Bone-conduction hearing unit

Abstract

To provide a bone-conduction hearing unit which is small and has low risk of providing an infection.SOLUTION: The bone-conduction hearing unit according to the present invention is a bone-conduction hearing unit buried in a scalp and includes a vibration generation unit for generating vibrations and an anchor. The bone-conduction hearing unit generates vibrations by applying a varying magnetic field from the outside of a scalp to the vibration generation unit, and transmits the vibrations to the cranial bone through the anchor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bone conduction hearing aid unit that provides hearing aid by transmitting vibrations to the inner ear through bone conduction in the skull. [Background technology]

[0002] For patients with conductive hearing loss who have a middle ear dysfunction, a hearing aid that transmits vibrations to the inner ear by bone conduction has been developed. The hearing aid of Patent Document 1 transmits vibrations to the inner ear by bone conduction and has a hearing aid drive unit that is embedded in the skull. The hearing aid drive unit of Patent Document 1 is attached directly to the skull, covered by the scalp, and connected to an external device equipped with a microphone by a cord. Therefore, measures must be taken to prevent infection between the scalp and the cord. Patent Document 1 also describes a hearing aid that connects the hearing aid drive unit and the external device by wireless communication. However, the cable is led out of the skin and connected to a battery outside the skin, and measures must be taken to prevent infection between the skin and the cable. An internal battery that generates electricity from the flow of blood is also described, but such internal electricity generation requires the occurrence of blood clots to be suppressed. In addition, if a battery is provided in the hearing aid drive unit, the scalp must be incised periodically to replace the battery. It is possible to charge a secondary battery by wireless power supply, but the device becomes large. Furthermore, the secondary battery must be replaced when it deteriorates.

[0003] The bone conduction hearing aid of Patent Document 2 has an oscillator wound with an oscillator driving coil in an internal unit embedded in the skull. An audible modulated transmission signal is transmitted from an external transmitting coil in the external unit to an internal receiving coil in the internal unit by a transmission magnetic flux, and an excitation current generated in the internal receiving coil is sent to the oscillator driving coil to drive the oscillator to expand and contract. In this way, an audible signal can be bone-conducted with high accuracy without providing a power supply or demodulation circuit in the internal unit. In addition, there is no wiring led out from the scalp, so there is a low risk of infection.

[0004] However, the bone conduction hearing aid of Patent Document 2 has an internal unit that includes an internal receiving coil and a transducer drive coil for the transducer, which results in a large internal unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-289219 A [Patent Document 2] Patent No. 5219037 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a bone conduction hearing aid unit that is small and has a low risk of infection. [Means for solving the problem]

[0007] The bone-conduction hearing aid unit in one embodiment of the present invention is a bone-conduction hearing aid unit that is implanted under the scalp, and is characterized in that it comprises a vibration generating unit that generates vibrations and an anchor, and generates vibrations by applying a fluctuating magnetic field to the vibration generating unit from outside the scalp, and transmits the vibrations to the skull via the anchor. Effect of the Invention

[0008] The present invention makes it possible to provide a small, highly efficient bone conduction hearing aid unit with a low risk of infection. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing the bone-conduction hearing aid unit of the first embodiment attached to the skull. [Diagram 2] 1 is a side view of the bone conduction hearing aid unit of Example 1 worn on the head, viewed from a first direction. [Diagram 3] 4 is a side view of the bone conduction hearing aid unit of Example 1 worn on the head, viewed from a second direction. FIG. [Figure 4] FIG. 2 is a top view of the extracorporeal unit of the first embodiment. [Diagram 5] FIG. 2 is a top view of the bone conduction hearing aid unit of the first embodiment. [Figure 6] FIG. [Figure 7] FIG. 3 is a cross-sectional view of the fixing plate of the first embodiment. [Figure 8] FIG. [Figure 9] FIG. 2 is a side view of the anchor of Example 1. [Figure 10] FIG. 2 is a top view of the bone conduction hearing aid unit of the first embodiment with the top case removed. [Figure 11] 1 is a view of the bone conduction hearing aid unit of Example 1 with the top case removed, viewed from the first reverse direction. [Figure 12] 4 shows the movement of the vibration generating part of the first embodiment as viewed from the reverse first direction. [Figure 13] 1 is a cross-sectional view of a bone conduction hearing aid unit according to a first embodiment. [Figure 14] FIG. 3 is a cross-sectional view showing a schematic state before a vibration generating device is attached to a skull in the first embodiment. [Figure 15] FIG. 11 is a top view of the fixing plate of the second embodiment. [Figure 16] FIG. 11 is a top view of the fixing plate of the third embodiment. [Figure 17] FIG. 13 is a top view of the fixing plate of the fourth embodiment. [Figure 18] FIG. 13 is a top view of the fixing plate of the fifth embodiment. [Figure 19] FIG. 13 is a cross-sectional view of a fixing plate according to a fifth embodiment. [Figure 20] FIG. 13 is a top view of another extracorporeal unit. [Figure 21] FIG. 11 is a cross-sectional view of another external unit worn on the head, viewed from a second direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0010] The bone conduction hearing aid system of the first embodiment can transmit vibrations to the inner ear by bone conduction and enable speech recognition for patients with conductive hearing loss who have a disorder in the middle ear function. The bone conduction hearing aid system of the first embodiment has an external unit 2 (shown in Figs. 2, 3, etc.), a sound collection unit 3 (not shown), and wiring 4 (not shown) connecting the external unit 2 and the sound collection unit 3, in addition to a bone conduction hearing aid unit 1 (shown in Figs. 1 to 3, etc.) which is an internal unit. These points are the same in other embodiments described later.

