Patent Application
20250152052
The subject matter described herein relates generally to systems, devices, and methods for analyte sensors. For example, systems, devices, and methods for mitigating the impact of radiologic procedures on on-body sensor puck assembly and measured analyte levels.
The detection and/or monitoring of analyte levels, such as glucose, ketones, lactate, oxygen, hemoglobin AIC, or the like, can be vitally important to the health of an individual having diabetes. Patients suffering from diabetes mellitus can experience complications including loss of consciousness, cardiovascular disease, retinopathy, neuropathy, and nephropathy. Diabetics are generally required to monitor their glucose levels to ensure that they are being maintained within a clinically safe range, and may also use this information to determine if and/or when insulin is needed to reduce glucose levels in their bodies, or when additional glucose is needed to raise the level of glucose in their bodies.
Growing clinical data demonstrates a strong correlation between the frequency of glucose monitoring and glycemic control. Despite such correlation, however, many individuals diagnosed with a diabetic condition do not monitor their glucose levels as frequently as they should due to a combination of factors including convenience, testing discretion, pain associated with glucose testing, and cost.
To increase patient adherence to a plan of frequent glucose monitoring, in vivo analyte monitoring systems can be utilized, in which a sensor control device may be worn on the body of an individual who requires analyte monitoring. To increase comfort and convenience for the individual, the sensor control device may have a small form-factor, and can be assembled and applied by the individual with a sensor applicator. The application process includes inserting a sensor, such as a dermal sensor that senses a user's analyte level in a bodily fluid located in the dermal layer of the human body, using an applicator or insertion mechanism, such that the sensor comes into contact with a bodily fluid. The sensor control device may also be configured to transmit analyte data to another device, from which the individual or her health care provider (“HCP”) can review the data and make therapy decisions.
While present continuous glucose monitors and sensors control devices can be convenient for users, they can be made more useful by being adapted for use during a magnetic resonance imaging (MRI) or other radiological diagnostic procedures.
Magnetic resonance imaging (MRI) is an effective, non-invasive imaging technique for generating sharp images of the internal anatomy of the human body, which provides an efficient means for diagnosing disorders such as neurological and cardiac abnormalities and for spotting tumors and the like. Briefly, the patient is placed within the center of a large superconducting magnetic that generates a powerful static magnetic field. The static magnetic field causes protons within tissues of the body to align with an axis of the static field. A pulsed radio-frequency (RF) magnetic field is then applied causing precession of the protons around the axis of the static field. Pulsed gradient magnetic fields are then applied to cause the protons within selected locations of the body to emit RF signals, which are detected by sensors of the MRI system. Based on the RF signals emitted by the protons, the MRI system then generates a precise image of the selected locations of the body, typically image slices of organs of interest.
A significant problem with MRI is that its strong magnetic fields can interfere with the operation of continuous glucose monitors (CGM). Typically, CGMs include a sensor control device positioned on a human body with a sensor in contact with the wearer's bodily fluid to measure analyte levels. Magnetic fields from MRI may cause changes in the functionality of CGMs. Therefore, wearers are generally advised to avoid exposure to MRIs.
However, it would be preferable to allow user to continue wearing the CGM device even during an MRI procedure, so long as any inaccurate CGM readings are addressed before being reported to the user. Accordingly, there is a need for systems, devices, and methods for mitigating the impact of radiologic procedures on sensor control devices, sensors, and measured analyte levels.
The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter is directed to a method including receiving a plurality of analyte data for a first time period monitored by an analyte sensor in fluid contact with bodily fluid under a skin surface, the plurality of analyte data corresponding to an analyte level, receiving a plurality of temperature data for the first time period from a temperature sensor, determining a rate of change of the plurality of temperature data over the first time period, if the determined rate of change of the plurality of temperature data is above a predetermined threshold, receiving user input to confirm exposure to radiologic procedure during the first time period, and adjusting the plurality of analyte data over the first time period based on the confirmed exposure to radiologic procedure.
According to embodiments, the time period can include one hour. The predetermined threshold can be 4 degrees Celsius over 15 minutes. The user input can be received via a reader device.
According to embodiments, adjusting the plurality of analyte data can include removing the plurality of analyte data for the first time period. Adjusting the plurality of analyte data can include ignoring the plurality of analyte data for the first time period.
According to embodiments, the temperature data can comprise on-skin temperature data. According to embodiments, confirming exposure to the radiologic procedure can include at least one of prompting and generating an alarm.
According to embodiments, the method can include receiving a user input indicating a first time period corresponding to anticipated exposure to a radiologic procedure, receiving a plurality of analyte data over the first time period monitored by an analyte sensor in fluid contact with bodily fluid under a skin surface, the plurality of analyte data corresponding to an analyte level, receiving a plurality of temperature data over the first time period for the skin surface from a temperature sensor, determining a rate of change of the plurality of temperature data over the first time period, confirming exposure to radiologic procedure during the first time period if the determined rate of change of the plurality of temperature data is above a predetermined threshold, and adjusting the plurality of analyte data over the first time period based on the confirmed exposure to radiologic procedure.
The details of the subject matter set forth herein, both as to its structure and operation, may be apparent by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the subject matter. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely.
Before the present subject matter is described in detail, it is to be understood that this disclosure is not limited to the particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.
As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
Generally, embodiments of the present disclosure include systems, devices, and methods for the use of analyte sensor insertion applicators for use with in vivo analyte monitoring systems. An applicator can be provided to the user in a sterile package with an electronics housing of the sensor control device contained therein. According to some embodiments, a structure separate from the applicator, such as a container, can also be provided to the user as a sterile package with a sensor module and a sharp module contained therein. The user can couple the sensor module to the electronics housing, and can couple the sharp to the applicator with an assembly process that involves the insertion of the applicator into the container in a specified manner. In other embodiments, the applicator, sensor control device, sensor module, and sharp module can be provided in a single package. The applicator can be used to position the sensor control device on a human body with a sensor in contact with the wearer's bodily fluid. The embodiments provided herein are improvements to reduce the likelihood that a sensor is improperly inserted or damaged, or elicits an adverse physiological response. Other improvements and advantages are provided as well. The various configurations of these devices are described in detail by way of the embodiments which are only examples.
