Multi-mode implantable sensor and signal acquisition system

Abstract

The invention discloses a multi-mode implantable sensor and a signal acquisition system, and relates to the technical field of medical instruments, and the multi-mode implantable sensor comprises two layers of flexible substrates which are oppositely arranged; the multi-mode electronic functional layer is located between the two layers of flexible substrates and comprises at least two sensors used for collecting different biological characteristic signals; the flexible substrate has a shape memory capability, so that the multi-mode implantable sensor can be converted from a contraction state to an expansion state. According to the invention, different biological characteristic signals can be monitored at the same time through the same multi-mode implantable sensor; in addition, the multi-mode implantable sensor can also realize form switching based on a flexible substrate with shape memory ability, so that the multi-mode implantable sensor can be implanted through a small-size contraction state to reduce implantation wounds, and can be converted from the contraction state to an expansion state after implantation is completed, so that multi-mode biological characteristic signals can be conveniently acquired.

Description

[0001] This application claims the priority of a Chinese patent application with the application number 202510578313.3 and the invention title "Implantable Sensor Encapsulation Structure and Biometric Signal Acquisition System", which was filed with the Chinese Patent Office on May 6, 2025. The entire content of this Chinese patent application is incorporated herein by reference. Technical Field

[0002] This application relates to the technical field of medical devices, and particularly to a multimodal implantable sensor and signal acquisition system. Background Art

[0003] An implantable sensor is a miniaturized sensing device that can be implanted into a living organism to collect biometric signals in real time and transmit the collected biometric signals to an external monitor in a wired or wireless manner. Its core value lies in long-term, in-situ, and dynamic tracking of target indicators, providing accurate data support for medical diagnosis.

[0004] Currently, the encapsulation structure of a conventional implantable sensor is generally a single-modal design of a tubular structure, that is, the encapsulation structure of the implantable sensor integrates a sensor chip for collecting a single biometric signal on a rigid catheter. The form of the implantable sensor encapsulation structure is fixed, and a multi-catheter implantation scheme is required during use to achieve multimodal biometric signal acquisition. Summary of the Invention

[0005] In view of the above problems, this application provides a multimodal implantable sensor and signal acquisition system to achieve the purpose of automatically switching the form and performing multimodal biometric signal acquisition with a single encapsulation structure. The specific solutions are as follows:

[0006] In a first aspect of this application, a multimodal implantable sensor is provided, including:

[0007] Two layers of flexible substrates arranged oppositely;

[0008] A multimodal electronic functional layer located between the two layers of flexible substrates, and the multimodal electronic functional layer includes at least two sensors for collecting different biometric signals;

[0009] Wherein, the flexible substrate has shape memory ability and can enable the multimodal implantable sensor to switch from a contracted state to an expanded state.

[0010] Optionally, in the above multimodal implantable sensor, it further includes:

[0011] A wireless communication functional layer, which is laminated between the two layers of flexible substrates together with the multimodal electronic functional layer; the wireless communication functional layer is electrically connected to the sensor and is used for wireless communication with an external circuit.

[0012] Optionally, in the above multi-modal implantable sensor, the wireless communication function layer includes:

[0013] A circuit board with wireless communication function, and the sensor is electrically connected to the circuit board;

[0014] A plurality of coils surrounding the circuit board, and the coils are used to form a circular magnetic field; if the multi-modal implantable sensor is unfolded in a plane, the plurality of coils are concentric rings.

[0015] Optionally, in the above multi-modal implantable sensor, the flexible substrate includes: a plurality of radial support arms, and one end of each radial support arm is connected to the same central position; the radial support arms are connected by support beams;

[0016] If the multi-modal implantable sensor is unfolded in a plane, each radial support arm is located on a different radius of the same circular area, and the central position is the center of the circular area; at least two support beams are connected between adjacent two radial support arms.

[0017] Optionally, in the above multi-modal implantable sensor, there are at least two concentric rings inside the circular area, and support beams are sequentially connected to the intersection points of the circumferences of the concentric rings and each radial support arm.

[0018] Optionally, in the above multi-modal implantable sensor, the support beam is a serpentine trace connected between two radial support arms.

[0019] Optionally, in the above multi-modal implantable sensor, the multi-modal electronic function layer includes a plurality of sensor components;

[0020] The sensor component includes at least two sensors for collecting different biometric signals;

[0021] The sensor component is located between the radially opposite support arms of two layers of flexible substrate laminates.

[0022] Optionally, in the above multi-modal implantable sensor, the sensor component includes: a circular detection area, N sensors are arranged in the circular detection area, and each sensor is respectively used to collect different biometric signals, where N is a positive integer greater than 1; the circular detection area is opposite to the end of the radial support arm far from the central position; among them,

[0023] The circular detection area is divided into N + 1 fan-shaped areas, and N of the N + 1 fan-shaped areas are used to respectively arrange one sensor, and the remaining one fan-shaped area is used to arrange the signal lines connected to each sensor;

[0024] Or, the circular detection area is divided into N concentric ring detection areas, and each of the N concentric ring detection areas is used to arrange one sensor.

[0025] Optionally, in the above multi-modal implantable sensor, the flexible substrate automatically switches from a contracted state to an expanded state when reaching the glass transition temperature of its own material, and the glass transition temperature range of the flexible substrate is 35°C to 45°C;

[0026] Alternatively, the multi-modal implantable sensor further includes: a visible marking layer for displaying the expanded state of the multi-modal implantable sensor;

[0027] Alternatively, the thicknesses of the two flexible substrates are different;

[0028] Alternatively, the thickness ratio of the two flexible substrates is not less than 2;

[0029] Alternatively, the material of the flexible substrate is a biodegradable polymer.

[0030] The second aspect of the present application provides a signal acquisition system, including:

[0031] The multi-modal implantable sensor of any one of the above;

[0032] An external monitor, which is communicatively connected to the multi-modal implantable sensor.

[0033] By means of the above technical solutions, in the technical solutions of the present application, at least two sensors for collecting different biometric signals are integrated in the multi-modal implantable sensor, and multi-modal biometric signals can be collected through the same multi-modal implantable sensor. Different biometric signals can be monitored simultaneously through the same multi-modal implantable sensor, eliminating the need for multi-catheter implantation and avoiding problems such as large implantation trauma and high infection risks caused by multi-catheter implantation. Moreover, the multi-modal implantable sensor can also achieve morphological switching based on a flexible substrate with shape memory ability, capable of switching from a contracted state to an expanded shape, enabling the multi-modal implantable sensor to be implanted in a small-sized contracted state to reduce implantation trauma. After implantation, the shape memory ability of the flexible substrate can be utilized to convert the multi-modal implantable sensor from a contracted state to an expanded state for facilitating the collection of multi-modal biometric signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0035] The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementation conditions of this application. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that this application can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in this application.

[0036] Figure 1 It is a sectional view in the thickness direction of a multimodal implantable sensor provided by an embodiment of this application;

[0037] Figure 2 It is another sectional view in the thickness direction of a multimodal implantable sensor provided by an embodiment of this application;

[0038] Figure 3 It is a top view of a wireless communication function layer provided by an embodiment of this application;

[0039] Figure 4 It is yet another sectional view in the thickness direction of a multimodal implantable sensor provided by an embodiment of this application;

[0040] Figure 5 It is a top view of a flexible substrate provided by an embodiment of this application, Figure 5 It is a top view of the flexible substrate when in the unfolded state;

[0041] Figure 6 It is a partial top view of a flexible substrate provided by an embodiment of this application;

[0042] Figure 7 It is an exploded view of a sensor packaging structure provided by an embodiment of this application;

[0043] Figure 8 It is a top view of a multimodal electronic function layer provided by an embodiment of this application;

[0044] Figure 9 It is a partially enlarged top view of a sensor assembly provided by an embodiment of this application;

[0045] Figure 10 It is another partially enlarged top view of a sensor assembly provided by an embodiment of this application;

[0046] Figure 11 It is a schematic structural diagram of a signal acquisition system provided by an embodiment of this application;

[0047] Figure 12 It is a schematic diagram of the implantation principle of a multimodal implantable sensor before signal acquisition by a signal acquisition system provided by an embodiment of this application;

[0048] Figure 13 Schematic diagram of the working principle of a signal acquisition system provided by an embodiment of the present application.

