Patent Application
20080175002
The present invention relates to sources of illumination. More particularly, embodiments of the present invention relate to the removal of undesired wavelengths from light. Even more particularly, embodiments of the present invention relate to systems and methods for removing undesired wavelengths from light using mirrors.
The human eye can suffer a number of maladies causing mild deterioration to complete loss of vision. While contact lenses and eyeglasses can compensate for some ailments, ophthalmic surgery is required for others. Generally, ophthalmic surgery is classified into posterior segment procedures, such as vitreoretinal surgery, and anterior segment procedures, such as cataract surgery. More recently, combined anterior and posterior segment procedures have been developed.
The surgical instrumentation used for ophthalmic surgery can be specialized for anterior segment procedures or posterior segment procedures or support both. Such surgical instrumentation can comprise a Vitreoretinal and Cataract microsurgical console. Such a surgical console can provide a variety of functions depending on the surgical procedure and surgical instrumentation. For example, surgical consoles can expedite cataract surgeries (e.g. phacoemulsification procedures) by helping manage irrigation and aspiration flows into and out of a surgical site. Surgical consoles can also provide other functions, as will be known to those having skill in the art.
Clearly seeing an area upon which a surgical procedures is being performed is obviously important. Therefore, microsurgical consoles typically provide a source of illumination, such that the source of illumination can be used to illuminate the area on which a procedure is being performed. These illuminators provide visible light from a light source through, for example, an optic fiber or the like.
In many cases, the light source may generate wavelengths of light which are not useful for illumination (e.g., those other than visible light), such as ultraviolet (UV) or infrared (IR) light. These wavelengths may adversely affect the surgical system by, for example, causing a reduction in the lifetime of lamp electrodes, thermal and UV damage to the system optical components over time, decreased optical performance due to spherical and chromatic aberrations, beam steering, etc. More specifically, the illuminator bulb electrodes, due to absorbing this undesired radiation, will erode more quickly, the optics of the system may heat up significantly leading to reliability issues (i.e. thermal shock and cracking) in the optics as well as their optical coatings, and thermal expansion can induce spherical and chromatic aberrations in the optics of the system, further reducing the performance of the system. This is an undesirable effect because damage to the surgical system optics or their optical coatings can lead to a dangerous amount of light passing through the optics and into the eye, resulting in eye damage. Furthermore, unwanted UV or IR radiation that reaches the eye can potentially cause eye damage.
In past illuminators the problem of reducing out of band emissions was addressed by placing a band pass mirror (also called a “hot mirror”) in the optical path to absorb or reflect undesired wavelengths of light. However, no specific hardware or methods were put in place to eliminate undesired radiation at the illuminator optical source or from the optical train upstream of the hot mirror. Thus, during the operation of these prior art systems the hot mirror and the optics upstream of the hot mirror continued to heat to unacceptable levels. Therefore, there is a need for a system and method that can effectively and efficiently reduce or eliminate undesired wavelengths in light provided by a light source.
Embodiments of the present invention provide an illumination system and method that can be utilized in conjunction with a surgical console and which are substantially safer, more durable and less expensive to operate than prior art systems and methods for providing illumination. One embodiment of the present invention includes a method for providing light to a source of illumination. The method can comprise the steps of: providing light from a light source wherein the light has two components, one component reflected from a mirror having a coating operable to reflect desired wavelengths of light and transmit undesired wavelengths and a second component provided directly from the light source (e.g. not reflected off the mirror). Other embodiments may provide other mirrors to further reduce the undesired wavelengths in the light provided through the source of illumination. For example, an additional coated mirror may be provided such that the light (e.g. both components) may be filtered using this mirror. One of these mirrors may be a hot mirror coated to reflect the desired wavelengths and transmit the undesired wavelengths.
By removing undesired wavelengths of light, such as those that fall outside the visible spectrum or certain wavelengths of blue-light, embodiments of the present invention provide the advantage that the lifetime and reliability of components within the optical path of an illuminator may be extended by reducing the amount of radiation absorbed by components within the optical path while simultaneously improving the performance of the illuminator by reducing spherical and chromatic aberrations. By reducing or eliminating such problems in the optical path, the safety of illumination systems incorporating an embodiment of the present invention, especially in a surgical context, may be greatly improved.
These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements.
A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:
Preferred embodiments of the invention are illustrated in the FIGURES, like numerals being used to refer to like and corresponding parts of the various drawings.
Vitreoretinal and Cataract microsurgical consoles can provide an illuminator. These illuminators provide visible light from a light source through, for example, an optic fiber or the like, and may be used to illuminate an area on which a procedure is being performed. The light source for these illuminators may generate wavelengths of light which are not useful for illumination (e.g., those other than visible light), such as ultraviolet (UV) or infrared (IR) light, or which may cause aphakic hazard weighted irradiance, such as certain wavelengths of blue light. These extraneous wavelengths may adversely affect the surgical system, including causing a reduction in the lifetime of certain components, decreased performance due to spherical and chromatic aberrations or other causes, etc. Damage to the optics or their optical coatings in a surgical setting can allow a dangerous amount of light to pass into the eye, resulting in eye damage. Furthermore, unwanted UV or IR radiation or blue light that reaches the eye can potentially cause eye damage. Thus, it is desirable that an illuminator, whether in a surgical console or a stand-alone device, effectively reduce or eliminate undesired wavelengths in the light that it provides.