Furthermore, many embodiments include in vivo analyte sensors structurally configured so that at least a portion of the sensor is, or can be, positioned in the body of a user to obtain information about at least one analyte of the body. It should be noted, however, that the embodiments disclosed herein can be used with in vivo analyte monitoring systems that incorporate in vitro capability, as well as purely in vitro or ex vivo analyte monitoring systems, including systems that are entirely non-invasive.
Furthermore, for each and every embodiment of a method disclosed herein, systems and devices capable of performing each of those embodiments are covered within the scope of the present disclosure. For example, embodiments of sensor control devices are disclosed and these devices can have one or more sensors, analyte monitoring circuits (e.g., an analog circuit), memories (e.g., for storing instructions), power sources, communication circuits, transmitters, receivers, processors and/or controllers (e.g., for executing instructions) that can perform any and all method steps or facilitate the execution of any and all method steps. These sensor control device embodiments can be used and can be capable of use to implement those steps performed by a sensor control device from any and all of the methods described herein.
As mentioned, a number of embodiments of systems, devices, and methods are described herein that provide for the improved assembly and use of dermal sensor insertion devices for use with in vivo analyte monitoring systems. In particular, several embodiments of the present disclosure are designed to improve the method of sensor insertion with respect to in vivo analyte monitoring systems and, in particular, to prevent the premature retraction of an insertion sharp during a sensor insertion process. Some embodiments, for example, include a dermal sensor insertion mechanism with an increased firing velocity and a delayed sharp retraction. In other embodiments, the sharp retraction mechanism can be motion-actuated such that the sharp is not retracted until the user pulls the applicator away from the skin. Consequently, these embodiments can reduce the likelihood of prematurely withdrawing an insertion sharp during a sensor insertion process; decrease the likelihood of improper sensor insertion; and decrease the likelihood of damaging a sensor during the sensor insertion process, to name a few advantages. Several embodiments of the present disclosure also provide for improved insertion sharp modules to account for the small scale of dermal sensors and the relatively shallow insertion path present in a subject's dermal layer. In addition, several embodiments of the present disclosure are designed to prevent undesirable axial and/or rotational movement of applicator components during sensor insertion. Accordingly, these embodiments can reduce the likelihood of instability of a positioned dermal sensor, irritation at the insertion site, damage to surrounding tissue, and breakage of capillary blood vessels resulting in fouling of the dermal fluid with blood, to name a few advantages. In addition, to mitigate inaccurate sensor readings which can be caused by trauma at the insertion site, several embodiments of the present disclosure can reduce the end-depth penetration of the needle relative to the sensor tip during insertion.
Before describing these aspects of the embodiments in detail, however, it is first desirable to describe examples of devices that can be present within, for example, an in vivo analyte monitoring system, as well as examples of their operation, all of which can be used with the embodiments described herein.
There are various types of in vivo analyte monitoring systems. “Continuous Analyte Monitoring” systems (or “Continuous Glucose Monitoring” systems), for example, can transmit data from a sensor control device to a reader device continuously without prompting, e.g., automatically according to a schedule. “Flash Analyte Monitoring” systems (or “Flash Glucose Monitoring” systems or simply “Flash” systems), as another example, can transfer data from a sensor control device in response to a scan or request for data by a reader device, such as with a Near Field Communication (NFC) or Radio Frequency Identification (RFID) protocol. In vivo analyte monitoring systems can also operate without the need for finger stick calibration.
In vivo analyte monitoring systems can be differentiated from “in vitro” systems that contact a biological sample outside of the body (or “ex vivo”) and that typically include a meter device that has a port for receiving an analyte test strip carrying bodily fluid of the user, which can be analyzed to determine the user's blood sugar level.
In vivo monitoring systems can include a sensor that, while positioned in vivo, makes contact with the bodily fluid of the user and senses the analyte levels contained therein. The sensor can be part of the sensor control device that resides on the body of the user and contains the electronics and power supply that enable and control the analyte sensing. The sensor control device, and variations thereof, can also be referred to as a “sensor control unit,” an “on-body electronics” device or unit, an “on-body” device or unit, or a “sensor data communication” device or unit, to name a few.
In vivo monitoring systems can also include a device that receives sensed analyte data from the sensor control device and processes and/or displays that sensed analyte data, in any number of forms, to the user. This device, and variations thereof, can be referred to as a “handheld reader device,” “reader device” (or simply a “reader”), “handheld electronics” (or simply a “handheld”), a “portable data processing” device or unit, a “data receiver,” a “receiver” device or unit (or simply a “receiver”), or a “remote” device or unit, to name a few. Other devices such as personal computers have also been utilized with or incorporated into in vivo and in vitro monitoring systems.
A memory 163 is also included within ASIC 161 and can be shared by the various functional units present within ASIC 161, or can be distributed amongst two or more of them. Memory 163 can also be a separate chip. Memory 163 can be volatile and/or non-volatile memory. In this embodiment, ASIC 161 is coupled with power source 170, which can be a coin cell battery, or the like. AFE 162 interfaces with in vivo analyte sensor 104 and receives measurement data therefrom and outputs the data to processor 166 in digital form, which in turn processes the data to arrive at the end-result glucose discrete and trend values, etc. This data can then be provided to communication circuitry 168 for sending, by way of antenna 171, to reader device 120 (not shown), for example, where minimal further processing is needed by the resident software application to display the data.
According to embodiments, the sensor control device 102 can include a temperature sensor for measurement of skin near the insertion site. The temperature readings may be used to adjust the measurement data generated from the analyte sensor 104, as discussed in further detail below. Additional details of suitable devices, systems, methods, components and the operation thereof along with related features are set forth in U.S. Patent Publication No. 2019/0069823, filed Nov. 5, 2018, which is incorporated by reference in its entirety herein.
The components of sensor control device 102 can be acquired by a user in multiple packages requiring final assembly by the user before delivery to an appropriate user location.
