CN1160530A - Method and apparatus for removing corneal tissue with infrared laser radiation - Google Patents
Method and apparatus for removing corneal tissue with infrared laser radiation Download PDFInfo
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- CN1160530A CN1160530A CN 96122077 CN96122077A CN1160530A CN 1160530 A CN1160530 A CN 1160530A CN 96122077 CN96122077 CN 96122077 CN 96122077 A CN96122077 A CN 96122077A CN 1160530 A CN1160530 A CN 1160530A
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Abstract
A surgical apparatus for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of incident radiation by the corneal tissue. The disclosed surgical system includes a scanning beam delivery system which allows uniform irradiation of the treatment region and utilizes low energy outputs to achieve controlled tissue removal. A real-time servo-controlled dynamic eye tracker, based on a multiple-detector arrangement, is also disclosed which senses the motion of the eye and provides signals that are proportional to the errors in the lateral alignment of the eye relative to the axis of the laser beam. Temporal and frequency discrimination are preferably utilized to distinguish the tracking illumination from the ambient illumination and the surgical laser beam.
Description
The present invention relates to revise the laser surgery technology on cornea surface, more particularly, relate to laser surgery, be commonly referred to as anaclasis keratectomy or PRK, it utilizes selectivity survey volume excision cornea to come corneal to organize direct integer.
In recent years, disclose and a lot of resembled myopia, hypermetropia, astigmatism and the cornea lithographic technique and relevant device of invention for correcting the dysopia.The cornea lithographic technique also is used to treat a large amount of pathological symptoms relevant with cornea in addition.For example authorize the United States Patent (USP) of L ' Esperance, be numbered 4,665,913; 4,732ml48 and 4,669,466 authorizes the United States Patent (USP) of Trokel, is numbered 5,108,388 and has all described by anterior cornea surface integer being realized the method for optical correction.And, much be used for the prototype instrument commercialization of refractive surgery recently, resemble the Model 2020 of California Visx of Santa Clara and the Model Exci-Med 200 of Massachusetts Summit of Watertown.
These commercial cornea lithographic method and device great majority open so far and that produce are to utilize the ultraviolet with certain wavelength, generally are the ultraviolet less than 200nm.For example a lot of equipment are to be operated in the 193nm wavelength with fluorine-argon laser.In general so short wavelength's ultraviolet has high photon energy greater than 6 electron-volts (eV), act on cornea tissue after, with disorganize intramolecule chemical combination key, make molecular breakdown.The advantage of the photochemical characteristic of this principle is that operation area peripheral edge cell is produced less indirect thermal damage.Because broken molecule is small volatile fragment usually, they have just evaporated when not burning hypothallus.And therefore the decomposition degree of depth that each laser pulse produces can obtain accurate tissue with ultraviolet and peel off less than 1 micron in the risk range of the minimum of not damaging the hypothallus structure.
In view of so little penetration depth, to take into account simultaneously and peel off enough dark tissue and the time of whole surgical procedures is reduced to minimum, great majority utilize the cornea lithographic technique of excimer laser to use " large tracts of land is peeled off ".It is that laser beam is acted on the big relatively operative site that large tracts of land is peeled off, and peels off the cornea thin layer gradually.Spot size generally is the size of foot in the optical region that covers whole cornea, that is, diameter is 5 to 7mm.Guarantee that pharosage required on the cornea just needs high relatively ultraviolet output energy.Have been found that and to guarantee that luminous flux is 150mJ/cm
2, just need the ultraviolet laser of a 200mJ with the speed of normally peeling off of safeguarding each pulse 0.2 micron (0.2microns/pulse) at least.Yet such laser instrument is too huge and expense is too high.
In addition, effectively large tracts of land peels off that to require on the projecting beam space be uniformly to obtain the cornea section of desired smooth.Therefore the excimer laser beam transmission system need be assisted and be added light beam integer equipment, as rotary prism, and reflecting mirror or space integral device.About going through of light beam integer transmission system, ask for an interview the United States Patent (USP) of authorizing Telfair, numbering 4,911,711 is combined in it herein by reference.Certainly various optical element will produce loss, increase the complexity of optical system significantly, and what bring is the raising that cost and system held are protected expense thereupon.
Other is based on utilizing ultraviolet laser scan control cornea to select the local lift-off technology in zone to produce.The scanning Asymptotical Method be with relatively little laser point to determine good pattern rapid scanning on cornea in advance, make cornea gradually integer become required geometry.The going through of laser scanner technique of relevant use generating laser asked for an interview the United States Patent (USP) of authorizing L ' Esperance, be numbered 4,665,913 or see Lin, J.T. make " using the small-sized excimer laser emitter of cornea integer of scanning device " (" Mini-Excimer Laser Corneal ReshapingUsing a Scanning Device ") SPIE proceedings the 2131st volume, medical laser and the III of system (1994).The scanning approach method has many good qualities, comprising: low-power, and low energy consumption, refraction correction and flattened section peel off in addition, do not require that outgoing laser beam has Space Consistency.For example laser scanning can be used to correct high myopia on a tapered optical processing region, and treated tissue comes off and processing region is increased to the 9mm diameter range can be used to correct hypermetropia.
Laser surgery based on excimer laser is good effective on a lot of the application.If overcome some restrictions that this technology had, it will obtain great progress on laser surgery uses.For example, quasi-molecule exciton technology uses toxic gas as medium, loss luminous energy in transmission system, and poor reliability, and have ultraviolet and produce the probability of potential variation by secondary fluor, this will be to the long-term harmful effect of the non-exposure tissue generation of eyes.
Therefore, proposed the device of alternative excimer laser in recent years, it relates to the shift frequency ray from solid state laser.Yet, as the restriction of the non-linear element of frequency displacement device, make the lower limit of wavelength available of this laser instrument be positioned at about 205nm, this may be too near region of variability, and this region of variability spike occurs at the 250nm place.In addition, the multiple shift Laser Devices also face the difficulty of required energy output, and device itself is quite complicated heavy, causes potential integrity problem, has increased cost and maintenance cost simultaneously.
Recently, T.Seiler and J.Wollensak are at his " photospallation cornea myoporthosis basic skills " (" Fundamental Mode Phobablation of the Cornea for MyopicCorrection "), Lasers and Light in Ophtalmology, 5,4 199-203 (1993) have proposed a kind of more attractive replacement scheme in the book.This scheme relates to the middle infrared wavelength on about 3 microns (microns) right left side of the absworption peak that is equivalent to cornea tissue main component water.Particularly a kind of erbium YAG laser (Er:YAG) that is called, emission wavelength is approximately 2.94 microns, is equivalent in water absorptance and surpasses 13000cm
-1This high coverage that causes less than 2 microns penetration depths that absorbs.
The photospallation mechanism relevant with excimer laser, be that the photochemistry decomposition is because the cause that molecule chemical combination bond energy absorbs, opposite with it, erbium laser (Er:YAG) is to utilize hydrone light evaporating principle or be called the photo-thermal volatilization, this heat causes phase transformation, thereby the cornea tissue burst is expanded the anterior corneal surface tissue is come off.