[0011] The bone-conduction hearing aid unit 1, which is the internal unit of the first embodiment, is attached to the temporal region of the skull SK, as shown in Fig. 1. In the present application, the temporal region where the bone-conduction hearing aid unit 1 is attached is described as the upper region. The direction from the cheekbone to the back of the head is described as the first direction, the opposite direction to the first direction is described as the reverse first direction, and the direction from the neck to the top of the head is described as the second direction. This is the same for the other embodiments described below.

[0012] As shown in Fig. 1, the bone-conduction hearing aid unit 1 of the first embodiment is attached at a position shifted in a first direction and a second direction from the external ear canal EK. The bone-conduction hearing aid unit 1 has a shape of a substantially isosceles triangle when viewed from above, and is attached to the skull SK so that the direction from the apex of the substantially isosceles triangle to the center of the base is substantially the same as the first direction. The same applies to the second to fourth embodiments described below.

[0013] Fig. 2 is a side view of the bone-conduction hearing aid unit 1 and the external unit 2 placed on the patient's head viewed from a first direction, and Fig. 3 is a side view of the bone-conduction hearing aid unit 1 and the external unit 2 placed on the patient's head viewed from a second direction. Figs. 2 and 3 show the state of a bone-conduction hearing aid system having the bone-conduction hearing aid unit 1 and the external unit 2 when in use. Fig. 2 shows a cross section of the skull SK, scalp SC, and external unit 2 taken along line BB in Fig. 1, and Fig. 3 shows a cross section of line AA in Fig. 1. When in use as shown in Figs. 2 and 3, the bone-conduction hearing aid unit 1 attached to the skull SK is covered by the scalp SC, and the external unit 2 is placed outside the scalp SC.

[0014] The bone-conduction hearing aid unit 1 has a structure in which a vibration generator 11 with a vibration generating unit inside is fixed to an anchor 12. The anchor 12 has a male screw-shaped portion, and is fixed by screwing it into the skull SK as shown in Figures 2 and 3. Meanwhile, the vibration generator 11 is not embedded in the skull SK, but is covered by the scalp SC. The bone-conduction hearing aid unit 1 is completely embedded inside the scalp SC, and there are no wirings leading out from the scalp SC. Therefore, there is no possibility of infection between the scalp SC and the wiring, and the risk of infection is low.

[0015] On the other hand, the external unit 2 is used by being placed outside the scalp SC, as shown in Figures 2 and 3. The external unit 2 is configured by winding a coil 21 around a magnetic body 22, placing it in a case 23, and closing it with a lid 24. Figure 4 shows a top view of the external unit 2 with the lid 24 removed. In the external unit 2, an electromagnet in which the coil 21 is wound around a thin cylindrical magnetic body 22 is housed in the case 23. This electromagnet is disk-shaped with a diameter larger than its axial length. Both ends of the coil 21 are led out to the outside of the case 23 and connected to wiring 4 (not shown).

[0016] In a bone conduction hearing aid system using the bone conduction hearing aid unit 1, a variable magnetic field is generated by applying a sound signal collected and amplified by a sound collection unit 3 (not shown) to a coil 21 of an external unit 2 via a wire 4. Then, as shown in Figs. 2 and 3, a variable magnetic field is applied to a vibration generator 11 covered by a scalp SC via the scalp SC. The sound collection unit 3 is a behind-the-ear type, and is used by hanging it on an earlobe. In the vibration generator 11, vibrations are generated by the variable magnetic field and transmitted to the skull SK via an anchor 12. The vibrations are then transmitted to the inner ear by bone conduction, and are recognized as sound by the patient. The energy of the vibrations generated by the vibration generator 11 is applied from the outside of the scalp SC by the variable magnetic field, so that as shown in Figs. 2 and 3, there is no wiring leading to the outside from the scalp SC, and the scalp SC is closed to the outside. Therefore, the risk of infection of the patient is low.

[0017] Next, the structure of the bone-conduction hearing aid unit 1 in Example 1 will be described. Fig. 5 is a top view of the bone-conduction hearing aid unit 1 shown in Figs. 1 to 3. Fig. 5 is an enlarged view of the bone-conduction hearing aid unit 1 shown in Fig. 1 rotated 90° to the right. In Fig. 5, a male screw 13 is inserted into a vibrator head 111a of a vibrator 111, and a screw head 131 is visible. Moreover, the portion other than the vibrator head 111a is covered with a top case 115.