Sheath 704 can maintain position within platform 808 with respect to housing 702 while housing 702 is distally advanced, coupling with platform 808 to distally advance platform 808 with respect to tray 810. This step unlocks and collapses platform 808 within tray 810. Sheath 704 can contact and disengage locking features (not shown) within tray 810 that unlock sheath 704 with respect to housing 702 and prevent sheath 704 from moving (relatively) while housing 702 continues to distally advance platform 808. At the end of advancement of housing 702 and platform 808, sheath 704 is permanently unlocked relative to housing 702. A sharp and sensor (not shown) within tray 810 can be coupled with an electronics housing (not shown) within housing 702 at the end of the distal advancement of housing 702. Operation and interaction of the applicator device 150 and tray 810 are further described below.
System 100, described with respect to
Referring briefly again to
According to embodiments of the present disclosure, the sensor control device 102 may be modified to provide a one-piece architecture that may be subjected to sterilization techniques specifically designed for a one-piece architecture sensor control device. A one-piece architecture allows the sensor applicator 150 and the sensor control device 102 to be shipped to the user in a single, sealed package that does not require any final user assembly steps. Rather, the user need only open one package and subsequently deliver the sensor control device 102 to the target monitoring location. The one-piece system architecture described herein may prove advantageous in eliminating component parts, various fabrication process steps, and user assembly steps. As a result, packaging and waste are reduced, and the potential for user error or contamination to the system is mitigated.
Unlike the sensor control device 102 of
As illustrated, the sensor control device 5002 includes an electronics housing 5004 that is generally disc-shaped and may have a circular cross-section. In other embodiments, however, the electronics housing 2004 may exhibit other cross-sectional shapes, such as ovoid or polygonal, without departing from the scope of the disclosure. The electronics housing 5004 may be configured to house or otherwise contain various electrical components used to operate the sensor control device 5002. In at least one embodiment, an adhesive patch (not shown) may be arranged at the bottom of the electronics housing 5004. The adhesive patch may be similar to the adhesive patch 105 of
As illustrated, the sensor control device 5002 includes an electronics housing 5004 that includes a shell 5006 and a mount 5008 that is matable with the shell 5006. The shell 5006 may be secured to the mount 5008 via a variety of ways, such as a snap fit engagement, an interference fit, sonic welding, one or more mechanical fasteners (e.g., screws), a gasket, an adhesive, or any combination thereof. In some cases, the shell 5006 may be secured to the mount 5008 such that a sealed interface is generated therebetween.
The sensor control device 5002 may further include a sensor 5010 (partially visible) and a sharp 5012 (partially visible), used to help deliver the sensor 5010 transcutaneously under a user's skin during application of the sensor control device 5002. As illustrated, corresponding portions of the sensor 5010 and the sharp 5012 extend distally from the bottom of the electronics housing 5004 (e.g., the mount 5008). The sharp 5012 may include a sharp hub 5014 configured to secure and carry the sharp 5012. As best seen in
The sensor control device 5002 may further include a sensor cap 5018, shown exploded or detached from the electronics housing 5004 in
The sensor cap 5018 may be removably coupled to the electronics housing 5004 at or near the bottom of the mount 5008. More specifically, the sensor cap 5018 may be removably coupled to the mating member 5016, which extends distally from the bottom of the mount 5008. In at least one embodiment, for example, the mating member 5016 may define a set of external threads 5026a (
In some embodiments, the sensor cap 5018 may comprise a monolithic (singular) structure extending between the first and second ends 5020a, b. In other embodiments, however, the sensor cap 5018 may comprise two or more component parts. In the illustrated embodiment, for example, the sensor cap 5018 may include a seal ring 5028 positioned at the first end 5020a and a desiccant cap 5030 arranged at the second end 5020b. The seal ring 5028 may be configured to help seal the inner chamber 5022, as described in more detail below. In at least one embodiment, the seal ring 5028 may comprise an elastomeric O-ring. The desiccant cap 5030 may house or comprise a desiccant to help maintain preferred humidity levels within the inner chamber 5022. The desiccant cap 5030 may also define or otherwise provide the engagement feature 5024 of the sensor cap 5018.
The sensor control device 5002 may provide or otherwise include a sealed subassembly that includes, among other component parts, the shell 5006, the sensor 5010, the sharp 5012, and the sensor cap 5018. The sealed subassembly of the sensor control device 5002 may help isolate the sensor 5010 and the sharp 5012 within the inner chamber 5022 (
The sensor 5010 may include a tail 5104 that extends out an aperture 5106 (
The sharp tip 5108 may be advanced through the electronics housing 5004 until the sharp hub 5014 engages an upper surface of the shell 5006 and the mating member 5016 extends out the aperture 5106 in the bottom 5102 of the mount 5008. In some embodiments, a seal member (not shown), such as an O-ring or seal ring, may interpose the sharp hub 5014 and the upper surface of the shell 5006 to help seal the interface between the two components. In some embodiments, the seal member may comprise a separate component part, but may alternatively form an integral part of the shell 5006, such as being a co-molded or overmolded component part.
The sealed subassembly may further include a collar 5112 that is positioned within the electronics housing 5004 and extends at least partially into the aperture 5106. The collar 5112 may be a generally annular structure that defines or otherwise provides an annular ridge 5114 on its top surface. In some embodiments, as illustrated, a groove 5116 may be defined in the annular ridge 5114 and may be configured to accommodate or otherwise receive a portion of the sensor 5010 extending laterally within the electronics housing 5004.
In assembling the sealed subassembly, a bottom 5118 of the collar 5112 may be exposed at the aperture 5106 and may sealingly engage the first end 5020a of the sensor cap 5018 and, more particularly, the seal ring 5028. In contrast, the annular ridge 5114 at the top of the collar 5112 may sealingly engage an inner surface (not shown) of the shell 5006. In at least one embodiment, a seal member (not shown) may interpose the annular ridge 5114 and the inner surface of the shell 5006 to form a sealed interface. In such embodiments, the seal member may also extend (flow) into the groove 5116 defined in the annular ridge 5114 and thereby seal about the sensor 5010 extending laterally within the electronics housing 5004. The seal member may comprise, for example, an adhesive, a gasket, or an ultrasonic weld, and may help isolate the enzymes and other chemistry included on the tail 5104.
