Self-bending artificial cochlea and preparation method thereof

Abstract

The invention provides a self-bending artificial cochlea and a preparation method thereof. The self-bending artificial cochlea comprises an electrode body and an electrode supporting device connected with the electrode body, wherein the electrode body comprises an electrode folding piece and a flexible film electrode layer, one end of the electrode folding piece is connected with the electrode supporting device, the flexible film electrode layer is laid on one side of the central axis of the electrode folding piece, and the flexible film electrode layer is used for generating current to stimulate cochlea inner wall neurons; the electrode folding piece comprises an initial shape and a temporary shape, the initial shape is in a bent and unfolded shape, the temporary shape is in a straight and folded shape, and the size of the electrode folding piece in the initial shape is larger than that of the electrode folding piece in the temporary shape. Under external stimulation, the electrode folding piece can drive the flexible film electrode layer to be bidirectionally converted between an initial shape and a temporary shape. The artificial cochlea can deform under external stimulation so as to be attached to the inner wall of the cochlea, and the hearing effect can be effectively improved while the cochlea structure is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments and in particular to a self-bending artificial cochlear implant and a preparation method thereof. Background Art

[0002] Cochlear implants are one of the effective means of treating sensorineural hearing loss. The most challenging component of a cochlear implant is the electrode array, which stimulates the auditory nerve to produce hearing. Most of the cochlear implant electrodes currently used in commercial production and clinical applications are manufactured using a traditional method, which involves manually assembling the electrode array, welding the wires, and injecting a silicone carrier around them to form the final shape. Due to the poor precision of manual assembly, the number of electrodes is limited to about 20, and the size of the produced electrode array is relatively large. The limited frequency that can be provided by a small number of electrodes makes the sound richness that a cochlear implant can provide poor. This traditional manufacturing method has many problems that need to be solved, such as high cost, long production process, narrow product frequency range, difficulty in distinguishing sounds in crowded environments, etc.

[0003] In the related technology, there are two types of electrode array structures used in clinical applications, one is a straight electrode and the other is a pre-bent electrode. Since the structure of the cochlea is spirally curved, the straight electrode cannot fit the cochlea and needs the support of the outer wall of the cochlea to maintain the curved shape. It is difficult to avoid damage to the cochlea during implantation, and the cochlea is damaged due to its own elasticity squeezing the cochlear structure. The pre-bent electrode can be closer to the inner wall of the cochlea due to its curved shape, but the curved shape makes it easy for the tip of the electrode to damage the spiral ligament, causing the electrode to shift and damage the cochlea.

[0004] Therefore, based on the above problems, there is an urgent need to provide a self-bending cochlear implant and a preparation method thereof. Summary of the invention

[0005] The embodiment of the present invention provides a self-bending cochlear implant and a preparation method thereof. The cochlear implant can be deformed under external stimulation so as to fit the inner wall of the cochlea, thereby effectively improving the hearing effect while protecting the cochlear structure.

[0006] In a first aspect, the present invention provides a self-bending cochlear implant, comprising an electrode body and an electrode support device connected to the electrode body; wherein:

[0007] The electrode body comprises an electrode folding part and a flexible thin film electrode layer, one end of the electrode folding part is connected to the electrode supporting device, the flexible thin film electrode layer is laid on one side of the central axis of the electrode folding part, and the flexible thin film electrode layer is used to generate current to stimulate neurons on the inner wall of the cochlea;

[0008] The electrode folding part includes an initial shape and a temporary shape, the initial shape is a bent and unfolded shape, the temporary shape is a flat and folded shape, and the size of the electrode folding part in the initial shape is larger than the size of the electrode folding part in the temporary shape. Under external stimulation, the electrode folding part can drive the flexible thin film electrode layer to transform bidirectionally between the initial shape and the temporary shape.

[0009] Preferably, the electrode folding member is composed of a plurality of foldable units; wherein each foldable unit is composed of two mutually parallel support plates and an origami bending section located between the two support plates;

[0010] A support plate is shared between two adjacent foldable units, and the sizes of the two support plates in each foldable unit are different. The size of the support plate close to one end of the electrode support device is different from the size of the support plate away from one end of the electrode support device, so that the size of the electrode folding part changes gradually.

[0011] Preferably, the size of the electrode folding part gradually decreases along the direction away from the electrode supporting device.

