WO2012041345A1

WO2012041345A1 - Microkeratome system for creating a flap on the human eye

Info

Publication number: WO2012041345A1
Application number: PCT/EP2010/005970
Authority: WO
Inventors: Tobias Jeglorz; Christof Donitzky
Original assignee: Wavelight Gmbh
Priority date: 2010-09-30
Filing date: 2010-09-30
Publication date: 2012-04-05

Abstract

The invention relates to a microkeratome system for creating a flap on the human eye, said system comprising a plurality of functionally different, separately replaceable components (14, 18, 28, 30), each with at least one characteristic feature. The system also comprises a control unit (36) for controlling the operation of the microkeratome system, the control unit having access to stored information that represents at least one pre-defined combination of the characteristic features of at least some of the components. Said system also comprises an input arrangement (46) for inputting information representing a desired combination of the characteristic features of at least some of the components. The control unit is designed to compare the desired combination of features with the at least one pre-defined combination of features and to cause a pre-determined reaction according to the result of the comparison. In this way, the user can be made aware of risky combinations with having to rely solely on his/her experience for the selection of the components.

Description

Microkeratome system for the production of flasks in the human eye

The invention relates to a microkeratome system for the production of flaps in the human eye.

For the treatment of refractive errors of the human eye, laser in situ keratomileusis (LASIK) is a widely used technique. In this case, on the surface of the cornea a disc commonly referred to in the art as a flap is cut out, which is not completely separated from the remaining corneal tissue, but hangs on a so-called hinge (usually referred to by the English term "hinge") on the remaining corneal tissue. The flap can easily be flipped aside to expose the underlying corneal tissue for ablative laser treatment. After the laser treatment, the flap is folded back again; the preceding corneal material removal then leads to a correspondingly altered form of the conical surface, which at best completely compensates for the ametropia to be corrected.

In classical LASIK, the flap is prepared by means of a mechanical microkeratome. This is a microsurgical planer with a razor-sharp, usually oscillating driven cutting blade. An exemplary microkeratome system is marketed by WaveLight GmbH under the trade name RONDO; a brief description of this marketable system can be found in the article "New Microkeratoms Still Coming to the Market" by Leah D. Farr in the periodical publication CATARACT & REFRACTIVE SURGERY TODAY EUROPE, November / December 2007, pages 66, 67.

A variant of the conventional LASIK is the Epi-LASIK. While in the LASIK technique, the flap is created by a cut into the stroma, the epi-LASIK avoids a stromal bed cut for the flap. Instead, an epithelial flap is created by incision along and above the Bowman's membrane.

Although laser flattening has been proposed and implemented in many cases in recent years, the conventional technique of producing a mechanical surface with a microkeratome continues to have a wide range of applications. not least because of their considerably lower costs compared to the laser-supported variant of flap production, often referred to as femto-LASIK.

The invention relates to mechanical microkeratome systems which produce a corneal flap with (at least) one cutting blade. There is no restriction on the applicability of the microkeratome systems considered here to one of the abovementioned mechanical techniques of flap production (LASIK, Epi-LASIK). In particular, the microkeratome systems considered in the context of the invention are suitable for both techniques.

Different patients with different medical indications require the generation of flaps of different sizes, thickness and hinge position. For the realization of different flap diameters and flap thicknesses, for example, correspondingly differently dimensioned components are generally required. For example, the flap diameter may be determined by the inner diameter of a suction ring to be placed on the eye. The larger the suction ring is (i.e., the larger its inner diameter is), the larger the diameter of the resulting flap. On the other hand, the flap thickness can be determined, for example, by the projection about which a cutting blade protrudes over a leveling surface (applanation surface) of a cutting head carrying it.

Different cutting heads can thus differ in their projecting surface by a different projection of the cutting blade.

Manufacturers of microkeratome systems therefore provide purchasers with complete sets of suction rings and / or cutting heads and / or other functional components, within each set of which the respective components differ by the value of at least one characteristic feature. For example, a manufacturer suction rings for the nominal flap diameter 8 mm, 9 mm and 10 mm, as well as cutting heads for the nominal Flapdicken 100 may pm, 130 pm and 150 [im an ^¬ offer (these numerical values are obviously purely illustrative and not intended to be limiting) , The surgeon then makes a suitable combination of suction ring, cutting head and optionally other components together to produce a flap with the desired dimensions.

Of course, the selection of a suitable combination places high demands on the experience of the surgeon. This is especially due to the abundance of possible combinations and that some of the possible combinations may be more risky than others (for example, very thin flap thicknesses with very large flap diameters). However, it must also be taken into account that in view of the large number of selection options, a mix-up of the components by the surgeon can easily occur.