The collar 5112 may then be received over (about) the mating member 5016 and advanced toward an inner surface 5204 of the shell 5006 to enable the annular ridge 5114 to engage the inner surface 5204. A seal member 5206 may interpose the annular ridge 5114 and the inner surface 5204 and thereby form a sealed interface. The seal member 5206 may also extend (flow) into the groove 5116 (
The sensor cap 5018 may be removably coupled to the sensor control device 5002 by threadably mating the internal threads 5026b of the sensor cap 5018 with the external threads 5026a of the mating member 5016. Tightening (rotating) the mated engagement between the sensor cap 5018 and the mating member 5016 may urge the first end 5020a of the sensor cap 5018 into sealed engagement with the bottom 5118 of the collar 5112. Moreover, tightening the mated engagement between the sensor cap 5018 and the mating member 5016 may also enhance the sealed interface between the sharp hub 5014 and the top of the shell 5006, and between the annular ridge 5114 and the inner surface 5204 of the shell 5006.
The inner chamber 5022 may be sized and otherwise configured to receive the tail 5104 and the sharp tip 5108. Moreover, the inner chamber 5022 may be sealed to isolate the tail 5104 and the sharp tip 5108 from substances that might adversely interact with the chemistry of the tail 5104. In some embodiments, a desiccant 5208 (shown in dashed lines) may be present within the inner chamber 5022 to maintain proper humidity levels.
In
As illustrated, the sheath 212 is also positioned within the sensor applicator 102, and the sensor applicator 102 may include a sheath locking mechanism 5310 configured to ensure that the sheath 212 does not prematurely collapse during a shock event. In the illustrated embodiment, the sheath locking mechanism 5310 may comprise a threaded engagement between the applicator cap 210 and the sheath 212. More specifically, one or more internal threads 5312a may be defined or otherwise provided on the inner surface of the applicator cap 210, and one or more external threads 5312b may be defined or otherwise provided on the sheath 212. The internal and external threads 5312a,b may be configured to threadably mate as the applicator cap 210 is threaded to the sensor applicator 102 at the threads 5308. The internal and external threads 5312a,b may have the same thread pitch as the threads 5308 that enable the applicator cap 210 to be screwed onto the housing 208.
In
With the sensor control device 5002 loaded within the sensor applicator 102 and the applicator cap 210 properly secured, the sensor control device 5002 may then be subjected to a gaseous chemical sterilization configured to sterilize the electronics housing 5004 and any other exposed portions of the sensor control device 5002. Since the distal portions of the sensor 5010 and the sharp 5012 are sealed within the sensor cap 5018, the chemicals used during the gaseous chemical sterilization process are unable to interact with the enzymes, chemistry, and biologies provided on the tail 5104, and other sensor components, such as membrane coatings that regulate analyte influx.
As illustrated, the cap post 5314 may define a receiver feature 5402 configured to receive the engagement feature 5024 of the sensor cap 5018 upon coupling (e.g., threading) the applicator cap 210 (
Many design variations of the receiver feature 5402 may be employed, without departing from the scope of the disclosure. In the illustrated embodiment, the receiver feature 5402 includes one or more compliant members 5404 (two shown) that are expandable or flexible to receive the engagement feature 5024 (
The compliant member(s) 5404 may further provide or otherwise define corresponding ramped surfaces 5406 configured to interact with one or more opposing camming surfaces 5408 provided on the outer wall of the engagement feature 5024. The configuration and alignment of the ramped surface(s) 5406 and the opposing camming surface(s) 5408 is such that the applicator cap 210 is able to rotate relative to the sensor cap 5018 in a first direction A (e.g., clockwise), but the cap post 5314 binds against the sensor cap 5018 when the applicator cap 210 is rotated in a second direction B (e.g., counter clockwise). More particularly, as the applicator cap 210 (and thus the cap post 5314) rotates in the first direction A, the camming surfaces 5408 engage the ramped surfaces 5406, which urge the compliant members 5404 to flex or otherwise deflect radially outward and results in a ratcheting effect. Rotating the applicator cap 210 (and thus the cap post 5314) in the second direction B, however, will drive angled surfaces 5410 of the camming surfaces 5408 into opposing angled surfaces 5412 of the ramped surfaces 5406, which results in the sensor cap 5018 binding against the compliant member(s) 5404.
As the applicator cap 210 is threaded to (screwed onto) the housing 208 (
To remove the applicator cap 210, the applicator cap 210 is rotated in the second direction B, which correspondingly rotates the cap post 5314 in the same direction and causes the camming surfaces 5408 (i.e., the angled surfaces 5410 of
Referring first to
The sensor carrier 5602 may also include one or more carrier arms 5608 (one shown) configured to interact with a corresponding one or more grooves 5610 (one shown) defined on the sharp carrier 5306. A spring 5612 may be arranged within a cavity defined by the sharp carrier 5306 and may passively bias the sharp carrier 5306 upward within the housing 208. When the carrier arm(s) 5608 are properly received within the groove(s) 5610, however, the sharp carrier 5306 is maintained in position and prevented from moving upward. The carrier arm(s) 5608 interpose the sheath 212 and the sharp carrier 5306, and a radial shoulder 5614 defined on the sheath 212 may be sized to maintain the carrier arm(s) 5608 engaged within the groove(s) 5610 and thereby maintain the sharp carrier 5306 in position.
In
As the sharp carrier 5306 moves upward within the housing 208, the sharp hub 5014 may correspondingly move in the same direction, which may cause partial retraction of the mating member 5016 such that it becomes flush, substantially flush, or sub-flush with the bottom of the sensor control device 5002. As will be appreciated, this ensures that the mating member 5016 does not come into contact with the user's skin, which might otherwise adversely impact sensor insertion, cause excessive pain, or prevent the adhesive patch (not shown) positioned on the bottom of the sensor control device 5002 from properly adhering to the skin.
