Abstract:
Devices associated with on-body analyte sensor units are disclosed. These devices include any of packaging and/or loading systems, applicators and elements of the on-body sensor units themselves. Also, various approaches to connecting electrochemical analyte sensors to and/or within associated on-body analyte sensor units are disclosed. The connector approaches variously involve the use of unique sensor and ancillary element arrangements to facilitate assembly of separate electronics assemblies and sensor elements that are kept apart until the end user brings them together.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/569,287, filed on Dec. 11, 2011, entitled “Analyte Sensor Devices, Connections, And Methods,” the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Diabetes Mellitus is an incurable chronic disease in which the body does not produce or properly utilize insulin. Insulin is a hormone produced by the pancreas that regulates blood sugar (glucose). In particular, when blood sugar levels rise, e.g., after a meal, insulin lowers the blood sugar levels by facilitating blood glucose to move from the blood into the body cells. Thus, when the pancreas does not produce sufficient insulin (a condition known as Type 1 Diabetes) or does not properly utilize insulin (a condition known as Type II Diabetes), the blood glucose remains in the blood resulting in hyperglycemia or abnormally high blood sugar levels. 
     The vast and uncontrolled fluctuations in blood glucose levels in people suffering from diabetes cause long-term, serious complications. Some of these complications include blindness, kidney failure, and nerve damage. Additionally, it is known that diabetes is a factor in accelerating cardiovascular diseases such as atherosclerosis (hardening of the arteries), leading to stroke, coronary heart disease, and other diseases. Accordingly, one important and universal strategy in managing diabetes is to control blood glucose levels. 
     One element of managing blood glucose levels is the monitoring of blood glucose levels. Conventional in vitro techniques, such as drawing blood samples, applying the blood to a test strip, and determining the blood glucose level using colorimetric, electrochemical, or photometric test meters, may be employed. Another technique for monitoring glucose levels uses an in vivo analyte monitoring system, which measures and stores sensor data representative of glucose levels automatically over time. 
     Unlike conventional in vitro blood glucose monitoring approaches, in vivo analyte monitoring systems use an insertable or implantable in vivo sensor that is positioned to be in contact with interstitial fluid of a user for a period of time to detect and monitor glucose levels. Prior to use of an in vivo sensor, at least a portion of the sensor is positioned under the skin. An applicator assembly can be employed to insert the sensor into the body of the user. For insertion of the sensor, a sharp engaged with the sensor, pierces the skin of the user and is then removed from the body of the user leaving the sensor in place. The in vivo-positioned sensor can be connected to other system components such as sensor electronics contained in a unit that can be held onto the skin. 
     To realize fully the advantages associated with such systems, what is needed are applicator systems configured to handle insertion, as well as packaging and user interface issues, that are easy-to-use, reliable and minimize both user inconvenience and pain. The present invention provides such solutions and additional or alternative advantages as described below and/or as may be appreciated by those of skill in the art upon review of the subject disclosure. 
     SUMMARY 
     The present invention includes packaging, loading systems, applicators, and elements of the on-body devices themselves. According to embodiments of the present invention, an on-body device includes an electronics assembly and a sensor assembly. The sensor assembly includes a sensor and a connector for coupling the sensor to the electronics assembly. In addition, a sharp can be provided that supports the sensor and allows a distal end of the sensor to be placed under a user&#39;s skin. In some embodiments, the invention includes the connection of electrochemical analyte sensors to and/or within associated other monitoring components such as system devices that are configured to be held in place on body. The approaches variously involve the use of unique sensor and unique ancillary element arrangements to facilitate assembly of separate on-body devices and sensor assembly units that are kept apart until the user brings them together. Methods associated with such use also form part of the inventive subject matter. 
     Certain embodiments are described that include an analyte sensor (e.g., a glucose sensor) and an applicator assembly to position a portion of the sensor beneath a skin surface, as well as methods of positioning at least a portion of the sensor and methods of analyte testing or monitoring. Further methods include the manner of preparing the applicator assembly. Namely, such acts associated with user assembly and mating of the component parts of a monitoring system. 
     As mentioned above, such a monitoring system includes an electronics assembly adapted to adhere to a skin of a subject, a sensor assembly coupled to the electronics assembly to form an on-body device, and an insertion sharp having a longitudinal body including a longitudinal opening to receive at least a portion of the sensor body. The details of the sensor may vary. Exemplary chemistries and constructions are described in any of U.S. Pat. Nos. 5,593,852, 6,284,478, and 6,329,161, each incorporated by reference herein in its entirety. Exemplary form-factors or configurations (e.g., for associated use with an insertion “sharp”) are described in any of U.S. Pat. Nos. 6,175,752, 6,565,509, 6,134,461 and 6,990,366 and in US Publication No. 2010/0230285, each incorporated by reference herein in its entirety. 
     Likewise, the details of the on-body device may vary. For instance, the on-body device may include sensor electronics and other adaptation to communicate with a monitoring device. Various options for communications facilities (e.g., wireless transmitters, transponders, etc.) are described in detail in US Publication Nos. 2010/0198034 and 2011/0213225, the entirety of the applications hereby incorporated by reference, including cited and incorporated references. 
     In some embodiments, systems and methods are provided for assembling and applying the on-body device including assembling the sensor assembly to the electronics assembly and inserting a portion of the sensor under the skin of a user. Thus, the sensor assembly includes a sensor that has a distal portion for operative contact with a fluid of the user. The on-body device also includes an electronics assembly including a housing defining a distal surface adapted for attachment to the skin of the user and a circuit coupleable to the sensor for detecting electrical signals from the sensor. In some embodiments, the system also includes an applicator assembly that has a sleeve defining a distal surface for placement on the skin of the subject, a handle for a user interface, and various internal support, coupling, guide, grasping, stop and detent features as well as driver elements. In some embodiments, the system may also include a container that stores one or more of the sensor, the sharp, and/or the mount/electronics assembly in a sealed environment within. The container is configured to releasably interface with the applicator assembly for the purpose of loading one or more of the sensor, the sharp, and/or the electronics assembly into the applicator assembly, and readying the applicator assembly for use. 
     The present disclosure includes the subject systems, devices, kits in which they are included, and methods of use and manufacture. A number of aspects of such manufacture are discussed herein. Further details can be appreciated in reference to the figures and/or associated description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of various aspects, features, and embodiments of the subject matter described herein is provided with reference to the accompanying drawings, which are briefly described below. The drawings are illustrative and may or may not be drawn to scale, with the possibility of some components and features being exaggerated for clarity. Similar components may be numbered identically or not. The drawings illustrate various aspects and features of the present subject matter and may illustrate one or more embodiment(s) or example(s) of the present subject matter in whole or in part. 
         FIG. 1  is a flowchart, indicating user activity in handling the subject devices; 
         FIGS. 2A-2G  illustrate such activity with additional detail; 
         FIG. 3  is an assembly view of an applicator or inserter; 
         FIG. 4  is an assembly view of a sensor container or loader; 
         FIGS. 5A and 5B  are section views of the container in  FIG. 4 ; 
         FIG. 6  is an assembly view of an alternative container; 
         FIG. 7  is a section view of the assembly of  FIG. 6 ; 
         FIG. 8  is an assembly view of yet another sensor container set or loader; 
         FIGS. 9A and 9B  are top and section views, respectively, of the container set assembly of  FIG. 8  in stages of operation; 
         FIGS. 10A-10N  variously illustrate the mechanics of preparing the applicator for use; 
         FIGS. 11A-11F  illustrate the mechanics of applicator use; 
         FIGS. 12A-12D  are perspectives illustrating another applicator/container set approach in which the container holds the electronics assembly; 
         FIGS. 13A-13C  variously illustrate use of the applicator in  FIGS. 12A-12D  in connection with a locking-sleeve feature; 
         FIGS. 14A and 14B  illustrate an applicator with a removable locking strip; 
         FIGS. 15A-15F  variously illustrate use of the applicator in  FIGS. 14A and 14B ; 
         FIGS. 16A and 16B  are sectional and detail to views, respectively, of features of the container in  FIGS. 15A-15D ; 
         FIGS. 17A and 17B  are perspective assembly views illustrating alternative container configurations to that illustrated in  FIGS. 16A and 16B ; 
         FIG. 18  is a side-section view illustrating the features of the applicator and container sets variously shown in  FIGS. 15A-15F ; 
         FIGS. 19A and 19B  are perspective views of a sensor assembly incorporated in the system shown in  FIG. 18 ; 
         FIGS. 20A and 20B  are perspective views of the operation of a sensor assembly retention unit incorporated in the system shown in  FIG. 18 ; 
         FIGS. 21A-21C  are perspective section views illustrating sensor assembly receipt by the sensor mount and sharp withdrawal from the assembled complex; 
         FIG. 22  is a perspective assembly view of advantageous sensor and sensor connector elements; 
         FIGS. 23A and 23B  are perspective assembly and final-assembly views, respectively of the sensor components in  FIG. 22 ; 
         FIGS. 24A and 24B  are top and bottom perspective views, respectively of circuit board components to be used with the assembly shown in  FIGS. 23A and 23B ; 
         FIGS. 25A and 25B  are perspective views illustrating assembly of the subject components in stages; 
         FIG. 26  is an assembly view of the on-body/sensor mount unit in  FIGS. 25A and 25B  illustrating an advantageous seal element; 
         FIGS. 27A and 27B  are section views further illustrating the seal element and its relation to the mount in  FIG. 26 ; 
         FIGS. 28A-F  are perspective views of another advantageous sensor and sensor element arrangement; 
