CA2791803A1 - Apparatus for the weight-compensating movable suspension of a focussing objective of a laser device - Google Patents
Apparatus for the weight-compensating movable suspension of a focussing objective of a laser device Download PDFInfo
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- CA2791803A1 CA2791803A1 CA2791803A CA2791803A CA2791803A1 CA 2791803 A1 CA2791803 A1 CA 2791803A1 CA 2791803 A CA2791803 A CA 2791803A CA 2791803 A CA2791803 A CA 2791803A CA 2791803 A1 CA2791803 A1 CA 2791803A1
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F9/00—Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
- A61F9/007—Methods or devices for eye surgery
- A61F9/008—Methods or devices for eye surgery using laser
- A61F9/00825—Methods or devices for eye surgery using laser for photodisruption
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
- A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/50—Supports for surgical instruments, e.g. articulated arms
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/50—Supports for surgical instruments, e.g. articulated arms
- A61B2090/5025—Supports for surgical instruments, e.g. articulated arms with a counter-balancing mechanism
- A61B2090/504—Supports for surgical instruments, e.g. articulated arms with a counter-balancing mechanism with a counterweight
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F9/00—Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
- A61F9/007—Methods or devices for eye surgery
- A61F9/008—Methods or devices for eye surgery using laser
- A61F2009/00861—Methods or devices for eye surgery using laser adapted for treatment at a particular location
- A61F2009/00872—Cornea
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- Laser Surgery Devices (AREA)
- Microscoopes, Condenser (AREA)
- Radiation-Therapy Devices (AREA)
- Telescopes (AREA)
- Optical Communication System (AREA)
- Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
- Optical Couplings Of Light Guides (AREA)
- Lenses (AREA)
Abstract
An apparatus for the weight-compensating movable suspension of a focussing objective (12) of a laser device (10) comprises a force generating arrangement for generating a counterforce component (G) counteracting the weight force of the focussing objective (12), a transmitting arrangement that transmits the counterforce component (G) to the focussing objective (12) and as an up/down compensation movement of the focussing objective, and a guide arrangement for movably guiding the focussing objective, in such a way that during an up/down compensation movement of the focussing objective (12) an optical axis (O) thereof maintains at least its spatial orientation and preferably its spatial position.
Description
Apparatus for the weight-compensating movable suspension of a focussing objective of a laser device The invention concerns movable weight-compensating suspension of a focussing objective of a laser system. The laser system preferably provides pulsed laser radiation, which is focussed by means of the focussing objective onto a desired location where the radiation is to act.
Movable weight-compensating suspension of the focussing objective is desired, not exclusively but above all, where treatment of living tissue is involved, and there is direct contact between the tissue and the laser system. Such direct contact is often produced, for example, in the case of operations on the human eye using laser surgery, when incisions in the cornea or other parts of the eye are to be made using ultra-short pulses of laser radiation. In this case, direct contact is intended to ensure precise positioning of the eye to be treated relative to the laser system in the direction of propagation of the radiation. Usually, a suitable interface unit (patient adapter) is connected in front of the focussing objective, and effects the physical coupling of the eye to the laser system.
The interface unit usually has a holder, which is coupled to the focussing objective, for a contact element which is to be brought into contact with the eye and is made of a material which is transparent to the laser radiation. The contact ele-ment can, for example, be a plane underside for applanation of the cornea.
Focussing objectives in laser systems are often multi-lens systems, which can put considerable weight on the scales. Several kilograms are not unusual for such focussing objectives. Obviously, in an eye operation the full weight of the focussing objective must not rest on the eye being treated. Weight-compensating suspension for the focussing objective is therefore provided. The force which the focussing objective still exerts on the eye in the case of such a weight-compensating solution is reduced to a few newtons (e.g. 1 to 2 N), for example. This makes it possible to deflect the focussing objective upward, gently and not dangerously to the eye, if the patient suddenly happens to raise his or her head involuntarily, e.g. in a panic reaction.
An example of weight-compensating suspension of a focussing objective is given in US 5,336,215. There the weight of the objective is compensated for by a spring system, by means of which the objective is movably suspended in a frame relative to the latter.
Movable weight-compensating suspension of the focussing objective is desired, not exclusively but above all, where treatment of living tissue is involved, and there is direct contact between the tissue and the laser system. Such direct contact is often produced, for example, in the case of operations on the human eye using laser surgery, when incisions in the cornea or other parts of the eye are to be made using ultra-short pulses of laser radiation. In this case, direct contact is intended to ensure precise positioning of the eye to be treated relative to the laser system in the direction of propagation of the radiation. Usually, a suitable interface unit (patient adapter) is connected in front of the focussing objective, and effects the physical coupling of the eye to the laser system.
The interface unit usually has a holder, which is coupled to the focussing objective, for a contact element which is to be brought into contact with the eye and is made of a material which is transparent to the laser radiation. The contact ele-ment can, for example, be a plane underside for applanation of the cornea.
