Surgical cutting bar

Abstract

To provide a surgery cutting bar comprising improved cooling effects.SOLUTION: There is provided a surgery cutting bar comprising: a shaft part which rotates around a rotary shaft line; and a cutting part arranged at a tip of the shaft part, the cutting part is formed into a spherical shape and has on its surface, diamond abrasive grains, and may be configured to have a vertical groove extending from a tip toward an axial direction. By such a configuration, using cooling water, heat generation on the cutting part which is generated when using the cutting bar for surgery, can be cooled efficiently. Therefore, in a site in which minute surgical operation is performed in which a tissue around a nerve is removed, it is possible to provide, the surgery cutting bar having improved cooling effects.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a surgical cutting bar, which is a medical instrument for surgical operations.

Background Art

[0002] Conventionally, in surgical operations, there has been a medical instrument that removes tissues such as bones and tumors by rotating a surgical cutting bar equipped with a cutting portion. The surgical cutting bar used in such a medical instrument includes a shaft portion that rotates around a rotation axis, and a cutting portion provided at the tip of this shaft portion. The cutting portion has a spherical shape, and a cutting surface is formed by attaching diamond abrasive grains to the surface (Patent Document 1). The operator attaches and rotates the above-described surgical cutting bar to the handpiece constituting the medical instrument, and uses it by pressing the rotating cutting surface against the object to be cut.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the surgical cutting bar described in Patent Document 1 is used by rotating it at a high speed (20,000 to 100,000 rpm), heat is generated due to friction when the cutting surface comes into contact with the object to be cut. As a result, when the heated surgical cutting bar approaches the periphery of the object to be cut, there is a risk of directly thermally damaging the object to be cut and indirectly thermally damaging important structures such as nerves due to heat conduction from the object to be cut, and there is a problem that careful operation is required. It has been pointed out that the heat generation of the surgical cutting bar poses a clinical risk of bone necrosis due to the heat of the object to be cut and thermal damage to nerves located in or close to the bone due to heat conduction from the bone. Against such a background, in the field of performing delicate surgery to remove tissues around nerves, there is an increasing demand for surgical cutting bars with higher cooling efficiency.

[0005] The present invention aims to solve the above problems and provides a surgical cutting bar with improved cooling effect.

Means for Solving the Problems

[0006] To solve the problems, a surgical cutting bar includes a shaft portion that rotates about a rotation axis and a cutting portion provided at the tip of the shaft portion. The cutting portion is spherical, has diamond abrasive grains on its surface, and has a longitudinal groove extending axially from the tip side. and a transverse groove connected to the longitudinal groove, and is provided with the transverse groove extends in a direction opposite to the rotational direction from the longitudinal groove it may be configured as such.

Effects of the Invention

[0007] According to the present invention, it is possible to improve the cooling effect of the surgical cutting bar.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0009] (Embodiment) Hereinafter, embodiments will be described with reference to the drawings. Here, as a medical device using the surgical cutting bar according to the present invention, a surgical system, which is an orthopedic surgical instrument, is exemplified, but the present invention is not limited thereto, and other medical devices for other uses such as dental use may also be used.

[0010] <Surgical System> FIG. 1 is a schematic configuration diagram of a surgical system 100. The surgical system 100 includes a control unit 101, a handpiece 103, a connection cable 105 that connects the handpiece 103 to the control unit 101, and a foot switch 107.

[0011] The handpiece 103 includes an attachment 103a and a grip portion 103b. A surgical cutting bar 200 is detachably attached to the attachment 103a at the tip of the handpiece 103. The handpiece 103 is provided with a power source such as an air motor or an electric motor (electric motor) that rotationally drives the surgical cutting bar 200. The power source is rotated or stopped by a foot switch 107 connected to the control unit 101. The control unit 101 controls the rotational drive of the handpiece 103. In addition, a hand switch that is manually operated to rotate or stop the drive source of the handpiece 103 may be provided on the handpiece 103, and the operation may be performed by operating this hand switch. Further, the handpiece 103 may be other than that used in the present embodiment as long as it imparts an appropriate rotational driving force to the surgical cutting bar 200.