         FIGS. 29A-D  are perspective views of another advantageous sensor and sensor connector arrangement; 
         FIGS. 30A-30C  are perspective views illustrating yet another advantageous sensor approach with the sensor as originally produced, modified for use, and shown coupled to a PCB, respectively; 
         FIG. 30  is a perspective view illustrating the sensor as configured in  FIG. 29B  in contact with a circuit board assembly; 
         FIG. 31  is a side-section view showing a comparative approach, in a final on-body sensor assembly; 
         FIGS. 32A and 32B  are perspective views of still other advantageous sensor configurations, these figures illustrating split-sensor approaches; 
         FIGS. 33A-33G  are plane, side, magnified, and sectional views of an additional sensor configuration; 
         FIGS. 33H-33J  are plane views of various sensor designs; 
         FIGS. 34A-34D  are perspective views illustrating combination electrical connector and sensor isolator in yet another advantageous sensor arrangement; 
         FIGS. 35A and 35B  are side assembly and section views, respectively, of the system shown in  FIGS. 34A-34D ; 
         FIG. 35C  is an end-section view, with detail view,  FIG. 35D , illustrating additional sensor features; 
         FIG. 36  is a perspective assembly view illustrating a sensor connection approach related to that in  FIGS. 34A-34D  for a sensor with contacts on a single side; 
         FIG. 37  is a perspective partial assembly view illustrating a mount-and-socket interface for the sensor assembly employing the components in  FIG. 36 ; 
         FIG. 38  is a complete assembly view of that illustrated in  FIG. 37 ; 
         FIGS. 39A and 39B  are perspective assembly and as-assembled views of a stacked non-directional sensor connect arrangement; 
         FIG. 40  is a side partial-sectional view of the sensor in  FIG. 39  received within an on-body device; 
         FIGS. 41A and 41B  are partial perspective assembly views of another stacked non-directional sensor connection arrangement; 
         FIG. 41C  is a section view of the complete assembly of the components variously illustrated in  FIGS. 41A and 41B ; 
         FIG. 42  is an assembly view of an advantageous radial arrangement sensor connector assembly; 
         FIGS. 43A and 43B  are reversed perspective views of the mount-side sensor connection component for use with an assembly as shown in  FIG. 42 ; 
         FIG. 44  is a section view of the complete assembly of the components variously illustrated in  FIGS. 42, 43A and 43B ; 
         FIGS. 45A and 45B  are reversed assembly views of an alternative advantageous sensor connection assembly that can be used like that in  FIG. 42 ; 
         FIGS. 46A and 46B  are assembly and sectional views, respectively of a complete on-body device employing the sensor and connection elements illustrated in  FIGS. 45A and 45B ; 
         FIG. 47A-47C  are assembly and cross-sectional views of an on-body device including an integrated connector for the sensor assembly; 
         FIGS. 48A-48D  are construction views of an on-body subassembly; 
         FIG. 48E  is a perspective view of a complete on-body electronics subassembly; 
         FIGS. 49A-49D  illustrate the process of co-molding/overmolding the assembly in  FIG. 48E ; 
         FIGS. 50A-50C  are assembly and sectional views of an alternative snap-together approach with the assembly in  FIG. 48E ; and 
         FIGS. 51A-51B  are assembly views illustrating adhesive backing application in producing a final on-body device ready for use as shown in perspective-view  FIG. 51C . 
     
    
    
     DETAILED DESCRIPTION 
     Before the present disclosure is further described, 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 will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein includes discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. 
     Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, exemplary methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. 
     As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. 
     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. 
     Various exemplary embodiments of the disclosure are described below. Reference is made to these examples in a non-limiting sense. They are provided to illustrate more broadly applicable aspects of the present disclosure. Various changes may be made to the disclosure described and equivalents may be substituted without departing from the true spirit and scope of the disclosure. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the present disclosure. All such modifications are intended to be within the scope of the claims made herein. 
     Applicator and Container Overview 
     Turning to  FIG. 1 , a flowchart depicting an example method  100  of using various systems of the present invention is provided. In some embodiments, a user starts with unpacking the container ( 102 ) and unpacking the applicator ( 104 ). Unpacking the container ( 102 ) can include removing a cover that provides a sterile seal to the container contents and unpacking the applicator ( 104 ) can include removing an end cap that provides a sterile seal to the internal portion of the applicator. Next, in an assembly operation ( 106 ), the applicator is inserted into the container to merge or connect the sensor assembly and the electronics assembly together to form an on-body device and an insertion needle or sharp. In some embodiments, the user unlocks the applicator or removes a locking element to ready the applicator for use. The process of the assembly operation ( 106 ) and the constituent components are described in detail below. 
     Next, once the user has chosen an application site, an on-body device application operation ( 108 ) is performed. In the application operation ( 108 ), the user places the applicator on the skin of the insertion site and then applies a force to install the on-body device. The applicator is driven to insert the distal end of the sensor through the user&#39;s skin, adhere the on-body device to the skin surface, and retract the sharp into the applicator for disposal. In some embodiments, the user performs the application operation ( 108 ) by applying force to the applicator where the force applied is a single, continuous pushing motion along the longitudinal axis of the applicator that once started, causes the applicator to perform the application operation ( 108 ) such that the applicator does not stop operation until completion. The applicator is configured to relay action/audible cues to the user so that all three of the above listed actions happen automatically in response to applying the force to the applicator causing it to trigger. Advantageously, an adhesive of the on-body device does not contact the user until the application operation ( 108 ) is performed. So, the even after the applicator has been placed on the skin, the applicator can be moved to a different location up until the application operation ( 108 ) is performed without damage to the apparatus or other system components. In a post application stage ( 110 ), use of the sensor for monitoring the user&#39;s analyte level occurs during wear followed by appropriate disposal. 
     Details of method  100  are illustrated in the sequence of drawings shown in  FIGS. 2A to 2G . In  FIG. 2A , one of the highlighted application sites  202 ,  204  on a user  200  is selected. In some embodiments, other application sites may be used. In some embodiments, a site preparation operation may optionally be performed. The application site  202 ,  204  may be shaved, exfoliated, cleaned, or otherwise treated to better adhere the on-body device. More specifically, the skin at the site of the user&#39;s body where the on-body device will be adhered may be prepared to receive the on-body device. For example, the skin may be shaved with a razor, cleaned with isopropyl alcohol (IPA), and exfoliated with an abrasive. A mechanically exfoliating element can be used to remove an outer layer of dead skin and expose newer skin below. These elements include: microfiber exfoliating cloths; pumice or other abrasive mineral; metal-stamped components of a rasp/file type configuration; synthetic scouring material, e.g., Scotch-Brite®; an alternate adhesive tape or patch to be applied and stripped off to remove dead skin; and organic abrasive elements such as salt, crushed almond shells, apricot kernels, etc. Likewise, a chemically exfoliating element may be used to prepare the site, including: mild acids such as alpha hydroxyl acid, beta-hydroxyl acid and salicylic acid; and fruit enzymes. Such chemically abrasive element(s) may be incorporated in a preparation pad, towelette, swab or be supplied otherwise. In some embodiments, the end cap of the applicator may include one or more exfoliating elements. In some embodiments, the end cap may be textured or otherwise formed to provide a surface that can be used to exfoliate the skin of the site where the on-body device will be adhered. Exfoliating away an outer layer of dead skin before application may allow the on-body device to better adhere to the skin for a longer period of time. 
       FIG. 2B  illustrates loader or container  206  preparation, including removing cover  208  from a casing  210 . The container  206  includes the casing  210  which holds the sensor assembly and a sharp (or in some embodiments, the electronics assembly).  FIG. 2C  illustrates applicator  212  preparation including separating a removable applicator end cap  214  from applicator assembly  216 . In some embodiments, container  206  and applicator  212  can initially be packaged connected together to simplify packaging and shipping. For example, the removable applicator end cap  214  may include a boss or other feature that couples or snaps to a corresponding feature on the exterior of the container  206 . This connection is only operative to hold the two pieces together for shipping purposes and not for operation of the system. Thus, in some embodiments, before removing the cover  208  from the casing  210  and separating the removable end cap  214  from the applicator assembly  216 , in an initial unpacking step, the container  206  and applicator  212  are separated from each other. 
     As shown in  FIG. 2D , once alignment indicators  218 ,  220  are aligned, the user assembly operation  106  ( FIG. 1 ) is achieved by pushing the applicator assembly  216  firmly into the container  206  to retrieve a sensor and a sharp from the container and to unlock a guide sleeve of the applicator assembly  216 . In  FIG. 2E , the assembled and unlocked applicator assembly  216  is placed on the application site  204  (or  202 ) and pushed down firmly to effect on-body device application  108  ( FIG. 1 ). As shown in  FIG. 2F , upon used applicator assembly  216  removal from the application site  204 , on-body device  222  is adhered to the user. In some embodiments, as illustrated in  FIG. 2G , analyte levels detected by the sensor of the on-body device  222  can be retrieved over a wireless communication link  224  via a communications facility (e.g., a transmitter, a transponder, etc.) within the on-body device  222  by a receiver unit  226  (referred to alternatively as a “reader unit” or “receiver device”, or in some contexts, depending on the usage, as a “display unit,” “handheld unit,” or “meter”). Relevant information (e.g., analyte level trend data, graphs, etc.) is presented on the receiver unit&#39;s display  228 . 
     The applicator  212 , container  206 , and associated components shown in  FIGS. 2A to 2G  are illustrated in more detail in  FIGS. 3 and 4 . In addition, numerous other variations are described in detail below. These alternative embodiments may operate differently insofar as their internal workings, but may present no difference concerning user activity. 
