Patent ID: 12213782

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

Certain terminology may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “top”, “bottom”, “upper”, “lower”, “above”, and “below” could be used to refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “side”, “outboard”, and “inboard” could be used to describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second”, and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.

As used herein, the term “axial” refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the “axial” direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term “axial” may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the “axial” direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term “radially” as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as “radially” aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms “axial” and “radial” (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominantly in the respective nominal axial or radial direction. As used herein, the term “transverse” denotes an axis that crosses another axis at an angle such that the axis and the other axis are neither substantially perpendicular nor substantially parallel.

As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

Embodiments of the present disclosure may be described herein in terms of schematic, functional and/or logical block components and various processing steps. It should be appreciated that such block components may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of the present disclosure may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any number of systems, and that the physiological characteristic sensor described herein is merely exemplary embodiments of the present disclosure.

For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure.

The following description relates to various embodiments of a physiological characteristic sensor system, which includes a physiological characteristic sensor and a sensor inserter. The systems described herein inhibit or mitigate the effects of an accidental mishandling of the sensor inserter during use, and also enable the sensor inserter to be properly disposed of once the physiological characteristic sensor is coupled to the user. It should be noted that while the physiological characteristic sensor is described herein as being a continuous glucose monitor, it will be understood that the physiological characteristic sensor may comprise a variety of other sensors, such as cardiac monitors, body temperature sensors, EKG monitors etc., medical devices, and/or other components that are intended to be affixed to the body of a user. Thus, while the non-limiting examples described below relate to a medical device used to treat diabetes (more specifically, a continuous glucose monitor), embodiments of the disclosed subject matter are not so limited.

Generally, the glucose sensor employed with the adhesive patch is a continuous glucose sensor of the type used by diabetic users. For the sake of brevity, conventional aspects and technology related to glucose sensors and glucose sensor fabrication may not be described in detail here. In this regard, known and/or conventional aspects of glucose sensors and their manufacturing may be of the type described in, but not limited to: U.S. Pat. Nos. 6,892,085, 7,468,033 and 9,295,786; and United States patent application number 2009/0299301 (which are each incorporated by reference herein). In addition, for the sake of brevity, conventional aspects and technology related to sensor inserters may not be described in detail here. In this regard, known and/or conventional aspects of sensor inserters may be of the type described in, but not limited to: U.S. Pat. No. 10,413,183 (which is incorporated by reference herein).

With reference toFIG.1,FIG.1is a perspective view of a physiological characteristic sensor system100. In one example, the physiological characteristic sensor system100includes a physiological characteristic sensor102and a sensor inserter104. Generally, with reference toFIG.2, the components of the physiological characteristic sensor102are coupled together as a single unit. The physiological characteristic sensor102and the sensor inserter104may be packaged together for use by a consumer or user.

In one example, with reference toFIG.3, the physiological characteristic sensor102includes a housing106, an antenna108, a sensor connector110, a power source assembly112, a glucose sensor114, at least one sealing member116, a printed circuit board assembly118and a coupling member or adhesive patch120. The housing106is composed of a polymer-based material, and is molded, cast, formed via additively manufacturing, etc. In this example, the housing106is substantially rectangular, however, the housing106may have any desired shape that cooperates with the sensor inserter104to couple the physiological characteristic sensor102to the anatomy. The housing106has rounded corners to reduce snagging of the housing106on a user's clothing, for example. In one example, the housing106is a two-piece housing, which includes a first, top housing portion122and a second, bottom housing portion124. The top housing portion122and the bottom housing portion124cooperate to enclose the antenna108, the sensor connector110, the power source assembly112, a portion of the glucose sensor114, the at least one sealing member116, and the printed circuit board assembly118. The top housing portion122includes a bore126, which enables a portion of the sensor inserter104to pass through the housing106to couple the physiological characteristic sensor102to the anatomy. The bottom housing portion124includes a second bore128, which cooperates with the bore126to enable the sensor inserter104and a portion of the glucose sensor114to pass through the housing106. The bottom housing portion124may also include one or more dividers or compartments, to assist in containing the components of the physiological characteristic sensor102. In addition, the bottom housing portion124may define a channel130about a perimeter of the bottom housing portion124to assist in coupling the top housing portion122to the bottom housing portion124.