[0012] Preferably, in the electrode folding part, one end of each supporting plate close to the inner wall of the cochlea is provided with a plurality of groove structures, and the bottom of the flexible thin film electrode layer is provided with a plurality of protrusion structures, the protrusion structures correspond to the positions of the groove structures, and the sizes of the protrusion structures are adapted to the sizes of the groove structures, and the electrode folding part is fixed to the electrode thin film layer through the groove structures and the protrusion structures.

[0013] More preferably, the opening area of ​​the groove structure is smaller than the inner area of ​​the groove structure.

[0014] Preferably, the flexible thin film electrode layer comprises an electrode layer and a plurality of wire layers arranged in sequence from top to bottom; wherein, a packaging layer is provided on the upper and lower surfaces of each wire layer, and the packaging layer is used to protect the wire layer.

[0015] Preferably, the electrode layer comprises a plurality of metal contact electrodes arranged in an array, and each metal contact electrode is composed of a plurality of periodically arranged metal hollow units.

[0016] More preferably, each packaging layer is provided with a plurality of electrode channels, and the wires in each wire layer are connected to the metal contact electrodes in the electrode layer through the electrode channels respectively.

[0017] Preferably, the electrode folding member is further provided with a flexible electrode head, and the flexible electrode head is located at an end away from the electrode supporting device, so as to prevent the electrode folding member from causing damage to the cochlea.

[0018] Preferably, the electrode supporting device is further provided with at least one marking ring, which is located at one end close to the electrode body and is used to control the implantation depth of the electrode body.

[0019] More preferably, the electrode support device is further provided with a wing-shaped handle, which is located on one side of the central axis of the electrode support device and opposite to the direction of the flexible thin film electrode layer, and is used to control the implantation direction of the electrode body.

[0020] Preferably, the electrode folding member is made of a bidirectional shape memory polymer material and has a bidirectional shape memory property;

[0021] More preferably, the shape memory deformation rate of the electrode folding member is 0.1-5 mm / s.

[0022] In a second aspect, the present invention provides a method for preparing a self-bending cochlear implant as described in any one of the first aspects above, the preparation method comprising the following steps:

[0023] (1) constructing a three-dimensional structural model of the initial shape of the electrode folding member according to the specific structural shape and size of the cochlea; wherein the initial shape of the electrode folding member is a bent and unfolded shape, and the temporary shape is a straight and folded shape;

[0024] (2) using a bidirectional shape memory polymer as a printing line, performing 4D printing according to the constructed three-dimensional structure model to obtain an electrode folding part of an initial shape;

[0025] (3) preparing a flexible thin film electrode layer, applying a medical epoxy resin on the protruding structure of the flexible thin film electrode layer, aligning the protruding structure of the flexible thin film electrode layer with the groove structure in the electrode folding part, fixing them with a clamp and curing them to obtain the electrode body;

[0026] (4) heating the electrode body in the initial shape to above the glass transition temperature, applying a load, and cooling and shaping to obtain the electrode body in a temporary shape;

[0027] (5) Fixing one end of the electrode body to the electrode supporting device to obtain the self-bending cochlear implant; wherein the size of the electrode folding part gradually decreases in the direction away from the electrode supporting device.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] (1) In the present invention, the electrode body is designed to be an electrode folding part and a flexible thin film electrode layer. The electrode folding part is printed using a bidirectional shape memory polymer and has a bidirectional shape memory property. The initial shape of the electrode folding part is designed to be a curved unfolded shape, and the temporary shape is designed to be a straight folded shape. Under external stimulation, the electrode folding part can drive the flexible thin film electrode layer to bidirectionally transform between the initial shape and the temporary shape. In the early stage of cochlear implantation, the electrode body is in a straight folded state and is small in size, which is convenient for initial implantation. After implantation, appropriate external stimulation is applied to make the electrode folding part in the electrode body produce shape memory properties and transform from a straight folded state to a curved unfolded state, so that the electrode body can fit well with the inner wall of the human cochlea, so that the flexible thin film electrode layer is close to the cochlear wall or basilar membrane, and can effectively reduce local nerve cell stimulation and excite current, thereby effectively improving the hearing effect while protecting the cochlear structure. At the same time, when the cochlear implant needs to be removed, appropriate stimulation is applied again to make the electrode folding part in the electrode body produce shape memory properties and transform from a curved unfolded state to a straight folded state;

