Flexible circuit board for continuous analyte monitoring device

Abstract

A flexible circuit board for a continuous analyte monitoring (CAM) device includes a plurality of physically separate circuit board cells, each having circuitry thereon. The flexible circuit board also includes a plurality of flexible interconnects, each connecting one of the physically separate circuit board cells to another of the physically separate circuit board cells. Each of the flexible interconnects is operable to couple power, an electrical signal, or both to the physically separate circuit board cell connected thereto. The flexible circuit board is bendable in multiple directions in three dimensions. As with other aspects, methods of constructing a flexible circuit board for a CAM device are also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This claims the benefit of U.S. Provisional Patent Application No. 63 / 131,273, filed December 28, 2020, the disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0002] The present disclosure relates to flexible circuit boards for continuous analyte monitoring devices. [Background technology]

[0003] Continuous analyte monitoring (CAM), such as continuous glucose monitoring (CGM), has become a routine monitoring practice, particularly for individuals with diabetes. By providing real-time analyte (e.g., glucose) readings, therapeutic interventions can be implemented in a more timely manner, and in the case of CGM, glucose status can be better controlled. The sensor of a CAM device is typically inserted subcutaneously into the user, while the CAM device is attached to the outer surface of the user's skin, such as the abdomen or the back of the upper arm. The CAM device operates continuously by the sensor providing a signal to a wireless transmitter in the CAM device. The signal indicates the user's analyte (e.g., glucose) level. A handheld CAM receiver (e.g., a smartphone) can process the signal received from the CAM device and display the analyte reading. Glucose readings can be provided automatically multiple times throughout the day (e.g., every few minutes or at some other predetermined time interval).

[0004] CAM devices can include flexible circuit boards, which are assemblies of electronic circuits and components (hereinafter referred to as "circuits") fabricated on a flexible substrate. Flexible circuit boards are intended to allow the CAM device to conform to a user's skin surface, ideally while the user moves about. However, the degree of flexibility and / or the directions in which known flexible circuit boards can bend can be limited, thus adversely affecting wearing comfort and the adherence of the CAM device to and on a user's skin surface.

[0005] Therefore, improved flexible circuit boards for CAM devices are desired. Summary of the Invention

[0006] In some embodiments, a flexible circuit board for a continuous analyte monitoring (CAM) device is provided, the flexible circuit board including a plurality of physically separate circuit board cells, each having circuitry thereon. The flexible circuit board also includes a plurality of flexible interconnects, each connecting one of the plurality of physically separate circuit board cells to another of the plurality of physically separate circuit board cells. Each of the plurality of flexible interconnects is operable to couple power, an electrical signal, or both to the physically separate circuit board cell connected thereto. The flexible circuit board is bendable in multiple directions in three dimensions.

[0007] In some embodiments, a method of constructing a flexible circuit board for a continuous analyte monitoring (CAM) device is provided, the method including providing a plurality of physically separate circuit board cells, each having circuitry thereon, and interconnecting each of the plurality of physically separate circuit board cells to another of the plurality of physically separate circuit board cells with a respective flexible interconnect operable to couple power, an electrical signal, or both to each of the plurality of physically separate circuit board cells and to another of the plurality of physically separate circuit board cells.

[0008] Further aspects, features, and advantages of the present disclosure will become readily apparent from the following detailed description and illustrations of several exemplary embodiments and implementations, including the best mode contemplated for carrying out the invention. The present disclosure may enable other different embodiments, and its several details may be modified in various respects, all without departing from the scope of the invention. For example, although the following description relates to CAM and CGM devices, the flexible circuit board described below can be readily adapted to other electronic devices, particularly small, user-wearable electronic devices, that benefit from circuit boards with increased flexibility. The present disclosure is intended to cover all modifications, equivalents, and alternatives within the scope of the appended claims (see further below). [Brief explanation of the drawings]