In addition, to have more clinical value than excimer laser be because it is light, efficient to erbium laser.Its energy high quality ray beam, the light loss of transmission system is little, has good optical coupling characteristic again.In addition, light evaporation itself is more efficient than photolysis, and it can once be peeled off and reach 3 microns tissue, thereby accelerates operation process.Middle infrared-ray is suitable for fiber-optic transfer.The former decoupling method of noting with introducing transmission system of laser makes it be more suitable for the indoor application of performing the operation.At last, the erbium laser ray can not make a variation, and has avoided potential long-term adverse effect.
Be based on a large scale by Seiler and the described erbium laser of Wollensak (Er:YAG) cornea lithographic technique and peel off.This system's purpose is under minimum pulsed quantity, utilizes the Gaussian beam face of laser beam, obtains refraction correction with each pulse.Another is people's descriptions in the PCT application such as cozean based on the system of peeling off on a large scale, and application number is 93/14817.It has an etching filter, organizes the degree of peeling off thereby be used for controlling the laser intensity control that is mapped on the cornea.
Except the advantage of above these technology, Seiler and Wdlensak, people's such as Cozean erbium laser also have some potential defectives, and they all are lift-off technologies on a large scale, therefore need a level and smooth light beam face uniformly, big pulse energy or complicated filtration control system.These systems in the past hypothesis to peel off be linear, i.e. the big more part of the energy density of light beam, organizing of peeling off is dark more.Yet this hypothesis is proved to be mistake in excimer laser is peeled off, and also is wrong in erbium laser is peeled off equally.
Except limitation discussed above, the technology of these controls and transmission mid-infrared laser bundle also has a shortcoming, that is, and and the hot injury of the non-stripping area of eye.This is owing to large impact ripple and the needed excessive energy density of these systems of peeling off required high energy pulse generation on a large scale are caused.In addition owing to need high impulse energy and high-quality laser beam, make complicated difficulty and the easy care not made of optical texture.
From above discussion as can be seen, the method and apparatus of control surgery cornea processing needs to improve.Need improved low-cost solid state laser and treat hypometropia, the method and apparatus that hypermetropia and light loose.Need the method and the computerized equipment of the middle infrared scan laser beam of improved scanning outer ocular surfaces and bottom Bowan layer and substrate in addition, with near the tissue minimizing eyes error of refraction and processing anterior corneal surface and the anterior corneal surface.Eye tracking mechanism in the surgery cornea tissue processing procedure also needs to improve in addition.
The surgical method and the device of infrared-ray removing corneal tissue tissue in a kind of the utilization are provided according to an aspect of the present invention.The short laser pulse that this surgical method and device utilization are scanned on the cornea zone makes cornea come off because of photospallation.Photospallation is a kind of photomechanical ablation mechanism, and it results from cornea tissue and absorbs incident illumination.When cornea tissue absorbs infrared-ray, produce two-way oscillatory surge ripple, its alternate compression and an extension angle membrane tissue.The fragment of tissue break apart also impact to be discharged between extensin period at shock wave.
According to characteristics of the present invention, transmission laser system comprises lasing light emitter, Q-switched erbium laser (Er:YAG) for example, and the pulse ray in its emission mid-infrared light spectral limit, its energy density is enough to make cornea tissue to be peeled off.In most preferred embodiment, the laser instrument emission is corresponding to about 3 micron wave length rays of the absorption maximum coefficient of cornea tissue Main Ingredients and Appearance water.Lasing light emitter is preferably with the about 5-100Hz of repetition rate, and width is less than the form divergent-ray of the discrete pulse of 50 nanoseconds (nanosecond).Light pulse will reduce the undesirable heat degree of injury around the tissue.Each pulse energy is preferably in 5 to 30 milli Jiao Er (mJ) scopes.
Laser beam in the enterprising line scanning in the specific central area of anterior corneal surface, so that peel off tissue selectively on the scanning area each point, is the shape that pre-establishes thereby make the cornea tissue integer with predetermined pattern by the scanning light beam transmission system.The scanning light beam transmitting device is combined by may command swing minute surface, with light beam acquiring and directive anterior corneal surface.Can utilize the photospallation of predetermined scan pattern control cornea, comprise corneal epithelial tissue, Bownan layer, and corneal stroma.To obtain the change of desirable cornea shape.
According to a further aspect in the invention, before each operation, can according to needed pulse overlap degree with peel off characteristic relation figure between the degree of depth, as one man change size and interval with the related light class of given scan pattern with the highest operative speed and the desired smoothness that peels off the requirement of posterior corneal surface.Given scan pattern is treatment with irradiation district equably preferably, and the line of the overexposure that can distinguish between the scanning line or under-exposure tissue is reduced to minimum.One or more discontinuous scan patterns can be used in each interval, with pulse distribution in the entire process zone, thereby waste heat is dispersed in the whole zone so that the temperature rise minimum in any regional area.
According to most preferred embodiment of the present invention, provide the eye tracking system together with the scanning light beam transmission system, be used for that the motion to eyes compensates in operation process.The eye tracking system detects the motion of eyeball and produces the signal that is directly proportional with deviation with respect to the eye level directrix of laser beam axis.The tracking radiation eyes also list the key character such as the limbus of corneae imaging of eyes at detector array, to detect the horizontal movement of eyes.According to feature of the present invention, described detector array comprise in vertical direction with horizontal direction on be at least four detectors at center with the center of this detector array.
In operation, when eyes principal character during with respect to laser beam axis centering, this patterns of features will with detector array to the center.Detector array produces zero-signal makes laser beam axis remain on its current position.Yet, when eyes misalign with respect to laser beam axis, the image that on detector, forms also not with its centering, detector array will produce deviation signal, this signal causes laser beam axis deflection and normally acts on the cornea tissue.
Following the tracks of light preferably is selected in the near infrared region so that make a distinction with ambient light and laser beam.In addition, preferably follow the tracks of light so that further make a distinction with ambient light and laser beam with predetermined instantaneous frequency modulation.Infrared or near-infrared light filter is contained in the front portion of detector array, with the contrast of further raising detection eyes key character, as limbus of corneae (limbus).
According to another feature of the present invention, cornea profile equipment is housed on operation device, be used for judging that the shape of cornea tissue is with the measurement before and after the assisted surgery.For the spatial discrimination refractometer also is equipped with in the refraction of measuring cornea tissue.In a plurality of embodiment of the present invention, alignment methods recited above cooperates the active feedback control of cornea profile or refraction map instrument again, so that further control operation process.
For obtaining more fully understanding to of the present invention, and other features and advantages of the present invention, please refer to accompanying drawing and following more detailed description.
Fig. 1 is the optics that explanation comprises the device of feature of the present invention, machinery and the emic block diagram of electrical equipment.