[0018] 5, the anchor 12 is removably fixed to the rear side of the position of the screw head 131. The vibration generator 11 has a substantially triangular shape and is removably fixed to the anchor 12 near one of the three vertices. The vibration generator 11 also has a substantially isosceles triangular shape and is removably fixed to the anchor 12 near the vertex farthest from the base.

[0019] 6 to 8 show the whole view of the vibrating body 111, in which the vibrating body head 111a is shown in FIG. 5. When the top case 115 and the male screw 13 are removed from the bone conduction hearing aid unit 1 in FIG. 5, the vibrating body 111 shown in FIG. 6 to 8 is obtained. The vibrating body 111 is integrally formed from titanium. FIG. 6 is a top view of the vibrating body 111, and FIG. 7 is a cross-sectional view of the vibrating body 111 in FIG. 6 taken along line AA. FIG. 8 is a bottom view corresponding to the rear side of the vibrating body 111 in FIG. 6. In the vibrating body 111, the vibrating body head 111a and the fixed plate 111f are connected by a vibration conducting part 111g. The upper surface of the fixed plate 111f is substantially rectangular, and the vibrating body head 111a is located to the side of the fixed plate long side Fl, which is the long side of the upper surface of the fixed plate 111f. As shown by line AA in FIG. 6, vibrator head 111a is positioned in a direction perpendicular to the long side Fl from the center of fixed plate long side Fl, with vibration conducting part 111g therebetween.

[0020] As shown in Figures 6 to 8, vibrator head 111a is provided with an annular locking plate 111b on the inside, and a circular locking hole 111c is provided on the inside of locking plate 111b. Locking plate 111b is provided between upper surface recess 111d and lower surface recess 111e of vibrator head 111a, as shown in Figure 7. Upper surface recess 111d is a circular recess as shown in Figures 6 and 7, and lower surface recess 111e is a polygonal recess having a substantially hexagonal shape as shown in Figures 7 and 8.

[0021] Fig. 9 shows a side view of the anchor 12. The anchor 12 is shaped like a hexagonal bolt, with anchor legs 122 protruding from a hexagonal column-shaped anchor head 121, and is made of titanium. The outer peripheral surface of the anchor head 121 is hexagonal, and the outer surface of the anchor legs 122 forms a male thread portion 124. The anchor head 121 of the anchor 12 attached to the skull SK is fitted and fixed in the lower surface recess 111e of the vibrating body head 111a of the vibrating body 111 shown in Figs. 7 and 8.

[0022] As shown in Figs. 6 to 8, the fixed plate 111f is rectangular and thin. The vibration conductive part 111g connects the vibrator head 111a and the fixed plate 111f. The vibration conductive part 111g is thinner than the vibrator head 111a and thicker than the fixed plate 111f. As shown in Figs. 6 and 7, there is a step between the upper surfaces of the vibration conductive part 111g and the fixed plate 111f, and the upper surface of the vibration conductive part 111g is located higher than the upper surface of the fixed plate 111f. On the other hand, as shown in Figs. 7 and 8, there is no step between the lower surface of the vibration conductive part 111g and the fixed plate 111f. The vibrator head 111a protrudes upward and downward from the vibration conductive part 111g.

[0023] 6 and 8, in the vibrating body 111, the vibration conducting part 111g is a rectangle having the same length as the fixed plate 111f, with the center on the vibrating body head 111a side protruding into a small rectangle. The vibration conducting part 111g has a convex shape with the center connected to the vibrating body head 111a protruding laterally.

[0024] The giant magnetostrictive element 112 and the like are fixed to the vibrating body 111. Fig. 10 shows a top view of the bone-conduction hearing aid unit 1 of Fig. 5 with the top case 115 removed. Fig. 11 shows the bone-conduction hearing aid unit 1 shown in Fig. 10 with the top case 115 removed, viewed from the first reverse direction. A rectangular parallelepiped giant magnetostrictive element 112 is fixed to the rectangular upper surface of the fixing plate 111f of the vibrating body 111. The giant magnetostrictive element 112 has a rectangular parallelepiped shape that is longest in the longitudinal direction Ld and shortest in the thickness direction Td, which is the up-down direction. The longitudinal direction Ld is a direction along the long side Fl of the fixing plate 111f.

[0025] Furthermore, permanent magnets 113 are provided on both ends of the giant magnetostrictive element 112 in the longitudinal direction Ld, and the giant magnetostrictive element 112 is sandwiched between the two permanent magnets 113. The permanent magnets 113 are fixed to the giant magnetostrictive element 112 and fixed plate 111f. In the longitudinal direction Ld, the combined length of the giant magnetostrictive element 112 and the two permanent magnets 113 is the same as the length of fixed plate 111f. The top surface of fixed plate 111f and the bonding surfaces of the giant magnetostrictive element 112 and the two permanent magnets 113 to fixed plate 111f have the same shape and size.

