Patent Description:
Conducting fluorescence-guided open surgery is commonly used for tumour resection. The fluorescence radiation deployed is usually detected by a camera, i.e. by a chip / photo sensor, or through an eyepiece with the help of respective filters which sort out radiation of any wavelength but the fluorescent radiation.

Currently, fluorescence-guided/supported open surgery is conducted in two ways.

First a special camera designed, constructed and bought only or at least mainly for the purpose of fluorescence-guided/supported open surgery is used. This special camera comprises a radiation source emitting the desired excitation radiation which causes fluorescence. The disadvantage of such a system is that separate equipment is needed which has to be bought to conduct fluorescence-guided open surgery.

Second a commonly used endoscope imager is used. An endoscope imager may be the camera to which the endoscope, e.g. via its eyepiece, is coupled during endoscopic surgery. This endoscope imager is used for acquiring the fluorescence image. The fluorescence is caused by an illumination apparatus which may be connected to the endoscope imager, e.g. via a coupler. Usually, an endoscope imager comprises exactly one such coupler accommodating the endoscope during endoscopic surgery. This is usually done by accommodating the eyepiece of the endoscope in the coupler. When the eyepiece of the endoscope is removed from the endoscope imager, the illumination apparatus described above may be connected thereto. Using an endoscope imager, the hospital does not need to buy an extra apparatus such as the first one described above to conduct fluorescence-guided/supported open surgery. However, the disadvantage with the second system is that a specially designed sterile cover is needed for the reasons explained hereinafter.

During endoscopic surgery, a standard sterile cover covering the endoscope imager is connected to the coupler together with the endoscope. Since the endoscope is usually sterilized before surgery, only the endoscope imager, which is not sterilisable due to the electric parts included, has to be shielded with a sterile cover.

However, when the endoscope imager is used without the endoscope for fluorescence-guided/supported open surgery, the coupler or the opening of the endoscope imager is occupied by the illumination apparatus. Normally, the standard cover cannot be connected to the coupler together with the illumination apparatus and even if that is possible, the standard sterile cover cannot cover both, the endoscope imager and the illumination apparatus. Since both, the endoscope imager and the illumination apparatus are usually not sterilisable, a special (non-standard) cover, which is expensive, has to be bought to use the second system described above.

<CIT> discusses a smartphone-based endoscope system for medical imaging.

The present invention seeks to overcome the disadvantages described above. Amongst others, the present invention seeks to provide a system that can utilize standard equipment which is present in most hospitals.

The problem described above is solved by the system according to claim <NUM>. Preferred embodiments are described in the dependent claims.

An illumination apparatus for illuminating the operating field during open surgery with radiation to cause fluorescence according to the present disclosure comprises a main body comprising an opening configured to release the radiation and attachment means for attaching the main body sideways to an endoscope imager.

Preferably, the main body is attached in a reversible / non-permanent fashion to the endoscope imager.

Using fluorescence imaging during surgery, for example in tumour resection, is known. Usually, the operating field, i.e. the part of the body to be operated, is illuminated with radiation causing fluorescence in a certain region or cell type. For example, <NUM>-aminolevulinic acid is given to the patient, accumulates in the metabolically active cancer cells and can thus support the surgeon in discriminating between healthy tissue and cancer cells, since only the latter will emit fluorescent radiation.

The fluorescence radiation, i.e. the radiation emitted by a fluorescent molecule such as <NUM>-aminolevulinic acid after absorbing the corresponding excitation radiation, lies within a narrow part of the electromagnetic spectrum so that the presence of absence of fluorescence can easily be detected using appropriate filters. On the one hand, the surgeon looks at the operating field using his eyes to conduct the surgery. On the other hand, the surgeon may look through an eyepiece or at a screen where the fluorescence image, taken by a suitable imaging means, is shown to help the surgeon discriminate between healthy tissue and, for example, cancerous tissue. The imaging means may be a camera specifically designed for that purpose or an endoscope imager which is then used without an endoscope connected thereto.

Within the scope of this disclosure, the term "endoscope imager" encompasses a camera suitable for taking image or video image of the operating field and for detecting the fluorescence radiation.

One advantage of the present disclosure is that endoscope imagers which are abundantly available in hospitals may be used for open surgery supported by fluorescence imaging. No separate camera has to be bought.

As will be explained below, the main body of the illumination apparatus can either comprise the radiation source emitting the excitation radiation which causes the fluorescence radiation, or the main body of the illumination apparatus can be connected to the radiation source via light guide cable or the like.

Preferably, the main body of the illumination apparatus is removably connected to the endoscope imager.

The apparatus according to the present disclosure, which is temporarily and not permanently connected to the endoscope imager, allows it to be used with different kinds of endoscope imagers and is thus very flexible in use.