[0049] Reference numerals:

[0050] 100 - Multimodal implantable sensor; 101 - First flexible substrate; 1011 - Radial support arm; 1012 - Support beam; 1013 - Node position; 1014 - Circular area; 1015 - Central position; 1016 - Concentric ring; 102 - Multimodal electronic functional layer; 1020 - Sensor assembly; 1021 - Pressure sensor; 1022 - Temperature sensor; 1023 - pH sensor; 1024 - Passive electrode array; 1025 - Active electrode array; 1026 - Signal line; 103 - Visual marking layer; 104 - Wireless communication functional layer; 1041 - Coil; 1042 - Circuit board; 105 - Second flexible substrate; 106 - Sensor; 107 - Circular detection area; 108 - Wiring area; 109 - Sector area; 110 - Concentric ring detection area; 200 - Monitor; 201 - Wireless reading module; 202 - Cable; 203 - Display instrument. Detailed implementation manners

[0051] Next, the embodiments in the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Those of ordinary skill in the art can know that with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0052] Intracranial monitoring technology refers to the technology of real - time monitoring of physiological, biochemical or electrophysiological parameters in the cranial cavity through invasive or non - invasive means, mainly used for neurocritical care, epilepsy surgery evaluation and brain function research. Clinically, traditional monitoring technologies, such as electroencephalogram (EEG), intracranial pressure (ICP) monitoring, cerebral oxygen saturation, cerebral blood flow assessment, etc., have provided great help to clinicians in clinical decision - making and intervention.

[0053] Traditional intracranial monitoring relies on invasive ventricular catheters or fiber optic probes, which have problems such as a high infection rate (>45%) and easy drift. Existing wireless implantable sensors have a single function, lack the ability of multi - parameter collaborative analysis, and non - degradable materials need to be removed by a second operation, increasing the risk to patients. In addition, existing devices are difficult to distinguish different encephalopathy characteristics (such as the pH difference between cerebral edema and cerebral hemorrhage), which limits the accuracy of clinical decision - making.

[0054] In view of this, an embodiment of the present application provides a multimodal implantable sensor. The multimodal implantable sensor belongs to the cross - field of biomedical engineering, microelectronics technology and intelligent medical devices. The implantable sensor package structure includes:

[0055] Two relatively arranged flexible substrates;

[0056] A multimodal electronic functional layer located between the two flexible substrates, the multimodal electronic functional layer including at least two sensors for collecting different biometric signals;

[0057] Wherein, the flexible substrate has shape memory ability and can enable the multimodal implantable sensor to switch from a contracted state to an expanded state.

[0058] In the embodiments of the present application, at least two sensors for collecting different biometric signals are integrated in the multimodal implantable sensor at the same time. The multimodal biometric signals can be collected through the same multimodal implantable sensor, and different biometric signals can be monitored simultaneously through the same multimodal implantable sensor. There is no need for multi-catheter implantation, and problems such as large implantation trauma and high infection risk caused by multi-catheter implantation can be avoided.

[0059] Moreover, the multimodal implantable sensor can also realize the morphological switching based on the flexible substrate with shape memory ability, and can switch from the contracted state to the expanded shape, so that the multimodal implantable sensor can be implanted in the contracted state with a small size to reduce the implantation trauma. After the implantation is completed, the shape memory ability of the flexible substrate can be used to make the multimodal implantable sensor switch from the contracted state to the expanded state, so as to facilitate the collection of multimodal biometric signals.

[0060] Furthermore, at least the flexible substrate in the multimodal implantable sensor can be made of biodegradable materials. The structural components prepared with biodegradable materials do not need to be removed by a second operation, which can reduce the trauma of the second operation.

[0061] It should be noted that, in the embodiments of the present application, the intracranial biometric signal collection is taken as an example for illustration. It is easy to know that the multimodal implantable sensor in the embodiments of the present application is not limited to intracranial biometric signal collection, and can also be used for biometric signal collection in other parts, such as biometric signal collection in the abdominal cavity or thoracic cavity, etc. The application scenarios of the multimodal implantable sensor in the embodiments of the present application are not limited.

[0062] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0063] Refer to Figure 1 , Figure 1 is a sectional view of a multimodal implantable sensor provided by an embodiment of the present application in the thickness direction. The shown multimodal implantable sensor 100 includes:

[0064] Two relatively arranged flexible substrates, and the two flexible substrates can be respectively set as the first flexible substrate 101 and the second flexible substrate 105;

[0065] A multimodal electronic functional layer 102 located between the two flexible substrates, and the multimodal electronic functional layer 102 includes at least two sensors 106 for collecting different biometric signals;

[0066] Among them, the flexible substrate has shape memory ability, which can enable the multimodal implantable sensor 100 to be converted from a contracted state to an expanded state.

[0067] Such as Figure 1 shown, the first flexible substrate 101, the multimodal electronic functional layer 102 and the second flexible substrate 105 are stacked vertically in Figure 1 . The two flexible substrates can not only realize the morphological switching of the multimodal implantable sensor, but also encapsulate and protect the multimodal electronic functional layer 102 therebetween.

[0068] At least two sensors for collecting different biometric signals are integrated in the multimodal implantable sensor 100 at the same time. The multimodal biometric signals can be collected through the same multimodal implantable sensor 100, and different biometric signals can be monitored simultaneously through the same multimodal implantable sensor. There is no need for multi-catheter implantation, and problems such as large implantation trauma and high infection risk caused by multi-catheter implantation can be avoided.

[0069] Moreover, the multimodal implantable sensor 100 can also realize the morphological switching based on the flexible substrate with shape memory ability, and can be switched from the contracted state to the expanded shape, so that the multimodal implantable sensor 100 can be implanted through the small-sized contracted state to reduce the implantation trauma. After the implantation is completed, the shape memory ability of the flexible substrate can be used to convert the multimodal implantable sensor from the contracted state to the expanded state for the collection of multimodal biometric signals.

[0070] The multimodal implantable sensor provided by the embodiment of the present application can be used for long-term real-time monitoring of intracranial physiological signals, and can provide differential diagnosis support for diseases such as traumatic brain injury and epilepsy based on the collected multiple biometric signals.

[0071] Reference Figure 2 , Figure 2 is a sectional view of another multimodal implantable sensor provided by the embodiment of the present application in the thickness direction. On the basis of other embodiments, Figure 2The multi-modal implantable sensor 100 shown also includes: a wireless communication function layer 104, which is stacked between two flexible substrates with the multi-modal electronic function layer 102; the wireless communication function layer 104 is electrically connected to the sensor and is used for wireless communication with an external circuit.

[0072] As Figure 2 shown, the first flexible substrate 101, the multi-modal electronic function layer 102, the wireless communication function layer 104, and the second flexible substrate 105 are stacked vertically in Figure 2 it. Optionally, the stacking order of the wireless communication function layer 104 and the multi-modal electronic function layer 102 between the two flexible substrates can be adjusted according to requirements, not limited to the Figure 2 shown stacking order, and the upper and lower stacking order of the wireless communication function layer 104 and the multi-modal electronic function layer 102 in the Figure 2 shown structure can be adjusted.

[0073] The manufacturing method of the wireless communication function layer 104 includes: laser etching a copper foil on a PDMS substrate to form a loop antenna, welding an NFC chip and encapsulating a capacitor to form a circuit board 1042 for NFC communication. The receiving coil 1041 can be prepared by magnetron sputtering a magnesium layer, formed into a planar spiral structure by ultraviolet laser engraving, and connected to the sensor layer through conductive silver glue.

[0074] Refer to Figure 3 , Figure 3 which is a top view of a wireless communication function layer provided by an embodiment of the present application, Figure 3 and is a top view of the wireless communication function layer 104 when in an unfolded state, that is, a top view when the wireless communication function layer 104 is unfolded to a planar state. On the basis of other embodiments, Figure 3 the wireless communication function layer 104 shown includes: a circuit board 1042 with wireless communication function, and the sensor is electrically connected to the circuit board 1042; a plurality of coils 1041 surrounding the circuit board 1042, and the coils 1041 are used to form a loop magnetic field; if the multi-modal implantable sensor 100 is unfolded in a plane, the plurality of coils 1041 are concentric rings.