[0030] (2) The electrode body in the present invention has a bidirectional shape memory property. The shape transformation process can be carried out without external force, and the shape memory deformation rate is controllable. This can reduce the complexity and difficulty of cochlear implant surgery, and can achieve non-traumatic implantation of cochlear implants to completely preserve the inner ear structure and physiological functions. At the same time, it can achieve non-traumatic removal to avoid secondary damage to the cochlea during the removal process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of a temporary shape structure of an electrode body in a self-bending cochlear implant provided by an embodiment of the present invention;

[0033] Figures 2 to 3 It is a schematic diagram of the initial shape structure of a stent body in a self-bending cochlear implant provided by an embodiment of the present invention;

[0034] Figure 4 It is a schematic structural diagram of a foldable unit in a self-bending cochlear implant provided by an embodiment of the present invention;

[0035] Figure 5is a schematic structural diagram of a foldable unit in a self-bending cochlear implant provided by another embodiment of the present invention;

[0036] Figure 6 It is a schematic diagram of the structure of a flexible thin film electrode layer in a self-bending cochlear implant provided by an embodiment of the present invention;

[0037] Figure 7 It is a schematic structural diagram of several metal contact electrodes in a flexible thin film electrode in a self-bending cochlear implant provided by an embodiment of the present invention;

[0038] Figure 8 It is a schematic diagram of the arrangement structure of a wire layer in a flexible thin film electrode in a self-bending cochlear implant provided by an embodiment of the present invention;

[0039] In the figure, 100-electrode body, 200-electrode supporting device, 101-electrode folding part, 102-flexible thin film electrode layer, 103-flexible electrode head, 104-marking ring, 105-wing-shaped handle, 1011-foldable unit, 1012-support plate, 1013-origami bending section, 1014-groove structure, 1021-electrode layer, 1022-wire layer, 1023-packaging layer, 1024-adhesive layer, 1025-protrusion structure, 1026-metal contact electrode. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] As mentioned above, the cochlear implant electrode array currently used in clinical practice has poor adhesion to the inner wall of the cochlea, making it difficult to effectively improve the hearing effect, and it is easy to damage the cochlear structure during the implantation process. Considering that the thin film electrode array (TFEA) has higher manufacturing precision, it can provide more electrodes while maintaining a smaller size, and can be mass-produced through micro-electromechanical systems (MEMS) technology to reduce costs and increase efficiency. In the embodiment of the present invention, it is considered to apply the thin film electrode array to the cochlear implant to improve the hearing effect. However, due to the shortcomings of the mechanical properties of TFEA, it cannot be directly applied to the cochlear implant, such as the high stiffness value that makes it easy to damage the cochlear structure when the electrode is implanted, or the high flexibility causes the electrode to be excessively bent when implanted.

[0042] Therefore, in an embodiment of the present invention, a self-bending electrode folding part is first designed, and the thin film electrode array is designed as a flexible thin film electrode layer. The electrode folding part is used as a carrier of the thin film electrode array to drive the flexible thin film electrode layer to deform. At the same time, since the initial shape and the temporary shape of the electrode folding part have different sizes, it can not only be implanted conveniently in the early stage, but also the flexible thin film electrode layer can better fit the inner wall of the cochlea after deformation in the later stage, thereby achieving the protection of the cochlear structure while effectively improving the hearing effect.

[0043] The above concept is described in detail below.

[0044] like Figures 1 to 2 As shown, the present invention provides a self-bending cochlear implant, comprising an electrode body 100 and an electrode support device 200 connected to the electrode body 100; wherein:

[0045] The electrode body 100 includes an electrode folding member 101 and a flexible thin film electrode layer 102. One end of the electrode folding member 101 is connected to the electrode supporting device 200. The flexible thin film electrode layer 102 is laid on one side of the central axis of the electrode folding member 101. The flexible thin film electrode layer 102 is used to generate current to stimulate neurons on the inner wall of the cochlea.

[0046] The electrode folding part 101 includes an initial shape and a temporary shape, the initial shape is a bent and unfolded shape, the temporary shape is a flat and folded shape, and the size of the electrode folding part in the initial shape is larger than the size of the electrode folding part in the temporary shape. Under external stimulation, the electrode folding part can drive the flexible thin film electrode layer to transform bidirectionally between the initial shape and the temporary shape.