For example, with reference toFIG.4, the top housing portion122is received within the channel130. The top housing portion122is coupled to the bottom housing portion124within the channel130, via welding, adhesives, etc. Generally, the top housing portion122is coupled to the bottom housing portion124to inhibit fluids, such as air, water, etc., from entering into the housing106. In addition, in one example, the bottom housing portion124includes a cylindrical post132, which is coupled to a mating cylindrical post134of the top housing portion122to couple the top housing portion122to the bottom housing portion124about the bore126and the second bore128. The cylindrical post132also defines a first angled surface132a, and the mating cylindrical post134also defines a second angled surface134a. The first angled surface132ais angled at upward from an inner perimeter of the cylindrical post132toward an outer perimeter of the cylindrical post132. The second angled surface134ais angled upward from an outer perimeter of the mating cylindrical post134toward the inner perimeter of the mating cylindrical post134. Thus, with reference toFIG.5, the angled surfaces132a,134acooperate to define a diamond shaped cavity136, which extends about a perimeter of the bore126and the second bore128. The diamond shaped cavity136compresses the at least one sealing member116to form the seal about the glucose sensor114, as will be discussed. In one example, the top housing portion122and the bottom housing portion124are coupled about a top surface of the cylindrical post132and the mating cylindrical post134to maintain a compression of the at least one sealing member116.

With reference back toFIG.6, the antenna108is coupled to the top housing portion122. In this example, the antenna108is coupled to stakes138of the top housing portion122via heat stake, ultrasonic welding, etc. In one example, the antenna108is any suitable antenna108that enables bi-directional communication between the physiological characteristic sensor102and a portable electronic device of the user. Thus, generally, the antenna108enables wireless communication between the physiological characteristic sensor102and another device, including, but not limited to, an infusion pump, handheld device (tablet, smart phone, etc.) or other monitoring device. In one example, the antenna108may include, but is not limited to, a near field communication (NFC) antenna, RF radio antenna, a far field communication antenna, a wireless communication system configured to communicate via a wireless local area network (WLAN) using IEEE 802.11 standards or by using cellular data communication, a Bluetooth antenna, etc. In one example, the antenna108of the physiological characteristic sensor102is a Bluetooth low energy (BLE) antenna.

In one example, with reference toFIG.7, the antenna108is electrically coupled to and in communication with the printed circuit board assembly118via spring contacts140. Thus, the antenna108is coupled to the printed circuit board assembly118without soldering, which reduces manufacturing complexity and time. In this example, the printed circuit board assembly118includes two spring contacts140, however, the printed circuit board assembly118may have any suitable contact configuration to couple the antenna108to the printed circuit board assembly118upon assembly of the top housing portion122to the bottom housing portion124. Thus, generally, with reference toFIG.7A, the antenna108is coupled to the housing106such that the antenna108is electrically coupled to the printed circuit board assembly118upon assembly of the top housing portion122to the bottom housing portion124of the housing106.

Alternatively, with reference toFIG.8, an antenna108′ is shown. The antenna108′ is substantially the same as the antenna108, but the antenna108′ includes spring contacts140′. The antenna108′ enables wireless communication between the physiological characteristic sensor102and another device, including, but not limited to, an infusion pump, handheld device (tablet, smart phone, etc.) or other monitoring device. In one example, the antenna108may include, but is not limited to, a near field communication (NFC) antenna, RF radio antenna, a far field communication antenna, a wireless communication system configured to communicate via a wireless local area network (WLAN) using IEEE 802.11 standards or by using cellular data communication, a Bluetooth antenna, etc. In one example, the antenna108′ of the physiological characteristic sensor102is a Bluetooth low energy (BLE) antenna. In this example, the spring contacts140′ are integrally formed with the antenna108′. The spring contacts140′ are defined as a portion of the antenna108′, which is folded upon itself. With reference toFIG.9, the spring contacts140′ touch contact pads141of the printed circuit board assembly118to electrically couple the antenna108′ to the printed circuit board assembly118such that the antenna108′ is in communication with the printed circuit board assembly118. Thus, the antenna108′ is coupled to the printed circuit board assembly118without soldering, which reduces manufacturing complexity and time.

With reference back toFIG.3, the sensor connector110provides a contact force between the glucose sensor114and the printed circuit board assembly118. The sensor connector110, in one example, is composed of a polymer-based material, and is cast, molded, additive manufactured, etc. When the top housing portion122is coupled to the bottom housing portion124, the sensor connector110is held against the glucose sensor114by the top housing portion122, which in turn, holds or maintains the glucose sensor114electrically coupled to the printed circuit board assembly118.

The power source assembly112supplies power to the printed circuit board assembly118. In one example, the power source assembly112includes at least one battery142, a first, top contact or first battery contact144and a second, bottom contact or second battery contact146. The at least one battery142, in this example, comprises two batteries142, each of which are coin-cell batteries. For example, the batteries142are each 1.55 volt (V) batteries. The first battery contact144and the second battery contact146are each composed of a metal or metal alloy, and may be stamped, cast, etc. The first battery contact144includes two spring tabs148, which are interconnected by a body150.