[0009] The drawings described below are for illustrative purposes and are not necessarily drawn to scale. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not as restrictive. The drawings are not intended to limit the scope of the invention in any way. [Figure 1] 1 shows a side view of a continuous glucose monitoring (CGM) device including a sensor circuit and a wireless communication circuit according to embodiments provided herein. [Figure 2A] 1 illustrates a (top) side view of a flexible circuit board configuration according to embodiments provided herein. [Figure 2B] 1 illustrates a plan view of a flexible circuit board configuration according to embodiments provided herein. [Figure 3] 1 illustrates a perspective view of another flexible circuit board configuration according to embodiments provided herein. [Figure 4A] 1 illustrates a cross-sectional side view of a layer stack of a flexible circuit board component according to embodiments provided herein. [Figure 4B] 1 illustrates a cross-sectional side view of a layer stack of a flexible circuit board component according to embodiments provided herein. [Figure 4C]1 illustrates a cross-sectional side view of a layer stack of a flexible circuit board component according to embodiments provided herein. [Figure 5] 5A and 5B illustrate plan views of a flexible circuit board ground grid according to embodiments provided herein, with FIG. 5A showing an enlarged portion of the ground grid of FIG. 5; [Figure 6A] 1 shows a perspective view of a continuous analyte monitoring (CAM) device having a flexible circuit board in a bent state according to embodiments provided herein. [Figure 6B] 1 shows a perspective view of a continuous analyte monitoring (CAM) device having a flexible circuit board in a bent state about the X-axis dimension, according to embodiments provided herein. [Figure 6C] 1 shows a perspective view of a continuous analyte monitoring (CAM) device having a flexible circuit board in a bent state about the Y-axis dimension, according to embodiments provided herein. [Figure 7] 1 shows a flowchart of a method for constructing a flexible circuit board according to embodiments provided herein. DETAILED DESCRIPTION OF THE INVENTION

[0010] The embodiments described herein provide a continuous analyte monitoring (CAM) device that can be comfortably donned and worn on a user's body (e.g., on the abdomen, upper arm, or other suitable location). The CAM device includes an electronic circuit and assembly of electronic components, which may be in the form of a printed circuit and individual electronic components (hereinafter collectively referred to as "circuit") that perform analyte monitoring. The CAM circuit is fabricated on a highly flexible circuit board. The highly flexible circuit board is advantageously compartmentalized into small, relatively physically independent circuit board cells that are interconnected using flexible interconnects that provide improved flexibility of the CAM device in multiple directions, thus improving the comfort of the CAM device while worn by a user.

[0011] Advantageously, CAM devices constructed using highly flexible circuit boards can be worn on a user's body regardless of the device's orientation, i.e., the omnidirectional flexibility of the CAM device provided by the highly flexible circuit board eliminates the need to follow any particular contours of the skin when positioning and wearing the CAM device relative to the user's body.

[0012] Each circuit board cell has circuitry fabricated thereon. The circuit board cells are interconnected with one another using flexible interconnects. The flexible interconnects are configured to provide electrical signals and power to the interconnected circuit board cells. In some embodiments, the flexible interconnects may also be fabricated with circuitry supported thereon by stiffeners applied to the flexible interconnects, if necessary. In some embodiments, one or more of the circuit board cells and the flexible interconnects may be high density interconnect (HDI) components.

[0013] Each circuit board cell may be constructed with an ultra-thin layer laminate that may include three signal layers. One or more signal layers may have a grid-like ground plane instead of a solid conductor ground plane. The grid-like ground plane further contributes to increased flexibility. In some embodiments, the layer laminate may have a total thickness of only about 6.5 mils (about 0.17 mm). This advantageously results in a highly flexible, ultra-low profile CAM device that may reduce interference with clothing, be more discreet, and improve overall wearing comfort throughout a user's range of motion.

[0014] According to one or more embodiments, provided herein are highly flexible circuit boards and methods for their construction, as well as devices and systems including such circuit boards, as described in more detail below in connection with FIGS. 1-7.