[0047] In the embodiment of the present invention, Figures 1 to 2As shown, by designing the electrode body 100 as an electrode folding part 101 and a flexible thin film electrode layer 102, the electrode folding part 101 is printed by a bidirectional shape memory polymer and has a bidirectional shape memory property, and by designing the initial shape of the electrode folding part 101 to be a curved unfolded shape, and the temporary shape to be a straight folded shape, the electrode folding part 101 can drive the flexible thin film electrode layer 102 to bidirectionally transform between the initial shape and the temporary shape under external stimulation; in the early stage of cochlear implantation, the electrode body 100 is in a straight folded state and has a small volume, which is convenient for initial implantation. After implantation, appropriate external stimulation is applied to make the electrode folding part 101 in the electrode body 100 produce shape memory properties, and transform from a straight folded state to a curved unfolded state, so that the electrode body 100 can fit well with the inner wall of the human cochlea, so that the flexible thin film electrode layer 102 is close to the cochlear wall or basilar membrane, thereby effectively reducing local nerve cell stimulation and exciting current, and effectively improving the hearing effect while protecting the cochlear structure. Meanwhile, when the cochlear implant needs to be removed, appropriate stimulation is applied again to make the electrode folding member 101 in the electrode body 100 produce shape memory properties and transform from a bent and unfolded state to a flat and folded state.

[0048] The electrode body 100 in the present invention has a bidirectional shape memory property, and the shape transformation process can be carried out without external force, and the shape memory deformation rate is controllable, which can reduce the complexity and difficulty of cochlear implant surgery, and can achieve non-traumatic implantation of cochlear implants to completely preserve the inner ear structure and physiological function. At the same time, it can achieve non-traumatic removal to avoid secondary damage to the cochlea during the removal process.

[0049] According to some preferred embodiments, the shape memory deformation rate of the electrode folding member 101 is 0.1-5 mm / s (for example, it may be 0.1 mm / s, 0.3 mm / s, 0.5 mm / s, 0.8 mm / s, 1 mm / s, 2 mm / s, 3 mm / s, 4 mm / s or 5 mm / s).

[0050] In an embodiment of the present invention, a bidirectional shape memory polymer material (such as a thermosetting acrylic resin) is used as the main raw material of the electrode folding member 101 and the electrode folding member 101 is printed using 4D printing technology, so that the electrode folding member 101 has a bidirectional shape memory property, that is, the electrode folding segment can be transformed between an initial shape and a temporary shape under two external stimuli, and the shape memory deformation rate of the electrode folding segment is controlled within the above range, so that the electrode body 100 can be controllably controlled during the implantation or removal of the cochlear implant, thereby preventing the deformation process of the cochlear implant from damaging the inner wall of the cochlea.

[0051] like Figures 1 to 2As shown, according to some preferred embodiments, the electrode folding member 101 is composed of a plurality of foldable units 1011; wherein each foldable unit 1011 is composed of two mutually parallel support plates 1012 and an origami bending section 1013 located between the two support plates 1012;

[0052] A support plate 1012 is shared between two adjacent foldable units 1011, and the sizes of the two support plates 1012 in each foldable unit 1011 are different. The size of the support plate 1012 close to one end of the electrode support device 200 is different from the size of the support plate 1012 away from one end of the electrode support device 200, so that the size of the electrode folding member 101 changes gradually.

[0053] According to some preferred embodiments, the size of the electrode folding member 101 gradually decreases in a direction away from the electrode supporting device 200 .

[0054] Continue to refer Figures 1 to 3 A plurality of foldable units 1011 constitute the electrode folding member 101 in the embodiment of the present invention, and by designing the size of the support plate 1012 in the electrode folding member 101, the size of the electrode folding member 101 gradually decreases in the direction away from the electrode support device 200, so that the electrode body 100 has a conical structure, with a thin end close to the cochlear structure and a thick end close to the electrode support device 200, so that the size structure of the electrode body 100 is more consistent with the internal structure of the human cochlea, further avoiding the electrode body 100 from damaging the inner wall of the human cochlea.