With reference toFIG.10, the first battery contact144is shown coupled to the top housing portion122. The first battery contact144is generally coupled to the top housing portion122via ultrasonic welding or heat stake welding with stake152. The stake152is large to protect the first battery contact144during coupling of the top housing portion122to the bottom housing portion124. The body150may define an opening150ato receive the stake152. The first battery contact144is generally coupled to the top housing portion122by the body150such that the spring tabs148are free to move relative to the body150. By enabling the spring tabs148to move relative to the body150, with reference toFIG.11, the first battery contact144self-balances when moments are applied as the spring tabs148compress during coupling the top housing portion122to the bottom housing portion124. This self-balancing of the first battery contact144via the spring tabs148minimizes damage to the first battery contact144during coupling of the top housing portion122to the bottom housing portion124. In addition, by being movable, the spring tabs148limit a reaction force applied to the top housing portion122during use of the physiological characteristic sensor102. With reference back toFIG.3, the first battery contact144is symmetrical about a longitudinal axis of the first battery contact144.

The second battery contact146comprises two second spring tabs154, which are discrete from each other or not interconnected. The second spring tabs154are electrically and physically coupled to the printed circuit board assembly118such that when the top housing portion122is coupled to the bottom housing portion124, the spring tabs148and154compress to electrically couple the batteries142together in series and to the printed circuit board assembly118.

The glucose sensor114is an electrochemical sensor that includes the glucose oxidase enzyme, as is well understood by those familiar with glucose sensor technology. The glucose oxidase enzyme enables the glucose sensor114to monitor blood glucose levels in a diabetic patient or user by effecting a reaction of glucose and oxygen. Again, although certain embodiments pertain to glucose sensors, the technology described here can be adapted for use with any one of the wide variety of sensors known in the art. Generally, a distal end114aof the glucose sensor114is cannulated and positionable in subcutaneous tissue of the user by an insertion needle of the sensor inserter104to measure the glucose oxidase enzyme.

In one example, the glucose sensor114includes a base156that is coupled to the distal end114aof the glucose sensor114at about a ninety degree angle. The base156couples the glucose sensor114to the printed circuit board assembly118. In this example, the base156includes two coupling bores158. The coupling bores158are spaced apart on the base156and couple or anchor the glucose sensor114on the printed circuit board assembly118. In one example, with reference toFIG.12, the base156is shown coupled to the printed circuit board assembly118via the coupling bores158. In this example, the bottom housing portion124includes coupling posts160, which extend through bores118bdefined in the printed circuit board assembly118to mate respectively with the coupling bores158. Each of the coupling bores158include a coupling tab158a. With reference toFIG.13, the coupling tab158ais bendable upon placement of the respective coupling bore158over the respective coupling post160to securely couple the base156, and thus, the glucose sensor114to the bottom housing portion124. The coupling of the base156to the coupling posts160, in turn, also electrically and mechanically couples the glucose sensor114to the printed circuit board assembly118. The coupling tab158aextends into the coupling bore158such that the bending of the coupling tab158aby the coupling post160creates an interference fit between the coupling tab158aand the coupling post160to retain the glucose sensor114on the printed circuit board assembly118. The interference fit between the coupling bores158and the coupling posts160also inhibits a sliding movement of the glucose sensor114relative to the printed circuit board assembly118.

With reference back toFIG.3, the at least one sealing member116includes two sealing members116a,116b. The sealing members116a,116bcomprise O-rings, which are composed of an elastomeric material. With reference toFIG.5, the sealing members116a,116bare positioned on either side of the base156of the glucose sensor114and surround the distal end114ato waterproof or inhibit fluids from entering into the housing106. The assembly of the top housing portion122to the bottom housing portion124causes the angled surfaces132a,134ato contact and compress the sealing members116a,116b, which causes the sealing members116a,116bto deform and fill the space surrounding the distal end114a. The deformation of the sealing members116a,116bby the top housing portion122seals about the distal end114aof the glucose sensor114, and inhibits fluids from entering into the housing106. Thus, the deformation of the sealing members116a,116bforms a seal between the top housing portion122and the bottom housing portion124about the distal end114aof the glucose sensor114. The seal formed between the top housing portion122and the distal end114aby the sealing member116aand the seal formed between the bottom housing portion124and the distal end114aby the sealing member116bis formed without requiring adhesives, grease or other components to ensure a waterproof seal, which reduces manufacturing complexity.

With reference toFIG.3, the printed circuit board assembly118includes a controller or control module162. The control module162includes at least one processor and a computer readable storage device or media, which are mounted to a printed circuit board164. The printed circuit board164is electrically and mechanically coupled to the spring contacts140, and electrically couples the batteries142, the glucose sensor114and the antenna108to the control module162. Thus, the batteries142, the glucose sensor114and the antenna108are in communication with the control module162. The processor can be any custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the control module162, a semiconductor based microprocessor (in the form of a microchip or chip set), a macroprocessor, any combination thereof, or generally any device for executing instructions. The computer readable storage device or media may include volatile and nonvolatile storage in read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM), for example. KAM is a persistent or non-volatile memory that may be used to store various operating variables while the processor is powered down. The computer-readable storage device or media may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable instructions, used by the control module162in controlling components associated with the physiological characteristic sensor102.