[0015] FIG. 1 illustrates a wearable continuous glucose monitoring (CGM) device 100, an example of a CAM device, according to one or more embodiments. As shown, the CGM device 100 may be attached (via an adhesive) to a user's skin 102. CGM devices, methods, and systems typically generate an electrochemical glucose signal continuously during operation and perform glucose measurements / estimations based on the generated signal, typically every few minutes. That is, the CGM device 100 is configured to continuously monitor and provide periodic glucose readings (e.g., every 5 minutes or other suitable time intervals). The CGM device 100 may include a housing 104 that may enclose a sensor circuit and a wireless communication circuit (neither of which are shown in FIG. 1 ). The housing 104 may include a flexible base 106 and an adhesive layer 108, which may be, for example, double-sided tape or a pressure-sensitive adhesive. One side of the adhesive layer 108 may adhere to the flexible base 106, while the other side of the adhesive layer 108 may adhere to the user's skin surface 102S. Although shown as being partially dome shaped, the housing 104 may be any other suitable shape.

[0016] The sensor circuitry of the CGM device 100 may include a sensor 110, a portion of which is shown inserted through the user's skin 102. The sensor 110 may extend from the sensor circuitry through the flexible base 106 and may be configured to be at least partially located in interstitial fluid within the user's subcutaneous region. The sensor 110 may be or include an analyte sensor or analyte sensor portion, such as at or near a sensor tip 110T. The sensor 110 may be inserted using an insertion device (not shown) having a sharp needle or "introducer" that pierces the skin to introduce the sensor 110 into the user's subcutaneous region.

[0017] The wireless communication circuitry of the CGM device 100 may include sensor circuitry and one or more electronic components that communicate with one or more external devices (e.g., a handheld CGM receiver or other portable device such as a smartphone running a suitable CGM application software program) to provide glucose measurement signals and / or measurement results.

[0018] 2A and 2B illustrate a highly flexible circuit board configuration 200 that can be fabricated to include, for example, sensor circuitry and wireless communication circuitry for CGM 100, according to one or more embodiments. Alternatively, other circuits may be fabricated thereon. Flexible circuit board configuration 200 can include circuit board cells 202, 204, and 206 and flexible interconnects 203 and 205. Circuit board cell 202 is interconnected to circuit board cell 204 via flexible interconnect 203, and circuit board cell 204 is interconnected to circuit board cell 206 via flexible interconnect 205. Flexible interconnect 203 is configured to connect electrical signals and power between circuit board cell 202 and circuit board cell 204, and flexible interconnect 205 is configured to connect electrical signals and power between circuit board cell 204 and circuit board cell 206. As shown, circuit board cells 202, 204, and 206 and flexible interconnects 203 and 205 are not limited to any particular size or any particular shape. In other embodiments, flexible circuit board configuration 200 can have other numbers of circuit board cells and flexible interconnects.

[0019] Flexible interconnects 203 and 205 are fixedly and / or permanently attached (in any suitable manner) to and / or integrally formed with circuit board cells 202, 204, and 206, respectively, during the flexible circuit board manufacturing process. Flexible interconnects 203 and 205 are not detachable connectors configured to be removable and reconnectable as are commonly used to connect printed circuit boards in larger electronic devices.

[0020] In some embodiments, a flexible interconnect, such as, for example, flexible interconnect 203, may have circuitry 207 fabricated thereon, and circuitry 207 may be supported by stiffeners 208 applied to flexible interconnect 203. Stiffeners 208 may be applied to the side of flexible interconnect 203 opposite the side on which circuitry 207 is fabricated.

[0021] Materials and layer stacks that may be used to construct one or more of the circuit board cells 202, 204, and 206 and / or flexible interconnects 203 and 205 are described below in connection with Figures 4A-4C.