Fig. 2 is the sketch map of the optical element of displaying.
Fig. 3 (a) and 3 (b) illustrate the scan pattern of laser beam through cornea.
Fig. 4 (a) and 4 (b) are that the intensity degree of function of the diameter of the laser beam after the conduct that measures on the cornea focuses on distributes.
Fig. 5 (a) and 5 (b) illustrate the transporting mechanism of laser beam from laser system to operation equipment.
Fig. 6 (a) and 6 (b) illustrate detection arrays, the calibration of eyes map and the non-calibrating position with respect to the integration type eye tracker.
Fig. 7 is electronic circuit and the SERVO CONTROL function embodiment sketch map relevant with eye tracker among Fig. 1 and Fig. 2.
As Fig. 1, shown in 2.Operation device 200 comprises infrared laser source and optical glass assembly, the latter sequentially comprises: light beam eyeglass 30, will discuss in Fig. 5, safety shutter 40, transmit reflecting mirror 50,60 with part, it focuses on output beam 10 on the cornea of patient's eyes 70, with the correction corneal curvature, play therapeutical effect.Lasing light emitter 20 preferably produces the middle infrared laser of short optical pulse, peels off to realize the cornea based on the photospallation principle that is discussed later.Laser beam 10 preferably scans on the specific central area of anterior corneal surface with predetermined pattern, makes corneal curvature by the predetermined control alteration of form.
According to feature of the present invention, lasing light emitter 20 is the Solid State Laser source preferably, the pulse ray in the emission mid-infrared light spectral limit, and its energy density is enough to make the cornea tissue decomposition that comes off.Laser instrument is preferably launched the ray at cornea absorption peak place, and promptly the ray of about 3 microns as 2.7 to 3.1 microns of wavelength is corresponding with the absorption maximum coefficient of cornea tissue Main Ingredients and Appearance water.Have now found that under this wavelength, the cornea tissue of eyes 70 produces fully in 1 to the 2 micrometer depth scope being absorbed in of laser energy and absorbs.As below will further discussing, have now found that thin absorber thickness and short radiation pulsion phase combine to make cornea tissue hot injury on every side be relieved to accessory degree.
As previously mentioned, according to feature of the present invention, surgical technic disclosed herein is based on the principle that is called " photospallation ".Infrared scan fast laser pulse bundle irradiation in the cornea tissue quilt.Photospallation is that the utilization opto-mechanical is peeled off principle in brief, makes cornea tissue absorb the incident ray.When cornea tissue absorbs infrared-ray, produce a two-way oscillatory surge ripple, it alternately compresses and the extension angle membrane tissue, tissue disruption is separated, and discharge between extensin period at shock wave.Going through of photospallation asked for an interview Jacques, S.L. " Laser-Tissue Interaction:Photochemical, Photothermal, and Photomachanical " Laser in General Sirgery, 72 (3), 531-558 (1992).Therefore photospallation is the pinch spalling process, so after peeling off, can produce faint heat around the remaining tissue.
Lasing light emitter 20 can realize that it transmits about 2.94 microns mid-infrared laser bundle with Q-Switched erbium YAG laser (Er:YAG).In addition, lasing light emitter 20 also can be the neodymium or the holmium doping laser instrument of optical parametric oscillator (OPO) shift frequency, and it launches about 3 microns ray.Certainly, other available lasing light emitter similar to erbium YAG laser (Er:YAG) also within the scope of the present invention.
Lasing light emitter 20 is about 5 to 100 hertz (Hz) of tranmitting frequency preferably, width is less than 50 millimicrons discrete pulse, laser pulse should enough be lacked so that in the photospallation process all the time, and the horizontal hot injury around the irradiation area tissue is limited in less than in 2 microns width ranges.Each pulse energy of laser 20 is preferably in 5 in 30mJ, so that incoming laser beam 14 is peeled off tissue partly, removes the imperceptible part of cornea.
As shown in Figure 1, 2, relevant with reference to the aspect with eyes for making surgical device 200, the sight line of eyes 70 need be transmitted axis 14 with incoming laser beam and really overlap.Consistent with customary definition, the term of using here " sight line " or " vision baseline " are meant by the chief ray in a branch of light of pupil arrival concave point, therefore are the lines of fixed concave point and pupil inlet.Therefore, should understand like this: sight line constitute directly limit by the patient rather than by measuring to certain externally measured eyes that limit of eyes.In addition,, can determine sight line uniquely, and for utilizing the localized objective measurement of real-time patient, sight line is the unique axis that can change for specified eyes.
Because the sight line of strict difinition is the central point of eye sight line, do not consider the fixed point direction of eyes axis of symmetry, it is generally acknowledged, for obtaining the optimal light effect, the cross point of cornea and sight line forms the desirable center of refracting process optical region, tries hard to recover visual sensitivity.Should be pointed out that as Fig. 1 shown in 2, during surgical operation, the orientation of eyes 70 sight lines can be vertical, level, perhaps the patient feels comfortable position between the two, does not influence the operation normal running again.
During corneal was implemented laser surgery, under doctor 55 guidance, the sight line of patient's eye 70 must be calibrated to consistent with the laser beam axis of adjusting through the two axial lines level conversion with known method.The doctor observes eyes 70 by surgery microscope 80, and with known method by prior correction, the anterior image center of judging eyes 70 is with respect to the cross-hair of indicating beam axis 14 positions or the number of degrees of other fixed reference labelling.The while doctor is by means of observing previous relatively the adjustment and microscope 80 optimum focusing fixed object planes, the number of degrees that eyes 70 imaging focus on, the axial location of judgement eyes 70.Can adjust to the axial location of eyes 70 corneas consistent from doctor 55 direction with best focus plane.
Preferably observe and watch focusing attentively to set up the orientation, inclination angle of required eyes 70 sight lines by the patient.By fixed target equipment 90 two axis light targets (not having expression among the figure) being projected to eyes 70 is that eye focuses on microscope 80.The axial distance that two target localization patient's eyes that manifest 70 are different, and everybody known method is adjusted in advance.The relevant adjustment technology that is fit to, all PCT applications of seeing Knopp and Yoder are numbered WO94/07908.Occur when overlapping when two targets (among the figure do not have expression) with the method, the axis of eyes 70 will really overlap on angle with the axis of microscope 80 axis and laser beam 14.
In most preferred embodiment, in the surgical procedure process by means of two-dimentional eye tracker 100, can ignore use that patient's eyes 70 occurs after the preliminary method of adjustment above-mentioned noting moving horizontally less than 5mm on the direction.Below in conjunction with Fig. 6,7 further discuss.Motion and generation that eye tracker 100 is measured eyes 70 are proportional to the signal of eye level directrix with respect to the deviation of laser beam axis 14.The signal that eye tracker produces is transformed into instruction makes local reflex mirror 60 produce small angle deflection.This low-angle deflection changes the direction of laser beam axis 14, makes its present position with eyes 70 consistent.Below in conjunction with Fig. 7 discussion this compensating signal from the electronic circuit generation.This electronic circuit utilizes one or more data wires to connect by eye tracker 100 to eyeglass 60, in the drawings by 102 expressions.
