JP4026967B2 - Cornea surgery device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a corneal surgery apparatus for incising a patient's ocular cornea in layers during corneal refractive surgery or the like.
[0002]
[Prior art]
In recent years, for corneal refraction correction treatment, a flap is formed by incising a layer having a thickness of about 150 μm extending from the corneal epithelium, leaving one end (hinge) of the cornea, and then excimer laser light. The LASIK operation (Laser in Situ Keratomileusis), which involves excision of the corrective refraction amount and the return of the flap, is attracting attention. In this LASIK operation, a corneal surgery device called a microkeratome is used to cut the cornea in layers.
[0003]
As a microkeratome, the suction ring is adsorbed and fixed from the corneal ring to the surface of the conjunctiva, the cornea is pressed flatly by the corneal pressing member, and the blade (blade) is laterally vibrated while being guided by a guide mechanism provided on the suction ring. It is known that the cornea is cut in layers with a substantially uniform thickness by moving straight along the hinge in the direction of the hinge. As a guide mechanism, a rack is provided on the suction ring, a rotating gear meshing with the rack is provided on the blade side, and the blade is moved by being guided by the rack by rotating the rotating gear, or provided on the suction ring. A configuration in which the blade moves along the guide groove is known.
[0004]
In addition, it has been devised that the lateral vibration of the blade and the straight movement in the hinge direction are performed by a single motor.
[0005]
[Problems to be solved by the invention]
However, those having a guide mechanism or gear mechanism on the suction ring may bite the patient's eyelashes with the guide mechanism during the operation, and the straight movement of the blade may stop. In this case, it is necessary to continue the operation again after removing the eyelashes, which places a burden on the patient's eyes. In addition, it is not possible to expect a layered incision of equal thickness by re-operation. Further, wear powder is generated in the guide mechanism, but if the guide mechanism is provided on the suction ring, the wear powder may enter the patient's eye.
[0006]
In addition, although characteristics such as cornea and intraocular pressure differ depending on the patient's eye, the one that performs the lateral vibration and movement of the blade with a single motor is used for feeding movement and lateral vibration to make the incision surface a good smooth surface. It is difficult to optimize the relationship.
[0007]
In view of the above problems, the present invention provides a corneal surgery device that eliminates the possibility of interruption of surgery caused by the guide mechanism and that can perform good surgery according to the condition of the patient's eye without burdening the patient's eye. It is a technical subject to do.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration.
[0009]
(1) A corneal surgery device that includes a device main body, a suction portion that fixes a patient's eye, and a cutting portion that has a blade and moves on the suction portion. A shaft that is supported by the apparatus main body, and that causes the blade to advance and retract by moving the shaft forward and backward, and causes the blade to undergo lateral vibration via an eccentric shaft provided on the shaft by rotating the shaft. It has a moving shaft, a feed screw portion having a first motor and rotated by the rotation of the first motor, and a connecting member that meshes with the feed screw portion and rotatably holds the blade moving shaft, and is built in the apparatus main body. The first drive means, the second motor, and the blade moving shaft are slidably held in the forward and backward directions, and the blade moving shaft is rotated by the rotation of the second motor. Possess a second drive means which is incorporated in the apparatus main body has a rotation transmitting member to the, characterized in that for advancing and retreating the blade movement shaft via the connecting member by rotation of said first motor.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
<Embodiment 1>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a top view of the corneal surgery apparatus according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line AA in FIG.
[0020]
Reference numeral 1 denotes a microkeratome body, and reference numeral 1a denotes a gripping part gripped by an operator during an operation. On the front side (left side in the figure) of the main body 1 are a suction part 3 for fixing to the patient's eye and a cutting part 2 having a blade 20 (described later) for incising the cornea and moving straight on the suction part 3. Is provided.
