Flexible circuit boards for continuous analyte monitoring devices

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 interconnections each connecting one of the physically separate circuit board cells to another of the physically separate circuit board cells. Each one of the flexible interconnections is operable to couple power, electrical signals, or both to the physically separate circuit board cells connected thereto. The flexible circuit board is bendable in multiple directions in three dimensions. Methods of constructing flexible circuit boards for CAM devices are also provided, as are other aspects.

Description

[Technical Field]

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 131273, filed on December 28, 2020, the entire contents of which are incorporated herein by reference for all purposes.

[0003] The present invention relates to a flexible circuit board for a continuous analyte monitoring device. [Previous Technology]

[0004] Continuous analyte monitoring (CAM), such as continuous glucose monitoring (CGM), has become a routine monitoring procedure, especially for patients with diabetes. By providing real-time analyte (e.g., blood glucose) readings, treatment actions can be taken more promptly, and in the case of CGM, blood glucose levels can be better controlled. The sensors of a CAM device are typically inserted subcutaneously, while the CAM device itself adheres to an external surface of the user's skin, such as on the abdomen or the back of the upper arm. The CAM device operates continuously, with the sensors providing signals to the CAM device's wireless transmitter. These signals indicate the user's analyte (e.g., blood glucose) level. A handheld CAM receiver (e.g., a smartphone) processes the signals received from the CAM device and displays the analyte readings. Analyte readings can be provided automatically multiple times throughout the day (e.g., every few minutes or at other preset time intervals).

[0005] The CAM device may include a flexible circuit board, which is a kit of electronic circuits and components (hereinafter referred to as "circuit") manufactured on a flexible substrate. The flexible circuit board is designed to allow the CAM device to conform to the user's skin surface, and ideally, to conform to the skin surface as the user moves. However, it is known that the degree of flexibility and / or direction of the flexible circuit board may be limited, which may be detrimental to the wearing comfort and adhesion of the CAM device on the user's skin surface.

[0006] Therefore, there is a need to improve the flexible circuit board used in CAM devices. [Summary of the Invention]

[0007] In some embodiments, a flexible circuit board is provided for a continuous analyte monitoring (CAM) device, comprising a plurality of physically separated circuit board units, each unit having a circuit system thereon. The flexible circuit board also includes a plurality of flexible interconnects, each flexible interconnect connecting one of the plurality of physically separated circuit board units to another of the plurality of physically separated circuit board units. Each of the plurality of flexible interconnects is operable to couple power, electrical signals, or both to the physically separated circuit board unit to which it is connected. The flexible circuit board can be bent in multiple directions in three dimensions.

[0008] In some embodiments, a method is provided for constructing a flexible circuit board for a continuous analyte monitoring (CAM) device. The method includes providing a plurality of physically separate circuit board units, each unit having a circuit system thereon, and interconnecting each of the plurality of physically separate circuit board units to another of the plurality of physically separate circuit board units using individual flexible interconnects, the individual flexible interconnects being operable to couple power, electrical signals, or both to the one and the other of the plurality of physically separate circuit board units.

[0009] Other aspects, features, and advantages of the invention will become apparent from the following detailed description and illustration of various exemplary embodiments and implementations, including the best mode contemplated for carrying out the invention. The invention is also applicable to other and different embodiments, and certain details may be modified in different aspects 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 applied to other electronic devices, particularly small wearable electronic devices, which will benefit from a circuit board with improved flexibility. The invention is intended to cover all modifications, equivalents, and alternatives (see below) that fall within the scope of the appended claims.

Implementation Method

[0018] The embodiments described herein provide a continuous analyte monitoring (CAM) device that can be comfortably worn and attached to a user's body (e.g., abdomen, upper arm, or other suitable location). The CAM device includes a suite of electronic circuits and components in the form of printed circuits and individual electronic components (collectively referred to as the "circuit system") capable of performing analyte monitoring. The CAM circuit system is fabricated on a highly flexible circuit board. The highly flexible circuit board is advantageously partitioned into small, relatively physically independent circuit board units, which are interconnected with flexible interconnects to provide improved flexibility of the CAM device in multiple directions, thereby improving the comfort of the CAM device when worn by the user.

