Treatment apparatus for surgical correction of defective eyesight, method of generating control data therefore, and method for surgical correction of defective eyesight

Patent metadata

Field	Value
Publication number	US-9370445-B2
Application number	US-201414182074-A
Country	US
Kind code	B2
Filing date	Feb 17, 2014
Priority date	Nov 10, 2006
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A treatment method and apparatus for surgical correction of defective-eyesight in an eye of a patient, wherein a laser device is controlled by a control device, said laser device separating corneal tissue by irradiation of laser radiation to isolate a volume located within a cornea, wherein the control device controls the laser device to focus the laser radiation, by providing target points located within the cornea, into the cornea, wherein the control device, when providing the target points, allows for focus position errors which lead to a deviation between the predetermined position and the actual position of the target points when focusing the laser radiation, by pre-offsets depending on the positions of the respective target points to compensate for said focus position errors.

First claim

The invention claimed is:

1. A treatment apparatus for surgical correction of defective eyesight in an eye of a patient, comprising a laser device which separates corneal tissue by irradiation of pulsed laser radiation to a focal point located within the corneal tissue, the laser device being controlled by a controller, wherein the controller controls the laser device such that said laser radiation is focused on and applied to target points arranged in a pattern in the cornea, and the controller provides control data to the laser device, wherein the control data specifies the target points to be points spaced apart on a path curve over which a focus of the laser radiation is shifted, wherein the control data causes the laser device to shift the focused laser radiation along the path curve via the target points of the pattern and to emit pulses of the pulsed laser radiation into the cornea at the target points and also to emit pulses of the pulsed laser radiation at additional intermediate points of laser application located between the target points on said path wherein the additional intermediate points of laser application are not specified target points of the control data.

2. The apparatus of claim 1 , wherein the laser device emits the pulses of the pulsed laser radiation into the cornea at a frequency f p and, wherein the laser device comprises elements shifting the focus position, to which elements the target points are supplied at a frequency f s , which is smaller than a frequency f p .

3. The apparatus of claim 1 , wherein a scanning device for shifting the focused laser radiation along said path located in the cornea and a control device, which controls the scanning device by a control signal, are provided.

4. The apparatus of claim 3 , wherein the laser device emits the pulses of the pulsed laser radiation into the cornea at a frequency f p and the maximum frequency of the control signal is smaller than f p , wherein the maximum frequency is the highest frequency at which the target points are delivered to the scanning device.

5. A method for generating control data for a laser device of a treatment apparatus for surgical correction of defective eyesight in an eye of a patient, which laser device separates corneal tissue by irradiation of focused laser radiation to a focal point located within the corneal tissue, the focused laser radiation having a certain pulse frequency, wherein the laser device is provided with control data that specifies target points for the focused pulsed laser radiation, which are arranged in a pattern in the cornea, wherein the control data define the target points as points of a path along which the focus of the laser radiation is to be shifted during the intended operation of the treatment apparatus, said target points of the control data being spaced apart on the path in such a manner that, due to the focus shifting speed and the pulse frequency of the laser device during operation of the treatment apparatus, pulses of the pulsed laser radiation are also emitted onto additional intermediate points of laser application in the cornea which are located on the path between the target points wherein the additional intermediate points of laser application are not specified target points of the control data.

6. The method of claim 5 , wherein a laser device having an adjustable pulse frequency is set to a pulse frequency which is greater than the frequency at which the target points are scanned along the path due to the focus shifting speed.

7. The method of claim 5 , wherein, in generating the control data, a functional equation is defined for the path first and evaluated at spaced-apart nodes second so as to determine the target points.

8. A method for surgical correction of defective eyesight in the eye of a patient, wherein pulsed laser radiation from a laser device controlled on a basis of a control data set is focused on specified target points that are identified in the control data set, arranged in a pattern in the cornea, to separate corneal tissue, wherein the specified target points define a path and the focused laser radiation is shifted along the path extending over the specified target points of the pattern and pulses of the pulsed laser radiation are emitted into the cornea at the specified target points and also at additional intermediate points of laser application which are located on the path between the specified target points wherein the additional intermediate points of laser application are not specified target points and are not identified in the control data set.

9. The method of claim 8 , wherein the laser device emits the pulses of the pulsed laser radiation into the cornea at a frequency f p and, wherein the laser device comprises elements shifting the focus position to which elements the target points are supplied at a frequency f s , which is smaller than the frequency f p .

10. The method of claim 8 , wherein a scanning device is provided for shifting the focused laser radiation along a path curve located in the cornea, which scanning device is controlled by a control signal.

11. The method of claim 10 , wherein the pulses of the pulsed laser radiation are emitted into the cornea at a frequency f p and the maximum frequency of the control signal is smaller than f p .

12. A planning device for determining control data for a treatment apparatus for surgical correction of defective eyesight in an eye of a patient, said planning device generating the control data for the treatment apparatus comprising a laser device, which separates corneal tissue by irradiation of pulsed laser radiation, said laser radiation being focused on target points arranged in a pattern within the cornea wherein the target points define a path along which a focus of the laser radiation is moved,
wherein the planning device
comprises an interface for supplying measurement data on parameters of the eye, and defective-eyesight data on the eyesight defect to be corrected in the eye,
defines a volume using supplied measurement and defective-eyesight data, wherein the volume is located within the cornea and wherein removal of the defined volume from the cornea causes the desired correction of defective eyesight,
determines a boundary surface, which confines the defined volume within the cornea, and
generates for said boundary surface control data to control the laser device, which control data defines a three-dimensional pattern of the target points in the cornea, which are located in the boundary surface and are arranged such that the boundary surface, after irradiation of the pulsed laser radiation according to the control data, is provided as a cut surface which isolates the defined volume in the cornea and, thus, makes the defined volume removable,
wherein the planning device generates the control data such that the control data define the target points as points of a path along which the focus of the laser radiation is to be shifted during the intended operation of the treatment apparatus, said target points of the control data being spaced apart on the path in such a manner that, due to the focus shifting speed and the pulse frequency of the laser device during operation of the treatment apparatus, pulses of the pulsed laser radiation are emitted onto the target points and also emitted onto additional intermediate points of laser application in the cornea which are located on the path between the target points wherein the additional intermediate points of laser application are not specified target points of the control data.

13. The device of claim 12 , wherein a laser device having an adjustable pulse frequency is set to a pulse frequency

Assignees

• Zeiss Carl Meditec Ag

Inventors

• Wiechmann Martin
• Bergt Michael
• Bischoff Mark
• Sticker Markus
• Stobrawa Gregor

Classifications

• A61F9/008 Primary

  using laser · CPC title

• A61F2009/00872

  Cornea · CPC title

• A61B34/10

  Computer-aided planning, simulation or modelling of surgical operations · CPC title

• A61F2009/00851

  Optical coherence topography [OCT] · CPC title

• A61F2009/00897

  Scanning mechanisms or algorithms · CPC title