DE202016008049U1 - Suction device and use of the suction device in a laser ablation - Google Patents

Abstract

A suction device configured to aspirate a cloud (300) resulting from material ablation on an object by laser (200), the suction device comprising: a tubular nozzle (100) extending in an axial direction (L) at its free end End (101a) has an opening with a cross-sectional area without corners connectable at its other end (101b) to an exhaust system having a pipe section having a predetermined length (LD) of substantially equal cross-section as measured from the free end; wherein the cross-sectional area has a short axis and a long axis.

Description

The invention relates to the field of laser ablation. More particularly, the invention relates to a suction device configured to aspirate a cloud of material formed upon ablation of an object by laser, in particular by means of an excimer laser, which has been ablated from the object. The invention further relates to the use of such a suction device for aspirating a resulting in the ablation of an object by means of laser, in particular excimer laser, cloud of material.

The invention further relates to a method for aspirating a resulting in an ablation of an object by means of laser, in particular excimer laser, cloud of material, in particular using the suction device described.

There are devices and methods for laser ablation, in particular excimer laser known. These devices and methods are particularly useful for the treatment of the human eye, such as LASIK treatment, e.g. for correcting a defective vision of a human eye and / or for restoring the vision of the human eye. In recent years, such excimer laser systems have been continuously improved, in particular, the laser pulse repetition rate has been continuously increased.

It is known that the excimer laser ablation creates a cloud of material over the eye. This cloud, also called "plume" in the following, may consist of tissue fragments detached during ablation, such as cell fragments, in particular of the cornea and stroma, lipid droplets and water droplets, but also of gases, especially CO _2, and biological materials, such as airborne viruses (eg papilloma or HIV ), Proteins (like prions), entrained bacteria and fungi.

The cloud is formed at a distance from the surface of the eye to be treated, whereby the laser beam used for the treatment can be affected by this cloud. The cloud allows the laser beam to be scattered and / or the energy of the laser pulses occurring on the surface to be treated to be reduced on the eye.

The following example explains the formation of the plume in the treatment of a human eye. After striking an excimer laser pulse on the cornea of the eye, due to the Fotoablationseffekts, tissue with a layer thickness of a few 100 nm vertically upwards blown away in the direction of the laser beam by evaporation. In this case, the weggespengte fabric in the first 500 ns can reach a speed of about 400 m / s (about 1.15 times the speed of sound). Thereafter, the flow rate is reduced very rapidly, until the tissue at a height of about 20 to 30 mm above the cornea to levitate (steady state) and the cloud (plume) forms. This steady state is reached after about 200 ms. The duration between two laser pulses in current devices is typically 1.0 to 2.0 ms, depending on the pulse repetition frequency (500 to 1000 Hz). The values mentioned relate to an exemplary laser system with a wavelength of 193 nm, which is operated in a pulsed mode and has a pulse duration of about 10 ns.

In the example mentioned, with increasing particle flux density, the stationary dimensions of the cloud, i. Plume dimensions. Furthermore, the plume propagation rates increase with increasing particle flux density. The particle size in the plume is about 0.22 μm on average. In a typical excimer laser design, the laser beam passes through the plume of detached material and is partially scattered and / or partially absorbed. As the laser pulse repetition rate increases, the plume formed per unit time increases, and hence the need for effective removal of the ablation products.

The US Pat. No. 6,497,700 B1 relates to a multifunctional surgical instrument for performing ophthalmological operations on the eye by means of a laser. The instrument includes upper and lower rings, with openings provided on the upper ring to control smoke and particulate created during ablation.

The EP 1 395 189 B1 relates to an arrangement for removing material by means of laser radiation from a surface of an object, wherein by means of an air conveyor and a suction device during the duration of the ablation process, an air flow over the Abtragungsort away.

The invention has for its object to provide a suction device and their use, with the reliable and effective in a laser ablation detached material can be removed.

This object is achieved with the features of the independent claims. The dependent claims relate to further aspects of the invention.

The invention is based on the idea to use a tubular nozzle, which is designed so that the cloud of eroded material safely and effectively removed. The invention is based on the finding that a laminar flow can be used to advantage. In particular, the effect is used that with a suitable selection of geometrical dimensions of the tubular nozzle and of suction parameters, a laminar suction flow can be generated, whereby the material sucks effectively and at the same time the technical complexity for the suction is reduced. It was further recognized that a certain orientation of the tubular nozzle relative to the object and / or depending on the dimensions and / or suction parameters is also advantageous for effective extraction.

In particular, in embodiments involving ablation of a portion of the human body, it has been found that, in the formation of a laminar flow, the natural flow due to delivered body heat should be considered technically.

