WO2022131233A1

WO2022131233A1 - Medical shaft assembly and medical shaft drill

Info

Publication number: WO2022131233A1
Application number: PCT/JP2021/045936
Authority: WO
Inventors: 美沙松本; 克也宮川
Original assignee: ニプロ株式会社
Priority date: 2020-12-14
Filing date: 2021-12-14
Publication date: 2022-06-23
Also published as: JPWO2022131233A1

Abstract

The present invention makes it possible to provide a medical shaft assembly in which the strength of connection between medical shafts is high.　A medical shaft assembly 100 comprises a first medical shaft 101 having a connection hole 111, a second medical shaft 102 inserted into the connection hole 111, and a connection pin 103 fixed to the first medical shaft 101. The connection pin 103 is inserted into a connection through hole 104 that extends through the peripheral wall of the connection hole 111 of the first medical shaft 101 and an inserted portion of the second medical shaft 102 in the connection hole 111.

Description

Medical shaft assembly and medical shaft drill

The present invention includes an invention relating to a medical shaft assembly and a method for manufacturing the same. The present invention also relates to a medical shaft drill that is used by being inserted into a through hole (channel) in the lens barrel of a rigid endoscope and is used for cutting bone by rotating a drill head with a rotating shaft. include.

In medical equipment, a medical shaft assembly in which two shafts are connected may be used. For example, in the case of a medical shaft drill used for endoscopic surgery, the shaft (shank) of the drill portion is connected to the tip of the drive shaft (see, for example, Patent Document 1). Patent Document 1 describes that the drive shaft and the shaft of the drill portion can be connected by press-fitting or screwing with a screw.

For example, a shaft drill is used in surgery that requires bone cutting. In a shaft drill, the drill portion constituting the tip portion is provided with a drill head, and the rotary shaft connected to the drill head rotates to cut a bone with the rotating drill head. For example, Japanese Patent Application Laid-Open No. It is disclosed in Japanese Patent Application Laid-Open No. 2013-18820 (Patent Document 2).

Special Table 2017-524402 Japanese Unexamined Patent Publication No. 2013-18820

[Issue 1]
By the way, in the medical shaft assembly, high safety is required because it is used for the human body. However, the connection between the shafts by press fitting or screwing cannot meet the requirements for tensile strength and torque strength to the extent that sufficient safety is ensured. In particular, recently, in order to reduce the burden on the patient, it is required to make the shaft thinner, and it is more difficult to connect the shafts by press fitting or to provide screws to screw them together. .. In addition, although shafts are connected to each other by welding, it is difficult to set welding conditions and ensure stability when directly welding thin-walled or small-diameter members, and welding is even more difficult when using different materials. Has the problem of being. These problems are common to all medical devices that must connect thin shafts, not just drills used under an endoscope.

[Problem 2]
Further, as shown in Patent Document 2, the shaft drill is used by being inserted into a through hole (channel) of a rigid endoscope, for example, in endoscopic spinal surgery. That is, the rotating shaft may rotate while being inserted into the channel of the rigid endoscope, and the vertebrae or the like may be cut under the endoscope by a drill head protruding toward the tip of the rigid endoscope.

However, as examined by the present inventor, when the rotating shaft inserted through the rigid endoscope is rotated at high speed, the rigid endoscope may be damaged due to contact with the rotating shaft, or the rotating shaft and the rigid endoscope may be damaged. A new issue has become clear that heat generation due to friction can be a problem. In addition, if the rotating shaft has a small diameter with respect to the inner peripheral surface of the channel of the rigid endoscope to avoid problems due to contact, the strength of the rotating shaft with a small diameter becomes insufficient, or when the rotating shaft rotates. It was thought that the blurring would increase.

Here, the method for manufacturing the medical shaft assembly and the medical shaft assembly according to the present invention has been made in view of the circumstances such as the above-mentioned [Problem 1], and the solution to the problem is the medical shaft. It is an object of the present invention to provide a medical shaft assembly having a novel structure with high connection strength between them.

Further, the medical shaft drill according to the present invention has been made in view of the circumstances such as the above-mentioned [Problem 2], and the solution to the problem is to stabilize the operation of the rotating shaft during rotation. It is an object of the present invention to provide a medical shaft drill having a novel structure capable of avoiding a defect due to contact of a rotating shaft with a rigid endoscope.

A first aspect of the medical shaft assembly of the present disclosure is a first medical shaft having a connecting hole, a second medical shaft inserted into the connecting hole, and the first medical shaft. It is provided with a connecting pin inserted into the connecting through hole penetrating the peripheral wall of the connecting hole and the insertion portion into the connecting hole in the second medical shaft and fixed to the first medical shaft. ..

According to the first aspect, the first medical shaft and the second medical shaft are fixed by a connecting pin inserted into the connecting through hole and fixed to the first medical shaft. Therefore, it is possible to prevent the occurrence of breakage in the vicinity of the welded portion, which has been a problem in the conventional connection structure by welding. Further, even if the first medical shaft and the second medical shaft are made of different materials, they can be easily connected while ensuring sufficient connection strength. Further, between the peripheral wall of the connecting hole in the first medical shaft and the second medical shaft, the inner diameter dimension of the peripheral wall of the connecting hole and the outer diameter dimension of the insertion portion into the connecting hole in the second medical shaft. Since it is possible to provide a clearance in consideration of the tolerance with the above, it becomes easy to assemble the first medical shaft and the second medical shaft.

The second aspect is that in the medical shaft assembly described in the first aspect, the first medical shaft and the second medical shaft rotate integrally. Since the strain generated at the connecting portion when the first medical shaft and the second medical shaft are rotated integrally can be dispersed, it is possible to prevent breakage even when the shaft is rotated integrally.

The third aspect is that in the medical shaft assembly according to the first or second aspect, one of the first medical shaft and the second medical shaft is a drill bit. .. The medical shaft assembly of the present disclosure has a high connection strength and can be used even when a large rotational torque such as a drill is required.

A fourth aspect is the medical shaft assembly according to any one of the first to third aspects, wherein the first medical shaft and the connecting pin are made of the same material and are made of the same material for the second medical use. The shaft is made of a material different from that of the first medical shaft. According to this aspect, since the first medical shaft and the second medical shaft made of different materials can be connected, the material selection of the first medical shaft and the second medical shaft becomes easy.

A fifth aspect is the medical shaft assembly according to any one of the first to fourth aspects, in which a sleeve-shaped outer shaft covering the outer peripheral side of the first medical shaft is provided. Is. According to this aspect, for example, when the shaft is inserted through the channel of a rigid endoscope and used, the outer shaft is interposed between the first medical shaft which is a rotating shaft and the inner peripheral surface of the channel. Therefore, damage to the channel due to contact with the rotating first medical shaft is avoided, and the generation of frictional heat is also suppressed.

In the sixth aspect, in the medical shaft assembly according to the fifth aspect, the outer peripheral side of the portion of the first medical shaft to which the connecting pin is fixed is covered with the outer shaft. be. According to this aspect, even if the connecting pin itself or the welding mark for fixing the connecting pin to the first medical shaft protrudes to the outer periphery from the first medical shaft, the protruding portion is a rigid endoscope. It is possible to prevent damage to the rigid endoscope by preventing contact with the channel of the mirror.

A seventh aspect is a method for manufacturing a medical shaft assembly, wherein the method includes a connecting hole extending in the axial direction and a first shaft through hole penetrating the peripheral wall of the connecting hole in the radial direction. A step of preparing a medical shaft, a step of preparing a second medical shaft having a second shaft through hole that can be inserted into the connecting hole and penetrates in the radial direction, and a step of preparing the first medical shaft. A step of inserting the second medical shaft into the connecting hole of the above to align the first shaft through hole and the second shaft through hole with each other, and the first shaft through hole and the second shaft through hole. It includes a step of inserting a connecting pin into the shaft through hole and fixing the connecting pin to the first medical shaft.

According to the method for manufacturing the medical shaft assembly shown in the seventh aspect, the connecting pin inserted into the connecting through hole is fixed to the first medical shaft, and the first medical shaft and the second medical shaft are fixed. Can be easily connected to each other so that breakage at the connecting portion is less likely to occur. Further, even if the first medical shaft and the second medical shaft are made of different materials, they can be easily connected while ensuring sufficient connection strength. Further, since a sufficient clearance between the second medical shaft and the connecting hole can be provided, assembly becomes easy.

The eighth aspect is a medical shaft assembly, in which the second medical shaft is inserted and fixed in a connecting hole opened in the axial end face of the first medical shaft, and the second medical shaft is inserted and fixed. On the outer peripheral surface of the above, a separation portion partially separated from the peripheral wall of the connection hole to the inner circumference is provided, and a connection pin that radially penetrates the peripheral wall of the connection hole in the first medical shaft. However, the first medical shaft and the second medical shaft are mutually positioned by being welded to the separated portion of the second medical shaft in an abutting state.

According to this aspect, the outer peripheral surface of the second medical shaft to which the connecting pin is abutted is a separation portion that is largely separated from the inner peripheral surface of the connecting hole of the first medical shaft. As a result, the length of the connecting pin can be lengthened, and a large amount of molten metal can be secured when the connecting pin is melted and fixed to the second medical shaft. Therefore, the first medical shaft and the second medical shaft can be firmly positioned and connected by welding the connecting pin penetrating the first medical shaft to the second medical shaft.

Further, since the first medical shaft and the second medical shaft are positioned by the connecting pin, a clearance should be set between the peripheral wall of the connecting hole in the first medical shaft and the second medical shaft. Is also possible. According to this, for example, regardless of the variation in the inner diameter of the peripheral wall of the connecting hole and the outer diameter of the insertion portion into the connecting hole in the second medical shaft, the second medical shaft is used as the first medical shaft. It can be easily inserted into the connecting hole of.

A ninth aspect is that in the medical shaft assembly according to the eighth aspect, at the insertion portion of the first medical shaft into the connecting hole in the second medical shaft, the separated portions are both ends. It is provided in the axial intermediate region off the portion.

According to this aspect, for example, both ends of the second medical shaft can be brought close to the peripheral wall of the connecting hole in the first medical shaft, and the inclination of the first medical shaft and the second medical shaft can be achieved. It becomes easier to prevent.

