US4994058A — Surface shaping using lasers

Claim 1

Independent Claim 81 words

An erodable mask for reprofiling a surface using laser radiation, the mask comprising a material erodable by laser radiation and positionable between a source of laser radiation and the surface, the mask providing a predefined profile of resistance to the said laser radiation, such that upon irradiation of the mask a portion of the laser radiation is selectively absorbed by the mask and another portion is transmitted to the surface in accordance with the mask profile, to selectively erode the surface.

Claim 2

Dependent Claim 81 words

An erodable mask for reprofiling a surface using laser radiation, the mask comprising a material erodable by laser radiation and positionable between a source of laser radiation and the surface, the mask providing a predefined profile of resistance to the said laser radiation, such that upon irradiation of the mask a portion of the laser radiation is selectively absorbed by the mask and another portion is transmitted to the surface in accordance with the mask profile, to selectively erode the surface.

Claim 3

Dependent Claim 15 words

The apparatus of claim 1 wherein the apparatus further comprises means for immobilizing the surface.

Claim 4

Dependent Claim 23 words

The mask of claim 1, wherein the mask material comprises a material selected from the group consisting of polymethylmethacrylate, polymethylstyrene and mixtures thereof.

Claim 5

Dependent Claim 17 words

The apparatus of claim 1, wherein the mask is disposed upon, and directly affixed to, the surface.

Claim 6

Dependent Claim 18 words

The mask of claim 4, wherein the mask varies in thickness to provide the predefined profile of resistance.

Claim 7

Dependent Claim 18 words

The mask of claim 4, wherein the mask varies in composition to provide the predefined profile of resistance.

Claim 8

Dependent Claim 79 words

A masking apparatus for use in laser reprofiling of corneal tissue comprising an erodable mask being erodable by radiation from a laser and capable of direct fixation upon a cornea, the mask having a predefined profile of resistance to the laser radiation, whereby upon irradiation of the mask, a portion of the laser radiation is selectively by the mask absorbed and another portion is transmitted to the cornea in accordance with the mask profile to selectively erode the tissue.

Claim 9

Dependent Claim 79 words

A masking apparatus for use in laser reprofiling of corneal tissue comprising an erodable mask being erodable by radiation from a laser and capable of direct fixation upon a cornea, the mask having a predefined profile of resistance to the laser radiation, whereby upon irradiation of the mask, a portion of the laser radiation is selectively by the mask absorbed and another portion is transmitted to the cornea in accordance with the mask profile to selectively erode the tissue.

Claim 10

Dependent Claim 16 words

The apparatus of claim 7, wherein the mask varies in thickness to provide the said profile.

Claim 11

Dependent Claim 16 words

The apparatus of claim 7, wherein the mask varies in composition to provide the said profile.

Claim 12

Dependent Claim 18 words

The apparatus of claim 7, wherein the mask is fixable to the corneal surface by a suction means.

Claim 13

Dependent Claim 45 words

The apparatus as claimed in claim 7, wherein the mask is formed at least in part from a material which is ablated or eroded by the laser radiation, the said resistance being a measure of the resistance to ablation or erosion by the laser radiation.

Claim 14

Dependent Claim 30 words

The apparatus of claim 7, wherein the mask has a diameter in the range of about 3 to 12 millimeters and a maximum thickness of about 2 millimeters or less.

Claim 15

Dependent Claim 16 words

The apparatus of claim 12, wherein the mask is formed from polymethylmethacrylate, polymethylstyrene, or mixtures thereof.

Claim 16

Dependent Claim 103 words

Laser apparatus for reprofiling a surface comprising a laser means, control means for controlling the laser means to project laser radiation towards the surface, and an erodable masking means adapted to be disposed between the laser means and the surface, said masking means being erodable by the radiation from the laser means and having a predefined profile of resistance to the laser radiation, so that upon irradiation of the masking means, a portion of the laser radiation is selectively absorbed by the masking means and another portion is transmitted to the surface in accordance with the mask profile to selectively erode the surface.