The investigations which led to the device and use according to the invention showed that the suction should take place stably over a distance range predetermined by a range of movement of the ablation point. The invention describes certain advantageous value ranges for the dimensions and arrangement of the tubular nozzle as well as the suction parameters in which for certain applications, e.g. the treatment of the human eye, a significantly improved suction is achieved. The following areas comprise several preferred embodiments, which are particularly advantageous in the treatment of the human eye by means of excimer lasers. In particular, the invention makes it possible to shorten the treatment time, as can be achieved, for example, by increasing the laser energy or by increasing the laser pulse repetition rate.

According to the invention, the suction device is configured to aspirate a laser-generated cloud upon material ablation on an object, the suction device comprising: a tubular nozzle extending in an axis direction having at its free (distal) end an opening with a cross-sectional area without corners connectable at its other (proximal) end to an aspirating system having a tubular portion having a predetermined length of substantially equal cross-section as measured from the free end and the cross-sectional area having a short axis and a long axis.

In one aspect of the invention, the particular length is greater than 15 mm and / or the short axis has a length of 6 to 14 mm and / or the long axis has a length of 16 to 24 mm.

In one aspect of the invention, the cross-sectional area is elliptical and / or the short axis to long axis length ratio a: b is in the range of 1: 4 to 7: 8, preferably 1: 2.

In one aspect of the invention, the tubular nozzle at least in the region of the pipe section has a wall thickness of about 1.5 mm, wherein the wall thickness is to be designed depending on the material so that the lowest possible noise occurs at the intended extraction speed. In other words, the wall thickness is preferably chosen as a function of the material used and the tube geometry so that low flow noise occurs and the tubular nozzle ensures sufficient stability in the air flow used. Preferably, the wall thickness over the length of the pipe section is the same or increases toward the free end.

In one aspect of the invention, the tubular nozzle, preferably the pipe section, and more preferably the free end of the tubular nozzle, is deformable, the outer shape being deformable with respect to the cross-sectional area and / or the axial direction of the tubular nozzle.

In one aspect of the invention, the tubular nozzle is made of a material that is deformable, preferably elastically deformable, wherein the material is preferably an elastomer.

In particular, in one aspect of the invention, the tubular nozzle is one or more of the following: the cross-section of the opening area, the cross-section of the opening shape, the length of the pipe section and the material of the pipe, in particular the properties of the pipe configured as stability and ductility, a laminar air flow to effect in front of the free end of the tubular nozzle and / or at least in the pipe section.

In one aspect of the invention, the laminar air flow has a velocity of the air flow measured at the opening of the free end of the tubular nozzle of 20-30 m / s.

The invention further relates to the use of a device according to one of the preceding aspects for aspirating a laser-generated cloud during ablation of an eye, wherein the device can be arranged along a nose side relative to the human eye such that the tubular nozzle is at an angle of about 36.7 degrees + 5 degrees relative to a treatment level and about 90 degrees ± 10 Degree relative to an axis which is parallel to the axis of connection of the two eyes of a human is arranged.

In one aspect of the invention, the free end may be at a distance from the ablation point of 10 to 40 mm, preferably 20 to 30 mm, and more preferably about 25 mm, and / or the free end in a plane parallel to a plane containing the ablation point , be arranged at a distance of 8 to 20 mm, preferably 10 to 16 mm and particularly preferably about 13 mm.

The invention further comprises a method for aspiration with a device according to one of the preceding aspects for aspirating a laser-generated cloud in an ablation of an eye, wherein the device is arranged along a nose side in such a way relative to the human eye that the tubular nozzle in a Angle of about 36.7 degrees + 5 degrees with respect to a treatment level and about 90 degrees + 10 degrees with respect to an axis that is parallel to the connecting axis of the two eyes of a human is arranged.

In one aspect of the method of the invention, the proximal end may be spaced from the ablation point by 10 to 40 mm, preferably 20 to 30 mm, and more preferably about 25 mm, in a plane parallel to a plane containing the ablation point at a distance of 8 to 20 mm, preferably 10 to 16 mm and more preferably about 13 mm are arranged.

The invention is particularly applicable to laser systems that operate at a higher laser repetition rate. Although the laser pulse repetition rate is greater, according to the invention the better suction removes the plume in the shorter time available between the laser pulses.

list of figures

• 1 die Vorrichtung gemäß einer Ausführungsform der Erfindung in einer Seitenansicht,
• 2 die Vorrichtung gemäß einer Ausführungsform der Erfindung in einer Draufsicht,
• 3a das distale Ende der rohrförmigen Düse gemäß einer Ausführungsform der Erfindung in einer Vorderansicht,
• 3b das distale Ende der rohrförmigen Düse in gedrehter Orientierung gemäß einer Ausführungsform der Erfindung in einer Vorderansicht,
• 4 die Vorrichtung gemäß einer Ausführungsform der Erfindung zur Behandlung eines menschlichen Auges in einer Draufsicht, und
• 5 die Vorrichtung gemäß einer Ausführungsform der Erfindung zur Behandlung eines menschlichen Auges in einer Seitenansicht.