[0022] 3 illustrates another highly flexible circuit board configuration 300 that can be fabricated to include, for example, sensor circuitry and wireless communication circuitry for CGM 100, according to one or more embodiments. Alternatively, other circuits may be fabricated thereon. Flexible circuit board 300 can include circuit board cells 302, 304, 306, and 308 and flexible interconnects 303, 305, 307, and 309. As shown, circuit board cell 302 is interconnected to circuit board cell 304 via flexible interconnect 303, circuit board cell 304 is interconnected to circuit board cell 306 via flexible interconnect 305, circuit board cell 306 is interconnected to circuit board cell 308 via flexible interconnect 307, and circuit board cell 308 is interconnected to circuit board cell 302 via flexible interconnect 309. Flexible interconnect 303 is configured to connect electrical signals and power between circuit board cell 302 and circuit board cell 304, flexible interconnect 305 is configured to connect electrical signals and power between circuit board cell 304 and circuit board cell 306, flexible interconnect 307 is configured to connect electrical signals and power between circuit board cell 306 and circuit board cell 308, and flexible interconnect 309 is configured to connect electrical signals and power between circuit board cell 308 and circuit board cell 302.

[0023] Flexible interconnects 303, 305, 307, and 309 are fixedly and / or permanently attached (in any suitable manner) to and / or integrally formed with circuit board cells 302, 304, 306, and 308, respectively, during the flexible circuit board manufacturing process. Flexible interconnects 303, 305, 307, and 309 are not detachable connectors configured to be removable and reconnectable such as those commonly used to connect printed circuit boards in larger electronic devices.

[0024] In some embodiments, the circuitry fabricated on the circuit board cells and flexible interconnects may be configured to perform CAM (or particularly CGM) and may be partitioned as follows: circuit board cell 302 may have sensor circuitry fabricated thereon, circuit board cell 304 may have interconnect circuitry fabricated thereon, circuit board cell 306 may have power circuitry and a power source fabricated thereon, and circuit board cell 308 may have wireless communication circuitry fabricated thereon. Other suitable circuit partitioning may also be implemented.

[0025] In some embodiments, any one or more of flexible interconnects 303, 305, 307, and / or 309 may have circuitry fabricated thereon, which may be supported by stiffeners applied to the flexible interconnects, as shown in Figures 2A and 2B for flexible interconnect 203.

[0026] Although the flexible circuit board configuration 300 is shown constructed and arranged to form a generally oval shape, other suitable shapes may be formed using the circuit board cells and flexible interconnects, thus advantageously allowing for customized use in, for example, unique or oddly shaped devices.

[0027] In other embodiments, the flexible circuit board configuration 300 may have other numbers of circuit board cells and flexible interconnects.

[0028] Materials and layer stacks that may be used to construct one or more of the circuit board cells 302, 304, 306, and 308 and / or flexible interconnects 303, 305, 307, and 309 are described below in connection with Figures 4A-4C.

[0029] The spacing between circuit board cells 202 and 204 and between circuit board cells 302, 304, 306, and 308 advantageously provides significantly increased flexibility of the circuit board in virtually any direction within a two-dimensional plane, as described in more detail below in connection with Figures 6A-6C.

[0030] Additionally, the cellular circuit board configuration may require less material usage, which advantageously reduces flexible circuit board manufacturing costs.

[0031] 4A, 4B, and 4C show layer stacks 400A, 400B, and 400C that can be used to construct circuit board cells and / or flexible interconnects according to one or more embodiments. The density of the circuitry to be fabricated on the circuit board and / or flexible interconnect and / or the number of signal lines required between circuit board cells may determine which of the layer stacks 400A, 400B, and 400C are used to construct the circuit board cells and / or flexible interconnects.