Focussing objectives in laser systems are often multi-lens systems, which can put considerable weight on the scales. Several kilograms are not unusual for such focussing objectives. Obviously, in an eye operation the full weight of the focussing objective must not rest on the eye being treated. Weight-compensating suspension for the focussing objective is therefore provided. The force which the focussing objective still exerts on the eye in the case of such a weight-compensating solution is reduced to a few newtons (e.g. 1 to 2 N), for example. This makes it possible to deflect the focussing objective upward, gently and not dangerously to the eye, if the patient suddenly happens to raise his or her head involuntarily, e.g. in a panic reaction.
An example of weight-compensating suspension of a focussing objective is given in US 5,336,215. There the weight of the objective is compensated for by a spring system, by means of which the objective is movably suspended in a frame relative to the latter.
-2-It is an object of the invention to give a reliably and precisely functioning solu-tion for weight compensation of a focussing objective in a laser system.
According to the invention, for this purpose movable weight-compensating sus-pension of a focussing objective of a laser system is provided, comprising:
- a force generation device to generate a counterforce component which coun-teracts the weight of the focussing objective, - a transmission device which transmits the counterforce component onto the focussing objective and permits upward/downward compensatory movement of the focussing objective, and - a guidance device for movable guidance of the focussing objective, in such a way that in the case of an upward/downward compensatory movement of the focussing objective, an optical axis of the focussing objective maintains at least its orientation in space, and preferably its position in space.
Guidance of the focussing objective through the guidance device prevents unde-sired tilting of the optical axis of the objective in the case of an up-ward/downward compensatory movement of the objective. "Upward/downward compensatory movement" is understood here as a movement of the focussing objective upward or downward relative to the laser system. Thus despite a com-pensatory movement of the objective, the optical axis remains in a specified orientation to the object which is being treated, e.g. to the optical axis of a hu-man eye which is being treated. It should be pointed out here that the invention can in principle be used with laser systems for any application purposes, and in particular for working on any materials (including dead matter), and is by no means restricted to ophthalmological application purposes.
The force generation device can include a counterweight, the mass of which is used to generate at least part, and in particular the whole, of the counterforce component. The counterweight can consist of a single counterweight member, or alternatively can consist of multiple (at least two) individual weight members, which for example can be used in changeable numbers or/and in changeable position relative to each other. The individual weight members can also be com-bined into a single total weight, and taken individually out of the total weight. By such variabilities of the counterweight, specially precise taring of the weight compensation is possible.
According to the invention, for this purpose movable weight-compensating sus-pension of a focussing objective of a laser system is provided, comprising:
- a force generation device to generate a counterforce component which coun-teracts the weight of the focussing objective, - a transmission device which transmits the counterforce component onto the focussing objective and permits upward/downward compensatory movement of the focussing objective, and - a guidance device for movable guidance of the focussing objective, in such a way that in the case of an upward/downward compensatory movement of the focussing objective, an optical axis of the focussing objective maintains at least its orientation in space, and preferably its position in space.
Guidance of the focussing objective through the guidance device prevents unde-sired tilting of the optical axis of the objective in the case of an up-ward/downward compensatory movement of the objective. "Upward/downward compensatory movement" is understood here as a movement of the focussing objective upward or downward relative to the laser system. Thus despite a com-pensatory movement of the objective, the optical axis remains in a specified orientation to the object which is being treated, e.g. to the optical axis of a hu-man eye which is being treated. It should be pointed out here that the invention can in principle be used with laser systems for any application purposes, and in particular for working on any materials (including dead matter), and is by no means restricted to ophthalmological application purposes.
The force generation device can include a counterweight, the mass of which is used to generate at least part, and in particular the whole, of the counterforce component. The counterweight can consist of a single counterweight member, or alternatively can consist of multiple (at least two) individual weight members, which for example can be used in changeable numbers or/and in changeable position relative to each other. The individual weight members can also be com-bined into a single total weight, and taken individually out of the total weight. By such variabilities of the counterweight, specially precise taring of the weight compensation is possible.
-3-Moreover, within the invention, generating part of the counterforce component by means of at least one elastic element should not be excluded. Because of the disadvantage, which is often associated with elastic elements, that the effective force depends on the distance (the elasticity depends on the state of deforma-tion of the elastic element), the force generation device preferably does not generate the counterforce component exclusively by means of elastic elements.
However, combining one or more elastic elements with a counterweight is also conceivable, e.g. to implement a desired force-distance dependency intention-ally.
The transmission device is preferably in the form of a rocker, on one side of which the counterforce component acts, and on the other side of which the weight of the focussing objective acts. Functionally, the rocker can be compared with a weighing beam.
For example, the rocker is formed of at least one lever body, one lever arm of which is connected to the focussing objective, and the other lever arm of which is connected to the force generation device. It is understood that two or more such lever bodies can be provided adjacently, parallel and at a distance, to form the rocker. A force application point of the force generation device on the lever body can be adjustable along it, so as to adjust the torque acting on the lever body. In general, preferably at least one force application point of the force generation device on the rocker can be adjusted with respect to its distance from a swivelling axis of the rocker.
