Low medicament sensor and medicament delivery device

Abstract

A low medicament sensor for a medicament delivery device having a reservoir, a pump, and a fluid path for medicament between the reservoir and the pump, the low medicament sensor comprising a switch and a bounce dome. The bounce dome is initially in contact with the switch, in fluid communication with the fluid path, and configured to bounce out of contact with the switch when a pressure within the bounce dome decreases below a predetermined pressure. Also disclosed is a clogging sensor and a medicament delivery device. The present application enables accurate detection of depletion and / or clogging of medicament in the reservoir.

Description

[0001] This application is a divisional application of Chinese Invention Patent Application No. 201910811016.3, entitled "Low-dosage sensor, clogging sensor and drug delivery device", filed on August 30, 2019. Technical Field

[0002] This invention relates to medical devices, and more particularly to a low-dose sensor for sensing an empty drug reservoir and / or a blockage sensor for sensing a blockage, and a drug delivery device with such a low-dose sensor and / or such a blockage sensor. Background Technology

[0003] Diabetes is a group of diseases characterized by high blood sugar levels, caused by the inability of people with diabetes to maintain adequate levels of insulin production when needed. For those with diabetes, if left untreated, diabetes can be dangerous and can lead to serious health complications and premature death. However, by utilizing one or more treatment options to help control diabetes and reduce the risk of complications, these complications can be minimized.

[0004] Treatment options for people with diabetes include specialized diets, oral medications, and / or insulin therapy. The primary goal of diabetes treatment is to control a person's blood glucose, or sugar levels. However, maintaining proper diabetes management is complex because it must be balanced with a person's activity level. People with type 1 diabetes (T1D) require insulin (e.g., via injection or infusion) to remove glucose from the bloodstream because their bodies typically cannot produce insulin. People with type 2 diabetes (T2D) are usually able to produce insulin, but their bodies cannot use it correctly to maintain blood glucose levels within a medically acceptable range. Unlike people with T1D, most people with T2D do not typically need daily insulin to sustain life. Many are able to manage their condition through a healthy diet and increased physical activity or oral medications. However, if they are unable to regulate their blood glucose levels, they will be prescribed insulin. For example, an estimated 6.2 million people with type 2 diabetes (e.g., in the United States, Western Europe, and Canada) manage their blood glucose using multiple daily injections (MDI) consisting of 24-hour basal insulin and short-acting rapid insulin administered with meals.

[0005] There are two main methods for daily insulin therapy in the treatment of type 1 diabetes (T1D) and sometimes type 2 diabetes (T2D). In the first method, the diabetic patient injects insulin themselves using a syringe or insulin pen as needed. This method requires a needle prick for each injection, and the diabetic patient may need to inject three to four times a day. The syringes and insulin pens used for insulin injection are relatively simple to use and cost-effective.

[0006] Another effective approach to insulin therapy and diabetes management is infusion therapy, or infusion pump therapy using an insulin pump. An insulin pump delivers a continuous infusion of insulin to a diabetic patient at varying rates to more closely match the function and behavior of a normally functioning pancreas in a non-diabetic patient, producing the required insulin. The pump can help maintain the diabetic patient's blood glucose levels within the target range based on their individual needs. Infusion pump therapy requires an infusion cannula, typically in the form of an infusion needle or flexible catheter, which punctures the diabetic patient's skin through which insulin is infused. Infusion pump therapy offers the advantages of continuous insulin infusion, precise dosing, and a programmable delivery schedule.

[0007] In infusion therapy, insulin doses are typically administered at a basal rate and in single-dose formulations. When insulin is administered at a basal rate, it is delivered continuously over 24 hours to maintain blood glucose levels in a diabetic patient within a consistent range between meals and rest (typically at night). Insulin pumps can also be programmed to vary the basal rate of insulin according to different times of day and night. Conversely, single-dose formulations are generally administered with meals and typically provide a single additional insulin injection to balance carbohydrate consumption. Insulin pumps can be configured to allow the diabetic patient to program the volume of the single dose based on the amount or type of meal. Furthermore, insulin pumps can be configured to infuse modified or supplemental single-dose insulin to compensate for low blood glucose levels when calculating a single dose for a specific meal to be eaten.

