DE4012882A1 - Surgical instrument for removing cataract from eye - has circular blade which is rotated by drive in handle - Google Patents

Abstract

A surgical instrument for operating on a cataract of the eye has a hollow handle (1) which receives the blade holder (4). The blade is made from a flat strip of flexible material which is bent to form a ring (5). The ring (5) is gripped between a roller (9) inside the ring (5) and two rollers (7, 8) outside the ring (5). A drive mechanism inside the handle rotates the rollers (7, 8) which cause the ring (5) to rotate so that its edge (6) cuts out the cataract. The internal mechanism also enables the ring to be elastically deformed and retracted inside the hollow handle. USE - Ophthalmic surgery.

Description

The invention relates to an ophthalmic scalpel for cataract operations with a shaft, a knife and a knife holder. This scalpel is used for Opening the anterior lens capsule in the case of extracapsular Extraction of the clouded lens nucleus.

Today's method for cataract surgery ent stops especially during particularly critical phases of the Opera tion workflows that are primarily based on skill and Depend on the surgeon's attention. One of the most important of these phases of operation is the opening of the Lin capsule that is as circular and edged as possible should deliver a smooth cut. This is precisely the phase  today's methodology of complications risks because there is a high mecha African eye strain that creates trauma table effect, and on the other hand by there is a risk of undiscovered or invisible ver there are injuries in the area of the back of the eyes, for example, tears in the rear lens capsule can lead to the escape of vitreous. A white The remaining high risk is caused by the remaining lenses Capsule parts that are essential for the use of the suction rinsing device difficult. It is also critical in this Working phase a large part of the total operating time consumed, so this work phase is not just risk rich, but also to be regarded as time-critical.

To clarify the procedure, let us briefly explain today usual surgical methodology described in order to then the Improvement through the ophthalmic scalpel according to to understand the invention better.

After opening the anterior chamber, first a Cut into the front of the lens capsule. With an injection cannula, the tip of which is 90 ° apart is angled, the surgeon tries, half-cutting, half tearing, a circular opening of about the size of the optical part to implant the plastic lens from the front area of the front Working out the lens capsule. Understand here significant mechanical forces at which the eye undesirably moves out of its rest position becomes. In addition, these forces are transferred if in an undesirable manner and for a long time clamp on the lens and on the holding device, d. H. the Zonula fibers. This procedure creates a  more or less circular opening in the front loading rich the front lens capsule with an inevitable strongly frayed characteristic of the opening edge, with strong cracking to the sides occurs. This jagged structure poses a danger to Wei tearing when the surgeon tries by suction to remove the remaining lens parts.

This critical phase of the operation is probably also the real operational risk. Because it can Case occur that the lens capsule, by the surgeon notices until it tears into the back part. The result is a vitreous leak, which is a very serious problem represents the further course of the operation. Wei Further complications also arise if during the Suction-rinsing process to remove the remaining lenses the remaining parts of the capsule fringe into the suction-rinsing device be sucked and thereby further invisible cracks in the remaining lens capsule.

This clearly shows that the opening of the front whose lens capsule is a critical phase for the Represents cataract surgery, the goal of which is to ge remove the cloudy lens from the capsule and then in the capsular bag to a lens made of plastic implant. The opening of the front lens capsule requires an enormous amount of skill in the ope rateurs and the use and changing of a variety of Instruments and represents a very high risk factor and a very high time factor combined with one represents a significant cost factor.

The object of the invention is now an ophthalmic Creating a scalpel for such cataract surgeries with which the working phase of the opening of the front Lin  capsule with reduced risk, in a shorter time and with can be made from a single instrument.

This task is accomplished through an ophthalmic scalpel solved as described in claim 1.

Preferred embodiments of this scalpel are in the Claims 2 to 13 specified.

An essential constructive feature of the scalpel According to the invention is that a knife from a ring knife flexible band-like material is used, which itself due to its flexibility to an elongated oval can bend so that it is in the cannula-like shaft scalpel can be retracted. This will make him is enough that the device only with the diameter of the shaft Cannula of approx. 3 mm in diameter, that is through a very small one small opening at the edge of the cornea, inserted into the eye can be. At this stage of the operation, no un necessary large opening on the side edge of the front eyes chamber can be cut so that unnecessary Ver lust for aqueous humor and the resulting collapse the anterior chamber can be prevented.