     Turning to  FIG. 3 , applicator  212  includes a removable cap  214  and applicator assembly  216 . The removable cap  214  can be secured to the applicator assembly  216  via complimentary threadings  306 ,  306 ′. End Cap  214  fits with the applicator  216  to create a sterile packaging for interior of the applicator  216 . Therefore, no additional packaging is required to maintain sterility of the interior of the applicator  216 . In some embodiments, the end (not visible) of the removable end cap  214  can include one or more openings, which can be sealed by a sterile barrier material such as DuPont™ Tyvek®, or other suitable material, to form seal  308 . Such provision allows for ethylene oxide (ETO) sterilization of the applicator  212  through the seal  308  when closed. In some embodiments, the openings in the removable cap  214  may not be present and the removable cap  214  may be made from a sterile process-permeable material so that the interior of the applicator can be sterilized when the cap is mated to it, but that maintains sterility of the interior of the cap after exposure to the sterility process. In some embodiments, ETO sterilization is compatible with the electronics within the electronics assembly  310  and with the associated adhesive patch  312 , both of which can be releasably retained within the applicator assembly  216  until applied to the user. As shown, the applicator assembly  216  includes a housing  314  including integrally formed grip features  316  and a translating sheath or guide sleeve  318 . 
     In reference to  FIG. 4 , the container  206  includes a cover  402  (e.g., made of a removable material such as foil) and casing  404 . Housed within the casing  404  is a desiccant body  412  and a table or platform  408 . In some embodiments, the desiccant body  412  can have an annular shape so that the desiccant body  412  can be disposed within the casing  404  and a sensor assembly support (not visible in  FIG. 4  but see  512  in  FIGS. 5A and 5B ) can extend up through the desiccant body  412 . This arrangement allows the container  206  to include a desiccant without requiring any additional height to accommodate the desiccant. A sensor assembly  410  is snap-fit or otherwise held by the sensor assembly support  512 . The sensor assembly  410  can also be snap-fit or otherwise held by the platform  408  (e.g., using fingers  414 ). With the cover  402  sealed, the container  206  can be subjected to gamma or radiation (e.g., e-beam) sterilization, an approach compatible with the chemistry of the sensor included in the sensor assembly  410 . Like the applicator  212 , the container  206  is its own sterile packaging so that no additional packaging, other than the casing  404  and the cover  402 , is required to maintain sterility of the interior of the casing. 
     The container  206  and the applicator  212  may be sterilized by different sterilization approaches. For example, a sensor contained in a container  206  may require one type of sterilization process and the contents of an applicator  212 —for example, electronics contained within the interior of the applicator  212 —may require another type of sterilization process. The utility of a two-piece separable but combinable system (i.e., the container  206  and the applicator  212 ) enables the respective sterilization of the two pieces and sterility maintenance before the two are connected together for use. In other words, separately sealing the container  206  and the applicator  212  facilitates the use of otherwise incompatible sterilization methods for these two components. For example, one type of sterilization which could damage the chemistry of the sensor can be used to sterilize the applicator  212  including the electronics assembly  310  including the adhesive patch  312 . Likewise, another sterilization process which could damage the electronics in the electronics assembly  310  (and/or the adhesive patch  312  used to adhere the electronics assembly  310  to the user&#39;s skin) can be used to sterilize the container  206  including the sensor therein. Still other advantages may exist, given different shelf-life attributes for the active (i.e., electronic, chemical, etc.) elements. In some embodiments, all components can be sterilized using the same sterilization technique, such as, but not limited to ETO and e-beam sterilization, etc. 
     In some embodiments, the platform  408  in the container  206  functions as an anti-tamper barrier for the sensor assembly  410  and prevents direct handling of the sensor assembly  410  by the user. More specifically, the platform  408  is disposed to protect and assist in the retention of the sensor, a sharp, and an associated connector. In some embodiments, the platform  408  is locked in place within the casing  404  until released by a longitudinally directed force from the applicator assembly  216  during the user assembly operation  106  ( FIG. 1 ). In other words, as the guide sleeve  318  of the applicator assembly  216  is inserted down against the platform  408 , the sleeve  318  releases a locking mechanism (e.g., a catch) and allows the platform to translate deeper into the casing  404 . Additionally, features of the casing  404  can be employed to unlock a guide sleeve lock feature of the applicator assembly  216 . In some embodiments, the platform  408  in the container  206  can only be unlocked if the guide sleeve  318  of the applicator assembly  216  is inserted into the container  206  with alignment marks on the applicator assembly  216  and the container  206  properly aligned. (See  FIG. 10C  and associated text below). 
       FIG. 5A  is an isometric, cross-sectional view of the casing  404  of  FIG. 4 .  FIG. 5B  is an assembled, isometric, cross-sectional view of the container  206  of  FIG. 4  including the component parts. As can be seen in  FIGS. 5A and 5B , platform  408  is surrounded by multiple locking features  502  (at least one is advantageously provided in some embodiments). Each of locking features  502  includes a cantilevered arm  504  with a tongue  506  received in a slot or groove  508 . So disposed, the platform  408  is locked in place. When the arm(s)  504  are urged inward, in the direction represented by arrows P and P′, from a concentrically disposed sleeve  318  (not shown) of the applicator assembly  216  riding over ramp(s)  510 , the locking feature(s)  502  are released and the platform  408  can translate in direction B along a longitudinal axis of the combined applicator assembly  216  interfaced with the container  206 . The translation of the platform  408  into the casing  404  provides access to sensor assembly  410  by the applicator assembly  216 . Until the platform  408  is unlocked and driven down into the casing  404 , the sensor assembly  410  is otherwise isolated from being touched or otherwise handled/accessed by a user. In some embodiments, additional detent ramp features can be provided to hold the platform  408  until depressed with force applied by a user. In addition, various key-and-way or slot-and-groove guidance features can be provided to control such motion and ensure that it is smooth and linear (i.e., to avoid platform canting, binding, etc.) 
     In some embodiments, the sleeve/ramp interface with associated locks relies only on detent features to maintain the platform&#39;s position. So configured, inadvertent handling of the sensor assembly can be avoided. The detent(s) can be tuned to require deliberate action to clear the platform  408 . 
     In some embodiments, alternative mechanisms and arrangements may be employed to provide a platform  408  that collapses upon application of force via the applicator assembly  216  by the user. For example,  FIGS. 6 and 7  depict an alternative container  600  embodiment including an alternative platform  602  arrangement. Here, a collapsible armature or linkage  604  supports the platform  602 . This linkage  604  is integrally guided and spring-loaded by virtue of the living hinge design of the linkage  604 . Alternatively, a coil spring could be employed along with guides for the platform  602 . A sleeve  318  ( FIG. 3 ) ( FIG. 3 ) of an applicator  216  or the base of sensor mount unit  606  itself, can be used to translate the platform  602  to provide clearance for sensor assembly  608  access and pick-up by the applicator  216  and incorporation as a complete assembled on-body device  222 . The container  600  includes a casing  610  and can also include a desiccant ring  612  to protect the sensor assembly  608  from moisture. 
     Another embodiment for sensor storage and protection is illustrated in  FIG. 8  with container  800 . As with the prior embodiments, this embodiment can also include an annular desiccant ring  612 . Casing  802  is provided in connection with a support base  804 . The support base  804  receives sensor assembly  608  and a frame  806 . The frame  806  includes a pivoting door  808 . As shown, the support base  804  incorporates three channels  810  for receipt of frame legs  812  to serve as guidance. In its up/closed position shown in  FIG. 9A , door  808  protects the sensor assembly  608  from contact by the user. Spiral ramp features interacting between the support base  804  and the frame  806  cause the door  808  to swing open as the frame  806  is moved down as shown in  FIG. 9B . Likewise, features of the frame  806  can hold the sensor assembly  608  against the support base  804  until the frame  806  is pushed down by user activity. 
     Similar to the container embodiment  206  shown in  FIGS. 5A and 5B , the frame  806  in container  800  can be locked in place and released by applicator sleeve introduction. A support ring  902  may lock against boss or tang  814  until the boss  814  is urged inward by the action of an applicator sleeve along angled interface surface  904  of each leg  812 . In some embodiments, the legs  812  can be biased outward with a preload but in other embodiments, the locking/unlocking function can operate without such biasing.  FIG. 9A  illustrates the locked configuration, whereas  FIG. 9B  illustrates unlocked/translated relation of components. 
       FIGS. 10A to 10N  illustrate example details of embodiments of the internal device mechanics of preparing the applicator  212  for use, using the container  206 . All together, these drawings represent an example sequence of assembling an on-body device  222  by connecting a sensor assembly  410  stored in the container  206  with an electronics assembly  310  stored in the applicator  212 . In addition, the sequence prepares the applicator  212  to apply the assembled on-body device  222  to the user. Modification of such activity for use with the alternative container embodiments (as described above or others) can be appreciated in reference to the same by those with skill in the art. 
       FIGS. 10A and 10B  show container  206  and applicator  212  with their constituent parts, along with arrows indicating the manner of cover  402  and cap  214  removal, respectively. Upon peeling off foil cover  402  from the casing  404 , the platform  408  within is locked, thus protecting the sensor assembly  410  (not visible but see  FIG. 4 ) which includes a sensor, a sensor support (also referred to as a plug), a connector, and a sharp. (These components are discussed in detail below.) Likewise, upon removal of cap  214  from the applicator assembly  216 , the applicator  212  is locked. As a result of being locked, a guide sleeve  318  (not visible but see  FIG. 3 ) cannot be collapsed into the applicator&#39;s housing  314 . 