[0019] Advantageously, the CAM device constructed from a highly flexible circuit board can be attached to the user's body regardless of the orientation of the device. That is, the omnidirectional flexibility of the CAM device provided by the highly flexible circuit board negates the necessity of following any particular contour of the skin when positioning and attaching the CAM device to the user's body.

[0020] Each circuit board unit has a circuit system fabricated thereon. The circuit board units are interconnected with each other by flexible interconnects. The flexible interconnects are used to provide electrical signals and power to the interconnected circuit board units. In some embodiments, the flexible interconnects may also have a circuit system fabricated thereon and be supported by reinforcements applied to the flexible interconnects when necessary. In some embodiments, one or more circuit board units and flexible interconnects may be high-density interconnect (HDI) components.

[0021] Each circuit board unit can be constructed with an ultra-thin layer stack, which may include three signal layers. One or more signal layers may have a lattice ground plane instead of a solid conductor ground plane. The lattice ground plane helps to further enhance flexibility. In some embodiments, the layer stack may have a total thickness of only about 6.5 mils (about 0.17 mm). This advantageously results in a highly flexible and ultra-low profile CAM device that reduces interference with clothing, allows for greater discretion, and improves overall wearing comfort through a range of user movements.

[0022] According to one or more embodiments, this document provides highly flexible circuit boards and methods of constructing the same, as well as apparatus and systems including such circuit boards, which will be explained in more detail below in conjunction with Figures 1 through 7.

[0023] Figure 1 illustrates a wearable continuous glucose monitoring (CGM) device 100 according to one or more embodiments, which is an example of a CAM device. As shown, the CGM device 100 can be attached (via adhesive) to a user's skin 102. CGM devices, systems, and methods typically generate electrochemical glucose signals continuously during operation and typically perform glucose measurement / estimation based on the generated signals every few minutes. That is, the CGM device 100 is used 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 encapsulates a sensor circuitry and a wireless communication circuitry (neither of which is shown in Figure 1). The housing 104 may include a flexible base 106 and an adhesive layer 108, which may be, for example, double-sided tape or pressure-sensitive adhesive. One side of the adhesive layer 108 can be adhered to the flexible base 106, while the other side of the adhesive layer 108 can be adhered to the user's skin surface 102S. Although shown as a partially dome shape, the housing 104 can be other suitable shapes.

[0024] 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 a flexible base 106 and may be used to at least partially locate in the interstitial fluid of the user's subcutaneous region. The sensor 110 may be attached to or may include an analyte sensor or a portion thereof, such as at or near the sensor tip 110T. The sensor 110 may be inserted into an insertion device (not shown) having a sharpening needle or "introducer" that penetrates the skin to introduce the sensor 110 into the user's subcutaneous region.

[0025] The wireless communication circuitry of the CGM device 100 may include one or more electronic components that communicate with the sensor circuitry and one or more external devices (e.g., a handheld CGM receiver or other portable device, such as a smartphone running CGM application software) to provide blood glucose measurement signals and / or measurement results.

[0026] Figures 2A and 2B illustrate a highly flexible circuit board configuration 200 according to one or more embodiments, which can be manufactured to include, for example, a sensor circuit system and a wireless communication circuit system of CGM 100. Other circuit systems can be manufactured thereon. The flexible circuit board configuration 200 may include circuit board units 202, 204, and 206 and flexible interconnects 203 and 205. Circuit board unit 202 is interconnected to circuit board unit 204 via flexible interconnect 203, and circuit board unit 204 is interconnected to circuit board unit 206 via flexible interconnect 205. Flexible interconnect 203 is used to connect electrical signals and power between circuit board units 202 and 204, while flexible interconnect 205 is used to connect electrical signals and power between circuit board units 204 and 206. As shown, circuit board units 202, 204, and 206 and flexible interconnects 203 and 205 are not limited to any particular size or any particular shape. In other embodiments, the flexible circuit board configuration 200 may have other numbers of circuit board units and flexible interconnects.

