Implant Devices

Abstract

The implant device of the present disclosure comprises a cylindrical housing with at least one end open and defining an internal space, a lid having one end closed and an inner surface facing the internal space and an outer surface opposite the inner surface, and a substrate disposed in the internal space and having an active surface, a substrate electrode disposed on the active surface, and a wireless communication circuit for communicating bioinformation acquired through the substrate electrode to the outside of the body, wherein the inner surface of the lid is provided with a recess in which the substrate is disposed and an internal electrode electrically connected to the substrate electrode, and the outer surface of the lid is provided with an external electrode electrically connected to the internal electrode.

Description

[Technical field]

[0001] (Related Applications) This application claims priority to U.S. Provisional Application No. 63 / 273,369, filed October 29, 2021, the entire contents of which are incorporated herein by reference.

[0002] (Government License Rights) This disclosure was made with government support under Grant No. 1554367 awarded by the National Science Foundation. The Government has certain rights in this disclosure.

[0003] The present disclosure relates to implant devices. [Background technology]

[0004] Patent Document 1 discloses an implant device including a housing, a circuit board provided inside the housing, and an end cap that closes an end of the housing.

[0005] The circuit board of the implant device of the '1999 patent has a flexible distal portion that extends beyond the end of the housing before the end cap is attached to the housing, and when the end cap is attached, the flexible distal portion provides an electrical connection between the circuit board and the end cap. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2021-511841 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the implant device of Patent Document 1 still has room for improvement in terms of assembly.

[0008] Accordingly, it is an object of the present disclosure to provide an implant device that is easy to assemble. [Means for solving the problem]

[0009] An exemplary embodiment of an implant device of the present disclosure comprises a cylindrical housing having at least one open end defining an internal space, a lid having one closed end and an inner surface facing the internal space and an outer surface opposite the inner surface, and a substrate disposed in the internal space and having an active surface, a substrate electrode disposed on the active surface, and a wireless communication circuit for communicating bioinformation acquired through the substrate electrode to the outside of the body, wherein the inner surface of the lid is provided with a recess in which the substrate is disposed and an internal electrode electrically connected to the substrate electrode, and the outer surface of the lid is provided with an external electrode electrically connected to the internal electrode.

[0010] Another exemplary aspect of an implant device of the present disclosure comprises a cylindrical housing having at least one open end defining an internal space, a lid having one end closed and an inner surface facing the internal space and an outer surface opposite the inner surface, a substrate disposed in the internal space and having an active surface, a substrate electrode disposed on the active surface, and a wireless communication circuit for communicating bioinformation acquired through the substrate electrode to the outside of the body, wherein the inner surface of the lid is provided with a convex portion in contact with the active surface, the convex portion is provided with an internal electrode electrically connected to the substrate electrode, and the outer surface of the lid is provided with an external electrode electrically connected to the internal electrode, and the implant device further comprises a connecting member connecting the internal electrode and the substrate electrode. Effect of the Invention

[0011] According to the present disclosure, an implant device that is easy to assemble can be provided. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of an implant device according to an exemplary embodiment of the present disclosure. [Diagram 2] Schematic diagram showing the inside of an implant device [Diagram 3] Cross-section of the implant device [Figure 4] Schematic diagram of circuit components on board [Diagram 5] Top view of the lid [Figure 6] Enlarged cross-sectional view of the lid and the substrate [Figure 7] 1 is a cross-sectional view of an implant device according to a first modified example. [Figure 8] 11 is a cross-sectional view of an implant device according to a second modification. [Figure 9A] Top view of the lid [Figure 9B] Enlarged cross-sectional view of the lid and the substrate [Figure 10] 11 is a cross-sectional view of an implant device according to a third modification. [Figure 11] 11 is a cross-sectional view of an implant device according to a fourth modification example. [Figure 12] Schematic diagram showing an embodiment of an implant device. [Figure 13A] FIG. 1 shows an unprocessed ECG signal including respiratory artifacts recorded by an implanted device. [Figure 13B] FIG. 1 shows an unprocessed ECG signal including respiratory artifacts recorded by conventional ECG electrodes. [Figure 14] FIG. 1 shows the filtered ECG signal after subtraction of respiratory artifacts. [Figure 15A] Figure 1. RR intervals extracted using a clean ECG signal. [Figure 15B] FIG. 1 shows the breath interval calculated from the interval between successive peaks in the ECG baseline. [Figure 16A] Diagram showing the magnitude of DFT applied to RR interval values ​​from implanted devices. [Figure 16B] Diagram showing the magnitude of DFT applied to the respiratory baseline from the implanted device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Background to this disclosure) Continuous and wireless physiological monitoring allows veterinarians, animal scientists, and biomedical researchers to better understand and monitor the health and welfare of animals. Traditional animal health monitoring devices, especially for small animals, require tabletop instruments connected to the animal by wires and are only suitable for clinical experiments. External attachment of biopotential electrodes also requires shaving or the use of adhesives, which can make the animals uncomfortable with the device over long-term use. Subcutaneous implantable sensors, on the other hand, allow the animal to move freely, providing deeper insight into the animal's physiological state in a natural or semi-natural environment.

[0014] Electrocardiography (ECG) can provide the most important physiological indices that can be used to assess the health and welfare status of animals, such as heart rate (HR), heart rate variability (HRV), and potentially respiratory rate (BR). To integrate the ECG recording circuitry into the device in an implantable form, miniaturized electrodes are required, but miniaturized electrodes are difficult to manufacture. The electrodes require a stable low impedance connection from the tissue to the circuitry, and the electronics inside the implant need to be completely isolated from the outside environment. This low impedance connection requires conductors protruding outward from the implant package and a larger contact area between the electrode and the tissue. For commercial applications, scalability and low cost electrode production processes are also required.

[0015] Existing electrode designs in the prior art use spiral wire or micro-machined metal as the conductor, and such methods have major drawbacks such as manual production, difficult production steps, increased costs, and lack of uniformity in the final product.

[0016] Existing devices include subcutaneous electrophysiology implant devices that use stainless steel wires as electrodes to monitor heart rate. In these implant devices, the electrodes have limited contact with the tissue and are spaced too close together, resulting in suboptimal measurements. In other existing devices, electrodes formed from conductive epoxy have shown comparable performance to other metallic alternatives. While epoxy electrodes offer more flexibility in packaging and encapsulating the implant device, there is still room for improvement in terms of electrode size, uniformity, and ease of manufacture.

[0017] Additive processing (i.e., 3D printing) techniques can play a key role in facilitating the mass production of low-cost biopotential electrodes. In this disclosure, the inventors have explored the adoption of a new technique for printing metal electrodes onto a co-fired ceramic substrate. This new technique can be used to produce a lid for a cylindrical housing (e.g., a glass tube) onto which a metal electrode is printed. The metal electrode can easily connect the external tissue surface to the electrophysiology front-end circuitry inside the implant device.

