemented externally to system 200 (e.g., remotely). Controller 221 can be configured to interact with one or more sensors (such as…) FIG. 8 Communicate with one or more level sensors (822).

[0095] As described above, the drug delivery device may include a reservoir (such as 225) to store liquid medications (e.g., insulin). For example, reservoir 225 may be filled or partially filled with a liquid medication or a liquid medication solution. In one example, the liquid medication solution is a mixture of the liquid medication and added preservatives. The reservoir may store the liquid medication until all the liquid medication has been dispensed (e.g., via a cannula into the patient). Therefore, the liquid medication (or solution) may be retained in the reservoir for a period of time (e.g., 1 day, 3 days, 1 week, 2 weeks, etc.).

[0096] FIG. 9B Compare FIG. 9A The view illustrates in more detail an example of a reservoir coupled to the drive mechanism 224. Similarly, FIG. 9CA perspective view of drive mechanism 250 is illustrated. As disclosed in later examples, drive mechanism 224 (shown in more detail in later examples) may include a coaxial ratchet, a drive arm, a sensor contact, and an actuator. The coaxial ratchet may be coupled to plunger 202 via extension shaft 254. At a higher level, the ratchet of drive mechanism 224 is engaged by the drive arm in response to a force applied by the actuator to progressively advance plunger 202 and extension shaft 254 into reservoir 225. Extension shaft 245 advances plunger 202 to dispense liquid medicine from reservoir 225. In one example, drive mechanism coupling 251 is operable to rotate drive element 252 in response to a force applied to a first or second ratchet of drive mechanism 224. Drive element 252 may include (or may be otherwise coupled to) a lead screw 253 coupled to plunger 202 (e.g., via extension shaft 254). The drive element 252 is operable to rotate, thereby causing the lead screw 253 to advance the elongation shaft 254 and the plunger 202 within the reservoir 225 to discharge the liquid medicine from the reservoir 225.

[0097] Now for reference FIG. 10 A system 1000 for a fluid meter used in a wearable medical device is shown. The system 1000 may include a plunger end 1004. The plunger end 1004 may be as referenced above. FIG. 5C As described. In some embodiments, the plunger end 1004 may be made of a metal plate, such as, but not limited to, copper, aluminum, steel, etc. The plunger end 1004 may be shaped as circular, oval, rectangular, and / or other shapes, but is not limited thereto. In some embodiments, the plunger end 1004 may have a length of approximately 1.5 inches. In some embodiments, the plunger end 1004 may have a length of approximately 0.6 inches to approximately 0.7 inches. In other embodiments, the plunger end 1004 may have a length greater than or less than approximately 1.5 inches. In some embodiments, the plunger end 1004 may have a thickness of approximately 2 mm. In other embodiments, the plunger end 1004 may have a thickness greater than or less than approximately 2 mm, but is not limited thereto.

[0098] The plunger end 1004 may have a marker 1024. The marker 1024 may be configured to connect to one or more components of a wearable medical device, such as a plunger, lever, lock, and / or other components. The marker 1024 may extend approximately 0.5 mm into the surface of the plunger end 1004. In other embodiments, the marker 1024 may extend into the width of the plunger end 1004 in a manner greater than or less than approximately 0.5 mm. The marker 1024 may be shaped as a cross, circle, square, rectangle, and / or other shapes, but is not limited thereto. In some embodiments, the marker 1024 may be a combination of shapes. As a non-limiting example, the marker 1024 may include a cross-shaped portion etched into the plunger end 1004 and a circular portion having four arcs intersecting the cross-shaped portion. In some embodiments, the marker 1024 may include a combination of protrusions and recesses. For example, the marker 1024 may include a recessed cross-shaped portion having a circular central portion and four protruding arcs, each arc connecting two lines of the cross-shaped portion.

[0099] Still referencing FIG. 10 The plunger end 1004 may include a tab 1008. The tab 1008 may be a recessed structure located on one side of the plunger end 1004. For example, but not limited to, the tab 1008 may be located on the top, bottom, left, or right side of the plunger end 1004. The tab 1008 may be machined or welded into the plunger end 1004. In some embodiments, the tab 1008 may be ultrasonically machined into the plunger end 1004. The tab 1008 may be configured to connect to or otherwise couple to one or more rods. For example, the tab 1008 may be configured to connect to a rod 1012. The rod 1012 may be made of steel, aluminum, copper, etc., but is not limited to these materials. The rod 1012 may have a thickness of approximately 0.5 mm, greater than approximately 0.5 mm, or less than approximately 0.5 mm, but is not limited to these materials. In some embodiments, the rod 1012 may be approximately 4 cm long, greater than 4 cm long, or less than 4 cm long, but is not limited to these materials. In some embodiments, the rod 1012 may have a length of approximately 2 mm. In some embodiments, the rod 1012 may be tapered. Tapering of the rod 1012 may result in an uneven distribution of the weight of the rod 1012. For example, but not limited to, the left side of the rod 1012 may be lighter and / or smaller than the right side of the rod 1012, while the right side may be heavier, and vice versa. Tapering of the rod 1012 may make the rod 1012 become wider / higher from the left side of the rod 1012 to the right side, and vice versa.