[0008] Insulin pumps advantageously deliver insulin over time, rather than as a single injection, typically resulting in less variation within the recommended glycemic range. Furthermore, insulin pumps can reduce the number of needle pricks that diabetic patients must endure and improve diabetes management, thereby enhancing their quality of life. For example, due to unmet clinical needs for improved control, many patients with type 2 diabetes (T2D) on prescription insulin therapy are expected to switch from injections to infusions. That is, a significant number of T2D patients on multiple daily injection (MDI) do not achieve target glycemic control or do not adequately adhere to their prescription insulin therapy.

[0009] For ease of infusion therapy, there are generally two types of insulin pumps: conventional pumps and patch pumps. Conventional pumps require disposable components, typically referring to infusion kits, tubing kits, or pump kits, which deliver insulin from the pump reservoir into the user's skin. Infusion kits include a pump connector, a tubing of a certain length, and a base or socket from which a cannula in the form of a hollow metal infusion needle or a flexible plastic catheter extends. The base usually has an adhesive that holds it on the skin surface during use. The cannula can be inserted into the skin manually or by means of a manual or automatic insertion device. The insertion device can be a separate unit required by the user.

[0010] Another type of insulin pump is the patch pump. Unlike traditional infusion pumps and infusion kits, patch pumps are integrated devices that combine most or all fluid components (including a fluid reservoir, pumping mechanism, and mechanism for automatic cannula insertion) in a single housing, which is adhesively attached to the infusion site on the patient's skin, eliminating the need for separate infusion or tubing kits. The patch pump containing insulin adheres to the skin and delivers insulin over a period of time through an integrated subcutaneous cannula. This device requires frequent replacement, such as every three days or when the insulin reservoir is depleted, otherwise complications such as blockage of the fluid path or restriction in the cannula or infusion site may occur.

[0011] It is important to determine when the insulin reservoir is depleted or when there is a blockage, so that patients are aware that they are not receiving the full expected dose of medication, such as insulin.

[0012] In traditional systems, low fluid volume levels or blockages in the fluid pathway may be detected too slowly or, in some cases, not at all, potentially leading to dangerous consequences for patients. For example, if a low fluid volume level or blockage is not detected during insulin infusion, the patient may not receive the necessary amount of medication to prevent potentially dangerous hyperglycemic events. Because the delivery of medication fluids can be critical to the delivery of healthcare services, rapid detection of depletion in reservoirs and blockages in medication delivery systems is essential.

[0013] Therefore, improved flow sensing is needed to accurately detect the depletion and / or blockage of the drug in the reservoir. Summary of the Invention

[0014] Therefore, one aspect of the present invention is to provide a sensor for accurately detecting the depletion and / or blockage of medicine in a reservoir.

[0015] The foregoing and / or other aspects of the present invention are achieved by providing a low-dose sensor for a drug delivery device having a reservoir, a pump, and a fluid path for the drug located between the reservoir and the pump. The sensor includes a switch and a snap dome. The snap dome is initially in contact with the switch, in fluid communication with the fluid path, and configured to snap away from the switch when the pressure within the snap dome decreases below a predetermined pressure.

[0016] The foregoing and / or other aspects of the present invention are also achieved by providing a drug delivery device comprising: a reservoir for storing a drug; a pump; a fluid path for the drug, the fluid path fluidly connecting the reservoir and the pump; a switch; and a bouncing dome. The bouncing dome initially contacts the switch, is in fluid communication with the fluid path, and is configured to bounce and disengage from the switch when the pressure within the bouncing dome decreases below a predetermined pressure.

[0017] The foregoing and / or other aspects of the invention are further achieved by providing a blockage sensor for a drug delivery device, the blockage sensor having a pump, a drug delivery sleeve, and a drug delivery fluid path for fluidly connecting the pump and the drug delivery sleeve, the blockage sensor including a switch and a bouncing dome. The bouncing dome is initially not in contact with the switch, is in fluid communication with the drug delivery fluid path, and is configured to bounce and contact the switch when the pressure in the fluid path increases to above a predetermined pressure.