     In  FIG. 10C , applicator assembly  216  is set within container  206 . The two components  206 ,  216  are rotated and advanced until mechanical alignment features M and M′ engage, allowing the applicator assembly  216  to register and sit level within the container  206 . Visual alignment indicators A and A′ assist or guide the user to quickly find the proper alignment position. Note that in some embodiments, the platform  408  cannot be unlocked to translate into the container  206  unless the alignment features M and M′ are properly aligned.  FIG. 10D  depicts the components  206 ,  216  with the mechanical alignment features M, M′ engaged. Sleeve  318  passes over platform  408 , with the platform  408  nested concentrically inside the inner diameter of sleeve  318 . 
     Cross-sectional views  FIGS. 10E and 10F  illustrate the relationship of parts overviewed in  FIGS. 10C and 10D . When the sleeve  318  of applicator assembly  216  is seated onto the platform  408  of the container  206  and pushed downward, platform locking features  502  disposed around the platform  408  on locking ribs  1002  are unlocked to allow the platform  408  to translate along a longitudinal axis (labeled “Z”) of the interfaced components  206 ,  216 . More specifically, a portion of platform  408  bends and platform locking arms  504  are displaced inward as indicated by arrow P to clear locking grooves  508  in the locking ribs  1002  of casing  404 , thus unlocking the platform  408 . At this point, the platform  408  is held in place by guide ribs  1004  each providing a detent feature  1006  between the platform  408  and the guide ribs  1004  that can be overcome by further downward pressure applied by the user upon further depression of the applicator assembly  216  in the direction of the longitudinal axis Z. 
     Turning now to  FIGS. 10G and 10H , the dropping of the unlocked platform  418  is illustrated.  FIG. 10G  depicts further depression of the applicator assembly  216  in the direction of the longitudinal axis Z. The force from the sleeve  318  causes inward, radial deflection of a portion of the platform  408 . The effect is that detent arms  1008  are flexed down, inward and away from the detent feature  1006  of guide ribs  1004  as shown. This action releases the platform  418  and the applicator assembly  216  into freefall into the container  206 . In some embodiments, the force to flex detent arms  1008 , or in other words, the force to overcome the resistance from the detent features  1006 , is selected to create a predetermined amount of momentum sufficient to ultimately properly mate the electronics assembly  310  with the sensor assembly  410  and unlock the sleeve  318 . In some embodiments, the force to overcome the resistance from the detent features  1006  is from approximately 1 N to approximately 23 N. Other practicable values are possible. 
     In  FIG. 10H , once detent arms  1008  of the platform  418  are past the detent features  1006 , a relieve or undercut  1010  in each of the guide ribs  1004  provides increased clearance for the platform  418  to reduce sliding friction as the sleeve  318  and platform  418  slide or telescope further into the container&#39;s casing  404  along the longitudinal axis Z ( FIG. 10F ). Also, one or more flexible grasping arms  1012  previously in contact with the sensor assembly  410 , particularly through sharp boss  1014 , are moved from a stabilizing configuration in  FIG. 10G  to a freed state or configuration in  FIG. 10H . In other words, as the platform  418  translates further into the container  206 , the sharp boss  1014  of the sensor assembly  410  protrudes through a central opening in the platform  418  and pushes the flexible grasping arms  1012  out of the way. 
     Turning now to  FIGS. 10I and 10J , a cross-sectional view depicting a slightly different cut plane than the prior views is provided to illustrate additional features. In  FIG. 10I , sleeve lock arms are shown engaged with a sleeve lock ledge  1018 . This engagement locks the applicator assembly  216  and prevents the sleeve  318  from being able to be retracted or pushed into the housing  314  of the applicator assembly  216 . In  FIG. 10J , as the applicator assembly  216  is further advanced into the container  206  along the longitudinal axis Z ( FIG. 10F ), sleeve unlock features contact and bend the sleeve lock arms  1016  clear of the sleeve lock ledge  1018  thereby unlocking the applicator assembly  216 . Note that in the particular example embodiment depicted in  FIGS. 10I and 10J , the sleeve lock ledge  1018  is formed in a carrier  1022  of the electronics assembly  310 . 
     When the platform  418  bottoms-out in the container  206  as shown in  FIG. 10J , the sleeve  318  of the applicator assembly  216  is fully unlocked/released and ready to move. Note that while the sleeve lock arms  1016  are shown flexing outward to unlock, in some embodiments, the sleeve lock arms  1016  can be oriented to flex radially inward to free the elements. The same may hold true for the various locking/unlocking features of the present invention. However, the present arrangement offers advantages in terms of a coordinated whole providing an advantageous form factor and minimized container casing size (a factor that affects the user experience) in which the carrier  1022  of the electronics assembly  310  is coaxially arranged. Regarding the carrier  1022 , it is advantageously designed with unique carrier arm features as detailed in, for example, U.S. patent application Ser. No. 13/071,461, the disclosure of which is incorporated herein by reference. 
     In  FIGS. 10K and 10L , now that the sleeve  318  of the applicator assembly  216  is fully unlocked, the momentum along the longitudinal axis Z ( FIG. 10F ) from the force used to overcome the resistance of the detent features  1006  ( FIG. 10H ) causes three additional concurrent actions. First, even though the sleeve  318  cannot descend any further into the container  206  (since it is in contact with the platform  418  which is bottomed-out), the housing  314  of the applicator assembly  216 , the carrier  1022 , and the electronics assembly  310  are free to continue to descend into the container  206 , now that the sleeve  318  is unlocked as shown in  FIG. 10L . 
     Second, as the electronics assembly  310  descends further along the longitudinal axis Z ( FIG. 10F ), the sensor assembly  410  is forced into an opening in the electronics assembly  310  which couples the sensor to the electronics and completes assembly of the on-body device  222  ( FIG. 2F ). In some embodiments, mating snap features on the sensor assembly  410  and the electronics assembly  310  can be used to compel the components to remain locked and compressed together to insure a sealed, reliable connection. As an alternative to mating snap features, in some embodiments, the sensor assembly  410  and the electronics assembly  310  may be coupled by a light press fit or other connection method. However, the positive interaction and lock of snap features is an advantage. So too is the minimal force used to deflect fine locking features that spring back for engagement. 
     Third, along with the housing  314 , the carrier  1022 , and the electronics assembly  310 , a sharp retraction assembly  1024  also continues to descend into the container  206  along the longitudinal axis Z ( FIG. 10F ) and is forced to receive the sharp boss  1014  of the sensor assembly  410 . The conical head of the sharp boss  1014  is pushed past a radial arrangement of flexible arms  1026  of the sharp retraction assembly  1024 . The flexible arms  1026  bend outwardly, as they are forced to ride against the passing conical surface of the head of the sharp boss  1014 . The sharp is thus thereby engaged by the sharp retraction assembly  1024  as the flexible arms  1026  snap back into place once the head of the sharp boss  1014  has passed by, securely grasping the head at the narrowed neck portion of the sharp boss  1014 . Note that a base of the sharp boss  1014  may be included to limit insertion into the sharp retraction assembly  1024  through interference with a stop limit or shoulder of the flexible arms  1026 .  FIG. 10K  illustrates the arrangement immediately before the above three actions have completed and  FIG. 10L  illustrates the resulting arrangement immediately after the actions have completed. 
     In some embodiments, the connection features between the sharp boss  1014  of the sensor assembly  410  and the sharp retraction assembly  1024  can be otherwise configured. For example, the sharp retraction assembly  1024  can include a conical channel formed from a radial arrangement of inwardly biased flexible finger members configured to receive the head of sharp boss  1014  such that once the head has passed through the channel, the flexible fingers conform to the narrowed neck of the sharp boss  1014 . With the fingers so conformed, the sharp boss  1014  is captured by the sharp retraction assembly  1024 . Retention force is limited only by material strength because the self-energizing lock is not prone to slip between the pieces. 
     Turning to  FIG. 10M , a slightly rotated view, relative to  FIG. 10L , is shown. When the sharp boss  1014  is engaged in the sharp retraction assembly  1024 , the sensor assembly  410  is coupled to the electronics assembly  310  completing assembly of the on-body-device  222 , and the sleeve  318  is unlocked, platform locking arms  504  and detent arms  1008  have engaged undercut grooves  1028  in the container  206 , thereby locking the platform  418  in the casing  404 . This engagement between the platform  418  and the casing  404  marks the final position of the container  206  from which the loaded applicator assembly  216  is withdrawn for use to apply the on-body device  222  to the user. 
     Now, once removed from the container  206 , the applicator assembly  216  is ready to “fire” as illustrated in  FIG. 10N . As such, the applicator assembly  216  is ready to use as in application  108  described in connection with  FIG. 2E . Here, the applicator assembly  216  has already been unlocked by interaction with the container  206 , and the sensor assembly  410  is coupled to the electronics assembly  310 . The sharp  1030  extends from the on-body device  222  which is held in the sleeve  318  of the applicator assembly  216  as shown. 
       FIGS. 11A to 11F  illustrate example details of embodiments of the internal device mechanics of “firing” the applicator assembly  216  to apply the on-body device  222  to a user and including retracting the sharp  1030  safely back into the used applicator assembly  216 . All together, these drawings represent an example sequence of driving the sharp  1030  (supporting a sensor coupled to the on-body device  222 ) into the skin of a user, withdrawing the sharp while leaving the sensor behind in operative contact with interstitial fluid of the user, and adhering the on-body device to the skin of the user with an adhesive. Modification of such activity for use with the alternative applicator assembly embodiments and components can be appreciated in reference to the same by those with skill in the art. 