In a preferred embodiment, the ring knife can of the invention, which will be described in detail later is simply inserted or removed with one hand will be thrown. This enables the surgeon to a ring knife with a optimal diameter for the respective application to select and insert into the device. The chosen one and inserted ring knife is drawn into the shaft, the scalpel is then inserted into the eye, and in the The eye becomes the ring mes through a sliding mechanism water pushed out of the shaft cannula, whereby it  unfolds and, due to the resilient elasticity of the metallic ring knife material, again its original circular shape. In this circular shape the ring knife is then with the cutting edge on the front Lens capsule placed and a drive device be does that in operative connection with the knife holder stands and the ring knife inserted over the knife neck drives rotation. With this rotating movement the ring knife makes a clean cut, the kei leaves frayed edges and no strong er exercises vibrations on the eye.

The depth of cut is expediently determined by a rule limited stop.

A suction and rinsing device, the suction and rinsing cannulas includes, inside the shaft up to the location of the ring knife, preferably up to about the middle of the ring knife, be performed. The suction cannula is subjected to negative pressure strikes while flushing cannulas flush solution like isotonic Bring saline (BSS) to the work site. By the automatically centered suction opening separated lens capsule remnants and loose pieces of Lin sucked clean.

An advantageous embodiment of the knife holder grips a holding claw that makes the ring knife eccentric takes hold. A simple but secure bracket consists of three cylindrical, conical or the purpose ent Talking shaped, rotatably mounted rollers, between which the ring knife is clamped so that a roller inside the ring and two rollers outside the rin and lie in the ring knife using spring force nen. By means of an operative connection of at least one of the rollers with a drive device that one or more whale  zen to rotation, the ring knife for the through leadership of the cut rotated. This rotation can be from Operators controlled, for example, via a foot switch be a servomotor of the drive device controls.

Any known drive mechanism can be used Drive device with gear can be used, wherein only has to be ensured that the driving parts can be sterilized well on the scalpel. That is why given preference to one drive, the least possible Parts included and simple in construction.

In the three-roller drive described serve the Shafts facing rollers on the one hand guiding the Ring knife and on the other hand by the rotary drive Take away due to friction. You can also use the Rollers ultrasound are transferred to the ring knife, to smash the lens core and move the ring knife.

In an expedient embodiment, the is on the Roller inside the ring in the axial direction of the Slidable shaft and is in the direction of the shaft spring-loaded via a bearing lever. By moving this roller against the spring force, which is achieved by means of a simple lever on the scalpel made by the surgeon the claw holder is held by the rollers loosened and the ring knife can fall down. To Recording a ring knife is opened accordingly nete claw holder held over a ring knife and reversed the shift of one roller, so that the spring force acts again between the three rollers and jammed the ring knife.

The spring loading ensures a secure clamping,  safe guidance and the necessary and correct approach pressing pressure of the ring knife on the drive rollers reached. A quick clamping and unclamping of the ring knife is possible Lich, so that the ring knife can be changed quickly can. So the knife change is sterile.

It will be appropriate to use new, sterile ring knives individually or stored in magazines in packaging so that they sterile from this pack without touching hands be removed in the manner described above can.

It may be desirable to have ultrasound on the ring knife is transmitted. It is described in the Shape of the knife holder and knife drive only necessary agile, the holding mechanism with a for the shape of the Kop suitable vibrations ultrasonic vibrating element peln. When the transmitted ultrasonic vibration power is high enough, the knife can be used without additional Drive mechanism for rotations through the cutting effect to lead. With this construction, the drive mechanism completely saved. In addition, some will be added receive constructive options that are practical Further improve the use of the scalpel.

In this case, for example, it becomes very easy with the tilting mechanism of the ring knife in its inclination change and thereby the respective conditions to adapt to the operation.

Advantageous in this embodiment of driving of the ring knife by means of ultrasound that a ver last uninvolved corneal and scleral parts by three parts is excluded and that the cutting of the circular opening in the front lens capsule and a  simultaneous smashing of the lens to be removed in a single, short process with the least possible mechanical load for the Eye is possible.