[0055] In a specific embodiment, Figure 4 As shown, the two support plates 1012 in the foldable unit 1011 are quadrilateral support plates 1012 of different sizes, and the two quadrilateral support plates 1012 are connected to each other through two foldable quadrilateral origami bending sections 1013, respectively. By adjusting the unfolding and folding states of the two origami bending sections 1013 between the support plates 1012 in the foldable unit 1011, the electrode body 100 can achieve the effects of straight unfolding and curved unfolding, and the bending angle is controllable, thereby regulating the state and shape of the entire cochlear implant flexible film electrode. Based on this feature, the unfolding and bending of each foldable unit 1011 can be adjusted according to the cochlear morphology of different patients, so that the cochlear implant is close to the center of the scala tympani, so as to further avoid damage to the fine structure of the cochlea.

[0056] In a specific embodiment, Figure 5As shown, the two support plates 1012 in the foldable unit 1011 are two regular hexagonal support plates 1012 of different sizes, and the two regular hexagonal support plates 1012 are connected to each other through a Kresling origami bending section 1013. The unfolding and folding states are achieved by adjusting the torsion of the Kresling origami bending section 1013 between the support plates 1012 in the foldable unit 1011. Applying different torques to the Kresling origami section can achieve the effects of straight unfolding and curved unfolding, and the bending angle is controllable, thereby regulating the state and shape of the entire cochlear implant flexible film electrode. Based on this feature, the unfolding and bending of each foldable unit 1011 can be adjusted according to the cochlear morphology of different patients, so that the cochlear implant is close to the center of the scala tympani, reducing damage to the fine structure of the cochlea.

[0057] like Figure 4 and Figure 6 As shown, according to some preferred embodiments, in the electrode folding part 101, one end of each supporting plate 1012 close to the inner wall of the cochlea is provided with a plurality of groove structures 1014, and the bottom of the flexible thin film electrode layer 102 is provided with a plurality of protrusion structures 1025, the protrusion structures 1025 correspond to the positions of the groove structures 1014, and the sizes of the protrusion structures 1025 are adapted to the sizes of the groove structures 1014, and the electrode folding part 101 is fixed to the electrode thin film layer through the groove structures 1014 and the protrusion structures 1025; the opening area of ​​the groove structure 1014 is smaller than the internal area of ​​the groove structure 1014.

[0058] Continue to refer Figure 4 In the embodiment of the present invention, a plurality of groove structures 1014 are provided on each support plate 1012 on one side of the bending direction of the electrode folding section in the electrode folding member 101, and a corresponding protrusion structure 1025 is further provided at the bottom of the flexible thin film electrode layer 102 at a position in contact with each support plate 1012, so that a mechanical interlocking can be formed between the electrode folding section and the flexible thin film electrode layer 102, and an organic adhesive is added to the groove structure 1014 and the protrusion structure 1025, so that the electrode body 100 and the flexible thin film electrode layer 102 can be fixed more firmly, which is not only conducive to the electrode body 100 to better drive the flexible thin film electrode layer 102 to change shape, but also can effectively prevent the flexible thin film electrode from falling off.

[0059] Furthermore, the opening area of ​​the groove structure 1014 is smaller than the internal area of ​​the groove structure 1014, and the protruding structure 1025 matches the groove structure 1014, so that the electrode body 100 and the flexible thin film electrode layer 1021102 can be bonded more firmly and stably. In the embodiment of the present invention, there is no specific restriction on the shape of the groove structure 1014, for example, it can be a regular polygonal pyramid or a hemisphere.

[0060] like Figure 6 As shown, according to some preferred embodiments, the flexible thin film electrode layer 102 includes an electrode layer 1021 and several wire layers 1022 arranged in sequence from top to bottom; wherein, a packaging layer 1023 is provided on the upper and lower surfaces of each wire layer 1022, and the packaging layer 1023 is used to protect the wire layer 1022.

[0061] According to some preferred embodiments, the flexible thin film electrode layer 102 also includes an adhesive layer 1024, which is located below the packaging layer 1023 away from the electrode layer 1021, and the bottom of the adhesive layer 1024 is provided with a plurality of protrusion structures 1025 matching the groove structure 1014, and the flexible thin film electrode layer 102 and the electrode folding part 101 are fixedly connected through the groove structure 1014 and the protrusion structure 1025.

[0062] According to some preferred embodiments, the electrode layer 1021 includes a plurality of metal contact electrodes 1026 arranged in an array, and each metal contact electrode 1026 is composed of a plurality of periodically arranged metal hollow units; a plurality of electrode channels are provided on each packaging layer 1023, and the wires in each wire layer 1022 are respectively connected to the metal contact electrodes 1026 in the electrode layer 1021 through the electrode channels.