[0012] <Surgical Cutting Bar> FIG. 2 is a configuration diagram of the surgical cutting bar 200. Here, a virtual line indicating the rotation center of the surgical cutting bar 200 is defined as a rotation axis L. The surgical cutting bar 200 has a rod-shaped shaft portion 210 along the rotation axis L and a ball-shaped cutting portion 220 provided at one tip of the shaft portion 210. The ball shape referred to here means that when the surgical cutting bar 200 is rotated about the rotation axis L, the shape of the curved surface forming the cutting portion 220 includes the surface shape of a sphere or a rotational ellipsoid centered on the rotation axis L.

[0013] This surgical cutting bar 200 is formed of a hard material such as stainless steel or cemented carbide (tungsten carbide). At the base end of the shaft portion 210 opposite to the cutting portion 220, a connecting portion 211 is provided which is connected and fixed to the rotation axis of the handpiece 103. The surgical cutting bar 200 fixed to the rotation axis rotates about the rotation axis L with the cutting portion 220 and the shaft portion 210 by the rotational drive of the handpiece 103.

[0014] In this surgical system 100, the operator rotates the surgical cutting bar 200 by operating the foot switch 107 while holding the handpiece 103. Then, with the cutting portion 220 of the surgical cutting bar 200 rotated, the operator presses it against the object to be resected such as bone or tumor, and appropriately moves the handpiece 103 to cut the object to be resected. Incidentally, the rotation direction R of the surgical cutting bar 200 is a clockwise rotation as viewed from the user holding the handpiece 103 in the case of this embodiment.

[0015] <Configuration of the cutting portion> Next, with reference to FIGS. 2 to 4, the configuration of the surgical cutting bar 200 will be described. In the following description, in the surgical cutting bar 200, based on the direction (axial direction) in which the rotation axis L extends, the side where the cutting portion 220 is located is defined as the tip side, and the side where the connecting portion 211 is located is defined as the rear end side. That is, in the cutting portion 220, based on the rotation axis L, the side where the shaft portion 210 is located is the rear end side, and the side opposite to the shaft portion 210 is the tip side. Also, at the surface of the tip of the cutting portion 220, there is a position through which the rotation axis L passes. This position where the rotation axis L passes through the surface of the cutting portion 220 is defined as the tip position M. For the same member or the same part, the same reference numeral is given to omit or simplify the description thereof.

[0016] FIG. 3 is a view of the cutting portion 220 of the surgical cutting bar 200 as seen from the axial direction of the rotation axis L. That is, FIG. 3 is a view of the surgical cutting bar 220 as seen from the tip position M side. On the cutting portion 220, diamond abrasive grains 221 are provided by electrodeposition so as to cover the entire spherical surface. The diamond abrasive grains 221 are granular materials obtained by finely crushing diamond. The cutting portion 220 on which the diamond abrasive grains 221 are electrodeposited has irregularities formed on the surface by the diamond abrasive grains 221. In this way, the surgical cutting bar 200 cuts and removes tissues such as bone and tumor to be excised by bringing the cutting portion 220 provided with the diamond abrasive grains 221 on the surface into contact with the tissues while rotating.

[0017] Next, the cutting portion 220 will be described with reference to FIGS. 3 to 4. FIGS. 4(a) to 4(e) are views showing the shape of the cutting portion 220 in an easy-to-understand manner, with the diamond abrasive grains 221 omitted. FIG. 4(a) is a view of the cutting portion 220 as seen from the axial direction. FIG. 4(b) is a view of the cutting portion 220 as seen from the radial direction. FIG. 4(c) is a view from a position rotated 90 degrees around the tip position M as the center from the viewpoint of FIG. 4(b). FIG. 4(d) is a view from a position rotated 90 degrees around the tip position M as the center from the viewpoint of FIG. 4(c). FIG. 4(e) is a view from a position rotated 90 degrees around the tip position M as the center from the viewpoint of FIG. 4(d).

[0018] A first longitudinal groove 222 is formed in the cutting portion 220. The first longitudinal groove 222 is a portion recessed from the surface of the cutting portion 220 extending from the tip side to the rear end side in the cutting portion 220. In other words, the first longitudinal groove 222 is a groove extending from the tip position M side to the side where the shaft portion 210 is located in the cutting portion 220. In addition, a second longitudinal groove 223 is formed in the cutting portion 220. The second longitudinal groove 223 is a portion that is recessed from the surface of the cutting portion 220 extending from the tip side toward the rear end side in the cutting portion 220. In other words, the second longitudinal groove 223 is a groove that extends from the tip position M side toward the side where the shaft portion 210 is located in the cutting portion 220.