The tracking illumination of 100 pairs of eyes 70 of eye tracker is to be realized by the coaxial light source 120 that preferably is integrated on the microscope 80.The a branch of light with respect to microscope 80 of this light source projects becomes 8 ° low-angle light beam 17.According to feature of the present invention, the wavelength of the tracking light beam 17 that is produced by light source 120 and instantaneous modulating frequency should be able to be to the maximum limit distinguish with the ray of room environment illumination and lasing light emitter 20.The electronic circuit of detector and eye tracker 100 inside and tracking light beam 17 can be realized above-mentioned requirements.Have instantaneous modulation and the spectral characteristic different with illumination of this way surrounding and laser beam 14, therefore, in fact follow the tracks of and detect them reactionless with following the tracks of light beam 17.
In addition, as shown in Figure 1, surgery systems 200 preferably contains safety shutter 40, and it will be below occurring be closed during situation automatically: laser beam can not be along the transmission of foregoing path, and lasing light emitter 20 pulse energy surveillances demonstration laser breaks down; Eye tracker 100 can not be followed the tracks of eye motion.
Further discuss below, as shown in Figure 1, operation device 200 is equipped with video camera 140, before operation, proofread and correct and surgical procedure during, the image of patient's eye is presented on the monitor 150 in real time, and videocorder 160 these video images of record are in order to operation back inspection amount with as the operation process history file.
As shown in Figure 1, computer 110 has multiple storage and control function.Especially, thus computer 110 communicate by letter with lasing light emitter 20 by wiring 101 it controlled.The scan pattern of computer 110 usefulness storage and order are by wiring 103 driven sweep eyeglasses 50 in addition, and scan pattern and order are imported computer by doctor 55 or assistant.Wiring 104 between computer 110 and the safety shutter 40 will be played the patient, the maximum safety effect of doctor and participant.Computer 110 utilizes wiring 105 to monitor the state of operation and eye tracker.In addition, as shown in Figure 1, computer 110 is connected with eye tracker 100 by wiring 106, links through wiring 107 and eyeglass 60 simultaneously.Computer 110 can directly be controlled the position of eyeglass 60 like this.Another kind of alternate scheme can be attached to scanning and eye tracker function on single eyeglass such as the eyeglass 60 computer 110 together, so wiring 103 can be removed.
Further introduce below, operation device 200 preferably contains cornea profile equipment 180 or spatial discrimination refractometer 190, as shown in Figure 1.Cornea appearance device 180 can be used for measuring the cornea tissue shape with assisted surgery before and operation back eyeball shape or curvature measurement.Another selective embodiment can comprise spatial discrimination refractometer (SRR) 190, is used for measuring the refractive index of cornea tissue.
Controlling chart 1 and Fig. 2 can notice, in normal function of the present invention, eyeglass 50 and 60 local reflex characteristic play an important role.When the ray of eye tracker 100 saw through eyeglass 50, laser beam 12 was reflected by eyeglass 50.This function is by for example surfacing on eyeglass 50 surfaces, is commonly referred to promptly that " heat mirror " finish.This coating is color separation, and in other words, coating has different reflections and transmission characteristic to the light of different wave length.The ray that lasing light emitter 20 is sent has about 2.9 micron wave lengths, and eyeglass 50 should have highly reflective to it, and the ray that eye tracker 100 takes place is greatly between 0.8 to 1.0 micron, and eyeglass 50 has high light transmission to it.
Similarly, preferably select the branch coloured light coating on the eyeglass 60 to make it under the wavelength of laser 20, highly reflective be arranged, and have about equally reflexive and penetrance for the visible wavelength that the doctor uses, be used on the wavelength of fixed target 90 and coaxial light source 120, observe the alignment case and the operation process of eyes and surgical apparatus.Because this is possible in visible-range, the wavelength of fixed target 90 and coaxial light source 120 is close and away from the wavelength of laser instrument 20. Eyeglass 50 and 60 can produce little horizontal displacement because angle of inclination and eyeglass groundwork thickness are limited, but this fixed position is easy to be compensated when the device design, and this professional those of ordinary skill can understand how to do.
In addition, though the eyeglass 130 between light beam 15 and 16 be not color separation also have a local light transmission.Coating on this eyeglass has about equally reflection and light transmission features for eye tracker light source 120 and most of visible light.In this way, the portion of energy of light beam 15 will be changed direction and become light beam 18 and enter video camera 140 as previously mentioned.Obviously, eyeglass 130 is that a light beam decomposes prism, has the double base cubic form of gummed usually, and is coated with the local reflex layer on inner surface.
As previously mentioned, as Fig. 1, the surgical apparatus 200 shown in 2 preferably has computer control scanning motion function.Make mid and far infrared pulse laser beam 14 with the zonule of each adjacency in the middle part of the cornea of predetermined pattern consecutive order ground irradiation eyes 70, as Fig. 3 (a), shown in 3 (b).In all cases, the diameter of processing region is 9mm.The size of the laser beam point that focuses on is about 0.5 to arrive the 0.2mm circumscribed circle diameter.
Shown in Fig. 3 (a), laser beam 14 orthoscopic scanning or be called raster scanning 310 to have covered with processing region 315 be the square region at center.When computer forecast to laser energy will run into the zone beyond cornea tissue the time, just laser beam 14 is closed.Shown in Fig. 3 (b), laser beam 14 is the center with processed regional 325, with the pattern scanning of concentric circular 322.As Fig. 3 (a) and the illustrated mode of 3 (b), laser beam 14 can move continuously from origin-to-destination.Another kind of operator scheme is scanning element to be become coordinate position cover the entire process zone, with discontinuous quick laser positioning scanning.Purpose is in order to reduce owing to Continuous irradiation the waste heat that produces in the scanning pattern peripheral region.In this embodiment, scanner has the random position ability.
Based on Fig. 3 disclosed herein (a), the scan pattern shown in 3 (b), or other is for the conspicuous continuous or discontinuous scan mode of this professional those of ordinary skill, and adjacent scan paths is eclipsed.By this way, the irradiation on the entire process zone 315,325 is uniform.This irradiation is that the minimum discernable line with overexposure or under-exposure tissue between two scanning lines carries out.The feature that please notes discontinuous scanning is in each interval pulse distribution to be arrived whole zone, and interval is shorter than whole scanning sequence, therefore can be dispersed in whole surface to waste heat better, with heat and the temperature rise that reduces any regional area.In a single day computer 110 has determined scan pattern, and operation can be carried out on anterior corneal surface discontinuously to obtain maximum smoothness and minimum heat effect.