The invention is explained below with reference to examples and the drawings. Show it:

• 1 the device according to an embodiment of the invention in a side view,
• 2 the device according to an embodiment of the invention in a plan view,
• 3a the distal end of the tubular nozzle according to an embodiment of the invention in a front view,
• 3b the distal end of the tubular nozzle in a rotated orientation according to an embodiment of the invention in a front view,
• 4 the device according to an embodiment of the invention for the treatment of a human eye in a plan view, and
• 5 the device according to an embodiment of the invention for the treatment of a human eye in a side view.

Detailed description of the invention

In 1 is the tubular nozzle according to the invention 100 shown in a side view. The nozzle 100 has a free or distal end 101 and another or proximal end 101b on. The ablation takes place by means of laser pulses in a treatment area of an eye, with a laser beam axis as an example 200 is shown at a point P0. Point P0 marks the center of the treatment area in a plane E0, also referred to as the treatment plane or ablation plane. The laser beam axis 200 also defines a first direction z. In the plane E0 is a second direction y, which is perpendicular to the first direction z. Parallel and above the plane E0 is a plane E1. In the plane E1 is at least a lower point of an outer periphery of the distal end 101 , ie the free end, of the tubular nozzle 100 lies. The distance between the planes E1 and E0 is labeled A1. In other words, A1 is the distance between the treatment plane and a lower point on the outer circumference of the distal end 101 a along the direction of the laser beam. With respect to the laser beam axis shown in the figure 200 has an upper point on the outer circumference of the distal end a distance A2. The extension of an axis L of the tubular nozzle 100 cuts a plane E2 in which the center of the plume 300 located at a point P1. The distance between the planes E1 and E2 is denoted by A5.

The distal end 101 is located in the z direction approximately at the distance A1 and in the y direction approximately at a distance A2 from the ablation point P0.

Further, the axis L is arranged at an angle α with respect to the plane E1.

In 2 is the tubular nozzle according to the invention 100 shown in a plan view in the direction z. Perpendicular to the second direction y, a third direction x is defined. The laser beam axis 200 and the point P0 and the planes E1 and E0 are superimposed in this projection, the latter being shown separately for illustration purposes. A distance between an intersection P2 of the axis L and the direction x in a projection on the plane E0 defines a distance A3. In other words, the axis L may be offset by a distance A3 to the ablation point P0. A distance between the direction x and the next point on the outer circumference of the proximal end 101 defines a distance A4. In other words, the distal end 101 is located approximately at the distance A4 with respect to the y direction. As a result, the distances A2 and A4 are similar. Further, the tubular nozzle with respect to the y axis rotation about the angle γ-7 °.

From the 1 and 2 result in the spatial arrangement of the tubular nozzle and the parameters required to determine the arrangement. In the case of ablation by means of a laser system, the ablation point is not always in the same place; instead, depending on the application, the ablation point constantly varies its position in the treatment area, the direction of the laser axis 200 is actively controlled.

In the treatment of the human eye, the ablation laser is preferably combined with an eye-tracking system, so that a targeted ablation despite moving eyes 401 . 403 is possible. In principle, it is possible to use the tubular nozzle 100 also nachzuführen. However, it is advantageous if the suction area is larger and thus the range of motion of the ablation point is included around the point P0 shown in the figure. In other words, the plume becomes 300 , which arises at a varying ablation point, always lie in the suction area. In particular, it should be emphasized here that the distances A5 and A3 can be very small or even zero. In this embodiment, the axis L is at a center of the plume 300 directed.

The in the in 3a and 3b shown embodiment of the tubular nozzle 100 has an elliptical cross-section. The tubular nozzle 100 has an extension a along the short axis and an extension b along the long axis. Both dimensions are measured on the outer circumference. The wall thickness, ie the mean distance between the outer peripheral surface and the inner peripheral surface is denoted by d. The internal dimensions of the cross section arise accordingly. Furthermore, as in 3a shown the tubular nozzle about the axis L at an angle φ to be rotated. Furthermore, in particular the angle φ can be zero; this embodiment is particularly preferred.

In other words, in a particularly preferred embodiment is a tubular nozzle 100 arranged so that the long axis of the preferably elliptical cross section is parallel to the body surface, ie the cheek or the forehead or eye socket.

In all embodiments of the invention, the proximal end is 101b the tubular nozzle 100 suitable to be directly or indirectly connected to a suction device, so that in the tubular nozzle 100 an airflow is created and a suction at the distal end 101 is possible.

According to the invention, suction parameters become the geometric dimensions of the tubular nozzle 100 and their arrangement with respect to the ablation point P0 and the laser beam axis 200 chosen so that a laminar flow of the suction air is achieved.