[0026] A bottom case 114 is provided on the back side of the vibrating body 111. The bottom case 114 and the vibrating body head 111a, together with the top case 115, form the outer surface of the vibration generator 11. When the vibration generator 11 is installed, the longitudinal direction Ld of the giant magnetostrictive element 112 is approximately parallel to the surface of the skull SK. In addition, the longitudinal direction Ld of the giant magnetostrictive element 112 is perpendicular to the direction in which the anchor 12 is screwed into the skull SK.

[0027] As shown in FIG. 10, the fixed plate 111f is connected to the vibrating body head 111a via the vibration conductive part 111g. The bottom case 114 is fixed to the vibrating body head 111a, but is not in contact with the fixed plate 111f and the vibration conductive part 111g as shown in FIG. 11. The fixed plate 111f and the vibration conductive part 111g are floating above the bottom case 114. The top case 115 shown in FIG. 5 is also fixed to the vibrating body head 111a and the bottom case 114, but is not in contact with the vibration conductive part 111g, the super magnetostrictive element 112, the permanent magnet 113, etc. Even if the fixed plate 111f vibrates, the fixed plate 111f does not come into contact with the bottom case 114 and the top case 115, and the vibration of the fixed plate 111f is transmitted to the vibrating body head 111a via the vibration conductive part 111g.

[0028] The anchor 12 is fitted and fixed at the position of the vibrator head 111a. The locking hole 111c is a hole through which the male screw 13 for locking the anchor 12 passes, and is the position of the anchor 12. In FIG. 10, the anchor 12 is fixed to the back side of the male screw 13, and the central axis of the male screw 13 coincides with the central axis of the anchor. As shown in FIG. 10, in the bone conduction hearing aid unit 1 of the first embodiment, the anchor axis Aa, which is the central axis of the anchor, is located at a right angle to the center line Cl extending in the longitudinal direction Ld of the super magnetostrictive element 112 and away from the super magnetostrictive element 112. In FIG. 10, the anchor axis Aa extends in a direction perpendicular to the drawing. Furthermore, the anchor axis Aa is provided at a position intersecting the perpendicular bisector Pb of the center line Cl in the longitudinal direction Ld of the super magnetostrictive element 112.

[0029] <Occurrence of vibration> Next, it will be described how vibrations are generated in the bone conduction hearing aid unit 1. Fig. 12 shows the vibration generating part that generates vibrations, viewed from the first reverse direction. The vibration generating part is formed by the giant magnetostrictive element 112, the permanent magnet 113, and the fixed plate 111f of the vibrating body 111.

[0030] When a magnetic field is applied to the giant magnetostrictive element 112, the length of the giant magnetostrictive element 112 changes. When a varying magnetic field is applied to the giant magnetostrictive element 112, the giant magnetostrictive element 112 expands and contracts. The permanent magnet 113 applies a bias magnetic field to the giant magnetostrictive element 112 to expand the expansion and contraction range. The permanent magnet 113 in the first embodiment is formed of a neodymium magnet.

[0031] The magnetic field causes the giant magnetostrictive element 112 to expand and contract, but the fixed plate 111f to which the giant magnetostrictive element 112 is fixed does not expand and contract. Therefore, when the giant magnetostrictive element 112 contracts as shown by arrow s in Fig. 12, the giant magnetostrictive element 112 and the fixed plate 111f bend in the direction of arrow S. When the giant magnetostrictive element 112 expands as shown by arrow e, the giant magnetostrictive element 112 and the fixed plate 111f bend in the direction of arrow E. Then, due to the varying magnetic field, the vibration generating part bends alternately in the directions of arrow S and arrow E, generating vibration.

[0032] In this way, by expanding and contracting the giant magnetostrictive element 112 by the fluctuating magnetic field, the vibration generating part having the giant magnetostrictive element 112 fixed to the fixed plate 111f bends alternately to one side and the other, and bending vibration is generated in the vibration generating part. Then, this vibration is transmitted from the fixed plate 111f shown in Figs. 6 to 8 and 11 through the vibration conducting part 111g to the vibrating body head 111a, and is transmitted to the skull SK via the anchor 12.

[0033] Fig. 13 shows a cross-sectional view of the bone conduction hearing aid unit 1 in Example 1. Fig. 13 is a cross-sectional view taken along line AA in Fig. 5. The vibrating body 111 has a bottom case 114 and a top case 115 fixed at the vibrating body head 111a. The bottom case 114 and the top case 115 are fixed to each other. The vibrating body head 111a, the bottom case 114, and the top case 115 are made of titanium, and form the outer surface of the vibrating body 111 to constitute the case.

[0034] Fig. 13 shows a state in which the anchor head 121 of the anchor 12 shown in Fig. 9 is fitted into the bottom surface recess 111e shown in Figs. 7 and 8. Then, the male screw 13, which is a fixing pin, is screwed into the female screw portion 125 of the anchor 12 from above the vibrating body head 111a. As a result, the locking plate 111b of the vibrating body 111 is sandwiched between the screw head 131 of the male screw 13 and the anchor head 121 of the anchor 12, and the anchor 12 is fixed to the vibrating body 111. Then, the anchor leg 122 protrudes below the vibration generator 11. The anchor 12 is also made of titanium.