[0018] Further and / or other aspects and advantages of the invention will be set forth in the description which follows, or will be apparent from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or other aspects and advantages of the embodiments of the present invention will be more readily understood from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 This is a perspective view of a patch pump according to an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 along Figure 1 A cross-sectional view taken from line 2-2;

[0022] Figure 3 yes Figure 1 A schematic diagram of the drug flow path of a patch pump;

[0023] Figure 4 This is a block diagram depicting an illustrative embodiment of a patch pump fluid architecture and metering subsystem according to an embodiment of the present invention;

[0024] Figure 5 This is a perspective view of a bistable element or bouncing dome component according to an embodiment of the present invention;

[0025] Figure 6 This is a plan view of the base of a patch pump according to an embodiment of the present invention, with components removed for clarity;

[0026] Figure 7 yes Figure 6 Exploded perspective view of the base;

[0027] Figure 8 yes Figure 6 A partial cross-sectional view taken along line 8-8 of the base, in which... Figure 5 The bouncy dome component is in the first steady-state position;

[0028] Figure 9 yes Figure 6 A partial cross-sectional view taken along line 8-8 of the base, in which... Figure 5 The bouncy dome component is in the second steady-state position;

[0029] Figure 10 This is a partial cross-sectional view according to another embodiment of the present invention;

[0030] Figure 11 This is a partial cross-sectional view according to another embodiment of the present invention; and

[0031] Figure 12 This is a partial cross-sectional view according to another embodiment of the present invention. Detailed Implementation

[0032] Reference will now be made in detail to embodiments of the invention illustrated in the accompanying drawings, wherein similar reference numerals denote similar elements throughout the drawings. The embodiments described herein are illustrative by way of example but do not limit the invention.

[0033] Those skilled in the art will understand that this disclosure is not limited to its application to the construction details and component arrangements set forth in the following description or shown in the accompanying drawings. The embodiments herein are capable of having other embodiments and can be practiced or performed in various ways. The phrases and terms used herein are for descriptive purposes and should not be considered limiting. The use of “comprising,” “including,” or “having,” and variations thereof herein is intended to cover items listed thereafter and their equivalents, as well as additional items. Unless otherwise limited, the terms “connection,” “link,” and “installation,” and variations thereof are used broadly herein and include direct and indirect connections, links, and installations. Furthermore, the terms “connection” and “link,” and variations thereof, are not limited to physical or mechanical connections or links. In addition, terms such as “upward,” “downward,” “bottom,” “top,” “front,” “back,” “up,” “down,” “upward,” “downward,” and other orientation descriptors are intended to facilitate the description of exemplary embodiments of the invention and are not intended to limit the structure of exemplary embodiments of the invention to any particular location or orientation. Those skilled in the art will understand that degree terms such as “basically” or “generally” refer to and include a reasonable range around a given value, for example, general tolerances associated with the manufacture, assembly, and use of the embodiments described.

[0034] Figure 1 This is a perspective view of a patch pump 1 according to an illustrative embodiment of the present invention. The patch pump 1 has a housing 10 including a main cover 2 that is liquid-sealed to, or preferably hermetically sealed to, a base 9. The base 9 carries various components as described below. The hermetically sealed seal prevents fluid ingress and prevents other particles from passing through the seal. Embodiments of the patch pump 1 also include vents or vent membranes that, together with the sealing method, provide pressure equalization. Embodiments of the seal include, for example, liquid-impermeable seals, O-ring seals or other mechanical seals, gaskets, elastomers, heat seals, ultrasonic welding seals, laser welding, chemical bonding, adhesives, solvent welding, or adhesive welding. Laser welding is a preferred sealing method because, when properly performed, it forms a seamless, completely hermetically sealed seal. The vents or vent membranes continuously serve to equalize internal pressure and provide a sterile environment.