     Turning now to  FIG. 11A , a sensor  1102  is supported within sharp  1030 , just above the skin  1104  of the user. Rails  1106  (optionally three of them) of an upper guide section  1108  may be provided to control applicator assembly  216  motion relative to the sleeve  318 . The sleeve  318  is held by detent features  1110  within the applicator assembly  216  such that appropriate downward force along the longitudinal axis of the applicator assembly  216  will cause the resistance provided by the detent features  1110  to be overcome so that the sharp  1030  and on-body device  222  can translate along the longitudinal axis into (and onto) the skin  1104  of the user. In addition, catch arms  1112  of carrier  1022  engage the sharp retraction assembly  1024  to maintain the sharp  1030  in a position relative to the on-body device  222 . 
     In  FIG. 11B , user force is applied to overcome or override detent features  1110  and sleeve  318  collapses into housing  314  driving the on-body device  222  (with associated parts) to translate down as indicated by the arrow L along the longitudinal axis. An inner diameter of the upper guide section  1108  of the sleeve  318  constrains the position of carrier arms  1112  through the full stroke of the sensor/sharp insertion process. The retention of the stop surfaces  1114  of carrier arms  1112  against the complimentary faces  1116  of the sharp retraction assembly  1024  maintains the position of the members with return spring  1118  fully energized. 
     In  FIG. 11C , sensor  1102  and sharp  1030  have reached full insertion depth. In so doing, the carrier arms  1112  clear the upper guide section  1108  inner diameter. Then, the compressed force of the coil return spring  1118  drives angled stop surfaces  1114  radially outward, releasing force to drive the sharp carrier  1120  of the sharp retraction assembly  1024  to pull the (slotted or otherwise configured) sharp  1030  out of the user and off of the sensor  1102  as indicated by the arrow R in  FIG. 11D . 
     With the sharp  1030  fully retracted as shown in  FIG. 11E , the upper guide section  1108  of the sleeve  318  is set with a final locking feature  1120 . As shown in  FIG. 11F , the spent applicator assembly  216  is removed from the insertion site, leaving behind the on-body device  222 , and with the sharp  1030  secured safely inside the applicator assembly  216 . The spent applicator assembly  216  is now ready for disposal. 
     Operation of the applicator  216  when applying the on-body device  222  is designed to provide the user with a sensation that both the insertion and retraction of the sharp  1030  is performed automatically by the internal mechanisms of the applicator  216 . In other words, the present invention avoids the user experiencing the sensation that he is manually driving the sharp  1030  into his skin. Thus, once the user applies sufficient force to overcome the resistance from the detent features of the applicator  216 , the resulting actions of the applicator  216  are perceived to be an automated response to the applicator being “triggered.” The user does not perceive that he is supplying additional force to drive the sharp  1030  to pierce his skin despite that all the driving force is provided by the user and no additional biasing/driving means are used to insert the sharp  1030 . As detailed above in  FIG. 11C , the retraction of the sharp  1030  is automated by the coil return spring  1118  of the applicator  216 . 
     As for further details of the operation, alternative embodiments may be appreciated in view of related approaches discussed below, others in review of the incorporated subject matter and still more appreciated by those with skill in the art based upon further review of the figures which depict actual hardware produced according to various aspects of the subject disclosure. 
     Turning to  FIGS. 12A to 12D  an alternative applicator/container set approach is now described. As shown in  FIG. 12A , the container  1200  holds the electronics assembly  1202 . This is in contrast to the above embodiments wherein the relationship between the sensor assembly and the electronics assembly was reversed. Upon aligning markers M and M′, the applicator  1204  is inserted in the container  1200 . In  FIG. 12B , the units are merged. In  FIG. 12C , the parts are separated. Finally, in  FIG. 12D  the applicator  1204  is unlocked (e.g., in some embodiments by twisting the sleeve  1206  within the applicator  1204 , in some embodiments by the act of loading the electronics assembly  1202  into the applicator  1204 , or in some embodiment by the act of removing a locking strip from the sleeve  1206 ) and ready for use with the assembled on-body device (not visible) including the sensor assembly loaded therein. These various alternative embodiments are illustrated in  FIG. 13A to 15F . 
       FIGS. 13A to 13C  variously illustrate use of the applicator  1204  of  FIGS. 12A to 12D  in connection with a locking-sleeve feature  1206 .  FIG. 13A  shows the sleeve  1206  locked as indicated by the closed window  1208 . After twisting the sleeve  1206  relative to the rest of the applicator  1204  to unlock the sleeve  1206 , a visual indication (e.g., open window  1208 ′) is seen when the applicator  1204  is ready for use as presented in  FIG. 13B . Upon use, as shown in  FIG. 13C , the unit is compressed with the sleeve  1206  collapsed into the applicator  1204 . 
       FIGS. 14A and 14B  illustrate an alternative applicator  1400  embodiment with a removable locking strip  1402 . With the locking strip  1402  in place around the sleeve  1406 , the sleeve  1406  cannot be pushed into the applicator  1400 . The strip  1402  includes a pull-tab  1404  and adhesive or other fastening member to keep it in place until removed and the applicator  1400  is ready for use. 
       FIGS. 15A to 15F  illustrate preparation of the applicator  1400  of  FIGS. 14A and 14B  for use with a container  1500 . Once the cover  1502  has been removed from the container  1500  and the cap  1506  removed from the applicator  1400 , the applicator  1400  is inserted into container  1500  to load the electronics assembly  1504  into the applicator  1400  and mate the sensor assembly (not shown) with the electronics assembly  1504  as shown in  FIGS. 15B and 15C . Once loaded, the applicator  1400  is removed from the container  1500  as shown in  FIG. 15D .  FIG. 15E  shows the applicator  1400  loaded with the assembled on-body device  222  and ready for sensor/sharp insertion. The locking strip  1402  is removed from the sleeve  1406  and the open ready indicator  1208 ′ signals that the applicator  1400  is ready to be used.  FIG. 15F  illustrates the system after such action has been taken in transferring the on-body device  222  from the applicator  1400  onto the skin of a user. 
       FIGS. 16A and 16B  are sectional and detail views, respectively, of features of the container  1500  in  FIGS. 15A-15F . Specifically, the on-body device  1604  is shown in the container  1500  with an adhesive patch  1602  and its backing  1606 . The backing  1606  is spiral-cut and attached to a boss so that when the on-body device  1604  is transferred from the container  1500 , the peel-away backing  1606  is left behind. In this fashion, the adhesive patch  1602  remains covered by the backing  1606  so it does not inadvertently adhere to the container  1500 . 
     As an alternative to the spiral peel-around backing approach of  FIGS. 16A and 16B ,  FIGS. 17A and 17B  are perspective assembly views illustrating alternative container  1702  configurations for capturing separate peel-off “butterfly” wings or bilateral liner panels from the adhesive-backed patch of the on-body device  1706 . In each case, a two-part base  1704  is provided for gripping the peel-away backing liner pieces. Naturally, the base  1704  is adapted to fit in the container casing. In some embodiments, the container  1702  can be configured differently. In the version depicted in  FIG. 17A , traction/tread  1708  is provided to assist with grip of the backing. In the version depicted in  FIG. 17B , ramps  1710  are provided to assist in removing the backing. In another version, the base can be a one-piece molding incorporating a living hinge in a “clamshell” arrangement. The backing liner piece(s) may be captured along a center line or at an offset location. However configured, the base  1704  may snap into place with complementary band and rib interface features associated with each of the base  1704  and container  1702 , snaps, or other features. As with other assemblies described herein, these features may alternatively be press fit, ultrasonically welded or otherwise secured in place. 
       FIG. 18  is a cross-sectional view illustrating features of the applicator and container sets shown in  FIGS. 15A-15F . The embodiment shown in  FIG. 18  includes several of the features described in connection with the alternative loading approach above. However, it is simplified in approach. Most notably, the container  1806  includes no active/mobile components. Once the applicator  1800  is pressed down into the container  1806 , the on-body device  1808  is assembled (e.g., the sensor assembly is mated with the electronics assembly), released from the container  1806  (e.g., using releasable latches), and held by the applicator  1800  (e.g., using latching arms). This embodiment offers an advantage of not having to expose the adhesive of the on-body device  1808  as in other embodiments. Furthermore, the position of the on-body device  1808  provides a stable surface for the sensor assembly insertion. Other embodiments where the applicator is pre-loaded with the on-body device do provide the advantage of not having to perform the above-described hand-off. Also, the use or inclusion of a protector for the sharp is avoided. 
       FIGS. 19A and 19B  show a sensor assembly  1902  in association with a needle guard  1904 . In use, a distal interface feature (e.g., a barb) of the needle guard  1904  is captured by a complimentary split ring or other feature in the container during the assembly of the on-body device. Then, when the applicator is separated from the container, the needle guard  1904  is retained in the container and the sharp is unsheathed. In some embodiments, the needle guard  1904  may be made from polypropylene with a thermoplastic elastomer (TPE) insert to releasably secure the sharp. Other materials may be selected. 
     Other materials may be selected for construction of other elements of the present invention. For example, the applicator housing may be made of polycarbonate or any other practicable material. The guide sleeve, container, etc. may be constructed from acetyl (for reason of lubricity of sliding parts). Any number of the parts may be injected molded, thermoformed or otherwise produced. 