Use of a counterweight which is applied on one side of the rocker (i.e. on one lever arm) to generate at least part of the counterforce component has the ad-vantage of the maximum possible constancy of the generated counterforce com-ponent over the whole operationally required movement travel of the focussing objective. By intentional displacement of the centre of gravity of the counter-weight relative to the rocker, the force-distance characteristic curve of the sus-pension apparatus can be set definitively. This makes taring possible even with an indivisible counterweight. On the other hand, if the force generation device includes at least one elastic element, the force-distance characteristic curve of the suspension apparatus can be set in addition to the typically spring-like force-distance characteristic of the elastic element, because the force application point of the elastic element is movable along the lever or along the rocker.
However, combining one or more elastic elements with a counterweight is also conceivable, e.g. to implement a desired force-distance dependency intention-ally.
The transmission device is preferably in the form of a rocker, on one side of which the counterforce component acts, and on the other side of which the weight of the focussing objective acts. Functionally, the rocker can be compared with a weighing beam.
For example, the rocker is formed of at least one lever body, one lever arm of which is connected to the focussing objective, and the other lever arm of which is connected to the force generation device. It is understood that two or more such lever bodies can be provided adjacently, parallel and at a distance, to form the rocker. A force application point of the force generation device on the lever body can be adjustable along it, so as to adjust the torque acting on the lever body. In general, preferably at least one force application point of the force generation device on the rocker can be adjusted with respect to its distance from a swivelling axis of the rocker.
Use of a counterweight which is applied on one side of the rocker (i.e. on one lever arm) to generate at least part of the counterforce component has the ad-vantage of the maximum possible constancy of the generated counterforce com-ponent over the whole operationally required movement travel of the focussing objective. By intentional displacement of the centre of gravity of the counter-weight relative to the rocker, the force-distance characteristic curve of the sus-pension apparatus can be set definitively. This makes taring possible even with an indivisible counterweight. On the other hand, if the force generation device includes at least one elastic element, the force-distance characteristic curve of the suspension apparatus can be set in addition to the typically spring-like force-distance characteristic of the elastic element, because the force application point of the elastic element is movable along the lever or along the rocker.
-4-The focussing objective is preferably supported on the rocker so that it can ro-tate relative to the rocker around an axis of rotation which runs parallel to a swivelling axis of the rocker at a distance. It is recommended, for spatial posi-tional stability of the optical axis of the objective, that the support of the focus-sing objective on the rocker is at a variable distance to the swivelling axis of the rocker. If the rocker is tilted, the focussing objective can then carry out a simul-taneous movement, meaning a change of distance from the rocker axis. In this way the objective can move up and down along a straight line instead of along a circular path, i.e. it maintains its transverse position (transverse means orthogo-1o nal to the objective axis) relative to the object being worked on.
The swivelling bearing of the rocker is preferably of low-friction form, and can for example be implemented by means of a plastic sliding bearing or a rolling bearing. Low friction is a desirable aim, to avoid, as far as possible, falsification of the effective force-distance characteristic of the suspension apparatus by overlaid friction forces.
In a preferred embodiment, the focussing objective is supported on a supporting surface arrangement of the rocker so that it can move freely. In particular, the supporting surface arrangement can be in such a form that the objective can be placed loosely on the rocker. The supporting surface arrangement can, for ex-ample, be formed of at least one longitudinal recess - into which the objective can be inserted with a suitable supporting pin or other supporting formation -of at least one lever body of the rocker. For example, the recess can be open up-ward, or/and it can - in relation to the longitudinal extent of the relevant lever arm, on which the objective grips - be open to the front or rear, so that the supporting formation of the objective can be inserted from the front or rear into the recess.
It is understood that the supporting surface arrangement can alternatively, for example, be in the form of an arrangement of one or more enclosed long holes, the objective engaging with each long hole by a suitable supporting projection.
It is also understood that according to a modification, the supporting surface arrangement can be formed on the objective, and suitable supporting formations for support on the supporting surface arrangement can be formed on the rocker.
In any case, the support of the objective on the rocker is preferably such that not only rotation of the objective relative to the rocker in the course of a swivel-ling movement of the rocker is made possible, but also a radial change of the distance between the axis of rotation of the objective and the rocker axis (ra-dially in relation to the rocker axis).
The guidance device is preferably in the form of a linear guide with a parallel guidance direction to the optical axis of the focussing objective. It preferably has guidance formations which prevent movements of the focussing objective trans-versely to the optical axis in the case of an upward/downward compensatory movement of the focussing objective. This is useful for stabilising the position of the objective in space.
For example, the guidance device can include a linear bearing and a slide which is guided in it. The slide can be fixed on the focussing objective. The linear bear-ing can also include at least one guidance groove. The slide can also include at least one guidance projection, which is set up to work with the guidance groove in such a way that movement of the slide in a horizontal direction is avoided.
In this way, guidance of the focussing objective in a vertical direction is made pos-sible, the optical axis of the focussing objective being able to maintain its align-ment and position in the case of a compensatory movement of it relative to an initial position. For this purpose, the guidance groove can be formed with an undercut, into which the guidance projection engages.