[0021]
A feed motor 11 for moving the cutting part 2 straightly in the incision direction and a vibration motor 12 for applying a lateral vibration to the blade 20 are fixed in the main body 1. A feed screw 13 having a screw portion for a distance for moving the cutting portion 2 linearly is connected to the rotation shaft of the feed motor 11. An attachment member 14 to which a tubular connecting member 17 connected to the cutting portion 2 is fixed is screwed to the feed screw 13. By forward / reverse rotation of the feed motor 11, the connecting member 17 moves back and forth via the feed screw 13 and the attachment member 14, thereby moving the cutting unit 2 back and forth. In addition, the connecting member 17 holds the rotating shaft 15 so that the rotating shaft 15 can rotate and move back and forth together. An eccentric shaft 16 is implanted at the tip of the rotating shaft 15 at a position deviated from the center of rotation, and the eccentric shaft 16 gives a lateral vibration to the blade 20 (described later).
[0022]
A so-called spline shaft is used for the rotating shaft 15 and its rotating mechanism is as follows. The front portion 15a of the rotating shaft 15 is formed in a circular cross-sectional shape, and is rotatable inside the connecting member 17 via a bearing. On the other hand, the rear portion 15b of the rotary shaft 15 is uniformly formed with a non-circular oval cross-sectional shape as shown in FIG. 2 (which is a BB cross section on FIG. 1B). . A driving gear 18 is attached to the rotating shaft 12 a of the vibration motor 12, and a rotating gear 19 that is rotatably held inside the main body 1 meshes with the driving gear 18. A shaft hole 19a through which the rear portion 15b of the rotary shaft 15 is inserted is provided at the rotation center of the rotary gear 19, and the shaft hole 19a is formed in the same oval sectional shape as the rear portion 15b. (See FIG. 2). With this configuration, the rotation of the vibration motor 12 is transmitted to the rotary shaft 15 via the drive gear 18 and the rotary gear 19. On the other hand, when the feed motor 11 is driven, the rotating shaft 15 freely slides in the shaft hole 19 a of the rotating gear 19 and moves straight along with the connecting member 17.
[0023]
By adopting the spline shaft in this way, the rotating shaft 15 can transmit the lateral vibration due to the rotational motion to the blade 20 and cope with the straight movement of the cutting unit 2 without moving the vibration motor 12. it can. That is, since the vibration motor 12 can be fixed to the main body 1, the load of the vibration motor 12 is not applied to the attachment portion 14, and the burden on the feed motor 11 can be reduced.
[0024]
Further, since the connecting member 17 also serves as a guide for linear movement, it is not necessary to provide a guide on the suction ring 31 (described later). Furthermore, since most of the contact portions that cause wear powder generation together with the motor and the like are configured in the main body 1, the scattering of the wear powder due to the high-speed rotation of the rotary shaft 15 is processed in the main body 1 and is caused by the wear powder. Little effect on patient's eyes.
[0025]
Next, the structure of the cutting part 2 and the suction part 3 is demonstrated based on FIG. 3, FIG. 3A and 3B are enlarged views of FIG. 1 regarding the cutting unit 2 and the suction unit 3. 4 is a cross-sectional view taken along the line CC of FIG.
[0026]
The cutting unit 2 includes a blade 20 for incising the cornea, a blade holder 21a and a holder block 21b that hold the blade 20 so as to be capable of lateral vibration, and a vibration transmission member 22 that transmits lateral vibration generated by the eccentric shaft 16 to the blade 20. The corneal pressing part 23 is fixed to the holder block 21b by the mounting member 23c. A rotation hole into which the rotation shaft 15 is inserted is provided inside the holder block 21b, and the distal end portion of the connecting member 17 is fixed.
[0027]
The blade 20 is a metal blade using stainless steel, steel, or the like, or a mineral blade using a diamond, sapphire, or other mineral as the cutting edge. The blade 20 is formed between the blade holder 21a and the holder block 21b at an appropriate angle with respect to the horizontal plane. It is held so that it can vibrate horizontally. On the blade holder 21a side, a shallow recess 210a is formed in a portion where the blade 20 is placed, and the lateral width of the recess 210a is larger than the vibration width caused by the lateral vibration of the blade 20.