[0100] In some embodiments, rod 1012 may include one or more bends. In some embodiments, rod 1012 may include a first bend 1028 and / or a second bend 1032. The first bend 1028 may be located at one end of rod 1012, such as at the left or right end of rod 1012, but is not limited thereto. In some embodiments, the first bend 1028 may bend a portion of rod 1012 at an angle. The angle of the first bend 1028 may include approximately 15 to 90 degrees, but is not limited thereto. In some embodiments, the angle of the first bend 1028 may be greater than 90 degrees or less than 15 degrees, but is not limited thereto. Rod 1012 may have a second bend 1032 that may be positioned adjacent to the first bend 1028. In some embodiments, the second bend 1032 may have an angle opposite to that of the first bend 1028. For example, the first bend 1028 may have a 90-degree angle relative to the x-axis, while the second bend 1032 may have a -90-degree angle. The first bend 1028 and the second bend 1032 can form a "Z" shape. The first bend 1028 can be positioned approximately 3 mm from the right end of the rod 1012, or more than approximately 3 mm from the right end of the rod 1012, or less than approximately 3 mm from the right end of the rod 1012, but is not limited thereto. The second bend 1032 can be located at one end of the first bend 1028. For example, the second bend 1032 can be positioned approximately 2 mm, more than approximately 2 mm, or less than approximately 2 mm from the first bend 1028, but is not limited thereto.

[0101] The first bend 1028 and the second bend 1032 can offset the positioning of the rod 1012 relative to the plunger end 1004. For example, the first bend 1028 and the second bend 1032 can allow the rod 1012 to be offset from the center of the plunger end 1004 by approximately 4 mm. In other embodiments, the first bend 1028 and the second bend 1032 can allow the rod 1012 to be offset from the central portion of the plunger end 1004 by more or less than approximately 4 mm. By offsetting the rod 1012 from the central position of the plunger end 1004, the first bend 1028 and the second bend 1032 can allow the rod 1012 to avoid other components of the wearable medical device, such as, but not limited to, O-ring caps, reservoirs, etc.

[0102] The rod 1012 can be configured to interact with a first spring 1016 and / or a second spring 1020. In some embodiments, the rod 1012 can be configured to interact with both the first spring 1016 and the second spring 1020. The first spring 1016 and the second spring 1020 can be made of any suitable material, such as, but not limited to, copper, aluminum, steel, etc. In some embodiments, the first spring 1016 and the second spring 1020 can be positioned on one side of the rod 1012, such as on the right side of the rod 1012 next to the second bend 1032. In other embodiments, the first spring 1016 and the second spring 1020 can be positioned along various lengths and / or sides of the rod 1012, such as, but not limited to, the center of the rod 1012, the left side of the rod 1012, etc. In some embodiments, the first spring 1016 can be positioned approximately 2 mm from the second spring 1020. In other embodiments, the first spring 1016 can be positioned greater than or less than approximately 2 mm from the second spring 1020. The first spring 1016 may have a length of approximately 5 mm, greater than 5 mm, or less than 5 mm, but is not limited thereto. The second spring 1020 may have a length different from that of the first spring 1016. In other embodiments, the first spring 1016 and the second spring 1020 have the same length.

[0103] Now for reference FIG. 11 , showed FIG. 10 A perspective view of system 1000. Rod 1012, first spring 1016, second spring 1020, plunger end 1004, and tab 1008 can be referenced as above. FIG. 10 As described, the tab 1008 can retain and / or fix one or more bent ends of the rod 1012. For example, as referenced above. FIG. 10 The first bend 1028 and / or the second bend 1032 are described. The tab 1008 can be located at the top, left, right, or bottom position of the plunger end 1004. The rod 1012 can be positioned at the top, bottom, left, or right position of the plunger end 1004, connected via the tab 1008. The first spring 1016 and / or the second spring 1020 can be positioned at the distal end of the rod 1012. For example, the first spring 1016 and / or the second spring 1020 can be positioned at the point on the rod 1012 furthest from the plunger end 1004. In some embodiments, three or more springs can be used and / or three or more springs can be connected to the rod 1012.

[0104] Now for reference FIG. 12A The diagram shows a side view of rod 1012, first spring 1016, and second spring 1020 in channels 1204 and 1208. Rod 1012, first spring 1016, and second spring 1020 can be referenced as above. FIG. 10As described, the rod 1012 can be configured to enter between the first channel 1204 and the second channel 1208. The first channel 1204 and the second channel 1208 can form a pocket through which the rod 1012 can pass. The first channel 1204 and / or the second channel 1208 can be made of plastic, rubber, etc., but are not limited thereto. In some embodiments, the first channel 1204 and / or the second channel 1208 can have a thickness of approximately 4 mm, greater than 4 mm, less than 4 mm, etc., but are not limited thereto. The pocket formed by the first channel 1204 and the second channel 1208 can be approximately 3 mm wide, greater than 3 mm wide, or less than 3 mm wide, but are not limited thereto.