[0075] Among them, the circuit board 1042 in the wireless communication function layer 104 includes an NFC chip and a ceramic capacitor. The wireless communication function layer 104 can be coupled with an external wireless reading module to realize wireless power supply and data backhaul with a short transmission distance. The non-degradable circuit board 1042 can be encapsulated in a PBAT-iodixanol composite layer, and after the flexible substrate and other biodegradable materials in the organism decompose after the operation, the circuit board 1042 can be taken out through a minimally invasive incision.

[0076] Optionally, the coil 1041 can be a magnesium coil. The magnesium material not only has good biocompatibility but also has the property of biodegradability. Therefore, the magnesium coil can be degraded in the body after a certain period of use, which can reduce the extraction volume of the multimodal implantable sensor 100 after it has completed its use.

[0077] The wireless communication function layer 104 can be provided with a coil 1041 having a plurality of concentric ring structures according to requirements. The number of coils 1041 is not limited to Figure 3 the two shown in

[0078] Reference Figure 4 , Figure 4 is a cross-sectional view of another multimodal implantable sensor provided by an embodiment of the present application in the thickness direction. On the basis of other embodiments, Figure 4 the multimodal implantable sensor 100 shown further includes: a visual marking layer 103, and the visual marking layer 103 is used to display the unfolded state of the multimodal implantable sensor 100 and can be used to track the device unfolding state in real time.

[0079] As Figure 4 shown, the first flexible substrate 101, the multimodal electronic function layer 102, the visual marking layer 103, the wireless communication function layer 104, and the second flexible substrate 105 are sequentially stacked in the Figure 4 vertical direction in Figure 4 . Optionally, the stacking order of the multimodal electronic function layer 102, the visual marking layer 103, and the wireless communication function layer 104 between the two flexible substrates can be adjusted according to requirements and is not limited to the Figure 4 stacking order shown. The up-and-down stacking order of the multimodal electronic function layer 102, the visual marking layer 103, and the wireless communication function layer 104 in the

[0080] shown structure can be adjusted arbitrarily.

[0081] The visual marking layer 103 is not limited to showing the deployed state of the multimodal implantable sensor 100 through X-ray sensitive materials. It can also be used to show the deployed state of the multimodal implantable sensor 100 through other visual marking principles, such as through terahertz wave sensitive materials to show the deployed state of the multimodal implantable sensor 100 after implantation based on terahertz waves, or through ultrasonic sensitive materials to show the deployed state of the multimodal implantable sensor 100 after implantation based on ultrasonic waves, or through materials capable of emitting fluorescence in a specific wavelength band to show the deployed state of the multimodal implantable sensor 100 after implantation based on the fluorescence of this wavelength band.

[0082] Optionally, when the visual marking layer 103 is prepared from non-biodegradable materials, in order to facilitate the removal of electronic components prepared from non-biodegradable materials such as the sensors 106 in the multimodal electronic function layer 102 and the circuit board 1042 in the wireless communication function layer 104 from the living body together with the visual marking layer 103 after use, the multimodal electronic function layer 102 and the wireless communication function layer 104 can be respectively arranged on one side surface of the visual marking layer 103, that is, the multimodal electronic function layer 102, the visual marking layer 103 and the wireless communication function layer 104 are stacked in sequence, and the positions of the multimodal electronic function layer 102 and the wireless communication function layer 104 can be interchanged.

[0083] Reference Figure 5 , Figure 5 is a top view of a flexible substrate provided by an embodiment of the present application. Figure 5 is a top view of the flexible substrate when in the deployed state, that is, the top view of the flexible substrate when it is deployed to a planar state. On the basis of other embodiments, Figure 5 in the shown manner, the flexible substrate includes: a plurality of radial support arms 1011, one end of each radial support arm 1011 is connected to the same central position 1015; the radial support arms 1011 are connected by support beams 1012; if the multimodal implantable sensor 100 is deployed in a plane, each radial support arm 1011 is located on different radii of the same circular region 1014, and the central position 1015 is the center of the circular region 1014; at least two support beams 1012 are connected between adjacent two radial support arms 1011.

[0084] When integrated with the above-mentioned wireless communication function layer 104, the multi-modal implantable sensor 100 realizes functional partitioning through the mechanical coupling of the support beams 1012 in the flexible substrate as the chassis. The central area of the flexible substrate can be used to arrange the rigid circuit board 1042, the middle circle can be used to layout the coil 1041, and the circular distal ends of the radial support arms 1011 in the outer circle can be used to layout the pressure sensor 1021, pH sensor 1023 and temperature sensor 1022 for monitoring stress and metabolic indicators; high-density passive electrode arrays 1024 and active electrode arrays 1025 are also laid out at the circular distal ends for capturing neural electrical activities. The arc design of the support beam 1012 can not only be used to provide the unfolding driving force, but also form a circular magnetic field as the carrier of the coil 1041 for optimizing the wireless energy transmission efficiency.

[0085] Optionally, the line width of the radial support arm 1011 can be 0.5 mm to 2 mm, such as 0.51 mm, or 0.8 mm, or 1 mm, or 1.52 mm, or 1.69 mm, etc. Within this line width range, not only can the effective encapsulation and protection of other film layers between the two flexible substrates be achieved, but also the flexible substrate can have good shape memory ability.

[0086] Optionally, the line width of the support beam 1012 is smaller than that of the radial support arm 1011. The line width of the support beam 1012 can be 100 μm to 500 μm, such as 110 μm, or 121 μm, or 150 μm, or 300 μm, or 355 μm, or 400 μm, etc. This method can provide a relatively large shape memory ability in the radial direction through the radial support arm 1011 with a larger line width, and provide a relatively small shape memory ability intersecting with the radial direction and improve the tensile strain that each film layer can withstand during lamination through the support beam 1012 with a smaller line width.

[0087] Among them, the number of the radial support arms 1011 can be set to any number according to requirements, not limited to Figure 5 the six shown, and can also be three, or five, or eight, etc., any number. The embodiments of the present application do not limit the number of the radial support arms 1011.

[0088] Optionally, each radial support arm 1011 can have the same length and be evenly distributed in the circular area 1014 for the convenience of the process preparation of the flexible substrate. In other embodiments, the lengths of the respective radial support arms 1011 can be different, and / or the respective radial support arms 1011 can be unevenly distributed in the circular area 1014.

[0089] If the multi-modal implantable sensor 100 unfolds in a plane, Figure 5In the flexible substrate with the structure shown, each radial support arm 1011 extends radially outward from the central position 1015 along different radial directions of the circular region 1014, and at least two support beams 1012 are connected between adjacent radial support arms 1011. Among them, the support beam 1012 and the radial support arm 1011 are connected at the node position 1013. At the node position 1013 of the support beam 1012 and the radial support arm 1011, the radial support arm 1011 and the support beam 1012 can form a grid structure, and this grid structure has the mechanical topological structure of a tent skeleton. After unfolding, the grid structure can better conformally cover and fit on the surface of the biological tissue to be detected based on its flexible and bendable characteristics.

[0090] Optionally, a polycaprolactone (PCL) fixing ring is embedded at the node position 1013, and it can be integrated with a degradable electronic layer (such as a magnesium coil and magnesium wire, etc.) through a heat-sealing process to ensure mechanical stability. The outer surface of the flexible substrate can be coated with a biological lubricating layer, and the composition of the biological lubricating layer includes glycerol-based hydrogel, which can ensure the smooth unfolding of the flexible substrate on the tissue surface in the living body by reducing the surface friction coefficient of the flexible substrate and avoid mechanical damage.

[0091] The graphic structures of the first flexible substrate 101 and the second flexible substrate 105 are the same in the top view, and they are arranged opposite to each other so that they can completely coincide in the flat unfolded state. In this way, the first flexible substrate 101 and the second flexible substrate 105 encapsulate and protect other film layer structures located between them through a lamination process.