Against this background, it is an object of the invention to provide a human eye surface microkeratome system which can provide the surgeon with better assurance of the suitability of a selected combination of components of the microkeratome system.

To solve this problem, the invention provides a microkeratome system for the production of flaps in the human eye, comprising

a plurality of functionally distinct, separately replaceable components each having at least one characteristic feature,

a control unit for controlling the operation of the microkeratome system, the control unit having access to stored information representative of at least one predetermined combination of the characteristic features of at least a part number of the components, and

an input device for inputting information which is representative of a desired combination of the characteristic features of at least a part number of the components, the control unit thereto

is set up to compare the desired combination of features with the at least one predetermined feature combination and to effect a predetermined reaction depending on the comparison result.

The invention enables the surgeon to have a desired combination of components (corresponding to a desired combination of characteristic features of these components) checked by the control unit for suitability, in particular for admissibility, before the start of an operation. For this purpose, he can enter suitable information about the input device, which specify the desired feature combination. The desired combination may relate to all exchange components of the microkeratome system which are available and usable in different variants (ie with different values of their characteristic features). However, it is also conceivable that only a combination of a number of parts of the total existing replacement components is the basis of the aptitude test. If, in fact, a particular combination of features of a partial number of the components is in principle not permitted, then it is unnecessary for the user, also for the other components to make desired specifications. For example, a cutting blade suitable for Epi-LASIK may only be used with a specially adapted cutting head suitable for Epi-LASIK. If, on the other hand, the user inputs a suitable cutting blade for the epi-LASIK in combination with a cutting head which is suitable only for the conventional LASIK, this already constitutes an impermissible combination, regardless of the concrete feature choice of any further components.

The characteristic features can take different forms. They can be numerical values, for example a diameter or thickness gauge, but they can also be properties other than a specific dimension, for example a specific structural design, which can be represented by a specific code, for example. If a value of a characteristic feature is mentioned here, this means any realization of the respective feature, regardless of whether the feature relates to a dimension, a constructive embodiment or another unique verifiable property of the assigned component. In the case of a motor drive unit of the microkeratome system, for example, such a peculiarity may relate to the number of motors contained in the drive unit (for example, one motor versus two motors). As mentioned, cutting heads may also differ structurally, e.g. depending on whether they are to be used for LASIK treatment or Epi-LASIK treatment.

In a preferred embodiment, the components comprise a suction ring to be placed on the eye and fixable there by negative pressure, the suction ring being assigned at least one size measure, in particular at least one diameter measure, as a characteristic feature. Suction rings are conventionally described at least by their inner diameter, often by their outer diameter. The inner diameter and possibly also the outer diameter of the suction ring can then each be used as a characteristic feature.

The components may further comprise a cutting blade, wherein preferably the shape of the cutting blade for one of at least two different forms of operation serves as a characteristic feature. The mentioned forms of surgery LASIK and Epi-LASIK are the first for possible forms of operation to call. Instead of an indication of the intended form of operation, the

However, cutting blade can also be defined over certain dimensions, for example over a sharpness of the blade (expressed for example by a radius of curvature of the cutting edge of the blade). This is based on the idea that Epi-LASIK typically uses a comparatively blunt cutting blade (blunt compared to cutting blades for conventional LASIK operations) to prevent inadvertent cutting of Bowman's membrane and cutting into the stream ,

In a further embodiment of the invention, the components can comprise a cutting head designed to hold a cutting blade and to be brought into engagement with a suction ring, wherein a flap thickness is assigned to the cutting head as a characteristic feature. As mentioned, the projection of the cutting blade over an applanation surface of the cutting head can be decisive for the achievable flap thickness. Accordingly, different cutting heads can be available for different flap thicknesses, which differ from each other due to the above-mentioned projection.

It has already been mentioned that, depending on the mode of operation (for example LASIK and Epi-LASIK), the cutting head can be designed differently. Therefore, the cutting head is preferably assigned its characteristic for one of at least two different forms of operation, in particular LASIK and Epi-LASIK, as a further characteristic feature.

In addition, the components may comprise a motor drive unit, which is assigned a motor characteristic, in particular an engine number, as a characteristic feature.

In a preferred development of the invention, the control unit can be set up to release or block the operation of the microkeratome system if the desired feature combination matches a stored predetermined feature combination. Insofar as the stored information relates to permissible combinations of features, the control unit checks an input desired feature combination as to whether it is permissible. When finding a stored same feature combination, the control unit then releases the microkeratomsystem for operation. Conversely, it is conceivable that the stored feature combinations illegal or at least risky Represent combinations. In this case, blocking of the microkeratome system may be desirable if, among the stored feature combinations, one corresponding to an entered desired feature combination is found.