[0035] FIG. 13 also shows a cross section of a vibration generating section having a fixed plate 111f and a super magnetostrictive element 112 fixed to the fixed plate 111f. The vibration generator 11 has a bottom case 114, a top case 115, and a vibrator head 111a that cover the vibration generating section and isolate it from the outside. The super magnetostrictive element 112 has a surface along the longitudinal direction Ld fixed to the upper surface of the fixed plate 111f with an adhesive. The vibration conducting part 111g is formed thicker than the fixed plate 111f and protrudes upward, and the super magnetostrictive element 112 is in contact with the side surface of the protruding part of the vibration conducting part 111g. However, they may be separated from each other without contacting each other, or the super magnetostrictive element 112 may be fixed to the side surface of the protruding part of the vibration conducting part 111g with an adhesive or the like.

[0036] The vibration transmitted from the fixed plate 111f to the vibrating body head 111a via the vibration conducting part 111g is transmitted to the anchor head 121 of the anchor 12. Then, the anchor leg 122 of the anchor 12 vibrates and transmits the vibration to the skull SK. The anchor leg 122 of the anchor 12 protrudes from the vibration generator 11 and is embedded in the skull SK.

[0037] <Installation of bone conduction hearing aid unit> The bone conduction hearing aid unit 1 is installed by implanting it in the patient's head through surgery. When installing it, as shown in Fig. 14, the vibration generator 11 and male screw 13 are fixed to an anchor 12 fixed to the skull SK, as indicated by the arrow. Fig. 14 is a cross-sectional view that shows a schematic state before the vibration generator 11 is attached to the skull SK.

[0038] When the bone conduction hearing aid unit 1 is installed in the patient, an incision is made in the second direction shown in FIG. 1 behind the ear, and the scalp SC is incised. Next, the skull SK is cut to form a hole for the anchor 12. Furthermore, the anchor leg 122 of the anchor 12 is screwed into the formed hole and fixed. The lower part of FIG. 14 shows the anchor 12 with the anchor leg 122 fixed to the skull SK. The anchor head 121 has a polygonal outer surface, and an anchor recess 123 recessed from the opposite side to the anchor leg 122 is formed. The outside of the anchor leg 122 is a male screw portion 124, and the anchor leg 122 having the male screw portion 124 is screwed into the skull SK by turning the hexagonal column-shaped anchor head 121 with a wrench. The inner surface of the anchor recess 123 is a female screw portion 125. The anchor leg 122 is embedded in the skull SK, but the anchor head 121 is not embedded and protrudes above the skull SK.

[0039] Thereafter, the vibration generator 11 is inserted from the bottom side between the skull SK and the scalp SC, and the anchor head 121 of the anchor 12 is covered with the lower surface recess 111e, which is a polygonal recess. Then, the male screw 13, which is a fixing pin, is removably fixed to the female screw portion 125 of the anchor recess 123 through the locking hole 111c, which is a hole that penetrates to the lower surface recess 111e in the vibration generator 11. In this way, the vibration generator 11 is removably fixed to the anchor 12.

[0040] 14 is a schematic cross-sectional view of the vibration generator 11 and male screw 13 before attachment to the anchor 12. After the vibration generator 11 is fixed to the anchor 12 by the male screw 13, the incised scalp SC is sutured. After surgery, as shown in FIGS. 2 and 3, there are no wiring leading out of the scalp SC, and the wound made during scalp SC is completely closed, so there is little risk of infection.

[0041] 10, in the bone conduction hearing aid unit 1 of Example 1, the anchor 12 is located to the side of the giant magnetostrictive element 112 extending in the longitudinal direction Ld, away from the giant magnetostrictive element 112. Then, as shown in Fig. 12, vibrations generated by bending the fixed plate 111f and the giant magnetostrictive element 112 are transmitted from the fixed plate 111f to the anchor 12 via the vibration conduction part 111g.

[0042] In the bone conduction hearing aid unit 1 of the first embodiment, the giant magnetostrictive element 112, which expands and contracts greatly in response to a magnetic field, is fixed to a fixed plate 111f, which does not expand or contract substantially in response to a magnetic field. This fixation allows the expansion and contraction vibration of the giant magnetostrictive element 112 caused by a fluctuating magnetic field to be converted into bending vibration of the fixed plate 111f, amplifying the vibration, and generating vibrations with high efficiency, as shown in Fig. 12. Furthermore, the longitudinal direction Ld of the giant magnetostrictive element 112 is approximately parallel to the surface of the skull SK, allowing the vibration generator 11 to be made thin.

[0043] Furthermore, the permanent magnets 113 provided on both ends of the giant magnetostrictive element 112 not only generate a bias magnetic field, but also function as a weight when the fixed plate 111f vibrates in a curved manner, thereby contributing to the generation of large vibrations. EXAMPLES

[0044] In the vibrating body 111 of the first embodiment, as shown in Fig. 6 and Fig. 8, the vibration conducting part 111g has a convex shape with a square protrusion from the center of a rectangle to form a step. However, the fixing plate may have another shape. Fig. 15 shows a top view of the vibrating body 511 in the bone conduction hearing aid unit 5 (not shown) of the second embodiment.