A tenth aspect is the medical shaft assembly according to the eighth or ninth aspect, in which the connecting pins are arranged at positions sandwiching the second medical shaft in the radial direction, respectively. ..

According to this aspect, the pair of connecting pins are fixed from both sides so as to sandwich the second medical shaft, so that the connecting strength between the first medical shaft and the second medical shaft can be efficiently obtained. can.

The eleventh aspect is in the medical shaft assembly according to any one of the eighth to tenth aspects, in which the plurality of connecting pins axial around the peripheral wall of the connecting hole in the first medical shaft. The plurality of connecting pins are welded to the separated portion extending in the axial direction of the second medical shaft in an abutting state.

According to this aspect, since the first medical shaft and the second medical shaft are positioned by the connecting pins at a plurality of points in the axial direction, the space in the axial direction is effectively utilized for the first and second medical treatments. It is possible to obtain a large connection strength of the shaft. Further, since the connecting pins arranged at a plurality of positions in the axial direction are abutted against one separation portion extending in the axial direction, the relative positions of the first and second medical shafts in the axial direction when positioning by the connecting pins. The error is tolerated and the assembly work of the medical shaft assembly becomes easy.

A twelfth aspect is a method of manufacturing a medical shaft assembly, wherein a first medical shaft having a connecting hole extending in the axial direction and a first shaft through hole penetrating the peripheral wall of the connecting hole is provided. A step of preparing, a step of preparing a second medical shaft which is insertable into the connecting hole of the first medical shaft and has a separation portion partially provided on the outer peripheral surface, and the first step. (1) The second medical shaft is inserted into the connecting hole of the medical shaft, and the first shaft through hole of the first medical shaft and the separation portion of the second medical shaft are mutually positioned. By inserting a connecting pin into the first shaft through hole of the first medical shaft and welding the connecting pin to the separated portion of the second medical shaft in an abutting state. , A step of mutually positioning the first medical shaft and the second medical shaft.

According to this aspect, the second medical shaft is in a separated portion where the connecting pin inserted into the first shaft through hole of the first medical shaft is largely separated from the inner peripheral surface of the connecting hole of the first medical shaft. The first shaft through hole and the separation portion are aligned with each other so as to be abutted against. Therefore, the length of the connecting pin can be increased, and a large amount of molten metal can be secured when the connecting pin abutted against the separation portion of the second medical shaft is melt-fixed. 1 The medical shaft and the second medical shaft can be firmly positioned and connected.

Further, since the first medical shaft and the second medical shaft are positioned by the connecting pin, it is possible to set a clearance between the peripheral wall of the connecting hole in the first medical shaft and the second medical shaft. It is possible, and the second medical shaft can be easily inserted into the connecting hole of the first medical shaft.

A thirteenth aspect is a medical shaft drill having a drill head provided at the tip and having a rotating shaft inserted into a channel in a lens barrel of a rigid endoscope, which is external to the rotating shaft. It has an inserted sleeve-shaped outer shaft, and the rotating shaft is rotatable within the outer shaft inserted into the channel in the lens barrel of the rigid endoscope.

According to a medical shaft drill having a structure according to this aspect, the rotating shaft connected to the drill head is guided by a non-rotating outer shaft, so that it is possible to prevent blurring during rotation and suppress heat generation due to friction. It is planned. Regardless of the outer diameter of the rotating shaft and the inner diameter of the channel of the lens barrel, the outer peripheral gap of the rotating shaft can be appropriately set by the thickness of the outer shaft, and blurring during rotation of the rotating shaft can be suppressed. ..

By interposing the outer shaft between the rotating shaft and the lens barrel of the rigid endoscope, contact of the rotating shaft with the lens barrel is prevented, damage to the lens barrel is prevented, and frictional heat transfer to the lens barrel is suppressed. Is planned.

A fourteenth aspect is the medical shaft drill according to the thirteenth aspect, wherein both the rotary shaft and the outer shaft are made of metal, and the outer peripheral surface of the rotary shaft and the inner surface of the outer shaft are provided. A low friction coating layer is provided on either one of the peripheral surfaces and the outer peripheral surface of the outer shaft.

According to this aspect, when the outer shaft is inserted and removed from the channel of the lens barrel, the frictional resistance of the outer shaft with respect to the inner surface of the channel of the lens barrel is reduced to avoid damage to the lens barrel and to insert the lens barrel by reducing friction. Workability is improved. By providing a low-friction coating layer on the outer peripheral surface of the outer shaft, the flow resistance of the fluid through the channel of the lens barrel can be reduced, and the outer shaft and rotation can be allowed while allowing the flow of fluid such as blood. It is possible to secure strength and take measures against blurring by increasing the diameter of the shaft. A low friction coating layer on the outer peripheral surface of the outer shaft inserted through the channel, such as when discharging saline solution to the bone cutting site through the channel or when discharging bone cutting debris to the outside through the channel of the lens barrel. By providing the above, stable flow of physiological saline and improvement of cutting waste discharge efficiency can be achieved.

By providing a low friction coating layer on the outer peripheral surface of the rotary shaft and the inner peripheral surface of the outer shaft, heat generation due to rotational contact between metals is avoided when the rotary shaft rotates in the outer shaft. can do. Further, since the clearance between the rotating shaft and the outer shaft can be reduced, it is possible to suppress the shake during rotation of the rotating shaft.

A fifteenth aspect is the medical shaft drill according to the thirteenth or fourteenth aspect, wherein the base end portion of the rotary shaft is engaged with the rotary output shaft to apply a driving force to the rotary shaft. An engaging member made of synthetic resin to be transmitted to is fixed, and is rotatably externally attached to the rotating shaft on the tip side of the engaging member so as to be connected to the base end portion of the outer shaft. It is provided with a gap ring made of synthetic resin arranged between them.

According to this aspect, the engaging member that rotates integrally with the rotating shaft and the base end portion of the outer shaft are indirectly in contact with the rotating shaft via a rotatable gap ring. ing. This makes it possible to prevent the generation of frictional heat due to the direct contact between the engaging member and the outer shaft.

Since the engaging member and the gap ring are made of synthetic resin, it is lighter than the case made of metal, and it is also possible to reduce heat generation by improving slipperiness and suppress heat transfer.

A sixteenth aspect is the medical shaft drill according to any one of the thirteenth to fifteenth aspects, wherein the rotary shaft includes a hollow shaft body, and the tip portion of the shaft body has the above-mentioned. The shank connected to the drill head is inserted and fixed.

According to this aspect, since the shaft body has a hollow structure, a good balance between strength and weight can be realized, and blurring during rotation can be suppressed. In addition, since the shaft body has a hollow structure, it has a large surface area and excellent cooling efficiency as compared with the solid structure, so that it is easy to release heat due to friction during rotation, and there is a problem due to heating. Hard to occur.

Since the shank of the drill head is inserted and fixed to the hollow shaft body, it can have a solid structure, is easy to manufacture, and can secure strength even with a small diameter.

In the seventeenth aspect, in the medical shaft drill according to any one of the thirteenth to sixteenth aspects, the outer diameter of the drill head of the rotating shaft is made smaller than the inner diameter of the outer shaft. At the same time, the tip portion of the rotating shaft protruding from the outer shaft is provided with a protrusion on the outer peripheral surface away from the tip of the outer shaft toward the tip side.

According to this aspect, when the drill head can pass through the outer shaft, the protrusion provided on the rotary shaft prevents the rotary shaft from being inadvertently pulled out from the outer shaft during transportation or handling of the shaft drill alone. Can be prevented by being locked to the tip of the outer shaft.

Since the protrusion provided on the rotary shaft is separated from the tip of the outer shaft when the shaft drill is used, the protrusion does not contact the outer shaft when the rotary shaft rotates, which is caused by the contact between the protrusion and the outer shaft. Heat generation and vibration are prevented.

Eighteenth aspect is the medical shaft drill according to the seventeenth aspect, wherein the tip portion of the rotary shaft has a tapered outer peripheral surface whose diameter gradually decreases toward the drill head. The protrusion is provided on a large-diameter portion on the proximal end side of the tapered outer peripheral surface.

According to this aspect, the tapered outer peripheral surface provided at the tip of the rotating shaft can improve the visibility of the drill head under an endoscope even when the drill head has a small diameter.

By providing a protrusion using a large diameter portion on the base end side of the tapered outer peripheral surface, it is possible to prevent the rotating shaft from coming off from the outer shaft due to the protrusion having a relatively low height.

A nineteenth aspect is the medical shaft drill according to any one of the thirteenth to eighteenth aspects, wherein a connector detachably attached to a handpiece is attached to a base end portion of the outer shaft. It is provided by a synthetic resin material.

According to this aspect, since the connector is made of a synthetic resin material, the shape and structure of the connector can be designed more easily than those made of metal. Further, even if the connector comes into contact with the rotating shaft, heat generation can be reduced and heat transfer can be suppressed as compared with the case where a metal member comes into contact with the connector.

According to the medical shaft assembly of the present disclosure, the medical shafts can be firmly connected to each other. Further, according to the medical shaft drill of the present disclosure, it is possible to avoid a defect due to contact of the rotary shaft with a rigid endoscope while stabilizing the operation of the rotary shaft during rotation.

A plan view showing a medical shaft assembly as the first embodiment of the present invention. II-II sectional view of FIG. Section III-III sectional view of FIG. Sectional drawing which shows the medical shaft assembly as another Embodiment of this invention. Sectional drawing which shows the medical shaft assembly as another embodiment of this invention. An exploded perspective view showing a tip portion of a medical shaft assembly as yet another embodiment of the present invention. A plan view showing a medical shaft assembly as a second embodiment of the present invention. VIII-VIII sectional view of FIG. FIG. 6 is an enlarged cross-sectional view showing the medical shaft assembly of FIG. 7, which corresponds to the IX-IX cross section of FIG. FIG. 7 is a cross-sectional view of a first medical shaft constituting the medical shaft assembly shown in FIG. 7, which corresponds to the XX cross section of FIG. XI-XI sectional view of FIG. Top view of the second medical shaft constituting the medical shaft assembly shown in FIG. 7. Front view of the second medical shaft shown in FIG. Perspective view of a medical drill device including a shaft drill as a third embodiment of the present invention. A perspective view showing the medical drill device of FIG. 14 in a state where the shaft drill and the handpiece are disassembled. Top view showing the medical drill instrument of FIG. 14 in a state where the shaft drill and the handpiece are disassembled. Sectional drawing of the shaft drill constituting the medical drill instrument shown in FIG. An exploded perspective view of the handpiece constituting the medical drill device shown in FIG. A photograph showing the usage state of the medical drill device shown in FIG. Top view showing the tip portion of the shaft drill as the 4th Embodiment of this invention. Top view showing the tip portion of the shaft drill as the 5th Embodiment of this invention.