[0028]
The vibration transmitting member 22 is fixed to the blade 20 and is movable in a lateral direction within a receiving groove 210b formed in the holder block 21b. The vibration transmission member 22 is formed with a longitudinal groove 22 a that engages with the eccentric shaft 16. When the rotary shaft 15 is rotated by the rotational drive of the vibration motor 12, the eccentric shaft 16 attached to the tip of the rotational shaft 15 is the longitudinal groove 22 a. And a lateral driving force works. As a result, the blade 20 vibrates laterally together with the vibration transmitting member 22.
[0029]
The cornea pressing portion 23 is provided on the front side (left side in the drawing) of the blade 20 and presses the patient's cornea flatly as the cutting portion 2 advances prior to incision by the blade 20. When the blade 20 cuts out the cornea pressed flat by the cornea pressing portion 23, a uniform layered flap is formed.
[0030]
The distance between the cutting edge of the blade 20 attached to the blade holder 21a and the lower surface of the cornea pressing portion 23 is about 150 microns so that the cornea can be cut in layers with this thickness.
[0031]
The suction part 3 includes a fixed member 30, a suction ring 31, and a suction pipe 32, and the suction ring 31 is fixed to the main body 1 by the fixed member 30. The suction ring 31 has a substantially cylindrical shape with a U-shaped cross section, and is formed with a circular recess 31a for contact with the patient's eye and an opening 31b concentric with the recess 31a. During the operation, when the suction ring 31 is placed on the patient's eye, the patient's cornea protrudes upward from the opening 31b, and the lower end of the suction ring 31 and the opening end of the opening 31b come into contact with the patient's eye. A space S for suction is secured by the contact.
[0032]
The suction pipe 32 is implanted in the suction ring 31 and connected to a vacuum tube (not shown). The vacuum tube extends to the pump 41. The suction passage 32a provided in the suction pipe 32 communicates with the recess 31a, and sucks and discharges the air in the space S through the suction passage 32a by the pump 41, thereby adsorbing the suction ring 31 to the patient's eye. Fix it. At the time of fixing, the operator can easily determine the position of the opening 31b by holding the grip portion 1a of the main body 1, and can stably hold the apparatus.
[0033]
Further, a pipe 33a for pressure detection is planted in the suction ring 31, and the pipe 33a is connected to the pressure detector 33 by a tube not shown. The pressure detector 33 detects the air pressure in the space S sucked by the pump 41 through the pipe 33a. The control unit 40 controls the operation of the apparatus based on the air pressure detected by the pressure detector 33. If there is a gap between the suction ring 31 and the patient's eye, or foreign matter is clogged in the suction passage 32a or the like, and the air pressure in the space S is not sufficiently negative, the corneal rigidity cannot be secured properly. there is a possibility. Therefore, a predetermined value for the upper limit of the air pressure necessary to ensure a certain degree of corneal rigidity is provided, and the operation of the apparatus (vibration and feed of the blade 20) is stopped when the positive pressure is higher than the predetermined value for the upper limit (operation). Lock the start of the device before and interrupt the operation of the device during surgery). In this case, the operator stops the input of the drive instruction signal by the foot switch 42, and confirms the contact state of the suction ring 31 and the clogged state of the suction passage 32a and the like. When the detected air pressure becomes negative than the upper limit predetermined value and the surgeon re-inputs the drive instruction signal by the foot switch 42, the apparatus can start or resume operation. It should be noted that it is convenient to notify the surgeon that the detected air pressure is lower than the predetermined upper limit value by using an alarm 46 such as a lamp or voice. For example, the buzzer is sounded while the detected air pressure is more positive than the upper limit value, and the buzzer is stopped when the negative pressure is higher than the upper limit value. May be sounded). Further, at the start of incision, the apparatus may be started when the detected air pressure becomes negative pressure above a predetermined upper limit value.
[0034]
On the contrary, if the air pressure in the space S becomes too negative due to the suction time being too long, the intraocular pressure of the patient's eye becomes too high. Therefore, in order to prevent this, a predetermined value for the lower limit of the air pressure is set, and if the detected air pressure becomes a negative pressure that is lower than the predetermined value for the lower limit, the operation of the device is stopped. Surgery can be performed without applying
[0035]
Note that the predetermined value for the upper limit and the lower limit for the air pressure may be set in advance as fixed values, or may be variably set by an operator using a switch or the like not shown.