     Regarding the sensor assembly hand-off to the electronics assembly,  FIGS. 20A and 20B  illustrate a manner of holding a sensor assembly boss  2006  to the element  2002  that will pick up the electronics assembly  2004  to form the on-body device. Spring armatures  2008  clip to a lip of the sensor assembly  2006  and hold the sensor assembly  2006  within the applicator during shipping and handling. When the applicator and the container are brought together, lever arms  2010  contact the on-body device  2004 , causing the associated spring armatures (or “spring arms”) to twist and rotate the connection away from the lip of the sensor assembly, thereby releasing the sensor assembly. A chamfer on the sensor assembly boss can help ensure alignment and proper actuation of the one or more (e.g., three) torqueing spring armatures  2008 . 
       FIGS. 21A-21C  illustrate an alternative hand-off approach. In this embodiment, a sensor assembly gripper  2106 , with a light snap fit, grabs and orients the sensor assembly  2104  for connection to the electronics assembly  2102 . After the sensor assembly  2104  is firmly snapped into the electronics assembly  2102 , the sensor assembly gripper  2106  is retracted with an amount of force that overcomes its grip. Such an approach offers simplicity by reducing the number of parts required (given that the snap features may be incorporated in the sharp hub/boss). 
     Electrical Connections Details 
     The selection of various hardware options from the above alternative embodiments will depend, at least in part, on the sensor assembly configuration. Sensor assembly configuration, in turn, depends on the mechanism selected for establishing electrical contact between the sensor assembly and the electronics assembly, as well as the method used to seal the contacts. A number of advantageous alternative embodiments are illustrated in  FIGS. 22 through 48 . 
     A first example is presented in  FIG. 22 . Here a sensor  2202  is provided with an elongate “tail” section. The distal portion of the tail is to be inserted through the skin surface guided by a sharp. The proximal portion of the sensor  2202  includes a “flag” type connector region. Three carbon-doped (for conductivity) silicone electrical connectors  2204  are provided to interface with the electrical contacts of the sensor  2202 . A split “V” portion of each connector  2204  receives the electrical contacts of the sensor  2202 . A flexible nubbin on the opposite side of each connector  2204  is provided for electrical contact with the circuit board incorporated in the electronics assembly. When inserted in a housing  2210 , the sensor  2202  and the connector  2204  are advantageously sealed, encased or potted with an adhesive. Epoxy, a UV cure or another type of dielectric (non-conductive) compound may be used. Generally, the compound selected is of such viscosity that it is able to flow around features and fully seal the sensor  2202  within its housing  2210  to avoid leakage. Such an approach avoids contamination and/or current leakage due to fluid intrusion.  FIGS. 23A and 23B  are perspective assembly and final-assembly cross-sectional views, respectively of the sensor components of  FIG. 22 . The tail of the sensor  2202  is supported within the sharp  2206  and the sharp  2206  extends through the connector housing  2210 . The electrical contacts of the sensor  2202  are seated in the connector  2204  and the assembly is sealed within the housing  2210  including the housing top  2208 . 
       FIGS. 24A and 24B  are top and bottom perspective views, respectively of circuit board components to be used with the sensor assembly  2300  of  FIGS. 23A and 23B . In each, a custom printed circuit board (PCB)  2402  is shown. The PCB  2402  includes a battery  2406  with mount  2408 , an application specific integrated circuit (ASIC)  2410 , or other appropriate processing unit, and various other circuitry, including a thermocouple. On its face, the PCB  2402  includes a housing  2404  with snap features for receiving the sensor assembly  2300  of  FIGS. 23A and 23B . On the reverse side of the PCB  2402 , heat stakes  2412  show the mode of attaching the housing  2404 . 
     Turning to  FIGS. 25A and 25B , in some embodiments, the on-body device  2502  is formed by over molding with a polymer “macromelt” (e.g., a thermoplastic hot-melt based on polyamide) or other compound and then affixing an adhesive patch with a releasable liner thereto. A completed on-body device  2502  is provided once fitted with a complimentary sensor assembly  2300 , as illustrated in  FIGS. 25A and 25B . Internal to such assembly, it may be desirable to include a seal or gasket  2604  as shown in assembly view  FIG. 26 . As shown in cross section, in  FIG. 27A , and magnified in  FIG. 27B , the gasket  2604  advantageously includes discrete ring/rim elements to compress and ensure sealing in critical areas, including around each circuit connection/nubbin. 
       FIGS. 28A-28F  illustrate another advantageous sensor  2802  and sensor mount or connector  2804  arrangement. This embodiment resembles the previous approach, but is configured with a bend and a curve imparted to the sensor connection “flag.” This permits package and sealing within in a roughly triangular envelope to shorten the length of the connector. Doing so results in a generally more compact sensor assembly body and the ability to downsize all associated components. Yet, it does not significantly complicate manufacture.  FIG. 28A  depicts the sensor  2802  before it is shaped to fit within the connector  2804 .  FIG. 28B  depicts the bent and curved sensor connection “flag.”  FIG. 28C  depicts the relative orientation of the sensor  2802  as it is inserted into the connector  2804 .  FIG. 28D  depicts a wedge  2806  that is press-fit into the connector  2804  to retain the sensor  2802  and press the connector&#39;s electrical contacts against the electrical contacts of the sensor  2802 .  FIG. 28E  depicts the relative orientation of the sharp  2808  as it is inserted into the connector  2804  and  FIG. 28F  depicts the completed sensor assembly including potting  2810  (e.g., UV potting) used to seal the electrical contacts. 
     An alternative embodiment is contemplated in connection with the sensor approach illustrated in  FIGS. 29A-29D . Using a sensor  2902  with a vertically disposed “flag” connector portion that is supported by coupling  2904 , coupling  2904  is configured to snap into connector block  2908  which is attached to PCB  2914 . Connector block  2908  includes a connector socket  2910  to receive the contacts portion of the sensor  2902 . Connector block  2908  also includes a coupling feature  2912  to receive snap-fit tab  2906  on the coupling  2904  which retains the sensor  2902  in the connector socket  2910 . 
     Another alternative embodiment is contemplated in connection with the sensor approach illustrated in  FIGS. 30A-30C . Here, a design is provided that eliminates a connection element and the need for separate spring contacts (be they metal or elastomeric as above). In addition, the approach offers the advantage of effectively converting a sensor with contacts on two sides into a sensor with contacts on a single side after folding. The sensor  3004  shown in  FIG. 30A  initially has two electrical contacts facing a first direction on the split contact area and one contact facing in a second, opposite direction (obscured by the view). When folded and optionally clamped, glued or otherwise affixed in the orientation shown in  FIG. 30B , all of the electrical contacts lie in a single plane, facing the same direction (e.g., downward in the drawing). Set within a housing (not shown) to restrain and/or seal the sensor  3004 , the sensor  3004  is coupled to electrical contacts on the PCB  3002  as shown in  FIG. 30C . 
     Such an approach in some embodiments includes a thinner (e.g., lower profile) on-body device relative to the on-body device  3102  variation shown in  FIG. 31 . The reduced thickness dimension is represented by height H. In  FIG. 31 , a flag type sensor is shown in a housing with separate electrical connectors. The “stack height” in  FIG. 31  includes these connectors as well as the housing. The approach shown in  FIG. 30  enables eliminating the connector height above the sensor  3004 . Thus, elements are eliminated without losing functionality. Moreover, the elimination of parts reduces cost, and impedance (relative at least to the inclusion of elastomeric connectors as shown in  FIG. 22 , etc.) between the sensor  3004  and the PCB. Another useful aspect is allowing a sensor with contacts on two sides to connect to the PCB without requiring vias or holes in the sensor, thereby helping with sealing considerations and ease of electrical connection. 
       FIGS. 32A and 32B  illustrate two additional sensor configurations. In these embodiments, sensors  3202 ,  3212  with contacts on two sides are split and bent in opposite directions to orient the electrical contacts  3204 ,  3214  onto a single face or plane. As above, orienting the electrical contacts  3204 ,  3214  onto a single plane facilitates ease of sealing the electrical connections. Moreover, overall sensor assembly height can be reduced relative to other approaches. Any of conductive adhesives, conductive films and/or mechanical contacts may be used to electrically connect with the sensor contacts so arranged. 
       FIGS. 33A-33G  depict a low-profile multilayer sensor configuration with the electrical contacts all on one side and some details of its construction.  FIGS. 33A and 33B  illustrate the two sides of this embodiment of a sensor  3300  and its overall shape. The example sensor  3300  includes a tail portion  3302  that is initially supported by a sharp and then disposed within the user&#39;s interstitial fluid or dermal space below the skin upon application of the on-body device. The tail portion  3302  includes electrodes  3304 ,  3306 ,  3308  that are used to contact the interstitial fluid and to sense (e.g., transmit and receive) the electrical signals used to measure the analyte concentration within the interstitial fluid. The sensor  3300  also includes an electrical contacts portion  3310  which includes electrical contacts  3312 ,  3314 ,  3316  that are disposed all on one side of the sensor  3300  and are in electrical communication with the electrodes  3304 ,  3306 ,  3308  via conductive traces (not visible in  FIGS. 33A and 33B  but see  FIG. 33F ). Note also that the electrical contacts portion  3310  is shaped to facilitate being securely held and sealed into a connector support that will be described below. For example, the electrical contacts portion  3310  includes securement features that hold the sensor to be secured to the connector support by friction fit, interference fit, etc., herein shown as tabs  3310 A and notches  3310 B that allow the electrical contacts portion  3310  to be held securely in the connector support which includes mating features. 