[0105] The first spring 1016 and / or the second spring 1020 may be positioned within a pocket between the first channel 1204 and the second channel 1208. The first spring 1016 may be positioned adjacent to the second spring 1020. In some embodiments, the first spring 1016 and the second spring 1020 may be located at one end of the pocket formed by the first channel 1204 and the second channel 1208. For example, but not limited to, the first spring 1016 and / or the second spring 1020 may be located at the left end, right end, or other end of the pocket formed by the first channel 1204 and the second channel 1208, but are not limited thereto. The first spring 1016 and / or the second spring 1020 may be configured to compress due to contact with the rod 1012. The first spring 1016 and / or the second spring 1020 may be compressed to approximately 2 mm, greater than 2 mm, or less than 2 mm, but are not limited thereto. The spring constant of the first spring 1016 and / or the second spring 1012 may be approximately (but not limited to) 5 N / M, greater than 5 N / M, or less than 5 N / M, but is not limited to this.

[0106] In some embodiments, the first spring 1016 and / or the second spring 1020 may be conductive. For example, the first spring 1016 and / or the second spring 1020 may have a conductivity of approximately 5.96 × 10⁷ σ (S / m), but are not limited thereto. The rod 1012 may be conductive and configured to provide an electrical connection between the first spring 1016 and the second spring 1020. In some embodiments, the first spring 1016 may have a positive voltage supply, while the second spring 1020 may act as ground, or vice versa. The first spring 1016 and / or the second spring 1020 may be connected to a sensing element, such as any sensing element and / or sensor described throughout this disclosure, but are not limited thereto. Sensing elements may include, but are not limited to, voltmeters, potentiometers, ohmmeters, ammeters, etc. In some embodiments, compression of the first spring 1016 and / or the second spring 1020 may change the resistivity of the first spring 1016 and / or the second spring 1020. For example, but not limited to, the second spring 1020 can function as a potentiometer, where the voltage changes due to compression. Compression of the first spring 1016 and / or the second spring 1020 can reduce the resistance of the first spring 1016 and / or the second spring 1020, which increases the voltage and / or current of either or both of the first spring 1016 and the second spring 1020. The change in resistivity can correspond to the change in the voltage and / or current of the first spring 1016 and / or the second spring 1020. A sensing element can be electrically connected to the first spring 1016 and / or the second spring 1020. The sensing element can be configured to receive the voltage and / or current values ​​of the first spring 1016 and / or the second spring 1020 and determine the change in the contact pressure of the lever 1012 and / or the change in the amount of liquid medicine dispensed. The change in the contact pressure of the lever 1012 can correspond to the change in the amount of liquid medicine dispensed by the plunger connected to the plunger end 1004. In some embodiments, when the plunger dispenses liquid medication, the lever 1012 may move forward with the plunger. The lever 1012 may be connected to the plunger and may increase the contact pressure of the first spring 1016 and / or the second spring 1020 as the liquid medication is discharged from the reservoir. A sensing element may be configured to determine the amount of liquid medication dispensed based on changes in the voltage and / or current of the first spring 1016 and / or the second spring 1020. As a non-limiting example, a voltage change of 50 mV may correspond to the discharge of 1 mL of liquid medication from the reservoir. The sensing element and / or processor of the wearable medical device may be configured to determine the amount of liquid medication remaining in the reservoir based on changes in the voltage and / or current of the first spring 1016 and / or the second spring 1020. For example, but not limited to, the sensing element and / or processor may determine that a voltage of 1.8 V across the second spring 1020 corresponds to 5 mL remaining in the reservoir of the wearable medical device.

[0107] Still referencingFIG. 12A In some embodiments, the lever 1012 may be energized during the initial phase of drug delivery. As the plunger is moved, the lever 1012 may increase contact with the first spring 1016 and / or the second spring 1020, which may cause a change in voltage and / or current at the first spring 1016 and / or the second spring 1020. A sensing element may be configured to determine the amount of liquid drug dispensed based on the change in voltage and / or current at the first spring 1016 and / or the second spring 1020. In some embodiments, the lever 1012 may be energized and may contact the first spring 1016 and / or the second spring 1020.

[0108] The sensing element and / or processor can determine the wake-up mode of the wearable medical device based on the contact between the charged lever 1012 and the first spring 1016 and / or the second spring 1020. The sensing element can also determine the wake-up mode based on changes in voltage and / or current between the first spring 1016 and / or the second spring 1020 and the uncharged lever 1012, as described above, but not limited thereto. In some embodiments, the lever 1012 may initially be positioned away from the first spring 1016 and / or the second spring 1020. The lever 1012 may contact the first spring 1016 and / or the second spring 1020, which can be sensed by the sensing element connected to the first spring 1016 and / or the second spring 1020. The sensing element and / or processor of the wearable medical device can cause the wearable medical device to enter a wake-up mode. The wake-up mode may include initialization or startup of the wearable medical device. The sensing element can transmit sensed data to the processor of the wearable medical device, which can initiate the wake-up mode of the wearable medical device.

[0109] Now for reference FIG. 12B The illustration shows a top view of the rod 1012 in a pocket. The rod 1012, the first spring 1016, the second spring 1020, the first channel 1204, and the second channel 1208 can be referenced as above. FIG. 12A As described, the rod 1012 can enter through the pocket formed by the first channel 1204 and the second channel 1208, which can cause compression of the first spring 1016 and / or the second spring 1020.

