JP4086388B2 - 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) is moved in a straight line or rotated in the hinge direction while vibrating laterally. By this, what cuts the cornea in layers with a substantially uniform thickness is known. At the time of corneal incision, since the cornea tends to escape with respect to the movement of the blade, a certain degree of corneal rigidity is required. As this method, there is a method in which the corneal rigidity is obtained by increasing the intraocular pressure of the patient's eye by increasing the suction pressure applied in the suction ring.
[0004]
[Problems to be solved by the invention]
However, if the suction ring is not sufficiently adsorbed and fixed, or if foreign matter is clogged in the suction tube, the air pressure in the space between the patient's eye and the suction ring may not be sufficiently negative, May rise (toward positive pressure). As a result, the corneal rigidity of the patient's eye is not sufficiently increased, and there is a problem that the incision cannot be performed or the cut surface is not uniform even if the incision is possible.
[0005]
In view of the above problems, an object of the present invention is to provide a corneal surgery apparatus that can easily and satisfactorily perform incision of the cornea.
[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) A suction ring that comes into contact with the patient's eye, a suction means that sucks air in a gap formed between the suction ring and the patient's eye to fix the suction ring to the patient's eye, and protrudes from the suction ring In a corneal surgical apparatus for incising a patient's ocular cornea in a layered manner, a blade for incising the cornea to be cut and a drive means for causing the blade to vibrate laterally and move linearly in the incision direction are changed by suction of the suction means. A pressure detector for detecting the air pressure of the air gap formed between the suction ring and the patient's eye, and a drive control means for controlling the operation of the blade drive means based on the pressure information detected by the pressure detector. A drive that changes the frequency of lateral vibration of the blade or the feed rate of linear movement linearly or stepwise based on the pressure information. Dynamic control means.
(2) In a corneal surgical apparatus for incising a patient's ocular cornea in layers, a suction ring that comes into contact with the patient's eye and a gap formed between the suction ring and the patient's eye to fix the suction ring to the patient's eye A suction means for sucking air, a blade for incising the cornea protruding from the suction ring, a drive means for driving the blade, and a pressure detection means for detecting the air pressure of the gap that changes due to the suction of the suction means A lower limit value setting means for setting a lower limit value for the air pressure detected by the pressure detection means; a drive control means for controlling the drive means based on pressure information detected by the pressure detection means; The drive control means has the drive means when the air pressure value detected by the pressure detection means is a negative pressure than the lower limit value. The operation of the stage is stopped.
[0016]
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.
[0017]
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.
[0018]
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 rotation motor 12 and a connecting member 17 to which the rotation motor 12 and the cutting unit 2 are connected are fixed to the attachment member 14. By forward / reverse rotation of the feed motor 11, the rotation 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).
[0019]
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.
[0020]
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.
[0021]
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.
[0022]
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.
[0023]
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.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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.
[0028]
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
[0029]
The blade is driven at a predetermined feed rate and frequency, but these may be changed according to the detected air pressure. For example, regarding the feed rate, if the air pressure decreases (toward negative pressure) and the corneal stiffness increases, the feed rate is increased, and if the air pressure increases (toward positive pressure) and the corneal stiffness decreases, the feed rate is decreased. . This change can be performed linearly as shown in FIG. 4 (a) or stepwise as shown in FIG. 4 (b). In this way, surgery can be performed more efficiently and accurately.
[0030]
Note that the predetermined upper limit value and the lower limit predetermined value of the air pressure described above may be preset as default 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.
[0032]
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.
[0033]
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.
[0034]
When the fixation of the apparatus is completed, the surgeon operates the foot switch 42 to rotationally drive the feed motor 11 and the vibration motor 12. At this time, the control unit 40 detects the air pressure detected by the pressure detector 33 as described above. The drive is controlled based on the above. 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. When the feed motor 11 is driven, the cutting unit 2 moves 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.
[0035]
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.
[0036]
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.
[0037]
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.
[0038]
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.
[0039]
Further, the blade feed and the lateral vibration may be performed by one motor, or only the blade lateral vibration may be performed by the motor, and the blade feed may be manually performed by a rotating gear or the like. In the latter case, only the lateral vibration of the blade is controlled by the detected air pressure.
[0040]
【The invention's effect】
As described above, according to the present invention, the corneal rigidity of the patient's eye can be sufficiently increased and a good flap can be easily formed.
[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 an explanatory diagram relating to control of a blade feed speed with respect to detected air pressure;
[Explanation of symbols]
11 Feed motor 12 Vibration motor 15 Rotating shaft 16 Eccentric shaft 20 Blade 31 Suction ring 33 Pressure detector 40 Control unit 41 Pump

Claims (2)

A suction ring that comes into contact with the patient's eye; a suction means that sucks air in a gap formed between the suction ring and the patient's eye to fix the suction ring to the patient's eye; and a cornea that protrudes from the suction ring. In a corneal surgical apparatus for incising a patient's ocular cornea in a layered manner, a suction ring that changes by suction of the suction means A pressure detector for detecting the air pressure of the air gap formed between the patient's eyes and a drive control means for controlling the operation of the blade drive means based on pressure information detected by the pressure detector; linear or stepwise alters the drive control based on the feed rate of the frequency or linear movement of the lateral vibration of the blade to the pressure information Corneal surgery apparatus, comprising: the stage, a.   In a corneal surgical apparatus for incising a patient's ocular cornea in layers, a suction ring that comes into contact with the patient's eye and air in a gap formed between the suction ring and the patient's eye to fix the suction ring to the patient's eye A suction means for sucking, a blade for incising the cornea protruding from the suction ring, a driving means for driving the blade, a pressure detection means for detecting the air pressure of the gap changed by the suction of the suction means, and the pressure A lower limit value setting means for setting a lower limit value for the air pressure detected by the detection means; and a drive control means for controlling the drive means based on pressure information detected by the pressure detection means. The drive control means operates the drive means when the value of the air pressure detected by the pressure detection means is negative pressure than the lower limit value. Corneal surgery apparatus, characterized in that the stop.

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