The realization of anterior corneal surface laser beam flying is by the gradient of the local reflecting optics 50 of control for diaxon, so that the generation by rights of reflection lasering beam departs from.Under the initial control of 110 pairs of surgical procedure of computer, this scanning motion signal is delivered to the electric drive wabbler mechanism that links to each other with eyeglass 50.
On processed regional 315,325 difference, the speed of scanning motion changes.This changes consistent with the algorithm of doctor's 55 regulations, peels off partial cornea tissue more or less, and the change that makes anterior surface of cornea obtain expecting to the refracting power of light is with the dysopia of correction patient's eye.Can astigmatism or tubular light with the speed drive scan mirror that changes, the speed of this variation is around the function of the position of light propagation axis rotation in the described pattern.Compared with near the tissue that divests the cornea quadrature radial line, this method can make laser beam 14 peel off near the radial line more cornea tissue.The asymmetric scanning motion that can superpose on normal symmetric scan pattern is so that revise spherical or simple shape refraction vision deviation simultaneously.
Shown in Fig. 4 (a), in order to help that processing region 315,325 is carried out uniform irradiation, at anterior corneal surface, the intensity distributions ideal situation of focussed laser beam 14 be exactly one rotational symmetric trapezoidal.Gaussian curve among Fig. 4 (b) levels off to idealized intensity distributions among Fig. 4 (a).Notice that promptly reach 2mm for the little beam diameter that contacts anterior corneal surface, it is close with the Gaussian curve shape that the excimer laser tissue is peeled off distribution, and irrelevant with the beam density curve.And for intermediate diameters, that is, from 2mm to 4mm, the beam intensity that peeling off distributes approaches excimer laser distributes.For major diameter, promptly from 4mm to 7mm more than, peel off distribution and compare with beam intensity, the edge is darker than the centre.
It is similar that photospallation and excimer laser discussed above are peeled off, and when laser point diameter during less than 2mm, in general laser beam intensity distributes for design or peels off pattern and be not strict with.Different with the photo-thermal effect peel angle membrane tissue of light evaporating principle, photospallation belongs to optomechanical effect.Therefore, peel off pattern and depend on beam diameter, rather than specific intensity distributions.Like this, as another advantage of the present invention, owing to the present invention is based on pulse diameters, and inresponsive especially for the little variable in the beam intensity, therefore, it is light that laser design work becomes.
As previously mentioned, laser beam 10 utilizes beam Propagation lens set 30 to be transferred to the major part of operation device 200, is represented more in detail by Fig. 5 (a) and 5 (b).It should be noted that for the often crowded environment of operating room propagate light beam effectively separation from laser system for making, equipment preferably can assemble flexibly.Shown in Fig. 5 (a), the beam propagation eyeglass contains amasthenic lens 160, with laser beam 10 optically focused and inject the hand-hole of separating mechanism 162, is a flexible optical cable as figure.Optical cable should have the ability of the strong infrared laser radiation of transmission in certain distance, and no optical cable itself damages or the laser energy severe attrition.
Optical cable 162 can be regarded the material that can transmit specific wavelength laser 20 single or that multi-bundle is formed as, as the blue chamber of glass stone, or other crystal.Notice in infrared wavelength range, because the loss that increase separating light beam transmission eyeglass 30 is produced is generally quite little.In addition, utilize soft hollow waveguide laser beam can be coupled to scanning device.
Preferably utilize optical cable 162 that laser 20 is connected on the operation device 200 main positions, and can be near operation device 200 flexible positioning.And it is unnecessary on an ad-hoc location.Shown in Fig. 5 (a), the laser beam that penetrates from the input hole of optical fiber 162 is converted lens 164 and receives the map that forms a delivery outlet 163.As shown in Figure 1, through 11,12,13 propagate the anterior surface of cornea that navigates to eyes 70 to local reflex mirror 50 and 60 with this map.At the operation device assembly process, the one-tenth image plane of convertible lens 164 is positioned, so that be on microscope 80 best focus plane.Optical cable 162 can be a turquoise stone product, commercial can obtaining from Saphikon company, and its product patent technology is seen United States Patent (USP) numbering 5,349,590.
The embodiment of another beam Propagation mirror 30 shown in Fig. 5 (b), the optical cable that replaces among Fig. 5 (a) with gimbal arms 166 flexibly among Fig. 5 (b).Gimbal arms 166 can be neatly around B-C, C-D, and D-E, E-F and the rotation of F-G axle, this can make things convenient for the location of laser beam 20 with respect to the main part of surgical apparatus 200.No longer need laser beam 20 to occupy certain location.Laser beam is finished by lens 168 and 170 at the optically focused and the transformation process in gimbal arms input and output hole.Its principle is actually the same with description to corresponding optical devices among Fig. 5 (a).Gimbal arms 166 can be the photoconduction arm, and its commercial product can be from DantecMeasurements Technology, and company obtains, and its patented technology is seen United States Patent (USP) numbering 4,896,015.
Another beam delivery system embodiment is that laser instrument is placed on a certain fixed position with respect to the main part operating microscope arm of operating theater instruments 200.Such layout needs certain rigid conversion device transmission ray, and needs to carry out the optics adjustment more carefully, increases extra packages limits simultaneously.Owing to such-and-such reason, beam splitting mean preferably adopts the system shown in Fig. 5 (a) and Fig. 5 (b).
Peel off (PRK) in the operation in all anaclasis, correct centering is handled and is considered to important link.The imbalance of eyes 70 can cause inhomogeneous astigmatism in the operation, and glare phenomenon reduces optic resolving power and contrast sensitivity.Therefore as previously mentioned, surgical apparatus 200 preferably should have eye tracker 100, and motion of its mensuration eye 70 and the horizontal guideline that generation is proportional to eyes 70 are with respect to the signal of the deviation of laser beam axis 14.Knopp waits people's PCT application numbers WO94/02007 to disclose the technology of relevant eye tracker, locates this as reference.
Among the figure 305, i.e. everybody eyes-affinity of knowing.The diameter of human eyes eyes-affinity is approximately 12mm, and is easy to see by circular contour, with the sclera comparison of white, can see the inherent colour of ocular tissue bottom by transparent cornea.From the front, eyes-affinity mobile and white sclera coloured or the toning border circular areas provides eyes 70 photometry contrast axial symmetry characteristics, helps eye tracking discussed here.In most preferred embodiment, redness or near-infrared light filter are installed in the detector front can be increased contrast and make Lan Se or green pupil present brown pupil on detector array 300.
Shown in Fig. 6 (a), the eyes-affinity details of being easy to act as eyes 70 most is during with respect to laser beam axis 14 centerings, and lens 320 formed eyes-affinity images are positioned at detection arrays 300 centers.Under the state of this centering, four detectors in the detection arrays 300 receive the luminous energy that equates from eyes-affinity image 305 respectively, produce zero-signal through related electronic device (among the figure not expression), signal connects to send to through 102 follows the tracks of eyeglass 60, and it is motionless to make eyeglass 60 remain on current location.