In the illustrated embodiment, the sheath arms 5604 of the sheath 212 may be configured to interact with a first detent 5702a and a second detent 5702b defined within the interior of the housing 208. The first detent 5702a may alternately be referred to a “locking” detent, and the second detent 5702b may alternately be referred to as a “firing” detent. When the sensor control device 5002 is initially installed in the sensor applicator 102, the sheath arms 5604 may be received within the first detent 5702a. As discussed below, the sheath 212 may be actuated to move the sheath arms 5604 to the second detent 5702b, which places the sensor applicator 102 in firing position.
In
Similar to the embodiment of
In
As the applicator cap 210 is unscrewed from the housing 208, the ribs 5704 defined on the sheath 212 may slidingly engage the tops of the ribs 5706 defined on the applicator cap 210. The tops of the ribs 5706 may provide corresponding ramped surfaces that result in an upward displacement of the sheath 212 as the applicator cap 210 is rotated, and moving the sheath 212 upward causes the sheath arms 5604 to flex out of engagement with the first detent 5702a to be received within the second detent 5702b. As the sheath 212 moves to the second detent 5702b, the radial shoulder 5614 moves out of radial engagement with the carrier arm(s) 5608, which allows the passive spring force of the spring 5612 to push upward on the sharp carrier 5306 and force the carrier arm(s) 5608 out of engagement with the groove(s) 5610. As the sharp carrier 5306 moves upward within the housing 208, the mating member 5016 may correspondingly retract until it becomes flush, substantially flush, or sub-flush with the bottom of the sensor control device 5002. At this point, the sensor applicator 102 in firing position. Accordingly, in this embodiment, removing the applicator cap 210 correspondingly causes the mating member 5016 to retract.
As illustrated, the sensor control device 9102 includes an electronics housing 9104, which may be generally disc-shaped and have a circular cross-section. In other embodiments, however, the electronics housing 9104 may exhibit other cross-sectional shapes, such as ovoid, oval, or polygonal, without departing from the scope of the disclosure. The electronics housing 9104 includes a shell 9106 and a mount 9108 that is matable with the shell 9106. The shell 9106 may be secured to the mount 9108 via a variety of ways, such as a snap fit engagement, an interference fit, sonic welding, laser welding, one or more mechanical fasteners (e.g., screws), a gasket, an adhesive, or any combination thereof. In some cases, the shell 9106 may be secured to the mount 9108 such that a sealed interface is generated therebetween. An adhesive patch 9110 may be positioned on and otherwise attached to the underside of the mount 9108. Similar to the adhesive patch 105 of
The sensor control device 9102 may further include a sensor 9112 and a sharp 9114 used to help deliver the sensor 9112 transcutaneously under a user's skin during application of the sensor control device 9102. Corresponding portions of the sensor 9112 and the sharp 9114 extend distally from the bottom of the electronics housing 9104 (e.g., the mount 9108). A sharp hub 9116 may be overmolded onto the sharp 9114 and configured to secure and carry the sharp 9114. As best seen in
The sensor control device 9102 may further include a sensor cap 9120, shown detached from the electronics housing 9104 in
The sensor cap 9120 may be removably coupled to the electronics housing 9104 at or near the bottom of the mount 9108. More specifically, the sensor cap 9120 may be removably coupled to the mating member 9118, which extends distally from the bottom of the mount 9108. In at least one embodiment, for example, the mating member 9118 may define a set of external threads 9128a (
In some embodiments, the sensor cap 9120 may comprise a monolithic (singular) structure extending between the first and second ends 9122a,b. In other embodiments, however, the sensor cap 9120 may comprise two or more component parts. In the illustrated embodiment, for example, the body of the sensor cap 9120 may include a desiccant cap 9130 arranged at the second end 9122b. The desiccant cap 9130 may house or comprise a desiccant to help maintain preferred humidity levels within the inner chamber 9124. Moreover, the desiccant cap 9130 may also define or otherwise provide the engagement feature 9126 of the sensor cap 9120. In at least one embodiment, the desiccant cap 9130 may comprise an elastomeric plug inserted into the bottom end of the sensor cap 9120.
The shell 9106 may define a first aperture 9202a and the mount 9108 may define a second aperture 9202b, and the apertures 9202a, b may align when the shell 9106 is properly mounted to the mount 9108. As best seen in
The mount 9108 may comprise a molded part made of a rigid material, such as plastic or metal. In some embodiments, a seal 9208 may be overmolded onto the mount 9108 and may be made of an elastomer, rubber, a-polymer, or another pliable material suitable for facilitating a sealed interface. In embodiments where the mount 9108 is made of a plastic, the mount 9108 may be molded in a first “shot” of injection molding, and the seal 9208 may be overmolded onto the mount 9108 in a second “shot” of injection molding. Accordingly, the mount 9108 may be referred to or otherwise characterized as a “two-shot mount.”
In the illustrated embodiment, the seal 9208 may be overmolded onto the mount 9108 at the pedestal 9204 and also on the bottom of the mount 9108. More specifically, the seal 9208 may define or otherwise provide a first seal element 9210a overmolded onto the pedestal 9204, and a second seal element 9210b (
The sensor control device 9102 may further include a collar 9212, which may be a generally annular structure that defines a central aperture 9214. The central aperture 9214 may be sized to receive the first seal element 9210a and may align with both the first and second apertures 9202a, b when the sensor control device 9102 is properly assembled. The shape of the central aperture 9214 may generally match the shape of the second aperture 9202b and the first seal element 9210a.
In some embodiments, the collar 9212 may define or otherwise provide an annular lip 9216 on its bottom surface. The annular lip 9216 may be sized and otherwise configured to mate with or be received into the channel 9206 defined on the inner surface of the mount 9108. In some embodiments, a groove 9218 may be defined on the annular lip 9216 and may be configured to accommodate or otherwise receive a portion of the sensor 9112 extending laterally within the mount 9108. In some embodiments, the collar 9212 may further define or otherwise provide a collar channel 9220 (
The sensor 9112 may include a tail 9224 that extends through the second aperture 9202b defined in the mount 9108 to be transcutaneously received beneath a user's skin. The tail 9224 may have an enzyme or other chemistry included thereon to help facilitate analyte monitoring. The sharp 9114 may include a sharp tip 9226 extendable through the first aperture 9202a defined by the shell 9106. As the sharp tip 9226 penetrates the electronics housing 9104, the tail 9224 of the sensor 9112 may be received within a hollow or recessed portion of the sharp tip 9226. The sharp tip 9226 may be configured to penetrate the skin while carrying the tail 9224 to put the active chemistry of the tail 9224 into contact with bodily fluids.