The instructions may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. The instructions, when executed by the processor, receive and process input signals, perform logic, calculations, methods and/or algorithms for controlling the components of the physiological characteristic sensor102, and generate signals to components of the physiological characteristic sensor102to monitor the glucose sensor114and control the antenna108based on the logic, calculations, methods, and/or algorithms Although only one control module162is shown, embodiments of the physiological characteristic sensor102can include any number of control modules that communicate over any suitable communication medium or a combination of communication mediums and that cooperate to process the signals from the glucose sensor114, transmit signals received from the glucose sensor114via the antenna108, perform logic, calculations, methods, and/or algorithms, and generate control signals to control features of the physiological characteristic sensor102.

In various embodiments, one or more instructions of the control module162, when executed by the processor, receive and process signals from the glucose sensor114to determine a blood glucose level of the user. The one or more instructions of the control module162, when executed by the processor, also communicate the blood glucose level via the antenna108to the portable electronic device associated with the user.

The printed circuit board assembly118also includes a magnet sensor119. The magnet sensor119observes a magnetic field, including, but not limited to a magnetic field generated by a magnet214associated with the sensor inserter104(FIG.14), and generates one or more sensor signals based on the observation of the magnetic field. In one example, the processor receives the sensor signals from the magnet sensor119and initiates the physiological characteristic sensor102for the monitoring of the blood glucose levels. Stated another way, based on the observation of a change in a magnetic field, such as due to a separation of the magnet214from the physiological characteristic sensor102, the physiological characteristic sensor102is activated to monitor the blood glucose levels. The magnet sensor119is electrically and mechanically coupled to the printed circuit board164, and is in communication with the control module162. In one example, the magnet sensor119is a tunneling magnetoresistive (TMR) sensor. The use of the magnet sensor119in cooperation with the magnet214maintains the physiological characteristic sensor102in a low-power state in the presence of the magnetic field generated by the magnet214, which preserves a life of the batteries142prior to the deployment of the physiological characteristic sensor102(i.e. when the physiological characteristic sensor102is on the shelf).

The adhesive patch120is coupled to the bottom housing portion124and affixes the bottom housing portion124, and thus, the glucose sensor114, to an anatomy, such as the skin of the user. The adhesive patch120may be composed of a flexible and breathable material with one or more adhesive layers, such as cloth, a bandage-like material, and the like. For example, suitable materials could include polyurethane, polyethylene, polyester, polypropylene, polytetrafluoroethylene (PTFE), or other polymers, to which one or more adhesive layers are applied. The adhesive patch120may be coupled to the bottom housing portion124via adhesives, ultrasonic welding, etc.

In one example, in order to assemble the physiological characteristic sensor102, with the bottom housing portion124formed, the second battery contact146is coupled to the bottom housing portion124. With the control module162and the spring contacts140coupled to the printed circuit board164, the printed circuit board164is coupled to the bottom housing portion124such that the coupling posts160pass through the bores118b(FIG.12). The sealing member116bis coupled to the bottom housing portion124adjacent to the cylindrical post132. With brief reference toFIG.12, the glucose sensor114is coupled to the bottom housing portion124by aligning the coupling bores158with the coupling posts160. The base156is advanced toward the printed circuit board assembly118, which causes the coupling tabs158ato bend. The bending of the coupling tabs158aretains the glucose sensor114on the bottom housing portion124and electrically coupled to the printed circuit board assembly118. With reference toFIG.4, the distal end114aof the glucose sensor114extends through the sealing member116band through the second bore128. The batteries142are positioned within the bottom housing portion124so as to be coupled to the second battery contact146.

With reference back toFIG.3, with the top housing portion122formed, the first battery contact144is coupled to the top housing portion122at the body150(FIG.10). The antenna108,108′ is coupled to the top housing portion122(FIG.6). The sealing member116ais positioned opposite the sealing member116b. The top housing portion122is coupled to the bottom housing portion124such that the top housing portion122is received within the channel130. The coupling of the top housing portion122to the bottom housing portion124causes the angled surfaces132a,134ato compress the sealing members116a,116bto form the seal about the distal end114aof the glucose sensor114. The coupling of the top housing portion122to the bottom housing portion124also causes the spring tabs148(FIG.3) of the first battery contact144to electrically couple the batteries142together in series. In addition, the coupling of the top housing portion122to the bottom housing portion124electrically couples the antenna108to the spring contacts140of the printed circuit board assembly118. Generally, the physiological characteristic sensor102provides for reduced assembly time and improved manufacturability.

With reference back toFIG.2, in various embodiments, the physiological characteristic sensor102is coupled to the sensor inserter104for shipping and delivering the physiological characteristic sensor102to the user. The sensor inserter104is manipulatable by a user to couple the glucose sensor114and the physiological characteristic sensor102to the user. With additional reference toFIG.14, the sensor inserter104includes a needle inserter198, a plunger200, a first biasing member or insertion spring202, a needle retractor204, a second biasing member or retraction spring206, a frame208, a sensor retainer210, a sensor carrier212, the magnet214and a cap216. In this example, the cap216includes a membrane218, as will be discussed further herein.