[0092] In Figure 5 In the manner shown, the graphic structure of the film layer encapsulated between the two flexible substrates and the graphic structure of the flexible substrate can form a multimodal implantable sensor 100 with a grid structure. The multimodal implantable sensor 100 is a new type of multimodal heterogeneous encapsulation structure, which can synchronously collect multiple biological characteristic signals on the same substrate framework (that is, two relatively arranged flexible substrates).

[0093] Optionally, as Figure 5As shown, there are at least two concentric rings 1016 inside the circular area 1014. Support beams 1012 are sequentially connected to the intersections of the circumferences of the concentric rings 1016 and each radial support arm 1011. The intersections of the circumferences of the concentric rings 1016 and each radial support arm 1011 form node positions 1013. The concentric rings 1016 and the circular area 1014 have the same center. In this way, based on the multiple concentric rings 1016 within the circular area 1014, each radial support arm 1011 is connected, thereby forming the above-mentioned grid structure. Based on the mechanical topology of this grid structure, the multi-modal implantable sensor 100 can be better deployed, and the multi-modal implantable sensor 100 can better conformally cover and adhere to the surface of the biological tissue to be detected based on its self-designed flexible characteristics and the mechanical topology of the grid structure.

[0094] In the embodiment of the present application, the flexible substrate is made of a biodegradable material and is integrated with multiple different sensors at the same time. It can collect different biological characteristic signals of the same type at one time, and has the advantages of high integration and small wound surface, which can significantly reduce the implantation trauma and infection risk.

[0095] In one implementation manner, as Figure 5 shown, each support beam 1012 can be an arc matching the circumference of the concentric ring 1016 where it is located.

[0096] Refer to Figure 6 , Figure 6 which is a partial top view of a flexible substrate provided by an embodiment of the present application. Figure 6 is a top view of two adjacent radial support arms 1011 and the connected support beams 1012 when the flexible substrate is in the unfolded state, that is, a top view of two adjacent radial support arms 1011 and the connected support beams 1012 when the flexible substrate 104 is unfolded to the planar state. Different from the Figure 5 shown manner, Figure 6 in the shown manner, the support beam 1012 is a serpentine trace connected between two radial support arms 1011. The support beam 1012 adopts a serpentine trace, which can withstand higher tensile strain during encapsulation, so that after the structures of each layer of the multi-modal implantable sensor 100 are stacked in sequence, lamination encapsulation can be carried out through two flexible substrates, avoiding cracks or fractures in the support beam 1012 due to large tensile strain during the lamination process.

[0097] Refer to Figure 7 , Figure 7 which is an exploded view of a sensor encapsulation structure provided by an embodiment of the present application. On the basis of other implementation manners, Figure 7The multi-modal implantable sensor 100 shown includes: two flexible substrates arranged opposite to each other; a multi-modal electronic functional layer 102, a visual marking layer 103, and a wireless communication functional layer 104 stacked in sequence between the two flexible substrates.

[0098] The two flexible substrates are configured as the base frame of the multi-modal implantable sensor 100. The thickness range of the flexible substrate can be 10μm - 200μm. Optionally, the thickness of the flexible substrate can be 30μm, or 50μm, or 61μm, or 100μm, or 122μm, or 150μm, etc. Setting the thickness value of the flexible substrate within this thickness range can not only effectively encapsulate and protect other film layer structures between the two flexible substrates, but also enable the base frame to have good shape memory ability.

[0099] At least the multi-modal electronic functional layer 102 can be sealed between the first flexible substrate 101 and the second flexible substrate 105. Further, at least one of the visual marking layer 103 and the wireless communication functional layer 104 can also be sealed between the first flexible substrate 101 and the second flexible substrate 105. If the multi-modal electronic functional layer 102, the visual marking layer 103, and the wireless communication functional layer 104 are stacked in sequence between the first flexible substrate 101 and the second flexible substrate 105, the stacking order of the multi-modal electronic functional layer 102, the visual marking layer 103, and the wireless communication functional layer 104 between the first flexible substrate 101 and the second flexible substrate 105 can be set according to requirements, not limited to Figure 7 the shown manner.

[0100] In the embodiments of the present application, by optimizing the graphic structure of the radial support arms 1011 and the support beams 1012, the flexible substrate can have a gradually changing shape memory ability from the central position 1015 to the four peripheral edges. For example, the shape memory ability of the flexible substrate can be gradually decreased or gradually increased from the central position 1015 to the four peripheral edges. In this way, the unfolding stress of the flexible substrate can show a gradually changing gradient from the central position 1015 to the four peripheral edges, so that the multi-modal implantable sensor 100 can present a three-dimensional unfolding with a certain convexity or concavity, rather than a flat planar unfolding. Combining its own flexible property, it can better conformally cover the surface of biological tissues with a curved surface.

[0101] For the same layer of flexible substrate, the line width of the support beams 1012 on each concentric ring 1016 can be set to gradually change along the radial direction, so that the expansion stress of the flexible substrate presents a gradual gradient change from the center position 1015 to the surrounding edges; or, the line width of each radial support arm 1011 can be set to gradually change along the radial direction, so that the expansion stress of the flexible substrate presents a gradual gradient change from the center position 1015 to the surrounding edges; or the line width of the support beams 1012 on each concentric ring 1016 and the line width of each radial support arm 1011 can be set to gradually change along the radial direction at the same time, so that the expansion stress of the flexible substrate presents a gradual gradient change from the center position 1015 to the surrounding edges.

[0102] Optionally, based on other embodiments, in one embodiment, the flexible substrate automatically switches from a contracted state to an expanded state when the glass transition temperature of its own material is met. The glass transition temperature range of the flexible substrate is 35°C to 45°C, and this temperature range can automatically trigger state switching through biological body temperature. In this method, the flexible substrate uses a glass transition temperature that can be stimulated by biological body temperature to automatically switch states, automatically switching from a contracted state to an expanded state, that is, the state switching of the multimodal implantable sensor 100 can be achieved through the shape memory ability of the flexible substrate material itself and the temperature-related properties, without the need for additional power devices that consume electrical energy, which can reduce energy consumption.

[0103] Optionally, based on other embodiments, in one embodiment, the thickness of the two layers of flexible substrates is different. In this method, the thickness of the two layers of flexible substrates can be designed differently so that the shape memory capabilities of the two layers of flexible substrates are different. In this method, based on the difference in the shape memory capabilities of the two layers of flexible substrates, the multimodal implantable sensor 100 can be convex toward one of the flexible substrates when the state is switched, so that the expanded state has a curved surface with a specific convex direction, which is better conformally covered on the surface of the biological tissue with a curved surface.

[0104] Furthermore, when the thicknesses of the two layers of flexible substrates are different, the thickness ratio of the two layers of flexible substrates can be made not less than 2. For example, the first flexible substrate 101 can be set to have a first thickness, the second flexible substrate 105 can have a second thickness, and the second thickness can be at least twice the first thickness. In this way, when the multimodal implantable sensor 100 is converted to the unfolded state, the first flexible substrate 101 can form a convex structure on the surface of the side away from the second flexible substrate 105, and the second flexible substrate 105 can form a concave structure on some surfaces away from the first flexible substrate 101. When collecting information, the concave structure of the second flexible substrate 105 can cover the biological tissue surface with the convex structure, which can increase the effective contact area between the multimodal implantable sensor 100 and the biological tissue surface, so as to improve the sensitivity and accuracy of information collection.

[0105] Optionally, based on other embodiments, in one embodiment, the two-layer flexible substrate can be prepared from different materials with different shape memory capabilities. For example, the first flexible substrate 101 is prepared from a first material with a first shape memory capability, and the second flexible substrate 105 can be prepared from a second geothermal material with a second shape memory capability, and the first material and the second material are different. When the two-layer flexible substrate has the same graphic structure, the first memory capability is different from the second memory capability.

[0106] Optionally, based on other embodiments, in one embodiment, the material of the flexible substrate is a biodegradable polymer. In this way, after the information collection is completed, the flexible substrate can automatically degrade in the organism, thereby reducing the volume of the multimodal implantable sensor 100 after use and reducing the extraction trauma after the operation.

