Medical device for detecting at least one analyte in bodily fluid
By designing high resistance conductors to limit current, the problem of high current flowing into the body in the event of electronic units failures is solved, achieving lower production costs and smaller device sizes.
Patent Information
- Application Number
- CN202380078529.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-14
- Filing Date
- 2023-11-13
- Publication Date
- 2025-06-20
AI Technical Summary
Existing medical devices for detecting analytes in body fluids may cause high currents to flow into the user's body when the electronic unit fails, increasing the safety risks of the user. In order to improve safety, redundant electrical components need to be added, resulting in increased production costs and larger device sizes.
By designing that the resistance of the first and second electrical conductors is higher than that of the first and second electrodes, the current flowing through the first and second electrodes is limited, so that redundant electrical components are not required to limit the current.
Reduces the risk of high current flowing into the user's body when an electronic unit or its components fail, while reducing production costs and device size.
Smart Images
Figure CN120187348A_ABST
Abstract
Description
[0001] The present invention relates to a medical device for detecting at least one analyte in a body fluid, the device comprising a substrate configured to reversibly attach the medical device to a patient's body; an insertable analyte sensor comprising an insertable portion configured to be at least partially inserted into a user's body tissue; and an electronic unit operatively connected to the insertable analyte sensor, wherein the insertable analyte sensor comprises a first electrode and a second electrode, both forming part of the insertable portion, wherein the first electrode comprises a first free end and a second end, wherein the second end of the first electrode is electrically connected to a first electrical conductor that electrically connects the first electrode of the insertable analyte sensor to the electronic unit, wherein the second electrode comprises a first free end and a second end, wherein the second end of the second electrode is electrically connected to a second electrical conductor that electrically connects the second electrode of the insertable analyte sensor to the electronic unit, and wherein the first electrode extending from the second end of the first electrode towards its first free end and the second electrode extending from the second end of the second electrode towards its first free end are configured to be at least partially in electrical contact with the user's body tissue during use of the medical device.
[0002] Medical devices known hitherto for detecting at least one analyte in a body fluid are removably attached to a user's body during use, wherein the insertable analyte sensor is inserted into the user's body tissue. Accordingly, the first electrode and the second electrode are in direct contact with the body tissue and are electrically connected to the electronic unit. Thus, a malfunction of the electronic unit (e.g., a short circuit) can cause a high current to flow through the first electrode and the second electrode into the user's body. Therefore, in order to increase user safety, known medical devices include redundant electronic components such that a malfunction of an electronic component does not cause a high current to flow into the user's body, but is compensated for by a corresponding redundant component. However, the increased number of additional redundant electrical components increases the production cost and results in a larger size of the medical device.
[0003] Accordingly, it is an object of the present invention to provide a medical device for detecting at least one analyte in a body fluid that avoids at least one drawback of the medical devices known hitherto. In particular, it is an object of the present invention to provide a medical device for detecting at least one analyte in a body fluid that reduces the risk of a high current flowing into the user's body tissue while allowing for a lower production cost.
[0004] At least one of the above objects is solved by providing the subject matter disclosed in the claims and throughout the specification.
[0005] According to a first aspect, there is provided a medical device for detecting at least one analyte in a body fluid, the medical device comprising a substrate configured to reversibly attach the medical device to a patient's body; an insertable analyte sensor comprising an insertable portion configured to be at least partially inserted into a user's body tissue; and an electronic unit operatively connected to the insertable analyte sensor, wherein the insertable analyte sensor comprises a first electrode and a second electrode, both forming part of the insertable portion, wherein the first electrode comprises a first free end and a second end, wherein the second end of the first electrode is electrically connected to a first electrical conductor that electrically connects the first electrode of the insertable analyte sensor to the electronic unit, wherein the second electrode comprises a first free end and a second end, wherein the second end of the second electrode is electrically connected to a second electrical conductor that electrically connects the second electrode of the insertable analyte sensor to the electronic unit, and wherein the first electrode extending from the second end of the first electrode towards its first free end and the second electrode extending from the second end of the second electrode towards its first free end are configured to be at least partially in electrical contact with the user's body tissue during use of the medical device, wherein the resistance of the first electrical conductor and the resistance of the second electrical conductor are higher than the resistance of the first electrode and the resistance of the second electrode.
[0006] A medical device for detecting at least one analyte in a body fluid may be removably attached to a user's body. For example, the substrate may adhere to the user's skin. For example, the substrate may comprise an adhesive layer or may comprise a patch containing an adhesive configured to removably adhere the medical device to the user's body.