The needle inserter198is composed of a polymer-based material, and is cast, molded, additive manufactured, etc. With reference toFIG.15, the needle inserter198is shown coupled to the physiological characteristic sensor102. Generally, the needle inserter198is coupled to the physiological characteristic sensor102prior to coupling the physiological characteristic sensor102to the sensor inserter104, which provides ease of assembly. The needle inserter198includes a carrier220and an insertion needle222. The carrier220is overmolded onto the insertion needle222. The carrier220includes a pair of arms224. Each of the arms224extend from either side of a carrier base226. The carrier base226provides a graspable portion for coupling the needle inserter198to the physiological characteristic sensor102. The arms224each include an arm tab228. With reference toFIG.16, the arm tabs228are coupled to and engage with a lip230of the needle retractor204. As will be discussed, the engagement between the arm tabs228and the lip230enables the needle retractor204to remove the insertion needle222from the anatomy. With reference back toFIG.15, the insertion needle222is generally a stainless steel needle, which extends for a distance beyond the distal end114aof the glucose sensor114to couple the glucose sensor114to the anatomy.

With reference back toFIG.14, the plunger200is composed of a biocompatible polymer, and may be molded, cast, printed, etc. The plunger200surrounds the frame208, and includes a plurality of threads236defined about a surface of the outer housing600adjacent to a second, bottom end200b. The threads236removably couple the cap216to the plunger200, as will be discussed. The plunger200is shaped to correspond to the shape of the physiological characteristic sensor102so that the user intuitively knows the position and orientation of the physiological characteristic sensor102when the sensor inserter104is used to couple the physiological characteristic sensor102to the anatomy. This enables the user to position the sensor inserter104at a location by feel, without having to see the insertion site, such as a back of an arm, for example. In one example, a first, top end200aof the plunger200includes a recess or dimple that is coaxial with the insertion needle222to enable the user to visualize the location of the distal end114awithin the anatomy.

With reference back toFIG.2, the plunger200also defines a first inner guide surface238and a second inner guide surface240. Each of the first inner guide surface238and the second inner guide surface240extend radially inward from an inner surface of the plunger200. In this example, each of the first inner guide surface238and the second inner guide surface240extend from the first, top end200atoward the bottom end200b. In one example, the first inner guide surface238includes a slot that cooperates with a rail242defined within the needle retractor204. The engagement of the rail242with the slot guides the needle retractor204toward the top end200aof the plunger200to ensure the insertion needle222associated with the needle inserter198that is coupled to the needle retractor204is retained within the plunger200after deployment of the physiological characteristic sensor102. The second inner guide surface240cooperates with the sensor carrier212to guide the sensor carrier212during deployment of the physiological characteristic sensor102. The plunger200also includes a plurality of projections244that extend radially inward spaced apart about an interior periphery of the plunger200. The projections244cooperate with slots246defined in the frame208. Generally, the projections244and the slots246cooperate to a guide a movement of the plunger200relative to the frame208. The plunger200also includes frame projections247. The frame projections247extend radially inward and are defined about a perimeter of the plunger200. As will be discussed, the frame projections247cooperate with the frame208to release the physiological characteristic sensor102when the sensor inserter104is in a second position.

The insertion spring202is a helical coil spring, which is composed of a suitable biocompatible material, such as a spring steel that is wound to form the insertion spring202. In one example, the insertion spring202is a tension spring, which is received between the second inner guide surface240of the plunger200and a surface212aof the sensor carrier212. Generally, the insertion spring202expands as the sensor carrier212moves toward a second, bottom end208bof the frame208to couple the physiological characteristic sensor102to the user and exerts a spring force F1along a longitudinal axis L to move the sensor carrier212toward the bottom end208bof the frame208for deployment of the physiological characteristic sensor102.

The needle retractor204is coupled to a second annular projection248of the sensor carrier212. With reference toFIG.14, the needle retractor204includes a first portion250and a second portion252. The first portion250has a greater diameter than the second portion252. The first portion250includes one or more guide projections254, which are spaced apart about a perimeter of the first portion250. The guide projections254contact the second annular projection248. The second portion252is coupled to the needle inserter198. The diameter of the second portion252is sized such that the retraction spring206is positioned between the first portion250and the sensor carrier212so as to surround the second portion252, as shown inFIG.2.

With continued reference toFIG.2, the retraction spring206is a helical coil spring, which is composed of a suitable biocompatible material, such as a spring steel that is wound to form the retraction spring206. In one example, the retraction spring206is a compression spring, which is received between the second portion252of the needle retractor204and a surface212bof the sensor carrier212. After deployment, the retraction spring206expands and exerts a spring force F2along the longitudinal axis L to move the needle retractor204toward the first inner guide surface238of the plunger200to retain the insertion needle222within the sensor inserter104.