[0063] In the embodiment of the present invention, the base material of the flexible film electrode layer 102 may be polyimide, and the electrode layer 1021 in the flexible film electrode layer 102 is designed to be a plurality of metal contact electrodes 1026 arranged in an array, and each metal contact electrode 1026 is composed of a plurality of periodically arranged metal hollow units so that each metal contact electrode 1026 is in a hollow paper-cut pattern (for example, it may be as follows Figure 7), by designing the distance between each metal contact electrode 1026 and the structure of the metal contact electrode 1026, the stretchability, foldability and flexibility of the flexible thin film electrode layer 102 are enhanced, so that the flexible thin film electrode can better fit the electrode body 100 during the deformation process, avoiding damage to the performance of the flexible thin film electrode during the deformation process, thereby further improving the overall function and effect of the cochlear implant, extending the service life of the flexible thin film electrode layer 102 in the cochlear implant and improving its reliability in long-term use.

[0064] In the embodiment of the present invention, continue to refer to Figure 6 and Figure 8 By designing a multi-layer wire layer 1022, two adjacent wire layers 1022 are separated by a packaging layer 1023 (polyimide) so as not to interfere with each other, and further a plurality of electrode channels are arranged in the central area of ​​the packaging layer 1023. The metal wire wiring in each wire layer 1022 is as follows: Figure 8 As shown in , each layer of metal wires is arranged on both sides of the width direction (electrode channel) of the wire layer 1022, so that the metal wires in each wire layer 1022 are routed from the inside to the outside to the middle electrode channel in sequence, and the electrode channel penetrates the electrode layer 1021 so that each metal wire is respectively connected to each metal contact electrode 1026. In this way, the number of channels of the cochlear implant electrode is increased while the original size of the flexible film electrode remains unchanged, the audio resolution is improved, and the patient can recognize more complex sounds, including speech and music, thereby improving the auditory experience, and the area of ​​the electric shock electrode can be larger because it does not need to be restricted by the wire, and the stimulation effect is better.

[0065] According to some preferred embodiments, the electrode folding member 101 is further provided with a flexible electrode head 103 , and the flexible electrode head 103 is located at an end away from the electrode supporting device 200 , and is used to prevent the electrode folding member 101 from causing damage to the cochlea.

[0066] In the embodiment of the present invention, continue to refer to Figure 3 A flexible electrode head 103 is further provided on the open end of the electrode folding member 101. The flexible electrode head 103 can be made of silicone material, for example. This can effectively prevent the electrode folding member 101 from changing from a straight shape to a Figure 3 The curved spiral shape shown here causes damage to the interior of the cochlea.

[0067] It should be noted that, in the embodiment of the present invention, the electrode body 100 can be transformed by different external stimulation modes, and different driving modes include but are not limited to thermal driving or magnetic driving.

[0068] In the present invention, when thermal driving is performed, for example, a temperature-triggered copolymer network of butyl acrylate and polycaprolactone prepared by a chemical crosslinking agent can be selected as the printing material of the electrode folding member 101, and the glass transition temperature (T g ) and response temperature (T high , T low ). When magnetic driving is performed, magnetic particles (such as Fe3O4) are introduced into the copolymer network, thereby changing the driving mode of the material of the electrode folding member 101 to magnetic driving.

[0069] According to some preferred embodiments, at least one marking ring 104 is further provided on the electrode support device 200, and the marking ring 104 is located at one end close to the electrode body 100 and is used to control the implantation depth of the electrode body 100;

[0070] The electrode support device 200 is also provided with a wing-shaped handle 105 , which is located on one side of the central axis of the electrode support device 200 and opposite to the direction of the flexible thin film electrode layer 102 , and is used to control the implantation direction of the electrode body 100 .

[0071] Continue to refer Figures 1 to 3 In the embodiment of the present invention, by setting a wing-shaped handle 105 on the electrode support device 200, the electrode body 100 can be implanted conveniently while indicating the direction of the electrode contact in the electrode body 100 in the cochlea, ensuring that the electrode contact of the implanted cochlea faces the modiolus. At the same time, by setting at least one marking ring 104, the depth of the cochlear implant entering the cochlea can be determined by the setting position of the marking ring 104, which plays a role of depth marking and facilitates the fixation of the cochlear implant. After the cochlear implant electrode is fixed at a certain depth, the electrode folding section begins to actively unfold and bend. The cochlear implant electrode has the property of self-programmable control because its electrode folding part 101 structure is controlled by shape memory polymer. After being implanted in the cochlea, it is almost located in the center of the tympanic scala, and does not contact the modiolus and the outer wall of the tympanic scala, which can minimize the damage to the internal structure of the cochlea.