When eyes 70 during with respect to the incomplete centering of laser beam axis 14, eyes-affinity image 305 more or less produces eccentric shown in Fig. 6 (b) on the detection arrays 300.Under this eccentric state, four detecting elements of detection arrays 300 receive the luminous energy that does not wait, and above-mentioned electronic installation produces the error signal that is directly proportional with horizontal level, these error signal drives eyeglass 60 mechanisms, cause eyeglass 60 deflections, make image get back to its center.
So the function of eye tracker 100 is to keep centering condition between laser beam axis 14 and eyes 70 corneas.In this way, laser beam is applied on the cornea through light beam 14, and it is not moving to seem that eyes are in the center always.In addition, for real-time tracking, track algorithm recited above is finished once in each pulse spacing at least.In giving embodiment, each pulse width is less than 50 nanoseconds, and frequency is 100 hertz, and be 10 milliseconds interpulse period, and promptly the response time of eye tracker is preferably less than 10 milliseconds.
Being appreciated that the eye tracking that puts on eyeglass 60 one algorithm that the scanning algorithm that puts on the eyeglass 50 and explained earlier are crossed can combine is applied on the single eyeglass, as eyeglass 60.In the present embodiment, eyeglass 50 is that a fixed beam separates mirror.This structure can reduce hardware cost, but the system logic complicated operation has increased simultaneously to single eyeglass 60 angular range requirements.Use two Separator lens can reduce area requirement to each eyeglass angle, simultaneously can simplified design, make with to separating scanning, the debugging of eye tracker function.
As previously mentioned, only eye tracker 100 operate as normal are necessary for the front irradiation of eyes 70.This irradiates light is provided by the coaxial light source 120 that is installed on the microscope 80.Coaxial light source 120 is to a branch of tracking light beam 17 of eyes 70 projections.This light beam is by cornea, and bottom ocular tissue forms different reflections and scattering with sclera around the eyes-affinity 305, lens 320 with suitable amplification with their imaging on detector array 300.
In most preferred embodiment of the present invention, the wavelength of light beam 17 is selected in the near-infrared wavelength scope, about 0.8 to 1.0 micron.Human eye is very low to the sensitivity of this wavelength, so it is considerably less to reflex to the light beam 17 of microscope 80 by anterior corneal surface, can not influence the observation of doctor 55 by 80 pairs of patient's eyes of microscope.In addition, because 70 pairs of near infrared light visibilitys of human eye are low, so the near infrared light of front irradiation can not hinder patient's eye to position by visible light or the target that is installed in localizing objects equipment 90 yet.
In addition, the intensity of light source 20 can be adjusted with suitable instantaneous frequency.So that distinguish mutually with nonadjustable room environment light further, or with distinguish mutually through the laser beam 14 that carries out suitable synchronous filtering with electronic circuit.This electronic circuit is connected with detector array 300.Detector array 300 is insensitive for the infrared-ray that lasing light emitter 20 sends, so at eye tracker 100 duration of works, it will not produce reaction to laser beam 14.
Rely on tracking light beam 17 to overlap with laser beam 14 low-angles, cornea tissue takes place to following the tracks of the mirror image reflection of light beam 17 near the inside with eyes-affinity 305 CC.This reflection can not hinder eye tracking system to detect eye motion, because this reflection can be by lens 320 imaging on detector array 300.Finding at present, is being in the prior art of representative with PCT application numbers WO94/02007, uses instantaneous modulated infrared light source and select on eyes 70 corneas can represent a significant improvement from the suitable incident angle of light beam of light source 17.
Fig. 7 schematically illustrates the embodiment that is used to drive the servosystem 50 of following the tracks of eyeglass 60, also comprises the input signal and the control of being correlated with from the tracking detector 300 of eye tracker 100 inside simultaneously.In most preferred embodiment of the present invention, be marked with four detectors of 300 as Fig. 2, each all comprises unit piece PIN silicon photo-detector, based on the needs of specific function instrument, also selects the dual-element detector for use.
Come the voltage signal 301 of self-detector to deliver to amplifier 330, the signal 331 after the amplification directly enters decoder 340 along separate routes.This decoder is synchronous with the tracking light source 120 of irradiation eyes by signal 122 control moments, guarantees to have only the light of appropriate frequency could be as tracking signal.As previously mentioned, this is used for the reflected light that instantaneous discriminating is used to follow the tracks of synchronously, increases signal level under the light background around further.From the gating signal 341 of decoder output by feed-in logic circuit 510.
Each is to the arithmetic difference of detector signal, in fact is directly proportional with the displacement of visual off-center position or zero position on the respective shaft.Logic circuit 510 forms and handles deviation signal, produces control eyeglass displacement command 511 then.This displacement command is sent to servo-driver 520.Driver 520 alternately encourages the motor 550 that links to each other with eyeglass 60, thereby eyeglass 60 is rotated around axis own.In the method,, revise the angle orientation of eyeglass 60 possibly according to the needs that on two-dimensional direction, follow the trail of the objective.
Provide feedback signal to deliver to logic circuit 510 with the changer 540 that eyeglass 60 mechanically links to each other through wiring 541.Changer 540 generally comprises position sensing element, and in most preferred embodiment, it is simple, and is easy-to-use.Transmitter 540 makes that tracer element is the motion stabilization of eyeglass 60 with respect to previously selected position.In addition, when tracking eyeglass 60 reached the moving range end points, transmitter 540 was measured motion and is also incited somebody to action no longer pursuit movement.When tracker was no longer followed eye motion, computer 110 stopped the work of lasing light emitter 20, or closed shutter 40.
In most preferred embodiment, as previously mentioned, the reference position of eyeglass 60 is corresponding to the correction position of patient's sight line on the instrumental optics axle.After doctor 55 proofreaies and correct the patient, computer 110 selected these reference positions.Notice that the signal 301,521,541 that indicates to tracking eyeglass 60 from eye tracker 300 among Fig. 7 is concentrated expression by wiring 102 in Fig. 1.Note, for clarity sake, Fig. 7 four servo-drivers 520 of servosystem that only draw, transmitter 540, in the motor 550 two.
The same with most servosystem, system shown in Figure 7 be one based on the zero offset measuring system of deviation signal being recalled to zero.Except the described system of Fig. 7, also have other servo-control system, under sufficiently high speed, accurately measure and control the displacement of eyes.Such servo-control system is also included within the scope of the invention.
As previously mentioned, the cornea appearance device can be used for the measurement of assisted surgery front and back to eye shape or curvature.As long as revise the position reference target according to the present invention, anyly all can be used for this purposes at commercial available profile instrument.Additional embodiments is equipped with spatial discrimination refractometer (SRR) in this position, be used to measure the real refractive index of whole cornea.
Consider that the present invention studies the cornea profile and measures and the integrated needs of independent refractive cornea surgical method, the ability of setting up the common reference face between different ophthalmological instruments is prior.It is generally accepted, accurately measure and the refractive status of definite eyes is that any refractive surgery success is necessary.