[0027] During the flexible circuit board manufacturing process, each of the flexible interconnects 203 and 205 is fixedly and / or permanently attached to (in any suitable manner) and / or integrated with circuit board units 202, 204, and 206. Flexible interconnects 203 and 205 are non-removable connectors configured to be detachable and reconnectable, and are typically used to connect printed circuit boards in large electronic devices.

[0028] In some embodiments, the flexible interconnect (such as, for example, flexible interconnect 203) may have a circuit system 207 fabricated thereon, which may be supported by a reinforcement 208 applied to the flexible interconnect 203. The reinforcement 208 may be applied to one side of the flexible interconnect 203, opposite to the side on which the circuit system 207 is fabricated.

[0029] The following description, in conjunction with Figures 4A to 4C, describes the materials and layer stacks that can be used to construct one or more of the circuit board units 202, 204, and 206 and / or flexible interconnects 203 and 205.

[0030] Figure 3 illustrates another highly flexible circuit board configuration 300 according to one or more embodiments, which can be manufactured to include, for example, a sensor circuit system and a wireless communication circuit system of CGM 100. Other circuit systems can be manufactured thereon. The flexible circuit board 300 may include circuit board units 302, 304, 306, and 308 and flexible interconnects 303, 305, 307, and 309. As shown, circuit board unit 302 is interconnected to circuit board unit 304 through flexible interconnect 303, circuit board unit 304 is interconnected to circuit board unit 306 through flexible interconnect 305, circuit board unit 306 is interconnected to circuit board unit 308 through flexible interconnect 307, and circuit board unit 308 is interconnected to circuit board unit 302 through flexible interconnect 309. Flexible interconnect 303 is used to connect the electrical signals and power between circuit board units 302 and 304, flexible interconnect 305 is used to connect the electrical signals and power between circuit board units 304 and 306, flexible interconnect 307 is used to connect the electrical signals and power between circuit board units 306 and 308, and flexible interconnect 309 is used to connect the electrical signals and power between circuit board units 308 and 302.

[0031] During the flexible circuit board manufacturing process, flexible interconnects 303, 305, 307, and 309 are each fixedly and / or permanently attached to (in any suitable manner) circuit board units 302, 304, 306, and 308 and / or integrated therewith. Flexible interconnects 303, 305, 307, and 309 are non-removable connectors configured to be detachable and reconnectable, and are typically used to connect printed circuit boards in large electronic devices.

[0032] In some embodiments, the circuitry fabricated on the circuit board units and flexible interconnects can be used to perform CAM (or more specifically CGM) and can be partitioned as follows: circuit board unit 302 may have a sensor circuitry fabricated thereon, circuit board unit 304 may have an interconnect circuitry fabricated thereon, circuit board unit 306 may have a power circuitry and power supply fabricated thereon, and circuit board unit 308 may have a wireless communication circuitry fabricated thereon. Other suitable circuitry partitioning may also be implemented.

[0033] In some embodiments, any one or more of the flexible interconnects 303, 305, 307 and / or 309 may have a circuit system manufactured thereon, which may be supported by reinforcements applied to the flexible interconnects, as shown in Figures 2A and 2B for the flexible interconnect 203.

[0034] Although the flexible circuit board configuration 300 is shown as configured and set to form a general elliptical shape, other suitable shapes can be formed by the circuit board units and flexible interconnects, thus advantageously allowing for customization in devices with unique or odd shapes, for example.

[0035] In other embodiments, the flexible circuit board configuration 300 may have other numbers of circuit board units and flexible interconnects.

[0036] The following description, in conjunction with Figures 4A to 4C, describes the materials and layer stacks that can be used to construct one or more of the circuit board units 302, 304, 306, and 308 and / or flexible interconnects 303, 305, 307, and 309.

[0037] The spacing between circuit board units 202 and 204 and between circuit board units 302, 304, 306 and 308 advantageously provides significantly improved circuit board flexibility in almost any direction in a two-dimensional plane, as described below in conjunction with Figures 6A to 6C.