[0072] In the embodiment of the present invention, continue to refer to Figure 3 When the thin film electrode layer 1021 is on one side of the central axis of the electrode folding part 101, there is a certain interval between the thin film electrode layer 1021 and the electrode support device 200, so that an insulating section can be formed between the electrode body 100 and the electrode support device 200, thereby preventing the current generated by the electrode contacts in the electrode body 100 from stimulating the spiral ganglion cells at non-target positions, thereby playing a buffering and protective role.

[0073] The embodiment of the present invention further provides a method for preparing the self-bending cochlear implant as described in any one of the above, the method comprising the following steps:

[0074] (1) constructing a three-dimensional structural model of the initial shape of the electrode folding member 101 according to the specific structural shape and size of the cochlea; wherein the initial shape of the electrode folding member 101 is a bent and unfolded shape, and the temporary shape is a straight and folded shape;

[0075] (2) using a bidirectional shape memory polymer as a printing line, performing 4D printing according to the constructed three-dimensional structure model to obtain an electrode folding part 101 of an initial shape;

[0076] (3) preparing a flexible thin film electrode layer 102, applying a medical epoxy resin on the protruding structures 1025 of the flexible thin film electrode layer 102, aligning the protruding structures 1025 of the flexible thin film electrode layer 102 with the groove structures 1014 in the electrode folding member 101, fixing them with a fixture and curing them to obtain the electrode body 100;

[0077] (4) heating the electrode body 100 in the initial shape to above the glass transition temperature, applying a load, and cooling and shaping to obtain the electrode body 100 in the temporary shape;

[0078] (5) Fixing one end of the electrode body 100 to the electrode support device 200 to obtain the self-bending cochlear implant; wherein the size of the electrode folding member 101 gradually decreases in the direction away from the electrode support device 200.

[0079] In the embodiment of the present invention, after the electrode folding member 101 is printed to obtain the initial shape (bent and unfolded shape), it is heated to the glass transition temperature T g Above (about 40-45°C), the electrode folding member 101 is compressed and folded into a temporary shape (straight folded shape), and then the electrode folding member 101 is cooled to a temperature lower than the response temperature T low (For example, it can be about 20°C) while maintaining the material deformation. At this time, the electrode folding member 101 can be maintained in a stable straight folded shape, completing the shaping process. high and T low ) to control the electrode folding member 101 to undergo bidirectional deformation. Specifically, the electrode folding member 101 is heated to a response temperature T high When the temperature of the folded electrode 101 is about 37°C (for example), the folded electrode 101 changes to the initial shape (bent and unfolded shape), completing the shape memory process. lowWhen the electrode folding member 101 is turned into a temporary shape (straight folded shape) reversibly, a two-way shape memory process is completed.

[0080] Before the cochlear implant electrode is implanted into the cochlea, the temperature of the cochlear implant electrode body 100 is raised to T g As described above, the electrode folding member 101 is formed into a temporary shape (straight folding shape). When the cochlear implant electrode is implanted into the cochlea, the temperature of the cochlear implant electrode folding member 101 is increased to T high At this time, even without external force, the electrode folding member 101 will return to its initial bent and unfolded shape, realizing the shape memory effect and completing the self-bending process. When the cochlear implant electrode needs to be removed, the temperature of the cochlear implant electrode body 100 is controlled to drop to T low At this time, the electrode folding member 101 can produce the shape memory effect again, self-fold, and change from a curved unfolded shape to a flat folded shape. This process can be carried out without external force, and the rate is controllable, which can achieve non-traumatic removal and avoid secondary damage to the cochlea during the removal process.