The medical shaft assembly 100 according to the first embodiment includes a first medical shaft 101 and a second medical shaft 102 as shown in FIGS. 1 to 3. In the present embodiment, the first medical shaft 101 is a drive shaft inserted into the body cavity from the working channel of the endoscope. The second medical shaft 102 is a drill bit connected to the tip of the first medical shaft 101, has a shaft (shank) 121, and a blade portion 122 provided at the tip of the shank 121, and has a first medical treatment. It rotates integrally with the shaft 101. The distal end side is the side closer to the patient, and the proximal end side is the opposite side.

The tip of the first medical shaft 101 is provided with a connecting recess 111 as a connecting hole extending in the axial direction. The inner diameter of the connecting recess 111 is the same as or slightly larger than the outer diameter of the second medical shaft 102, and the base end portion of the second medical shaft 102 is inserted into the connecting recess 111. A first shaft through hole 113 that penetrates the first medical shaft 101 in the radial direction is formed in a portion of the first medical shaft 101 where the connecting recess 111 is formed. A second shaft through hole 123 that radially penetrates the second medical shaft 102 is formed at the base end portion of the second medical shaft 102. By inserting the second medical shaft 102 into the connecting recess 111, the first shaft through hole 113 and the second shaft through hole 123 communicate with each other to form the connecting through hole 104. A connecting pin 103 is inserted into the connecting through hole 104, and the connecting pin 103 is fixed to the first medical shaft 101, but not to the second medical shaft 102.

The first medical shaft 101 and the connecting pin 103 can be fixed by welding, for example. Among them, laser welding using a laser is preferable because the thin connecting pin 103 can be firmly fixed to the first medical shaft 101 at a pinpoint. Since laser welding requires a very short welding time, it is possible to reduce metal fatigue caused by welding. When the first medical shaft 101 and the connecting pin 103 are fixed by welding, the first medical shaft 101 and the connecting pin 103 are preferably formed of materials having similar melting points, and are formed of the same material. Is more preferable.

In the present embodiment, the first medical shaft 101 and the second medical shaft 102 are connected via a connecting pin 103 inserted into the connecting through hole 104. Therefore, since the rotational torque is applied to the entire second medical shaft 102 via the connecting pin 103, the second medical shaft is less likely to be distorted and broken.
The adverse effect of heating the second medical shaft 102 is reduced as compared with the case where the second medical shaft 102 itself is heated and welded.

Further, in the present embodiment, since the second medical shaft 102 does not need to be welded to the first medical shaft 101 and the connecting pin 103, regardless of the material of the first medical shaft 101 and the connecting pin 103, the second medical shaft 102 does not need to be welded. The material of the second medical shaft 102 can be freely selected. Therefore, the second medical shaft 102 can be formed of a material different from that of the first medical shaft 101, which is advantageous for the mutually different required performances of the first medical shaft 101 and the second medical shaft 102. It will be possible to realize. However, the first medical shaft 101 and the second medical shaft 102 can also be formed of the same material. The connecting pin 103 may be made of a material that can be easily welded to the first medical shaft 101, and the connecting pin 103 and the first medical shaft 101 are preferably made of the same material.

When the first medical shaft 101 and the second medical shaft 102 are directly welded, the inner diameter of the connecting recess 111 and the outer diameter of the second medical shaft 102 match as much as possible in order to increase the connecting strength. It is preferable to make it so that there is no gap. On the other hand, in the present embodiment, since a sufficient clearance can be provided between the connecting recess 111 and the second medical shaft 102, the component dimensions of the first medical shaft 101 and the second medical shaft 102 are set. Regardless of the tolerance and the like, the assembly of the first medical shaft 101 and the second medical shaft 102 becomes easy.

The first medical shaft 101 and the second medical shaft 102 are connected so that their central axes match. When a screw groove is provided at the connecting portion between the first medical shaft 101 and the second medical shaft 102 and both are screwed together, or when the first medical shaft 101 and the second medical shaft 102 are screwed with a screw member. When stopping, the shaft tends to shake. In the present embodiment, the structure of the connecting portion between the first medical shaft 101 and the second medical shaft 102 is simple, the shaft is less likely to shake, and the shaft can be rotated smoothly. Further, when the screw member is used, problems such as deterioration, misalignment, and dropout of the screw member are likely to occur. In this embodiment, since the connecting pin 103 made of the same material as the first medical shaft 101 is pinpoint welded, such a problem is unlikely to occur.

When the first medical shaft 101 is a drive shaft inserted into the working channel of the endoscope, its diameter is about 2 mm to 4 mm, and its total length can be set as needed, but it is about 100 mm to 400 mm. .. In this case, the wall thickness of the wall surface of the first medical shaft 101 in the connecting recess 111 is preferably about 0.1 mm to 0.5 mm from the viewpoint of obtaining sufficient strength, although it depends on the material. Further, the thickness of the connecting pin 103 is preferably about 0.5 mm to 1.5 mm. The length of the overlapping portion between the first medical shaft 101 and the second medical shaft 102 is not particularly limited and can be freely set, and is preferably about 10 mm to 400 mm as needed. The position of the connecting through hole 104 is not particularly limited, but if it is formed at a position covered by a sleeve 124, which will be described later, about 5 mm to 20 mm from the tip of the first medical shaft 101, the welded portion of the connecting pin 103 is exposed to the outside. It is preferable because it does not.

The first medical shaft 101 can be a hollow shaft such as a hollow strand cable made of a plurality of stranded wires that are tightly twisted in a spiral shape. In this case, the tip portion of the hollow shaft may be a connecting recess 111. The first medical shaft 101 may have a configuration in which a core material is inserted into a hollow portion of the hollow shaft. In this case, the connecting recess 111 may be formed so that the core material does not exist at the tip portion. The core material can be fixed to the outer hollow shaft by welding. However, the first medical shaft 101 may be a solid shaft. In this case, a hole in the axial direction may be drilled from the tip surface of the first medical shaft 101 with a drill or the like to form a connecting recess 111 into which the second medical shaft 102 is inserted.

In the present embodiment, the second medical shaft 102 is a drill bit having a blade portion 122 at the tip end portion of the shank 121. In the present embodiment, the blade portion 122 has a hemispherical shape having a larger outer diameter than the shank 121. A hard abrasive such as diamond is electrodeposited on the blade portion 122. That is, the hard abrasive is adhered to the outer peripheral surface of the blade portion 122, and the hard grinding material is held by the blade portion 122 by providing an electrodeposition layer such as diamond-like carbon (DLC) on the surface. .. Since the outer diameter of the blade portion 122 is larger than that of the shank 121, the structure can be ground not only on the tip end side of the blade portion 122 but also on the proximal end side (shank side). However, the shape of the blade portion 122 is not limited to such a shape, and for example, a screw-shaped blade portion having a sharp thread can be used.

When the second medical shaft 102 is a drill bit, its total length is not particularly limited, but it is preferably about 20 mm to 50 mm from the viewpoint of strength and the like. However, the second medical shaft 102 is not limited to the drill bit, and may be a medical driver or the like. Even in such a case, the total length of the second medical shaft 102 can be set to a required length.

When the first medical shaft 101 is a drive shaft inserted into the working channel of the endoscope, an outer shaft covering the outside of the first medical shaft 101 is virtually shown by a two-dot chain line in FIG. The sleeve 124 may be provided. The sleeve 124 has, for example, the same structure and material as the outer shaft 36 described later, has a cylindrical shape, and can be made of resin or metal. When the sleeve 124 is provided, if the sleeve 124 covers the fixed portion of the connecting pin 103 in the first medical shaft 101, the tissue can be less likely to be caught even if the welded portion of the connecting pin 103 has slight irregularities. preferable. Further, the fixing portion of the connecting pin 103 is covered with the sleeve 124 to improve the appearance. Further, by providing the sleeve 124, it is possible to prevent the first medical shaft 101 from coming into contact with the inside of the endoscope channel to generate heat or damaging the inside of the channel.

A plurality of connecting pins 103 can be provided. By providing a plurality of connecting pins 103, the connecting strength can be further increased. Further, by providing a plurality of connecting pins 103, it is possible to reduce the shake of the shaft even if the gap between the connecting recess 111 and the second medical shaft 102 is large. When a plurality of connecting pins 103 are provided, for example, as shown in FIG. 4, the connecting pins 103 may be provided so as to be offset from each other in the axial position and intersect with each other. Further, as shown in FIG. 5, a plurality of connecting pins 103 may be provided so as to be parallel to each other when the radial cross section of the shaft is viewed. The number of connecting pins 103 may be three or more.

The medical shaft assembly 100 of this embodiment can be formed as follows. First, a first medical shaft 101 having a connecting recess 111 extending in the axial direction is prepared. When the entire first medical shaft 101 is hollow, the tip of the lumen may be a connecting recess 111. Further, in the case of a configuration in which the core is inserted into the hollow shaft, a portion without a core may be provided on the tip side to form a connecting recess 111. In the case of the solid first medical shaft 101, the connecting recess 111 can be formed by grinding from the tip surface.

Next, a first shaft through hole 113 penetrating in the radial direction is formed with respect to the peripheral wall portion of the connecting recess 111 in the first medical shaft 101.

Next, a second medical shaft 102 having a shank 121 that can be inserted into the connecting recess 111 and having a second shaft through hole 123 that penetrates the shank 121 is prepared. The shank 121 of the second medical shaft 102 is inserted into the connecting recess 111 of the first medical shaft 101 from the tip side, and the blade portion 122 of the second medical shaft 102 is on the tip side of the first medical shaft 101. It is in a state of being exposed to. When the shank 121 of the second medical shaft 102 is inserted into the connecting recess 111 of the first medical shaft 101, the first shaft through hole 113 and the second shaft through hole 123 are aligned with each other and communicate with each other. As a result, the connecting through hole 104 is formed. Then, the connecting pin 103 is inserted into the connecting through hole 104.

