The present application relates to a probe for use in ophthalmic procedures and more particularly to a multispot laser probe for use in photocoagulation.
Laser photocoagulation therapy addresses ocular conditions such as retinal detachments and tears as well as proliferative retinopathy resulting from diseases such as diabetes. The abnormally high blood sugar in a diabetic stimulates the retinal vessels to release growth factors that in turn encourage an undesirable proliferation of blood vessels and capillaries over the retinal surface. These proliferated blood vessels are very delicate and will readily bleed into the vitreous. The body responds to the damaged vessels by producing scar tissue, which may then cause the retina to detach so as to eventually cause blindness.
In laser photocoagulation, a laser probe is used to cauterize the blood vessels at various laser burn spots across the retina. Because the laser will also damage the rods and cones that are present in the retina to allow vision, eyesight, as well as the blood vessels, is affected. Since vision is most acute at the central macula of the retina, the surgeon arranges the resulting laser burn spots in the peripheral areas of the retina. In this fashion, some peripheral vision is sacrificed to preserve central vision. During the procedure, the surgeon drives the probe with a non-burning aiming beam such that the retinal area to be photocoagulated is illuminated. Due to the availability of low-power red laser diodes, the aiming beam is generally a low-power red laser light. Once the surgeon has positioned the laser probe so as to illuminate a desired retinal spot, the surgeon activates the laser through a foot pedal or other means to then photocoagulate the illuminated area. Having burned a retinal spot, the surgeon repositions the probe to illuminate a new spot with the aiming light, activates the laser, repositions the probe, and so on until a suitable array of burned laser spots are distributed across the retina.
The number of required laser photocoagulations for any one treatment of the retina is large—for example, 1,000 to 1,500 spots are commonly burned. It may thus be readily appreciated that if the laser probe was a multi-spot probe enabling the burning of multiple spots with each position of the probe, the photocoagulation procedure would be faster (assuming the laser source power is sufficient). Existing multi-spot probes may be inadequate in some respects and thus, there is a need in the art for improved multi-spot laser probes.
Further aspects, forms, embodiments, objects, features, benefits, and advantages of the present invention shall become apparent from the detailed drawings and descriptions provided herein.
In one embodiment, an ophthalmic laser probe system comprises an array of optical waveguides and an adapter operable to connect with a laser source. The laser probe system further includes a first reflective surface within the adapter. The first reflective surface is movable about a first axis. The laser probe system also includes a second reflective surface within the adapter. The second reflective surface is movable about a second axis, orthogonal to the first axis. The first reflective surface is configured to receive a laser beam emitted from the laser source and redirect the laser beam toward the second reflective surface.
In another embodiment, a method of laser photocoagulation comprises providing an adapter for connecting a laser source to array of optical waveguides and directing a laser beam from the laser source toward a first reflective surface arranged in a first configuration. The method also includes receiving the laser beam reflected from the first reflective surface at a second reflective surface and directing the laser beam from the second reflective surface to a first optical waveguide in the array of optical waveguides.
In still another embodiment, a laser probe adapter comprises a first connector portion sized and configured for connection to a subminiature version A (SMA) connector on a laser source. The adapter further includes a second connector portion sized and configured for connection to an array of optical waveguides. The adapter further includes a first reflective surface movable about a first axis and a second reflective surface movable about a second axis orthogonal to the first axis. The first reflective surface is configured to receive a laser beam emitted from the laser source and redirect the laser beam toward the second reflective surface.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
a, 10b, 10c, and 10d are radial cross sectional views of a multi-fiber array with an optical assembly in four different configurations according to an embodiment of the present disclosure.
a, 12b, 12c, 12d are different configurations of multiple laser beam spots on an image plane according to the embodiment of
a, 14b, 14c, 14d, 14e, and 14f are different configurations of multiple laser beam spots on an image plane according to the embodiment of
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments, or examples, illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one of ordinary skill in the art to which the invention relates.
The adapter 102 includes an adapter body 111 in which a bore 112 extends. In this embodiment, the adapter body 111 includes a proximal male connector 114 and a distal female connector 116. The male connector 114 may be sized and shaped to connect with the interconnect 108, and thus may be, for example, a male SMA connector. The female connector 116 may be sized and shaped to interconnect with the optical connector 106. It is understood that the male and female configurations of the adapter connectors are merely examples and other types of known interconnect formations may be suitable. In this embodiment, a ring connector 107 threadedly connects with the interconnect 108 to secure the adapter 102 to the laser source 104. A retaining ring 109 retains the ring connector 107, preventing it from slipping distally off of the adapter housing 111.