[0107] Among them, the degradation period of the biodegradable polymer used to prepare the flexible substrate can be 6 to 12 months, and the required degradation period is relatively long. Long-term monitoring can be achieved within the degradation period. When used for brain signal collection, this time length can meet the signal collection cycle requirements of brain tumors to ensure full coverage of the treatment process, and solve the problem that conventional multimodal implantable sensors cannot perform long-term continuous monitoring.

[0108] Optionally, in one embodiment, the two flexible substrates can be made of the same material. For example, the flexible substrate material can be poly(lactide-co-caprolactone) / poly(lactic-co-glycolic acid) (PLCL-PLGA), so as to form a double-layer PLCL-PLGA substrate framework. In the embodiments of the present application, the materials of the two-layer flexible substrates can also be different. The materials for preparing the biodegradable flexible substrate include but are not limited to PLCL-PLGA, and can also be other polymer materials, and the embodiments of the present application do not make any limitations in this regard.

[0109] PLCL-PLGA is a biodegradable material and has a shape memory effect. The flexible substrate prepared based on this material has good shape memory ability, and its glass transition temperature is between 35°C and 45°C, and it can form a shape memory body with thermal response characteristics. The flexible substrate prepared based on this material not only has biodegradable characteristics but also has shape memory ability. Based on the shape memory ability of the flexible substrate, the multimodal implantable sensor 100 can be implanted into the organism in a contracted state with a smaller volume, realizing minimally invasive channel implantation, and can also automatically switch from the contracted state to the expanded state based on the memory ability of the material itself after the implantation is completed, conformally covering the surface of biological tissues (such as the surface of the cerebral cortex), so as to better cover the surface of the tissue to be measured and realize effective biological characteristic signals.

[0110] In addition, since PLCL-PLGA is a biodegradable material, its degradation period can match the healing period of biological tissues, enabling signal acquisition covering the entire treatment process.

[0111] In an embodiment of the present application, in one implementation, the biodegradable flexible substrate can be mainly composed of PLCL-PLGA and is prepared by precise solution blending and spin coating processes. The preparation method includes: First, PLGA (lactic acid: glycolic acid = 85:15) and PLCL (lactic acid: caprolactone = 50:50) are mixed and dissolved in a 20wt% chloroform solution in a weight ratio of 1:1, and spin-coated on a glass substrate treated with silanization (trichlorooctadecylsilane) at a rotation speed to form a micron-thick film. The substrate frame adopts a double-layer laminated structure, and the two flexible substrates are PLCL-PLGA layers with a radial network structure. Through holes can be opened at corresponding positions on the first flexible substrate 101 to achieve electrical connection. A poly(butylene adipate-co-terephthalate) (PBAT) containing 30wt% iodixanol can be inserted between the two flexible substrates as an X-ray sensitive visual marking layer 103, and three-layer sealing is achieved through hot pressing at 80°C, that is, the three-layer structure of the two flexible substrates and the visual marking layer 103 seals other film layers.

[0112] The manufacturing method of the X-ray sensitive visual marking layer 103 includes: making a film by mixing poly(butylene adipate-co-terephthalate) (PBAT) and iodixanol in a weight ratio of 3:1, and placing it between the multimodal electronic functional layer 102 and the wireless communication functional layer 104. The high atomic number of iodixanol makes it show significant contrast under X-rays.

[0113] Figure 7 The multimodal implantable sensor 100 with the shown structure can adopt a hierarchical hot pressing assembly process. The multi-layer heterogeneous integration technology not only ensures the mechanical reliability of the multimodal implantable sensor 100 when folded, but also realizes the control of biodegradation synchronization after implantation. In the flexible substrate, the hydrolysis of the PLGA segment (ester bond breakage) and the enzymatic hydrolysis of PLCL (catalyzed by lipase) act synergistically to achieve gradient degradation matching the tissue healing period, causing the sensor to gradually soften and fragment in the body after 6 - 8 weeks; after the flexible substrate degrades, the magnesium material in the sensor can be dissolved within 4 weeks through electrochemical corrosion (Mg → Mg²⁺ + 2e⁻), and the silicon nanomembrane generates silicic acid through hydrolysis and is finally metabolized and excreted as urine. This design breaks through the rigidity limitations of traditional implantable sensors and realizes the full-cycle intelligence of "implantation-functionalization-disappearance" through the integration of biomaterial mechanics, transient electronics, and wireless power supply technology, providing a new product structure with both minimally invasive, multimodal sensing, and biological safety for in-vivo implantable diagnosis and treatment (such as encephalopathy diagnosis and treatment).

[0114] Reference Figure 8 , Figure 8A top view of a multimodal electronic functional layer provided by an embodiment of the present application Figure 8 It is a top view of the multimodal electronic functional layer 102 when in the unfolded state, that is, the top view when the multimodal electronic functional layer 102 is unfolded to the planar state. On the basis of other embodiments Figure 8 In the manner shown, the multimodal electronic functional layer 102 includes a plurality of sensor components 1020; the sensor component 1020 includes at least two sensors 106 for collecting different biometric signals

[0115] Combined with Figure 7 and Figure 8 shown, the sensor component 1020 is located between the radially extending support arms 1011 where two flexible substrate layers are stacked opposite to each other. For example, both the first flexible substrate 101 and the second flexible substrate 105 have six radially extending support arms 1011, and the radially extending support arms 1011 in the first flexible substrate 101 and the second flexible substrate 105 are stacked opposite to each other one by one. The sensor component 1020 can be arranged between the radially extending support arms 1011 where the first flexible substrate 101 and the second flexible substrate 105 are stacked opposite to each other. In this way, the encapsulation protection of each sensor component 1020 can be realized through the radially extending support arms 1011 where two flexible substrate layers are stacked opposite to each other

[0116] Referring to Figure 9 , Figure 9 It is a partially enlarged top view of a sensor component provided by an embodiment of the present application. On the basis of other embodiments Figure 9 The sensor component 1020 shown includes: a circular detection area 107, where N sensors 106 are arranged in the circular detection area 107, and each sensor 106 is respectively used to collect different biometric signals, and N is a positive integer greater than 1; the circular detection area 107 is opposite to the end of the radially extending support arm 1011 away from the center position; wherein, the circular detection area 107 is divided into N + 1 sector areas 109, N of the N + 1 sector areas are used to respectively arrange one sensor 106, and the remaining one sector area 109 is used to arrange the signal lines 1026 connected to each sensor 106, and the fan-out wiring of each sensor 106 is realized through this sector area 109

[0117] Optionally, the signal line 1026 can be a magnesium wire. Magnesium material not only has good biocompatibility, but also has the characteristic of biodegradability. Therefore, the magnesium wire can be degraded in the body after a certain period of use, so as to reduce the removal volume of the multimodal implantable sensor 100 after use

[0118] The structure of the sensor 106 is not limited to Figure 9For the circular structure shown, its graphic structure can also be designed as a sector structure that is the same as or approximately the same as the shape of the sector area 109, so as to increase the effective detection area of the sensor 106, increase the intensity of the collected signal, and improve the detection sensitivity and accuracy.

[0119] The sensor assembly 1020 further includes a wiring area 108 connected to the circular detection area 107. The wiring area 108 is located between the radially arranged support arms 1011 of the two-layer flexible substrate stacked opposite to each other, and the wiring area 108 is encapsulated and protected by the radially arranged support arms 1011 of the two-layer flexible substrate stacked opposite to each other.

[0120] Combined with Figures 7 - 9 As shown, on the surface of the wiring area 108, the signal lines 1026 connected to each sensor 106 can extend along the length direction of the radially arranged support arm 1011 towards the central area of the multimodal implantable sensor 100, and are electrically connected to the circuit board 1042 through conductive holes in the central area.

[0121] Optionally, in Figure 9 the shown manner, the sector area 109 for setting the signal line 1026 and the wiring area 108 are arranged opposite to each other, that is, the bisector of the central angle of the sector area 109 coincides with the midline parallel to the length direction in the wiring area 108 connected thereto.