To work with the scalpel according to the invention various operating facilities required. Reason In addition, the device is divided into a) an external ver care unit, b) an operating unit and c) the Scalpel itself. The external supply unit delivers the drive for rotations (e.g. via rotating shafts), includes a reservoir and pump for a rinse solution and a vacuum chamber or vacuum pump for that Suction-rinsing system, or optionally includes a gene ultrasound generator. It is about well-known technical utilities that also arranged in rooms other than the operating room could be. The control unit includes control elements elements such as foot switches for the surgeon or an assistant permanent sister, for example for the ready rinsing solution, vacuum, ultrasound, etc. With this Operating unit is the actual scalpel over one flexible connection for the transition from non-sterile Parts connected to the sterile part on the scalpel itself. The longer this transition, the more precise it can be Separation of the sterile part must be observed. The Flexible connection to the scalpel is made possible by very light and highly flexible, combined into one unit Hose line manufactured.

A connection between the control switches and the Supply unit that includes all pumps, storage tanks, includes electrical and hydraulic units by means of electrical lines.  

The use of the ophthalmic scalpel according to the Invention for opening the front lens capsule in cataract operations, the fol advantages:

• 1. The opening of the front lens capsule is in one single very short operation with an exact run the cut in a span of a few seconds carried out.
• 2. The destruction of the lens can be caused by exposure of the ring knife with ultrasound in the same work course.
• 3. The cut out lens capsule piece and the smash Parts of the lens can be done in the same operation through an integrated rinsing and suction device be removed from the eye.
• 4. There is no risk of tearing the lead lens capsule because the cut is flawless and is performed exactly circular.
• 5. There is no danger to the eye from being left behind lens capsule fringes, since there is only a single circle cut out the round lens capsule piece and at the same time is removed.
• 6. The eye suffers during the cutting process lowest possible mechanical load.
• 7. There is no "inflating" the anterior chamber with very expensive viscoelastic special liquids necessary because to insert the scalpel according to the Invention only a relatively small incision in the  Cornea is necessary and thereby the leakage of Aqueous humor is avoided.
• 8. All necessary operational steps for opening the lens capsule are inte- freezes. This eliminates the use of multiple In instruments in a row.
• 9. The required "skill" of the surgeon remains kept to a minimum, d. H. also with surgeons with less practical experience is the chance for a positive outcome of cataract surgery increased to a significant extent.
• 10. The use of instruments and materials will reduced to a minimum; precious operation time is saved to a considerable extent; the mechanical The eye is burdened by the shorter operation time and secondly through the Surgical procedure itself significantly reduced; the course of the operation is less complicated and therefore less risky.
• Saving time, instruments and material brings a not inconsiderable saving of costs with it.

In the following, the invention is illustrated by way of example le for the new ophthalmic scalpel tert. It also refers to the attached drawings Referred.

The drawings show:  

Figure 1 is an ophthalmic scalpel for cataract surgery according to the invention in perspective view.

Fig. 2 is a schematic representation for understanding the principle of the invention;

. FIG. 3 shows the scalpel of Figure 1 in the working Stel lung in one eye;

Fig. 4 different embodiments of Ringmes ser in cross section;

Figures 5 to 8 different embodiments of the drive device for the cutting movement of the ring knife.

Figs. 9 and 10, means for receiving and holding or releasing the ring blade;

pull FIGS. 11 and 12, a driving means for turning on and moving out of the ring diameter in the shaft opening and

Fig. 13 shows an arrangement with which the ring knife tends ge can be held.

Fig. 1 shows an ophthalmic scalpel according to the invention in a perspective view. The shaft 1 summarizes a handle portion, the portion 2 merges into a front shaft with a smaller diameter. Tele skopartig retractable in the front shaft part 2 is a shaft tube 3, the ver with the knife carriage 4 and connected to the blade moving into the front shank portion is moved. 2 Inserted into the knife holder 4 is a ring knife 5 made of a band-like flexible material, one circumferential cutting edge 6 of which is exposed along the entire circumference of the ring.

The handle section shown in Fig. 1 is shown cylin drisch, although in practice an ergonomically optimally designed shape should be chosen to ensure safe and fatigue-free handling for the surgeon.

