Filter assembly and filter kit for use with an endoscopic system

A filter assembly is configured to optically couple a camera head to an endoscope. The filter assembly includes a first end adapted to be removably coupled to the camera head and a second end opposite and spaced apart from the first end, the second end adapted to be removably coupled to the endoscope. The filter assembly includes an optic housing disposed between the first end and the second end, the optic housing includes an optical path length maximizer and a first window. The first window has a first surface that is angled with respect to a plane that is perpendicular to a longitudinal axis of the optic housing so as to minimize a narcissus reflection within the optic housing and an optical filter to reject laser irradiation.

TECHNICAL FIELD

The disclosure relates to a filter for use with an endoscopic system.

BACKGROUND

Endoscopic systems300are used for surgical procedures. The endoscopic system300provides a video or camera image of a surgical site. The endoscopic system300includes a camera head306having an image sensor308and an endoscope302having a lens304. An illustrative example of an endoscopic system is provided inFIG.1.

The endoscope302is configured to be removably mounted to the camera head.FIG.1depicts the endoscope302having a mounting feature disposed on a proximal end. The mounting feature is adapted to engage gripping mechanism of the camera head. When mounted, the endoscope is positioned with respect to the image sensor so as to provide a focused image.

Some endoscopic procedures use lasers to treat medical conditions such as controlling hemorrhaging or destroying neoplastic tissue. Laser irradiation may generate a very large signal level which can saturate a camera's image. Thus, certain endoscopic systems include filters for reducing the laser signal level. Many types of lasers may be used, each emitting light within a narrow wavelength band. This requires multiple endoscopic systems having many endoscopes or many camera heads, each with a corresponding filter to block the reflected light within the narrow wavelength band.

SUMMARY

One aspect of the disclosure provides an endoscopic system having a filter assembly. The filter assembly is configured to optically couple a camera head to an endoscope. The filter assembly includes a first end that is adapted to be removably coupled to the camera head. The filter assembly includes a second end that is opposite of the first end and spaced apart therefrom. The second end is adapted to be removably coupled to the endoscope. Accordingly, the filter couples the camera head to the endoscope.

The filter assembly includes an optic housing. The optic housing is disposed between the first end and the second end. An optical path length maximizer is housed within the optic housing. The optical path length maximizer is configured to compensate for the displacement of the exit pupil of a lens system of an attached endoscope relative to the image sensor so as to maintain the field of view and optical quality of the optical image while accommodating a laser filter.

The optic housing further includes a first window. The first window has an operating surface configured to reflect an image away from a longitudinal axis of the optic housing. In one aspect, the operating surface is an angled surface with respect to a plane that is perpendicular to a longitudinal axis of the optic housing so as to minimize a narcissus reflection when working with the camera image sensor.

In one aspect of the filter assembly, the filter assembly includes a first coating. The first coating is configured to filter a first pre-determined wavelength of light so as to prevent the pre-determined wavelength of light from reaching the camera head.

In another aspect of the filter assembly, the first coating is disposed on one of either the optical path length maximizer or the first window.

In yet another aspect of the disclosure, the filter assembly includes a second window disposed within the optic housing. The second window is spaced apart from the first window, and the second window is angled with respect to the plane that is perpendicular to the longitudinal axis of the optic housing.

In yet another aspect of the disclosure, the first and second ends are removably attached from the optic housing so as to allow the user to change or replace a respective first or second window as the case may be.

In yet another aspect of the disclosure, a filter kit is provided. The filter kit is configured to optically couple a camera head to an endoscope. The filter kit includes a plurality of filters, each of the filters having a first end, a second end and an optic housing. Wherein, the first end is adapted to be removably coupled to the camera head, and the second end is opposite and spaced apart from the first end, and the second end is adapted to be removably coupled to the endoscope. In such an aspect, each of the first and second ends are the same in structure with each other so as to be interchangeable with respect to a predetermined camera head and a predetermined endoscope.

The optic housing of each of the filters is disposed between the first end and the second end of the optic housing and includes a first window. The first window is angled with respect to the plane that is perpendicular to the longitudinal axis of the optic housing In such an embodiment, the first window includes a first coating configured to filter a predetermined wave length of light from reaching the camera head, wherein the first coating filters a predetermined wavelength of light different from each other.

In yet another aspect of the filter kit, the first windows of each of the plurality of filters may be angled differently from each other.