[0007] When attached to the user's body, the insertable portion of the insertable analyte sensor is inserted into the user's body tissue, wherein the first electrode and the second electrode are in electrical contact with the body tissue and are electrically connected to the electronic unit via a first conductor and a second conductor, respectively. The presence of an analyte in the body tissue will affect the current flowing between the first electrode and the second electrode. The change in current can be evaluated by the electronic unit, thereby allowing the detection of individual analytes. By way of example only, the electronic unit may be a printed circuit board.
[0008] The analyte may be one or more analytes, preferably metabolites, such as glucose, lactate, triglycerides, cholesterol or analytes in a body fluid such as, for example, blood or interstitial fluid or other body fluids. For example, the insertable analyte sensor may be an electrochemical sensor configured to detect at least one analyte, wherein the first electrode is configured as a working electrode and serves as a transducer, and the second electrode is configured as a counter electrode.
[0009] The medical device may include a power source configured to supply power to the electronic unit. The power source may be a battery or a rechargeable battery configured to supply power to the electronic unit. By way of example only, the battery may be configured to supply 3.4V of power.
[0010] To mitigate the risk of uncontrolled current flowing into the user's body in the event of a malfunction of the electronic unit or its components, the resistance of the first conductor and the second conductor is higher than the resistance of the first electrode and the second electrode. During use, current flows between the first electrode and the second electrode, and the first electrical conductor and the second electrical conductor together with the first electrode and the second electrode form a potentiometer. The higher resistance of the first conductor and the second conductor limits the current flowing through the first conductor and the second conductor, such that the current flowing through the first electrode and the second electrode is also limited. Therefore, redundant electrical components for limiting the current flowing through the first electrode and the second electrode in the event of a malfunction of the electronic unit or its parts are not required. In the absence of redundant electrical components, the total number of electronic components of the electronic unit can be reduced, such that the medical device can have a smaller size and a lower production cost.
[0011] According to an embodiment, the sum of the resistance of the first electrical conductor and the resistance of the second electrical conductor is higher than the sum of the resistance of the first electrode and the resistance of the second electrode. For example, the sum of the resistance of the first electrode and the resistance of the second electrode may be 9 kOhm, while the sum of the resistance of the first electrical conductor and the resistance of the second electrical conductor may be 90 kOhm.
[0012] The resistance of the first electrode and the resistance of the second electrode may be the same, and / or the resistance of the first electrical conductor and the resistance of the second electrical conductor may be the same. To facilitate the production of the potentiometer and to obtain a symmetric potentiometer, it is beneficial for the resistance of the first electrode to be equal to the resistance of the second electrode. Similarly, the resistance of the first conductor is equal to the resistance of the second conductor. In the context of the present invention, equal means the same measured value; however, these same measured values may deviate due to common measurement errors and production errors.
[0013] In an embodiment, the resistance of the first electrical conductor and the resistance of the second electrical conductor are at least 2 times, at least 4 times, at least 5 times, or at least 10 times the resistance of the first electrode and the resistance of the second electrode. For example, the resistance of the first electrode and the resistance of the second electrode may each be 9 kOhm, while the resistance of the first electrical conductor and the resistance of the second electrical conductor may each be 90 kOhm.
[0014] In the case of a malfunction of the electronic unit or its components, if the current exceeds 50 μA, an uncontrolled current flowing through the first and second electrodes into the body tissue may damage the body tissue. Therefore, the resistances of the first electrical conductor and the second electrical conductor that limit the maximum current flowing through the first and second electrodes during use are selected such that the voltage of the power supply divided by the sum of the resistances of the first and second electrical conductors is less than or equal to 50 μA. By knowing the voltage of the power supply, for example, the voltage of the battery, the resistance of the first electrical conductor, and the resistance of the second electrical conductor can be determined to limit the maximum current flowing through the first and second electrodes. The sum of the resistances of the first and second electrical conductors can be equal to the voltage of the power supply divided by the maximum allowable current, which here is 50 μA.
[0015] In an embodiment, the first electrode extending from its second end towards its first free end and the second electrode extending from its second end towards its first free end are configured to be in electrical contact with the body tissue during use of the medical device. When inserted, the first and second electrodes forming at least a part of the insertable portion are in electrical contact with the body tissue. On at least one side of each of the first and second electrodes, there is no electrical isolation shielding the first and second electrodes from the body tissue. On the other hand, the first and second electrical conductors can be configured to be electrically isolated from the body tissue during use of the medical device. Since the first and second electrical conductors limit the maximum current flowing through the first and second electrodes during use of the medical device, the first and second electrical conductors should not be in direct electrical contact with the body tissue.