[0110] Now for reference FIG. 12C The image shows a side view of the lever 1012 entering the pocket. The lever 1012, the first spring 1016, the second spring 1020, the first channel 1204, and the second channel 1208 can be referenced as above. FIG. 12AAs described. The second spring 1020 can be compressed by the rod 1012, while the first spring 1016 may not be compressed because the rod 1012 does not reach the first spring 1016 within the pocket formed by the first channel 1204 and the second channel 1208. In some embodiments, both the first spring 1016 and the second spring 1020 can be compressed by the rod 1012.

[0111] FIG. 13 It shows the relationship with FIG. 10 The diagram illustrates a system superimposed circuit diagram 1300. Circuit 1300 may include a voltage source 1304. Voltage source 1304 may be supplied by a battery or other power source of the wearable medical device. In some embodiments, a first spring 1016 may be directly connected to voltage source 1304. In some embodiments, voltage source 1304 may include a voltage of approximately 4.5V. In other embodiments, voltage source 1304 may be greater than or less than approximately 4.5V, but is not limited thereto. In some embodiments, first spring 1016 may act as voltage source 1304, and second spring 1020 may act as potentiometer 1308. For example, when second spring 1020 is compressed, the resistance of second spring 1020 may decrease; and when second spring 1020 is decompressed, its resistance may increase. Rod 1012 may act as a circuit wire / line. Rod 1012 may connect first spring 1016 to second spring 1020. For example, initially, lever 1012 may not initially be in contact between the first spring 1016 and the second spring 1020, but may come into contact with the first spring 1016 and the second spring 1020 as the plunger connected to lever 1012 moves. Lever 1012 may be tapered. Due to a heavier weight distribution on one side of lever 1012, tapering lever 1012 may allow for increased contact pressure on the second spring 1020 as lever 1012 moves with the plunger. In some embodiments, tapering lever 1012 may allow for increased contact pressure on the second spring 1020 due to increased displacement of the second spring 1020. A sensing element (not shown) may be connected to circuitry 1300 and / or the processor of the wearable medical device. The sensing element may be configured to detect changes in voltage across the second spring 1020 and determine one or more parameters, such as, but not limited to, the amount of dispensed liquid medication, the amount of remaining liquid medication, etc. In some embodiments, the second spring 1020 can act as a voltage source 1304 and the first spring 1016 can act as a potentiometer 1308.

[0112] FIG. 14 The diagram shows FIG. 10 The left-side view of the system. The plunger end 1004, rod 1012, first spring 1016, and second spring 1020 can be as shown in the reference above. FIG. 10As described. The first spring 1016 and / or the second spring 1020 may be positioned closer to the plunger end 1004. In some embodiments, the first spring 1016 and / or the second spring 1020 may be positioned at the base of the rod 1012, which may be larger than the distal end of the rod 1012 due to the tapering of the rod 1012. As a non-limiting example, the first spring 1016 and / or the second spring 1020 may be positioned below the large base of the tapered portion of the rod 1012, which may be adjacent to the plunger end 1004.

[0113] FIG. 15 The diagram shows FIG. 10 Another exemplary embodiment of the system. The plunger end 1004, rod 1012, first spring 1016, and second spring 1020 can be as described above (reference provided). FIG. 10 As described. The first spring 1016 and / or the second spring 1020 may be positioned at the distal end of the rod 1012. For example, the rod 1012 may be tapered, and the first spring 1016 and / or the second spring 1020 may be positioned at the smaller left end of the tapered portion of the rod 1012 relative to the larger base end on the right side of the rod 1012. The first spring 1016 and / or the second spring 1020 may be positioned away from the plunger end 1004.

[0114] FIG. 16Another exemplary embodiment of a fluid meter system for a wearable medical device is illustrated. In some embodiments, a first spring 1016 and / or a second spring 1020 may have a first electrical contact 1602 and / or a second electrical contact 1604. The first electrical contact 1602 and / or the second electrical contact 1604 may comprise a circular, rectangular, or other shaped material. The first electrical contact 1602 and / or the second electrical contact 1604 may be made of a conductive material, such as, but not limited to, copper, aluminum, iron, etc. In some embodiments, the first spring 1016 may include a first electrical contact 1602 aligned on the left, right, or other side of the coil of the first spring 1016. In some embodiments, the first electrical contact 1602 may be aligned on both the left and right sides of the first spring 1016. The second spring 1020 may include a second electrical contact 1604. The second electrical contact 1604 may be the same as the first electrical contact 1602. The second spring 1020 may have a second electrical contact 1604 located on the left, right, or other side of the second spring 1020. In some embodiments, the second spring 1020 may have electrical contacts 1604 located on both sides of the second spring 1020. The first electrical contact 1602 and / or the second electrical contact 1604 may be placed on every other turn of the first spring 1016 and / or the second spring 1020, respectively. In other embodiments, the first electrical contact 1602 and / or the second electrical contact 1604 may be positioned such that they are spaced apart by two or more spring coils of the first spring 1016 and / or the second spring 1020. The electrical contacts 1602 and / or 1604 may be placed on each spring coil of the first spring 1016 and / or the second spring 1020. In some embodiments, the electrical contacts 1602 and / or 1604 may have two or more contacts. In other embodiments, the electrical contacts 1602 and / or 1604 may include a single contact. When the first spring 1016 and / or the second spring 1020 are compressed from the rod 1012, the electrical contacts 1602 and / or 1604 along one or more sides of the first spring 1016 and / or the second spring 1020 can touch each other. One or more of the electrical contacts 1602 and / or 1604 can act as a short-circuit connection of the first spring 1016 and / or the second spring 1020. For example, the second spring 1020 can be compressed, which may cause two or more contacts of the second electrical contacts 1604 to touch, thereby creating a short circuit. A processor communicating with the sensing element can determine the amount of liquid medicine dispensed based on changes in the voltage and / or current of the first spring 1016 and / or the second spring 1020.