[0045] The fixed plate 511f is rectangular and thin. The vibration conducting part 511g connecting the vibrating body head 511a and the fixed plate 511f is thinner than the vibrating body head 511a and thicker than the fixed plate 511f. The fixed plate 511f side of the vibration conducting part 511g is formed to have the same length as the fixed plate 511f, and the vibrating body head 511a side is shorter than the fixed plate 511f. As in the first embodiment, the vibration conducting part 511g and the fixed plate 511f have different thicknesses, and a step is formed on the upper surface side. As in the first embodiment, the vibrating body head 511a protrudes from the vibration conducting part 511g to the upper surface side and the lower surface side. As in the first embodiment, a super magnetostrictive element and a permanent magnet are fixed to the fixed plate 511f of the vibrating body 511.

[0046] Unlike the first embodiment, the vibration conducting section 511g of the vibrating body 511 in the second embodiment does not have a step. The vibration conducting section 511g in the second embodiment has a shape of an approximately isosceles triangle with the side of the fixed plate 511f as the base, the apex of which is embedded in the vibrating body head 511a. In the second embodiment, vibration caused by the curvature of the fixed plate 511f is also transmitted to the vibrating body head 511a via the vibration conducting section 511g. In the second embodiment, a fluctuating magnetic field is applied to the vibration generating device 51 by the external unit 2 similar to that in the first embodiment shown in Figs. 2-3 to generate vibration. In the bone conduction hearing aid unit 5 in the second embodiment, the configuration other than the vibration conducting section 511g is similar to that in the first embodiment.

[0047] The vibration conduction unit 511g of the second embodiment has a shape of an approximately isosceles triangle. The locking hole 511c is located near the position where the equal sides of the vibration conduction unit 511g intersect. The position of the locking hole 511c is the position of the anchor (not shown). The super magnetostrictive element (not shown) is fixed to the fixing plate 511f along the base of the vibration conduction unit 511g. In the bone conduction hearing aid unit 5 of the second embodiment, the anchor axis, which is the central axis of the anchor, is also provided at a position intersecting with the perpendicular bisector of the center line in the longitudinal direction of the super magnetostrictive element. The angle θ formed by the two equal sides of the vibration conduction unit 511g, which corresponds to the vertex angle, is preferably 60° or more and 100° or less. EXAMPLES

[0048] The fixing plate may have other shapes. FIG. 16 shows a top view of the vibrator 611 in the bone conduction hearing aid unit 6 (not shown) of the third embodiment. The fixing plate 611f is rectangular when viewed from above and is formed thin. The vibration conducting part 611g connecting the vibrator head 611a and the fixing plate 611f is formed thinner than the vibrator head 611a and thicker than the fixing plate 611f. The fixing plate 611f side of the vibration conducting part 611g is formed to have the same length as the fixing plate 611f, and the vibrator head 611a side is formed shorter than that. As in the first and second embodiments, the vibration conducting part 611g and the fixing plate 611f have different thicknesses, and a step is formed on the upper surface side. As in the first and second embodiments, the vibrator head 611a protrudes from the vibration conducting part 611g to the upper surface side and the lower surface side. A giant magnetostrictive element and a permanent magnet are fixed to a fixing plate 611f of the vibrating body 611, similarly to the first embodiment.

[0049] As in the second embodiment, the vibration conduction part 611g in the vibrating body 611 in the third embodiment has a shape in which the apex of a triangle with the side of the fixed plate 611f as the base is embedded in the vibrating body head 611a. However, unlike the second embodiment, the vibrating body head 611a is located to the side of the fixed plate long side Fl, which is the long side of the upper surface of the fixed plate 611f, at a position shifted from the center. The vibration conduction part 611g in the third embodiment has a shape of a right-angled triangle with one of the apexes in contact with the fixed plate 611f forming a right angle. In the third embodiment as well, the vibration caused by the curvature of the fixed plate 611f is transmitted to the vibrating body head 611a via the vibration conduction part 611g.

[0050] In the third embodiment, the vibrator head 611a is located to the side of the fixed plate 611f at a position offset from the center of the long side of the upper surface thereof, and the bottom case and the top case are shaped to match this. The other configurations are the same as those in the first and second embodiments. Also in the third embodiment, a fluctuating magnetic field is applied to the vibration generator 61 by the external unit 2 similar to that in the first embodiment shown in Figs. 2 and 3 to generate vibration. EXAMPLES

[0051] FIG. 17 shows a top view of the vibrator 711 of the bone conduction hearing aid unit 7 (not shown) in Example 4, which has yet another shape. The fixed plate 711f is rectangular when viewed from above and is formed thin. The vibration conductive part 711g connecting the vibrator head 711a and the fixed plate 711f is formed thinner than the vibrator head 711a and thicker than the fixed plate 711f. The fixed plate 711f side of the vibration conductive part 711g is formed to have the same length as the fixed plate 711f. As in Examples 1 to 3, the vibration conductive part 711g and the fixed plate 711f have different thicknesses, and a step is formed on the upper surface side. As in Examples 1 to 3, the vibrator head 711a protrudes from the vibration conductive part 711g to the upper surface side and the lower surface side. As in Examples 1 to 3, a giant magnetostrictive element and a permanent magnet are fixed to the fixed plate 711f of the vibrator 711. As in the third embodiment, the vibrating body head 711a in the fourth embodiment is located to the side of the fixed plate long side Fl, which is the long side of the upper surface of the fixed plate 711f, at a position shifted from the center.