[0038] In addition, the cellular circuit board configuration can reduce the use of materials, which helps to reduce the manufacturing cost of flexible circuit boards.

[0039] Figures 4A, 4B, and 4C illustrate layer stacks 400A, 400B, and 400C according to one or more embodiments, which can be used to construct circuit board units and / or flexible interconnects. The density of the circuit system fabricated on the circuit board and / or flexible interconnects and / or the number of signal lines required between circuit board units can determine which layer of layer stacks 400A, 400B, and 400C should be used to construct the circuit board unit and / or flexible interconnect.

[0040] Figure 4A illustrates the construction of circuit board units 402 and 404 using a layer stack 400A and a flexible interconnect 403. Circuit board unit 402 constructed using layer stack 400A may 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 configured as shown. Flexible interconnect 403 constructed using layer stack 400A may include cover layers 420 and 419; two signal layers 416 and 418; and a polyimide core 417 configured as shown. Circuit board unit 404 constructed using layer stack 400A may 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 configured as shown. Note that the flexible interconnect 403 is partially integrated with the circuit board units 402 and 404. The layer stack 400A can be used to construct the circuit board unit on which a dense circuit system can be fabricated. The circuit board unit constructed from the layer stack 400A can be regarded as a rigid-flexible circuit board unit.

[0041] Figure 4B illustrates the construction of a circuit board unit 406 using a layer stack 400B. The circuit board unit 406 constructed using the layer stack 400B may include cover layers 432 and 439; three signal layers 433, 435, and 438; two polyimide cores 434 and 437; and an adhesive layer 436 configured as shown. The layer stack 400B can be used to construct circuit board units that may not have a dense circuit system fabricated thereon. A circuit board unit constructed using the layer stack 400B can be considered a flexible circuit board unit.

[0042] Figure 4C illustrates the construction of a circuit board unit and / or flexible interconnect 40X using a layer stack 400C. The circuit board unit / flexible interconnect 40X constructed using the layer stack 400C may include a cover layer 442; three signal layers 443, 445, and 448; two polyimide cores 444 and 447; an adhesive layer 446; cover layer portions 449A and 449B; a suitably positioned adhesive layer 450; and a suitably positioned reinforcing layer 452 configured as shown. The adhesive layer 450 and the reinforcing layer 452 may be suitably positioned at any location along the bottom of the layer stack 400C to provide support for a dense circuit system manufactured thereon. Therefore, the layer stack 400C can be used to construct circuit board units and / or flexible interconnects, a portion of which may have a dense circuit system fabricated thereon, while the remainder of which may not have a dense circuit system fabricated thereon (if any).

[0043] Any suitable material may be used to construct the 400A, 400B, and 400C layer stacks. For example, the capping layer may be a polyimide material, such as, for example, Kapton®. The rigid and reinforcing layers may be made of FR4, which is 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 bonding layer. The signal layer may be formed using copper, although other suitable conductive materials may be used.

[0044] In some embodiments, the circuit board unit 406 may have a total height or thickness ranging from 6.5 to 7.0 mils (0.165 to 0.18 mm). An additional 6.5 to 7.0 mils (0.165 to 0.18 mm) may be added to the total height or thickness of the circuit board unit using a rigid layer or reinforcing layer. In some embodiments, the total height of the CAM device constructed from the circuit board unit and flexible interconnects described herein and enclosed in a housing may be approximately 2.5 mm (+ / - 5%) (e.g., measured vertically from the surface of the user's skin to which the CAM device is attached).

[0045] Figure 5 illustrates a portion 500 of a signal layer 502 of a circuit board unit having a grid-like ground plane 504 according to one or more embodiments. The grid-like ground plane 504 may extend over areas not occupied by signal lines 506 and may be on various signal layers of the circuit board unit. The grid-like ground plane 504 may be made of copper, but other suitable conductor materials may also be used. The grid-like ground plane 504 has a grid or mesh structure, as better shown in the enlarged view of Figure 5A. The openings in the grid-like ground plane 504 may typically be square or rectangular in shape. Other suitable shapes are also possible. Compared to conventional solid conductor ground planes, the grid-like ground plane 504 improves the flexibility of the circuit board unit while maintaining the quality of RF (radio frequency) signals conventionally provided by solid conductor ground planes.