According to another point of view, the invention provides a laser system, com-prising:
- a laser radiation source, preferably of pulsed laser radiation, - a focussing objective for focussing the laser radiation, the focussing objective having an optical axis, - an interface unit, which is arranged on the radiation exit side of the focussing objective and is preferably separably coupled to it, with a contact element, which is transparent to the laser radiation, for placing on an object on which work is to be done using the laser radiation, - a suspension apparatus, in particular of the type described above, for movable weight-compensating suspension of the focussing objective, this apparatus hav-ing a rocker, with two rocker arms, which is supported on a housing member so that it can be swivelled around a rocker axis of the laser system, the focussing objective being supported on one of the rocker arms so that it can rotate relative to the rocker around a parallel axis of rotation to the rocker axis, and on the other rocker arm a counterweight to generate a counterforce component which compensates for at least a predominant part of the weight of the focussing ob-jective being attached, and the apparatus also having a guidance system for linearly movable guidance of the focussing objective along the optical axis thereof.
The invention is further explained below, on the basis of the attached drawing.
Fig. 1 shows, schematically and not at all to scale, an embodiment of a laser system for making incisions in the cornea or other tissue parts of a human eye.
Of the laser system, which as whole is marked with 10, only the "output stage"
is shown in the drawing, i.e. essentially only a focussing objective 12 with a patient adapter 13 arranged on the radiation exit side of it. The focussing objec-tive 12 is weight-compensated and movably suspended by a suspension appara-tus 14. If "weight compensation" is mentioned here, it means compensation for at least a predominant part of the weight of the objective 12. A particularly small residual part of the objective weight can remain without compensation, e.g. of the order of magnitude of a few newtons of weight. The focussing objective 12 focusses, in a way which is not shown in more detail, an afocal beam of rays of the laser radiation provided by the laser system 10 onto a focus location within the eye tissue to be cut. The laser radiation which is used has, for example, pulse durations in the femtosecond range, and a wavelength in the low infrared range (e.g. between approx. 1000 and approx. 1100 nm), or in the UV range, preferably above about 300 nm.
The suspension apparatus 14, in the shown embodiment of Fig. 1, has a force generation arrangement with a counterweight 16, which generates a vertically directed weight component 6, with which it is intended that the weight of the focussing objective 12 should be at least partly compensated for. The suspen-sion apparatus 14 also includes a transmission arrangement in the form of a rocker 18, which at its right-hand end in Fig. 1 is separably joined to the coun-terweight 16, whereas at its other, left-hand end in Fig. 1 it has a bearing seat 20 for separable coupling with the focussing objective 12. The counterweight can be shifted along the appropriate lever arm of the rocker, so that the effec-tive force application point K of the counterweight, and thus the effective counterforce moment, can be changed.
The rocker 18 is carried by a bearing 22 so that it can rotate around a swivelling axis X at a distance between the points of application of the objective 12 and of the counterweight 16. The bearing 22 supports the rocker 18, via one or more connecting cheeks 21, on a schematically indicated supporting part 23, which itself can be arranged stationarily or movably relative to other components of the laser system 10.
The rocker 18 can have, for example, an oblong, in particular essentially straight lever rod 19, which at one of its ends is coupled to the objective 12, and at its other end is coupled to the counterweight 16. Purposefully, two such lever rods 19 are provided, parallel to each other, on both sides of the objective 12 (i.e.
behind and in front of the objective 12 in the viewing direction of Fig. 1).
How-ever, in the further description only one lever rod will be mentioned, but the following explanations apply analogously to both lever rods.
In the shown example, the above-mentioned bearing seat 20 is formed by a laterally made recess 24 of the lever rod 19 (indicated by a dotted line), which is open on more than one side, that is upward and to the left in the figure. The floor 24a of this recess 24 forms a supporting surface for a vertical journal which stands laterally away from the objective 12 and projects into the recess.
The focussing objective 12 rests loosely on the lever rod 19 via its vertical jour-nal 26. If the rocker 18 is swivelled, not only is the objective 12 rotated around the journal axis relative to the rocker 18, but also the vertical journal 26 is dis-placed within the bearing seat 20. With this displacement, the radial distance of the vertical journal 26 from the swivelling axis X changes. This makes it possible, despite upward or downward movement of the objective 12, to keep the position and orientation of an optical objective axis 0 in space unchanged. So that the displacement of the vertical journal 26 in the bearing seat 20 takes place without friction as far as possible, for example the vertical journal 26 can carry a ring 28, which can roll on the floor 24a of the recess 24, on a sliding or rolling bearing.
The suspension apparatus 14 also includes a guidance system for vertical linear guidance of the focussing objective 12. Whereas the possibility of displacing the vertical journal 26 in the bearing seat 20 creates the precondition for a constant position in space of the objective axis 0 when the objective 12 moves, the guid-ance system ensures that the objective axis 0 is actually not tilted or displaced transversely (to the axis 0).
The guidance system, in the shown embodiment, includes a linear bearing 30 which is fixed relative to the focussing objective 12, and a slide 32 which is guided on it and fixed on the focussing objective 12. The linear bearing 30 is provided with a guidance groove 34, which is in the form of an undercut and engages with a guidance projection 36 of the slide 32. The guidance projection 36 is T-shaped in cross-section in the embodiment shown in Fig. 1, the two T
side arms 36a of the guidance projection 36 engaging with the undercut guid-ance groove 34 in such a way that a horizontal (transverse) movement of the focussing objective 12 away from the linear bearing 30 (to the right in Fig.