In yet another aspect of the filter kit, a second window may be provided. The second window is also angled with respect to the plane that is perpendicular to the longitudinal axis of the optic housing. The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features and advantages will be apparent from the description and drawings and from the claims.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Implementations herein are directed toward a filter assembly and a filter kit. The filter assembly is configured to removably and optically couple a camera head to an endoscope. The filter assembly includes one or more features to block reflected light from one or more lasers emissions within predefined wavelength bands. The filter assembly kit may include a plurality of filter assemblies, each capable of blocking a different band of wavelengths. Each filter assembly also includes one or more features to reduce a narcissus phenomenon caused by self-imaging of the image sensor. As shown inFIG.3, the endoscope is configured to attach to a camera head. In such a configuration, the focal point of the camera head is based upon the distance of the lens with respect to the image sensors of the camera head. Thus, when mounted together the camera view is in focus. It should be appreciated that the displacement of the endoscope and the lens therein from the image sensor defocuses the camera image. Thus, in such an embodiment, the endoscope system may obtain a blurry image when used in a procedure involving laser beams.

As such, a filter assembly is provided herein which has an optical path length maximizer configured to compensate for the displacement of the exit pupil of the lens system of the endoscope with respect to the image sensor so as to maintain the field of view and optical quality of the optical image. Furthermore, the filter assembly includes a window configured to have an angled or arcuate surface so as to reflect the re-image of the sensor surface and reduce narcissus reflection.

With reference now toFIG.2a perspective view of the filter assembly10is provided. The filter assembly10is configured to be used with an endoscopic system200. The endoscopic system200includes an endoscope202having a lens204fixed therein and a camera head206having an image sensor208fixed therein. The filter assembly10includes a first end12adapted to be removably coupled to the camera head206and a second end14opposite and spaced apart from the first end12. The second end14is adapted to be removably coupled to the endoscope202.

With reference now toFIG.3, an illustrative depiction of an endoscopic system200is provided. The endoscope202includes a mating end, commonly referenced as an eyecup210, which is configured to be seated within an endoscope gripping mechanism212of the camera head206, placing the lens204of the endoscope202in a set distance with the image sensor208of the camera head206so as to place the camera image in focus.

FIG.3also shows how the endoscopic system200may be configured such that the endoscope202is directly attached to the camera head206, or the endoscope202may be released from the camera head206and filter assembly10disposed between the endoscope202and the camera head206. In particular, the first end12of the filter assembly10is shown having the same dimension as the eyecup210of the endoscope202and the second end14of the filter assembly10is shown having the same dimension as the endoscope gripping mechanism212of the camera head206.

FIG.3illustrates how the endoscopic system200may be used with or without the filter assembly10. Thus, the endoscopic system200may be adapted for use in surgical procedures utilizing lasers. It should be appreciated that the dimension of the first and second ends12,14of the filter assembly10shown in the drawings are for illustrative purposes and may be shaped otherwise so as to mimic the shape of the eyecup210and an endoscope gripping mechanism212of the respective endoscope202and camera head206.

With reference again toFIG.2and now also toFIG.4, a description of the filter assembly10is provided. The filter assembly10is optically coupled between the endoscope202and the camera head206. The filter assembly10is configured to compensate for the displacement of the exit pupil of the lens204, accommodating for a displacement of the lens204with respect to the image sensor208so as to maintain the field of view and optical quality of the optical image.

The filter assembly10includes an optic housing16. The optic housing16is disposed between the first end12and the second end14. The optic housing16includes an optical path length maximizer18and at least a first window20. The optic housing16may be a generally tubular member having a through-hole22. The optical path length maximizer18is disposed within the through-hole22and is generally centered between the first and second ends12,14. The opposing ends of the optic housing16are spaced apart from respective first and second ends12,14so as to accommodate the first window20.

The optical path length maximizer18may be a relay optic or high glass index. The optical path length maximizer18is configured to compensate for the displacement of the exit pupil of the lens204so as to maintain the field of view and optical quality of the optical image detected by the camera when the lens204is displaced from the camera head206. The optical path length maximizer18may be formed of a cylinder of high index of refraction optical material such as sapphire or another lens relay assembly.

The first window20is configured to reduce a narcissus reflection, in particular the first window includes a surface24configured to reflect laser light away from a longitudinal axis of the optic housing16. In one aspect, the filter assembly may include a second window30that is also configured reflect laser light away from a longitudinal axis of the optic housing16. The first window20and second window30may be formed of any durable optical material compatible with necessary coatings and human tissue contact.