[0018] By providing a recess or protrusion on the lid having the printed metal electrodes, it becomes easier to align the metal electrodes with the electrophysiology front-end circuitry, thus providing an implant device that is easy to assemble.

[0019] The implant device of a first aspect of the present disclosure comprises a cylindrical housing having at least one open end defining an internal space, a lid having one end closed and an inner surface facing the internal space and an outer surface opposite the inner surface, and a substrate disposed in the internal space and having an active surface, a substrate electrode disposed on the active surface, and a wireless communication circuit for communicating bioinformation acquired through the substrate electrode to the outside of the body, wherein the inner surface of the lid is provided with a recess in which the substrate is disposed and an internal electrode electrically connected to the substrate electrode, and the outer surface of the lid is provided with an external electrode electrically connected to the internal electrode.

[0020] This configuration facilitates alignment of the substrate with respect to the lid, which can facilitate assembly of the implant device.

[0021] As an implant device of a second aspect, in the implant device of the first aspect, the recess is defined by an inner wall surface having a first inner wall surface and a second inner wall surface opposed to each other.

[0022] With this configuration, when the first inner wall surface and the second inner wall surface face the substrate, the substrate can be held in a sandwiched and aligned state between the first inner wall surface and the second inner wall surface.

[0023] As a third embodiment of the implant device, in the implant device of the second embodiment, the first inner wall surface is part of a first convex portion on the inner surface of the lid, the second inner wall surface is part of a second convex portion on the inner surface of the lid, and the concave portion is located between the first convex portion and the second convex portion.

[0024] With this configuration, the substrate can be firmly held by the first convex portion and the second convex portion regardless of the thickness of the lid, that is, regardless of the depth of the concave portion.

[0025] As an implant device according to a fourth aspect, in the implant device according to the third aspect, at least one of the first convex portion and the second convex portion covers an end portion of the substrate.

[0026] As an implant device of a fifth aspect, in the implant device of any one of the second to fourth aspects, the internal electrode is located on the inner wall surface, and the substrate electrode is located on a portion of the substrate arranged in the recess.

[0027] With this configuration, electrical connection can be achieved between the internal electrodes and the board electrodes.

[0028] As an implant device of a sixth aspect, in the implant device of any one of the second to fifth aspects, the substrate is in contact with at least one of the first inner wall surface or the second inner wall surface.

[0029] With this configuration, the contact area between the recess and the substrate is increased, so that the substrate can be held more firmly.

[0030] As an implant device of a seventh aspect, in the implant device of the sixth aspect, the substrate is in contact with the first inner wall surface and the second inner wall surface.

[0031] With this configuration, the contact area between the recess and the substrate is increased, so that the substrate can be held more firmly.

[0032] As an implant device of an eighth aspect, in the implant device of any one of the first to seventh aspects, the outer electrode has a larger area than the inner electrode.

[0033] As an implant device of a ninth aspect, in the implant device of any one of the first to eighth aspects, the outer diameter of the lid is smaller than the inner diameter of the housing.

[0034] With this configuration, the substrate and the lid can be assembled in an aligned state, and then the substrate and the lid can be inserted into the housing.

[0035] As an implant device of the 10th aspect, in the implant device of any of the 1st to 9th aspects, the one end is a first open end, the lid is a first lid, and the housing has a second open end opposite the first open end, and further comprises a second lid that closes the second open end.

[0036] With this configuration, the boards disposed within the housing can be easily accessed from both ends of the housing.

[0037] An eleventh aspect of the implant device is the implant device according to the tenth aspect, wherein an outer diameter of the first lid and an outer diameter of the second lid are smaller than an inner diameter of the housing.

[0038] With this configuration, both lids can be attached to the board before it is inserted into the housing.

[0039] A twelfth aspect of the implant device is the implant device of any one of the first to eleventh aspects, wherein the lid has a ceramic material and a metal material.

[0040] With this configuration, the internal electrode and the external electrode can be formed integrally with the lid.

[0041] As an implant device of a thirteenth aspect, in the implant device of any one of the first to twelfth aspects, the lid has a through conductor that penetrates the lid and electrically connects the external electrode and the internal electrode.

[0042] With this configuration, electrical connection can be achieved between the internal electrodes and the external electrodes.

[0043] As an implant device according to a fourteenth aspect, in the implant device according to the thirteenth aspect, the through conductor is inclined with respect to the thickness direction of the lid.

[0044] With this configuration, the lid can be easily produced by firing.

[0045] The implant device of a fifteenth aspect of the present disclosure comprises a cylindrical housing having at least one open end defining an internal space, a lid having one end closed and an inner surface facing the internal space and an outer surface opposite the inner surface, a substrate arranged in the internal space and having an active surface, a substrate electrode arranged on the active surface, and a wireless communication circuit for communicating bioinformation acquired through the substrate electrode to the outside of the body, the inner surface of the lid being provided with a convex portion in contact with the active surface, the convex portion being provided with an internal electrode electrically connected to the substrate electrode, the outer surface of the lid being provided with an external electrode electrically connected to the internal electrode, and the implant device further comprising a connecting member connecting the internal electrode and the substrate electrode.

[0046] This configuration facilitates alignment of the substrate with respect to the lid, which can facilitate assembly of the implant device.

[0047] As an implant device of a sixteenth aspect, in the implant device of the fifteenth aspect, the internal electrode is formed on the surface of the convex portion opposite to the surface in contact with the active surface, and the connection member is conductive.

[0048] With this configuration, the connecting members can be provided more easily than when the internal electrodes are formed on the surface that contacts the active surface.

[0049] As an implant device of a seventeenth aspect, in the implant device of the fifteenth or sixteenth aspect, the outer diameter of the lid is smaller than the inner diameter of the housing.

[0050] As an implant device of an 18th aspect, in the implant device of any of the 15th to 17th aspects, the one end is a first open end, the lid is a first lid, the housing has a second open end opposite the first open end, and further comprises a second lid closing the second open end, and the outer diameter of the first lid and the outer diameter of the second lid are smaller than the inner diameter of the housing.

[0051] As a 19th aspect of the implant device, in an implant device in any of the 15th to 18th aspects, the lid has a through conductor that penetrates the lid and electrically connects the external electrode and the internal electrode, and the through conductor is inclined with respect to the thickness direction of the lid.

[0052] As an implant device of the 20th aspect, in the implant device of any of the 15th to 19th aspects, the convex portion is a first convex portion and further includes a second convex portion arranged on the inner surface of the lid, and the substrate is arranged between the first convex portion and the second convex portion.

[0053] Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings, in which the dimensions of each element are exaggerated for clarity.