1) is prevented. Additionally, the engagement of the T side arms 36a with the under-cut guidance groove 34 ensures that the focussing objective 12 does not tilt.
It is always held by the guidance arrangement in a specified orientation.
The engagement of the guidance projection 36 with the guidance groove 34 provides sufficient vertical play to ensure the necessary movement travel of the focussing objective 12 in the vertical direction.
If the focussing objective 12, with its patient adapter 13, is placed on the eye (not shown) to be treated, the focussing objective 12 can be deflected vertically upward by a slight counter-pressure caused by the eye. In the case of this com-pensatory movement of the focussing objective 12, the vertical journal 26 shifts by rolling (or alternatively sliding) along the floor 24a of the recess 24, while the rocker 18 rotates clockwise around the rocker axis X, and simultaneously the objective 12 rotates relative to the rocker 18 around the axis of the vertical journal 26. In contrast, if, in an imaginary hypothetical case, the focussing ob-jective 12 was joined rigidly to the rocker 18, an upward or downward move-ment of the focussing objective 12 would result in tilting the optical axis 0.
However, in the shown embodiment, such tilting is excluded, because of the movable support of the objective 12 on the rocker 18, and because of the linear guidance of the objective 12 by the linear bearing 30.
The swivelling bearing of the rocker is preferably of low-friction form, and can for example be implemented by means of a plastic sliding bearing or a rolling bearing. Low friction is a desirable aim, to avoid, as far as possible, falsification of the effective force-distance characteristic of the suspension apparatus by overlaid friction forces.
In a preferred embodiment, the focussing objective is supported on a supporting surface arrangement of the rocker so that it can move freely. In particular, the supporting surface arrangement can be in such a form that the objective can be placed loosely on the rocker. The supporting surface arrangement can, for ex-ample, be formed of at least one longitudinal recess - into which the objective can be inserted with a suitable supporting pin or other supporting formation -of at least one lever body of the rocker. For example, the recess can be open up-ward, or/and it can - in relation to the longitudinal extent of the relevant lever arm, on which the objective grips - be open to the front or rear, so that the supporting formation of the objective can be inserted from the front or rear into the recess.
It is understood that the supporting surface arrangement can alternatively, for example, be in the form of an arrangement of one or more enclosed long holes, the objective engaging with each long hole by a suitable supporting projection.
It is also understood that according to a modification, the supporting surface arrangement can be formed on the objective, and suitable supporting formations for support on the supporting surface arrangement can be formed on the rocker.
In any case, the support of the objective on the rocker is preferably such that not only rotation of the objective relative to the rocker in the course of a swivel-ling movement of the rocker is made possible, but also a radial change of the distance between the axis of rotation of the objective and the rocker axis (ra-dially in relation to the rocker axis).
The guidance device is preferably in the form of a linear guide with a parallel guidance direction to the optical axis of the focussing objective. It preferably has guidance formations which prevent movements of the focussing objective trans-versely to the optical axis in the case of an upward/downward compensatory movement of the focussing objective. This is useful for stabilising the position of the objective in space.
For example, the guidance device can include a linear bearing and a slide which is guided in it. The slide can be fixed on the focussing objective. The linear bear-ing can also include at least one guidance groove. The slide can also include at least one guidance projection, which is set up to work with the guidance groove in such a way that movement of the slide in a horizontal direction is avoided.
In this way, guidance of the focussing objective in a vertical direction is made pos-sible, the optical axis of the focussing objective being able to maintain its align-ment and position in the case of a compensatory movement of it relative to an initial position. For this purpose, the guidance groove can be formed with an undercut, into which the guidance projection engages.
According to another point of view, the invention provides a laser system, com-prising:
- a laser radiation source, preferably of pulsed laser radiation, - a focussing objective for focussing the laser radiation, the focussing objective having an optical axis, - an interface unit, which is arranged on the radiation exit side of the focussing objective and is preferably separably coupled to it, with a contact element, which is transparent to the laser radiation, for placing on an object on which work is to be done using the laser radiation, - a suspension apparatus, in particular of the type described above, for movable weight-compensating suspension of the focussing objective, this apparatus hav-ing a rocker, with two rocker arms, which is supported on a housing member so that it can be swivelled around a rocker axis of the laser system, the focussing objective being supported on one of the rocker arms so that it can rotate relative to the rocker around a parallel axis of rotation to the rocker axis, and on the other rocker arm a counterweight to generate a counterforce component which compensates for at least a predominant part of the weight of the focussing ob-jective being attached, and the apparatus also having a guidance system for linearly movable guidance of the focussing objective along the optical axis thereof.
The invention is further explained below, on the basis of the attached drawing.
Fig. 1 shows, schematically and not at all to scale, an embodiment of a laser system for making incisions in the cornea or other tissue parts of a human eye.