Embodiments of the present invention solve this problem by using one or more mirrors in the optical path of an illuminator. In a preferred embodiment, one or more cold mirrors in the optical path are coated such that they are operable to reflect light in the desired wavelengths (e.g. visible wavelengths), while transmitting other wavelengths of light (e.g. IR, UV or selected wavelengths of blue light). Thus, as light from a light source is reflected off these cold mirrors, undesired wavelengths of light may be substantially removed from the light before it is utilized to illuminate an area. In other embodiments, one or more hot mirrors mirror may also be provided in the optical path, wherein these hot mirrors are coated such that they are operable to transmit the desired wavelengths of light and reflect or absorb undesired wavelengths. Thus, by transmitting the light through these hot mirrors additional undesired wavelengths may be removed from the light (relative to utilizing no mirrors, or cold mirrors alone) before the light is used to illuminate an area.
Surgical console 100 also includes a connection panel used to connect various tools and consumables to surgical console 100. The connection panel can include, for example, a coagulation connector, balanced salt solution receiver, connectors for various hand pieces and a fluid management system (“FMS”) or cassette receiver. Surgical console 100 can also include a variety of user friendly features, such as a foot pedal control (e.g., stored behind a panel of the console) and other features. One of these features may be one or more illuminators 200 to provide visible (or other wavelengths) of light to an area undergoing examination or surgical procedure.
Surgical console 100 is provided by way of example and embodiments of the present invention can be implemented with a variety of surgical systems. Example surgical systems in which various embodiments of the present invention can be used include, for example, the Constellation® Surgical Console, Series 2000® Legacy® cataract surgical system, the Accurus® 400VS surgical system, and the Infiniti™ Vision System surgical system available from Alcon Laboratories Inc. of Fort Worth, Tex. While embodiments of the invention may be discussed with reference to such surgical consoles, it will be apparent that embodiments of the present invention can be implemented in other suitable surgical systems or, in general, in any system where it may be desirable to provide illumination.
As discussed above, surgical console 100 may provide illuminators 200.
As mentioned above, it may be desirable to remove undesired wavelengths from light delivered to optic fiber 212a, especially those wavelengths of light that fall substantially within the UV and IR spectrums. To achieve this, in one embodiment of the invention, light from light source 220 is filtered by selecting appropriate glass material or optical coatings for components for one or more components within the optical path of the light from light source 220 such that undesired wavelengths are removed from the light before it is condensed onto optic fiber 212.
More specifically, in one embodiment, specific coatings may be placed on one or more components within the optical path based upon the component's position or function within the optical path. Dichroic coatings are an effective way of separating light in one wavelength band from light in another band by transmitting one wavelength and reflecting another. These dichroic coatings may comprise multiple layers of one or more materials chosen based on their material properties (e.g. refractive indices) and the properties of the substrate material (e.g. glass). The thickness or order in which these coatings are deposited on the optical component may be varied in order to achieve an effect on the transmittance or reflectance of the optical component. Thus, a dichroic coating operable to remove IR and UV may be applied to one or more reflective optics within the optical path of an illuminator while an absorptive/dichroic coating may be applied to the transmittive optics within the optical path.
The use of such coatings may be better elucidated with reference to illuminator 200 depicted in
The respective properties of these coatings may be better understood with reference to the graphs of
The efficacy of these respective coatings may be illustrated in more detail with reference to
The effect of the various coated components within the optical path may be explained with reference back to
As cold mirror 250a may similarly be coated with a dichroic coating operable to transmit (or absorb) IR and UV wavelengths of light while reflecting visible wavelengths of light, the light may be filtered using cold mirror 250a and light reflected from cold mirror 250a may comprise light substantially within the visible wavelengths while remaining out of band wavelengths may be absorbed or collected in out of band radiation dump 252a. The light reflected from cold mirror 250a may then be passed through hot mirror 260a, which is coated with a dichroic/absorptive coating operable to reflect (or absorb) UV and IR wavelengths and transmit visible wavelengths. Thus, by filtering the light using hot mirror 260a, any residual wavelengths of light not within the visible spectrum are reflected by hot mirror 260a and absorbed or collected in out of band radiation dump 252a while visible wavelengths are transmitted through hot mirror 260a and attenuator 270 before being condensed onto optical fiber 212a by condensing lens 280a. In one embodiment, hot mirror 260a may additionally be tuned to meet any desired aphakic properties of illuminator 200.
Thus, by using various coated optical components within an optical path to remove undesired wavelengths of light a number of advantages may be achieved. Namely, the use of a dichroic spherical mirror may prevent undesired wavelengths from re-imaging onto the bulb electrodes and decrease the amount of out-of-band light that could be potentially absorbed into optical components in the optical path downstream. By reducing the amount of out-of-band light at various points in the optical path the operating temperature of any hot mirrors within the optical path may be reduced, reducing the likelihood of component failure or degradation. Similarly, by absorbing undesired wavelengths of light transmitted or reflected by the various mirrors, the amount of radiation absorbed by other components within the system may be reduced, reducing the heating or other stresses placed on these components. Furthermore, by applying different coatings based upon the type of light source utilized in a particular embodiment of illuminator, various specifications (e.g., hazard specifications or the like) may be obtained.
Although the present invention has been described in detail herein with reference to the illustrated embodiments, it should be understood that the description is by way of example only and is not to be construed in a limiting sense. It is to be further understood, therefore, that numerous changes in the details of the embodiment of this invention and additional embodiments of this invention will be apparent, and may be made by, persons of ordinary skill in the art having reference to this description. For example, thought embodiments of the invention have been described in conjunction with a two port illuminator having a spherical mirror, a cold mirror and a hot mirror it will be understood that embodiments of the present invention may apply equally well to illuminators with more or fewer ports or more or fewer spherical, cold or hot mirrors. It is contemplated that all such changes and additional embodiments are within scope of the invention as claimed below.