The adapter 102 further includes an optical assembly 117 which includes a collimating lens 118, such as a GRIN lens, disposed in the bore 112 to receive and collimate the laser beam 105. The adapter 102 also includes a movable reflective device 120 to redirect the collimated laser beam 105. The adapter 102 also includes a movable reflective device 122 to redirect the collimated laser beam 105. Each of the reflective devices 120, 122 may be, for example, a micro-electromechanical mirror that is pivotable between one or more positions. The adapter 102 also include a focusing lens 124, such as a GRIN lens, which receives and focuses the laser beam 105. Movement of the reflective devices 120, 122 allows the focused laser beam 105 to be moved in two dimensions on an image plane, as will be discussed in greater detail below.
An actuation system 123 operates the movable reflective devices 120, 122. The actuation system 123 includes electrical wires to deliver power to motors which operate the devices 120, 122. Portions of the actuation system 123 may be located in the adapter 102. The actuation system 123 is controlled by a control system 125. The control system 125, such as a laptop computer running control software, is also connected to the laser source 104. The control system 125 may be used to synchronize the laser with the motion of the reflective devices 120, 122. For example, the laser 104 may be blocked when the reflective devices 120, 122 are in motion and unblocked when the reflective devices are stopped. Alternatively the laser 104 may be pulsed when the reflective devices 120, 122 are stopped and not pulsed when the reflective devices are in motion. Other techniques to generate an on/off pattern for the laser, as are known in the art, may be used to synchronize the laser with the scanning of the reflective devices.
The optical connector 106 has a proximal end 126 inserted into the female connector 116 of the adapter 102. The optical connector 106 may be, for example, a straight tip (ST) connector to permit rotational alignment between adapter 102 and an array of waveguides in the optical connector 106. The proximal end 126 of the optical connector 106 is separated from the distal end of the GRIN lens 124 by a suitable air gap such as a 220 micrometer (μm) air gap. The optical connector 106 includes ferrule 127 inserted into a connector body 128. The ferrule 127 and the connector body 128 may be formed of a relatively rigid material such as stainless steel. The ferrule 127 includes a tapered passage 129 through which an array of optical waveguides 132 extend. The array of optical waveguides 132 extends from the ferrule 127 through the connector body 128 and to a handpiece and cannula, as known in the art of laser probes. Optionally, a cylindrical sleeve 130 encloses the array of optical waveguides 132. The cylindrical sleeve 130 may be formed of a relatively flexible material, such as a polymer material. In this embodiment, the plurality of optical waveguides are an array of four optical fibers. In alternative embodiments, arrays of different sizes or different wave transmission structures may be used. In one embodiment, the array of optical fibers may comprise four 75 μm core glass fibers, each with a numerical aperture (NA) of 0.22. The optical waveguides, the cannula, and/or the handpiece may be disconnected from the adapter and disposed of after a single use, allowing the adapter to be reused for subsequent procedures. During procedures using the laser probe assembly 100, the adapter 106 may be located within or outside of the sterile field. If the adapter is located within the sterile field it may remain sterilized through multiple procedures or, alternatively, may be sterilized after each procedure.
The optical assembly 117, as described, provides a predictable mechanism for directing laser light in two dimensions by using two reflective devices 120, 122 that are angularly adjusted about axes that are orthogonal to one another. In alternative embodiments, a single reflective device pivotable about one or more axes may be used to generate an array of laser beam spots. In still another alternative, more than two reflective devices pivotable about one or more axes may be used to generate an array of laser beam spots. In still another embodiment, one or more of the reflective devices may be fixed while other reflective devices may be movable. In still another embodiment, a single reflective device can be rotated to approximately 45° relative to the beam exiting the first GRIN lens, directing the beam into a second GRIN lens positioned substantially orthogonal to the first GRIN lens. In this case, the fiber array would be orthogonal to the initial axis of the beam.