[0122] Optionally, on the basis of other embodiments, in one embodiment, at least two of the sensors 106 in the multimodal implantable sensor 100 may include at least two of a pressure sensor 1021, a temperature sensor 1022, a pH sensor 1023, a passive electrode array 1024, and an active electrode array 1025. In other ways, at least two of the sensors 106 in the multimodal implantable sensor 100 may also include other types of sensors, such as at least one of a blood glucose sensor, a lactate sensor, a neurotransmitter sensor, an inflammation marker sensor, and a tumor marker sensor.

[0123] Optionally, the pressure sensor 1021 can be formed based on a boron-doped silicon nanomembrane. The pressure sensor 1021 can utilize the piezoresistive effect to sense the mechanical deformation of tissues in the living body (such as brain tissue). When used for intracranial biometric signal acquisition, it can detect intracranial pressure changes or blood vessel pulsations, and the linear response range covers 0 to 15% strain.

[0124] Among them, the manufacturing method of the pressure sensor 1021 includes: spin-coating photoresist on the surface of the SOI wafer, forming a microporous array through ultraviolet exposure and development, using a mixed gas of sulfur hexafluoride and oxygen for reactive ion etching to penetrate the silicon layer, and wet etching with hydrofluoric acid to remove the underlying silicon dioxide to release the silicon nanomembrane. Transfer the nanomembrane to the polyimide (PI) / silicon temporary substrate through a polydimethylsiloxane (PDMS) transfer stage, magnetron sputter deposit a magnesium layer as the signal line 1026 connected to the pressure sensor 1021, form a strain-sensitive area through negative photoresist lithography, and finally coat a PBAT-iodixanol protective layer.

[0125] Optionally, a temperature sensor 1022 can be formed based on the magnesium thin film resistance. The temperature sensor 1022 can achieve short-term body temperature monitoring through the oxidation degradation characteristics of magnesium, and can be used to detect local cortical inflammation or metabolic abnormalities when collecting intracranial biometric signals.

[0126] Among them, the manufacturing method of the temperature sensor 1022 includes: magnetron sputter depositing a high-purity magnesium layer on the PI (polyimide) temporary substrate, and performing microfabrication using an excimer laser to form a meandering resistance structure. The surface of the sensor is covered with a PBAT encapsulation layer, and the active area is exposed through laser drilling to improve the thermal response speed, and the thermal sensitivity coefficient reaches 0.35% / °C.

[0127] Optionally, a pH sensor 1023 can be formed based on a phosphorus-doped silicon nanomembrane modified with 3-aminopropyltriethoxysilane (APTES). The pH sensor 1023 can measure pH through the surface potential change caused by amino protonation (sensitivity 45 mV / pH), and can be used to monitor the acid-base balance of cerebrospinal fluid after surgery when collecting intracranial biometric signals.

[0128] Among them, the manufacturing method of the pH sensor 1023 includes: doping phosphorus elements into the SOI wafer through a thermal diffusion process at 1050 °C to form an n-type semiconductor layer, and performing vapor deposition in an aminopropyltriethoxysilane (APTES) vapor to complete surface functionalization. The pH sensor 1023 adopts an interdigitated electrode design, is isolated from the underlying circuit through a silicon dioxide insulating layer, and magnesium leads are arranged at the edges to achieve impedance signal output.

[0129] Optionally, a passive electrode array 1024 can be formed based on an array of molybdenum (Mo) square electrode units. The passive electrode array 1024 can be annularly distributed at the distal end of the radial support arm 1011 away from the central position 1015. The passive electrode array 1024 can be connected to the circuit board 1042 through the corresponding signal line 1026, and can be used to collect electrocorticogram (ECoG) signals on the surface of the cerebral cortex. The high conductivity and controllable degradation rate of molybdenum balance the requirements for signal quality and service life.

[0130] Optionally, an active electrode array 1025 can be formed based on silicon-nanomembrane-based n-type metal-oxide semiconductor field effect transistors (MOSFETs) arranged in an array. The active electrode array 1025 can achieve time-division multiplexing of multi-channel signals through gate voltage switching, with a spatial resolution reaching the millimeter level. When used for intracranial biometric signal acquisition, it can be dedicated to the spatio-temporal localization of epileptic foci.

[0131] Among them, the electrode unit includes manufacturing methods for both passive and active types. The passive electrode array 1024 made of molybdenum material deposits a molybdenum layer on a PI substrate through radio frequency magnetron sputtering, forms square electrodes through positive photoresist lithography, and the edge impedance is polished electrochemically; the active electrode array 1025 including metal-oxide semiconductor field effect transistors (MOSFETs) grows silicon dioxide on an SOI wafer as a doping blocking layer, forms channels through selective phosphorus diffusion after lithography window opening, the source / drain electrodes are deposited with molybdenum metal by electron beam evaporation, and the gate is formed with a silicon dioxide dielectric layer by atomic layer deposition, and finally a multi-channel array is integrated to achieve a high signal-to-noise ratio.

[0132] In one implementation, the structures of the respective sensor components 1020 can be the same, having the same number and type of sensors 106. For example, each sensor component 1020 includes a pressure sensor 1021, a temperature sensor 1022, a pH sensor 1023, a passive electrode array 1024, and an active electrode array 1025. Among them, in this way, the multimodal implantable sensor 100 can achieve synchronous acquisition of multimodal signals such as pressure, pH, temperature, and electrical signals on the same substrate frame.

[0133] Reference Figure 10 , Figure 10 is a partially enlarged top view of another sensor component provided by the embodiments of the present application. On the basis of other implementations, Figure 10 In the shown sensor component 1020, the circular detection area 107 is divided into N concentric ring detection areas 110, and each of the N concentric ring detection areas 110 is used to set a sensor 106.

[0134] In Figure 10 the shown manner, the graphic structure of the sensor 106 is a ring structure that is the same as or approximately the same as the shape of the concentric ring detection area 110 where it is located, so as to increase the effective detection area of the sensor 106, increase the intensity of the collected signals, and improve the detection sensitivity and accuracy.

[0135] Based on the above description, in the multimodal implantable sensor 100 provided by the embodiments of the present application, a substrate frame is formed by two flexible substrates with a specific grid shape, and a variety of sensors 106 are integrated on the substrate frame at the same time, which can realize the co-design of material mechanics and microelectronics technology; it can be implanted based on the contracted state of a smaller volume, and minimally invasive implantation can be achieved; after implantation, it can automatically convert from the contracted state to the unfolded state based on the shape memory ability of the flexible substrate, and can achieve large-area coverage with the surface of biological tissues to effectively collect various biological characteristic signals; different biological characteristic signals can be synchronously collected by a variety of different sensors 106 to achieve multi-modal multi-signal synchronous collection; wireless data interaction with an external monitor can be realized through the wireless communication function layer 104; structures such as the flexible substrate, signal lines 1026, and coils 1041 can be made of biodegradable materials, which can greatly reduce the required removal volume. For the second surgery, it is only necessary to remove the circuit board 1042 fixed in the visual marking layer 103 and the chip structures of each sensor 106, which can reduce the volume of the multimodal implantable sensor 100 required to be removed in the second surgery and reduce the surgical risk.

[0136] It should be noted that for the convenience of illustration, the schematic diagrams of the unfolded states of the multimodal implantable sensor 100 and its internal film layers provided by the embodiments of the present application are all illustrated in the unfolded state to a planar state. As described above, the embodiments of the present application can optimize the unfolded state of the multimodal implantable sensor 100 by one or more of the following methods: differentiating the thickness and / or material of the two flexible substrates, differentiating the line widths of the support beams on different concentric rings 1016 in the same flexible substrate, and differentiating the line widths of the radial support arms 1011 in the same flexible substrate, so that it can be unfolded flat or in a curved surface with a certain curvature. The embodiments of the present application do not make any limitations in this regard.

[0137] Based on the multimodal implantable sensor 100 provided in the above embodiments, another embodiment of the present application further provides a signal acquisition system, the structure of which is as Figure 11 shown.

