EP0293126A1
Expired / Lapsed
EP
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Photocoagulation apparatus
Assignee: Keeler Ltd
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Filing: 1988-05-17
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Granted: —
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Expires: 2008-05-17
Abstract
Abstract The invention provides a photocoagulator using an infrared laser diode source (70). A dichroic beam splitter (68) is used to combine the optical path of the laser system with the viewing system. Such an arrangement affords the clinician an uninterupted, uncolour view of the patient's eye during treatment, without any risk of damage to the clinician's eye. There is also provided an alignment system using a visible laser diode (80). The alignment system may include a number of mutually non parallel beams which pass through different portions of the pupil and provide information on aim, focus and vignetting.
Inventors
- 👤 Anthony Raven
- 👤 John Marshall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 21:41
CPC Classifications
A; A61; A61F; A61F9/00; A61F9/007; A61F9/008; A61F9/00821; A61B; A61B18/00; A61B18/18; A61B18/20; A61B2018/2015; A61B2018/2025; A61F2009/00861; A61F2009/00863
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
100 words
A laser photocoagulator including a laser system and a viewing system, characterised in that the laser system includes a laser source which operates in the infrared range, and said viewing system and said laser system have in common a dichroic beam splitter which, in use, seperates infrared light from visible light, said viewing system and said laser system sharing a substantially common ray path between said dichroic beam splitter and the eye of a patient, whereby the clinician may view a patient's eye through the beam splitter substantially without risk of exposure to the infrared laser light used for treatment.
Claim 2
Dependent Claim
100 words
A laser photocoagulator including a laser system and a viewing system, characterised in that the laser system includes a laser source which operates in the infrared range, and said viewing system and said laser system have in common a dichroic beam splitter which, in use, seperates infrared light from visible light, said viewing system and said laser system sharing a substantially common ray path between said dichroic beam splitter and the eye of a patient, whereby the clinician may view a patient's eye through the beam splitter substantially without risk of exposure to the infrared laser light used for treatment.
Claim 3
Dependent Claim
20 words
A photocoagulator as claimed in claim 1, wherein said infrared laser source emits light with a wavelength of substantially 800nm.
Claim 4
Dependent Claim
21 words
A photocoagulator as claimed in claims 1 or 2, wherein said dichroic beam splitter reflects infrared light and transmits visible light.
Claim 5
Dependent Claim
38 words
A photocoagulator as claimed in claims 1, 2 or 3, wherein said laser system includes means for reducing the magnification in one direction of the image of the infrared laser which, in use, is produced on the retina.
Claim 6
Dependent Claim
31 words
A photocoagulator as claimed in claim 4, wherein said magnification reducing means comprises an anamorphic prism pair arranged so as to reduce the magnification of the image in its longest direction.
Claim 7
Dependent Claim
36 words
A photocoagulator as claimed in any preceding claim, wherein said laser system includes optical means providing an optimum beam diameter of the infrared laser light which, in use, passes through the pupil of the patient's eye.
Claim 8
Dependent Claim
14 words
A photocoagulator as claimed in claim 6, wherein said optical means comprises a telescope.
Claim 9
Dependent Claim
22 words
A photocoagulator as claimed in any preceding claim, wherein the laser system further includes an alignment system incorporating a visible light source.
Claim 10
Dependent Claim
17 words
A photocoagulator as claimed in claim 8 wherein the visible light source comprises a visible laser diode.
Claim 11
Dependent Claim
59 words
A photocoagulator as claimed in claim 8 or 9, wherein said laser system includes a dichroic beam combiner or polarising beam combiner so arranged as to cause the visible light from said alignment system to share the same optical path with the infrared laser light between said dichroic beam combiner or polarising beam and the eye of the patient.
Claim 12
Dependent Claim
92 words
A photocoagulator as claimed in claim 8, 9 or 10, wherein said alignment system, in use, provides a plurality of beams of visible light incident on the retina, said beams being arranged to pass through different portions of the pupil such that if said photocoagulator is misaligned with the iris at least one of the beams will be at least partly blocked by the iris, and the pattern produced by the beams on the retina also providing an indication of whether or not the infrared laser light is focused on the retina.