[0052] On the other hand, unlike the third embodiment, the vibration conductive part 711g of the vibrating body 711 in the fourth embodiment has a shape in which a notch is provided on the oblique side of the vibration conductive part 611g in the third embodiment, and is substantially L-shaped when viewed from above. The vibration conductive part 711g in the fourth embodiment can be said to have a shape in which a small rectangular parallelepiped protrusion between the vibration conductive part 111g in the first embodiment and the vibrating body head 111a is moved to one side. The vibration conductive part 711g has a shape in which a long rectangular parallelepiped along the side of the fixed plate 711f is connected to a rectangular parallelepiped protruding vertically from the side near one end of the side. In the fourth embodiment as well, the vibration caused by the curvature of the fixed plate 711f is transmitted to the vibrating body head 711a via the vibration conductive part 711g.

[0053] In the fourth embodiment, the vibrator head 711a is located at a position offset from the center of the long side Fl of the fixed plate 711f, so the bottom case and the top case are shaped accordingly. The other configurations are the same as those of the first and second embodiments. The bottom case and the top case may be shaped similarly to those of the third embodiment, or may be shaped with a notch reflecting the notch of the fixed plate 711f. In the fourth embodiment, a fluctuating magnetic field is applied to the vibration generator 71 by the external unit 2 similar to that of the first embodiment shown in Figs. 2 to 4 to generate vibration. EXAMPLES

[0054] The shape of the fixing plates 111f, 511f, 611f, and 711f in the first to fourth embodiments is rectangular. The shapes of the vibration conducting parts 111g, 511g, 611g, and 711g are convex, isosceles, right-angled, and L-shaped. The shapes of the case and the vibration generator also reflect these shapes. However, other shapes may also be used. Figs. 18 and 19 show the vibrating body 811 and the like in the disc-shaped bone conduction hearing aid unit 8 (not shown) of the fifth embodiment. Fig. 18 is a top view, and Fig. 19 is a cross-sectional view taken along the line CC in Fig. 18. In Figs. 18 and 19, the case that houses the vibrating body 811 and the like is omitted.

[0055] In the bone conduction hearing aid unit 8 of the fifth embodiment, a disk-shaped giant magnetostrictive element 812 is fixed to a fixed plate 811f of a disk-shaped vibrating body 811. As explained in FIG. 12 of the first embodiment, the fixed plate 811f is curved and vibrated due to the expansion and contraction of the giant magnetostrictive element 812 caused by the fluctuating magnetic field. The vibration is transmitted to the vibrating body head 811a via the vibration conducting part 811g, and furthermore, the anchor 82 fixed to the skull SK vibrates. The vibration is further transmitted from the anchor 82 to the skull SK, and is transmitted to the inner ear by bone conduction.

[0056] <Other extracorporeal units> In the first to fifth embodiments, the fluctuating magnetic field is applied by the external unit 2 shown in Figs. 2 to 4. However, the fluctuating magnetic field may be applied by another external unit. Fig. 20 shows a top view of the electromagnet in the external unit 9. Fig. 21 shows a cross-sectional view of the external unit 9 attached to the outer surface of the head on which the bone conduction hearing aid unit 1 of the first embodiment is installed. The external unit 9, scalp SC, and skull SK are shown in cross section. In the external unit 9, an electromagnet in which a coil 91 is wound around a long cylindrical magnetic body 92 is housed in a case 93. The external unit 9 in Fig. 20 is shown without the case 93. This electromagnet is rod-shaped with an axial length greater than its diameter.

[0057] As shown in FIG. 21, the extracorporeal unit 9 is placed near the super magnetostrictive element 112 and outside the scalp SC so that the central axis of the electromagnet consisting of the coil 91 and the magnetic body 92 is parallel to the center line Cl (see FIG. 10) of the super magnetostrictive element 112 in the bone-conduction hearing aid unit 1. The electromagnet is placed at a position that almost overlaps with the super magnetostrictive element 112 when viewed from above. In the extracorporeal unit 9, a variable magnetic field is formed near the electromagnet in which the coil 91 is wound around a long cylindrical magnetic body 92. Then, the variable magnetic field formed on the side (lower side in FIG. 21) of the electromagnet consisting of the coil 91 and the magnetic body 92 expands and contracts the super magnetostrictive element 112, generating vibration. The same applies to the bone-conduction hearing aid units 5 to 8 of Examples 2 to 5.