The sensor control device 9102 may provide a sealed subassembly that includes, among other component parts, portions of the shell 9106, the sensor 9112, the sharp 9114, the seal 9208, the collar 9212, and the sensor cap 9120. The sealed subassembly may help isolate the sensor 9112 and the sharp 9114 within the inner chamber 9124 (
Once the sensor 9112 is properly located, the collar 9212 may be installed on the mount 9108. More specifically, the collar 9212 may be positioned such that the first seal element 9210a of the seal 9208 is received within the central aperture 9214 defined by the collar 9212 and the first seal element 9210a generates a radial seal against the collar 9212 at the central aperture 9214. Moreover, the annular lip 9216 defined on the collar 9212 may be received within the channel 9206 defined on the mount 9108, and the groove 9218 defined through the annular lip 9216 may be aligned to receive the portion of the sensor 9112 that traverses the channel 9206 laterally within the mount 9108. In some embodiments, an adhesive may be injected into the channel 9206 to secure the collar 9212 to the mount 9108. The adhesive may also facilitate a sealed interface between the two components and generate a seal around the sensor 9112 at the groove 9218, which may isolate the tail 9224 from the interior of the electronics housing 9104.
The shell 9106 may then be mated with or otherwise coupled to the mount 9108. In some embodiments, as illustrated, the shell 9106 may mate with the mount 9108 via a tongue-and-groove engagement 9308 at the outer periphery of the electronics housing 9104. An adhesive may be injected (applied) into the groove portion of the engagement 9308 to secure the shell 9106 to the mount 9108, and also to create a sealed engagement interface. Mating the shell 9106 to the mount 9108 may also cause the annular ridge 9222 defined on the inner surface of the shell 9106 to be received within the collar channel 9220 defined on the upper surface of the collar 9212. In some embodiments, an adhesive may be injected into the collar channel 9220 to secure the shell 9106 to the collar 9212, and also to facilitate a sealed interface between the two components at that location. When the shell 9106 mates with the mount 9108, the first seal element 9210a may extend at least partially through (into) the first aperture 9202a defined in the shell 9106.
The sharp 9114 may then be coupled to the sensor control device 9102 by extending the sharp tip 9226 through the aligned first and second apertures 9202a, b defined in the shell 9106 and the mount 9108, respectively. The sharp 9114 may be advanced until the sharp hub 9116 engages the seal 9208 and, more particularly, engages the first seal element 9210a. The mating member 9118 may extend (protrude) out the second aperture 9202b at the bottom of the mount 9108 when the sharp hub 9116 engages the first seal element 9210a.
The sensor cap 9120 may then be removably coupled to the sensor control device 9102 by threadably mating the internal threads 9128b of the sensor cap 9120 with the external threads 9128a of the mating member 9118. The inner chamber 9124 may be sized and otherwise configured to receive the tail 9224 and the sharp tip 9226 extending from the bottom of the mount 9108. Moreover, the inner chamber 9124 may be sealed to isolate the tail 9224 and the sharp tip 9226 from substances that might adversely interact with the chemistry of the tail 9224. In some embodiments, a desiccant (not shown) may be present within the inner chamber 9124 to maintain proper humidity levels.
Tightening (rotating) the mated engagement between the sensor cap 9120 and the mating member 9118 may urge the first end 9122a of the sensor cap 9120 into sealed engagement with the second seal element 9210b in an axial direction (e.g., along the centerline of the apertures 9202a, b), and may further enhance the sealed interface between the sharp hub 9116 and the first seal element 9210a in the axial direction. Moreover, tightening the mated engagement between the sensor cap 9120 and the mating member 9118 may compress the first seal element 9210a, which may result in an enhanced radial sealed engagement between the first seal element 9210a and the collar 9212 at the central aperture 9214. Accordingly, in at least one embodiment, the first seal element 9210a may help facilitate axial and radial sealed engagements.
As mentioned above, the first and second seal elements 9210a,b may be overmolded onto the mount 9108 and may be physically linked or otherwise interconnected. Consequently, a single injection molding shot may flow through the second aperture 9202b of the mount 9108 to create both ends of the seal 9208. This may prove advantageous in being able to generate multiple sealed interfaces with only a single injection molded shot. An additional advantage of a two-shot molded design, as opposed to using separate elastomeric components (e.g., O-rings, gaskets, etc.), is that the interface between the first and second shots is a reliable bond rather than a mechanical seal. Hence, the effective number of mechanical sealing barriers is effectively cut in half. Moreover, a two-shot component with a single elastomeric shot also has implications to minimizing the number of two-shot components needed to achieve all the necessary sterile barriers. Once properly assembled, the sealed subassembly 9302 may be subjected to a radiation sterilization process to sterilize the sensor 9112 and the sharp 9114. The sealed subassembly 9302 may be subjected to the radiation sterilization prior to or after coupling the sensor cap 9120 to the sharp hub 9116. When sterilized after coupling the sensor cap 9120 to the sharp hub 9116, the sensor cap 9120 may be made of a material that permits the propagation of radiation therethrough. In some embodiments, the sensor cap 9120 may be transparent or translucent, but can otherwise be opaque, without departing from the scope of the disclosure.
As shown in
In
Securing the applicator cap 9506 to the housing 9504 may also cause the second end 9122b of the sensor cap 9120 to be received within a cap post 9510 located within the interior of the applicator cap 9506 and extending proximally from the bottom thereof. The cap post 9510 may be configured to receive at least a portion of the sensor cap 9120 as the applicator cap 9506 is coupled to the housing 9504.