Of the laser system, which as whole is marked with 10, only the "output stage"
is shown in the drawing, i.e. essentially only a focussing objective 12 with a patient adapter 13 arranged on the radiation exit side of it. The focussing objec-tive 12 is weight-compensated and movably suspended by a suspension appara-tus 14. If "weight compensation" is mentioned here, it means compensation for at least a predominant part of the weight of the objective 12. A particularly small residual part of the objective weight can remain without compensation, e.g. of the order of magnitude of a few newtons of weight. The focussing objective 12 focusses, in a way which is not shown in more detail, an afocal beam of rays of the laser radiation provided by the laser system 10 onto a focus location within the eye tissue to be cut. The laser radiation which is used has, for example, pulse durations in the femtosecond range, and a wavelength in the low infrared range (e.g. between approx. 1000 and approx. 1100 nm), or in the UV range, preferably above about 300 nm.
The suspension apparatus 14, in the shown embodiment of Fig. 1, has a force generation arrangement with a counterweight 16, which generates a vertically directed weight component 6, with which it is intended that the weight of the focussing objective 12 should be at least partly compensated for. The suspen-sion apparatus 14 also includes a transmission arrangement in the form of a rocker 18, which at its right-hand end in Fig. 1 is separably joined to the coun-terweight 16, whereas at its other, left-hand end in Fig. 1 it has a bearing seat 20 for separable coupling with the focussing objective 12. The counterweight can be shifted along the appropriate lever arm of the rocker, so that the effec-tive force application point K of the counterweight, and thus the effective counterforce moment, can be changed.
The rocker 18 is carried by a bearing 22 so that it can rotate around a swivelling axis X at a distance between the points of application of the objective 12 and of the counterweight 16. The bearing 22 supports the rocker 18, via one or more connecting cheeks 21, on a schematically indicated supporting part 23, which itself can be arranged stationarily or movably relative to other components of the laser system 10.
The rocker 18 can have, for example, an oblong, in particular essentially straight lever rod 19, which at one of its ends is coupled to the objective 12, and at its other end is coupled to the counterweight 16. Purposefully, two such lever rods 19 are provided, parallel to each other, on both sides of the objective 12 (i.e.
behind and in front of the objective 12 in the viewing direction of Fig. 1).
How-ever, in the further description only one lever rod will be mentioned, but the following explanations apply analogously to both lever rods.
In the shown example, the above-mentioned bearing seat 20 is formed by a laterally made recess 24 of the lever rod 19 (indicated by a dotted line), which is open on more than one side, that is upward and to the left in the figure. The floor 24a of this recess 24 forms a supporting surface for a vertical journal which stands laterally away from the objective 12 and projects into the recess.
The focussing objective 12 rests loosely on the lever rod 19 via its vertical jour-nal 26. If the rocker 18 is swivelled, not only is the objective 12 rotated around the journal axis relative to the rocker 18, but also the vertical journal 26 is dis-placed within the bearing seat 20. With this displacement, the radial distance of the vertical journal 26 from the swivelling axis X changes. This makes it possible, despite upward or downward movement of the objective 12, to keep the position and orientation of an optical objective axis 0 in space unchanged. So that the displacement of the vertical journal 26 in the bearing seat 20 takes place without friction as far as possible, for example the vertical journal 26 can carry a ring 28, which can roll on the floor 24a of the recess 24, on a sliding or rolling bearing.
The suspension apparatus 14 also includes a guidance system for vertical linear guidance of the focussing objective 12. Whereas the possibility of displacing the vertical journal 26 in the bearing seat 20 creates the precondition for a constant position in space of the objective axis 0 when the objective 12 moves, the guid-ance system ensures that the objective axis 0 is actually not tilted or displaced transversely (to the axis 0).
The guidance system, in the shown embodiment, includes a linear bearing 30 which is fixed relative to the focussing objective 12, and a slide 32 which is guided on it and fixed on the focussing objective 12. The linear bearing 30 is provided with a guidance groove 34, which is in the form of an undercut and engages with a guidance projection 36 of the slide 32. The guidance projection 36 is T-shaped in cross-section in the embodiment shown in Fig. 1, the two T
side arms 36a of the guidance projection 36 engaging with the undercut guid-ance groove 34 in such a way that a horizontal (transverse) movement of the focussing objective 12 away from the linear bearing 30 (to the right in Fig.
1) is prevented. Additionally, the engagement of the T side arms 36a with the under-cut guidance groove 34 ensures that the focussing objective 12 does not tilt.
It is always held by the guidance arrangement in a specified orientation.
The engagement of the guidance projection 36 with the guidance groove 34 provides sufficient vertical play to ensure the necessary movement travel of the focussing objective 12 in the vertical direction.
If the focussing objective 12, with its patient adapter 13, is placed on the eye (not shown) to be treated, the focussing objective 12 can be deflected vertically upward by a slight counter-pressure caused by the eye. In the case of this com-pensatory movement of the focussing objective 12, the vertical journal 26 shifts by rolling (or alternatively sliding) along the floor 24a of the recess 24, while the rocker 18 rotates clockwise around the rocker axis X, and simultaneously the objective 12 rotates relative to the rocker 18 around the axis of the vertical journal 26. In contrast, if, in an imaginary hypothetical case, the focussing ob-jective 12 was joined rigidly to the rocker 18, an upward or downward move-ment of the focussing objective 12 would result in tilting the optical axis 0.