     The sensor  3300  also includes a bendable portion  3318  that allows the electrical contacts portion  3310  to be arranged parallel to the circuit board of the electronics assembly to facilitate a relatively flat or low profile within the electronics assembly. The bendable portion  3318  also allows the tail portion  3302  to extend down from the electronics assembly so that it can be inserted below the skin of the user while the electrical contacts portion  3310  lays parallel to the circuit board. Lastly, the sensor  3300  includes an armature portion  3320  that allows the sensor  3300  to be held securely to the connector support of the sensor assembly. The armature portion  3320  also provides a leverage point to apply a biasing force to compel the tail portion  3302  into a channel of the sharp as described below in  FIG. 35D  and the associated text. 
       FIG. 33C  depicts a side view of the sensor  3300 . The encircled portion labeled D is shown in more detail in  FIG. 33D .  FIG. 33D  provides a magnified side view of the distal most part of the tail portion  3302  of the sensor  3300 . The encircled portion labeled E is shown in more detail in  FIG. 33E .  FIG. 33E  provides an even further magnified view of the electrodes  3304 ,  3306 ,  3308  of the tail portion  3302 . As can be seen in  FIG. 33E , the electrodes  3304 ,  3306 ,  3308  are formed as layers on a substrate  3322 . The substrate  3322  is made of a flexible, non-conductive dielectric material. In some embodiments, a clear, high-gloss, heat stabilized polyester film may be used for the substrate  3322  and conductive carbon ink can be used to create the trace layers used for the electrodes  3304 ,  3306 ,  3308 . In other embodiments, other materials may be used for the substrate  3322  such as polymeric or plastic materials and ceramic materials and for the trace layers such as carbon or gold. 
     Dielectric layers  3324 ,  3326 ,  3328  are disposed between and upon the electrodes  3304 ,  3306 ,  3308  to insulate the electrodes  3304 ,  3306 ,  3308  from each other. In some embodiments, an ultraviolet (UV) light curable dielectric material may be used for the dielectric layers  3324 ,  3326 ,  3328 . In other embodiments, other practicable materials may be used. In the particular example embodiment shown, electrode  3304  is a counter electrode, electrode  3306  is a working electrode, and electrode  3308  is a reference electrode. Note that reference electrode  3308  also includes a secondary conductive layer  3330 , e.g., an Ag/AgCl layer. In certain embodiments, the lateral surface of the secondary conducive layer  3330  is covered by a dielectric layer  3328  resulting in only the side edges the secondary conductive layer  3330 , which extend along the side edges of the substrate  3322 , being uncovered by dielectric layer  3328  and, as such, are exposed to the environment when in operative use. In such embodiments, dielectric layer  3328  covers the entire lateral surface of the secondary conducive layer  3330 , i.e., 100% of the lateral surface of the secondary conducive layer  3330  is covered by dielectric layer  3328 . As such, dielectric layer  3328  has at least the same lateral width and at least the same length as conductive layer  3330 . 
     Further details of the arrangement, dimensions, chemistry, and manufacturing methods of the sensor  3300  may be found in U.S. patent application Ser. No. 13/526,136, entitled “Connectors For Making Connections Between Analyte Sensors And Other Devices,” which was filed Jun. 18, 2012, and which is incorporated by reference herein in its entirety and for all purposes. 
       FIG. 33F  depicts a view of the sensor  3300  of  FIGS. 33A and 33B  including hidden lines representing different layers of electrically conductive trace lines  3332 ,  3334 ,  3336  connecting the electrical contacts  3312 ,  3314 ,  3316  to the electrodes  3304 ,  3306 ,  3308 . The electrical contacts  3314 ,  3316  for the electrodes on the opposite side of the sensor  3300  are coupled to the respective conductive traces  3334 ,  3336  using vias  3338 ,  3340  (only two labeled).  FIG. 33G  is a cross-sectional view of the sensor  3300  taken along line GG of  FIG. 33F . As can be seen, conductive trace  3332  covered by dielectric layer  3324  is on one side of the substrate  3322  while conductive traces  3334 ,  3336  separated by dielectric layer  3326  and covered by dielectric layer  3328  is on the opposite side on the substrate  3322 . The electrical contacts  3314 ,  3316  are accessible via openings in the dielectric layer  3328 . 
       FIGS. 33H to 33J  depict three alternative sensor designs  3342 ,  3344 ,  3300  side by side for comparison. Notably sensor  3342  includes an aperture  3346  to receive a rivet or other fastener for physical attachment to the PCB of the electronics assembly. Details of sensor  3342  are provided in previously incorporated U.S. patent application Ser. No. 13/526,136, entitled “Connectors For Making Connections Between Analyte Sensors And Other Devices,” which was filed Jun. 18, 2012. Sensors  3344  and  3300  are suitable for use with the alternative connector arrangements described below with respect to  FIGS. 34A-35D . 
     Turning now to  FIGS. 34A-35D , an alternative connector arrangement for connecting a circuit board to a sensor  3300  such as depicted in  FIGS. 33A, 33B, and 33J  is described. As shown in  FIG. 34A , a flexible one-piece seal or connector  3402  is molded in silicone or other practicable elastic material. Separate doped silicone conductive elements are set therein which provide electrical contacts  3410  for connection to a circuit board. In some embodiments, the conductive elements can alternatively be over molded or insert-molded into place. The result is a generally malleable/flexible hybrid connection and sealing unit or connector  3402  incorporating a living hinge joining two (as-shown) symmetrical sections. Alternatively, a two-piece design is possible. Yet, with the unitary design, the arrangement can be neatly secured using a single catch boss or post  3412  opposite the hinged section. In some embodiments, two or more posts can be used to secure the connector  3402  folded around and sealing both sides of the contacts portion of the sensor  3300 . Thus, even if a dielectric coating on the sensor  3300  fails (e.g., pinhole leaks), the connector  3402  insures that the sensor contacts  3312 ,  3314 ,  3316  are protected from moisture or any contaminants. The one-piece design also facilitates assembly as illustrated, in which the flexible connector  3402  is set in a rigid or semi-rigid housing or connector support  3404  with one side located on the post  3412 . Then a sensor  3300  is inserted, and bent approximately ninety degrees at the bendable portion  3318  of the sensor  3300 . Once bent, the sensor  3300  is then captured with the upper part of the connector  3402  by folding over the connector  3402  as indicated by arrow S in  FIG. 34C . The connector  3402  is illustrated as bilaterally symmetrical, however, the connector  3402  can be formed in a direction-specific orientation because in some embodiments, certain of the electrical contacts  3410  may not be necessary. In some embodiments, all the sensor&#39;s electrical contacts  3312 ,  3314 ,  3316  can be provided on a single side of the sensor  3300  or, in other embodiments, both sides of the sensor  3300 . 
     As shown in  FIG. 34D , in some embodiments, the top surface of the connector  3402  includes a raised lip  3418  disposed at the top surface edge of the connector  3402  that encircles the electrical contacts  3410  of the connector  3402 . The raised lip  3418  can be integrally formed in the elastomeric material that forms the connector  3402  and is thus compressible when the sensor assembly is inserted into the electronics assembly. Alternatively, the raised lip can be embodied as gasket or o-ring on the top surface of the connector  3402 . The raised lip  3418  functions to ensure that a seal is formed around the electrical contacts  3410  of the connector  3402  and the electrical contacts of the PCB before any electrical connectivity between the sensor and the electronics assembly is established. Thus, the raised lip  3418  provides a failsafe against a short by insuring the order of assembly includes creating a seal and then creating electrical connectivity as the sensor assembly is mated with the electronics assembly. 
     In any case, with the sensor  3300  captured within the seal  3402 , a sharp  3408  is then introduced, with its hub  3414  contacting the connector support  3404  as shown in  FIG. 34D .  FIG. 35A  illustrates the orientation of the sharp  3408  prior to the insertion of the sharp  3408  into the connector support  3404 .  FIGS. 35B and 35C  provide a cross-sectional overview of the relationship of the sharp  3408  to the sensor  3300 . Notably, once inserted in the connector support  3404 , the sharp  3408  surrounds and supports the tail portion  3302  of the sensor  3300 . In  FIG. 35D , further details of the sensor configuration are visible. Particularly, biasing features are shown that abut surfaces of the connector support  3404  in order to center and bias the sensor  3300  into the channel of the sharp  3408 . Specifically, armature portion  3320  abuts the surface at arrow  3502  of the connector support  3404  which causes the biasing feature  3508  to act as a fulcrum at arrow  3504  to push the tail portion  3302  of the sensor  3300  into the sharp  3408  at arrow  3506 . 
     In some embodiments, the curved section  3508  of the sensor  3300  can overlie a corresponding surface of the connector support  3404  to help limit the insertion depth (i.e., provide a depth stop) for the sensor  3300 . Sensor  3300  vertical placement, including insertion depth, is also controlled based on the relationship between the seal  3402  halves. As noted with respect to the other sensor assembly housings/supports discussed herein, the sensor assembly of  FIG. 35C  can also include various clip or snap features for its precise associations with a socket in the electronics assembly within the on-body device. 