[0054] Illustrative Embodiments Fig. 1 is a schematic diagram of an implant device 1 according to an exemplary embodiment. Fig. 2 is a schematic diagram showing the inside of the implant device 1. Fig. 3 is a cross-sectional view of the implant device 1. Fig. 4 is a schematic diagram of components of the circuit of the substrate 5.

[0055] For example, the implant device 1 is a device that is implanted in an animal to obtain biological information. For example, the implant device 1 may be implanted in a chicken. The biological information may include, for example, an electrocardiogram.

[0056] 1 to 3, the implant device 1 has a housing 2, two lids 3 and 4, and a base plate 5. The base plate 5 is housed in the housing 2, and both ends of the housing 2 are closed by the lids 3 and 4.

[0057] 1 shows an example in which the implant device 1 further includes a battery 6 as a power source. In this case, the battery 6 is arranged alongside the substrate 5, between the end of the substrate 5 and the lid 4. However, the present disclosure is not limited to such a configuration, and other types of power sources may be used. In the other drawings, the battery 6 is omitted for simplicity.

[0058] The housing 2 is a cylindrical member for housing the substrate 5. The housing 2 defines an internal space R1 therein, and the entire substrate 5 is housed in the internal space R1. The internal space R1 refers to the space inside the housing 2, and in contrast, the external space R2 refers to the space outside the housing 2, i.e., the space in contact with the biological tissue. In an exemplary embodiment, the housing 2 is a cylindrical member with both ends open, and the outer diameter of the ends of the housing 2 is smaller than the length of the housing 2. The inner diameter of the housing 2 is, for example, 4 mm.

[0059] Here, a direction passing through the centers of both ends of the housing 2 is defined as an axial direction L. The axial direction L of the housing 2 is parallel to the thickness direction of the lid 3 and parallel to the longitudinal direction of the substrate 5.

[0060] The housing 2 may be made of glass, for example, borosilicate glass.

[0061] 3, the lids 3 and 4 are disk-shaped members that respectively close the open ends 2A and 2B of the housing 2. When the lids 3 and 4 close the housing 2, the internal space R1 is sealed and the internal space R1 is separated from the external space R2.

[0062] The lid 3 is electrically connected to one end 2A of the substrate 5. The lid 4 may be separate from the other end 2B of the substrate 5.

[0063] The lid 3 has an electrode so as to realize an electrical connection with the substrate 5. First, the lid 3 has an inner surface 3A facing the internal space R1 and an outer surface 3B opposite to the inner surface 3A and facing the external space R2. An internal electrode 13 is disposed on the inner surface 3A, and an external electrode 23 is disposed on the outer surface 3B. The internal electrode 13 is electrically connected to the substrate 5, and the external electrode 23 is electrically connected to the biological tissue in the external space R2. The external electrode 23 and the internal electrode 13 are electrically connected to each other by a through conductor 18 penetrating the lid 3. Therefore, the bioelectric potential in the external space R2 is conducted to the substrate 5 through the external electrode 23 and the internal electrode 13.

[0064] In an exemplary embodiment, the lid 3 has one internal electrode 13 and one external electrode 23. The external electrode 23 is larger than the internal electrode 13. Therefore, the external electrode 23 can ensure a large contact area with the biological tissue.

[0065] Two protrusions 31 are provided on the inner surface 3A of the lid 3. The protrusions 31 protrude from the inner surface 3A in the axial direction L along the substrate 5. A recess 32 in which the substrate 5 is disposed is provided between the two protrusions 31 on the inner surface 3A of the lid 3. The recess 32 is recessed toward the tip of the protrusion 31, and a gap is formed between the protrusions 31. When the substrate 5 is inserted into the recess 32, the two protrusions 31 are configured to sandwich the substrate 5 in the thickness direction K. With this structure, the substrate 5 can be easily aligned with the lid 3 by being guided by the protrusions 31 and inserted into the recess 32.

[0066] Here, a convex portion means a structure that protrudes from its surroundings, and conversely, a concave portion means a structure that is recessed from its surroundings.

[0067] One of the internal electrodes 13 is formed on the protrusion 31. The protrusion 31 extends along the substrate 5. By providing the internal electrode 13 on the protrusion 31, the internal electrode 13 can be brought closer to the electrode on the substrate 5 (substrate electrode 15 described below) even if the electrode on the substrate 5 (substrate electrode 15 described below) is located inside the end of the substrate 5.

[0068] The substrate 5 is a member equipped with an electronic circuit that acquires bioinformation related to the external space R2 and communicates the bioinformation to a device or system outside the body. The electronic circuit is composed of a circuit pattern formed on the substrate 5 and electronic components electrically connected to the circuit pattern. The substrate 5 is, for example, a printed circuit board. As shown in FIG. 2, the substrate 5 is a plate-shaped member, and at least one surface of the substrate 5 is an active surface 5A on which the electronic components are mounted.

[0069] As shown in FIG. 3, a circuit pattern and board electrodes 15 are arranged on an active surface 5A of the substrate 5, and a plurality of electronic components are mounted thereon.

[0070] The board electrode 15 is formed near the edge of the board 5. In the exemplary embodiment, the board electrode 15 is disposed inside the edge of the board 5 and is spaced apart from the internal electrode 13 along the axial direction L. By separating the board electrode 15 from the edge of the board 5, it is possible to avoid processing the conductor when processing the edge of the board 5, and to suppress the generation of burrs.

[0071] The board electrode 15 is connected to the internal electrode 13 via a connection member 17. The connection member 17 is a member that has conductivity and electrically connects the internal electrode 13 and the board 5. The connection member 17 is made of a conductive material. The connection member 17 is, for example, solder or a conductive adhesive. Furthermore, the board 5 is fixed to the internal electrode 13 by the connection member 17. That is, the connection member 17 is a member that electrically and mechanically connects the internal electrode 13 and the board 5.

[0072] The substrate 5 has mounted electronic components, which are electrically connected to the internal electrode 13 of the lid 3 through the substrate electrode 15 and the connection member 17. The mounted electronic components include at least a control circuit, a wireless communication circuit, a power supply circuit, and an analog-digital (AD) conversion circuit. The control circuit is a controller that controls the entire implant device 1. The control circuit includes a general-purpose processor such as a CPU, MPU, FPGA, DSP, or ASIC that realizes a predetermined function by executing a program. The control circuit can realize various controls in the implant device 1 by calling and executing a control program stored in a memory (not shown). The control circuit is not limited to a circuit that realizes a predetermined function by cooperation between hardware and software, and may be a hardware circuit designed specifically to realize a predetermined function. The wireless communication circuit communicates biological information to outside the body. The AD conversion circuit converts an analog signal into a digital signal.

[0073] 4, in an exemplary embodiment, the mounted electronic components include an analog front-end 51 having an AD conversion circuit, a microcontroller 52 having a control circuit, an antenna 53 having a wireless communication circuit, and a power supply circuit 54. With this configuration, the board 5 communicates biological information measured by the analog front-end 51 to a device or system outside the living body under the control of the microcontroller 52.