[0115] Now for reference FIG. 17 The illustration shows an embodiment of a plunger end with a flange. The plunger end 1700 may include a rod 1704, which can be connected to the above-referenced... FIG. 10The rod 1012 described is identical. In some embodiments, the plunger end 1700 may include a flange 1708. The flange 1708 may include a conduit or other structure. In some embodiments, the flange 1708 may be a rod shaped into a circle. The flange 1708 may be threaded. In some embodiments, the flange 1708 may have one or more holes 1712 at its base. The holes 1712 of the flange 1708 may be configured to serve as heat stakes for one or more posts on the back of the plunger. The rod 1012 may include one or more springs, such as those referenced above. FIG. 10 The first spring 1016 and / or the second spring 1020 are described. In some embodiments, a nut (such as a swivel nut) can be screwed onto the flange 1708. The nut can advance the plunger to a position in the reservoir, which can cause one or more fluids to be discharged. A screw can be insert-molded into the plunger, which allows for a rigid connection to couple the movement of the plunger to a lead screw.

[0116] Referring now to FIG. 18, an embodiment of a spring for a fluid meter system in a wearable medical device is presented. The spring may include a first contact 1804, a second contact 1808, and / or a connecting portion 1812. The connecting portion 1812 may be U-shaped or other shapes. In some embodiments, the connecting portion 1812 may connect the first contact 1804 to the second contact 1808. The first contact 1804 and / or the second contact 1808 may be shaped, but not limited to, circular, elliptical, square, rectangular, etc. In some embodiments, the first contact 1804 and / or the second contact 1808 may extend outward from a portion of the connecting portion 1812. For example, the first contact 1804 and / or the second contact 1808 may include a convex structure, which may be dome-shaped or other surfaces, but is not limited thereto. The first contact 1804 may have a diameter of approximately 1 mm. In other embodiments, the first contact 1804 may have a diameter greater than or less than approximately 1 mm. The first contact 1804 may extend from the connecting portion 812 by approximately 0.5 mm. In other embodiments, the first contact 1804 may extend from the connecting portion 812 by more or less than approximately 0.5 mm. The second contact 1808 may be the same as the first contact 1804. In other embodiments, the second contact 1808 may have different dimensions, such as, but not limited to, diameter, circumference, height, etc.

[0117] The first contact 1804 and / or the second contact 1808 may be in contact during an initial phase, such as before a liquid medication is dispensed by a plunger from a wearable medical device. The connecting portion 1812 may be bent at one or more ends at approximately, but not limited to, 95 degrees, 100 degrees, 115 degrees, and / or other angles. One or more bends in the connecting portion 1812 may cause the first contact 1804 and / or the second contact 1808 to press against each other. For example, the first contact 1804 and / or the second contact 1808 may press against each other during an initial phase. In some embodiments, the first contact 1804 and / or the second contact 1808 may be conductive. For example, the first contact 1804 and / or the second contact 1808 may be made of, but not limited to, copper, iron, aluminum, etc. The connecting portion 1812 may be flexible, thereby allowing the first contact 1804 and / or the second contact 1808 to be pulled away and / or pushed away. In some embodiments, a metal beam spring 1800 may replace the above reference. FIG. 10 The first spring 1016 and / or the second spring 1020 are positioned, but not limited to this. The rod (such as the one referenced above) FIG. 10 The described lever 1012 can be actuated between the first contact 1804 and / or the second contact 1808. The lever (such as lever 1012) can form an electrical connection between the first contact 1804, the second contact 1808, and / or the connecting portion 1812. A sensing element can be connected to the lever and / or the metal beam spring 1800. The sensing element can be configured to detect a voltage / current difference between the first contact 1804 and / or the second contact 1808 and can correlate this with a change in the amount of liquid medicine dispensed by the plunger. For example, the lever can be tapered, as described above. FIG. 10 The described rod 1012 can increase resistance when the smaller end of the rod moves between the first contact 1804 and the second contact 1808 toward the wider end of the rod.

[0118] In some embodiments, the first contact 1804 and / or the second contact 1808 may initially be separated and then electrically connected to each other by sliding a rod through the first contact 1804 and the second contact 1808. In embodiments, the first contact 1804 and the second contact 1808 may be separate tabs without a connecting portion 1812. For example, but not limited to, the first contact 1804 and the second contact 1808 may be individually soldered to the circuit board of a wearable medical device. In some embodiments, the metal beam spring 1800 may provide a more secure grip on one or more automated manufacturing tools, such as robotic arms or other gripping devices.