Next, the connecting pin 103 inserted in the connecting through hole 104 is welded to and fixed to the first medical shaft 101. Laser welding using a YAG (yttrium-aluminum-garnet) laser or the like can be used for welding. If necessary, the welded portion may be polished. The connecting pin 103 can be fixed to the first medical shaft 101 by welding other than laser welding, metal joining or bonding in a liquid phase or a solid phase, and the fixing means is not limited. .. Further, the length dimension of the connecting pin 103, that is, the protruding dimension from the outer peripheral surface of the second medical shaft 102 may be set before the insertion into the connecting through hole 104 or by cutting or the like after the insertion. .. Further, when inserting the connecting pin 103, for example, it is conceivable to heat and cool the first medical shaft 101 and / or the second medical shaft 102 to heat-fit them to suppress the gap in the insertion portion. ..

In the present embodiment, an example is shown in which the first medical shaft 101 is on the proximal end side of the medical device and the second medical shaft 102 is on the distal end side of the medical device. Conversely, the second medical shaft 102 may be on the proximal end side of the medical device and the first medical shaft 101 may be on the distal end side of the medical device.

Although the first medical shaft is a drive shaft inserted into the working channel of the endoscope and the second medical shaft is a drill bit, the present disclosure shows that the medical shaft assembly is 2 It can be used in various applications to which the medical shaft of a book is connected. For example, it can also be used for a medical driver or the like.

Further, a structure such as the medical shaft assembly 130 shown in FIG. 6 can also be adopted. That is, the medical shaft assembly 130 includes a first medical shaft 132 having a connecting recess 111 as a connecting hole and a second medical shaft 134 having a shank 121 inserted into the connecting recess 111. I have. The peripheral wall portion of the connecting recess 111 in the first medical shaft 132 is formed with

cuts

136, 136 as first shaft through holes that open in the inner peripheral surface and the tip surface. The shank 121 of the second medical shaft 134 is provided with a connecting pin 103 protruding from the outer peripheral surface. The connecting pin 103 is separated from the shank 121 and is inserted into the second shaft through hole 123 formed in the shank 121. However, the connecting pin 103 can also be in the shape of a protrusion integrally formed with the shank 121.

Then, when the shank 121 is inserted into the connecting recess 111 of the first medical shaft 132, the connecting pin 103 is inserted into the

notch

136, 136 from the tip side. With the connecting pin 103 radially penetrating the peripheral wall of the connecting recess 111 at the

cuts

136 and 136, the diameter of the first medical shaft 132 is reduced on the tip side of the connecting pin 103 to open the tip side of the cut 136. By narrowing the gap, the connecting pin 103 is prevented from coming off to the tip side with respect to the notch 136. As a result, the first shaft through hole penetrating the connecting recess 111 is formed by the

cuts

136 and 136, and the connecting pin 103 penetrates the peripheral wall portion of the connecting recess 111 in the

cut

136 and 136 and the shank 121. It is inserted into the second shaft through hole 123 of.

According to the medical shaft assembly 130 shown in FIG. 6, the accuracy required for positioning the first shaft through hole 136 and the second shaft through hole 123 is relaxed, and the first medical shaft 132 The second medical shaft 134 can be easily assembled.

The means for fixing the connecting pin 103 inserted in the

cuts

136 and 136 to the first medical shaft 132 is not limited to the diameter reduction processing of the first medical shaft 132. For example, the opening on the tip side of the

cuts

136, 136 may be closed or narrowed by welding or adhesion, or the connecting pin 103 may be fixed to the first medical shaft 132 by welding or bonding to fix the tip of the

cut

136, 136. The side openings can also be left open.

Further, the

cuts

136 and 136 may, for example, penetrate the peripheral wall of the connecting recess 111 only in a part in the circumferential direction, or may penetrate the peripheral wall of the connecting recess 111 on both sides in the radial direction. .. In the latter case, the connecting pins 103 of the shank 121 are provided so as to project to both sides in the radial direction.

7 to 9 show a medical shaft assembly 200 as a second embodiment of the present invention. The medical shaft assembly 200 includes a first medical shaft 202 and a second medical shaft 204. In the following description, members and parts substantially the same as those in the first embodiment may be designated by the same reference numerals and detailed description thereof may be omitted.

As shown in FIGS. 10 and 11, the first medical shaft 202 includes a shaft body 206. The shaft body 206 has a hollow cylindrical shape with a circular cross section, and a good balance between high strength and weight is realized in terms of weight ratio. The shaft body 206 is made of a metal such as stainless steel for medical use or a titanium alloy, and has high strength. The shaft body 206 may be provided with a low friction coating layer on the outer peripheral surface. The low-friction coating layer is a coating layer that enhances the slipperiness of the surface (reduces the coefficient of friction), and is, for example, a fluororesin such as polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), silicon, and the like. Various known materials such as ceramic can be appropriately adopted. The inner and outer diameter dimensions of the shaft body 206 are not particularly limited, but for example, the inner diameter dimension is 2.2 mm and the outer diameter dimension is 2.7 mm. Therefore, the thickness dimension of the peripheral wall of the shaft main body 206 is set to, for example, about 0.25 mm.

Four first shaft through

holes

208, 208, 208, 208 are formed in the shaft body 206. The first shaft through hole 208 is a circular hole that penetrates the peripheral wall of the shaft body 206 in the radial direction. The first shaft through holes 208 are provided at two locations in the circumferential direction that are opposite to each other in the radial direction and are separated from each other in the axial direction. Therefore, the two sets of first shaft through

holes

208 and 208 arranged at the same axial position are arranged side by side in series in the radial direction.

Filling 209 is arranged in the hollow part in the shaft body 206. The filling 209 is not particularly limited and may be a solid or a gel-like body. The filling 209 of the present embodiment is solid, and is housed in the inner circumference of the shaft main body 206. The filling 209 may be made of a single material as a whole, or may be formed of, for example, a tip portion and a base end portion made of different materials. In this case, the tip portion and the base end portion made of different materials may be independent of each other, and the entire filling 209 does not necessarily have to be continuous. Since the filling 209 is housed inside the hollow shaft body 206, the posture is stabilized by increasing the inertia during rotation, and the shake during rotation of the first medical shaft 202 is suppressed. ..

The filling 209 is not arranged at the tip portion of the shaft main body 206, and four first shaft through

holes

208, 208, 208, 208 are formed at the tip portion of the shaft main body 206 in which the filling 209 is removed toward the tip side. ing. Further, in the tip portion of the first medical shaft 202 which is hollow without filling 209, a connecting recess 111 as a connecting hole is formed by the central hole of the shaft main body 206, and the second medical shaft 204 is formed. It is inserted into the connecting recess 111 from the tip side.

As shown in FIGS. 12 and 13, the second medical shaft 204 is provided with a drill head 210 at its tip. The drill head 210 has a substantially spherical shape, and cutting particles such as diamond are fixed to the outer peripheral surface thereof. The drill head 210 may have an electrodeposition layer such as a DLC layer covering the surface, similarly to the blade portion 122 of the first embodiment. The specific structure of the drill head 210 is not particularly limited, and may include, for example, a cutting edge instead of the cutting particles.

The second medical shaft 204 includes a shank 212 that protrudes from the drill head 210 toward the base end. The shank 212 has a solid rod shape and has a smaller diameter than the outer diameter of the drill head 210. The shank 212 is made of a metal such as a titanium alloy or a cemented carbide. The shank 212 is integrally formed with the drill head 210 and is connected to the drill head 210, and the second medical shaft 204 of the present embodiment includes the drill head 210 and the shank 212.

A pair of

flat portions

214 and 214 are provided on the outer peripheral surface of the shank 212. The flat portion 214 is composed of a plane extending orthogonal to the radial direction of the shank 212 having a cylindrical shape. The pair of

flat portions

214, 214 extend substantially parallel to each other. The flat portion 214 extends continuously in the axial direction with a predetermined length. The axial length dimension of the flat portion 214 is not particularly limited, but is larger than the distance between the axial outer ends of the first shaft through

holes

208 and 208 arranged axially apart in the first medical shaft 202. It is lengthened and is more than twice as long as the distance between the axial outer ends of the first shaft through

holes

208 and 208. The length dimension of the flat portion 214 is preferably 1/3 or more of the length dimension of the shank 212, and is, for example, 7 mm or more. Further, in the present embodiment, the width dimension of the flat portion 214 is substantially the same as the diameter of the first shaft through hole 208 (connecting pin 216 described later). However, the width dimension of the flat portion 214 may be smaller or larger than, for example, the first shaft through hole 208. In FIG. 12, the position of the first shaft through hole 208 (connecting pin 216 described later) with respect to the flat portion 214 in the connected state (described later) of the first medical shaft 202 and the second medical shaft 204 is indicated by a two-dot chain line. Indicated.

As shown in FIG. 8, the second medical shaft 204 is connected to the first medical shaft 202 by fixing the shank 212 to the tip portion of the shaft main body 206 without the padding 209 in the inserted state.

As shown in FIGS. 8 and 9, the shank 212 of the second medical shaft 204 is provided with the first medical treatment by the connecting pin 216 inserted into the first shaft through hole 208 of the shaft body 206 of the first medical shaft 202. It is fixed to the shaft 202. It is desirable that the connecting pin 216 has a substantially cylindrical shape or a disk shape corresponding to the hole cross-sectional shape of the first shaft through hole 208, and is inserted into the first shaft through hole 208 without having a large gap. It is preferable that it is possible. The connecting pin 216 is preferably made of the same metal material as at least one of the shaft body 206 and the shank 212, and is made of, for example, stainless steel. The connecting pin 216 has a length of about 0.3 mm and a diameter of about 1.0 mm.