[0074] Analog front end 51 (e.g. MAX30003, 2.9 x 2.7 x 0.6 mm 3 ,Maxim Integrated,San Jose, CA, USA) measures bio-information in the external space R2. In an exemplary embodiment, the analog front end 51 measures the heart rate based on an electrocardiogram (ECG). The analog front end 51 has an analog-to-digital converter for converting the measured analog signal to a digital signal. The analog front end 51 may be connected to the substrate electrodes 15 by a network of components that act as signal filters.

[0075] The microcontroller 52 controls the implant device 1. The microcontroller 52 is connected to a radio transceiver 55 (e.g., CC2640, 2.7×2.7×0.5 mm) to form a system-on-chip. 3 , Texas Instruments, Dallas, TX, USA). The radio transceiver 55 functions as a wireless communication circuit and has a BLE (Bluetooth (registered trademark) Low Energy) radio for wireless communication. The radio transceiver 55 may perform wireless communication according to other standards to transmit and receive data.

[0076] The radio transceiver 55 communicates via an antenna 53. The antenna 53 is (e.g., 2450AT, 5.0×2.0×1.5 mm 3, Johanson Technology, Inc., Camarillo, Calif., USA) with an integrated RF antenna that communicates via radio waves, for example, 2.4 GHz.

[0077] Power supply circuit 54 is a circuit for connecting to a power source (not shown) to supply power to substrate 5. In an exemplary embodiment, the power source is a pin-type Li-ion battery (FIG. 1) having a diameter of 3.6 mm, soldered via wires to one end of substrate 5.

[0078] Other electronic components may be mounted on the substrate 5. For example, a storage unit for storing biometric information may be mounted on the substrate 5. The storage unit is a recording medium for recording various information and control programs, and may be a memory that functions as a working area for the microcontroller 52. The storage unit is realized by, for example, a flash memory, an SSD (Solid State Device), a hard disk, a RAM, other storage devices, or an appropriate combination of these.

[0079] Furthermore, electronic components for acquiring biological information other than an electrocardiogram may be mounted on the substrate 5. For example, the substrate 5 may be mounted with a thermistor for measuring body temperature or an acceleration sensor for measuring movement.

[0080] Each electronic component is, for example, soldered to the substrate 5. After each electronic component is soldered to the substrate 5, a medical grade epoxy may be applied to the substrate 5 and the electronic components to encapsulate the substrate 5 and the electronic components.

[0081] The width of the substrate 5 is smaller than the inner diameter of the housing 2 so that the substrate 5 can be accommodated in the internal space R1, and is, for example, 3.6 mm. The substrate 5 may be disposed in contact with the housing 2.

[0082] The lid 3 will be described in detail below.

[0083] Fig. 5 is a plan view of the lid 3 showing the inner surface 3A. For ease of understanding, the internal electrodes 13 are hatched in Fig. 5. Fig. 6 is an enlarged cross-sectional view of the lid 3 and the substrate 5. The cross section in Fig. 6 is taken along line AA in Fig. 5.

[0084] As shown in Fig. 5, each of the protrusions 31 has a contact surface 33 and an open surface 34 opposite the contact surface 33. One surface of the tip of the protrusion 31 is the contact surface 33, and the other surface is the open surface 34. The contact surfaces 33 of the two protrusions 31 face each other across the recess 32. Here, the facing surfaces may mean that the surfaces face each other and are substantially parallel to each other. The distance between the contact surfaces 33, i.e., the dimension in the thickness direction K of the recess 32, may be about 1 mm.

[0085] 6, both contact surfaces 33 are in contact with the substrate 5, and one contact surface 33 is in contact with the active surface 5A. The open surface 34 faces away from the substrate 5. The internal electrode 13 is formed on the open surface 34 of the protrusion 31 that is in contact with the active surface 5A. In an exemplary embodiment, the internal electrode 13 is provided near the tip of the protrusion 31 on the open surface 34.

[0086] When the lid 3 is made of an elastic material such as resin, the internal electrode 13 may be formed on the contact surface 33. When the lid 3 is made of an elastic material, a stable electrical connection can be obtained simply by inserting the substrate 5 into the recess 32. That is, in this case, the connection member 17 may be omitted from the structure of the implant device 1.

[0087] 5, the width of the protrusion 31 narrows as it moves away from the inner surface 3A. With this structure, a larger space can be secured on the substrate 5 for electronic components.

[0088] 6, the contact surface 33 extends along the axial direction L. In an exemplary embodiment, the contact surface 33 is parallel to the active surface 5A of the substrate 5. With this structure, the substrate 5 can be stably held by the contact surface 33 while the internal electrode 13 can be brought closer to the substrate electrode 15. Meanwhile, the open surface 34 is inclined with respect to the active surface 5A, and approaches the contact surface 33 as it extends toward the inside of the substrate 5.

[0089] The inner surface 3A can be divided into a first region X1 disposed in the internal space R1 and a second region X2 surrounding the first region X1. The second region X2 faces the end 2A of the housing 2 (FIG. 3). The outer diameter of the first region X1 is approximately the same as the inner diameter of the housing 2. The outer diameter of the first region X1 is, for example, small enough to be inserted into the internal space R1 and large enough to be fixed to the internal space R1. The outer diameter of the second region X2 (i.e., the outer diameter of the lid 3) is larger than the inner diameter of the housing 2, for example, 5 mm. The thickness of the lid 3 in the second region X2 is smaller than the thickness of the lid 3 in the first region X1, and a wall surface 35 along the axial direction L is formed between the second region X2 and the first region X1. By bringing the wall surface 35 into contact with the inner peripheral surface of the housing 2, it is possible to suppress the intrusion of liquid from the external space R2 into the internal space R1. Furthermore, it becomes easier to align the centers of the lid 3 and the housing 2.

[0090] Here, the outer diameter of a certain component means the maximum distance between two points on the outer circumference of the cross section of the component, and the inner diameter of a certain component means the maximum distance between two points on the inner circumference of the cross section of the component.

[0091] The through conductor 18 electrically connecting the internal electrode 13 and the external electrode 23 is formed, for example, of the same material as the internal electrode 13 and / or the external electrode 23. The through conductor 18 is inclined with respect to the axial direction L. Specifically, the through conductor 18 is inclined from the outer surface 3B toward the inner surface 3A so as to approach the center of the lid 3. With such a structure, the occurrence of cracks in the through conductor 18 can be suppressed, and the lid 3 can be easily manufactured by firing.

[0092] In an exemplary embodiment, the substrate of the lid 3 is made of ceramic, and the internal and external electrodes 13, 23 and vias 18 are made of copper or any other suitable metallic material. The lid 3 is manufactured by a method combining a multi-material 3D printing process with multiple specialized inks for the ceramic, copper and support material, respectively. Different specialized inks may be used for each material.