[0019] Here, the first longitudinal groove 222 and the second longitudinal groove 223 have substantially the same shape and are arranged at equal intervals in the rotational direction in the cutting portion 220. In other words, the first longitudinal groove 222 and the second longitudinal groove 223 are grooves having a point-symmetrical shape with respect to each other with the tip position M as a reference in the cutting portion 220. Furthermore, the first longitudinal groove 222 and the second longitudinal groove 223 extending in the axial direction in the cutting portion 220 are formed in the cutting portion 220 so as to incline in the rotational direction of the surgical cutting bar 200 such that the tip position M side is a position on the rotational direction side from the shaft portion 210 side.

[0020] Next, a first transverse groove 224 extending from the first longitudinal groove 222 is formed in the cutting portion 220. The first transverse groove 224 extends in a direction opposite to the rotational direction of the surgical cutting bar 200 with the first longitudinal groove 222 as a starting point. Also, the internal space of the first transverse groove 224 and the internal space of the first longitudinal groove 222 are connected. In the present embodiment, two first transverse grooves 224 extending from the first longitudinal groove 222 are formed at intervals in the longitudinal direction.

[0021] In addition, a second transverse groove 225 extending from the second longitudinal groove 223 is formed in the cutting portion 220. The second transverse groove 225 extends in a direction opposite to the rotational direction of the surgical cutting bar 200 with the second longitudinal groove 223 as a starting point. Also, the internal space of the second transverse groove 225 and the internal space of the second longitudinal groove 223 are connected. In the present embodiment, two second transverse grooves 225 extending from the second longitudinal groove 223 are formed at intervals in the longitudinal direction.

[0022] Here, the first transverse groove 224 and the second transverse groove 225 are arranged so as not to overlap in the rotational direction. That is, the first transverse groove 224 and the second transverse groove 225 are arranged with a shift in the longitudinal direction so as not to overlap in the rotational direction. In addition, the first transverse groove 224 is formed shallower in depth than the first longitudinal groove 222. In other words, the internal space of the first transverse groove 224 is formed smaller than the internal space of the first longitudinal groove 222. Similarly, the second transverse groove 225 is formed shallower in depth than the second longitudinal groove 223. In other words, the internal space of the second transverse groove 225 is formed smaller than the internal space of the second longitudinal groove 224. In addition, diamond abrasive grains are provided on the surface of the cutting portion 220 by electrodeposition, and diamond abrasive grains are also provided in each of the above grooves 222, 223, 224, and 225 to such an extent that the internal space of the groove is not completely filled.

[0023] The surgical cutting bar 200 configured as described above is used in a surgical operation as follows to excise tissues such as bone and tumor to be excised. First, the operator operates the foot switch 107 to drive an air motor or an electric motor to rotationally drive the surgical cutting bar 200. Then, while supplying cooling water to the cutting portion 220 of the rotating surgical cutting bar 200, the cutting portion 220 is brought into contact with the object to be excised to perform the operation of excising the object to be excised.

[0024] That is, when the cutting portion 220 rotates, the diamond abrasive grains constituting the surface of the cutting portion 220 come into contact with the object to be excised, and the object to be cut is shaved off. At this time, when the diamond abrasive grains come into contact with the object to be excised at high speed, frictional heat is generated and the temperature of the cutting portion 220 rises. The reason for performing the operation while supplying cooling water to the rotating cutting portion 220 is to cool the cutting portion 220 so that it does not become too hot due to frictional heat with the object to be cut.

[0025] And the supplied cooling water acts on the cutting portion 220 during the excision operation as follows. Refer to Fig. 5 showing the flow W of cooling water in the cutting part 220 during use. The cutting part 220 rotates in the supplied cooling water. As a result, the cooling water enters the inside of the first longitudinal groove 222 and the second longitudinal groove 223, and cooling is promoted in the axial direction of the cutting part 220. In particular, since the first longitudinal groove 222 and the second longitudinal groove 223 are regions recessed from the cutting part 220, it is easy to hold the cooling water inside the grooves, and the area where the cooling water contacts the cutting part 220 can be widened. Therefore, the cooling effect by the cooling water can be enhanced.