[0035] Figure 2 This is a cross-sectional view of the patch pump 1, showing the various components. The main cover 2 and base 9 define an interior 12 divided by a barrier 20 into a first interior region 14 and a second interior region 16. According to one embodiment, the patch pump 1 preferably includes a reservoir 4 for storing a medication (e.g., insulin) and a pump 3 for pumping the medication out of the reservoir 4. The patch pump 1 also preferably includes electronics 8 for programming and operating the patch pump 1 and an insertion mechanism 7 for inserting a cannula 47 into the patient's skin to deliver the medication.

[0036] As previously described, the interior 12 of the patch pump 1 is divided into a first internal region 14 and a second internal region 16 by a barrier 20. According to one embodiment, the barrier 20 is part of the main cover 2. Preferably, the barrier 20 is integrally formed with the main cover 2 as a single structure. The barrier 20 is preferably sealed to a protrusion on the base 9 such that the interface between the barrier 20 and the protrusion is hermetically connected using any of the methods described above or any other suitable conventional sealing method. Alternatively, the interface between the barrier 20 and the protrusion may be liquid-sealed. The barrier 20 separates the first internal region 14 from the second internal region 16 and protects the first internal region 14 from fluid ingress. According to one embodiment, the second internal region 16 is not sealed to prevent fluid ingress.

[0037] The first internal region 14 includes components such as the pump 3 and electronic devices 8. Examples of electronic devices 8 include semiconductor chips, controllers, diodes, antennas, coils, batteries, discrete components (e.g., resistors and capacitors), and circuit boards (e.g., printed circuit boards (PCBs)) for operating and controlling the patch pump 1. As will be readily understood by those skilled in the art, a dry environment is desired for the normal operation of these components, especially electronic devices 8. The second internal region 16 includes an insertion mechanism 7 and a cannula 47. According to one embodiment, because the insertion mechanism 7 interacts with the patient's skin, the second internal region 16 is neither an airtight nor a liquid-impermeable environment.

[0038] According to one embodiment, the components of the first internal region 14 are different from those of the second internal region 16. Alternatively, the first internal region 14 and the second internal region 16 may share some of the same components. For example, in some embodiments, portions of the reservoir 4 are disposed in both the first internal region 14 and the second internal region 16. However, when the reservoir and the insertion mechanism 7 are separated by the barrier 20, the two internal regions 14, 16 are in fluid communication to effectively operate the patch pump 1.

[0039] Figure 3 This is a schematic diagram of an exemplary fluid path in a patch pump 1 according to an illustrative embodiment of the present invention. Medication enters the patch pump 1 through the filling port 43 to fill the reservoir 4. During operation of the patch pump 1, the pump 3 draws the medication out of the reservoir 4 and into the filling port 43 via an auxiliary port, then flows through the second fluid channel 26 to the inlet of the pump 3. Next, the pump 3 drives the medication out of the pump 3, into the first fluid channel 24, and into the container 32 of the insertion mechanism 7. Finally, the insertion mechanism 7 receives the medication from the container 32 via a conduit and delivers the medication to the patient's skin through the cannula 47.

[0040] Figure 4 yes Figure 1An exemplary patch pump fluid architecture and metering subsystem diagram of patch pump 1 is provided. The power storage subsystem for patch pump 1 includes a battery 5A. The control electronics 8 of patch pump 1 may include a microcontroller 81, sensing electronics 82, a pump and valve controller 83, sensing electronics 85, and deployment electronics 87, which control the actuation of patch pump 1. Patch pump 1A includes a fluid subsystem that may include a reservoir 4, a reservoir filling port 43 for receiving a refill syringe to refill reservoir 4, and low-volume sensors 101, 201 as described below. The fluid subsystem may include a metering system 41, which includes a pump and valve actuator 411 and an integrated pump and valve mechanism 413. The fluid subsystem may also include a deployment actuator 7, a cannula 47 for insertion into an infusion site on the user's skin, and occlusion sensors 301, 401 as described below.