A further main advantage is that most endoscope imagers comprise a coupler, which allows the endoscope imager to be connected to the endoscope, whose shaft is then introduced into the body of the patient. The coupler may comprise a focussing ring, which allows adjusting the focus of the image taken by the endoscope imager.

In open surgery this coupler is not occupied by a shaft, since the shaft is only needed in endoscopy surgery but not in open surgery. Therefore, a standard sterile cover which can usually be connected to the coupler mentioned above can be connected to this coupler for covering both, the endoscope imager and the illumination apparatus, without the need to provide a separate sterile cover. Since the main body of the illumination apparatus is connected sideways to the endoscope imager, both can easily be covered using the same cover.

This is usually not possible using equipment according to the state of the art.

Since state-of-the-art illumination apparatuses are connected to the coupler mentioned above, they require a separate sterile cover which is often very expensive, since either the standard cover or the illumination apparatus (but not both) can be connected to the coupler. In case, however, both the illumination apparatus and the sterile cover can be connected to the coupler, standard sterile covers cannot cover the illumination apparatus because it is connected in a longitudinal fashion - as opposed to sideways - to the endoscope imager. The present disclosure overcomes this problem.

As described above, standard sterile covers may accommodate an endoscope, especially its eyepiece. Thus, the endoscope may be coupled to the sterile cover so that the endoscope imager "sees" the image through the eyepiece of the endoscope while the endoscope imager is housed in the sterile cover during surgery. Since this capability of coupling is given in standard equipment, the illumination apparatus according to the present disclosure can be coupled to the endoscope imager also during endoscopic surgery.

The advantage is, that sometimes endoscopic - i.e. minimally invasive - surgery cannot be performed and the surgeon has to open the body of the patient because endoscopic surgery does not work. In this case, the illumination apparatus according to the present disclosure is already attached sideways to the endoscope imager and the surgeon can just remove the endoscope and go on with open surgery which may be fluorescence-guided open surgery thanks to the illumination apparatus.

There is also another mode of use how the illumination apparatus according to the present disclosure may be employed: Sometimes angled endoscopes have to be used because the area to be operated is hardly accessible. The illumination apparatus may be attached sideways to the endoscope imager and the endoscope and the sterile cover may be present at the same time. Thus, the illumination apparatus may illuminate the area to be investigated and/or operated by the angled endoscope.

According to another example, the combination explained before comprising illumination apparatus, sterile cover and endoscope imager may also be used with a standard endoscope which is straight without any angle.

The attachment means of the illumination apparatus according to the present disclosure may be chosen from the list comprising snap-on means, clip-on-means, strapping-on-means, positive-locking means, screw-means, silicone rubber or other non-permanent adhesive means.

The main body of the illumination apparatus according to the present disclosure may comprise a radiation source which provides the radiation, i.e. the excitation radiation causing the fluorescence. Integrating the radiation source, for example a LED-light-source, into the main body, leads to the advantage that no separate light source / radiation source is needed and the apparatus can immediately and easily be used during surgery.

Alternatively, the main body may not comprise the light source but rather be connected to the light source which provides the radiation causing the fluorescence. Separating main body and light source leads to the advantage that the illumination apparatus can be constructed in a very simple and straightforward way and that the main body does not heat up during surgery due to the heat generated by the light source providing the excitation radiation. Another advantage over integrated radiation sources is that a separate radiation source / light source usually renders the illumination apparatus more lightweight.

The main body of the illumination apparatus according to the present disclosure may comprise finger accommodation means. These means are configured to accommodate the fingers of the surgeon handling the illumination apparatus.

The illumination apparatus may at least partially be formed as a handle, so that the surgeon does not hold the endoscope imager but rather the illumination apparatus during surgery.

The finger accommodation means provide at least two advantages.

First, they provide for a more ergonomical positioning of the hand.

Second, in case the illumination apparatus and the endoscope imager are connected in one specific way, i.e. both adopt one specific (and not any random or arbitrary) position relative to each other, the surgeon will automatically hold the endoscope imager in the correct position and angle.

For example, there might only one way in which the illumination apparatus can be connected to the endoscope imager. Alternatively, there are markings or the like indicating how to connect both parts. Both alternatives may be implemented according to the present disclosure.

When the endoscope imager comprises a chip / photo sensor, which is preferred according to the present disclosure, it is not clear by intuition how, i.e. especially in which angle, to hold the endoscope imager in order to create the desired image without inadvertently turning the image for example by <NUM>° or <NUM>°.