[0119] For reference FIG. 19 An embodiment of a gear system for a fluid meter in a wearable medical device is illustrated. The gear system 1900 may include a rod 1012 and / or a plunger end 1004, as referenced above.FIG. 10 As described. In some embodiments, the lever 1012 may have teeth 1908. Teeth 1908 may run along the underside of the lever 1012, but are not limited thereto. In some embodiments, teeth 1908 may include seven teeth, fewer than seven teeth, or more than seven teeth. Each tooth in teeth 1908 may be configured to mate with one or more protrusions of gear 1904. Gear 1904 may include a spur gear, a helical gear, a skew gear, and / or other gears. In some embodiments, gear 1904 may be configured to rotate in a direction, such as clockwise, counterclockwise, etc. Gear 1904 may rotate due to a torque applied by one or more teeth in teeth 1908. In some embodiments, gear 1904 and teeth 1908 may have multiple teeth and tooth cutouts, which may allow precise movement of the lever 1012. As a non-limiting example, gear 1904 and teeth 1908 may include 50 or more tooth-hole pairs. In some embodiments, multiple gears, such as two or more gears, may be implemented. For example, a second, smaller gear can be connected to gear 1904. The smaller gear connected to gear 1904 allows for greater rotation, which can be achieved by providing increased rotational data generation through sensing elements.

[0120] The sensing element can be configured to detect rotation of gear 1904. For example, an encoder can be used within system 1900. The encoder may include, but is not limited to, a rotary encoder, a linear encoder, a position encoder, and / or an optical encoder. In some embodiments, a rotary potentiometer may be used. The sensing element of system 1900 can be configured to determine the degree of rotation of gear 1904, the difference between the current position of gear 1904 and the previous position of gear 1904, and / or other rotation data. For example, a rotary encoder may be configured to detect rotation in 15-degree increments, but is not limited to this. The sensing element and / or processor can be connected to the encoder and can correlate the degree of rotation with the amount of liquid medication dispensed. For example, each 10-degree rotation may correspond to the amount of liquid medication dispensed, approximately 0.1 ml. In some embodiments, the sensing element and / or processor can be configured to wake up or otherwise initialize a wearable medical device based on received rotation data generated by gear 1904.

[0121] Now for reference FIG. 20 It presented FIG. 19 A side view of the gear system. The gear system 2000 may include a plunger end 1004, a rod 1012, teeth 1908 and / or gears 1904, as shown in the reference above. FIG. 19As described, but not limited to, the lever 1012 can be configured to move in the Z direction. One or more teeth of the gears 1908 can move in the Z direction and can engage with the gear 1904, which can cause the gear 1904 to rotate in the G direction. When the gear 1904 rotates in the G direction, the encoder can be configured to detect one or more degrees of rotation of the gear 1904. The sensing element and / or processor can be configured to receive data from the encoder and correlate the degrees of rotation with the amount of liquid medicine dispensed. For example, the sensing element and / or processor can determine that every 15 degrees of rotation corresponds to the dispensing of approximately 2 ml of liquid medicine.

[0122] In at least one embodiment, a drive mechanism is provided that may include a pair of coaxial ratchet arms (i.e., a first ratchet and a second ratchet) driven by a first drive arm and a second drive arm. In some examples, a sensor contact arrangement coupled to the first and second ratchet arms allows the drive mechanism to respond to the travel of the respective ratchet arms in various implementations and configurations. In this context, a coaxial arrangement refers to an arrangement in which the first and second ratchet arms rotate about the same axis or a common axis.

[0123] Some examples of the disclosed devices may be implemented, for example, using a storage medium, a computer-readable medium, or an article of manufacture capable of storing instructions or sets of instructions, which, if executed by a machine (i.e., a processor or microcontroller), can cause the machine to perform methods and / or operations according to the examples of this disclosure. Such a machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, etc., and may be implemented using any suitable combination of hardware and / or software. Computer-readable media or articles of art may include, for example, any suitable type of memory unit, memory, memory article, memory medium, storage device, storage article, storage medium and / or memory unit, such as memory (including non-transitory memory), removable or non-removable media, erasable or non-erasable media, writable or rewritable media, digital or analog media, hard disk, floppy disk, compact disk read-only memory (CD-ROM), compact disk recordable (CD-R), compact disk rewriteable (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or discs, various types of digital multifunction discs (DVD), tapes, cassettes, etc. Instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, encrypted code, programming code, etc., implemented using any suitable high-level, low-level, object-oriented, visual, compiled and / or interpreted programming language. Programming code implemented in a non-transitory computer-readable medium can enable a processor to perform functions, such as those described herein, when executing the program code.

[0124] The foregoing has described certain examples of this disclosure. However, it is explicitly stated that this disclosure is not limited to those examples, but rather intended to indicate that additions and modifications to the content explicitly described herein are also included within the scope of the disclosed examples. Furthermore, it should be understood that the features of the various examples described herein are not mutually exclusive and can exist in various combinations and substitutions, even if such combinations or substitutions are not expressed herein, without departing from the spirit and scope of the disclosed examples. Indeed, those skilled in the art will conceive of variations, modifications, and other implementations of the content described herein without departing from the spirit and scope of the disclosed examples. Therefore, the disclosed examples are not limited to the foregoing illustrative description.