As an alternative or in addition to a blocking of the microkeratome system, the control unit can be set up to match the desired combination of features with a stored predetermined feature combination

Output of an acoustic and / or visual indication to effect. Such an indication may inform the surgeon e.g. warn that the combination of components he proposes poses risks to the patient.

The invention will be explained below with reference to the accompanying Figure 1 on. This represents in a highly simplified, schematic form an embodiment of a Mikrokeratomsystems 10 for generating a corneal flap on a human eye 12. The microkeratome system 10 comprises a replaceable with a cutting blade 14 equipped handpiece 16 and a suction ring unit 18, which consists essentially of a the eye 12 aufzusetzenden suction ring 20 and a preferably integrally formed with the suction ring 20, obliquely extending away from this connecting piece 22 composed. The connecting piece 22 contains in a manner not shown, but known per se one or more evacuation channels, which are connected to a corresponding number in the suction ring 20 formed evacuation chambers (not shown in detail). At least one evacuation chamber of the suction ring 20 serves for the suction of the same to the surface of the eye 12th

At the connecting piece 22 a consisting of one or more hose lines hose assembly 24 can be connected, which in turn is connected to a running example of a desktop unit central control console 26 of the microkeratome system 10. The control console 26 includes a Vakuumpumpanordnung, not shown, by means of the hose line assembly 24 and the connecting piece 22, a vacuum in each evacuation chamber of the suction ring 20 can be generated.

The handpiece 16 has a serving as a holder for the cutting blade 14 cutting head 28 and a releasably coupled to the cutting head 28 motor drive unit 30. The cutting head 28 is not shown by Füh- supported information on the suction ring 20 guided in a linear direction of movement. For example, the guide formations may comprise two spaced-apart toothed tracks formed on the suction ring, in which two pinions arranged on the cutting head 28 and in drive connection with the drive unit 30 intermesh. In this way, a linear reciprocating movement of the cutting head 28 relative to the suction ring 20 and consequently relative to the eye 12 is possible. This reciprocating movement of the cutting head 28 is illustrated in FIG. 1 by a double arrow 32.

The cutting blade 14 is in turn received laterally movable in the cutting head 28, wherein laterally a direction perpendicular to the direction of movement 32 of the cutting head 28 means. For lateral oscillation is also the cutting blade 14 in a non-illustrated drive connection with the drive unit 30th

To drive the cutting head 28 and the cutting blade 14, the drive unit 30 may include a single drive motor (electric motor) or separate motors. A solution with separate motors is shown, for example, in EP 1 757 253 B1; with regard to a single-motor solution, reference may be made, for example, to EP 0 442 156 A1.

An electrical control line 34 connects the control console 26 to the handpiece 16.

In the control console 26, a microprocessor-based control unit 36 is included, which operates in accordance with a control program contained in a memory 38. The control unit 36 controls the operation of the handpiece 16 (more precisely the operation of the drive unit 30) and preferably also the operation of the mentioned vacuum pumping arrangement. In addition, the control console 26 is connected in the illustrated embodiment via a further electrical connection line 40 with a reading device 42, which allows the reading of a manufacturer-mounted identifier 44 (represented for example by a bar code) of at least a portion of the components of the microkeratome system 10. In FIG. 1, such an identifier 44 is present on the drive unit 30, on the cutting head 28 and on the suction ring unit 18 (specifically on the suction ring 20). It is understood that the cutting blade 14 may be provided with such an identifier. The identifier 44 contains information which ensures an unambiguous identification of the component concerned, and not only by component type (eg cutting head, driebsei beauty, cutting blade, suction ring), but also according to specific expression of each type. The characteristic is represented by one or more characteristic features of each component, by which the different characteristics of the same component type clearly differ from one another.

In the concrete example case, the user can choose for the drive unit 16 under at least two variants (characteristics), a variant with a single motor and a variant with two motors. For the suction ring unit 18, he can choose between a plurality of variants, which differ in each case by the inner diameter of the suction ring 20 and thus by the flap diameter. As for the cutting head 28, the user may choose between two sets of variants, a first group for LASIK operations and a second group for epi-LASIK operations. Each group in turn consists of several variants, which differ by a different value of achievable with this cutting head flap thickness. Finally, with regard to the cutting blade 14, the user may also choose between different forms, a distinguishing feature being the suitability of the cutting blade 14 for LASIK or Epi-LASIK treatments.