Utilize eye system to calculate and dissect the cornea profile of making, the mensuration of perioperatively corneal profile can be provided.The nearest Other Instruments that occurs, as Orbtek, the Orbscan product of Inc company can provide the information of cornea local shape, and this is for optimizing certain type of error of refraction, and is helpful as scattered-light rectification.Then, for the repeated measurement of eyes same position, the result of apparatus measures must be consistent, and these instruments are worked effectively.In this direction, foregoing eye follows the tracks of and location technology will work, and it is unique at the patient rather than at instrument.Comprise this bearing calibration,, also allow in operation process, to measure the cornea profile, increase the operation precision to reach, the purpose of the bad variation of the prediction of eliminating the effects of the act as perioperative active feedback signal.The United States Patent (USP) of Smith, numbering No.5,350,374 have described the probability that active feedback control loop is used for operation process have been installed.This controls environment based on a kind of special cornea profile equipment.
In various embodiments, the present invention also tries hard to use the profile with various available cornea measurement device compatibilities to feed back, with many advantages in conjunction with prior art equipment, but, enlarged their scope, peeled off (PRX) operation so that comprise the mid-infrared laser refraction of using the scanning light beam transmission system.
Another profile equipment is dioptric imaging equipment, that is, usage space is differentiated refraction (SRR) method.See Webb.R.M. about going through of SRR, Murray Penny, C., Thompson, K.P., " Measurement of Ocular Local Wavefront Distortion With aSpahally Resolved Refractometer " the Applied Opfice that writes, 31,19,3678-3686 (1992).Refractometer (SRR) utilizes the patient to proofread and correct the refractive index of cornea every bit on two stationary source point measurement pupils by aperture.By cornea, this aperture is converted map to the cornea every bit that reflects measurement respectively.Because the purpose that anaclasis is peeled off is to correct patient's error of refraction, is ideal input so refractometer (SRR) map is peeled off (PRK) system for anaclasis, it has improved the refractometry in the refraction passage and the power map of profile system.These preoperative input data can help to determine lift-off profile and pattern that in addition, refractometer (SRR) is used for to the eyes map at intra-operative.
Certainly, embodiment given here and various explanation, explanation are the elaboration to the principle of the invention.This professional those of ordinary skill can not exceed scope of the present invention, does not also violate under the situation of spirit of the present invention and carries out various modifications.
Claims (43)
1. peel off the method for patient's cornea tissue, it is characterized in that this method may further comprise the steps:
Produce the laser beam pulsed light beam of peel angle membrane tissue, this light beam is middle infrared-ray, and wavelength is approximately the cornea absorption peak, and
The sector scanning that makes described light beam cross described cornea tissue with predetermined pattern.
2. according to the method for claim 1, it is characterized in that peeling off described cornea tissue is for revising the curvature of described cornea.
3. according to the method for claim 1, it is characterized in that peeling off described cornea tissue is to change treatment means.
4. according to the method for claim 1, it is characterized in that its pulse width of described pulse laser beam is few less than 50 millimicros.
5. according to the method for claim 1, it is characterized in that described pulse laser beam causes photospallation, so that divest a part of cornea tissue.
6. according to the method for claim 1, it is characterized in that described pulse laser beam is is 2.94 microns infrared-ray by the wavelength that the erbium YAG laser produces.
7. according to the method for claim 1, it is characterized in that described pulse laser beam be the scope of solid state laser emission at 1 to 2 micron ray, and also comprise and with optical parametric oscillator described ray shift frequency be approximately 3 microns step to wavelength.
8. according to the method for claim 1, it is characterized in that described pulse laser beam is the infrared ray ray of wavelength in 2.7 to 3.1 micrometer ranges that solid state laser produces.
9. according to the method for claim 1, it is characterized in that also comprising that the motion of following the tracks of eyes shines directly into the step of described cornea tissue to guarantee described light beam.
10. according to the method for claim 1, it is characterized in that also comprising and utilize the two point technique for fixing that described patient's sight line is registered to the step of being scheduled on the optical axis.
11., it is characterized in that described light beam scans to finish, on cornea tissue so that reduce the indirect injury of eyes with discontinuous manner according to the method for claim 1.
12., it is characterized in that the energy of described light beam pulse arrives between about 30mJ at about 5mJ according to the method for claim 1.
13., it is characterized in that described scanning step utilizes size at the about 0.3mm luminous point in about 2mm scope according to the method for claim 1.
14., it is characterized in that further comprising the steps of: utilize the interior cornea outline devices of machine to carry out the mensuration of cornea tissue shape according to the method for claim 1.
15. according to the method for claim 1, it is characterized in that peeling off described cornea so that change the eyes refracting characteristic, and, further comprising the steps of: as to utilize the spatial discrimination refractometer to measure the refractive index of cornea tissue.
16. from the armarium of patient's eye removing corneal tissue tissue, it is characterized in that described equipment comprises: produce the lasing light emitter of intermediate infrared radiation pulse, the wavelength of described infra-red radiation is approximately corresponding to the absorption peak of cornea,
Described scan deflection device, it makes the pulse ray scan described cornea tissue with predetermined pattern.
17. according to the equipment of claim 16, it is characterized in that peeling off described cornea tissue is in order to revise corneal curvature.
18., it is characterized in that peeling off described cornea tissue and be purpose in order to treat according to the equipment of claim 16.
19., it is characterized in that described pulse has the width less than 50 nanoseconds according to the equipment of claim 16.
20., it is characterized in that also comprising the eye tracking apparatus of the motion that is used for measuring and compensate eyes according to the equipment of claim 16.
21., it is characterized in that also comprising the two point fixed system that is used for described patient's sight line and described equipment optical axis alignment according to the equipment of claim 16.
22., it is characterized in that described lasing light emitter being coupled to described scan deflection device by the decoupling transmission laser system according to the equipment of claim 16.
23., it is characterized in that described pulse ray causes photospallation, to remove the described cornea tissue of part according to the equipment of claim 16.
24., it is characterized in that described lasing light emitter is that the generation wavelength is the erbium YAG laser of 2.94 microns infrared-rays according to the equipment of claim 16.
25. according to the equipment of claim 16, it is characterized in that described pulsed light beam is produced at 1 to 2 micron ray solid state laser by transmitting boundary, and described equipment comprises also and being used for described ray shift frequency to the optical parametric oscillator that is approximately 3 micron wave lengths.
26., it is characterized in that described lasing light emitter is that the generation wavelength is the solid state laser of 2.7 to 3.1 micrometer ranges according to the equipment of claim 16.
27. according to the equipment of claim 16, the energy that it is characterized in that described pulse at about 5mJ between the 30mJ.
28., it is characterized in that described scan deflection device produces size at the scope luminous point of about 0.3mm to 2mm according to the equipment of claim 16.
29., it is characterized in that also comprising the cornea profile equipment of the shape that is used to measure cornea tissue according to the equipment of claim 16.