The telescopic knife retraction by moving the shaft tube 3 in the front shaft section 2 allows easy disassembly when the front part of the scalpel must be cleaned and sterilized.

The knife holder 4 comprises two outside of the Ringmes sers arranged transport rollers 7 and 8 and a pressure and transport roller 9 , which is carried by a spring-loaded Hal tehebel 10 and is arranged within the ring knife.

Fig. 2 shows schematically the deformation to a longitudinal union oval of the ring knife 5 when retracting in front of the shaft section 2 . The front edge of the Schaftab section 2 presses the ring knife 5 together when pulling in, and the flexibility of the band-like material of the ring knife causes an exactly circular ring to be formed again after the ring knife has been extended from the shaft.

All parts of the scalpel itself are made of physiological compatible materials. For the Ringmes It is preferred to use high quality stainless oil Gated spring steel used during parts of the shaft can consist of lightweight high-strength titanium alloys.

Fig. 3 shows the scalpel shown in Fig. 1 in the working position. Through a small incision in the cornea 11 , the scalpel is inserted into the anterior chamber with the ring knife 5 retracted and positioned so that the ring knife 5 is extended in front of the lens. It is then attached to the front lens capsule 12 and actuated. Within a short time, a circular flap is cut out of the front lens capsule 12 , which is suctioned off via a suction and rinsing system guided in the shaft.

A stop on the knife holder 4 limits the cutting depth of the ring knife 5 , which penetrates into the lens core 13 .

The rotary movement of the ring knife 5 is also transmitted to the lens core 13 , which is to be removed. By a driving effect when gluing the lens core to the ring knife holding and fixing elements of the lens core are released from the capsular bag, so that thereby the lens is released from the capsular bag without having to exert asymmetrical mechanical forces on the lens. The lens core can then be removed more easily in a later operation.

To hold the ring knife 5 in the knife holder 4 between the rollers 7 , 8 and 9 , the knife cross section is provided with holding projections. Fig. 4 shows examples of knife geometries.

FIGS. 4a to 4f show different cross sections of ring diameters. 5 The cutting edge 6 of the ring knife 5 is in the representations below. Fig. 4a shows a first embodiment of the ring blade 5 with a peripheral bead 14 which engages in corresponding counter-grooves in the rollers 7, 8 and 9.

A ring knife, as shown in Fig. 4a, can for example be made from a drawn spring steel tube Herge by beading a piece of pipe and hammering on one edge to form a cutting edge 6 .

A ring knife 5 with a triangular cross section is shown in Fig. 4b. A ring knife of this type is used, for example, in the knife holders which are shown in FIGS . 9 to 13.

To hold and adjust the ring knife 5 , outer latching lugs 15 or inner latching projections 16 can also be formed on the ring knife cross section, as is shown, for example, in FIGS. 4d and 4e.

In Figs. 5 to 7 mechanical drives are shown for rotation of the ring blade 5.

The drive of the two closer to the shaft Trans port or drive rollers 7 and 8 can be done, for example, by a torsion shaft with bevel gear or by a linearly vibrating linear tappet on an inhibitor mechanism. The respective type of drive sets one or both drive guide rollers in rotation, which is then transferred to the ring knife by friction.

Any type of drive known per se can be used, provided sufficiently clean and close the parts near the knife are sterilizing.

Fig. 5 for example shows a wheel train that is driven via a rotary shaft in the axial direction of the shaft. Fig. 6 shows a rotation shaft 17 which ends in a gear 18 . In this embodiment, the ring knife 5 has teeth 19 on the edge facing away from the cutting edge 6 , which is in engagement with the gear 18 . In this case, the ring knife 5 is driven directly for rotation. This embodiment of the ring knife 5 thus requires a relatively expensive polished circular toothing on the upper edge. On the other hand, any slippage is avoided with this direct drive, and the friction properties of the material are irrelevant.

In Fig. 7, a cable drive for the Transportwal zen 7 and 8 is provided. The cable material consists, for example, of plastic material that is easy to sterilize.

Mechanical rotary drives are preferably carried out by a hydraulic vane motor. Mechanical linear an shoots are preferably made with a kickback-free Oscillating piston. Both drive types are preferred as the same liquids used for the Flushing in the suction and flushing system integrated in the shaft be used.