[0138] Refer to Figure 11 , Figure 11 which is a schematic structural diagram of a signal acquisition system provided by an embodiment of the present application. The signal acquisition system includes: the multimodal implantable sensor 100 provided in any one of the above embodiments; an external monitor 200, and the external monitor 200 is communicatively connected to the multimodal implantable sensor 100. The multimodal implantable sensor 100 is a multi-layer composite structure provided by the above embodiments and can simultaneously collect a variety of different biological characteristic signals.

[0139] Optionally, the extracorporeal monitor 200 includes a display instrument 203, and the display instrument 203 can display image information related to the biometric signals collected by the multimodal implantable sensor 100. When used for collecting brain biometric signals, the display instrument 203 can display the electroencephalogram signal distribution, intracranial pressure waveform, temperature trend, and pH value in real time, with a built-in threshold alarm function, supporting Bluetooth and cloud data transmission for remote medical platform access.

[0140] In one implementation, as Figure 11 shown, the extracorporeal monitor 200 is connected with a wireless reading module 201 through a cable 202. The wireless reading module 201 is a transmitting and receiving coil, which can generate an alternating magnetic field to power the multimodal implantable sensor 100 and collect signals through electromagnetic induction.

[0141] Optionally, the signal acquisition system can pre-store an application program that can execute a set of pathological specificity algorithms in the extracorporeal monitor according to the biometric signals collected by the multiple sensors integrated in the multimodal implantable sensor 100. When used for brain disease diagnosis, corresponding feature extraction models and decision thresholds can be developed for different brain diseases.

[0142] Refer to Figure 12 , Figure 12 which is a schematic diagram of the implantation principle of the multimodal implantable sensor before signal acquisition provided by the embodiment of the present application. The multimodal implantable sensor 100 can be implanted through a flexible wire 300. The multimodal implantable sensor 100 can be in a smaller contracted state during the implantation process and can present a radially expanded network structure after being implanted into a living being. This method can reduce the diameter of the flexible wire 300 required for implantation. A flexible wire 300 with a diameter of dozens of millimeters can be used for in-vivo implantation. The required diameter of the flexible wire 300 is small, which can reduce the implantation trauma. The diameter of the flexible wire 300 can be 5 mm to 80 mm, such as 21 mm, or 30 mm, or 33 mm, or 50 mm, or 62 mm, or 75 mm, etc.

[0143] During clinical surgery, the multimodal implantable sensor 100 can be implanted through a 5-mm aperture. The flexible substrate made of PLCL-PLGA can be triggered to automatically expand when encountering body temperature, and the X-ray sensitive visual marking layer 103 can be used to assist in confirming the coverage area. When used for intracranial signal acquisition, a multi-channel electrode array can be used to locate epileptic discharge foci, and the data collected by the pressure sensor 1021 and the pH sensor 1023 can be transmitted to an external system in real time through the wireless communication function layer 104 to form a closed-loop nerve monitoring network.

[0144] Refer to Figure 13 , Figure 13Schematic diagram of the working principle of a signal acquisition system provided by an embodiment of this application. In the multimodal implantable sensor 100, the multimodal electronic functional layer 102 includes multimodal sensors for collecting biometric signals such as temperature, pressure, pH, and electroencephalogram. The wireless communication functional layer 104 in the multimodal implantable sensor 100 includes an NFC chip for data interaction with an external monitor 200. The NFC chip can perform wireless communication with a wireless reading module 201 through an electromagnetic field to achieve data interaction with the external monitor 200 and power input for the devices in the multimodal implantable sensor 100. The external monitor 200 includes a readout circuit and a display instrument 203.

[0145] Taking the brain implant scenario as an example, the clinical implant process of the multimodal implantable sensor 100 includes:

[0146] 1.1) Preoperative planning and positioning.

[0147] Multimodal image fusion: Based on preoperative 3T magnetic resonance imaging (MRI) and computed tomography (CT) angiography data, a three-dimensional model of the target brain region is constructed through medical image processing software to plan the implantation site of the multimodal implantable sensor 100 (usually select the region without large blood vessels in the temporal lobe or parietal lobe).

[0148] Stereotactic frame calibration: Fix the patient's head using a stereotactic headframe, and calculate the stereotactic coordinates of the implantation path (accuracy ±0.5 mm) in combination with preoperative image data, avoiding functional areas and key blood vessels.

[0149] 1.2) Minimally invasive implantation surgery.

[0150] Local anesthesia and incision: Perform local infiltration anesthesia at the skull drilling site (diameter 5 mm). After incising the skin and periosteum, use a microtrephine to create a skull window and expose the dura mater.

[0151] Sensor delivery: Pre-fold the multimodal implantable sensor 100 and load it into a special flexible catheter 300. The folded state is maintained at low temperature (4°C saline circulation) through the thermoresponsive characteristics (glass transition temperature Tg≈35°C) of the flexible substrate made of PLCL-PLGA material.

[0152] Catheter-guided implantation: Under the guidance of a neuronavigation system, insert the flexible catheter 300 through the bone window into the subdural space and advance it along the preset path to the target brain region.

[0153] Temperature-triggered deployment: After pushing the multimodal implantable sensor 100 out of the flexible catheter 300 using a syringe, the flexible catheter 300 is withdrawn and the cryogenic circulation is stopped. The body temperature (37°C) triggers the glass transition of the PLCL-PLGA-based flexible substrate, and the multimodal implantable sensor 100 can complete radial deployment within 30 seconds, achieving adaptive fitting to the surface of the meninges through the elastic release of the serpentine support beam 1012.

[0154] Intraoperative functional verification: Real-time X-ray monitoring, using a C-arm X-ray machine to observe the deployment pattern of the iodixanol-labeled layer to ensure that the electrode array completely covers the target area (spatial error < 1 mm). Impedance testing, activating the electrodes through the wireless NFC module in the wireless communication functional layer and measuring the impedance values of each channel to exclude wire breakage or poor contact caused by folding.

[0155] 1.3) Postoperative treatment and recovery.

[0156] Incision suture: The bone window is sealed with absorbable bone wax, and the subcutaneous tissue and skin are sutured layer by layer. The intracranial pressure (normal value 7 - 15 mmHg) and local inflammatory response are monitored 24 hours after the operation.

[0157] Degradation component management: 10 weeks after the operation (after the magnesium coil is completely dissolved), based on the non-degradable visual marker layer 103, the non-degradable chips in the NFC module on the circuit board 1042 (the PBAT encapsulation layer has softened, and the incision only needs to be 3 mm) and each non-degradable sensor chip in the multimodal electronic functional layer 102 are removed through a minimally invasive subcutaneous incision. Each chip is located and removed by X-ray together with the visual marker layer 103.

[0158] Data monitoring and intelligent analysis of the multimodal implantable sensor 100 include:

[0159] 2.1) Multimodal data acquisition.

[0160] Real-time transmission protocol: The wireless reading module 201 polls sensor data packets at a rate of 100 frames per second; the electrophysiological signals in each frame include: multi-channel electrocorticogram signals ECoG (sampling rate 1 kHz, resolution 12 bit), covering the frequency band of 0.5 - 300 Hz, and the biophysical signals include: three signal parameters of temperature (±0.1°C), pressure (0.1% resolution), and pH (0.01 precision), with a sampling rate of 10 Hz.

[0161] Data preprocessing: Dynamic baseline calibration, eliminating slow-varying drifts (such as electrode polarization effects) based on the moving average algorithm of a sliding window (10 seconds); power frequency noise suppression, using an adaptive notch filter (center frequency 50 / 60 Hz, Q = 30) to eliminate environmental interference.

[0162] 2.2) Intelligent analysis engine.

[0163] Feature extraction and fusion: Time-frequency analysis, perform continuous wavelet transform on ECoG signals (Morlet basis function, scale 1 - 100 Hz), and extract the energy proportion in the γ band (30 - 80 Hz) as a marker of epileptic activity.

[0164] Multi-sensor association: Establish a cross-modal association matrix of temperature-strain-pH to identify abnormal metabolic-mechanical coupling events (such as local edema caused by inflammation).