However, in the shown embodiment, such tilting is excluded, because of the movable support of the objective 12 on the rocker 18, and because of the linear guidance of the objective 12 by the linear bearing 30.
Claims (9)
1. Apparatus for movable weight-compensating suspension of a focussing objective (12) of a laser system (10), comprising:
- a force generation device to generate a counterforce component (~) which counteracts the weight of the focussing objective (12), - a transmission device which transmits the counterforce component (~) onto the focussing objective (12) and permits upward/downward compensatory movement of the focussing objective, and - a guidance device for movable guidance of the focussing objective, in such a way that in the case of an upward/downward compensatory movement of the focussing objective (12), an optical axis (O) of the focussing objective main-tains at least its orientation in space, and preferably its position in space.
- a force generation device to generate a counterforce component (~) which counteracts the weight of the focussing objective (12), - a transmission device which transmits the counterforce component (~) onto the focussing objective (12) and permits upward/downward compensatory movement of the focussing objective, and - a guidance device for movable guidance of the focussing objective, in such a way that in the case of an upward/downward compensatory movement of the focussing objective (12), an optical axis (O) of the focussing objective main-tains at least its orientation in space, and preferably its position in space.
2. Apparatus according to Claim 1, wherein the force generation device includes a counterweight (16), the mass of which is used to generate at least part, and in particular the whole, of the counterforce component.
3. Apparatus according to Claim 1 or 2, wherein the transmission device is in the form of a rocker, on one side of which the counterforce component acts, and on the other side of which at least part of the weight of the focussing objective (12), in particular the whole weight, acts.
4. Apparatus according to Claim 3, wherein at least one force application point (K) of the force generation device on the rocker can be adjusted with respect to its distance from a swivelling axis (X) of the rocker.
5. Apparatus according to Claim 3 or 4, wherein the focussing objective (12) is supported on the rocker so that it can rotate relative to the rocker around an axis of rotation which runs parallel to a swivelling axis (X) of the rocker at a distance.
6. Apparatus according to Claim 5, wherein the support of the focussing objective (12) on the rocker is at a variable distance to the swivelling axis (X) of the rocker.
7. Apparatus according to one of the preceding claims, wherein the guidance device is in the form of a linear guide with a parallel guid-ance direction to the optical axis (O) of the focussing objective (12).
8. Apparatus according to Claim 7, wherein the guidance device has guidance formations which prevent movements of the focussing objective transversely to the optical axis (O) in the case of an upward/downward compensatory movement of the focussing objective.
9. Laser system (10), comprising:
- a laser radiation source, preferably of pulsed laser radiation, - a focussing objective (12) for focussing the laser radiation, the focussing objective having an optical axis (O), - an interface unit, which is arranged on the radiation exit side of the focussing objective and is preferably separably coupled to it, with a contact element, which is transparent to the laser radiation, for placing on an object on which work is to be done using the laser radiation, - an apparatus, in particular in a form according to one of the preceding claims, for movable weight-compensating suspension of the focussing objective, this apparatus having a rocker, with two rocker arms, which is supported on a housing member of the laser system so that it can be swivelled around a rocker axis (X), the focussing objective being supported on one of the rocker arms so that it can rotate relative to the rocker around a parallel axis of rotation to the rocker axis, and on the other rocker arm a counterweight (16) to generate a counterforce component which compensates for at least a predominant part of the weight of the focussing objective being attached, and the apparatus also having a guidance system for linearly movable guidance of the focussing objec-tive along the optical axis thereof.
- a laser radiation source, preferably of pulsed laser radiation, - a focussing objective (12) for focussing the laser radiation, the focussing objective having an optical axis (O), - an interface unit, which is arranged on the radiation exit side of the focussing objective and is preferably separably coupled to it, with a contact element, which is transparent to the laser radiation, for placing on an object on which work is to be done using the laser radiation, - an apparatus, in particular in a form according to one of the preceding claims, for movable weight-compensating suspension of the focussing objective, this apparatus having a rocker, with two rocker arms, which is supported on a housing member of the laser system so that it can be swivelled around a rocker axis (X), the focussing objective being supported on one of the rocker arms so that it can rotate relative to the rocker around a parallel axis of rotation to the rocker axis, and on the other rocker arm a counterweight (16) to generate a counterforce component which compensates for at least a predominant part of the weight of the focussing objective being attached, and the apparatus also having a guidance system for linearly movable guidance of the focussing objec-tive along the optical axis thereof.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2010/001319 WO2011107113A1 (en) | 2010-03-03 | 2010-03-03 | Apparatus for the weight-compensating movable suspension of a focussing objective of a laser device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2791803A1 true CA2791803A1 (en) | 2011-09-09 |