Fig. 8 shows an embodiment of the scalpel according to the invention, in which the ring knife 5 is opened with ultrasound. An ultrasonic vibrating element 20 has in its front end facing the ring knife 5 one or more guide surfaces for the ring knife, against which the ring knife is pressed by means of a pressure roller 9 under spring force. After the ring knife 5 has been positioned at the operation site, the operator actuates an operating lever with the effect that the ring knife 5 is subjected to ultrasound. If the vibrating ring knife is pressed with light pressure on the front lens capsule, a cutting effect is exerted. At the same time, the ultrasound has a crushing effect on the lens to be removed.

Both with mechanical drive and with the transmission Ultrasound can be applied to the ring knife flushing and suction integrated into the shaft opening the use of an additional suction and flushing device be saved. This leads to further savings in terms of instruments, materials and time.

FIGS. 9 and 10 show details of the components that serve for receiving and holding or releasing of the annular knife.

The ring knife 5 is in Fig. 9 between a tapered roller 9 , which is arranged inside the ring knife, and two cylindrical rollers, which are arranged outside the ring knife and of which only the front 8 is visible, clamped. The holding lever 10 of the roller 9 extends through the shaft tube 3 to a flag 21 , the extension of which is guided as an operating lever 22 on the outside of the shaft. On the flag 21 , a tension spring 23 is held at one end, which is attached at its other end to a second flag 24 which is rigidly connected to the rollers 8 and 9 via a lever rod 25 . The spring 23 causes the roller 9 to be pressed against the rollers 7 and 8 and clamps a ring knife 5 with a triangular cross section between them. This triangular cross section is adapted to the cone angle of the roller 9 .

When the operating lever 22 is pushed in the arrow direction shown in FIG. 10, the roller 9 is released from engagement with the rollers 7 and 8 against the tension of the spring 23 via the holding lever 10 . The ring knife 5 falls down. By moving the knife holder over a ring edge of a ring knife, a ring knife can be added again.

The ring knife 5 is thus picked up and removed without having to touch the sterile parts by hand.

Ringmes are expediently provided in sterile plastic packaging. Form the packaging is designed so that the ring knife grouped by diameter in a kind of magazine stand and by appropriate shaping of the plastic magazine easily and without touching your hand in it Scalpel can be used.

Figs. 11 and 12 show an embodiment for the drive means to retract the knife ring into the shaft - for the insertion of the scalpel through a small corneal incision in the anterior chamber - is used. The same operating lever 22 , which causes the knife holder 4 to be opened by pushing it in front, enables light by pulling back in the opposite direction, so that the flag 21 on the lever 10 moves to the rear, the roller 9 pressing the rollers 7 and 8 and thus pushes the entire knife holder 4 into the shaft of the scalpel.

A - not shown - driver ensures before pushing the operating lever 22 that the knife holder 4 does not open, that is, the roller 9 remains pressed against the rollers 7 and 8 .

This security system against unintentional opening is designed so that the ring during the opera Do not detach active intervention and remain in the eye can.  

The shapes that the ring knife assumes in the position according to FIG. 11 or FIG. 12 are shown in FIG. 2 Darge. Fig. 11 shows a position which is selected for insertion into the front eye chamber, while Fig. 12 shows the position in which the ring knife 5 has its circular shape.

Finally, FIG. 13 shows a variant in which the ring knife 5 has an inclination against the axial direction of the shaft in order to assume a more favorable working position. In Fig. 13, the roller 9 is cylindrical, while the roller is formed conically. 8 The cross section of the ring knife 5 is an elongated triangle that fits into the gap between the rollers 9 and 8 that the ring plane receives an inclination against the shaft axis. An inclination of the ring knife can also be designed to be variable using suitable adjusting devices. The choice of the inclination of the ring knife, the diameter of the ring knife, depth of cut and the like enable the surgeon to develop his own working method.