With reference now toFIG.4, a cross-sectional view of the filter assembly10is provided. The optical path length maximizer18is shown generally centered within the optic housing16. A gap26is formed between opposite ends of the optical path length maximizer18and the respective first and second ends12,14of the filter assembly10. One of the gaps26is dimensioned to accommodate a first window20.

The cross-sectional view provides an illustrative depiction of the first window20with respect to the optical path length maximizer18. The surface24of the second window30is illustratively shown as being an angled surface of approximately 20 degrees, (a tilt angle “A”) with respect to a plane that is perpendicular to a longitudinal axis of the optic housing16. However, it should be appreciated that the tilt angle “A” of the surface24may be anywhere between 10 degrees to 45 degrees, depending on the desired reflection, or the surface24may be curved.

The dashed arrow indicates an optical path for light that pass through the lens204. In particular, the lens204disposed on the endoscope202reflects the light down a longitudinal path which is defined by the axial length of the optic housing16. When used in a laser procedure, light from the laser beam passes through the second window30and is reflected away from the camera head206as illustrated by the solid arrow. In particular, the light from the laser beam is reflected at an angle of incidence determined by the tilt of the window30.

With reference now toFIG.6A, an aspect of the filter assembly10having a first coating28is provided. The first coating28is configured to filter a first predetermined wavelength of light so as to prevent the first predetermined wavelength of light from reaching the camera head206. In particular, the first coating28may be configured to filter a laser having a center wavelength or approximately 1064 nm as may be found in a Nd:YAG laser or any standard ion laser having wavelengths within the visible and ultraviolet spectra, for example centered about 351.1 nm, 363.8 nm, 454.6 nm, 457.9 nm, 465.8 nm, 476.5 nm, 488.0 nm, 496.5 nm, 501.7 nm, 514.5 nm, 528.7 nm, and 1092.3 nm. Such coatings are currently known and used, and any such coating may be adapted for use herein.FIG.5shows the first coating28disposed on both the end surface of the optical path length maximizer18and the first window20. However, it should be appreciated that the first coating28may be disposed on just one of either the optical path length maximizer18or the first window20.

The first coating28can be placed on any or all of the internal optical surfaces. Preferably, the first coating28is disposed on an interior surface of the first window20.FIG.6Aillustrates an example where the first coating28is disposed on the surface of the optical path length maximizer18facing the first window20. It should be appreciated that the first coating28may be disposed on a single surface and is shown as being on both the optical path length maximizer18and the first window20for illustrative purposes.

FIG.6Bdiscloses another aspect of the filter assembly10, wherein the filter assembly10includes the second window30. The second window30also includes a surface24that is configured to direct light away from the longitudinal axis of the optic housing16.

The second window30is disposed within the optic housing16.FIG.6Bshows the second window30disposed on one end of the optic housing16opposite of the first window20. The first surface24of the first window20and the second window30may be an angled surface angled the same as each other but symmetrical to each other. However, it should be appreciated that the first surface24of the first and second windows30may be angled differently from each other or may be oriented in the same direction.

The use of a second window30may help further reduce narcissus effect. The second window30may further include a second coating32. The second coating32may be configured to filter a second predetermined wavelength of light, the second predetermined wavelength of light being different than the first predetermined wavelength of light.

As such, the advantages of having a second coating32allows for the filter assembly10to be used for different laser procedures. For instance, some surgical procedures may utilize a laser having a center wavelength of 454.6 nm, whereas another surgical procedure may use a laser having a center wavelength of 476.5 nm. Assuming the first coating28filters a center wavelength of 454.6 nm and the second coating32filters a center wavelength of 476.5 nm, it should be appreciated that the same filter assembly10may be used for either surgical procedure, thus eliminating the need to use a separate endoscopic system200for each respective surgical procedure.

With reference now toFIGS.6A-6B, another aspect of the filter assembly10is provided wherein the first and second ends12,14are configured to be removably attached to the optic housing16. In such an embodiment, the first and second ends12,14may be threaded onto the optic housing16as indicated by the threads34adisposed on the ends of the optic housing16, wherein the first and second ends12,14have a threaded bore34bso as to be simply screwed onto the ends of the optic housing.