[0041] In some patch pumps, the low-capacity sensors 101, 201 for reservoir 4 include a piston with a plunger connected to a switch. When a low pressure is generated, the plunger moves, thereby triggering the switch. However, such sensors may encounter viscosity issues, potential high reagent residue problems, and sealing issues that need to be addressed in the design and assembly of such sensors. These sensors also require many components and numerous connections. Force-sensing resistors that are in direct or indirect contact with the fluid path can also be used. Force-sensing resistors work well, but calibration, repeatability, and cost can be issues. Microelectromechanical systems (MEMS) can also be placed in contact with the fluid path. Although MEMS sensors have been proven and reliable, they can be very expensive.

[0042] like Figures 5 to 8 As shown, according to one embodiment of the invention, the bistable element or bouncing dome element 100 can be used together with the switch 102 as a low-capacity sensor 101 for the reservoir 4. Figure 6 Although pump 3 and reservoir 4 are not shown, the location of pump 3 at pump connection point 103 on base 109 and the location of reservoir 4 at reservoir connection point 105 on base 109 are shown. A fluid path 110 fluidly connects reservoir 4 and pump 3. According to one embodiment, fluid path 110 is a recess in base 109 covered by a pressure-sensitive adhesive, diaphragm, or film 104, which fluidly seals the recess to form fluid path 110.

[0043] like Figure 6As shown, a portion of the fluid path 110 travels beneath the bouncy dome 100, such that the bouncy dome 100 is in fluid communication with the fluid path 110. According to one embodiment, the bouncy dome 100 and this portion of the fluid path 110 are covered by a pressure-sensitive adhesive or film 104 (e.g., a Mylar film), which can fluidly seal this portion of the fluid path 110. In this embodiment, the bouncy dome 100 is disposed within the fluid path 110.

[0044] According to one embodiment, pump 3 is a positive displacement pump. For each stroke, a known amount of fluid is drawn from the reservoir. According to one embodiment, in each stroke, the pump draws 5 microliters from reservoir 4. According to one embodiment, reservoir 4 is a flexible, self-collapsed reservoir 4, thereby minimizing the pressure required to draw liquid from the reservoir, allowing the use of a small pump 3, and avoiding high pressure in the fluid path 110.

[0045] like Figure 8 As clearly shown, when reservoir 4 is full, switch 102 contacts the spring-loaded dome 100, which is in a first steady-state position with its dome arched upwards. Once reservoir 4 is nearly empty, pumping by pump 3 reduces the pressure within fluid path 110. The spring-loaded dome 100 is configured to spring back and contact switch 102 (see Figure 102) once the pressure inside or below the spring-loaded dome 100 (within fluid path 110) decreases below a predetermined pressure. Figure 9 The switch 100 disengages from the reservoir and enters a second steady-state position. In other words, when the bouncy dome 100 is in the fluid path, as the reservoir is full, a substantially uniform negative pressure or vacuum exists (within a predetermined range of variation) as the pump 3 draws fluid from the reservoir 4 along the fluid path. However, as the reservoir 4 approaches empty, the continued pumping of the pump 3 and the reduction in fluid volume generate a greater negative pressure. Under sufficient negative pressure, the bouncy dome 100 is pulled downwards by the negative pressure to the second steady-state position and disengages from the switch 102 (see [link to relevant documentation]). Figure 9 ).

[0046] In other words, because the bouncing dome 100 interacts with the fluid path 110 (as it is part of the fluid path 110), when a predetermined negative pressure is reached due to the pump 3 drawing more and more vacuum with each stroke as the reservoir 3 approaches empty, the vacuum pulls the bouncing dome 100 away from the switch 102, and the bouncing dome 100 moves to its second steady-state position. Figure 9 ).

[0047] According to one embodiment, the second steady-state position of the bouncy dome 100 is a downwardly arched position. According to another embodiment, the second steady-state position of the bouncy dome 100 is substantially flat. According to yet another embodiment, the second steady-state position of the bouncy dome 100 is upwardly arched, but less arched than the first steady-state position.