[0081] In the embodiment of the present invention, the flexible thin film electrode layer is prepared by using a micro-electromechanical system process. The specific preparation method of the process is not described in detail in this embodiment. In summary, the self-bending cochlear implant of the present invention uses a low-cost, mass-producible micro-electromechanical system process and economical and affordable 4D printing technology to achieve the excellent effects of low cost, rapid manufacturing and customization.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-bending cochlear implant, characterized in that: It comprises an electrode body and an electrode support device connected to the electrode body; wherein: The electrode body comprises an electrode folding part and a flexible thin film electrode layer, one end of the electrode folding part is connected to the electrode supporting device, the flexible thin film electrode layer is laid on one side of the central axis of the electrode folding part, and the flexible thin film electrode layer is used to generate current to stimulate neurons on the inner wall of the cochlea; The electrode folding part includes an initial shape and a temporary shape, the initial shape is a bent and unfolded shape, the temporary shape is a flat and folded shape, and the size of the electrode folding part in the initial shape is larger than the size of the electrode folding part in the temporary shape. Under external stimulation, the electrode folding part can drive the flexible thin film electrode layer to transform bidirectionally between the initial shape and the temporary shape.

2. The cochlear implant according to claim 1, characterized in that: The electrode folding member is composed of a plurality of foldable units; wherein each foldable unit is composed of two mutually parallel support plates and an origami bending section located between the two support plates; A support plate is shared between two adjacent foldable units, and the sizes of the two support plates in each foldable unit are different. The size of the support plate close to one end of the electrode support device is different from the size of the support plate away from one end of the electrode support device, so that the size of the electrode folding part changes gradually.

3. The cochlear implant according to claim 2, characterized in that: The size of the electrode folding part gradually decreases in a direction away from the electrode supporting device.

4. The cochlear implant according to claim 2, characterized in that: In the electrode folding part, one end of each support plate close to the inner wall of the cochlea is provided with a plurality of groove structures, and the bottom of the flexible film electrode layer is provided with a plurality of protrusion structures, the protrusion structures correspond to the positions of the groove structures, and the sizes of the protrusion structures match the sizes of the groove structures, and the electrode folding part is fixed to the electrode film layer through the groove structures and the protrusion structures; Preferably, the opening area of ​​the groove structure is smaller than the inner area of ​​the groove structure.

5. The cochlear implant according to claim 2, characterized in that: The flexible film electrode layer comprises an electrode layer and a plurality of wire layers which are arranged in sequence from top to bottom; wherein a packaging layer is provided on the upper and lower surfaces of each wire layer, and the packaging layer is used to protect the wire layer.

6. The cochlear implant according to claim 5, characterized in that: The electrode layer comprises a plurality of metal contact electrodes arranged in an array, each of which is composed of a plurality of periodically arranged metal hollow units; and / or A plurality of electrode channels are arranged on each packaging layer, and the wires in each wire layer are connected to the metal contact electrodes in the electrode layer through the electrode channels.

7. The cochlear implant according to claim 1, characterized in that: The electrode folding member is also provided with a flexible electrode head, which is located at an end away from the electrode supporting device and is used to prevent the electrode folding member from causing damage to the cochlea.

8. The cochlear implant according to claim 1, characterized in that: The electrode support device is also provided with at least one marking ring, which is located at one end close to the electrode body and is used to control the implantation depth of the electrode body; Preferably, the electrode support device is further provided with a wing-shaped handle, which is located on one side of the central axis of the electrode support device and opposite to the direction of the flexible thin film electrode layer, and is used to control the implantation direction of the electrode body.

9. The cochlear implant according to claim 1, characterized in that: The shape memory deformation rate of the electrode folding part is 0.1-5 mm / s.

10. The method for preparing a self-bending cochlear implant according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) constructing a three-dimensional structural model of the initial shape of the electrode folding member according to the specific structural shape and size of the cochlea; wherein the initial shape of the electrode folding member is a bent and unfolded shape, and the temporary shape is a straight and folded shape; (2) using a bidirectional shape memory polymer as a printing line, performing 4D printing according to the constructed three-dimensional structure model to obtain an electrode folding part of an initial shape; (3) preparing a flexible thin film electrode layer, applying a medical epoxy resin on the convex structure of the flexible thin film electrode layer, aligning the convex structure of the flexible thin film electrode layer with the groove structure in the electrode folding part, fixing them with a clamp and curing them to obtain the electrode body; (4) heating the electrode body in the initial shape to above the glass transition temperature, applying a load, and cooling and shaping to obtain the electrode body in a temporary shape; (5) Fixing one end of the electrode body to the electrode supporting device to obtain the self-bending cochlear implant; wherein the size of the electrode folding part gradually decreases in the direction away from the electrode supporting device.

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