[0032] 4A illustrates the construction of circuit board cells 402 and 404 and flexible interconnect 403 using layer stack 400A. Circuit board cell 402 constructed using layer stack 400A can include cover layers 412 and 419, three signal layers 413, 416, and 418, a rigid layer 414, an adhesive layer 415, and a polyimide core 417 arranged as shown. Flexible interconnect 403 constructed using layer stack 400A can include cover layers 420 and 419, two signal layers 416 and 418, and a polyimide core 417 arranged as shown. Additionally, circuit board cell 404 constructed using layer stack 400A can include cover layers 422 and 419, three signal layers 423, 416, and 418, a rigid layer 424, an adhesive layer 425, and a polyimide core 417 arranged as shown. Note that flexible interconnect 403 is integrally formed with portions of circuit board cells 402 and 404. Layer stack 400A can be used to construct circuit board cells that may have high density circuitry fabricated thereon. Circuit board cells constructed using layer stack 400A can be considered rigid-flex circuit board cells.

[0033] 4B illustrates the construction of a circuit board cell 406 using layer stack 400B. Circuit board cell 406 constructed using layer stack 400B may include cover layers 432 and 439, three signal layers 433, 435, and 438, two polyimide cores 434 and 437, and adhesive layer 436 arranged as shown. Layer stack 400B may be used to construct circuit board cells that may not have high-density circuitry fabricated thereon. Circuit board cells constructed using layer stack 400B may be considered flexible circuit board cells.

[0034] 4C illustrates the construction of a circuit board cell and / or flexible interconnect 40X using layer stack 400C. The circuit board cell / flexible interconnect 40X constructed using layer stack 400C may include a cover layer 442 arranged as shown, three signal layers 443, 445, and 448, two polyimide cores 444 and 447, an adhesive layer 446, cover layer portions 449A and 449B, an appropriately positioned adhesive layer 450, and an appropriately positioned stiffener layer 452. The adhesive layer 450 and stiffener layer 452 may be appropriately positioned anywhere along the bottom of layer stack 400C to provide support for the circuitry created above, which may be dense. Thus, layer stack 400C can be used to construct circuit board cells and / or flexible interconnects that may have portions with high density circuitry fabricated thereon, while the remainder of the circuit board cell or flexible interconnect does not have high density circuitry (if any) fabricated thereon.

[0035] Any suitable material may be used to construct the layer stack 400A, 400B, and 400C. For example, the cover layer may be a polyimide material such as Kapton®. The stiffness and stiffener layers may be made using FR4, a rigid glass-reinforced epoxy resin laminate. Other possible materials may include fiber-reinforced laminates, UV-cured resins, and thermoplastics. Kapton® may be used to form the polyimide core. Any suitable acrylic adhesive may be used to form the adhesive layers. Additionally, the signal layers may be formed using copper, although other suitable conductive materials may be used.

[0036] In some embodiments, the circuit board cell 406 can have an overall height or thickness in the range of 6.5-7.0 mils (0.165-0.18 mm). The use of stiffening or stiffening layers can add an additional 6.5-7.0 mils (0.165-0.18 mm) to the overall or total thickness of the circuit board cell. In some embodiments, the overall height of a CAM device constructed using the circuit board cells and flexible interconnects described herein and enclosed within a housing can be approximately 2.5 mm (+ / - 5%) (e.g., measured perpendicular to the surface of the skin of a user wearing the CAM device).

[0037] FIG. 5 illustrates a portion 500 of a signal layer 502 of a circuit board cell having a lattice ground plane 504 according to one or more embodiments. The lattice ground plane 504 may extend over areas not occupied by signal lines 506 and may be present on each signal layer of the circuit board cell. The lattice ground plane 504 may be copper, although other suitable conductive materials may alternatively be used. The lattice ground plane 504 has a mesh or net-like structure, as better shown in the enlarged view of FIG. 5A . The openings in the lattice ground plane 504 may form a generally square or rectangular shape. Other suitable shapes may be possible. The lattice ground plane 504 increases the flexibility of the circuit board cell compared to a traditional solid conductor ground plane while maintaining the RF (radio frequency) signal quality traditionally provided by a solid conductor ground plane.