[0048] Material choices for the bouncy dome 100 include stainless steel, beryllium, copper, other metal alloys, or plastics (e.g., acrylonitrile-butadiene-styrene (ABS), cyclic olefin copolymers (COP), or polypropylene). Ideally, the bouncy dome should have sufficient elasticity to bounce back to its original steady-state position. The desired thickness of a given material providing the desired elasticity is a factor in material selection, especially when attempting to minimize the size of the bouncy dome. Another factor is the force required to actuate the bouncy dome 100, as vibration-induced actuation is undesirable, and this factor interacts with the size and performance of the pump 3. Consistency (to reduce false actuation) is also desirable. Experiments have determined that an acceptable balance between size and performance can be achieved using a 14mm stainless steel bouncy dome (i.e., the bouncy dome can be defined by a circle with a 14mm diameter).

[0049] Switch 102 can be a mechanical switch, such as an SPVR switch from ALPS. Alternatively, switch 102 can be an electrical switch. For example, if a conductive material is chosen for the bouncy dome 100, then the portion of the film 104 covering the bouncy dome 100 and the portion of the fluid path 110 located below the bouncy dome 100 can have openings 111 therein to provide electrical contact between the bouncy dome 100 and switch 102. When the bouncy dome is actuated, the electrical contact is broken. Alternatively, film 104 can be conductive. As yet another alternative, a conductive pad can be provided on film 104 such that there are no openings in film 104, and when the bouncy dome 100 is actuated, the conductive pad 113 (see [link to relevant documentation]) is activated. Figure 11 The electrical contact between the switch 102 and the switch 103 is broken.

[0050] Once switch 102 is triggered by the actuation of the spring dome component 100, controller 81 can provide various indications to the user to let them know that the medication delivery is complete, such as sound and / or vibration, or text display. The triggering of the switch can also be a signal for controller 81 to stop pump 3. Alternatively, once the switch is triggered, controller 81 can control pump 3 to continue pumping for a predetermined amount of time, since the approximate capacity remaining in the reservoir and the approximate amount pumped in each cycle are known. The triggering of switch 102 can also be used as a signal for controller 81 to withdraw the injection needle.

[0051] exist Figure 10In another embodiment shown, the bouncing dome 200 can be used together with the switch 202 as a low-capacity sensor 201. In this embodiment, the bouncing dome 200 is not located within the fluid path 210, but rather has an opening or hole 215 in the base 209 through which the fluid path communicates with the space 218 below the bouncing dome. The hole 215 is sized such that pressure can be balanced between the fluid path 210 and the space 218 below the bouncing dome 200, but the surface tension of the agent in the fluid path 210 prevents the agent from flowing through the hole 215.

[0052] In this embodiment, as in the previous embodiments, with the bouncy dome 200 in fluid communication with the fluid path 210 through the orifice 215 to balance the pressure between them, as the reservoir 4 approaches empty, the continued pumping of the pump 3 and the reduction in fluid volume together generate a greater negative pressure in the fluid path 210 and the space 218 below the bouncy dome 200. Under sufficient negative pressure, the bouncy dome 200 is actuated by the negative pressure and displaced, disengaging from the switch 202.

[0053] exist Figure 11 In another embodiment shown, instead of the bouncing dome 100 or 200 used as a low-volume sensor, or additionally in addition to the bouncing dome 100 or 200 used as a low-volume sensor, a bouncing dome 300 may be used together with a switch 302 as a blockage sensor 301. In this embodiment, the downstream fluid path 320 connects the pump 3 and the delivery sleeve 47. The bouncing dome 300 is configured to be in fluid communication with the downstream fluid path 320 and to be out of contact with the switch 302. In this embodiment, the bouncing dome 300 is inverted, i.e., the bouncing dome is configured to arch downwards and to be in fluid contact with the downstream fluid path 320. In this embodiment, the combination of the bouncing dome 300 and the switch 302 serves as a blockage sensor. For example, if a blockage occurs in the downstream fluid path 320, the pressure in the downstream fluid path 320 increases as the pump 3 continues to pump the agent. Once the pressure increases to a predetermined threshold, the inverted bouncing dome 300 is actuated and bounces into contact with the switch 302. The controller 81 can use this switch trigger as a blockage detection.