[0093] First, the lid 3 is designed by a commercial CAD tool (3D-CAD, Autodesk, Inc., San Rafael, CA, USA). The design file containing the design of the lid 3 is converted so that it can be used by an inkjet printer. The inkjet printer head deposits ink containing low-temperature co-fired ceramic (e.g., LTCC), ink containing copper, and ink containing a support material on a heated platform in layers at the same time. The layers solidify when the solvent evaporates. Also, due to the different melting temperatures and sintering rates of ceramic and copper, the via conductor 18 is inclined with respect to the axial direction L. After the deposition of the materials is completed, the formed multilayer structure is placed in an oxygen-deficient environment containing an N2 / H2 atmosphere and heated to above 800°C. This co-firing process removes the support material and forms the lid 3. Finally, the surfaces of the electrodes 13, 23 are plated with electroless nickel immersion gold (ENIG).

[0094] By the above method, it is possible to form a lid 3 having electrodes 13 and 23 communicating with each other, as shown in FIG.

[0095] The positional relationship between the lid 3 and the substrate 5 will be described in detail below.

[0096] 6, the protrusion 31 of the lid 3 covers the substrate 5 near the end 5B of the substrate 5. The internal electrode 13 is formed near the tip of the protrusion 31 covering the active surface 5A of the substrate 5. Therefore, the end 5B of the substrate 5 is disposed on the outer side L1 of the internal electrode 13, that is, near the outer surface 3B. This allows the internal electrode 13 to be disposed closer to the substrate electrode 15.

[0097] In the exemplary embodiment, the depth of the recess 32 is designed so that the bottom 32A of the recess 32 is located outside L1 from the internal electrode 13. The end 5B of the substrate 5 is disposed near the bottom 32A of the recess 32.

[0098] This positional relationship can reduce the distance D1 in the axial direction L between the internal electrode 13 and the board electrode 15 disposed inside the end 5B of the board 5. Therefore, by reducing the size of the implant device 1 and shortening the length of the connection member 17 connecting the internal electrode 13 and the board electrode 15, noise in the measurement results due to the board 5 can be reduced.

[0099] Here, a method of assembling the implant device 1 will be described. First, a part of the substrate 5 is inserted into the recess 32 of the lid 3. By inserting the substrate 5 into the recess 32, the substrate 5 can be easily aligned with respect to the lid 3. Next, in the aligned state, the substrate 5 and the lid 3 are fixed to each other by the connecting member 17. Specifically, the substrate 5 and the lid 3 are soldered. By soldering, the substrate 5 and the lid 3 can be electrically and mechanically connected while maintaining the correct positional relationship. As a result, the substrate 5 and the lid 3 are conducted and fixed to each other. The correct positional relationship is a positional relationship for the electrical connection between the internal electrode 13 and the substrate electrode 15, and is also a positional relationship for suppressing interference between the electronic components of the substrate 5 and the inner peripheral surface of the housing 2. Next, the substrate 5 is inserted into the housing 2 while connected to the lid 3, and one end 2A of the housing 2 is closed with the lid 3. Next, the other end 2B of the housing 2 is closed with the lid 4. The two lids 3, 4 are attached to the housing 2 by any means which attaches the two parts to each other.

[0100] [Usage example] An example of how the implant device 1 is used will now be described.

[0101] The implant device 1 may be implanted in the living body of a chicken using local anesthesia, and biometric information may be collected by a computer outside the living body of the chicken (i.e., outside the living body in which the implant device 1 is implanted).

[0102] Specifically, the analog front end 51 measures an electrocardiogram related to the external space R2 through the substrate electrode 15, the external electrode 23, and the internal electrode 13. The analog front end 51 converts the biopotential signal into a digital signal and transmits the digital signal to the microcontroller 52. The analog front end 51 transmits the digital signal to the microcontroller 52, for example, via an SPI bus. When communication between the external computer and the implant device 1 is established, the microcontroller 52 transmits the digital signal to the computer outside the body in real time using the radio transceiver 55. With this configuration, bioinformation can be acquired in real time.

[0103] The implant device 1 according to the exemplary embodiment can provide the following advantages.

[0104] The implant device 1 according to an exemplary embodiment includes a cylindrical housing 2 having at least one end 2A open and defining an internal space R1. The implant device 1 further includes a lid 3 that closes the one end 2A and has an inner surface 3A facing the internal space R1 and an outer surface 3B opposite to the inner surface 3A. The implant device 1 further includes a substrate 5 that is disposed in the internal space R1 and has an active surface 5A, a substrate electrode 15 disposed on the active surface 5A, and an antenna 53 (e.g., a wireless communication circuit) that communicates biological information acquired through the substrate electrode 15 to the outside of the body. A recess 32 into which the substrate 5 is inserted is formed on the inner surface 3A of the lid 3, and an internal electrode 13 electrically connected to the substrate electrode 15 is disposed on the outer surface 3B of the lid 3.

[0105] By providing the recess 32 in the lid 3 with such a structure, it becomes easy to align the substrate 5 with respect to the lid 3 and to hold the substrate 5. Therefore, it is possible to easily assemble the implant device 1.

[0106] In the implant device 1 according to the exemplary embodiment, the recess 32 is defined by an inner wall surface having a contact surface 33 (eg, a first inner wall surface) and a contact surface 33 (eg, a second inner wall surface) opposed to each other.

[0107] With such a structure, the substrate 5 can be sandwiched between the opposing contact surfaces 33, so that the substrate 5 can be held more firmly.

[0108] In an exemplary embodiment of the implant device 1, one contact surface 33 is part of a first convex portion 31 on the inner surface 3A of the lid 3, and the other contact surface 33 is part of a second convex portion 31 on the inner surface 3A of the lid 3, and the concave portion 32 is located between the first convex portion 31 and the second convex portion 31.

[0109] With such a structure, regardless of the thickness of the lid 3, and therefore the depth of the recess 32, the convex portion 31 can be formed with the necessary protrusion amount to hold the substrate 5, so that the substrate 5 can be held more firmly.

[0110] In the exemplary embodiment of the implant device 1 , the substrate 5 is in contact with at least one of the contact surfaces 33 .

[0111] With such a structure, the contact area between the recess 32 and the substrate 5 is increased, so that the substrate 5 can be held more firmly.

[0112] In the exemplary embodiment of the implant device 1 , the substrate 5 is in contact with both contact surfaces 33 .

[0113] With such a structure, the contact area between the recess 32 and the substrate 5 is further increased, so that the substrate 5 can be held more firmly.