[0036]
The control unit 40 is connected to the pressure detector 33, the foot switch 42, and the like. The control unit 40 controls the operations of the motors 11 and 12 and the pump 41. Further, an input device 43 that can set and input the vibration frequency, feed rate, and the like of the blade 20 may be provided and connected to the control unit 40. As the input device 43, a switch or the like that can switch the rotation of each motor that determines the vibration frequency and feed rate of the blade 20 in several stages, or a variable resistor that can be continuously changed is provided on the main body 1 side. be able to.
[0037]
The operation of the apparatus having the above configuration will be described below. The surgeon confirms the inclination state of the suction ring 31 (main body 1), the position of the pupil center, and the like based on the mark previously attached to the patient's cornea with an instrument such as a marker. And the suction ring 31 is placed on the patient's eye.
[0038]
After installing the suction ring 31, the surgeon operates the pump 41 with the position and posture of the main body 1 maintained, sucks the air in the space S between the suction ring 31 and the patient's eye, and reduces the air pressure. (Let the negative pressure.) The operation of the pump 41 is controlled by the control unit 40 so as to maintain the air pressure when the air pressure in the space S drops to a certain value (at a sufficient negative pressure). Thereby, the suction ring 31 is sucked and fixed to the patient's eye.
[0039]
When the fixation of the apparatus is completed, the surgeon operates the foot switch 42 to rotate the feed motor 11 and the vibration motor 12. The control unit 40 controls the rotation of the vibration motor 12 so that the blade 20 undergoes lateral vibration at a fixed frequency (or set by the input device 43) in response to the input of the drive instruction signal by the foot switch 42. . Since the vibration frequency of the blade 20 vibrates once per rotation of the rotary shaft 15, the vibration frequency can be easily controlled by the rotation speed of the motor 12 due to the relationship of the gear ratio between the drive gear 18 and the rotation gear 19.
[0040]
Further, the control unit 40 controls the rotational speed of the feed motor 11 according to the fixed feed rate (or set by the input device 43), and moves the cutting unit 2 straight in the hinge direction. At this time, the rotating shaft 15 slides in the traveling direction together with the cutting unit 2 while rotating to impart lateral vibration to the blade 20.
[0041]
In this way, while controlling the motors of the feeding motor 11 and the vibration motor 12, the patient's ocular cornea sequentially pressed flat by the cornea pressing portion 23 is incised by the blade 20 and the operation proceeds. At the time of this incision, since the guide mechanism is not provided on the suction ring, the cutting part 2 moves smoothly without biting dust and wrinkles.
[0042]
When the tip of the blade 20 is incised leaving the hinge portion and the formation of the flap is completed, the feed motor 11 is rotated in the reverse direction to return the cutting portion 2 to the initial position. At this time, the blades 20 are pulled out of the flaps while avoiding unnecessary vibrations of the blades 20 by separately controlling the respective motors such as stopping the rotation of the vibration motor 12. Thereby, possibility that the formed flap may be cut off in the middle can be reduced.
[0043]
After returning the cutting unit 2 to the initial position, air is introduced into the space S to release the suction and the apparatus is removed. Thereafter, the laser beam is used to perform a substantial resection of the corrected refraction amount, and the flap is returned to the original position to complete the operation.
[0044]
The shape of the rear portion 15b of the rotating shaft 15 described above may be a cross-sectional shape provided with a plurality of grooves extending in the axial direction, and a slide key may be used instead of the spline shaft.
[0045]
Further, a detector such as a sensor 44 for detecting the position in the feed direction may be provided, and the feed speed and the frequency may be controlled based on the position of the blade 20. For example, since the incision is relatively difficult at the corneal incision start position, it is possible to control by slowing the feed rate, detecting that the incision has progressed to some extent by the sensor 44, and increasing the feed rate from that position. . Further, a changeover switch 45 or the like for switching the feed speed and vibration frequency of the blade 20 in a plurality of stages is provided, and the surgeon switches according to the progress of the operation so that the feed speed and vibration frequency of the blade 20 are controlled. Also good.
