JP3916333B2 - 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 limbus to the conjunctival surface, the cornea is pressed flat by the corneal pressing member, and the blade (blade) moves in the hinge direction (straight forward movement or rotational movement). ) To cut the cornea into a layer with a substantially uniform thickness is known. As such a microkeratome, one that separately controls the vibration and movement of the blade, and one that can variably set the vibration frequency and movement speed of the blade have been proposed.
[0004]
[Problems to be solved by the invention]
However, if the relationship between the blade frequency and the moving speed is not appropriate, the following problems may occur. If the moving speed is too fast compared to the frequency (if the frequency is too slow compared to the moving speed), the cut surface of the cornea may become non-uniform. Also, if the moving speed is too slow compared to the vibration frequency (if the vibration speed is too high compared to the moving speed), frictional heat is generated on the cut surface, and it takes extra time to complete the incision. bad.
[0005]
In view of the above-described problems, an object of the present invention is to provide a corneal surgical apparatus that can efficiently and satisfactorily perform incision of the cornea by appropriately determining the vibration frequency and moving speed of the blade.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized by having the following configuration.
[0007]
(1) In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, vibration means for laterally vibrating the blade, movement means for moving the blade in the incision direction, the vibration frequency of the blade by the vibration means, and the Setting means for variably setting at least one of the moving speeds of the blades by the moving means, storage means for storing a relative setting allowable range of the vibration frequency and moving speed, and a setting allowable range stored by the storage means And determining means for determining whether or not the relationship between the vibration frequency set by the setting means and the moving speed is appropriate.
(2) In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, a vibration means for laterally vibrating the blade, a moving means for moving the blade in the incision direction, and a blade by the vibration means as two parameters The setting means for variably setting the vibration frequency and the moving speed of the blade by the moving means, the storage means for storing the relative setting allowable range of the vibration frequency and the moving speed, and the setting means Limiting means for limiting the setting allowable range of the other parameter corresponding to the setting value of one parameter based on the setting allowable range stored by the storage means, and the vibration means and the movement based on the setting by the setting means Control means for controlling the means.
(3) In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, a vibration means for laterally vibrating the blade, a moving means for moving the blade in the incision direction, and a blade by the vibration means as two parameters First setting means for variably setting one of the vibration frequency and the moving speed of the blade by the moving means, storage means for storing an optimum combination of the vibration frequency and the moving speed, and the first setting means Second setting means for setting the other parameter corresponding to the one parameter set by the storage means based on the combination stored by the storage means, and the setting based on the setting by the second setting means and the first setting means And control means for controlling the vibration means and the moving means .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a top view of a corneal surgery apparatus according to the present invention, and FIG. 1B is a cross-sectional view taken along the line AA in FIG.
[0018]
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 corneal surface, 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.
[0019]
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 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 (described later).
[0020]
Next, the structure of the cutting part 2 and the suction part 3 is demonstrated based on FIG. 2, FIG. 2A and 2B are enlarged views of FIG. 1 regarding the cutting unit 2 and the suction unit 3. FIG. 3 is a cross-sectional view taken along the line CC in FIG.
[0021]
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.
[0022]
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.
[0023]
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.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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.
[0028]
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 device (feeding and vibration of the blade 20) is stopped when the positive pressure is higher than the predetermined value of 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 upper limit predetermined value by the 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.
[0029]
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
[0030]
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.
[0031]
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. Reference numeral 43 denotes an input device that can set and input the vibration frequency, feed rate, and the like of the blade 20. 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. (Details will be described later).
[0032]
The operation of the apparatus having the above configuration will be described below. First, the surgeon operates the input device 43 to set the vibration frequency and feed speed of the blade 20. The memory 47 connected to the control unit 40 stores the relative setting allowable range of the vibration frequency and the feed rate as a table or a calculation formula, and the control unit 40 is set for the set vibration frequency. It is determined whether the feed speed is within the set allowable range. If the set feed speed is within the set allowable range, the error lamp as the alarm 48 is not lit, and the feed motor 11 and the vibration motor 12 can be rotated by operating the foot switch 42. When the set feed speed is outside the setting allowable range, the error lamp as the alarm 48 is turned on. Further, the control unit 40 does not accept the drive instruction signal from the foot switch 42, the control unit 40 does not emit the drive signal to the feed motor 11 and the vibration motor 12, and the feed motor 11 and The vibration motor 12 is locked, for example, and the rotational drive of each motor is prohibited. In this case, the control unit 40 causes the display 49 to display a setting allowable range of the feed rate for the set frequency (see FIG. 4). Thereby, the surgeon can reset the feed speed within the setting allowable range. Note that the notification of the error by the notification device 48 may be performed by voice or the like.
[0033]
In addition, the above-described pass / fail determination of the rotational drive start of the feed motor 11 and the vibration motor 12 is performed based on the determination as to whether or not the set frequency is within the set allowable range. Also good. In this case, when it is determined that the set frequency is outside the set allowable range, the control unit 40 causes the display 49 to display the set allowable range of the frequency for the set feed speed. In addition, regardless of whether the frequency or the feed rate is used as a determination criterion, the control unit 40 displays each setting allowable range of the frequency and the feed rate on the display 49 so that the operator can reset both. Good.
[0034]
Alternatively, only the feed rate may be set with the frequency fixed (the memory 47 stores only the feed rate setting allowable range, and the display 49 displays the feed rate set allowable range). Only the frequency may be set with the feed rate fixed (the memory 47 stores only the allowable setting range of the frequency, and the display 49 displays the allowable setting range of the frequency).
[0035]
Furthermore, when it is determined that the feed rate set for the set (or fixed) frequency is outside the set allowable range, the control allowable range closest to the set feed rate by the control unit 40 is set. The value in may be reset. Needless to say, the frequency and feed rate may be reversed.
[0036]
As another method, when the frequency is first set by the input device 43, the control unit 40 sets the allowable range of the feed speed for the set frequency from the table or the calculation formula stored in the memory 47. derive. Then, the set allowable range of the feed rate can be displayed on the display 49, and the surgeon can set the feed rate within the set allowable range according to the display. Further, it is possible to prevent a value other than the set allowable range of the derived feed speed from being set. In this case, if a value outside the setting allowable range is set, the setting signal is not accepted and an error is displayed on the display 49 (or an error is notified by the notification device 48).
[0037]
Further, as another method, when the frequency is first set by the input device 43, the control unit 40 derives the optimum value of the feed speed for the set frequency from the table or calculation formula stored in the memory 47. The derived optimum value may be set as the feed speed. In these cases, it goes without saying that the frequency and the feed rate may be reversed.
[0038]
When the setting of the vibration frequency and feed rate of the blade 20 is completed, the surgeon preliminarily refers to the inclination state of the suction ring 31 (main body 1), the position of the pupil center, etc. , The center of the opening 31b is positioned with respect to the pupil center, and the suction ring 31 is placed on the patient's eye.
[0039]
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.
[0040]
When the fixation of the device 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 by the input of the drive instruction signal from the foot switch 42 so that the blade 20 performs lateral vibration at the frequency set by the above-described method. Since the vibration frequency of the blade 20 is one vibration per one rotation of the rotary shaft 15, the vibration frequency can be easily controlled by the rotation number of the vibration motor 12.
[0041]
Further, the control unit 40 controls the rotational speed of the feed motor 11 according to the feed speed set by the above-described method, 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.
[0042]
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.
[0043]
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.
[0044]
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.
[0045]
In the present embodiment, the blade feeding mechanism is described as moving the blade straight in the incision direction. However, the blade may be rotated. For the rotary movement of this blade, refer to Japanese Patent Application No. 10-157127, etc. by the present applicant.
[0046]
【The invention's effect】
As described above, according to the present invention, the incision of the cornea can be efficiently and satisfactorily performed by appropriately determining the blade frequency and the moving speed.
[Brief description of the drawings]
FIG. 1 is a top view of an apparatus of the present invention, a cross-sectional view taken along line AA, and a schematic diagram of a control system.
FIG. 2 is an enlarged explanatory view of a cutting part and a suction part.
FIG. 3 is a cross-sectional view taken along the line C-C for explaining a cutting portion.
FIG. 4 is a display example of a setting range of a feed rate when a blade frequency is set.
[Explanation of symbols]
11 Feed motor 12 Vibration motor 15 Rotating shaft 16 Eccentric shaft 20 Blade 40 Control unit 43 Input device 47 Memory