[0165] Machine learning models: Epilepsy warning, train an LSTM network to learn the temporal features of ECoG, and combine clinical seizure marker data to achieve epilepsy prediction 5 - 10 minutes in advance. Intracranial pressure abnormality detection, a gradient boosting decision tree (GBDT) model based on data collected by pressure sensors, identifies deformation mutation patterns through feature importance ranking (Shapley value). Cloud deep learning, encrypt data and upload it to the medical cloud platform, integrate multi-patient data through a graph convolutional network (GCN), and mine disease subtypes and treatment response patterns.

[0166] 2.3) Clinical interaction and decision support.

[0167] Doctor's console, support: Dynamic heat map display, spatial power spectral density mapping of multi-channel ECoG signals, overlay temperature / pressure pseudo-color layers; Event backtracking, automatically annotate the time axis of abnormal events (such as high-frequency oscillations, sudden pH drops), support the playback of original signals and expert annotation; Performance decay compensation, dynamically correct the impact of electrode impedance drift on signal amplitude through the recursive least squares (RLS) algorithm; Life termination prediction, based on the magnesium corrosion kinetics model and real-time pH data, estimate the remaining time of sensor function (error ±2 days), and prompt to replace or remove the node.

[0168] The applications of the multi-modal implantable sensor 100 in different craniocerebral diseases include:

[0169] 3.1) Brain trauma monitoring.

[0170] Multi-modal dynamic monitoring: Real-time tracking of intracranial pressure (ICP), continuously monitor the subdural pressure change through a flexible pressure sensor (resolution 0.1%), and invert the ICP fluctuation by combining skull deformation data (error ±2 mmHg), and give a real-time warning of the risk of intracranial hypertension (>20 mmHg); Detection of metabolic abnormalities, capture the accumulation of brain tissue lactic acid through a pH sensor (accuracy 0.01), and identify local inflammatory reactions through a temperature sensor (±0.1 °C) (temperature difference >0.5 °C indicates infection or hematoma expansion).

[0171] Intelligent early warning and decision-making: Predict secondary injury, analyze the time-series data of ICP, pH, and temperature based on the LSTM network (input window of 10 minutes), predict the risk of delayed hematoma or brain hernia (sensitivity of 95%), and initiate hypothermia therapy or surgical intervention in advance.

[0172] Optimization of treatment plan: Integrate sensor data and CT perfusion imaging, evaluate the cerebral oxygen extraction fraction through a random forest model, and dynamically adjust the infusion rate of mannitol.

[0173] 3.2) Precise management of brain tumors.

[0174] Analysis of the tumor microenvironment: Monitor the metabolic state, draw the acidic area around the tumor (pH 6.5 - 7.0) through a pH sensor, register it with the dynamic contrast-enhanced MRI data, and define the tumor infiltration boundary (spatial matching error < 2 mm); Capture electrophysiological markers, identify high-frequency oscillations in the peritumoral cortex with multi-channel ECoG, and separate epileptiform discharges and tumor-related activities through independent component analysis.

[0175] Evaluation and optimization of treatment response: Dynamically correct the radiotherapy target area, train a support vector machine (SVM) based on real-time pH and temperature data, predict the risk of radiation necrosis, and adjust the isocenter dose of the gamma knife during the operation.

[0176] Short-term monitoring (for brain trauma): Use sensors encapsulated with rapidly degradable PLGA (completely absorbed in 4 weeks) to avoid secondary removal surgery.

[0177] Long-term monitoring (for brain tumors): Prepare a flexible substrate using a PLCL-PBAT hybrid material (degradation period of 6 - 12 months) to ensure full coverage throughout the treatment.

[0178] Through precise minimally invasive surgery and intelligent data analysis, this signal acquisition system realizes the full-cycle closed-loop management from "structural implantation" to "functional service" and then to "safe disappearance", providing a dynamically adaptable solution for the precise diagnosis and treatment of brain diseases.

[0179] The signal acquisition system includes multi-modal implantable sensors. Therefore, the signal acquisition system provided in the embodiments of this application has the same or similar technical effects as the multi-modal implantable sensors provided in the above embodiments, and the embodiments of this application will not be elaborated further.

[0180] The various embodiments in the description of this application are described in a progressive, or parallel, or a combination of progressive and parallel manners. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other. The embodiments provided in the embodiments of this application can be combined with each other without conflict.

[0181] It should be noted that in the description of this application, it should be understood that the descriptions of the drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments of the specification identify the same structures. Additionally, for the sake of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. At the same time, it can be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element can be directly on the other element or there can be intervening elements. Additionally, "on" means positioning the element on or below another element, but does not inherently mean positioning on the upper side of another element according to the direction of gravity.

[0182] The orientation or positional relationship indicated by terms such as "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be intervening components present simultaneously.

[0183] It should also be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variation thereof is intended to cover non-exclusive inclusion, such that an article or device including a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the presence of additional identical elements in the article or device including the above elements.

[0184] The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but rather is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multimodal implantable sensor, characterized in that, Comprising: Two relatively arranged flexible substrates; A multimodal electronic functional layer located between the two flexible substrates, the multimodal electronic functional layer including at least two sensors for collecting different biometric signals; Wherein, the flexible substrate has shape memory ability and can convert the multimodal implantable sensor from a contracted state to an expanded state.

2. The multimodal implantable sensor according to claim 1, wherein It further comprises: A wireless communication functional layer, the wireless communication functional layer and the multimodal electronic functional layer are stacked between the two flexible substrates; the wireless communication functional layer is electrically connected to the sensor and is used for wireless communication with an external circuit.

3. The multimodal implantable sensor according to claim 2, wherein The wireless communication functional layer includes: A circuit board with wireless communication function, the sensor is electrically connected to the circuit board; A plurality of coils surrounding the circuit board, the coils are used to form a circular magnetic field; if the multimodal implantable sensor is unfolded in a plane, the plurality of coils are concentric circles.

4. The multimodal implantable sensor according to claim 1, wherein The flexible substrate includes: a plurality of radial support arms, one end of each radial support arm is connected to the same central position; the radial support arms are connected by support beams; If the multimodal implantable sensor is unfolded in a plane, each radial support arm is located at a different radius of the same circular area, and the central position is the center of the circular area; at least two support beams are connected between adjacent two radial support arms.

5. The multimodal implantable sensor according to claim 4, wherein At least two concentric circles are arranged inside the circular area, and support beams are sequentially connected to the intersection points of the circumferences of the concentric circles and each radial support arm.

6. The multimodal implantable sensor according to claim 4, characterized in that, The support beam is a serpentine trace connected between two radial support arms.

7. The multimodal implantable sensor according to claim 4, wherein The multimodal electronic functional layer includes a plurality of sensor components; The sensor component includes at least two sensors for collecting different biometric signals; The sensor component is located between the radially opposite support arms of the two stacked flexible substrates.

8. The multimodal implantable sensor according to claim 7, characterized in that, The sensor component includes: a circular detection area, N sensors are arranged in the circular detection area, each sensor is respectively used for collecting different biometric signals, N is a positive integer greater than 1; the circular detection area is opposite to the end of the radial support arm far from the central position; wherein, The circular detection area is divided into N + 1 fan-shaped areas, N of the N + 1 fan-shaped areas are used to respectively arrange one sensor, and the remaining one fan-shaped area is used to arrange the signal lines connected to each sensor; Or, the circular detection area is divided into N concentric circular detection areas, and the N concentric circular detection areas are respectively used to arrange one sensor.

9. The multimodal implantable sensor according to any one of claims 1-8, characterized in that, The flexible substrate automatically converts from the contracted state to the expanded state when reaching the glass transition temperature of its own material, and the glass transition temperature range of the flexible substrate is 35°C to 45°C; Or, the multimodal implantable sensor further comprises: a visual marking layer, the visual marking layer is used to display the expanded state of the multimodal implantable sensor; Or, the thicknesses of the two flexible substrates are different; Or, the thickness ratio of the two flexible substrates is not less than 2; Alternatively, the material of the flexible substrate is a biodegradable polymer.

10. A signal acquisition system, characterized in that, Comprising: The multimodal implantable sensor according to any one of claims 1-9; An external monitor communicatively connected to the multimodal implantable sensor.

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