[0016] According to an embodiment, the first electrical conductor includes a first cable cross-sectional area, the second electrical conductor includes a second cable cross-sectional area, the first electrode includes a third cable cross-sectional area, and the second electrode includes a fourth cable cross-sectional area, where the first and second cable cross-sectional areas are smaller than the third and fourth cable cross-sectional areas. The resistance of each electrical conductor or electrode depends in particular on the cross-sectional area, where a smaller cross-sectional area provides a higher resistance than a larger cross-sectional area of the same material. For example, the cross-sectional areas of the first and second electrodes can be reduced by laser ablation.
[0017] The first cable cross-sectional area can be smaller than the third cable cross-sectional area, and the second cable cross-sectional area can be smaller than the fourth cable cross-sectional area. For example, the first cable cross-sectional area is equal in size to the second cable cross-sectional area, and / or the third cable cross-sectional area is equal in size to the fourth cable cross-sectional area.
[0018] The first and second cable cross-sectional areas can be at most 1 / 2, at most 1 / 4, at most 1 / 5, or at most 1 / 10 of the third and fourth cable cross-sectional areas.
[0019] According to an embodiment, the substrate includes a sleeve, wherein an electronic unit is arranged on a first side of the sleeve and an insertable portion of an analyte sensor that is insertable is arranged on a second side of the sleeve opposite the first side, wherein both the electrical connection of the first electrode to a second end of a first electrical conductor and the electrical connection of the second electrode to a second end of a second electrical conductor are located inside the sleeve or at the first side of the sleeve including the electronic unit or at the second side of the sleeve including the insertable portion of the insertable analyte sensor. The sleeve has a first side and a second side and provides a passage for the first electrical conductor and the second electrical conductor that are electrically connected to the electronic unit and / or for the first electrode and the second electrode. For example, when located on the first side or inside the sleeve, the contact points between the first electrode and the first electrical conductor and between the second electrode and the second electrical conductor, i.e., the second ends of the first electrode and / or the second ends of the second electrode, are protected by the substrate or the sleeve. According to an embodiment, the sleeve can be a through-hole or a duct in the substrate, which allows the first electrical conductor and the second electrical conductor and / or the first electrode and the second electrode to penetrate into and out of the substrate. Like the substrate, the sleeve can be made of an electrically insulating material.
[0020] From the following description of the embodiments and the drawings, further advantages, features, and technical effects of the present invention are apparent.
[0021] Figure 1 A schematic diagram of a medical device for detecting at least one analyte in a body fluid according to an embodiment is shown.
[0022] Figure 2 A schematic diagram of a medical device for detecting at least one analyte in a body fluid according to another embodiment is shown, and
[0023] Figure 3 A schematic diagram of a medical device for detecting at least one analyte in a body fluid according to yet another embodiment is shown.
[0024] Figure 1 A schematic diagram of a medical device 1 is shown. The medical device 1 is configured to detect at least one analyte in a body fluid. The medical device 1 includes a substrate 2, which is configured to be removably attached to a patient's body. The substrate 2 houses an electronic unit 5, which is operably connected to an insertable analyte sensor 3.
[0025] The insertable analyte sensor 3 includes an insertable portion 4, which is configured to be at least partially inserted into a user's body tissue. The insertable portion 4 protrudes from the substrate 2 such that the insertable portion can be inserted into the body tissue by attaching the substrate 2 to the user's skin.
[0026] To detect the presence of an analyte in body tissue, an analyte sensor 3 that can be inserted includes a first electrode 6 and a second electrode 7, both of which form part of the insertable portion 4. The first electrode 6 and the second electrode 7 each include a first free end 6a, 7a and a second end 6b, 7b. The second end 6b of the first electrode 6 is electrically connected to a first electrical conductor 8. The electrical conductor 8 electrically connects the first electrode 6 to the electronic unit 5. Similarly, the second end 7b of the second electrode 7 is electrically connected to a second electrical conductor 9. The second electrical conductor 9 electrically connects the second electrode 7 to the electronic unit 5 such that during use of the medical device 1, current can flow through the first electrode 6 and the second electrode 7.
[0027] The first electrode 6 extending from the second end 6b of the first electrode 6 to the first free end 6a of the first electrode and the second electrode 7 extending from the second end 7b of the second electrode 7 to the first free end 7a of the second electrode are configured to be in electrical contact with the user's body tissue during use of the medical device 1. The first electrical conductor 8 and the second electrical conductor 9 are not in electrical contact with the body tissue except for being electrically connected to the first electrode 6 and the second electrode 7 respectively.