Claims (3)

In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, vibration means for laterally vibrating the blade, movement means for moving the blade in the incision direction, the vibration frequency of the blade by the vibration means, and the movement means Based on setting means for variably setting at least one of the moving speeds of the blade, storage means for storing a relative setting allowable range of the vibration frequency and the moving speed, and a setting allowable range stored by the storage means A corneal surgery apparatus comprising: a determination unit that determines whether or not a relationship between the vibration frequency set by the setting unit and the moving speed is appropriate. In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, vibration means for laterally vibrating the blade, moving means for moving the blade in the incision direction, and vibration frequency of the blade by the vibration means that are two parameters And a setting means for variably setting the moving speed of the blade by the moving means, a storage means for storing a relative setting allowable range of the vibration frequency and the moving speed, and one parameter set by the setting means Limiting means for limiting the setting allowable range of the other parameter corresponding to the set value based on the setting allowable range stored by the storage means, and controlling the vibrating means and the moving means based on the setting by the setting means A corneal surgery apparatus, comprising: In a corneal surgical apparatus for incising a patient's ocular cornea in layers with a blade, vibration means for laterally vibrating the blade, moving means for moving the blade in the incision direction, and vibration frequency of the blade by the vibration means that are two parameters And a first setting means for variably setting one of the moving speeds of the blade by the moving means, a storage means for storing an optimal combination of the vibration frequency and the moving speed, and a first setting means. Second setting means for setting the other parameter corresponding to the other parameter based on the combination stored by the storage means, the vibration means based on the setting by the second setting means and the first setting means, and And a control means for controlling the moving means .

Images