[0026] Also, the first longitudinal groove 222 and the second longitudinal groove 223 are formed in the cutting part 220 so as to incline in the rotational direction of the surgical cutting bar 200 such that the tip position M side is a position on the rotational direction side rather than the shaft part 210 side. That is, the first longitudinal groove 222 and the second longitudinal groove 223 are provided in the cutting part 220 so as to form a helix and the tip position M side extends toward the shaft part 210 side.

[0027] As a result, when the cutting part 220 rotates, a force associated with the rotation acts on the flow W of the cooling water that has entered the inside of the first longitudinal groove 222 and the second longitudinal groove 223. Thereby, a flow W of the cooling water from the tip position M side toward the shaft part 210 side is generated along the inside of the grooves 222, 223. That is, in the cutting part 220, an axial flow W of the cooling water that cools the cutting part 220 is formed from the tip position M side toward the shaft part 210 side, and the cooling effect of the cutting part 220 can be improved.

[0028] Furthermore, a first transverse groove 224 extending from the first longitudinal groove 222 is formed in the cutting part 220. The first transverse groove 224 extends in a direction opposite to the rotational direction of the surgical cutting bar 200 with the first longitudinal groove 222 as a base point. Also, the internal space of the first transverse groove 224 and the internal space of the first longitudinal groove 222 are connected. Since the first transverse groove 224 and the first longitudinal groove 222 are connected in this way and the first transverse groove 224 extends in a direction opposite to the rotational direction, a part of the cooling water located inside the first longitudinal groove 222 becomes a flow W of the cooling water reaching the first transverse groove 224 as the cutting part 220 rotates.

[0029] As a result, a flow W of cooling water in the rotational direction from the first longitudinal groove 222 toward the first transverse groove 224 is formed in the cutting portion 220, improving the cooling effect. In addition, with respect to the second transverse groove 225 extending from the second longitudinal groove 223, the same effect as that of the first transverse groove 224 and the first longitudinal groove 222 can be obtained.

[0030] Here, although the first transverse groove 224 and the second transverse groove 225 are each formed to extend in the rotational direction from the corresponding longitudinal groove, the first transverse groove 224 and the second transverse groove 225 are formed to have an axial displacement relationship so as not to overlap in the rotational direction of the cutting portion 220. In this way, since the transverse grooves 224 and 225 are axially displaced so as not to overlap in the rotational direction, the cutting portion 220 can be cooled over a wide range in the rotational direction.

[0031] Further, in the present embodiment, the positional relationship between the first longitudinal groove 222 and the second longitudinal groove 223, and between the first transverse groove 224 and the second transverse groove 225 is formed to be point-symmetrical with respect to the tip position M. Since the cutting portion 220 is formed in this way, the weight of the cutting portion 220 can be balanced with respect to the rotation axis line L. As a result, the vibration of the cutting portion 220 from the rotation axis line L during rotation can be suppressed, and the cutting operation can be easily performed.

Explanation of Reference Numerals

[0032] L Rotation axis line M Tip position W Flow of cooling water R Rotational direction of surgical cutting bar 100 Surgical system 101 Control unit 103 Handpiece 103a Attachment 103b Gripping portion 105 Connection cable 107 Foot switch 200 Surgical cutting bar 210 Shaft part 211 Connection part 220 Cutting part 221 Diamond abrasive grains 222 First longitudinal groove 223 Second longitudinal groove 224 First transverse groove 225 Second transverse groove

Claims

1. A surgical cutting bar comprising a shaft portion that rotates about a rotation axis and a cutting portion provided at the tip of the shaft portion, The cutting portion has a spherical shape, is provided with diamond abrasive grains on its surface, and includes a longitudinal groove extending in the axial direction from the tip side and a transverse groove connected to the longitudinal groove. The transverse groove extends in a direction opposite to the rotation direction from the longitudinal groove, and is a surgical bar.

2. The surgical bar according to claim 1, wherein a plurality of the transverse grooves are provided, and each of the transverse grooves is arranged offset in the axial direction.

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