Hereinafter, an example of the manufacturing method of the medical shaft assembly 200 of the present embodiment will be described. First, a pair of flat portions 214, a first medical shaft 202 having a connecting recess 111 and four first shaft through

holes

208, 208, 208, 208, and a shank 212 that can be inserted into the connecting recess 111. A second medical shaft 204 equipped with 214 is prepared. Next, the shank 212 of the second medical shaft 204 is inserted into the connecting recess 111 provided at the tip of the first medical shaft 202, and is flat with the first shaft through

holes

208, 208, 208, 208. The

portions

214 and 214 are mutually positioned in the circumferential direction. The outer peripheral surface of the shank 212 is largely separated from the inner peripheral surface of the shaft main body 206 at two points in the circumferential direction where the

flat portions

214 and 214 are located, and the separated portions of the present embodiment are separated by the

flat portions

214 and 214 in the circumferential direction. It is composed of two places. The

flat portions

214 and 214 constituting the separation portion are provided in the intermediate region in the axial direction away from both end portions at the insertion portion of the first medical shaft 202 into the connecting recess 111 in the second medical shaft 204. There is.

Next, the connecting pins 216 are inserted into the first shaft through

holes

208, 208, 208, 208 arranged on the pair of

flat portions

214, 214, respectively. The connecting pin 216 inserted into the first shaft through hole 208 penetrates the shaft body 206 of the first medical shaft 202, and the end face on the inner peripheral side is abutted against the flat portion 214 of the second medical shaft 204. .. In the present embodiment, four connecting

pins

216, 216, 216, 216 penetrate the first medical shaft 202 at four points and are abutted against the outer peripheral surface of the second medical shaft 204.

Then, the connecting pin 216 in the first shaft through hole 208 is irradiated with a laser, and the connecting pin 216 is heated by the laser. By heating and melting the connecting pin 216 inserted in the first shaft through hole 208 by a laser, the connecting pin 216 is fixed to the first medical shaft 202 on the inner peripheral surface of the first shaft through hole 208. , At the end on the inner peripheral side, is fixed to the outer peripheral surface (flat portion 214) of the shank 212 of the second medical shaft 204. As a result, the first medical shaft 202 and the second medical shaft 204 are welded and fixed at four points by connecting

pins

216, 216, 216, 216 to obtain the medical shaft assembly 200. The laser irradiated to the connecting pin 216 is not particularly limited, and may be, for example, a pulse type such as a YAG laser or a ruby laser, or a continuous type such as carbon dioxide gas, and may be made of a material or size. In consideration of the above, various welding methods other than laser welding, such as resistance welding, can also be adopted.

According to the medical shaft assembly 200 having a structure according to the present embodiment, even if a force in the twisting direction is applied when cutting the bone by the drill head 210, the first one is welded and fixed by the connecting pin 216. The second

medical shafts

202 and 204 are unlikely to cause damage such as breakage. The reason why the strength of the first and second

medical shafts

202 and 204 is advantageously secured is that, for example, the first and second

medical shafts

202 and 204 themselves are heated and welded. It is conceivable that the change in material, residual stress, deformation, etc. due to heating of the first and second

medical shafts

202 and 204 are reduced, and the strength of the first and second

medical shafts

202 and 204 is secured. .. In particular, in the second medical shaft 204 on the inner peripheral side where breakage due to torsional stress is likely to occur, damage to the second medical shaft 204 is prevented during bone cutting by avoiding a decrease in strength due to heating. To.

Further, in the second medical shaft 204, since the welded portion by the connecting pin 216 is a separated portion in which the radial separation distance from the first medical shaft 202 is increased by the flat portion 214, the connecting pin 216 is used. The length of the shaft can be increased to obtain a large volume, and the fixing strength can be improved by welding.

The joint portion of the connecting pin 216 melted by heating and the second medical shaft 204 joined to the connecting pin 216 is prevented from being mechanically restricted in surface texture by the separation portion, and excessive to the surroundings. Heat transfer can also be reduced. Therefore, the joint portion is easily spread so as to enter between the radial directions of the first and second

medical shafts

202 and 204. As a result, the fixing area of the connecting pin 216 to the outer peripheral surface (flat portion 214) of the shank 212 of the second medical shaft 204 is increased, and the fixing strength of the connecting pin 216 to the second medical shaft 204 is largely secured. .. Further, the connecting pin 216 is easily locked to the opening peripheral portion of the first shaft through hole 208 in the first medical shaft 202, and the fixing strength of the connecting pin 216 to the first medical shaft 202 is largely secured. Therefore, it is possible to obtain a large connection strength by the connecting pin 216 between the first medical shaft 202 and the second medical shaft 204, and the medical shaft set in the welded portion of the first and second

medical shafts

202 and 204. Damage to the solid 200 is more advantageously prevented.

Further, the connecting pin 216 penetrates the peripheral wall of the shaft body 206 and is abutted against the outer peripheral surface of the shank 212 of the second medical shaft 204 without penetrating the second medical shaft 204. It is welded. As described above, since the through hole for inserting the connecting pin 216 is not required in the second medical shaft 204, the second medical shaft 204 can be easily manufactured and the second medical shaft 204 can be manufactured. It becomes easy to secure the strength of. In particular, in the present embodiment, the second medical shaft 204 is a drill head 210 that requires strength, and the strength is improved by eliminating the through hole, and the through hole that is difficult to form is formed. By eliminating the need, manufacturing can be facilitated.

Further, it is necessary to position the first medical shaft 202 and the second medical shaft 204 with higher accuracy than the structure in which the connecting pin penetrates the first medical shaft 202 and the second medical shaft 204. It is easy to assemble the first and second

medical shafts

202 and 204.

In particular, in the present embodiment, since the flat portion 214 of the second medical shaft 204 to which the connecting pin 216 is abutted extends in the axial direction, the first and second

medical shafts

202 and 204 are particularly easy in the axial direction. Can be positioned to. Further, since the flat portion 214 extends in the axial direction, for example, the relative position of the first shaft through hole 208 with respect to the flat portion 214 in the axial direction is appropriately adjusted to appropriately adjust the position of the first medical shaft 202 of the shank 212. It is also possible to change and set the exposure length from. In the present embodiment, two connecting

pins

216 and 216 provided at two positions separated from each other in the axial direction are abutted against one flat portion 214 and welded to the first medical shaft 202 and the second. Alignment with the medical shaft 204 in the axial direction is easy.

Since the first and second

medical shafts

202 and 204 are connected at four points by four connecting

pins

216, 216 and 216, 216, the first and second

medical shafts

202 and 204 are connected by the connecting pins 216. The fixed strength of is greatly secured. Further, since the welding positions of the first and second

medical shafts

202 and 204 by the four connecting

pins

216, 216, 216 and 216 are separated from each other in the circumferential direction and the axial direction, the first and second medical treatments are performed. Efficiently ensuring the fixing strength of the

shafts

202 and 204 and preventing shaft shake during rotation are advantageous. In particular, in the present embodiment, two points in the circumferential direction in which the first and second

medical shafts

202 and 204 are welded are located on both sides in one radial direction, and the welded parts are the medical shaft assembly 200. It is provided substantially symmetrically with respect to the central axis, and the mutual distance in the circumferential direction is lengthened. As a result, it is possible to advantageously secure the fixing strength of the first and second

medical shafts

202 and 204 and prevent shaft shake during rotation with a small number of welded parts.

In the present embodiment, the number, arrangement, shape, size, etc. of the connecting pins 216 can be appropriately changed as needed. For example, it is also possible to provide connecting pins 216 in two radial directions orthogonal to each other of the first and second

medical shafts

202 and 204, whereby the fixing force is circulated while strengthening the fixing force. It can work in a well-balanced manner in the direction.

In the present embodiment, the separated portions are formed by providing the

flat portions

214 and 214 on the outer peripheral surface of the shank 212. For example, the inner peripheral surface of the shaft body 206 is a cylindrical surface and the shank 212 is provided with a cylindrical surface. Since the outer peripheral surface is an elliptical cylindrical surface, separation portions may be formed on both sides in the radial direction of the shank 212 in the minor axis direction. Further, the separated portion may be formed by forming a concave portion or a concave groove that opens on the outer peripheral surface of the shank 212.

The separation portion may be provided so as to extend in the circumferential direction, and for example, the separation portion may be formed by an annular groove that is continuous over the entire circumference. According to this, the positioning of the first medical shaft 202 and the second medical shaft 204 in the circumferential direction becomes easy, and the molten connecting pin 216 spreads in the circumferential direction to facilitate the positioning of the first medical shaft 202 and the second medical shaft 204 in the circumferential direction. By entering between the radial oppositions of 202 and 204, it is possible to advantageously realize the securing of the welding area and the like. Further, the separation portions may be provided at a plurality of locations in the axial direction separated from each other.

The connection structure between the first medical shaft 202 and the second medical shaft 204 shown in the present embodiment can be applied to a medical shaft assembly other than the illustrated shaft drill as in the first embodiment. can. Further, the tip end side may be the first medical shaft 202, and the proximal end side may be the second medical shaft 204.

14 to 16 show a medical drill device 12 provided with a medical shaft drill (hereinafter, shaft drill) 10 as a third embodiment of the present invention. The medical drill device 12 has a structure in which a handpiece 14 is attached to a base end portion of a shaft drill 10. In the following description, as a general rule, the tip side refers to the left side in FIG. 16 which is the drill head 16 side described later, and the proximal end side refers to the right side in FIG. 16 which is the handpiece 14 side. Further, as a general rule, the vertical direction means the vertical direction in FIG.

As shown in FIGS. 15 to 17, the shaft drill 10 is provided with a drill head 16 at its tip. The drill head 16 has a substantially spherical shape, and cutting particles such as diamond are fixed to the outer peripheral surface thereof. The drill head 16 may have an electrodeposition layer such as a DLC layer covering the surface, similarly to the blade portion 122 of the first embodiment. The specific structure of the drill head 16 is not particularly limited, and for example, a cutting edge may be provided instead of the cutting particles.

As shown in FIG. 17, the shank 18 of the drill head 16 projects toward the proximal end. The shank 18 has a solid rod shape and has a smaller diameter than the outer diameter of the drill head 16. The shank 18 is made of a metal such as stainless steel for medical use, a titanium alloy, or a cemented carbide. The shank 18 is integrally formed with the drill head 16 and is connected to the drill head 16.