[0125] The programmatic aspect of the technology can be considered a "product" or "article of manufacture," typically in the form of executable code and / or associated data carried or implemented on a non-transitory, machine-readable medium. Storage-type media include any or all tangible memory of computers, processors, etc., or their associated modules, such as various semiconductor memories, tape drives, disk drives, etc., which can provide non-transitory storage for software programming at any time. It is important to emphasize that this abstract is provided to allow the reader to quickly determine the nature of the technological disclosure. It is submitted under the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, various features are grouped together in a single example to simplify this disclosure. This approach to the disclosure should not be construed as reflecting an intention to claim more features than are expressly set forth in each claim. Rather, as reflected in the following claims, the inventive subject matter lies in fewer than all the features of a single disclosed example. Therefore, the following claims are incorporated herein by reference to the detailed description, wherein each claim exists independently as a separate example. In the appended claims, the terms “including” and “in which” are used as concise English equivalents to the corresponding terms “comprising” and “wherein”, respectively. Furthermore, the terms “first,” “second,” “third,” etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0126] For illustrative and descriptive purposes, the foregoing description has been presented as an example. It is not intended to be exhaustive or to limit this disclosure to the precise form disclosed. Many modifications and variations are possible in accordance with this disclosure. It is intended to show that the scope of this disclosure is not limited by this detailed description, but rather by the appended claims. Future applications claiming priority to this application may claim protection for the disclosed subject matter in different ways and, in general, may include any set of one or more limitations disclosed herein or otherwise shown.

[0127] In particular, although the invention is defined in the appended claims and described above, it should be understood that the invention may alternatively be limited according to the following embodiments:

[0128] 1. A system for determining the liquid level in a pharmaceutical delivery device, the system comprising:

[0129] Sensor circuit system;

[0130] First electrical contact;

[0131] The second electrical contact, wherein the first and second electrical contacts are coupled to the logic circuit system;

[0132] A conductive strip configured to slide past a first electrical contact, wherein the conductive strip is electrically connected to a first electrical contact and a second electrical contact; and wherein a sensor circuit system is operable to determine the resistance between the first electrical contact and the second electrical contact, and wherein the resistance is used to determine the liquid level based on the determined resistance.

[0133] 2. The system as described in Example 1 further includes a tensioner coupled to the second electrical contact.

[0134] 3. The system as described in Embodiment 1 or 2 further includes a tension meter coupled to the second electrical contact.

[0135] 4. The system as described in Example 3, wherein a tension meter is configured to couple with a conductive strip to maintain the conductive strip in tension between a first electrical contact and a second electrical contact.

[0136] 5. The system as described in any one of Embodiments 1 to 4 further includes a tensioner coupled to the conductive strip and configured to hold the conductive strip in a preset state between the first electrical contact and the second electrical contact.

[0137] 6. The system as described in any one of Embodiments 1 to 5 further includes: a first alignment member and a second alignment member configured to align conductive strips; and wherein the first alignment member and the second alignment member are adjacent to the electrical path between the first electrical contact and the second electrical contact.

[0138] 7. The system as described in Example 6, wherein a first alignment member is fixedly attached to a first end of the plunger of the drug delivery device, and a second alignment member is fixedly attached to a second end of the plunger of the drug delivery device.

[0139] 8. The system as described in any one of Examples 1 to 7, wherein the conductive strip is formed in a shape that is at least partially curved and has a convex inner surface.

[0140] 9. The system as described in Example 8 further includes an insulating member deployed within the convex inner surface of the conductive strip.

[0141] 10. The system as described in any one of embodiments 1 to 9, wherein at least one of the first electrical contact and the second electrical contact is a spring.

[0142] 11. The system as described in any one of Examples 1 to 10, wherein the second electrical contact is fixedly attached to the plunger of the drug delivery device.

[0143] 12. The system as described in any one of Examples 1 to 11, wherein the conductive strip comprises graphene.

[0144] 13. The system as described in any one of Examples 1 to 12, wherein the conductive strip comprises carbon nanotubes.

[0145] 14. The system as described in any one of Examples 1 to 13, wherein the conductive strip is flexible.

[0146] 15. The system as described in any one of Examples 1 to 14, wherein the first and second electrical contacts are made of a highly conductive material.

[0147] 16. A method for determining the volume of fluid in a pharmaceutical delivery device, the method comprising: determining a resistance between a first electrical contact and a second electrical contact, wherein the first electrical contact is electrically connected to the second electrical contact via a variable-length conductive strip; comparing the determined resistance with the table of known resistances associated with a known fluid volume; and identifying the known fluid volume based on the result of the comparison.

[0148] 17. The method as described in Example 16, wherein a specific detected resistance corresponds to a specific length of a variable-length conductive strip extending from the first electrical contact to the second electrical contact.

[0149] 18. The method as described in Example 16 or 17, wherein the length of the variable-length conductive strip detected between the first and second electrical contacts increases as the fluid volume decreases.

[0150] 19. The method as described in any one of Examples 16 to 18, wherein the length of the variable-length conductive strip detected between the first electrical contact and the second electrical contact decreases as the fluid volume decreases.