[0038] The grid ground plane 504 may be used for any one or more signal layers within layer stack 400A-C (FIGS. 4A-4C), and within any one or more circuit board cells and flexible interconnects of flexible circuit board configuration 200 (FIG. 2), and within any one or more circuit board cells and flexible interconnects of flexible circuit board configuration 300 (FIG. 3).

[0039] 6A, 6B, and 6C illustrate an unflexed state and two flexed states, respectively, of a CAM device 602 constructed using a flexible circuit board (e.g., having flexible circuit board configuration 200 or 300) according to one or more embodiments. In particular, FIG. 6A illustrates CAM device 602 in unflexed state 600A. FIG. 6B illustrates CAM device 602 in flexed state 600B, in which CAM device 602 is flexed laterally along the X-axis dimension. FIG. 6C illustrates CAM device 602 in flexed state 600C, in which CAM device 602 is flexed longitudinally along the Y-axis dimension. Advantageously, CAM device 600 may be flexible in directions other than those illustrated. For example, CAM device 600 may be flexible in any direction in three dimensions (e.g., the XYZ plane as shown) and have varying degrees of simultaneous lateral and longitudinal flexion in both the X-axis and Y-axis dimensions.

[0040] FIG. 7 illustrates a method 700 for constructing a flexible circuit board for a CAM device according to one or more embodiments. At process block 702, method 700 may provide a plurality of physically separate circuit board cells, each having circuitry thereon. For example, the physically separate circuit board cells may be, for example, circuit board cells 202, 204, and / or 206 of FIGS. 2A and 2B or circuit board cells 302, 304, 306, and / or 308 of FIG. 3. The circuitry on the circuit board cells may include, for example, CAM sensor circuitry, wireless communication circuitry, power supply circuitry, and / or interconnect circuitry, partitioned as shown in FIG. 3.

[0041] At process block 704, method 700 may include interconnecting each of the plurality of physically separate circuit board cells to another of the plurality of physically separate circuit board cells with a respective flexible interconnect operable to couple power, an electrical signal, or both to the two interconnected circuit board cells. For example, as shown in FIGS. 2A and 2B and 3, each flexible interconnect may be any one of flexible interconnects 203, 205, 303, 305, 307, and / or 309. Note that the flexible interconnects are not detachable connectors configured to be detachable and reconnectable; instead, the flexible interconnects are fixedly and / or permanently attached to and / or integrally formed with the circuit board cells to form an integrated, highly flexible circuit board configuration.

[0042] It should be noted that in some embodiments, method 700 may include a process block (not shown) of enclosing a plurality of physically separate circuit board cells, each interconnected to another of the plurality of physically separate circuit board cells using flexible interconnects, within a housing configured to be worn on the skin surface of a user.

[0043] It should also be noted that in some embodiments, method 700 may include a process block (not shown) of providing a grid-like ground plane to at least one of the physically separate circuit board cells, and / or a process block (not shown) of constructing at least one of the physically separate circuit board cells according to one of layer stacks 400A-C (FIGS. 4A-4C).

[0044] While the disclosure is susceptible to various modifications and alternative forms, specific method and apparatus embodiments have been shown by way of example in the drawings and are herein described in detail. It will be understood, however, that the specific methods and apparatus disclosed herein are not intended to limit the scope of the disclosure or the claims.

Claims

1. 1. A flexible circuit board for a continuous analyte monitoring (CAM) device, comprising: a plurality of physically distinct circuit board cells each having circuitry thereon; a plurality of flexible interconnects, each connecting one of the plurality of physically separate circuit board cells to another of the plurality of physically separate circuit board cells, each of the plurality of flexible interconnects operable to couple power, electrical signals, or both to the physically separate circuit board cell connected thereto; a plurality of flexible interconnects are used to allow the plurality of physically separate circuit board cells to bend independently in multiple directions in three dimensions; a flexible circuit board communicatively coupled to the at least one subcutaneous analyte sensor of the CAM device such that an analyte signal indicative of a user's analyte level is received from the at least one subcutaneous analyte sensor by one of the plurality of physically separate circuit board cells.