The shank 18 is inserted and fixed to the tip of the shaft body 20. The shaft body 20 has a hollow cylindrical shape with a circular cross section, and a good balance between high strength and weight is realized in terms of weight ratio. The shaft body 20 is made of a metal such as stainless steel for medical use or a titanium alloy, and has high strength. The shaft body 20 is provided with a low friction coating layer on the outer peripheral surface. The low-friction coating layer is a coating layer that enhances the slipperiness of the surface, and is variously known such as fluororesin such as polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), silicon, and ceramic. Can be adopted as appropriate. The outer diameter of the shaft body 20 is not particularly limited as long as it can be inserted into the outer shaft 36 described later, but is, for example, 2.75 mm.

Filling 22 is arranged in the hollow portion in the shaft body 20. The filling 22 is not particularly limited and may be a solid or a gel-like body. The filling 22 of the present embodiment is solid and is housed in the shaft body 20. The filling 22 may be made of a single material as a whole, or may be formed of, for example, a tip portion and a base end portion made of different materials. In this case, the tip portion and the base end portion made of different materials may be independent of each other, and the entire filling 22 does not necessarily have to be continuous. Since the filling 22 is housed inside the hollow shaft main body 20, the posture is stabilized by increasing the inertia during rotation, and the shake during rotation of the shaft main body 20 is suppressed. The entire filling 22 may be housed in the shaft body 20.

The filling 22 is not arranged at the tip of the shaft body 20, but the shank 18 is inserted and fixed to the tip of the hollow shaft body 20, and the shank 18 and the shaft body 20 together form a medical shaft assembly. The rotating shaft 24 as a solid is configured. In the present embodiment, the shaft body 20 provided with the padding 22 is used as the first medical shaft, and the shank 18 is used as the second medical shaft, and the tip portion of the hollow shaft body 20 is connected. It is said to be a hole.

The rotating shaft 24 having a structure in which the shank 18 having a solid structure is inserted and fixed to the shaft body 20 having a hollow structure allows the strength of the shank 18 close to the drill head 16 to which a particularly strong force is applied to be secured by the solid structure, and further, the shaft body. 20 can be prevented from breaking by having a large-diameter hollow structure that makes it easy to secure strength. The shank 18 may be press-fitted and fixed to the shaft body 20, or may be fixed by means such as welding, bonding, pinning, caulking, and screwing in the inserted state. The shank 18 can be detachably fixed to the shaft body 20, whereby the drill bit composed of the drill head 16 and the shank 18 can be removed from the shaft body 20 for maintenance or replacement. Become.

By fixing the shank 18 to the shaft body 20, a drill head 16 is provided at the tip of the rotating shaft 24. The drill head 16 is fixed to the rotary shaft 24 and can rotate integrally with the rotary shaft 24. The shank 18 and the shaft body 20 constituting the rotary shaft 24 are made of metal.

At the tip of the rotating shaft 24, a step portion 26 is formed by the difference between the outer diameter of the shaft body 20 and the outer diameter of the shank 18, and the tip side of the step portion 26 has a smaller diameter than the proximal end side. There is. The shank 18 constitutes a small diameter portion on the tip side of the step portion 26, and the shaft body 20 constitutes a large diameter portion on the proximal end side of the step portion 26.

An engaging member 28 is fixed to the base end of the rotating shaft 24. The engaging member 28 has a bottomed cylindrical shape, and the base end portion of the shaft body 20 is fixed in the inserted state. It is desirable that the engaging member 28 is made of a material capable of achieving low friction on the surface and low heat transfer coefficient. The engaging member 28 is made of synthetic resin, and is formed of, for example, PEEK having a small surface friction coefficient and a small heat transfer coefficient (excellent in heat resistance). The engaging member 28 includes an engaging ridge 30 that projects to the outer periphery. The engaging ridge 30 projects to the outer peripheral surface and extends linearly in the axial direction. In the present embodiment, the engaging ridges 30 are provided at four locations in the circumferential direction of the engaging member 28 and are arranged at substantially equal intervals in the circumferential direction, but the number of formations, arrangement, and the like are not particularly limited. .. The engaging ridge 30 of the present embodiment has a substantially semicircular cross section, but may have another cross-sectional shape such as a substantially rectangular cross section.

A gap ring 32 is extrapolated to the rotating shaft 24. The gap ring 32 is made of synthetic resin like the engaging member 28, and is formed of, for example, PEEK. The gap ring 32 is extrapolated so as to be rotatable relative to the rotating shaft 24. The gap ring 32 is formed with lightening recesses 34 that open on the outer peripheral surface at two locations in the circumferential direction, and the heat dissipation performance is improved by increasing the surface area. The gap ring 32 is extrapolated to the rotating shaft 24 on the distal end side of the engaging member 28. The gap ring 32 has a larger diameter than the engaging member 28, and the outer peripheral surface is located on the outer peripheral side of the tip of the engaging ridge 30 of the engaging member 28.

The outer shaft 36 is extrapolated to the rotating shaft 24. The outer shaft 36 has a sleeve shape having an inner diameter substantially the same as or slightly larger than the outer diameter of the shaft main body 20. The outer shaft 36 is made of a metal such as stainless steel for medical use or a titanium alloy. The outer shaft 36 is extrapolated to the shaft body 20, and the rotating shaft 24 is rotatable within the outer shaft 36. Similar to the outer peripheral surface of the shaft main body 20, a low friction coating layer is provided on the inner peripheral surface and the outer peripheral surface of the outer shaft 36. The inner diameter of the outer shaft 36 is not particularly limited as long as the rotating shaft 24 can be inserted, but is, for example, 2.8 mm.

A connector 38 is attached to the base end portion of the outer shaft 36. The connector 38 is made of a synthetic resin material such as polycarbonate. The connector 38 has a hollow cylindrical shape as a whole, and the outer shaft 36 is fixed to the inner peripheral surface. The connector 38 is provided with an operation piece 40 projecting from the outer peripheral surface at the tip portion thereof. Although the operation piece 40 has an elliptical plate shape in the present embodiment, it may have a disk shape, a polygonal plate shape, a deformed plate shape, or the like. For example, in order to prevent the shaft drill 10 from rolling, it is desirable that the outer peripheral surface shape of the operation piece 40 is other than a circular shape, and an elliptical shape or a polygonal shape is preferable. The connector 38 includes a connecting protrusion 42 protruding from the upper surface of the base end portion. The connecting protrusion 42 is a protrusion extending in a substantially U-shape with the tip side open in a top view, and includes a pair of locking

portions

44, 44 protruding outward from the left and right at the intermediate portion.

The rotary shaft 24 inserted through the outer shaft 36 projects toward the proximal end side from the connector 38. The engaging member 28 fixed to the proximal end portion of the rotating shaft 24 is located closer to the proximal end side than the connector 38. The gap ring 32 extrapolated to the rotary shaft 24 is arranged between the connector 38 provided at the base end portion of the outer shaft 36 and the engaging member 28 provided at the base end portion of the rotary shaft 24 in the axial direction. Has been done. The gap ring 32 has a larger diameter than the outer shaft 36, and cannot be inserted into the outer shaft 36. The gap ring 32 has a larger diameter than the opening on the base end side of the connector 38.

The shaft drill 10 is used by being connected to the handpiece 14 by attaching the connector 38 to the tip portion of the handpiece 14. The handpiece 14 is a portion that the practitioner grips and operates by hand. As shown in FIG. 18, the handpiece 14 of the present embodiment includes an electric motor 46 that generates a rotational driving force, a power supply device 48 such as a battery pack that supplies electric power to the electric motor 46, and an electric motor from the power supply device 48. It has a built-in control board 50 that controls the power supply to the 46. However, the handpiece 14 may be connected to an external power supply device by a power cord and supplied with power from the outside, or exert a rotational driving force by the pressure of air supplied and discharged by an external pump. It may be pneumatic. The housing of the handpiece 14 of the present embodiment is a pen-holding type having a linear shape, but may be, for example, an L-shaped gun type.

The rotary shaft 24 is connected to the rotary output shaft 52 of the electric motor 46 built in the handpiece 14, and the rotary shaft 24 is rotated by the generated driving force of the electric motor 46. Specifically, the rotary output shaft 52 of the electric motor 46 includes a connection recess 54 that is open toward the tip, and is fixed to the base end portion of the rotary shaft 24 at the tip end portion of the connection recess 54. The engaging member 28 is inserted. The rotary output shaft 52 of the electric motor 46 is provided with a plurality of concave grooves corresponding to the engaging ridges 30 of the engaging member 28 on the inner peripheral surface of the connecting recess 54, and the engaging protrusions with respect to the concave grooves. When the strip 30 is inserted and engaged in the circumferential direction, the rotational driving force of the electric motor 46 is transmitted from the rotary output shaft 52 to the rotary shaft 24. The gap ring 32 arranged on the tip side of the engaging member 28 is housed in the housing of the handpiece 14.

The handpiece 14 is provided with a power switch 56 and a rotation control switch 58 for controlling the operation of the electric motor 46 on the upper surface. The handpiece 14 can switch the operation and stop of the electric motor 46 by the practitioner pressing the power switch 56, and adjusts the rotation speed of the electric motor 46 by sliding the rotation control switch 58. be able to. Therefore, by operating the power switch 56 and the rotation control switch 58, the practitioner can switch between rotation and stop of the drill head 16 provided at the tip of the rotation shaft 24, control the rotation speed, and the like. .. Since the practitioner grips the tip portion of the handpiece 14 having a relatively small diameter, the rotation control switch 58 is arranged at the tip portion of the handpiece 14, making it easy to operate the rotation control switch 58 during use. At the same time, the power switch 56 is arranged at the rear end portion of the handpiece 14 to avoid erroneous operation of the power switch 56.

The connector 38 fixed to the outer shaft 36 is inserted into a connecting cylinder portion 60 whose base end portion is provided at the tip of the handpiece 14. The connection cylinder portion 60 is provided with a notch-shaped connecting recess 62 at the upper portion. The connecting recess 62 has a shape corresponding to the connecting protrusion 42 of the connector 38 in the top view shown in FIG. 16, and the locking recesses 64, 64 corresponding to the locking

portions

44, 44 of the connecting protrusion 42 are provided. It is formed on both the left and right sides. Then, the connecting protrusion 42 of the connector 38 is inserted into the connecting recess 62 of the handpiece 14, and the locking

portions

44, 44 of the connecting protrusion 42 are inserted into the locking recesses 64, 64 of the connecting recess 62. As a result, the locking

portions

44, 44 are axially locked to the inner surfaces of the locking recesses 64, 64, and the connector 38 is restricted from coming off from the connecting cylinder portion 60. As a result, the outer shaft 36 is attached to the handpiece 14 via the connector 38 and is arranged so as to extend from the handpiece 14 toward the tip end side. It should be noted that the ridges (not shown) protruding outward on the opposite side of the connector 38 from the connecting protrusion 42 and extending in the axial direction open to the inner peripheral surface on the side opposite to the connecting recess 62 in the connecting cylinder 60, which is a groove-shaped concave portion (not shown). The outer shaft 36 and the handpiece 14 are also positioned with each other in the circumferential direction by being inserted into the ridge and the groove-shaped concave portion being locked in the circumferential direction.