[0151] 20. The method as described in any one of Examples 16 to 19, further comprising the steps of: comparing the determined resistance with a threshold activation resistance; and activating the drug delivery device if the determined resistance is higher than the threshold.

[0152] 21. The method as described in any one of Examples 16 to 20, further comprising the steps of: comparing the determined resistance with a threshold activation resistance; and activating the drug delivery device if the determined resistance is below the threshold.

[0153] 22. A system for detecting the volume of liquid medicine in a reservoir of a pharmaceutical delivery device, comprising:

[0154] The liquid reservoir includes a first end and a second end opposite to the first end;

[0155] A plunger, which is positioned within the reservoir and operable to move within the reservoir;

[0156] A conductive strip coupled to the plunger and configured to maintain contact with the plunger as the plunger moves within the reservoir;

[0157] A first contact, operable to contact a conductive strip at a first position;

[0158] A second contact, operable to contact a conductive strip at a second position; and

[0159] A circuit system coupled to a first contact and a second contact, wherein the circuit system is operable to determine the volume of a liquid drug based on the length of a conductive strip between a first position and a second position.

[0160] 23. The system as described in Example 21 or 22, wherein: a conductive strip is folded over an insulator to form a first side and a second side of the conductive strip, and a first contact contacts the first side of the folded conductive strip and a second contact contacts the second side of the folded conductive strip.

[0161] 24. The system as described in Example 23, wherein: a folded conductive strip extends from the rear side of the plunger.

Claims

1. A system for determining a fluid level in a drug delivery device, the system comprising: a reservoir for containing a liquid drug; a plunger within the reservoir, wherein movement of the plunger toward a distal end of the reservoir causes a quantity of the liquid drug to be delivered from the reservoir; a first spring on the reservoir; a second spring on the reservoir and positioned adjacent to the first spring; a rod configured to move with movement of the plunger, wherein the rod is configured to compress the first spring and contact the second spring, wherein compression of the first spring causes a change in voltage across the first spring; and a sensing element in communication with the first spring and the second spring, wherein the sensing element is configured to detect the change in voltage across the first spring caused by the compression of the first spring by the rod, wherein the change in voltage corresponds to a change in quantity of the liquid drug contained within the reservoir.

2. The system of claim 1, wherein the rod has a double bend and is inserted into a tab of a plunger end of the drug delivery device.

3. The system of claim 1 or 2, wherein each of the first spring and the second spring includes one or more electrical contacts.

4. The system of one of claims 1 to 3, wherein the rod includes a tapered structure that causes an increase in contact pressure with the first spring as it moves toward the distal end of the reservoir.

5. The system of claims 1 to 4, wherein the first spring and the second spring are metal beam springs each including: a first contact; a second contact; and a connecting portion connecting the first contact to the second contact.

6. The system of claim 5, wherein the connecting portion pushes the first contact and the second contact against each other.

7. The system of claims 1 to 6, further comprising a flange connected to a base of a plunger end of the drug delivery device, the flange adjacent to the rod, wherein the base of the flange includes a hole for heat staking the plunger to the flange.

8. An apparatus for a fluid gauge of a drug delivery device, comprising: a rod extending from a plunger end of the drug delivery device, the rod having a first plurality of teeth; a first gear positioned proximate to the rod and having a second plurality of teeth, wherein the first plurality of teeth and the second plurality of teeth are configured to interface with each other; and an encoder configured to correlate a number of rotations of the first gear to a quantity of a liquid drug dispensed from the drug delivery device.

9. The apparatus of claim 8, further comprising a second gear smaller than the first gear and coupled to the first gear, wherein the first gear is configured to rotate the second gear.

10. The apparatus of claim 8 or 9, further comprising a plunger end of the drug delivery device, wherein the rod is inserted into a tab of the plunger end.

11. The apparatus of one of claims 8 to 10, wherein the encoder is a rotary encoder.

12. The apparatus of one of claims 8 to 11, wherein the rod is configured to move with a plunger of the drug delivery device.

13. A method for material metering of a drug delivery device, comprising: ​ moving the rod to bring the rod into contact with the first spring; contacting the second spring with the rod, wherein contacting the second spring creates an electrical circuit between the first spring and the second spring; sensing, by a sensing element in communication with the first spring and the second spring, a change in voltage across the first spring; and calculating, by a processor in communication with the sensing element, an amount of liquid drug within the drug delivery device based on the change in voltage across the first spring.

14. The method of claim 13, wherein the rod has a double bend and is inserted into a tab of a plunger end of the drug delivery device.

15. The method of claim 13 or 14, wherein each of the first spring and the second spring includes one or more electrical contacts.

16. The method of one of claims 13 to 15, wherein each of the first spring and the second spring includes one or more electrical contacts.

17. The method of claim 16, wherein the one or more electrical contacts are located on every other turn of the first spring and the second spring.

18. The method of one of claims 13 to 17, wherein the rod has a tapered structure.

19. The method of one of claims 13 to 18, wherein the rod is electrically charged prior to contacting the first spring.

20. The method of one of claims 13 to 19, further comprising the step of: waking up the drug delivery device based on the sensing of the voltage difference to the first spring by the processor.

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