[0058] <Modification> In the vibration generating units of Examples 1 to 4, a bias magnetic field is applied by a permanent magnet, but even without a bias magnetic field, curvature occurs due to a magnetic field. Therefore, it is possible to configure the vibration generating units of Examples 1 to 4 without providing a permanent magnet. In the bone conduction hearing aid unit of Example 1, the outer surface of the anchor head 121 of the anchor 12 is hexagonal, and the lower surface recess 111e is a polygonal recess with an approximately hexagonal inner side as shown in Figures 7 and 8. This is the same in the other Examples. However, these may be other polygonal shapes such as a pentagon. Also, a shape may be a circle with a deformation portion provided in part to prevent rotation.

[0059] In addition, the specific configuration is not limited to the embodiments and modifications, and the present invention includes design changes within the scope of the present invention. In addition, the above-mentioned embodiments and modifications can be combined by utilizing each other's technologies as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0060] SK skull EK external auditory canal SC scalp Ld Longitudinal direction Td Thickness direction Cl center line Pb perpendicular bisector Aa Anchor shaft Fl Long side of fixed plate 1 Bone conduction hearing aid unit 11 Vibration Generator 111 Vibration body 111a Vibrator head 111b Locking plate 111c Locking hole 111d Top recess 111e Bottom recess 111f Fixed plate 111g Vibration Conduction Part 112 Giant magnetostrictive element 113 Permanent Magnets 114 Bottom Case 115 Top Case 12. Anchor 121 Anchor head 122 Anchor leg 123 Anchor recess 124 Male thread 125 Female thread 13 Male thread 131 Screw head 2. Extracorporeal Unit 21 Coil 22 Magnetic material 23 cases 24 Lid 3 Sound collection unit 4. Wiring 5 Bone conduction hearing aid unit 511 Vibration Body 511a Vibrator head 511b Locking plate 511c Locking hole 511d Top recess 511f Fixed plate 511g Vibration Conduction Part 6 Bone conduction hearing aid unit 611 Vibration Body 611a Vibrator head 611b Locking plate 611c Locking hole 611d Top recess 611f Fixed plate 611g Vibration conduction part 7 Bone conduction hearing aid unit 711 Vibration Body 711a Vibrator head 711b Locking plate 711c Locking hole 711d Top recess 711f Fixed plate 711g Vibration conduction part 8 Bone conduction hearing aid unit 81 Vibration Generator 811 Vibration Body 811a Vibrator head 811f Fixed plate 811g Vibration conduction part 812 Giant magnetostrictive element 82 Anchor 9. Extracorporeal Unit 91 Coil 92 Magnetic material 93 cases

Claims

1. A bone conduction hearing aid unit that is implanted under the scalp, The vibration generating unit generates vibrations, and an anchor. A fluctuating magnetic field is applied from the outside of the scalp to the vibration generating unit to generate vibrations; A bone conduction hearing aid unit, characterized in that the vibration is transmitted to the skull via the anchor.

2. 2. The bone conduction hearing aid unit according to claim 1, wherein the vibration generating section has a giant magnetostrictive element.

3. the vibration generating unit includes a fixing plate for fixing the giant magnetostrictive element, 3. The bone conduction hearing aid unit according to claim 2, wherein the vibration is generated by bending the fixed plate and the magnetostrictive element by expanding and contracting the magnetostrictive element using a fluctuating magnetic field.

4. The giant magnetostrictive element has a surface along a longitudinal direction fixed to the fixed plate, 4. The bone conduction hearing aid unit according to claim 3, wherein the vibration is generated by bending the fixed plate and the magnetostrictive element by expanding and contracting the magnetostrictive element in the longitudinal direction using a fluctuating magnetic field.

5. an anchor axis, which is a central axis of the anchor, is located away from the giant magnetostrictive element in a direction perpendicular to the longitudinal direction of the giant magnetostrictive element; 5. The bone conduction hearing aid unit according to claim 4, wherein the fixing plate transmits the vibration generated by bending the fixing plate and the giant magnetostrictive element to the anchor via a vibration conduction section.

6. 6. The bone conduction hearing aid unit according to claim 5, wherein the anchor axis is provided at a position intersecting a perpendicular bisector of a center line in the longitudinal direction of the giant magnetostrictive element.

7. The vibration conduction portion has a shape of a substantially isosceles triangle, The anchor is located near a position where the equilateral sides of the vibration conducting portion intersect, 7. The bone conduction hearing aid unit according to claim 6, wherein the giant magnetostrictive element is fixed along a bottom side of the vibration conducting part.

8. 8. The bone conduction hearing aid unit according to claim 7, wherein the angle between the two equal sides of the vibration conducting portion is greater than or equal to 60 degrees and less than or equal to 100 degrees.

9. 9. The bone conduction hearing aid unit according to claim 2, wherein the giant magnetostrictive element is sandwiched between two permanent magnets.

10. 9. The bone conduction hearing aid unit according to claim 3, wherein the vibration generating section does not have a permanent magnet.

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