When the surgeon, however, does not hold the endoscope imager (showing no indication in which angle to hold it), but the illumination apparatus with finger accommodation means, the surgeon will intuitively hold the illumination apparatus - and thus also the endoscope imager connected thereto - in the correct angle.

Without the finger accommodation means of the illumination apparatus, the surgeon might somehow "grab" the endoscope imager and hold it in a way that the picture taken from the endoscope imager and presented on the screen is turned by <NUM>° or <NUM>°.

The present disclosure comprises, in general, means for making sure that the endoscope imager and the illumination apparatus are connected in only one specific way and orientation.

The illumination apparatus, preferably its main body, may comprise means allowing it to be connected to a stand. Those means may be an alternative to the finger accommodation means described above. Preferably, those means are additionally present in or at the main body of the illumination apparatus so that the surgeon can decide whether to hold it in his hands or connect it to a stand. Such stands are known from commonly used cameras for taking time-exposure-images.

A filter may be inserted in the opening of the illumination apparatus, wherein the filter allows only the radiation used to cause fluorescence to pass.

The direction in which the radiation leaves the illumination apparatus may be inclined with respect to the optical axis of the optics of the endoscope imager. The inclination or angle may be chosen so that within a distance of <NUM> to <NUM>, preferably <NUM> to <NUM>, a major part of the illumination provided by the illumination apparatus is directed at the optical axis of the endoscope imager. In other words and more generally speaking, the illumination apparatus may comprise means for directing the radiation so that the area "seen" by the endoscope imager is well illuminated. Since the endoscope imager - and thus also the illumination apparatus according to the present disclosure - is usually placed between <NUM> to <NUM> from the operating field, the illumination apparatus after being mounted or attached to the endoscope imager may direct a major part of the radiation in a direction so that within a distance of <NUM> to <NUM> the optical axis lies essentially in the center of the radiated area.

The direction of the radiation / illumination leaving the illumination apparatus preferably refers to an imaginary central axis of the light cone / radiation cone leaving the illumination apparatus.

An additional advantage of the radiation leaving the illumination apparatus with some extent of inclination is that the probability of unwanted reflections may be reduced. The probability of reflections is higher when the illumination/radiation is co-axial with the optical axis of the endoscope imager and lower when the radiation proceeds in a direction that is inclined with respect to the optical axis. Using the inclination according to an embodiment of the present disclosure lower false signal is created and the depth of fluorescence detection is increased.

According to an embodiment of the present disclosure, the illumination apparatus comprises means such as a hinge or the like for varying the inclination, i.e. the angle between the direction of the illumination / radiation leaving the illumination apparatus and the optical axis of the endoscope imager. These means are preferably integrated in the illumination apparatus and change the direction of the illumination leaving the latter. Alternatively, the angle of attachment between the illumination apparatus and the endoscope imager may be changed to vary the inclination.

In varying the inclination the user can adjust the working distance. The Illumination apparatus may be installed and used so that the point of intersection between the optical axis and the imaginary central axis equals the working distance. Thus the illumination / radiation provided by the illumination apparatus is used most efficiently. The means for varying the inclination may be provided so that the point of intersection can be adjusted at a distance to the illumination apparatus and / or to the endoscope imager between <NUM> and <NUM>.

Generally speaking, the illumination apparatus may comprise means for varying the inclination of the radiation exiting the illumination apparatus when it is attached to an endoscope imager. Varying the inclination preferably results in the possibility of adjusting the working distance between <NUM> and <NUM> from the illumination apparatus and / or endoscope imager.

The main body of the illumination apparatus may comprise means allowing it to be connected to a stand or a robotic arm or a semi-automatic arm.

The present disclosure also encompasses a system comprising an illumination apparatus described above and an endoscope imager describer above.

Advantages, features and details become more evident from the figures, which show in.

<FIG> shows an endoscope <NUM> according to the state of the art with an eyepiece <NUM>, a light guide inlet <NUM> and a shaft <NUM>. Moreover, an endoscope imager <NUM> is shown comprising an opening <NUM> and a coupler <NUM>.

In <FIG>, the eyepiece <NUM> of the endoscope <NUM> is mounted at the coupler <NUM>. <FIG> differs from <FIG> only in that the eyepiece <NUM> - and thus the whole endoscope <NUM> - is detached from the coupler <NUM>.

The arrangement shown in <FIG> is utilized in endoscopic surgery. Via a connecting piece <NUM> an imager cable (not shown) can be connected to the endoscope imager <NUM> so that the image from within the body is transferred to a screen (not shown).

The standard endoscope <NUM> best shown in <FIG> may also be used in endoscopic surgery without the endoscope imager <NUM>. The surgeon then looks into eyepiece <NUM> and light is introduced into the body via light guide inlet <NUM>. The apparatuses and arrangements shown in <FIG> are known from the state of the art.