a, 10b, 10c, and 10d are radial cross sectional views of the fiber array 132 looking backward toward the GRIN lens 124. These figures depict the fiber array 132 with an optical assembly 117 in four different configurations. The fiber array 132 includes optical fibers 160, 162, 164, 166. In
Thus, as demonstrated in
As shown in
In an alternative embodiment, the reflective devices 120, 122 may be controlled to stop at one or more angular tilt positions along the continuum between +/−θmax. For example, as shown in
As shown in
Referring now to
As compared to laser probe systems that produce only a single laser beam, the embodiments of this disclosure may increase the number of locations at a target tissue site that may be treated while decreasing the time to treat the multiple locations. Further, more complicated scan patterns may be generated. The embodiments described permit reconfiguration of the scan pattern in real time. Compared to diffraction-based beam splitting multi-spot laser probes that may deliver 70% or less of the laser beam to the optical fibers and then divide the beam among the multiple optical fiber, the embodiments of the present disclosure are more efficient and deliver more power to the tissue site with each scan of the laser probe. The embodiments of this disclosure may have near 100% efficiency. In one embodiment, with a 2 Watt (W) laser at nearly 100% efficiency, approximately 250 milliwatt (mW) may be delivered to each spot in a nine-spot pattern, enough to yield adequate burns for some applications. For example, a laser calibrated to deliver 2 Watts (2000 milliwatts) out of the distal end of a conventional 90% optical transmittance probe may provide an input beam 105 of 2222 milliwatts (i.e., 2000/0.9) to compensate for the optical loss in the probe. Since, in some embodiments, the optical transmittance of the laser probe assembly 100 may be near 100%, that same input laser beam 105 (2222 milliwatts) may provide an average power for each spot of a nine spot pattern of approximately 2222/9=246.9 milliwatts. In other words, while the laser beam leaving the probe assembly 100 is directed at a particular spot in the pattern, the instantaneous power on the spot may be 2222 milliwatts (in this example), but the average power into each beam spot may be calculated as the energy applied to a particular spot divided by the entire time it takes to make the pattern (which, in this example, results in an average power of approximately 246.9 milliwatts per spot). As further compared to diffraction-based multi-spot laser probes, coupling both a red aiming beam and a green treatment beam, which diffract at different angle, to a common optical fiber is simplified using the embodiments as disclosed.
In various embodiments, a laser probe adapter may include a first connector portion sized and configured for connection to a subminiature version A (SMA) connector on a laser source, a second connector portion sized and configured for connection to an array of optical waveguides, a first reflective surface movable about a first axis, and a second reflective surface movable about a second axis substantially orthogonal to the first axis (the first reflective surface may be configured to receive a laser beam emitted from the laser source and redirect the laser beam toward the second reflective surface). In some embodiments, the laser probe adapter may further include a micro-electromechanical mirror which includes the first reflective surface. In some embodiments, the laser probe adapter may further include a gradient index lens configured to receive the laser beam emitted from the laser source and direct the laser beam toward the first reflective surface. In some embodiments, the laser probe adapter may further include a gradient index lens configured to receive the laser beam reflected from the second reflective surface. In some embodiments, the first reflective surface may have a first configuration for directing the laser beam to a first optical waveguide in the array of optical waveguides. In some embodiments, the first reflective surface may have a second configuration for directing the laser beam to a second optical waveguide in the array of optical waveguides. In some embodiments, the first reflective surface may have a third configuration for directing the laser beam to a third optical waveguide in the array of optical waveguides.
In various embodiments, an ophthalmic laser probe system may include an array of optical waveguides, an adapter operable to connect with a laser source, a first gradient index lens within the adapter, a second gradient index lens within the adapter positioned substantially orthogonal to the first gradient index lens, a first reflective surface within the adapter, disposed along an optical path between the first and second gradient lenses and configured direct a laser beam received from the first gradient index lens toward the second gradient index lens.
The term “such as,” as used herein, is intended to provide a non-limiting list of exemplary possibilities. The term “approximately” or “about,” as used herein, should generally be understood to refer to both numbers in a range of numerals. Moreover, all numerical ranges herein should be understood to include each whole integer and tenth of an integer within the range. It is understood that all spatial references, such as “upper,” “lower,” “above,” and “below” are for illustrative purposes only and can be varied within the scope of the disclosure.
While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art having the benefit of this disclosure would recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Thus, the breadth and scope of the invention should not be limited by any of the above-described embodiments, but should be defined only in accordance with the following claims and their equivalents. While the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood that various changes in form and details may be made.
This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/568,695 titled “Devices and Methods for Reconfigurable Multispot Scanning”, filed on Dec. 9, 2011, whose inventors are Ronald T. Smith and Bruno Dacquay, which is hereby incorporated by reference in its entirety as though fully and completely set forth herein.
Number | Date | Country | |
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61568695 | Dec 2011 | US |