By applying a force toward the tip side of the connector 38, the locking

portions

44, 44 can be pulled out from the locking recesses 64, 64, and the connector 38 can be separated from the handpiece 14. In this way, the outer shaft 36 is detachably attached to the handpiece 14, facilitating replacement in the event of damage or failure, and making it compact in storage. Further, since the shaft drill 10 and the handpiece 14 can be separated from each other, for example, the shaft drill 10 can be used once and the handpiece 14 can be used a plurality of times. It can be kept clean and the cost can be reduced by using the expensive handpiece 14 multiple times. The method of applying the force toward the tip side to the connector 38 is not particularly limited, but for example, by pushing the operation piece 40 toward the tip side or pulling it from the tip side, the force toward the tip side is applied to the connector 38. , The connector 38 can be removed from the handpiece 14.

In the state where the connector 38 is attached to the handpiece 14, the outer shaft 36 is fixed to the handpiece 14 and is not rotatable. Therefore, when the rotating shaft 24 is rotated by the driving force of the electric motor 46 of the handpiece 14, the rotating shaft 24 rotates relative to the outer shaft 36.

As shown in FIG. 19, the medical drill instrument 12 having such a structure is inserted through a rigid endoscope 66 and used when cutting a bone in an endoscopic operation. As virtually shown in FIG. 16, the rigid endoscope 66 includes a rigid lens barrel 68, and a shaft drill 10 is inserted through a channel 70 penetrating the lens barrel 68. The drill head 16 of the shaft drill 10 may be positioned so as to project toward the tip end side from the lens barrel 68. The rigid endoscope 66 is provided with a camera, a light, or the like (not shown) at the tip portion thereof, and the drill head 16 protruding from the lens barrel 68 to the tip can be visually recognized under the endoscope. The base end portion of the shaft drill 10 projects toward the base end side of the lens barrel 68, and the handpiece 14 is arranged on the base end side of the lens barrel 68. The outer shaft 36 may be largely separated from the inner peripheral surface of the channel 70 of the rigid endoscope 66, but it is desirable that the outer shaft 36 is in contact with or slightly separated from the inner peripheral surface.

Since the outer shaft 36 is made of metal, it has high strength and can sufficiently obtain pushability when it is inserted into the channel 70 of the rigid endoscope 66. Since the low friction coating layer is provided on the outer peripheral surface of the outer shaft 36, frictional resistance and catching are suppressed when the shaft drill 10 is inserted into the channel 70 of the rigid endoscope 66, which makes it easy. Can be inserted into. In addition, resistance when liquids such as blood and saline, and cut bone fragments (cutting debris) move between the inner peripheral surface of the channel 70 and the outer peripheral surface of the outer shaft 36 is reduced. As a result, it is possible to secure the field of view under the endoscope by discharging the physiological saline solution, and to efficiently discharge the cutting chips by suction.

As shown in FIG. 19, when the practitioner grips and uses the handpiece 14 and the lens barrel 68, the outer shaft 36 is attached to the rigid endoscope 66 unless the practitioner intentionally rotates it. On the other hand, it does not rotate. The rotary shaft 24 inserted through the outer shaft 36 is rotatable within the outer shaft 36 inserted through the channel 70 of the lens barrel 68. In a state where the shaft drill 10 is inserted through the channel 70, the outer shaft 36 is interposed between the rotating shaft 24 and the rigid endoscope 66, and the rotating shaft 24 and the rigid endoscope 66 do not come into contact with each other. In addition, in FIG. 16, the cross section of the rigid endoscope 66 passing through the channel 70 is shown.

The medical drill device 12 can scrape the bone by bringing the rotating drill head 16 into contact with the bone to be cut under the endoscope. Since the outer peripheral surface of the rotary shaft 24 continuous with the drill head 16 and the inner peripheral surface of the outer shaft 36 inserted into the channel 70 of the rigid endoscope 66 have a low friction coating layer, the rotary shaft 24 Is efficiently rotatable in the outer shaft 36, and heat generation due to friction is also reduced. Since the rotary shaft 24 is made of metal, it has high strength, and the drill head 16 can be brought into contact with the bone with sufficient force, and the reaction force when the drill head 16 comes into contact with the bone. Damage to the rotary shaft 24 due to the above is avoided.

When the rotary shaft 24 is rotated by the generated driving force of the electric motor 46, the rotary shaft 24 is covered with the outer shaft 36 and does not come into contact with the rigid endoscope 66. The damage and heating of 66 are prevented. Further, by adjusting the thickness dimension of the outer shaft 36 according to the difference between the outer diameter dimension of the rotary shaft 24 and the inner dimension of the channel 70 of the rigid endoscope 66, the rotary shaft 24 is formed by the outer shaft 36. It can be guided appropriately, and the blurring of the rotating shaft 24 during rotation can be suppressed.

When the rotating shaft 24 rotates, a gap ring 32 is arranged between the engaging member 28 fixed to the rotating shaft 24 and the connector 38 fixed to the outer shaft 36. Since the gap ring 32 is rotatable relative to both the rotary shaft 24 and the outer shaft 36, when the rotary shaft 24 is rotationally driven, a part of the rotational force of the rotary shaft 24 is transmitted. Although it goes around, the rotation speed of the gap ring 32 is lower than the rotation speed of the rotary shaft 24. Therefore, the frictional heat generated between the engaging member 28 and the gap ring 32 and the frictional heat between the gap ring 32 and the connector 38 are more than the frictional heat when the engaging member 28 rotating at high speed is in direct contact with the connector 38. The amount of heat generated is smaller for the frictional heat generated between them. As a result, the gap ring 32 prevents damage to the engaging member 28 and the connector 38 due to heat.

The outer shaft 36, the engaging member 28, the handpiece 14, and the like shown in the present embodiment can also be adopted in combination with the

medical shaft assemblies

100 and 200 according to the first and second embodiments. In other words, the

medical shaft assemblies

100 and 200 can also be adopted as the rotary shaft 24 of the present embodiment.

FIG. 20 shows a tip portion of a medical shaft drill 80 as a fourth embodiment of the present invention. In the following description, the members and parts substantially the same as those in the third embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

The shaft drill 80 includes a shank 82 extending from the drill head 16 toward the base end. The shank 82 has a tapered outer peripheral surface 84 whose tip portion connected to the drill head 16 gradually decreases in diameter toward the drill head 16. The outer peripheral surface of the shank 82 is a cylindrical surface whose base end side extends with a substantially constant diameter from the tapered outer peripheral surface 84, and the base end portion of the shank 82 having the cylindrical surface is inserted and fixed to the shaft body 20. There is. Since the shank 82 is inserted and fixed to the shaft body 20, the portion of the rotary shaft 24 composed of the shaft body 20 has a larger diameter than the portion composed of the shank 82, and the tip of the rotary shaft 24 has a larger diameter. A step portion 26 is formed in the portion. The rotary shaft 24 has a tip portion smaller than the step portion 26 formed by the shank 82 and a smaller diameter than the base end portion of the step portion 26 formed by the shaft main body 20. The tip portion of the rotary shaft 24 with respect to the step portion 26 is provided with a tapered outer peripheral surface 84 having a smaller diameter toward the tip.

The drill head 16 of the present embodiment has an outer dimension smaller than the inner diameter dimension of the outer shaft 36, and has a size capable of passing through the outer shaft 36. The specific size is not particularly limited, but for example, the drill head 16 has cutting particles fixed to a spherical body having a diameter of 2.5 mm, and the inner diameter of the outer shaft 36 is 2.8 mm.

A ring member 86 constituting a protrusion is attached to a large diameter portion on the base end side of the step portion 26 formed by the shaft main body 20. The ring member 86 is extrapolated to the shaft main body 20 constituting the large diameter portion on the base end side of the step portion 26 in the rotary shaft 24, and is provided so as to project on the outer peripheral surface of the large diameter portion of the shaft main body 20. ing. The ring member 86 is fixed to the shaft body 20 by means such as welding, caulking, and press-fitting. The ring member 86 is made of a metal that is harmless to the human body, such as medical stainless steel and titanium alloy. The outer diameter of the ring member 86 is larger than the inner diameter of the outer shaft 36, so that the ring member 86 cannot pass through the outer shaft 36. Specifically, for example, the outer diameter of the ring member 86 is 3.1 mm. Preferably, the outer diameter of the ring member 86 is less than or equal to the outer diameter of the outer shaft 36, whereby the ring member 86 is less likely to be caught when inserted into a through hole of a rigid endoscope (not shown), and also , It is unlikely to adversely affect the tip field of view of the camera under an endoscope.

The ring member 86 is arranged at a position away from the tip of the outer shaft 36 toward the tip. The ring member 86 does not come into contact with the outer shaft 36 when the shaft drill 80 is in use. In the state of using the shaft drill 80, since the base ends of the outer shaft 36 and the rotary shaft 24 are mounted on a handpiece (not shown), the outer shaft 36 and the rotary shaft 24 are positioned so as not to be relatively movable in the axial direction and rotate. The ring member 86 fixed to the shaft 24 does not come into contact with the outer shaft 36.

According to the shaft drill 80 having a structure according to the present embodiment, a step portion 26 is provided at the tip portion of the rotary shaft 24, the tip side of the step portion 26 has a smaller diameter, and the shank 82 has a smaller diameter. It is provided with a tapered outer peripheral surface 84 whose tip portion has a smaller diameter toward the drill head 16. As a result, when using the shaft drill 80 under an endoscope, for example, even when the drill head 16 has a small diameter, the tip portion of the rotating shaft 24 is provided in the view of the camera provided at the tip of the endoscope. The drill head 16 can be seen by the camera without getting in the way. Further, the ring member 86 is provided at a position separated from the drill head 16 toward the base end side, and the ring member 86 does not easily interfere with the visual recognition of the drill head 16 by the camera.