[0028] To reduce the risk of uncontrolled current flow in the event of a short circuit failure in the electronic unit 5 or its components, the resistance of the first electrical conductor 8 and the resistance of the second electrical conductor 9 are higher than the resistance of the first electrode 6 and the resistance of the second electrode 7.
[0029] Figure 2 Another embodiment of the medical device 1 for detecting at least one analyte in body fluid is shown. This embodiment is different from the embodiment of the medical device 1 according to Figure 1 in that it further includes a power source 11, here referring to a battery. The battery 11 supplies power to the electronic unit 5. For example, the battery 11 supplies 3.4V. The electronic unit 5 can be a printed circuit board.
[0030] The substrate 2 further includes a patch 13, where the patch 13 further includes an adhesive for removably adhering the medical device 1 to the user's body through the patch 13.
[0031] In addition, the first electrode 6 and the second electrode 7 are carried by a carrier 12. The carrier 12 supports the first electrode 6 and the second electrode 7 and thus provides greater stability for the first electrode 6 and the second electrode 7. The carrier 12 projects from the substrate 2 and is at least partially inserted into the body tissue together with the first electrode 6 and the second electrode 7 during use of the medical device 1.
[0032] The substrate 2 further includes a sleeve 10 for allowing the first electrical conductor 8 and the second electrical conductor 9 to pass through the substrate 2 from the electronic unit 5 to reach the second end portion 6b of the first electrode 6 and the second end portion 7b of the second electrode 7 respectively. The sleeve 10 includes a first side 10a and a second side 10b, where the electronic unit 5 is present on the first side 10a of the sleeve 10, and where the insertable portion 4 of the analyte sensor 3 can be inserted is present on the second side 10b of the sleeve 10 opposite to the first side 10a.
[0033] The transitions from the first electrical conductor 8 to the first electrode 6 and the second electrical conductor 9, namely the second end portion 6b of the first electrode 6 and the second end portion 7b of the second electrode 7, are located within the sleeve 10. Thus, the sleeve 10 protects the contact points between the first electrical conductor 8 and the first electrode 6 and between the second electrical conductor 9 and the second electrode 7.
[0034] Again, the first electrode 6 extending from the second end portion 6b to its first free end portion 6a and the second electrode 7 extending from the second end portion 7b to its free end portion 7a are configured to make direct electrical contact with the user's body tissue during the use of the medical device 1. The resistance of the first electrode 6 and the resistance of the second electrode 7 are each 9 kOhm, where the resistance of the first electrical conductor 8 and the resistance of the second electrical conductor 9 are each 90 kOhm. Accordingly, the resistances of the first electrical conductor 8 and the second electrical conductor 9 are equal to each other and are 10 times the resistances of the first electrode 8 and the second electrode 9. The resistance of the first electrode 6 is equal to the resistance of the second electrode 7.
[0035] Figure 3 A schematic diagram of another embodiment of a medical device 1 for detecting an analyte in a body fluid is shown. Figure 3 The embodiment shown is different from Figure 2 the embodiment of the medical device 1 shown in that the second end portion 6b of the first electrode 6 and the second end portion 7b of the second electrode 7 are arranged on the first side 10a of the sleeve 10.
[0036] List of reference numerals
[0037] 1 Medical device
[0038] 2 Substrate
[0039] 3 Insertable analyte sensor
[0040] 4 Insertable portion
[0041] 5 Electronic unit
[0042] 6 First electrode
[0043] 6a First free end portion of the first electrode
[0044] 6b Second end portion of the first electrode
[0045] 7 Second electrode
[0046] 7a First free end portion of the second electrode
[0047] 7b Second end portion of the second electrode
[0048] 8 First electrical conductor
[0049] 9 Second electrical conductor
[0050] 10 Sleeve
[0051] 10a First side of the sleeve
[0052] 10b Second side of the sleeve
[0053] 11 Power supply
[0054] 12 Carrier
[0055] 13 Patch
Claims
1. A medical device (1) for detecting at least one analyte in a body fluid, the medical device comprising: · a substrate (2) configured to reversibly attach the medical device (1) to a patient's body; · an insertable analyte sensor (3) including an insertable portion (4) configured to be at least partially inserted into a user's body tissue; and · an electronic unit (5) operably connected to the insertable analyte sensor (3), · wherein the insertable analyte sensor (5) includes a first electrode (6) and a second electrode (7), both the first electrode and the second electrode forming part of the insertable portion (4), · wherein the first electrode (6) includes a first free end (6a) and a second end (6b), and wherein the second end (6b) of the first electrode (6) is electrically connected to a first electrical conductor (8) that electrically connects the first electrode (6) of the insertable analyte sensor (3) to the electronic unit (5), · wherein the second electrode (7) includes a first free end (7a) and a second end (7b), and wherein the second end (7b) of the second electrode (7) is electrically connected to a second electrical conductor (9) that electrically connects the second electrode (7) of the insertable analyte sensor (3) to the electronic unit (5), and · wherein the first electrode (6) extending from the second end (6b) towards its first free end (6a) and the second electrode (7) extending from the second end (7b) towards its first free end (7a) are configured to be at least partially in electrical contact with the user's body tissue during use of the medical device (1), characterized in that · the resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) are higher than the resistance of the first electrode (6) and the resistance of the second electrode (7).