[0114] The implant device 1 according to an exemplary embodiment includes a cylindrical housing 2 having at least one end 2A open and defining an internal space R1. The implant device 1 further includes a lid 3 that closes the one end 2A and has an inner surface 3A facing the internal space R1 and an outer surface 3B opposite to the inner surface 3A. The implant device 1 further includes a substrate 5 that is disposed in the internal space R1 and has an active surface 5A, a substrate electrode 15 disposed on the active surface 5A, and an antenna 53 that communicates biological information acquired through the substrate electrode 15 to the outside of the living body. The inner surface 3A of the lid 3 is provided with a convex portion 31 that contacts the active surface 5A. The convex portion 31 is provided with an internal electrode 13 electrically connected to the substrate electrode 15. The outer surface 3B of the lid 3 is provided with an external electrode 23 electrically connected to the internal electrode 13. The implant device 1 further includes a connection member 17 that connects the internal electrode 13 and the substrate electrode 15.

[0115] This configuration makes it easy to align the substrate 5 with the lid 3, facilitating assembly of the implant device 1. Furthermore, by providing the protrusion 31, it becomes easier to arrange the internal electrode 13 and the substrate electrode 15 close to each other. This allows the implant device 1 to be made smaller, and by shortening the distance between the electrodes, noise can be reduced.

[0116] In the implant device 1 according to an exemplary embodiment, the internal electrode 13 is formed on the surface (open surface 34) of the convex portion 31 opposite to the surface (contact surface 33) that contacts the active surface 5A, and the connection member 17 is conductive.

[0117] With this configuration, the electrical connection between the internal electrode 13 and the board electrode 15 is stably maintained through the connection member 17, while the connection member 17 can be easily provided compared to when the internal electrode 13 is formed on the contact surface 33.

[0118] In the implant device 1 according to the exemplary embodiment, one end 2A of the housing 2 is a first open end and the lid 3 is the first lid. The housing 2 has a second open end (end 2B) opposite the end 2A. The implant device 1 further comprises a second lid (lid 4) that closes the end 2B.

[0119] With this configuration, both ends of the housing 2 can be closed by the end of the manufacturing process, starting from a state in which both ends of the housing 2 are open at the start of the manufacturing process of the implant device 1. This enables access to the substrate 5 from both ends of the housing 2 during the manufacturing process, making it easier to manufacture the implant device 1.

[0120] In the implant device 1 according to the exemplary embodiment, the lid 3 comprises a ceramic material and a metallic material.

[0121] With this configuration, the internal electrode 13 and the external electrode 23 can be integrally formed with the lid 3. This simplifies the structure of the implant device 1 and facilitates assembly.

[0122] In the implant device 1 according to the exemplary embodiment, the lid 3 has a through conductor 18 that passes through the lid 3 and electrically connects the external electrode 23 and the internal electrode 13 .

[0123] With this configuration, electrical connection between the internal electrode 13 and the external electrode 23 can be achieved.

[0124] In the implant device 1 according to the exemplary embodiment, the through conductors 18 are inclined with respect to the axial direction L (for example, the thickness direction of the lid 3).

[0125] With this configuration, the lid 3 can be easily produced by firing. Also, the occurrence of cracks in the through conductors 18 can be suppressed.

[0126] In the exemplary embodiment, an example in which both ends 2A and 2B of the housing 2 are open has been described, but the present invention is not limited to this. The housing 2 is a cylindrical housing with at least one end open. For example, one end of the housing 2 may be closed, and the lid 4 may be omitted.

[0127] In the exemplary embodiment, the housing 2 is cylindrical, but the present invention is not limited to this. For example, the housing 2 may be a cylindrical member having a polygonal cross section. In this case, the shape of the lids 3 and 4 may be designed to match the cross section of the housing 2.

[0128] In the exemplary embodiment, the protrusions 31 sandwich the substrate 5 in the thickness direction K, but the present invention is not limited to this. For example, the protrusions 31 may be formed so as to sandwich the substrate 5 in the width direction. The protrusions 31 may also be formed so as to sandwich the substrate 5 in both the thickness direction K and the width direction, in which case the protrusions 31 may surround the substrate 5 and be formed as one continuous protrusion.

[0129] In the exemplary embodiment, the contact surface 33 is in contact with the substrate 5 and is parallel to the active surface 5A of the substrate 5, but is not limited to this. For example, the contact surface 33 may have a curved shape with respect to the substrate 5, and other members such as an adhesive or a filler may be disposed between the contact surface 33 and the substrate 5.

[0130] In the exemplary embodiment, the open surface 34 of the protrusion 31 is inclined and the protrusion 31 has a triangular cross section, but the present invention is not limited to this. The protrusion 31 may have a cross section of another shape, such as a rectangular cross section, along the axial direction L. On the other hand, if the protrusion 31 has a shape in which the contact surface 33 fits along the substrate 5, it becomes easier to align the substrate 5 with the lid 3.

[0131] In the exemplary embodiment, the microcontroller 52 transmits a digital signal to a computer outside the body, but the present invention is not limited to this. Instead of a computer, another external data aggregator that establishes communication with the implant device 1 through BLE may be provided.

[0132] In the exemplary embodiment, the lid 3 has two protrusions 31, but the present invention is not limited to this. For example, as shown in Modification 1 described later, the lid 3 may have only one protrusion 31 that faces the active surface 5A of the substrate 5.

[0133] Furthermore, for example, as shown in Modification 2 described later, the lid 3 does not have to be provided with the protrusion 31.

[0134] In the exemplary embodiment, the implant device 1 has the lids 3 and 4, but the present invention is not limited to this. For example, the implant device 1 may have two lids 3. In this case, for example, as shown in Modification 3 described later, the outer diameter of the lid 3 may be smaller than the inner diameter of the housing 2, which makes it easy to assemble the implant device.

[0135] In the exemplary embodiment, an example has been described in which one of the two protrusions 31 has the internal electrode 13, but the present invention is not limited to this. For example, as shown in Modification 4 described later, in the lid 3, the internal electrodes 13 may be formed on both of the protrusions 31 that face the substrate 5. When both surfaces of the substrate 5 are active surfaces, if the lid 3 has the internal electrodes 13 on each of the two protrusions 31, the design freedom of the substrate 5 is improved.

[0136] [Variation 1] Fig. 7 is a cross-sectional view of an implant device 101 according to a first modified example of the exemplary embodiment. As shown in Fig. 7, the implant device 101 according to the first modified example differs from the implant device 1 according to the above-described embodiment in that it includes a lid 103. In the first modified example, unless otherwise specified, the other configurations of the implant device 101 are the same as those of the implant device 1 according to the exemplary embodiment, and configurations that are the same as or equivalent to those in the exemplary embodiment are denoted with the same reference numerals and will be described in the same manner. The same applies to other modified examples described later.