The frame208is received within the plunger200. Generally, the frame208extends a distance beyond the plunger200when the physiological characteristic sensor102is coupled to the sensor inserter104. The frame208is composed of a biocompatible polymer, and may be molded, cast, printed, etc. With reference toFIG.14, the frame208includes a first frame portion260and a second frame portion262. The slots246are defined in the first frame portion260and extend from a top surface208aof the frame208to the second frame portion262. The second frame portion262surrounds the sensor carrier212such that the physiological characteristic sensor102is positioned within the second frame portion262of the frame208. In one example, with reference toFIG.17, the second frame portion262includes at least one or a plurality of ribs264.FIG.17is an end view of the physiological characteristic sensor102coupled to the sensor retainer210, and the sensor retainer210is coupled to the frame208. As shown, the ribs264are spaced apart about the inner perimeter of the frame208, and extend for a distance to engage with the sensor retainer210. As will be discussed, in a first position, the ribs264engage with the sensor retainer210to retain the physiological characteristic sensor102. In the second position, the ribs264are released, via contact between the frame projections247of the plunger200and the ribs264, which causes the sensor retainer210to release the physiological characteristic sensor102for deployment onto the anatomy.

The sensor retainer210is coupled to and received about a perimeter of the sensor carrier212. In one example, the sensor retainer210assists in coupling or retaining the physiological characteristic sensor102on the sensor carrier212. The sensor retainer210defines a central bore211that receives the physiological characteristic sensor102(FIGS.14and18). The sensor retainer210may be composed of a biocompatible polymer, and may be molded, cast, printed, etc. With reference toFIG.17, the sensor retainer210includes at least one or plurality of retainer arms266, which are spaced apart about a perimeter of the sensor retainer210and are spaced apart about the central bore211. InFIG.17, the sensor retainer210is shown with the retainer arms266in a first, fired or released state. Each of the retainer arms266is cantilevered from the sensor retainer210, and includes a contact surface268that retains the physiological characteristic sensor102in a second, pre-fired or coupled state. In the first state, the contact surface268of the retainer arms266do not contact the physiological characteristic sensor102such that the physiological characteristic sensor102is released or uncoupled from the sensor retainer210when the retainer arms266are in the first state. In the first state, a gap269is defined between a terminal end266aof each of the retainer arms266and a surface210bof the sensor retainer210.

With reference toFIG.18, in the second state, each of the ribs264of the frame208contact a respective one of the retainer arms266to bias or compress the retainer arms266into the second state. In the second state, the gap269is substantially eliminated and the terminal end266aof each of the retainer arms266contacts a surface210bof the sensor retainer210. In the second state, as also shown inFIG.19, the contact surface268is held against the physiological characteristic sensor102to retain the physiological characteristic sensor102on the sensor retainer210. As shown inFIG.19, the contact surface268is substantially L-shaped, and at least partially contacts a surface124aof the bottom housing portion124of the physiological characteristic sensor102.

With reference toFIG.20, the sensor retainer210is shown released from the frame208to deploy the physiological characteristic sensor102on the anatomy. The frame projections247of the plunger200contact the ribs264of the frame208, which pushes the ribs264outward, thereby releasing the retainer arms266. The release of the retainer arms266moves the retainer arms266from the second state to the first state, as shown inFIG.21. InFIG.21, the retainer arms266have moved to the first state, which releases the contact surface268from the physiological characteristic sensor102. By the retainer arms266moving to the first state from the second state, the user is able to separate the physiological characteristic sensor102from the sensor inserter104with little to zero force and without disturbing the insertion site.

With reference back toFIG.14, the sensor carrier212moves relative to the frame208to deploy the physiological characteristic sensor102onto the user. The sensor carrier212may be composed of a biocompatible polymer, and may be molded, cast, printed, etc. The sensor carrier212includes a support body270and a retaining flange272. With reference toFIG.22, the support body270is annular, and includes a first annular projection274and the second annular projection248that are concentric. The first annular projection274couples the sensor carrier212to the frame208, and the second annular projection248couples the needle retractor204to the sensor carrier212. The second annular projection248may also include opposed slots276, which cooperate with the needle retractor204to couple the needle retractor204to the sensor carrier212. With reference toFIG.23, the sensor carrier212also includes insertion snaps278. The insertion snaps278extend outwardly from the first annular projection274, and are received within the slots246of the frame208. As shown inFIG.23, in the first position, the insertion snaps278are spaced apart from a surface246aof the slots246to inhibit a relative movement between the sensor carrier212and the frame208. As will be discussed, with reference toFIG.24, the cap216applies a force F3to the physiological characteristic sensor102in the first position, which causes the insertion snaps278of the sensor carrier212to be spaced apart from the surface246aof the frame208(FIG.23) and free floating. With reference back toFIG.23, a space280defined between the insertion snaps278and the surface246aensures that if the sensor inserter104is accidentally mishandled in the first position, the sensor carrier212is not inadvertently released. Stated another way, the space280ensures that the sensor inserter104remains in the first position until the user pushes on the plunger200and inhibits an accidental movement of the sensor inserter104from the first position to the second position.