<FIG> show different perspectives of an embodiment of an illumination apparatus <NUM> according to the present disclosure.

The illumination apparatus <NUM> is attached to a conventional endoscope imager <NUM> via attachment means <NUM>.

Moreover, <FIG> show the opening <NUM> of the illumination apparatus <NUM>, the attachment means <NUM> in the form of clips <NUM>, finger accommodation means <NUM>, a stand <NUM>, a coupler <NUM>, a connecting piece <NUM> for the imager cable <NUM>, a light guide cable <NUM>, the hand <NUM> of a user and a protrusion <NUM>.

Referring to <FIG>, the illumination apparatus <NUM> according to the present disclosure works as follows:
Via attachment means <NUM>, the main body <NUM> of the illumination apparatus <NUM> is connected sideways to a conventional endoscope imager <NUM>. Referring to <FIG>, any known endoscope imager <NUM> may be used.

Since the illumination apparatus <NUM> according to the present disclosure does not occupy the coupler <NUM>, the latter may accommodate a sterile cover as explained below.

As shown only in <FIG> and <FIG>, a standard sterile cover <NUM> may be connected to the coupler <NUM> and cover both, the endoscope imager <NUM> and the illumination apparatus <NUM>. The radiation <NUM> emitted by the illumination apparatus <NUM> permeates the sterile cover <NUM>, which is usually transparent. Thus, the operating field (not shown) is illuminated by the illumination apparatus <NUM> although the latter is covered by the sterile cover <NUM>.

Standard sterile covers <NUM> are designed so that they are easily connected to the coupler <NUM> and cover the whole endoscope imager <NUM>.

Since the optics of the endoscope imager "sees" the operating field through opening <NUM>, the part of the cover <NUM> covering the opening <NUM> is designed so that the vision is not impaired. A combined imaging window and connecting piece <NUM> as shown in <FIG> may be employed. Piece <NUM> combines a connecting piece which may accommodate an endoscope, for example, and a transparent imaging window which makes sure that the vision of opening <NUM> is not blocked or impaired. Such a cover <NUM> is known from the state of the art.

The image taken by the endoscope imager <NUM> in <FIG> is transported via the imager cable <NUM> connected to the connecting piece <NUM> to a processor or the like and eventually to a screen (not shown).

The radiation or illumination <NUM> sent by the illumination apparatus <NUM> to the operating field (not shown) is provided by a light source (not shown), which is connected to the illumination apparatus <NUM> via the light guide cable <NUM> connected to the illumination apparatus <NUM>.

Comparing <FIG> and <FIG> it is evident how the finger accommodation means <NUM> allow the user to get hold of the illumination apparatus <NUM> instinctively.

<FIG> shows how the illumination apparatus <NUM> can be connected to a stand <NUM> in case the user does not want to hold it in the hand <NUM>. The stand <NUM> is easily connected to the protrusion <NUM> with the recess <NUM> shown in <FIG> and <FIG>.

Together with the recess <NUM> next to it, the protrusion <NUM> may form both, a connection piece to connect the illumination apparatus <NUM> to the stand <NUM> and one of the finger accommodation means <NUM>. The design of the protrusion <NUM> shown in <FIG> is especially suitable accommodating the finger and being connected to a stand <NUM>, since it has a high surface area.

As can be seen in <FIG> and <FIG>, the direction of the radiation <NUM> leaving the illumination apparatus may be inclined in a way so that within a distance of <NUM> to <NUM>, the area around the optical axis <NUM> of the endoscope imager <NUM> is illuminated well.

As shown in <FIG>, the radiation <NUM> leaving the opening <NUM> of the main body <NUM> of the illumination apparatus <NUM> travels through the transparent sterile cover <NUM>. Because the main body <NUM> is attached sideways to the endoscope imager <NUM>, there are no parts blocking the radiation <NUM> from exiting the sterile cover <NUM>.

Claim 1:
System comprising an endoscope imager (<NUM>) and an illumination apparatus (<NUM>) for illuminating the operating field during open surgery with radiation to cause fluorescence,
the illumination apparatus (<NUM>) comprising
a main body (<NUM>) comprising an opening (<NUM>) configured to release the radiation (<NUM>),
characterized in that the apparatus (<NUM>) comprises
attachment means (<NUM>) for attaching the main body (<NUM>) sideways to the endoscope imager (<NUM>), wherein the endoscope imager comprises a coupler (<NUM>), which allows the endoscope imager (<NUM>) to be connected to an endoscope (<NUM>), further wherein the coupler comprises a focussing ring which, in use, allows adjusting the focus of the image taken by the endoscope imager.