[0137] A single protrusion 131 is formed on the inner surface 103A of the lid 103. The protrusion 131 protrudes along the axial direction L of the housing 2 and contacts the active surface 5A of the substrate 5. In other words, the protrusion 131 is a structure for positioning the substrate 5 in the thickness direction K within the housing 2. The substrate 5 is mechanically connected to the protrusion 131 by the connecting member 17 so that the substrate 5 does not separate from the protrusion 131. By providing the protrusion 131, it is possible to suppress the substrate 5 from approaching the inner peripheral surface of the housing 2 with a simple structure and to suppress the electronic components on the substrate 5 from interfering with the inner peripheral surface of the housing 2. Therefore, it is possible to suppress the failure of the substrate 5. Note that a recess 32 may be further formed on the inner surface 103A of the lid 103.

[0138] The internal electrode 13 is formed on the surface of the protrusion 131 opposite to the surface that contacts the substrate 5 .

[0139] [Variation 2] Fig. 8 is a cross-sectional view of an implant device 201 according to an exemplary embodiment of Variation 2. Fig. 9A is a plan view of the lid 203. Fig. 9B is an enlarged cross-sectional view of the lid 203 and the substrate 5.

[0140] As shown in FIG. 8, an implant device 201 in the second modification example differs from the implant device 1 according to the aforementioned exemplary embodiment in that a lid 203 is provided.

[0141] 8 and 9A, one recess 232 is formed in the inner surface 203A of the lid 203. The substrate 5 is inserted into the recess 232. The recess 232 allows the substrate 5 to be aligned with respect to the lid 203. An edge of the substrate 5 may contact a bottom 232A of the recess 232.

[0142] The recess 232 opens in a rectangular shape. Specifically, the recess 232 is defined by inner wall surfaces 233, 234 and inner wall surfaces 235, 236. The inner wall surfaces 233, 234 face each other, and the inner wall surfaces 235, 236 face each other. The distance between the inner wall surfaces 233, 234 corresponds to the thickness of the substrate 5, the inner wall surface 233 contacts the active surface 5A of the substrate 5, and the inner wall surface 234 contacts the rear surface of the substrate 5. On the other hand, the distance between the inner wall surfaces 235, 236 corresponds to the width of the substrate 5, and the inner wall surfaces 235, 236 contact the side surfaces of the substrate 5 that face each other. With this structure, the substrate 5 can be sandwiched between the inner wall surfaces 234, 234, 235, 236 and fixedly held in a state of being aligned with the lid 203. If the lid 203 is made of an elastic material, the substrate 5 can be held more stably within the recess 232 .

[0143] 9B, the depth from the opening of recess 232 to bottom 232A is greater than distance D3 between the edge of substrate 5 and substrate electrode 15. Therefore, at least a portion of substrate electrode 15 is disposed inside recess 232 and contacts inner wall surface 233.

[0144] The internal electrode 213 is located on the inner wall surface 233, and the board electrode 15 is located in a portion of the substrate 5 that is inserted into the recess 232. A distance D2 between the bottom 232A of the recess 232 and the tip 213A of the internal electrode 213 that is distant from the bottom 232A is greater than a distance D3 between the end of the substrate 5 and the board electrode 15. Therefore, the internal electrode 213 comes into contact with the board electrode 15. Even if the connecting member 17 is not provided, electrical connection between the internal electrode 213 and the board electrode 15 can be achieved.

[0145] With such a structure, electrical connection between the lid 203 and the substrate 5 can be achieved by disposing the substrate 5 in the recess 232. Therefore, other components for electrical connection can be omitted. This allows the implant device 201 to be miniaturized and the structure to be simplified.

[0146] On the other hand, a connecting member 17 such as an adhesive may be provided in the recess 232 .

[0147] In addition, in the second modification, a convex portion may be formed around the concave portion 232. For example, the inner surface 203A may be formed with a first convex portion on one side of the concave portion 232 and a second convex portion on the opposite side of the concave portion 232. The inner wall surface 233 is a part of the first convex portion, and the inner wall surface 234 is a part of the twelfth convex portion. The concave portion 232 is located between the first convex portion and the second convex portion.

[0148] In the second modification, the internal electrode 213 is located on the inner wall surface 233, but the present invention is not limited to this. For example, the internal electrode 213 may be formed on the inner side surface 203A around the recess 232.

[0149] [Variation 3] 10 is a cross-sectional view of an implant device 301 according to an exemplary embodiment of Variation 3. As shown in FIG. 10, the implant device 301 according to Variation 3 differs from the implant device 1 according to the aforementioned exemplary embodiment in that it includes a lid 303.

[0150] The implant device 301 includes a housing 2 and two lids 303. Both ends 2A, 2B of the housing 2 are open, and the two lids 303 close both ends 2A, 2B of the housing 2, respectively. The outer peripheral surface of the lid 303 comes into contact with the inner peripheral surface of the housing 2, thereby sealing the housing 2. The ends 2A, 2B of the housing 2 may be crimped to the lid 303.

[0151] The outer diameter of the lid 303 is smaller than the inner diameter of the housing 2. Therefore, the lid 303 can pass through the housing 2 from one end to the other end of the housing 2. With this structure, in assembling the implant device 301, both lids 303 can be attached to the substrate 5 and connected by the connecting member 17, and the structure in which the substrate 5 and the lid 303 are integrated can be inserted into the housing 2. Therefore, even when the implant device 301 has two lids 303, the implant device 301 can be easily assembled.

[0152] Note that one lid 303 may be combined with another lid. Even in this case, the end of the substrate 5 to which the lid 303 is connected passes through the housing 2, so that the substrate 5 and both lids can be assembled in advance and then inserted into the housing 2.

[0153] [Variation 4] 11 is a cross-sectional view of an implant device 401 according to an exemplary embodiment of Variation 4. As shown in FIG. 11, the implant device 401 according to Variation 4 differs from the implant device 1 according to the aforementioned exemplary embodiment in that it includes a lid 403.

[0154] On the inner surface 403A of the lid 403, each of the two protrusions 31 has an internal electrode 413. The two internal electrodes 413 are disposed so as to sandwich the substrate 5 therebetween, and are disposed symmetrically in the thickness direction K with respect to the substrate 5.

[0155] [Example] To confirm the accuracy of prediction of heart rate (HR) and respiration rate (BR) by the implant device 1 according to the embodiment, a test was performed comparing the implant device 1 with a conventional ECG electrode. All animal experiments were approved by the Institutional Animal Care and Use Committee (IACUC) of NC State University.

[0156] FIG. 12 is a schematic diagram showing an embodiment of the implant device 1.

[0157] A proof-of-concept in vivo experiment was conducted using 22-week-old White Leghorn chickens (Gallus gallus domesticus) as subjects, as shown in Figure 12. In addition, needle electrodes connected to commercial devices (e.g., Go Direct® EKG Sensor, Vernier Software & Technology, Beaverton, OR, USA) were used as conventional ECG electrodes.