With brief reference toFIG.2, a ramp surface279defined interiorly within the plunger200contacts the insertion snaps278as the plunger200moves relative to the frame208. The contact between the ramp surface279and the insertion snaps278causes the insertion snaps278(FIG.23) to deflect, thereby releasing the insertion snaps278(FIG.23) from the slots246(FIG.23) and from the frame208. The release of the sensor carrier212from the frame208enables the insertion spring202to apply the force F1to couple the physiological characteristic sensor102to the anatomy.

With reference toFIG.25, the retaining flange272is substantially rectangular in shape, and is coupled to the sensor retainer210. The retaining flange272includes a plurality of retaining tabs284and defines a contact surface286(FIG.26). The retaining tabs284couple the sensor retainer210to the sensor carrier212. With reference toFIG.26, the contact surface286is continuous and is defined about a perimeter of the retaining flange272. The contact surface286presses the adhesive patch120(FIG.22) against the anatomy of the user upon deployment of the physiological characteristic sensor102to ensure that the adhesive patch120is coupled to the user over an entirety of the adhesive patch120. Thus, the contact surface286provides for improved adhesion of the adhesive patch120to the anatomy of the user.

With reference back toFIG.14, the magnet214is coupled to the cap216. In this example, the magnet214is annular to be coupled to the cap216. The magnet214comprises any suitable permanent magnet composed of a ferromagnetic material that is axially magnetized. In one example, with reference toFIG.27, the magnet214generates a three dimensional vector with radial component magnetic field lines290, which cover a large percentage of the printed circuit board164. By covering a large percentage of the printed circuit board164, the magnet sensor119may be moved or repositioned on the printed circuit board164while remaining responsive to the magnetic field provided by the magnet214. In addition, the radial component magnetic field lines290are axially symmetric, which results in the magnetic field being the same regardless of the axial position of the cap216. This enables the cap216to be coupled to the plunger200at different final locations during assembly without affecting the magnetic field generated by the magnet214. Thus, the magnet214also compensates for manufacturing tolerances, which reduces assembly time.

In this example, with reference toFIG.24, the magnet214is coupled to the cap216via heat or ultrasonic welding, and may be retained within an annular channel292defined in a projection294of the cap216. The annular channel292may include a lip296, which extends over an uppermost surface of the magnet214to further assist in coupling the magnet214to the cap216.

With reference toFIG.2, the cap216may be composed of a biocompatible polymer, and may be molded, cast, printed, etc. The cap216includes the projection294, a cap base298and a sidewall300. The projection294extends axially upward from the cap base298and defines the annular channel292that is coupled to the magnet214. With brief reference toFIG.24, the projection294terminates in a tip302. The tip302applies the force F3against the bottom housing portion124, which causes the insertion snaps278(FIG.23) to float within the slots246. The tip302is generally annular, such that the force F3is distributed over an annular surface302aand is not a point load. The tip302also enables the adhesive patch120of the physiological characteristic sensor102to be retained within the sensor inserter104without a backing layer. By eliminating the backing layer, the physiological characteristic sensor102is easier to deploy on the user.

With reference back toFIG.2, the cap base298has a first base surface304opposite a second base surface306and defines a plurality of openings308(FIG.14). The first base surface304is coupled to or integrally formed with the projection294. The second base surface306defines a circular recess310, which receives the membrane218. The membrane218is a gas permeable polymeric material, such as Tyvek® manufactured by DuPont™ of Midland, Michigan, which is coupled to the cap216along a surface of the recess310, via adhesives, heat bond, for example. The openings308are covered by the membrane218. The openings308cooperate with the membrane218to enable the sterilization of the physiological characteristic sensor102contained within the sensor inserter104. Generally, the plunger200and the cap216cooperate to form a seal, such that during a sterilization procedure, the sterilization gas may penetrate into and out of the sensor inserter104, via the openings308, and sterilize the physiological characteristic sensor102and an interior of the sensor inserter104. In one example, with reference toFIG.27, the bottom end200bof the plunger200is coupled to the cap216in an interference fit, which inhibits fluids, such as air and liquids, to flow into the sensor inserter104. In this example, the sidewall300of the cap216includes a lip312, which circumscribes the cap216and receives the bottom end200bof the plunger200with the interference fit. Generally, the bottom end200bof the plunger200is deflected slightly to be received within the cap216, which creates the interference fit between a surface200cof the bottom end200band a surface312aof the lip312. The cap base298may also include a frame receiving channel299, which receives the bottom end208bof the frame208. The frame receiving channel299generally mates tightly with the frame208, which inhibits the frame208from deforming inward and disengaging with the cap216if the sensor inserter104is mishandled or dropped.