Alternatively, a snap fit engagement may be used to couple the two parts together. It should be appreciated that any known fastening mechanism may be used to removably attach the first and second ends12,14to the optic housing16. In such an embodiment the removal of the first or second ends12,14provide access to the optic housing16so as to allow the user to change or replace any of the first or second windows20,30with a different window so as to facilitate cleaning of the filter assembly10and also allow the filter assembly10to operate in various conditions with laser of different wavelengths.

With reference now toFIG.5a perspective view of a filter kit100is provided, wherein like elements are referenced by the same number increased by 100. The filter kit100includes a plurality of filter assemblies110as described above. For illustrative purposes, the filter kit100is shown as having three filter assemblies110a,110b,110c. The bi-directional arrow indicates that the filter assemblies110a,110b,110cmay be interchanged. Accordingly, each filter assembly10includes a first end112adapted to be removably coupled to the camera head206and a second end114opposite and spaced apart from the first end112. The second end114is adapted to be removably coupled to the endoscope202.

With again toFIGS.6A-6Ca cross-sectional view of exemplary filter assemblies110to be used in a filter kit100is provided. Each filter assembly110is configured to compensate for the displacement of the exit pupil of the lens204so as to maintain the field of view and optical quality of the optical image detected by the camera accommodating for a displacement of the lens204with respect to the image sensor208. However, the components of a respective filter assembly110are different from each other so as to achieve a specific optical function. For instance, each of the filter assemblies110a,110b,110cmay be used for a laser operation having a laser generating light in different wavelength spectrums. It should be appreciated that a particular filter assembly may be configured to be used for procedures implementing multiple laser wavelengths. For example, filter assembly110bis shown as having both the first and second coating128,132.

Each filter assembly110includes an optic housing116. The optic housing116is disposed between the first end112and the second end114. The optic housing116includes an optical path length maximizer118and a first window120. The optic housing116may be a generally tubular member having a through-hole122. The optical path length maximizer18is disposed within the through-hole122and is generally centered between the first and second ends112,114. As discussed above, the optical path length maximizer118may be a relay optic or high glass index. The optical path length maximizer118is configured to compensate for the displacement of the exit pupil of the lens204so as to maintain the field of view and optical quality of the optical image detected by the camera when the lens204is displaced from the camera head206. The optical path length maximizer118as realized as a relay optic as inFIG.8cmay be formed of conventional optical glass materials and processes (BK7 for example).

With reference first toFIG.6A, the filter assembly110aincludes a first window120. The first window120has a first surface124configured to reflect light away from a longitudinal axis of the optic housing116so as to minimize the narcissus reflection within the optic housing116. The first coating128is configured to filter a first predetermined wavelength of light from reaching the camera head206. In particular, the first coating128may be configured to filter a wavelength between 400 nm to 2000 nm. As described above, such coatings are currently known and used, and any such coating may be adapted for use herein, illustratively including multilayer dielectric coatings.

FIG.6Bdepicts a filter assembly110bof the filter kit100having a first window120and a second window130, both of which are configured to reflect light away from a longitudinal axis of the optic housing116so as to minimize the narcissus reflection within the optic housing116. The second window130includes a second coating132. The second coating132may be configured to filter a predetermined wavelength of light different than the first coating128. Such a filter assembly110bmay be useful in surgeries where two to more different laser procedures are implemented.

FIG.6Cdepicts a filter assembly110cof the kit having a first window120and a second window130. The first surface124of the first window120is arcuate. The first coating128is shown disposed on an inner surface of the first window120. The second window130is arcuate so as to preserve the focus of the image transmission.

It should be appreciated that the filter assemblies110a,110b,110cshown inFIGS.6A-6Care illustrative and not limiting to the scope of the appended claims. The filter assemblies110a,110b,110cprovide optical benefits different from each other that are suitable for different laser procedures. Accordingly, the filter kit100may be configured with filter assemblies other than what is shown in the figures without deviating from the scope of the appended claims. For instance, the filter assemblies may be configured to have a first end112and a second end114that is removable.

It should further be appreciated that the shape and dimension of the first window120and the second window130are provided for illustrative purposes and other shapes may be used to perform the function of directing light away from the longitudinal axis of the optic housing16. For instance,FIGS.7A-7DCshow different window shapes that may be incorporated herein. Each of the shapes having a first surface24that is configured to reflect an image on the respective window away from the longitudinal axis of the optic housing16.