30. according to the equipment of claim 16, it is characterized in that peeling off described cornea tissue and be in order to change the eyes refracting characteristic, and described equipment also comprises the spatial discrimination refractometer of the refractive index that is used to measure described cornea tissue.
31. follow the tracks of the method for patient's eye motion in the operation process, described operation process comprises laser beam is directly projected step on the described eyes, it is characterized in that said method comprising the steps of:
Shine a certain zone of described eyes with tracking illumination, wherein described tracking illumination and described laser beam can be distinguished.
The optical image of described characteristic is focused on the detector means, discern described tracking eyes characteristic by detecting the visual contrast that goes up above the part of reservation threshold, described checkout gear contains the array of detecting element, described array comprise with the eyes characteristic be the center, across at least two detecting elements of first, and with the eyes characteristic be the center, across at least two detecting elements perpendicular to first axis
When described checkout gear and described eyes characteristic roughly during centering, produce zero-signal,
When described eyes characteristic and described checkout gear misalign, produce and be proportional to respect to institute
When described eyes characteristic and described checkout gear misalign, produce the signal that is proportional to respect to the deviation of the alignment of the described checkout gear of described eyes characteristic, and
Utilize described deviation signal to keep between the optical axis of described laser beam and the described eyes the roughly state of centering.
32. method according to claim 31, it is characterized in that described laser beam utilizes at least one optical glass that described laser beam is projected on the described eyes, and described utilize deviation signal to keep roughly the step of centering state comprises according to the step that requires the described eyeglass of deflection that described laser beam is projected on the described eyes.
33., it is characterized in that the step of the described eyeglass of described deflection comprises that SERVO CONTROL moves the step that eyeglass relocates according to the method for claim 31.
34. according to the method for claim 31, described illumination step is included on the axis direction step to described eye illumination.
35., it is characterized in that its wave-length coverage of described tracking illumination at about 0.8 micron to 1.0 microns, and laser beam has the mid-infrared light wavelength according to the method for claim 31.
36., it is characterized in that further comprising the steps of according to the method for claim 31:
Modulate described tracking illumination with preset frequency, and make that described light image is focused on the step and the described preset frequency of described checkout gear is synchronous, so that further distinguish described illumination light and surround lighting and described laser beam.
37., it is characterized in that described imaging feature is the intersection of the sub-circular of cornea and sclera according to the method for claim 31.
38., it is characterized in that further comprising the steps of: one or more red filters are installed with enhancing contrast ratio in the checkout gear front according to the method for claim 31.
39., it is characterized in that further comprising the steps of: one or more near-infrared light filters are installed with enhancing contrast ratio in the checkout gear front according to the method for claim 31.
40. according to the method for claim 31, it is characterized in that described laser beam is a pulse laser beam, described pulse has the pulse spacing less than 10 milliseconds, described generation deviation signal also keeps carrying out once in per at least 10 milliseconds of the step of centering state with it.
41. follow the tracks of the device of patient's eye motion at intra-operative, described operation process comprises laser beam is projected described eyes, it is characterized in that described device comprises:
Be used for the light source to the area illumination of described eyes, described light source produces the tracking illumination that can distinguish with described laser beam,
Be used to receive the detector array of eye feature light image, in described optical image, distinguish described eye feature with respect to the contrast of the background parts of described image according to described feature, described detector means comprises the detecting element array, described array comprise with the eyes characteristic be the center, across at least two detecting elements of first, and be the center with the eye feature, across at least two detecting elements perpendicular to first axis
Be used for roughly sending during centering the device of zero-signal when eye feature and checkout gear,
Be used for sending when eye feature and checkout gear roughly misalign the device of deviation signal, described signal is proportional to the deviation of the alignment of described eye feature with respect to described checkout gear, and
Be used for keeping between described laser beam optical axis and the described eyes optical axis the roughly device of centering according to described deviation signal.
42. according to the device of claim 41, it is characterized in that its wave-length coverage of described tracking illumination from about 0.8 micron to about 1.0 microns, described laser beam has middle infrared wavelength.
43. according to the device of claim 41, it is characterized in that also comprising device, and make described checkout gear and described preset frequency synchronously so that further distinguish described tracking illumination and surrounding environment light and described laser beam with preset frequency modulation tracking illumination.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96122077 CN1160530A (en) | 1995-10-27 | 1996-10-25 | Method and apparatus for removing corneal tissue with infrared laser radiation |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US549,385 | 1995-10-27 | ||
| CN 96122077 CN1160530A (en) | 1995-10-27 | 1996-10-25 | Method and apparatus for removing corneal tissue with infrared laser radiation |
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| Publication Number | Publication Date |
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| CN1160530A true CN1160530A (en) | 1997-10-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96122077 Pending CN1160530A (en) | 1995-10-27 | 1996-10-25 | Method and apparatus for removing corneal tissue with infrared laser radiation |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100463664C (en) * | 2004-08-23 | 2009-02-25 | 瑞杰夫·劳特 | Incising cell to basement membrane bonds |
| CN1794945B (en) * | 2003-03-24 | 2010-11-03 | 博士伦公司 | Apparatus for eye alignment |
| CN103889375A (en) * | 2011-10-10 | 2014-06-25 | 威孚莱有限公司 | Device and process for surgery on the human eye |
| CN103892959A (en) * | 2009-05-26 | 2014-07-02 | 威孚莱有限公司 | System for ophthalmic laser surgery |
| CN111801065A (en) * | 2018-01-25 | 2020-10-20 | 克拉诺瓦公司 | Apparatus and method for controlling movement of an eye treatment apparatus comprising an articulating support arm |
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1996
- 1996-10-25 CN CN 96122077 patent/CN1160530A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1794945B (en) * | 2003-03-24 | 2010-11-03 | 博士伦公司 | Apparatus for eye alignment |
| CN100463664C (en) * | 2004-08-23 | 2009-02-25 | 瑞杰夫·劳特 | Incising cell to basement membrane bonds |
| CN103892959A (en) * | 2009-05-26 | 2014-07-02 | 威孚莱有限公司 | System for ophthalmic laser surgery |
| CN103892959B (en) * | 2009-05-26 | 2016-04-06 | 视乐有限公司 | For the system of ophthalmology laser surgery |
| CN103889375A (en) * | 2011-10-10 | 2014-06-25 | 威孚莱有限公司 | Device and process for surgery on the human eye |
| CN103889375B (en) * | 2011-10-10 | 2016-08-24 | 视乐有限公司 | For the operating apparatus and method of human eye |
| CN111801065A (en) * | 2018-01-25 | 2020-10-20 | 克拉诺瓦公司 | Apparatus and method for controlling movement of an eye treatment apparatus comprising an articulating support arm |
| CN111801065B (en) * | 2018-01-25 | 2023-08-11 | 克拉诺瓦公司 | Apparatus and method for controlling movement of an ocular treatment instrument comprising an articulating support arm |
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