Further, when the drill head 16 is small enough to pass through the outer shaft 36, the rotary shaft 24 is pulled out toward the proximal end side with respect to the outer shaft 36 in the shaft drill 80 alone which is not attached to the handpiece (not shown). There is a risk of separation. Therefore, a ring member 86 having a size that cannot pass through the outer shaft 36 is attached to the rotary shaft 24, and the ring member 86 is locked to the tip of the outer shaft 36 so that the rotary shaft 24 is outside. It is possible to prevent the shaft 36 from coming off to the proximal end side. It should be noted that, for example, the engagement member fixed to the base end portion of the rotary shaft 24 allows the engaging member fixed to the base end portion of the rotary shaft 24 to come off from the outer shaft 36 of the rotary shaft 24 through the gap ring or directly to the base end of the outer shaft 36. It is prevented by being locked in the axial direction to the connector fixed to the portion.

The ring member 86 is located on the tip side of the tip of the outer shaft 36 when the shaft drill 80 is attached to the handpiece, and does not come into contact with the outer shaft 36. Therefore, even if the ring member 86 rotates together with the rotating shaft 24, problems such as damage and heat generation due to contact with the outer shaft 36 do not occur.

In the present embodiment, the protrusions for preventing the rotary shaft 24 from coming off from the outer shaft 36 are formed of the ring member 86, but the protrusions are, for example, in the circumferential direction on the outer peripheral surface of the shaft body 20. Can be partially provided. Further, the step portion 26 is not limited to the one formed by the difference in the outer diameter dimension between the shaft main body 20 and the shank 82. For example, the tip portion of the shaft main body 20 is machined to have an outer diameter larger than that of the base end portion. By reducing the size, the step portion 26 can be formed in the middle of the shaft body 20.

FIG. 21 shows a shaft drill 90 as a fifth embodiment of the present invention. The shaft drill 90 has a shorter axial length of the tapered outer peripheral surface 84 than the shaft drill 80 of the fourth embodiment. Further, the distance from the tip of the outer shaft 36 to the drill head 16 is also lengthened. Even with the shaft drill 90 having a structure according to the present embodiment, the same effect as that of the shaft drill 80 of the fourth embodiment can be obtained.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description thereof. For example, the specific structure of the handpiece 14 is not particularly limited, and various conventionally known structures can be adopted. Further, the connection structure between the handpiece 14 and the shaft drill 10 is not limited as long as the outer shaft 36 is held so as not to rotate and the rotary driving force is applied to the rotary shaft 24.

The ring member 86 is not necessarily provided only when the outer diameter of the drill head 16 is smaller than the inner diameter of the outer shaft 36. If the ring member 86 is provided when the outer diameter of the drill head 16 is larger than the inner diameter of the outer shaft 36, contact of the drill head 16 with the outer shaft 36 is avoided in the single state of the shaft drill.

The medical shaft assembly disclosed in the present disclosure is useful in medical equipment or the like in which the connection strength between medical shafts is high and a large force is applied to the shafts. Further, the medical shaft drill of the present disclosure is a rigid endoscope because the operation of the rotary shaft during rotation is stabilized and the trouble caused by the contact of the rotary shaft with the rigid endoscope is avoided. It is useful when cutting bones etc. in the procedure below.

100 Medical shaft assembly (first embodiment)
101 1st medical shaft 102 2nd medical shaft 103 Connecting pin 104 Connecting through hole 111 Connecting recess (connecting hole)
113 1st shaft through hole 121 Shank 122 Blade part 123 2nd shaft through hole 124 Sleeve (outer shaft)
130 Medical Shaft Assembly (Another Embodiment)
132 1st medical shaft 134 2nd medical shaft 136 Notch (1st shaft through hole)
200 Medical shaft assembly (second embodiment)
202 1st medical shaft 204 2nd medical shaft 206 Shaft body 208 1st shaft through hole 209 Filling 210 Drill head 212 Shank 214 Flat part (separation part)
216 Connecting pin 10 Medical shaft drill (third embodiment)
12 Medical drill equipment 14 Handpiece 16 Drill head 18 Shank 20 Shaft body 22 Filling 24 Rotating shaft 26 Step 28 Engagement member 30 Engagement ridge 32 Gap ring 34 Lightening recess 36 Outer shaft 38 Connector 40 Operation piece 42 Connecting protrusion 44 Locking part 46 Electric motor 48 Power supply device 50 Control board 52 Rotating output shaft 54 Connection recess 56 Power switch 58 Rotation control switch 60 Connection cylinder part 62 Connecting recess 64 Locking recess 66 Rigid endoscope 68 Endoscope 70 channel 80 medical shaft drill (4th embodiment)
82 Shank 84 Tapered outer surface 86 Ring member (protrusion)
90 Medical shaft drill (fifth embodiment)

Claims

A first medical shaft with a connecting hole,
A second medical shaft inserted into the connecting hole,
It is inserted into a connecting through hole penetrating the peripheral wall of the connecting hole in the first medical shaft and the insertion portion into the connecting hole in the second medical shaft, and is fixed to the first medical shaft. A medical shaft assembly equipped with a connecting pin.
The medical shaft assembly according to claim 1, wherein the first medical shaft and the second medical shaft rotate integrally.
The medical shaft assembly according to claim 2, wherein one of the first medical shaft and the second medical shaft is a drill bit.
The first medical shaft and the connecting pin are made of the same material.
The medical shaft assembly according to any one of claims 1 to 3, wherein the second medical shaft is made of a material different from that of the first medical shaft.
The medical shaft assembly according to any one of claims 1 to 4, wherein a sleeve-shaped outer shaft covering the outer peripheral side of the first medical shaft is provided.
The medical shaft assembly according to claim 5, wherein the outer peripheral side of the portion of the first medical shaft to which the connecting pin is fixed is covered with the outer shaft.
A step of preparing a first medical shaft having a connecting hole extending in the axial direction and a first shaft through hole that radially penetrates the peripheral wall of the connecting hole.
A step of preparing a second medical shaft that is insertable into the connecting hole and has a second shaft through hole that penetrates in the radial direction.
A step of inserting the second medical shaft into the connecting hole of the first medical shaft to align the first shaft through hole and the second shaft through hole with each other.
A method for manufacturing a medical shaft assembly, comprising a step of inserting a connecting pin into the first shaft through hole and the second shaft through hole and fixing the connecting pin to the first medical shaft.
The second medical shaft is inserted into the connecting hole that opens on the axial end face of the first medical shaft, and the second medical shaft is inserted.
On the outer peripheral surface of the second medical shaft, a separation portion partially separated from the peripheral wall of the connection hole to the inner circumference is provided.
The first medical shaft has a connecting pin that radially penetrates the peripheral wall of the connecting hole of the first medical shaft and is welded to the separated portion of the second medical shaft in an abutting state. A medical shaft assembly in which a medical shaft and the second medical shaft are mutually positioned.
The medical use according to claim 8, wherein in the insertion portion of the first medical shaft into the connecting hole of the second medical shaft, the separation portion is provided in an axial intermediate region deviating from both end portions. Shaft assembly.
The medical shaft assembly according to claim 8 or 9, wherein the connecting pins are arranged at positions sandwiching the second medical shaft in the radial direction, respectively.
A plurality of the connecting pins penetrate the peripheral wall of the connecting hole in the first medical shaft at a plurality of points in the axial direction, and also
The medical shaft set according to any one of claims 8 to 10, wherein the plurality of connecting pins are welded to one of the separated portions extending in the axial direction of the second medical shaft in an abutting state. Solid.
A step of preparing a first medical shaft having a connecting hole extending in the axial direction and a first shaft through hole penetrating the peripheral wall of the connecting hole.
A step of preparing a second medical shaft which is insertable into the connecting hole of the first medical shaft and has a separation portion partially provided on the outer peripheral surface.
The second medical shaft is inserted into the connecting hole of the first medical shaft so that the first shaft through hole of the first medical shaft and the separated portion of the second medical shaft are mutually exchanged. And the process of aligning to
The first medical treatment is performed by inserting a connecting pin into the first shaft through hole of the first medical shaft and welding the connecting pin to the separated portion of the second medical shaft in an abutting state. A method of manufacturing a medical shaft assembly comprising a step of mutually positioning a medical shaft and the second medical shaft.
A medical shaft drill having a drill head at the tip and a rotating shaft that is used by being inserted into a channel in the lens barrel of a rigid endoscope.
It has a sleeve-shaped outer shaft extrapolated to the rotary shaft, and the rotary shaft is rotatable within the outer shaft inserted into the channel in the lens barrel of the rigid endoscope. There is a medical shaft drill.
The rotary shaft and the outer shaft are both made of metal, and one of the outer peripheral surface of the rotary shaft and the inner peripheral surface of the outer shaft and the outer peripheral surface of the outer shaft are each coated with low friction. The medical shaft drill according to claim 13, which is provided with a layer.
An engaging member made of synthetic resin that engages with the rotary output shaft and transmits the driving force to the rotary shaft is fixed to the base end portion of the rotary shaft.
13. Claim 13 provided with a gap ring made of synthetic resin rotatably extrapolated to the rotating shaft and arranged between the base end portion of the outer shaft and the tip side of the engaging member. Or the medical shaft drill according to 14.
The rotating shaft is provided with a hollow shaft body.
The medical shaft drill according to any one of claims 13 to 15, wherein a shank connected to the drill head is inserted and fixed at the tip end portion of the shaft body.
The outer diameter of the drill head of the rotating shaft is made smaller than the inner diameter of the outer shaft, and
13. Shaft drill for medical use.
The tip portion of the rotary shaft has a tapered outer peripheral surface whose diameter gradually decreases toward the drill head, and the protrusion is provided on a large diameter portion on the proximal end side of the tapered outer peripheral surface. The medical shaft drill according to claim 17.
The medical shaft drill according to any one of claims 13 to 18, wherein a connector detachably attached to the handpiece is provided at the base end portion of the outer shaft by using a synthetic resin material.