Claims (13)

1. Ophthalmological scalpel for cataract operations with a shaft, a knife and a knife holder, characterized in that
that the shaft ( 1 ) is hollow and the knife holder tion ( 4 ) can be drawn into the interior of the shaft,
that the knife comprises a ring knife ( 5 ) which consists of a band-like flexible material forming a ring and can be inserted into the knife holder in such a way that the ring plane extends essentially in the axial direction of the cavity in the shaft, and
that a first drive device is provided which moves the knife holder ( 4 ) with the inserted ring knife ( 5 ) into the shaft ( 1 ) and out of the shaft,
the ring knife is elongated in the shaft and takes on its ring shape outside the shaft,
and a second drive device is provided which is in operative connection with the knife holder ( 4 ) and drives it, which in turn drives the ring knife ( 5 ) used in it for the cutting movement. 2. Scalpel according to claim 1, characterized in that the knife holder ( 4 ) comprises three rollers, two of which ( 7, 8 ) outside and one ( 9 ) inside the ring knife ( 5 ) are arranged and at least one roller of the second drive device is driven to rotate and drives the ring knife via frictional forces, Fe elements ( 23 ) ensuring the pressure of the rollers. 3. scalpel according to claim 1, characterized in that the knife holder ( 4 ) spring-loaded Füh approximately rollers or rollers, between which the ring knife ( 5 ) is guided and of which at least one ( 9 ) within and two ( 7, 8 ) are arranged outside half of the ring knife, and the ring knife on the side facing away from the cutting edge ( 6 ) has a toothing ( 19 ) in which the two te drive device engages and drives the ring knife water directly for rotation. 4. scalpel according to one of claims 1 to 3, characterized in that on the shaft ( 1 ) an operating element ( 22 ) is seen before, which is connected via levers ( 21 , 10 ) with the measuring serhalterung ( 4 ) and a direct mechanical The knife holder can be moved in the direction of the shaft axis. 5. scalpel according to one of claims 2, 3 or 4, characterized in that on the shaft ( 1 ) an operating element ( 22 ) is seen before, with the lever ( 21 , 10 ; 24 , 25 ) the pressure spring force between the rollers ( 9 ; 7 , 8 ) of the knife holder ( 4 ) can be changed until the ring knife ( 5 ) is released. 6. scalpel according to claim 5, characterized in that the knife holder ( 4 ) comprises at least one conical roller ( 9 ) which cooperates with one or more cylindrical rollers ( 7 , 8 ), and the cross section of the band-like material of the ring knife ( 5 ) is a slender triangle, the cone angle of the tapered roller (s) is adapted to the triangle angle at the cutting edge ( 6 ) and the ring knife fits in the gap between the tapered roller (s) and the cylindrical roller (s). 7. scalpel according to claim 1, characterized in that the shaft ( 1 ) at the front, the knife-carrying end comprises a cylindrical tube ( 3 ) with the knife holder ( 4 ) in a further concentrically overlying tube ( 2 ) telescopic is retractable, the outer tube ( 2 ) deforming the ring knife ( 5 ) when it is retracted into the inside of the shaft. 8. Scalpel according to claim 2 or 3, characterized in that the band-like material of the ring knife ( 5 ) has a circumferential bead ( 14 ), outer locking lug ( 15 ) or an inner circumferential shoulder or locking projection ( 16 ) which rotate with one the opposing groove, counter groove or a circumferential shoulder on the rollers or rollers of the knife holder ( 4 ) comes into engagement and positions and holds the ring knife. 9. scalpel according to claim 1, characterized in that the ring knife ( 5 ) is made from a tube of a high quality non-corroding alloy spring steel. 10. Scalpel according to one of claims 1 to 9, characterized in that in the interior of the shaft ( 1 ) suction and rinsing devices are provided which extend to the front opening of the shaft. 11. A scalpel according to claim 10, characterized in that the opening of the suction and flushing lines is at the location of the ring knife ( 5 ) driven for an operation. 12. Scalpel according to claim 1, characterized in that the knife holder ( 4 ) comprises an ultrasonic vibration element ( 20 ) which is coupled to an ultrasonic generator, and the ring knife ( 5 ) is acted upon by the ultrasonic vibration element for the cutting movement with ultrasonic energy. 13. Scalpel according to claim 12, characterized in that the knife holder ( 4 ) is connected to a lever linkage ge, the actuation of which causes an inclination of the ring plane of the ring knife ( 5 ) against the axis direction of the shaft.