2. 10. The flexible circuit board of claim 1, wherein at least one of the plurality of physically separate circuit board cells comprises three signal layers, two of the three signal layers being integrally formed with one of the plurality of flexible interconnects.

3. The flexible circuit board of claim 1 , wherein at least one of the plurality of physically distinct circuit board cells comprises a grid-like ground plane.

4. 10. The flexible circuit board of claim 1, wherein one of the plurality of flexible interconnects comprises a circuit fabricated thereon and a stiffener applied thereto to support the circuit.

5. The flexible circuit board of claim 1 , wherein one of the plurality of physically separate circuit board cells comprises a CAM sensor circuit associated with the at least one subcutaneous analyte sensor.

6. The flexible circuit board of claim 1 , wherein one of the plurality of physically separate circuit board cells comprises wireless communication circuitry.

7. The flexible circuit board of claim 1 , wherein one of the plurality of physically separate circuit board cells comprises a power circuit and a power source.

8. The flexible circuit board of claim 1 , wherein one of the plurality of physically separate circuit board cells comprises an interconnect circuit.

9. The flexible circuit board of claim 1 , wherein the CAM device is a continuous glucose monitoring device.

10. 1. A continuous analyte monitoring (CAM) device comprising: The flexible circuit board according to claim 1; a housing configured to be worn on the skin surface of the user, the housing enclosing the flexible circuit board of claim 1; A continuous analyte monitoring (CAM) device, wherein the CAM device has a height of about 2.5 mm measured from the skin surface.

11. 1. A method of constructing a flexible circuit board for a continuous analyte monitoring (CAM) device, comprising: providing a plurality of physically separate circuit board cells each having circuitry thereon; interconnecting each of the plurality of physically separate circuit board cells to another of the plurality of physically separate circuit board cells with a respective flexible interconnect operable to couple power, an electrical signal, or both to said each of the plurality of physically separate circuit board cells and to said another of the plurality of physically separate circuit board cells; a plurality of flexible interconnects are used to allow the plurality of physically separate circuit board cells to bend independently in multiple directions in three dimensions; The method, wherein the flexible circuit board is communicatively coupled to at least one subcutaneous analyte sensor of the CAM device such that an analyte signal indicative of a user's analyte level is received from the at least one subcutaneous analyte sensor by one of the plurality of physically separate circuit board cells.

12. 12. The method of claim 11, further comprising enclosing the plurality of physically separate circuit board cells, each interconnected to another of the plurality of physically separate circuit board cells with the respective flexible interconnect, within a housing configured to be worn on a skin surface of a user.

13. 12. The method of claim 11, further comprising constructing at least one of the plurality of physically separate circuit board cells to include three signal layers, two of the three signal layers being integrally formed with one of the respective flexible interconnects.

14. The method of claim 11 , further comprising providing a grid-like ground plane to at least one of the plurality of physically separate circuit board cells.

15. The method of claim 11 , further comprising creating a circuit on one of the respective flexible interconnects and applying a stiffener to support the circuit.

16. 12. The method of claim 11, further comprising fabricating a CAM sensor circuit in one of the plurality of physically separate circuit board cells, the CAM sensor circuit being associated with the at least one subcutaneous analyte sensor.

17. The method of claim 11 , further comprising fabricating wireless communication circuitry in one of the plurality of physically separate circuit board cells.

18. The method of claim 11 , further comprising fabricating a power supply circuit and a power source in one of the plurality of physically separate circuit board cells.

19. The method of claim 11 , further comprising fabricating interconnect circuitry in one of the plurality of physically separate circuit board cells.

20. 12. The method of claim 11, wherein the CAM device is a continuous glucose monitoring device having a height of about 2.5 mm.

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