[0054] As with the previously described alternative embodiments, such as Figure 12 As shown, the bouncing dome 400 can be used together with the switch 302 as a blockage sensor 401. In this embodiment, the base 409 may have an orifice 415 in fluid communication with the downstream fluid path 420. The orifice 415 is sized such that pressure can be balanced between the downstream fluid path 420 and the space 418 below the bouncing dome 400, but the surface tension of the agent in the downstream fluid path 420 prevents the agent from flowing through the orifice 415.

[0055] As an alternative blockage sensor, switches 302 and 402 can be disposed within downstream fluid paths 320 and 420 and initially contact the bouncing dome 300 and 400. Once the bouncing dome is actuated by a predetermined increased pressure, the bouncing dome 300 and 400 bounce and disengage from switches 302 and 402.

[0056] Embodiments of the invention include a bouncing dome (typically metal, but also plastic, a bistable material, or a diaphragm that buckles under pressure) attached and sealed to a fluid path to bounce when a pharmaceutical reservoir is emptied. This bouncing should be designed and controlled to occur under a reasonable negative pressure. The dome switch is attached to and sealed to the fluid path via a pressure-sensitive adhesive or any other permanently welded and sealed membrane. The attachment does not constrain the ends of the bouncing dome, so the membrane does not affect the function of the bouncing dome. The switch can be positioned to contact an undeflected (untriggered or unactuated) bouncing dome such that the switch is activated when the bouncing dome is triggered. The switch can be normally closed and then open, or vice versa, i.e., the switch can be normally open and then closed. The dome can be sealed to the fluid path such that the top of the dome (if metal) is exposed, allowing the circuit to be closed using simple mechanical contact and then opened when the dome is activated and pulled away. Alternatively, the sealant may be coated with a conductive material or may be conductive.

[0057] These embodiments are inexpensive options for detecting low / empty capacity in reservoirs. They achieve their minimum cost, particularly when used with simple mechanical contacts and conductive covers / tops. The cost of the spring-loaded dome assembly is very low, yet its function is highly repeatable.

[0058] While only a few embodiments of the invention have been shown and described, the invention is not limited to the described embodiments. Those skilled in the art will understand that other changes can be made to the disclosed embodiments without departing from the scope of the invention. Furthermore, any embodiments, features, and / or elements disclosed herein can be combined with each other to form various additional combinations not specifically disclosed, provided that the combined embodiments, features, and / or elements do not conflict with each other. All such variations and combinations are considered to fall within the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A low-dose sensor for a drug delivery device having a reservoir, a pump, and a fluid path for the drug between the reservoir and the pump, the low-dose sensor comprising: switch; and Bouncy dome component, The bouncy dome component initially contacts the switch; The bouncy dome component is in fluid communication with the fluid path; and The bouncy dome is configured to bounce and disengage from the switch when the pressure inside the bouncy dome drops below a predetermined pressure. in: The bouncy dome component includes conductive metal; The bouncy dome component is disposed within the fluid path; The bouncy dome component is sealed to the fluid path with a diaphragm; and The outer portion of the bouncy dome is not covered by the diaphragm to provide electrical contact between the bouncy dome and the switch.

2. A drug delivery device, comprising: Storage container for storing medicines; Pump; A fluid path for the pharmaceutical preparation, the fluid path being fluidly connected to the reservoir and the pump; switch; and Bouncy dome component, The bouncy dome component initially contacts the switch; The bouncy dome component is in fluid communication with the fluid path; and The bouncy dome is configured to bounce and disengage from the switch when the pressure inside the bouncy dome drops below a predetermined pressure. in: The bouncy dome component is disposed within the fluid path; The bouncy dome component is sealed to the fluid path with a diaphragm; and The outer portion of the bouncy dome is not covered by the diaphragm to provide electrical contact between the bouncy dome and the switch.

Images