With reference back toFIG.2, the sidewall300includes the lip312, a plurality of threads314and a frame projection316. The plurality of threads314are defined so as to be spaced apart from the lip312. The plurality of threads314engage with the threads236of the plunger200to removably couple the cap216to the plunger200. The frame projection316cooperates with a thread208cdefined on the frame208(FIG.14). In one example, the frame projection316acts as a thread such that the cap216is screwed onto both the frame208and the plunger200. By screwing the cap216onto both the frame208and the plunger200, the frame208is locked in position relative to the plunger200, which inhibits the frame208from moving relative to the plunger200in an instance where the sensor inserter104is mishandled or dropped.

In one example, the cap216also includes a tamper evident band or tamper band320. The tamper band320may be composed of a biocompatible polymer, and may be molded, cast, additive manufactured, etc. The tamper band320may be coupled to the cap216via a plurality of bridges320a(FIG.1), which are breakable upon unscrewing or uncoupling the cap216from the plunger200. The tamper band320may be integrally formed with the cap216, and the bridges320a(FIG.1) may be defined through a post processing step. The tamper band320provides a visual indicator as to whether or not the cap216has been removed from the plunger200. In this example, the plunger200also define a tamper bead retaining wall322and a tamper bead retaining catch324about an outer perimeter of the plunger200. With reference toFIG.29, the tamper bead retaining wall322receives a corresponding tamper bead326defined on the tamper band320. The tamper bead retaining catch324extends outward for a distance greater than the tamper bead retaining wall322and is received in a corresponding groove328. The tamper bead326on the tamper band320vertically overlaps the tamper bead retaining catch324such that as the user is removing the cap216, the tamper bead326of the tamper band320contacts the tamper bead retaining catch324. The contact between the tamper bead326and the tamper bead retaining catch324, along with the continued applied force by the user, separates the cap216from the tamper band320at the bridges320a(FIG.1), leaving the tamper band320about the plunger200to visually indicate the cap216has been removed.

In one example, with reference toFIG.14, in order to assemble the sensor inserter104, the needle inserter198is coupled to the physiological characteristic sensor102. The retraction spring206is positioned about the needle inserter198. The needle inserter198is coupled to the needle retractor204such that the retraction spring206is disposed about the needle retractor204. The sensor carrier212is coupled to the needle retractor204, and the sensor retainer210is coupled to the sensor carrier212. The frame208is coupled to the sensor carrier212. The insertion spring202is coupled to the sensor carrier212, and the plunger200is coupled to the frame208. The cap216, with the membrane218and the tamper band320coupled to the cap216, is threaded onto the plunger200. The sensor inserter104, including the physiological characteristic sensor102, may be sterilized and shipped to an end user.

Once received, with reference toFIG.30, the user may remove the cap216. As the user unscrews the cap216, the tamper band320breaks along the bridges320a(FIG.1) and remains coupled to the plunger200. With the cap216removed, the physiological characteristic sensor102is exposed for insertion. In addition, the removal of the cap216removes the magnetic field generated by the magnet214. Based on the sensor signals from the magnet sensor119(FIG.3), the control module162(FIG.3) begins to monitor the sensor signals from the glucose sensor114(FIG.3). Stated another way, the removal of the cap216activates the physiological characteristic sensor102to monitor the glucose sensor114and transmit the blood glucose levels via the antenna108,108′. With reference toFIG.31, the user may position the sensor inserter104at the desired insertion site, which may or may not be visible to the user. The user may depress the plunger200, which releases the sensor carrier212(FIG.14) and the retainer arms266of the sensor retainer210(FIG.14). The release of the sensor carrier212and the retainer arms266(FIG.14) separates the physiological characteristic sensor102from the sensor inserter104. Once the sensor carrier212is released from the frame208(FIG.14), the insertion spring202applies the force F1to couple the physiological characteristic sensor102to the user, as shown inFIG.31A. The sensor inserter104is in the second position inFIG.31A.

Generally, with reference toFIG.31B, once the insertion spring202deploys the sensor carrier212, the retraction spring206applies the force F2(FIG.2) and retracts the needle retractor204upward, which in turn, retracts the needle inserter198(FIG.14) into the plunger200. InFIG.31B, the sensor inserter104is in the third position. This inhibits the user accidentally contacting the insertion needle222(FIG.14) and inhibits a reuse of the sensor inserter104. With reference toFIGS.32and32A, once the physiological characteristic sensor102is coupled to the user at the insertion site, the sensor inserter104is removed from the insertion site and disposed of. The sensor inserter104remains in the third position inFIGS.32and32A.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.

It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device.

In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer).

Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.