Additional details of suitable devices, systems, methods, components and the operation thereof along with related features are set forth in International Publication No. WO2018/136898 to Rao et. al., International Publication No. WO2019/236850 to Thomas et. al., International Publication No. WO2019/236859 to Thomas et. al., International Publication No. WO2019/236876 to Thomas et. al., and U.S. Patent Publication No. 2020/0196919, filed Jun. 6, 2019, each of which is incorporated by reference in its entirety herein. Further details regarding embodiments of applicators, their components, and variants thereof, are described in U.S. Patent Publication Nos. 2013/0150691, 2016/0331283, and 2018/0235520, all of which are incorporated by reference herein in their entireties and for all purposes. Further details regarding embodiments of sharp modules, sharps, their components, and variants thereof, are described in U.S. Patent Publication No. 2014/0171771, which is incorporated by reference herein in its entirety and for all purposes.
Increasingly greater number of patients are incorporating use of continuous glucose monitors into their diabetes management regimens. While continuous glucose monitors (CGM) have been demonstrated to be reliable and accurate, some concerns remain regarding stability of CGMs during radiologic procedures. Indeed, patients who wear CGMs are advised to avoid exposure to whole-body millimeter wave scanners at airport security checkpoints, to avoid putting sensors through baggage x-ray machines and to remove their sensor prior to MRI, CT or X-ray diagnostic procedures. As used here, “CGM” refers to sensor control device 102, and “radiologic procedure” can include exposure to whole-body millimeter wave scanners at airport security checkpoints, exposure to baggage x-ray machines, or user exposure to MRI, CT or X-ray diagnostic procedures.
In an exemplary study, a comprehensive evaluation of the effects of common radiologic procedures of computed tomography (CT), X-ray scanning and MRI on the sensor and sensor control devices was conducted. In particular, evaluation was performed on CGMs having sensor control devices approximately 5 mm thick and 21 mm in diameter (exemplary embodiment A1 and A2) and approximately 3 mm thick and 35 mm in diameter (exemplary embodiment B) and including an analyte sensor for insertion in bodily fluid of a subject.
For CT and X-ray testing, CGM devices were tested under three different radiation exposure conditions: direct radiation, indirect radiation, and scattered radiation. More specifically, for CT, system maximum settings of 140 kV and 360 mAs were used for a total of ten imaging sessions with data collected every 15 minutes. Analyte sensors were evaluated after each exposure for the first three sessions, and then every 15 minutes of sequential exposure until 10 sessions were completed. Similarly, for X-ray, system maximum settings of 150 kV and 500 mAs were used for the first eleven X-ray exposures after which the settings were dropped by 20% to 120 kV and 400 mAs for the remaining nine exposures to address overheating of the X-ray system. Analyte sensors were evaluated after each exposure session (front and side orientations) for the first 3 sessions, and then every 15 minutes of sequential exposures until 10 sessions (20 exposures) were completed.
Acceptance criterion was glucose error of ≤10 mg/dL for nominal glucose readings of 100 mg/dL. All devices passed the functionality testing acceptance criteria in all exposure conditions and orientations after each repeated exposure session at the maximum exposure scan settings allowable by each scanner. Because a single sensor is only on the patient's arm for approximately 14 days and since the maximum exposure conditions were used for each scan, the amount of X-ray and CT radiation exposure is well beyond what a single device would be exposed to clinically. Accordingly, the exemplary study demonstrated CGM sensor functionality is not impacted by X-ray or CT exposure. Furthermore, sensor components were clearly visible with both X-ray and CT imaging modalities, and therefore would allow clinical accounting when reading images. Additionally, there was minimal image artifact created by the CGM.
Similarly, CGM functionality testing was performed under an MRI system with a static magnetic field of 1.5 Tesla (1.5 T) and 3 Tesla (3 T) by comparing sensor current before and immediately after MRI exposure. Sensors were also tested for functionality 1 hour and 6 hours after MRI exposure. Acceptance criterion was glucose error of ≤10 mg/dL for nominal glucose readings of 100 mg/dL. Several sensors reported glucose readings outside the acceptance criteria during MRI exposure, however, glucose readings from all sensors returned within the acceptance criteria 1 hour after exposure and remained within their acceptance range 6 hours following MRI exposure. In reference to
Additionally, displacement force testing was conducted near the bore entrance and on the axis of the bore of a 3 T scanner where the spatial gradient of the static magnetic field is known to be maximum. Based on the results of the displacement force testing, the maximum allowable spatial gradients at magnetic field strengths of 1.5 T and 3 T were determined. The displacement forces for exemplary embodiment A1 was 0.132 N, for exemplary embodiment A2 was 0.109 N, which are more than 100× smaller than the force of 15.97 N required to dislodge the sensor control device 102 from the skin of a wearer. Similarly, the displacement forces for exemplary embodiment B was 0.063 N, which, is more than 100× smaller than the force of 7.95 N required to dislodge the sensor control device from the skin of a wearer. These pull-off forces were used to calculate the spatial gradient required to dislodge the sensor and compared to the expected maximum spatial gradient of 19 T/m. The calculated spatial gradients required to dislodge the sensor were found to be 334.9 T/m and 328.2 T/m for exemplary embodiments A and B, respectively, far exceeding what is expected during clinical MRI imaging procedures.
Magnetically induced torque testing was conducted near the isocenter of the 3 T scanner in order to assess the interaction of the maximum uniform static magnetic field with the magnetization in the test sample. Testing was performed in three orientations, based on the qualitative torque results. The acceptance criterion for was defined such that if the test sample did not exhibit discernible torque effects, it could be concluded that the device poses no risk in the MRI environment in terms of device pull-off due to torque. The maximum acceptable magnetically-induced torque of the sensors was set to be less than calculated pull-off torque of the devices, which was calculated by assuming rotation about its central plane and by simplifying the adhesive force to a single point force at the center of mass of the semicircle of the sensor. The resulting pull-off torque was determined to be 0.05 Nm for exemplary embodiment A1 and A2, and 0.018 Nm for exemplary embodiment B.