[0046] The grid-like ground plane 504 can be used for any one or more signal layers in the layer stack 400A~C (Figures 4A to 4C), any one or more circuit board units and flexible interconnects in the flexible circuit board configuration 200 (Figure 2), and any one or more circuit board units and flexible interconnects in the flexible circuit board configuration 300 (Figure 3).

[0047] Figures 6A, 6B, and 6C respectively illustrate a non-bent state and two bent states of a CAM device 602 constructed using a flexible circuit board (having, for example, flexible circuit board configuration 200 or 300) according to one or more embodiments. Specifically, Figure 6A illustrates the CAM device 602 in a non-bent state 600A. Figure 6B illustrates the CAM device 602 in a bent state 600B, wherein the CAM device 602 is laterally bent in the direction along the X-axis dimension. Figure 6C illustrates the CAM device 602 in a bent state 600C, wherein the CAM device 602 is longitudinally bent in the direction along the Y-axis dimension. Advantageously, the CAM device 600 can be flexible in directions other than those shown. For example, the CAM device 600 can be flexible in any direction in three dimensions (e.g., the XYZ plane shown), bending laterally and longitudinally with varying degrees in both the X and Y-axis dimensions.

[0048] Figure 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 units, each unit having a circuit system thereon. For example, the physically separate circuit board units may be, for example, circuit board units 202, 204, and / or 206 of Figures 2A to 2B, or circuit board units 302, 304, 306, and / or 308 of Figure 3. The circuit system on the circuit board unit may include, for example, CAM sensor circuit systems, wireless communication circuit systems, power circuit systems, and / or interconnect circuit systems, as shown in Figure 3.

[0049] At process block 704, method 700 may include interconnecting one of a plurality of physically separate circuit board units to another of a plurality of physically separate circuit board units using individual flexible interconnects, wherein the individual flexible interconnects are operable to couple power, electrical signals, or both to the two interconnected circuit board units. For example, as shown in Figures 2A to 2B and Figure 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 configured as removable and reconnectable detachable connectors, but are fixedly and / or permanently attached to and / or integrated with the circuit board unit to form an integrated, highly flexible circuit board configuration.

[0050] Note that in some embodiments, method 700 may include process blocks (not shown) that encapsulate a plurality of physically separate circuit board units within a housing for attachment to the surface of a user’s skin, wherein each circuit board unit is interconnected to another of the plurality of physically separate circuit board units using flexible interconnects.

[0051] It should also be noted that in some embodiments, method 700 may include process blocks (not shown) that provide at least one of the solidly separated circuit board units having a grid-like ground plane, and / or construct at least one of the solidly separated circuit board units according to one of the layer stacks 400A~C (Figures 4A to 4C).

[0052] Although the present invention is susceptible to various modifications and alternatives, specific methods and apparatus embodiments have been illustrated by way of example and described in detail herein. However, it should be understood that the specific methods and apparatus disclosed herein are not intended to limit the scope of the invention or the patent application. [Simplified Explanation of the Diagram]

[0010] The illustrations described below are for illustrative purposes and are not necessarily drawn to scale. Therefore, these illustrations and descriptions should be considered illustrative rather than restrictive. The illustrations are not intended to limit the scope of the invention in any way.

[0011] Figure 1 illustrates a side view of a continuous glucose monitoring (CGM) device, which includes a sensor circuit system and a wireless communication circuit system according to embodiments provided herein.

[0012] Figures 2A and 2B respectively illustrate a (top) side view and a plan view of a flexible circuit board configuration according to an embodiment provided herein.

[0013] Figure 3 illustrates a perspective view of another flexible circuit board configuration according to an embodiment provided herein.

[0014] Figures 4A, 4B and 4C illustrate cross-sectional side views of the layer stack of a flexible circuit board assembly according to embodiments provided herein.