[0046]
<Embodiment 2>
Next, modifications of the present invention will be described with reference to the drawings. FIG. 5A is a top view of the corneal surgery apparatus according to the second embodiment of the present invention, and FIG. 5B is a cross-sectional view taken along the line AA in FIG. In the following description and drawings, the same reference numerals as those in the first embodiment indicate the same components.
[0047]
A feed screw 13 having a screw portion corresponding to a distance for moving the cutting portion 2 linearly is connected to the rotation shaft of the feed motor 11 fixed in the main body 1. An attachment member 14 is screwed onto the feed screw 13, and a vibration motor 12 and a connecting member 17 to which the vibration motor 12 and the cutting unit 2 are connected are fixed to the attachment member 14. By the forward / reverse rotation of the feed motor 11, the vibration motor 12 and the connecting member 17 are moved back and forth via the feed screw 13 and the attachment member 14, whereby the cutting unit 2 is moved back and forth. A rotating shaft 15 is rotatably held by the connecting member 17. An eccentric shaft 16 is implanted at the tip of the rotating shaft 15 at a position deviated from the center of rotation, and the eccentric shaft 16 gives a lateral vibration to the blade 20.
[0048]
As described above, in the second embodiment, the spline shaft is not adopted for the rotary shaft 15, and the vibration motor 12 moves with respect to the straight movement of the cutting unit 2. Therefore, since the load of the vibration motor 12 is applied to the attachment portion 14, the burden on the feed motor 11 is increased compared to the first embodiment. However, since the structure can be simplified such that the drive gear 18 and the rotation gear 19 are not required, there is an advantage that the cost can be reduced compared to the first embodiment.
[0049]
【The invention's effect】
As described above, according to the present invention, an incision can be made by laterally vibrating the blade with a simple configuration without providing a blade feed mechanism on the suction ring. In addition, bites such as wrinkles into the feeding mechanism and scattering of wear powder by the feeding mechanism and the rotating mechanism can be suppressed, so that surgery can be performed smoothly.
Furthermore, a favorable flap can be formed according to the condition of the patient's eye by controlling each of the blade feed and vibration.
[Brief description of the drawings]
FIG. 1 is a top view, an AA cross-sectional view, and a control system schematic diagram of an apparatus according to a first embodiment.
2 is a cross-sectional view taken along the line B-B for explaining the spline shaft according to the first embodiment.
FIG. 3 is an enlarged explanatory view of a cutting part and a suction part.
FIG. 4 is a cross-sectional view taken along the line C-C for explaining a cutting portion.
FIG. 5 is a top view, an AA cross-sectional view, and a control system schematic diagram of the apparatus according to the second embodiment.
[Explanation of symbols]
11 Feed motor 12 Vibration motor 13 Feed screw 14 Mounting member 15 Rotating shaft 16 Eccentric shaft 17 Connecting member 18 Drive gear 19 Rotating gear 20 Blade 40 Controller

Claims (1)

A corneal surgery device that includes a device main body, a suction portion that fixes a patient's eye, and a cutting portion that has a blade and moves on the suction portion. A shaft that is supported by the main body, wherein the blade is advanced and retracted by advancing and retreating the shaft, and rotating the shaft and causing a blade to vibrate laterally via an eccentric shaft provided on the shaft; A first screw which has a first motor and has a feed screw portion rotated by the rotation of the first motor and a connecting member which meshes with the feed screw portion and rotatably holds the blade moving shaft, and is built in the apparatus main body. A driving means, a second motor, and a blade moving shaft are slidably held in the forward / backward direction, and the blade moving shaft is rotated by the rotation of the second motor. Possess a second drive means which is incorporated in the apparatus main body having a transmission member, a corneal surgery apparatus according to claim by the rotation of the first motor to advance and retract the blade movement shaft via the coupling member.

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