RF-induced heating evaluations were conducted with temperature probes placed above and below the sensor and at the sensor tip. Calorimetry testing was performed with the phantom filled with saline in the 64 MHz and 128 MHz RF coils, with the sensors aligned with the scanner axis, and the measured and scanner-reported whole-body specific absorption rate (SAR) values were documented for each scan. The acceptance criterion was defined such that the RF-induced temperature rise is less than 6° C. over 15 minutes of scanning in Normal Operating Mode at a whole-body console specific absorption rate (SAR) of 2.0 W/kg, as determined by the Whole Body Modeling Described below. A custom pulsed waveform with a 10 Hz frequency was used for testing. The RF signal was delivered at a frequency of 63.66 MHz for 1.5 T testing and 128.23 MHz for 3 T testing. The input power was set so that the whole body SAR was 2.0 W/kg. The temperature was monitored during the 15 minutes of applied RF signal, as well as 2 minutes before and after the signal. The temperature rise was defined as the difference between the maximum measured temperature and initial temperature. The high electric fields resulted in temperature rises of 2.1° C. at 1.5 T and 2.5° C. at 3 T at a SAR of 2.0 W/kg, well below the acceptance criteria of <6.0° C. As can be seen in
Gradient-induced heating testing was conducted by exposing the sensor control device to a gradient field |dB/dt| rms of 54.1 T/s based on the maximum Normal Operating Mode |dB/dt| RMS exposure for a device at a radial position of 25 cm from isocenter in a scanner with a slew rate of 200 T/m/s, which is approximately the distance of a sensor control device positioned on the lateral upper arm of a wearer. Acceptance criterion for this evaluation was a temperature change <6.0° C. with a gradient coil dB/dt=54 T/s. A sinusoidal waveform with a frequency of 1750 Hz and an amplitude of 1.25 V was used for testing. Temperature probes were placed at locations of highest expected heating based on an initial hotspot evaluation. A fourth probe was used to monitor the bulk temperature in the homogeneous region of the gradient coil at least 2 cm from the device. The temperature was monitored during 15 minutes of applied gradient signal, as well as 2 minutes before and after the signal. The temperature rise was defined as the difference between the maximum measured temperature and initial temperature. The measured temperature change was scaled to a dB/dt of 54.1 T/s. As can be seen in
During artifact testing, and as can be seen in
Accordingly,
According to embodiments, confirming that the sensor control device has been exposed to a radiologic procedure can include the step of generating an alarm or alert to confirm whether the sensor control device has been exposed to a radiologic procedure, such as an MRI. For example, according to embodiments, in response to the alarm, the user may be required to confirm that the sensor control device has been exposed to a radiologic procedure. The alarm can be auditory, visual, haptic, or any other type of alarm. The alarm can be generated on the on-body unit or the user's computer system (i.e., laptop, desktop, tablet, phablet, smartphone, set-top box, video game console, or other computing device), as described above.
According to embodiments, a prompt can also be provided to the user of the estimated time period for which the on-body unit was subject to radiologic procedure. According to embodiments, the user can confirm or adjust the estimated time period for which the on-body unit was subject to radiologic procedure. For example, upon receiving a prompt of the estimated time period, the user can confirm whether the estimated time period is accurate. Alternatively, the user can adjust (e.g., upwards or downwards) the estimated time period of radiologic procedure.
According to embodiments, confirmation that the sensor control device has been exposed to radiologic procedure can include user-based input. For example, not limitation, upon detection of an increase in the plurality of time spaced temperature data during the first time period, user input may be sought (for example, not limitation, via reader device 120) to confirm whether user had been exposed to a radiologic procedure. According to embodiments, user-based input may be retrospectively retrieved from memory 223 of reader device 120. For example, not limitation, based on user input prior to exposure to radiologic procedure, such as, when a user, prior to exposure to radiologic procedure, inputs a future, anticipated time period when the user expects sensor control device to be exposed to radiologic procedure.
Referring back to
According to embodiments, the routine associated with determining exposure to radiologic procedure of a sensor control device can be performed by processor 166 of sensor control device 102, processing core 206 of reader device 120, or by a network device on network 190.
While monitoring glucose level in addition to monitoring and determining temperature as described in conjunction with the various aspects of the present disclosure, other parameters may be monitored and used to initiate the routine to determine exposure to radiologic procedure. For example, an increase in analyte levels as measured by analyte sensor data during the first time period may be used to determined exposure to radiologic procedure. For example, gradient sensors and/or accelerometers may be used to determine exposure to radiologic procedure. Additional description of gradient sensors and/or accelerometers for determining exposure to radiologic procedures is provided in U.S. Patent Publication No. 2020/0188678A1, filed Feb. 24, 2020, and U.S. Pat. No. 10,668,292, Jun. 2, 2020, disclosures of each of which are incorporated herein by reference.
It should be noted that all features, elements, components, functions, and steps described with respect to any embodiment provided herein are intended to be freely combinable and substitutable with those from any other embodiment. If a certain feature, element, component, function, or step is described with respect to only one embodiment, then it should be understood that that feature, element, component, function, or step can be used with every other embodiment described herein unless explicitly stated otherwise. This paragraph therefore serves as antecedent basis and written support for the introduction of claims, at any time, that combine features, elements, components, functions, and steps from different embodiments, or that substitute features, elements, components, functions, and steps from one embodiment with those of another, even if the following description does not explicitly state, in a particular instance, that such combinations or substitutions are possible. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for purposes of illustration and description. It is explicitly acknowledged that express recitation of every possible combination and substitution is overly burdensome, especially given that the permissibility of each and every such combination and substitution will be readily recognized by those of ordinary skill in the art.
While the embodiments are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It will be apparent to those skilled in the art that various modifications and variations can be made in the method and system of the disclosed subject matter without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter include modifications and variations that are within the scope of the appended claims and their equivalents. Furthermore, any features, functions, steps, or elements of the embodiments may be recited in or added to the claims, as well as negative limitations that define the inventive scope of the claims by features, functions, steps, or elements that are not within that scope.
This application claims the benefit, under 35 U.S.C. § 119 (e), of U.S. Provisional Patent Application No. 63/312,742, filed Feb. 22, 2022, which is incorporated herein by reference in its entirety and for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2023/013528 | 2/21/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63312742 | Feb 2022 | US |