In one embodiment of the invention, the cross-section is the tubular nozzle 100 elliptical. The person skilled in the art recognizes that, according to the invention, further cross sections without corners are possible, which enable the formation of a laminar flow. An elliptical or quasi-elliptical cross section is particularly preferred. In each embodiment, the parameters described herein are selected to achieve laminar flow.

In 4 the device according to an embodiment of the invention for the treatment of a human eye is shown in a plan view. In addition to the in 2 shown elements are two eyes 401 and 403 as well as a nose 402 shown schematically. The arrangement of the tubular nozzle 100 in relation to the eye to be treated 401 is shown. For the treatment of the other eye 403 The angles and distances of the embodiment result from reflection on an axis along the nose 402 ,

In 5 the device according to an embodiment of the invention for treating a human eye is shown in a side view. In addition to the in 1 The elements shown are the eye to be treated 401 and the nose 402 shown.

In one embodiment, the device of the invention is configured to be integrated with a human eye treatment system. The treatment system is designed for use in accordance with the invention. Furthermore, at least one further component selected from the following is integrated in the treatment system: a suction device, a laser source, a suction control device, a tubular nozzle position changing device 100 ,

It should be noted that all elements in the figures, in particular the tubular nozzle 100 , the plume 300 , and the distances A1 to A5 are shown only schematically, and can be derived no relative size ratios.

Although the invention by means of the figures and the associated description and illustrated are described in detail, these illustrations and this detailed description are illustrative and exemplary and not limiting as the invention. It should be understood that those skilled in the art can make changes and modifications without departing from the scope and spirit of the following claims. In particular, the invention also includes embodiments with any combination of features that are referred to or shown in various embodiments.

The invention also comprises individual features in the figures, even if they are shown there in connection with other features and / or not mentioned. The disclosure includes embodiments that include only the features described in the claims and the embodiments, as well as those that include additional other features.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 6497700 B1 [0008]
• EP 1395189 B1 [0009]

Claims (10)

A suction device configured to aspirate a cloud (300) resulting from material ablation on an object by laser (200), the suction device comprising: a tubular nozzle (100), which extends in an axis direction (L) having at its free end (101a) an opening with a cross-sectional area without corners, which is connectable to an exhaust system at its other end (101b), which has a pipe section which, measured from the free end, has a specific length (LD) of essentially the same cross-section, wherein the cross-sectional area has a short axis and a long axis. Device after Claim 1 , wherein the determined length (LD) is greater than 15 mm, and / or wherein the short axis (a) has a length of 6 to 14 mm and / or the long axis (b) has a length of 16 to 24 mm. Device after Claim 1 or 2 wherein the cross-sectional area is ellipsoidal and / or the short axis to long axis a: is in the range of 1: 4 to 7: 8, preferably 1: 2. Device according to one of Claims 1 to 3 wherein the tubular nozzle (100) has a wall thickness (d) at least in the region of the tube section and wherein preferably the wall thickness (d) is equal over the length of the tube section or increases towards the free end (101a), the wall thickness being preferably dependent From the material used and the tube geometry is chosen so that low flow noise and the tubular nozzle ensures sufficient stability in the air flow used. Device according to one of Claims 1 to 4 in which the tubular nozzle (100), preferably the tube section and particularly preferably the free end (101a) of the tubular nozzle (100), is deformable, the external shape being relative to the cross-sectional area and / or the axial direction of the tubular nozzle (100). 100) is designed deformable. Device after Claim 5 wherein the tubular nozzle (100) is made of a material which is deformable, preferably elastically deformable, wherein the material is preferably an elastomer. Device according to one of the preceding claims, wherein the tubular nozzle (100) in particular one or more of the following: the cross section of the opening area, the cross section of the opening shape, the length of the pipe section and the material of the tube, in particular the properties of the tube such as stability and deformability is configured to cause a laminar flow of air in front of the free end of the tubular nozzle and / or at least in the pipe section. Device after Claim 7 wherein the laminar air flow has a velocity of the air flow measured at the opening of the free end (101a) of the tubular nozzle (100) of 20-30 m / s. Use of a device according to any one of the preceding claims for aspirating a cloud (300) resulting from an ablation of an eye by laser (200), the device being arranged along a nose side relative to the human eye (401) such that the tubular nozzle (100) at an angle of about 36.7 degrees + 5 degrees with respect to a treatment plane (E0) and / or about 90 degrees + 10 degrees relative to an axis parallel to the axis of connection of the two eyes (401, 402) of a human is located. Use after Claim 9 wherein the free end (101a) is spaced apart from an ablation point (P0), the distance being in a range of 10 to 40 mm, preferably 20 to 30 mm, and more preferably about 25 mm, and / or the free one End in a plane parallel to a plane (E0) containing the ablation point (P0), at a distance of 8 to 20 mm, preferably 10 to 16 mm and particularly preferably about 13 mm is arranged.

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