2. The medical device (1) according to claim 1, wherein The sum of the resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) is higher than the sum of the resistance of the first electrode (6) and the resistance of the second electrode (7).
3. The medical device (1) according to claim 1 or 2, wherein The resistance of the first electrode (6) and the resistance of the second electrode (7) are equally high, and / or the resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) are equally high.
4. The medical device (1) according to any one of claims 1 to 3, wherein The resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) are at least 2 times, at least 4 times, at least 5 times or at least 10 times higher than the resistance of the first electrode (6) and the resistance of the second electrode (7).
5. The medical device (1) according to any one of claims 1 to 4, wherein The first electrical conductor (8) has a first cable cross-sectional area, the second electrical conductor (9) has a second cable cross-sectional area, the first electrode (6) has a third cable cross-sectional area, and the second electrode (7) has a fourth cable cross-sectional area, wherein the first cable cross-sectional area and the second cable cross-sectional area are smaller than the third cable cross-sectional area and the fourth cable cross-sectional area.
6. The medical device (1) according to claim 5, wherein The first cable cross-sectional area is smaller than the third cable cross-sectional area, and the second cable cross-sectional area is smaller than the fourth cable cross-sectional area.
7. The medical device (1) according to claim 5 or 6, wherein The cross-sectional area of the first cable is equal to the cross-sectional area of the second cable, and / or the cross-sectional area of the third cable is equal to the cross-sectional area of the fourth cable.
8. The medical device (1) according to any one of claims 5 to 7, wherein The cross-sectional area of the first cable and the cross-sectional area of the second cable are at most 1 / 2, at most 1 / 4, at most 1 / 5, or at most 1 / 10 of the cross-sectional area of the third cable and the cross-sectional area of the fourth cable.
9. The medical device (1) according to any one of claims 1 to 8, wherein The substrate (2) includes a sleeve (10), wherein the electronic unit (5) is arranged on a first side (10a) of the sleeve (10) and the insertable portion (4) of the insertable analyte sensor (3) is arranged on a second side (10b) of the sleeve (10) opposite to the first side (10a), wherein both the second end (6b) of the first electrode (6) electrically connected to the first electrical conductor (8) and the second end (7b) of the second electrode (7) electrically connected to the second electrical conductor (9) are located inside the sleeve (10) or at the first side (10a) of the sleeve (10) containing the electronic unit (5) or at the second side (10b) of the sleeve (10) containing the insertable portion (4) of the insertable analyte sensor (3).
10. The medical device (1) according to any one of claims 1 to 9, wherein The first electrode (6) from its second end (6b) towards its first free end (6a) and the second electrode (7) from its second end (7b) towards its first free end (7a) are configured to be in electrical contact with the body tissue during use of the medical device (1) along their respective lengths.
11. The medical device (1) according to any one of claims 1 to 10, wherein The first electrical conductor (8) and the second electrical conductor (9) are configured to be electrically isolated from the body tissue during use of the medical device (1) along their respective lengths.
12. The medical device (1) according to any one of claims 1 to 11, wherein The medical device (1) includes a power source (11) configured to supply power to the electronic unit (5).
13. The medical device (1) according to claim 12, wherein The resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) are selected such that the voltage of the power source (11) divided by the sum of the resistance of the first electrical conductor (8) and the resistance of the second electrical conductor (9) is less than or equal to 50 μA.
14. The medical device (1) according to any one of claims 1 to 13, whereinThe insertable portion (4) of the insertable analyte sensor (3) includes a carrier (12) configured to carry the first electrode (6) and the second electrode (7).
15. The medical device (1) according to any one of claims 1 to 14, characterized in that, The substrate (2) includes a patch (13), wherein the patch (13) includes an adhesive configured to adhere the medical device (1) to the body of a user.