[0015] According to the embodiments provided herein, Figure 5 illustrates a plan view of the grid ground plane of the flexible circuit board, and Figure 5A illustrates a magnified portion of the grid ground plane of Figure 5.

[0016] Figures 6A, 6B, and 6C illustrate perspective views of a continuous analyte monitoring (CAM) device according to embodiments provided herein, the device having flexible circuit boards in a non-bent state, a bent state about the X-axis dimension, and a bent state about the Y-axis dimension, respectively.

[0017] Figure 7 illustrates a flowchart of a method for constructing a flexible circuit board according to an embodiment provided herein. [Biomaterial Storage]

[0054] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A flexible circuit board for a continuous analyte monitoring (CAM) device, comprising: a plurality of physically separated circuit board units, each circuit board unit having a circuit system thereon; and a plurality of flexible interconnects, each flexible interconnect connecting one of the physically separated circuit board units to another of the physically separated circuit board units, each of the flexible interconnects being operable to couple electrical power, electrical signals, or both to the plurality of physically separated circuit board units connected thereto; wherein the flexible circuit board is bendable in multiple directions in three dimensions.

2. The flexible circuit board as claimed in claim 1, wherein at least one of the physically separated circuit board units comprises three signal layers, wherein two of the three signal layers are integrated with one of the flexible interconnects.

3. The flexible circuit board as claimed in claim 1, wherein at least one of the physically separated circuit board units includes a grid-like ground plane.

4. The flexible circuit board as claimed in claim 1, wherein one of the flexible interconnects includes a circuit system manufactured thereon and a reinforcement applied thereto to support the circuit system.

5. The flexible circuit board as claimed in claim 1, wherein one of the physically separated circuit board units includes a CAM sensor circuit system.

6. The flexible circuit board as claimed in claim 1, wherein one of the physically separated circuit board units includes a wireless communication circuit system.

7. The flexible circuit board as claimed in claim 1, wherein one of the physically separated circuit board units includes a power circuit system and a power supply.

8. The flexible circuit board as claimed in claim 1, wherein one of the physically separated circuit board units includes an interconnect circuit system.

9. The flexible circuit board as claimed in claim 1, wherein the CAM device is a continuous blood glucose monitoring device.

10. A continuous analyte monitoring (CAM) device comprising: a flexible circuit board as described in claim 1; and a housing for attaching to a skin surface of a user, the housing enclosing the flexible circuit board as described in claim 1; wherein the CAM device has a height of approximately 2.5 mm as measured from the skin surface.

11. A method of constructing a flexible circuit board for a continuous analytical monitoring (CAM) device, the method comprising the steps of: providing a plurality of physically separate circuit board units, each unit having a circuit system thereon; and interconnecting one of the physically separate circuit board units to another of the physically separate circuit board units using a separate flexible interconnect, the separate flexible interconnect being operable to couple power, electrical signals, or both to the one and the other of the physically separate circuit board units.

12. The method as described in claim 11, further comprising the steps of: encapsulating the physically separate circuit board units in a housing for attachment to a user's skin surface, wherein each circuit board unit is interconnected to another of the physically separate circuit board units using the individual flexible interconnect.

13. The method as described in claim 11, further comprising the step of: constructing at least one of the physically separated circuit board units to include three signal layers, wherein two of the three signal layers are integrated with one of the individual flexible interconnects.

14. The method as described in claim 11, further comprising the step of: providing a grid-like ground plane to at least one of the physically separated circuit board units.

15. The method as described in claim 11 further comprises the steps of: fabricating a circuit system on one of the individual flexible interconnects and applying a reinforcement to support the circuit system.

16. The method as described in claim 11 further comprises the step of: fabricating a CAM sensor circuit system on one of the physically separate circuit board units.

17. The method as described in claim 11 further comprises the step of: manufacturing a wireless communication circuit system on one of the physically separate circuit board units.

18. The method as described in claim 11 further comprises the step of manufacturing an electrical circuit system and a power supply on one of the physically separate circuit board units.

19. The method as described in claim 11 further comprises the step of: fabricating an interconnect circuit system on one of the physically separate circuit board units.

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

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