The multitude of characteristics of the individual components of the microkeratome system 10 creates an even greater variety of possible combinations. In order to facilitate the selection of a suitable combination for the user, a list of different combinations of components of the microkeratome system 10 is stored in the memory 38, wherein the combinations differ by different values of at least one characteristic feature of at least one of the components. The list can contain all conceivable combinations of components; however, it may contain only those combinations that are permitted, or alternatively those that are not permitted or risky. The components considered in a listed combination comprise according to a preferred embodiment at least the cutting head 28 with the flap thickness as a characteristic feature and the suction ring unit 18 with the inner diameter of the suction ring 20 as a characteristic feature. In addition, the drive unit 30 may be taken into account with the number of its motors as a characteristic feature in the listed combinations. The design of the cutting head 28 for LASIK treatments or for epi-LASIK treatments may be considered as another characteristic feature of the cutting head 28 in the listed combinations. Alternatively or additionally, the cutting blade 14 as another Component, in particular as regards its suitability for LASIK treatments or Epi-LASIK treatments.

The mentioned list of combinations of components can be inscribed in the memory unit 38 by the manufacturer or can be registered by a purchaser of the microkeratome system 10, e.g. be programmed before the first use of the same. In any case, it is preferred if the surgeon in the context of planning a specific intervention has no way to change the stored list. Either the list is permanently permanently stored in the memory 38 or only under certain conditions, for example, only with proof of certain access rights, changeable. Regardless, the control console 26 may allow the user to retrieve the stored list to display on a screen, not shown, so that the operator may be able to ascertain in advance as to which combinations of components are permitted or inadmissible.

In the list, the components can be identified, for example, by elements of their identifier 44, in particular by those elements which indicate the type and the concrete characteristics of the respective component.

As part of the operation planning, the surgeon can also enter a desired combination of components in the control center 26. This can be done for example by reading the identifiers 44 of the desired components with the reader 42. Alternatively or additionally, the control console 26 can have a manually operable input unit 46, for example in the form of a touch screen, via which the surgeon can enter his desired combination. By means of a suitable menu navigation, the surgeon can, for example, call up the available characteristics of the individual components and select a desired one. As a result, the control panel 26 displays on the touch screen 46 or a screen separate therefrom the admissibility or inadmissibility of the selected combination. In the case of an impermissible combination, the control unit 36 may block the operation of the microkeratome system 10 and, in particular, the operation of the drive unit 30, unless an allowable component combination is selected by the operator. Cases are also conceivable in which a desired combination is not fundamentally impermissible, but entails an increased risk of surgery. In such cases, although the operation of the operation can be released to the surgeon, but it can on the Touch Screen 46 or another screen will be given a warning text that alerts him to the dangers of the selected combination.

Claims

claims

1. Microkeratome system for human eye flap production, comprising

a plurality of functionally different, separately replaceable components (14, 18, 28, 30) each having at least one characteristic feature,

a control unit (36) for controlling the operation of the microkeratome system, the control unit having access to stored information representative of at least one predetermined combination of the characteristic features of at least a part number of the components, and

an input device (46) for inputting information which is representative of a desired combination of the characteristic features of at least a part number of the components, wherein the control unit is adapted to compare the desired feature combination with the at least one predetermined feature combination and depending on the comparison result effect predetermined reaction.

2. microkeratome system according to claim 1, wherein the components comprise a aufzusetzenden on the eye and there fixable by vacuum suction ring (20), wherein the suction ring is assigned at least one size measure, in particular at least one diameter measure, as a characteristic feature.

The microkeratome system according to claim 1 or 2, wherein the components comprise a cutting blade (14), wherein preferably the characteristic of the cutting blade for one of at least two different forms of operation serves as a characteristic feature.

4. The microkeratome system of claim 3, wherein the surgical forms comprise LASIK and Epi-LASIK.

5. microkeratome system according to any one of the preceding claims, wherein the components comprise a cutting head for holding a cutting blade (14), to be brought into engagement with a suction ring (20) to be brought, wherein the cutting head is associated with a flap thickness as a characteristic feature.

6. microkeratome system according to claim 5, wherein the cutting head (28) its expression for one of at least two different forms of operation, in particular LASIK and Epi-LASIK, is assigned as another characteristic feature.

7. microkeratome system according to any one of the preceding claims, wherein the components comprise a motor drive unit (30), which is associated with a motor characteristic, in particular an engine number, as a characteristic feature.

8. microkeratome system according to any one of the preceding claims, wherein the control unit (36) is adapted to enable or disable the operation of the microkeratome system in accordance with the desired feature combination with a stored predetermined combination of features.

9. microkeratome system according to any one of the preceding claims, wherein the control unit (36) is adapted to effect the output of an audible and / or visual warning message in accordance with the desired feature combination with a stored predetermined combination of features.