Claim 17

Dependent Claim 103 words

Laser apparatus for reprofiling a surface comprising a laser means, control means for controlling the laser means to project laser radiation towards the surface, and an erodable masking means adapted to be disposed between the laser means and the surface, said masking means being erodable by the radiation from the laser means and having a predefined profile of resistance to the laser radiation, so that upon irradiation of the masking means, a portion of the laser radiation is selectively absorbed by the masking means and another portion is transmitted to the surface in accordance with the mask profile to selectively erode the surface.

Claim 18

Dependent Claim 37 words

Laser apparatus as claimed in claim 15, in which the masking means is formed from material which is ablated by absorption of the laser radiation so that the masking means is progressively destroyed during the surface reprofiling.

Claim 19

Dependent Claim 33 words

Laser apparatus as claimed in claim 14, in which the masking means comprises a tray or well of optically transparent material in which a quantity of a selected masking material can be contained.

Claim 20

Dependent Claim 26 words

Laser apparatus as claimed in claim 14, in which the material forming the masking means is selected to have similar ablation characteristics to the surface material.

Claim 21

Dependent Claim 21 words

Laser apparatus as claimed in claim 14, in which the masking means is formed from polymethylmethacrylate or polymethylstyrene or mixtures thereof.

Claim 22

Dependent Claim 28 words

Laser apparatus as claimed in claim 14, in which the masking means comprises a mask which is adapted to be disposed upon, and directly affixed to, the surface.

Claim 23

Dependent Claim 47 words

Laser apparatus as claimed in claim 19, in which the mask is constructed so as to have a first surface contoured to conform to the surface to be eroded and a second surface contoured to provide the desired surface contour following erosion by exposure to laser radiation.

Claim 24

Dependent Claim 14 words

The apparatus of claim 14, wherein the laser means is a pulsed excimer laser.

Claim 25

Dependent Claim 21 words

The apparatus of claim 21 wherein the excimer laser is an Argon-Fluoride laser operating at a wavelength of about 193 nanometers.

Claim 26

Independent Claim 99 words

A method of reprofiling a surface comprising: locating a laser means relative to a surface, the laser means being operable to deliver laser radiation to the surface; and disposing an erodable masking means between the laser means and the surface, the masking means being erodable by radiation from the laser means and having a predefined profile of resistance to the laser radiation, and irradiating the masking means, whereby a portion of the radiation is selectively absorbed by the masking means and another portion is transmitted to the surface, in accordance with the mask profile, to selectively erode the surface.

Claim 27

Independent Claim 99 words

A method of reprofiling a surface comprising: locating a laser means relative to a surface, the laser means being operable to deliver laser radiation to the surface; and disposing an erodable masking means between the laser means and the surface, the masking means being erodable by radiation from the laser means and having a predefined profile of resistance to the laser radiation, and irradiating the masking means, whereby a portion of the radiation is selectively absorbed by the masking means and another portion is transmitted to the surface, in accordance with the mask profile, to selectively erode the surface.

Claim 28

Dependent Claim 32 words

A method as claimed in claim 23 wherein the step of locating a laser means relative to a surface further comprises locating the laser means relative to a cornea of the eye.

Claim 29

Dependent Claim 40 words

A method as claimed in claim 23 wherein the step of locating a laser means relative to a surface further comprises locating the laser means relative to a biological tissue such as a ligament or a cartilage in a bone.

Claim 30

Dependent Claim 25 words

A method as claimed in claim 23, wherein the method further includes varying the thickness of the masking means to provide the profile of resistance.

Claim 31

Dependent Claim 25 words

A method as claimed in claim 23, wherein the method further includes varying the composition of the masking means to provide the profile of resistance.

Claim 32

Dependent Claim 26 words

A method as claimed in claim 23, wherein the step of irradiating the masking means further includes irradiating the masking means with a pulsed laser means.

Claim 33

Dependent Claim 42 words

A method as claimed in claim 28, wherein the step of irradiating the masking means further includes irradiating the masking means with a single pulse which is set to erode a depth in the range 0.1 to 1 micrometer of surface material.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-02-18	1994-08-20	1995-02-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-02-18	1998-08-20	1999-02-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-02-18	2002-08-20	2003-02-19	$7700.00	Window Closed / Lapsed

Surface shaping using lasers

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