[0158] In this experiment, local anesthesia was applied to the back of the chicken, and several feathers were plucked to prepare the insertion site for implant device 1. After that, implant device 1 was inserted subcutaneously in the neck between the shoulder blades, and wireless data communication was established between implant device 1 and a remote laptop computer. The chicken was subcutaneously fitted with three needle electrodes for the Go Direct device so that ECG signals could be recorded from conventional ECG electrodes simultaneously with implant device 1. Two needle electrodes were inserted adjacent to implant device 1, and one needle electrode was inserted in the right leg. The Go Direct device was connected to the computer via a USB cable.

[0159] FIG. 13A shows an unprocessed ECG signal (dotted line) modulated by respiratory artifacts recorded by implant device 1 with a sampling frequency of 128 Hz. FIG. 13B shows an unprocessed ECG signal (dotted line) modulated by respiratory artifacts recorded by conventional ECG electrodes with a sampling frequency of 128 Hz. In FIG. 13A and FIG. 13B, the thin solid line shows the baseline of the respiratory modulation. FIG. 14 shows filtered ECG signals after subtraction of the respiratory artifacts by implant device 1 and conventional ECG electrodes. In FIG. 14, the R-peaks of the cardiac cycles recorded by implant device 1 are marked with a square and the R-peaks of the cardiac cycles recorded by conventional ECG electrodes are marked with a circle.

[0160] A 15-point moving average filter was used to extract the respiratory baseline. By subtracting the baseline from the raw ECG signal, a clean ECG signal was obtained, as shown in Figure 14, and the clean ECG signals from both devices were consistent with each other.

[0161] Peak detection was performed on the filtered ECG signal and the ECG baseline to obtain the RR and respiration intervals, respectively, using the library function “findpeaks” in MATLAB (Mathworks, Natick, MA, USA). The filtered ECG signal and the ECG baseline have a duration of 3 min.

[0162] Figure 15A shows the RR intervals extracted using clean ECG signals from both devices, and Figure 15B shows the respiratory intervals calculated from the intervals between successive peaks of the ECG baseline. In Figure 15A, the respiratory baseline is shown as a dashed line to show the effect of respiratory sinus arrhythmia.

[0163] Heart rate in beats per minute (BPM) and respiratory rate in breaths per minute (BrPM) were calculated from the peak intervals shown in Figures 15A and 15B.

[0164] [Table 1]

[0165] As shown in Table 1, the mean absolute percentage error and Pearson correlation coefficient between the heart rate values ​​of the two devices were 1.72% and 0.77, and the mean absolute percentage error and Pearson correlation coefficient between the respiratory rate values ​​of the two devices were 4.38% and 0.79. These and other statistics derived therefrom confirm the ability of implant device 1 to provide accurate physiological information.

[0166] In FIG. 15A, a periodic modulation was observed in the heart beat interval (or heart rate) that is related to respiratory artifacts. This modulation is known as respiratory sinus arrhythmia (RSA). This physiological phenomenon causes the RR interval to shorten on inspiration and lengthen on expiration, and is commonly seen in humans (especially newborns) and other vertebrates. In FIG. 15A, the respiratory baseline is plotted to show the effect of RSA. To verify the effect of RSA on the RR interval, a discrete Fourier transform (DFT) was applied to the instantaneous signals of the RR interval values ​​collected from the implant device 1 and the respiratory baseline of the ECG waveform.

[0167] Figure 16A shows the magnitude of the DFT applied to the RR interval values ​​from implant device 1. Figure 16B shows the magnitude of the DFT applied to the respiratory baseline.

[0168] Both signals showed a peak at the same frequency corresponding to BR. This common peak at approximately 0.47 Hz (28.2 BrPM) confirmed the effectiveness of RSA. This result further confirmed the functionality of the implant device 1 in capturing useful physiological information.

[0169] A subcutaneously implantable biopotential sensor system, implant device 1, capable of continuously recording ECG to obtain heart rate and respiration rate in animals, has been developed. Previously, difficulties in connecting biopotential electrodes and integrating the electrodes into a small package have hindered the design and manufacture of such implant devices. To facilitate mass production of biopotential electrodes for such implants, a multi-material 3D printing technique was used. In Example 1, implant device 1 also demonstrated accuracy comparable to that of a commercial tabletop ECG system.

[0170] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various modifications and variations are apparent to those skilled in the art. The configurations of the above-mentioned embodiments and modifications may be combined. [Industrial Applicability]

[0171] The implant device of the present disclosure is easy to assemble and therefore useful for animal scientists, veterinarians, and biomedical researchers as an implant device for continuous, real-time, high-resolution monitoring of vital signs.

Claims

1. A cylindrical housing having at least one open end and defining an interior space; a lid that closes the one end and has an inner surface facing the internal space and an outer surface opposite to the inner surface; a substrate disposed in the internal space along an axial direction passing from the one end to the other end, the substrate having an active surface along the axial direction, a substrate electrode disposed on the active surface, and a wireless communication circuit configured to communicate biological information acquired through the substrate electrode; The inner surface of the lid is provided with a protrusion that comes into contact with the active surface, The protrusion is provided with an internal electrode electrically connected to the substrate electrode, an external electrode electrically connected to the internal electrode is provided on the outer surface of the lid; a connection member that connects the internal electrode and the substrate electrode; the protrusion has a first surface on one side that contacts the active surface, and a second surface on the other side that faces in a direction intersecting the axial direction, the internal electrode is disposed on the second surface of the protrusion, An implant device, wherein the connecting member is electrically conductive.

2. The implant device of claim 1 , wherein an outer diameter of the lid is smaller than an inner diameter of the housing.

3. The one end is a first end, The lid is a first lid, The housing has a second end opposite the first end, a second lid closing the second end; The implant device of claim 1 , wherein an outer diameter of the first lid and an outer diameter of the second lid are smaller than an inner diameter of the housing.

4. the lid has a through conductor penetrating the lid and electrically connecting the external electrode and the internal electrode, The implant device according to claim 1 , wherein the through conductor is inclined with respect to a thickness direction of the lid.

5. The convex portion is a first convex portion, Further comprising a second protrusion disposed on the inner surface of the lid, The implant device of claim 1 , wherein the substrate is disposed between the first convex portion and the second convex portion.

6. A recess is formed between the first convex portion and the second convex portion, The implant device of claim 5 , wherein the substrate is disposed in the recess.

7. An implant device as described in claim 6, wherein the recess is defined by an inner wall surface having a first inner wall surface and a second inner wall surface opposing each other.

8. An implant device as described in claim 7, wherein the substrate contacts at least one of the first inner wall surface or the second inner wall surface.

9. An implant device as described in claim 8, wherein the substrate contacts the first inner wall surface and the second inner wall surface.

10. An implant device as described in claim 1, wherein the external electrode has a larger area than the internal electrode.

11. The implant device of claim 1, wherein the lid has a ceramic material and a metal material.

12. An implant device as described in claim 1, wherein the second surface is inclined toward the active surface.

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