The present disclosure relates to ophthalmic illumination systems and more particularly to an ophthalmic illumination filter selection mechanism.
This section provides background information related to the present disclosure which is not necessarily prior art.
When ophthalmic surgery is performed, an ophthalmic illumination system is used to illuminate the interior of a patients eye so that the surgeon may view the surgical site. An ophthalmic illumination system typically includes a light source to which is coupled a length of optical fiber. Light travels through the fiber to the tip of an endo-illuminator, or probe, inserted into an incision in the eye.
Surgeons can obtain enhanced visualization of various eye features if a nominally white light source is filtered to provide various colored tints. A filtering device may be used to allow a surgeon to select one or more color tints during surgery. For example, a disk in which several color filters are circularly arranged may be rotated to place a filter that produces a selected tint in the path of the light source. Alternatively, a surgeon may select one of several color filters linearly arranged in an oblong slider by moving the slider linearly in front of the light source. Filter disks and sliders, however, tend to occupy considerable space when inserted into ophthalmic illumination systems.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
In one configuration, the present disclosure is directed to an ophthalmic illumination filter selection mechanism for use with an ophthalmic illumination system. The mechanism includes a plurality of filters each mounted in a corresponding holder. Each holder is mounted on a first shaft and rotatable on the first shaft into an optical light path determined by the ophthalmic illumination system. A plurality of cams are mounted on a second shaft. Each cam is configured to move a corresponding holder on the first shaft to position the corresponding filter in the optical light path in a predefined sequence relative to the other filters as the second shaft is rotated in a forward direction. Each cam has a cam profile that ensures one of the filters remains in the optical light path until the next filter in the predefined sequence is driven into the optical light path. Each cam has a pin extending into a corresponding slot on the second shaft. The pin and corresponding slot are configured to allow the second shaft to be rotated relative to the cam for a predetermined radial distance to allow a last remaining filter to be removed from the optical light path when the second shaft is rotated in a reverse direction.
In another configuration, the disclosure is directed to an ophthalmic illumination filter selection mechanism for use with an ophthalmic illumination system. The mechanism includes a plurality of filters each mounted in a corresponding holder. Each holder is mounted on a first shaft and rotatable on the first shaft into a collimated portion of an optical light path determined by the ophthalmic illumination system. A plurality of cams are mounted on a second shaft. Each cam is drivable by the second shaft to move a corresponding holder on the first shaft to position the corresponding filter in the optical light path in a predefined sequence relative to the other filters as the second shaft is rotated in a forward direction. Each cam has a cam profile that ensures one of the filters remains in the optical light path until the next filter in the predefined sequence is driven into the optical light path. Each cam has a backlash configured to allow the second shaft to be rotated in a reverse direction for a radial distance to allow a last remaining filter to be removed from the optical light path. Additionally, the radial distance is predetermined to allow one of the filters to be rotated away from the optical light path without another filter being driven into the optical light path by rotation of the second shaft in a reverse direction.
In yet another configuration, the disclosure is directed to an ophthalmic illumination system having a light source and a light probe that receives light from the light source via an optical light path. The system includes a color filter selection mechanism having three filters. Each filter is mounted in a corresponding holder rotatable on a first shaft into a collimated portion of the optical light path. Three cams are mounted on a second shaft of the filter selection mechanism, each cam corresponding to one of the holders and drivable by the second shaft to move the corresponding holder on the first shaft to position the corresponding filter in the optical light path. The positioning is performable in a predefined sequence relative to the other filters as the second shaft is rotated in a forward direction. Each cam has a cam profile to ensure one of the filters remains in the optical light path until the next filter in the predefined sequence is driven into the optical light path. Each cam has a pin extending into a corresponding slot on the second shaft. The pin and corresponding slot are configured to allow the second shaft to be rotated in a reverse direction for a predetermined radial distance to allow a last remaining filter to be removed from the optical light path. The predetermined radial distance allows one of the filters to be rotated away from the optical light path without another filter being driven into the optical light path by rotation of the second shaft in a reverse direction.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
A diagrammatic representation of an ophthalmic illumination system is indicated generally in
One configuration of the ophthalmic illumination filter selection mechanism 100 is shown in
A cross-sectional view of the shaft 128 and a cam 124 mounted on the shaft 128 is indicated generally in
A spring 220 is provided between the pin 204 and an end 224 of the corresponding slot 208. The spring 220 holds the cam 124 at an end 230 of the slot 208, i.e., the slot end that corresponds to a forward direction 234 of rotation of the shaft 128. The spring 220 is configured to compress as the shaft 128 is rotated in a reverse direction 234 to remove a filter from the optical light path 116 and to unload as the shaft 128 is rotated in a forward direction.
Operation of the filter selection mechanism 100 shall be described with reference to
When it is desired to obtain unfiltered light output from the light source 24, the filter selection mechanism 100 is operated in reverse to release all filters, e.g., as shall be described with reference to
A side perspective view of one configuration of an ophthalmic illumination filter selection mechanism is indicated generally in
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of a device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.