Claim 13
Dependent Claim
85 words
An alignment system for a photocoagulator, the system producing, in use, a plurality of beams of visible light which are incident on the retina, said beams being arranged to pass through different portions of the pupil, such that if the photocoagulator is misaligned with the pupil at least one of said beams will be at least partly blocked by the iris, and the pattern produced by said beams on the retina also being indicative of whether or not the photocoagulator is focused on the retina
Claim 14
Dependent Claim
85 words
An alignment system for a photocoagulator, the system producing, in use, a plurality of beams of visible light which are incident on the retina, said beams being arranged to pass through different portions of the pupil, such that if the photocoagulator is misaligned with the pupil at least one of said beams will be at least partly blocked by the iris, and the pattern produced by said beams on the retina also being indicative of whether or not the photocoagulator is focused on the retina
Claim 15
Dependent Claim
23 words
An alignment system for a photocoagulator as claimed in claim 12, wherein the light source for the alignment system produces visible laser light.
Claim 16
Dependent Claim
20 words
An alignment system for a photocoagulator as claimed in claim 13, wherein the light source is a visible laser diode.
Claim 17
Dependent Claim
31 words
An alignment system as claimed in claim 12, wherein said visible beams converge to a spot or well defined pattern on the retina when the photocoagulator is focused on the retina.
Claim 18
Dependent Claim
45 words
An alignment system as claimed in claim 12, wherein said beams are mutually non-parallel, the arrangement being such that the configuration of a pattern produced on the retina by the visible beams is indicative of whether or not the photocoagulator is focused on the retina.
Claim 19
Dependent Claim
46 words
An alignment system as claimed in claim 16, wherein each of said visible beams has a non-circular cross-section when incident on the retina, the relative alignment of the shapes produced on the retina being indicative of whether or not the photocoagulator is focused on the retina.
Claim 20
Dependent Claim
27 words
An alignment system as claimed in claims 16 or 17, wherein beams are provided by illuminating a target with a plurality of nonparallel collimated beams of light.
Claim 21
Dependent Claim
22 words
An alignment system as claimed in claim 18, wherein said nonparallel collimated beams are provided by one or more split field screens.
Claim 22
Dependent Claim
29 words
An alignment system as claimed in any of claims 16 to 19, wherein said mutually nonparallel beams produce a cross-shaped pattern when the photocoagulator is focused on the retina.
Claim 23
Dependent Claim
35 words
An alignment system as claimed in claim 20, wherein said target comprises a circular disc formed with four slits disposed on orthogonal radii and extending inwards towards, but without reaching, the centre of said disc.
Claim 24
Dependent Claim
43 words
An alignment system as claimed in claim 19 and in claims 20 or 21 including a pair of split field screens disposed on the optical axis of alignment system, the second of the screens being rotated by 90° with respect to the first.
Claim 25
Dependent Claim
19 words
An alignment system as claimed in claim 21 and 22, wherein said screens are incorporated in the target disc.
Claim 26
Dependent Claim
21 words
A photocoagulator as claimed in claim 11, wherein said alignment system is as claimed in any of claims 15 to 23.
Claim 27
Dependent Claim
31 words
A photocoagulator as claimed in any of claims 1 to 11 or 24, wherein said viewing system is in the general form of a direct or indirect ophthalmoscope or slit lamp.
Claim 28
Dependent Claim
56 words
A photocoagulator as claimed in any of claims 1 to 11 or 24 wherein said viewing system is in the general form of a slit lamp and a diverging lens is disposed between the slit lamp and the patient's eye so as to move the focal point of the slit lamp further from the slit lamp.
Claim 29
Dependent Claim
18 words
A photocoagulator as claimed in claim 25 or 26, wherein said viewing system is demountable from said photocoagulator.
Claim 30
Dependent Claim
18 words
A photocoagulator as claimed in any preceding claim, wherein said infrared light source includes an infrared laser diode.
Claim 31
Dependent Claim
33 words
A photocoagulator as claimed in claim 28, wherein said infrared light source includes at least one further infrared laser diode and means for combining the infrared light produced by said infrared laser diodes.
Claim 32
Dependent Claim
20 words
A laser photocoagulator including an alignment system incorporating a laser diode providing an output in the visible range of wavelengths.
Claim 33
Dependent Claim
20 words
A laser photocoagulator including an alignment system incorporating a laser diode providing an output in the visible range of wavelengths.
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