| CA2791803C CA2791803C (en) | 2015-07-14 |
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| CA2791803A Active CA2791803C (en) | 2010-03-03 | 2010-03-03 | Apparatus for the weight-compensating movable suspension of a focussing objective of a laser device |
Country Status (16)
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| EP (1) | EP2542934B1 (en) |
| JP (1) | JP5785197B2 (en) |
| KR (1) | KR101472740B1 (en) |
| CN (1) | CN102834755B (en) |
| AR (1) | AR081100A1 (en) |
| AU (1) | AU2010347608B2 (en) |
| BR (1) | BR112012022135B1 (en) |
| CA (1) | CA2791803C (en) |
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| RU (1) | RU2520920C2 (en) |
| TW (1) | TW201135301A (en) |
| WO (1) | WO2011107113A1 (en) |
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| EP3434235B1 (en) * | 2013-03-13 | 2023-04-26 | AMO Development, LLC | Laser eye surgery system |
| DE102018120807A1 (en) * | 2018-08-27 | 2020-02-27 | Sick Ag | Focus adjustable optics |
| US20230000674A1 (en) * | 2021-06-30 | 2023-01-05 | Amo Development, Llc | Counterbalance mechanism in ophthalmic laser system employing a variable beam balance to provide a variable net load |
Family Cites Families (11)
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|---|---|---|---|---|
| AU528966B2 (en) * | 1979-05-22 | 1983-05-19 | Warman International Limited | Cyclone underflow density controller |
| US4896015A (en) * | 1988-07-29 | 1990-01-23 | Refractive Laser Research & Development Program, Ltd. | Laser delivery system |
| US5336215A (en) * | 1993-01-22 | 1994-08-09 | Intelligent Surgical Lasers | Eye stabilizing mechanism for use in ophthalmic laser surgery |
| DE4316037C2 (en) * | 1993-05-13 | 2001-10-31 | Zeiss Carl | Adapter for positioning a medical therapy and / or diagnostic instrument arranged on a stand and stand with adapter |
| JP3998883B2 (en) * | 2000-02-08 | 2007-10-31 | パイオニア株式会社 | Lens drive device for disc player |
| US7038166B2 (en) * | 2003-03-18 | 2006-05-02 | Loma Linda University Medical Center | Containment plenum for laser irradiation and removal of material from a surface of a structure |
| DE102005001249A1 (en) * | 2005-01-11 | 2006-07-20 | Carl Zeiss Meditec Ag | Safety mechanism for a laser treatment device |
| RU2306584C1 (en) * | 2006-07-03 | 2007-09-20 | Российская Федерация,от имени которой выступает Государственный заказчик- Федеральное Агентство по атомной энергии | Device for protecting optical system from influence of laser radiation |
| ES2647581T3 (en) * | 2006-08-01 | 2017-12-22 | Wavelight Gmbh | Servo assisted medical applicator |
| JP5242596B2 (en) * | 2007-02-14 | 2013-07-24 | ツィーマ ホールディング アクチェンゲゼルシャフト | Ophthalmic device for disassembling eye tissue |
| US8771262B2 (en) * | 2007-02-14 | 2014-07-08 | Ziemer Holding Ag | Ophthalmological device for resolving eye tissue |
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2010
- 2010-03-03 PT PT107089203T patent/PT2542934T/en unknown
- 2010-03-03 MX MX2012010183A patent/MX2012010183A/en active IP Right Grant
- 2010-03-03 RU RU2012141541/28A patent/RU2520920C2/en not_active IP Right Cessation
- 2010-03-03 BR BR112012022135A patent/BR112012022135B1/en not_active IP Right Cessation
- 2010-03-03 EP EP10708920.3A patent/EP2542934B1/en active Active
- 2010-03-03 AU AU2010347608A patent/AU2010347608B2/en active Active
- 2010-03-03 KR KR1020127025909A patent/KR101472740B1/en active IP Right Grant
- 2010-03-03 WO PCT/EP2010/001319 patent/WO2011107113A1/en active Application Filing
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- 2010-03-03 ES ES10708920.3T patent/ES2598481T3/en active Active
- 2010-03-03 CN CN201080065117.8A patent/CN102834755B/en active Active
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2011
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Also Published As
| Publication number | Publication date |
|---|---|
| CA2791803C (en) | 2015-07-14 |
| EP2542934B1 (en) | 2016-08-24 |
| EP2542934A1 (en) | 2013-01-09 |
| PT2542934T (en) | 2016-10-25 |
| AU2010347608B2 (en) | 2014-02-13 |
| CN102834755A (en) | 2012-12-19 |
| RU2520920C2 (en) | 2014-06-27 |
| BR112012022135B1 (en) | 2019-10-22 |
| TW201135301A (en) | 2011-10-16 |
| DK2542934T3 (en) | 2016-10-24 |
| JP2013521024A (en) | 2013-06-10 |
| KR101472740B1 (en) | 2014-12-15 |
| MX2012010183A (en) | 2013-02-21 |
| BR112012022135A2 (en) | 2016-10-25 |
| ES2598481T3 (en) | 2017-01-27 |
| PL2542934T3 (en) | 2017-01-31 |
| JP5785197B2 (en) | 2015-09-24 |
| AR081100A1 (en) | 2012-06-13 |
| CN102834755B (en) | 2015-09-02 |
| RU2012141541A (en) | 2014-04-10 |
| KR20130028907A (en) | 2013-03-20 |
| AU2010347608A1 (en) | 2012-10-04 |
| WO2011107113A1 (en) | 2011-09-09 |
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