     A related arrangement to that described in connection with  FIGS. 34A-34D and 35A-35D  is presented in  FIGS. 36 to 38 . In  FIG. 36 , a sensor  3300  with all electrical contacts on the same side is shown with a sharp  3602  for insertion in a connector support  3604 . The connector support  3604  includes an elastomeric (e.g., silicone) seal backing. Once such a sensor assembly set is in a container (or alternatively in an applicator), the sensor assembly can be coupled to the sensor electronics to form an on-body device  222 . As shown in  FIG. 37 , the sensor assembly  3702  is shaped to fit within a socket  3704  that includes a second elastomeric unit with electrical contacts in the elastomer body of the socket  3704 . Note that in  FIG. 37 , the enclosure of the electronics assembly is not shown so that the socket can be more clearly displayed. The socket  3704  is affixed to a circuit board  3706  via any practicable method. The socket  3704  and/or the connector support  3604  can include various coupling features (e.g., a snap fit lip and hook arrangement) to ensure that the electrical contacts are pressed tightly together and sealed within the socket  3704  and sensor assembly  3702 . Once the sensor assembly  3702  is received within the socket  3704 , the on-body device (e.g., with the complete over-mold enclosure around the circuit board  3706  and adhesive patch  3802  as shown in  FIG. 38 ) is ready for use. 
     The electrical contacts/connector approaches described above are “directional.” In other words, before the sensor assembly is mated with the electronics assembly, the two are aligned relative to each other both longitudinally and rotationally. In some embodiments, the coupling arrangement is “non-directional” and the sensor assembly can be mated with the electronics assembly without aligning the two rotationally. For example, the sensor assembly construction shown in  FIGS. 39A and 39B  offers such an approach. Separate conductive (e.g., optionally metal) bands  3904  mounted on a core support  3906  connect to sensor electrical contacts  3908  as shown in  FIGS. 39A and 39B . The assembled unit (i.e., the sensor assembly  3910 ), with sharp  3902  in place, is received in the socket of an electronics assembly  4002  to form an on-body device as illustrated in  FIG. 40 . In some embodiments, brush-type connectors  4004  on the circuit board in the electronics assembly  4002  reach up to the individual levels of the conductive bands  3904 . Such a sensor assembly  3910  can be inserted into the socket of the electronics assembly  4002  in any radial/rotational orientation. 
     A “reversed” approach is illustrated in the sensor assembly  4100  of  FIGS. 41A-41C . Here, the circuit board  4102  includes a socket connector  4104  that has an arrangement of stacked conductive elastomeric O-rings  4106  disposed within the inner diameter of the socket connector  4104 . A sensor support  4108  is adapted to hold the electrical contacts  4110  of the sensor  4112  in a corresponding stack facing radially outward. When the sensor support  4108  is inserted into the socket connector  4104 , the conductive elastomeric O-rings  4106  align vertically with the electrical contacts of the sensor as shown in  FIG. 41B  (with the socket connector  4104  not shown so that the conductive elastomeric O-rings  4106  are more clearly visible) and in the cross-sectional view of  FIG. 41C . In some embodiments, the electrical contacts  4110  of the sensor  4112  can be formed by rolling up a sensor with contacts all on the same side or using the oppositely directed folding/rolling approach shown in connection with  FIG. 40 —but oriented vertically. Other approaches may be utilized as well. In any case, the electrical contacts of the sensor subtend less than 360 degrees while the conductive elastomeric O-rings on the circuit board provide a multi-level encircling relationship. As with the approach associated with  FIGS. 39A to 40 , such a sensor assembly  4100  can be inserted into the socket connector  4104  of the electronics assembly  4102  in any radial/rotational orientation. 
     The sensor connections associated with the circuit board  4404  in the embodiment shown in  FIGS. 42 to 44  are arranged in concentric rings. The sensor  4202  includes electrical contacts  4204  held within housing member  4206  and base  4208 . The electrical contacts  4204  include “micro-spring” wireform connectors. These springs provide compliance as well as a discrete top loop. Each electrical contact  4204  is disposed at a different radial distance from the center corresponding to a different concentric conductive track  4304  on a circuit board coupling  4302 . Thus, no matter the rotational orientation of the sensor assembly  4200  relative to the circuit board coupling  4302 , the electrical contacts  4204  of the sensor  4202  align with the correct concentric conductive tracks  4304 . Very fine wire can be used for the springs, thus producing an easily miniaturized system. 
     Turning now to  FIGS. 45A and 45B , another non-directional sensor assembly connection approach that can be employed with a concentric electronics assembly connection is depicted. As illustrated in the isometric top and bottom views of  FIGS. 45A and 45B , a sensor  4504  bent approximately ninety degrees with contacts positioned along different radial paths or arcs, connects with conductive elastomeric contacts  4508  supported by two opposing discs  4502 ,  4506 . Two of the elastomeric contacts  4508  are set on one disc  4506 , and a third, configured to pass through a sensor via, is set on the other disc  4502 . As shown in  FIG. 46A , this sensor assembly  4500  can then be received by a circuit board coupling  4604  which includes concentric tracks for connecting the radially disposed conductive elastomeric contacts  4508  of the sensor assembly  4500  to the circuit board  4606 . The enclosure  4608  snap fits or is otherwise adhered to (e.g., using adhesive/welding) a base supporting the circuit board  4606 . The as-assembled on-body device  4600  is depicted in  FIG. 46B . 
     Turning now to  FIGS. 47A to 47C , an alternative sensor assembly/electronics assembly connection approach is illustrated. As shown, the sensor assembly  4702  includes sensor  4704 , connector support  4706 , and sharp  4708 . Notably, sensor assembly  4702  does not include a separate connector or seal to enclose the sensor&#39;s connectors within the connector support  4706  as in the embodiment depicted in  FIGS. 34A to 34D  (i.e., no seal  3402 ). Instead, a recess  4710  formed directly in the enclosure of the electronics assembly  4712  includes an elastomeric sealing member  4714  (including conductive material coupled to the circuit board and aligned with the electrical contacts of the sensor  4704 ). Thus, when the sensor assembly  4702  is snap fit or otherwise adhered to the electronics assembly  4712  by driving the sensor assembly  4702  into the integrally formed recess  4710  in the electronics assembly  4712 , the on-body device  4714  depicted in  FIG. 47C  is formed. This embodiment provides an integrated connector for the sensor assembly  4702  within the electronics assembly  4712 . 
     On-Body Device Construction Details 
     Certain elements of the on-body device fabrication may apply to any or all of the above electrical connection configurations.  FIGS. 48A-48D  provide top ( FIG. 48A ) and bottom ( FIG. 48B-48D ) construction views of an exemplary on-body device subassembly. A socket  4802  or mount is fit through vias in a printed circuit board  4800  along with other associated components including a processor  4804  (e.g., an ASIC including a communications facility), thermistor/thermocouple  4806 , a battery mount  4808 , etc. Once the circuit board  4800  has been populated with these components as shown in  FIG. 48C , the socket  4802  is adhered to the circuit board  4800  (e.g., using heat stakes). Once a battery  4810  is set in place, the circuit board  4800  as shown in  FIG. 48E  is prepared for incorporation into an on-body device. 
     The circuit board  4800  is ready for an over-mold process or other sealing method. As illustrated in  FIGS. 49A-49D , the circuit board  4800  is first set in the two-piece mold  4902 ,  4904 . With the mold slide  4906  inserted and mold  4902 ,  4904  closed as shown in  FIG. 49B . As depicted in  FIG. 49C , a thermoplastic material is injected into the mold  4902 ,  4904 , encasing the circuit board  4800 . The mold  4902 ,  4904  is opened and the near-final part ejected as shown in  FIG. 49D . 
     Alternatively, the enclosure of the electronics assembly of the on-body device  222  may include elements snap-fit (or welded/adhered) together as illustrated in the assembly view of  FIG. 50A , the as-assembled view of  FIG. 50B , and in cross-sectional perspective view of  FIG. 50C . An enclosure including a top shell  5002  and a mounting base  5004  can be used to sealably enclose and protect the circuit board  4800 . When snap-fit, various interference or snap fit elements (e.g., annular rims  5006 ) may be provided around the entirety of the periphery of the enclosure or as discrete snap-fit connectors (not shown). Notably, such an approach may benefit from additional O-ring sealing elements to avoid fluid intrusion. Alternatively or additionally, adhesive set at the snap junction(s) may be used to ensure good sealing, especially in connection with continuous annular snap-fit features  5006 . As seen in  FIG. 50C , a trough  5008  or other features can be provided to insure that adhesive  5010  that may be squeezed out during assembly is not forced into areas that could interfere with operation or assembly of the on-body device  222 . In some embodiments, when the a top shell  5002  and a mounting base  5004  are fit together with a bead of adhesive  5010  in place as shown, the trough  5008  not only provides space to capture the adhesive  5010  squeezed out but also provides additional surface area for a thicker layer of adhesive  5010  to seal the joint. 
     However constructed, final assembly of the electronics assembly of on-body device  222  involves adhesive patch installation. An exemplary approach is illustrated in  FIGS. 51A-51C . First, a double-sided adhesive patch  5104  has the inner liner  5102  removed. This exposed adhesive is set over the on-body device body  5106  (with the temperature sensor  4806  folded to seat within a complimentary pocket) and adhered with a first window  5108  aligned for temperature sensing and second window  5110  for sensor assembly receipt. As such, it is ready for placement in an applicator assembly upon removal of the outer release liner, or alternatively ready for placement in a container with or without the outer liner in place, depending on the presence or absence of any liner-puller features provided therein. 
     Various other modifications and alterations in the structure and method of operation of the embodiments of the present disclosure will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. Although the present disclosure has been described in connection with certain embodiments, it should be understood that the present disclosure as claimed should not be unduly limited to such embodiments. It is intended that the following claims define the scope of the present disclosure and that structures and methods within the scope of these claims and their equivalents be covered thereby.